Oceanography and Atmospheric Sciences and Meteorology Commons^™

The Tropical Cyclone Diurnal Cycle, Jason Paul Dunion

Legacy Theses & Dissertations (2009 - 2024)

The research presented in this thesis explores a phenomenon referred to as the tropical cyclone (TC) diurnal cycle (TCDC) and presents satellite, numerical modeling, and observational perspectives pertaining to how it can be monitored, its evolution in time and space, its relevance to TC structure and intensity, and how it manifests in numerical simulations of TCs. Infrared satellite imagery was developed and used to investigate diurnal oscillations in TCs and finds a diurnal pulsing pattern that occurs with notable regularity through a relatively deep layer from the inner core to the surrounding environment. A combination of satellite, numerical model simulations, …

Understanding The Dependence Of Radiative Feedbacks And Clouds On The Spatial Structure Of Ocean Heat Uptake, Lance Rayborn

Legacy Theses & Dissertations (2009 - 2024)

Ocean heat uptake and radiative forcing are important for understanding transient climate change. Differences in efficacy of ocean heat uptake (suppression of surface warming per unit energy flux into the deep oceans relative to CO2 forcing) account for a substantial fraction of the spread in transient warming between models. Rose et al. (2014) studied the dependence of efficacy on the spatial pattern of ocean heat uptake in an ensemble of aquaplanet simulations with prescribed ocean heat uptake, and found large differences in model responses to high versus low latitude uptake. This study accurately quantifies these model responses through the use …

Examination Of Water Vapor Characteristics During The 2013 Colorado Flood, Hannah Kristine Huelsing

Legacy Theses & Dissertations (2009 - 2024)

During September 9-16, 2013, the Front Range region of Colorado experienced heavy rainfall which resulted in severe flooding. Precipitation totals during the event exceeded 450mm in Boulder, Colorado, 9 lives were lost, and damages to public and private properties were estimated to be over $2 billion. This study analyzes the characteristics of water vapor surrounding the event, including the abnormality of total column water vapor, the sources of moisture, and the relationship between water vapor and precipitation characteristics. It was found that the atmosphere was very near saturation during the duration of the event and monthly-averaged precipitable water (PW) was …

Air-Sea Carbon Dioxide Exchange In The Southern Ocean And Antarctic Sea Ice Zone, Brian Butterworth

Legacy Theses & Dissertations (2009 - 2024)

The Southern Ocean is an important part of the global carbon cycle, responsible for roughly half of the carbon dioxide (CO2) absorbed by the global ocean. The air-sea CO2 flux (Fc) can be expressed as the product of the water-air CO2 partial pressure difference (ΔpCO2) and the gas transfer velocity (k), an exchange coefficient which represents the efficiency of gas exchange. Generally, Fc is negative (a sink) throughout the Southern Ocean and Antarctic sea ice zone (SIZ), but uncertainty in k has made it difficult to develop an accurate regional carbon budget. Constraining the functional dependence of k on wind …

Chilean Coastal Orographic Precipitation Experiment : A Tale Of Two Rain Regimes, Adam Massmann

Legacy Theses & Dissertations (2009 - 2024)

The Chilean Coastal Orographic Precipitation Experiment Pilot Project (CCOPE-2015) was an exploratory field campaign to better understand the mechanisms of orographic precipitation enhancement in the Nahuelbuta Mountains of Southern Chile (38 deg. S.). Observations collected include: (1) surface rainfall from a network of 10 data logging rain gauges, (2) vertical precipitation profiles from a pair of K-band Micro Rain Radars, (3) rain drop size distributions from an optical disdrometer, (4) upstream wind and thermodynamic profiles from radiosonde launches, and (5) aerosol number concentration and size distribution measurements from a condensation particle counter and an ultra-high sensitivity aerosol spectrometer.

Hydroclimate Changes In The South-Central Great Plains Of The United States : A Synoptic Approach, Pawel Slaski

Legacy Theses & Dissertations (2009 - 2024)

Hydroclimate changes over the Southern Central Great Plains (SCGP) of the United States have been occurring throughout the last century. These changes have had a major impact on the local ecosystems, agriculture, and human society in the region by, e.g., producing a higher frequency of drought over the last century. Climate models project further increases of drought in the 21st century over this region under increasing greenhouse gases. This study analyzes climate model simulations to examine changes in synoptic conditions associated with the projected drought increases over the SCGP. Synoptically, mesoscale convective complexes (MCCs) produce a large portion of the …

The Network Average Gust Factor, Its Measurement And Environmental Controls, And Role In Gust Forecasting, Alexander Austin Gallagher

