Physical Sciences and Mathematics Commons^™

Performance Analysis: Using The Northern Sea Route As An Alternative To Traditional Routes, Liangkun Xu, Qing Yu

Journal of Marine Science and Technology

The grounding accident of M/V EVER GIVEN in the Suez Canal causes a catastrophic loss on shipping companies. Alternatively, previous studies have presented encouraging findings of the remarkable benefits of time and cost saving in the Northern sea route (NSR) due to extend the ice-free time and shorten the distance. Ships using the NSR could shorten as much as 40% of the sailing distance from China (Shanghai) to Europe (Rotterdam) compared with the traditional route via the Suez Canal. This paper investigates the economic potential of using the NSR as a cost-effective route in comparison with Suez Canal Route (SCR) …

Numerical And Approximate Analytic Solutions Of Second- Order Nonlinear Boundary Value Problems, Chein-Shan Liu, Jian-Hung Shen, Yung-Wei Chen

Journal of Marine Science and Technology

The shooting method consists of guessing unknown initial values, transforming a second-order nonlinear boundary value problem (BVP) to an initial value problem and integrating it to obtain the values at the right end to match the specified boundary condition, which acts as a target equation. In the shooting method, the key issue is accurately solving the target equation to obtain highly precise initial values. Due to the implicit and nonlinear property, we develop a generalized derivative-free Newton method (GDFNM) to solve the target equation, which offers very accurate initial values. Numerical examples are examined to show that the shooting method …

Optimization Of Circular Silencers Internally Hybridized With Multiple Reverse Chambers Using The Ga Method, Min-Chie Chiu, Ying-Chun Chang, Tian-Syung Lan, Ho-Sheng Chen

Journal of Marine Science and Technology

A noise abatement method using an eigen function in conjunction with an optimizer (Genetic Algorithm) under a space-constrain situation is proposed in this study concerning a high order wave propagation effect. An eigen function is used to describe an acoustical field and shorten the acoustical model in a four-pole transfer matrix form. The system’s four-pole matrix estimates the Transmission Loss (TL) for the silencers by multiplying individual four-pole matrices.

Additionally, a case study of an air compressor’s broadband noise elimination is introduced. Three types of circular reverse silencers (silencers A-C) internally hybridized with multiple straight chambers are adopted to efficiently …

Numerical Investigation Of The Uncertainty Of Typhoon Wave Parameters Retrieval Using Hf Radar, Toan Duy Dao, Hwa Chien

Journal of Marine Science and Technology

The aim of this study was to identify the sources of uncertainties of typhoon wave field monitoring using HF radar and to quantitatively assess the bias of the wave parameters, such as significant wave height and mean period, retrieved under various conditions. The strategy was to apply a purely numerical simulation of the Doppler-range spectra and then compare the estimation results to the target. For the quantitative investigation, a numerical test-bed was established. The test-bed was used to simulate the Doppler spectra based on Barrick’s (1972) theory by using the input of the directional wave spectra. The typhoon wave spectra …

A Fused Data Based Real-Time Collision Warning System For Ferries In The Yangtze River, Xiaojia Liu, Ke Zhang, Han Xue, Yingtang Li

Journal of Marine Science and Technology

The risks for ferries in the Yangtze River are relatively high, as they frequently cross the main traffic flows, leading to more intersections with other upwards and downwards ships. Although some studies have developed many models to assess collision risks in the Yangtze River, collision warning studies on ferries are scant. Meanwhile, most of the current collision studies evaluate risk based on AIS data, which are incapable of providing real-time ship information as they are discrete-time series data. In this work, fused data combining radar and AIS data are applied in a real-time ship collision warning model to assess the …

Experimental Study Of The Effect Of A Solid Wing Conveyor On Marine Debris Collection, Erik Sugianto, Jeng-Horng Chen

Journal of Marine Science and Technology

Marine debris is a global problem that has not been resolved. This has encouraged the emergence of marine debris cleaning technologies, one of which is a conveyor ship. However, how effective conveyors are in collecting waste has not been studied. In this paper, experimental research on conveyors as marine debris collectors is investigated. The capability of catamarans with or without solid wing conveyors to collect marine debris is explored. Three kinds of marine debris collection models are used: no-wing conveyor, a 12.5-cm-long wing conveyor, and an 18.75-cm-long wing conveyor. Artificial marine debris (AMD) is spread on the water surface in …

