Oceanography and Atmospheric Sciences and Meteorology Commons^™

Maine Won't Wait One-Year Progress Report, 2021, Maine Climate Council, Governor's Office Of Policy Innovation And The Future, Ivan Fernandez, Stephen Dickson, Susie Arnold, Cassaundra Rose, Troy Jackson, Russell Black, Nicole Grohski, Amanda Collamore, Linda Bacon, Brian Beal, Sean Birkel, Alix Contosta, Amanda Cross, Adam Daigneault, Phillips Demaynadier, Susan Elias, Glenn Hodgkins, Joe Kelley, Glen Koehler, Rebecca Lincoln, Pamela Lombard, Brandfield Lyon, Nicole Price, Jonathan Rubin, Joseph Salisbury, Peter Slovinsky, Alyssa Soucy, Robert Steneck, Sally Stockwell, Richard Wahle, Aaron Weiskittel, Carl Wilson

General University of Maine Publications

This document, an “Maine Climate Science Update 2021”, is an interim communication to the Maine Climate Council and the public about the ongoing work of the scientific community and recent events associated with climate change. It is divided into three sections: (1) current events that reflect the acceleration of extreme weather events in Maine and elsewhere with possible connections to climate change; (2) noteworthy scientific reports with national and international scope released in 2021; and (3) examples of recent peer-reviewed publications from the ongoing work of the scientific community to understand climate change in Maine.

Forced And Unforced Permafrost Changes In The Northern Hemisphere During 1901-2100, Hong Guo

Graduate Theses and Dissertations

Permafrost regions are very sensitive to rapid changes in climate and environment. In recent decades, there has been growing interest to better understand the permafrost degradation over the Northern Hemisphere in the context of human-induced climate change. Understanding permafrost dynamics is not only important for infrastructure but also for environmental protection in cold regions. In-situ permafrost measurements are important for assessing permafrost conditions. However, direct permafrost observations are sparse and asymmetrical in both spatial and temporal coverage. Active layer thickness (ALT) modeling is another approach that can overcome many of these limitations, but the models have large uncertainty in predicting …

The Contributions Of Dynamical And Diabatic Processes Preceding And Accompanying Major Greenland Ice-Melt Events, Scott Feldman

Legacy Theses & Dissertations (2009 - 2024)

Extratropical cyclones and/or short-wave disturbances can reinforce Greenland blocking through upper-level flow amplification and can increase poleward heat and moisture transport into the Arctic. Increased poleward heat and moisture transport into the Arctic may enhance Greenland ice melt during the spring, summer, and fall months. The need to better understand the underlying dynamical and diabatic processes that may contribute to Greenland ice melt motivates this thesis. The purpose of this thesis is to investigate: 1) the role of advective warming due to poleward heat and moisture transport into the Arctic in facilitating Greenland ice melt, 2) the role of adiabatic …

The Impacts Of Transported Wildfire Smoke Aerosol On Surface Air Quality In New York State, Wei-Ting Hung

Legacy Theses & Dissertations (2009 - 2024)

In New York State (NYS), summertime long-range transported smoke plumes and high fine mode particulate matter (PM2.5) concentration during the smoke episodes have been reported. Since the frequency, intensity, and burned area of wildfires over Northern America have increased in recent years, the contribution of transported smoke aerosols to local air quality could become more significant. This study aimed to characterize the transport of smoke aerosols and quantify their impacts on the local air quality over NYS. A case study of a transported smoke event in mid-August of 2018 and multi-year analysis of the smoke cases during the summer seasons …

A Global Agenda For Advancing Freshwater Biodiversity Research, Alain Maasri, Sonja C. Jähnig, Hendrik Freitag, 93 Co-Authors

Biology Faculty Publications

Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.

