Oceanography and Atmospheric Sciences and Meteorology Commons^™

Impact Of Extreme Summer Temperatures On Bridge Structures, Ryan Hagedorn

Graduate Theses and Dissertations

Climate change and its effect on weather in the United States is a well-documented phenomenon. In particular, extreme heat waves have become more intense, more frequent, and longer lasting, especially in the southern United States. As with much of America’s transportation infrastructure, prestressed concrete bridge girders experience the effects of these heat waves. Uneven heating of optimized bridge girder sections results in large non-linear temperature gradients. In this study, temperature was monitored in three different AASHTO I-girders to determine the vertical and transverse temperature gradients in a pre-deck placement condition. It was determined that the current design standard, which uses …

A Pilot Study For Examining Population Movement During The Peri-Medieval Climatic Anomaly In The Nebraska Sand Hills, Nora C. Greiman

Department of Anthropology: Theses and Student Research

The Sand Hills of Nebraska comprise a dynamic environment of sand dunes that has changed much over the millennia since their formation. Periods of dune reactivation have occurred throughout history, including one such period at approximately A.D. 900-1300 associated with the Medieval Climatic Anomaly (MCA). Much is known about the geologic activity during this period but little is known about how human populations responded to changing environments. I examine the chronology of three sites occupied during the peri-MCA and the change or stasis in population movements via chemical characterization of ceramic artifacts. Optically stimulated luminescence (OSL) dating was performed on …

Influence Of Topography On Convective Patterns Across The Greater Capital Region Of New York, Rachel O’Donnell

Atmospheric & Environmental Sciences

The greater Albany region is unique in regards to its terrain. The various mountain ranges and river valleys play a significant role in convective patterns due to modification of flow. The purpose of this research is to compare the days of convection, both severe and non-severe, to the large scale flow pattern. Lightning data from the National Lightning Detection Network was used to analyze the role terrain plays in organizing convection and the associated lightning. The greater Capital Region was divided into 0.1° grid boxes, and the number of total lightning strikes (both cloud-to-cloud and cloud-to-ground) was recorded within that …

Agroecosystem And Ecosystem Resiliency To Extreme Hydrometeorological And Climate Events, Katherine M. Werner

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The purpose of this study was to understand how a large-scale representation of agroecosystems and ecosystems respond to extreme hydrometeorological and climate extreme events (EHCE) within the Platte River Basin. The ability for agroecosystems and ecosystems to adapt to a changing and variable climate is vital for global water, energy, and food security. Two model experiments were performed, the first with a time span from 2000 to 2013 in which a dynamic leaf area index (LAI) MODIS15A2 product was implemented. The second experiment ran from 1950 through 2013 used a climatological fixed seasonal cycle calculated as the average from the …

Differing Roles Of The Great Plains Low-Level Jet In Producing Warm Season Precipitation Over The Central United States In 2002, Mengyuan Shang

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

The purpose of this research is to describe and compare different roles of the Great Plains low-level jet (GPLLJ) in producing warm season precipitation over the central United States by model simulation. After going through 35 years’ (from 1979- 2013) NCEP North American Regional Reanalysis (NARR) data, year 2002 was selected for model simulation as it contained a “wet period” (May- June) and a “dry period” (July- August). The model simulation was done by using Weather Research and Forecasting (WRF) Regional Model. In this study, the GPLLJ was defined by the low-level wind at 925 hPa. The results showed the …

Drinking Water Treatment: Salt-Free Water “Softener” Options, Bruce I. Dvorak

Department of Civil and Environmental Engineering: Faculty Publications

New no-salt technologies may be effective in treating hard water, but consumers should carefully investigate product claims prior to buying a specific treatment device.

Hard water is not a health risk, but many Nebraska consumers find hard water to be a nuisance because of mineral buildup on plumbing fixtures, including water heaters; unsightly film on glass and crystal wares; and poor soap and/or detergent performance. Water described as “hard” contains high amounts of dissolved calcium and magnesium, which are positively charged contaminants called cations.

Water hardness often is expressed as grains of hardness per gallon of water (gpg) or milligrams …

Geospatial Analysis Of Droughts, Rice And Wheat Production, And Agrarian Vulnerability: A District-Level Study Of The Self-Calibrated Palmer Drought Severity Index In India, Aaron Michael Shew

Graduate Theses and Dissertations

Droughts have affected more people than any other natural disaster in the last century, causing billions in economic damages and millions of deaths. As the Sea Surface Temperatures (SST) have heated in the Indian Ocean, drought patterns across South Asia have changed; the Indian monsoon has become more volatile and less predictable. In this study, monthly self-calibrated Palmer Drought Severity Index (sc-PDSI) data for the time period between 1950 and 2009 were interpolated to India’s districts; then the data were analyzed for changes in frequency and severity. The data were further evaluated using Anselin’s Local Moran’s I Statistic to elicit …

