Science.gov

Sample records for ice making system

  1. Low energy ice making apparatus

    SciTech Connect

    Aleksandrow, J.

    1982-11-09

    A low energy ice making apparatus employing a low volume Carnot cycle refrigeration system is disclosed. Ice is progressively formed on a plurality of improved evaporator plates and harvested by a secondary condenser grid heated by the warm liquid refrigerant discharged by a primary water cooled condenser. The apparatus incorporates an improved water manifold and secondary condenser grid construction.

  2. Peak shifting potential of ice-making thermal energy storage systems for residential cooling

    SciTech Connect

    Johnson, R.R.; Coplon, M.; Hilson, D.W.; Sendaula, M.

    1982-08-01

    This paper describes the simulation and analysis of the load-shifting potential of ice-making or chilled water thermal energy storage (TES) systems for residential cooling. Histograms of the time-of-day average electrical demand over a cooling season are presented for three system configurations and load management strategies. The histograms are analyzed for load-shifting capability, total energy consumption and utility/customer benefits. Simulations are presented for a conventional airconditioning system providing cooling on demand, a conventional system with an externally controlled management device to limit demand onpeak, and an ice-making storage system. Results indicate that although there is a significant impact of the system configuration on the load-shifting potential, it is the heat pump performance that is critical. For ice-storage systems to be attractive for diurnal use, the coefficient of performance (COP) of the ice-maker needs to be substantially better than those currently available. Peak-shifting could come at the expense of total energy consumption or for some control strategies, cooling comfort.

  3. Making an Ice Core.

    ERIC Educational Resources Information Center

    Kopaska-Merkel, David C.

    1995-01-01

    Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)

  4. Let's Make Metric Ice Cream

    ERIC Educational Resources Information Center

    Zimmerman, Marianna

    1975-01-01

    Describes a classroom activity which involved sixth grade students in a learning situation including making ice cream, safety procedures in a science laboratory, calibrating a thermometer, using metric units of volume and mass. (EB)

  5. Dynamic-Type Ice Thermal Storage Systems

    NASA Astrophysics Data System (ADS)

    Ohira, Akiyoshi

    This paper deals with reviews for research and development of a dynamic-type ice thermal storage system. This system has three main features. First, the ice thermal storage tank and the ice generator are separate. Second, ice is transported to the tank from the ice generator by water or air. Third, the ice making and melting processes are operated at the same time. Outlet water temperature from the dynamic-type ice thermal storage tank remains low for a longer time. In this paper, dynamic-Type ice thermal storage systems are divided into three parts: the ice making part, the ice transport part, and the cold energy release part. Each part is reviewed separately.

  6. Making EBSD on water ice routine.

    PubMed

    Prior, D J; Lilly, K; Seidemann, M; Vaughan, M; Becroft, L; Easingwood, R; Diebold, S; Obbard, R; Daghlian, C; Baker, I; Caswell, T; Golding, N; Goldsby, D; Durham, W B; Piazolo, S; Wilson, C J L

    2015-09-01

    Electron backscatter diffraction (EBSD) on ice is a decade old. We have built upon previous work to select and develop methods of sample preparation and analysis that give >90% success rate in obtaining high-quality EBSD maps, for the whole surface area (potentially) of low porosity (<15%) water ice samples, including very fine-grained (<10 μm) and very large (up to 70 mm by 30 mm) samples. We present and explain two new methods of removing frost and providing a damage-free surface for EBSD: pressure cycle sublimation and 'ironing'. In general, the pressure cycle sublimation method is preferred as it is easier, faster and does not generate significant artefacts. We measure the thermal effects of sample preparation, transfer and storage procedures and model the likelihood of these modifying sample microstructures. We show results from laboratory ice samples, with a wide range of microstructures, to illustrate effectiveness and limitations of EBSD on ice and its potential applications. The methods we present can be implemented, with a modest investment, on any scanning electron microscope system with EBSD, a cryostage and a variable pressure capability. PMID:25925223

  7. Effects of Ice Bridging Phenomena on Ice-making Characteristics of an Ice-on-coil Type Thermal Storage Apparatus

    NASA Astrophysics Data System (ADS)

    Mito, Daisuke; Kozawa, Yoshiyuki; Tanino, Masayuki; Saito, Hitoshi

    Effects of ice bridging phenomena on ice-making characteristics of an ice-on-coil type thermal storage apparatus has been clarified, taking into account of two and three dimensional heat flow in analysis. These analytical results have agreed well with the experimental ones. Moreover, it has been possible to explain quantitatively not only both effects of geometrical and thermofluid dynamic conditions on the thermal performance after incipience of ice bridging, but also the development of ice bridging area. In the case of direct expansion type ice making, the ice making ability is strongly affected by the arrangement of the heat transfer tubes. On the other hand, in the case of brine type, though the local ice making ability is determined by the ice layer profile along the brine flow direction, the ability averaged in a whole of the ice storage tank is not so affected by the tube arrangement.

  8. Making sea ice Motion Data From RGPS More Accessible

    NASA Astrophysics Data System (ADS)

    Gens, R.; Barker, E.; Backstrom, L.

    2007-12-01

    The Radarsat Geophysical Processing System (RGPS) was designed to generate sea ice products providing information about sea ice motion, deformation and sea ice thickness. Radarsat-1 ScanSAR Wide B (SWB) imagery has been acquired over more than a decade for the Arctic Ocean with a spatial resolution of 100 m. At the beginning of each winter season a regular grid is initialized and the grid points are tracked over the season to monitor the sea ice motion. With the changing ice conditions the regular grid becomes distorted in shape and location. The distorted Lagrangian grid is used to generate the RGPS data products which reflect the ice condition for a three-day snapshot. These products are currently distributed in a custom designed binary format. They are only used for the long-term monitoring of sea ice on the Arctic basin scale, hence the data is vastly underutilized. The resolution also allows long-term monitoring studies on the regional scale as well as on a local scale. The goal of this prototype development is to make the RGPS data more accessible to allow the data to be used at the regional and local scale, e.g. to develop lead typologies or verify ice charting forecasts. A prototype has been developed that makes the RGPS data more accessible to the research community. A number of raster and vector products are generated for the nominal three-day snapshot. The image mosaics for the part of the Arctic basin that is covered in the snapshot have a 500 m spatial resolution. Basic metadata are provided that allow the user to identify features of interest in the mosaics and their corresponding image within an image data coverage layer. With this metadata the imagery of interest can be directly ordered. Additionally, a weather data layer is derived from model data. For RGPS data that has already been processed the sea ice monitoring information a sea ice layer is created that include all the relevant information from the RGPS database. These vector layers are now available in the commonly used ArcGIS shape file format. This allows for a more streamlined and user friendly access to RGPS data. Image mosaics from more than a decade can now be used for long-term monitoring of the Arctic basin. Based on this prototype the study of sea ice phenomena at regional and local scale becomes more feasible.

  9. 21 CFR 1250.86 - Water for making ice.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Water for making ice. 1250.86 Section 1250.86 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.86 Water for making ice. Only potable...

  10. 21 CFR 1250.86 - Water for making ice.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Water for making ice. 1250.86 Section 1250.86 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.86 Water for making ice. Only potable...

  11. 21 CFR 1250.86 - Water for making ice.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Water for making ice. 1250.86 Section 1250.86 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.86 Water for making ice. Only potable...

  12. 21 CFR 1250.86 - Water for making ice.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Water for making ice. 1250.86 Section 1250.86 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.86 Water for making ice. Only potable...

  13. CO2 (dry ice) cleaning system

    NASA Technical Reports Server (NTRS)

    Barnett, Donald M.

    1995-01-01

    Tomco Equipment Company has participated in the dry ice (solid carbon dioxide, CO2) cleaning industry for over ten years as a pioneer in the manufacturer of high density, dry ice cleaning pellet production equipment. For over four years Tomco high density pelletizers have been available to the dry ice cleaning industry. Approximately one year ago Tomco introduced the DI-250, a new dry ice blast unit making Tomco a single source supplier for sublimable media, particle blast, cleaning systems. This new blast unit is an all pneumatic, single discharge hose device. It meters the insertion of 1/8 inch diameter (or smaller), high density, dry ice pellets into a high pressure, propellant gas stream. The dry ice and propellant streams are controlled and mixed from the blast cabinet. From there the mixture is transported to the nozzle where the pellets are accelerated to an appropriate blasting velocity. When directed to impact upon a target area, these dry ice pellets have sufficient energy to effectively remove most surface coatings through dry, abrasive contact. The meta-stable, dry ice pellets used for CO2 cleaning, while labeled 'high density,' are less dense than alternate, abrasive, particle blast media. In addition, after contacting the target surface, they return to their equilibrium condition: a superheated gas state. Most currently used grit blasting media are silicon dioxide based, which possess a sharp tetrahedral molecular structure. Silicon dioxide crystal structures will always produce smaller sharp-edged replicas of the original crystal upon fracture. Larger, softer dry ice pellets do not share the same sharp-edged crystalline structures as their non-sublimable counterparts when broken. In fact, upon contact with the target surface, dry ice pellets will plastically deform and break apart. As such, dry ice cleaning is less harmful to sensitive substrates, workers and the environment than chemical or abrasive cleaning systems. Dry ice cleaning system components include: a dry ice pellet supply, a non-reactive propellant gas source, a pellet and propellant metering device, and a media transport and acceleration hose and nozzle arrangement. Dry ice cleaning system operating parameters include: choice of propellant gas, its pressure and temperature, dry ice mass flow rate, dry ice pellet size and shape, and acceleration nozzle configuration. These parameters may be modified to fit different applications. The growth of the dry ice cleaning industry will depend upon timely data acquisition of the effects that independent changes in these parameters have on cleaning rates, with respect to different surface coating and substrate combinations. With this data, optimization of cleaning rates for particular applications will be possible. The analysis of the applicable range of modulation of these parameters, within system component mechanical constraints, has just begun.

  14. CO2 (dry ice) cleaning system

    NASA Astrophysics Data System (ADS)

    Barnett, Donald M.

    1995-03-01

    Tomco Equipment Company has participated in the dry ice (solid carbon dioxide, CO2) cleaning industry for over ten years as a pioneer in the manufacturer of high density, dry ice cleaning pellet production equipment. For over four years Tomco high density pelletizers have been available to the dry ice cleaning industry. Approximately one year ago Tomco introduced the DI-250, a new dry ice blast unit making Tomco a single source supplier for sublimable media, particle blast, cleaning systems. This new blast unit is an all pneumatic, single discharge hose device. It meters the insertion of 1/8 inch diameter (or smaller), high density, dry ice pellets into a high pressure, propellant gas stream. The dry ice and propellant streams are controlled and mixed from the blast cabinet. From there the mixture is transported to the nozzle where the pellets are accelerated to an appropriate blasting velocity. When directed to impact upon a target area, these dry ice pellets have sufficient energy to effectively remove most surface coatings through dry, abrasive contact. The meta-stable, dry ice pellets used for CO2 cleaning, while labeled 'high density,' are less dense than alternate, abrasive, particle blast media. In addition, after contacting the target surface, they return to their equilibrium condition: a superheated gas state. Most currently used grit blasting media are silicon dioxide based, which possess a sharp tetrahedral molecular structure. Silicon dioxide crystal structures will always produce smaller sharp-edged replicas of the original crystal upon fracture. Larger, softer dry ice pellets do not share the same sharp-edged crystalline structures as their non-sublimable counterparts when broken. In fact, upon contact with the target surface, dry ice pellets will plastically deform and break apart. As such, dry ice cleaning is less harmful to sensitive substrates, workers and the environment than chemical or abrasive cleaning systems. Dry ice cleaning system components include: a dry ice pellet supply, a non-reactive propellant gas source, a pellet and propellant metering device, and a media transport and acceleration hose and nozzle arrangement. Dry ice cleaning system operating parameters include: choice of propellant gas, its pressure and temperature, dry ice mass flow rate, dry ice pellet size and shape, and acceleration nozzle configuration. These parameters may be modified to fit different applications. ice cleaning industry will depend upon timely data acquisition of the effects that independent changes in these parameters have on cleaning rates, with respect to different surface coating and substrate combinations. &With this data, optimization of cleaning rates for particular applications will be possible. The analysis of the applicable range of modulation of these parameters, within system component mechanical constraints, has just begun.

  15. A Terminal Area Icing Remote Sensing System

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Serke, David J.

    2014-01-01

    NASA and the National Center for Atmospheric Research (NCAR) have developed an icing remote sensing technology that has demonstrated skill at detecting and classifying icing hazards in a vertical column above an instrumented ground station. This technology is now being extended to provide volumetric coverage surrounding an airport. With volumetric airport terminal area coverage, the resulting icing hazard information will be usable by aircrews, traffic control, and airline dispatch to make strategic and tactical decisions regarding routing when conditions are conducive to airframe icing. Building on the existing vertical pointing system, the new method for providing volumetric coverage will utilize cloud radar, microwave radiometry, and NEXRAD radar. This terminal area icing remote sensing system will use the data streams from these instruments to provide icing hazard classification along the defined approach paths into an airport. Strategies for comparison to in-situ instruments on aircraft and weather balloons for a planned NASA field test are discussed, as are possible future applications into the NextGen airspace system.

  16. 21 CFR 1250.86 - Water for making ice.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Water for making ice. 1250.86 Section 1250.86 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Sanitation Facilities and...

  17. Ice Sheet and Sea Ice Observations from Unmanned Aircraft Systems

    NASA Astrophysics Data System (ADS)

    Crocker, R. I.; Maslanik, J. A.

    2011-12-01

    A suite of sensors has been assembled to map ice sheet and sea ice surface topography with fine-resolution from small unmanned aircraft systems (UAS). This payload is optimized to provide coincident surface elevation and imagery data, and with its low cost and ease of reproduction, it has the potential to become a widely-distributed observational resource to complement polar manned-aircraft and satellite missions. To date, it has been deployed to map ice sheet elevations near Jakobshavn Isbræ in Greenland, and to measure sea ice freeboard and roughness in Fram Strait off the coast of Svalbard. Data collected during these campaigns have facilitate a detailed assessment of the system's surface elevation measurement accuracy, and provide a glimpse of the summer 2009 Fram Strait sea ice conditions. These findings are presented, along with a brief overview of our future Arctic UAS operations.

  18. ISSM: Ice Sheet System Model

    NASA Technical Reports Server (NTRS)

    Larour, Eric; Schiermeier, John E.; Seroussi, Helene; Morlinghem, Mathieu

    2013-01-01

    In order to have the capability to use satellite data from its own missions to inform future sea-level rise projections, JPL needed a full-fledged ice-sheet/iceshelf flow model, capable of modeling the mass balance of Antarctica and Greenland into the near future. ISSM was developed with such a goal in mind, as a massively parallelized, multi-purpose finite-element framework dedicated to ice-sheet modeling. ISSM features unstructured meshes (Tria in 2D, and Penta in 3D) along with corresponding finite elements for both types of meshes. Each finite element can carry out diagnostic, prognostic, transient, thermal 3D, surface, and bed slope simulations. Anisotropic meshing enables adaptation of meshes to a certain metric, and the 2D Shelfy-Stream, 3D Blatter/Pattyn, and 3D Full-Stokes formulations capture the bulk of the ice-flow physics. These elements can be coupled together, based on the Arlequin method, so that on a large scale model such as Antarctica, each type of finite element is used in the most efficient manner. For each finite element referenced above, ISSM implements an adjoint. This adjoint can be used to carry out model inversions of unknown model parameters, typically ice rheology and basal drag at the ice/bedrock interface, using a metric such as the observed InSAR surface velocity. This data assimilation capability is crucial to allow spinning up of ice flow models using available satellite data. ISSM relies on the PETSc library for its vectors, matrices, and solvers. This allows ISSM to run efficiently on any parallel platform, whether shared or distrib- ISSM: Ice Sheet System Model NASA's Jet Propulsion Laboratory, Pasadena, California uted. It can run on the largest clusters, and is fully scalable. This allows ISSM to tackle models the size of continents. ISSM is embedded into MATLAB and Python, both open scientific platforms. This improves its outreach within the science community. It is entirely written in C/C++, which gives it flexibility in its design, and the power/speed that C/C++ allows. ISSM is svn (subversion) hosted, on a JPL repository, to facilitate its development and maintenance. ISSM can also model propagation of rifts using contact mechanics and mesh splitting, and can interface to the Dakota software. To carry out sensitivity analysis, mesh partitioning algorithms are available, based on the Scotch, Chaco, and Metis partitioners that ensure equal area mesh partitions can be done, which are then usable for sampling and local reliability methods.