Legacy Theses & Dissertations (2009 - 2024)

There exists a strong, well documented linear relationship between network averaged sustained (or mean) wind and gust speeds within the San Diego Gas and Electric (SDGE) mesonet that is characterized by the slope of the linear regression between the two known as the network average gust factor (GF). The network average GF potentially contains information on the average obstruction of the stations within the network and when paired with numerical model output, may be used for gust prediction. Using the network average GF for gust prediction can also result in the correction of biases due to poorly resolved terrain or …

Gross And Microscopic Lesions In Corals From Micronesia, T. M. Work, G. S. Aeby, K. A. Hughen

United States Geological Survey: Staff Publications

The authors documented gross and microscopic morphology of lesions in corals on 7 islands spanning western, southern, and eastern Micronesia, sampling 76 colonies comprising 30 species of corals among 18 genera, with Acropora, Porites, and Montipora dominating. Tissue loss comprised the majority of gross lesions sampled (41%), followed by discoloration (30%) and growth anomaly (29%). Of 31 cases of tissue loss, most lesions were subacute (48%), followed by acute and chronic (26% each). Of 23 samples with discoloration, most were dark discoloration (40%), with bleaching and other discoloration each constituting 30%. Of 22 growth anomalies, umbonate growth anomalies composed …

Bioaccessibility Tests Accurately Estimate Bioavailability Of Lead To Quail, W. Nelson Beyer, Nicholas T. Basta, Rufus L. Chaney, Paula F.P. Henry, David E. Mosby, Barnett A. Rattner, Kirk G. Scheckel, Daniel T. Sprague, John S. Weber

United States Geological Survey: Staff Publications

Hazards of soil-borne lead (Pb) to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, the authors measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from 5 Pb-contaminated Superfund sites had relative bioavailabilities from 33% to 63%, with a mean of approximately 50%. Treatment of 2 of the soils with phosphorus (P) significantly reduced the bioavailability …

A Personal Perspective On Searching For The Ivory-Billed Woodpecker: A 41-Year Quest, Paul W. Sykes Jr.

United States Geological Survey: Staff Publications

I first learned about the Patuxent Wildlife Research Center (Patuxent) in Laurel, MD, while attending high school in the mid-1950s. Patuxent wildlife biologists Brooke Meanley, Chandler (Chan) S. Robbins, and Robert (Bob) E. Stewart, Sr., visited me at my parents’ home in Norfolk, VA. I was the compiler of the Norfolk County Christmas Bird Count (which included the eastern portion of the Virginia sector of the Dismal Swamp). As part of that count, we had for several years been estimating populations of red-winged blackbirds (Agelaius phoeniceus) and common grackles (Quiscalus quiscula) in the millions. Patuxent was …

Patuxent’S Role In The Development Of The North American Breeding Bird Survey, John R. Sauer

United States Geological Survey: Staff Publications

The North American Breeding Bird Survey (BBS) is a roadside survey of the breeding birds of North America. The BBS provides data from the contiguous United States, Alaska, southern and central Canada, and northern Mexico. Begun in 1966 by Chandler (Chan) S. Robbins at the U.S. Geological Survey (USGS) Patuxent Wildlife Research Center (Patuxent), and now jointly managed by Patuxent, the Canadian Wildlife Service, and the Mexican Commission for the Knowledge and Use of Biodiversity, the survey is conducted primarily in June along more than 5,000 roadside survey routes that are surveyed once each year. Volunteer observers drive the 39.4-kilometer …

Patuxent’S Long-Term Research On Wolves, David L. Mech

United States Geological Survey: Staff Publications

The gray wolf (Canis lupus) was one of the first species placed on the Endangered Species List in 1967. The Endangered Species Act of 1973 legally protected the wolf along with other listed species. Patuxent Wildlife Research Center (Patuxent) in Laurel, MD, began its Endangered Wildlife Program in 1966, and U.S. Fish and Wildlife Service (USFWS) biologist Ray Erickson was assigned to lead it. In 1973, I was transferred to the program from Region 3 of the USFWS, having been employed there since 1969 to study wolves in Minnesota. Endangered Species Act protection of the wolf fostered its …

A Spatio-Temporal Comparison Of Avian Migration Phenology Using Citizen Science Data, Ali Arab, Jason R. Courter, Jessica Zelt

