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Articles 1111 - 1140 of 2652

Full-Text Articles in Oceanography

Gelatinous Zooplankton Abundance And Benthic Boundary Layer Currents In The Abyssal Northeast Pacific: A 3-Yr Time Series Study, Kenneth Smith, Christine Huffard, Paul Mcgill, Alana Sherman, Thomas Connolly, Susan Von Thun, Linda Kuhnz Jan 2019

Gelatinous Zooplankton Abundance And Benthic Boundary Layer Currents In The Abyssal Northeast Pacific: A 3-Yr Time Series Study, Kenneth Smith, Christine Huffard, Paul Mcgill, Alana Sherman, Thomas Connolly, Susan Von Thun, Linda Kuhnz

Faculty Research, Scholarly, and Creative Activity

Gelatinous zooplankton are prominent fauna in the deep ocean, especially in the water column associated with the sea floor. This interface zone, the benthic boundary layer, is critical to biogeochemical exchanges between pelagic and benthic communities. A conspicuous member of this benthic boundary layer community in the abyssal Northeast Pacific (Sta. M; 4000 m depth) is the hydrozoan medusa, Benthocodon pedunculata. A 3-year time-series study was conducted of B. pedunculata from October 2014 to November 2017 using an autonomous time-lapse camera system and acoustic current meter deployed on the sea floor. Remotely operated vehicle benthic video transects and collections were …


Arctic Sea Ice Predictability And Prediction, Chao-Yuan Yang Jan 2019

Arctic Sea Ice Predictability And Prediction, Chao-Yuan Yang

Legacy Theses & Dissertations (2009 - 2024)

Arctic sea ice has experienced dramatic changes for the past few decades, which has profound global climatic effects, or feedbacks. The drastic changes and their associated impacts have led to increasing demand for sea ice predictions from a wide scope of stakeholders across seasonal to decadal timescales. Thus, it is important to improve our understanding of sea ice predictability on different timescales and our ability to predict Arctic sea ice.


Surface Waves Over Currents And Uneven Bottom, Alan Compelli, Rossen Ivanov, Calin I. Martin, Michail D. Todorov Jan 2019

Surface Waves Over Currents And Uneven Bottom, Alan Compelli, Rossen Ivanov, Calin I. Martin, Michail D. Todorov

Articles

The propagation of surface water waves interacting with a current and an uneven bottom is studied. Such a situation is typical for ocean waves where the winds generate currents in the top layer of the ocean. The role of the bottom topography is taken into account since it also influences the local wave and current patterns. Specific scaling of the variables is selected which leads to approximations of Boussinesq and KdV types. The arising KdV equation with variable coefficients, dependent on the bottom topography, is studied numerically when the initial condition is in the form of the one soliton solution …


The Links Between Gulf Of Mexico Seafloor Characteristics And Petroleum Hydrocarbons Following The Deepwater Horizon Oil Spill, Kimberly J. Schindler Jan 2019

The Links Between Gulf Of Mexico Seafloor Characteristics And Petroleum Hydrocarbons Following The Deepwater Horizon Oil Spill, Kimberly J. Schindler

Theses and Dissertations--Earth and Environmental Sciences

The Gulf of Mexico (GoMx) is among the most productive regions for offshore oil and natural gas recovery. In 2010, the Deepwater Horizon (DWH) drilling rig exploded, burned for three days, sank, and released over 4 million barrels of oil in the subsequent 84 days before it was capped. Some oil was buoyant enough to float to the ocean surface, where some was removed via a myriad techniques. Importantly, a plume of oil remained suspended in the water column at approximately 1,100 m water depth, where it drove a marine snow event, and deposited large quantities of oil on the …


Modeling Ocean Eddies On Antarctica's Cold Water Continental Shelves And Their Effects On Ice Shelf Basal Melting, Stefanie L. Mack, Michael S. Dinniman, John M. Klinck, Dennis J. Mcgillicuddy, Laurence Padman Jan 2019

