Oceanography and Atmospheric Sciences and Meteorology Commons^™

Upper White River Bmp Implementation Project (Nps Final Report), Paul F. Vendrell, K. F. Steele, M. A. Nelson, R. W. Mcnew

Arkansas Water Resources Center Technical Reports

The project objective was to monitor agricultural best management practices implemented to minimize sediment, nutrient, and bacterial impact on water quality of the Upper White River watershed. The project targeted the primary agricultural causes of non-point source nutrient and bacterial pollution in three sub-basins of the White River in the Beaver Lake Watershed. Areas with high animal densities targeted high source areas. High source areas were treated with best management practices (BMP) in an effort to reduce the impact to the White River and Beaver Lake. The predominant BMP implemented was waste management, a component of the farm nutrient management …

Extended Water Quality Monitoring Of The Lincoln Lake Watershed, Paul F. Vendrell, K. F. Steele, M. A. Nelson, L. W. Cash, R. W. Ncnew

Arkansas Water Resources Center Technical Reports

For seven years, the Lincoln Lake (Moores Creek and Beatty Branch) watershed was monitored for improvements in water quality resulting from agricultural best management practices (BMP) implemented to reduce nutrient transport. During the first three years of monitoring (1991 to 1994), nitrogen transport declined significantly (Edwards et al., 1994, 1996, and 1997) under both base and storm flow conditions. This decline in nitrogen transport was again observed in the three-year period following 1994 (Vendrell et al. 1998). This monitoring effort has demonstrated that water quality bas improved in the Lincoln Lake watershed. However, since the nitrogen transport continued to decline …

Improving Water Quality Through Bmps For Crop Production Systems Whole Farm Soil And Water Management, J. T. Gilmour, L. R. Frye, N. A. Slaton

Arkansas Water Resources Center Technical Reports

The major objective of this demonstration project was to assess the usefulness of Global Positioning Systems/Geographic Information Systems (GPS/GIS), water testing, soil testing and yield monitoring in a whole farm water and soil management plan. An important part of this objective was to make recommendations to increase crop productivity and decrease the potential for surface water degradation through erosion and runoff at the farm. The farm was located on 2400 acres in the Bayou de View watershed in Monroe County, Arkansas. The farm lies approximately five miles southwest of the town of Brinkley straddling Highway 17 just south of its …

Flow Near Submarine Canyons Driven By Constant Winds, Jun She, John M. Klinck

CCPO Publications

Circulation over coastal submarine canyons driven by constant upwelling or downwelling wind stress is simulated and analyzed with a primitive equation ocean model. Astoria Canyon, on the west coast of North America, is the focus of this study, and model results are consistent with most major features of mean canyon circulation observed in Astoria Canyon. Near-surface flow crosses over the canyon, while a closed cyclone occurs within the canyon. Upwelling prevails within the canyon and is larger than wind-driven upwelling along the adjacent shelf break. Water rises from depths reaching 300 m to the canyon rim and, subsequently, onto the …

Modeling High-Frequency Seafloor Backscattering Of Gassy Sediments: The Eel River Margin Case, Luciano E. Fonseca, Larry A. Mayer

Center for Coastal and Ocean Mapping

Models of acoustic backscatter typically take into account two different processes: interface scattering and volume scattering. What happens to these two contributions when the sediment is charged with gas bubbles? For the interface backscatter contribution we adopted the model developed by Jackson et al. (1986), but added modifications to accommodate gas bubbles, which when present, even in very small quantities, can dominate the acoustic characteristics of the sediment. The model parameters that are affected by gas content are the density ratio, the sound speed ratio and the loss parameter. To a first approximation, the model roughness parameters are not influenced …

Osl Dating Supports "High" Sedimentation Rates In Central Arctic Ocean, Martin Jakobsson, Andrew Murray, Jan Backman, Reidar Lovlie

Center for Coastal and Ocean Mapping

No abstract provided.

