Oceanography Commons^™

Impacts Of Oil Spills On Altimeter Waveforms And Radar Backscatter Cross Section, Yongcun Cheng, Jean Tournadre, Xiaofeng Li, Qing Xu, Bertrand Chapron

CCPO Publications

Ocean surface films can damp short capillary-gravity waves, reduce the surface mean square slope, and induce "sigma0 blooms" in satellite altimeter data. No study has ascertained the effect of such film on altimeter measurements due to lack of film data. The availability of Environmental Response Management Application (ERMA) oil cover, daily oil spill extent, and thickness data acquired during the Deepwater Horizon (DWH) oil spill accident provides a unique opportunity to evaluate the impact of surface film on altimeter data. In this study, the Jason-1/2 passes nearest to the DWH platform are analyzed to understand the waveform distortion caused by …

Cruise Data For Neuston Net And Paired Bongo Net Tows From 48 Stations In The Northern Gulf Of Mexico From R/V Blazing Seven Cruises Lf2015a And Lf2015b June 2015 And July 2015, Jay R. Rooker, R.J. David Wells

DEEPEND Datasets

Shelf and slope waters in the Deep Water Horizon oil spill (DWHOS) area are known to serve as critical spawning, nursery, and foraging habitat of several important oceanic species including billfishes (e.g. blue marlin, white marlin, sailfish), tunas (bluefin tuna, yellowfin tuna), and other pelagic taxa (swordfish, dolphinfishes). The aim of this component was to further investigate potential ecological effects of the DWHOS on pelagic fishes during the early life period. Larval fishes were sampled from 48 stations in the northern Gulf of Mexico and cruise data was collected at each site including latitude/longitude, date, time and environmental data (sea …

Experimental Impacts Of Climate Warming And Ocean Carbonation On Eelgrass Zostera Marina, Richard C. Zimmerman, Victoria J. Hill, Malee Jinuntuya, Billur Celebi, David Ruble, Miranda Smith, Tiffany Cedeno, W. Mark Swingle

OES Faculty Publications

CO₂ is a critical and potentially limiting substrate for photosynthesis of both terrestrial and aquatic ecosystems. In addition to being a climate-warming greenhouse gas, increasing concentrations of CO₂ will dissolve in the oceans, eliciting both negative and positive responses among organisms in a process commonly known as ocean acidification. The dissolution of CO₂ into ocean surface waters, however, also increases its availability for photosynthesis, to which the highly successful, and ecologically important, seagrasses respond positively. Thus, the process might be more accurately characterized as ocean carbonation. This experiment demonstrated that CO₂ stimulation of primary production enhances …

Multiple Metabolisms Constrain The Anaerobic Nitrite Budget In The Eastern Tropical South Pacific, Andrew R. Babbin, Brian D. Peters, Calvin W. Mordy, Brittany Widner, Karen L. Casciotti, Bess B. Ward

OES Faculty Publications

The Eastern Tropical South Pacific is one of the three major oxygen deficient zones (ODZs) in the global ocean and is responsible for approximately one third of marine water column nitrogen loss. It is the best studied of the ODZs and, like the others, features a broad nitrite maximum across the low oxygen layer. How the microbial processes that produce and consume nitrite in anoxic waters interact to sustain this feature is unknown. Here we used ¹⁵N-tracer experiments to disentangle five of the biologically mediated processes that control the nitrite pool, including a high-resolution profile of nitrogen loss rates. …

Multiple Mating By Females In The Chesapeake Bay Blue Crab Callinectes Sapidus Population, S. Wells, J. Mcconaugha, L. Horth

OES Faculty Publications

Mature females of the Chesapeake Bay (USA) blue crab Callinectes sapidus population mate multiple times. Microsatellite DNA analysis of sperm stored in the spermathecae has shown that virtually all (~97%, 104 out of 107) females collected in a 2009−2010 study mated with at least 2 males. Enumeration of stored sperm revealed that despite multiple mating, some females did not have enough sperm to fulfill their lifetime reproductive potential, suggesting that female blue crabs may experience varying levels of sperm limitation. This could result from multiple factors. The average body size of males in the population has decreased, which reduces the …

