Oceanography and Atmospheric Sciences and Meteorology Commons^™

Greenhouse Gas Fluxes In Southeastern U.S. Coastal Plain Wetlands Under Contrasting Land Uses, Jennifer L. Morse, Marcelo Ardón, Emily S. Bernhardt

Environmental Science and Management Faculty Publications and Presentations

Whether through sea level rise or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions about environmental trade-offs. Wetland restoration is often implemented in agricultural catchments to improve water quality through nutrient removal. Yet flooding of soils can also increase production of the greenhouse gases nitrous oxide and methane, representing a potential environmental trade-off. Our study aimed to quantify and compare greenhouse gas emissions from unmanaged and restored forested wetlands, as well as actively managed agricultural fields within the North Carolina coastal plain, USA. In sampling …

Habitat- And Region-Specific Reproductive Biology Of Female Red Snapper (Lutjanus Campechanus) In The Gulf Of Mexico, Dannielle Helen Kulaw

LSU Master's Theses

This study compares reproductive biology estimates of female red snapper among three habitat types (natural shelf-edge banks, standing petroleum platforms and toppled petroleum platforms) and among six regions in the Gulf of Mexico (central Florida, northwest Florida, Alabama, Louisiana, north Texas and south Texas). In both studies, batch fecundity and spawning frequency increased with length, weight and age, and batch fecundity was best correlated with maternal length. Gulf-wide, 75% maturity was achieved by age-3 and 100% maturity was reached by age-8. Sizes- and ages-at-maturity differed among habitat types and regions. Females from natural habitat reached 50% maturity the slowest (age-5, …

Hildebrandt Teaches Lessons About Tornadoes, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

An Evaluation Of Alternative Approaches For Simulating Animal Movement In Spatially-Explicit Individual-Based Models, Katherine Shepard Watkins

LSU Doctoral Dissertations

Simulating animal movement in spatially-explicit individual-based models (IBMs) is both challenging and critically important to accurately estimating population dynamics. I compared four distinct movement approaches or sub-models (restricted-area search, kinesis, event-based, and run and tumble) in a series of simulation experiments. I used an IBM loosely based on a small pelagic fish that simulated growth, mortality, and movement of a cohort on a 2-dimensional grid. First, I tested the sub-models calibrated (i.e., trained) with a genetic algorithm in one set of environmental conditions in three other novel environments. The sub-models performed well, except restricted-area search and event-based that needed to …

What Does The ¹⁴C Method For Estimating Photosynthetic Rates In The Ocean Really Measure?, Shaofeng Pei

LSU Doctoral Dissertations

The ¹⁴C method has been used extensively by both limnologists and oceanographers to measure photosynthetic rates in aquatic systems, and the large database of ¹⁴C measurements that now exists is the ground truth with which satellite algorithms for estimating marine photosynthetic rates on a basin and global scale have been calibrated. However, disconcerting uncertainties still remain with respect to whether and under what circumstances the ¹⁴C method provides an estimate of net or gross photosynthesis, or something in between. My study combined batch and continuous culture studies to clarify this ambiguous issue. The batch culture work with …

The Effects Of Climate On The Growth Of Winter Wheat And Spring Barley In An Irish Context, Adrian Kennedy

Theses

The climate of earth is always changing due to natural events, however it is thought that the rapid warming period currently taking place is primarily due human activity to (environmental protection agency 2012). Climate change is altering the environment and this will have consequences for agriculture (Teagasc publications 2012). In this study we examine the relationship between weather and the yield of winter wheat and spring barley in an Irish context using data gathered from 2004-2010 at the Teagasc Oak Park research centre in Carlow. The data was analysed using a mixed effect model to test which if any weather …

Disparities In Weather Education Across Professional Flight Baccalaureate Degree Programs, Thomas A. Guinn, Krista M. Rader, Thomas A. Guinn

Publications

The required meteorology coursework for 22 accredited professional flight baccalaureate degree programs was examined and compared. Significant differences were noted in both the number of required meteorology courses as well as the number of required meteorology credit hours. While all programs required at least one three-credit meteorology course, not all programs required an aviation-specific meteorology course. In addition to the required number of meteorology courses and credit hours, topics within the aviation-specific meteorology courses were also examined. The study showed the topics of “flight hazards” and “aviation weather reports and charts” were identified most frequently in course descriptions, followed third …

Process-Evaluation Of Tropospheric Humidity Simulated By General Circulation Models Using Water Vapor Isotopic Observations: 2. Using Isotopic Diagnostics To Understand The Mid And Upper Tropospheric Moist Bias In The Tropics And Subtropics, Camille Risi, David Noone, John Worden, Christian Frankenberg, Gabriele Stiller, Michael Kiefer, Bernd Funke, Kaley Walker, Peter Bernath, Matthias Schneider, Sandrine Bony, Jeonghoon Lee, Derek Brown, Christophe Sturm

