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Articles 241 - 270 of 3305

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Permafrost Carbon: Progress On Understanding Stocks And Fluxes Across Northern Terrestrial Ecosystems, Claire C. Treat, Anna-Maria Virkkala, Eleanor Burke, Lori Bruhwiler, Abhishek Chatterjee, Joshua B. Fisher, Josh Hashemi, Frans-Jan W. Parmentier, Brendan M. Rogers, Sebastian Westermann, Jennifer D. Watts, Elena Blanc-Betes, Matthias Fuchs, Stefan Kruse, Avni Malhotra, Kimberley Miner, Jens Strauss, Amanda Armstrong, Howard E. Epstein, Bradley Gay, Mathias Goeckede, Aram Kalhori, Dan Kou, Charles E. Miller, Susan M. Natali, Youmi Oh, Sarah Shakil, Oliver Sonnentag, Ruth K. Varner, Scott Zolkos, Edward A.G. Schuur, Gustaf Hugelius Jan 2024

Permafrost Carbon: Progress On Understanding Stocks And Fluxes Across Northern Terrestrial Ecosystems, Claire C. Treat, Anna-Maria Virkkala, Eleanor Burke, Lori Bruhwiler, Abhishek Chatterjee, Joshua B. Fisher, Josh Hashemi, Frans-Jan W. Parmentier, Brendan M. Rogers, Sebastian Westermann, Jennifer D. Watts, Elena Blanc-Betes, Matthias Fuchs, Stefan Kruse, Avni Malhotra, Kimberley Miner, Jens Strauss, Amanda Armstrong, Howard E. Epstein, Bradley Gay, Mathias Goeckede, Aram Kalhori, Dan Kou, Charles E. Miller, Susan M. Natali, Youmi Oh, Sarah Shakil, Oliver Sonnentag, Ruth K. Varner, Scott Zolkos, Edward A.G. Schuur, Gustaf Hugelius

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Significant progress in permafrost carbon science made over the past decades include the identification of vast permafrost carbon stocks, the development of new pan-Arctic permafrost maps, an increase in terrestrial measurement sites for CO2 and methane fluxes, and important factors affecting carbon cycling, including vegetation changes, periods of soil freezing and thawing, wildfire, and other disturbance events. Process-based modeling studies now include key elements of permafrost carbon cycling and advances in statistical modeling and inverse modeling enhance understanding of permafrost region C budgets. By combining existing data syntheses and model outputs, the permafrost region is likely a wetland methane …


Delayed Coastal Inundations Caused By Ocean Dynamics Post-Hurricane Matthew, Kyungmin Park, Emanuele Di Lorenzo, Yinglong J. Zhang, Tal Ezer, Fei Yi Jan 2024

Delayed Coastal Inundations Caused By Ocean Dynamics Post-Hurricane Matthew, Kyungmin Park, Emanuele Di Lorenzo, Yinglong J. Zhang, Tal Ezer, Fei Yi

CCPO Publications

Post Hurricane Abnormal Water Level (PHAWL) poses a persistent inundation threat to coastal communities, yet unresolved knowledge gaps exist regarding its spatiotemporal impacts and causal mechanisms. Using a high-resolution coastal model with a set of observations, we find that the PHAWLs are up to 50 cm higher than the normal water levels for several weeks and cause delayed inundations around residential areas of the U.S. Southeast Coast (USSC). Numerical experiments reveal that while atmospheric forcing modulates the coastal PHAWLs, ocean dynamics primarily driven by the Gulf Stream control the mean component and duration of the shelf-scale PHAWLs. Because of the …


The Effect Of Seasonal Ice Cover Duration On Shoreline Erosion In Lake Michigan, Ryan S. Navarre Jan 2024

The Effect Of Seasonal Ice Cover Duration On Shoreline Erosion In Lake Michigan, Ryan S. Navarre

