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Articles 9481 - 9510 of 14022

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Shallow Surveying In Hazardous Waters, Thomas C. Lippmann, Gabriel M. Smith May 2009

Shallow Surveying In Hazardous Waters, Thomas C. Lippmann, Gabriel M. Smith

Center for Coastal and Ocean Mapping

Of order one importance to any study of nearshore processes is knowledge of the bathymetry in shallow water. This is true for studies on open coast sandy beaches where surf zone dynamics drive the system, inlet environments where bathymetric evolution can rapidly change navigation channels, and in more benign, lower-energy coastal environments that evolve slowly over 10’s to 100’s of years. Difficulties in obtaining shallow bathymetry where depth-limited wave breaking occurs, submerged hazards are present, or other harsh environments has led to the development of survey systems on highly maneuverable personal watercraft (Beach, et al., 1994; Cote, 1999; Dugan, et …


Uncertainty Wedge Analysis: Quantifying The Impact Of Sparse Sound Speed Profiling Regimes On Sounding Uncertainty, Jonathan Beaudoin, J Hiebert, Brian R. Calder, Gretchen Imahori May 2009

Uncertainty Wedge Analysis: Quantifying The Impact Of Sparse Sound Speed Profiling Regimes On Sounding Uncertainty, Jonathan Beaudoin, J Hiebert, Brian R. Calder, Gretchen Imahori

Center for Coastal and Ocean Mapping

Recent advances in real-time monitoring of uncertainty due to refraction have demonstrated the power of estimating and visualizing uncertainty over the entire potential sounding space. This representation format, referred to as an uncertainty wedge, can be used to help solve difficult survey planning problems regarding the spatio-temporal variability of the watercolumn. Though initially developed to work in-line with underway watercolumn sampling hardware (e.g. moving vessel profilers), uncertainty wedge analysis techniques are extensible to investigate problems associated with low-density watercolumn sampling in which only a few sound speed casts are gathered per day. As uncertainty wedge analysis techniques require no sounding …


Extension Of Gutenberg-Richter Distribution To Mw -1.3, No Lower Limit In Sight, Margaret S. Boettcher, Art Mcgarr, Malcolm J. Johnston May 2009

Extension Of Gutenberg-Richter Distribution To Mw -1.3, No Lower Limit In Sight, Margaret S. Boettcher, Art Mcgarr, Malcolm J. Johnston

Center for Coastal and Ocean Mapping

With twelve years of seismic data from TauTona Gold Mine, South Africa, we show that mining-induced earthquakes follow the Gutenberg-Richter relation with no scale break down to the completeness level of the catalog, at moment magnitude MW −1.3. Events recorded during relatively quiet hours in 2006 indicate that catalog detection limitations, not earthquake source physics, controlled the previously reported minimum magnitude in this mine. Within the Natural Earthquake Laboratory in South African Mines (NELSAM) experiment's dense seismic array, earthquakes that exhibit shear failure at magnitudes as small as MW −3.9 are observed, but we find no evidence that …


Constraints On The Utility Of Mno2 Cartridge Method For The Extraction Of Radionuclides: A Case Study Using 234Th, M. Baskaran, P. W. Swarzenski, B. A. Biddanda Apr 2009

Constraints On The Utility Of Mno2 Cartridge Method For The Extraction Of Radionuclides: A Case Study Using 234Th, M. Baskaran, P. W. Swarzenski, B. A. Biddanda

Environmental Science and Geology Faculty Research Publications

Large volume (102–103 L) seawater samples are routinely processed to investigate the partitioning of particle reactive radionuclides and Ra between solution and size-fractionated suspended particulate matter. One of the most frequently used methods to preconcentrate these nuclides from such large volumes involves extraction onto three filter cartridges (a prefilter for particulate species and two MnO2-coated filters for dissolved species) connected in series. This method assumes that the extraction efficiency is uniform for both MnO2-coated cartridges, that no dissolved species are removed by the prefilter, and that any adsorbed radionuclides are not desorbed from …


Landscape Limnology: Nutrient Fluxes & Biotic Stability In Complex Mountain Watersheds, Wayne A. Wurtsbaugh, Michelle Kang, Dave M. Epstein Apr 2009

Landscape Limnology: Nutrient Fluxes & Biotic Stability In Complex Mountain Watersheds, Wayne A. Wurtsbaugh, Michelle Kang, Dave M. Epstein

Watershed Sciences Faculty Publications

No abstract provided.