Continuous Turbidity Data Used To Compute Constituent Concentrations In The South Loup River, Nebraska, 2017–18, David L. Rus, Brenda K. Densmore

United States Geological Survey: Water Reports and Publications

The South Loup River in central Nebraska has been impaired by bacteria since at least 2004, which has resulted in the river not meeting its intended use as a recreational waterway. As part of a strategy for reducing the bacterial load in the river, the United States Geological Survey (USGS), in cooperation with the Lower Loup Natural Resources District, made continuous estimates of Escherichia coli (E. coli) and nutrient concentrations during seasonal monitoring at the South Loup River at Saint Michael, Nebraska, during 2017–18. Continuous turbidity data were collected from mid-April through October in 2017 and 2018 …

Analysis Of Titan's Fluvial Features Using Numerical Modeling, Jeshurun Horton

Mechanical Engineering Undergraduate Honors Theses

River channels have been observed near the Huygens probe landing site on the surface of Titan, along with evidence of rounded water ice boulders transported through fluid flow. Evidence near the landing site suggests active flow of liquid methane, which has motivated the study of the effects of sediment load and channel sizes on Titan’s fluvial features. A numerical model is used to determine the viscosity, flow velocity, and critical boulder transport diameter based on channel size, slope, and a range of sediment concentrations. This model achieves two ends: first, observed boulder diameters are used to determine the ideal channel …

Iron Geochemistry Across An Estuary-To-Coastal Gradient, Lissett G. Diaz

Honors Theses

Iron is a ubiquitous earth element that participates in biogeochemical processes that occur in marine sediments. Microorganisms utilize iron for many purposes, including cell growth, conserving energy, and for maintaining metabolic activity. In coastal sedimentary settings, understanding the redox reactions involving ferric iron, Fe³⁺, and ferrous iron, Fe²⁺, in its solid phase and pore-water phases, respectively, enable an appreciation of biogeochemical transformations occurring in the coastal zone. In this study, iron concentrations in sediment of ranging permeability were determined at four stations marking an estuary-coast transition zone in Singleton Swash in Myrtle Beach, South Carolina. The …

Changes In The Abundance And Distribution Of Benthic Mollusks In Polluted Sediments Of A Shallow Subtropical Estuary, Rachael Holtsberg Stark

Theses and Dissertations

The Indian River Lagoon (IRL) has been degraded by decades of eutrophication, and has accumulated an abundance of fine-grained, organic-rich sediments (muck). To quantify the impacts of organic sediments and environmental dredging, benthic mollusks were chosen to serve as bioindicators of environmental change, sediment health, and water quality. Data on species richness, biodiversity, and abundances was collected alongside sediment and water quality data before, during and after dredging. Organic sediment content was found to have an inverse logarithmic relationship benthic mollusk biodiversity, species richness, and abundance. Sediments low in percent organic content (0.7% to 6.1%) were located near the adjacent …

Development And Optimization Of A Denitrification System To Promote Biological Nutrient Removal In A Subtropical Estuary, Abigail Gering

Theses and Dissertations

Eutrophication impacts coastal ecosystems globally and triggers phytoplankton and algal blooms, leading to an increase in oxygen demand in the water column and sediments due to various biogeochemical processes. Naturally, biological nitrification, denitrification and anammox processes help to remove nitrogen predominately by nitrifying and denitrifying bacteria in the sediments. Eutrophic systems have increased nutrient and organic matter loading and are prone to the accumulation of ‘muddy’, fine-grained, organic-rich sediments (locally termed ‘muck’) that may not be able to support high enough populations of these bacteria, and therefore, may not adequately support nitrification/denitrification processes that would otherwise remove nitrogen. To decrease …

Validation Of Landsat 8 High Resolution Sea Surface Temperature Using Surfers, Quinton Vanhellemont, Robert J. W. Brewin, Philip J. Bresnahan, Tyler Cyronak

