Oceanography and Atmospheric Sciences and Meteorology Commons^™

Sediment Records From Coastal Ponds: Temporal Archives Of Storm Inundation And Environmental Change, Christine M. Brandon

Doctoral Dissertations

Hurricanes are powerful storms that can cause billions of dollars in damage and kill many people when they strike populated coastal areas. Understanding how frequently coastal cities can expect storms of a certain magnitude would help inform more effective mitigation and adaptation strategies. Unfortunately, current estimates of hurricane frequency rely on numerical models based on weather observations that, on the east coast of the United States, only extend ~150 years into the past. While this is sufficient for estimating the characteristics (i.e. wind speed and storm surge height) of annual or decadal storms, the properties of larger, rarer, and more …

Spectral Attenuation And Backscattering As Indicators Of Average Particle Size, Wayne Homer Slade, Emmanuel Boss

Marine Sciences Faculty Scholarship

Measurements of the particulate beam attenuation coefficient at multiple wavelengths in the ocean typically exhibit a power law dependence on wavelength, and the slope of that power law has been related to the slope of the particle size distribution (PSD), when assumed to be a power law function of particle size. Recently, spectral backscattering coefficient measurements have been made using sensors deployed at moored observatories, on autonomous underwater vehicles, and even retrieved from space-based measurements of remote sensing reflectance. It has been suggested that these backscattering measurements may also be used to obtain information about the shape of the PSD. …

Climate Change Sentiment On Twitter: An Unsolicited Public Opinion Poll, Emily M. Cody, Andrew J. Reagan, Lewis Mitchell, Peter Sheridan Dodds, Christopher M. Danforth

College of Engineering and Mathematical Sciences Faculty Publications

The consequences of anthropogenic climate change are extensively debated through scientific papers, newspaper articles, and blogs. Newspaper articles may lack accuracy, while the severity of findings in scientific papers may be too opaque for the public to understand. Social media, however, is a forum where individuals of diverse backgrounds can share their thoughts and opinions. As consumption shifts from old media to new, Twitter has become a valuable resource for analyzing current events and headline news. In this research, we analyze tweets containing the word "climate" collected between September 2008 and July 2014. Through use of a previously developed sentiment …

Magnetohydrodynamic Modeling Of Three Van Allen Probes Storms In 2012 And 2013, J. Paral, M. K. Hudson, B. T. Kress, M. J. Wiltberger

Dartmouth Scholarship

Coronal mass ejection (CME)-shock compression of the dayside magnetopause has been observed to cause both prompt enhancement of radiation belt electron flux due to inward radial transport of electrons conserving their first adiabatic invariant and prompt losses which at times entirely eliminate the outer zone. Recent numerical studies suggest that enhanced ultra-low frequency (ULF) wave activity is necessary to explain electron losses deeper inside the magnetosphere than magnetopause incursion following CME-shock arrival. A combination of radial transport and magnetopause shadowing can account for losses observed at radial distances into L=4.5, well within the computed magnetopause location. We compare ULF wave …

Black Carbon Concentrations In Snow At Tronsen Meadow In Central Washington From 2012 To 2013: Temporal And Spatial Variations And The Role Of Local Forest Fire Activity, Ian Delaney, Susan D. Kaspari, Matthew Jenkins

Geological Sciences Faculty Scholarship

Characterizing black carbon (BC) concentrations in the seasonal snowpack is of interest because BC deposition on snow can reduce albedo and accelerate melt. In Washington State, USA snowmelt from the seasonal snowpack provides an important source of water resources, but minimal work has been done characterizing BC concentrations in snow in this region. BC concentrations in snow were monitored over two winters (2012 and 2013) at Tronsen Meadow, located near Blewett Pass in the eastern Cascade Mountains in Central Washington, to characterize spatial and temporal variations in BC concentrations, and the processes affecting BC concentrations in the snowpack. BC concentrations …

Simulation Of Groundwater Flow And Analysis Of The Effects Of Water-Management Options In The North Platte Natural Resources District, Nebraska, Steven M. Peterson, Amanda T. Flynn, Joseph Vrabel, Derek W. Ryter

United States Geological Survey: Water Reports and Publications

The North Platte Natural Resources District (NPNRD) has been actively collecting data and studying groundwater resources because of concerns about the future availability of the highly inter-connected surface-water and groundwater resources. This report, prepared by the U.S. Geological Survey in cooperation with the North Platte Natural Resources District, describes a groundwater-flow model of the North Platte River valley from Bridgeport, Nebraska, extending west to 6 miles into Wyoming. The model was built to improve the understanding of the interaction of surface-water and groundwater resources, and as an optimization tool, the model is able to analyze the effects of water-management options …

Public Schools Ask To Join Odu-Led Sea Level Rise Pilot Project, Public Affairs & News Bureau, Old Dominion University

News Items

No abstract provided.

