Oceanography and Atmospheric Sciences and Meteorology Commons^™

Characterizing El Niño-Southern Oscillation Effects On The Blue Nile Yield And The Nile River Basin Precipitation Using Empirical Mode Decomposition, Justin A. Le, Hesham El-Askary, Mohamed Allali, Eman Sayed, Hani Sweliem, Thomas C. Piechota, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Using new mathematical and data-driven techniques, we propose new indices to measure and predict the strength of different El Niño events and how they affect regions like the Nile River Basin (NRB). Empirical Mode Decomposition (EMD), when applied to Southern Oscillation Index (SOI), yields three Intrinsic Mode Functions (IMF) tracking recognizable and physically significant non-stationary processes. The aim is to characterize underlying signals driving ENSO as reflected in SOI, and show that those signals also meaningfully affect other physical processes with scientific and predictive utility. In the end, signals are identified which have a strong statistical relationship with various physical ...

Effect Of Lockdown On Hcho And Trace Gases Over India During March 2020, Akshansha Chauhan, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

COVID-19 is one of the deadly Epidemics that has impacted people living in more than 200 countries. In order to mitigate the impact of COVID-19, India observed total lockdown in the first phase for a period of 21 days (24 March–13 May 2020), so that social distancing is maintained. However, this sudden decision severely affected the normal life of people. The air quality improved due to lockdown, some relaxation was given in different cities and within some areas in the city where the people were not affected by COVID-19. In this paper, we discuss results of detailed analysis of ...

Global Phylogeography Suggests Extensive Eucosmopolitanism In Mesopelagic Fishes (Maurolicus: Sternoptychidae), D. J. Reese, Jan Y. Poulsen, Tracey Sutton, Paulo A. S. Cost, Mauricio F. Landaeta

Marine & Environmental Sciences Faculty Articles

Fishes in the mesopelagic zone (200–1000 m) have recently been highlighted for potential exploitation. Here we assess global phylogeography in Maurolicus, the Pearlsides, an ecologically important group. We obtained new sequences from mitochondrial COI and nuclear ITS-2 from multiple locations worldwide, representing 10 described species plus an unknown central South Pacific taxon. Phylogenetic analyses identified five geographically distinct groupings, three of which comprise multiple described species. Species delimitation analyses suggest these may represent four species. Maurolicus muelleri and M. australis are potentially a single species, although as no shared haplotypes are found between the two disjunct groups, we suggest ...

Shrinking Salmon: Is Climate Change Linked To Animal Body Size?, Monica D. Bacchus

Scientific Communication News

No abstract provided.

A Modeling Study On The Influence Of Sea-Level Rise And Channel Deepening On Estuarine Circulation And Dissolved Oxygen Levels In The Tidal James River, Virginia, Usa, Ya Wang, Jian Shen

VIMS Articles

The impact of channel deepening and sea-level rise on the environmental integrity of an estuary is investigated using a three-dimensional hydrodynamic-eutrophication model. The model results show that dissolved oxygen (DO) only experienced minor changes, even when the deep channel was deepened by 3 m in the mesohaline and polyhaline regions of the James River. We found that vertical stratification decreased DO aeration while the estuarine gravitational circulation increased bottom DO exchange. The interactions between these two processes play an important role in modulating DO. The minor change in DO due to channel deepening indicates that the James River is unique ...

Tidal Locking And The Gravitational Fold Catastrophe, Andrea Ferroglia, Miguel C. N. Fiolhais

Publications and Research

The purpose of this work is to study the phenomenon of tidal locking in a pedagogical framework by analyzing the effective gravitational potential of a two-body system with two spinning objects. It is shown that the effective potential of such a system is an example of a fold catastrophe. In fact, the existence of a local minimum and saddle point, corresponding to tidally locked circular orbits, is regulated by a single dimensionless control parameter that depends on the properties of the two bodies and on the total angular momentum of the system. The method described in this work results in ...

Plio-Pleistocene Antarctic Ice-Ocean Interactions In The Ross Sea, Catherine Prunella

Graduate Theses and Dissertations

Warm, intermediate-depth Southern Ocean waters are implicated in recent Antarctic ice mass loss. Direct observations of Antarctic Ice Sheet (AIS) retreat are temporally limited, necessitating paleoceanographic records of ocean-ice interactions during past warm climate intervals. Deepsea and ice-proximal sediments record orbitally-paced glacial-interglacial fluctuations in AIS volume during the Plio-Pleistocene (last 5 million years; Ma), but the total contribution of the AIS and the role of ocean heat in these fluctuations remain unresolved. To address the response of Antarctica’s ice sheets to changing ocean temperatures during the Plio-Pleistocene, International Ocean Discovery Program (IODP) Expedition 374 recovered sediments from the Ross ...

