Oceanography and Atmospheric Sciences and Meteorology Commons^™

The Effects Of Varying Temperatures And Food Availability On The Reproductive Output Of The Acorn Barnacle: Chthamalus Fissus, Karina L. Rog

McNair Summer Research Program

Climate change is predicted to intensify ocean warming and the reduction in phytoplankton abundance, potentially disrupting reproductive processes in filter-feeding intertidal invertebrates. This study investigated the combined effects of water temperature increases and food availability on the reproductive output on Chthamalus fissus, a dominant intertidal barnacle species found along the Southern California coastline. Using a controlled laboratory experiment, adult barnacles collected from the nearshore rocky intertidal habitat in La Jolla, California, were exposed to two temperature regimes (ambient water temperature ~ 18°C and elevated water temperature ~ 20-21°C) and two food concentration treatments (low and high phytoplankton and rotifer …

2025 August 7 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Exploring The Use Of A Random Forest In Correcting Gfs Tropical Cyclone Landfall Errors, Victoria Grace Maxwell

Theses and Dissertations

While Tropical Cyclone (TC) track forecasting has improved over the years it has been slow. These improvements can be attributed to increased computer capability and better model inputs. Machine learning has been used for forecasting different TC track and intensity. The study here looks to use a Random Forest to predict the TC latitude/longitude “landfall” at 72-hr and quantify improvements to the GFS forecast. Principal Component Analysis was used to reduce the dimensionality of the meteorological variables. Stepwise regression was used to determine the principal components that were important for forecasting landfall. These variables were then tested with a multivariate …

A 12,800-Year-Old Layer With Cometary Dust, Microspherules, And Platinum Anomaly Recorded In Multiple Cores From Baffin Bay, Christopher R. Moore, Vladimir A. Tselmovich, Malcolm A. Lecompte, Allen West, Stephen J. Culver, David J. Mallinson, Mohammed Baalousha M.Sc, Ph.D., James P. Kennett, William M. Napier, Michael Bizimis, Victor Adedeji, Seth R. Sutton, Gunther Kleteschka, Kurt A. Langworthy, Jesus P. Perez, Timothy Witwer, Marc D. Young, Jordan Jeffreys, Richard C. Greenwood, James A. Malley

Faculty Publications

The Younger Dryas Impact Hypothesis (YDIH) posits that ~12,800 years ago Earth encountered the debris stream of a disintegrating comet, triggering hemisphere-wide airbursts, atmospheric dust loading, and the deposition of a distinctive suite of extraterrestrial (ET) impact proxies at the Younger Dryas Boundary (YDB). Until now, evidence supporting this hypothesis has come only from terrestrial sediment and ice-core records. Here we report the first discovery of similar impact-related proxies in ocean sediments from four marine cores in Baffin Bay that span the YDB layer at water depths of 0.5–2.4 km, minimizing the potential for modern contamination. Using scanning electron microscopy …

A Deep Learning Framework With Explainable Ai For Atmospheric Blocking Detection And Interpretation, Devansh Khandelwal

Discovery Undergraduate Interdisciplinary Research Internship

Atmospheric blocking is a large-scale quasi-stationary phenomenon in mid-latitude circulation, characterized by persistent high-pressure systems that disrupt the typical west-to-east flow of the jet stream. These systems can cause extreme weather events—such as heatwaves, cold spells, or droughts—that persist for days or even weeks. This study proposes a deep learning framework to predict and interpret the occurrence of atmospheric blocking by integrating geophysical precursors such as geopotential height (Z500), stream function (SF200), and potential vorticity. These features, which are dynamically linked to blocking onset and persistence, serve as inputs to a Convolutional Neural Network model trained on the CESM Large …

Expanded Genetic And Functional Diversity Of Oceanic Fungi, Xuefeng Peng, David L. Valentine

Faculty Publications

Background

Fungi are known members of marine microbiomes that can act as saprotrophs, parasites, and pathogens. Although a few studies utilizing cultivation-based methods and metabarcoding have been conducted, the diversity, ecological roles, and functional activities of fungi in the open ocean remain vastly underexplored. This gap in knowledge is particularly notable in oxygen minimum zones (OMZ) of the ocean, which have expanded over the past 50 years, affecting marine ecosystems and biogeochemical cycles. The eastern tropical North Pacific Ocean (ETNP) is the largest oxygen minimum zone where fungi have been implicated in the production of the potent greenhouse gas nitrous …

Tree Rings And The Broader Ocean-Atmospheric Circulation In The Highland Himalayas, Sanjaya Bhandari

