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2001

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Articles 31 - 60 of 151

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Degradation Of Reef Structure, Coral And Fish Communities In The Red Sea By Ship Groundings And Dynamite Fisheries, Bernhard Riegl Sep 2001

Degradation Of Reef Structure, Coral And Fish Communities In The Red Sea By Ship Groundings And Dynamite Fisheries, Bernhard Riegl

Marine & Environmental Sciences Faculty Articles

Reef degradation was investigated on 66 Egyptian Red Sea reefs—60 reefs for dynamite damage (using line transects) and six ship grounding sites (using 1 m sample squares). Ship groundings and dynamite fishing caused similar damage, reduction of the reef to rubble (65% of reefs were dynamited, mostly leeward, 58%). Changes in coral (line transect study) and fish communities (point count study) in impacted sites were documented. On impacted reefs, coral cover decreased, bare substratum and rubble increased, and fish dominance shifted away from Pomacentridae. Oceanographic conditions result in a stable pattern of coral communities (windward Acropora, leeward Porites). …


Airglow Variations Associated With Nonideal Ducting Of Gravity Waves In The Lower Thermosphere Region, Michael P. Hickey Ph.D. Aug 2001

Airglow Variations Associated With Nonideal Ducting Of Gravity Waves In The Lower Thermosphere Region, Michael P. Hickey Ph.D.

Publications

A numerical full-wave model is used to study the response of the O2 atmospheric airglow to ducted gravity waves in the mesopause region. For an isothermal, quasi-adiabatic, and motionless background atmosphere the calculated phase differences between airglow brightness fluctuations and fluctuations of temperatures derived from the airglow, as given by Krassovsky's ratio, are in good agreement with the predictions of published theory. Significant departures from the predictions of the basic theory are obtained when we consider ducting in the presence of the eddy and molecular diffusion of heat and momentum in a nonisothermal background atmosphere. Wind shears also affect the …


Biological Survey Report For The Calypso Natural Gas Pipeline: Shore Approach Route North Of Port Everglades Entrance Channel With Landing South Of Port Everglades Entrance Channel, Richard E. Dodge, Susan L. Thornton, David S. Gilliam, Richard Shaul Aug 2001

Biological Survey Report For The Calypso Natural Gas Pipeline: Shore Approach Route North Of Port Everglades Entrance Channel With Landing South Of Port Everglades Entrance Channel, Richard E. Dodge, Susan L. Thornton, David S. Gilliam, Richard Shaul

Marine & Environmental Sciences Faculty Reports

The Calypso Natural Gas Pipeline Project (project) will include a 24-inch pipeline which will extend from the Exclusive Economic Zone (EEZ) off the southeast Florida coastline to a shore approach at Port Everglades in Fort Lauderdale, Florida.

This report, which was commissioned in May 2001 and completed in July, 2001, documents the results of a detailed biological survey of underwater marine habitats from 5 to 200 feet water depth for the pipeline route. The route, which was established based on the subsea survey that was completed in May 2001 by Williamson & Associates, Inc., includes a shore approach from the …


Improvement Of Image Alignment Using Camera Attitude Information, Yuri Rzhanov, Lloyd C. Huff, Randy G. Cutter Jr. Aug 2001

Improvement Of Image Alignment Using Camera Attitude Information, Yuri Rzhanov, Lloyd C. Huff, Randy G. Cutter Jr.

Center for Coastal and Ocean Mapping

We discuss a proposed technique for incorporation of information from a variety of sensors in a video imagery processing pipeline. The auxiliary information allows one to simplify computations, effectively reducing the number of independent parameters in the transformation model. The mosaics produced by this technique are adequate for many applications, in particular habitat mapping. The algorithm, demonstrated through simulations and hardware configuration, is described in detail


Application Of Neuro-Fuzzy Technique+2:9s To Predict Ground Water Vulnerability In Northwest Arkansas, B. Dixon, H. D. Scott, J. V. Brahana, A. Mauromoustakos Jul 2001

Application Of Neuro-Fuzzy Technique+2:9s To Predict Ground Water Vulnerability In Northwest Arkansas, B. Dixon, H. D. Scott, J. V. Brahana, A. Mauromoustakos

Arkansas Water Resources Center Technical Reports

Contamination of ground water has been a major concern in recent years of local, state and federal agencies involved with the management, quality, and quantity of water and their relationships with human health. The Springfield Plateau aquifer, which lies beneath the study area in northwest Arkansas, has been shown to have higher nitrate-N (NO3-N) concentrations than the national median. The dominant landuse (LULC) of this area is agriculture (primarily pasture/cattle and woodlands) and an encroaching urbanization. The major sources of nitrogen in the study area are poultry/cattle wastes, inorganic fertilizers (Peterson et. al., 1998) and septic filter fields. Many of …


