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Articles 8821 - 8850 of 14012

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Ace-Fts Measurements Of Trace Species In The Characterization Of Biomass Burning Plumes, K. A. Tereszchuk, G. González Abad, C. Clerbaux, D. Hurtmans, P.-F. Coheur, P. F. Bernath Jan 2011

Ace-Fts Measurements Of Trace Species In The Characterization Of Biomass Burning Plumes, K. A. Tereszchuk, G. González Abad, C. Clerbaux, D. Hurtmans, P.-F. Coheur, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

To further our understanding of the effects of biomass burning emissions on atmospheric composition, we report measurements of trace species in biomass burning plumes made by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) instrument on the SCISAT-1 satellite. An extensive set of 15 molecules, C2H2, C2H6, CH3OH, CH4, CO, H2CO, HCN, HCOOH, HNO3, NO, NO2, N2O5, O-3, OCS and SF6 are used in our analysis. Even though most biomass burning smoke is typically confined to the …


Improved Verification And Analysis Of National Weather Service Point Forecast Matrices, Paul Fajman Jan 2011

Improved Verification And Analysis Of National Weather Service Point Forecast Matrices, Paul Fajman

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Verification is the process of determining the quality of forecast information. Office and personal forecast verifications are significantly lacking throughout the National Weather Service for many reasons. The primary reasons are that verification is time consuming, tedious, and monotonous. This research attempted to ease that process by creating new computer procedures to automate the verification process. The new procedures were tested using two years of forecasting data from November 2007 to November 2009 from the Omaha/Valley Weather Forecasting Office to serve as a framework for future verifications. Point Forecast Matrices (PFM) produced by the National Weather Service twice daily and …


Aerosol Climatology Over Nile Delta Based On Modis, Misr And Omi Satellite Data, H. S. Marey, J. C. Gille, Hesham El-Askary, E. A. Shalaby, Mohamed El Raey Jan 2011

Aerosol Climatology Over Nile Delta Based On Modis, Misr And Omi Satellite Data, H. S. Marey, J. C. Gille, Hesham El-Askary, E. A. Shalaby, Mohamed El Raey

Mathematics, Physics, and Computer Science Faculty Articles and Research

Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the “black cloud” during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) at 550 nm were examined for the 10 yr period from 2000–2009. Significant monthly variability is observed in the AOD with maxima in April or May (_0.5) and October (_0.45), and a …


Extremely Large Anthropogenic-Aerosol Contribution To Total Aerosol Load Over The Bay Of Bengal During Winter Season, Dimitris G. Kaskaoutis, Shailesh Kumar Kharol, P. R. Sinha, Ramesh P. Singh, H. D. Kambezidis, Anu Rani Sharma, K. V. S. Bardarinath Jan 2011

Extremely Large Anthropogenic-Aerosol Contribution To Total Aerosol Load Over The Bay Of Bengal During Winter Season, Dimitris G. Kaskaoutis, Shailesh Kumar Kharol, P. R. Sinha, Ramesh P. Singh, H. D. Kambezidis, Anu Rani Sharma, K. V. S. Bardarinath

Mathematics, Physics, and Computer Science Faculty Articles and Research

Ship-borne observations of spectral aerosol optical depth (AOD) have been carried out over the entire Bay of Bengal (BoB) as part of the W-ICARB cruise campaign during the period 27 December 2008-30 January 2009. The results reveal a pronounced temporal and spatial variability in the optical characteristics of aerosols mainly due to anthropogenic emissions and their dispersion controlled by local meteorology. The highest aerosol amount, with mean AOD(500)> 0.4, being even above 1.0 on specific days, is found close to the coastal regions in the western and northern parts of BoB. In these regions the Angstrom exponent is also found …


Estimation Of Nox Emissions From Delhi Using Car Max-Doas Observations And Comparison With Omi Satellite Data, R. Shaiganfar, S. Beirle, Manish Sharma, A. Chauhan, Ramesh P. Singh, T. Wagner Jan 2011

Estimation Of Nox Emissions From Delhi Using Car Max-Doas Observations And Comparison With Omi Satellite Data, R. Shaiganfar, S. Beirle, Manish Sharma, A. Chauhan, Ramesh P. Singh, T. Wagner