  19. Airborne Tomographic Swath Ice Sounding Processing System

    NASA Technical Reports Server (NTRS)

    Wu, Xiaoqing; Rodriquez, Ernesto; Freeman, Anthony; Jezek, Ken

    2013-01-01

    Glaciers and ice sheets modulate global sea level by storing water deposited as snow on the surface, and discharging water back into the ocean through melting. Their physical state can be characterized in terms of their mass balance and dynamics. To estimate the current ice mass balance, and to predict future changes in the motion of the Greenland and Antarctic ice sheets, it is necessary to know the ice sheet thickness and the physical conditions of the ice sheet surface and bed. This information is required at fine resolution and over extensive portions of the ice sheets. A tomographic algorithm has been developed to take raw data collected by a multiple-channel synthetic aperture sounding radar system over a polar ice sheet and convert those data into two-dimensional (2D) ice thickness measurements. Prior to this work, conventional processing techniques only provided one-dimensional ice thickness measurements along profiles.

  20. Continuous Ice Formation in a Tube by Using Water-Oil Emulsion for Dynamic-type Ice-Making Cold Thermal Energy Storage

    NASA Astrophysics Data System (ADS)

    Oda, Yoshinari; Nakagawa, Shinji; Okada, Masashi; Matsumoto, Koji; Kawagoe, Tetsuo

    Dynamic-type of ice-making cold thermal energy storage systems using water-silicone oil emulsion with an additive, (C2H50)3SiC3H6NH2, has been proposed. Two kinds of heat exchanger were examined and the performances were compared with each other. One type of heat exchanger was a spiral tube and it was immersed in a low temperature thermostatic bath. The other was coil-shaped double tube heat exchanger using two tubes. The emulsion was circulated to make ice continuously. These systems were operated under various cooling conditions (flow rates of the emulsion and brine temperatures). The effects of the tube materials (fluororesin and non-fluororesin) and thickness were also examined. Slurry ice was formed continuously without adhesion of ice to the cooling wall under certain conditions. Using the fluororesin tube prevented ice from the adhesion and it enlarged the range of the cooling conditions under which slurry ice was formed continuously. Furthermore, by making thickness of the tube thinner and increasing the heat transfer coefficient on the outside of the tube, ice was made continuously without lowering the rate of ice formation at a higher brine temperature.

  1. Development and Performance Evaluation of an Ozone-Contained Ice Making Machine Employing Pressurized Air Tight Containers

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kenji; Akiyama, Tomoaki; Hirofuji, Yushi; Koyama, Shigeru

    Ozone has the capability of sterilization and deodorization due to high oxidation power. It is also effective for the conservation of perishable foods and purification of water. However, ozone has a disadvantage, that is, conservation of ozone is difficult because it reacts to oxygen. Recently, ozone-contained ice is taken attention for the purpose of its conservation. The use of ozone-contained ice seems to keep food fresher when we conserve and transport perishable foods due to the effects of cooling and sterilization of ozone-contained ice. In the present study, we have developed an ozone-contained ice making machine employing pressurized air tight containers with commercially available size. And the performance evaluation of the system is also carried out. Furthermore, we investigated the sterilization effect of ozone-contained ice on conservation of fish. It was seen that ozone-contained ice is effective for sterilization of surface of fish.

  2. An Ice Storage System using Supercooled Water

    NASA Astrophysics Data System (ADS)

    Moriya, Mitsuru; Tanino, Masayuki; Kikuchi, Sakae; Hayashi, Toshio; Okonogi, Tokio; Kozawa, Yoshiyuki

    The storage and melting characteristics of slurry-ice mixtures in several tanks were investigated exprimentally. For ice storage processes, three different kinds ofice-feeding methods were tested in connection with the fluidizable water-ice two-phase mixture produced in the system. It was confirmed that the achievable bulk IPF in any tank and using any of these methods was 30-40% under stable operational conditions. For ice melting processes, two different kinds of methods were considered and tested. Both were advantageous in that almost all ice stored in a tank could be consumed, thereby maintaining high system performance. By a modeling analysis of ice melting processes in the tank, it was possible to predict accurately the time history of tank outlet water temperatures.

  3. An Ice Storage System using Supercooled Water

    NASA Astrophysics Data System (ADS)

    Tanino, Masayuki; Iribe, Masatake; Okonogi, Tokio; Kozawa, Yoshiyuki

    The economic aspects of an ice storage system employing supercooled water were compared with those of a chilled water system. In this analysis, the characteristics of the thermal storage tank and the system-COP were selected as technological factors, that have particular relevance to the economic issues at introduction of tharmal storage systems. The following results were obtained : (1) The cooling rate of the ice storage system was comparable with the rate of a chilled water storage system. (2) The cooling rate of the ice storage system was not hardly influenced by the cost of thermal storage tank. (3) In the hybrid thermal storage system, the ice storage system could surely satisfy the requirement for large peak shift.

  4. Ice Storage System for School Complex.

    ERIC Educational Resources Information Center

    Montgomery, Ross D.

    1998-01-01

    Describes a project at the Manatee Education Center in Naples, Florida, which won an ASHRAE award. Project involved the implementation of ice-storage technology in 19 schools. Compares the performance of ice-storage systems with traditional chiller designs in two other schools. Tables illustrate costs for the campuses. Addresses the maintenance…

  5. An Ice Storage System using Supercooled Water

    NASA Astrophysics Data System (ADS)

    Moriya, Mitsuru; Tanino, Masayuki; Kikuchi, Sakae; Hayashi, Toshio; Okonogi, Tokio; Kozawa, Yoshiyuki

    An ice storage system using supercooled water has been developed. In this system, only water is circulated and slurry-ice is stored in tanks. Since one of the critical components of the system is the supercooing heat exchanger, the first step in component development consisted in verification of stable conditions for supercooling water control by basic and integrated experiments. The results of these experiments yielded designcriteria concerning the degree of wall supercooling and the inlet water temperatures (i.e.,conditions for absence of ice nuclei). In addition, realistic operating techniques for supercooling heat exchangers with redundancy have been demonstrated by the field experiment.

  6. The feasibility and economics of slush ice district cooling systems

    SciTech Connect

    Metz, P.; Margen, P.

    1987-06-01

    District cooling systems offer advantages over individual building systems by allowing the selection of central sites close to rivers or other low summer temperature heat sinks, sites close to open spaces for cool storage, and the advantage of reducing specific chiller and cool storage costs by economy of scale. These advantages are obtained at the penalty of the cost of an additional distribution system. This paper examines the technology status of slush ice district cooling systems. Then, using the BNL District Heating and Cooling (DHC) Technology Characterization Computer Model with delivered energy cost as the figure of merit, a wide range of central and individual building cooling systems are compared. Slush ice district systems are found to be most competitive with sharply-peaked cooling loads, premium piping installation costs, premium storage cost, and high on-peak electric rates. Research and development needs include an efficient low-cost reliable ice-making evaporator, an efficient heat-activated ice-making chiller, greater slush ice storage experience, and flow research -- particularly concerning frictional factors and segregation behavior.

  7. Evolution of density in solar system ices

    NASA Technical Reports Server (NTRS)

    Smoluchowski, R.; Mcwilliam, A.; Marie, M.

    1984-01-01

    Pores present in ices in the solar system do not remain unchanged. In isothermal conditions they shrink, while in a thermal gradient they migrate towards the higher temperature and escape so that the ice densifies. This motion has been investigated for pure H2O- and CO2-ices in a very simple one-dimensional model assuming uniform thermal conductivity and temperature gradient. The results indicate that the densification of H2O-ice is so slow that it could be significant only for icy satellites having an internal heat source. On the other hand, CO2-ice densifies orders of magnitude faster and the effect should be important for the CO2 component of cometary nuclei. No effect is expected for icy planetary rings.

  8. A Systems-Level Perspective on Engine Ice Accretion

    NASA Technical Reports Server (NTRS)

    May, Ryan David; Guo, Ten-Huei; Simon, Donald L.

    2012-01-01

    Talk covers: (1) Problem of Engine Power Loss;(2) Modeling Engine Icing Effects; (3) Simulation of Engine Rollback; (4) Icing/Engine Control System Interaction; (5) Detection of Ice Accretion; (6) Potential Mitigation Strategies.

  9. Prediction of Ice Storage Process in Dynamic-type Ice Storage System

    NASA Astrophysics Data System (ADS)

    Tanino, Masayuki; Kozawa, Yoshiyuki; Hijikata, Kunio; Nakabeppu, Osamu

    The distribution of ice-rich layer in an ice storage tank is an important factor to estimate the thermal performance of a dynamic-type ice storage system. The ice-rich layer distribution and the water permeability were tested by using cylindrical tanks. The accumulation of ice-rich layer was predicted by a model analysis in which Darcy's law was applied. From the results of both experiments and analyses, the effect of water flow rate on the time history of the ice-rich layer formation were revealed. An average downward superficial velocity in the ice-rich layer is a dominant factor in the component design for an efficient use of an ice storage tank. This calculation model for the distribution of ice-rich layer can be considered to be applicable to realize the high thermal performance for large-scaled ice storage tanks.

  10. Ice block making and storage system

    SciTech Connect

    Wilson, R.B.

    1986-07-22

    The method of home freezing water in relatively large blocks is described which consists of: filling flexible open top containers of a certain configuration with water to a preferred level; placing a first filled container on the floor of a freezer; surrounding the first container with a first set of four upstanding grid-like sidewalls extending from the freezer floor upwardly beyond the top of the first container; supporting a first temporary grid-like floor upon the first upstanding sidewalls above the first container by inserting the upper circumferential edges of the upstanding walls into a groove on the lower face of the first grid-like floor; and placing a second filled container on the first grid-like floor slightly within a depression of the first grid-like floor so as to prevent horizontal movement of the second container with respect to the first grid-like floor.

  11. Supporting decision making and action selection under time pressure and uncertainty: the case of in-flight icing.

    PubMed

    Sarter, N B; Schroeder, B

    2001-01-01

    Operators in high-risk domains such as aviation often need to make decisions under time pressure and uncertainty. One way to support them in this task is through the introduction of decision support systems (DSSs). The present study examined the effectiveness of two different DSS implementations: status and command displays. Twenty-seven pilots (9 pilots each in a baseline, status, and command group) flew 20 simulated approaches involving icing encounters. Accuracy of the decision aid (a smart icing system), familiarity with the icing condition, timing of icing onset, and autopilot usage were varied within subjects. Accurate information from either decision aid led to improved handling of the icing encounter. However, when inaccurate information was presented, performance dropped below that of the baseline condition. The cost of inaccurate information was particularly high for command displays and in the case of unfamiliar icing conditions. Our findings suggest that unless perfect reliability of a decision aid can be assumed, status displays may be preferable to command displays in high-risk domains (e.g., space flight, medicine, and process control), as the former yield more robust performance benefits and appear less vulnerable to automation biases. PMID:12002006

  12. Laboratory performance of a dynamic ice storage system

    SciTech Connect

    Stovall, T.K.; Tomlinson, J.J.

    1991-06-01

    The performance of a commercial 30-ton dynamic ice storage system was measured in a dedicated laboratory test facility and the results analyzed. The ice storage system was tested over a wide range of operating conditions to characterize the ice generating performance as a function of condensing conditions, ice build time, and defrost time. The overall efficiency of ice production was determined and the effect of refrigeration system component performance on the overall system efficiency was evaluated. The ability of the charged system -- a tank of ice slush -- to meet a simulated cooling load over was also evaluated. 18 refs., 9 figs.

  13. Secondary electron yields of solar system ices

    NASA Technical Reports Server (NTRS)

    Suszcynsky, David M.; Borovsky, Joseph E.; Goertz, Christoph K.

    1992-01-01

    The secondary electron yields of H2O, CO2, NH3, and CH3OH ices have been measured as a function of electron beam energy in the 2- to 30-keV energy range. The ices were produced on a liquid-nitrogen-cooled cold finger and transferred under vacuum to a SEM where the yield measurements were made. The imaging capabilities of the SEM provide a means of correlating the yield measurements with the morphology of the ices and are also used to monitor charging effects. The yields were determined by measuring the amplified current from a secondary electron detector and calibrating this current signal with the amplified current signal from samples of metals with known secondary electron yields. Each of the measured yields is found to decrease with an increase in energy in the 2- to 30-keV range. Estimates are given for the maximum secondary electron yield Y(max) of each ice and the energy at which this maximum yield occurs. Implications for the charging of solar system ice grains are discussed.

  14. Ice matrix in reconfigurable microfluidic systems

    NASA Astrophysics Data System (ADS)

    Bossi, A. M.; Vareijka, M.; Piletska, E. V.; Turner, A. P. F.; Meglinski, I.; Piletsky, S. A.

    2013-07-01

    Microfluidic devices find many applications in biotechnologies. Here, we introduce a flexible and biocompatible microfluidic ice-based platform with tunable parameters and configuration of microfluidic patterns that can be changed multiple times during experiments. Freezing and melting of cavities, channels and complex relief structures created and maintained in the bulk of ice by continuous scanning of an infrared laser beam are used as a valve action in microfluidic systems. We demonstrate that pre-concentration of samples and transport of ions and dyes through the open channels created can be achieved in ice microfluidic patterns by IR laser-assisted zone melting. The proposed approach can be useful for performing separation and sensing processes in flexible reconfigurable microfluidic devices.

  15. Surface ices in the outer solar system

    NASA Astrophysics Data System (ADS)

    Roush, Ted L.; Cruikshank, Dale P.

    Planetary volatile inventories are products of several factors: (1) condensation-accretion of pre-planetary material which determines the bulk volatile inventory; (2) energy history of a planet, including timing, causes, and mechanisms of degassing; (3) the volatile sinks, including temporary, long term, and permanent; and (4) external processes operating on the volatile inventory. Information regarding the current surface compositions provide insight into both internal and surface-atmosphere evolutionary history. Our discussion focuses upon the surface composition of outer solar system planets and satellites as determined by spacecraft and telescopic spectral observations. We provide a review and an update of the recent work by Cruikshank and Brown that includes more recent observations and interpretations. In the context of formation and evolution of solar system bodies, the interesting ices typically considered are simple molecules formed from elements having high cosmic abundances. These mainly include ices of H2O, NH3, SO2, H2S, CH4, CO, CO2, and N2. In the solid state, these ices have vibrational spectral features, analogous to their gaseous counterparts but rotational transitions are quenched, that lie in the near- and mid-infrared. The overtone and combination modes, occurring in the visible and near-IR region, are of particular importance as standard observational techniques used to identify these ices rely upon reflected solar energy. Table I summarizes the ices found on various bodies in the outer solar system. H2O is most abundant surface material in the inner and middle regions while more volatile species appear to dominate surfaces in the outermost edge of the outer solar system.

