Oceanography and Atmospheric Sciences and Meteorology Commons^™

Statistical Evaluation Of A New Orleans Historic Rainfall Dataset (1840–1893), Arielle C. Filostrat

LSU Master's Theses

This study evaluates the climatic credibility of a newly identified historical rainfall dataset for New Orleans, Louisiana, spanning 1840–1893. The New Orleans Historical Dataset (NOHD) is compared to a modern observational record from the Audubon rain gauge (1893–2024) to determine whether nineteenth-century rainfall observations are consistent with known precipitation behavior in the region. Establishing the reliability of early records is critical for extending climatological baselines and improving understanding of long-term rainfall variability.

Historical rainfall observations were first evaluated through archival review using the New Orleans Medical and Surgical Journal and other nineteenth-century meteorological records to verify notable rainfall events. Daily …

Recent Wetland Elevation Dynamics In Coastal Louisiana, Usa, Elizabeth Harris

LSU Master's Theses

Coastal marshes globally are increasingly vulnerable to accelerating relative sea-level rise (RSLR), which threatens their capacity to maintain elevation through feedbacks among sediment supply, vegetation productivity, hydrology, and soil processes. Although many marshes can persist under moderate rates of sea-level rise through vertical accretion and belowground biomass production, this resilience is strongly constrained by sediment availability and subsurface processes such as autocompaction and organic matter decomposition. High accretion is often assumed to confer marsh resilience; however, subsurface processes, particularly autocompaction driven by surface loading, can substantially offset elevation gains. Coastal Louisiana experiences among the highest rates of RSLR worldwide due …

Biogeochemical Controls On Phosphorus Transport And Legacy Storage Across A Coastal Watershed, Lee Potter

LSU Doctoral Dissertations

Excess phosphorus (P) loading is a key driver of eutrophication and harmful algal blooms (HABs) in aquatic systems worldwide. This relationship is of increasing concern in coastal Louisiana, where climate variability, altered hydrology, and land-use change converge, resulting in increased hydrologic and nutrient loading into coastal systems. This dissertation examines controls on P cycling in the Lake Pontchartrain Basin through a multi-scale framework linking estuarine processes, watershed loading, climate and weather patterns, and sediment dynamics. The dissertation begins with an overview of the study region, P dynamics, and changes in hydrology and nutrient loading patterns. Chapter 2 presents a spatial …

Metacommunity Coupled Epidemiological And Biophysical Modeling Of An Emergent Coral Disease, Benjamin Holmes Farmer

LSU Doctoral Dissertations

Emerging infectious diseases pose imminent risk to the marine realm and coral reefs in particular. Since its emergence in 2014, stony coral tissue loss disease (SCTLD) has dramatically reduced living coral cover in Florida and charted a similar course in the Caribbean. SCTLD is by far the most severe coral disease in history and has driven highly susceptible species to local extinction, yet the mechanisms driving the regional epizootic are not well understood. Here, we developed reef-scale parameterizations of disease spread using model sites in the lower Florida Keys, developed extensive metacommunity habitat maps for the US Caribbean, and then …

Investigating The Relationships Among Suspended Sediment Concentration, And Marsh Edge Erosion In Barataria Bay, La, Lily Vowels

LSU Master's Theses

Barataria Bay, Louisiana, USA exhibits a unique microtidal, wind-driven hydrodynamic climate where extensive levee infrastructure throughout Louisiana has starved Barataria Bay and similar interdistributary bays of the historic levels of terrigenous sediment import. This has contributed to extreme coastal wetland loss in Louisiana. This project seeks to understand how hydrodynamic and meteorological conditions are linked to sediments’ fate after erosion from the marsh edge. Specifically, this project seeks to differentiate the roles of wave resuspension and marsh edge erosion (MEE) in sediment dynamics in Barataria Bay. An acoustic wave and current profiler (AWAC) was used to capture hydrodynamic conditions, and …

Investigating The Role Of Aerosols In Extreme Precipitation Events Along The Gulf Coast Of The U.S.A., Wenjia Cao

LSU Doctoral Dissertations

Atmospheric aerosols have been found to influence tropical cyclone (TC) and flood event development. In this study, the Weather Research and Forecasting model is applied to investigate specific microphysical impacts and aerosol sensitivity to heavy precipitation and TC events in the U.S. Gulf Coastal area. The Thompson aerosol-aware scheme with regular and adjusted aerosol concentration scenarios is used to quantify precipitation, wind field, horizontal/vertical structures, and track variations, by aerosol mixing ratio. In general, results for the three storms analyzed (the 2016 Baton Rouge, Louisiana, flood event (Chapter 2); Hurricane Harvey in 2017 (Chapter 3); and an idealized storm event …