Dissertations, Master's Theses and Master's Reports

Shoreline erosion in Lake Michigan has been a significant concern for coastal management. Promoting coastal stability and resilience is paramount to protecting these environments, especially amid climate change. While several factors are key in understanding shoreline erosion, seasonal ice cover duration is a prominent yet understudied factor in the Great Lakes region. Here, the relationship between ice cover duration and shoreline erosion rates is assessed across 7 regions of Lake Michigan. An ice cover duration dataset was created for Lake Michigan for 2011 – 2020 and its shorelines were digitized for years with available high-resolution aerial imagery. The statistical relationship …


Using Phenology To Unravel Differential Soil Water Use And Productivity In A Semiarid Savanna, Blake Steiner, Russell L. Scott, Jia Hu, Natasha Mcbean, Andrew Richardson, David J. P. Moore Jan 2024

Using Phenology To Unravel Differential Soil Water Use And Productivity In A Semiarid Savanna, Blake Steiner, Russell L. Scott, Jia Hu, Natasha Mcbean, Andrew Richardson, David J. P. Moore

University Administration Publications

Savannas are water-limited ecosystems characterized by two dominant plant types: trees and an understory primarily made up grass. Different phenology and root structures of these plant types complicate how savanna primary productivity responds to changes in water availability. We tested the hypothesis that productivity in savannas is controlled by the temporal and vertical distribution of soil water content (SWC) and differences in growing season length of understory and tree plant functional types. To quantify the relationship between tree, understory, and savanna-wide phenology and productivity, we used PhenoCam and satellite observations surrounding an eddy covariance tower at a semiarid savanna site …


Stage And Discharge Prediction From Documentary Time-Lapse Imagery, Kenneth W. Chapman, Troy E. Gilmore, Mehrube Mehrubeoglu, Christian D. Chapman, Aaron R. Mittelstet, John E. Stranzl Jr. Jan 2024

Stage And Discharge Prediction From Documentary Time-Lapse Imagery, Kenneth W. Chapman, Troy E. Gilmore, Mehrube Mehrubeoglu, Christian D. Chapman, Aaron R. Mittelstet, John E. Stranzl Jr.

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Imagery from fixed, ground-based cameras is rich in qualitative and quantitative information that can improve stream discharge monitoring. For instance, time-lapse imagery may be valuable for filling data gaps when sensors fail and/or during lapses in funding for monitoring programs. In this study, we used a large image archive (> 40,000 images from 2012 to 2019) from a fixed, ground-based camera that is part of a documentary watershed imaging project (https://plattebasintimelapse.com/). Scalar image features were extracted from daylight images taken at one-hour intervals. The image features were fused with United States Geological Survey stage and discharge data as …


Determining The 2022-2023 Mass Balance Of The Palisade Glacier In The Sierra Nevada Mountains Of California With Remote Sensing, Density Modeling, And Temperature-Index Techniques, Vijay Jain, Eric Grosfils, Sarah Kavassalis Jan 2024

Determining The 2022-2023 Mass Balance Of The Palisade Glacier In The Sierra Nevada Mountains Of California With Remote Sensing, Density Modeling, And Temperature-Index Techniques, Vijay Jain, Eric Grosfils, Sarah Kavassalis

CMC Senior Theses

Small, alpine glaciers, such as those in the Sierra Nevada, are difficult to study because of their small size and remoteness, however, they are important recorders of the impacts of climate change in temperate, alpine environments. Previous studies have attempted to characterize the health of these glaciers using extent change techniques, but these methodologies can only roughly approximate the rudimentary measurement of changing ice volume. This thesis uses the Airborne Snow Observatory Inc.’s (ASO’s) aerial lidar snow depth datasets to perform a mass balance calculation for the Palisade Glacier over the remarkable 2022-2023 water year (October 1 through September 30), …