All-Inclusive List of Electronic Theses and Dissertations

Climate change has altered tree-growth patterns and resulted in higher sea-surface temperatures across the planet. The Himalayan biome is one of the most vulnerable areas in the world to climate change because it has caused changes in forests’ growth and glaciers’ retreat. Dendrochronology has been used to understand the impact of climate change on tree growth and for climate reconstruction. In this dissertation, I discuss the growth of trees in the highlands of the eastern, central, and western Himalayas for the last 500 years and relate these patterns to the present global warming scenario and broad-scale climate modes. I reconstructed …

2025 August - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

Ocean-Ice Sheet Interactions During Super-Interglacial Mis 31: Comparison Of Rock Magnetic Records From The Scotia Sea (59.1°S) And Fram Strait (76.5°N), Olga Libman-Roshal

Theses, Dissertations and Culminating Projects

The mid-Pleistocene transition (MPT) was a period spanning ~1.2-0.7 Ma when glacial-interglacial cyclicity changed from 41 kyr obliquity paced to 100 kyr eccentricity paced cycles with increased glacial-interglacial contrast post-MPT. Marine Isotope Stage (MIS) 31 was a “super-interglacial” within the MPT and occurred in the recent geological past (1.08-1.06 Ma). During MIS 31, the tectonic configuration resembled the present day, but Earth’s orbital parameters were marked by maximum values of eccentricity and obliquity while atmospheric CO2 remained at pre-industrial levels (below 280 ppm). MIS 31 therefore offers a valuable baseline for testing the impacts of modern anthropogenic CO2 levels combined …

Simulation Of Photochemical Effects On Air Quality, Grace Li

Chemical Engineering Undergraduate Honors Theses

Nitrogen dioxide (NO₂) and ozone (O₃) are both EPA criteria air pollutants in the troposphere, largely generated by combustion and therefore present in significant concentrations in urban areas. Sunlight facilitates chemical reactions between pollutants and ambient air. Aerosols modulate the amount of available energy required to drive such photochemical reactions, ultimately impacting air quality. Simulating photolysis rates with FastJX software is a resource-efficient strategy to study how these aerosols can affect air quality.

Depuration Of A Solitary Ascidian Depletes Transient Bacteria Without Altering Microbiome Alpha-Diversity, Brenna Hutchings, Susanna López-Legentil, Lauren M. Stefaniak, Marie L. Nydam, Patrick M. Erwin

Marine Science

Depuration, or the process of clearing impurities from the gut, is commonly applied to marine food products due to its efficacy in removing human pathogens from shellfish and edible ascidians. Recent studies also reported that depuration of filter-feeding animals helped reduce transient bacteria and identify resident symbionts in gut microbiome studies. Here, we examined the impact of depuration on bacteria in the branchial sac, gut, and hepatic gland of the solitary ascidian Pyura vittata. Replicates were kept in filtered seawater for 4 days prior to dissection (aquaria-depuration) and compared to samples that were immediately processed following collection (wild-no depuration) and …

Assessing Meteorological Impacts On Hydrological Switches In The Conus, Surendra Maharjan, Wenzhao Li, Sujan Shrestha, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydrological switches, defined as rapid transitions between extreme meteorological events such as droughts and floods, are becoming increasingly frequent across the contiguous United States (CONUS) due to climate variability. This study analyzes the spatial and temporal patterns of these hydrological switches and their correlation with large-scale meteorological indices, such as the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Streamflow data from the US Geological Survey (USGS) is analyzed to investigate the impact of meteorological drivers on hydrological variability. Results indicate that regions dependent on snowmelt exhibit delayed hydrological responses to climatic conditions, while areas in the Eastern …

Improving Coastal Hydrodynamic Model Performance Through Parameter Sensitivity Analysis And Optimization, Sunni Siqueira Allen

LSU New Orleans Theses and Dissertations

This thesis presents a framework for parameter sensitivity analysis and optimization of coastal hydrodynamic models. The research uses the Generalized Likelihood Uncertainty Estimation (GLUE) method to quantify parameter sensitivity and identify optimal values for currents, wave height, and water level. A variance-based technique guides parameter selection when GLUE yields competing values or when observations are unavailable.