Solving Nonlinear Boundary Value Problems With Nonlinear Integral Boundary Conditions By Local And Nonlocal Boundary Shape Functions Methods, Chein-Shan Liu, Yung-Wei Chen, Jian-Hung Shen

Journal of Marine Science and Technology

The paper considers the second-order nonlinear boundary value problem (NBVP), which is equipped with nonlinear integral boundary conditions (BCs). Two novel iterative algorithms are developed to overcome the difficulty of NBVP with double nonlinearities involved. In the first iterative algorithm, two nonlocal shape functions incorporating the linear integral terms are derived, and a nonlocal boundary shape function (NBSF) is formulated to assist the solution. Let the solution be the NBSF so that the NBVP can be exactly transformed into an initial value problem. The new variable is a free function in the NBSF, and its initial values are given. For …

2022 December 8 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Larval Ecology Of Atlantic Bluefin Tuna (Thunnus Thynnus): New Insights From Otolith Microstructure, Biotic, And Abiotic Analyses From The Gulf Of Mexico And Mediterranean Sea, Estrella Malca

All HCAS Student Capstones, Theses, and Dissertations

Atlantic bluefin tuna (ABT), Thunnus thynnus, spawn in the Gulf of Mexico (GoM) and the Mediterranean Sea (MED). Spawning occurs within narrow temporal and environmental parameters. Efforts to characterize growth of ABT in wild conditions revealed a wide range of growth variability during the early life stages. This series of studies examined potential biotic and abiotic influences of larval growth from seven ABT cohorts, and identified several key drivers of growth for this commercially valuable species. A detailed investigation of larval dynamics using otolith microstructure was conducted as follows. First, companion growth curves and stable isotope analysis from the same …

Methane Emissions From Agricultural Ponds Are Underestimated In National Greenhouse Gas Inventories, Martino E. Malerba, Tertius De Kluyver, Nicholas J. Wright, Lukas Schuster, Peter I. Macreadie

Climate Science Research Articles

Agricultural ponds have some of the highest methane emissions per area among freshwater systems, and these anthropogenic emissions should be included in national greenhouse gas inventories. Here we deliver a continental-scale assessment of methane emissions from agricultural ponds in the United States and Australia. We source maps of agricultural ponds, compile a meta-analysis for their emissions and use published data to correct for temperature and the relative contributions of two methane fluxes (diffusion and ebullition). In the United States, 2.56 million agricultural ponds cover 420.9 kha and emit about 95.8 kt year−1 of methane. In Australia, 1.76 million agricultural ponds …

Closing The Concern-Action Gap Through Relational Climate Conversations: Insights From Us Climate Activists, Julia Coombs Fine

Environmental Studies Faculty Publications

Several studies have found that relational climate conversations can be an effective method of increasing conversational participants’ concern about the climate crisis and encouraging them to take collective action. However, little work has yet examined how such conversations are practiced by climate activists, a group with expertise in relational organizing. Drawing on surveys and semi-structured interviews with climate activists across the USA, this analysis finds that activists frequently have climate conversations with friends and family, most of whom are politically progressive and somewhat to very concerned about the climate crisis. These findings might seem to suggest that climate activists only …

Wrack Lines Volume 22, Number 2, Fall-Winter 2022-2023, Nancy C. Balcom, Juliana Barrett, Judy Benson, Ben Crnic, Sto Len

Wrack Lines

With the theme, "Looking Ahead: People and Projects Shaping the Future," the Fall-Winter 2022-2023 leads with the first in what will be a series of articles about offshore wind development impacting Connecticut. That is followed by the inspiring story of how a dying forest was replanted for climate resilience. Next, a profile of longtime marine educator Tim Visel tells about his lasting impact on Connecticut schools and students. Lastly, the complex challenge of dealing with Contaminants of Emerging Concern is examined, with descriptions of how Sea Grant is involved and the particularly troublesome group of substances called PFAS.

