Oceanography Commons^™

Sea-Ice Production And Air/Ice/Ocean/Biogeochemistry Interactions In The Ross Sea During The Pipers 2017 Autumn Field Campaign, S. F. Ackley, S. Stammerjohn, T. Maksym, M. Smith, J. Cassano, P. Guest, J.-L. Tison, B. Delille, B. Loose, Peter N. Sedwick, L. Depace, L. Roach, J. Parno

OES Faculty Publications

The Ross Sea is known for showing the greatest sea-ice increase, as observed globally, particularly from 1979 to 2015. However, corresponding changes in sea-ice thickness and production in the Ross Sea are not known, nor how these changes have impacted water masses, carbon fluxes, biogeochemical processes and availability of micronutrients. The PIPERS project sought to address these questions during an autumn ship campaign in 2017 and two spring airborne campaigns in 2016 and 2017. PIPERS used a multidisciplinary approach of manned and autonomous platforms to study the coupled air/ice/ocean/biogeochemical interactions during autumn and related those to spring conditions. Unexpectedly, the …

Hydrodynamics, Sediment Transport, And Water Quality Of Two Contrasting Dredge Pits On The Louisiana Shelf, Robert Bales

LSU Master's Theses

Sediment is needed for coastal restoration in Louisiana and is often excavated offshore from both mud-capped and sandy dredge pits. The mined sand from mud-capped pits, like Sandy Point which is west of modern Mississippi Delta of Louisiana, was originally from a paleo river channel and later covered by mud from modern coastal processes. Sandy pits, like Caminada pit in eastern Ship Shoal on Louisiana shelf, generally experience higher energy conditions. To better understand the post-dredging effects on hydrodynamics, sediment transport, and water quality, two tripods were deployed at Caminada and Sandy Point pits in summer 2018 and 2019, respectively, …

The Effect Of Phytoplankton Properties On The Ingestion Of Marine Snow By Calanus Pacificus, Grace Cawley

Theses

The aggregation of phytoplankton into marine snow provides a mechanism by which smaller particles can coagulate to form larger particles, which can be consumed at various depths or readily transported to the deep ocean and sequestered from the atmosphere on time scales of a thousand years or more. Zooplankton interacting with these large carbon-rich aggregates can obtain nutrition in environments where the phytoplankton size spectrum is small and not directly available, enhancing the possibility of obtaining adequate nutrition in environments dominated by small cells. In addition, interactions between zooplankton and marine snow can result in fragmentation, thus affecting the particle …

Effects Of Surfactants On The Generation Of Sea Spray During Tropical Cyclones, Breanna L. Vanderplow

All HCAS Student Capstones, Theses, and Dissertations

Despite significant improvement in computational and observational capabilities, predicting intensity and intensification of major tropical cyclones remains a challenge. In 2017 Hurricane Maria intensified to a Category 5 storm within 24 hours, devastating Puerto Rico. In 2019 Hurricane Dorian, predicted to remain tropical storm, unexpectedly intensified into a Category 5 storm and destroyed the Bahamas. The official forecast and computer models were unable to predict rapid intensification of these storms. One possible reason for this is that key physics, including microscale processes at the air-sea interface, are poorly understood and parameterized in existing forecast models.

Under tropical cyclones, the air-sea …

The Influence Of El Niño-Southern Oscillation (Enso) On Indonesian Throughflow (Itf), Farrah Hanifah

International Programs

No abstract provided.

Analysis Of Vector Sensor Data Collected In Gulf Of Mexico, Timothy S. Vann

LSU New Orleans Theses and Dissertations

In 2015, the Naval Oceanographic Office collected vector sensor data in approximately 100 meters of water southwest of Panama City, Florida in the Gulf of Mexico. The vector sensor was deployed at a center mass height of one foot above the seafloor and de-coupled from its mooring through lightweight springs to measure local acoustical pressure and particle velocity.

