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Articles 91 - 120 of 1293

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Tracing Geochemical Sources And Health Risk Assessment Of Uranium In Groundwater Of Arid Zone Of India, P. Pandit, Atul Saini, Sabarathinam Chidambaram, Vinod Kumar, Banjarani Panda, A. L. Ramanathan, Netrananda Sahu, A. K. Singh, Rohit Mehra Jun 2022

Tracing Geochemical Sources And Health Risk Assessment Of Uranium In Groundwater Of Arid Zone Of India, P. Pandit, Atul Saini, Sabarathinam Chidambaram, Vinod Kumar, Banjarani Panda, A. L. Ramanathan, Netrananda Sahu, A. K. Singh, Rohit Mehra

Nebraska Water Center: Faculty Publications

Water quality degradation and metal contamination in groundwater are serious concerns in an arid region with scanty water resources. This study aimed at evaluating the source of uranium (U) and potential health risk assessment in groundwater of the arid region of western Rajasthan and northern Gujarat. The probable source of vanadium (V) and fluorine (F) was also identified. U and trace metal concentration, along with physicochemical characteristics were determined for 265 groundwater samples collected from groundwater of duricrusts and palaeochannels of western Rajasthan and northern Gujarat. The U concentration ranged between 0.6 and 260 μg L−1 with a mean …


Speciation With Gene Flow In A Narrow Endemic West Virginia Cave Salamander (Gyrinophilus Subterraneus), Evan H. Campbell Grant, Kevin P. Mulder, Adrianne B. Brand, Douglas B. Chambers, Addison H. Wynn, Grace Capshaw, Matthew L. Niemiller, John G. Phillips, Jeremy F. Jacobs, Shawn R. Kuchta, Rayna C. Bell Jun 2022

Speciation With Gene Flow In A Narrow Endemic West Virginia Cave Salamander (Gyrinophilus Subterraneus), Evan H. Campbell Grant, Kevin P. Mulder, Adrianne B. Brand, Douglas B. Chambers, Addison H. Wynn, Grace Capshaw, Matthew L. Niemiller, John G. Phillips, Jeremy F. Jacobs, Shawn R. Kuchta, Rayna C. Bell

United States Geological Survey: Staff Publications

Due to their limited geographic distributions and specialized ecologies, cave species are often highly endemic and can be especially vulnerable to habitat degradation within and surrounding the cave systems they inhabit. We investigated the evolutionary history of the West Virginia Spring Salamander (Gyrinophilus subterraneus), estimated the population trend from historic and current survey data, and assessed the current potential for water quality threats to the cave habitat. Our genomic data (mtDNA sequence and ddRADseq-derived SNPs) reveal two, distinct evolutionary lineages within General Davis Cave corresponding to G. subterraneus and its widely distributed sister species, Gyrinophilus porphyriticus, that …


Toxicological Responses To Sublethal Anticoagulant Rodenticide Exposure In Free‑Flying Hawks, Nimish B. Vyas, Barnett A. Rattner, J. Michael Lockhart, Craig S. Hulse, Clifford P. Rice, Frank Kuncir, Kevin Kritz May 2022

Toxicological Responses To Sublethal Anticoagulant Rodenticide Exposure In Free‑Flying Hawks, Nimish B. Vyas, Barnett A. Rattner, J. Michael Lockhart, Craig S. Hulse, Clifford P. Rice, Frank Kuncir, Kevin Kritz

United States Geological Survey: Staff Publications

An important component of assessing the hazards of anticoagulant rodenticides to non-target wildlife is observations in exposed free-ranging individuals. The objective of this study was to determine whether environmentally realistic, sublethal first-generation anticoagulant rodenticide (FGAR) exposures via prey can result in direct or indirect adverse effects to free-flying raptors. We offered black-tailed prairie dogs (Cynomys ludovicianus) that had fed on Rozol® Prairie Dog Bait (Rozol, 0.005% active ingredient chlorophacinone, CPN) to six wild-caught red-tailed hawks (RTHA, Buteo jamaicensis), and also offered black-tailed prairie dogs that were not exposed to Rozol to another two wild-caught RTHAs for 7 …


Within‑Marsh And Landscape Features Structure Ribbed Mussel Distribution In Georgia, Usa, Marshes, William K. Annis, Elizabeth A. Hunter, John M. Carroll May 2022

Within‑Marsh And Landscape Features Structure Ribbed Mussel Distribution In Georgia, Usa, Marshes, William K. Annis, Elizabeth A. Hunter, John M. Carroll