Nutrient Enrichment Drives Gulf Of Mexico Hypoxia, Donald F. Boesch, Walter R. Boyton, Larry B. Crowder, Robert J. Diaz, Robert W. Howarth, Laurence D. Mee, Scott W. Nixon, Nancy N. Rabalais, Rutger Rosenberg, James G. Sanders, Donald Scavia, R. Eugene Turner Apr 2009

Nutrient Enrichment Drives Gulf Of Mexico Hypoxia, Donald F. Boesch, Walter R. Boyton, Larry B. Crowder, Robert J. Diaz, Robert W. Howarth, Laurence D. Mee, Scott W. Nixon, Nancy N. Rabalais, Rutger Rosenberg, James G. Sanders, Donald Scavia, R. Eugene Turner

Faculty Publications

No abstract provided.


Sfa Weather Station-April 2009, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Apr 2009

Sfa Weather Station-April 2009, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sustainable Portland: Implementation Series 2, New England Environmental Finance Center Apr 2009

Sustainable Portland: Implementation Series 2, New England Environmental Finance Center

Climate Change

The Portland Municipal Climate Change Working Group prepared a report in March 2008 that outlined several recommendations as a commitment by the City to address greenhouse gas emissions (GHG) produced during daily municipal operations. The Municipal Climate Action Plan was written in partnership with Clean Air – Cool Planet and Portland officials, and acknowledges under Recommendation #2 that an employee energy efficiency program would provide significant positive impact on the City’s reduction of greenhouse gas emissions. Best practices from three cities show that focus on the greening of City Hall is critical in developing a program that promotes partnerships, community …


Markov Models For Linking Environments And Facies In Space And Time (Recent Arabian Gulf, Miocene Paratethys), Bernhard Riegl, Samuel J. Purkis Apr 2009

Markov Models For Linking Environments And Facies In Space And Time (Recent Arabian Gulf, Miocene Paratethys), Bernhard Riegl, Samuel J. Purkis

Marine & Environmental Sciences Faculty Books and Book Chapters

This special publication Perspectives in Carbonate Geology is a collection of papers most of which were presented at a symposium to honor the 80th birthday of Bob Ginsburg at the meeting of Geological Society of America in Salt Lake City in 2005. The majority of the papers in this publication are connected with the study of modern carbonate sediments. Bob Ginsburg pioneered the concept of comparative sedimentology - that is using the modern to compare to and relate to and understand the ancient. These studies are concerned with Bob's areas of passion: coral reefs and sea-level; submarine cementation and formation …


Rayleigh-Lidar Observations Of Mesospheric Instabilities, Gabriel C. Taylor, Durga N. Kafle, Vincent B. Wickwar Apr 2009

Rayleigh-Lidar Observations Of Mesospheric Instabilities, Gabriel C. Taylor, Durga N. Kafle, Vincent B. Wickwar

Posters

From 1993 to 2004 the Utah State University Rayleigh lidar, known as the USU green laser, collected 900 nights of data from the mesosphere (45-90 km). From these observations profiles of relative neutral densities and absolute temperatures were derived. Usually, the atmosphere is horizontally stratified with a balance between gravitational and pressure forces. When this balance is perturbed, it leads to the generation of buoyancy or “gravity” waves. An example of these is clear air turbulence, which can have dramatic effects on airplanes. As these waves propagate upward, the decrease in atmospheric density and conservation of energy combine to give …


Spring 2009, Nsu Oceanographic Center Apr 2009

Spring 2009, Nsu Oceanographic Center

Currents

No abstract provided.