A Six Thousand-Year Record Of Climate And Land-Use Change From Mediterranean Seagrass Mats, Lourdes Lopez-Merino, Nieves Colas-Ruiz, Maria Adame, Oscar Serrano, Antonio Cortizas, Miguel-Angel Mateo

Research outputs 2014 to 2021

The Mediterranean seagrass Posidonia oceanica maintains a biodiverse ecosystem and it is a world-wide important carbon sink. It grows for millennia, accumulating organic-rich soils (mats) beneath the meadows. This marine habitat is protected by the European Union; however, it is declining rapidly due to coastal development. Understanding its response to disturbances could inform habitat restoration, but many environmental impacts predate monitoring programs (years).
This research explores the palaeoecological potential of Posidonia mats to reconstruct six thousand years of environmental change that could have affected Posidonia meadows and, in turn, left an imprint on the mats.
Palynological, microcharcoal, magnetic susceptibility and …

Implications Of Sea Ice On Southern Ocean Microseisms Detected By A Seismic Array In West Antarctica, Martin J. Pratt, Douglas A. Wiens, J. Paul Winberry, Sridhar Anandakrishnan, Garrett G. Euler

All Faculty Scholarship for the College of the Sciences

The proximity of Southern Ocean storms coupled with seasonal variation in sea ice make Antarctica ideal for the study of microseism sources. We explore frequency-dependent beamforming results using a short-duration, 60 km aperture, broad-band seismic array located on the Whillans Ice Stream, West Antarctica. Locations of single-frequency microseism (13–16 s period) generation are in regions where the continental shelf is ice-free, consistent with previous studies, and show Rayleigh wave sources remaining at consistent backazimuths throughout the duration of the array. Beamforming analysis of daily noise correlations shows that long-period double-frequency microseisms (9–11 s) consist predominantly of Rayleigh waves excited by …

Subset Data From The Nauru 1999 And African Monsoon Multidisciplinary Analysis (Amma) 2006 Cruise And Matlab Code For Generating Plots For The Paper: Wong And Minnett (2017): The Response Of The Ocean Thermal Skin Layer To Variations In Incident Infrared Radiation., Elizabeth Wong

Supplementary Data and Tools

Data in this collection is largely comprised of subsetted data from two research cruises, the Nauru cruise held from June to July 1999 and the African Monsoon Multidisciplinary Analysis (AMMA) cruise held from May to July 2006. The data subset is limited to night conditions under low wind speeds of < 10 m/s and consists of the surface fluxes, radiance measurements from the Marine Atmospheric Emitted Radiance Interferometer (M-AERI), the retrievals of the skin sea surface temperatures and skin sea surface temperature profiles from the M-AERI's radiance spectral measurements. Also included are line-by-line-radiative transfer simulations provided by Dr. Goshka Szczodrak, transmission coefficient spectra obtained from the HITRAN database, and wind speed data from the Special Sensing Microwave Imager (SSM/I) version 6. provided by Dr. Chelle Gentemann. Matlab code is provided which reads the datafile (DATA.mat) and outputs the figures illustrated in the paper Wong and Minnett (2017) (https://doi.org/10.1002/2017JC013351).

Data From: Observing System Simulation Experiments For An Array Of Autonomous Biogeochemical Profiling Floats In The Southern Ocean, Igor Kamenkovich, Angelique Haza, Alison R. Gray, Carolina O. Dufour, Zulema Garraffo

Supplementary Data and Tools

Data in this collection is from Observation System Simulation Experiments (OSSEs) that were carried in support of the SOCCOM program. Synthetic profiles were extracted from model-simulated dissolved oxygen and inorganic carbon. Full maps were then reconstructed from these sparse datasets, using objective mapping. For description of the model and reconstruction method please see Kamenkovich, I., A. Haza, A. Gray, C. Dufour, and Z. Garraffo: "Observing System Simulation Experiments for an array of autonomous biogeochemical profiling floats in the Southern Ocean", Journal of Geophysical Research, DOI: 10.1002/2017JC012819

Coral Bleaching And The Effect Of Disturbances On The Damselfish Community On Lizard Island, Australia, Alejandra Munoz

Independent Study Project (ISP) Collection

Coral reefs are characterized by their dynamic ecological processes that supports a high diversity through the recruitment of marine species and temporal disturbances that can have positive effects on the system. In the face of global climate change however, coral reefs face intense coral bleaching and increased degradation as they may begin to have less time to recover between bleaching events in the near future. Little is known on the long term effects of coral bleaching and habitat degradation on reef fish communities and much less is known about the mechanisms that bring about changes to reef fish assemblages.