Marine & Environmental Sciences Faculty Articles

Nearshore coastal waters are highly dynamic in both space and time. They can be difficult to sample using conventional methods due to their shallow depth, tidal variability, and the presence of breaking waves. High resolution satellite sensors can be used to provide synoptic views of Surface Temperature (ST), but the performance of such ST products in the nearshore zone is poorly understood. Close to the shoreline, the ST pixels can be influenced by mixed composition of water and land, as a result of the sensor’s spatial resolution. This can cause thermal adjacency effects due to the highly different diurnal temperature …

Snook (Centropomus Undecimalis) Behavior And Accelerometer Telemetry In The Bahia Grande Of Texas, Jonathan Truett Cawlfield

Theses and Dissertations

There has been very little study of the Texas population of snook. No studies have have looked at behavior in the Texas snook population. In this study we look at behavioral patterns and activity level in Lower Laguna Madre snook utilizing accelerometer telemetry tags. Twenty-one common snook were surgically implanted with tags and monitored from summer and fall of 2019 until September 2020. The accelerometer tags which sum acceleration over the x, y, and z planes calculated (ODBA) which was used to estimate behavior. This behavior was then compared with environmental data like diel period, tidal period, water temperature, and …

Assessment And Monitoring Of Deltaic Wetlands And Fluvial Systems: Refining And Validating A Multimetric Index Of Resaca Ecosystem Health, David Lecusay Jr.

Theses and Dissertations

Resacas are ancient distributary channels of the lower Rio Grande River historically serving as floodwater drainage pathways onto the Laguna Madre, Texas. Resacas provide numerous ecosystem services and critical habitat for many species. Mainly influenced by urbanization, integrating a multimetric index for assessing and monitoring resaca ecosystem health is required for adaptive management. The Resaca Health Index (RHI) integrates structural and functional components: (1) nonredundant metrics describing fish communities (Fish Community Index); (2) Trophic State Index derived from Secchi depth; (3) decay constant from riparian vegetation leaf litter decomposing in the water column; and (4) a riparian quality index based …

Managing Water Resource And Land Use In Lower Rio Grande Valley Of South Texas Using A Groundwater Vulnerability Model, Leslie Soto Sanchez

Theses and Dissertations

The Lower Rio Grande Valley (LRGV) has three Metropolitan Statistical Areas. These are Brownsville-Harlingen, Laredo, and McAllen-Edinburg-Mission, the latter with a population of around 1 million people and had an estimated growth of 62% from the period of 2010-2018 (Texas State Data Center, 2020). Low precipitations, intensive agricultures as well as growth in the manufacturing and tourism industries have resulted in an increasing concern of scarce water supply especially the region relies primarily on a single water source, the Rio Grande River. These circumstances could potentially disrupt economic development, negatively affecting the local manufacturing industry, agriculture, and the community. With …

Comparison Of Seasonal Foes And Fbes Occurrence Rates Derived From Global Digisonde Measurements, Dawn K. Merriman, Omar A. Nava, Eugene V. Dao, Daniel J. Emmons Ii

Faculty Publications

A global climatology of sporadic-E occurrence rates (ORs) based on ionosonde measurements is presented for the peak blanketing frequency, fbEs, and the ordinary mode peak frequency of the layer, foEs. ORs are calculated for a variety of sporadic-E frequency thresholds: no lower limit, 3, 5, and 7 MHz. Seasonal rates are calculated from 64 Digisonde sites during the period 2006–2020 using ionograms either manually or automatically scaled with ARTIST-5. Both foEs and fbEs ORs peak in the Northern Hemisphere during the boreal summer, with a decrease by roughly a factor of 2–3 in fbEs rates relative to foEs rates without …

Shipboard Lidar As A Tool For Remotely Measuring The Distribution And Bulk Characteristics Of Marine Particles, Brian Leigh Collister