Estimating The Future Frequency Of Bonnet Carré Spillway Openings, Kayla Thomas

LSU Master's Theses

In the 2010s, the Bonnet Carré Spillway (BCS) in southeastern Louisiana, U.S.A., experienced an unprecedented uptick in openings to mitigate the possibility of flooding, including a record double-opening in 2019. Both the environmental consequences of BCS openings associated with nutrients that run from the Mississippi River into Lake Pontchartrain and the synoptic-scale meteorological conditions that necessitate these openings are poorly understood. With the unexpectedly frequent openings in recent years and the ever-present threat of climate change, it is vital to consider the future shift of synoptic-scale climate patterns and how it can relate to BCS openings. Understanding the potential for …

Global Ocean Bottom Temperature Observation Design: Observing System Simulation Experiments For Strategic Deployment Of Smart Subsea Cables, Karen E. Renninger-Rojas

LSU Master's Theses

Deep-ocean observations below 2000 meters remain limited, restricting our ability to model global ocean processes critical to climate prediction. This thesis evaluates the potential of SMART (Science Monitoring and Reliable Telecommunications) subsea cables to address these observational gaps by conducting Observing System Simulation Experiments (OSSEs) and adjoint sensitivity analyses using the MITgcm ocean model and ECCO outputs.

Vertical decorrelation analysis showed that temperature and salinity in key regions decouple from the upper ocean beyond 2000 m. Over 60% of the proposed SMART cable sites exhibited decorrelation depths exceeding Argo’s maximum sampling depth, highlighting their strategic value for deployment.

A comparison …

Impacts Of Extreme Weather Conditions On Coastal Fisheries Near Bayou Teche, Louisiana From 2019–2023, Georgia C. Davis

LSU Master's Theses

The region of Southcentral Louisiana, particularly around Bayou Teche, thrives on its commercial and recreational fisheries. These fisheries are occasionally subject to events like extreme weather that cause sudden and unexpected losses (NOAA Fisheries, 2024a). Between 2019 and 2023, a series of extreme weather events impacted southcentral Louisiana near Bayou Teche. This series of extreme events includes Hurricane Barry (2019), Hurricane Laura (2020), Hurricane Delta (2020), Hurricane Zeta (2020), Hurricane Ida (2021), and a United States Drought Monitor (USDM) D4 drought (2023). This study analyzes the impacts of the extreme weather series on coastal fish observed species richness (SR) in …

Intraspecific Variation In Morphological And Biochemical Responses To Salinity And Flooding In Phragmites Australis, Olivia Hurley

LSU Master's Theses

Phragmites australis is a widespread wetland plant species with numerous haplotypes, several of which are highly invasive. In low-lying coastal marshes of Louisiana, the Delta-type (haplotype M1) dominates across a wide range of salinity and flooding environments. This suggests that Phragmites may be highly adaptable to diverse environmental conditions and that there may be a genetic component, as seen in other coastal wetland plant species. While non-native Phragmites haplotypes are targeted for control and removal in many areas, they are considered beneficial for marsh stabilization and contributing to elevation gain in coastal Louisiana, where several areas experience rapid land loss. …

Identifying Saharan Air Layer Events And Their Relationship To Instability And Rainfall Patterns In The Tropical North Atlantic Ocean, Charles H. Dolce

LSU Master's Theses

Every year, strong North African winds across the Sahara loft dust particles and advect them westward within the Saharan Air Layer (SAL). These plumes of dust often reach the Caribbean Sea and can heavily affect regional weather patterns by suppressing convection. When concentrations are high, decreased rainfall can yield negative societal and ecological impacts, potentially leading to drought. The Puerto Rican early rainfall season (ERS), spanning from 1 April through 31 July, overlaps with Saharan dust migration periods, and systematically detecting instances of SAL activity near the island is important for understanding longer-term drought-forcing trends in the region.