Accuracy of the data across frequency and source azimuth is measured by evaluating acoustical impedance as a function of frequency and source azimuthal direction. Results indicate the vector sensor has an effective band from 50 to 450 Hz with mooring reflections and …

Toward Near‐Field Tsunami Forecasting Along The Cascadia Subduction Zone Using Rapid Gnss Source Models, Amy L. Williamson, Diego Melgar, Brendan W. Crowell, Diego Argas, Timothy I. Melbourne, Yong Wei, Kevin Kwong

Geological Sciences Faculty Scholarship

Over the past 15 years and through multiple large and devastating earthquakes, tsunami warning systems have grown considerably in their efficacy in providing timely and accurate forecasts to affected communities. However, one part of tsunami warning that still needs improvement is forecasts catered to local, near‐field communities in the time after an earthquake rupture but before coastal inundation. In this study, we test a rapid, Global Navigation Satellite Systems (GNSS)‐driven earthquake characterization model using a large data set of synthetic megathrust ruptures for its near‐field tsunami forecasting potential. We also provide a framework for tsunami forecasting that focuses on the …

Prioritizing The Largest, Oldest Corals For Disease Intervention In A Coral Disease-Ravaged Area: Southeast Florida Coral Reef Ecosystem Conservation Area, Alysha Brunelle

All HCAS Student Capstones, Theses, and Dissertations

Coral diseases appear to be more devastating than ever before. When a virulent disease ravages a coral ecosystem, it can significantly change the population’s demographics and cause local extinctions. Disease intervention response during such an event is impossible at a landscape scale, therefore priorities must be considered. Saving the largest, oldest colonies of reef-building species is a good choice due to their high fecundity and ecological function. Their size, as a proxy for age, is an indicator of their resistance to previous perturbations which may indicate higher fitness. Their size also provides habitat to many organisms and wave resistance in …

The Source Detection Of 28 September 2018 Sulawesi Tsunami By Using Ionospheric Gnss Total Electron Content Disturbance, Jann-Yenq Liu, Chi-Yen Lin, Yuh-Ing Chen, Tso-Ren Wu, Meng-Ju Chung, Tien-Chi Liu, Yu-Lin Tsai, Loren C. Chang, Chi-Kuang Chao, Dimitar Ouzounov, Katsumi Hattori

Mathematics, Physics, and Computer Science Faculty Articles and Research

The 28 September 2018 magnitude Mw7.8 Palu, Indonesia earthquake (0.178° S, 119.840° E, depth 13 km) occurred at 10:02 UTC. The major earthquake triggered catastrophic liquefaction, landslides, and a near-field tsunami. The ionospheric total electron content (TEC) derived from records of 5 ground-based global navigation satellite system (GNSS) receivers is employed to detect tsunami traveling ionospheric disturbances (TTIDs). In total, 15 TTIDs have been detected. The ray-tracing and beamforming techniques are then used to find the TTID source location. The bootstrap method is applied in order to further explore the possible location of the tsunami source based on results of …

Algal Coverage Detection And Classification Using Envi: Correlation With Dissolved Oxygen Levels In Elkhorn Slough, Ca, Jason Dawson

All HCAS Student Capstones, Theses, and Dissertations

Estuaries are exposed to varying stressors, whether they be physical, chemical, or environmental. The most notable of stressors is eutrophication of coastal and inland ecosystems. This is a result of increased supply of nutrients fueling production within the system. One outcome of this increased nutrient load to the system is that of algal blooms. These blooms can impact the aesthetic appearance and degrade the quality of health of the system. Many of these coastal zones and waterways are critical habitats for many biological (some endangered) species and serve as recreational areas for human populations. Elkhorn Slough, California is one of …

Bonnet Carré Spillway Freshwater Transport And Corresponding Biochemical Properties In The Mississippi Bight, Sabrina M. Parra, Virginie Sanial, Adam D. Boyette, M. Kemal Cambazoglu, Inia M. Soto, Adam T. Greer, Luciano M. Chiaverano, Angie Hoover, Michael S. Dinniman

