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Initial statistical evaluation of ARAC COAMPS forecasts

Description: This informal workshop was organized to bring together scientists and engineers from St0 and LLNL with a common interest in using and developing new in-situ measurement techniques for studying the coastal ocean, particularly near-surface waters in the biologically active photic layer. Much of the discussion focused on the current and potential capabilities of the LLNL ''IMEEDS'' ocean observation capability (Integrated Marine Environmental Element Detection System), and ways to complement and process the data that can be obtained from the system. Two important goals of the workshop were to identify the range of current activities that could be usefully integrated with the capabilities of the LLNL system, and to explore additional scientific problems of the coastal ocean that could be addressed through collaborative LLNL - SIO efforts. A short summary of the issues addressed follows, with lead discussants identified. A series of action items developed during the course of the workshop, a list of participants, and a conference agenda conclude this report.
Date: June 30, 1999
Creator: Pace, J.C.
Partner: UNT Libraries Government Documents Department

PREDICTION OF SURFACE SETTLEMENT DUE TO THE DISPLACEMENT OF SOFT ZONES

Description: In areas composed of coastal plain sediments, soft zones subjected to partial overburden may be present in the subsurface. During or after a seismic event, these soft zones may be compressed. The resulting displacement due to the deformation of the soft zones will propagate to the ground surface and cause the surface to settle. This paper presents a method to predict the settlement at the surface due to the propagation of the displacement from the soft zones. This method is performed by discretizing the soft zones into multiple clusters of finite sub-areas or subspaces. Settlement profile at the ground surface due to the displacement of each sub-area or subspace is computed assuming the shape is a normal distribution function. Settlement due to the displacement of the soft zones can then be approximated by adding the settlements computed for all the sub-areas or subspaces. This method provides a simple and useful tool for the prediction of the settlement profile and the results are consistent with those obtained from the finite difference analysis.
Date: March 3, 2008
Creator: Li, W
Partner: UNT Libraries Government Documents Department

Summary of Training Workshop on the Use of NASA tools for Coastal Resource Management in the Gulf of Mexico

Description: A two-day training workshop was held in Xalapa, Mexico from March 10-11 2009 with the goal of training end users from the southern Gulf of Mexico states of Campeche and Veracruz in the use of tools to support coastal resource management decision-making. The workshop was held at the computer laboratory of the Institute de Ecologia, A.C. (INECOL). This report summarizes the results of that workshop and is a deliverable to our NASA client.
Date: March 1, 2009
Creator: Judd, Chaeli; Judd, Kathleen S.; Gulbransen, Thomas C. & Thom, Ronald M.
Partner: UNT Libraries Government Documents Department

Fifth Annual Report: 2008 Pre-Construction Eelgrass Monitoring and Propagation for King County Outfall Mitigation

Description: This is the fifth and final report in a series documenting progress of the pre-construction eelgrass restoration and mitigation activities for the proposed King County Brightwater marine outfall, discharging to Puget Sound near Point Wells, Washington. King County began implementing a multiyear eelgrass monitoring and restoration program in 2004, with the primary goal of returning intertidal and shallow subtidal habitat and eelgrass to pre-construction conditions, after construction of the outfall. Major eelgrass mitigation program elements include: a) pre-construction monitoring, i.e., documenting initial eelgrass conditions and degree of fluctuation over a 5 year period prior to construction, b) eelgrass transplanting, including harvesting, offsite propagation and stockpiling of local plants for post-construction planting, and c) post-construction planting and subsequent monitoring, occurring in 2009 and beyond. The overall program is detailed in the Eelgrass Restoration and Biological Resources Implementation Workplan (King County 2008).
Date: January 1, 2010
Creator: Woodruff, Dana L.; Judd, Chaeli; Thom, Ronald M.; Sather, Nichole K. & Kaufmann, Ronald M.
Partner: UNT Libraries Government Documents Department

The dominant processes responsible for subsidence of coastal wetlands in south Louisiana