Modeling Early Life: Ontogenetic Growth And Behavior Affect Population Connectivity In Gulf Of Mexico Marine Fish, Kelly Vasbinder

Graduate Theses and Dissertations

This dissertation is an examination of growth, behavior, and dispersal during the early life stages of marine fishes in the Gulf of Mexico. Understanding movements of early life stages is a key part of managing exploited fish populations. Position in the water column can impact larval dispersal, since it determines those currents to which larvae are exposed. First, I investigated the relationship between length and age in early life stages of marine fishes. I found that demersal fish taxa tend to be represented by exponential models, while pelagic fish tend to be represented by linear models. I suggest this may ...

Coral Reef Restoration In The Tropical West Atlantic Amid The Covid-19 Pandemic, Linden Cheek

Graduate Theses and Dissertations

Climate change is increasing threats to coasts, both from storm surge and sea level rise. Healthy coral reefs provide reduction in storm surges, wave energy, coastal flooding and everyday erosion, and are found across a variety of spatial scales. Given the state of coral reefs worldwide, active Coral Reef Restoration (CRR) in emerging as a necessary component of coastal protection. CRR can be classified as a nature-based solutions (NbS) for coastal protection that also provides a multitude of ecosystem-based services to both humans and other life. Nearly all literature on coral restoration efforts assume a steady-state of human-ecological interactions, but ...

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman

Chemistry Faculty Publications

This Special Issue provides the first literature collection focused on the development and implementation of unmanned aircraft systems (UAS) and their integration with sensors for atmospheric measurements on Earth. The research covered in the Special Issue combines chemical, physical, and meteorological measurements performed in field campaigns as well as conceptual and laboratory work. Useful examples for the development of platforms and autonomous systems for environmental studies are provided, which demonstrate how careful the operation of sensors aboard UAS must be to gather information for remote sensing in the atmosphere. The work serves as a key collection of articles to introduce ...

Analytical Methods And Critical Analyses Supporting Thermodynamically Consistent Characterizations Of The Marine Co2 System, Jonathan D. Sharp

Graduate Theses and Dissertations

Chemical equilibria describing the unique behavior of gaseous and ionic forms of dissolved carbon dioxide (CO₂) in seawater comprise what is known as the marine CO₂ (or carbonate) system. Observations of the marine CO₂ system with high degrees of accuracy, reproducibility, spatial coverage, and temporal resolution are critical for evaluating natural cycles of carbon within the Earth system, as well as chemical and biological responses to anthropogenic CO₂ emissions.

One component of the CO₂ system is the carbonate ion (CO²−₃), a dissolved ion that is produced when carbonic acid (H₂CO_{3 ...}

Trophic Structure And Sources Of Variation Influencing The Stable Isotope Signatures Of Meso- And Bathypelagic Micronekton Fishes, Travis M. Richards, Tracey Sutton, R. J.David Wells

Marine & Environmental Sciences Faculty Articles

To better understand spatiotemporal variation in the trophic structure of deep-pelagic species, we examined the isotope values of particulate organic matter (POM) (isotopic baseline) and seven deep-pelagic fishes with similar diet compositions but contrasting vertical distributions across mesoscale features in the Gulf of Mexico using stable isotope and amino acid compound-specific isotope analyses. Species examined included four migratory (Benthosema suborbitale, Lepidophanes guentheri, Melamphaes simus, Sigmops elongatus) and three non-migratory zooplanktivorous fishes (Argyropelecus hemigymnus, Cyclothone obscura, Sternoptyx pseudobscura). Isotopic values of POM increased with depth, with meso- and bathypelagic samples characterized by higher δ C and δ N values relative to ...

S3e8: What’S So Cool About Cold-Water Corals?, Ron Lisnet, Rhian Waller

The Maine Question

When people think of coral reefs, they might imagine snorkeling in warm Caribbean waters. But corals also live in the Gulf of Maine and in some of the most extreme environments on Earth, including the Arctic and Antarctic.

Rhian Waller, associate professor of marine sciences and a National Geographic Explorer, dives deep in near-freezing water around the world to learn about what she calls the rainforests of the ocean. She examines how climate change, fishing and oil exploration affect their ecology and reproduction. And she studies the effects that their altered life cycle might have on the marine ecosystem and ...

Potential Effect Of Bio-Surfactants On Sea Spray Generation In Tropical Cyclone Conditions, Breanna L. Vanderplow, Alexander Soloviev, Cayla W. Dean, Brian K. Haus, Roger Lukas, Muhammad Sami, Isaac Ginis

Marine & Environmental Sciences Faculty Articles

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 h, 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. Here we show that surfactants ...

Weather And Climate Summary And Forecast: November 2020 Report, Gregory V. Jones

Linfield University Wine Studies Reports

This report provides a summary of the weather and climate forecast for November 2020. It includes forecast information specific to the Pacific Northwest and the western United States, as well as forecast information for other portions of the United States and abroad.

