Oceanography Commons^™

A Stochastic Sailing Speed Optimization And Vessel Deployment Problem In Liner Shipping, Dung-Ying Lin, Pak Weng Leong

Journal of Marine Science and Technology–Taiwan

In this research, we consider the stochastic sailing speed optimization and vessel deployment problem and examine the trade-off between sailing speed and the number of vessels required to provide a certain service in international liner shipping. Solving this kind of stochastic program is a challenging task. To address this issue, we construct a mathematical formulation based on Ng (1) and Ng (2) and enhance the linearization techniques from Wang and Meng (3) so that problem instances of an even larger scale can be solved. The proposed formulation has been numerically applied to solve realistic cases, and the empirical results show …

Vehicle Assignment For Chemicals Transportation, Yu-Liang Liu, Juan Huang, Ching-Wu Chu

Journal of Marine Science and Technology–Taiwan

Vehicle assignment is a significant challenge faced by chemical logistics companies. The chemical industry typically outsources the delivery of chemicals to professional logistics companies to meet customers' complex and demanding needs. In this regard, this research explores the case study of a logistics company that selects its delivery modes and formulates its vehicle assignment plans based on its personnel’s experience rather than any formal system and plans its vehicle routes on the day before the delivery. This study seeks to improve the efficiency and immediacy of logistics companies’ vehicle assignments, understand vehicle route planning, maximize space utilization, and minimize transportation …

A Hybrid Finite Difference Method For Singularly Perturbed Delay Partial Differential Equations With Discontinuous Coefficient And Source, Nitika Sharma, Aditya Kaushik

Journal of Marine Science and Technology–Taiwan

The article presents a hybrid finite difference scheme to solve a singularly perturbed parabolic functional differential equation with discontinuous coefficient and source. The simultaneous presence of deviating argument with a discontinuous source and coefficient makes the problem stiff. The solution of the problem exhibits turning point behaviour across discontinuity as tends to zero. The hybrid scheme presented is a composition of a central difference scheme and a midpoint upwind scheme on a specially generated mesh. At the same time, an implicit finite difference method is used to discretize the time variable. Consistency, stability, and convergence of the presented numerical approach …

Simulating And Predicting Offshore Oil Spills By Using Cellular Automata, Lin Liu, Wanwu Li, Yumeng Cui, Guanghui Hu, Hang Li

Journal of Marine Science and Technology–Taiwan

In recent years, offshore oil spill accidents have caused substantial damage to both marine organisms and marine ecology. Accurate simulation and prediction of oil spills could provide a scientific basis for assessing losses due to oil spills and provide support for emergency decisions regarding oil spills. We analyzed the advantages and disadvantages of existing oil spill models and constructed an offshore oil spill model based on cellular automata (CA). By considering both the flow field and wind field, we formulated new CA rules for the diffusion and drift of a pollution zone, and in our model, the cellular state in …

Design And Testing Of A Bearing Less Piezo Jet Micro Heat Sink, Rong-Tsu Wang, Jung-Chang Wang, Sih-Li Chen

Journal of Marine Science and Technology–Taiwan

The present study utilized piezoelectric ceramics (PC) as actuators to design five new piezoelectric heatsinks and preliminarily investigated the different design types and their operating conditions, such as the frequency, placement distance, thickness between piezoelectric sheets, piezoelectric sheet size, and noise produced. The results showed that when the micro heatsink bearingless piezo jet was placed too close to the heat source, the high temperature sucked back the surrounding fluids, causing the fluid chamber temperature to rise and the cooling effect to be reduced. Therefore, the heatsink should be placed between 10 and 20 mm from the heat source. With the …

Supporting Dataset For Observed And Projected Global Warming Pressure On Coastal Hypoxia, Michael M. Whitney

Department of Marine Sciences

This archive contains the supporting dataset for the Biogeosciences article “Observed and projected global warming pressure on coastal hypoxia” by Michael M. Whitney. The main objective of the article is studying global patterns exacerbating coastal hypoxia by analyzing linear trends in SST, surface oxygen capacity (saturation concentration), and (vertical-minimum) oxygen concentration. Observations from a satellite-derived SST global climate dataset are analyzed to provide a context of coastal SST and oxygen-capacity trends observed over the last four decades. New analysis of 21st century projections from the Community Earth System Model (CESM) Large Ensemble Project is completed for coastal areas. Observed and …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