OES Theses and Dissertations

Light detection and ranging (lidar) can provide remote estimates of the vertical distribution of optical properties in the ocean, potentially revolutionizing our ability to characterize the spatial structure of upper ocean ecosystems. However, challenges associated with quantifying the relationship between lidar measurements and biogeochemical properties of interest have prevented its adoption for routinely mapping the vertical structure of marine ecosystems. To address this, we developed a shipboard oceanographic lidar that measures attenuation (α) and linear depolarization (δ) at scales identical to those of in-water optical and biogeochemical measurements. The instrument’s ability to resolve the distribution of optical and biogeochemical properties …

Phytoplankton Community Response To Upwelling Events: Distribution And Abundance Investigated Using Genomic Methods, Sveinn V. Einarsson

OES Theses and Dissertations

Upwelling events are known to support blooms of phytoplankton, important primary producers at the base of the oceanic food web. Phytoplankton community structure changes in response to upwelling support higher trophic level growth and increased efficiency of carbon export from the euphotic zone. While these events occur globally, this study examined upwelling in coastal regions, where alongshore winds can drive Ekman transport and upwelling of deeper waters. The two upwelling regimes examined were the California Current System and the Alaskan Beaufort Sea. In the California Current System, the relative diatom community composition was examined using 18S sequencing to determine how …

Spatiotemporal Variations Of Precipitation And Climate-Resilient Structure Design In Virginia, Xiaomin Yang

Civil & Environmental Engineering Theses & Dissertations

How to consider effects of climate change on the design and management of hydrology related infrastructure is crucial but remains a challenge for sustaining resilient society. To address this challenge, existing hydrologic design procedures may need to be revised and/or redeveloped to take into account the precipitation non-stationarity resulting from climate change. Using the state of Virginia as a testbed and advanced statistical techniques such as nonparametric test, spatial autocorrelation, linear regression, distribution fitting, and spatial interpolation, this dissertation developed an innovative framework to detect the historical spatiotemporal variations of various precipitation characteristics, namely maximum precipitation intensity, precipitation amount, simple …

Estimating The Risk Of Future Plastic Marine Debris Resulting From The Urban Coastal Built Environment, Kelly C. Jones

OES Theses and Dissertations

The growing urban built environment in the coastal zone poses an unknown risk to the marine biosphere as a source of marine debris. Plastic, since its introduction in the mid- 1900s, is now used in nearly all aspects of human life. Growth in human population and urbanization in coastal zones has resulted in the accumulation of large stocks of plastic in the coastal built environment, and these stocks are still growing exponentially. The coastal zone is exposed to a number of hazards including storms, tsunamis, and sea level rise, and most of these hazards are expected to change in the …

Atlantic Ocean Variability And European Alps Winter Precipitation, Giuseppe Formetta, Jonghun Kam, Sahar Sadeghi, Glenn Tootle, Thomas Piechota

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Winter precipitation (snowpack) in the European Alps provides a critical source of freshwater to major river basins such as the Danube, Rhine, and Po. Previous research identified Atlantic Ocean variability and hydrologic responses in the European Alps. The research presented here evaluates Atlantic Sea Surface Temperatures (SSTs) and European Alps winter precipitation variability using Singular Value Decomposition. Regions in the north and mid-Atlantic from the SSTs were identified as being tele-connected with winter precipitation in the European Alps. Indices were generated for these Atlantic SST regions to use in prediction of precipitation. Regression and non-parametric models were developed using the …

Statistical Spectral Characteristics Of Three-Dimensional Winds In The Mesopause Region Revealed By The Andes Lidar, Qian Li, Alan Z. Liu, Shao Dong Zhang, Chun Ming Huang, Kai Ming Huang, Yun Gong, Quan Gan, Yan Ying Yan, Hang Liu