Corridors of …

Coastal Sedimentary Records Of Extreme Events And Human Activity: Examples From Hurricanes And Microplastics, Nicholas T. Culligan

LSU Doctoral Dissertations

Coastal regions are uniquely vulnerable to a myriad of natural and anthropogenically caused stresses such as hurricane strikes and chronic microplastic pollution. Both hurricanes and microplastics have major negative effects on global coastlines and are forecast to become more damaging in the future. However, current model trends are based on limited modern data and may not provide an accurate or comprehensive view of the future. Therefore, this dissertation investigates coastal stratigraphic records to determine long-term past trends of these presses and pulses so that researchers, stakeholders, and policy makers can use them to enact strategies to mitigate damages from worsening …

Impacts Of Morphological Changes On Water Residence Times In River Deltas, Md. Muzahidul Islam

LSU Master's Theses

Coastal river deltas possess substantial socioeconomic and ecological importance and are expected to encounter increasing risks because of global climate change. The long-term sustainability of many deltaic systems is at risk due to a mix of natural and human-induced factors. Deltas are characterized by their continuous reconfiguration of channels and floodplains due to allogenic and autogenic processes. Sediment supply and composition, sea level rise, vegetation, river discharge, and human development may affect the morphological evolution of river deltas. The timescales and patterns of hydrological transport within a river delta are important indicators of ecological function. One such metric, the water …

Benthic Community Response To The Impacts Of Proposed Sediment Diversions In Louisiana Estuaries, Jillian C. Tupitza

LSU Doctoral Dissertations

Sediment diversions designed to mitigate land loss in coastal Louisiana will likely cause ecosystem-wide shifts. The first diversion, planned for Barataria Bay, will divert fresh water and sediment from the Mississippi River into the surrounding wetlands to help them keep pace with high rates of relative sea-level rise (RSLR). Estuarine benthic communities were used in this study as tools to characterize ecological patterns in the context of anticipated salinity changes. I reviewed relevant literature, conducted a two-year survey of Barataria Bay benthos, executed a reciprocal transplant experiment to describe changes that might occur in both community composition and trophic dynamics, …

Quantification Of Belowground Biomass And Sediment Accretion In Mangroves Of Different Coastal Environmental Settings Of The Costa Rican Pacific Coast, Denise M. Poveda

LSU Master's Theses

The adaptation of intertidal ecosystems such as mangroves to anticipated accelerated relative sea level rise is dependent on net increase of sediment surface elevations and forest migration inland. Ecosystem models developed to simulate trajectories of ecosystem adaptations have determined that rates of soil formation are most sensitive to surface sediment (organic and inorganic) deposition and subsurface organic production by mangrove roots. Mangrove belowground biomass contributes to soil organic matter accumulation, while mangrove litter has minor contribution due to export and annual decay. In addition to belowground biomass production, inorganic sediment loading is also key contribution to soil formation and accretion. …

Applied Depositional Geosystems Of The Coos Bay Basin, Oregon: Organic Geochemistry, Maturation, Paleoenvironmental Reconstruction And Biostratigraphy Of The Coaledo Delta During The Middle Eocene Climatic Optimum (Meco), Allison K. Barbato

LSU Doctoral Dissertations

The Coos Bay Basin on the southwestern coast of Oregon is a forearc basin that contains exceptionally preserved Eocene to Miocene, tidal to wave-dominated, shallow deltaic to deep marine sediments of the Coaledo Delta. Coastal depositional environments are known to host source, reservoir, and seal rocks. Climate, topographic relief, and geographical position all play an important role in regional vegetation development and oceanic setting. This study assesses 84 outcrop and 12 core samples from Coos Bay for their organic geochemical characteristics and microfossil assemblage to provide source rock characterization information, organofacies descriptions, environmental reconstructions, and age control.

Results indicate the …

Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Marine Cyanobacterium Synechococcus Sp. Ccmp 1334, Alyssa K. Sharbaugh

LSU Master's Theses

The marine cyanobacterium Synechococcus sp. CCMP 1334 was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO2 (400 and 1000 ppmv, respectively), nitrate availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21°C, 24°C, 28°C, 32°C, and 35°C. The maximum median nutrient-replete growth rate was ~1.15 d−1 at 32 –35°C. Median growth rates at 1000 ppmv pCO2 were higher than those at 400 ppmv at all temperatures, but most of the differences were statistically insignificant. Carbon:nitrogen ratios were independent of pCO2 at a fixed relative growth rate but decreased with …

Sensor Analytics For Subsea Pipeline And Cable Inspection: A Review, Connor R. Vincent

LSU Master's Theses

Submarine pipelines and cables are vital for transmitting physical and digital resources across bodies of water, necessitating regular inspection to assess maintenance needs. The safety of subsea pipelines and cables is paramount for sustaining industries such as telecommunications, power transmission, water supply, waste management, and oil and gas. Incidents like those involving the Nord Stream subsea pipeline and the SEA-ME-WE 4 subsea communications cable exemplify the severe economic and environmental consequences of damage to these critical infrastructures. Existing inspection methods often fail to meet accuracy requirements, emphasizing the need for advancements in inspection technologies. This comprehensive survey covers the sensors …