Contrasting Sea-Ice Algae Blooms In A Changing Arctic Documented By Autonomous Drifting Buoys, Victoria Hill, Bonnie Light, Michael Steele, Andrew Lowy Sybrandy

OES Faculty Publications

Novel observations of the seasonal evolution of an ice algal bloom on the Chukchi shelf were collected by two autonomous buoys deployed 180 km apart in first-year drifting sea ice. High attenuation of blue light in the bottom of the ice indicated considerable accumulation of ice algae biomass with derived Chlorophyll-a concentrations (Chl a) up to 184 mg m⁻². Differences in the magnitude and persistence of ice algae biomass under each buoy appear to have been driven by differences in snow thickness, as ice thickness was similar between the sites. Minimal snow cover (0.02 m) around …

Ocean Eddies And Frontal Zones In The Gulf Of Mexico And Straits Of Florida, Yingjun Zhang

USF Tampa Graduate Theses and Dissertations

Ocean eddies and fronts in the Gulf of Mexico (GoM) and the Straits of Florida (SoF) play important roles in ocean physics, biology, and ecology. These two ubiquitous physical features have been studied worldwide for decades, yet many questions remain unanswered or poorly studied for the GoM and SoF. This study aims to improve the understanding of ocean eddies and frontal zones in the GoM and SoF using satellite remote sensing, in situ observations and model outputs, as well as state-of-the-art algorithms, with the following objectives: 1) analyze the three-dimensional (3-D) statistical characteristics and thermohaline structure of mesoscale eddies in …

Water Quality Correlations With Phytoplankton Community Composition In A Polluted Shallow Subtropical Estuary, Connor Joseph Wong

Theses and Dissertations

The Indian River Lagoon (IRL) estuary has experienced eutrophication and degraded water quality due to high nutrient input, urbanization, and anthropogenic stressors. High nutrient input and restricted estuarine hydrology promotes algal blooms. Algal blooms or harmful algal blooms (HABs) are a global concern as they can cause negative ecological and economic impacts. The frequency and range of HABs is expected to be exacerbated by climate change and altered oceanic and estuarine conditions. Research on the formation and frequency of HABs is an ongoing global effort, but algal blooms are often dynamic and patchy making them difficult to study. This study …

Developing A Miniature Smart Boat For Marine Research, Michael Isaac Eirinberg

Computer Engineering

This project examines the development of a smart boat which could serve as a possible marine research apparatus. The smart boat consists of a miniature vessel containing a low-cost microcontroller to live stream a camera feed, GPS telemetry, and compass data through its own WiFi access point. The smart boat also has the potential for autonomous navigation. My project captivated the interest of several members of California Polytechnic State University, San Luis Obispo’s (Cal Poly SLO) Marine Science Department faculty, who proposed a variety of fascinating and valuable smart boat applications.

Inter-Annual Variability In Growth And Maturation Of The Swordtip Squid Uroteuthis Edulis In Yilan Bay Off Northeastern Taiwan, Jing-Yu Chen, Tzu-Yun Ching, Chih-Shin Chen

Journal of Marine Science and Technology–Taiwan

The swordtip squid Uroteuthis edulis, distributed in the temperate and tropical neritic waters in the Indo-Pacific region, is a crucial component of marine ecosystems and is a target species of fisheries in the Northwest Pacific. Although studies have elucidated the growth and maturation of the squid in the southern East China Sea (ECS) shelf, few have assessed the population biology of the squid in waters in the vicinity of the southern ECS. We collected samples of swordtip squid from a trawler in Yilan Bay (YLB) between January 2011 and December 2012 to examine the growth and maturation of the squid …

Study On The Improved Radiation Boundary Conditions Based On The Quadratic B-Spline Rankine Panel Method, Ming-Chung Fang, Chun-Hsien Wu

Journal of Marine Science and Technology–Taiwan

This study presents a higher-order Rankine source method that is based on a biquadratic B-spline scheme with an improved radiation boundary condition. This method solves flow problems under all conditions, where , including the undercritical condition ( < 0.25); this condition is present when a ship undergoes slow translational motion. The proposed method is thus more flexible than the many Rankine-source models in the literature that are applicable only to the overcritical condition ( > 0.25). Specifically, the improved radiation boundary condition is derived from upstream Seto radiation boundary conditions and by incorporating the Rayleigh damping distribution over a free surface; the improved condition is explicit and efficient for solving flow problems. In evaluations, the proposed method yields accurate solutions for unsteady flows, which are produced by an oscillating, translationally moving submerged singularity. The method is also compared …

