Physical Sciences and Mathematics Commons^™

Predictability Of The Overland Reintensification Of North Atlantic Tropical Cyclone Erin (2007), Ariel Tickner-Ernst

Theses and Dissertations

Tropical cyclones (TC) typically decrease in intensity upon interacting with land because of increased surface roughness and decreased surface evaporation. However, several studies have documented cases in which TCs maintain their intensity or even intensify over land within non- or weakly baroclinic environments. Yet, our understanding of the precise physical processes that support maintenance or intensification over land in non- or weakly baroclinic environments remains limited, and the predictive skill for these outcomes has yet to be quantified.

We begin this process by quantifying the predictive skill and forecast uncertainty of the overland intensification of North Atlantic Tropical Storm Erin …

Decadal Climate Variability In Mesoscale-Resolving Coupled Models, Ilijana Mastilovic

Theses and Dissertations

Most of our knowledge about the causes of 20th-century climate change comes from simulation using numerical models. However, the observed climate variability and the one simulated by the state-of-the-art climate models exhibit substantial discrepancies at the decadal-to-multidecadal time scale and thus it hinders our fundamental understanding of the observed climate change. Evidence is mounting that vigorous intrinsic variability associated with mesoscale oceanic features contributes significantly to large-scale low-frequency climate variability, with fundamental implications for decadal climate low-frequency climate prediction. As of yet, extensive simulation of these decadal effects using high-resolution state-of-the-art coupled climate models has been computationally prohibitive, as it …

A Protocol To Build Trust With Black Box Models, Timothy K. Thielke

Theses and Dissertations

Data scientists are more widely using artificial intelligence and machine learning (ML) algorithms today despite the general mistrust associated with them due to the lack of contextual understanding of the domain occurring within the algorithm. Of the many types of ML algorithms, those that use non-linear activation functions are especially regarded with suspicion because of the lack of transparency and intuitive understanding of what is occurring within the black box of the algorithm. In this thesis, we set out to create a protocol to delve into the black box of an ML algorithm set to predict synoptic severe weather patterns …

Development And Use Of An Agent-Based Model To Assess The Effect Of Forecast Credibility On Urban Traffic During Snow Events, Lillie Farrell

Theses and Dissertations

With the difficulties in snow accumulation prediction, the potential for false alarms and forecast misses arise. These forecast errors can lead to a lack of public trust and poor decisions in responding to future weather hazards. There has been little research on how individuals respond in the future to false alarms and forecast inconsistencies. We developed an agent-based traffic model to demonstrate how snow forecasts and public response interplay. This model factors receptiveness to expertise, forecast severity, and forecast credibility into the agents’ work-related travel decisions. Agents are grouped into three categories: firm workers, service workers, and household workers, where …

Interactions Between Tropical Cyclones And The Midlatitude Waveguide: Downstream Impacts And The Role Of Convective Processes, Kevin Prince

Theses and Dissertations

Significant amplification to the waveguide can occur when a recurving tropical cyclone (TC) interacts with the midlatitude flow, leading to significant downstream impacts. To this point in time, TC-midlatitude waveguide interactions have been conceptualized as primarily being driven by large-scale processes, with convective-scale contributions having been parameterized or neglected. This three-part study diagnoses the impact TC-midlatitude waveguide interactions have on the intensity evolution of downstream TCs and the role convective-scale processes play in TC-midlatitude waveguide interactions. Recurving TCs in both the North Atlantic and western North Pacific basins frequently interact favorably with upstream troughs, where a favorable interaction entails the …

Do State Fairs With Firework Displays Impact Pm2.5 Levels In Nearby Communities?, Victoria Lang

Theses and Dissertations

This study identified state fairs with known firework displays to evaluate whether they impact local air quality. Previous research has shown firework displays are linked with the short-term degradation of local air quality due to increased concentrations of fine particulate matter (PM2.5) as a result of the display. These studies observed increased PM2.5 concentrations associated with widespread firework displays such as the Lantern Festival in China, Diwali Festival in India, and Independence Day in the United States. However, it has not been investigated whether a signal of increased PM2.5 concentrations from firework displays during a state fair could be observed …

