Oceanography and Atmospheric Sciences and Meteorology Commons^™

A Three-Year Study Of The Magnetic Field Fluctuations In The Magnetospheric Cusp, Christina Seiman Chu

Master's Theses - Daytona Beach

The high-altitude magnetospheric cusps are regions of significant magnetic field turbulence. There are also magnetic field fluctuations that cannot be called turbulence. Some of the low frequency fluctuations observed in the cusp have been shown to be motion of the cusp structure by the spacecraft (back and forth motion of the boundaries surrounding the cusp); others are transient reconnection signatures or flux transfer events (FTEs). Turbulence is important to understand because it has been proposed as a mechanism for particle energization in the cusps to MeV levels. High resolution magnetic field data from the Fluxgate Magnetometer instruments on the Cluster …

R/V Thompson Em302 Sat -- Cruise Report, Jonathan Beaudoin, Val E. Schmidt

Center for Coastal and Ocean Mapping

No abstract provided.

Plankton Community Respiration And Productivity For The Louisiana Offshore Ecosystem, July 2007 Results, Brandon Michael Boyd

Honors Capstones

No abstract provided.

Wave Heights During Hurricane Katrina: An Evaluation Of Ppp And Ppk Measurements Of The Vertical Displacement Of The Gps Antenna, Stephan D. Howden, David Dodd, Leslie C. Bender Iii, Norman Guinasso, Josh Kohut

Faculty Publications

In August 2005 the eye of Hurricane Katrina passed 49 n mi to the west of a 3-m discus buoy operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). Buoy motions were measured with a strapped-down 6 degrees of freedom accelerometer, a three-axis magnetometer, and a survey-grade GPS receiver. The significant wave heights were computed from the buoy's accelerometer record and from the dual-frequency GPS measurements that were processed in two different ways. The first method was postprocessed kinematic (PPK) GPS, which requires another GPS receiver at a fixed known location, and the other was precise point positioning …

Extensive Aerosol Optical Properties And Aerosol Mass Related Measurements During Tramp/Texaqs 2006 – Implications For Pm Compliance And Planning, Monica Elizabeth Wright, Dean B. Atkinson, Luke Ziemba, Robert Griffin, Naruki Hiranuma, Sarah D. Brooks, James Flynn, Ryan Perna, Bernhard Rappenglück, Winston Luke, Paul Kelley

Chemistry Faculty Publications and Presentations

Extensive aerosol optical properties, particle size distributions, and Aerodyne quadrupole aerosol mass spectrometer measurements collected during TRAMP/TexAQS 2006 were examined in light of collocated meteorological and chemical measurements. Much of the evident variability in the observed aerosol-related air quality is due to changing synoptic meteorological situations that direct emissions from various sources to the TRAMP site near the center of the Houston-Galveston-Brazoria (HGB) metropolitan area. In this study, five distinct long-term periods have been identified. During each of these periods, observed aerosol properties have implications that are of interest to environmental quality management agencies. During three of the periods, long …

Lsuhsc Facilities Daily Update: October 2010, Lsuhsc Property And Facilities Management

LSUHSC Facilities Daily Updates: 2010

LSUHSC Facilities Daily Updates from October 2010.

October 4, 2010 is listed as a daily update but that page is blank in all seven instances captured by Archive.org.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

Lsuhsc Facilities Biweekly Update: October 2010, Lsuhsc Property And Facilities Management

LSUHSC Facilities Biweekly Updates: 2010

LSUHSC Facilities Biweekly Updates from October 8 and 22, 2010.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

Correction Of Bathymetric Survey Artifacts Resulting From Apparent Wave-Induced Vertical Position Of An Auv, Val E. Schmidt, Nicole A. Raineault, Adam Skarke, Arthur Trembanis, Larry A. Mayer