Publications

By analyzing data recorded at the Andes Lidar Observatory in Cerro Pachon, Chile (30.3°S, 70.7°W) from May 2014 to July 2019, we investigated the fundamental features of three-dimensional wind and temperature spectra. The vertical wavenumber spectral amplitudes of horizontal winds show obvious seasonal variations that are closely related to the seasonal variations in the source and background winds. The wavenumber spectral slopes of the horizontal winds are systematically less negative than −3, with mean values of −1.96 and −2.18 for zonal and meridional winds, respectively. The zonal and meridional wind frequency spectra have mean slopes of −1.37 and −1.56, respectively; …

Low Impact Sampling Of Speleothems – Reconciling Scientific Study With Cave Conservation, Claire L.V. Macgregor, John C. Hellstrom, Jon D. Woodhead, Russell N. Drysdale, Rolan S. Eberhard

International Journal of Speleology

Speleothems are increasingly valued as important paleoclimate archives and yet the removal of samples from caves can come at a cost to natural heritage, impacting delicate environments with limited mechanisms for repair. Conservation of cave environments is a key responsibility for scientists and, with this in mind, we are working to develop and implement techniques that allow us to extract valuable scientific data, with minimal impact. In this study, we demonstrate the utility of low-impact reconnaissance dating surveys on caves in southern Tasmania and southwest Western Australia as a precursor to the removal of stalagmites for paleoclimate reconstruction. Small flakes …

Dioxins Contamination In Sediment And Their Effect On Accumulation In The Portuguese Oyster (Crassostrea Angulata) And White Shrimp (Litopenaeus Vannamei), Yin-Yu Chen, Yu-Sheng Wu, Hsiang-Yin Chen, Zhen-Hao Liau, Fan-Hua Nan

Journal of Marine Science and Technology

This research aims to realize whether the dioxin accumulation in the oyster and white shrimp which were cultured in the dioxin pollutant sediment. This presented evidence indicated that dioxin was detected in all experimental groups with high concentration accumulated in experiment animals. Observation of the concentration, the PCDD/F, 2,3,7,8-T4CDD was with high concentration in the sediment and declined with the time elapsed. Detection of the dioxin accumulated in the animal, the accumulative maximum amounts was in the oyster as 3746.16 (pg-TEQ/g d.w.) and in the shrimp as 705.44 (pg-TEQ/g d.w.). The detected amount of dioxin in the supernatant was quite …

A Meshless Method With Radial Basis Function For Solving Unsaturated Flow In Heterogeneous Porous Media, Cheng-Yu Ku, Chih-Yu Liu, Wei-Po Huang, Jing-En Xiao

Journal of Marine Science and Technology

This paper presents a study for solving unsaturated flow in heterogeneous porous media using the meshless method with the radial basis function (RBF). For modeling the nonlinear hydrological process in unsaturated zone, an exponential model is introduced in the Richards equation such that we may obtain the linearized Richards equation. We adopt the multiquadric function as the RBF in the meshless method for solving the linearized Richards equation. For simulating the unsaturated flow problems in layered heterogeneous soils, the flux and the head must satisfy the continuity condition at the interface. Several examples are carried out for modeling the hydrological …

Catch Rates And Distribution Pattern Of The Silky Shark, Carcharhinus Falciformis, Caught By The Taiwanese Large-Scale Longline Fishery In The Indian Ocean, Chia Yun Li, Xing-Han Wu, Shang Yin Vanson Liu, Sheng-Ping Wang, Wen-Pei Tsai

Journal of Marine Science and Technology

The silky shark, Carcharhinus falciformis, is widely distributed in tropical and temperate waters, and it is a common bycatch species for tuna longline fisheries. This study examined the distribution of and presents relative abundance indices of the silky shark in the Indian Ocean by using logbook and observer data from the Taiwanese large-scale tuna longline fishery between 2005 and 2019. Due to the high zero catch rate, a zero-inflated negative binomial (ZINB) model was used to standardize catch per unit effort. Due to a lack of detailed targeting information, the fishery strategy was identified by using cluster analysis based on …