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present the first Multi-Axis-(MAX-) DOAS observations in India performed during April 2010 and January 2011 in Delhi and nearby regions. The MAX-DOAS instrument was mounted on a car roof, which allowed us to perform measurements along individual driving routes. From car MAX-DOAS observations along closed circles around Delhi, together with information on wind speed and direction, the NOx emissions from the greater Delhi area were determined: our estimate of 4.4 x 10(25) molecules s(-1) is found to be slightly lower than the corresponding emission estimates using the EDGAR emission inventory and substantially smaller compared to a recent study by …


Contrasting Aerosol Trends Over South Asia During The Last Decade Based On Modis Observations, Dimitris G. Kaskaoutis, Shailesh Kumar Kharol, P. R. Sinha, Ramesh P. Singh, K. V. S. Badarinath, Waseem Mehdi, Manish Sharma Jan 2011

Contrasting Aerosol Trends Over South Asia During The Last Decade Based On Modis Observations, Dimitris G. Kaskaoutis, Shailesh Kumar Kharol, P. R. Sinha, Ramesh P. Singh, K. V. S. Badarinath, Waseem Mehdi, Manish Sharma

Mathematics, Physics, and Computer Science Faculty Articles and Research

Atmospheric aerosols over south Asia constitute a major environmental and climate issue. Thus, extensive land and cruise campaigns have been conducted over the area focusing on investigating the aerosol properties and climate implications. Except from the ground-based instrumentation, several studies dealt with analyzing the aerosol properties from space, focusing mainly on the spatial distribution of the aerosol optical depth (AOD) and possible feedbacks of aerosols on the monsoon system. However, except from some works using ground-based instrumentation or satellite observations over a specific region, there is lack of studies dealing with monitoring of the aerosol trend over south Asia. The …


Evaluation Of Satellite-Retrieved Extreme Precipitation Rates Across The Central United States, A. Aghakoucak, A. Behrangi, S. Sorooshian, K. Hsu, Eyal Amitai Jan 2011

Evaluation Of Satellite-Retrieved Extreme Precipitation Rates Across The Central United States, A. Aghakoucak, A. Behrangi, S. Sorooshian, K. Hsu, Eyal Amitai

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Water resources management, forecasting, and decision making require reliable estimates of precipitation. Extreme precipitation events are of particular importance because of their severe impact on the economy, the environment, and the society. In recent years, the emergence of various satellite-retrieved precipitation products with high spatial resolutions and global coverage have resulted in new sources of uninterrupted precipitation estimates. However, satellite-based estimates are not well integrated into operational and decision-making applications because of a lack of information regarding the associated uncertainties and reliability of these products. In this study, four satellite-derived precipitation products (CMORPH, PERSIANN, TMPA-RT, and TMPA-V6) are evaluated with …


Factors That Contribute To Turbidity On The West Fork Of The White River In Arkansas, Chris Cotton, Brian Haggard Jan 2011

Factors That Contribute To Turbidity On The West Fork Of The White River In Arkansas, Chris Cotton, Brian Haggard

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

The West Fork of the White River (WFWR) exceeds the water quality standard for turbidity (10 NTU) set by the Arkansas Department of Environmental Quality and, since 1998, the river has been on Arkansas’s 303 (d) list of impaired water bodies unsuitable for aquatic life because of turbidity exceedances. To understand the factors that could be related to turbidity, total suspended solids (TSS), total inorganic suspended solids (TISS), total volatile suspended solids (TVSS), sestonic chlorophyll-a (Chl-a) concentrations, and turbidity were measured on three sample dates from nine sites on the WFWR. As the site location changed in the downstream direction, …


Improving Simulations Of The Upper Ocean By Inclusion Of Surface Waves In The Mellor-Yamada Turbulence Scheme, Chuan Jiang Huang, Fangli Qiao, Zhenya Song, Tal Ezer Jan 2011

Improving Simulations Of The Upper Ocean By Inclusion Of Surface Waves In The Mellor-Yamada Turbulence Scheme, Chuan Jiang Huang, Fangli Qiao, Zhenya Song, Tal Ezer

CCPO Publications

The Mellor-Yamada turbulence closure scheme, used in many ocean circulation models, is often blamed for overly high simulated surface temperature and overly low simulated subsurface temperature in summer due to insufficient vertical mixing. Surface waves can enhance turbulence kinetic energy and mixing of the upper ocean via wave breaking and nonbreaking-wave-turbulence interaction. The influences of wave breaking and wave-turbulence interaction on the Mellor-Yamada scheme and upper ocean thermal structure are examined and compared with each other using one-dimensional and three-dimensional ocean circulation models. Model results show that the wave-turbulence interaction can effectively amend the problem of insufficient mixing in the …