United States Geological Survey: Staff Publications

Ribbed mussels, Geukensia demissa, are marsh fauna that are used in coastal management and restoration due to the ecosystem services they provide. Ribbed mussel restoration efforts may be improved with a greater understanding of the environmental drivers of ribbed mussel distribution at multiple spatial scales to predict areas where restoration could be successful. This study sought to estimate the effects of within-marsh (4 m) and landscape (500 m) factors on ribbed mussel distribution. Ribbed mussel densities were surveyed at 11 sites along the coast of Georgia, USA, and overlaid with spatial data for within-marsh factors (elevation, distance to marsh …


Influences Of Seasonality And Habitat Quality On Great Lakes Coastal Wetland Fish Community Composition And Diets, Sara N. Diller, Anna M. Harrison, Kurt P. Kowalski, Valerie J. Brady, Jan J. H. Ciborowski, Matthew J. Cooper, Joshua D. Dumke, Joseph P. Gathman, Carl R. Ruetz Iii, Donald G. Uzarski, Douglas A. Wilcox, Jeffrey S. Schaeffer May 2022

Influences Of Seasonality And Habitat Quality On Great Lakes Coastal Wetland Fish Community Composition And Diets, Sara N. Diller, Anna M. Harrison, Kurt P. Kowalski, Valerie J. Brady, Jan J. H. Ciborowski, Matthew J. Cooper, Joshua D. Dumke, Joseph P. Gathman, Carl R. Ruetz Iii, Donald G. Uzarski, Douglas A. Wilcox, Jeffrey S. Schaeffer

United States Geological Survey: Staff Publications

Great Lakes coastal wetlands (GLCW) have been severely degraded by anthropogenic activity over the last several decades despite their critical role in fish production. Many Great Lakes fish species use coastal wetland habitats for spawning, feeding, shelter, and nurseries throughout the year. The goal of our study was to compare GLCW fish community composition in the spring, summer, and fall months and investigate how water quality relates to fish diversity, the presence of functional groups, and juvenile fish diets. We summarized fish data collected from GLCW across the basin and used the coastal wetland monitoring program’s water quality-land use indicator …


A Critical Review Of Bioaccumulation And Biotransformation Of Organic Chemicals In Birds, Dave T. F. Kuo, Barnett A. Rattner, Sarah C. Marteinson, Robert Letcher, Kim J. Fernie, Gabriele Treu, Markus Deutsch, Mark S. Johnson, Sandrine Deglin, Michelle Embry May 2022

A Critical Review Of Bioaccumulation And Biotransformation Of Organic Chemicals In Birds, Dave T. F. Kuo, Barnett A. Rattner, Sarah C. Marteinson, Robert Letcher, Kim J. Fernie, Gabriele Treu, Markus Deutsch, Mark S. Johnson, Sandrine Deglin, Michelle Embry

United States Geological Survey: Staff Publications

A literature review of bioaccumulation and biotransformation of organic chemicals in birds was undertaken, aiming to support scoping and prioritization of future research. The objectives were to characterize available bioaccumulation/ biotransformation data, identify knowledge gaps, determine how extant data can be used, and explore the strategy and steps forward. An intermediate approach balanced between expediency and rigor was taken given the vastness of the literature. Following a critical review of >500 peer-reviewed studies, >25,000 data entries and 2 million information bytes were compiled on >700 organic compounds for ~ 320 wild species and 60 domestic breeds of birds. These data …


Nutrient Restoration Of A Large, Impounded, Ultra-Oligotrophic Western River To Recover Declining Native Fishes, Ryan S. Hardy, Tyler J. Ross, Kevin N. Mcdonnell, Michael C. Quist, Charlie Holderman, Bryan S. Stevens May 2022

Nutrient Restoration Of A Large, Impounded, Ultra-Oligotrophic Western River To Recover Declining Native Fishes, Ryan S. Hardy, Tyler J. Ross, Kevin N. Mcdonnell, Michael C. Quist, Charlie Holderman, Bryan S. Stevens

United States Geological Survey: Staff Publications

Declines in many fish populations in large, western rivers have been primarily attributed to the anthropogenic reduction of nutrient inputs and subsequent impacts to the food web. The largest known river fertilization program was implemented starting in 2005 on the Kootenai River in northern Idaho to restore resident fisheries. Annual electrofishing surveys were conducted at multiple sites in Idaho and Montana before and during nutrient addition to evaluate assemblage and population-level responses. Although few responses in fish assemblage structure were observed, the addition of liquid ammonium polyphosphate fertilizer (3 μg/L) to the Kootenai River increased fish abundance and biomass over …