Circulation, Vol. 8, No. 2, Center For Coastal Physical Oceanography, Old Dominion University, Larry P. Atkinson Jul 2001

Circulation, Vol. 8, No. 2, Center For Coastal Physical Oceanography, Old Dominion University, Larry P. Atkinson

CCPO Circulation

Summer 2001 issue of CCPO Circulation featuring article "Oceanographic Research in the Antarctic" by Larry Atkinson


Responses Of Three Coral Communities To The 1997–98 El Niño–Southern Oscillation: Galápagos Islands, Ecuador, Joshua S. Feingold Jul 2001

Responses Of Three Coral Communities To The 1997–98 El Niño–Southern Oscillation: Galápagos Islands, Ecuador, Joshua S. Feingold

Marine & Environmental Sciences Faculty Articles

One deep (13–15 m depth) and two shallow water (1.5 and 7 m) coral communities in the Galápagos Islands, Ecuador were monitored for tissue response (bleaching, paling, morbidity) and secondary responses during and after elevated temperature stress associated with the 1997–98 El Niño–Southern Oscillation (ENSO) event. Between March and May 1998, the fungiid coral Diaseris distorta paled and bleached (up to 88.0% of all individuals bleached) at 13–15 m depth. The small branching colonial coral, Psammocora stellata, paled (79.2% of all colonies) with very little bleaching (11.1%), also at 13–15 m depth. However, by May 1998 colonies of this …


Moving Icons, Detection And Distraction, Lyn Bartram, Colin Ware, Tom Calvert Jul 2001

Moving Icons, Detection And Distraction, Lyn Bartram, Colin Ware, Tom Calvert

Center for Coastal and Ocean Mapping

Simple motion has great potential for visually encoding information but there are as yet few experimentally validated guidelines for its use. Two studies were carried out to look at how efficiently simple motion cues were detected and how distracting they were in different task contexts. The results show that motion outperforms static representations and identify certain types of motions which are more distracting and irritating than others.


Announcements: Summer/Fall 2001 Jul 2001

Announcements: Summer/Fall 2001

Drought Network News (1994–2001)

Contents:

Allocating and Managing Water for a Sustainable Future: Lessons from Around the World

Defending the Integrity of Ground Water: Understanding the Impacts of Natural and Manmade Disasters

Conference on Energy Climate, Environment and Water—Issues and Opportunities for Irrigation and Drainage


Hydrographic Variability On Decadal And Interdecadal Scales In The Northern Gulf Of Alaska, Nandita Sarkar Jul 2001

Hydrographic Variability On Decadal And Interdecadal Scales In The Northern Gulf Of Alaska, Nandita Sarkar

OES Theses and Dissertations

The mixed layer depth (MLD) in the North Pacific is important to vertical mixing and hence the flux nutrients into the euphotic zone. A time series of hydrographic measurements, tem perature and salinity versus depth, at a coastal site in the northern Gulf of Alaska is used to determine the seasonal and interannual variations in the MLD. Data from this station called GAK 1 (59°50.7‘X. 149C28.0'\V) in 203 m of water begin in 1974 and end in 1998. The MLD changes seasonally from about 50 m in summer to more than 130 m in winter. These changes are in response …


Trichodesmium Spp.: Numerical Studies Of Resource Competition, Carbohydrate Ballasting, And Remote-Sensing Reflectance, Tonya Denise Clayton Jul 2001

Trichodesmium Spp.: Numerical Studies Of Resource Competition, Carbohydrate Ballasting, And Remote-Sensing Reflectance, Tonya Denise Clayton

OES Theses and Dissertations

In recent years, a new appreciation for the role of diazotrophy in the oceans has emerged. This dissertation reports on three modeling studies designed to investigate ecological processes associated with Trichodesmium spp., the most conspicuous marine diazotroph: (1) characterization of a generalized model Trichodesmium and issues of macronutrient resource competition; (2) carbohydrate ballasting by Trchodesmium and implications for the formation of surface accumulations; and (3) the vertical distribution of Trichodesmium and implications for detection from space.