Accumulation And Bioavailability Of Heavy Metals (Cadmium, Chromium, Nickel, Lead And Zinc) In Water And Sediment Samples In The Musa Creek, Northwest Coasts Of The Persian Gulf, Saghafiankhoo Sedigheh, Battaleb-Looie Sedigheh, Amanipoor Hakimeh, Dravishi Khatooni Javad, Ghanemi Kamal

Journal of Marine Science and Technology

The current study aimed to investigate the total concentrations of heavy metals in water and sediment samples as well as their bioavailability in sediments of Musa Creek. Twenty samples including 10 sediments and 10 water samples were collected from 10 stations. The concentration of heavy metals was measured using inductively coupled plasma–mass spectrometry. The bioavailability of heavy metals was carried out by first step of Tessier sequential extraction method so called single extraction in the manuscript. The results showed that the mean concentrations of cadmium, chromium, nickel, and zinc in water samples was 0.17, 7.44, 43.80, and 8.85 µg/L, respectively. …

Parametric Analyses Of The Dynamic Response And Fatigue Life Of A Compliant Vertical Access Riser With Internal Flow, Fuheng Li, Haiyan Guo, Xiaomin Li, Zhen Liu, Honglu Gu, Peng Cui

Journal of Marine Science and Technology

Subsea interventions on wellheads can be directly performed from a platform using a compliant vertical access riser (CVAR), thereby incurring tremendous economic benefits. The dynamic response and the fatigue damage of a CVAR subjected to regular waves are important for assessing its application feasibility. Therefore, a reasonable numerical model is presented for assessing the damage to a CVAR considering the internal flow using the slender rod theory. The finite element method combined with a Newmark-β scheme is employed to discretize the equations and update the time integration. The Palmgren-Miner rule is applied for fatigue life prediction, focusing on the wave-induced …

Using The Inverse Method To Investigate Flow Models For Mixed Convection Of Annular Finned Tube Heat Exchanger, Han-Taw Chen, Cheng-Hui You, Wei-Lun Hsu, Jiang-Ren Chang

Journal of Marine Science and Technology

The inverse heat conduction method (IHCM) and three-dimensional (3D) computational fluid dynamic (CFD) in combination with are used to select the appropriate flow model and near-wall treatment for the mixed convection of the annular finned tube heat exchanger. Thus, the numerical results obtained by all k-ε models and near-wall treatments are yielded for 4 m/s ≤ Va ≤ 5 m/s. First, IHCM combined with is applied to estimate and Q values. The obtained estimates of and Q are used as reference values for CFD. The results show that the Tk and results obtained by the standard (STD) k-ε model with …

Prediction Of Remaining Useful Life Of Wind Turbine Shaft Bearings Using Machine Learning, Jinsiang Shaw, Bingjie Wu

Journal of Marine Science and Technology

Wind turbines are a major trend in the current green energy market. Wind energy is abundant, and if utilized properly, can result in significant reductions in carbon emissions. Therefore, the development of wind power systems is urgently required. However, wind turbines are mainly built in unmanned areas. Regular inspections require substantial manpower and material resources, and doubts regarding the accuracy of the inspected data may occur. Therefore, it is necessary to establish an automatic diagnostic method for determining the remaining useful life (RUL) of a wind turbine to facilitate predictive maintenance. In this study, a multi-class support vector machine (SVM) …

Supply Chain Management For Superyacht Construction In Taiwan, Chun Pong Wong

Journal of Marine Science and Technology

In the last 20 years, Taiwan’s superyacht construction industry has performed well in the global market; however, numerous yacht builders still practice traditional supply chain management (SCM), which is often inefficient and regularly leads to time and cost overruns. This study aimed to answer two research questions: 1) what SCM challenges does the superyacht construction industry face? and 2) what SCM strategies and practices should be adopted to improve the efficacy and profitability of superyacht construction companies?

Numerous studies have explored supply chains (SCs) and SCM, but few have focused on the superyacht construction industry. Superyacht construction projects are highly …