On A Guiding Of Whistler-Mode Waves By Density Gradients, Anatoly V. Streltsov

Publications

Observations from satellites demonstrate that in the magnetosphere, VLF whistler-mode waves are frequently detected in the narrow transition regions, where the plasma density changes its magnitude over a short distance across the ambient magnetic field. These observations suggest that the small-scale, isolated density gradients can guide the VLF whistler-mode waves along the field. We investigate the guiding of the whistler-mode waves by the transverse density gradients with a size much less than the characteristic perpendicular size of the wave. We found analytical solutions describing these waves in the plasma with a sharp density discontinuity between two homogeneous regions, and confirm …

The Contribution Of Non-Tropical Cyclone Vortices To The Rainfall Of The Philippines, Lyndon Mark P. Olaguera, Jun Matsumoto, John A. Manalo

Physics Faculty Publications

Weaker disturbances than tropical cyclones (TCs) such as tropical depressions and cold surges can significantly induce heavy rainfall and flooding events over the Philippines. However, the analysis of these disturbances including their rainfall contributions are often neglected in previous studies. As the first attempt to address this research gap, this study investigates the rainfall contribution of non-TC vortices over the Philippines from 1979 to 2020. Only those rainfall-producing non-TC vortices that formed and appeared within a 500-km radius from the Philippine coastline were examined in this study. A total of 7,686 non-TC vortex days (50% of the total days during …

Workshops Report For Mesophotic And Deep Benthic Community Fish, Mobile Invertebrates, Sessile Invertebrates And Infauna, Rachel Bassett, Stacey L. Harter, Randy Clark, Ian Zink, Katherine Hornick, Jennifer Hart, Hanna Bliska, Melissa Carle, Tracey Sutton, Amanda Demopoulos, Andy David, Kristopher Benson, Jill Bourque, Martha Nizinski, Nancy Prouty, Stephanie Sharuga, Alicia Caporaso, Jennifer Le, Jennifer Herting, Cheryl Morrison, Matthew Poti

Marine & Environmental Sciences Faculty Reports

Two workshops with subject matter experts in the appropriate fields, were held in November and December 2021 to elicit guidance and feedback from the broader mesophotic and deep benthic scientific community. These workshops focused on best practices/approaches and identifying data gaps relative to habitat assessment and evaluation goals of the Mesophotic and Deep Benthic Community (MDBC) restoration portfolio. The first workshop was a combined effort of the Habitat Assessment and Evaluation (HAE) Project Team and the Deepwater Horizon (DWH) Program. Industrial Economics, Inc. (IEc) provided extensive workshop planning, organizing, execution, and facilitation support during all stages of the workshop. Based …

Black And Brown Carbon Optical Characterization In The El Paso - Ciudad Juarez Airshed, Pamela I. Lara

Open Access Theses & Dissertations

Black (EBC) and Brown (BrC) Carbon are ubiquitous constituents of atmospheric particulate matter that affect peopleâ??s health, disrupt ecosystems, and modulate local and global climate. Tracking the local deposition and sources of these aerosol particles is essential to better understanding their multidimensional environmental impact. The main goal of the current study is to measure the absorption coefficient (Babs) of particles within the Planetary Boundary Layer (PBL) of the El Paso (US)–Ciudad Juárez (Mexico) airshed and assess the contribution of black and brown carbon particles to the total optical absorption. Measurements were taken during winter (January, 2022), spring (May, 2022), and …

Identifying Particulate Matter Spatial Variation In The El Paso Del Norte Region Using Land-Use Regression Modeling And Data Obtained From A Network Of Low-Cost Sensors, Leonardo Demetrio Vazquez-Raygoza

Open Access Theses & Dissertations

The emergence and rise in popularity of low-cost sensors for atmospheric observation aresetting a new precedent in identifying emission hotspots and providing high-resolution spatial and temporal data. Furthermore, low-cost sensors are becoming popular among institutions and the public, allowing community scientists to become more involved in air quality monitoring. However, concerns about the accuracy and precision of low-cost sensors have been questioned. Most recent research has focused on the utility of real-time monitoring and calibration requirements for these sensors. A low-cost monitoring project has deployed sensors in the El Paso del Norte region in low and high annual average daily …