Unlv Title Iii Aanapisi & Mcnair Scholars Institute Research Journal 2024, Jesica Godinez-Paredes, Kian Hassankhan, Apia Hickman, Robin Ruth Kee, Kevin Ayala Pineda, Briana Melendez, Kalli Ramos, Saturn L. Reyes, Fabian Leija, Selena Pepe, Silva Topchyan, Celeste Ainsley, Mayra Arzate, Jessica Balistreri, Zantana Ephrem, Mirella Jasso, Karl Panou, Nichole Pelaez, Miklo Alcala, Akshay Dave, Mey Mey Heng, Michael Finkle, Janessa Montenegro, Reynafe Naol Aniga, Victor Mejia, Angelica G. Diaz, Anayeli Flores-Garibay, Kari Lee Joe Goold, Samantha Hernandez, Lianelys Cabrera Martinez, Caitlin Reynolds, Kimberly N. Usbeck, Abdulrahman Alahdal, Angelica Diaz, Willaine Mae Kahano, Raquel Jackson, Cecia Ruiz-Hernandez, Kers Ung-Watson, Yessenia Henriquez, Vanessa Marie Booth, Alexia Brown, Darlyn Magana, Bianca Navarro, Nicholas Pereira, Gia Renemae Calip, Lucky Heng, Ralph Sagun, Lucas Abreu, Alexandra Maria Acosta, Tristan Benally, Cosset Hernandez Pena, Adrian Montenegro, Cierra Paaaina-Daquioag, Nicole Torosian, Tracy Fuentes, Julissa Martinez, Medina Mcallister, Michal Newhouse-Van Vlerin, Tiria Carr, Nima Abkenar, Isabella Aceituno, Yuhan Bi, Victoria Campos, Melika Cummings, Zachary J. Johnigan, Alexis Sotolongo-Marin Jan 2024

Unlv Title Iii Aanapisi & Mcnair Scholars Institute Research Journal 2024, Jesica Godinez-Paredes, Kian Hassankhan, Apia Hickman, Robin Ruth Kee, Kevin Ayala Pineda, Briana Melendez, Kalli Ramos, Saturn L. Reyes, Fabian Leija, Selena Pepe, Silva Topchyan, Celeste Ainsley, Mayra Arzate, Jessica Balistreri, Zantana Ephrem, Mirella Jasso, Karl Panou, Nichole Pelaez, Miklo Alcala, Akshay Dave, Mey Mey Heng, Michael Finkle, Janessa Montenegro, Reynafe Naol Aniga, Victor Mejia, Angelica G. Diaz, Anayeli Flores-Garibay, Kari Lee Joe Goold, Samantha Hernandez, Lianelys Cabrera Martinez, Caitlin Reynolds, Kimberly N. Usbeck, Abdulrahman Alahdal, Angelica Diaz, Willaine Mae Kahano, Raquel Jackson, Cecia Ruiz-Hernandez, Kers Ung-Watson, Yessenia Henriquez, Vanessa Marie Booth, Alexia Brown, Darlyn Magana, Bianca Navarro, Nicholas Pereira, Gia Renemae Calip, Lucky Heng, Ralph Sagun, Lucas Abreu, Alexandra Maria Acosta, Tristan Benally, Cosset Hernandez Pena, Adrian Montenegro, Cierra Paaaina-Daquioag, Nicole Torosian, Tracy Fuentes, Julissa Martinez, Medina Mcallister, Michal Newhouse-Van Vlerin, Tiria Carr, Nima Abkenar, Isabella Aceituno, Yuhan Bi, Victoria Campos, Melika Cummings, Zachary J. Johnigan, Alexis Sotolongo-Marin

McNair Journal

Journal articles based on research conducted by undergraduate students in the AANAPISI, LSAMP, and McNair Scholars Program.

Table of Contents

About AANAPISI

Dr. Chris Heavey, Interim President

Dr. Keith Rogers, Vice President for Student Affairs

Ms. Zhanna Aronov, Associate Vice President for Retention & Outreach


Geoelectrical And Hydrochemical Characterization Of Submarine Groundwater Discharge In Florida Bay, Ifeanyi Emmanuel Eze Jan 2024

Geoelectrical And Hydrochemical Characterization Of Submarine Groundwater Discharge In Florida Bay, Ifeanyi Emmanuel Eze

College of Graduate Studies: Theses & Dissertations

Florida Bay, situated at the southern tip of Everglades National Park and underlain by the Miami Limestone formation, is an ecosystem of global significance. Over the past century, the bay has faced threats such as droughts, seagrass mortality, and hypersalinity. Despite various studies and management efforts, the dynamics of submarine groundwater discharge (SGD) in the region remain underexplored. Given that SGD plays a significant role in the chemical dynamics of coastal ecosystems, it warrants thorough investigation. This study aims to characterize the spatial and temporal patterns of SGD in Florida Bay by surveying three basins – Rankin, Whipray, and Rabbit …