Description: Wetland loss in coastal areas of Terrebonne and Lafourche Parishes, Louisiana, largely results from two subsurface processes: (1) consolidation of recently deposited Holocene deltaic sediments and (2) active growth faulting. Locally, settlement is high where the thickness of valley fill is great and in broad interdistributary basins where the thickness of consolidation-prone, peaty soils is great. The delta cycle is identified as the fundamental sedimentologic unit that constitutes the lower delta plain. Peaty soils from the waning phase of the delta cycle are identified as the deltaic facies most subject to consolidation settlement. Data indicate direct relationships between the thickness of deltaic sediments in individual delta cycles, and the thickness of peaty soils capping these cycles, with present patterns of coastal tract land loss. In addition, active growth faulting is correlated with new areas of interior tract wetland loss. Consolidation and faulting largely explain the curious nature of wetland loss patterns in south Louisiana. Subsidence in The Netherlands has been attributed to similar causes, i.e. thick deposits of consolidation-prone sediments that accumulate on the downthrown sides of basin margin faults.
Date: December 31, 1995
Creator: Kuecher, G.J.
Partner: UNT Libraries Government Documents Department

An automatic coastline detector for use with SAR images

Description: SAR imagery for coastline detection has many potential advantages over conventional optical stereoscopic techniques. For example, SAR does not have restrictions on being collected during daylight or when there is no cloud cover. In addition, the techniques for coastline detection witth SAR images can be automated. In this paper, we present the algorithmic development of an automatic coastline detector for use with SAR imagery. Three main algorithms comprise the automatic coastline detection algorithm, The first algorithm considers the image pre-processing steps that must occur on the original image in order to accentuate the land/water boundary. The second algorithm automatically follows along the accentuated land/water boundary and produces a single-pixel-wide coastline. The third algorithm identifies islands and marks them. This report describes in detail the development of these three algorithms. Examples of imagery are used throughout the paper to illustrate the various steps in algorithms. Actual code is included in appendices. The algorithms presented are preliminary versions that can be applied to automatic coastline detection in SAR imagery. There are many variations and additions to the algorithms that can be made to improve robustness and automation, as required by a particular application.
Date: September 1, 1998
Creator: Erteza, Ireena A.
Partner: UNT Libraries Government Documents Department

Impacts of WRF Physics and Measurement Uncertainty on California Wintertime Model Wet Bias

Description: The Weather and Research Forecast (WRF) model version 3.0.1 is used to explore California wintertime model wet bias. In this study, two wintertime storms are selected from each of four major types of large-scale conditions; Pineapple Express, El Nino, La Nina, and synoptic cyclones. We test the impacts of several model configurations on precipitation bias through comparison with three sets of gridded surface observations; one from the National Oceanographic and Atmospheric Administration, and two variations from the University of Washington (without and with long-term trend adjustment; UW1 and UW2, respectively). To simplify validation, California is divided into 4 regions (Coast, Central Valley, Mountains, and Southern California). Simulations are driven by North American Regional Reanalysis data to minimize large-scale forcing error. Control simulations are conducted with 12-km grid spacing (low resolution) but additional experiments are performed at 2-km (high) resolution to evaluate the robustness of microphysics and cumulus parameterizations to resolution changes. We find that the choice of validation dataset has a significant impact on the model wet bias, and the forecast skill of model precipitation depends strongly on geographic location and storm type. Simulations with right physics options agree better with UW1 observations. In 12-km resolution simulations, the Lin microphysics and the Kain-Fritsch cumulus scheme have better forecast skill in the coastal region while Goddard, Thompson, and Morrison microphysics, and the Grell-Devenyi cumulus scheme perform better in the rest of California. The effect of planetary boundary layer, soil-layer, and radiation physics on model precipitation is weaker than that of microphysics and cumulus processes for short- to medium-range low-resolution simulations. Comparison of 2-km and 12-km resolution runs suggests a need for improvement of cumulus schemes, and supports the use of microphysics schemes in coarser-grid applications.
Date: July 22, 2009
Creator: Chin, H S; Caldwell, P M & Bader, D C
Partner: UNT Libraries Government Documents Department

California cooperative oceanic fisheries investigations. Reports volume 37, January 1--December 31, 1995

Description: Scientists from the California Department of Fish and Game (CDFG), the Southwest Fisheries Science Center of the National Marine Fisheries Service (NMFS), and the Scripps Institution of Oceanography, University of California, San Diego (UCSD), have collaborated for 46 years in the longest-running large-scale study ever undertaken in the ocean. This study was begun in order to understand the causes of changes in population, over time, of commercially important fishes in California`s coastal waters. When the study began, the Pacific sardine was by far the most significant species of economic concern to the State of California. Because its population changes were thought to be caused by a diversity of atmospheric, oceanic, and biological variables, a wide array of measurements in the California Current region were begun and have been continued to this day. This long time series of data allows not only a better understanding of the flux of fish populations, but also lays the foundation for understanding interdecadal and secular change in the seas. This document contains papers from symposium of the 1995 CalCOFI Conference related to interdecadal changes in the ecology of the California current.
Date: October 1, 1996
Creator: Olfe, J.
Partner: UNT Libraries Government Documents Department

