Oceanography Commons^™

Ocean Currents Break Up A Tabular Iceberg, Alex Huth, Alistair Adcroft, Olga Sergienko, Nuzhat Khan

Publications and Research

In December 2020, giant tabular iceberg A68a (surface area 3900 km 2 ) broke up in open ocean much deeper than its keel, indicating that the breakage was not immediately caused by collision with the seafloor. Giant icebergs with lengths exceeding 18.5 km account for most of the calved ice mass from the Antarctic Ice Sheet. Upon calv - ing, they drift away and transport freshwater into the Southern Ocean, modifying ocean circulation, disrupting sea ice and the marine biosphere, and potentially triggering changes in climate. Here, we demonstrate that the A68a breakup event may have been triggered by ocean-current …

A Numerical And Machine Learning Investigation Of Water Quality In The Northern Gulf Of Mexico, From Estuaries To Shelf, Yanda Ou

LSU Doctoral Dissertations

In this study, numerical and machine learning (ML) models are developed and adapted to investigate the water quality of the Barataria Estuary and the Louisiana-Texas (LaTex) Shelf in northern Gulf of Mexico. By using a 3-D hydrodynamic ROMS model, the salinity variability of the Barataria Estuary is found highly influenced by the Mississippi River discharges and man-made river diversion systems. The Mississippi River freshwater can intrude into the estuary through the middle and the east passes. Sensitivity tests indicate that decreases in lower estuarine salinity due to the elevated Mississippi River discharges are more apparent than the salinity increases due …

Keys To Genus Of Calanoid Copepods Of China Seas, Chang-Tai Shih, Qing-Chao Chen, Yang-Chi Lan, Shih-Hui Hsiao, Chi-Yu Weng

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Calanoid Copepods Of China Seas, Chang-Tai Shih, Qing-Chao Chen, Yang-Chi Lan, Shih-Hui Hsiao, Chi-Yu Weng

Journal of Marine Science and Technology–Taiwan

Calanoid copepods are a well-recognized taxonomic group of Crustacea. They were already placed, with one cyclopoid (Scribella) and five calanoid (Acartia, Calanus, Candacia, Euchirus (= Euchaeta), and Pontella) genera, under a single taxonomic unit, the Calanidae, by Dana [1]. Giesbrecht and Sars are the two early principal contributors to the taxonomy of Copepoda, including the Calanoida.

Based on the location of the body articulation, Giesbrecht [2] divided copepods into two groups, the Gymnopleoden and Podopleoden. All copepods, characterized by an articulation between the fifth pedigerous (leg-bearing) somite and genital somite, separating the body into an anterior part (prosome) and a …

Calanoid Copepods Of China Seas-Introduction And Acknowledgement, Chang-Tai Shih, Qing-Chao Chen, Yang-Chi Lan, Shih-Hui Hsiao, Chi-Yu Weng

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Caviar Of The Pacific: Palolo Fishing Today And Its Association With Coral Reef Health, Emma Letti Lee

Independent Study Project (ISP) Collection

Palolo is a traditional delicacy of Samoa. It is the reproductive part of a marine worm that is released twice a year, October and November in Samoa, making palolo season a culturally significant time. Coral reefs, the palolo worm’s habitat, is under a plethora of environmental threats, which is an extremely prevalent concern for Pacific Islanders. Hundreds of palolo harvesters walking on corals twice a year adds extra pressure on coral reefs. Despite these vulnerabilities, prices of palolo are soaring year by year, while there is little to no research about the palolo worm and documentation of current harvesting practices …

Evaluating The Impact Of Submarine Groundwater Discharge On Nutrients And Trace Elements In Coastal Systems: The Examples Of The Tuckean Swamp (Australia) And The Mississippi Sound (Usa), Amy Moody

Dissertations

Submarine groundwater discharge (SGD) is the advective flow of both fresh terrestrial groundwater and recirculating seawater through aquifer sediments, which is released into the coastal ocean. In this dissertation, I evaluated the impact of SGD on the distributions and input of trace metals and nutrients. In the Tuckean Swamp, an estuary in Australia dominated by coastal acid sulfate soils, I determined the impact of groundwater on Ba and U during the flood season, when the local aquifer is flushed out after a rapid increase in water table elevation. For Ba and U, groundwater contributed up to 18 and 66 % …

Laguncularia Racemosa Top-Layer Sediment Microorganism Makeup In Relation To Differing Levels Of Perceived Anthropogenic Impact In Bocas Del Drago, Bocas Del Toro, Panama, Gabrielle Glendening

Independent Study Project (ISP) Collection

As mangrove forests are destroyed by human factors across the earth, many crucial ecological processes that take place in these systems of trees are obstructed. One of the most important roles played by mangroves is their ability to sequester carbon in the sediment, as this storage of carbon helps diminish atmospheric warming. Many sediment microorganisms help in this process of carbon sequestration and play various other vital roles in mangrove ecosystems. Microorganisms in marine sediments can be used to assess the health of the surrounding environment. Past research has found significant differences in sediment microorganism composition, abundance, and diversity in …