  16. 14 CFR 121.283 - Induction system ice prevention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Induction system ice prevention. 121.283... Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  17. 14 CFR 121.283 - Induction system ice prevention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Induction system ice prevention. 121.283... Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  18. 14 CFR 125.181 - Induction system ice prevention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Induction system ice prevention. 125.181... Requirements § 125.181 Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  19. 14 CFR 125.181 - Induction system ice prevention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Induction system ice prevention. 125.181... Requirements § 125.181 Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  20. 14 CFR 121.283 - Induction system ice prevention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Induction system ice prevention. 121.283... Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  1. 14 CFR 121.283 - Induction system ice prevention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Induction system ice prevention. 121.283... Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  2. 14 CFR 121.283 - Induction system ice prevention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Induction system ice prevention. 121.283... Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  3. 14 CFR 125.181 - Induction system ice prevention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Induction system ice prevention. 125.181... Requirements § 125.181 Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  4. 14 CFR 125.181 - Induction system ice prevention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Induction system ice prevention. 125.181... Requirements § 125.181 Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  5. 14 CFR 125.181 - Induction system ice prevention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Induction system ice prevention. 125.181... Requirements § 125.181 Induction system ice prevention. A means for preventing the malfunctioning of each engine due to ice accumulation in the engine air induction system must be provided for each airplane....

  6. Hybrid system for producing and storing ice

    NASA Astrophysics Data System (ADS)

    Francis, C. E.; Larash, R. C.; Gorski, A. J.

    Refrigeration, cooling and/or chilling methods usually require rather large amounts of energy for operation. This system uses naturally frozen ice in long term storage to provide an economical source of ice for various cooling or chilling purposes. Initial research and computer simulations indicate that in areas where the winter is suffuciently cold and of sufficient duration, this system would be an economical, viable option for uses such as simple refrigeration, summer air conditioning, or simply for effective dehumidification. In a 36 day melting period in June and July 1984, the system ran nearly continuously for 768 hours, recovering a total of 743 tons of cooling with an estimated 5 to 8% of the stored cooling capacity remaining. The seasonal melting loss was approximately 50% of the stored capacity.

  7. Improving Arctic sea ice edge forecasts by assimilating high horizontal resolution sea ice concentration data into the US Navy's ice forecast systems

    NASA Astrophysics Data System (ADS)

    Posey, P. G.; Metzger, E. J.; Wallcraft, A. J.; Hebert, D. A.; Allard, R. A.; Smedstad, O. M.; Phelps, M. W.; Fetterer, F.; Stewart, J. S.; Meier, W. N.; Helfrich, S. R.

    2015-08-01

    This study presents the improvement in ice edge error within the US Navy's operational sea ice forecast systems gained by assimilating high horizontal resolution satellite-derived ice concentration products. Since the late 1980's, the ice forecast systems have assimilated near real-time sea ice concentration derived from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSMI and then SSMIS). The resolution of the satellite-derived product was approximately the same as the previous operational ice forecast system (25 km). As the sea ice forecast model resolution increased over time, the need for higher horizontal resolution observational data grew. In 2013, a new Navy sea ice forecast system (Arctic Cap Nowcast/Forecast System - ACNFS) went into operations with a horizontal resolution of ~ 3.5 km at the North Pole. A method of blending ice concentration observations from the Advanced Microwave Scanning Radiometer (AMSR2) along with a sea ice mask produced by the National Ice Center (NIC) has been developed, resulting in an ice concentration product with very high spatial resolution. In this study, ACNFS was initialized with this newly developed high resolution blended ice concentration product. The daily ice edge locations from model hindcast simulations were compared against independent observed ice edge locations. ACNFS initialized using the high resolution blended ice concentration data product decreased predicted ice edge location error compared to the operational system that only assimilated SSMIS data. A second evaluation assimilating the new blended sea ice concentration product into the pre-operational Navy Global Ocean Forecast System 3.1 also showed a substantial improvement in ice edge location over a system using the SSMIS sea ice concentration product alone. This paper describes the technique used to create the blended sea ice concentration product and the significant improvements in ice edge forecasting in both of the Navy's sea ice forecasting systems.

  8. Advanced ice protection systems test in the NASA Lewis icing research tunnel

    NASA Technical Reports Server (NTRS)

    Bond, Thomas H.; Shin, Jaiwon; Mesander, Geert A.

    1991-01-01

    Tests of eight different deicing systems based on variations of three different technologies were conducted in the NASA Lewis Research Center Icing Research Tunnel (IRT) in June and July 1990. The systems used pneumatic, eddy current repulsive, and electro-expulsive means to shed ice. The tests were conducted on a 1.83 m span, 0.53 m chord NACA 0012 airfoil operated at a 4 degree angle of attack. The models were tested at two temperatures: a glaze condition at minus 3.9 C and a rime condition at minus 17.2 C. The systems were tested through a range of icing spray times and cycling rates. Characterization of the deicers was accomplished by monitoring power consumption, ice shed particle size, and residual ice. High speed video motion analysis was performed to quantify ice particle size.

  9. 14 CFR 25.1093 - Induction system icing protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction system.... (c) Supercharged reciprocating engines. For each engine having a supercharger to pressurize the...

  10. 14 CFR 25.1093 - Induction system icing protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction system.... (c) Supercharged reciprocating engines. For each engine having a supercharger to pressurize the...

  11. 14 CFR 25.1093 - Induction system icing protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction system.... (c) Supercharged reciprocating engines. For each engine having a supercharger to pressurize the...

  12. 14 CFR 25.1093 - Induction system icing protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction system.... (c) Supercharged reciprocating engines. For each engine having a supercharger to pressurize the...

  13. Ice Sheet System Model as Educational Entertainment

    NASA Astrophysics Data System (ADS)

    Perez, G.

    2013-12-01

    Understanding the importance of polar ice sheets and their role in the evolution of Sea Level Rise (SLR), as well as Climate Change, is of paramount importance for policy makers as well as the public and schools at large. For example, polar ice sheets and glaciers currently account for 1/3 of the SLR signal, a ratio that will increase in the near to long-term future, which has tremendous societal ramifications. Consequently, it is important to increase awareness about our changing planet. In our increasingly digital society, mobile and web applications are burgeoning venues for such outreach. The Ice Sheet System Model (ISSM) is a software that was developed at the Jet Propulsion Laboratory/CalTech/NASA, in collaboration with University of California Irvine (UCI), with the goal of better understanding the evolution of polar ice sheets. It is a state-of-the-art framework, which relies on higher-end cluster-computing to address some of the aforementioned challenges. In addition, it is a flexible framework that can be deployed on any hardware; in particular, on mobile platforms such as Android or iOS smart phones. Here, we look at how the ISSM development team managed to port their model to these platforms, what the implications are for improving how scientists disseminate their results, and how a broader audience may familiarize themselves with running complex climate models in simplified scenarios which are highly educational and entertaining in content. We also look at the future plans toward a web portal fully integrated with mobile technologies to deliver the best content to the public, and to provide educational plans/lessons that can be used in grades K-12 as well as collegiate under-graduate and graduate programs.

  14. FLYSAFE, nowcasting of in flight icing supporting aircrew decision making process

    NASA Astrophysics Data System (ADS)

    Drouin, A.; Le Bot, C.

    2009-09-01

    FLYSAFE is an Integrated Project of the 6th framework of the European Commission with the aim to improve flight safety through the development of a Next Generation Integrated Surveillance System (NGISS). The NGISS provides information to the flight crew on the three major external hazards for aviation: weather, air traffic and terrain. The NGISS has the capability of displaying data about all three hazards on a single display screen, facilitating rapid pilot appreciation of the situation by the flight crew. Weather Information Management Systems (WIMS) were developed to provide the NGISS and the flight crew with weather related information on in-flight icing, thunderstorms, wake-vortex and clear-air turbulence. These products are generated on the ground from observations and model forecasts. WIMS supply relevant information on three different scales: global, regional and local (over airport Terminal Manoeuvring Area). Within the flysafe program, around 120 hours of flight trials were performed during February 2008 and August 2008. Two aircraft were involved each with separate objectives : - to assess FLYSAFE's innovative solutions for the data-link, on-board data fusion, data-display, and data-updates during flight; - to evaluate the new weather information management systems (in flight icing and thunderstorms) using in-situ measurements recorded on board the test aircraft. In this presentation we will focus on the in-flight icing nowcasting system developed at Météo France in the framework of FLYSAFE: the local ICE WIMS. The local ICE WIMS is based on data fusion. The most relevant information for icing detection is extracted from the numerical weather prediction model, the infra-red and visible satellite imagery and the ground weather radar reflectivities. After a presentation of the local ICE WIMS, we detail the evaluation of the local ICE WIMS performed using the winter and summer flight trial data.

  15. Validation Ice Crystal Icing Engine Test in the Propulsion Systems Laboratory at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Oliver, Michael J.

    2014-01-01

    The Propulsion Systems Laboratory (PSL) is an existing altitude simulation jet engine test facility located at NASA Glenn Research Center in Clevleand, OH. It was modified in 2012 with the integration of an ice crystal cloud generation system. This paper documents the inaugural ice crystal cloud test in PSLthe first ever full scale, high altitude ice crystal cloud turbofan engine test to be conducted in a ground based facility. The test article was a Lycoming ALF502-R5 high bypass turbofan engine, serial number LF01. The objectives of the test were to validate the PSL ice crystal cloud calibration and engine testing methodologies by demonstrating the capability to calibrate and duplicate known flight test events that occurred on the same LF01 engine and to generate engine data to support fundamental and computational research to investigate and better understand the physics of ice crystal icing in a turbofan engine environment while duplicating known revenue service events and conducting test points while varying facility and engine parameters. During PSL calibration testing it was discovered than heated probes installed through tunnel sidewalls experienced ice buildup aft of their location due to ice crystals impinging upon them, melting and running back. Filtered city water was used in the cloud generation nozzle system to provide ice crystal nucleation sites. This resulted in mineralization forming on flow path hardware that led to a chronic degradation of performance during the month long test. Lacking internal flow path cameras, the response of thermocouples along the flow path was interpreted as ice building up. Using this interpretation, a strong correlation between total water content (TWC) and a weaker correlation between median volumetric diameter (MVD) of the ice crystal cloud and the rate of ice buildup along the instrumented flow path was identified. For this test article the engine anti-ice system was required to be turned on before ice crystal icing would occur. The ice crystal icing event, an uncommanded reduction in thrust, was able to be turned on and off by manipulating cloud TWC. A flight test point where no ice crystal icing event occurred was also duplicated in PSL. Physics based computational tools were successfully used to predict tunnel settings to induce ice buildup along the low pressure compression system flow path for several test points at incrementally lower altitudes, demonstrating that development of ice crystal icing scaling laws is potentially feasible. Analysis of PSL test data showed that uncommanded reduction in thrust occurs during ice crystal cloud on operation prior to fan speed reduction. This supports previous findings that the reduction of thrust for this test article is due to ice buildup leading to a restricted airflow from either physical or aerodynamic blockage in the engine core flow path.

  16. Validation Ice Crystal Icing Engine Test in the Propulsion Systems Laboratory at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Oliver, Michael J.

    2014-01-01

    The Propulsion Systems Laboratory (PSL) is an existing altitude simulation jet engine test facility located at NASA Glenn Research Center in Cleveland, OH. It was modified in 2012 with the integration of an ice crystal cloud generation system. This paper documents the inaugural ice crystal cloud test in PSL--the first ever full scale, high altitude ice crystal cloud turbofan engine test to be conducted in a ground based facility. The test article was a Lycoming ALF502-R5 high bypass turbofan engine, serial number LF01. The objectives of the test were to validate the PSL ice crystal cloud calibration and engine testing methodologies by demonstrating the capability to calibrate and duplicate known flight test events that occurred on the same LF01 engine and to generate engine data to support fundamental and computational research to investigate and better understand the physics of ice crystal icing in a turbofan engine environment while duplicating known revenue service events and conducting test points while varying facility and engine parameters. During PSL calibration testing it was discovered than heated probes installed through tunnel sidewalls experienced ice buildup aft of their location due to ice crystals impinging upon them, melting and running back. Filtered city water was used in the cloud generation nozzle system to provide ice crystal nucleation sites. This resulted in mineralization forming on flow path hardware that led to a chronic degradation of performance during the month long test. Lacking internal flow path cameras, the response of thermocouples along the flow path was interpreted as ice building up. Using this interpretation, a strong correlation between total water content (TWC) and a weaker correlation between median volumetric diameter (MVD) of the ice crystal cloud and the rate of ice buildup along the instrumented flow path was identified. For this test article the engine anti-ice system was required to be turned on before ice crystal icing would occur. The ice crystal icing event, an uncommanded reduction in thrust, was able to be turned on and off by manipulating cloud TWC. A flight test point where no ice crystal icing event occurred was also duplicated in PSL. Physics based computational tools were successfully used to predict tunnel settings to induce ice buildup along the low pressure compression system flow path for several test points at incrementally lower altitudes, demonstrating that development of ice crystal icing scaling laws is potentially feasible. Analysis of PSL test data showed that uncommanded reduction in thrust occurs during ice crystal cloud on operation prior to fan speed reduction. This supports previous findings that the reduction of thrust for this test article is due to ice buildup leading to a restricted airflow from either physical or aerodynamic blockage in the engine core flow path.

  17. Ice Crystal Icing Engine Testing in the NASA Glenn Research Center's Propulsion Systems Laboratory: Altitude Investigation

    NASA Technical Reports Server (NTRS)

    Oliver, Michael J.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) conducted a full scale ice crystal icing turbofan engine test using an obsolete Allied Signal ALF502-R5 engine in the Propulsion Systems Laboratory (PSL) at NASA Glenn Research Center. The test article used was the exact engine that experienced a loss of power event after the ingestion of ice crystals while operating at high altitude during a 1997 Honeywell flight test campaign investigating the turbofan engine ice crystal icing phenomena. The test plan included test points conducted at the known flight test campaign field event pressure altitude and at various pressure altitudes ranging from low to high throughout the engine operating envelope. The test article experienced a loss of power event at each of the altitudes tested. For each pressure altitude test point conducted the ambient static temperature was predicted using a NASA engine icing risk computer model for the given ambient static pressure while maintaining the engine speed.

  18. ICE stereocamera system - photogrammetric setup for retrieval and analysis of small scale sea ice topography

    NASA Astrophysics Data System (ADS)

    Divine, Dmitry; Pedersen, Christina; Karlsen, Tor Ivan; Aas, Harald; Granskog, Mats; Renner, Angelika; Spreen, Gunnar; Gerland, Sebastian

    2013-04-01

    A new thin-ice Arctic paradigm requires reconsideration of the set of parameterizations of mass and energy exchange within the ocean-sea-ice-atmosphere system used in modern CGCMs. Such a reassessment would require a comprehensive collection of measurements made specifically on first-year pack ice with a focus on summer melt season when the difference from typical conditions for the earlier multi-year Arctic sea ice cover becomes most pronounced. Previous in situ studies have demonstrated a crucial importance of smaller (i.e. less than 10 m) scale surface topography features for the seasonal evolution of pack ice. During 2011-2012 NPI developed a helicopter borne ICE stereocamera system intended for mapping the sea ice surface topography and aerial photography. The hardware component of the system comprises two Canon 5D Mark II cameras, combined GPS/INS unit by "Novatel" and a laser altimeter mounted in a single enclosure outside the helicopter. The unit is controlled by a PXI chassis mounted inside the helicopter cabin. The ICE stereocamera system was deployed for the first time during the 2012 summer field season. The hardware setup has proven to be highly reliable and was used in about 30 helicopter flights over Arctic sea-ice during July-September. Being highly automated it required a minimal human supervision during in-flight operation. The deployment of the camera system was mostly done in combination with the EM-bird, which measures sea-ice thickness, and this combination provides an integrated view of sea ice cover along the flight track. During the flight the cameras shot sequentially with a time interval of 1 second each to ensure sufficient overlap between subsequent images. Some 35000 images of sea ice/water surface captured per camera sums into 6 Tb of data collected during its first field season. The reconstruction of the digital elevation model of sea ice surface will be done using SOCET SET commercial software. Refraction at water/air interface can also be taken into account, providing the valuable data on melt pond coverage, depth and bottom topography -the primary goals for the system at its present stage. Preliminary analysis of the reconstructed 3D scenes of ponded first year ice for some selected sites has shown a good agreement with in situ measurements demonstrating a good scientific potential of the ICE stereocamera system.