This …

Upper Water Structure And Mixed Layer Depth In Tropical Waters: The Seats Station In The Northern South China Sea, Jen-Hua Tai, George T. F. Wong, Xiaoju Pan

OES Faculty Publications

The variability of the upper water hydrographic structure, the efficacy of the different schemes for estimating the mixed layer depth (MLD), the inter-comparability estimation of the MLDs and diurnal and intra-annual MLD climatology in the tropical waters in the northern South China Sea were accessed in 702 depth-profiles of potential temperature (θ) and salinity collected in 64 cruises between 17.5 and 18.5°N and 115.3 and 116.3°E from 1997 to 2013. The hydrographic structure may be subdivided into three principal types: the classical type, with quasi-isopycnal surface mixed layer followed by an abrupt increase in the depth-gradient in θ and potential …

Spatial Patterns Of Sea Level Variability Associated With Natural Internal Climate Modes, Weiqing Han, Gerald A. Meehl, Detlef Stammer, Aixue Hu, Benjamin Hamlington, Jessica Kenigson, Hindumathi Palanisamy, Philip Thompson

OES Faculty Publications

Sea level rise (SLR) can exert significant stress on highly populated coastal societies and low-lying island countries around the world. Because of this, there is huge societal demand for improved decadal predictions and future projections of SLR, particularly on a local scale along coastlines. Regionally, sea level variations can deviate considerably from the global mean due to various geophysical processes. These include changes of ocean circulations, which partially can be attributed to natural, internal modes of variability in the complex Earth's climate system. Anthropogenic influence may also contribute to regional sea level variations. Separating the effects of natural climate modes …

Eukaryotic Microbes, Principally Fungi And Labyrinthulomycetes, Dominate Biomass On Bathypelagic Marine Snow, Alexander B. Bochdansky, Melissa A. Clouse, Gerhard J. Herndl

OES Faculty Publications

In the bathypelagic realm of the ocean, the role of marine snow as a carbon and energy source for the deep-sea biota and as a potential hotspot of microbial diversity and activity has not received adequate attention. Here, we collected bathypelagic marine snow by gentle gravity filtration of sea water onto μm filters from similar to 1000 to 3900 m to investigate the relative distribution of eukaryotic microbes. Compared with sediment traps that select for fast-sinking particles, this method collects particles unbiased by settling velocity. While prokaryotes numerically exceeded eukaryotes on marine snow, eukaryotic microbes belonging to two very distant …

Elevated Trace Metal Content Of Prokaryotic Communities Associated With Marine Oxygen Deficient Zones, Daniel C. Ohnemus, Sara Rauschenberg, Gregory A. Cutter, Jessica N. Fitzsimmons, Robert M. Sherrell, Benjamin S. Twining

OES Faculty Publications

Little is known about the trace metal content of marine prokaryotes, in part due to their co-occurrence with more abundant particulate phases in the upper ocean, such as phytoplankton and biogenic detritus, lithogenic minerals, and authigenic Mn and Fe oxyhydroxides. We attempt to isolate these biomass signals in particulate data from the US GEOTRACES Eastern Pacific Zonal Transect (cruise GP16) in the Eastern Tropical South Pacific (ETSP), which exhibited consistent maxima in P and other bioactive trace metals, and minima in particulate Mn, in the oxygen deficient zones (ODZs) of 13 stations. Nitrite maxima and nitrate deficits indicated the presence …

Critical Decisions In Metaproteomics: Achieving High Confidence Protein Annotations In A Sea Of Unknowns, Emma Timmins-Schiffman, Damon H. May, Molly Mikan, Michael Riffle, Chris Frazar, H. R. Harvey, William S. Noble, Brook L. Nunn

OES Faculty Publications

No abstract provided.