High-Resolution Seafloor Mapping And An Assessment Of The Effectiveness Of The Western Gulf Of Maine Closure Area (Wgomca), Raymond E. Grizzle, Mashkoor A. Malik, Larry G. Ward Apr 2009

High-Resolution Seafloor Mapping And An Assessment Of The Effectiveness Of The Western Gulf Of Maine Closure Area (Wgomca), Raymond E. Grizzle, Mashkoor A. Malik, Larry G. Ward

Center for Coastal and Ocean Mapping

No abstract provided.


Oceanic Transform Fault Seismicity Earthquakes Of A Different Kind, Margaret S. Boettcher, Jeffrey Mcguire, Thomas Jordan Apr 2009

Oceanic Transform Fault Seismicity Earthquakes Of A Different Kind, Margaret S. Boettcher, Jeffrey Mcguire, Thomas Jordan

Center for Coastal and Ocean Mapping

No abstract provided.


Droughtscape, Spring 2009, Kelly Smith Apr 2009

Droughtscape, Spring 2009, Kelly Smith

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

U.S. Drought Monitor Publishes Map 500!

Weakening La Niña May Mean Relief for Texas

Upcoming Workshops

Drought Impacts Worst in California, Texas

CoCoRaHS to Request Drought Impact Data, Too

NDMC Adds Researcher

K-12 Students Learn About Drought


High Time Resolution Pfisr And Optical Observations Of Naturally Enhanced Ion Acoustic Lines, R G. Michell, K A. Lynch, C J. Heinselman, H C. Stenbaek-Nielsen Apr 2009

High Time Resolution Pfisr And Optical Observations Of Naturally Enhanced Ion Acoustic Lines, R G. Michell, K A. Lynch, C J. Heinselman, H C. Stenbaek-Nielsen

Dartmouth Scholarship

Observations of naturally enhanced ion acoustic lines (NEIALs) taken with the Poker Flat Incoherent Scatter Radar (PFISR) using a mode with very high time resolution are presented. The auroral event took place over Poker Flat, Alaska on 8 February 2007 at 09:35 UT (∼22:00 MLT), and the radar data are complemented by common-volume high- resolution auroral imaging. The NEIALs occurred during only one of the standard 15-s integration periods. The raw data of this time show very intermittent NEIALs which oc- cur only during a few very short time intervals (≤1 s) within the 15-s period. The time sampling of …


Limnological Assistance For The Lake Mead National Recreation Area In Meeting The Challenge Of The Water 2025 Initiative: Quarterly Report, Period Ending April 1, 2009, Margaret N. Rees Apr 2009

Limnological Assistance For The Lake Mead National Recreation Area In Meeting The Challenge Of The Water 2025 Initiative: Quarterly Report, Period Ending April 1, 2009, Margaret N. Rees

Limnological Studies

Project 1: Technical input has been provided at two advisory team meetings attended this quarter.

Project 2: Surface Water Monitoring for Indicator Bacteria in High-use Sites of the Lake Mead National Recreation Area (poster) was presented at the Lake Mead Science Symposium; a journal article is in preparation.

Project 3: A draft document titled “Interagency Monitoring Action Plan (I-MAP): Quagga Mussels in Lakes Mead and Mohave” has been subdivided into four major sections and corresponding sub-groups have been formed to provide review and input. Six oral presentations related to quagga mussels were presented at the Lake Mead Science Symposium. Two …


Unlv Magazine, Michelle Mouton, Tony Allen, Afsha Bawany, Shane Bevell, Phil Hagen, Greg Lacour, Erin O'Donnell, Karyn S. Hollingsworth Apr 2009

Unlv Magazine, Michelle Mouton, Tony Allen, Afsha Bawany, Shane Bevell, Phil Hagen, Greg Lacour, Erin O'Donnell, Karyn S. Hollingsworth

UNLV Magazine

No abstract provided.