  19. New Icing Cloud Simulation System at the NASA Glenn Research Center Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Irvine, Thomas B.; Oldenburg, John R.; Sheldon, David W.

    1999-01-01

    A new spray bar system was designed, fabricated, and installed in the NASA Glenn Research Center's Icing Research Tunnel (IRT). This system is key to the IRT's ability to do aircraft in-flight icing cloud simulation. The performance goals and requirements levied on the design of the new spray bar system included increased size of the uniform icing cloud in the IRT test section, faster system response time, and increased coverage of icing conditions as defined in Appendix C of the Federal Aviation Regulation (FAR), Part 25 and Part 29. Through significant changes to the mechanical and electrical designs of the previous-generation spray bar system, the performance goals and requirements were realized. Postinstallation aerodynamic and icing cloud calibrations were performed to quantify the changes and improvements made to the IRT test section flow quality and icing cloud characteristics. The new and improved capability to simulate aircraft encounters with in-flight icing clouds ensures that the 1RT will continue to provide a satisfactory icing ground-test simulation method to the aeronautics community.

  20. Monitoring System of Power Line Icing Based on GPRS

    NASA Astrophysics Data System (ADS)

    Wancheng, Xie

    GPRS-based power line monitoring system for ice. The system is based on the images to monitor the power line monitoring device for ice. System through the use of simplified Sobel algorithm and Hough transform to image edge detection, with DSP high-speed computing performance and optimization of DSP code, and realized the power line ice thickness of the terminal identification and automatic alarm function; using the terminal identification means, is intelligent Monitoring of a new attempt.

  1. The effect of icing with the pro-stim edema management system on cutaneous cooling.

    PubMed

    Holcomb, W R; Mangus, B C; Tandy, R

    1996-04-01

    The simultaneous administration of ice, compression, and electrical stimulation is a technique sometimes used to control the magnitude and duration of edema. The Pro-Stim Edema Management System (TKO, Inc, Alameda, CA) was developed to make this simultaneous treatment both simplistic and more effective. The system is designed to be more effective because the stimulating electrodes are incorporated into the fabric of the ice pack thus providing little insulation to cold. The purpose of our study was to test the effectiveness of icing with Pro-Stim on cutaneous cooling by comparing it to ice bag application with conventional stimulator electrodes. Twelve subjects received the ice portion of the two experimental conditions for 30 minutes. Cutaneous temperatures were monitored at two sites: one under the electrode and one away from the electrode (centered between the stimulating electrodes). Temperatures were recorded via surface probes interfaced to digital thermometers each minute for 5 minutes before and after icing and during the 30 minutes of ice application. Temperature data were analyzed with three-way factorial analysis of variance with repeated measures. The administration of ice decreased the temperature for all conditions. However, the temperature under the electrode with Pro-Stim was significantly lower during the treatment period than the temperature under the electrode with the conventional system. Thus, Pro-Stim provides more cooling of the entire treatment area. Further research should include an investigation of the effect of the Pro-Stim Edema Management System on cooling while using electrical stimulation. PMID:16558385

  2. IceVal DatAssistant: An Interactive, Automated Icing Data Management System

    NASA Technical Reports Server (NTRS)

    Levinson, Laurie H.; Wright, William B.

    2007-01-01

    As with any scientific endeavor, the foundation of icing research at the NASA Glenn Research Center (GRC) is the data acquired during experimental testing. In the case of the GRC Icing Branch, an important part of this data consists of ice tracings taken following tests carried out in the GRC Icing Research Tunnel (IRT), as well as the associated operational and environmental conditions during those tests. Over the years, the large number of experimental runs completed has served to emphasize the need for a consistent strategy to manage the resulting data. To address this situation, the Icing Branch has recently elected to implement the IceVal DatAssistant automated data management system. With the release of this system, all publicly available IRT-generated experimental ice shapes with complete and verifiable conditions have now been compiled into one electronically-searchable database; and simulation software results for the equivalent conditions, generated using the latest version of the LEWICE ice shape prediction code, are likewise included and linked to the corresponding experimental runs. In addition to this comprehensive database, the IceVal system also includes a graphically-oriented database access utility, which provides reliable and easy access to all data contained in the database. In this paper, the issues surrounding historical icing data management practices are discussed, as well as the anticipated benefits to be achieved as a result of migrating to the new system. A detailed description of the software system features and database content is also provided; and, finally, known issues and plans for future work are presented.

  3. IceVal DatAssistant: An Interactive, Automated Icing Data Management System

    NASA Technical Reports Server (NTRS)

    Levinson, Laurie H.; Wright, William B.

    2008-01-01

    As with any scientific endeavor, the foundation of icing research at the NASA Glenn Research Center (GRC) is the data acquired during experimental testing. In the case of the GRC Icing Branch, an important part of this data consists of ice tracings taken following tests carried out in the GRC Icing Research Tunnel (IRT), as well as the associated operational and environmental conditions documented during these tests. Over the years, the large number of experimental runs completed has served to emphasize the need for a consistent strategy for managing this data. To address the situation, the Icing Branch has recently elected to implement the IceVal DatAssistant automated data management system. With the release of this system, all publicly available IRT-generated experimental ice shapes with complete and verifiable conditions have now been compiled into one electronically-searchable database. Simulation software results for the equivalent conditions, generated using the latest version of the LEWICE ice shape prediction code, are likewise included and are linked to the corresponding experimental runs. In addition to this comprehensive database, the IceVal system also includes a graphically-oriented database access utility, which provides reliable and easy access to all data contained in the database. In this paper, the issues surrounding historical icing data management practices are discussed, as well as the anticipated benefits to be achieved as a result of migrating to the new system. A detailed description of the software system features and database content is also provided; and, finally, known issues and plans for future work are presented.

  4. Forthcoming Northern Hemisphere Snow and Ice Earth System Data Records

    NASA Astrophysics Data System (ADS)

    Robinson, D. A.; Estilow, T. W.; Anderson, M. R.; Hall, D. K.; Henderson, G. R.; Mote, T. L.; Tschudi, M. A.

    2013-12-01

    For approximately the past five years, a multi-institutional team has been assembling satellite-derived Northern Hemisphere (NH) snow cover Earth System Data Records (ESDR). With the culmination of our NASA-supported Making Earth Science Data Records for Use in Research Environments (MEaSUREs) project come mid 2014, it is timely to bring the user community that encompasses the research community, decision-makers, and stakeholders up to date on our progress and with products soon to be available. Datasets include snow extent and melt state over NH continents, snowmelt state over Greenland, snowmelt onset and age of sea ice. Fused snow extent and melt state products over land and ice are also being generated. Visible and microwave satellite data are employed in these efforts. Datasets of both individual and integrated ESDRs will be available for downloading from the National Snow and Ice Data Center. Products are being generated at 25 km (1999-2010) or 100 km (1967-2010) resolution using the Equal-Area Scalable Earth Grid 2.0 and are available in netCDF format. Extensive metadata will accompany the datasets. Project data and information are also available at http://snowcover.org. Here, we will present examples of the development and utility of these individual and fused datasets.

  5. Structure of Water Ice in the Solar System

    NASA Technical Reports Server (NTRS)

    Blake, David; Jenniskens, Peter; Chang, Sherwood (Technical Monitor)

    1996-01-01

    Nearly all of the properties of solar system ices (chemical reaction rates, volatile retention and release, vaporization behavior, thermal conductivity, infrared spectral characteristics and the like) are a direct consequence of ice structure. However, the characterization of astrophysical ices and their laboratory analogs has typically utilized indirect measurements which yield phenomenological interpretations. When water ice is vapor-deposited at 14 K and warmed until it volatilizes in moderate vacuum, the ice undergoes a series of amorphous to amorphous and amorphous to crystalline structural transitions which we have characterized by diffraction methods. These structural transitions correlate with and underlie many phenomena observed in laboratory infrared and gas release experiments. The elucidation of the dynamic structural changes which occur in vapor-deposited water ice as a function of time, temperature and radiation history allows for the more complete interpretation of remote observations of astrophysical ices and their laboratory analogs.

  6. 14 CFR 27.1093 - Induction system icing protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction system icing protection. 27.1093... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Induction System § 27.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  7. 14 CFR 27.1093 - Induction system icing protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Induction system icing protection. 27.1093... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Induction System § 27.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  8. 14 CFR 27.1093 - Induction system icing protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Induction system icing protection. 27.1093... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Induction System § 27.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  9. 14 CFR 27.1093 - Induction system icing protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Induction system icing protection. 27.1093... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Induction System § 27.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  10. 14 CFR 29.1093 - Induction system icing protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Induction system icing protection. 29.1093... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  11. 14 CFR 29.1093 - Induction system icing protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Induction system icing protection. 29.1093... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  12. 14 CFR 27.1093 - Induction system icing protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Induction system icing protection. 27.1093... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Induction System § 27.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  13. 14 CFR 29.1093 - Induction system icing protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Induction system icing protection. 29.1093... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  14. Practical Use Study of the Direct Conveyance and Cooling System for Iced Water by the Propylene Glycol Solutio

    NASA Astrophysics Data System (ADS)

    Seki, Mitsuo; Ninomiya, Tohru; Matsubara, Kazuo; Aikawa, Keisuke; Ikoma, Kenji

    In a cold storage warehouse, by developing the thermal energy storage technique using cheap electric powerin the night, it is necessary to construct a high-efficient and energy-saving-type refrigeration system in which air conditioning is possible at 0 degrees c. We created a brine iced water (ice slurry) cooled under 0 degreesc by a closed supercooling ice making method. For a practical application, the brine iced water was directly sent to the load side, and it was utilized as the secondary refrigerant for the heat exchange. As a result, by replacing the pure water with a marketed propylene glycol solution, it was proven that the conventional closed supercooling ice making method could be similarly utilized for the ice making. However, it is necessary to control the evaporation temperature in the refrigerator, because the freezing temperature changes with the brine concentration. In the refrigerator entrance, it is necessary to heat at a constant temperature so that the inflow brine may not freeze. In case of the brine iced water, the fluidity of the brine iced water is high, and the ice particle is carried away by the flow. Therefore, it is necessary to prevent runoff of the ice particle from an intake of the thermal storage tank in case of thebrine water. This proposal system was confirmed that there was practically no problem by an operation of a 15kW refrigerator system.

  15. Interferometric System for Measuring Thickness of Sea Ice

    NASA Technical Reports Server (NTRS)

    Hussein, Ziad; Jordan, Rolando; McDonald, Kyle; Holt, Benjamin; Huang, John; Kugo, Yasuo; Ishimaru, Akira; Jaruwatanadilok, Semsak; Akins, Torry; Gogineni, Prasad

    2006-01-01

    The cryospheric advanced sensor (CAS) is a developmental airborne (and, potentially, spaceborne) radar-based instrumentation system for measuring and mapping the thickness of sea ice. A planned future version of the system would also provide data on the thickness of snow covering sea ice. Frequent measurements of the thickness of polar ocean sea ice and its snow cover on a synoptic scale are critical to understanding global climate change and ocean circulation.

  16. Energy-Efficient Systems Eliminate Icing Danger for UAVs

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Ames Research Center engineer Leonard Haslim invented an anti-icing t echnology called an electroexpulsive separation system, which uses m echanical force to shatter potentially dangerous ice buildup on an ai rcraft surface. Temecula, California-based Ice Management Systems (no w known as IMS-ESS) licensed the technology from Ames and has discov ered a niche market for the lightweight, energy-efficient technology: unmanned aerial vehicles (UAVs). IMS-ESS systems now prevent damagi ng ice accumulation on military UAVs, allowing the vehicles to carry out crucial missions year round.

  17. Multiscale Observation System for Sea Ice Drift and Deformation

    NASA Astrophysics Data System (ADS)

    Lensu, M.; Haapala, J. J.; Heiler, I.; Karvonen, J.; Suominen, M.

    2011-12-01

    The drift and deformation of sea ice cover is most commonly followed from successive SAR images. The time interval between the images is seldom less than one day which provides rather crude approximation of the motion fields as ice can move tens of kilometers per day. This is particulary so from the viewpoint of operative services, seeking to provide real time information for ice navigating ships and other end users, as leads are closed and opened or ridge fields created in time scales of one hour or less. The ice forecast models are in a need of better temporal resolution for ice motion data as well. We present experiences from a multiscale monitoring system set up to the Bay of Bothnia, the northernmost basin of the Baltic Sea. The basin generates difficult ice conditions every winter while the ports are kept open with the help of an icebreaker fleet. The key addition to SAR imagery is the use of coastal radars for the monitoring of coastal ice fields. An independent server is used to tap the radar signal and process it to suit ice monitoring purposes. This is done without interfering the basic use of the radars, the ship traffic monitoring. About 20 images per minute are captured and sent to the headquarters for motion field extraction, website animation and distribution. This provides very detailed real time picture of the ice movement and deformation within 20 km range. The real time movements are followed in addition with ice drifter arrays, and using AIS ship identification data, from which the translation of ship cannels due to ice drift can be found out. To the operative setup is associated an extensive research effort that uses the data for ice drift model enhancement. The Baltic ice models seek to forecast conditions relevant to ship traffic, especilly hazardous ones like severe ice compression. The main missing link here is downscaling, or the relation of local scale ice dynamics and kinematics to the ice model scale behaviour. The data flow when combined with SAR images gives information on how large scale ice cover motions manifest as local scale deformations. The research includes also ice stress measurements for relating the kinematic state and modeled stresses to local scale ice cover stresses, and ice thickness mappings with profiling sonars and EM methods. Downscaling results based on four-month campaing during winter 2011 are presented.

  18. Investigation of Icing Characteristics of Typical Light Airplane Engine Induction Systems

    NASA Technical Reports Server (NTRS)

    Coles, W. D.

    1949-01-01

    The icing characteristics of two typical light-airplane engine induction systems were investigated using the carburetors and manifolds of engines in the horsepower ranges from 65 to 85 and 165 to 185. The smaller system consisted of a float-type carburetor with an unheated manifold and the larger system consisted of a single-barrel pressure-type carburetor with an oil-jacketed manifold. Carburetor-air temperature and humidity limits of visible and serious Icing were determined for various engine power conditions. Several.methods of achieving ice-free induction systems are discussed along with estimates of surface heating requirements of the various induct ion-system components. A study was also made of the icing characteristics of a typical light-airplane air scoop with an exposed filter and a modified system that provided a normal ram inlet with the filter located in a position to Induce inertia separation of the free water from the charge air. The principle of operation of float-type carburetors is proved to make them inherently more susceptible to icing at the throttle plate than pressure-type carburetors.. The results indicated that proper jacketing and heating of all parts exposed to the fuel spray can satisfactorily reduce or eliminate icing in the float-type carburetor and the manifold. Pressure-type carburetors can be protected from serious Icing by proper location of the fuel-discharge nozzle combined with suitable application of heat to critical parts.