Aviation Bird Hazard In Nexrad Dual Polarization Weather Radar Confirmed By Visual Observations, Bradley M. Muller, Frederick R. Mosher, Christopher G. Herbster, Anthony T. Brickhouse

International Journal of Aviation, Aeronautics, and Aerospace

Birds represent a significant hazard to flying aircraft as illustrated by the “Miracle on the Hudson” encounter in 2009 between U.S. Airways Flight 1549 and a flock of Canada Geese, forcing the flight to ditch in the river. Birds are common in the skies over Florida during the spring migration season, and often appear in the National Weather Service’s (NWS) NEXRAD weather radar imagery as an easily recognizable signature known as a “roost ring.” This paper presents a NEXRAD roost ring case in central Florida in a rare instance where the signatures were confirmed by visual observations of the birds. …

Global Optimized Isothermal And Nonlinear Models Of Earth’S Standard Atmosphere, Nihad E. Daidzic, Ph.D.,

International Journal of Aviation, Aeronautics, and Aerospace

Both, a global isothermal temperature model and a nonlinear quadratic temperature model of the ISA was developed and presented here. Constrained optimization techniques in conjunction with the least-square-root approximations were used to design best-fit isothermal models for ISA pressure and density changes up to 47 geopotential km for NLPAM, and 86 orthometric km for ISOAM respectively. The mass of the dry atmosphere and the relevant fractional-mass scale heights have been computed utilizing the very accurate eight-point Gauss-Legendre numerical quadrature for both ISOAM and NLPAM. Both, the ISOAM and the NLPAM represent viable alternatives to ISA in many practical applications and …

Retrieval Of Aerosol Microphysical Properties From Aeronet Photopolarimetric Measurements, Xiaoguang Xu

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Atmospheric aerosols play an important role in earth climate by scattering and absorbing solar and terrestrial radiation, and indirectly through altering the cloud formation, life- time, and radiative properties. However, accurate quantification of these effects is in no small part hindered by our limited knowledge about the particle size distribution (PSD) and refractive index, the aerosol microphysical properties essentially pertain to aerosol optical and cloud-forming properties. The research goal of this thesis is to obtain the aerosol microphysical properties of both fine and coarse modes from the polarimetric solar radiation measured by the SunPhotometer of the Aerosol Robotic Network (AERONET). …

Regional Ocean-Colour Chlorophyll Algorithms For The Red Sea, Robert J.W. Brewin, Dionysios E. Raitsos, Giorgio Dall'olmo, Nikolaos Zarokanellos, Thomas Jackson, Marie Fanny Racault, Emmanuel S. Boss, Shubha Sathyendranath, Burt H. Jones, Ibrahim Hoteit

Marine Sciences Faculty Scholarship

The Red Sea is a semi-enclosed tropical marine ecosystem that stretches from the Gulf of Suez and Gulf of Aqaba in the north, to the Gulf of Aden in the south. Despite its ecological and economic importance, its biological environment is relatively unexplored. Satellite ocean-colour estimates of chlorophyll concentration (an index of phytoplankton biomass) offer an observational platform to monitor the health of the Red Sea. However, little is known about the optical properties of the region. In this paper, we investigate the optical properties of the Red Sea in the context of satellite ocean-colour estimates of chlorophyll concentration. Making …

Ecological And Biogeographic Null Hypotheses For Comparing Rarefaction Curves, Luis Cayuela, Nicholas J. Gotelli, Robert K. Colwell

College of Arts and Sciences Faculty Publications

The statistical framework of rarefaction curves and asymptotic estimators allows for an effective standardization of biodiversity measures. However, most statistical analyses still consist of point comparisons of diversity estimators for a particular sampling level. We introduce new randomization methods that incorporate sampling variability encompassing the entire length of the rarefaction curve and allow for statistical comparison of i ≥ 2 individual-based, sample-based, or coverage-based rarefaction curves. These methods distinguish between two distinct null hypotheses: the ecological null hypothesis (H0eco) and the biogeographical null hypothesis (H0biog). H0eco states that the i samples were drawn from a single assemblage, and any differences …

Climate Change Resilience And Socioeconomic Impacts Of Mpas And Mpa Networks In The Caribbean - Case Study: Evaluation Of The Effectiveness Of The Management Of Mpas And Coastal Zones In The Dominican Republic, Andrea Isabella Vogel

HCNSO Student Capstones

Many Caribbean nations have established MPAs to preserve marine biodiversity and maintain their economically important marine resources. In some Caribbean nations, in particular the Dominican Republic, most MPAs have failed in these respects and have remained “paper parks” due to being modeled along traditional conservation lines without careful consideration of socioeconomic factors, good management practices or increasingly important climate change factors. Successful Caribbean MPAs and MPA networks effectively function as refuges, attractions, sources of socioeconomic development and ecosystem-based climate change resilience mechanisms. The latter is of utmost importance to Small Island Developing States (SIDS) and other larger island developing states …