Center for Coastal and Ocean Mapping

Recent increases in the capability and reliability of autonomous underwater vehicles (AUVs) have provided the opportunity to conduct bathymetric seafloor surveys in shallow water (< 50 m). Unfortunately, surveys of this water depth may contain artifacts induced by large amplitude wave motion at the surface. The artifacts occur when an onboard pressure sensor determines the depth of the AUV. Waves overhead induce small pressure fluctuations at depth, which modulate the AUV’s pressure sensor output without causing actual vertical movement of the AUV. Since bathymetric measurements are made with respect to the AUV’s depth, these pressure fluctuations, in turn, modulate the measurement of the seafloor. The result is a periodic across-track, vertical offset of the seafloor profile (similar to a heave artifact sometimes common in surface vessel surveys). In this paper we describe our experience with the “Gavia” model AUV (Hafmynd EHF, Iceland) in a recent bathymetric survey during which wave action overhead induced such an artifact with a peak-to-peak amplitude as large as 1 meter. A method for removing the artifact as well as recommendations for modifications to the sonar, INS and AUV to mitigate the effect in the future are provided.

Real-Time Monitoring Of Uncertainty Due To Refraction In Multibeam Echo Sounding, Jonathan Beaudoin

Center for Coastal and Ocean Mapping

A software toolkit has been developed to objectively monitor uncertainty due to refraction in multibeam echosounding, specifically mapping systems that employ underway sound speed profiling hardware. The toolkit relies on the use of a raytrace simulator which mimics the sounding geometry of any given echosounder, specifically array type, angular sector, draft, and availability of a surface sound speed probe. The simulator works by objectively comparing a pair of consecutively collected sound speed profiles and reporting sounding uncertainty across the entire potential sounding space. Realtime visualizations of the uncertainty as a function of time and space allow the operator to tune …

Phosphorus Uptake In Rhodomonas Salina (Wislouch) And Its Effect On Allocation And Elimination In Acartia Tonsa (Dana), Danna Palladino

OES Theses and Dissertations

Phosphorus is a key element in important biochemical compounds, such as RNA and phospholipids, and can become limiting in a variety of marine systems. The uptake of phosphorus into biochemical fractions (protein, low molecular weight (LMW) compounds, lipid, polysaccharide and nucleic acid) in Acartia tonsa fed ³³P -labeled Rhodomonas salina was examined. R. salina was cultured on two variations of one media that in one case contained phosphorus in balance and the other out of balance with relation to other standard f/2 components. The P-balanced (PB) media had a N:P ratio of 24.5, which is higher than that found …

Limnological Assistance For Lake Mead National Recreation Area: Quarterly Report, Period Ending September 30, 2010, Margaret N. Rees

Limnological Studies

Project 1

• Technical assistance with the implementation of the Interagency Monitoring Action Plan (I-MAP) for Quagga Mussels is ongoing. During this quarter, analysis was completed for 11 adult/juvenile samples from the winter 2009 – spring 2010 sampling. Two manuscripts related to the I-MAP were submitted to the peer-reviewed journal, Aquatic Invasions.

Project 2

• Topics and analyses have been approved for annual report development as prescribed by the Limnological and Aquatic Resource Monitoring and Research Plan for Lakes Mead and Mohave.
• Content, including links and photos for the front page, four limnology category web pages, and one associated page have been …

Beneath The Salt Marsh Canopy: Loss Of Soil Strength With Increasing Nutrient Loads, R. Eugene Turner

Faculty Publications

Although the broadly observed increase in nutrient loading rates to coastal waters in the last 100 years may increase aboveground biomass, it also tends to increase soil metabolism and lower root and rhizome biomass—responses that can compromise soil strength. Fourteen different multiyear field combinations of nutrient amendments to salt marshes were made to determine the relationship between soil strength and various nitrogen, phosphorus, and nitrogen+phosphorus loadings. There was a proportional decline in soil strength that reached 35% in the 60- to 100-cm soil layer at the highest loadings and did not level off. These loading rates are equivalent to those …

Determining The Index Of Refraction Of An Unknown Object Using Passive Polarimetric Imagery Degraded By Atmospheric Turbulence, Milo W. Hyde Iv