Hurricane Induced Land And Vegetation Changes In The Breton Sound Estuary And Chandeleur Islands Using Landsat 5 Tm, Vandana Varshini Raghunathan Jan 2011

Hurricane Induced Land And Vegetation Changes In The Breton Sound Estuary And Chandeleur Islands Using Landsat 5 Tm, Vandana Varshini Raghunathan

LSU Master's Theses

This study focuses on hurricane-induced changes in land and vegetation primarily in two study areas, the Breton Sound Estuary and the Chandeleur Islands, southeast of New Orleans, Louisiana. Breton Sound Estuary consists of the Caernarvon Diversion, a fresh water diversion of the Mississippi River that supplies this region with managed pulses of fresh water and sediments. The Chandeleur Islands are a chain of barrier islands that are uninhabited and transgressive in nature. A sequence of hurricanes in the past two decades has greatly altered both areas significantly. Satellite data were analyzed for a period of 24 years (1987-2011) of Breton …


Fate Of Mississippi River Diverted Nitrate On Vegetated And Non-Vegetated Coastal Marshes Of Breton Sound Estuary, Christine M. Vanzomeren Jan 2011

Fate Of Mississippi River Diverted Nitrate On Vegetated And Non-Vegetated Coastal Marshes Of Breton Sound Estuary, Christine M. Vanzomeren

LSU Master's Theses

The Caernarvon Diversion meters Mississippi River water into coastal marshes of Breton Sound. Elevated levels of nitrogen in river water have sparked concerns that nutrient loading may affect marsh resilience and belowground biomass, as evidence from several marsh fertilization studies. These concerns resulted from observation that fresh and brackish Breton Sound marshes suffered extensive damage from Hurricane Katrina. The goal of this study is to determine the fate of nitrate (the dominant inorganic nitrogen form in the Mississippi River) in Breton Sound Estuary marshes. We hypothesized that most nitrate would be removed by denitrification and that nitrate loading would not …


A Terrestrial Gamma Ray Flash Observed From An Aircraft, D. M. Smith, Michael E. Splitt, Steven M. Lazarus Jan 2011

A Terrestrial Gamma Ray Flash Observed From An Aircraft, D. M. Smith, Michael E. Splitt, Steven M. Lazarus

Aerospace, Physics, and Space Science Faculty Publications

On 21 August 2009, the Airborne Detector for Energetic Lightning Emissions (ADELE), an array of six gamma-ray detectors, detected a brief burst of gamma rays while flying aboard a Gulfstream V jet near two active thunderstorm cells. The duration and spectral characteristics of the event are consistent with the terrestrial gamma ray flashes (TGFs) seen by instruments in low Earth orbit. A long-duration, complex +IC flash was taking place in the nearer cell at the same time, at a distance of ∼10 km from the plane. The sferics that are probably associated with this flash extended over 54 ms and …


Spatial Ecology Of Adult Spotted Seatrout, Cynoscion Nebulosus, In Louisiana Coastal Waters, Jody Lynn Callihan Jan 2011

Spatial Ecology Of Adult Spotted Seatrout, Cynoscion Nebulosus, In Louisiana Coastal Waters, Jody Lynn Callihan

LSU Doctoral Dissertations

Spotted seatrout, Cynoscion nebulosus, are common in estuaries and coastal waters of the south Atlantic and Gulf of Mexico and are of considerable recreational and economic importance. Still, the spatial ecology of this species is under-studied and poorly resolved, especially in Louisiana waters. To address this important knowledge gap, I examined the movements, distribution, and habitat use of adult spotted seatrout in coastal Louisiana primarily using high-resolution acoustic telemetry and secondarily, conventional tagging (mark-recapture) data. At the largest spatial scale investigated, I found that adults exhibited a high degree of estuarine fidelity and rarely undertook large-scale movements in excess of …


Variability In Red Snapper Otolith Microchemistry Among Gulf Of Mexico Regions, Michelle Zapp Sluis Jan 2011