An Agent-Based Exploration Of The Hurricane Forecast-Evacuation System Dynamics, Austin Reed Harris

Theses and Dissertations

In the mainland US, the hurricane-forecast-evacuation system is uncertain, dynamic, and complex. As a result, it is difficult to know whether to issue warnings, implement evacuation management strategies, or how to make forecasts more useful for evacuations. This dissertation helps address these needs, by holistically exploring the system’s complex dynamics from a new perspective. Specifically, by developing – and using – an empirically informed, agent-based modeling framework called FLEE (Forecasting Laboratory for Exploring the Evacuation-system). The framework represents the key, interwoven elements to hurricane evacuations: the natural hazard (hurricane), the human system (information flow, evacuation decisions), the built environment (road …

The Influences Of Sea-Surface Temperature Uncertainty On Cool-Season High-Shear, Low Cape Severe Weather Event Predictability In The Southeast United States, Michelle Rose Spencer

Theses and Dissertations

Environments conducive to severe weather and tornadoes occur throughout the southeastern United States, particularly during the cold-season. Throughout the cold-season, severe weather in this region predominantly occurs in environments characterized by high-shear, low-CAPE (HSLC). An important aspect to the production of severe weather in HSLC environments in the southeast United States is that air parcels that help contribute to the limited positive-buoyancy generation originate over areas such as the Gulf of Mexico, western Caribbean Sea, and western Atlantic Ocean. These relatively warm bodies of water, particularly outside of the cooler coastal shelf regions, allow the air parcels to warm and …

Transport And Fate Of Phosphorus In The Nearshore Zone Of Lake Michigan, Nathan Van Ee

Theses and Dissertations

Bioavailable phosphorus loads exported to Lake Michigan from the Milwaukee and Sheboygan River Watersheds appear to have increased in the last 40 years despite meeting total phosphorus (TP) loading goals set by the Great Lakes Water Quality Agreement (GLWQA).Overall, bioavailability of P delivered from the Milwaukee and Sheboygan Rivers was highest during the warmer months, which coincides with the nearshore nuisance algae growth season. However, first order loss rates of SRP calculated during baseflow recession were also greatest during the summer, suggesting that increased river residence time during the summer could reduce export of bioavailable P. Observations of phosphorus partitioning …

A South Polar View Of Late Paleozoic Glaciation: Physical Sedimentology And Provenance Of Glacial Successions In The Tasmanian And Transantarctic Basins, Elizabeth Rosa Woodford Ives

Theses and Dissertations

The Late Paleozoic Ice Age (LPIA; ~ 374 – 256 Ma) is the longest Phanerozoic icehouse interval. this interval in Earth’s history was largely defined by extensive glaciation of the southern hemisphere at both polar and temperate latitudes. Glaciers are powerful climatic and geologic actors, especially during icehouse periods, and widespread glaciation can have a significant influence on both regional and global climate and geology. Therefore, constraining the characteristics of LPIA glaciers is essential to developing a global-scale understanding of this key climatic event in Earth’s history. The manuscripts in this dissertation examine the sedimentology, transport directions, stratigraphy, and detrital …

An Investigation Into The Thermodynamics Of Overland Tropical Cyclone Intensity Change In Weakly/Non-Baroclinic Environments, Michael Partrick Vossen

Theses and Dissertations

There are two leading theories regarding how tropical cyclones can maintain or increase their intensity over land in weakly to non-baroclinic environments. In the first, tropical cyclones are maintained overland by enhanced upward surface enthalpy fluxes facilitated by the tropical cyclone’s rains, whereas in the second, tropical cyclones are maintained by enhanced enthalpy fluxes under inflowing trajectories at larger radii from the cyclone’s center. These theories have yet to be rigorously tested, however. To rigorously test these hypotheses, this study uses a quasi-idealized version of the Weather Research and Forecasting model lacking parameterized radiation to test the sensitivity of overland …

Verification Of Environmental-Regime–Stratified Gfs Short-Range Vertical Sounding Forecasts, Dillon Blount