A Method Comparison And Stressor-Response Experimental Study Of Nitrogen And Phosphorus Impacts To Periphyton In Ozark Streams, Ashley Renee Rodman

Graduate Theses and Dissertations

Stream bioassessment is important for understanding algal-nutrient relationships and the development of scientifically defensible numeric nutrient criteria. However, multiple methods of periphyton data collection are currently used, and little is known about the comparability of resulting datasets. Literature also suggests other factors besides nutrients (i.e. variable grazing, light, and flow) can confound algal-nutrient relationships. A one-year method comparison study and 31-day algal biomass-nutrient manipulative experiment were conducted in the southern Ozarks of Arkansas. The method comparison study was implemented using two common bioassessment procedures (whole-surface and delimiter-reduced periphyton removal) to assess the potential for combining datasets. During the manipulative experiment, …

Summer 2015 Internship: Enterprise Gis Support For The National Audubon Society, Monica Noon

Sustainability and Social Justice

From May to August 2015, I worked with the National Audubon Society as an Enterprise GIS Support Intern, under the supervision of Doreen Whitley Rogers. I assisted the department with the GIS help desk requests and supported ArcGIS users with project assistance and training. This report summarizes the structure of the organization, my role as an Enterprise GIS Support Intern and my assessment and reflection of my experience.

Investigation Into Regional Climate Variability Using Tree-Ring Reconstruction, Climate Diagnostics And Prediction, Daniel A. Barandiaran

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This document summarizes research conducted to develop and apply climate analysis tools toward a better understanding of the past and future of climate variability in the state of Utah. Two pilot studies developed analysis tools through the investigation of natural variability in precipitation systems in Africa, and research into long-term changes and trends in spring rainfall over the U.S. Great Plains. Our third study used tree-ring data to estimate snowpack in the state of Utah to 1850, doubling the length of record and offering a better understanding of the history of snowpack in the state. Our final study looked at …

Dietary Effects On The Stoichiometry Of Growth, Regulation, And Wastes Of Ozark Stream Insect Detritivores, Halvor Matthew Halvorson

Graduate Theses and Dissertations

A widespread stressor, anthropogenic nitrogen (N) and phosphorus (P) pollution can increase resource nutrient content and alter animal community composition in freshwater ecosystems. In this dissertation, I used ecological stoichiometry theory to examine effects of diet nutrient content and leaf litter type on growth, regulation, and wastes of aquatic invertebrate detritivores. I tested effects of leaf litter diet carbon:phosphorus (C:P) on growth and stoichiometric regulation of the detritivorous caddisfly Pycnopsyche lepida and used results to determine a threshold elemental ratio of oak litter C:P=1620 that confers peak growth of this species. This empirical, growth-based approach provided a more accurate estimate …

The Role Of Hydrologic Regimes In Driving Morphologic Divergence And The Trait Compositions Of Fish Assemblages, Lindsey A. Bruckerhoff

Graduate Theses and Dissertations

The hydrologic regime is an important determinant of the ecological integrity of a stream. Hydrologic regimes are defined by the magnitude, timing, frequency, rate of change, and duration of high and low flow events and capture long term patterns of variability and predictability of water movement in a stream. Flow regimes influence many aspects of the biophysical environment in lotic systems; therefore organisms have adapted to natural flow patterns. We investigated how fish have adapted to flow regimes at both a population and community level. In the first study presented in this thesis, we hypothesized fish exhibit phenotypic divergence to …

Drought Forecasting Isn't Just About Water- To Get Smart We Need Health And Financial Data Too, Neville Crossman, Ian Overton, Jamie Hannaford, Kerstin Stahl, Kevin Collins, Mark D. Svoboda, Mike Acreman, Nicole Wall

National Drought Mitigation Center: Faculty Publications

The Millennium Drought taught Australians many lessons about living under extremely dry conditions – not just about how to conserve water, but also about human suffering.

In a drought, farmers find it more difficult to make an income, leading to mental health problems and raising the rate of male suicides. In the city, the impact is felt through water restrictions and more expensive infrastructure.

With very dry conditions returning to Tasmania, central Queensland and western Victoria, are we better prepared for the next big drought?