Mass And Number Size Distributions Of Rbc In Snow And Firn Samples From Pine Island Glacier, West Antarctica, Luciano Marquetto, Susan Kaspari, Jefferson Cardia Simões

Geological Sciences Faculty Scholarship

An extended‐range Single Particle Soot Photometer (SP2) coupled to a Marin‐5 nebulizer was used to measure the refractory black carbon (rBC) mass and number size distributions in 1,004 samples from a West Antarctica snow/firn core. The SP2 was calibrated using Aquadag and a Centrifugal Particle Mass Analyzer for BC particles ranging from 0.5 to 800 fg. Our results indicate a significant contribution of rare, large particles of mass‐equivalent diameter (D_BC) > 500 nm to the total rBC mass (36%), while small particles (D_BC < 100 nm) are abundant but contribute <8% to total rBC mass. We observed a primary mass median diameter of 162 ± 40 nm, smaller than reported for snow in other regions of the globe but similar to East Antarctica rBC size distributions. In addition, we observed other modes at 673, 1,040, and >1,810 nm (uncontained mode). We compared two sets of ...

An Exploratory Study Of General Aviation Visual To Instrument Meteorological Condition Contextual Factors, James Harry Hartman Iii

PhD Dissertations and Master's Theses

The purpose of this dissertation was to bridge the existing literature gap of outdated contextual factor (CF) research through examination and determination of current General Aviation (GA) Title 14 Code of Federal Regulations (CFR) Part 91 visual flight rules (VFR)-into-instrument meteorological condition (IMC) contextual factors. Contextual factors are a multifaceted arrangement of pertinent events or occurrences contributing to pilot accidents in weather-related decision-making errors. A total of 46 contextual factors were identified and examined from the reviewed research literature. The study examined and determined the presence of the 46 contextual factors, frequencies, and manifestations in the GA VFR-into-IMC Aviation ...

Seasonal Grassland Productivity Forecast For The U.S. Great Plains Using Grass-Cast, Melannie D. Hartman, William J. Parton, Justin D. Derner, Darin K. Schulte, William K. Smith, Dannele E. Peck, Ken A. Day, Stephen J. Del Grosso, Susan Lutz, Brian Fuchs, Maosi Chen, Wei Gao

Drought Mitigation Center Faculty Publications

Every spring, ranchers in the drought-prone U.S. Great Plains face the same difficult challenge —trying to estimate how much forage will be available for livestock to graze during the upcoming summer grazing season. To reduce this uncertainty in predicting forage availability, we developed an innovative new grassland productivity forecast system, named Grass-Cast, to provide science-informed estimates of growing season aboveground net primary production (ANPP). Grass-Cast uses over 30 yr of historical data including weather and the satellite-derived normalized vegetation difference index (NDVI)—combined with ecosystem modeling and seasonal precipitation forecasts—to predict if rangelands in individual counties are likely ...

Under-Ice Phytoplankton Blooms: Shedding Light On The "Invisible" Part Of Arctic Primary Production, Mathieu Ardyna, C. J. Mundy, Nicolas Mayot, Lisa C. Matthes, Laurent Oziel, Christopher Horvat, Eva Leu, Philipp Assmy, Victoria Hill, Patricia A. Matrai, Matthew Gale, Igor A. Melnikov, Kevin R. Arrigo

OEAS Faculty Publications

The growth of phytoplankton at high latitudes was generally thought to begin in open waters of the marginal ice zone once the highly reflective sea ice retreats in spring, solar elevation increases, and surface waters become stratified by the addition of sea-ice melt water. In fact, virtually all recent large-scale estimates of primary production in the Arctic Ocean (AO) assume that phytoplankton production in the water column under sea ice is negligible. However, over the past two decades, an emerging literature showing significant under-ice phytoplankton production on a pan-Arctic scale has challenged our paradigms of Arctic phytoplankton ecology and phenology ...

Potential Virus-Mediated Nitrogen Cycling In Oxygen-Depleted Oceanic Waters, M. Consuelo Gazitúa, Dean R. Vik, Simon Roux, Ann C. Gregory, Benjamin Bolduc, Brittany Widner, Margaret R. Mulholland, Steven J. Hallam, Osvaldo Ulloa, Matthew B. Sullivan

OEAS Faculty Publications

Viruses play an important role in the ecology and biogeochemistry of marine ecosystems. Beyond mortality and gene transfer, viruses can reprogram microbial metabolism during infection by expressing auxiliary metabolic genes (AMGs) involved in photosynthesis, central carbon metabolism, and nutrient cycling. While previous studies have focused on AMG diversity in the sunlit and dark ocean, less is known about the role of viruses in shaping metabolic networks along redox gradients associated with marine oxygen minimum zones (OMZs). Here, we analyzed relatively quantitative viral metagenomic datasets that profiled the oxygen gradient across Eastern Tropical South Pacific (ETSP) OMZ waters, assessing whether OMZ ...