Theses and Dissertations

In recent years, the United States’ operational global numerical weather prediction model, the Global Forecast System (GFS), has been upgraded to include a new dynamical core and an updated turbulence parameterization. This updated turbulence parameterization uses a hybrid eddy-diffusivity, countergradient, and mass-flux formulation to approximate near-surface turbulent vertical mixing. The precise formulation used is based on the local stability, with the eddy-diffusivity, countergradient, and mass flux formulations used under stable, weakly unstable, and strongly unstable conditions, respectively. In this study, an objective classification of environmental regimes is used to verify GFS short-range vertical soundings, focusing on the planetary boundary layer …

Investigating The Potential Of A Combined Air Quality-Heat Index In Predicting Mortality, Shayna Fever

Theses and Dissertations

Although the development of the Air Quality Index (AQI) has been significant in informing and protecting the public, it may not be entirely reflective of the health effects from exposure to air pollutants. Meteorological factors that are considered in the heat index (HI), temperature and relative humidity, are not considered when calculating the AQI. It may be important to consider certain meteorological factors when assessing the quality of the air because such factors affect the dynamics of air movement as well as the formation of certain pollutants.Through a series of Quasi-Poisson regression models, we investigated whether the relationship between the …

Autumn Tree Phenology In Northern Wisconsin: Humans Versus Photographs, Trevor Iglinski

Theses and Dissertations

Ecosystem primary productivity halts when plants go dormant, and so the timing of dormancy as it relates to autumn phenology has been a focus of much interdisciplinary research. While monitoring plant phenology has its roots in directly observing specimens, digital sensors along with modern methods have also become a mainstay in phenology. Results from different methods often vary, so there is still a need to better understand how digital cameras record autumn phenology, especially in comparison with ground-based observations (Keenan et al. 2014). This study compared autumn phenology derived from direct ground observations with upward-facing fisheye photography, in the context …

Late Paleozoic Climatic Reconstruction Of Western Argentina: Glacial Extent And Deglaciation Of Southwestern Gondwana, Kathryn N. Pauls

Theses and Dissertations

Throughout its history Earth has experienced both icehouse and greenhouse conditions. Shifts and transitions from one end member to the other are driven by numerous driving mechanisms on global, orbital and more local scales. In particular, the late Paleozoic ice age (LPIA) is thought to have been driven by global drivers such as the drift of the Gondwanan continent across the South Pole, fluctuations in atmospheric CO2 concentrations, and Milankovitch cycles. It was also affected by more local and regional drivers such as active tectonism along accretionary margins and changes in atmospheric and oceanic circulation patterns. South American Gondwana provides …

Biennial And Low-Frequency Components Of El Niño/Southern Oscillation, James Michael Ryan

Theses and Dissertations

El Niño/Southern Oscillation (ENSO) is a coupled oscillation of sea surface temperatures (SSTs), winds, and air pressure in the eastern and central tropical Pacific, that repeats with quasi-regularity, every 2–7 years. Although the ENSO’s spectral peak is found at a 4–7-yr period, composite El Niño events, taken as the 84 months before and after the peak of each El Niño, show that the length of each event, and often the following La Niña if there is one, usually falls within a quasi-biennial (QB) range of around 18–42 months. We argue that the biennial range of ENSO events stems from the …

Predicting Peak Wind Gusts During Specific Weather Types With The Meteorologically Stratified Gust Factor Model, Teresa Jean Turner

Theses and Dissertations

Peak wind gusts were estimated by the meteorologically stratified gust factor model at Milwaukee, WI (KMKE) for eight different weather types during 2010-2017. The gust factor model couples gust factors with wind speed and direction forecast guidance to produce peak gust forecasts. The model evaluated used two model output statistics (MOS) guidance products at lags ranging from 6-24 hr and was compared with peak gust forecasts provided by the Localized Aviation MOS Program (LAMP) as well as observed gusts reported by automated surface observing systems (ASOS).