  19. An Analysis on Ice Storing CharacterIstics in Dynamic-type Ice Storage System using Supercooled Water

    NASA Astrophysics Data System (ADS)

    Aizawa, Naoki; Tanino, Masayuki; Kozawa, Yoshiyuki

    For an application of the Dynamic-type Ice Storage System to the District Cooling and Heating System, the effects of ice content (IPF) and mass flow rate of supplying ice-slurry on the ice storing characteristics in a tank were investigated by experiments and analyses. In the analytical model, we considered that the ice-rich layer would be ununiform by raising of IPF and the water permeability in the ice-rich layer increases. By raising of IPF and reducing of mass flow rate of supplying ice-slurry, ice-rich layer could not spread in a tank. The porosity of ice-rich layer was contracting to the value of 0.8-0.9 in the ice storing process. The stored ice quantity depends on distribution and porosity of ice-rich layer in a tank decreased to 10% by raising IPF from 2.5wt% to 10wt% and reducing mass flow rate as constant ice flow rate. The analytical results could express the experimental results about stored ice quantity. Our analytical model is considered to be applicable to prediction of the ice storing characteristics and to design of an ice storage tank.

  20. Integrated Human Centered Systems Analysis for Aircraft Separation from Icing Conditions

    NASA Technical Reports Server (NTRS)

    Hansman, Robert John; Vigeant-Langlois, Laurence N.

    2003-01-01

    This document contains five papers on coping with ice formation during the operation of aircraft. The first paper uses a pilot survey to identify the desired attributes of future information systems for aircraft icing. The second paper investigates the influence of potential remote ice-detection system features on pilot decision making. The third paper investigates the effectiveness of aviation weather forecasting along aircraft trajectories. The fourth paper applied a human-centered systems analysis to the adverse aircraft weather encounter problem in order to identify desirable functions of weather and icing information. The objective of the fifth paper, a viewgraph presentation, is to propose means to improve aviation weather information, training, and procedures based on a human-centered systems approach.

  1. Radiative transfer in atmosphere-sea ice-ocean system

    SciTech Connect

    Jin, Z.; Stamnes, K.; Weeks, W.F.; Tsay, S.C.

    1996-04-01

    Radiative energy is critical in controlling the heat and mass balance of sea ice, which significantly affects the polar climate. In the polar oceans, light transmission through the atmosphere and sea ice is essential to the growth of plankton and algae and, consequently, to the microbial community both in the ice and in the ocean. Therefore, the study of radiative transfer in the polar atmosphere, sea ice, and ocean system is of particular importance. Lacking a properly coupled radiative transfer model for the atmosphere-sea ice-ocean system, a consistent study of the radiative transfer in the polar atmosphere, snow, sea ice, and ocean system has not been undertaken before. The radiative transfer processes in the atmosphere and in the ice and ocean have been treated separately. Because the radiation processes in the atmosphere, sea ice, and ocean depend on each other, this separate treatment is inconsistent. To study the radiative interaction between the atmosphere, clouds, snow, sea ice, and ocean, a radiative transfer model with consistent treatment of radiation in the coupled system is needed and is under development.

  2. Icing tunnel tests of a glycol-exuding porous leading edge ice protection system on a general aviation airfoil

    NASA Technical Reports Server (NTRS)

    Kohlman, D. L.; Schweikhard, W. G.; Albright, A. E.; Evanich, P.

    1981-01-01

    A glycol-exuding porous leading edge ice protection system was tested. Results show that the system is very effective in preventing ice accretion (anti-ice mode) or removing ice from an airfoil. Minimum glycol flow rates required for anti-icing are a function of velocity, liquid water content in the air, ambient temperature, and droplet size. Large ice caps were removed in only a few minutes using anti-ice flow rates. It was found that the shed time is a function of the type of ice, size of the ice cap, angle of attack, and glycol flow rate. Wake survey measurements show that there is no significant drag penalty for the installation or operation of the system tested.

  3. The Arctic sea ice-climate system: Observations and modeling

    SciTech Connect

    Barry, R.G.; Serreze, M.C.; Maslanik, J.A. ); Preller, R.H. )

    1993-11-01

    Significant advances are being made in our understanding of the Arctic sea ice-climate system. The mean circulation of the Arctic sea ice cover is now well defined through analysis of data from drifting stations and buoys. Analysis of nearly 20 years of daily satellite data from optical, infrared, and passive microwave sensors has documented the regional variability in monthly ice extent, concentrations, and surface albedo. Advances in modeling include better treatments of sea ice dynamics and thermodynamics, improved atmosphere-ice-ocean coupling, and the development of high resolution regional models. Diagnostic studies of monthly and interannual sea ice variability have benefited from better sea ice data and geostrophic wind analyses that incorporate drifting buoy data. Some evidence exists for a small retreat of Arctic sea ice over the last 2 decades, but there are large decadal fluctuations in regional ice extent. Antiphase relationships between ice anomalies in different sectors can be related to changes in atmospheric circulation. Evidence suggests that episodes of significant salinity reduction in the North Atlantic, associated with extensive sea ice in the Greenland Sea, may be a manifestation of a decadal oscillation in the Arctic climate system. Aspects of the Arctic system in need of further attention include the surface energy budget and its variability, particularly with respect to the roles of cloud cover and surface types in summer. Sea ice thickness distribution data remain meager, and there are many unknowns regarding the circulation and hydrologic cycle of the Arctic Ocean and its links to the world ocean. Planned measurements from a new generation of satellites, supported by field programs, will provide much needed data to address these issues. 195 refs., 20 figs., 2 tabs.

  4. Icing-Protection Requirements for Reciprocating-Engine Induction System

    NASA Technical Reports Server (NTRS)

    Coles, Willard D; Rollin, Vern G; Mulholland, Donald R

    1950-01-01

    Despite the development of relatively ice-free fuel-metering systems, the widespread use of alternate and heated-air intakes, and the use of alcohol for emergency de-icing, icing of aircraft-engine induction systems is a serious problem. Investigations have been made to study and to combat all phases of this icing problem. From these investigations, criterions for safe operation and for design of new induction systems have been established. The results were obtained from laboratory investigations of carburetor-supercharger combinations, wind-tunnel investigations of air scoops, multicylinder-engine studies, and flight investigations. Characteristics of three forms of ice, impact, throttling, and fuel evaporation were studied. The effects of several factors on the icing characteristics were also studied and included: (1) atmospheric conditions, (2) engine and air-scoop configurations, including light-airplane system, (3) type fuel used, and (4) operating variables, such as power condition, use of a manifold pressure regulator, mixture setting, carburetor heat, and water-alcohol injection. In addition, ice-detection methods were investigated and methods of preventing and removing induction-system ice were studied. Recommendations are given for design and operation with regard to induction-system design.

  5. Systems Engineering Techniques for ALS Decision Making

    NASA Technical Reports Server (NTRS)

    Rodriquez, Luis F.; Drysdale, Alan E.; Jones, Harry; Levri, Julie A.

    2004-01-01

    The Advanced Life Support (ALS) Metric is the predominant tool for predicting the cost of ALS systems. Metric goals for the ALS Program are daunting, requiring a threefold increase in the ALS Metric by 2010. Confounding the problem, the rate new ALS technologies reach the maturity required for consideration in the ALS Metric and the rate at which new configurations are developed is slow, limiting the search space and potentially giving the perspective of a ALS technology, the ALS Metric may remain elusive. This paper is a sequel to a paper published in the proceedings of the 2003 ICES conference entitled, "Managing to the metric: an approach to optimizing life support costs." The conclusions of that paper state that the largest contributors to the ALS Metric should be targeted by ALS researchers and management for maximum metric reductions. Certainly, these areas potentially offer large potential benefits to future ALS missions; however, the ALS Metric is not the only decision-making tool available to the community. To facilitate decision-making within the ALS community a combination of metrics should be utilized, such as the Equivalent System Mass (ESM)-based ALS metric, but also those available through techniques such as life cycle costing and faithful consideration of the sensitivity of the assumed models and data. Often a lack of data is cited as the reason why these techniques are not considered for utilization. An existing database development effort within the ALS community, known as OPIS, may provide the opportunity to collect the necessary information to enable the proposed systems analyses. A review of these additional analysis techniques is provided, focusing on the data necessary to enable these. The discussion is concluded by proposing how the data may be utilized by analysts in the future.

  6. Icing Research Tunnel rotating bar calibration measurement system

    NASA Technical Reports Server (NTRS)

    Gibson, Theresa L.; Dearmon, John M.

    1993-01-01

    In order to measure icing patterns across a test section of the Icing Research Tunnel, an automated rotating bar measurement system was developed at the NASA Lewis Research Center. In comparison with the previously used manual measurement system, this system provides a number of improvements: increased accuracy and repeatability, increased number of data points, reduced tunnel operating time, and improved documentation. The automated system uses a linear variable differential transformer (LVDT) to measure ice accretion. This instrument is driven along the bar by means of an intelligent stepper motor which also controls data recording. This paper describes the rotating bar calibration measurement system.

  7. Icing research tunnel rotating bar calibration measurement system

    NASA Technical Reports Server (NTRS)

    Gibson, Theresa L.; Dearmon, John M.

    1993-01-01

    In order to measure icing patterns across a test section of the Icing Research Tunnel, an automated rotating bar measurement system was developed at the NASA Lewis Research Center. In comparison with the previously used manual measurement system, this system provides a number of improvements: increased accuracy and repeatability, increased number of data points, reduced tunnel operating time, and improved documentation. The automated system uses a linear variable differential transformer (LVDT) to measure ice accretion. This instrument is driven along the bar by means of an intelligent stepper motor which also controls data recording. This paper describes the rotating bar calibration measurement system.

  8. Air conditioning system with supplemental ice storing and cooling capacity

    DOEpatents

    Weng, Kuo-Lianq; Weng, Kuo-Liang

    1998-01-01

    The present air conditioning system with ice storing and cooling capacity can generate and store ice in its pipe assembly or in an ice storage tank particularly equipped for the system, depending on the type of the air conditioning system. The system is characterized in particular in that ice can be produced and stored in the air conditioning system whereby the time of supplying cooled air can be effectively extended with the merit that the operation cycle of the on and off of the compressor can be prolonged, extending the operation lifespan of the compressor in one aspect. In another aspect, ice production and storage in great amount can be performed in an off-peak period of the electrical power consumption and the stored ice can be utilized in the peak period of the power consumption so as to provide supplemental cooling capacity for the compressor of the air conditioning system whereby the shift of peak and off-peak power consumption can be effected with ease. The present air conditioning system can lower the installation expense for an ice-storing air conditioning system and can also be applied to an old conventional air conditioning system.

  9. Methods and systems for detection of ice formation on surfaces

    NASA Technical Reports Server (NTRS)

    Alfano, Robert R. (Inventor); Wang, Wubao (Inventor); Sztul, Henry (Inventor); Budansky, Yury (Inventor)

    2007-01-01

    A system for detecting ice formation on metal, painted metal and other material surfaces can include a transparent window having an exterior surface upon which ice can form; a light source and optics configured and arranged to illuminate the exterior surface of the window from behind the exterior surface; and a detector and optics configured and arranged to receive light backscattered by the exterior surface and any ice disposed on the exterior surface and determine the thickness of the ice layer. For example, the system can be used with aircraft by placing one or more windows in the wings of the aircraft. The system is used for a novel optical method for real-time on-board detection and warning of ice formation on surfaces of airplanes, unmanned aerial vehicles (UAVs), and other vehicles and stationary structures to improve their safety and operation.

  10. Performance of Vacuum Freezing Type Ice Producing System

    NASA Astrophysics Data System (ADS)

    Asaoka, Tatsunori; Saito, Akio; Okawa, Seiji; Hozumi, Tsutomu; Izumi, Naoki; Uji, Yoshihiro

    In this study, the ice slurry producing system, which was introduced in our previous study, was used and the effect of sublimation of ice was investigated. In the system, ethanol solution, as a thermal storage material, is evaporated under low-pressure condition, and the remaining solution is cooled and partially frozen as a consequence of the latent heat of evaporation. In our previous study, it was clarified that the ethanol concentration of vapor phase became lower during the ice producing process of this system, than that under the condition of vapor-liquid equilibrium, in which ice is not generated in the liquid phase. The reason for this is expected to be the effect of the sublimation of ice generated in the liquid phase. In this study, the effect of sublimation of ice on the composition of the vapor phase was investigated. Using the results, the COP and non-dimensional ice production rate of this system was calculated, and the effects of sublimation of ice on them were also evaluated.

  11. Global ice-sheet system interlocked by sea level

    SciTech Connect

    Denton, G.H.; Hughes, T.J.; Karlen, W.

    1986-01-01

    Denton and Hughes postulated that sea level linked a global ice-sheet system with both terrestrial and grounded marine components during later Quaternary ice ages. Summer temperature changes near Northern Hemisphere melting margins initiated sea-level fluctuations that controlled marine components in both polar hemispheres. It was further proposed that variations of this ice-sheet system amplified and transmitted Milankovitch summer half-year insolation changes between 45 and 75/sup 0/N into global climatic changes. New tests of this hypothesis implicate sea level as a major control of the areal extent of grounded portions of the Antarctic Ice Sheet. But factors other than areal changes of the grounded Antarctic Ice Sheet may have strongly influenced Southern Hemisphere climate and terminated the last ice age simultaneously in both polar hemispheres. Atmospheric carbon dioxide linked to high-latitude oceans is the most likely candidate, but another potential influence was high-frequency climatic oscillations. It is postulated that variations in atmospheric carbon dioxide acted through an Antarctic ice shelf linked to the grounded ice sheet to produce and terminate Southern Hemisphere ice-age climate. It is further postulated that Milankovitch summer insolation combined with a warm-high frequency oscillation caused marked recession of Northern Hemisphere ice-sheet melting margins and the North Atlantic polar front about 14,000 /sup 14/C yr B.P. This permitted renewed formation of North Atlantic Deep Water, which could well have controlled atmospheric carbon dioxide. Combined melting and consequent sea-level rise from the three warming factors initiated irreversible collapse of the interlocked global ice-sheet system, which was at its largest but most vulnerable configuration.

  12. Aircraft Icing Weather Data Reporting and Dissemination System

    NASA Technical Reports Server (NTRS)

    Bass, Ellen J.; Minsk, Brian; Lindholm, Tenny; Politovich, Marcia; Reehorst, Andrew (Technical Monitor)

    2002-01-01

    The long-term operational concept of this research is to develop an onboard aircraft system that assesses and reports atmospheric icing conditions automatically and in a timely manner in order to improve aviation safety and the efficiency of aircraft operations via improved real-time and forecast weather products. The idea is to use current measurement capabilities on aircraft equipped with icing sensors and in-flight data communication technologies as a reporting source. Without requiring expensive avionics upgrades, aircraft data must be processed and available for downlink. Ideally, the data from multiple aircraft can then be integrated (along with other real-time and modeled data) on the ground such that aviation-centered icing hazard metrics for volumes of airspace can be assessed. As the effect of icing on different aircraft types can vary, the information should be displayed in meaningful ways such that multiple types of users can understand the information. That is, information must be presented in a manner to allow users to understand the icing conditions with respect to individual concerns and aircraft capabilities. This research provides progress toward this operational concept by: identifying an aircraft platform capable of digitally capturing, processing, and downlinking icing data; identifying the required in situ icing data processing; investigating the requirements for routing the icing data for use by weather products; developing an icing case study in order to gain insight into major air carrier needs; developing and prototyping icing display concepts based on the National Center for Atmospheric Research's existing diagnostic and forecast experimental icing products; and conducting a usability study for the prototyped icing display concepts.