Modeling Ocean Eddies On Antarctica's Cold Water Continental Shelves And Their Effects On Ice Shelf Basal Melting, Stefanie L. Mack, Michael S. Dinniman, John M. Klinck, Dennis J. Mcgillicuddy, Laurence Padman

CCPO Publications

Changes in the rate of ocean‐driven basal melting of Antarctica's ice shelves can alter the rate at which the grounded ice sheet loses mass and contributes to sea level change. Melt rates depend on the inflow of ocean heat, which occurs through steady circulation and eddy fluxes. Previous studies have demonstrated the importance of eddy fluxes for ice shelves affected by relatively warm intrusions of Circumpolar Deep Water. However, ice shelves on cold water continental shelves primarily melt from dense shelf water near the grounding line and from light surface water at the ice shelf front. Eddy effects on basal …


Delivering Sustained, Coordinated, And Integrated Observations Of The Southern Ocean For Global Impact, Louise Newman, Petra Heil, Rowan Tebilco, Katsuro Katsumata, Andrew Constable, Esmee Van Wijk, Karen Assmann, Joana Beja, Phillippa Bricher, Richard Coleman, Daniel Costa, Steve Diggs, Riccardo Farneti, Sarah Fawcett, Sarah T. Gille, Katharine R. Hendry, Sian Henly, Eileen Hofmann, Ted Maksym, Matthew Mazloff, Andrew Meijers, Michael M. Meredith, Sebastien Moreau, Burcu Ozsoy, Robin Robertson, Irene Schloss, Oscar Schofield, Jiuxin Shi, Elisabeth Sikes, Inga J. Smith, Sebastiaan Swart, Anna Wahlin, Guy Williams, Michael J. M. Williams, Laura Herraiz-Borreguero, Stefan Kern, Jan Lieser, Robert A. Massom, Jessica Melbourne-Thomas, Patricia Miloslavich, Gunnar Spreen Jan 2019

Delivering Sustained, Coordinated, And Integrated Observations Of The Southern Ocean For Global Impact, Louise Newman, Petra Heil, Rowan Tebilco, Katsuro Katsumata, Andrew Constable, Esmee Van Wijk, Karen Assmann, Joana Beja, Phillippa Bricher, Richard Coleman, Daniel Costa, Steve Diggs, Riccardo Farneti, Sarah Fawcett, Sarah T. Gille, Katharine R. Hendry, Sian Henly, Eileen Hofmann, Ted Maksym, Matthew Mazloff, Andrew Meijers, Michael M. Meredith, Sebastien Moreau, Burcu Ozsoy, Robin Robertson, Irene Schloss, Oscar Schofield, Jiuxin Shi, Elisabeth Sikes, Inga J. Smith, Sebastiaan Swart, Anna Wahlin, Guy Williams, Michael J. M. Williams, Laura Herraiz-Borreguero, Stefan Kern, Jan Lieser, Robert A. Massom, Jessica Melbourne-Thomas, Patricia Miloslavich, Gunnar Spreen

CCPO Publications

The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical, and ecological systems, which makes recent observed changes to this system cause for global concern. The enhanced understanding and improvements in predictive skill needed for understanding and projecting future states of the Southern Ocean require sustained observations. Over the last decade, the Southern Ocean Observing System (SOOS) has established networks for enhancing regional coordination and research community groups to advance development of observing system capabilities. These networks support delivery of the SOOS 20-year vision, which is to develop a circumpolar system that ensures time …


Resuscitation Of Microalgae From Mississippi River Plume Sediments, Chase C. Chaplin, Marnie Tabor, Israel A. Marquez, Kanchan Maiti, Jeffrey W. Krause Jan 2019

Resuscitation Of Microalgae From Mississippi River Plume Sediments, Chase C. Chaplin, Marnie Tabor, Israel A. Marquez, Kanchan Maiti, Jeffrey W. Krause

Gulf and Caribbean Research

No abstract provided.