Proceedings Of The Arkansas Water Resources Center Annual Conference: Environmental Hydrology, Kenneth F. Steele

Arkansas Water Resources Center Technical Reports

The papers and abstracts in these proceedings are the result of a joint conference of the Arkansas Water Resources Center (A WRC) with the SouthCentral Section of the Geological Society of America. The joint conference was a success with about 250 participants. A WRC sponsored two sessions on Environmental Hydrology and a short course titled "Hydrogeology and Geochemistry of Salt Water Contamination." The Environmental Hydrology presentations covered wide-ranging topics that reflect the diversity of the environmental settings across Arkansas. Topics ranged from salt water and critical ground water issues in the Delta to endangered species and interbasin ground-water recharge in …

Modifications Of The C37 Alkenone And Alkenoate Composition In The Water Column And Sediment: Possible Implications For Sea Surface Temperature Estimates In Paleoceanography, Joan O. Grimalt, Jürgen Rullkötter, Marie-Alexandrine Sicre, Roger Summons, John Farrington, H. Rodger Harvey, Miguel Goñi, Ken Sawada

OES Faculty Publications

The literature pertaining to C37 alkenone and C37 and C38 alkenoate production and diagenesis has been reviewed and evaluated for issues that might jeopardize their usefulness in paleotemperature estimation. We also examined the use of the C37 alkenones as paleoproductivity indicators, the stability of their δ13C isotopic compositions, and their incorporation into the nonsolvent extractable organic matter fraction. Biological transformation of organic matter by bacteria and zooplankton does not appear to cause significant changes to the ratio of C37:2 and C37:3 alkenones, but there are major alterations in the relative composition of alkenoates. Studies of water column processes and postdepositional …

Application Of Tree-Structured Regression For Regional Precipitation Prediction Using General Circulation Model Output, Xiangshang Li, David J. Sailor

Mechanical and Materials Engineering Faculty Publications and Presentations

This study presents a tree-structured regression (TSR) method to relate daily precipitation with a variety of free-atmosphere variables. Historical data were used to identify distinct weather patterns associated with differing types of precipitation events. Models were developed using 67% of the data for training and the remaining data for model validation. Seasonal models were built for each of 2 US sites: San Francisco, California, and San Antonio, Texas. The average correlation between observed and simulated daily precipitation data series is 0.75 for the training set and 0.68 for the validation set. Relative humidity was found to be the dominant variable …

Inference Of Tidal Elevation In Shallow Water Using A Vessel-Towed Acoustic Doppler Current Profiler, Chunyan Li, Arnoldo Valle-Levinson, Larry P. Atkinson, Tom C. Royer

CCPO Publications

Vessel-towed acoustic Doppler current profilers (ADCPs) have been widely used to measure velocity profiles. Since the instrument is usually mounted on a catamaran floating on the surface, previous studies have used the water surface as the reference level from which the vertical coordinate for the velocity profile is defined. However, because of the tidal oscillation, the vertical coordinate thus defined is time-dependent in an Earth-coordinate system, which introduces an error to the estimated harmonic constants for the velocity. As a result, the total transport will also be in error. This is particularly a problem in shallow waters where the tidal …

Secular Variations Of Atomic Oxygen In The Mesopause Region Induced By Transient Gravity Wave Packets, Michael P. Hickey Ph.D., R. L. Walterscheid, Philip G. Richards

Publications

We employ a 2-dimensional, time-dependent, fully nonlinear model of minor species in the mesopause region and our Spectral Full-Wave Model to simulate the response of atomic oxygen (O) to a gravity wave packet in the mesopause region. We demonstrate that gravity waves affect the time-averaged distribution of O in the mesosphere and lower thermosphere (MLT) region through the constituent fluxes the waves induce. Our conclusions are based on simulations of two wave packets that violate the non-acceleration conditions through transience and dissipation. The net cycle-averaged effect of the waves is to significantly increase (by as much as 50%) the O …

Photochemical Production Of Gas Phase No X From Ice Crystal No3 −, R E. Honrath, S Guo, Matthew C. Peterson, M P. Dziobak, Jack E. Dibb, Matthew Arsenault