  13. Short-term sea ice forecasting: An assessment of ice concentration and ice drift forecasts using the U.S. Navy's Arctic Cap Nowcast/Forecast System

    NASA Astrophysics Data System (ADS)

    Hebert, David A.; Allard, Richard A.; Metzger, E. Joseph; Posey, Pamela G.; Preller, Ruth H.; Wallcraft, Alan J.; Phelps, Michael W.; Smedstad, Ole Martin

    2015-12-01

    In this study the forecast skill of the U.S. Navy operational Arctic sea ice forecast system, the Arctic Cap Nowcast/Forecast System (ACNFS), is presented for the period February 2014 to June 2015. ACNFS is designed to provide short term, 1-7 day forecasts of Arctic sea ice and ocean conditions. Many quantities are forecast by ACNFS; the most commonly used include ice concentration, ice thickness, ice velocity, sea surface temperature, sea surface salinity, and sea surface velocities. Ice concentration forecast skill is compared to a persistent ice state and historical sea ice climatology. Skill scores are focused on areas where ice concentration changes by ±5% or more, and are therefore limited to primarily the marginal ice zone. We demonstrate that ACNFS forecasts are skilful compared to assuming a persistent ice state, especially beyond 24 h. ACNFS is also shown to be particularly skilful compared to a climatologic state for forecasts up to 102 h. Modeled ice drift velocity is compared to observed buoy data from the International Arctic Buoy Programme. A seasonal bias is shown where ACNFS is slower than IABP velocity in the summer months and faster in the winter months. In February 2015, ACNFS began to assimilate a blended ice concentration derived from Advanced Microwave Scanning Radiometer 2 (AMSR2) and the Interactive Multisensor Snow and Ice Mapping System (IMS). Preliminary results show that assimilating AMSR2 blended with IMS improves the short-term forecast skill and ice edge location compared to the independently derived National Ice Center Ice Edge product.

  14. ICE System: Interruptible control expert system. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Vezina, James M.

    1990-01-01

    The Interruptible Control Expert (ICE) System is based on an architecture designed to provide a strong foundation for real-time production rule expert systems. Three principles are adopted to guide the development of ICE. A practical delivery platform must be provided, no specialized hardware can be used to solve deficiencies in the software design. Knowledge of the environment and the rule-base is exploited to improve the performance of a delivered system. The third principle of ICE is to respond to the most critical event, at the expense of the more trivial tasks. Minimal time is spent on classifying the potential importance of environmental events with the majority of the time used for finding the responses. A feature of the system, derived from all three principles, is the lack of working memory. By using a priori information, a fixed amount of memory can be specified for the hardware platform. The absence of working memory removes the dangers of garbage collection during the continuous operation of the controller.

  15. Antarctic sea ice carbon dioxide system and controls

    NASA Astrophysics Data System (ADS)

    Fransson, Agneta; Chierici, Melissa; Yager, Patricia L.; Smith, Walker O., Jr.

    2011-12-01

    In austral summer, from December 2008 to January 2009, we investigated the sea-ice carbon dioxide (CO2) system and CO2 controls in the Amundsen and Ross Seas, Antarctica. We sampled seawater, brine and sea ice for the measurements of total alkalinity (AT), total inorganic carbon (DIC), pH, inorganic nutrients, particulate organic carbon (POC) and nitrogen (PON), chlorophyll a, pigments, salinity and temperature. Large variability in all measured parameters was observed in time and space due to the complex sea-ice dynamics. We discuss the controls of the sea-ice CO2 system, such as brine rejection, biological processes, calcium carbonate (CaCO3) precipitation/dissolution and CO2 exchange. Most (80 to 90%) of the DIC loss was due to brine rejection, which suggests that the sea ice acted as an efficient DIC sink from 0.8 and 2.6 mol m-2 yr-1 (9.6-31 g C m-2 yr-1). The remaining change in DIC was to a large extent explained by net biological production. The AT:DIC ratio in the sea ice was higher than in the under-ice water (UIW), with ratios reaching 1.7, which indicated CaCO3 precipitation and concomitant DIC loss in the sea ice. Elevated AT:DIC ratios and carbonate concentrations were also observed in the UIW, which reflect the solid CaCO3 rejected from the ice during melt. The potential for uptake of atmospheric CO2 in the mixed layer increased by approximately 56 μatm due to the combined effect of CaCO3 precipitation during ice formation, and ice melt in summer.

  16. NASA Glenn Propulsion Systems Lab (PSL) Icing Facility Update

    NASA Technical Reports Server (NTRS)

    Thomas, Queito P.

    2015-01-01

    The NASA Glenn Research Center Propulsion Systems Lab (PSL) was recently upgraded to perform engine inlet ice crystal testing in an altitude environment. The system installed 10 spray bars in the inlet plenum for ice crystal generation using 222 spray nozzles. As an altitude test chamber, PSL is capable of simulation of in-flight icing events in a ground test facility. The system was designed to operate at altitudes from 4,000 ft. to 40,000 ft. at Mach numbers up to 0.8M and inlet total temperatures from -60F to +15F.

  17. Phase Relations and Properties of Salty ices VI and VII: Implications for Solar System Ices

    NASA Astrophysics Data System (ADS)

    Daniel, I.; Manning, C. E.

    2008-12-01

    Ice VI and ice VII may be important in the interiors of Europa, Ganymede, Callisto and Titan. Oceans and interior pore waters in these bodies likely contain dissolved salts. To address the role of salt on ice VI and ice VII, we investigated phase equilibria in the system H2O -NaCl at 1 molal (5.5 wt%) NaCl in an externally heated diamond-anvil cell. Phase identifications were made by optical microscopy combined with Raman spectroscopy. Experiments were conducted at 22-150°C and up to 5 GPa by allowing the cell to thermally equilibrate at a given temperature and then varying pressure isothermally while observing phase changes. The liquidus curves of ice VI and ice VII in a 5.5 wt% NaCl solution were determined. Melting was observed from 22 to 80°C (ice VI) and from 35 to 150°C (ice VII). Both melting curves are steeper than the respective NaCl-free curves, indicating that the freezing-point depression at this bulk composition increases with pressure. The intersection of the two liquidus curves indicates that VI-VII-liquid triple point is shifted toward lower T and higher P relative to pure H2O. The 5.5 wt% NaCl bulk composition crystallizes into a single solid phase of NaCl-bearing ice VI or ice VII solid solution over the investigated T range (the subscript 'ss' indicates solid solution). Large single crystals of ice VIss or ice VIIss can also be grown by slow compression of the cell from near-liquidus conditions to the solidus. Raman spectra of these crystals clearly show zoning in these crystals. The zoning persists for days at 22°C, indicating relatively slow Na+ and Cl- diffusivity. The large depression of the freezing point in a 1 molal NaCl solution has important implications for the oceans and interiors of the icy satellites of Jupiter and Saturn. Salty fluids may remain stable to much greater depth than expected. This would promote extensive hydrothermal metamorphism of the silicate interiors. If not limited to ice VI and VII, this behavior may suppress formation of ices at the bottoms of deep oceans in Titan and the Galilean satellites. The observation that ices VI and VII form solid solutions with NaCl from 22 to 150°C is also important. The qualitative inference of low Na+ and Cl- diffusivity suggests that compositional gradients could persist over at least modest time scales in these ices. Moreover, the presence of NaCl in ice VI and VII will likely reduce their viscosity and increase electrical conductivity.

  18. Monstrous Ice Cloud System in Titan's Present South Polar Stratosphere

    NASA Astrophysics Data System (ADS)

    Anderson, Carrie; Samuelson, Robert; McLain, Jason; Achterberg, Richard; Flasar, F. Michael; Milam, Stefanie

    2015-11-01

    During southern autumn when sunlight was still available, Cassini's Imaging Science Subsystem discovered a cloud around 300 km near Titan's south pole (West, R. A. et al., AAS/DPS Abstracts, 45, #305.03, 2013); the cloud was later determined by Cassini's Visible and InfraRed Mapping Spectrometer to contain HCN ice (de Kok et al., Nature, 514, pp 65-67, 2014). This cloud has proven to be only the tip of an extensive ice cloud system contained in Titan's south polar stratosphere, as seen through the night-vision goggles of Cassini's Composite InfraRed Spectrometer (CIRS). As the sun sets and the gloom of southern winter approaches, evidence is beginning to accumulate from CIRS far-IR spectra that a massive system of nitrile ice clouds is developing in Titan's south polar stratosphere. Even during the depths of northern winter, nothing like the strength of this southern system was evident in corresponding north polar regions.From the long slant paths that are available from limb-viewing CIRS far-IR spectra, we have the first definitive detection of the ν6 band of cyanoacetylene (HC3N) ice in Titan’s south polar stratosphere. In addition, we also see a strong blend of nitrile ice lattice vibration features around 160 cm-1. From these data we are able to derive ice abundances. The most prominent (and still chemically unidentified) ice emission feature, the Haystack, (at 220 cm-1) is also observed. We establish the vertical distributions of the ice cloud systems associated with both the 160 cm-1 feature and the Haystack. The ultimate aim is to refine the physical and possibly the chemical relationships between the two. Transmittance thin film spectra of nitrile ice mixtures obtained in our Spectroscopy for Planetary ICes Environments (SPICE) laboratory are used to support these analyses.

  19. Ice Crystal Icing Engine Testing in the NASA Glenn Research Center's Propulsion Systems Laboratory (PSL): Altitude Investigation

    NASA Technical Reports Server (NTRS)

    Oliver, Michael J.

    2015-01-01

    The National Aeronautics and Space Administration conducted a full scale ice crystal icing turbofan engine test in the NASA Glenn Research Centers Propulsion Systems Laboratory (PSL) Facility in February 2013. Honeywell Engines supplied the test article, an obsolete, unmodified Lycoming ALF502-R5 turbofan engine serial number LF01 that experienced an un-commanded loss of thrust event while operating at certain high altitude ice crystal icing conditions. These known conditions were duplicated in the PSL for this testing.

  20. NASA Glenn Propulsion Systems Lab (PSL) Icing Facility Update

    NASA Technical Reports Server (NTRS)

    Griffin, Thomas A.

    2014-01-01

    This oral presentation is an update to the Propulsion Systems Lab (PSL) engine ice testing. It provides a summary of the modifications done to the facility and recently completed calibrations and test program.

  1. A Systems-Level Perspective on Engine Ice Accretion

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Guo, Ten-Huei; Simon, Donald L.

    2013-01-01

    The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation sector. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. This work focuses on developing an accurate and reliable algorithm for detecting the accretion of ice in the low pressure compressor of a generic 40,000 lbf thrust class engine. The algorithm uses only the two shaft speed sensors and works regardless of engine age, operating condition, and power level. In a 10,000-case Monte Carlo simulation, the detection approach was found to have excellent capability at determining ice accretion from sensor noise with detection occurring when ice blocks an average of 6.8% of the low pressure compressor area. Finally, an initial study highlights a potential mitigation strategy that uses the existing engine actuators to raise the temperature in the low pressure compressor in an effort to reduce the rate at which ice accretes.

  2. Micrometeorite impact annealing of ice in the outer Solar System

    NASA Astrophysics Data System (ADS)

    Porter, Simon B.; Desch, Steven J.; Cook, Jason C.

    2010-07-01

    The spectra of water ice on the surfaces of icy satellites and Kuiper Belt Objects (KBOs) indicate that the surface ice on these bodies is in a crystalline state. This conflicts with theoretical models, which predict that radiation (galactic cosmic rays and solar ultraviolet) should damage the crystalline structure of ice on geologically short timescales. Temperatures are too low in the outer Solar System for the ice to anneal, and reflectance spectra of these bodies should match those of amorphous solid water (ASW). We assess whether the kinetic energy deposited as heat by micrometeorite impacts on outer Solar System bodies is sufficient to anneal their surface ice down to a near-infrared optical depth (350?m). We calculate the kinetic energy flux from interplanetary micrometeorite impacts, including gravitational focusing. We also calculate the thermal diffusion of impact heat in various surfaces and the rate of annealing of ice. We conclude that the rate of annealing from micrometeorite impacts is sufficient to explain the crystallinity of ice on nearly all the surfaces of the saturnian, uranian and neptunian satellites. We discuss how the model can be used in conjunction with spectra of KBOs to probe dust fluxes in the Kuiper Belt.

  3. Global ice-sheet system interlocked by sea level

    NASA Astrophysics Data System (ADS)

    Denton, George H.; Hughes, Terence J.; Karlén, Wibjörn

    1986-07-01

    Denton and Hughes (1983, Quaternary Research20, 125-144) postulated that sea level linked a global ice-sheet system with both terrestrial and grounded marine components during late Quaternary ice ages. Summer temperature changes near Northern Hemisphere melting margins initiated sea-level fluctuations that controlled marine components in both polar hemispheres. It was further proposed that variations of this ice-sheet system amplified and transmitted Milankovitch summer half-year insolation changes between 45 and 75°N into global climatic changes. New tests of this hypothesis implicate sea level as a major control of the areal extent of grounded portions of the Antarctic Ice Sheet, thus fitting the concept of a globally interlocked ice-sheet system. But recent atmospheric modeling results ( Manabe and Broccoli, 1985, Journal of Geophysical Research90, 2167-2190) suggest that factors other than areal changes of the grounded Antarctic Ice Sheet strongly influenced Southern Hemisphere climate and terminated the last ice age simultaneously in both polar hemispheres. Atmospheric carbon dioxide linked to high-latitude oceans is the most likely candidate ( Shackleton and Pisias, 1985, Atmospheric carbon dioxide, orbital forcing, and climate. In "The Carbon Cycle and Atmospheric CO 2: Natural Variations Archean to Present" (E. T. Sundquest and W. S. Broecker, Eds.), pp. 303-318. Geophysical Monograph 32, American Geophysical Union, Washington, D.C.), but another potential influence was high-frequency climatic oscillations (2500 yr). It is postulated that variations in atmospheric carbon dioxide acted through an Antarctic ice shelf linked to the grounded ice sheet to produce and terminate Southern Hemisphere ice-age climate. It is further postulated that Milankovitch summer insolation combined with a warm high-frequency oscillation caused marked recession of Northern Hemisphere ice-sheet melting margins and the North Atlantic polar front about 14,000 14C yr B.P. This permitted renewed formation of North Atlantic Deep Water, which could well have controlled atmospheric carbon dioxide ( W. S. Broecker, D. M. Peteet, and D. Rind, 1985, Nature ( London) 315, 21-26). Combined melting and consequent sea-level rise from the three warming factors initiated irreversible collapse of the interlocked global ice-sheet system, which was at its largest but most vulnerable configuration.

  4. Great Lakes all-weather ice information system

    NASA Technical Reports Server (NTRS)

    Schertler, R. J.; Mueller, R. A.; Jirberg, R. J.; Cooper, D. W.; Heighway, J. E.; Holmes, A. D.; Gedney, R. T.; Mark, H.

    1975-01-01

    A system is described which utilizes an X-band Side-Looking-Airborne-Radar (SLAR) for determining type, location, and aerial distribution of the ice cover in the Great Lakes and an airborne, S-band, short pulse radar for obtaining ice thickness. The SLAR system is currently mounted aboard a U.S. Coast Guard C-130B aircraft. Digitized SLAR data are relayed in real-time via the NOAA-GOES-1 satellite in geosynchronous orbit to the U.S. Coast Guard Ice Center in Cleveland, Ohio. SLAR images along with hand-drawn interpretative ice charts for various winter shipping areas in the Great Lakes are broadcast to facsimile recorders aboard Great Lakes vessels. The operational aspects of this ice information system are being demonstrated by NASA, U.S. Coast Guard, and NOAA/National Weather Service. Results from the 1974-75 winter season demonstrated the ability of this system to provide all-weather ice information to shippers in a timely manner.

  5. Ice Cloud Properties in Ice-Over-Water Cloud Systems Using TRMM VIRS and TMI Data

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Huang, Jianping; Lin, Bing; Yi, Yuhong; Arduini, Robert F.; Fan, Tai-Fang; Ayers, J. Kirk; Mace, Gerald G.