Climate variability and climate change vulnerability and adaptation. Workshop summary

Description: Representatives from fifteen countries met in Prague, Czech Republic, on September 11-15, 1995, to share results from the analysis of vulnerability and adaptation to global climate change. The workshop focused on the issues of global climate change and its impacts on various sectors of a national economy. The U.N. Framework Convention on Climate Change (FCCC), which has been signed by more than 150 governments worldwide, calls on signatory parties to develop and communicate measures they are implementing to respond to global climate change. An analysis of a country`s vulnerability to changes in the climate helps it identify suitable adaptation measures. These analyses are designed to determine the extent of the impacts of global climate change on sensitive sectors such as agricultural crops, forests, grasslands and livestock, water resources, and coastal areas. Once it is determined how vulnerable a country may be to climate change, it is possible to identify adaptation measures for ameliorating some or all of the effects.The objectives of the vulnerability and adaptation workshop were to: The objectives of the vulnerability and adaptation workshop were to: Provide an opportunity for countries to describe their study results; Encourage countries to learn from the experience of the more complete assessments and adjust their studies accordingly; Identify issues and analyses that require further investigation; and Summarize results and experiences for governmental and intergovernmental organizations.
Date: December 31, 1995
Creator: Bhatti, N.; Cirillo, R.R. & Dixon, R.K.
Partner: UNT Libraries Government Documents Department

Innovative approach for restoring coastal wetlands using treated drill cuttings

Description: The leading environmental problem facing coastal Louisiana regions is the loss of wetlands. Oil and gas exploration and production activities have contributed to wetland damage through erosion at numerous sites where canals have been cut through the marsh to access drilling sites. An independent oil and gas producer, working with Southeastern Louisiana University and two oil field service companies, developed a process to stabilize drill cuttings so that they could be used as a substrate to grow wetlands vegetation. The U.S. Department of Energy (DOE) funded a project under which the process would be validated through laboratory studies and field demonstrations. The laboratory studies demonstrated that treated drill cuttings support the growth of wetlands vegetation. However, neither the Army Corps of Engineers (COE) nor the U.S. Environmental Protection Agency (EPA) would grant regulatory approval for afield trial of the process. Argonne National Laboratory was asked to join the project team to try to find alternative mechanisms for gaining regulatory approval. Argonne worked with EPA's Office of Reinvention and learned that EPA's Project XL would be the only regulatory program under which the proposed field trial could be done. One of the main criteria for an acceptable Project XL proposal is to have a formal project sponsor assume the responsibility and liability for the project. Because the proposed project involved access to private land areas, the team felt that an oil and gas company with coastal Louisiana land holdings would need to serve as sponsor. Despite extensive communication with oil and gas companies and industry associations, the project team was unable to find any organization willing to serve as sponsor. In September 1999, the Project XL proposal was withdrawn and the project was canceled.
Date: November 2, 1999
Creator: Veil, J. A. & Hocking, E. K.
Partner: UNT Libraries Government Documents Department

Sediment studies at Bikini Atoll part 2. inventories of transuranium elements in surface sediments

Description: This is the second of three reports on Bikini sediment studies, which discusses the concentrations and inventories of {sup 241}Am and {sup 239+240}Pu in sediments from the lagoon. Surface sediment samples were collected from 87 locations over the entire lagoon at Bikini Atoll during 1979. The collections were made to map the distribution of long-lived radionuclides associated with the bottom material and to show what modifications occurred in the composition of the sediment as a result of the testing program. Present inventories for {sup 241}Am and {sup 239+240}Pu in the surface 2 cm of sediment are estimated to be 14 and 17 TBq, respectively. These values are estimated to represent only 14% of the total inventory in the sediment column. Sediment inventories of {sup 239+240}Pu and {sup 241}Am are changing only slowly with time through chemical- physical processes that continuously mobilize small amounts of the transuranics to the water column. The lowest concentrations and inventories are associated with deposits logoonward of the eastern reef.
Date: October 1, 1997
Creator: Noshkin, V. E.; Eagle, R. J.; Wong, K. M. & Robison, W. L.
Partner: UNT Libraries Government Documents Department