Green On The Map - The Influence Of Conservation Easements On The Naturalness Of Landscapes In The United States, Nakisha Fouch

All Dissertations

Large protected areas have long been the cornerstone of conservation biology, however, in an era branded by the human dominance of ecosystems, regional landscape structure and function are often a consequence of accumulated land-use decisions that may or may not include a nod to conservation planning. With underrepresentation of habitats in publicly protected areas, attention has focused on the function of alternative land conservation mechanisms. Private conservation easements (CEs) have proliferated in the United States, yet assessing landscape-level function is confounded by holder and donor intent, national and regional policy, regional landscape contexts, varying extents, resolution, and temporal scale. Over …

Analysis Of Precipitation Reversals Over The State Of Arkansas, Mallory Hoff

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Recent studies have examined hydroclimate precipitation reversals, but because it is a newly defined concept, there is minimal research available on how reversals are changing, and it has not been widely investigated. Precipitation reversal is the rapid switch between wet and dry periods or “precipitation extremes and the opposite” (McKay, 2018), based on precipitation measurements in this case. A single reversal is the immediate transition from a wet to a dry period or from a dry to a wet period. Changes in reversals have not been thoroughly reported and this gap in research creates a risk of unpredictable conditions that …

One Health In Action: Flea Control And Interpretative Education At Badlands National Park, David Eads, Lindsey Buehler, Anne Esbenshade, Jason Fly, Evan Miller, Holly Redmond, Emily Ritter, National Park Service, Sasha Wittmann, Paul Roghair, Eddie Childers

United States Geological Survey: Staff Publications

No abstract provided.

A Protocol To Build Trust With Black Box Models, Timothy K. Thielke

Theses and Dissertations

Data scientists are more widely using artificial intelligence and machine learning (ML) algorithms today despite the general mistrust associated with them due to the lack of contextual understanding of the domain occurring within the algorithm. Of the many types of ML algorithms, those that use non-linear activation functions are especially regarded with suspicion because of the lack of transparency and intuitive understanding of what is occurring within the black box of the algorithm. In this thesis, we set out to create a protocol to delve into the black box of an ML algorithm set to predict synoptic severe weather patterns …

¿Aviso O Alerta? Developing Effective, Inclusive, And Consistent Watch And Warning Translations For U.S. Spanish Speakers, Joseph E. Trujillo-Falcón, América R. Gaviria Pabón, Joseph T. Ripberger, Abby Bitterman, Jonathan B. Thornton, Mackenzie J. Krocak, Sean R. Ernst, Estilita Cassiani Obeso, John Lipski

NOAA Technical Reports and Related Materials

Spanish-speaking populations in the United States are more vulnerable in disaster contexts due to inequities, such as language barriers, that prevent them from receiving life-saving information. For the past couple of decades, governmental organizations have addressed these issues by translating weather watches, warnings, and advisories into Spanish. Previous studies suggest that these Spanish translations do not communicate the same level of urgency as their English counterparts. To identify whether these translated products result in inequities between English and Spanish speaker reception and comprehension of forecast information, we asked a representative sample of U.S. English (n = 1,550) and Spanish (n …

2022 December 1 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Probabilistic Forecasting Of Winter Mixed Precipitation Types In New York State Utilizing A Random Forest, Brian Chandler Filipiak

Legacy Theses & Dissertations (2009 - 2024)

Operational forecasters face a plethora of challenges when making a forecast; they must consider multiple data sources ranging from radar and satellites to surface and upper air observations, to numerical weather prediction output. Forecasts must be done in a limited window of time, which adds an additional layer of difficulty to the task. These challenges are exacerbated by winter mixed precipitation events where slight differences in thermodynamic profiles or changes in terrain create different precipitation types across small areas. In addition to being difficult to forecast, mixed precipitation events can have large-scale impacts on our society.