Sensitive Analysis Of The Static Response Of Compliant Vertical Access Risers, Fuheng Li, Haiyan Guo, Xiaomin Li, Honglu Gu

Journal of Marine Science and Technology–Taiwan

Compliant vertical access risers (CVARs) are considered as efficient and robust alternative options to achieve cost efficiency and safety. Design uncertainties emerge owing to the limited understanding of the effects of various parameters related to the structural properties and marine loads. In this paper, a reasonable three-dimensional (3D) numerical model of CVAR with internal flow is presented based on the slender rod theory. Accordingly, the finite element method combined with a Newton-Raphson scheme is employed to discretize and solve the equations. A sensitivity analysis is performed to investigate the influence of the structural and external load parameters on the static …

Influence Of Boundary Conditions And Internal Fluid Types On Dynamic Characteristics Of A Deepwater Riser, Lei Guo, Zong-Ming Zhu, Zhong-Jian Pan, Zhi-Ming Guo

Journal of Marine Science and Technology–Taiwan

Deepwater Steel Catenary Riser (DSCR) is the key structure of oil and gas production system in the ocean. To design an optimized DSCR system, the dynamic characteristics of the DSCR are analyzed by setting some different boundary condi-tions and internal fluid types. The main vibration mode of the DSCR is found orthogonal to both mass and stiffness according to the normalization condition of the main mode, and then the regular mode function and the jth order principal stiffness Kpj are obtained. Under different initial conditions, the transverse responses of DSCR represented by regular coordinates under arbitrary excitation are obtained. Then, …

Variance Of Td-Mosaic Dual-Vortex Interactions Between In-Fa And Cempaka (2021) In The North Pacific, Tsorng-Lin Chia, Guang-Yang Pan, Ji-Chyun Liu

Journal of Marine Science and Technology–Taiwan

A study of the different types of dual-vortex interactions or “Fujiwara effects” between two storms is crucial for considerably improving weather forecasts. This study combined remote sensing images, empirical formulas based on the possibility of storm interaction (Liou–Liu formula), and vector addition techniques to accurately analyze In-Fa and Cempaka typhoons and the surrounding weather patterns during the 2021 typhoon season in the North Pacific. Although the distance separating the typhoons In-Fa and Cempaka was 1,800–2,040 km, the influence of middle air flow and a tropical depression (TD) caused a "vector superposition TD-mosaic double-vortex" interaction between the two typhoons. Therefore, this …

Optimal Deployment Of Flood Emergency Response Materials Under Stochastic Demands, Shangyao Yan, Jenn-Rong Lin, Chia-Fu Ku

Journal of Marine Science and Technology–Taiwan

This study aims to develop a planning model for the deployment of flood emergency response materials under stochastic demands. For ease of modeling, a deterministic demand model is first proposed, from which the stochastic model is further extended. These models are used to determine the allocation of materials the transport truck routes and distribution of the stockpiled materials to emergency sites. The models are formulated as multiple integer network flow problems with special side constraints which are characterized as NP-hard in terms of optimization. To solve the complicated stochastic model efficiently, we also develop a solution algorithm based on a …

Murphy Scale: A Locational Equivalent Intensity Scale For Hazard Events, Yi Victor Wang, Antonia Sebastian

Institute for ECHO Articles and Research

Empirical cross-hazard analysis and prediction of disaster vulnerability, resilience, and risk requires a common metric of hazard strengths across hazard types. In this paper, the authors propose an equivalent intensity scale for cross-hazard evaluation of hazard strengths of events for entire durations at locations. The proposed scale is called the Murphy Scale, after Professor Colleen Murphy. A systematic review and typology of hazard strength metrics is presented to facilitate the delineation of the defining dimensions of the proposed scale. An empirical methodology is introduced to derive equivalent intensities of hazard events on a Murphy Scale. Using historical data on …

A New Model For Predicting The Drag And Lift Forces Of Turbulent Newtonian Flow On Arbitrarily Shaped Shells On The Seafloor, Carley R. Walker, James V. Lambers, Julian Simeonov