Sponges Structure Water-Column Characteristics In Shallow Tropical Coastal Ecosystems, Marla M. Valentine, Mark J. Butler Iv Jan 2019

Sponges Structure Water-Column Characteristics In Shallow Tropical Coastal Ecosystems, Marla M. Valentine, Mark J. Butler Iv

Biological Sciences Faculty Publications

Sponges can have powerful effects on ecosystem processes in shallow tropical marine ecosystems. They drive benthic-pelagic coupling by filtering dissolved and particulate organic matter from the water column, alter water chemistry in association with their symbiotic microorganisms, and increase habitat structural complexity. Anthropogenic degradation of coastal waters is widespread and can reduce the density and diversity of foundation species such as sponges, potentially diminishing their contributions to ecosystem processes. We used a novel mesocosm design that minimized artifacts associated with traditional single-species and closed-system filtration experiments to examine the effects of water turnover and sponge biomass on water-column properties. Using …


Spatial Patterns Of Particulate Organic Carbon Concentrations And Isotopic Signatures Across A Salinity Gradient In A River Dominated Estuary, Lauren E. Alvaro, John C. Lehrter, Mai Fung Jan 2019

Spatial Patterns Of Particulate Organic Carbon Concentrations And Isotopic Signatures Across A Salinity Gradient In A River Dominated Estuary, Lauren E. Alvaro, John C. Lehrter, Mai Fung

Gulf and Caribbean Research

No abstract provided.


Improving Stem Recruitment Through A Theme-Based Summer Residential Camp Focused On Sea Level Rise, Vukica M. Jovanović, Balša Terzić, Mujde Erten-Unal, Victoria Hill, George Mcleod, Michelle Covi, David Burdige, Jenifer Alonzo, Justin Mason, Tysha Batts, Cynthia Tomovic Jan 2019

Improving Stem Recruitment Through A Theme-Based Summer Residential Camp Focused On Sea Level Rise, Vukica M. Jovanović, Balša Terzić, Mujde Erten-Unal, Victoria Hill, George Mcleod, Michelle Covi, David Burdige, Jenifer Alonzo, Justin Mason, Tysha Batts, Cynthia Tomovic

Engineering Technology Faculty Publications

In this paper, the authors present an enrichment program that focuses on Science, Technology, Engineering, and Math (STEM) concepts. The program is named Building Leaders to Advance Science and Technology (BLAST) and is held each summer at three universities across the Commonwealth of Virginia: Old Dominion University, the University of Virginia, and the Virginia Polytechnic Institute. BLAST is sponsored in partnership among these three universities and the Virginia Space Grant Consortium (VSGC), and is funded by the General Assembly of Commonwealth of Virginia. Its main purpose is to expose high school students to topics related to different STEM fields through …


Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi Jan 2019

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …


Spatial Variability In Recruitment Of Chilipepper Rockfish (Sebastes Goodei) In The California Current System, Laura K. Solinger Jan 2019

Spatial Variability In Recruitment Of Chilipepper Rockfish (Sebastes Goodei) In The California Current System, Laura K. Solinger

Cal Poly Humboldt theses and projects

Properly describing variability in population dynamics (e.g., growth, fecundity, recruitment) is expected to improve management of important fisheries stocks (Maunder & Piner, 2014). As recruitment to most fish stocks is determined during early life history stages (Houde, 1997; Iles & Beverton, 2000), and early life history stages are influenced by oceanographic conditions (Bjorkstedt et al. 2002; Laidig, 2010), understanding how environmental stochasticity influences recruitment deviations has potential to improve estimates of stock productivity and how productivity might change over time to support more effective management. Chilipepper Rockfish (Sebastes goodei) are an important commercial species that is managed as …


Wamsi 2 - Kmrp [Kimberley Marine Research Program] Project 2.2.9: Historical Water Quality Using Sediment Records, John Keesing, Dongyan Liu, Zineng Yuan, Yajun Peng, Yujue Wang, Pierre Richard, Pere Masque´, Yingjun Che, Yin Fang Jan 2019