Compared with climatology, the gust factor model showed skill when coupled with MOS in …

An Investigation Into The Trophic Magnification Of Polychlorinated Biphenyls In The Lake Michigan Food Web, Philip Hurst

Theses and Dissertations

Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants known to contribute to several adverse health conditions in humans including cancers and a suite of liver diseases. While there exist 209 unique PCB congeners, the World Health Organization has identified 12 that pose the greatest health risk to humans due to these congeners’ functional similarity to dioxins, another notoriously toxic class of contaminants. Along with methylmercury, PCBs are the primary drivers behind fish consumption advisories in the Great Lakes. These guidelines are informed primarily by surveys of contaminants in freshwater biota. However, the proliferation of invasive species, such as …

A Feasibility Study Of Microbialites As Paleomagnetic Recorders, Ji-In Jung

Theses and Dissertations

Microbialites are carbonate organosedimentary deposits formed by benthic microbial communities that trap and bind detrital sediments, and/or inorganic and biologically influenced calcification. Any ferromagnetic particles incorporated into the microbialite structure have the potential to preserve variations in Earth’s magnetic field. A paleomagnetic record in microbialites would be useful for reconstructing the geomagnetic field because it may record at a high temporal resolution based on estimated growth rates, thus preserving relatively short-period variations of the Earth’s magnetic field. In addition, microbialites can be found in the geologic record going back ~3.5 Ga, hence potentially providing information on very ancient variations in …

Multidecadal Climate Variability In Observed And Simulated Surface Air Temperature And Sea-Level Pressure, Andrew Aden Westgate

Theses and Dissertations

Accurate estimates of multidecadal climate variability generated internally within the climate system are required to gauge anthropogenic contribution to warming trends and to develop efficient strategies to mitigate climate change. Previous analyses of historical surface air temperatures (SAT) showed that numerical climate prediction models lack a pronounced global mode of observed internal variability — the stadium wave (SW), — which represents a multidecadal undulation originating in the North Atlantic and propagating to other regions of the globe. The present study extends these analyses by exploring co-variability of SAT and sea-level pressure (SLP) within the SW. Addition of SLP data does …

Modeling Of Cloud Droplet Formation: Software Development And Sampling Strategies, Niklas Selke

Theses and Dissertations

Updraft speeds are an important factor in the formation of cloud droplets which play an important role in an atmospheric simulation. The updraft speeds are varying very strongly in small areas of space. Current models do not account for this kind of variability. Support for a probability density function (PDF) based approach in representing the variability of the updraft speeds has been implemented in the Energy Exascale Earth System Model (E3SM). Specifics of the implementation process have been discussed.

Different sampling strategies were tested to analyze the convergence behavior of the new approach to the cloud droplet formation process. It …

Sedimentological And Geochemical Analysis Of Deep-Water Deposits In The Mojón De Hierro Formation At Arroyo Garrido, Tepuel-Genoa Basin, Patagonia, Argentina, Natalie Beatrice Mcnall

Theses and Dissertations

The Earth has had multiple Phanerozoic glacial intervals but the Late Paleozoic Ice Age (LPIA) was its longest and most extensive, lasting from the Late Devonian (~372 Ma) until the Late Permian (~254 Ma). The LPIA is the last complete climate shift from a greenhouse to icehouse and back to a greenhouse state and the only one to occur on a biologically complex Earth. Therefore, it provides perspectives on deep-time climatic transitions, the parameters controlling them, and the Earth’s physical, chemical and biological responses to such climate changes. Research on mid to high-latitude deposits in Gondwana provides evidence that the …

Visualization Of Uncertain Boundaries Of Undersea Features, Hyowon Ban, Hyo Hyun Sung

International Journal of Geospatial and Environmental Research

There have been several studies that detect, measure, analyze, and visualize the undersea features by using technologies in multiple disciplines including geography and oceanography. However, definitions of the undersea features often vary among the existing leading literature. Due to this reason the geographical boundary for a certain undersea feature is sometimes not identical among the definitions. In this study, we explore semantic uncertainty in the definitions of some undersea features and apply approaches from fuzzy-set theory and geographic information science on empirical bathymetric data to visualize the uncertain boundaries of the undersea features. Results from this study demonstrate that the …

Component Microenvironments And System Biogeography Structure Microorganism Distributions In Recirculating Aquaculture And Aquaponic Systems, Ryan Bartelme, Osvaldo J. Sepulveda-Villet, Ryan J. Newton, Matthew C. Smith