Theses and Dissertations

In this research, an algorithm is developed to estimate the index of refraction of an unknown object using passive polarimetric images degraded by atmospheric turbulence. The algorithm uses a variant of the maximum-likelihood blind-deconvolution algorithm developed by LeMaster and Cain to recover the true object (i.e., the first Stokes parameter), the degree of linear polarization, and the polarimetric-image point spread functions. Nonlinear least squares is then used to find the value of the complex index of refraction which best fits the theoretical degree of linear polarization, derived using a polarimetric bidirectional reflectance distribution function, to the turbulence-corrected degree of linear …

Release Of Mercury Halides From Kcl Denuders In The Presence Of Ozone, Seth N. Lyman, Daniel A. Jaffe, Mae S. Gustin

USU Uintah Basin Faculty Publications

KCl-coated denuders have become a standard method for measurement of gaseous oxidized mercury, but their performance has not been exhaustively evaluated, especially in field conditions. In this study, KCl-coated and uncoated quartz denuders loaded with HgCl₂ and HgBr₂ lost 29–55% of these compounds, apparently as elemental mercury, when exposed to ozone (range of 6–100 ppb tested). This effect was also observed for denuders loaded with gaseous oxidized mercury at a field site in Nevada (3–37% of oxidized mercury lost). In addition, collection efficiency decreased by 12–30% for denuders exposed to 50 ppb ozone during collection of HgCl_{2 …}

Sfa Weather Station-September 2010, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.

Effects Of Bubbles And Sea Spray On Air–Sea Exchange In Hurricane Conditions, Alexander Soloviev, Roger Lukas

Marine & Environmental Sciences Faculty Articles

The lower limit on the drag coefficient under hurricane force winds is determined by the break-up of the air–sea interface due to Kelvin–Helmholtz instability and formation of the two-phase transition layer consisting of sea spray and air bubbles. As a consequence, a regime of marginal stability develops. In this regime, the air–sea drag coefficient is determined by the turbulence characteristics of the two-phase transition layer. The upper limit on the drag coefficient is determined by the Charnock-type wave resistance. Most of the observational estimates of the drag coefficient obtained in hurricane conditions and in laboratory experiments appear to lie between …

Lsuhsc Facilities Daily Update: September 2010, Lsuhsc Property And Facilities Management

LSUHSC Facilities Daily Updates: 2010

LSUHSC Facilities Daily Updates from September 2010.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

Lsuhsc Facilities Biweekly Update: September 2010, Lsuhsc Property And Facilities Management

LSUHSC Facilities Biweekly Updates: 2010

LSUHSC Facilities Biweekly Updates from September 24, 2010.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

Modeling Acoustic Scattering From The Seabed Using Transport Theory, Jorge Quijano, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

Radiative Transfer (RT) theory has established itself as an important tool for electromagnetic remote sensing in parallel plane geometries with random distributions of scatterers, and most recently it has also been proposed as a model for the propagation of elastic waves in layered ocean sediments. In this work the capabilities of this model are illustrated, as the RT method is used to predict backscattering strength from laboratory models of random media. The RT model is characterized by its flexibility on accommodating scatterers in a broad variety of sizes, shapes, and acoustic contrast relative to the background media. Additionally, this formulation …

High Resolution Calibration Of A Multibeam Echo Sounder, Carlo Lanzoni, Thomas C. Weber

Center for Coastal and Ocean Mapping

Calibration can greatly increase the utility of collecting seafloor backscattering strength with multibeam echo sounders (MBES). A calibration procedure to determine high resolution, three dimensional transmit and receive beam patterns of a Reson SeaBat 7125 MBES was performed using the fresh water calibration tank at the University of New Hampshire. The measurements employed an omni-directional Reson TC4034 projector/hydrophone as a reference transducer at an acoustic distance of 13 m. The multibeam sonar system was configured for 256 beams equi-angle mode and operating frequency of 396 kHz. The transmit beam pattern was computed for across-track angular range between +/–90o in 0.1o …