United States Geological Survey: Staff Publications

The effects of climate change have wide-ranging impacts on wildlife species and recent studies indicate that birds’ spring arrival dates are advancing in response to changes in global climates. In this paper, we propose a spatio-temporal approach for comparing avian first arrival data for multiple species. As an example, we analyze spring arrival data for two long-distance migrants (Rubythroated Hummingbird Archilochus colubris; and Purple Martin Progne subis) in eastern North America from 2001–2010 using Citizen Science data. The proposed approach provides researchers with a tool to compare mean arrival dates while accounting for spatial and temporal variability. Our results show …

Phosphorus Retention In A Lowland Neotropical Stream Following An Eight-Year Enrichment Experiment, Gaston E. Small, Marcelo Ardón, John H. Duff, Alan P. Jackman, Alonso Ramírez, Frank J. Triska, Catherine M. Pringle

United States Geological Survey: Staff Publications

Human alteration of the global P cycle has led to widespread P loading in freshwater ecosystems. Much research has been devoted to the capacity of wetlands and lakes to serve as long-term sinks for P inputs from the watershed, but we know much less about the potential of headwater streams to serve in this role. We assessed storage and retention of P in biotic and abiotic compartments after an 8-y experimental P addition to a 1st-order stream in a Neotropical wet forest. Sediment P extractions indicated that nearly all P storage was in the form of Fe- and Al-bound P …

Droughtscape, Winter 2016, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Director’s column

California drought FAQ

October-December 2015 drought

October-December 2015 impacts

2015 drought impacts in review

NDMC hiring geospatial analyst

CA drought exposes social vulnerability

UA helps Arizona ranchers, Forest Service work together

NDMC and partners help southern Plains ranchers manage drought

Chickasaw ranching workshop

Sensitivity Of Maize Yield Potential To Regional Climate In The Southwestern U.S., Seung Hee Kim, Boksoon Myoung, David Stack, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The sensitivity of maize yields to the regional climate in the Southwestern U.S. (SWUS) has been investigated by using the Agricultural Production Systems sIMulator (APSIM) model in conjunction with meteorological forcings [daily maximum and minimum temperature (Tmax and Tmin), precipitation, and radiation] from the North American Regional Reanalysis (NARR) dataset. Sensitivity experiments showed that potential crop production responded nonlinearly to variations in Tmax, Tmin, and downwelling solar radiation at the surface. Mean annual yield potential (Yp) was changed by -3.0 and 1.79 Mg ha-1 for the +1 and -1 standard deviations (σ) of Tmax variation for entire the SWUS. The …

The Effect Of Restoration On Nitrate Reduction And Biogeochemical Functioning In Louisiana Wetlands: Bottomland Hardwood Forests And Deltaic Sediments, Nia R. Hurst

LSU Master's Theses

Nitrogen loading in the Mississippi River from increased N fertilization of agricultural land helps to trigger an area of hypoxic water in the northern Gulf of Mexico (GOM) every summer. Louisiana wetlands can play a vital role in removing nitrate from river waters prior to discharge in the GOM. However, Louisiana’s wetlands have experienced significant losses in recent years. Efforts to restore wetlands include reconnecting floodplain wetlands to rivers and utilizing river diversions to re-introduce sediment to coastal wetlands. Increasing wetland connection to rivers can reduce water nitrate by expanding opportunities for nitrate reduction. I examined soil physicochemical properties, microbial …

Simulating Behavioral Microcystin Impairment In Fish, Nicholas Richard Keeney

LSU Master's Theses

Fish experiencing blooms of the cyanobacteria genera Microcystis and Anabaena acquire microcystin and saxitoxin through ingestion of contaminated food and absorption of dissolved toxin. Even low chronic doses induce sensory and motor impairment—the impact of which is unquantified in wild populations. Here, I introduce Lagrangian particle models for cyanobacteria and fish which test the hypotheses that impairment symptoms suppress movement and growth. This is implemented within the Finite-Volume Coastal Ocean Model (FVCOM). Cyanobacteria particles move vertically according to mixing and buoyancy (a function of cellular reservoirs). Fish navigate the horizontal domain, foraging in high growth areas, and fleeing when toxin …

A Contemporary Approach To A Classic Model: Exploring The Influence Of Local Interactions And Disturbance On Mangrove Forest Dynamics With A Spatially-Explicit Version Of Forman, Kieley Shannon Hurff

LSU Master's Theses

The mangrove forest gap dynamic model, FORMAN, was the first individual-based model (IBM) to simulate the long-term successional dynamics of three Caribbean mangrove species, Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle. Assumptions under the spatially implicit approach of gap dynamic models limit their application to small-scale simulations. An expanded, spatially-explicit version of FORMAN was developed to allow for simulations of larger spatial grids, through the inclusion of localized soil conditions and neighborhood-based light resource competition. This expanded model was used to investigate the influence of localized interactions and disturbances of varying size on forest dynamics. A data-model comparison using field …