Age And Water-Quality Characteristics Of Groundwater Discharge To The South Loup River, Nebraska, 2019, Christopher M. Hobza, John E. Solder May 2022

Age And Water-Quality Characteristics Of Groundwater Discharge To The South Loup River, Nebraska, 2019, Christopher M. Hobza, John E. Solder

United States Geological Survey: Water Reports and Publications

Streams in the Loup River Basin are sensitive to groundwater withdrawals because of the close hydrologic connection between groundwater and surface water. The U.S. Geological Survey, in cooperation with the Upper Loup and Lower Loup Natural Resources Districts, and the Nebraska Environmental Trust, studied the age and water-quality characteristics of groundwater near the South Loup River to assess the possible effects of a multiyear drought on streamflow.

Groundwater sampled in wells screened in Quaternary-age deposits displayed a wide range of mean ages (27 to 2,100 years), fraction modern, and susceptibility index values. Groundwater with higher concentrations of chloride and higher …


Air, Land, And Water Variables Associated With The First Appearance And Current Spatial Distribution Of Toxic Prymnesium Parvum Blooms In Reservoirs Of The Southern Great Plains, Usa, Shisbeth Tábora-Sarmiento, Reynaldo Patiño, Carlos Portillo-Quintero, Cade Coldren Apr 2022

Air, Land, And Water Variables Associated With The First Appearance And Current Spatial Distribution Of Toxic Prymnesium Parvum Blooms In Reservoirs Of The Southern Great Plains, Usa, Shisbeth Tábora-Sarmiento, Reynaldo Patiño, Carlos Portillo-Quintero, Cade Coldren

United States Geological Survey: Staff Publications

This study examined the association of air, land, and water variables with the first historical occurrence and current distribution of toxic Prymnesium parvum blooms in reservoirs of the Brazos River and Colorado River, Texas (USA). One impacted and one reference reservoir were selected per basin. Land cover and use variables were estimated for the whole watershed (WW) and a 0.5-km zone on either side of streams (near field, NF). Variables were expressed in annual values. Principal component and trend analyses were used to determine (1) differences in environmental conditions before and after the 2001 onset of toxic blooms in impacted …


An Investigation Of Water Obstructions And Related Weather Conditions For Nebraska Roadways, Logan Bundy Apr 2022

An Investigation Of Water Obstructions And Related Weather Conditions For Nebraska Roadways, Logan Bundy

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

Roadway resilience across the 10,000 miles of road and 3,500 bridges in Nebraska is critical to the economic success of production and logistics. In a state where historical flooding scenarios, such as the one in March 2019 that caused $150 million in damage, could potentially be increasing, it has become essential to understand the spatial and temporal distribution of high-frequency water obstruction areas on roadways. Using Nebraska Department of Transportation (NDOT) historical water obstruction data from June 2016 through August 2021, statistical and spatial analyses were conducted to quantify the relationship between water obstructions and their associated meteorological conditions, and …


Comparing Polarimetric Signatures Of Proximate Tornadic And Non-Tornadic Supercells In Similar Environments, Devon Healey Apr 2022

Comparing Polarimetric Signatures Of Proximate Tornadic And Non-Tornadic Supercells In Similar Environments, Devon Healey

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

While much research has shown that characteristics of the environment surrounding supercells can potentially indicate their likelihood to become tornadic, it is not uncommon for tornadic and non-tornadic supercells to coexist in seemingly similar environments. In these situations, it is difficult operationally to separate tornadic from non-tornadic supercells using environmental observations alone. Given that tornadic and non-tornadic supercells have been found to coexist in similar environments, something must be occurring beneath the observational and/or model gridscale that is supporting tornadogenesis in some supercells while inhibiting it in others. This study examines dual-polarimetric radar signatures of proximate tornadic and non-tornadic supercells …


Spatial And Temporal Distribution And Habitat Selection Of Native Yellowstone Cutthroat Trout And Nonnative Utah Chub, Darcy K. Mccarrick, Jeffrey C. Dillon, Brett High, Michael C. Quist Apr 2022

Spatial And Temporal Distribution And Habitat Selection Of Native Yellowstone Cutthroat Trout And Nonnative Utah Chub, Darcy K. Mccarrick, Jeffrey C. Dillon, Brett High, Michael C. Quist