Wamsi 2 - Kmrp [Kimberley Marine Research Program] Project 2.2.9: Historical Water Quality Using Sediment Records, John Keesing, Dongyan Liu, Zineng Yuan, Yajun Peng, Yujue Wang, Pierre Richard, Pere Masque´, Yingjun Che, Yin Fang

Research Datasets

The remote Kimberley coast of north-western Australia is one of the few marine environments domains on earth largely unaffected by human use. However, the region is undergoing increasing economic importance as a destination for tourism and significant coastal developments associated with oil and gas exploration. The objective of the project was to reconstruct a timeline of inferred water quality changes from the sediment record for a selected set of sites in the Kimberley, Western Australia. The project made use of palaeoecological approaches to reconstruct a chronology of change over the last approximately 100 years using a series of biogeochemical proxies …


Toward Using High-Frequency Coastal Radars For Calibration Of S-Ais Based Ocean Vessel Tracking Models, Ben Freidrich Jan 2019

Toward Using High-Frequency Coastal Radars For Calibration Of S-Ais Based Ocean Vessel Tracking Models, Ben Freidrich

Theses and Dissertations (Comprehensive)

Most of the world relies on ships for transportation, shipping, and tourism. Automatic Identification System messages are transmitted from ships and provide a wealth of positional data on these open ocean vessels. This data is being utilized to determine the optimal path for ships, as well as predicting where a ship may be going in the near future. It has only been in the past decade that Automatic Identification Systems (AIS) signals have been easily received with satellites (S-AIS) so there have been few studies that look at using available information and pairing it with the new abundance of ship …


Leveraging Student Experience With Water For Active Learning In A Large Introductory Oceanography Classroom, Rebecca Freeman Dec 2018

Leveraging Student Experience With Water For Active Learning In A Large Introductory Oceanography Classroom, Rebecca Freeman

Earth and Environmental Sciences Faculty Publications

No abstract provided.


Summertime Connecticut River Water Pathways And Wind Impacts, Yan Jia, Michael M. Whitney Dec 2018

Summertime Connecticut River Water Pathways And Wind Impacts, Yan Jia, Michael M. Whitney

Department of Marine Sciences

Long Island Sound is a large macrotidal estuary. Connecticut River as the primary freshwater source enters near the sound’s mouth. The summertime pathways of river water under low discharge and mild wind conditions are studied through both numerical simulations with a passive dye pulse and field surface drifter observations. Within the 19-day modeling analysis period, a third of the river dye pulse moves up-estuary with the near-bottom dense inflow into central and western sound with a spring-neap tidal modulation; another third leaves the sound with the near-surface outflow towards the continental shelf through Block Island Sound. The latter pathway is …


Aliased Tidal Variability In Mesoscale Sea Level Anomaly Maps, Edward Zaron, Richard D. Ray Dec 2018

Aliased Tidal Variability In Mesoscale Sea Level Anomaly Maps, Edward Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Sea level anomaly (SLA) maps are routinely produced by objective analysis of data from the constellation of satellite altimeter missions in operation since 1992. Beginning in 2014, changes in the Data Unification and Altimeter Combination System (DUACS) used to create the SLA maps resulted in improved spatial resolution of mesoscale variability, but it also increased the levels of aliased tidal variability compared to the methodology employed prior to 2014. The present work investigates the magnitude and spatial distribution of these tidal signals, which are typically smaller than 1 cmin the open ocean but can reach tens of centimeters in the …


Along-Shelf Connectivity And Circumpolar Gene Flow In Antarctic Silverfish (Pleuragramma Antarctica), Jilda Alicia Caccavo, Chiara Papetti, Maj Wetjen, Rainer Knust, Julian R. Ashford, Lorenzo Zane Dec 2018

Along-Shelf Connectivity And Circumpolar Gene Flow In Antarctic Silverfish (Pleuragramma Antarctica), Jilda Alicia Caccavo, Chiara Papetti, Maj Wetjen, Rainer Knust, Julian R. Ashford, Lorenzo Zane