Earth Sciences

Recent measurements have demonstrated that sunlight irradiation of snow results in the release of significant amounts of gas phase NO_x (NO+NO₂). We report here the results of a series of experiments designed to test the hypothesis that the observed NO_x production is the result of nitrate photolysis. Snow produced from deionized water with and without the addition of nitrate was exposed to natural sunlight in an outdoor flow chamber. While NO_x release from snow produced without added NO⁻₃ was minimal, the addition of 100 µM NO⁻₃resulted in the release …

The Influence Of Wave– And Zonal Mean–Ozone Feedbacks On The Quasi-Biennial Oscillation, Eugene Cordero, Terrence R. Nathan

Faculty Publications, Meteorology and Climate Science

The effects of wave and zonal mean ozone heating on the evolution of the quasi-biennial oscillation (QBO) are examined using a two-dimensional mechanistic model of the equatorial stratosphere. The model atmosphere is governed by coupled equations for the zonal mean and (linear) wave fields of ozone, temperature, and wind, and is driven by specifying the amplitudes of a Kelvin wave and a Rossby–gravity wave at the lower boundary. Wave–mean flow interactions are accounted for in the model, but not wave–wave interactions.

A reference simulation (RS) of the QBO, in which ozone feedbacks are neglected, is carried out and the results …

Investigation Of Optimum Sample Number And Timing For Determining Pollution Loads, T. S. Soerens, Marc A. Nelson

Arkansas Water Resources Center Technical Reports

In order to determine the impacts of non point source (NPS) pollution and to develop Total Maximum Daily Loads (Tr\tfDLs), accurate measurements of pollution loads in streams are critical. The objectives of this study were to accurately detemline pollutant loads at two sites by intensive storm sampling, to develop sub-sampling and other data analysis techniques, to detemline the effect of sample interval on load calculation accuracy, and to find the minimum sample interval required to determine storm loads at a required accuracy. The two stream sites used were a 1st order and a 3rd order stream in the Illinois River …

Multiple Spatial Scale Assessment Of Coral Reef And Hard-Bottom Community Structure In The Florida Keys National Marine Sanctuary, Steven Miller, Dione W. Swanson, Mark Chiappone

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The zoning plan for the Florida Keys National Marine Sanctuary (FKNMS) established 23 relatively small no-fishing zones distributed mostly along the offshore reef tract in 1997. In 1999, a two-stage, stratified random sampling design based on the proportion of coral reef and hard-bottom types within the FKNMS was conducted. Our study focused on differences in coverage, density, and condition of benthic organisms with respect to habitat type, regional variations, and differences between no-fishing zones and reference sites at 80 locations spanning 200 km. Most variables exhibited significant spatial differences by habitat type or between individual no-fishing zones and reference sites …

Circulation, Vol. 7, No. 3, Center For Coastal Physical Oceanography, Old Dominion University

CCPO Circulation

Fall 2000 issue of CCPO Circulation featuring article "Worldwide Coastal Ocean Research at CCPO"

Announcements: Fall 2000

Drought Network News (1994–2001)

Contents:

2000 National Disaster Medical System Conference

Management Strategies to Mitigate Drought in the Mediterranean: Monitoring, Risk Analysis and Contingency Planning

Potential Use Of Noaa/Avhrr Satellite Data For Monitoring Environmental Change In Turkey, Ali Umran Komuscu

Drought Network News (1994–2001)

In Turkey, desertification has been taking place in areas of low rainfall and minimal vegetative cover. In particular, the central, eastern, and southeastern parts of the country are vulnerable to desertification because of erosion, deforestation, and degradation of vegetative cover. Rivers of those regions are characterized by very high sediment yields. Nearly 60% of the country’s soils are subjected to severe erosion and approximately 450 million tons of sediment are carried to rivers each year. Meanwhile, wind erosion has been a very effective desertification process in central and southeastern parts of the country, where annual rainfall varies around 400–500 mm/year. …