United States Geological Survey: Staff Publications

Henrys Lake, Idaho, is a renowned trophy trout fishery that faces an uncertain future following the establishment of Utah Chub (UTC) Gila atraria. Utah Chub were first documented in the lake in 1993 and have become abundant over the past two decades. Little is known about the ecology of UTC, but they typically have negative effects on salmonids in systems where they have been introduced. We sought to fill knowledge gaps in UTC ecology and provide insight on potential interactions with Yellowstone Cutthroat Trout (YCT) Oncorhynchus clarkii bouvieri. Ninety-four YCT and 95 UTC were radio-tagged in spring 2019 …


Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant Apr 2022

Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant

United States Geological Survey: Staff Publications

  1. Most applications of single-scale occupancy models do not differentiate between availability and detectability, even though species availability is rarely equal to one. Species availability can be estimated using multi-scale occupancy models; however, for the practical application of multi-scale occupancy models, it can be unclear what a robust sampling design looks like and what the statistical properties of the multi-scale and single-scale occupancy models are when availability is less than one.
  2. Using simulations, we explore the following common questions asked by ecologists during the design phase of a field study: (Q1) what is a robust sampling design for the multi-scale occupancy …


Using Field Scale Electrical Data To Understand Real-Time Agricultural Water Delivery, Bradley Dowell Apr 2022

Using Field Scale Electrical Data To Understand Real-Time Agricultural Water Delivery, Bradley Dowell

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

Areas across the High Plains (Ogallala) Aquifer region are experiencing unsustainable groundwater level declines and impacts to streamflow due to increasing human influence, posing challenges for sustaining future agricultural economies and groundwater resources. State and local agencies manage water using groundwater models, which are not at the same temporal and spatial scale as water management on farms. Well-informed agricultural water usage cannot be achieved without reliable and cost-effective water use at farm scale. Water meters are expensive and rarely installed unless required by the state or other regulatory agency; however, most center pivots have their own power supply, which reports …


Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist Mar 2022

Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist

United States Geological Survey: Staff Publications

Henrys Lake, Idaho, supports a popular fishery for Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and Yellowstone Cutthroat Trout × Rainbow Trout O. mykiss hybrids. A majority of the adult population of fish in Henrys Lake are of hatchery origin that were stocked as fingerlings. The fishery is closed to angling during the late winter and spring months, but fisheries managers are considering opening the fishery year-round with catch-and-release- only regulations or with a two-fish bag limit during the extended season. However, there is concern that the proposed management actions may negatively affect the current fishery. Therefore, we developed an integrated …


Virtual Training Prepared For The Former Afghanistan Ministry Of Energy And Water—Streamgaging, Fluvial Sediment Sampling, Bathymetry, And Streamflow And Sediment Modeling, Joel T. Groten, Joshua F. Valder, Brenda K. Densmore, Logan W. Neal, Justin Krahulik, Thomas J. Mack Mar 2022

Virtual Training Prepared For The Former Afghanistan Ministry Of Energy And Water—Streamgaging, Fluvial Sediment Sampling, Bathymetry, And Streamflow And Sediment Modeling, Joel T. Groten, Joshua F. Valder, Brenda K. Densmore, Logan W. Neal, Justin Krahulik, Thomas J. Mack

United States Geological Survey: Water Reports and Publications

The United States Geological Survey (USGS) created a virtual training series for the Afghanistan Ministry of Energy and Water (MEW), now known as the National Water Affairs Regulation Authority (NWARA), to provide critical hydrological training as an alternative to an in-person training. The USGS was scheduled to provide in-person surface-water training for NWARA during 2020; however, travel was halted because of the Coronavirus disease 2019 (COVID–19) pandemic. The virtual training consisted of prerecorded and live presentations that were scheduled during 4 weeks in August 2021. However, the training was halted after the second week due to the collapse of the …


Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin Feb 2022

Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin

United States Geological Survey: Staff Publications

Background: Movement information can improve conservation of imperiled species, yet movement is not quantified for many organisms in need of conservation. Prairie chub (Macrhybopsis australis) is a regionally endemic freshwater fish with unquantified movement ecology and currently considered for listing under the Endangered Species Act. The purpose of this study was to test competing ecological theories for prairie chub movement, including the colonization cycle hypothesis (CCH) that posits adults must make upstream movements to compensate for downstream drift at early life stages, and the restricted movement paradigm (RMP) that describes populations as heterogeneous mixes of mostly stationary …


Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-Macinnis Feb 2022

Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-Macinnis

United States Geological Survey: Staff Publications

Fluid exsolution and melt evolution at the magmatic-hydrothermal transition are critical processes driving the metal enrichment of porphyry systems. Coeval fluid and melt inclusion assemblages in unidirectional solidification textures (USTs) at Saginaw Hill—a small, porphyry Cu system in southwestern Arizona—record a dynamic and repetitious process of fluid accumulation and release. The cores of quartz crystals throughout the UST bands host coeval silicate melt and brine inclusions but lack vapor-rich inclusions. This could indicate preferential expulsion of vapor and trapping of high-density brine during episodes of fracturing or the direct exsolution of single-phase high-salinity brine from the silicate melt. In contrast, …


Modeling Vapor Transfer In Soil Water And Heat Simulations: A Modularized, Partially-Coupled Approach, Zhuangji Wang, Dennis Timlin, David Fleisher, Wenguang Sun, Sahila Beegum, Sanai Li, Ya Chen, Vandimalla R. Reddy, Katherine Tully, Robert Horton Jan 2022

Modeling Vapor Transfer In Soil Water And Heat Simulations: A Modularized, Partially-Coupled Approach, Zhuangji Wang, Dennis Timlin, David Fleisher, Wenguang Sun, Sahila Beegum, Sanai Li, Ya Chen, Vandimalla R. Reddy, Katherine Tully, Robert Horton

Nebraska Water Center: Faculty Publications

Coupled water and heat transfer models are widely used to analyze soil water content and temperature dynamics, evaluate agricultural management systems, and support crop growth modelling. In relatively dry soils, vapor transfer, rather than liquid water flux, becomes the main pathway for water redistribution. However, in some modularized soil simulators, e.g., 2DSOIL (Timlin et al., 1996), vapor transfer is not included, which may induce errors in soil water and heat modelling. Directly embedding vapor transfer into existing water and heat transfer modules may violate the modularized architecture of those simulators. Therefore, the objectives of this study are to design a …


Main-Stem Seepage And Base-Flow Recession Time Constants In The Niobrara National Scenic River Basin, Nebraska, 2016–18, Kellan R. Strauch, Philip J. Soeksen Jan 2022

Main-Stem Seepage And Base-Flow Recession Time Constants In The Niobrara National Scenic River Basin, Nebraska, 2016–18, Kellan R. Strauch, Philip J. Soeksen

United States Geological Survey: Water Reports and Publications

The Niobrara River of northern Nebraska is a valuable water resource that sustains irrigated agriculture and recreation, as well as a diverse ecosystem. Large-quantity withdrawals from the source aquifer system have the potential to reduce the flow into the river and to adversely affect the free-flowing condition of the Niobrara National Scenic River (NSR). Therefore, to understand the magnitude and characteristics of those flows, the United States Geological Survey (USGS), in cooperation with the National Park Service, began a study to quantify seepage gains/losses along the eastern half of the Niobrara NSR and to create a map characterizing the base-flow …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


An Analysis Of Associations Between Polarimetric Supercell Signatures, Erik Green Jan 2022

An Analysis Of Associations Between Polarimetric Supercell Signatures, Erik Green

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

Supercell thunderstorms produce unique polarimetric radar signatures that are not often observed in unorganized deep convection. Repetitive signatures include deep and persistent differential reflectivity (ZDR) columns and the ZDR arc signature, which are both indicative of thermodynamic and microphysical processes intrinsic to supercells. Prior investigations of supercell polarimetric signatures, both those observed by operational and research radars, and those simulated numerically, reveal positive correlations between the ZDR column depth and cross-sectional area and quantitative characteristics of the radar reflectivity field. This study expands upon prior work by incorporating a dataset of discrete, right moving supercells …


A Greenhouse Gas Emissions Inventory For Nebraska: Livestock And Coal Loom Large, Eric R. Holley, Adam Liska Jan 2022

A Greenhouse Gas Emissions Inventory For Nebraska: Livestock And Coal Loom Large, Eric R. Holley, Adam Liska

Adam Liska Papers

Mitigation of climate change requires the systematic identification and cataloging of emissions sources at city, state, and national levels. In this study, an inventory of annual greenhouse gas emissions from the state of Nebraska was created based on industry data, and emissions inventories were completed each year from 1990 to 2016. Nebraska’s net emissions were found to increase from 56.2 million metric tons of carbon dioxide equivalents (MMtCO2e) in 1990 to 87.4 MMtCO2e in 2016. Agriculture was found to be the sector with the most emissions (36 MMtCO2e) followed by electricity generation (21 MMtCO …


Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs Jan 2022

Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs

United States Geological Survey: Staff Publications

The primary last interglacial, marine isotope substage (MIS) 5e records on the Pacific coast of North America, from Washington (USA) to Baja California Sur (Mexico), are found in the deposits of erosional marine terraces. Warmer coasts along the southern Golfo de California host both erosional marine terraces and constructional coral reef terraces. Because the northern part of the region is tectonically active, MIS 5e terrace elevations vary considerably, from a few meters above sea level to as much as 70m above sea level. The primary paleo-sea-level indicator is the shoreline angle, the junction of the wave-cut platform with the former …


Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray Jan 2022

Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Improvement of nutrient use efficiency and limiting trace elements such as arsenic and uranium bioavailability is critical for sustainable agriculture and food safety. Arsenic and uranium possess different properties and mobility in soils, which complicates the effort to reduce their uptake by plants. Here, we postulate that unsaturated soil amended with ferrihydrite nanominerals leads to improved nutrient retention and helps reduce uptake of these geogenic contaminants. Unsaturated soil is primarily oxic and can provide a stable environment for ferrihydrite nanominerals. To demonstrate the utility of ferrihydrite soil amendment, maize was grown in an unsaturated agricultural soil that is known to …


Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan Dec 2021

Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan

Nebraska Water Center: Faculty Publications

The present research reports the level of nitrate (NO3-), associated health risks and possible sources of contamination in groundwater from south India. Many samples (32%) are above or approaching the recommended level of NO3- for safe drinking water. The correlation analysis indicates different sources of NO3- contamination in different regions rather than a common origin. The isotopic measurements provide information about potential nitrogen sources contributing NO3- to the groundwater. Based on isotope analysis, the sources of NO3- in the groundwater of this region are likely to be from (a) …


Implications From Uranium-Series Disequilibria In A Bi-Lithologic Melt With Varying Lithospheric Caps, Juliet Messer Dec 2021

Implications From Uranium-Series Disequilibria In A Bi-Lithologic Melt With Varying Lithospheric Caps, Juliet Messer

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

Both spreading rates and local magma supply to mid-ocean ridges affect crustal construction styles and ridge morphology, alternately leading to either asymmetrical (detachment faulting) or symmetrical faulting styles. Uranium-series isotopic disequilibria in mid-ocean ridge basalts (MORB) may provide insight into how melt supply variations relate to ridges’ accretion styles, a processes that are not well understood. I use Reactive Porous Flow (RPF) equilibrium and disequilibrium modeling to simulate U-series disequilibria at mid-ocean ridge (MOR) generated by melt supply variations at both asymmetrical and symmetrical ridge segments.

Guided by my modeling, I predict that enhanced melt contributions from enriched pyroxenitic mantle …


Biostratigraphy Of Paleogene Diatom Assemblages In The Southern Ocean, Angela Kaup Dec 2021

Biostratigraphy Of Paleogene Diatom Assemblages In The Southern Ocean, Angela Kaup

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

The record of siliceous microfossil sedimentation in the high latitude South Atlantic Ocean has great potential for dating seismic and stratigraphic units. Over the last several decades, scientists have documented diatom biostratigraphic record from sediment cores and drill cores in the Falkland Plateau and Maurice Ewing Bank region, as well as other areas of the Southern Ocean, and a robust chronostratigraphic framework is available for Neogene sequences. Given the complicated nature of ocean bathymetry, tectonic plate motion (vertical and lateral), and ocean current flow, the sedimentological evolution of this oceanic region is not well understood. Sampling sediment cores at high …


Continuous Turbidity Data Used To Compute Constituent Concentrations In The South Loup River, Nebraska, 2017–18, David L. Rus, Brenda K. Densmore Dec 2021

Continuous Turbidity Data Used To Compute Constituent Concentrations In The South Loup River, Nebraska, 2017–18, David L. Rus, Brenda K. Densmore

United States Geological Survey: Water Reports and Publications

The South Loup River in central Nebraska has been impaired by bacteria since at least 2004, which has resulted in the river not meeting its intended use as a recreational waterway. As part of a strategy for reducing the bacterial load in the river, the United States Geological Survey (USGS), in cooperation with the Lower Loup Natural Resources District, made continuous estimates of Escherichia coli (E. coli) and nutrient concentrations during seasonal monitoring at the South Loup River at Saint Michael, Nebraska, during 2017–18. Continuous turbidity data were collected from mid-April through October in 2017 and 2018 …