OES Faculty Publications

The Antarctic silverfish (Pleuragramma antarctica) is a critically important forage species with a circumpolar distribution and is unique among other notothenioid species for its wholly pelagic life cycle. Previous studies have provided mixed evidence of population structure over regional and circumpolar scales. The aim of the present study was to test the recent population hypothesis for Antarctic silverfish, which emphasizes the interplay between life history and hydrography in shaping connectivity. A total of 1067 individuals were collected over 25 years from different locations on a circumpolar scale. Samples were genotyped at fifteen microsatellites to assess population differentiation and …


Predicted Deepwater Bathymetry From Satellite Altimetry: Non-Fourier Transform Alternatives, Maxsimo Salazar Dec 2018

Predicted Deepwater Bathymetry From Satellite Altimetry: Non-Fourier Transform Alternatives, Maxsimo Salazar

Dissertations

Robert Parker (1972) demonstrated the effectiveness of Fourier Transforms (FT) to compute gravitational potential anomalies caused by uneven, non-uniform layers of material. This important calculation relates the gravitational potential anomaly to sea-floor topography. As outlined by Sandwell and Smith (1997), a six-step procedure, utilizing the FT, then demonstrated how satellite altimetry measurements of marine geoid height are inverted into seafloor topography. However, FTs are not local in space and produce Gibb’s phenomenon around discontinuities. Seafloor features exhibit spatial locality and features such as seamounts and ridges often have sharp inclines. Initial tests compared the windowed-FT to wavelets in reconstruction of …


Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis Dec 2018

Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis

Master's Theses

Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 x10 …


Dynamics Of Prochlorococcus Diversity And Photoacclimation During Short-Term Shifts In Water Column Stratification At Station Aloha, Anne W. Thompson, Ger Van Den Engh, Nathan A. Ahlgren, Kathleen Kouba, Samantha Ward, Samuel T. Wilson, David M. Karl Dec 2018

Dynamics Of Prochlorococcus Diversity And Photoacclimation During Short-Term Shifts In Water Column Stratification At Station Aloha, Anne W. Thompson, Ger Van Den Engh, Nathan A. Ahlgren, Kathleen Kouba, Samantha Ward, Samuel T. Wilson, David M. Karl

Biology Faculty Publications and Presentations

The cyanobacterium Prochlorococcus is the dominant phototroph in surface waters of the vast oligotrophic oceans, the foundation of marine food webs, and an important component of global biogeochemical cycles. The prominence of Prochlorococcus across the environmental gradients of the open ocean is attributed to its extensive genetic diversity and flexible chlorophyll physiology, enabling light capture over a wide range of intensities. What remains unknown is the balance between temporal dynamics of genetic diversity and chlorophyll physiology in the ability of Prochlorococcus to respond to a variety of short (approximately 1 day) and longer (months to year) changes in the environment. …


Trash Talk: The Effects Of Plastic Pollution On Seabirds In Narragansett Bay, Erin A. O'Neill Dec 2018

Trash Talk: The Effects Of Plastic Pollution On Seabirds In Narragansett Bay, Erin A. O'Neill

Pell Scholars and Senior Theses

Plastic pollution in the ocean is a global concern with more than 8 million tons of plastic dumped into our oceans every year. This policy paper assesses plastic pollution in Narragansett Bay and the negative implications it holds on local seabird populations. Also, essential background information on plastic production and throwaway culture is provided. Moreover, the biological significance of seabirds is described, highlighting the vital role such populations play in local ecosystems such as Narragansett Bay. This paper contributes research to the global issue of plastic pollution by observing declining native wildlife life populations, such as seabirds, on a local …


Lighting A Path To Biofouling Prevention: Investigating The Effect Of Ultraviolet Light On Biofouling, Cierra Rose Braga Dec 2018

Lighting A Path To Biofouling Prevention: Investigating The Effect Of Ultraviolet Light On Biofouling, Cierra Rose Braga