Dissertations

Currently, all forecasts of currents, waves, and seafloor evolution are limited by a lack of fundamental knowledge and the parameterization of small-scale processes at the seafloor-ocean interface. Commonly used Euler-Lagrange models for sediment transport require parameterizations of the drag and lift forces acting on the particles. However, current parameterizations for these forces only work for spherical particles. In this dissertation we propose a new method for predicting the drag and lift forces on arbitrarily shaped objects at arbitrary orientations with respect to the direction of flow that will ultimately provide models for predicting the sediment sorting processes that lead to …

Analysis Of Fossil Pollen From A Pleistocene Cypress Forest Preserved On The Northern Gulf Of Mexico Continental Shelf, Kathryn Joyce Garretson

Master's Theses

This study presents the findings of fossil pollen analysis performed on terrestrial sediments preserved on the northern Gulf of Mexico continental shelf (site hereafter known as the Underwater Forest or DF). This research aims to establish vegetation composition on a continental shelf glacial refuge and provide a better understanding of vegetation response to sea-level rise. Two cores (15DF1 and 15DF3B) located at different locations within the forest were recovered and analyzed. Pollen results from both cores were similar, with high percentages of Taxodium and Nyssa pollen in the lowermost sections reflecting an assemblage typical of contemporary baldcypress swamps. Pollen assemblages …

Understanding Biogeochemical And Physical Controls On Methane Air-Sea Exchange Fluxes In The Pacific Ocean, Sarah Raney

Master's Theses

Methane and trace element samples were collected on GEOTRACES GP15 Pacific Meridional Transect (PMT) cruise conducted between the Aleutian Islands (57 °N) and Tahiti (20 °S) from September to November 2018. Uncertainty in methane air-sea exchange fluxes was determined using a propagation of errors approach. Fluxes ranged from -0.88 to 4.9 µmol CH₄ m^-2 d^-1. Average CH₄ flux along the Alaskan margin was 2.2 ± 2.9 µmol CH₄ m^-2 d^-1. Methane fluxes decreased moving southward and increased to their open ocean maximum around 20 °N before declining in equatorial waters. Near …

A Step Toward Reconstructing Climate Variability Druing The Last Ice Age Cycle In The Northeast Pacific Region, Blaine Lynch-Gadaleta

Senior Honors Projects

This study is designed as a step toward reconstructing the climate variability in the Northeast Pacific during the last ice age cycle, including the glacial and deglacial transitions. Reconstruction may also contribute to the regional picture of climate change and potentially provide new insights into the pattern of variability in the Northeast Pacific. Deep-sea sediment core AT26-19 09PC was collected west of the Juan de Fuca Ridge in the Northeast Pacific Ocean. Samples were analyzed in 1 cm intervals, representing approximately 300-year resolution. The abundance of mineral grains, planktonic foraminifera, and the polar foraminifera N.pachyderma was quantified using split aliquots …

Using Stock And Flow Modeling To Address Knowledge Gaps In Marine Plastic Pollution Data, Daniel P. Martin

OES Theses and Dissertations

As plastic becomes a ubiquitous part of society, its growth outpaces waste disposal infrastructure and enters the environment as physical and chemical pollution. Plastic can also erode during the use cycle and reach the environment without any chance of being arrested by collection efforts. Plastic is a hazard to many parts of the earth’s life support system but there are many knowledge gaps regarding the processes by which plastic moves through the use cycle and environment. In particular, the ocean is generally regarded as a sink for plastic out of which it is difficult to escape, but plastic can sink …

Climate-Driven Stock Shifts And Expansions In The U.S. Northeast Shelf: Identifying Challenges, Opportunities, And Barriers Through Fishermen And Manager Perspectives, Sophie A. Swetz

All Theses And Dissertations

Climate-driven warming in the U.S. Northeast Shelf (NES) has led to changes in the spatial distributions of many marine resources. Shifts and expansions of commercially important fish stocks pose major challenges to fishermen and fisheries managers in this region. American lobster (Homarus americanus) in the Gulf of Maine (GOM) is one of these impacted stocks and is projected to continue its shift towards more northern and offshore areas. Continued ocean warming could potentially reduce the GOM lobster stock by up to 60% over the next several decades. Given Maine’s reliance on its lobster fishery—which contributes over 80% of …

Understanding The Public Perception Of Available Scientific Resources In Coastal Southern Maine, James Gallagher

Senior Honors Projects

I have focused my education as an undergrad towards the effective communication of scientific fact to non-scientific groups. This area of study has recently been dubbed Science Communication and it encompasses the effective articulation, communication, and education of scientific topics to people who haven’t dedicated their lives to scientific study. A major component of effective Scientific Communication is understanding your audience and what kind of communication strategies are best for a chosen demographic.