The first study focuses on issues of nitrogen and phosphorus competition and ecosystem structure. It utilizes a simple ecosystem model that includes dissolved nitrogen …


Transverse Variability Of The Flow And Density In Inlets Of Southern Chile, Mario Arturo Cáceres Muñoz Jul 2001

Transverse Variability Of The Flow And Density In Inlets Of Southern Chile, Mario Arturo Cáceres Muñoz

OES Theses and Dissertations

Measurements of velocity and density profiles were made to describe the flow transverse structure in three inlets of southern Chile. The inlets show marked differences in their transverse dynamics in response to external forcing. In Aysen Fjord (45.2°S) the mean flow showed a three layer structure that was consistent with up-fjord wind-induced exchange, while in Chacao Channel (41.8°S), the mean flow exhibited predominantly a lateral structure that featured sharp velocity shears. In both cases, a bank in the center of the sections seemed to play an important role in shaping the mean flows. In Ventisquero Sound (44.4°S), the presence of …


Dynamical Sedimentary Models Of Shallow Marine Environments, Yong Zhang Jul 2001

Dynamical Sedimentary Models Of Shallow Marine Environments, Yong Zhang

OES Theses and Dissertations

This treatise represents a contribution of quantitative, dynamical sedimentary modeling to the analytical understanding of sedimentary processes in shallow marine environments. The dynamical sedimentary models in this treatise numerically simulate the sedimentary processes from an event time scale, based on the fundamental physics of sediment dynamics in coastal and shelf depositional environments, to a longer, facies time scale. The simulated geologic processes serve to the illustrate shoreface equilibrium profile, shelf storm bed generation, and the shelf sedimentary facies system.

This treatise presents a nearshore profile evolution model for the abandoned Huanghe Delta, a two-dimensional storm deposition model, and a sedimentary …


Water Rights As Contested Terrain: The Case Of Tenmile Creek, Oregon, Marcie L. Allen Jun 2001

Water Rights As Contested Terrain: The Case Of Tenmile Creek, Oregon, Marcie L. Allen

Dissertations and Theses

This thesis examines the complex conflict over water rights at Tenmile Creek, located along the south central Oregon Coast. The research is an exploratory case study identifying the main motivations of actors, the constraints they faced, and the conditions that encouraged or dissuaded collaborative behavior.

The main objectives are (1) to refine the understanding of the relationship between societies and their physical environment in market societies that are both motivated to exploit and preserve natural resources and, (2) to explore the kinds of institutional arrangements that may be required to manage the water supply in a collaborative and sustainable manner. …


Ctd/O2 Measurements Collected Abroad The R/V Knorr, February-March 2001: Redsox-1, Williams Johns, Hartmurt Peters, Rainer Zantopp, Amy Bower, David Fratantoni Jun 2001

Ctd/O2 Measurements Collected Abroad The R/V Knorr, February-March 2001: Redsox-1, Williams Johns, Hartmurt Peters, Rainer Zantopp, Amy Bower, David Fratantoni

RSMAS Technical Reports

Summaries of Conductivity-Temperature-Depth (CTD/ O2) measurements acquired on an oceanographic research cruise into the Gulf of Aden during February/March 2001 aboard the Woods Hole Oceanographic Institution ship R/V Knorr are presented. The data acquisition and processing system is described and calibrartion procedures are documented.


Ozone And Tracer Transport Variations In The Summer Northern Hemisphere Stratosphere, E. C. Cordero, S. R. Kawa Jun 2001

Ozone And Tracer Transport Variations In The Summer Northern Hemisphere Stratosphere, E. C. Cordero, S. R. Kawa

Faculty Publications, Meteorology and Climate Science

Constituent observations from the Upper Atmosphere Research Satellite (UARS) in combination with estimates of the residual circulation are used to examine the transport and chemical budgets of HF, CH4 and O3 in the summer Northern Hemisphere. Budget calculations of HF, CH4 and O3 show that the transport tendency due to the residual circulation increases in magnitude and is largely opposed by eddy motions through the summer months. Ozone budget analyses show that between 100 and 31 hPa, the magnitudes of the mean circulation and eddy transport terms increase through the summer months, producing tendencies that are …


Protection Of Cave Spring Cave Biota And Groundwater Basin, G. O. Graening, A. V. Brown Jun 2001

Protection Of Cave Spring Cave Biota And Groundwater Basin, G. O. Graening, A. V. Brown