Investigating Species And Population Level Foraging Variation And Individual Specialization In Pygoscelis Penguins Using Stable Isotope Analysis, Rachael W. Herman

LSU Master's Theses

Gentoo Penguins (Pygoscelis papua) are known to be generalist foragers, while Adélie (P. adeliae) and Chinstrap (P. Antarctica) tend to specialize on krill within the Western Antarctic Peninsula and South Shetland Islands, particularly during the breeding season. However, little is known on temporal consistency in diet and foraging habitat of these species, particularly at the individual level. We used stable isotope analysis (SIA) of blood and feathers to evaluate seasonal and individual foraging consistency within Adélie, Chinstrap and Gentoo Penguins breeding in the South Shetland Islands, as well as among three Gentoo Penguins’ populations in the Western Antarctic Peninsula and …

Fishes Associated With Oil And Gas Platforms In Louisiana's River-Influenced Nearshore Waters, Ryan Thomas Munnelly

LSU Master's Theses

A distinctive feature of coastal Louisiana is the unrivaled network of oil and gas installations (platforms) extending from inshore waters to the deep Gulf of Mexico. Since 2007 there has been a 38% reduction in platform numbers with the highest removal rates occurring in shallow (< 18 m) nearshore waters. Many fishes and invertebrates are attracted to platforms, presenting a unique opportunity to study detailed species-specific responses to the river-influenced hydrographic characteristics of Louisiana’s nearshore zone (5–25 km water depth). Prior studies of fishes around platforms focused on a few relatively large platforms in water depths ≥ 18 m. However, about one-third of all platforms are small, unmanned and non-drilling platforms located in waters < 18 m depth. Paired video and hydrographic data were collected at 150 small platforms in < 18 m water depth during the summers of 2013–2014. Fifty-four species of fishes were associated with small platforms. The assemblage(s) included juveniles of 29 species, indicating the importance of nearshore platforms as diverse nursery habitat. The coastal zone was divided into three regions based on broad-scale interactions between freshwater input and bathymetry driving major distinctions in interregional hydrography and fish assemblages. Co-occurring within this expansive artificial reef network is the second largest hypoxic area (dissolved oxygen (DO) < 2.0 mg l−1) on Earth. Platforms offer reef-like habitat features in the upper water column that may offer refugia for some reef-associated species during hypoxic events. Significant intraregional differences in physicochemical features were related to the presence of hypoxia (defined as DO < 50% saturation), as well as the distribution of sandy shoals. Eleven species accounted for most of the assemblage dissimilarities, composing ~93% of fishes observed. Habitat suitability indices for these 11 species provided information about habitat selection across horizontal and vertical physicochemical gradients throughout the coastal zone, and within hypoxic and well-oxygenated stratified water columns. East Bay, near the outlet of the Mississippi River, exhibited less hypoxia and a distinct fauna that included four adult goliath grouper (Epinephelus itajara). This endangered fish was observed during spawning season (summer), suggesting that East Bay might support a spawning aggregation.

Characterization And Modeling Of Sediment Settling, Consolidation And Suspension To Optimize The Retention Rate Of Sediment Diversions For Coastal Restoration, Xiaoyu Sha

LSU Master's Theses

Many research efforts have been made to the Mississippi coastal restoration, but long-term rheological and sedimentological experiments for sediment erosion, deposition and consolidation in diversion receiving basins are still lacking. Push cores and sediment samples were collected from West Bay, a semi-enclosed bay located on the Mississippi River Delta, and Big Mar pond, a receiving basin of the Caernarvon freshwater diversion from the Mississippi River, Louisiana. A dual-core Gust Erosion Microcosm System was used to measure time-series (0.5, 1, 2, 3, 4, 5, and 6-month after initial settling) erodibility at seven shear stress regimes (0.01-0.60 Pa) using experimental cores prepared …

The Effect Of Artificial Light On The Community Structure And Distribution Of Reef-Associated Fishes At Oil And Gas Platforms In The Northern Gulf Of Mexico, Victoria Anne Barker

LSU Master's Theses

The northern Gulf of Mexico (GOM) contains approximately 2,500 oil and gas platforms, resulting in one of the largest de facto artificial reef systems in the world. As of 2013, 1,227 additional structures had ceased to produce oil and gas and have been decommissioned and removed. While active platforms are lit by high-pressure mercury vapor lights, inactive platforms are only minimally lit for navigation. The positively phototaxic behavior of many fish species causes lit oil platforms to act as fish attraction devices, especially at night. Though a variety of fish species have been reported near these structures, changes in fish …