Workshop On Drought-Related Issues In Fars Province, Iran: Critical Points And Resolutions, M. J. Nazemosadat, S. Amin, A. A. Kamgare-Haghighi, D. Khalili

Drought Network News (1994–2001)

As a result of the occurrence of overwhelming severe drought over most parts of the Islamic Republic of Iran, an educational/professional workshop on drought issues was held at the College of Agriculture, Shiraz University in Iran, October 18–19, 2000. The workshop was sponsored by the College of Agriculture, the office of Fars Provincial Government, the Agricultural Bank, and Shiraz Abfa Company. The workshop was mainly focused on the assessment of drought impacts and severity in Fars province, in the southern part of Iran.

The inauguration ceremony was attended by some of the parliament members (from Fars province), the Chancellor of …

From The Director: Fall 2000, Donald A. Wilhite

Drought Network News (1994–2001)

The NDMC hosted the first annual “Drought Monitor Forum” in November. Most of the readers of Drought Network News are probably aware of the Drought Monitor web site (http://enso.unl.edu/ monitor/index.html) and the products that are provided to users. (Mark Svoboda of the NDMC provided an overview of the Drought Monitor product in the Winter/Spring 2000 issue of Drought Network News.) This weekly product, jointly produced by the NDMC, U.S. Department of Agriculture, and NOAA’s Climate Prediction Center, has been widely accepted in the United States, and other countries are considering the adoption of a similar technique for mapping drought …

Improving Drought Early Warning Systems In The Context Of Drought Preparedness And Mitigation, Donald A. Wilhite, M. V. K. Sivakumar, Deborah Wood

Drought Network News (1994–2001)

Effective drought early warning systems are an integral part of efforts worldwide to improve drought preparedness. Timely and reliable data and information must be the cornerstone of effective drought policies and plans. In pursuit of the goal of improving the effectiveness of drought early warning systems, participants of the experts meeting were asked to address three fundamental questions:

1. What is your assessment of the current status of drought early warning systems?
2. What are the shortcomings, limitations, and needs for drought early warning systems?
3. How can drought early warning systems be improved to better support drought preparedness and …

Using The Spi To Monitor The 1999-2000 Drought In Northeastern Argentina, Roberto Zanvettor, Andres Ravelo

Drought Network News (1994–2001)

Drought risk is a major concern across many regions of Argentina because precipitation is extremely variable. One of these regions, the Pampas, is the main agricultural and livestock production area, extending over 60 million hectares. This region was recently surveyed to detect, monitor, and assess the occurrence of drought using a network of 27 meteorological stations and the Standardized Precipitation Index (SPI), developed by McKee et al. (1993). The SPI has various categories that define drought intensities. A period is considered humid when the SPI value is greater than +1 and a period is considered dry when the value of …

Copper Complexation And Speciation In The Western South And Equatorial Atlantic Ocean, John A. Consolvo

Chemistry & Biochemistry Theses & Dissertations

Presented here are the first data on copper complexation and speciation in the South Atlantic Ocean. Samples were collected at six vertical profile stations and along the surface (1m) transect during the 1996 IOC Baseline Contaminant Survey. Copper complexation measurements were made for the surface transect (1m) samples and three of the six vertical profile stations (1m - ~500m) using differential pulse anodic stripping voltammetry (DPASV) with a thin mercury film, rotating glassy carbon disk electrode (TMFRGCDE).

A strong organic copper complexing ligand (L₁; log K' _cuL1/cu2+ > 11. 8 ± 0 .4) was detected in 57% of all …

Fall 2000, Nsu Oceanographic Center

Currents

No abstract provided.