Diatom Productivity And Nutrient Dynamics In The Ross Sea, Antarctica During Warm Events In The Neogene, Marialena Christopoulou Jan 2024

Diatom Productivity And Nutrient Dynamics In The Ross Sea, Antarctica During Warm Events In The Neogene, Marialena Christopoulou

Graduate Research Theses & Dissertations

Increased melting of the Antarctic Ice Sheet (AIS) in recent decades, has had a significant impact on many aspects of the global ocean. Models indicate that by the end of the 21st century atmospheric carbon dioxide (CO2) concentrations may exceed 500 ppm, and the average global temperature will likely warm by more than 2°C. However, data that provide model constraints on potential feedbacks in ice-ocean-atmosphere system are limited by short-timescales (e.g., decadal- to centennial-scale) and incomplete spatial coverage. In particular, little is known about the impacts of future warming and widespread melting of AIS on marine biological productivity, silicate weathering …


Tracing Past Climate Signals Through Multi-Proxy Analysis: Insights From Sedimentary Plant Wax Hydrogen Isotope Data And Long-Term Hydroclimate Records In Estonia, Mariliis Eensalu Jan 2024

Tracing Past Climate Signals Through Multi-Proxy Analysis: Insights From Sedimentary Plant Wax Hydrogen Isotope Data And Long-Term Hydroclimate Records In Estonia, Mariliis Eensalu

Graduate Research Theses & Dissertations

In light of the rising global temperatures, there is an increasing need to understand the potential shifts in hydroclimate. Past climate reconstructions offer a glimpse into the possible temperature-moisture dynamics by providing quantitative constraints for hydroclimate variability under different temperature conditions, which can ultimately aid in decreasing the uncertainty in future climate projections. The research presented in this dissertation focuses on utilizing various proxies to reconstruct past hydroclimate conditions, particularly in the Baltic region, with a specific emphasis on Estonia. The second and third chapter aim to improve the understanding of sedimentary plant wax hydrogen isotope (δ2H) data by first …


Dust-Driven Mechanism For Marine Particle Aggregation: Interactions Between Clay Minerals, Heterotrophic Bacteria And Organic Matter Influences Aggregation In Marine Systems, Vignesh Gokuladas Menon Jan 2024

Dust-Driven Mechanism For Marine Particle Aggregation: Interactions Between Clay Minerals, Heterotrophic Bacteria And Organic Matter Influences Aggregation In Marine Systems, Vignesh Gokuladas Menon

Dartmouth College Master’s Theses

Atmospheric dust deposition plays a crucial role in marine biogeochemical cycles, yet mechanisms underlying its impact on particle dynamics remain unclear. This study investigates the synergistic interactions between marine heterotrophic bacteria and clay minerals in seawater, focusing on their effect on Transparent Exopolymer Particles (TEP) production and organoclay aggregation. Field experiments in the Gulf of Maine and laboratory roller tank studies were conducted using natural microbial communities and model heterotrophic bacterial strains (Alteromonas sp. EZ55, Marinobacter adhaerens HP15, and Sulfitobacter sp. NAS-14.1). Results demonstrate that clay exposure significantly enhances TEP production by bloom-associated heterotrophic bacteria, with increases up to …


Assessing Stormwater Management Pond Water Quality, Function, And The Potential Biotic Effects To Receiving Waters, Mitchell Elstone Jan 2024

Assessing Stormwater Management Pond Water Quality, Function, And The Potential Biotic Effects To Receiving Waters, Mitchell Elstone

Theses and Dissertations (Comprehensive)

The use of stormwater management ponds (SWMPs) has been increasing over the past five decades. However, an in-depth understanding of the daily performance of SWMPs and functionality during cold periods is limited. This is in part because mandated monitoring is relatively infrequent, and the assumption that SWMPs are inactive between storm events and during the winter. The goals of this research were to better understand daily stormwater (SW) characteristics, the performance of SWMPs based on current forms of evaluation and assess the potential for SWMP effluent to impact downstream biota. Influent and effluent samples from two SWMPs were collected daily …