Community Production Modulates Coral Reef Ph And The Sensitivity Of Ecosystem Calcification To Ocean Acidification, Thomas M. Decarlo, Anne L. Cohen, George T. F. Wong, Fuh-Kwo Shiah, Steven J. Lentz, Kristen A. Davis, Kathryn E. F. Shamberger, Pat Lohmann

OES Faculty Publications

Coral reefs are built of calcium carbonate (CaCO₃) produced biogenically by a diversity of calcifying plants, animals, and microbes. As the ocean warms and acidifies, there is mounting concern that declining calcification rates could shift coral reef CaCO3 budgets from net accretion to net dissolution. We quantified net ecosystem calcification (NEC) and production (NEP) on Dongsha Atoll, northern South China Sea, over a 2 week period that included a transient bleaching event. Peak daytime pH on the wide, shallow reef flat during the nonbleaching period was ~8.5, significantly elevated above that of the surrounding open ocean (~8.0-8.1) as …

Impact Of Glacial/Interglacial Sea Level Change On The Ocean Nitrogen Cycle, Haojia Ren, Daniel M. Sigman, Alfredo Martínez-García, Robert F. Anderson, Chen Min-Te, Ana Christina Ravelo, Marietta Straub, George T. F. Wong, Gerald H. Haug

OES Faculty Publications

The continental shelves are the most biologically dynamic regions of the ocean, and they are extensive worldwide, especially in the western North Pacific. Their area has varied dramatically over the glacial/interglacial cycles of the last million years, but the effects of this variation on ocean biological and chemical processes remain poorly understood. Conversion of nitrate to N2 by denitrification in sediments accounts for half or more of the removal of biologically available nitrogen ("fixed N") from the ocean. The emergence of continental shelves during ice ages and their flooding during interglacials have been hypothesized to drive changes in sedimentary denitrification. …

Phytoplankton Plastid Proteomics: Cracking Open Diatoms To Understand Plastid Biochemistry Under Iron Limitation, Skyler J. Nunn, Phoebe Dreux Chappell, Kristofer Gomes, Anasthasia Bonderenko, Bethany D. Jenkins, Brook L. Nunn

OES Faculty Publications

Diatoms, such as Thalassiosira pseudonana, are important oceanic primary producers, as they sequester carbon dioxide (CO₂) out of the atmosphere, die, and precipitate to the ocean floor. In many areas of the world’s oceans, phytoplankton, such as diatoms, are limited in growth by the availability of iron (Fe). Fe is an essential nutrient for phytoplankton, as it is central in the electron transport chain component of photosynthesis. Through this study, we examined if Fe-limitation makes a significant difference in the proteins expressed within the chloroplast, the power source for diatoms. Here, we utilized a new plastid isolation technique specific …

Flooding And Inundation Modeling In The Great Bay Estuary, Anna E. Simpson

Honors Theses and Capstones

As part of this research, FVCOM, a finite-volume coastal ocean numerical hydrodynamic model (Chen, et al., 2003), was implemented into the Great Bay estuary. FVCOM is one of several community models that have been developed for coastal regions, and was selected because it utilizes an unstructured grid to discretize the model domain. The unstructured grid provides the ability to have fine scale resolution near the boundary or coastline and decreased resolution away from the boundary where the flow field is less complicated, resulting in greatly reduced computational expense in less dynamic regions allowing model runs to be completed in …

Spaceborne Synthetic Aperture Radar Survey Of Subsidence In Hampton Roads, Virginia (Usa), D.P.S. Bekaert, B. D. Hamlington, B. Buzzanga, C. E. Jones

CCPO Publications

Over the past century, the Hampton Roads area of the Chesapeake Bay region has experienced one of the highest rates of relative sea level rise on the Atlantic coast of the United States. This rate of relative sea level rise results from a combination of land subsidence, which has long been known to be present in the region, and rising seas associated with global warming on long timescales and exacerbated by shifts in ocean dynamics on shorter timescales. An understanding of the current-day magnitude of each component is needed to create accurate projections of future relative sea level rise upon …