Sources And Cycling Of Neodymium And Rare Earth Elements In The Arctic Amerasian Basin And Bering Sea, Brian D. Duggan

Theses and Dissertations

The isotopic composition of dissolved neodymium (¹⁴³Nd/¹⁴⁴Nd, expressed as εNd) behaves quasi-conservatively in the ocean and has been used as a palaeoceanographic tracer of ocean circulation. The εNd value of water masses is acquired—and often altered—during interaction with sediments along the margins; however, the processes involved in seawater εNd acquisition remains poorly characterized and quantified. Here we report the results of 349 Nd isotope and 354 rare earth element (REE) concentration measurements from 27 water column profiles across the Bering shelf and through the Arctic Amerasian Basin collected during U.S. Arctic GEOTRACES cruise HLY1502 (GEOTRACES section …

Arctic Ocean And Subarctic Seas Dynamics In A Changing Climate, Sarah B. Hall

Theses and Dissertations

Salinity is the primary determinant of the Arctic Ocean’s vertical density stratification in the upper ocean, which has major implications on the ocean’s physical dynamics alongside a period of rapidly declining sea ice. In recent decades, the Arctic’s freshwater content (FWC) has increased as a result of the accumulation of freshwater source inputs. Additional freshwater exported to the North Atlantic may hinder overturning processes that are vital to the regulation of global climate. This dissertation employs in situ measurements, satellite observations, and ocean model simulations to better understand salinity and freshwater changes in the Arctic Ocean during this changing climate. …

Tropical Cyclone And Ocean-Atmosphere Interactions In The Gulf Of Mexico, Emily Nichole Eley

Theses and Dissertations

The Gulf of Mexico (GoM) is historically a favorable region for the formation, maintenance and intensification of tropical cyclones that frequently evolve into powerful hurricanes. These natural disasters threaten the basin’s innate habitat and wildlife diversity, and the expansive coastal economies and communities. The dominant ocean circulation feature in the GoM is the Loop Current System (LCS) which includes the Loop Current (LC) and its associated mesoscale eddy field. The LC originates at the Yucatán Channel, loops anticyclonically into the basin, and ends at the Florida Straits; further it produces both anticyclonic and cyclonic eddies. The existence of the LCS …

Sea Level Rise Estimation On The Pacific Coast From Southern California To Vancouver Island, Xiaoxing He, Jean-Philippe Montillet, Rui Fernandes, Timothy I. Melbourne, Weiping Jiang, Zhengkai Huang

Geological Sciences Faculty Scholarship

Previous studies have estimated the sea level rise (SLR) at various locations on the west coast of the USA and Vancouver Island in Canada. Here, we construct an entire SLR profile from Vancouver Island in the Pacific Northwest to San Diego in Southern California. First, we process global navigation satellite system (GNSS) measurements at 405 stations blanketing the whole coast to generate a profile of vertical land motion (VLM) known to bias century-long tide gauge (TG) measurements recording relative SLR (RSLR). We are then able to estimate the absolute SLR (ASLR) by correcting the SLR with the VLM. Our study …

Climate Warming Amplifies The Frequency Of Fish Mass Mortality Events Across North Temperate Lakes, Simon P. Tye, Adam M. Siepielski, Andrew Bray, Andrew L. Rypel, Nicholas B.D. Phelps, Samuel B. Fey

Biological Sciences Faculty Publications and Presentations

Recent increases of animal mass mortality events have coincided with substantial changes in global climate. Yet, tractable approaches that predict how climate change will accentuate occurrences of these ecological catastrophes remain nascent. We compiled one of the most comprehensive datasets of lentic fish mortality events, thermal tolerances of affected families, and 1.2 million air and water temperature profiles across 8891 north temperate lakes in North America. Temperature extremes within and across lakes were strongly associated with the three most frequent cause types (infectious agents, summerkills, winterkills). Thermal tolerances mediated the lethality of direct thermal stress, but mortalities of warm- and …

Purification Of Artepillin C (Arc) With Anticancer Activities From Supercritical Co2-Ethanol Extracts Of Brazilian Green Propolis By Using Adsorption Column Chromatography, Lin-Hsiang Chuang, Wen-Chin Chen, Wen Pei, Ming-Hsi Chuang, Todd Hsu, Po-Chao Chuang

Journal of Marine Science and Technology–Taiwan

Phenolic compounds with varying phenolic structures are present in both terrestrial and marine organisms. Artepillin C (ARC) is a prenylated phenolic compound produced specifically in Brazilian green propolis. Earlier studies have demonstrated the potential of ARC as a dietary supplement for cancer prevention due to its ability to suppress tumor growth and metastasis. Here we report the development of an effective adsorption chromatography combined with supercritical CO2 extraction for the massive purification of ARC. A mixture of supercritical CO2 and ethanol extract of Brazilian green propolis was passed through a stainless chromatographic column packed with protruding metals at 4,000 psi …

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 …