The framework is demonstrated through two case studies: Hurricane Michael (2018) and the ExCaliBur field study (2022) near Oceanside, CA. Results from Hurricane Michael show higher optimal hydrodynamic model bottom friction values near the hurricane's landfall location. The Oceanside study identifies the hydrodynamic model's …

Assessment Of Estuarine Respiration And Benthic Nutrient Fluxes In Mississippi Sound, Nur Pasha Sufian

Master's Theses

This study quantified seasonal and spatial variability of both water column and benthic respiration rates as well as benthic nutrient fluxes along the Mississippi Sound. Respiration was measured in recirculating incubation chambers using Firesting optical DO sensors (PyroScience GmbH), and changes in nutrient concentrations were assessed. Mean water column respiration rates ranged from 0.35 and 2.76 µM O₂ hr⁻¹, with the lowest rates in the winter and the highest in the summer while detectable nutrient concentrations (ammonium, (NH₄⁺), and soluble reactive phosphate (PO₄³⁻)) showed only slight decreases (< 1 µM) over all seasons. Sediment incubation chambers consistently had much greater oxygen declines than the water incubations and showed seasonal trends with the highest mean respiration rates measured in the summer and the lowest mean in the winter, with a range from 107.4 to 1514.9 µmol O₂ m⁻² hr⁻¹ (2.6 to 36.3 mmol O₂ m⁻² d⁻¹). Sediment incubations consistently showed increases in NH₄⁺ concentrations in the overlying water, resulting in calculated NH₄⁺ benthic flux rates of 0.73 to 379.01 µM N m⁻² hr⁻¹ with the lowest rates in the winter and highest rates in the summer. Although PO₄³⁻ concentrations were often below detection in cooler seasons, PO₄³⁻ flux also peaked during the summer (< 28.8 µmol P m⁻² hr⁻¹). In this study, temperature was a key regulator for estuarine respiration and benthic nutrient flux rates, and these rates were positively correlated with porewater nutrient concentrations and sedimentary organic matter. These findings illustrate that benthic respiration can contribute to water column hypoxia and that sediments serve as a source of nutrients to the water column. Overall, these findings provide us with valuable insight about the seasonal coupling of oxygen demand and nutrient flux in the Mississippi Sound and provide valuable baseline data for future biogeochemical modelling of hypoxia, eutrophication, and productivity.

Enhanced Point Cloud Generation From A Novel 360° Underwater Lidar, Olagoke E. Daramola

Dissertations

This dissertation presents novel algorithms to improve the mapping capabilities of a 360-degree underwater Pulsed Laser Line Scanner LiDAR (PLLS-360°). Due to its 360° field-of-view (FOV), the PLLS-360° is a compact full-waveform omnidirectional imager suitable for seafloor mapping, underwater asset inspection, object detection, ice-sheet mapping, and construction progress monitoring. The proposed methodology includes an improved waveform fitting technique for saturated waveform recovery, detection array response correction, radiometric corrections, and fusion of LiDAR and sonar bathymetric datasets. The first part of this dissertation assesses the LiDAR’s performance and describes how the data for this unique 360° FOV architecture is processed. The …

Comparison Of Nutrient Concentrations And Primary Production Indicators Across Plume Fronts, Taylor Dishon

Electronic Theses and Dissertations

Coastal buoyant plumes carry low-salinity waters containing particulate and dissolved terrestrial materials with an abundance of nutrients into the coastal ocean, including inorganic nitrogen and phosphorous. Plume fronts act as transport barriers created from the convergence of a fresher plume with an older, saltier plume or with ambient waters, leading to potential accumulation of phytoplankton and nutrients. This accumulation creates an optimal environment for primary production. The primary goals of this study were: to investigate the distribution of and potential relationships between nutrient concentrations and chlorophyll a across plume fronts of the Winyah Bay River Plume, and examine potential relationships …

Low-Level Polarimetric Signatures Of Supercells During Ef3+ Tornado Production, Anthony Noah Began

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

Most EF3+ tornadoes are produced by supercells. Understanding of microscale features surrounding intense tornado production remains limited. This research aims to determine commonalities in low-level microphysical processes during intense tornado production via polarimetric radar signature assessment with a Python-based algorithm. Polarimetric variables hypothesized to reflect low-level wind profiles such as the differential reflectivity (Z_DR) arc and the Z_DR–K_DP (specific differential phase) separation vector will be investigated. Supercells which produced EF3+ tornadoes will be examined since these tornadoes pose the highest threat. From 2010 to 2024, the United States recorded approximately 19,100 tornadoes which resulted in …

Evaluation Of Performance Characteristics And Groundwater Contamination Risks Associated With On-Farm Swine Carcass Disposal Via Composting And Shallow Burial With Carbon, Gustavo Castro Garcia

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation evaluates the performance of three on-farm swine carcass disposal methods: whole carcass composting (WCC), ground carcass composting (GCC), and shallow burial with carbon (SBC), focusing on biosecurity factors and groundwater contamination risks. Foreign animal diseases (FADs), such as African swine fever and classical swine fever, pose severe economic and animal well-being risks if introduced to the United States. With confirmation of an FAD, swine movement will be halted, creating an urgent need for practical, biosecure, and environmentally responsible on-farm disposal strategies for swine carcasses. Nebraska, as a leading swine-producing state, exemplifies the vulnerability of high-density livestock regions to …