    2007-01-01

    A multi-layered cloud retrieval system (MCRS) is updated and used to estimate ice water path in maritime ice-over-water clouds using Visible and Infrared Scanner (VIRS) and TRMM Microwave Imager (TMI) measurements from the Tropical Rainfall Measuring Mission spacecraft between January and August 1998. Lookup tables of top-of-atmosphere 0.65- m reflectance are developed for ice-over-water cloud systems using radiative transfer calculations with various combinations of ice-over-water cloud layers. The liquid and ice water paths, LWP and IWP, respectively, are determined with the MCRS using these lookup tables with a combination of microwave (MW), visible (VIS), and infrared (IR) data. LWP, determined directly from the TMI MW data, is used to define the lower-level cloud properties to select the proper lookup table. The properties of the upper-level ice clouds, such as optical depth and effective size, are then derived using the Visible Infrared Solar-infrared Split-window Technique (VISST), which matches the VIRS IR, 3.9- m, and VIS data to the multilayer-cloud lookup table reflectances and a set of emittance parameterizations. Initial comparisons with surface-based radar retrievals suggest that this enhanced MCRS can significantly improve the accuracy and decrease the IWP in overlapped clouds by 42% and 13% compared to using the single-layer VISST and an earlier simplified MW-VIS-IR (MVI) differencing method, respectively, for ice-over-water cloud systems. The tropical distribution of ice-over-water clouds is the same as derived earlier from combined TMI and VIRS data, but the new values of IWP and optical depth are slightly larger than the older MVI values, and exceed those of single-layered layered clouds by 7% and 11%, respectively. The mean IWP from the MCRS is 8-14% greater than that retrieved from radar retrievals of overlapped clouds over two surface sites and the standard deviations of the differences are similar to those for single-layered clouds. Examples of a method for applying the MCRS over land without microwave data yield similar differences with the surface retrievals. By combining the MCRS with other techniques that focus primarily on optically thin cirrus over low water clouds, it will be possible to more fully assess the IWP in all conditions over ocean except for precipitating systems.

  6. A Real-Time Satellite-Based Icing Detection System

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Smith, William L., Jr.; Nguyen, Louis; Khaiyer, Mandana M.; Spangenberg, Douglas A.; Heck, Patrick W.; Palikonda, Rabindra; Bernstein, Ben C.; McDonough, Frank

    2004-01-01

    Aircraft icing is one of the most dangerous weather conditions for general aviation. Currently, model forecasts and pilot reports (PIREPS) constitute much of the database available to pilots for assessing the icing conditions in a particular area. Such data are often uncertain or sparsely available. Improvements in the temporal and areal coverage of icing diagnoses and prognoses would mark a substantial enhancement of aircraft safety in regions susceptible to heavy supercooled liquid water clouds. The use of 3.9 microns data from meteorological satellite imagers for diagnosing icing conditions has long been recognized (e.g., Ellrod and Nelson, 1996) but to date, no explicit physically based methods have been implemented. Recent advances in cloud detection and cloud property retrievals using operational satellite imagery open the door for real-time objective applications of those satellite datasets for a variety of weather phenomena. Because aircraft icing is related to cloud macro- and microphysical properties (e.g., Cober et al. 1995), it is logical that the cloud properties from satellite data would be useful for diagnosing icing conditions. This paper describes the a prototype realtime system for detecting aircraft icing from space.

  7. Physical State of Ices in the Outer Solar System. Revised

    NASA Technical Reports Server (NTRS)

    Roush, Ted L.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Comparison of the identity and abundances of ices observed around protostars and those associated with comets clearly suggests that comets preserve the heritage of the interstellar materials that aggregated to form them. However, the ability to identify these same species on icy satellites in the outer solar system is a complex function of the composition of the original ices, their subsequent thermal histories, and their exposure to various radiation environments. Our ability to identify the ices currently present on objects in the outer solar system relies upon observational and laboratory, and theoretical efforts. To date there is ample observational evidence for crystalline water ice throughout the outer solar system. In addition, there is growing evidence that amorphous ice may be present on some bodies. More volatile ices, e.g. N2, CH4. CO, and other species, e.g. ammonia hydrate, are identified on objects lying at and beyond Uranus. Both photolysis and radiolysis play important roles in altering the original surfaces due to chemical reactions and erosion of the surface. Ultraviolet photolysis appears to dominate alteration of the upper few hundred Angstroms, although sputtering the surface can sometimes be a significantly competitative process; dominating on icy surfaces embedded in a strong planetary magnetospheric field. There is growing observational evidence that the by-products of photolysis and radiolysis, suggested on a theoretical basis, are present on icy surfaces.

  8. Experimental study of fluid deicing system in the NASA Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    1983-01-01

    An investigation of the icing of horizontal control surfaces at the VFW in 1970 led them to select the NASA Icing Research Tunnel at LRC for their tests. Tests were performed for the VFW 614 aircraft. The TKS ice warning system, the Rosemont ice warning system and the liquid water content indicator were investigated and found to be appropriate for the aircraft.

  9. Study on Supercooling Release in Encapsulated Ice System

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Yooko; Hasagawa, Hiromi; Iwatsubo, Tetsushiro

    As regards the super cooling phenomena which is important matter in encapsulated ice system, the system efficient suffering from the super cooling release of water was estimated and the performance of release reagent was determined. The following conclusions were reached. (1) It was clear that the COP of heat storing of the system fell by 3% with decreasing release temperature by 1 degree centigrade. (2) As a result of determinations about release reagents, Xanthomonas campestris (ice nuclei bacteria) was very effective in release the super cooling state, and the performance was maintained in continuous application of freezing and melting.

  10. Ice Detector and Deicing Fluid Effectiveness Monitoring System

    NASA Technical Reports Server (NTRS)

    Seegmiller, H. Lee B. (Inventor)

    1996-01-01

    An ice detector and deicing fluid effectiveness monitoring system for an aircraft is disclosed. The ice detection portion is particularly suited for use in flight to notify the flight crew of an accumulation of ice on an aircraft lifting and control surfaces, or helicopter rotors, whereas the deicing fluid effectiveness monitoring portion is particularly suited for use on the ground to notify the flight crew of the possible loss of the effectiveness of the deicing fluid. The ice detection portion comprises a temperature sensor and a parallel arrangement of electrodes whose coefficient of coupling is indicative of the formation of the ice, as well as the thickness of the formed ice. The fluid effectiveness monitoring portion comprises a temperature sensor and an ionic-conduction cell array that measures the conductivity of the deicing fluid which is indicative of its concentration and, thus, its freezing point. By measuring the temperature and having knowledge of the freezing point of the deicing fluid, the fluid effectiveness monitoring portion predicts when the deicing fluid may lose its effectiveness because its freezing point may correspond to the temperature of the ambient.

  11. Mass budget of the grounded ice in the Lambert Glacier-Amery Ice Shelf system

    NASA Astrophysics Data System (ADS)

    Jiahong, Wen; Yafeng, Wang; Jiying, Liu; Jezek, Kenneth C.; Huybrechts, Philippe; Csathó, Beata M.; Farness, Katy L.; Bo, Sun

    We used remote-sensing and in situ measurements of surface accumulation rate, ice surface velocity, thickness and elevation to evaluate the mass budgets of grounded ice-flow regimes that form the Lambert Glacier-Amery Ice Shelf system. Three distinct drainage regimes are considered: the western and eastern margins of the ice shelf, and the southern grounding line at the major outlet glacier confluence, which can be identified with drainage zones 9, 11 and 10 respectively of Giovinetto and Zwally (2000). Our findings show the entire grounded portion of the basin is approximately in balance, with a mass budget of -4.2±9.8 Gta-1. Drainages 9, 10 and 11 are within balance to the level of our measurement uncertainty, with mass budgets of -2.5±2.8 Gta-1, -2.6±7.8 Gta-1 and 0.9±2.3 Gta-1, respectively. The region upstream of the Australian Lambert Glacier basin (LGB) traverse has a net mass budget of 4.4±6.3 Gta-1, while the downstream region has -8.9±9.9 Gta-1. These results indicate that glacier drainages 9, 10 and 11, upstream and downstream of the Australian LGB traverse, are in balance to within our measurement error.

  12. The NASA Icing Remote Sensing System

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Brinker, David J.; Ratvasky, Thomas P.; Ryerson, Charles C.; Koenig, George G.

    2005-01-01

    NASA and the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) have an on-going activity to develop remote sensing technologies for the detection and measurement of icing conditions aloft. A multiple instrument approach is the current emphasis of this activity. Utilizing radar, radiometry, and lidar, a region of supercooled liquid is identified. If the liquid water content (LWC) is sufficiently high, then the region of supercooled liquid cloud is flagged as being an aviation hazard. The instruments utilized for the current effort are an X-band vertical staring radar, a radiometer that measures twelve frequencies between 22 and 59 GHz, and a lidar ceilometer. The radar data determine cloud boundaries, the radiometer determines the sub-freezing temperature heights and total liquid water content, and the ceilometer refines the lower cloud boundary. Data are post-processed with a LabVIEW program with a resultant supercooled LWC profile and aircraft hazard identification. Remotely sensed measurements gathered during the 2003-2004 Alliance Icing Research Study (AIRS II) were compared to aircraft in-situ measurements. Although the comparison data set is quite small, the cases examined indicate that the remote sensing technique appears to be an acceptable approach.

  13. 14 CFR 33.68 - Induction system icing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Induction system icing. 33.68 Section 33.68 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.68 Induction system...

  14. 14 CFR 33.68 - Induction system icing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Induction system icing. 33.68 Section 33.68 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.68 Induction system...

  15. 14 CFR 33.68 - Induction system icing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Induction system icing. 33.68 Section 33.68 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.68 Induction system...

  16. 14 CFR 33.68 - Induction system icing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Induction system icing. 33.68 Section 33.68 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.68 Induction system...

  17. 14 CFR 33.68 - Induction system icing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction system icing. 33.68 Section 33.68 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.68 Induction system...

  18. 14 CFR 23.1093 - Induction system icing protection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Induction System § 23.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating... power or thrust setting in a manner acceptable to the Administrator. (c) Reciprocating engines with Superchargers. For airplanes with reciprocating engines having superchargers to pressurize the air before...

  19. 14 CFR 23.1093 - Induction system icing protection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Induction System § 23.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating... power or thrust setting in a manner acceptable to the Administrator. (c) Reciprocating engines with Superchargers. For airplanes with reciprocating engines having superchargers to pressurize the air before...

  20. 14 CFR 23.1093 - Induction system icing protection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Induction System § 23.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating... power or thrust setting in a manner acceptable to the Administrator. (c) Reciprocating engines with Superchargers. For airplanes with reciprocating engines having superchargers to pressurize the air before...

  1. 14 CFR 23.1093 - Induction system icing protection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Induction System § 23.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating... power or thrust setting in a manner acceptable to the Administrator. (c) Reciprocating engines with Superchargers. For airplanes with reciprocating engines having superchargers to pressurize the air before...

  2. Ice-sheet sourced juxtaposed turbidite systems in Labrador Sea

    USGS Publications Warehouse

    Hesse, R.; Klaucke, I.; Ryan, William B. F.; Piper, D.J.W.

    1997-01-01

    Ice-sheet sourced Pleistocene turbidite systems of the Labrador Sea are different from non-glacially influenced systems in their facies distribution and depositional processes. Two large-scale sediment dispersal systems are juxtaposed, one mud-dominated and associated with the Northwest Atlantic Mid-Ocean Channel (NAMOC), the other sand-dominated and forming a huge submarine braided sandplain. Co-existence of the two systems reflects grain-size separation of the coarse and fine fractions on an enormous scale, caused by sediment winnowing at the entrance points of meltwater from the Laurentide Ice Sheet (LIS) to the sea (Hudson Strait, fiords) and involves a complex interplay of depositional and redepositional processes. The mud-rich NAMOC system is multisourced and represents a basinwide converging system of tributary canyons and channels. It focusses its sand load to the central trunk channel in basin centre, in the fashion of a "reverse" deep-sea fan. The sand plain received its sediment from the Hudson Strait by turbidity currents that were generated either by failure of glacial prodelta slopes at the ice margin, or by direct meltwater discharges with high bedload concentration. We speculate that the latter might have been related to subglacial-lake outburst flooding through the Hudson Strait, possibly associated with ice-rafting (Heinrich) events.

  3. Breath from the little ice age makes non-sorted circles CO2 sources

    NASA Astrophysics Data System (ADS)

    Becher, Marina; Olofsson, Johan; Klaminder, Jonatan

    2013-04-01

    The mass-movement of soil induced by differential heave and thaw cycles (cryoturbation) is thought to reduce respiration losses from high latitude soils as it translocate carbon into cold mineral soil layers where microbial processes proceeds at slow rates (Bockheim, 2007). However, it is not straightforward to always view cryogenic processes as processes that contribute positively to the build-up of carbon in patterned ground systems, such as non-sorted circles. In these systems differential heave and ice-formation may affect plant growth negatively and thus lower the carbon input to the soil. In this study, we test the hypothesis that; increased cryogenic activity within non-sorted circles reduces the rate in which plant fixate CO2 from the atmosphere. To test our hypothesis we measured gross ecosystem photosynthesis (GEP) and soil respiration (R) in 3 fields of non-sorted circles (total amount of 15 circles, total 190 measurements) formed along a permafrost gradient close to Abisko, Northern Sweden. Measurements were conducted every second week for one summer and GEP and R fluxes were used to calculate the net ecosystem exchange (NEE) of CO2 in the fields. In the fields, the churning of carbon into mineral soil layers by cryoturbation occurred mainly in the past under different climatic conditions, i.e. mainly during the little ice age and a period around 1100 AD as indicated by 14C dating (Becher et al., 2013). In contrary to our hypothesis, we did not find any major difference in GEP between the fields in the permafrost gradient that seems to depend on contemporary cryogenic activity in the centre of the circles. However, we note that all circles respired more carbon than was fixated by photosynthesis. We therefore suggest that respiration losses from the pool buried mainly during the little ice age is strongly affecting the carbon balance of the circles. Consequently, non-sorted circles in northern Sweden may currently act as carbon sources. References Becher, M., C. Olid, and J. Klaminder, 2013. Buried Soil Organic Inclusions in Non-sorted Circles Fields in Northern Sweden: Age and Paleoclimatic Context. J. Geophys. Re., in press. Bockheim, J.G., 2007. Importance of Cryoturbation in Redistributing Organic Carbon in Permafrost-Affected Soils. Soil Sci. Soc. Am. J., 71:1335-1342.