Arkansas Water Resources Center Technical Reports

This is the fourth in a series of reports on the status of endangered biota and of environmental quality in Cave Springs Cave (CSC), Benton County, Arkansas (Brown et al., 1998; Graening and Brown, 1999, 2000), funded by the Arkansas Natural Heritage Commission (ANHC). As a result of these studies, Cave Springs Cave is now one of the most thoroughly studied cave ecosystems in Arkansas. This series of studies has spawned a renewed interest in cave ecosystems and their vulnerable condition. There are now many projects focusing upon the documentation of subterranean biodiversity and its protection. Partners include the Arkansas …


An Analysis Of Recent Drought Conditions In Turkey In Relation To Circulation Patterns, Ali Umran Komuscu Jun 2001

An Analysis Of Recent Drought Conditions In Turkey In Relation To Circulation Patterns, Ali Umran Komuscu

Drought Network News (1994–2001)

Drought commonly is perceived to be a prolonged period with a significant reduction in precipitation. Namias (1985) argues that drought is associated with persistent or persistently recurring atmospheric circulation patterns. For example, the North Atlantic Oscillation (NAO) has a major role in controlling European climate and appears to exert a strong influence in modulating North Atlantic ecosystems. During the positive phases of NAO, the North Atlantic westerlies, which provide much of the atmospheric moisture to north Africa and Europe, shift northward. This, in turn, results in drier conditions over southern Europe, the Mediterranean Sea, and northern Africa (Hurrell, 1995; Hurrell …


Oregon Aquatic Nuisance Species Management Plan, Erik Hanson, Mark Sytsma Jun 2001

Oregon Aquatic Nuisance Species Management Plan, Erik Hanson, Mark Sytsma

Center for Lakes and Reservoirs Publications and Presentations

Aquatic Nuisance Species (ANS) are a serious problem in Oregon. There are currently over 134 nonindigenous aquatic species reported in Oregon. More species are expected to arrive. Current state activities and authorities address some ANS, their prevention, and control. Yet, the activities are not coordinated or comprehensively managing the impacts of ANS. The importance of Oregon’s aquatic resources requires a coherent response to the threat posed by ANS. This management plan is the initial step in establishing a program in Oregon to specifically address ANS issues.


Groundwater Study Of The Pingelly Townsite, Edward K. Crossley May 2001

Groundwater Study Of The Pingelly Townsite, Edward K. Crossley

Resource management technical reports

A groundwater study was carried out in the townsite of Pingelly, Western Australia. It aimed to accelerate the implementation of effective salinity management options. The study consisted of a drilling investigation, expansion of a piezometer network, groundwater flow modelling and a flood risk analysis.


Announcements: Spring 2001 May 2001

Announcements: Spring 2001

Drought Network News (1994–2001)

Contents:

IAEM’s 49th Annual Conference and Exhibit

International Conference on Drought Mitigation and Prevention of Land Desertification

New Book


Results Of A Rapid Appraisal Study: Agricultural Producers’ Perceptions Of Drought Vulnerability And Mitigation—Howard County, Nebraska, Cody L. Knutson, Matthew L. Blomstedt, Kara Slaughter May 2001

Results Of A Rapid Appraisal Study: Agricultural Producers’ Perceptions Of Drought Vulnerability And Mitigation—Howard County, Nebraska, Cody L. Knutson, Matthew L. Blomstedt, Kara Slaughter

Drought Network News (1994–2001)

Drought is the leading natural disaster in the United States in terms of monetary losses. The National Research Council (1995) estimates that drought costs the United States an average of $6–8 billion per year. Because of these losses and the great effects of drought on many citizens’ quality of life, drought planning is gaining widespread support in the United States. However, U.S. drought planning within the agricultural sector has historically focused on response measures that help producers, primarily farmers, deal with and recover from drought. It has been found that these often ad-hoc drought responses are very expensive and do …


Droughts And Dew Bean Productivity In Northwestern Arid Rajasthan, India, Pratap Narain, R. S. Singh, D. Kumar May 2001

Droughts And Dew Bean Productivity In Northwestern Arid Rajasthan, India, Pratap Narain, R. S. Singh, D. Kumar

Drought Network News (1994–2001)

Arid ecosystems constitute an important part of the world’s dry climates. The Indian arid zone is characterized by a harsh and fragile system, which influences the productivity (both quantitative and qualitative) and socioeconomic status of the inhabitants. The study discussed in this article was conducted in the Bikaner region, which is one of the most drought-prone districts of Rajasthan (Figure 1). Annual rainfall in the district is 268 mm, of which 85% occurs during the southwest summer monsoon (July–September). The region is known to experience extreme variations in diurnal and seasonal temperatures and high wind velocity, particularly during summers, associated …