Environmental Controls Of Hail In Quasi-Linear Convective Systems, Cameron A. Barker

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

A study of hail occurrence in quasi-linear convective systems (QLCS), as well as severe weather parameters contributing to the likelihood and intensity of hail, is presented. Rapid Refresh (RAP) proximity soundings for 218 QLCS events from 2012 to 2022 are selected to sample QLCS environments near peak intensity. Study objectives are to assess common environmental parameter spaces that favor hail in QLCSs while connecting these findings to results for supercells. Hail occurrence is also examined in terms of synoptic regime.

Six synoptic regimes were identified to support QLCSs with hail, from high shear, low cape (HSLC) to low shear, high …

Surveys And Modeling: Using An Existing Survey To Describe And Compare Populations To Better Inform On Groundwater Model Inputs, M. Austin Wise

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

The Mississippi River Valley “Alluvial Aquifer” is among the most agriculturally significant aquifers in the United States. However, parts of the aquifer are exceeding sustainable yield as development of the water source continues. Survey research in other aquifers, such as the High Plains (Ogallala) Aquifer, has helped to understand the perceptions and attitudes of irrigators withdrawing from their aquifers. This led to numerous questions: What are the attitudes of irrigators in the Alluvial Aquifer region? How do they compare to irrigators in other regions of the country? Can their intentions be used to generate more accurate inputs when modeling adoption …

Exploring The Application Of Repeated Microgravity Surveys To Monitor Groundwater Level Variations In Nebraska, Kaitlin M. Steinauer

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

Groundwater is an important resource in the state of Nebraska for supporting industries and ecosystems. Monitoring this vast resource ensures its continued availability for generations to come. However, monitoring utilizes well data, and if a well is not present in a desired location, geophysical methods can be explored. This project tests the capability of repeated gravity surveys over Nebraska’s aquifers to monitor groundwater levels throughout 2024.

Two study areas were selected in Eastern Nebraska. The first is in Oakland, Nebraska, over a confined aquifer system. The second is in Plymouth, Nebraska, and exhibits unconfined conditions. Four sites were chosen to …

Experimental Investigation Of Photovoltaic Soiling Losses And Aerosol Absorption And Scattering Related To Dust In The Chihuahuan Desert Region, German Rodriguez Ortiz

Open Access Theses & Dissertations

This dissertation explores the interaction between mineral dust and solar radiation in the Chihuahuan Desert, one of the dustiest areas in North America. I focused on two main aspects: (1) the characterization of atmospheric aerosol optical properties during dust events, and (2) the effects of dust deposition (soiling) on the performance of photovoltaic (PV) modules. I characterized the intrinsic optical properties of aerosols in El Paso, Texas during the peak of the 2021 dust season. Ground-level, high-resolution optical and meteorological data were collected at the Black and Brown Carbon (BC^2) study site, whereas particulate matter and additional meteorological parameters were …

Assessing Coastal Vulnerability And Climate-Driven Migration Risk In West Africa, Wenzhao Li, Surendra Maharjan, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study presents a GIS-based multi-criteria decision-making framework to assess climate-induced migration risk along the West African coast. We developed a comprehensive risk index that integrates environmental hazards such as flood frequency and socio-economic vulnerability indicators, including poverty levels, population density, and adaptive capacity. By utilizing datasets such as the Geocoded Disasters (GDIS) dataset, Social Vulnerability Index (SVI), Poverty and Adaptive Capacity Index (PACI), and the Population Exposure Index (PEI), the study identifies regions most susceptible to displacement. Results reveal that areas like Benin’s Abomey-Calavi, Cotonou, and Akpo-Misserete are especially vulnerable due to high disaster frequency, substantial population exposure, and …

From Storm To Strength: Katrina's Legacy Of Health, Healing, And Hope, Lsu Health Sciences Center - New Orleans

LSUHSC Hurricane Katrina Archive: Reports & Presentations

This is the schedule for "From Storm to Strength" Katrina Symposium organized by LSU Health New Orleans to commemorate the 20th Anniversary of Hurricane Katrina.

A speaker panel session was held each day from Monday, August 24, 2025 to Thursday, August 28, 2025 for LSU Health faculty, staff and guests to share their remembrances of the hurricane and its impact on the school, on the City, and on their lives.