The Impacts Of Nature-Based Sediment Restoration Practices On Coastal Wetland Soil Biogeochemistry, Jacob Z. Cheng

LSU Master's Theses

Coastal marshes provide many valuable ecosystem services. However, these wetlands are threatened worldwide, being subject to sea level rise, sediment starvation, subsidence, coastal edge erosion, etc. Many efforts are being made to counteract this wetland loss and preserve the ecosystem services. Two such methods are sediment diversion and the thin layer placement (TLP) of dredged sediment.

Sediment diversion involves reconnecting the main channel of a river body to disconnected wetlands, supplying much needed soil-building materials. However, this method affects the salinity of the waters, introducing large amounts of freshwater into the system. Salinity changes can affect marsh biogeochemistry. Most ecological …

Translation Speed Influence On Tropical Cyclone Storm Tide And Surge Generation Along The Gulf Of Mexico Coast, Samantha L. Camarda

LSU Master's Theses

This research examines tropical cyclone translation speed as a factor in storm tide and surge height upon landfall on the United States Gulf Coast. Understanding the effect of translation speed on peak storm tide/surge height is needed to better prepare for and predict future damage from tropical cyclone events. Tropical cyclone data are taken from hourly interpolated best-track HURDAT2 data from 1970–2021. This study uses the HURDAT2 hourly interpolated observation data points (24-hours) pre-landfall to landfall. Translation speed is calculated based on the distance traversed between hourly points. Peak storm tide and storm surge data are taken from SURGEDAT from …

Interactive Effects Of The Partial Pressure Of Co2, Temperature, And Nutrient-Limitation On The Physiology And Growth Of The Coccolithophore E. Huxleyi Grown On A 12:12 L:D Cycle Of Illumination, James Bradley

LSU Master's Theses

I studied the interactive effects of pCO2, temperature, and nutrient limitation on the growth and physiology of the marine coccolithophore, Emiliania huxleyi. This was done to look at the effect of climate change factors on the widespread and abundant calcifying marine organism as a predictor of what the future has to hold. The strain of E. huxleyi (PnB 272 B10) was grown on a 12:12 L:D cycle of illumination and exposed to either high or low pCO2 under nutrient-replete or nitrate-limited conditions across a temperature range of 10–28C. I examined the direct and interactive effects of temperature, pCO2, and nutrient …

Effects Of Coastal Freshening On Porewater Salinity And Nitrogen Cycling In Brackish Marsh Soils: Implications For Biogeochemical Resilience In Barataria Basin, La, Robert C. Feder

LSU Master's Theses

The Mid-Barataria Sediment Diversion will divert sediments and fresh water from the Mississippi River into mid-Barataria Basin, LA for the purposes of building and sustaining coastal marshes, potentially reducing the estuarine salinity to 0 during operation. Increased freshwater inputs to the area of project influence may reduce porewater salinity and induce ammonium adsorption in brackish marsh soils of the region, potentially impacting the activity of ammonium-producing and denitrifying bacteria. However, brackish soils occur in zones of intermediate salinity and may, therefore, exhibit biogeochemical resilience to episodic changes in surface water salinity. I hypothesized that inundating brackish marsh soils with fresh …

Ecology Of Viruses In Marine And Coastal Oxygen-Depleted Waters, Sophie Jurgensen

LSU Doctoral Dissertations

Deoxygenation of marine and coastal waters, both caused and exacerbated by a suite of abiotic and biotic factors, has been documented for more than sixty years. The incidence and severity of low-oxygen areas is predicted to expand globally in the coming decades. Despite their colloquial moniker “dead zones,” low-oxygen areas contain thriving and diverse microorganisms that have significant impacts on global biogeochemical cycles including contributing to positive feedback loops that further expand low-oxygen areas. While the diversity and activity of these microorganisms is beginning to be elucidated, the ecology of their viruses is particularly understudied. In this dissertation, I present …

Atmospheric Impacts From The 2010 Deepwater Horizon Oil Spill, Charles Philip Johnson

LSU Master's Theses

Although the ecological devastations induced by an oil spill are well studied, the hydrometeorological impacts from a long-term slick have gone unnoticed. The ocean-surface alterations stemming from the lasting oil footprint increase solar radiation absorption which in turn alters the surface pressure and moisture gradients and wind speeds thereby influencing precipitation surrounding the oil spill. Revealing the potential impacts from these could better aid in the safety of crews cleaning spills and provide a better understanding of how humans alter the landscape. This thesis examines the changes in local hydrometeorology brought on by the 2010 summer Deepwater Horizon (DWH) oil …