Evaluation Of Extratropical Cyclone Precipitation In The North Atlantic Basin: An Analysis Of Era-Interim, Wrf, And Two Cmip5 Models, James F. Booth, Catherine M. Naud, Jeff Willison

Publications and Research

The representation of extratropical cyclones (ETCs) precipitation in general circulation models (GCMs) and a weather research and forecasting (WRF) model is analyzed. This work considers the link between ETC precipitation and dynamical strength and tests if parameterized convection affects this link for ETCs in the North Atlantic Basin. Lagrangian cyclone tracks of ETCs in ERA-Interim reanalysis (ERAI), the GISS and GFDL CMIP5 models, and WRF with two horizontal resolutions are utilized in a compositing analysis. The 20-km resolution WRF model generates stronger ETCs based on surface wind speed and cyclone precipitation. The GCMs and ERAI generate similar composite means and …

Ecological Connectivity Of Kimberley Marine Communities. Synthesis Report Of Project 1.1.3 Prepared For The Kimberley Marine Research Program, Zoe Richards, Oliver Berry, Jim Underwood, Kathryn Mcmahon, Mike Travers, Glenn Moore, Udhi Hernawan, Joseph Dibattista, Richard Evans, James Gilmour

Research outputs 2014 to 2021

The overarching objective of KMRP Project 1.1.3 (Ecological Connectivity of Kimberley Marine Communities) was to provide the first estimates of ecological connectivity across multiple spatial scales for a suite of model/priority marine organisms in the Kimberley. More specifically, this project aimed to provide species-specific estimates of realised connectivity at a reef-scale ( < 1 > km), inter-reef scale (1-100 km) and inter-region scale (100 + km) through genetic analyses of seven key animals and plants with contrasting dispersive life histories that are representative of common taxa.

Editorial—The 7th International Workshop On Modeling The Ocean (Iwmo 2015), Lie-Yauw Oey, Xiao Hua Wang, Tal Ezer, Yign Noh, Andrew Mcc. Hogg

CCPO Publications

IWMO2015 was held in the pristine campus of the Australian National University, Canberra, Australia, from June 1–5, 2015. Despite the negative Coriolis spin that many of us from the northern half of the globe experienced for the first time, we were positively impressed by the vastness and beauty of Australia and the kindness and friendliness of its people. Late fall in Canberra displayed spectacular starry nights and brisk sunny days. The workshop was attended by more than 80 participants from 16 countries around the globe. Seventy papers including both oral and posters were presented, covering a very broad range of …

Editorial-The 6th International Workshop On Modeling The Ocean (Iwmo 2014), Lie-Yauw Oey, Tal Ezer, Jinyu Sheng, Fei Chai, Jianping Gan, Kevin Lamb

CCPO Publications

The 6th International Workshop on Modeling the Ocean (IWMO 2014) was held on June 23–27, 2014, at Dalhousie University in Halifax, Nova Scotia, Canada. After three meetings in Asia (Oey et al. 2010, 2013a, b) and one in Europe (Berntsen et al. 2014), the IWMO returned to North America for the second time (since IWMO 2010 in the USA; Ezer et al. 2011). Readers are referred to https://www.dal.ca/sites/iwmo. html for more information on IWMO 2014 and http://www. ccpo.odu.edu/POMWEB /meetings.htm for information on the past meetings and future planned meetings.