Variability In Red Snapper Otolith Microchemistry Among Gulf Of Mexico Regions, Michelle Zapp Sluis

LSU Doctoral Dissertations

Red snapper, Lutjanus campechanus, has been an economically important reef fish in the Gulf of Mexico (Gulf) for over 150 years and is currently overfished. Catch statistics and demographic differences have lead to the population being categorized into eastern and western substocks divided by the Mississippi River, but data is recombined to set a Gulf-wide annual catch limit. The two objectives of this study were to apply otolith nursery chemical signatures to estimate red snapper mixing dynamics in the western Gulf, and to determine if signatures based upon trace metals associated with oil and gas platforms could discriminate between region …


Quantitative Mapping Of Cyanobacterial Blooms Using Oceansat-1 Ocm Satellite Data, Padmanava Dash Jan 2011

Quantitative Mapping Of Cyanobacterial Blooms Using Oceansat-1 Ocm Satellite Data, Padmanava Dash

LSU Doctoral Dissertations

Cyanobacteria represent a major harmful algal group in fresh to brackish water environments. Lac des Allemands, a freshwater lake of 49 km2 southwest of New Orleans, Louisiana, provides a natural laboratory for remote characterization of cyanobacteria blooms because of their seasonal occurrence. This dissertation makes a contribution to research methodology pertaining to atmospheric correction of satellite data and development of remote sensing algorithms to quantify cyanobacterial pigments. The Ocean Color Monitor (OCM) sensor provides radiance measurements similar to Sea-viewing Wide Field-of-View Sensor (SeaWiFS) but with higher spatial resolution. However, OCM does not have a standard atmospheric correction procedure and …


Microphytobenthos Of The Northern Gulf Of Mexico Hypoxic Area And Their Role In Oxygen Dynamics, Melissa Millman Baustian Jan 2011

Microphytobenthos Of The Northern Gulf Of Mexico Hypoxic Area And Their Role In Oxygen Dynamics, Melissa Millman Baustian

LSU Doctoral Dissertations

The presence or absence of microphytobenthos on the seafloor provides clues about whether benthic oxygen evolution contributes significantly to the oxygen budget of the hypoxic area in the northern Gulf of Mexico. Hypoxia (oxygen < 2 mg l-1) creates inadequate concentrations of dissolved oxygen to support most organisms, such as fish, shrimp and crabs, and occurs over large areas of the Louisiana continental shelf from spring through summer in most years. Oxygen production by benthic autotrophs may offset a decline in oxygen concentrations if there is a functioning community and sufficient light. I sampled three stations (14, 20 and 23 m depths) ~ 100 km west of the Mississippi River over three hypoxic annual cycles (2006 – 2008), and 11 stations along a 14 - 20 m contour on the shelf in late-July in 2006, 2007 and 2008. I used microscopy and high-performance liquid chromatography to estimate the biomass and composition of phytoplankton and microphytobenthos. The potential seasonal oxygen production was estimated in 2007 and 2008 by incubating coupled light/dark sediment cores and bottom water from two stations. The sediment community (cells > 3 um) differed from those in the water column and were frequently benthic pennate diatoms and filamentous cyanobacteria (58-88% seasonally and 1-99% in mid-summer). The concentration of microphytobenthic biomass was usually < 2.0 ug g dry sed-1, and various biotic parameters were influenced by light at the seafloor. Declines in dissolved oxygen over a seasonal cycle in 2007 and 2008 were affected more by the initial dissolved oxygen concentration than by the presence of microphytobenthos that could generate oxygen. The sediment (1.2 - 27.3 mmol O2 m-2 d-1, n = 97) and bottom-water (1.1 - 17.5 mmol m-2 d-1, n = 23) oxygen consumption rates were within the range of the few previously-reported data. This work adds to these data and also provides the only sediment oxygen consumption rates at fixed sites over seasonal time scales. These results provide critical input to three-dimensional, physical-biological models of oxygen dynamics for this hypoxic area.


Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico, Sean Brandon Creekmore Jan 2011

Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico, Sean Brandon Creekmore

LSU Master's Theses

The northwestern Gulf of Mexico currently experiences a large hypoxic area (“dead zone”) during the summer. While the local effects of hypoxia on organisms have been documented, the population-level effects are largely unknown. I developed a spatially-explicit, individual-based model to analyze how hypoxia effects on Atlantic croaker reproduction, growth, and mortality in the northwestern Gulf of Mexico could lead to population-level responses. The model follows the hourly growth, mortality, reproduction, and movement of individuals on a 300 x 800 spatial grid of 1 km2 cells for 100 years. Chlorophyll-a concentration, water temperature, and dissolved oxygen were specified daily for each …


Oceanic Light Absorption Properties: Assessment And Characterization In The Southeastern Bering Sea Using Field And Satellite Observations, Puneeta Suresh Naik Jan 2011

Oceanic Light Absorption Properties: Assessment And Characterization In The Southeastern Bering Sea Using Field And Satellite Observations, Puneeta Suresh Naik

LSU Doctoral Dissertations

In recent decades the Bering Sea has been subjected to large climatic variability with cascading consequences on its productive marine ecosystem. Long-term as well as short-term monitoring is essential if we are to maintain its capability to supply the resources on which the national and local economy depend. Remote sensing together with in-situ and laboratory measurements of physical, biological and optical properties have considerable potential for monitoring and measuring the effects of climate-driven changes on this ecosystem. A major shortcoming to obtain accurate estimates of optically active components (such as colored dissolved organic matter, non-algal particulate matter, and phytoplankton) from …


Assessment Of Black Carbon In Snow And Ice From The Tibetan Plateau And Pacific Northwest, Matthew Glen Jenkins Jan 2011

Assessment Of Black Carbon In Snow And Ice From The Tibetan Plateau And Pacific Northwest, Matthew Glen Jenkins

All Master's Theses

An ice core from Mt. Geladandong, Tibetan Plateau, spanning 1853-1983, and snow samples collected over two winters from the Cascade Mountains were analyzed for concentrations of black carbon (BC) using a Single Particle Soot Photometer (SP2). From the ice core, the high-resolution BC record displayed substantial variability, a 2-fold increase in peak concentrations from 1853-1930 to 1930-1983, and a 1.6-fold increase in average concentrations from 1853-1975 to 1975-1983. Concentrations were also higher than at two areas closer to BC sources and analyzed by the same method. In the Pacific Northwest, BC concentrations varied seasonally and annually, with the highest concentrations …


State Of The River Report For The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, And Contaminants 2011, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University Jan 2011

State Of The River Report For The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, And Contaminants 2011, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University

State of the River Report

No abstract provided.


Nonlinear Behaviour Of Sea Surface Waves Based On Low-Gradient Phase-Only Scattering Effects, Jonathan Blackledge, Eugene Coyle, Derek Kearney Jan 2011

Nonlinear Behaviour Of Sea Surface Waves Based On Low-Gradient Phase-Only Scattering Effects, Jonathan Blackledge, Eugene Coyle, Derek Kearney

Conference papers

Nonlinear sea waves generated by the wind, including freak waves, are considered to be phenomena that can be modelled using the nonlinear (cubic) Schrodinger equation, for example. However, there is a problem with this approach which is that sea surface waves, driven by wind speeds of varying strength, must be considered to be composed of two distinct types, namely, linear waves and nonlinear waves. In this paper, we consider a different approach to modelling ‘nonlinear’ waves that is based on a solution to the linear wave equation under a low-gradient, phase-only condition. This approach is entirely compatible with the fluid …


Upscaling Carbon Fluxes Over The Great Plains Grasslands: Sinks And Sources, Li Zhang, Bruce K. Wylie, Lei Ji, Tagir G. Gilmanov, Larry L. Tieszen, Daniel M. Howard Jan 2011

Upscaling Carbon Fluxes Over The Great Plains Grasslands: Sinks And Sources, Li Zhang, Bruce K. Wylie, Lei Ji, Tagir G. Gilmanov, Larry L. Tieszen, Daniel M. Howard

Natural Resource Management Faculty Publications

Previous studies suggested that the grasslands may be carbon sinks or near equilibrium, and they often shift between carbon sources in drought years and carbon sinks in other years. It is important to understand the responses of net ecosystem production (NEP) to various climatic conditions across the U.S. Great Plains grasslands. Based on 15 grassland flux towers, we developed a piecewise regression model and mapped the grassland NEP at 250 m spatial resolution over the Great Plains from 2000 to 2008. The results showed that the Great Plains was a net sink with an averaged annual NEP of 24 ± …


