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Improved Arctic Cloud and Aerosol Research and Model Parameterizations

Description: In this report are summarized our contributions to the Atmospheric Measurement (ARM) program supported by the Department of Energy. Our involvement commenced in 1990 during the planning stages of the design of the ARM Cloud and Radiation Testbed (CART) sites. We have worked continuously (up to 2006) on our ARM research objectives, building on our earlier findings to advance our knowledge in several areas. Below we summarize our research over this period, with an emphasis on the most recent work. We have participated in several aircraft-supported deployments at the SGP and NSA sites. In addition to deploying the Polarization Diversity Lidar (PDL) system (Sassen 1994; Noel and Sassen 2005) designed and constructed under ARM funding, we have operated other sophisticated instruments W-band polarimetric Doppler radar, and midinfrared radiometer for intercalibration and student training purposes. We have worked closely with University of North Dakota scientists, twice co-directing the Citation operations through ground-to-air communications, and serving as the CART ground-based mission coordinator with NASA aircraft during the 1996 SUCCESS/IOP campaign. We have also taken a leading role in initiating case study research involving a number of ARM coinvestigators. Analyses of several case studies from these IOPs have been reported in journal articles, as we show in Table 1. The PDL has also participated in other major field projects, including FIRE II and CRYSTAL-FACE. In general, the published results of our IOP research can be divided into two categories: comprehensive cloud case study analyses to shed light on fundamental cloud processes using the unique CART IOP measurement capabilities, and the analysis of in situ data for the testing of remote sensing cloud retrieval algorithms. One of the goals of the case study approach is to provide sufficiently detailed descriptions of cloud systems from the data-rich CART environment to make them suitable for application ...
Date: March 1, 2007
Creator: Sassen, Kenneth
Partner: UNT Libraries Government Documents Department

Proposal for Reservoir Engineering Studies in the State of Alaska

Description: Alaska has a significant geothermal potential. While other sources of energy such as petroleum and coal are in abundance, there has been a definite move towards geothermal exploitation. The State has recognized the opportunity cost of petroleum as a source of materials and has expressed interest in the development of geothermal energy as a desirable and alternative resource. More than 11 million acres have been identified as potential geothermal reservoirs capable of producing electric power as well as direct heating. Reservoirs of the latter type are found in the interior of the state. Considering the winter temperatures of these regions (at times dipping to -60{degree}F) direct utilization is attractive. A comprehensive reservoir engineering proposal is presented to better assess the extent and potential of the geothermal areas in Alaska. The purpose of this paper is to acquaint the participants of the Stanford Geothermal Workshop with the enormous potential, as yet untapped, of the State of Alaska.
Date: December 18, 1980
Creator: Economides, Michael J.; Ehlig-Economides, Christine & Wescott, Eugene
Partner: UNT Libraries Government Documents Department

Arctic Troposphere Carbon Dioxide: Low-Altitude Aircraft Sampling

Description: Data from low altitude (<4500 m) aircraft sampling for CO/sub 2/ in the arctic atmosphere are presented. The data cover the period from late spring to late summer when environmental changes at the tundra and sea ice are most pronounced. Results of the data analysis show the effect of regional sources and sinks for CO/sub 2/ on the lower troposphere. The annual ice and open water zones of the Arctic Ocean covered by the flights transects appear to act as a potential sink for carbon dioxide.
Date: January 1, 1982
Creator: Gosink, Thomas A. & Kelley, John J.
Partner: UNT Libraries Government Documents Department

TRANSPORTATION ISSUES IN THE DELIVERY OF GTL PRODUCTS FROM ALASKAN NORTH SLOPE TO MARKET

Description: The Alaskan North Slope (ANS) is one of the largest hydrocarbon reserves in the United States where Gas-to-Liquids (GTL) technology can be successfully implemented. The proven and recoverable reserves of conventional natural gas in the developed and undeveloped fields in the Alaskan North Slope (ANS) are estimated to be 38 trillion standard cubic feet (TCF) and estimates of additional undiscovered gas reserves in the Arctic field range from 64 TCF to 142 TCF. Because the domestic gas market in the continental United States is located thousands of miles from the ANS, transportation of the natural gas from the remote ANS to the market is the key issue in effective utilization of this valuable and abundant resource. The focus of this project is to study the operational challenges involved in transporting the gas in converted liquid (GTL) form through the existing Trans Alaska Pipeline System (TAPS). A three-year, comprehensive research program was undertaken by the Petroleum Development Laboratory, University of Alaska Fairbanks, under cooperative agreement No. DE-FC26-98FT40016 to study the feasibility of transporting GTL products through TAPS. Cold restart of TAPS following an extended winter shutdown and solids deposition in the pipeline were identified as the main transportation issues in moving GTL products through the pipeline. The scope of work in the current project (Cooperative Agreement No. DE-FC26-01NT41248) included preparation of fluid samples for the experiments to be conducted to augment the comprehensive research program.
Date: January 1, 2004
Creator: Chukwu, Godwin
Partner: UNT Libraries Government Documents Department

A Geological and Geophysical Study of the Geothermal Energy Potential of Pilgrim Springs, Alaska