Multi-Crop Systems And Crop-Switching Strategies To Enhance Water Use Efficiency And Climate Resilience In Arid Agricultural Regions, Shahryar Fazli, Wenzhao Li, Surendra Maharjan, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Agriculture in the Lower Colorado River (LCR) region faces mounting challenges from climate change, arid conditions, and water scarcity. This study evaluates water use efficiency (WUEc) and crop-switching strategies under SSP2-4.5 and SSP5-8.5 scenarios for 2025–2049, 2050–2074, and 2075–2099. Using historical data, climatic drivers such as temperature and precipitation were analyzed for their influence on key crops, including durum wheat, winter wheat, and corn. Results show SSP2-4.5 supports water use reductions up to 16%, stable profits (80–90%), and modest calorie increases (up to 15%), while SSP5-8.5 poses severe challenges, with water use reductions of 2–5%, profits dropping to around 20%, …

Decoding Teleconnection Impacts On Hydrological Switches In The Conus Using Wavelet Analysis, Surendra Maharjan, Wenzhao Li, Shahryar Fazli, Hesham Morgan, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydrometeorological teleconnections are key drivers of hydrological processes, representing the influence of large-scale atmospheric circulation patterns on regional climates. Understanding these teleconnections provides crucial insights into the mechanisms underlying hydrometeorological phenomena, particularly hydrological switches—rapid transitions between extreme events such as droughts and floods. These switches have become increasingly prevalent across the contiguous United States (CONUS), fueled by climate variability and evolving atmospheric patterns. This study utilizes cross-wavelet transform analysis to examine the spatial and temporal dynamics of hydrological switches and their correlations with major teleconnection indices, including NAO, ONI, WP, PDO, PNA, and QBO. The findings indicate significant coherence between …

Understanding Hydroclimate In The Contiguous United States: Roles Of Temperature Vs Precipitation And Subtropical Pacific Warming, Grace Esenam Affram

All Graduate Theses and Dissertations, Fall 2023 to Present

This study investigates the physical drivers and mechanisms of hydroclimate variability across the Contiguous United States (U.S.), using a combination of observable data, reanalysis data, land modeling, and coupled climate model experiments. One of the major findings is that the historic 2021 drought event across the Western U.S. was primarily driven by a severe lack of precipitation rather than increased temperatures. The study further finds that anthropogenic forcing has substantially increased the risk of this extreme drought by approximately 26 times relative to a world without the influence.

Additionally, the study reveals that the Pacific Meridional Mode (PMM) characterized by …

Drift Dynamics Of Early Life-Stage Invasive Carps, Saurav Karki

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Asian carp species pose significant ecological threats to North American freshwater systems due to their invasive nature and prolific reproduction. Their semi buoyant eggs develop while drifting downstream with the river current. Understanding early life-stage transport is therefore critical for predicting recruitment potential and guiding management efforts. Existing fluvial egg drift models, including those relying on 1-D hydraulics and fully 3-D CFD-based models, are either inadequate for complex braided rivers or too computationally demanding for large-scale application. The Platte River in Nebraska, characterized by wide, shallow, multi-threaded channels, is dominated by two-dimensional flow conditions, making a depth-averaged 2-D modeling approach …

Development And Evaluation Of Supported Ionic Liquid Membrane And Porphyrin Frameworks For Carbon Capture Separation, Sarang Ismail

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The global urgency to mitigate anthropogenic CO₂ emissions has intensified the pursuit of energy-efficient separation technologies. Supported Ionic Liquid Membranes (SILMs) have emerged as promising candidates for CO₂ capture due to their tunable solubility-selectivity and low energy requirements. However, challenges such as mechanical instability, limited scalability, and trade-offs in transport performance have impeded their widespread adoption.

This thesis explores a systematic approach to designing and optimizing SILMs for enhanced CO₂ separation by tailoring polymer–ionic liquid interactions, processing conditions, and material architectures. A comprehensive set of studies were conducted using poly(vinylidene fluoride) (PVDF) with varying molecular weights, different grades of PEBAX®, …

The Influence Of Monsoon Variability On The Circulation Of The Near-Surface Indian Ocean And The Depth-Integrated Chlorophyll, Marufa Ishaque

OES Theses and Dissertations

The Indian Ocean experiences a strong semiannual reversal of monsoon winds, which determines the weather and climate of Asia, including freshwater fluxes between the atmosphere, land, and ocean. Studies and model projections suggest that the timing and intensity of the seasonal monsoon have already started to change, with more dramatic changes likely in the future. However, the impact of these changes on the Indian Ocean circulation system, including the inter-basin salt/freshwater transport between the Bay of Bengal and the Arabian Sea, remains unclear. To better understand how monsoon variability affects Indian Ocean circulation patterns, a Regional Ocean Modeling System simulation …