CCPO Publications

Large freshwater pulses to coastal ecosystems change local hydrologic regimes and alter biogeochemical processes. The Mississippi Bight coastal ecosystem, located in the northern Gulf of Mexico shelf, is influenced by extensive freshwater inputs: the Mississippi River (MSR) and several smaller rivers to the east. Under river flood conditions, MSR waters flow through the Bonnet Carré Spillway (BCS) to relieve pressure on levees in New Orleans, Louisiana. In 2015, mild wintertime temperatures and heavy rainfall throughout the MSR watershed led to extreme flooding and prompted an unusually early BCS opening on January 10, 2016 for 23 days. This study examines the …

Freshwater Endmembers Impacting Carbonate Chemistry In The Mississippi Sound, Allison Savoie

Master's Theses

Coastal ecosystems are highly dynamic areas for carbon cycling and are likely to be negatively impacted by increasing ocean acidification. This research focused on dissolved inorganic carbon (DIC) and total alkalinity (TA) in the Mississippi Sound in order to understand the influence of local rivers that supply alkalinity to the area and buffer against ocean acidification. This area receives large fluxes of freshwater from local rivers, in addition to episodic inputs from the Mississippi River through a human-built diversion, the Bonnet Carré Spillway. Sites in the Mississippi Sound were sampled monthly during August 2018 to November 2019 and at weekly …

Using Disruptive Coloration And Ultraviolet Light To Prevent Barnacle Settlement, Kailey Nicole Richard

Theses and Dissertations

Biofouling or the accumulation of unwanted micro and macro organisms is problematic for the shipping industry. Barnacles are one of the most abundant fouling organisms and their settlement on ship hulls can result in costly damage. Several methods have been developed to prevent the formation of biofouling, including antifouling coatings and mechanical techniques, but the search for more effective and environmentally friendly solutions is still ongoing. This thesis investigated two methods aimed at barnacle prevention: color patterning and the application of ultraviolet light. The first method utilized disruptive coloration, a common mechanism observed in nature by terrestrial organisms (i.e. butterflies) …

Organic Sediment Impacts On Seagrasses And Their Associations With Benthic Fauna, Sean Matthew Crowley

Theses and Dissertations

Human-population growth and rapid rates of urbanization have led to eutrophic conditions in estuaries throughout the world. Effects often include severe algal blooms, decreased dissolved oxygen levels, and the accumulation of fine-grained organic-rich sediments. One frequent negative consequence of eutrophication is the decline of seagrasses, a vital component of coastal ecosystems. Seagrasses provide shelter from predation, serve as nursery habitat, stabilize sediments, act as a sink for excess carbon, produce oxygen, and are a food source for many herbivores. Seagrasses are also sensitive to environmental changes, such as declining water quality and increased sedimentation rates. This study examines the impacts …

Statement Of World Aquatic Scientific Societies On The Need To Take Urgent Action Against Human-Caused Climate Change, Based On Scientific Evidence [Dear Colleague Letter], Scott A. Bonar, Brian R. Murphy, Leanne H. Roulson, Jesse T. Trushenski, Douglas J. Austen, Michael Edward Douglas

United States Fish and Wildlife Service: Publications

Dear Colleague Letter from the American Fisheries Society to fellow scientific societies, July 25, 2020, about the urgent need for responsive collective action to mitigate impending radical climate change. Includes the Statement of World Aquatic Scientific Societies on the Need to Take Urgent Action Against Human-Caused Climate Change, Based on Scientific Evidence, emphasizing the importance of aquatic ecosystems. Includes extensive citations and notes.

"Water is the most important natural resource on Earth as it is vital for life. Aquatic ecosystems, freshwater or marine, provide multiple benefits to human society, such as provisioning of oxygen, food, drinking water, genetic resources; regulation …