Lsuhsc Facilities Daily Update: April 2009, Lsuhsc Property And Facilities Management Apr 2009

Lsuhsc Facilities Daily Update: April 2009, Lsuhsc Property And Facilities Management

LSUHSC Facilities Daily Updates: 2009

LSUHSC Dailly Facilities Updates from April 2009.

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: April 2009, Lsuhsc Property And Facilities Management Apr 2009

Lsuhsc Facilities Biweekly Update: April 2009, Lsuhsc Property And Facilities Management

LSUHSC Facilities Biweekly Updates: 2009

LSUHSC Facilities Biweekly Updates from April 10 and 24, 2009.

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.


Diagnostique Sur La Santé Des Récifs Coralliens À Nosy Tanikely Et La Baie D’Ambanoro, Chelsea Nahill Apr 2009

Diagnostique Sur La Santé Des Récifs Coralliens À Nosy Tanikely Et La Baie D’Ambanoro, Chelsea Nahill

Independent Study Project (ISP) Collection

Pendant mon étude, les récifs coralliens à Nosy Tanikely et à la Baie d’Ambanoro étaient examinées avec le but de déterminer la condition de chaque récif et la biomasse des poissons. La durée de cette étude est de trois semaines et j’ai plongé en apnée quatre fois du 10 avril 2009 au 23 avril 2009, pour examiner les trois sites. Il y avait six stations au total, quatre pour examiner le premier site à Nosy Tanikely et deux dans la Baie d’Ambanoro, où sont le deuxième et troisième site. Utilisant les données collectées au long du transect de cent mètres, …


A Compact Lidar For Aircraft Ozone Atmospheric Measurements, Joel A. Marcia Apr 2009

A Compact Lidar For Aircraft Ozone Atmospheric Measurements, Joel A. Marcia

Electrical & Computer Engineering Theses & Dissertations

Researchers and the general public have expressed great concern over how human activities exacerbate pollution's deteriorating impact upon the environment. Effects such as global warming, air quality and ozone layer depletion are but a few examples that can have a dramatic effect on the quality of life worldwide.

A compact lidar system for the purpose of aircraft ozone atmospheric measurements was tested and evaluated. This system will eventually be deployed for aircraft-based, and possibly unpiloted atmospheric vehicle (UAV), ozone and aerosol measurements to improve our understanding of ozone production and transport. Each of the major subsystems was characterized and from …


Factors Affecting Adult Foraging And Chick Growth Of Adélie Penguins (Pygoscelis Adeliae) Off The Western Antarctic Peninsula: A Modeling Study, Erik W. Chapman Apr 2009

Factors Affecting Adult Foraging And Chick Growth Of Adélie Penguins (Pygoscelis Adeliae) Off The Western Antarctic Peninsula: A Modeling Study, Erik W. Chapman

OES Theses and Dissertations

Coupled individual-based models that simulate Adélie penguin ( Pygoscelis adeliae) chick growth and adult foraging behavior during the chick growth period were developed and used to explore factors that influence chick fledging mass and adult foraging energetics off the western Antarctic Peninsula (WAP). Adélie penguin colonies in this region are undergoing changes in population size that have been correlated with climate-driven alteration of the marine and terrestrial environment. Simulations were selected to highlight possible mechanistic linkages between climate variability and chick growth and adult foraging processes. These processes were the focus of this study because chicks that fledge at …


Characterization Of Antibiotic Resistance In Vibrio Cholerae Isolated From Ships' Ballast And Other Environmental Sources, Frank Kornegay Thomson Iii Apr 2009

Characterization Of Antibiotic Resistance In Vibrio Cholerae Isolated From Ships' Ballast And Other Environmental Sources, Frank Kornegay Thomson Iii