Cooperative Monitoring Center Occasional Paper/11: Cooperative Environmental Monitoring in the Coastal Regions of India and Pakistan

Description: The cessation of hostilities between India and Pakistan is an immediate need and of global concern, as these countries have tested nuclear devices, and have the capability to deploy nuclear weapons and long-range ballistic missiles. Cooperative monitoring projects among neighboring countries in South Asia could build regional confidence, and, through gradual improvements in relations, reduce the threat of war and the proliferation of weapons of mass destruction. This paper discusses monitoring the trans-border movement of flow and sediment in the Indian and Pakistani coastal areas. Through such a project, India and Pakistan could initiate greater cooperation, and engender movement towards the resolution of the Sir Creek territorial dispute in their coastal region. The Joint Working Groups dialogue being conducted by India and Pakistan provides a mechanism for promoting such a project. The proposed project also falls within a regional framework of cooperation agreed to by several South Asian countries. This framework has been codified in the South Asian Seas Action Plan, developed by Bangladesh, India, Maldives, Pakistan and Sri Lanka. This framework provides a useful starting point for Indian and Pakistani cooperative monitoring in their trans-border coastal area. The project discussed in this paper involves computer modeling, the placement of in situ sensors for remote data acquisition, and the development of joint reports. Preliminary computer modeling studies are presented in the paper. These results illustrate the cross-flow connections between Indian and Pakistani coastal regions and strengthen the argument for cooperation. Technologies and actions similar to those suggested for the coastal project are likely to be applied in future arms control and treaty verification agreements. The project, therefore, serves as a demonstration of cooperative monitoring technologies. The project will also increase people-to-people contacts among Indian and Pakistani policy makers and scientists. In the perceptions of the general public, the project will ...
Date: June 1, 1999
Creator: Rajen, Gauray
Partner: UNT Libraries Government Documents Department

Data Summary for the Near-Shore Sediment Characterization Task of the Clinch River Environmental Restoration Program

Description: The purpose of the Near-Shore Sediment Characterization Task of the Clinch River Environmental Restoration Program (CR-ERP) was to quantify potential human health risks associated with Department of Energy (DOE)-related contamination of surface sediments in Watts Bar Reservoir (WBR). An estimated 700 Ci of {sup 137}Cs and 325 Ci of {sup 60}Co were released from White Oak Lake into the Clinch River between 1949 and 1992 (DOE, 1988). A number of previous studies have documented sediment contamination in the deep-water sediments but no study specifically targeted the near-shore environment, which has the most potential for exposure to humans.
Date: January 1, 1994
Creator: Levine, D.A.
Partner: UNT Libraries Government Documents Department

The Community Climate System Model: CCSM3

Description: A new version of the Community Climate System Model (CCSM) has been developed and released to the climate community. CCSM3 is a coupled climate model with components representing the atmosphere, ocean, sea ice, and land surface connected by a flux coupler. CCSM3 is designed to produce realistic simulations over a wide range of spatial resolutions, enabling inexpensive simulations lasting several millennia or detailed studies of continental-scale climate change. This paper will show results from the configuration used for climate-change simulations with a T85 grid for atmosphere and land and a 1-degree grid for ocean and sea-ice. The new system incorporates several significant improvements in the scientific formulation. The enhancements in the model physics are designed to reduce or eliminate several systematic biases in the mean climate produced by previous editions of CCSM. These include new treatments of cloud processes, aerosol radiative forcing, land-atmosphere fluxes, ocean mixed-layer processes, and sea-ice dynamics. There are significant improvements in the sea-ice thickness, polar radiation budgets, equatorial sea-surface temperatures, ocean currents, cloud radiative effects, and ENSO teleconnections. CCSM3 can produce stable climate simulations of millenial duration without ad hoc adjustments to the fluxes exchanged among the component models. Nonetheless, there are still systematic biases in the ocean-atmosphere fluxes in western coastal regions, the spectrum of ENSO variability, the spatial distribution of precipitation in the Pacific and Indian Oceans, and the continental precipitation and surface air temperatures. We conclude with the prospects for extending CCSM to a more comprehensive model of the Earth's climate system.
Date: December 27, 2004
Creator: Collins, W D; Blackmon, M; Bitz, C; Bonan, G; Bretherton, C S; Carton, J A et al.
Partner: UNT Libraries Government Documents Department