Comparison Of The Age And Growth Of Red Snapper (Lutjanus Campechanus) Amongst Habitats And Regions In The Gulf Of Mexico, Courtney Rose Saari Jan 2011

Comparison Of The Age And Growth Of Red Snapper (Lutjanus Campechanus) Amongst Habitats And Regions In The Gulf Of Mexico, Courtney Rose Saari

LSU Master's Theses

The Gulf of Mexico (GOM) red snapper stock has been exploited since the mid 1800s; yet it is still one of the most economically important fisheries in the GOM. Red snapper have been managed as a unit stock and are currently overfished, but perhaps no longer undergoing overfishing. Habitat varies greatly throughout the GOM and while numerous studies have aged red snapper, none have simultaneously compared the age and size structure and growth rates among standing and toppled oil and gas platforms with natural habitats. The objectives of this study were to examine the size and age structure and growth …


Aerosol Properties Over The Indo‐Gangetic Plain: A Mesoscale Perspective From The Tigerz Experiment, D. M. Giles, B. N. Holben, Sachchida N. Tripathi, Thomas F. Eck, W. Wayne Newcomb, Ilya Slutsker, Russell R. Dickerson, Anne M. Thompson, Shana Mattoo, Sheng-Hsiang Wang, Ramesh P. Singh, Aliaksandyr Sinyuk, Joel S. Schafer Jan 2011

Aerosol Properties Over The Indo‐Gangetic Plain: A Mesoscale Perspective From The Tigerz Experiment, D. M. Giles, B. N. Holben, Sachchida N. Tripathi, Thomas F. Eck, W. Wayne Newcomb, Ilya Slutsker, Russell R. Dickerson, Anne M. Thompson, Shana Mattoo, Sheng-Hsiang Wang, Ramesh P. Singh, Aliaksandyr Sinyuk, Joel S. Schafer

Mathematics, Physics, and Computer Science Faculty Articles and Research

High aerosol loading over the northern Indian subcontinent can result in poor air quality leading to human health consequences and climate perturbations. The international 2008 TIGERZ experiment intensive operational period (IOP) was conducted in the Indo-Gangetic Plain (IGP) around the industrial city of Kanpur (26.51 degrees N, 80.23 degrees E), India, during the premonsoon (April-June). Aerosol Robotic Network (AERONET) Sun photometers performed frequent measurements of aerosol properties at temporary sites distributed within an area covering similar to 50 km(2) around Kanpur to characterize pollution and dust in a region where complex aerosol mixtures and semi-bright surface effects complicate satellite retrieval …


Three-Year Ground Based Measurements Of Aerosol Optical Depth Over The Eastern Mediterranean: The Urban Environment Of Athens, E. Gerasopoulos, V. Amiridis, S. Kazadzis, P. Kokkalis, K. Eleftheratos, M. O. Andrae, T. W. Andrae, Hesham El-Askary, C S. Zerefos Jan 2011

Three-Year Ground Based Measurements Of Aerosol Optical Depth Over The Eastern Mediterranean: The Urban Environment Of Athens, E. Gerasopoulos, V. Amiridis, S. Kazadzis, P. Kokkalis, K. Eleftheratos, M. O. Andrae, T. W. Andrae, Hesham El-Askary, C S. Zerefos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Three years (2006–2008) of ground-based observations of the Aerosol Optical Depth (AOD) in the urban environment of Athens, in the Eastern Mediterranean, are analysed in this work. Measurements were acquired with a Multi-Filter Rotating Shadowband Radiometer at five wavelengths. The daily average AOD at 500 nm is 0.23, and the mean A° ngstro¨m coefficient calculated between 415 and 867 nm is 1.41. The annual variability of AOD has a spring maximum dominated by coarse dust particles from the Sahara (AOD 0.34–0.42), while the diurnal pattern is typical for urban sites, with AOD steadily increasing throughout the day. The greatest contribution …


Evaluating Spawning Migration Patterns And Predicting Spawning Success Of Shovelnose Sturgeon In The Lower Missouri River, M. L. Wildhaber, S. H. Holan, G. M. Davis, D. W. Gladish, A. J. Delonay, Diana M. Papoulias, D. K. Sommerhauser Jan 2011