OES Theses and Dissertations

Ships' ballast has been implicated as a vector in the dispersal of invasive species into new environments. Numerous cases have been documented for the introduction of macroorganisms via ballasting operations, but what is less known is the role of ballast water and residuals in the spread of potentially harmful microbes, especially with reference to novel genotypes. Of particular interest are the genes encoding for various forms of antibiotic resistance, many of which are carried on mobile genetic elements. A four-year sampling effort has yielded over 300 putative isolates of Vibrio cholerae from ships' ballast tanks and various environmental sources, of …


A Bio-Optical Model For Syringodium Filiforme Canopies, Margaret A. Stoughton Apr 2009

A Bio-Optical Model For Syringodium Filiforme Canopies, Margaret A. Stoughton

OES Theses and Dissertations

Seagrasses are significant ecological and biogeochemical agents in shallow water ecosystems throughout the world. In many regions, seagrass meadows occupy a sufficient fraction of the coastal zone, and generate optical signatures that can be observed from space. Bio-optical models of light absorption and scattering by submerged plant canopies for certain species such as Thalassia testudinum and Zostera marina have successfully modeled the plane irradiance distribution and photosynthesis within the submerged canopies. Syringodium filiforme differs &om T. testudinttm and Z marina, in leaf morphology and canopy architecture. The objective of this study was to develop a radiative transfer model that …


Using Oceanic-Atmospheric Oscillations For Long Lead Time Streamflow Forecasting, Ajay Kalra, Sajjad Ahmad Mar 2009

Using Oceanic-Atmospheric Oscillations For Long Lead Time Streamflow Forecasting, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

We present a data-driven model, Support Vector Machine (SVM), for long lead time streamflow forecasting using oceanic-atmospheric oscillations. The SVM is based on statistical learning theory that uses a hypothesis space of linear functions based on Kernel approach and has been used to predict a quantity forward in time on the basis of training from past data. The strength of SVM lies in minimizing the empirical classification error and maximizing the geometric margin by solving inverse problem. The SVM model is applied to three gages, i.e., Cisco, Green River, and Lees Ferry in the Upper Colorado River Basin in the …


Operations-Focused Optimized Theater Weather Sensing Strategies Using Preemptive Binary Integer Programming, Andrew J. Geyer Mar 2009

Operations-Focused Optimized Theater Weather Sensing Strategies Using Preemptive Binary Integer Programming, Andrew J. Geyer

Theses and Dissertations

This thesis describes a method that optimally deploys weather sensors of all types in a battlefield environment. Gridded climatology models are used to determine an estimate for the weighted frequency of occurrence of operationally significant inclement weather events. That data is used to formulate a series of preemptive Binary Integer Linear Programs that maximize detection of expected operationally significant inclement weather occurrences within the constraints of feasibility of sensor deployment, sensor operational lifespan and the sensor’s ability to detect the operationally significant inclement weather elements. The preemptive Binary Integer Linear Programs are combined into a single objective function that maintains …


Analysis On Typhoon Longwang Intensity Changes Over The Ocean Via Satellite Data, Chung-Chih Liu, Tian-Yow Shyu, Chun-Chieh Chao, Yu-Feng Lin Mar 2009

Analysis On Typhoon Longwang Intensity Changes Over The Ocean Via Satellite Data, Chung-Chih Liu, Tian-Yow Shyu, Chun-Chieh Chao, Yu-Feng Lin

Journal of Marine Science and Technology–Taiwan

The changes in the typhoon intensity are a very important process. In this study, we used satellite data to analyze the cloud structure of Typhoon Longwang. Results show that the changes in the high level cirrus pattern seemed to have a connection to the typhoon intensity. During the time period from 0600UTC to 1200UTC 30 September 2005, the high level cirrus clouds of Typhoon Longwang radiated from the inner core region. The cloud area that Typhoon Longwang covered grew larger, and the pattern changed from a asymmetric to symmetric distribution during 0000UTC to 1200UTC 30 September 2005. The best track …