A Radiocarbon Chronology of Hunter-Gatherer Occupation from Bodega Bay, California, USA

Description: The evolution of hunter-gatherer maritime adaptations in western North America has been a prominent topic of discussion among archaeologists in recent years (e.g. Arnold 1992; Erlandson and Colten 1991; Erlandson and Glassow 1997; Lightfoot 1993). Although vast coastal regions of the northeastern Pacific (for example, southern California) have been investigated in detail, our understanding of hunter-gatherer developments along the coast of northern California is limited. Previous research indicates that humans have exploited marine mammals, fish and shellfish along the northern California shoreline since the early Holocene (Schwaderer 1992). By the end of the late Holocene, some groups remained year-round on the coast subsisting primarily on marine resources (e.g. Gould 1975; Hildebrandt and Levulett 2002). However, a paucity of well-dated cultural deposits has hindered our understanding of these developments, particularly during the early and middle Holocene. The lack of a long and reliable chronological sequence has restricted our interpretations of behavioral change, including the adaptive strategies (such as foraging, mobility and settlement) used by human foragers to colonize and inhabit the coastal areas of this region. These shortcomings have also hindered comparative interpretations with other coastal and inland regions in western North America. Here we present a Holocene radiocarbon chronology of hunter-gatherer occupation based on contemporaneous samples of charcoal and Mytilus californianus (California sea mussel) shell recovered from seven archaeological sites near Bodega Bay, California. A series of 127 {sup 14}C ages reveal a chronological sequence that spans from ca. 8940-110 cal BP (1{sigma}) (7890-160 {sup 14}C yr BP = charcoal; 8934-101 {sup 14}C yr BP = shell). As part of this sequence, we report new {sup 14}C dates from the stratified cave and open-air midden deposits at Duncan's Landing (CA-SON-348/H). In addition, we present {sup 14}C ages from three middle Holocene sites located in the Bodega Dunes, and from three ...
Date: April 27, 2005
Creator: Kennedy, M A; Russell, A D & Guilderson, T P
Partner: UNT Libraries Government Documents Department

Energy in the Mountain West: Colonialism and Independence

Description: In many ways, the mountain west (Alaska, Arizona, Colorado, Idaho, Montana, New Mexico, Nevada, Utah, Wyoming) is an energy colony for the rest of the United States: it is rich in energy resources that are extracted to fuel economic growth in the wealthier and more populous coastal regions. Federal agencies and global corporations often behave as if the mountain west is a place to be exploited or managed for the benefit of customers and consumers elsewhere. Yet, the area. is not vast empty space with a limitless supply of natural resources, but rather a fast-growing region with a diverse economic base dependent on a limited supply of water. New decision processes and collaborations are slowly changing this situation, but in a piecemeal fashion that places local communities at odds with powerful external interests. Proper planning of major development is needed to insure that the west has a strong economic and cultural future after the fossil energy resources decline, even if that might be a century from now. To encourage the necessary public discussions, this paper identifies key differences between the mountain west and the rest of the United States and suggests some holistic approaches that could improve our future. This paper is designed to provoke thought and discussion; it does not report new analyses on energy resources or usage. It is a summary of a large group effort.
Date: August 1, 2007
Creator: Piet, Steven; Brown, Lloyd; Cherry, Robert; Cooper, Craig; Heydt, Harold; Holman, Richard et al.
Partner: UNT Libraries Government Documents Department

1978 Houston-Galveston and Texas Gulf Coast vertical-control surveys

Description: Comparisons between leveling surveys of different epochs are used to determine vertical displacement of permanent bench marks. Displacement of bench marks usually represents the movement of the surrounding area. In this report, the 1978 Houston-Galveston and Texas Gulf Coast releveling surveys are compared to the 1963, 1973, and 1976 releveling results. The changes in elevations of bench marks common to two or more epochs are tabulated and plotted in Appendix A. From these differences, contour maps were prepared for the 1963 to 1978 and 1973 to 1978 epochs in the 2/sup 0/ x 2/sup 0/ area of maximum subsidence. Annual subsidence rates computed for the 1973 to 1978 period are about 25% less in the maximum subsidence area than the rates computed for the 1963 to 1973 period.
Date: November 1, 1980
Creator: Balazs, E.I.
Partner: UNT Libraries Government Documents Department