Enhancing A Computer Model To Evaluate Rainwater Harvesting And Reuse Strategies For Landscape Irrigation Under Current And Future Climate Conditions, Siyu Li Jan 2024

Enhancing A Computer Model To Evaluate Rainwater Harvesting And Reuse Strategies For Landscape Irrigation Under Current And Future Climate Conditions, Siyu Li

Electronic Theses & Dissertations (2024 - present)

Urbanization and climate change have detrimental impacts on water quantity and quality. Rainwater harvesting/reuse for landscape irrigation with rain barrels/cisterns, which can assist urban hydrological/water quality restoration and provide a beneficial resource for irrigating landscape, holds significant potentials in urban areas under current and future climates. However, the impacts of rainwater harvesting/reuse strategies for landscape irrigation under a changing climate need to be comprehensively evaluated to assist decision-making. In addition, a comprehensive tool is needed to help stakeholders develop efficient strategies to harvest rainwater for landscape irrigation with rain barrels/cisterns.

To address the needs, the simulation of the sub-daily hydrological …


Investigating The Effects Of A Southward Flow In The Southeastern Florida Shelf Using Robotic Instruments, Alfredo Quezada Dec 2023

Investigating The Effects Of A Southward Flow In The Southeastern Florida Shelf Using Robotic Instruments, Alfredo Quezada

All HCAS Student Capstones, Theses, and Dissertations

We deployed a Slocum G3 glider fitted with an acoustic Doppler current profiler (ADCP), a Conductivity-Temperature-Depth sensor (CTD), optics sensor channels, and a propeller on the Southeastern Florida shelf. The ADCP and CTD provide continuous measurements of Northern and Eastern current velocity components, salinity, temperature, and density, throughout the water column in a high-current environment. The optics sensor channels are able to provide measurements of chlorophyll concentrations, colored dissolved organic matter (CDOM), and backscatter particle counts. Additionally, for one of the glider deployments, we deployed a Wirewalker wave-powered profiling platform system also fitted with an ADCP and a CTD in …


Prevalence, Faunal Composition, And Vertical Distribution Of Bioluminescence In The Pelagic Gulf Of Mexico: Fishes, Crustaceans, Cephalopods And Gelatinous Megaplankton, Devynne M. Brown Dec 2023

Prevalence, Faunal Composition, And Vertical Distribution Of Bioluminescence In The Pelagic Gulf Of Mexico: Fishes, Crustaceans, Cephalopods And Gelatinous Megaplankton, Devynne M. Brown

All HCAS Student Capstones, Theses, and Dissertations

Bioluminescence is the phenomenon of light emission by living organisms. It occurs through a chemical reaction within an organism and serves various purposes. The diversity of bioluminescent capabilities and occurrence in unrelated taxa suggest that bioluminescence has evolved independently numerous times amongst taxa thriving in certain environments. One such environment is the deep ocean, where little to no sunlight penetrates the water column, specifically in the mesopelagic (200-1000 m depth) and bathypelagic (> 1000 m) zones. The mesopelagic and bathypelagic zones have been extensively sampled and well documented in the Gulf of Mexico (GoM), one of the few places globally …


Wonderstone And Its Connection To Liesegang, Microbes, And Beyond, Haden S. Mandery Dec 2023

Wonderstone And Its Connection To Liesegang, Microbes, And Beyond, Haden S. Mandery

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

In the western and southwestern United States, the term wonderstone is used to describe volcanic, volcaniclastic, and sedimentary rocks with variegated banding produced by iron oxide mineralization or staining. This iron oxide mineralization is typically described as Liesegang banding. In this paper I will (1) test if the banding in wonderstone follows the spacing and width laws characteristic of Liesegang, (2) identify the source of iron that ultimately precipitated in the bands, and (3) examine the role that microbes played in the formation of the mineralization in these rocks. I conclude that the iron oxide mineralization is not Liesegang banding. …


Wavelet Compression As An Observational Operator In Data Assimilation Systems For Sea Surface Temperature, Bradley J. Sciacca Dec 2023