Crop Updates - 2009 Katanning, Murray Scholz, Peter Newman, Glenn Adam, Trevor Bell, Michael Whitehead, W. K. Anderson, Chris Gazey, J. Andrew, R. Pearce, Bill Bowden, Wayne Pluske, Jeremy Lemon, D. C. Edmeades, J. J. Russell, Blakely H. Paynter, David Ferris, Abul Hashen, Catherine Borger, Stephen B. Powels, Qin Yu, Mechelle Owen, Roberto Busi, Sudheesh Manalil, Sally Peltzer, David Minkey, Raj Malik Mar 2009

Crop Updates - 2009 Katanning, Murray Scholz, Peter Newman, Glenn Adam, Trevor Bell, Michael Whitehead, W. K. Anderson, Chris Gazey, J. Andrew, R. Pearce, Bill Bowden, Wayne Pluske, Jeremy Lemon, D. C. Edmeades, J. J. Russell, Blakely H. Paynter, David Ferris, Abul Hashen, Catherine Borger, Stephen B. Powels, Qin Yu, Mechelle Owen, Roberto Busi, Sudheesh Manalil, Sally Peltzer, David Minkey, Raj Malik

Crop Updates

This session covers seventeen papers from different authors

  1. GM canola – How will it affect the way I farm? Murray Scholz, 2008 Nuffield scholar, Southern NSW

  2. Eight years of IWM smashes tyegrass seed banks by 98% over 31 focus paddocks, Peter Newman, Glenn Adam & Trevor Bell, Department of Agriculture and Food

  3. The global economic climate and impacts on agriculture, profile on Michael Whitehead Rabobank New York

  4. Lessons from five years of cropping systems research, W.K. Anderson, Department of Agriculture and Food

  5. Case study of a 17year old agricultural lime trial, C. Gazey, Department of Agriculture …


Demonstration And Verification Of A Broad Spectrum Anomalous Dispersion Effects Tool For Index Of Refraction And Optical Turbulence Calculations, J. Jean Cohen Mar 2009

Demonstration And Verification Of A Broad Spectrum Anomalous Dispersion Effects Tool For Index Of Refraction And Optical Turbulence Calculations, J. Jean Cohen

Theses and Dissertations

An atmospheric optical turbulence strength model with a broad wavelength range of 355nm (ultraviolet) to 8.6m (radio frequencies) has been created at AFIT and implemented into the High Energy Laser End-to-End Operational Simulation tool (HELEEOS). This modeling and simulation tool is a first principles atmospheric propagation and characterization model. Within HELEEOS lies the High-Resolution Transmission Molecular Absorption (HITRAN) database, containing 1,734,469 spectral lines for 37 different molecules as of version 12.0 (2004). HITRAN affords HELEEOS incredible accuracy for electromagnetic (EM) propagation prediction. A full understanding of optical turbulence is needed to successfully predict EM radiation propagation, particularly within the application …


A Computational Tool For Evaluating Thz Imaging Performance In Brownout Conditions At Land Sites Throughout The World, Seth L. Marek Mar 2009

A Computational Tool For Evaluating Thz Imaging Performance In Brownout Conditions At Land Sites Throughout The World, Seth L. Marek

Theses and Dissertations

This study quantifies terahertz (THz) or sub-millimeter imaging performance during simulated rotary-wing brownout or whiteout environments based on geographic location and recent/current atmospheric weather conditions. The atmospheric conditions are defined through the Air Force Institute of Technology Center for Directed Energy (AFIT/CDE) Laser Environmental Effects Definition and Reference or LEEDR model. This model enables the creation of vertical profiles of temperature, pressure, water vapor content, optical turbulence, and atmospheric particulates and hydrometeors as they relate to line-by-line layer extinction coefficient magnitude at wavelengths from the UV to the RF. Optical properties and realistic particle size distributions for the brownout and …