Winter Drought In Iran: Associations With Enso, M. J. Nazemosadat May 2001

Winter Drought In Iran: Associations With Enso, M. J. Nazemosadat

Drought Network News (1994–2001)

The Islamic Republic of Iran (Figure 1) has an area of 1,648,000 km2 and a population of 65 million people (1995 estimate). The country has arid and semiarid climates and the occurrence of rainfall is unreliable, with a coefficient of variation as high as 70%. The average annual precipitation over the country is around 250 mm. Two mountain ridges, the Alborz and Zagros (Figure 1), which run east and southeast from the northwest corner of the country, play an influential role in determining the amount and spatial distribution of rainfall. The peaks of Alborz and Zagros are about 5,700 …


Groundwater Study Of The Piawaning Townsite, Russell John Speed, Ali S. Mahtab May 2001

Groundwater Study Of The Piawaning Townsite, Russell John Speed, Ali S. Mahtab

Resource management technical reports

A groundwater study was carried out in and around the townsite of Piawaning. It aimed to accelerate the implementation of effective salinity management options. The study consisted of a drilling investigation, expansion of a piezometer network, a pumping test and a flood risk analysis.


Spring/Summer 2001, Nsu Oceanographic Center May 2001

Spring/Summer 2001, Nsu Oceanographic Center

Currents

No abstract provided.


Automatic Detection Of Outliers In Multibeam Echo Sounding Data, Tianhang Hou, Lloyd C. Huff, Larry A. Mayer May 2001

Automatic Detection Of Outliers In Multibeam Echo Sounding Data, Tianhang Hou, Lloyd C. Huff, Larry A. Mayer

Center for Coastal and Ocean Mapping

The data volumes produced by new generation multibeam systems are very large, especially for shallow water systems. Results from recent multibeam surveys indicate that the ratio of the field survey time, to the time used in interactive editing through graphical editing tools, is about 1:1. An important reason for the large amount of processing time is that users subjectively decide which soundings are outliers. There is an apparent need for an automated approach for detecting outliers that would reduce the extensive labor and obtain consistent results from the multibeam data cleaning process, independent of the individual that has processed the …


Error Estimation Of Bathymetric Grid Models Derived From Historic And Contemporary Data Sets, Martin Jakobsson, Brian R. Calder, Larry A. Mayer, Andy Armstrong May 2001

Error Estimation Of Bathymetric Grid Models Derived From Historic And Contemporary Data Sets, Martin Jakobsson, Brian R. Calder, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

The past century has seen remarkable advances in technologies associated with positioning and the measurement of depth. Lead lines have given way to single beam echo sounders, which in turn are being replaced by multibeam sonars and other means of remotely and rapidly collecting dense bathymetric datasets. Sextants were replaced by radio navigation, then transit satellite, GPS and now differential GPS. With each new advance comes tremendous improvement in the accuracy and resolution of the data we collect. Given these changes and given the vastness of the ocean areas we must map, the charts we produce are mainly compilations of …


Trophic Cascades, Nutrients, And Lake Productivity: Whole-Lake Experiments, Stephen R. Carpenter, Jonathan J. Cole, James R. Hodgson, James F. Kitchell, Michael L. Pace, Darren Bade, Kathryn L. Cottingham May 2001

Trophic Cascades, Nutrients, And Lake Productivity: Whole-Lake Experiments, Stephen R. Carpenter, Jonathan J. Cole, James R. Hodgson, James F. Kitchell, Michael L. Pace, Darren Bade, Kathryn L. Cottingham

Dartmouth Scholarship

Responses of zooplankton, pelagic primary producers, planktonic bacteria, and CO2 exchange with the atmosphere were measured in four lakes with contrasting food webs under a range of nutrient enrichments during a seven-year period. Prior to enrichment, food webs were manipulated to create contrasts between piscivore dominance and planktivore dominance. Nutrient enrichments of inorganic nitrogen and phosphorus exhibited ratios of N:P > 17:1, by atoms, to maintain P limitation. An unmanipulated reference lake, Paul Lake, revealed baseline variability but showed no trends that could confound the interpretation of changes in the nearby manipulated lakes. Herbivorous zooplankton of West Long Lake (piscivorous fishes) …


Robust Automatic Multi-Beam Bathymetric Processing, Brian R. Calder, Larry A. Mayer May 2001

Robust Automatic Multi-Beam Bathymetric Processing, Brian R. Calder, Larry A. Mayer

Center for Coastal and Ocean Mapping

No abstract provided.