Theses and Dissertations

Ultraviolet light (UV) is considered an environmentally friendly antifouling method because it disrupts biological growth without the release of harmful toxins. The application of UV for the marine shipping industry is a relatively new concept, and there still remains many unknowns before it can be fully implemented. This research investigated several aspects of applying UVC for the control of fouling. A novel method of using embedded UV LEDs within a silicone coating for fouling control proved to be very effective at preventing fouling. The research also investigated the effect of using an external UVC light treatment to control fouling on …


Evolution Of 21st Century Sea Level Rise Projections, Andra J. Garner, Jeremy L. Weiss, Adam Parris, Robert E. Kopp, Radley M. Horton, Jonathan T, Overpeck, Benjamin P. Horton Nov 2018

Evolution Of 21st Century Sea Level Rise Projections, Andra J. Garner, Jeremy L. Weiss, Adam Parris, Robert E. Kopp, Radley M. Horton, Jonathan T, Overpeck, Benjamin P. Horton

School of Earth & Environment Departmental Research

The modern era of scientific global‐mean sea level rise (SLR) projections began in the early 1980s. In subsequent decades, understanding of driving processes has improved, and new methodologies have been developed. Nonetheless, despite more than 70 studies, future SLR remains deeply uncertain. To facilitate understanding of the historical development of SLR projections and contextualize current projections, we have compiled a comprehensive database of 21st century global SLR projections. Although central estimates of 21st century global‐mean SLR have been relatively consistent, the range of projected SLR has varied greatly over time. Among studies providing multiple estimates, the range of upper projections …


Flux Of Particulate Elements In The North Atlantic Ocean Constrained By Multiple Radionuclides, Christopher T. Hayes, Erin E. Black, Robert F. Anderson, Mark Baskaran, Ken O. Buesseler, Matthew A. Charette, Hai Cheng, J. Kirk Cochran, R. Lawrence Edwards, Patrick Fitzgerald, Phoebe J. Lam, Yanbin Lu, Stephanie O. Morris, Daniel C. Ohnemus, Frank J. Pavia, Gillian Stewart, Yi Tang Nov 2018

Flux Of Particulate Elements In The North Atlantic Ocean Constrained By Multiple Radionuclides, Christopher T. Hayes, Erin E. Black, Robert F. Anderson, Mark Baskaran, Ken O. Buesseler, Matthew A. Charette, Hai Cheng, J. Kirk Cochran, R. Lawrence Edwards, Patrick Fitzgerald, Phoebe J. Lam, Yanbin Lu, Stephanie O. Morris, Daniel C. Ohnemus, Frank J. Pavia, Gillian Stewart, Yi Tang

Environmental Science and Geology Faculty Research Publications

Sinking particles strongly regulate the distribution of reactive chemical substances in the ocean, including particulate organic carbon and other elements (e.g., P, Cd, Mn, Cu, Co, Fe, Al, and 232Th). Yet, the sinking fluxes of trace elements have not been well described in the global ocean. The U.S. GEOTRACES campaign in the North Atlantic (GA03) offers the first data set in which the sinking flux of carbon and trace elements can be derived using four different radionuclide pairs (238U:234Th ;210Pb:210Po; 228Ra:228Th; and 234U:230Th) at stations co-located with sediment trap fluxes for comparison. Particulate organic carbon, particulate P, and particulate Cd …


Impacts Of Pacific Ssts On Atmospheric Circulations Leading To California Winter Precipitation Variability: A Diagnostic Modeling, Boksoon Myoung, Sang-Wook Yeh, Jinwon Kim, Menas Kafatos Nov 2018

Impacts Of Pacific Ssts On Atmospheric Circulations Leading To California Winter Precipitation Variability: A Diagnostic Modeling, Boksoon Myoung, Sang-Wook Yeh, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

One of the primary meteorological causes of the winter precipitation deficits and droughts in California (CA) is anomalous developments and maintenance of upper-tropospheric ridges over the northeastern Pacific. In order to understand and find the key factors controlling the winter precipitation variability in CA, the present study examines two dominant atmospheric modes of the 500 hPa geopotential height in the Northern Hemisphere using an Empirical Orthogonal Function (EOF) and their associated large-scale circulation patterns for the last 41 winters (1974/75–2014/15). Explaining 17.5% of variability, the second mode (EOF2) shows strong anti-cyclonic circulations in the North Pacific and cyclonic circulations in …