Wavelet Compression As An Observational Operator In Data Assimilation Systems For Sea Surface Temperature, Bradley J. Sciacca

LSU New Orleans Theses and Dissertations

The ocean remains severely under-observed, in part due to its sheer size. Containing nearly billion of water with most of the subsurface being invisible because water is extremely difficult to penetrate using electromagnetic radiation, as is typically used by satellite measuring instruments. For this reason, most observations of the ocean have very low spatial-temporal coverage to get a broad capture of the ocean’s features. However, recent “dense but patchy” data have increased the availability of high-resolution – low spatial coverage observations. These novel data sets have motivated research into multi-scale data assimilation methods. Here, we demonstrate a new assimilation approach …


Enhancing Our Understanding Of Ancient Oceans Through The Investigation Of Molybdenum Behavior Under Sulfidic Conditions, Rachel Faye Phillips Dec 2023

Enhancing Our Understanding Of Ancient Oceans Through The Investigation Of Molybdenum Behavior Under Sulfidic Conditions, Rachel Faye Phillips

Open Access Theses & Dissertations

The most abundant trace metal in the ocean today, molybdenum (Mo), exhibits distinct behavior in oxygenated water, where it remains predominantly dissolved, compared to euxinic (i.e., oxygen-free and sulfidic) water, in which it is sequestered into the sediment. This dissimilar behavior allows us to use Mo concentrations and isotopic compositions in sediment to reconstruct marine oxygenation conditions throughout geologic history. However, Mo sequestration mechanisms under euxinic conditions remain unresolved, which limits the accuracy and precision of reconstructions made using Mo signatures in the rock record. For my doctoral research, I experimentally investigated abiotic and biotic Mo sequestration mechanisms under various …


Reducing Inputs And Adding Value To Turfgrass Systems Through Clover Inclusion And Plant Growth-Promoting Rhizobacteria Applications, Paige E. Boyle Dec 2023

Reducing Inputs And Adding Value To Turfgrass Systems Through Clover Inclusion And Plant Growth-Promoting Rhizobacteria Applications, Paige E. Boyle

All Graduate Theses and Dissertations, Fall 2023 to Present

Recently, the US has seen an expansion in the amount of turfgrass land cover (lawns, parks, roadsides, sports fields, and golf courses), as well as an interest in reducing fertilizer, water, and pesticide use in these grass systems. To help maintain quality and function while reducing resource inputs, two promising approaches have emerged: planting clover into lawns and applying plant growth-promoting rhizobacteria.

White clover and grass mixtures have been studied for their ability to cut down on fertilizer usage and provide a uniform, dark green lawn, but other clover types have not been as widely studied and may provide similar …


Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo Dec 2023

Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo

Graduate Theses and Dissertations (2019 - present)

Shallow, river-influenced coastal sediments are important for global carbon storage and nutrient cycling and provide a habitat for diverse communities of invertebrates (infauna). Elevated bed shear stress from extreme storms can resuspend, transport, and deposit sediments, disrupting the cohesive structure of muds, and sorting and depositing sand eroded from beaches. These physical disruptions can also resuspend or smother infauna, decreasing abundances and changing community structure. Infaunal activities such as burrowing, tube construction, and feeding can impact sediment structure and stability. However, little is known about how physical disturbance impacts short and long-term sediment habitat suitability and whether disturbance-tolerant infauna influence …


Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger Dec 2023

Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Dyer’s woad (Isatis tinctoria L.) is a non-native forb that continues to threaten natural areas throughout Northern Utah and much of the Intermountain West. Once introduced, dyer’s woad can become extremely invasive, decreasing forage quality, and displacing native species. While dyer’s woad is found throughout much of Northern Utah, its range in other states remains limited. If promptly managed, control success in these areas will be much higher and populations may be kept at bay before ecological damage becomes severe.