Probing The Past 30-Year Phenology Trend Of Us Deciduous Forests, X. Yue, N. Unger, Xiaoyang Zhang, C.S. Vogel

GSCE Faculty Publications

Phenology is experiencing dramatic changes over deciduous forests in the USA. Estimates of trends in phenology on the continental scale are uncertain, however, with studies failing to agree on both the magnitude and spatial distribution of trends in spring and autumn. This is due to the sparsity of in situ records, uncertainties associated with remote sensing data, and the regional focus of many studies. It has been suggested that reported trends are a result of recent temperature changes, though multiple processes are thought to be involved and the nature of the temperature forcing remains unknown. To date, no study has …

Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman

STAR Program Research Presentations

Tropical forest soils have an important role in global carbon (C) stocks. Small changes in the cycling of C could drastically affect atmospheric carbon dioxide (CO2) concentrations and active cycling of carbon in a forest community. Currently, little is understood of how tropical forest soils will respond to the increasing global temperatures. To examine the effects of warming/ drought on losses of older versus younger soil C pools, we implemented radiocarbon (14C) isotopic characterization of various soil plot samples and depths from the Luquillo Experimental Forest, Puerto Rico. 14C was measured using Accelerated Mass Spectrometry (AMS) from catalytically condensed carbon …

Chesapeake Bay Nitrogen Fluxes Derived From A Land-Estuarine Ocean Biogeochemical Modeling System: Model Description, Evaluation, And Nitrogen Budgets, Yang Feng, Marjorie A.M. Friedrichs, John Wilkin, Hanqin Tian, Qichun Yang, Eileen E. Hofmann, Jerry D. Wiggert, Raleigh R. Hood

Faculty Publications

The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land-estuarine-ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within-estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite-derived data, and a simulation using environmental conditions for 2001–2005 was conducted to quantify the Chesapeake Bay nitrogen …

Predictability Of Sea Ice Near Bifurcations, Dawn Marie Kopacz

Theses and Dissertations

There is evidence in Earth’s history of relatively stable climate regimes abruptly transitioning to alternative states. It has been argued that the greatest potential for such abrupt transitions in Earth’s system in the near future is located in the Arctic. Here we analyze the Arctic sea ice evolution of two current generation climate models that exhibit critical transitions. We demonstrate the detectability of two early warning signals: increased variance and increased autocorrelation. We introduce another metric that forewarns of abrupt changes in sea ice; a decrease in predictability before the threshold points. Observations of Arctic sea ice extent are searched …

The Distribution Of Dissolved Barium Along The U.S. Geotraces North Atlantic Transect: Impact Of Biogeochemical Processes, Circulation And Phase Association, Karen Renee Grissom

Master's Theses

During the last four decades, since the completion of the GEOSECS program, there has been a growing interest in the biogeochemical cycle of barium (Ba) due to its potential as a proxy for interpreting the geologic record. The typical barium distribution exhibits removal in the upper water column and regeneration at depth, consistent with its classification as a bio-intermediate element and similar to the nutrient-like profiles of silicic acid and alkalinity. To better constrain the uses of Ba, trace element clean samples were collected during the North Atlantic US GEOTRACES cruises.

The cycling of barium in the North Atlantic region …

Time-Series Evaluation Of Suspect Rickettsiales-Like Bacteria Presence In Acropora Cervicornis Off Of Broward County From Years 2001–2012, Steven Di Lauro

HCNSO Student Theses and Dissertations

Rickettsiales-like organisms (RLOs) are thought to be related to bacteria in the order Rickettsiales. They have been reported to occur in the staghorn coral (Acropora cervicornis), and this study investigated trends of infection over time, and in relation to the health of infected corals. This study focuses on tissue samples taken mostly from visibly healthy A. cervicornis thickets in Broward County, Florida, and processed for histological examination. Samples were originally collected and analyzed to document reproduction during years 2001 through 2012, and tissue loss diseases (white-band disease [WBD] types I and II, and rapid tissue loss). …

A Comparative Evaluation Of Mitigation Wetlands In Broward County, Florida, Using Chironomid (Ditera) Pupal Exuviae: A Potential Technique For Assessing Mitigation Success, Ryan St. George

HCNSO Student Theses and Dissertations

Wetland resources in South Florida are regulated at three redundant jurisdictional levels: local or municipal regulations set forth by many independent jurisdictions, State regulations derived directly from Florida Statutes, and Federal regulations promulgated primarily under the Clean Water Act. All three levels of government can have jurisdiction over projects that affect regulated wetland resources, yet inconsistent policies and standards remain and continue to confound regulators despite decades of intensive coordination efforts and a rapidly growing scientific research base. The size of a wetland mitigation area is of primary consideration when evaluating its perceived ecological value, although wetland mitigation areas constructed …