A Stable Isotopic Profile Of Atmospheric River Precipitation Impacting Northern California, Erika Clarise Ornouski

LSU Master's Theses

Atmospheric river (AR) storms are an integral part of California’s hydrologic cycle, providing 30–50% of the state’s annual precipitation. However, “too much of a good thing” can swell

rivers beyond capacity leading to widespread flooding, erosion, and environmental damage. Northern California’s steep topography coupled with its seasonal Sierra Nevada snowpack puts this region at risk for floods and extreme weather hazards that can be triggered by strong ARs. Identifying AR contributions in the water cycle is crucial for informing water resource and emergency management decisions Stable isotope analysis provides a means to understand the movement of precipitation based on fractionation …

Evaluating Fungal Population Response To The Miocene Climatic Optimum: High-Resolution Palynological Insights From The South China Sea And Mcmurdo Sound, Antarctica, Mallory Pilie

LSU Master's Theses

Fungi play key and specific roles in ecosystems, specifically as many have restricted geographic distributions, known host/substrate preferences, and are important local environmental indicators due to their short dispersal distances. This study of fossil fungi from a time interval of pronounced global warming, the Miocene Climatic Optimum (MCO), allows analysis of fungal response to an analogue for future climate change scenarios. The research presented herein is part of a larger project, Fungi in a Warmer World (FiaWW), which is using globally-distributed sediment samples to provide foundational information on fungal community distribution patterns and will provide the first fungi-based climatological reconstructions …

An Analysis Of Hurricane Laura's Storm Surge In Cameron Parish Using Synthetic Storm Tracks, Climatology, And Statistics, Cameron Goff

LSU Master's Theses

Cameron Parish is a large coastal parish in southwest Louisiana that has been impacted by several powerful tropical cyclones. In 2020, the strongest hurricane in recorded history to ever hit this region, Hurricane Laura, set a state record for the highest storm surge measurement at 6.34 meters. I examine the climatology of tropical cyclone landfalls in this parish, looking for trends in intensity and frequency with time. I then compare the extreme surge of Hurricane Laura with a dataset of 645 synthetic tropical cyclones generated and used by the Coastal Hazards System for Louisiana. Plots comparing various meteorological statistics to …

20-Year Assessment Of Total Suspended Sediment (Tss) Variability In Barataria Bay From Modis Ocean Color Using A Combination Of Adaptive Semi-Analytical And Neural Network Algorithms, Bijaylaxmi Sahoo

LSU Master's Theses

Barataria Bay, a hydrologically dynamic basin in the northern Gulf of Mexico, exhibits a distinct spatio-temporal distribution of total suspended sediment (TSS). However, studies on sediment distribution are limited by availability of in-situ data as well as the limitation of ocean color algorithms for suspended sediments in shallow optically complex waters. Barataria Bay TSS concentration profile is complex, influenced in the upper basin by fresh water sources such as the Davis Pond Freshwater Diversion, and in the lower bay by the river plume and marine influence near the mouth of the bay. To efficiently study the sediment dynamics in the …

Quantifying Mud Settling Velocity As A Function Of Turbulence And Salinity In A Deltaic Estuary, Michael W. Mcdonell

LSU Master's Theses

Mud settling velocity is controlled by flocculation, which in turn strongly depends on turbulence and on the chemistry and biology of the water-sediment mixture. As a result, mud settling velocity can be poorly constrained in coastal areas and vary in space and time by orders of magnitude. Here we quantified mud settling velocity in Barataria Basin, a deltaic estuary in Louisiana (USA), using three independent methods: eddy covariance (one station for 200 days), floc cameras (4 stations at one time), and Rouse profile inversion (14 stations, replicated 10-30 times each). Eddy covariance indicates that settling velocity increases with turbulence, at …

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran

LSU Doctoral Dissertations

This dissertation explores the mechanisms driving sediment transport and deposition on the continental shelf and within the bays of the northern Gulf of Mexico via a suite of geophysical methods and sediment cores on a variety of timescales. This dissertation is comprised of three main chapters, each focusing on a different location, environment, and process but tied together using geophysical survey, a thematic focus on geomorphic change and sediment transport within the deltaic cycle and deltaic plain environments, and the implications this change poses for both past and future sediment transport and environmental change in response to sea level change. …