Oceanography and Atmospheric Sciences and Meteorology Commons^™

Investigation Of Colored Dissolved Organic Matter And Dissolved Organic Carbon Using Combination Of Ocean Color Data And Numerical Model In The Northern Gulf Of Mexico, Nazanin Chaichitehrani

LSU Master's Theses

The first part of this thesis includes evaluating and developing empirical band ratio algorithms for the estimation of colored dissolved organic matter (CDOM) and dissolved organic carbon (DOC) for SeaWiFS, MODIS and MERIS ocean color sensors for the northern Gulf of Mexico. For CDOM, matchup comparison between SeaWiFS-derived CDOM absorption coefficients and in situ absorption measurements at 412 nm (aCDOM(412)) were examined using the D’Sa et al. (2006) and the Mannino et al. (2008) algorithms. These reflectance band ratio algorithms were also assessed to retrieve aCDOM(412) from MODIS and MERIS data using the Rrs(488)/Rrs(555) and Rrs(510)/Rrs(560) band ratios, respectively. Since …

Wet, Wild & Convivial? Investigating Australia’S Ocean Pools, Marie-Louise Mcdermott

ECU Research Week

No abstract provided.

Eukaryotic Microbes In The Deep Sea: Abundance, Diversity, And The Effect Of Pressure, Danielle Morgan-Smith

OES Theses and Dissertations

The dark ocean is vast, high in pressure, cold, and scarce in resources, but has been shown to support a diverse and active microbial community wherever it is studied. Such studies, however, are scarce due to the difficulty of sampling at such depths, and are difficult to interpret due to compounding effects of pressure and temperature on physiology. Protists, functionally defined as the microbial portion of the domain Eukarya, are particularly neglected in studies of deep-sea microbiology. Here, I present three studies on microbial eukaryotes in the deep sea: first, a study of the abundance of microbial eukaryotes in the …

Variability And Trends Of Aerosol Properties Over Kanpur, Northern India Using Aeronet Data (2001–10), Dimitris G. Kaskaoutis, Ramesh P. Singh, Ritesh Gautam, Manish Sharma, P. G. Kosmopoulos, S. N. Tripathi

Mathematics, Physics, and Computer Science Faculty Articles and Research

Natural and anthropogenic aerosols over northern India play an important role in influencing the regional radiation budget, causing climate implications to the overall hydrological cycle of South Asia. In the context of regional climate change and air quality, we discuss aerosol loading variability and trends at Kanpur AERONET station located in the central part of the Indo-Gangetic plains (IGP), during the last decade (2001-10). Ground-based radiometric measurements show an overall increase in column-integrated aerosol optical depth (AOD) on a yearly basis. This upward trend is mainly due to a sustained increase in the seasonal/monthly averaged AOD during the winter (Dec-Feb) …

Establishing Baseline Nutrient And Sediment Input In The Lower Cache River Watershed, Ar, A. M. Gilmer, C. A. Rosado-Berrios, J. L. Bouldin

Journal of the Arkansas Academy of Science

Contaminants in waterways continue to be a problem especially in watersheds dominated by land use changes such as agriculture. Clearing the land for agricultural use is needed to support the population; however, agricultural contaminants are cited as contributing the greatest input of suspended solids and nutrients to waterways. Quantifying various contaminants in surface water is useful in determining their origin, thus aiding in their mitigation. This study, focused on the Cache River Watershed, reports pH, dissolved oxygen (DO), conductivity, turbidity, total suspended solids (TSS), NO3 - , NO2 - , and PO4 3- in the lower sub watersheds. It was …

State Of The River Report For The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, And Contaminants 2012, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University

State of the River Report

No abstract provided.

Effect Of Hurricane Forward Speed And Approach Angle On Coastal Storm Surge, Chenguang Zhang

LSU Master's Theses

Hurricane induced storm surges can be destructive and can pose great threats to coastal communities. There are many factors affecting storm surges, including the hurricane’s intensity and movement, the bathymetry and coastline of affected area, rainfall, tide, and river stage. This thesis focuses on the effects of hurricane approach angle (θ) and forward speed (U), which together describe the hurricane’s motion. The problem is approached through several numerical experiments with increasing complexity. First are some process studies of long wave propagations near the coast, followed by examination of the generation of long waves by a traveling wind field. The central …

Nitrogen Biogeochemistry In A Restored Mississippi River Delta: A Modeling Approach, Benjamin Lee Branoff

LSU Master's Theses

There is evidence that significant reductions (about 50%) in surface water nitrate concentrations within coastal deltaic wetlands receiving diverted Mississippi River water can be contributed to denitrification. Yet there is also contrasting evidence that other processes could be responsible for this nitrate reduction. As Louisiana plans the implementation of major Mississippi River sediment diversions, a thorough understanding of nitrogen dynamics is necessary to reduce risks of coastal eutrophication and offshore hypoxia. A mechanistic numerical computer model has been developed to simulate nitrogen biogeochemistry within the wetlands of the prograding Wax Lake Delta. This model is calibrated to observed fluxes within …

The Effects Of Carbon On Nitrogen Transformations In Restored Wetland And Wastewater Soils, Jared M. Theriot

LSU Master's Theses

Since the industrialization of the Haber-Bosch process in the 1940’s, anthropogenic activity has nearly doubled the Earth’s nitrogen fixation. Furthermore, nitrate has become the number one groundwater contaminant in the United States and has harmful effects such as eutrophication, algal blooms, and pollution of drinking water. Soils from two sites influenced by high nitrate loading were examined to determine their biogeochemical integrity. First, the Loosahatchie Bar, located northwest of Memphis, Tennessee, is influenced by excess surface water nitrate loading by the Mississippi River. The Loosahatchie Bar is a newly restored wetland that now has similar hydrologic influence to an upstream …