This project tested the ability of dyer’s woad seedlings to compete with common rangeland grasslands at varied densities as …


New Observations On The Age And Origin Of The Geologist Seamounts, South Hawaiian Seamount Province, Brandon Chester Scott Dec 2023

New Observations On The Age And Origin Of The Geologist Seamounts, South Hawaiian Seamount Province, Brandon Chester Scott

UNLV Theses, Dissertations, Professional Papers, and Capstones

Investigation into seamounts that stem from intraplate volcanism—that is volcanism occurring far from plate boundaries—presents an opportunity to deconvolve processes associated with mantle compositional heterogeneities and melting dynamics. Upwelling and decompression of thermochemically anomalous mantle plumes is the primary mechanism for significant intraplate volcanism; however, many seamounts dotted across the Pacific Plate do not correlate spatially, temporally, or geochemically with mantle plume volcanism. One region of enigmatic volcanism in the ocean basins that is not clearly attributable to plume-derived magmatism are the Geologist Seamounts and the wider South Hawaiian Seamount Province (∼19°N, 157°W). Here we present merged multibeam (<100 m) and satellite altimetry bathymetric maps of the Geologist Seamounts region, new 40 …


Tree-Ring Reconstruction Of Ouachita River Streamflow, Keaton Cade Jenkins-Joyce Dec 2023

Tree-Ring Reconstruction Of Ouachita River Streamflow, Keaton Cade Jenkins-Joyce

Graduate Theses and Dissertations

The Ouachita River drains the Ouachita Mountains and Upper Coastal Plain in Arkansas and Louisiana. The Ouachita River is used for navigation, power generation, recreation, water supply, and wastewater treatment. The river has been prone to low flows during drought and extreme flooding, which were principal justifications for the construction of three large multipurpose dams on the stream. It is likely that the use of the Ouachita River will be stressed by future population growth, economic expansion, and climate change. For this study, tree-ring chronologies from various locations in and near the Ouachita River drainage basin were used to reconstruct …


The Tidal Prism, Viable Eelgrass Habitat, And The Effects Of Sea Level Rise In Morro Bay, Kaden A. Caliendo Dec 2023

The Tidal Prism, Viable Eelgrass Habitat, And The Effects Of Sea Level Rise In Morro Bay, Kaden A. Caliendo

Master's Theses

The tidal prism, or the volume of water exchanged from the sea to an estuary from mean low to mean high tide, influences system hydrodynamics and ecological functioning. Since 1884, the tidal prism in Morro Bay, California has been estimated to be decreasing over time due to sedimentation from upstream practices. What is the current tidal prism in Morro Bay and how will that change with sea level rise? How will eelgrass respond to rising sea levels?

For this study, inexpensive tidal gauges were deployed at four locations in Morro Bay from March to August 2023 to measure spatially varying …


Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy Nov 2023

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km2 and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …


Emerging Sensing, Imaging, And Computational Technologies To Scale Nano-To Macroscale Rhizosphere Dynamics – Review And Research Perspectives, Amir H. Ahkami, Odeta Qafoku, Tiina Roose, Quanbing Mou, Yi Lu, Zoe G. Cardon, Yuxin Wu, Chunwei Chou, Joshua B. Fisher, Tamas Varga, Pubudu Handakumbura, Jayde A. Aufrecht, Arunima Bhattacharjee, James J. Moran Nov 2023

Emerging Sensing, Imaging, And Computational Technologies To Scale Nano-To Macroscale Rhizosphere Dynamics – Review And Research Perspectives, Amir H. Ahkami, Odeta Qafoku, Tiina Roose, Quanbing Mou, Yi Lu, Zoe G. Cardon, Yuxin Wu, Chunwei Chou, Joshua B. Fisher, Tamas Varga, Pubudu Handakumbura, Jayde A. Aufrecht, Arunima Bhattacharjee, James J. Moran

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The soil region influenced by plant roots, i.e., the rhizosphere, is one of the most complex biological habitats on Earth and significantly impacts global carbon flow and transformation. Understanding the structure and function of the rhizosphere is critically important for maintaining sustainable plant ecosystem services, designing engineered ecosystems for long-term soil carbon storage, and mitigating the effects of climate change. However, studying the biological and ecological processes and interactions in the rhizosphere requires advanced integrated technologies capable of decoding such a complex system at different scales. Here, we review how emerging approaches in sensing, imaging, and computational modeling …


Tidal Bed Stress Asymmetry And Sediment Transport In Estuaries, Austin Scott Hudson Nov 2023

Tidal Bed Stress Asymmetry And Sediment Transport In Estuaries, Austin Scott Hudson

Dissertations and Theses

Rivers and estuaries provide numerous ecological, economic, and cultural resources. The value of these resources is greatly influenced by sediment transport processes, which can be affected by human activities and climate variability. A key driver of sediment transport in tidal rivers and estuaries is tidal asymmetry of velocity and bed stress, which can manifest from both non-linear tidal interactions and linear interactions among astronomical tidal constituents.