Feeding Ecology Of Red Snapper And Greater Amberjack At Standing Platforms In The Northern Gulf Of Mexico: Disentangling The Effects Of Artificial Light, Kristin Leanne Foss

LSU Master's Theses

Approximately 2,300 petroleum platforms are currently operating in the Gulf of Mexico (GOM), and are estimated to provide an additional 4 to 12 km2 of artificial reef habitat. The ecological role of platforms has often been overlooked and little is known about the effect of artificial light from the active platforms on surrounding fish communities. This is the first study to address the potential impacts of artificial light on the trophic ecology of fish communities surrounding offshore platforms through gut content (GCA) and stable isotope (SIA) analyses. Red snapper (Lutjanus campechanus) were collected quarterly from February 2014 to November 2015 …

A Step In The Right Direction: Streambank Restoration Efforts At The Botanical Garden Of The Ozarks, Dylan S. Milholen, Madison Brown, Steven Thao, Lisa S. Wood

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The Botanical Garden of the Ozarks (BGO) is a unique destination in Northwest Arkansas that draws more than 80,000 visitors a year. While the BGO manages low-input practices, run-off from pesticide application and synthetic fertilizers containing phosphorus and nitrogen are of concern to water quality, habitat, and overall ecological interactions of the BGO streambanks and adjacent Hilton Creek, which flows directly into Lake Fayetteville. One way to reduce pollution to waterbodies is through the use of riparian buffers. This project sought to establish a riparian buffer immediately adjacent to a portion of Hilton Creek in an effort to improve ecological …

Coastal Ecosystem Resiliency After Major Disturbances, Giovanna Mcclenachan

LSU Doctoral Dissertations

Disturbances are a common occurrence in coastal ecosystems and can provide opportunity for adaptation and renewal in healthy systems; hurricanes bring mineral accretion to a marsh, floods provide a pulse of freshwater and nutrients to estuaries, and fires increase species diversity and abundance in forests. Humans, however, have depleted the resiliency of many coastal systems via top down and bottom up mechanisms, leaving these ecosystems more vulnerable to both natural and anthropogenic disturbances. Louisiana’s wetlands have been modified for centuries via canals, levees, agricultural impoundments, etc., leading to a decreased resiliency to land loss. The Deepwater Horizon (DWH) oil spill …

Changing Winds And Rising Tides On Beach Renourishment In Florida: Short-Term Alternatives And Long-Term Sustainable Solutions Using Law And Policy From Florida And Nearby States, Lewis Van Alstyne Iii

Florida A & M University Law Review

Sandy beaches make up 825 miles of Florida's 1,260 total miles of coastline around the Sunshine State's peninsula. These beaches are changing over time due to the natural erosional forces of wind and water. Coastal engineering attempts to halt natural forces with man-made structures such as buildings, piers, groins, jetties, breakwaters, sea walls, ports, inlets, and in some cases, it creates new sandy beaches and world-class cities where none existed. In an effort to protect the new real estate from the erosion that has always existed, engineers created beach nourishment. This Article focuses on building up beaches through beach nourishment. …

Data From: How Uncertainty In The Neutral Wind Limits The Accuracy Of Ionospheric Modeling And Forecasting, Michael David, Jan Sojka, Robert W. Schunk

Browse all Datasets

Output files from runs of the TDIM ionospheric model used for the figures and calculations in the article in JGR Space Physics.

River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2016, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Gerry Pinto, Nisse Goldberg, Radha Pyati, Peter Bacopoulos, Anthony Ouellette, Gretchen Bielmyer-Fraser, An-Phong Le, Ray Oldakowski

State of the River Report

No abstract provided.

Assessing The Impact Of Vertical Land Motion On Twentieth Century Global Mean Sea Level Estimates, B. D. Hamlington, P. Thompson, W. C. Hammond, G. Blewitt, R. D. Ray

CCPO Publications

Near-global and continuous measurements from satellite altimetry have provided accurate estimates of global mean sea level in the past two decades. Extending these estimates further into the past is a challenge using the historical tide gauge records. Not only is sampling nonuniform in both space and time, but tide gauges are also affected by vertical land motion (VLM) that creates a relative sea level change not representative of ocean variability. To allow for comparisons to the satellite altimetry estimated global mean sea level (GMSL), typically the tide gauges are corrected using glacial isostatic adjustment (GIA) models. This approach, however, does …