Experimental Goes Sounder Products For The Assessment Of Downburst Potential, Gary P. Ellrod, James P. Nelson Iii, Michael R. Witiw, Lynda Bottos, William P. Roeder

Aeronautics Faculty Publications

Several experimental products derived from Geostationary Operational Environmental Satellite (GOES) Sounder retrievals (vertical profiles of temperature and moisture) have been developed to assist weather forecasters in assessing the potential for convective downbursts. The product suite currently includes the wind index (WINDEX), a dry microburst index, and the maximum difference in equivalent potential temperature (θe) from the surface to 300 hPa. The products are displayed as color-coded boxes or numerical values, superimposed on GOES visible, infrared, or water vapor imagery, and are available hourly, day and night, via the Internet. After two full summers of evaluation, the products have been shown …

Response Of A First-Order Stream In Maine To Short-Term In-Stream Acidification, S. A. Norton, R. Wagai, T. Navratil, J. M. Kaste, F. A. Rissberger

Dartmouth Scholarship

An experimental short-term acidification with HCl at a first-order stream in central Maine, USA was used to study processes controlling the changes in stream chemistry and to assess the ability of stream substrate to buffer pH. The streambed exerted a strong buffering capacity against pH change by ion exchange during the 6-hour acidification. Streambed substrates had substantial cation and anion exchange capacity in the pH range of 4.1 to 6.5. The ion exchange for cations and SO₄^2- were rapid and reversible. The speed of release of cations from stream substrates was Na¹⁺> Ca²⁺ > Mg²⁺ > Al …

Resolving Ambiguities In Gravity Wave Propagation Directions Inherent In Satellite Observations: A Simulation Study, Michael P. Hickey Ph.D., Jason S. Brown

Publications

We simulate space-based, sub-limb viewing observations of airglow brightness fluctuations caused by atmospheric gravity wave interactions with the O2 atmospheric airglow, and we demonstrate that, due to the geometry associated with such observations, the brightness fluctuations observed for the optically thick 0–0 band emission will always appear stronger for waves traveling towards the observer (satellite). The effect should be most noticeable for waves having relatively small vertical wavelengths (∼10 km) and horizontal wavelengths of 50 km or greater. For waves of short (∼100 km) horizontal wavelength, the brightness fluctuation anisotropy with respect to viewing direction may also be evident in …

Spatial And Temporal Changes In Land Use And Land Cover From 1988 To 1992 In The Upper White River Watershed, H. D. Scott, J. M. Mckimmey

Arkansas Water Resources Center Technical Reports

Changes in Land Use and Land Cover (LULC) in the upper White River Watershed from 1988 to 1992 were analyzed and plotted using the geographic information system known as Geographic Resources Analyses Support System (GRASS). This portion of the White River Watershed includes two sub-basins the East Fork and the Middle Fork. In addition, LULC changes were determined for two smaller sub-basins, Shumate Creek and Cannon Creek, located in the East Fork of the White River. The sources and methods of interpretation of the 1988 and 1992 of data were different. Thus, there were variations in how certain portions of …

Ground Water In Northwest Arkansas: Minimizing Nutrient Contamination From Non-Point Sources In Karst Terrane, R. K. Davis, J. V. Brahana, J. S. Johnston

Arkansas Water Resources Center Technical Reports

The purpose of the project is to evaluate the effectiveness of Best Management Practices (BPMs) in preventing non-point source contamination of the ground-water resources in the karst terrane of northwestern Arkansas. Limestone and dolomite aquifers in the region are highly vulnerable to contamination. Ground-water studies performed in the region during the last two decades indicate degradation of these carbonate aquifers by nutrients and bacteria. The expeditious growth of the poultry industry during this period, in combination with the inordinate population growth of the region constitute a threat to the ground-water resources from both point sources and non-point sources of contamination. …

Illinois River 1999 Pollutant Loads At Arkansas Higway 59 Bridge, Marc A. Nelson, Thomas S. Soerens

Arkansas Water Resources Center Technical Reports

Automatic water samplers and aU. S. Geological Survey gauging station were established in 1995 on the main stem of the Illinois River at the Arkansas Highway 59 Bridge. Since that time, continuous stage and discharge measurements and water quality sampling have been used to determine pollutant concentrations and loads in the Arkansas portion of the Illinois River. This report represents the results from the measurement and sampling for January 1, 1999 to December 31, 1999.