Modelin the Transport and Chemical Evolution of Onshore and Offshore Emissions and Their Impact on Local and Regional Air Quality Using a Variable-Grid-Resolution Air Quality Model

Description: The overall objective of this research project was to develop an innovative modeling technique to adequately model the offshore/onshore transport of pollutants. The variable-grid modeling approach that was developed alleviates many of the shortcomings of the traditionally used nested regular-grid modeling approach, in particular related to biases near boundaries and the excessive computational requirements when using nested grids. The Gulf of Mexico region contiguous to the Houston-Galveston area and southern Louisiana was chosen as a test bed for the variable-grid modeling approach. In addition to the onshore high pollution emissions from various sources in those areas, emissions from on-shore and off-shore oil and gas exploration and production are additional sources of air pollution. We identified case studies for which to perform meteorological and air quality model simulations. Our approach included developing and evaluating the meteorological, emissions, and chemistry-transport modeling components for the variable-grid applications, with special focus on the geographic areas where the finest grid resolution was used. We evaluated the performance of two atmospheric boundary layer (ABL) schemes, and identified the best-performing scheme for simulating mesoscale circulations for different grid resolutions. Use of a newly developed surface data assimilation scheme resulted in improved meteorological model simulations. We also successfully ingested satellite-derived sea surface temperatures (SSTs) into the meteorological model simulations, leading to further improvements in simulated wind, temperature, and moisture fields. These improved meteorological fields were important for variable-grid simulations, especially related to capturing the land-sea breeze circulations that are critical for modeling offshore/onshore transport of pollutants in the Gulf region. We developed SMOKE-VGR, the variable-grid version of the SMOKE emissions processing model, and tested and evaluated this new system. We completed the development of our variable-grid-resolution air quality model (MAQSIP-VGR) and performed various diagnostic tests related to an enhanced cloud parameterization scheme. We also developed an important tool ...
Date: October 16, 2008
Creator: Hanna, Adel
Partner: UNT Libraries Government Documents Department

Selenium fractionation and cycling in the intertidal zone of the Carquinez Strait. Annual report, October 1, 1995--December 31,1996

Description: Selenium geochemistry in tidal wetlands is a topic of continuing study at Lawrence Berkeley National Laboratory. The program of studies described in this report was initiated in the fall of 1994 in response to concerns about elevated Se concentrations in waters, sediments, and biota in the Carquinez Strait. Processes by which selenium is introduced and potentially released from the sediment system have been the focus of research in 1996.
Date: October 1, 1997
Creator: Zawislanski, P.T.; McGrath, A.E. & Benson, S.M.
Partner: UNT Libraries Government Documents Department

Volcanic gas emissions and their impact on ambient air character at Kilauea Volcano, Hawaii

Description: Gas emissions from Kilauea occur from the summit caldera, along the middle East Rift Zone (ERZ), and where lava enters the ocean. We estimate that the current ERZ eruption of Kilauea releases between 400 metric tonnes of SO{sub 2} per day, during eruptive pauses, to as much as 1850 metric tonnes per day during actively erupting periods, along with lesser amounts of other chemically and radiatively active species including H{sub 2}S, HCl and HF. In order to characterize gas emissions from Kilauea in a meaningful way for assessing environmental impact, we made a series of replicate grab-sample measurements of ambient air and precipitation at the summit of Kilauea, along its ERZ, and at coastal sites where lava enters the ocean. The grab-sampling data combined with SO{sub 2} emission rates, and continuous air quality and meteorological monitoring at the summit of Kilauea show that the effects of these emissions on ambient air character are a complex function of chemical reactivity, source geometry and effusivity, and local meteorology. Prevailing tradewinds typically carry the gases and aerosols released to the southwest, where they are further distributed by the regional wind regime. Episodes of kona, or low speed variable winds sometimes disrupt this pattern, however, and allow the gases and their oxidation products to collect at the summit and eastern side of the island. Summit solfatara areas of Kilauea are distinguished by moderate to high ambient SO{sub 2}, high H{sub 2}S at one location, and low H{sub 2}S at all others, and negligible HCl concentrations, as measured 1 m from degassing point-sources. Summit solfatara rain water has high sulfate and low chloride ion concentrations, and low pH.
Date: December 31, 1994
Creator: Sutton, A.J.; Elias, T. & Navarrete, R.
Partner: UNT Libraries Government Documents Department