I grew up in Ocean Park Maine, a small town on the coast of Southern Maine which drove my interest in Marine Science. With my experience in …

Near-Inertial Wave Energetics Modulated By Background Flows In A Global Model Simulation, Keshav J. Raja, Maarten J. Buijsman, Jay F. Shriver, Brian K. Arbic, Oladeji Siyanbola

Faculty Publications

We study the generation, propagation, and dissipation of wind-generated near-inertial waves (NIWs) in a global 1/25° Hybrid Coordinate Ocean Model (HYCOM) simulation with realistic atmospheric forcing and background circulation during 30 days in May–June 2019. The time-mean near-inertial wind power input and depth-integrated energy balance terms are computed for the total fields and the fields decomposed into vertical modes to differentiate between the radiative and (locally) dissipative components of NIW energy. Only 30.3% of the near-inertial wind input projects onto the first five modes, whereas the sum of the NIW energy in the first five modes adds up to 58% …

Testing The Efficacy Of Uvc Leds For Biofouling Control, Margaret Jeannette Giggie

Theses and Dissertations

The use of ultraviolet-C (UVC) light as a biofouling preventative has been successfully demonstrated using mercury-based lamps. However, these lamps have several limitations (such as fragility and use of mercury), and the use of UVC LEDs (light-emitting diodes) has been suggested as an alternative. Several experiments were conducted to assess the efficacy of LED strips (29 W, 270 nm, emittance angle of 130º) for biofouling control, as well as to compare them to a classic lamp (25 W, 254 nm, emits UVC light at 360º). Experiment #1 assessed the biofouling abundance and community composition on test panels exposed to either …

Coastal Sediment Response To The Diel Oxygen Cycle, Kara Gadeken

Graduate Theses and Dissertations (2019 - present)

Shallow coastal sediments are sites of intense respiration and organic matter breakdown. Macroinfauna bioturbate and bioirrigate sediments which supplies microbes with oxygen and newly deposited organic material from surface sediments, facilitating microbial remineralization of organic matter. These processes depend heavily on the concentration of dissolved oxygen in overlying water. Shallow water oxygen patterns often follow a diel cycle as dissolved oxygen decreases at night due to respiration and then increases during the day with photosynthesis, creating recurring suboxic conditions that are potentially stressful to organisms. Sediment oxygen flux is known to depend on ambient dissolved oxygen concentration, but behavioral responses …

Exploring Indicator Displacement Assays For Phosphate Detection In Seawater, Francis Radics

Chemistry & Biochemistry Student Scholarship

Francis Radics ’22
Major: Biochemistry
Faculty Mentor: Dr. John Breen, Chemistry and Biochemistry

Indicator displacement assays are based on the optical signal modulation of a noncovalently bound indicator upon dissociation by an analyte species. Our work has focused on exploring the lower detection limits for luminescent displacement assays for inorganic phosphate in seawater using complex ions containing two di(2-picolyl)amine ligands (also called DPA or bis(2-pyridylmethyl)amine), each coordinating a zinc cation. Following the work of B.D. Smith and coworkers, we have prepared three ligands by covalently attaching two DPA moieties, 2,6-bis(chloromethyl) benzene, and 2,6-bis(chloromethyl)-4-methylphenol, and 1,2-phenylenedimethylamine, for assays with 6,7-dihydroxy-4-methanesulfonic acid …

Sedimentation Processes In A Dredge Pit And Surrounding Environment In Northern Gulf Of Mexico, Adam M. Gartelman

LSU Master's Theses

Louisiana’s Coastal Protection and Restoration Authority has been using dredged sand from onshore and offshore sites for barrier island restoration and beach nourishment projects. Caminada dredge pit (CDP) located on eastern Ship Shoal in inner Louisiana shelf underwent two increments in 2014 and 2016, with material used to restore Caminada Headland and nearby areas. Multiple pits in East Terrebonne borrow areas (ET) right next to CDP were then used for East Timbalier Island and other barrier islands near Terrebonne Bay. ET1, north of CDP, was dredged in 2020, and ET2, west of CDP, was dredged in 2020 and 2021 used …