Large-Scale Flow Patterns Conducive To Central American Extreme Precipitation Events During Autumn, Alexander Kyle Mitchell

Legacy Theses & Dissertations (2009 - 2024)

Extreme precipitation events (EPEs), characterized by daily widespread heavy rainfall exceeding the 95th percentile across Central America, can have large impacts on agriculture, life, and property during the rainy season. EPEs during the Northern Hemisphere (NH) autumn, however, have been observed to be influenced by both tropical and extratropical originating phenomena such as easterly waves and cold surges, respectively. Given the limited research in this area, the novelty of this work is to apply a systematic approach for identifying and better understanding EPEs, and investigating their associated synoptic-scale variability using daily high-resolution observations and reanalysis products over Central America. An …

Comparison Of 2018-2021 Tropical Cyclone Track Forecasts Before And After Noaa G-Iv Missions, Melissa Piper

Legacy Theses & Dissertations (2009 - 2024)

Tropical cyclone (TC) hazards are primarily dictated by the TC position; thus, it is important to produce accurate TC track forecasts. Many different features can influence a TC’s motion, yet these features are not always well sampled by in-situ observations over the open ocean, creating a need for supplemental observation collected via aircraft, including the deployment of dropsondes. In 1997, the National Hurricane Center (NHC) began operational synoptic surveillance missions in the near-storm environments of TCs using the Gulfstream IV-SP jet aircraft (G-IV), with the goal of reducing track forecast errors. In the first 10 years of operational missions, the …

The Simulated Sensitivity Of The North American Monsoon At Convection-Permitting Scales, Brendan Wallace

Legacy Theses & Dissertations (2009 - 2024)

The North American Monsoon (NAM) is a major contributor to annual rainfall for large portions of the North American Southwest. Much of the prior work examining the NAM using numerical models has been done at scales exceeding 20-km grid spacing. At these coarse scales, unresolved processes and poorly resolved geographic features can impact model performance. This can present a problem when simulating the NAM particularly with regard to orographic precipitation, precipitation on sub-daily timescales, and land surface-atmosphere interactions. This dissertation seeks to better understand the NAM through examination of several sets of convection-permitting regional climate model output. The primary goal …

Investigating The Relationship Between Dissolved Oxygen And Nitrate Concentration As A Proxy For Marine Ecosystem Health, Natalia M. Moore

Theses and Dissertations

Coastal environments such as seagrass meadows span a wide range of spatial scales and can experience disturbances that cause rapid shifts to ecosystem dynamics. Increased pressure to the coastal zone has highlighted the need for constant, real-time monitoring to monitor current ecosystem status. A custom, low cost, high resolution, in situ sensor network was designed and tested in the Lower Laguna Madre, Texas to characterize primary productivity in seagrass meadows through gradient patterns of dissolved oxygen concentration, with the purpose of determining whether seagrass or phytoplankton were the more dominant primary producer. There was a distinct vertical and horizontal gradient …

Sea Level Rising And Its Impact On Nyc, Angela Knafo, Jeff Mao, Andray Whyte, Filip Valencin, Erick Humala, Jubran Alawdi, Jonathan Carangui

Publications and Research

Climate change is not only about the rising temperatures, which is usually the most discussed topic in news, but it also involves other Earth sciences like hydrology, oceanography and other parts of meteorology In our poster we are focusing on sea level rising and its impact on NYC, and how people could mitigate and adapt to it

Systematic Review Of A Ramsar Wetland And Unesco Biosphere Reserve In A Climate Change Hotspot (Ichkeul Lake, Tunisia), Sabrine Sahbani, Béchir Béjaoui, Sihem Benabdalla, Rachid Toujani, Afef Fathalli, Noureddine Zaaboub, Jalel Aouissi, Zeineb Kassouk, Nabil Hamdi, Nabiha Ben Mbarek, Hechmi Missaoui, Leila Basti, Reginald Blake, Hamidreza Norouzi

Publications and Research

Tunisia's Ichkeul Lake is among the most productive ecosystems in the Mediterranean, with a great regional value thanks to its diversity of habitats. It is an important overwintering area for waterfowl species. It is a RAMSAR wetland, a National Park, a UNESCO World Heritage, and a Biosphere Reserve. This review paper provides a broad overview of the climatic, hydraulic, biogeochemical features, bio-resources, and bio-productivity of the Lake. The interconnectivity between the different environmental components of the lake is presented, highlighting the main characteristics of this vital ecosystem. Its ecosystem consists of a permanent lake bordered by temporary marshes. It is …