Global Atmospheric Budget Of Acetone: Air-Sea Exchange And The Contribution To Hydroxyl Radicals, Siyuan Wang, Eric C. Apel, Rebecca H. Schwantes, Kelvin H. Bates, Daniel J. Jacob, Emily V. Fischer, Rebecca S. Hornbrook, Alan J. Hills, Louisa K. Emmons, Laura L. Pan, Shawn Honomichl, Simone Tilmes, Jean‐François Lamarque, Mingxi Yang, Christa A. Marandino, E. S. Saltzman, Warren J. De Bruyn, Sohiko Kameyama, Hiroshi Tanimoto, Yuko Omori, Samuel R. Hall, Kirk Ullmann, Thomas B. Ryerson, Chelsea R. Thompson, Jeff Peischl, Bruce C. Daube, Róisín Commane, Kathryn Mckain, Colm Sweeney, Alexander B. Thames, David O. Miller, William H. Brune, Glenn S. Diskin, Joshua P. Digangi, Steven C. Wofsy

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Acetone is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere. The oceans impose a strong control on atmospheric acetone, yet the oceanic fluxes of acetone remain poorly constrained. In this work, the global budget of acetone is evaluated using two global models: CAM‐chem and GEOS‐Chem. CAM‐chem uses an online air‐sea exchange framework to calculate the bidirectional oceanic acetone fluxes, which is coupled to a data‐oriented machine‐learning approach. The machine‐learning algorithm is trained using a global suite of seawater acetone measurements. GEOS‐Chem uses a fixed surface seawater concentration of acetone to calculate the oceanic fluxes. Both …

Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates

LSU Master's Theses

Man-made levees along the lower Mississippi River prevent delivery of sediment from building and maintaining Louisiana’s coastal wetlands. The Mid-Barataria sediment diversions is designed to reintroduce Mississippi River water, sediment, and nutrients into the sediment-starved Barataria Basin. Phosphorus (P) is an important macronutrient for regulating primary production in coastal marine ecosystems. Wetlands can serve as a sink or source for phosphorus to the overlying water column through various retention and release processes, dependent on concentration. Louisiana coastal systems can be phosphorus limited due to much higher concentrations of bioavailable Nitrogen in river water. The high soluble molar N:P ( >50:1) …

The Medium-Term And Event-Scale Tropical Cyclone-Driven Morphodynamics Of A Vulnerable Barrier System With Emphasis On The Role Of Backbarrier Wetlands, Cody Lee Johnson I

LSU Doctoral Dissertations

Coastal mainland barriers and barrier islands provide the first line of defense against oceanic and meteorological forces. Coastal morphological change, which may degrade these barrier's defensive capabilities, occurs over a range of time scales, from geological epochs (>1000 years) to hours and seconds. Coastal morphological change at a vulnerable, but economically strategic, barrier system---the Caminada-Moreau Headlands, Louisiana---is investigated in terms of tropical cyclone impacts and their effects over a 15 year LIDAR survey time series. Analysis of the barrier's three-dimensional morphodynamics at medium-term (decadal) time scales reveals that, while subaerial volume was approximately conserved through time, the impact of …

Reproductive Effort Of Montastraea Cavernosa Across Depth In The Context Of Both Climate Change Refugia And Emergent Disease, Jeanne Bloomberg

LSU Master's Theses

As coral populations on shallow reefs decline globally, mesophotic coral ecosystems (MCE) have been suggested as potential coral refugia in the face of climate changes, leading to the development of a comprehensive deep reef refugia hypothesis. The current study assesses the climate and disease refuge potential of MCEs in the U.S. Virgin Islands (USVI) for the gonochoric, broadcast-spawning species Montastraea cavernosa. Polyp, population, and total habitat fecundities were estimated across the species’ depth range, and changes to population oocyte production over time due to recent ecosystem disturbances were considered. The number of gonads producing oocytes in each polyp and oocyte …

Identification And Quantification Of Microplastic Pollution In Water Samples And Four Species Of Fish From The Mississippi River, Kerrin E. Toner

LSU Master's Theses

Microplastics (£5 mm) have become a persistent anthropogenic pollutant and a growing environmental concern with evidence of them being found throughout several ecosystems. In recent years, there has been a growing recognition that rivers play a major role in transporting plastics from the land to the sea. The Mississippi River is the largest river in North America, draining land populated by over 100 million people. With high numbers of microplastics found in the waters of the northern of the Gulf of Mexico, it is likely that the Mississippi River is the primary source of these plastics. This study quantifies and …