This is an issue not just for Australia, but across the world, from California, to …

Acoustic Repertoire Of Sperm Whale (Physeter Macrocephalus) Bachelor Groups In The Waters Surrounding Ischia, Italy (Tyrrhenian Sea), Cristina M. Ledon

HCNSO Student Theses and Dissertations

The subpopulation of sperm whales (Physeter macrocephalus) in the Mediterranean Sea is presently list as “Endangered”. This study is an attempt to provide detailed data on sperm whale Bachelor Groups surrounding Ischia, Italy in the Tyrrhenian Sea (Mediterranean Sea). 24 hours, 38 minutes, and 38 seconds of sperm whale Bachelor Group acoustic data was analyzed in order to describe acoustic repertoire, classify behavioral associations to acoustic types, and identify habitat-use. The data showed that the acoustic repertoire of sperm whale Bachelor Groups is dominated by Usual Clicks. Additionally, a click type that maintains an inter-click interval (ICI) in …

Geographic And Depth Distributions Of Decapod Shrimps (Caridea: Oplophoridae) From The Northeastern Gulf Of Mexico With Notes On Ontogeny And Reproductive Seasonality, Eric A. Burdett

HCNSO Student Theses and Dissertations

This thesis presents the first description of the geographic and depth distributions of pelagic decapod shrimps in the area located around the Deepwater Horizon oil spill, based on the NOAA (National Oceanic and Atmospheric Administration) NRDA (National Resource Damage Assessment) trawl samples collected from April – June, 2011. This information is important in ecosystem models investigating trophic effects of the spill because pelagic decapod shrimp are consumed by a variety of organisms occupying higher trophic levels. One of the most abundant and diverse groups of decapods is the Family Oplophoridae. Their roles in pelagic food webs in the Gulf of …

Effects Of Sedimentation On The Physiology And Oxidative Stress Of Two Common Scleractinian Corals, Margaret E. Rushmore

HCNSO Student Theses and Dissertations

This study examined the effect of a growing environmental stressor, sedimentation, on the physiology and oxidative stress throughout the different life stages of two common scleractinian corals Montastraea cavernosa and Porites astreoides. Physiology, oxidative stress, and settlement success of newly released P. astreoides larvae were measured after exposure to various turbidity treatments. No significant effects were seen on larval settlement and photosynthetic efficiency, however carbonyl content and catalase activity were significantly higher in 2015 compared to 2014; highlighting a possible inter-annual variability in susceptibility. Larval settlement deterrence in the presence of a layer of accumulated fine- or coarse-grained sediment …

Constraining Neogene Temperature And Precipitation Histories In The Central Great Plains Using The Fossil Record Of Alligator, Evan Whiting

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

Most amphibians and reptiles (excluding birds) are poikilothermic; their internal body temperature varies with that of their external environment. This makes them useful as climate proxies, especially when linked to geographic distributions of ambient climate. I evaluate the utility of the extant crocodylian genus Alligator as a paleoclimate proxy for the Central Great Plains (CGP) using species distribution modeling. Alligator is a readily identifiable taxon with a good CGP fossil record during the Neogene (~23–2.6 Ma). Alligator first appeared in the CGP in the late Eocene (~37 Ma), was absent during most of the Oligocene, reappeared in the early Miocene …

Sea Turtle Conservation: Reviewing The Efficacy Of Land- And Sea-Based Management Strategies For Loggerhead (Caretta Caretta) And Leatherback (Dermochelys Coriacea) Sea Turtles, Glenn D. Goodwin

HCNSO Student Capstones

As cosmopolitan species, loggerhead and leatherback turtles are confronted with a multitude of threats as they progress through their respective life stages. These range from depredation and poaching of eggs, hatchlings, and females on nesting beaches, to incidental hooking in pelagic longline fisheries and capture in trawl fisheries. Some threats are species specific on regional scales, though most impact both species. To confront these threats, various conservation strategies have been developed and implemented, including monitoring and caging of nests and changes to hook shape and trawl design. Here, current conservation methods are presented and discussed on a global scale for …

Global Genetic Connectivity And Diversity In A Shark Of High Conservation Concern, The Oceanic Whitetip, Carcharhinus Longimanus, Cassandra L. Ruck

HCNSO Student Theses and Dissertations

The oceanic whitetip shark, Carcharhinus longimanus, is a circumtropical pelagic shark of high conservation concern (IUCN Red List: “Critically Endangered” in the Western North and Western Central Atlantic and “Vulnerable” globally). I present the first, population genetic assessment of the oceanic whitetip shark on a global scale, based on analysis of two mitochondrial genome regions (entire 1066-1067 bp control region and 784 bp partial ND4 gene), and nine nuclear microsatellite loci. No population structure was detected within the Western Atlantic. However, highly significant population structure was detected between Western Atlantic and Indo-Pacific Ocean sharks across all markers. Additionally, a …

Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang

GSCE Faculty Publications

Climate influences geographic differences of vegetation phenology through both contemporary and historical variability. The latter effect is embodied in vegetation heterogeneity underlain by spatially varied genotype and species compositions tied to climatic adaptation. Such long-term climatic effects are difficult to map and therefore often neglected in evaluating spatially explicit phenological responses to climate change. In this study we demonstrate a way to indirectly infer the portion of land surface phenology variation that is potentially contributed by underlying genotypic differences across space. The method undertaken normalized remotely sensed vegetation start-of-season (or greenup onset) with a cloned plants-based phenological model. As the …