Pathways And Supply Of Dissolved Iron In The Amundsen Sea (Antarctica), P. St-Laurent, P. L. Yager, R. M. Sherrell, S. E. Stammerjohn, M. S. Dinniman

CCPO Publications

Numerous coastal polynyas fringe the Antarctic continent and strongly influence the productivity of Antarctic shelf systems. Of the 46 Antarctic coastal polynyas documented in a recent study, the Amundsen Sea Polynya (ASP) stands out as having the highest net primary production per unit area. Incubation experiments suggest that this productivity is partly controlled by the availability of dissolved iron (dFe).As a first step toward understanding the iron supply of the ASP, we introduce four plausible sources of dFe and simulate their steady spatial distribution using conservative numerical tracers. The modeled distributions replicate important features from observations including dFe maxima at …

Development Of An Age-Frequency Distribution For Ocean Quahogs Arctica Islandica On Georges Bank, Sara M. Pace, Eric N. Powell, Roger Mann, M. Chase Long, John M. Klinck

CCPO Publications

Ocean quahogs [Arctica islandica (Linnaeus, 1769)] are the longest-lived, noncolonial animal known today, with a maximum life span exceeding 500 y. Ocean quahogs are a commercially important bivalve, inhabiting the continental shelf of the North Atlantic Basin. Although considerable information exists on the growth and physiology of A. islandica, limited information is available regarding recruitment; accordingly, sustainably managing the fishery is a challenge. To investigate long-term recruitment trends, the age of ocean quahogs from Georges Bank which were fully recruited to the commercial fishery (>80 mm shell length) was determined by analysis of annual growth lines in …

Investigating Coral Bleaching In A Changing Climate: Our State Of Understanding And Opportunities To Push The Field Forward, Mark E. Warner, Daniel Barshis, Sarah Davies, Andréa G. Grottoli, Todd C. Lajeunesse, Robert Van Woesik

Biological Sciences Faculty Publications

[First Paragraph]

Coral reefs throughout the world are facing the consequences of large-scale changes in Earth’s climate. In particular, ocean warming is leading to frequent coral bleaching, which is threatening the long-term stability of coral reefs. Coral bleaching is a stress response that results in the disassociation of the mutualistic symbioses (i.e., dysbiosis) between corals and their endosymbiotic algae (Symbiodinium spp.). In the past two decades, there have been four substantial bleaching events, which have affected large geographic areas across the globe, including the worst recorded bleaching event on the Great Barrier Reef in 2016 (Berkelmans et al. 2004; Eakin …

Loop Current Spin-Off Eddies, Slope Currents And Dispersal Of Reef Fish Larvae From The Flower Gardens National Marine Sanctuary And The Florida Middle Grounds, Donald R. Johnson, Harriet Perry, Guillermo Sanchez-Rubio, Mark A. Grace

Gulf and Caribbean Research

Large energetic spin—off eddies from Loop Current intrusions into the Gulf of Mexico play a major role in water exchange between the continental shelf and the deep basin in the northern Gulf. Reef fish larvae, spawned on the outer shelf and planktonic during their early life history, are broadly dispersed by this mechanism, but may be lost to the cohort by transport away from suitable settlement habitat. In this study, satellite altimeter data—assimilative ocean model currents (HYCOM) from 2003—2015 are used to calculate kinetic energy of the mixed layer over the upper continental slope (200 m —1000 m) due to …

Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale

Dissertations, Master's Theses and Master's Reports

In the past century, extensive research has been done regarding the sound propagation in arctic ice sheets. The majority of this research has focused on low frequency propagation over long distances. One of the most commonly used excitation methods for air-ice-water layers has been explosives. However, environmental regulation has become more stringent, disallowing the use of almost all explosive excitation types. Due to changing climate conditions in these environments, new experimentation is warranted to determine sound propagation characteristics in, through, and under thin ice sheets, in shallow water, over short distances. In April, 2016 several experiments were conducted approximately 2 …

Mapping The Nonstationary Internal Tide With Satellite Altimetry, Edward Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

t Temporal variability of the internal tide has been inferred from the 23 year long combined records of the TOPEX/Poseidon, Jason-1, and Jason-2 satellite altimeters by combining harmonic analysis with an analysis of along-track wavenumber spectra of sea-surface height (SSH). Conventional harmonic analysis is first applied to estimate and remove the stationary components of the tide at each point along the reference ground tracks. The wavenumber spectrum of the residual SSH is then computed, and the variance in a neighborhood around the wavenumber of the mode-1 baroclinic M2 tide is interpreted as the sum of noise, broadband nontidal processes, and …