Evaluating Spawning Migration Patterns And Predicting Spawning Success Of Shovelnose Sturgeon In The Lower Missouri River, M. L. Wildhaber, S. H. Holan, G. M. Davis, D. W. Gladish, A. J. Delonay, Diana M. Papoulias, D. K. Sommerhauser

United States Geological Survey: Staff Publications

Approaches using telemetry, precise reproductive assessments, and surgically implanted data storage tags (DSTs) were used in combination with novel applications of analytical techniques for fish movement studies to describe patterns in migratory behavior and predict spawning success of gravid shovelnose sturgeon. From 2004 to 2007, over 300 gravid female shovelnose sturgeon (Scaphirhynchus platorynchus) from the Lower Missouri River, that were expected to spawn in the year they were collected, were surgically implanted with transmitters and archival DSTs. Functional cluster modeling of telemetry data from the spawning season suggested two common migration patterns of gravid female shovelnose sturgeon. Fish …


Land Change Variability And Human–Environment Dynamics In The United States Great Plains, Mark A, Drummond, Roger F. Auch, Krista A. Karstensen, Kristi L. Sayler, Janis L. Taylor, Thomas Loveland Jan 2011

Land Change Variability And Human–Environment Dynamics In The United States Great Plains, Mark A, Drummond, Roger F. Auch, Krista A. Karstensen, Kristi L. Sayler, Janis L. Taylor, Thomas Loveland

United States Geological Survey: Staff Publications

Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km × 10 km blocks is used to efficiently identify the types and rates …


Introduction To “Environmental Contaminants In Biota, 2nd Edition”, W. Nelson Beyer, James P. Meador Jan 2011

Introduction To “Environmental Contaminants In Biota, 2nd Edition”, W. Nelson Beyer, James P. Meador

United States Geological Survey: Staff Publications

Ecotoxicology is the study of the movement of environmental contaminants through ecosystems and their effects on plants and animals. Examining tissue residues of these contaminants in biota is basic to ecotoxicology, both for understanding the movement of contaminants within organisms and through food chains, and for understanding and quantifying injuries to organisms and their communities. This book provides guidance on interpreting tissue concentrations of environmental contaminants.

Tissue concentrations have long been used both to identify the cause of toxicity in animals and as a measure of the severity of toxicity. More recently, they have been incorporated into environmental models, tying …


Lead In Birds, J. Christian Franson, Deborah J. Pain Jan 2011

Lead In Birds, J. Christian Franson, Deborah J. Pain

United States Geological Survey: Staff Publications

Lead is a highly toxic heavy metal that acts as a nonspecific poison affecting all body systems and has no known biological requirement. Absorption of low concentrations may result in a wide range of sublethal effects in animals, and higher concentrations may result in mortality (Demayo et al. 1982).

Lead has been mined and smelted by humans for centuries, but the use of lead-based products increased greatly following the Industrial Revolution. Consequently, lead today is ubiquitous in air, water, and soil, in both urban and rural environments (Eisler 2000). Vertebrates are exposed to lead mainly via inhalation and ingestion. A …


Spatial Patch Occupancy Patterns Of The Lower Keys Marsh Rabbit, Mitchell J. Eaton, Phillip T. Hughes, James D. Nichols, Anne Morkill, Chad Anderson Jan 2011

Spatial Patch Occupancy Patterns Of The Lower Keys Marsh Rabbit, Mitchell J. Eaton, Phillip T. Hughes, James D. Nichols, Anne Morkill, Chad Anderson

United States Geological Survey: Staff Publications

Reliable estimates of presence or absence of a species can provide substantial information on management questions related to distribution and habitat use but should incorporate the probability of detection to reduce bias. We surveyed for the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) in habitat patches on 5 Florida Key islands, USA, to estimate occupancy and detection probabilities. We derived detection probabilities using spatial replication of plots and evaluated hypotheses that patch location (coastal or interior) and patch size influence occupancy and detection. Results demonstrate that detection probability, given rabbits were present, was <0.5 and suggest that naı¨ve estimates (i.e., estimates without consideration of imperfect detection) of patch occupancy are negatively biased. We found that patch size and location influenced probability of occupancy but not detection. Our findings will be used by Refuge managers to evaluate population trends of Lower Keys marsh rabbits from historical data and to guide management decisions for species recovery. The sampling and analytical methods we used may be useful for researchers and managers of other endangered lagomorphs and cryptic or fossorial animals occupying diverse habitats.