Chemistry & Biochemistry Faculty Publications

Evaluating the representation of processes controlling tropical and subtropical tropospheric relative humidity (RH) in atmospheric general circulation models (GCMs) is crucial to assess the credibility of predicted climate changes. GCMs have long exhibited a moist bias in the tropical and subtropical mid and upper troposphere, which could be due to the mis-representation of cloud processes or of the large-scale circulation, or to excessive diffusion during water vapor transport. The goal of this study is to use observations of the water vapor isotopic ratio to understand the cause of this bias. We compare the three-dimensional distribution of the water vapor isotopic …

Grazing On Synechococcus Spp. By The Red-Tide Dinoflagellate Karenia Brevis: Implications For Bloom Dynamics In The Gulf Of Mexico, Leo A. Procise

OES Theses and Dissertations

Karenia brevis, the toxic dinoflagellate responsible for massive red tides in the Gulf of Mexico (GOM), causes fish kills, shellfish poisoning, and acute respiratory irritation in humans. Bloom initiation and maintenance have been linked to the physical environment as well as various nutrient input mechanisms. To date, efforts to quantify nitrogen (N) sources fueling K. brevis blooms in the GOM have not included mixotrophic grazing although many dinoflagellates, including K. brevis, are known to be capable of mixotrophy. This dissertation reports field and laboratory results demonstrating that natural bloom populations and K. brevisisolates from the West Florida …

Do Bioclimate Variables Improve Performance Of Climate Envelope Models?, James I. Watling, Stephanie S. Romanach, David N. Bucklin, Carolina Speroterra, Laura A. Brandt, Leonard G. Pearlstine, Frank J. Mazzotti

United States Geological Survey: Staff Publications

Climate envelope models are widely used to forecast potential effects of climate change on species distributions. A key issue in climate envelope modeling is the selection of predictor variables that most directly influence species. To determine whether model performance and spatial predictions were related to the selection of predictor variables, we compared models using bioclimate variables with models constructed from monthly climate data for twelve terrestrial vertebrate species in the southeastern USA using two different algorithms (random forests or generalized linear models), and two model selection techniques (using uncorrelated predictors or a subset of user-defined biologically relevant predictor variables). There …

History And Evaluation Of National-Scale Geochemical Data Sets For The United States, David B. Smith, Steven M. Smith, John D. Horton

United States Geological Survey: Staff Publications

Six national-scale, or near national-scale, geochemical data sets for soils or stream sediments exist for the United States. The earliest of these, here termed the ‘Shacklette’ data set, was generated by a U.S. Geological Survey (USGS) project conducted from 1961 to 1975. This project used soil collected from a depth of about 20 cm as the sampling medium at 1323 sites throughout the conterminous U.S. The National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance (NUREHSSR) Program of the U.S. Department of Energy was conducted from 1975 to 1984 and collected either stream sediments, lake sediments, or soils at more …

Remote Sensing Of Evapotranspiration For Operational Drought Monitoring Using Principles Of Water And Energy Balance, Gabriel B. Senay, Stefanie Bohms, James P. Verdin

United States Geological Survey: Staff Publications

Evapotranspiration (ET) is an important component of the hydrologic budget because it reflects the exchange of mass and energy between the soil–water–vegetation system and the atmosphere. Prevailing weather conditions influence potential or reference ET through variables such as radiation, temperature, wind, and relativity humidity. In addition to these weather variables, actual ET (ET_a) is also affected by land cover type and condition, as well as soil moisture. The dependence of ET_a on land cover and soil moisture, and its direct relationship with carbon dioxide assimilation in plants, makes it an important variable for monitoring drought, crop yield, …

On Thinning Of Chains In Mcmc, William A. Link, Mitchell J. Eaton

United States Geological Survey: Staff Publications

1. Markov chain Monte Carlo (MCMC) is a simulation technique that has revolutionised the analysis of ecological data, allowing the fitting of complex models in a Bayesian framework. Since 2001, there have been nearly 200 papers using MCMC in publications of the Ecological Society of America and the British Ecological Society, including more than 75 in the journal Ecology and 35 in the Journal of Applied Ecology.

2. We have noted that many authors routinely ‘thin’ their simulations, discarding all but every kth sampled value; of the studies we surveyed with details on MCMC implementation, 40% reported thinning.