In this study, an analytical framework is developed to examine and describe the dynamics of bed stress asymmetry in semidiurnal, diurnal, and mixed-tide estuaries (Chapter 1). While tidal velocity asymmetry has been previously analyzed, …


The Seasonal Origins And Ages Of Water Provisioning Streams And Trees In A Tropical Montane Cloud Forest, Emily Burt, Gregory R. Goldsmith, Roxanne M. Cruz-De Hoyos, Adan Julian Ccahuana Quispe, A. Joshua West Nov 2023

The Seasonal Origins And Ages Of Water Provisioning Streams And Trees In A Tropical Montane Cloud Forest, Emily Burt, Gregory R. Goldsmith, Roxanne M. Cruz-De Hoyos, Adan Julian Ccahuana Quispe, A. Joshua West

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Determining the sources of water provisioning streams, soils, and vegetation can provide important insights into the water that sustains critical ecosystem functions now and how those functions may be expected to respond given projected changes in the global hydrologic cycle. We developed multi-year time series of water isotope ratios (δ18O and δ2H) based on twice-monthly collections of precipitation, lysimeter, and tree branch xylem waters from a seasonally dry tropical montane cloud forest in the southeastern Andes mountains of Peru. We then used this information to determine indices of the seasonal origins, the young water fractions …


Examining The Corn Seedling Emergence–Temperature Relationship For Recent Hybrids: Insights From Experimental Studies, Sahila Beegum, Charles Hunt Walne, Krishna N. Reddy, Vangimalla Reddy, Kambham Raja Reddy Oct 2023

Examining The Corn Seedling Emergence–Temperature Relationship For Recent Hybrids: Insights From Experimental Studies, Sahila Beegum, Charles Hunt Walne, Krishna N. Reddy, Vangimalla Reddy, Kambham Raja Reddy

Nebraska Water Center: Faculty Publications

Corn seedling emergence is a critical factor affecting crop yields. Accurately predicting emergence is crucial for precise crop growth and development simulation in process-based crop models. While various experimental studies have investigated the relationship between corn seedling emergence and temperature, there remains a scarcity of studies focused on newer corn hybrids. In the present study, statistical models (linear and quadratic functional relationships) are developed based on the seedling emergence of ten current corn hybrids, considering soil and air temperatures as influencing factors. The data used for model development are obtained from controlled soil plant atmospheric research chamber experiments focused on …


Analysis Of Wastewater Samples To Explore Community Substance Use In The United States: Pilot Correlative And Machine Learning Study, Marie A. Severson, Sathaporn Onanong, Alexandra Dolezal, Shannon L. Bartelt-Hunt, Daniel D. Snow, Lisa M. Mcfadden Oct 2023

Analysis Of Wastewater Samples To Explore Community Substance Use In The United States: Pilot Correlative And Machine Learning Study, Marie A. Severson, Sathaporn Onanong, Alexandra Dolezal, Shannon L. Bartelt-Hunt, Daniel D. Snow, Lisa M. Mcfadden

Nebraska Water Center: Faculty Publications

Background: Substance use disorder and associated deaths have increased in the United States, but methods for detecting and monitoring substance use using rapid and unbiased techniques are lacking. Wastewater-based surveillance is a cost-effective method for monitoring community drug use. However, the examination of the results often focuses on descriptive analysis.

Objective: The objective of this study was to explore community substance use in the United States by analyzing wastewater samples. Geographic differences and commonalities of substance use were explored.

Methods: Wastewater was sampled across the United States (n=12). Selected drugs with misuse potential, prescriptions, and over-the-counter drugs …