Freshwater Faculty Articles

ABSTRACT Flowthrough and pond aquaculture system microbiome management practices aim to mitigate fish disease and stress. However, the operational success of recirculating aquaculture systems (RAS) depends directly on system microbial community activities. In RAS, each component environment is engineered for a specific microbial niche for waste management, as the water continuously flowing through the system must be processed before returning to the rearing tank. In this study, we compared waste management component microbiomes (rearing tank water, pH correction tank, solid-waste clarifier, biofilter, and degassing tower) within a commercial-scale freshwater RAS by high-throughput 16S rRNA gene sequencing. To assess consistency among …

An Analysis Of Momentum Flux Budgets And Profiles In A Large-Eddy Model, Steffen Domke

Theses and Dissertations

Momentum fluxes and variances play an important role in the characterization and forecast of weather phenomena, but cannot be measured easily.

A subdivision of the flux changes into budget terms by the underlying physical processes, such as buoyancy transport, can assist in understanding their sources and influences.

Momentum flux and variance budgets for SAM, the System for Atmospheric Modeling, have been implemented and are compared to existing budgets from other simulations.

A tool for the visualization of these quantities from three-dimensional grid data has been developed to show and explain their distribution in conjunction with shallow cumulus and stratocumulus clouds. …

Green Energy At Any Cost: How Ethanol Producer Magazine Uses Science To Frame Ethanol Production, Ashley Kappers

Theses and Dissertations

This thesis investigates the use of science by media to shape discussions about policy in society. Specifically, it investigates how one influential trade publication, Ethanol Producer Magazine, used science in its construction of pro-ethanol production stories. This study is a multi-method analysis of Ethanol Producer Magazine’s feature articles. To determine how sources and writers use science to frame ethanol production during policy changes in the industry, 36 feature stories from four issues in 2009 and 2010 of Ethanol Producer Magazine were analyzed. The results of this study found that Ethanol Producer Magazine is a publication that presents one side of …

An Analysis Of Momentum Flux Budgets And Profiles In A Large-Eddy Model, Steffen Domke

Theses and Dissertations

Momentum fluxes and variances play an important role in the characterization and forecast of weather phenomena, but cannot be measured easily.

A subdivision of the flux changes into budget terms by the underlying physical processes, such as buoyancy transport, can assist in understanding their sources and influences.

Momentum flux and variance budgets for SAM, the System for Atmospheric Modeling, have been implemented and are compared to existing budgets from other simulations.

A tool for the visualization of these quantities from three-dimensional grid data has been developed to show and explain their distribution in conjunction with shallow cumulus and stratocumulus clouds. …

Using Evolutionary Programming To Generate A Tropical Cyclone Intensity Model, Jesse Schaffer

Theses and Dissertations

An innovative statistical-dynamical tropical cyclone (TC) intensity model is developed from a large ensemble of algorithms through evolutionary programming (EP). EP mimics the evolutionary principles of genetic information, reproduction, and mutation to develop through selective pressure a population of algorithms with skillful predictor combinations. From this process the 100 most skillful algorithms as determined by root-mean square error on cross-validation data is kept and bias corrected. Bayesian model combination is then used to assign individual weights to a subset of ten algorithms from the 100 best algorithms list, which are chosen to minimize mean-absolute error (MAE) and maximize mean-absolute difference …

Using Evolutionary Programming To Generate A Tropical Cyclone Intensity Model, Jesse Schaffer

Theses and Dissertations

An innovative statistical-dynamical tropical cyclone (TC) intensity model is developed from a large ensemble of algorithms through evolutionary programming (EP). EP mimics the evolutionary principles of genetic information, reproduction, and mutation to develop through selective pressure a population of algorithms with skillful predictor combinations. From this process the 100 most skillful algorithms as determined by root-mean square error on cross-validation data is kept and bias corrected. Bayesian model combination is then used to assign individual weights to a subset of ten algorithms from the 100 best algorithms list, which are chosen to minimize mean-absolute error (MAE) and maximize mean-absolute difference …

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, …