3. Thinning …

Sea-Level History During The Last Interglacial Complex On San Nicolas Island, California: Implications For Glacial Isostatic Adjustment Processes, Paleozoogeography And Tectonics, Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Lindsey T. Groves, Jerry X. Mitrovica, Deanna Laurel

United States Geological Survey: Staff Publications

San Nicolas Island, California has one of the best records of fossiliferous Quaternary marine terraces in North America, with at least fourteen terraces rising to an elevation of ~270 m above present-day sea level. In our studies of the lowest terraces, we identified platforms at 38–36 m (terrace 2a), 33–28 m (terrace 2b), and 13–8 m (terrace 1). Uranium-series dating of solitary corals from these terraces yields three clusters of ages: ~120 ka on terrace 2a (marine isotope stage [MIS] 5.5), ~120 and ~100 ka on terrace 2b (MIS 5.5 and 5.3), and ~80 ka (MIS 5.1) on terrace 1.We …

Tectonic Influences On The Preservation Of Marine Terraces: Old And New Evidence From Santa Catalina Island, California, R. Randall Schumann, Scott A. Minor, Daniel R. Muhs, Lindsey T. Groves, John P. Mcgeehan

United States Geological Survey: Staff Publications

The California Channel Islands contain some of the best geologic records of past climate and sea-level changes, recorded in uplifted, fossil-bearing marine terrace deposits. Among the eight California Channel Islands and the nearby Palos Verdes Hills, only Santa Catalina Island does not exhibit prominent emergent marine terraces, though the same terrace-forming processes that acted on the other Channel Islands must also have occurred on Santa Catalina. We re-evaluated previous researchers' field evidence and examined new topographic, bathymetric, and stream-profile data in order to find possible explanations for the lack of obvious marine terrace landforms or deposits on the island today. …

Patterns Of Extinction Risk And Threat For Marine Vertebrates And Habitat-Forming Species In The Tropical Eastern Pacific, Beth A. Polidoro, T. Brooks, Kent E. Carpenter, G. J. Edgar, S Henderson, J. Sanciangco, D. R. Robertson

Biological Sciences Faculty Publications

Marine conservation activities around the globe are largely undertaken in the absence of comprehensive species-specific information. To address this gap, complete regional species assemblages of major marine taxa are being progressively assessed against the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. The present study is the first analysis of entire major components of the biota of a large marine biogeographic region conducted in the Tropical Eastern Pacific (TEP). It is based on recently completed IUCN Red List assessments for all known species of bony and cartilaginous shorefishes, corals, mangroves, …

Recent Changes In The Growth And Nutrient Limitation Of Benthic And Pelagic Algae In Arctic Tundra Ponds, Christina Hernandez

Open Access Theses & Dissertations

Arctic ponds are a dominant feature in Barrow, Alaska. Ponds may function as carbon sinks during the growing season from production of photosynthetic organisms like algae; however, little work has been done on this topic. Environmental changes have been occurring in the Arctic stemming from climate change and human perturbations. The focus of this study was to assess a historically studied region for changes in algal primary production that may have been produced due to increases in temperature over the past 40 years and increased human development. Additionally, this study aimed to determine nutrient limitation of algal production in the …

Analysis Of Aerosol Particle Size Distributions Observed During Aerose V Campaign, Mariana Guereque

Open Access Theses & Dissertations

The African continent is the principal contributor of mineral aerosols into the atmosphere. It is also a significant source of carbonaceous aerosols resulting from rampant biomass burning activities. Both aerosol types have a profound impact on climate change and are an important factor in climate modeling, regional weather forecasting, as well as health-impact studies. Due to their importance, it is beneficial to characterize the transport and evolution of these aerosols from their origins in Africa, across the Atlantic Ocean and into the Americas. In-situ aerosol number distributions were collected during the 2009 Aerosols and Ocean Science Expeditions (AEROSE) V campaign, …

Acoustic Sensing Of Gas Seeps In The Deep Ocean With Split-Beam Echosounders, Thomas C. Weber, Kevin W. Jerram, Larry A. Mayer

Center for Coastal and Ocean Mapping

When in the form of free gas in the water column, methane seeps emanating from the seabed are strong acoustic targets that are often detectable from surface vessels using echo sounders.In addition to detecting that a seep is present at some location, it is also desirable to characterize the nature of the seep in terms of its morphology and flux rates. Here, we examine how much we can learn about seeps in the deep (> 1000 m) northern Gulf of Mexico using narrow-band split-beam echo sounders operating at fixed frequencies (18 kHz and 38 kHz).Methane seeps in this region are …

Circulation And Water Properties And Their Relationship To The Oyster Disease Msx In Delaware Bay, Zhiren Wang, Dale B. Haidvogel, David Bushek, Susan E. Ford, Eileen E. Hofmann, Eric N. Powell, John Wilkin

CCPO Publications

We apply a high-resolution hydro-dynamical model to investigate the role of physical factors influencing infection prevalence of Haplosporidium nelsoni, causative agent of MSX disease in the eastern oyster (Crassostrea virginica), in Delaware Bay, USA. Validation studies conducted for the years 2000 and 2010-2011 confirm that the model, based upon the Regional Ocean Modeling System, has significant skill in the recovery of observed water level, temperature, salinity, and velocity. Multi-year simulations are performed for periods representing temporal and spatial variations in H. nelsoni infection prevalence (1974-76, 1979-81, 1984-86, 1990-92, and 2006-09) to assess the degree to which the …