Description: The Pilgrim Springs geothermal area, located about 75 km north of Nome, was the subject of an intensive, reconnaissance-level geophysical and geological study during a 90-day period in the summer of 1979. The thermal springs are located in a northeast-oriented, oval area of thawed ground approximately 1.5 km{sup 2} in size, bordered on the north by the Pilgrim River. A second, much smaller, thermal anomaly was discovered about 3 km northeast of the main thawed area. Continuous permafrost in the surrounding region is on the order of 100 m thick. Present surface thermal spring discharge is {approx} 4.2 x 10{sup -3} m{sup 3} s{sup -1} (67 gallons/minute) of alkali-chloride-type water at a temperature of 81 C. The reason for its high salinity is not yet understood because of conflicting evidence for seawater vs. other possible water sources. Preliminary Na-K-Ca geothermometry suggests deep reservoir temperatures approaching 150 C, but interpretation of these results is difficult because of their dependence on an unknown water mixing history. Based on these estimates, and present surface and drill hole water temperatures, Pilgrim Springs would be classified as an intermediate-temperature, liquid-dominated geothermal system.
Date: January 1, 1980
Creator: Turner, Donald L. & Forbes, Robert B.
Partner: UNT Libraries Government Documents Department

Resource Evaluation and Development Plans for a 120 MW Geothermal Power Plant on Milos Island, Greece

Description: Five deep wells have been drilled on the Island of Milos, Greece, identifying a high-temperature, high-enthalpy geothermal reservoir. The thermodynamic properties of the fluid, and the estimated porosity and presumed thickness of the formation suggest a fluid and heat storage capacity that could support a 60 MWe power plant for 85 years or a 120 MWe for half that time. The existing five wells can deliver 180 t/h of steam at 10 bar abs pressure, capable of generating a maximum electric power output of slightly less than 20 MWe. This paper describes the geology, the drilling and the well testing results pertaining to the five wells, and discusses the reservoir potential for a 60 MWe geothermal power plant.
Date: December 15, 1983
Creator: Economides, M. J.; Ehlig-Economides, C. A.; Speliotis, G. & Vrouzi, F.
Partner: UNT Libraries Government Documents Department

Advanced Techniques for Power System Identification from Measured Data

Description: Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model to test the performance of the algorithms. University of Wyoming researchers participated in four primary activities: (1) Block and adaptive processing techniques for mode estimation from ambient signals and probing signals, (2) confidence interval estimation, (3) probing signal design and injection method analysis, and (4) performance assessment and validation from simulated and field measured data. Subspace based methods have been use to improve previous results from block processing techniques. Bootstrap techniques have been developed to estimate confidence intervals for the electromechanical modes from field measured data. Results were obtained using injected signal data provided by BPA. A new probing signal ...
Date: November 25, 2008
Creator: Pierre, John W.; Wies, Richard & Trudnowski, Daniel
Partner: UNT Libraries Government Documents Department

A Summary of Geothermal Exploration and Data from Stratigraphic Test Well No. 1 Makushin Volcano, Unalaska Island

Description: Geothermal resource investigations have been conducted for the past four years on Unalaska Island in the Aleutian Chain. The focus of the work has been Makushin Volcano, about 12 miles from the cities of Unalaska and Dutch Harbor. In the summer of 1982, three widely spaced deep temperature gradient holes were drilled which encountered high temperatures. During the summer of 1983, a three inch diameter "slim hole" well, ST-1, was drilled to 1,949 feet. A shallow, low pressure, steam zone and a relatively productive hot water zone at total depth were encountered. The lower zone produced 47,000 lb/hr, limited by reaching critical mass velocity at the orifice. The static bottomhole pressure and temperature were 478 psig and 379{degrees}F, respectively. Analysis of transient pressure and flow data yielded a productivity inex of 3,470 lb/hr/psi and a permeability-thickness of 50,900 md-ft for the three-foot (at the wellbore) lower zone fracture. A preliminary reservoir/wellbore flow evaluation for a possible power plant indicates two commercial-size wells could fuel a 10 megawatt facility.
Date: December 15, 1983
Creator: Campbell, Don A. & Economides, Michael J.
Partner: UNT Libraries Government Documents Department

Geologic Results from the Long Valley Exploratory Well

Description: As a deep well in the center of a major Quaternary caldera, the Long Valley Exploratory Well (LVEW) provides a new perspective on the relationship between hydrothermal circulation and a large crustal magma chamber. It also provides an important test of models for the subsurface structure of active continental calderas. Results will impact geothermal exploration, assessment, and management of the Long Valley resource and should be applicable to other igneous-related geothermal systems. Our task is to use the cuttings and core from LVEW to interpret the evolution of the central caldera region, with emphasis on evidence of current hydrothermal conditions and circulation. LVEW has reached a depth of 2313 m, passing through post-caldera extrusives and the intracaldera Bishop Tuff to bottom in the Mt. Morrison roof pendant of the Sierran basement. The base of the section of Quaternary volcanic rocks related to Long Valley Caldera was encountered at 1800 m of which 1178 m is Bishop Tuff. The lithologies sampled generally support the classic view of large intercontinental calderas as piston-cylinder-like structures. In this model, the roof of the huge magma chamber, like an ill-fitting piston, broke and sank 2 km along a ring fracture system that simultaneously and explosively leaked magma as Bishop Tuff. Results from LVEW which support this model are the presence of intact basement at depth at the center of the caldera, the presence of a thick Bishop Tuff section, and textural evidence that the tuff encountered is not near-vent despite its central caldera location. An unexpected observation was the presence of rhyolite intrusions within the tuff with a cumulative apparent thickness in excess of 300 m. Chemical analyses indicate that these are high-silica, high-barium rhyolites. Preliminary {sup 40}Ar/{sup 39}Ar analyses determined an age of 626 {+-} 38 ka (this paper). These observations would indicate that ...
Date: March 24, 1992
Creator: McConnell, Vicki S.; Eichelberger, John C.; Keskinen, Mary J. & Layer, Paul W.
Partner: UNT Libraries Government Documents Department