Biomass And Mass Balance Isotope Content Of Mussel Seep Populations, Philip Martin Riekenberg

LSU Master's Theses

Cold seep mussels, Bathymodiolus childressi, are common cold seep constituents that form large populations at upper continental slope (500-1000 m) cold seep sites in the Northern Gulf of Mexico. These mussels utilize methane present through symbiotic relationships with methanotrophic bacteria. This study uses a coupled isotope technique to determine the relative incorporation of respiratory carbon in the shell as a measure of the availability of methane between different seep sites. This method indicates a higher abundance of methane at the Brine Pool site than at the Bush Hill site which appears significantly more resource limited and that changes in methane …

Effects Of Mimic Artificial Oyster Reefs On The Ecology Of Juvenile Fishes In Marsh Ponds: A Before-After-Control-Impact Analysis, Steven B. Garner

LSU Master's Theses

I sought to assess the enhancement potential of mimic artificial oyster reefs (MAORs) on trophic dynamics of juvenile estuarine fishes in marsh ponds. Tropic dynamics were investigated by determining the impacts of MAOR addition on meiofauna and macrofauna and then comparing these results to the gut contents and condition of four abundant estuarine fishes: Atlantic croaker (Micropogonias undulatus), bay whiff (Citharichthys spilopterus), sand seatrout (Cynoscion arenarius), and pinfish (Lagodon rhomboides). Samples were collected every other month for two years (March 2009 – 11) employing a Before-After-Control-Impact (BACI) design. Halfway through the experiment (March 2010), two mud sites in two marsh …

Occurrence, Toxicity, And Diversity Of Pseudo-Nitzschia In Florida Coastal Waters, Sheila O'Dea

USF Tampa Graduate Theses and Dissertations

Domoic acid (DA), a potent neurotoxin that has the potential to cause amnesic shellfish poisoning (ASP), is produced by members of the marine diatom genus Pseudo-nitzschia. Outbreaks of ASP in humans and of DA poisoning in birds and marine mammals have been reported across the United States and Canada since the late 1980's. Pseudo-nitzschia species can be extremely abundant in Florida waters, with densities often exceeding 10⁶ cells/L, and sometimes exceeding 10⁷ cells/L. Based on preliminary data, it is evident that at least nine species of Pseudo-nitzschia are found in Florida coastal waters. At least six of …

On The Spatial And Temporal Variability Of Upwelling In The Southern Caribbean Sea And Its Influence On The Ecology Of Phytoplankton And Of The Spanish Sardine (Sardinella Aurita), Digna Tibisay Rueda-Roa

USF Tampa Graduate Theses and Dissertations

The Southern Caribbean Sea experiences a strong upwelling process along the coast from about 61°W to 75.5°W and 10-13°N. In this dissertation three aspects of this upwelling system are examined: (A) A mid-year secondary upwelling that was previously observed in the southeastern Caribbean Sea between June-July, when land based stations show a decrease in wind speed. The presence and effects of this upwelling along the whole southern Caribbean upwelling system were evaluated, as well as the relative forcing contribution of alongshore winds (Ekman Transport, ET) and wind-curl (Ekman Pumping, EP). (B) Stronger upwelling occurs in two particular regions, namely the …

Sea Surface Height: A Versatile Climate Variable For Investigations Of Decadal Change, Philip Robert Thompson

USF Tampa Graduate Theses and Dissertations

Decadal variations in climate are important, because the magnitude of sustained decadal change is often much larger than the often discussed background trends. Climate variability at interannual and longer periods is most often discussed in the context of climate modes defined by sea level pressure (SLP) and sea surface temperature (SST) patterns. However, SLP and SST are not capable descriptors of ocean dynamics. The approximately two decades of global sea surface height (SSH) measurements from satellite altimetry reveal substantial low-frequency redistributions of heat and salt in the ocean, which may or may not be related to defined climate modes. In …

Thermal Determinants Of Nest Site Selection In Loggerhead Sea Turtles, Caretta Caretta, At Casey Key, Florida, Lindsey Nicole Flynn

USF Tampa Graduate Theses and Dissertations

Many environmental cues are thought to influence nest site selection by loggerhead sea turtles, Caretta caretta, and much debate exists over the possible influence of sand temperature. This study had two primary objectives: (1) to measure thermal differences across transects of a major nesting beach of Casey Key (28.7 N, 82.3 W), Florida and (2) to evaluate thermal pattern variation that influenced nesting patterns of adult female loggerhead sea turtles. A secondary objective of this study was to determine the efficacy of infrared thermometers to collect sand surface temperatures in the field.

Temperature data were collected from 145 nest …

Responses To Chemical Exposure By Foraminifera: Distinguishing Dormancy From Mortality, Benjamin James Ross

USF Tampa Graduate Theses and Dissertations

The Deepwater Horizon blowout in 2010 released an estimated 4.9 million barrels of crude oil into the Gulf of Mexico in the 83 days between the initial explosion and the capping of the well. Response included extensive use of Corexit© oil dispersant. Although South Florida was spared exposure by currents, this event highlights the need for effective bioassay organisms for coral reefs. Amphistegina spp. are benthic foraminifers that host diatom symbionts in a relationship similar to that of coral and their zooxanthellae. Amphistegina spp. occur abundantly in reef communities nearly worldwide, are easily collected and maintained in culture, and are …

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 …