Risk assessment for produced water discharges to Louisiana open bays

Description: Potential human health and environmental impacts from discharge of produced water to the Gulf of Mexico concern regulators at the State and Federal levels, environmental interest groups, industry and the public. Current regulations in the United States require or propose azero discharge limit for coastal facilities based primarily on studies performed in low energy,poorly flushed environments. Produced water discharges in coastal Louisiana, however,include a number located in open bays, where potential and impacts are likely to be larger than the minimal impacts associated with offshore discharges, but smaller than those demonstrated in low-energy canal environments. This paper summarizes results of a conservative screening-level health and ecological assessment for contaminants discharged in produced water to open bays in Louisiana, and reports results of a probabilistic human health risk assessment for radium and lead. The initial human health and ecological risk assessments consisted of conservative screening analyses that identified potentially important contaminants and excluded others from further consideration. A more quantitative probabilistic risk assessment was completed for the human health effects of the two contaminants identified in this screen: radium and lead. This work is part of a series of studies on the health and ecological risks from discharges of produced water to the Gulf of Mexico, supported by the United States Department of Energy (USDOE).
Date: November 1, 1995
Creator: Meinhold, A.F.; Holtzman, S. & DePhillips, M.P.
Partner: UNT Libraries Government Documents Department

The Dependence of Cloud Particle Size on Non-Aerosol-Loading Related Variables

Description: An enhanced concentration of aerosol may increase the number of cloud drops by providing more cloud condensation nuclei (CCN), which in turn results in a higher cloud albedo at a constant cloud liquid water path. This process is often referred to as the aerosol indirect effect (AIE). Many in situ and remote sensing observations support this hypothesis (Ramanathan et al. 2001). However, satellite observed relations between aerosol concentration and cloud drop size are not always in agreement with the AIE. Based on global analysis of cloud effective radius (r{sub e}) and aerosol number concentration (N{sub a}) derived from satellite data, Sekiguchi et al. (2003) found that the correlations between the two variables can be either negative, or positive, or none, depending on the location of the clouds. They discovered that significantly negative r{sub e} - N{sub a} correlation can only be identified along coastal regions of the continents where abundant continental aerosols inflow from land, whereas Feingold et al. (2001) found that the response of r{sub e} to aerosol loading is the greatest in the region where aerosol optical depth ({tau}{sub a}) is the smallest. The reason for the discrepancy is likely due to the variations in cloud macroscopic properties such as geometrical thickness (Brenguier et al. 2003). Since r{sub e} is modified not only by aerosol but also by cloud geometrical thickness (H), the correlation between re and {tau}{sub a} actually reflects both the aerosol indirect effect and dependence of H. Therefore, discussing AIE based on the r{sub e}-{tau}{sub a} correlation without taking into account variations in cloud geometrical thickness may be misleading. This paper is motivated to extract aerosols' effect from overall effects using the independent measurements of cloud geometrical thickness, {tau}{sub a} and r{sub e}.
Date: March 18, 2005
Creator: Shao, H. & Liu, G.
Partner: UNT Libraries Government Documents Department

Visibility Trends for Coastal Regions

Description: Increased biomass burning (e.g., forest fires, controlled burns, etc.) and anthropogenic emissions into the earth's atmosphere in the past century have led to much debate with regard to greenhouse gases, atmospheric carbon buildup, aerosol increases, and global warming. Atmospheric aerosols are linked to reduced air quality and visibility (V) in many parts of the world. In south-central South Carolina visibility reduction has been responsible for traffic fatalities on public highways, with resulting lawsuits against governmental entities. Congress passed the Clean Air Act in 1963, with amendments in 1970, 1977, and 1990 to improve air quality. The actual implementation of the Clean Air Act has been an intermittent process because of litigation over some provisions of the Act. However, it is reasonable to assume that visibility has improved in the U.S. over the past decades due to implementation of the Clean Air Act's provisions. In this study visibility data have been acquired for seven weather stations along or near the U.S. East Coast to study how conditions have changed from the 1980s to the 1990s.
Date: November 24, 2003
Creator: Weber, A.H.
Partner: UNT Libraries Government Documents Department