Evaluation Of Spatial Generalization Characteristics Of A Robust Classifier As Applied To Coral Reef Habitats In Remote Islands Of The Pacific Ocean, Justin J. Gapper, Hesham El-Askary, Erik J. Linstead, Thomas Piechota Nov 2018

Evaluation Of Spatial Generalization Characteristics Of A Robust Classifier As Applied To Coral Reef Habitats In Remote Islands Of The Pacific Ocean, Justin J. Gapper, Hesham El-Askary, Erik J. Linstead, Thomas Piechota

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study was an evaluation of the spectral signature generalization properties of coral across four remote Pacific Ocean reefs. The sites under consideration have not been the subject of previous studies for coral classification using remote sensing data. Previous research regarding using remote sensing to identify reefs has been limited to in-situ assessment, with some researchers also performing temporal analysis of a selected area of interest. This study expanded the previous in-situ analyses by evaluating the ability of a basic predictor, Linear Discriminant Analysis (LDA), trained on Depth Invariant Indices calculated from the spectral signature of coral in one location …


A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. Mcchesney, J. E. Hertzberg, J. F. Mcmanus Nov 2018

A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. Mcchesney, J. E. Hertzberg, J. F. Mcmanus

OES Faculty Publications

The mean state and variability of the tropical Pacificis influenced by the depth of the thermocline. During the Last Glacial Maximum (~21,000 years ago), the zonal sea surface temperature gradient across the equatorial Pacific was reduced and productivity was generally lower than modern. To understand the thermocline depth’s role in determining the Last Glacial Maximum tropical mean state, we reconstruct the upper ocean δ18O profile from multiple species of planktic foraminifera. We synthesize existing records of surface and subsurface dwelling foraminifera to reconstruct the vertical δ18O gradient throughout the eastern equatorial Pacific. We find the thermocline …


Ground-Truthing Social Vulnerability Indices Of Alaska Fishing Communities, Anna Lavoie, Kim Sparks, Stephen Kasperski, Amber Himes-Cornell, Kristin Hoelting, Conor Maguire Oct 2018

Ground-Truthing Social Vulnerability Indices Of Alaska Fishing Communities, Anna Lavoie, Kim Sparks, Stephen Kasperski, Amber Himes-Cornell, Kristin Hoelting, Conor Maguire

All Faculty Scholarship for the College of the Sciences

Community vulnerability is increasingly evaluated through quantitative social indices, typically developed using secondary data sources rather than primary data collection. It is necessary to understand the validity of these indices if they will be used to inform policy and decision making. This paper presents a ground-truthing effort to validate quantitative indices that characterize the well-being of Alaska fishing communities. We utilized ethnographic data collected from 13 representative communities and a capital assets framework to ground-truth the indices, in which qualitative ranks of vulnerability were compared against quantitative indices. The majority (73.8%) of ranks were in complete or moderate agreement and …


Eddy Flux Measurements Of Sulfur Dioxide Deposition To The Sea Surface, Jack G. Porter, Warren J. De Bruyn, Eric S. Saltzman Oct 2018

Eddy Flux Measurements Of Sulfur Dioxide Deposition To The Sea Surface, Jack G. Porter, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Deposition to the sea surface is a major atmospheric loss pathway for many important trace gases, such as sulfur dioxide (SO2). The air–sea transfer of SO2 is controlled entirely on the atmospheric side of the air–sea interface due to high effective solubility and other physical– chemical properties. There have been few direct field measurements of such fluxes due to the challenges associated with making fast-response measurements of highly soluble trace gases at very low ambient levels. In this study, we report direct eddy covariance air–sea flux measurements of SO2, sensible heat, water vapor, and momentum. The measurements were made over …