  4. High Resolution Continuous Flow Analysis System for Polar Ice Cores

    NASA Astrophysics Data System (ADS)

    Dallmayr, Remi; Azuma, Kumiko; Yamada, Hironobu; Kjær, Helle Astrid; Vallelonga, Paul; Azuma, Nobuhiko; Takata, Morimasa

    2014-05-01

    In the last decades, Continuous Flow Analysis (CFA) technology for ice core analyses has been developed to reconstruct the past changes of the climate system 1), 2). Compared with traditional analyses of discrete samples, a CFA system offers much faster and higher depth resolution analyses. It also generates a decontaminated sample stream without time-consuming sample processing procedure by using the inner area of an ice-core sample.. The CFA system that we have been developing is currently able to continuously measure stable water isotopes 3) and electrolytic conductivity, as well as to collect discrete samples for the both inner and outer areas with variable depth resolutions. Chemistry analyses4) and methane-gas analysis 5) are planned to be added using the continuous water stream system 5). In order to optimize the resolution of the current system with minimal sample volumes necessary for different analyses, our CFA system typically melts an ice core at 1.6 cm/min. Instead of using a wire position encoder with typical 1mm positioning resolution 6), we decided to use a high-accuracy CCD Laser displacement sensor (LKG-G505, Keyence). At the 1.6 cm/min melt rate, the positioning resolution was increased to 0.27mm. Also, the mixing volume that occurs in our open split debubbler is regulated using its weight. The overflow pumping rate is smoothly PID controlled to maintain the weight as low as possible, while keeping a safety buffer of water to avoid air bubbles downstream. To evaluate the system's depth-resolution, we will present the preliminary data of electrolytic conductivity obtained by melting 12 bags of the North Greenland Eemian Ice Drilling (NEEM) ice core. The samples correspond to different climate intervals (Greenland Stadial 21, 22, Greenland Stadial 5, Greenland Interstadial 5, Greenland Interstadial 7, Greenland Stadial 8). We will present results for the Greenland Stadial -8, whose depths and ages are between 1723.7 and 1724.8 meters, and 35.520 to 35.636 kyr b2k 7), respectively. The results show the conductivity measured upstream and downstream of the debubbler. We will calculate the depth resolution of our system and compare it with earlier studies. 1) Bigler at al, "Optimization of High-Resolution Continuous Flow Analysis For Transient Climate Signals in Ice Cores". Environ. Sci. Technol. 2011, 45, 4483-4489 2) Kaufmann et al, "An Improved Continuous Flow Analysis System for High Resolution Field Measurements on Ice Cores". Environmental Environ. Sci. Technol. 2008, 42, 8044-8050 3) Gkinis, V., T. J. Popp, S. J. Johnsen and T, Blunier, 2010: A continuous stream flash evaporator for the calibration of an IR cavity ring down spectrometer for the isotopic analysis of water. Isotopes in Environmental and Health Studies, 46(4), 463-475. 4) McConnell et al, "Continuous ice-core chemical analyses using inductively coupled plasma mass spectrometry. Environ. Sci. Technol. 2002, 36, 7-11 5) Rhodes et al, "Continuous methane measurements from a late Holocene Greenland ice core : Atmospheric and in-situ signals" Earth and Planetary Science Letters. 2013, 368, 9-19 6) Breton et al, "Quantifying Signal Dispersion in a Hybrid Ice Core Melting System". Environ. Sci. Technol. 2012, 46, 11922-11928 7) Rasmussen et al, " A first chronology for the NEEM ice core". Climate of the Past. 2013, 9, 2967--3013

  5. A Study of the Effects of Altitude on Thermal Ice Protection System Performance

    NASA Technical Reports Server (NTRS)

    Addy, Gene; Oleskiw, Myron; Broeren, Andy P.; Orchard, David

    2013-01-01

    Thermal ice protection systems use heat energy to prevent a dangerous buildup of ice on an aircraft. As aircraft become more efficient, less heat energy is available to operate a thermal ice protections system. This requires that thermal ice protection systems be designed to more exacting standards so as to more efficiently prevent a dangerous ice buildup without adversely affecting aircraft safety. While the effects of altitude have always beeing taked into account in the design of thermal ice protection systems, a better understanding of these effects is needed so as to enable more exact design, testing, and evaluation of these systems.

  6. Fast ice image retrieval based on a multilayer system

    NASA Astrophysics Data System (ADS)

    Lu, Guoyu; Sorensen, Scott; Kambhamettu, Chandra

    2014-02-01

    We propose a multilayer system to perform ice image retrieval. Ice images are typically texture-less, which adds difficulty in retrieving the images. To achieve high accuracy, high level local features are usually used in retrieving the images. However, most high level features contain high dimensionality that slows down the retrieval process. To overcome this problem, we divide the retrieval process into 3 steps. Each step filters out a large portion of images. As the features are constructed according to the ice image properties, one image can be quickly localized compared with the use of high-level features. The ice images are captured in Arctic, where the ice state changes dramatically due to the environmental and other influences. We build the first layer of the system on the utilization of color information and edges, as the color and the edges are the most critical characteristics of ice images. We divide the second layer into two sub-layers. The first sublayer is on the use of edge histogram. For the second sublayer, we detect salient points based on pixel values on the edge position and connect every adjacent points with straight lines. A new feature is built on the basis of distance scale of every adjacent salient points and the angles between connected lines. Our new feature is invariant to transformation, rotation and scaling. As the features in the first two layers are holistic features, the time performance is much better than high-level local features. The third layer is to apply Harris detector to find the correspondences between two features on a small set of filtered images. The experiments show that our system achieves good accuracy while maintaining much better time performance.

  7. Making the System Work for Poor Children.

    ERIC Educational Resources Information Center

    Weissbourd, Richard

    This paper, developed from the discussions of the Executive Session on Making the System Work for Poor Children, describes why the current human service system is failing to help many poor children, and maps out the dimensions of a system that could greatly improve these children's prospects. The argument is made that the current system's problems…

  8. Radar imaging of solar system ices

    NASA Astrophysics Data System (ADS)

    Harcke, Leif J.

    We map the planet Mercury and Jupiter's moons Ganymede and Callisto using Earth-based radar telescopes and find that all of these have regions exhibiting high, depolarized radar backscatter and polarization inversion (m c > 1). Both characteristics suggest significant volume scattering from water ice or similar cold-trapped volatiles. Synthetic aperture radar mapping of Mercury's north and south polar regions at fine (6 km) resolution at 3.5 cm wavelength corroborates the results of previous 13 cm investigations of enhanced backscatter and polarization inversion (0.9 <= m c <= 1.3) from areas on the floors of craters at high latitudes, where Mercury's near-zero obliquity results in permanent Sun shadows. Co-registration with Mariner 10 optical images shows that this enhanced scattering cannot be caused by simple double-bounce geometries, since the bright, reflective regions do not appear on the radar-facing wall but, instead, in shadowed regions not directly aligned with the radar look direction. Thermal models require the existence of such a layer to preserve ice deposits in craters at other than high polar latitudes. The additional attenuation (factor 1.64 +/- 15%) of the 3.5 cm wavelength data from these experiments over previous 13 cm radar observations is consistent with a range of layer thickness from 0 +/- 11 to 35 +/- 15 cm, depending on the assumed scattering law exponent n. Our 3.5 cm wavelength bistatic aperture synthesis observations of the two outermost Galilean satellites of Jupiter, Ganymede and Callisto, resolve the north-south ambiguity of previous images, and confirm the disk-integrated enhanced backscatter and polarization inversion noted in prior investigations. The direct imaging technique more clearly shows that higher backscatter are as are associated with the terrain that has undergone recent resurfacing, such as the sulci and the impact crater basins. The leading hemispheres of both moons have somewhat higher (20% +/- 5%) depolarized echoes than their trailing hemispheres, suggesting additional wavelength-scale structure in the regolith. Two improvements to existing delay-Doppler techniques enhance data reduction. First, correlation using subsets of the standard, repetitive pseudo-noise code alleviates Doppler dimension aliasing by properly sampling the output of the range compression stage. Second, a spectral weighting technique reduces clutter in long-code processing by equalizing clutter in the delay and Doppler dimensions.

  9. Automatic control study of the icing research tunnel refrigeration system

    NASA Technical Reports Server (NTRS)

    Kieffer, Arthur W.; Soeder, Ronald H.

    1991-01-01

    The Icing Research Tunnel (IRT) at the NASA Lewis Research Center is a subsonic, closed-return atmospheric tunnel. The tunnel includes a heat exchanger and a refrigeration plant to achieve the desired air temperature and a spray system to generate the type of icing conditions that would be encountered by aircraft. At the present time, the tunnel air temperature is controlled by manual adjustment of freon refrigerant flow control valves. An upgrade of this facility calls for these control valves to be adjusted by an automatic controller. The digital computer simulation of the IRT refrigeration plant and the automatic controller that was used in the simulation are discussed.

  10. Determination of Ice Water Path in Ice-over-Water Cloud Systems Using Combined MODIS and AMSR-E Measurements

    NASA Technical Reports Server (NTRS)

    Huang, Jianping; Minnis, Patrick; Lin, Bing; Yi, Yuhong; Fan, T.-F.; Sun-Mack, Sunny; Ayers, J. K.

    2006-01-01

    To provide more accurate ice cloud properties for evaluating climate models, the updated version of multi-layered cloud retrieval system (MCRS) is used to retrieve ice water path (IWP) in ice-over-water cloud systems over global ocean using combined instrument data from the Aqua satellite. The liquid water path (LWP) of lower layer water clouds is estimated from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) measurements. With the lower layer LWP known, the properties of the upper-level ice clouds are then derived from Moderate Resolution Imaging Spectroradiometer measurements by matching simulated radiances from a two-cloud layer radiative transfer model. Comparisons with single-layer cirrus systems and surface-based radar retrievals show that the MCRS can significantly improve the accuracy and reduce the over-estimation of optical depth and ice water path retrievals for ice over-water cloud systems. During the period from December 2004 through February 2005, the mean daytime ice cloud optical depth and IWP for overlapped ice-over-water clouds over ocean from Aqua are 7.6 and 146.4 gm(sup -2), respectively, significantly less than the initial single layer retrievals of 17.3 and 322.3 gm(sup -2). The mean IWP for actual single-layer clouds was 128.2 gm(sup -2).

  11. The Ice Core Data Gateway: The one stop gateway to ice core data held at the Antarctic Glaciological Data Center (AGDC), the World Data Center for Paleoclimatology, and the Arctic System Science's Data Coordination Center (ADCC).

    NASA Astrophysics Data System (ADS)

    Bauer, R.; Scambos, T.; Eakin, M.; Anderson, D.; McNeave, C.

    2002-12-01

    The Ice Core Data Gateway archives and distributes physical and geochemical data from ice cores collected in both the northern and southern hemispheres. Typical data sets include age-depth relationships, oxygen and hydrogen isotope concentrations, major element chemistry, accumulation rates and pollen. The data are in general presented as ASCII files with a short text metadata description. The archive is designed to provide access to ice core data sets over the long term, thereby making them available for comparison with future data: a critical component of change detection studies. By facilitating broad data access, the center promotes interdisciplinary scientific research. Investigators are encouraged to contribute data sets derived from ice cores to the Ice Core Data Gateway. Data center staff will work with you to compile data set documentation prior to making the data available to users. Contributing scientists are given prominent recognition in the documentation, and while the data center answers technical questions about format, citations for usage, etc., it can refer scientific questions to contributors if requested. Contributing your data to the Ice Core Data Gateway and associated data centers directly supports to NSF Office of Polar Programs Guidelines and Award Conditions for Scientific Data (http://www.nsf.gov/pubsys/ods/getpub.cfm?opp991). This effort is being coordinated with the West Antarctic Ice Sheet (WAIS) Initiative and U.S. component of the International Trans Antarctic Science Expedition (ITASE), and includes data from the Arctic System Science Program's Greenland Ice Sheet Project 2 (GISP2) ice core.

  12. Evaluating an Ice-Storage System in a Deregulated Environment.

    ERIC Educational Resources Information Center

    Staniewicz, Theodore J.; Watson, Joseph J.

    2001-01-01

    Examines the difficulties the electric industry's deregulation created for St. Joseph's University's (Philadelphia) development of a thermal ice-storage system as part of its HVAC design and the school's solution. A monthly equipment summary sheet with year-to-date figures is provided. (GR)

  13. Ethane Ices in the Outer Solar System: Spectroscopy and Chemistry

    NASA Technical Reports Server (NTRS)

    Hudson, R. L.; Moore, M. H.; Raines, L. L.

    2009-01-01

    We report recent experiments on ethane ices made at temperatures applicable to the outer Solar System. New near- and mid-infrared data for crystalline and amorphous ethane, including new spectra for a seldom-studied solid phase that exists at 35-55 K, are presented along with radiation-chemical experiments showing the formation of more-complex hydrocarbons,

  14. Ethane Ices in the Outer Solar System: Spectroscopy and Chemistry

    NASA Technical Reports Server (NTRS)

    Hudson, R. L.; Moore, M. H.; Raines, L. L.

    2009-01-01

    We report recent experiments on ethane ices made at temperatures applicable to the outer Solar System. New near- and mid-infrared data for crystalline and amorphous ethane, including new spectra for a seldom-studied solid phase that exists at 35-55 K, are presented along with radiation-chemical experiments showing the formation of more-complex hydrocarbons

  15. Decadal variability in coupled sea-ice-thermohaline circulation systems

    SciTech Connect

    Yang, J.; Neelin, J.D.

    1997-12-01

    An interdecadal oscillation in a coupled ocean-ice system was identified in a previous study. This paper extends that study to further examine the stability of the oscillation and the sensitivity of its frequency to various parameters and forcing fields. Three models are used: (i) an analytical box model; (ii) a two-dimensional model for the ocean thermohaline circulation (THC) coupled to a thermodynamic ice model, as in the authors` previous study; and (iii) a three-dimensional ocean general circulation model (OGCM) coupled to a similar ice model. The box model is used to elucidate the essential feedbacks that give rise to this oscillation and to identify the most important parameters and processes that determine the period. The counted model becomes more stable toward low coupling, greater diffusion, and weaker THC feedback. Nonlinear effects in the sea-ice model become important in the higher ocean-ice coupling regime where the effective sea-ice damping associated with this nonlinearity stabilizes the model. The 3D OGCM is used to test this coupled ocean-ice mechanism in a more realistic model setting. This model generates an interdecadal oscillation whose characteristics and phase relations among the model variables are similar to the oscillation obtained in the 2D models. The major difference is that the oscillation frequency is considerably lower. The difference can be explained in terms of the analytical box model solution in which the period of oscillation depends on the rate of anomalous density production by melting/cooling of sea ice per SST anomaly, times the rate of warming/cooling by anomalous THC heat advection per change in density anomaly. The 3D model has a smaller THC response to high-latitude density perturbations than the 2D model, and anomalous velocities in the 3D case tend to follow the mean isotherms so anomalous heat advection is reduced. This slows the ocean-ice feedback process, leading to the longer oscillation period. 36 refs., 27 figs.

  16. A system of system lenses for leadership decision-making.

    PubMed

    Cady, Phil

    2016-01-01

    The sheer volume and dynamics among system agents in healthcare makes decision-making a daunting task at all levels. Being clear about what leaders mean by "healthcare system" is critical in aligning system strategy and leadership decision-making. This article presents an emerging set of lenses (ideology and beliefs, rational and irrational information processing, interpersonal social dynamics, process and value creation, and context) to help frame leadership decision-making in healthcare systems. PMID:26656390

  17. Surface roughness due to residual ice in the use of low power deicing systems

    NASA Technical Reports Server (NTRS)

    Shin, Jaiwon; Bond, Thomas H.

    1993-01-01

    Thicknesses of residual ice are presented to provide information on surface contamination and associated roughness during deicing events. Data was obtained from low power ice protection systems tests conducted in the Icing Research Tunnel at NASA Lewis Research Center (LeRC) with nine different deicing systems. Results show that roughness associated with residual ice is not characterized by uniformly distributed roughness. Results also show that deicing systems require a critical mass of ice to generate a sufficient expelling force to remove the ice.

  18. Flow of ices in the Ammonia-Water System

    NASA Technical Reports Server (NTRS)

    Durham, W. B.; Kirby, S. H.; Stern, L. A.

    1993-01-01

    We have fabricated in the laboratory and subsequently deformed crystalline hydrates and partial melts of the water-rich end of the NH3-H2O system, with the aim of improving our understanding of physical processes occurring in icy moons of the outer solar system. Deformation experiments were carried out at constant strain rate. The range of experimental variables are given. Phase relationships in the NH3-H2O system indicate that water ice and ammonia dihydrate, NH3-2H2O, are the stable phases under our experiment conditions. X-ray diffraction of our samples usually revealed these as the dominant phases, but we have also observed an amorphous phase (in unpressurized samples only) and occasionally significant ammonia monohydrate, NH3-H2O. The onset of partial melting at the peritectic temperature at about 176 K appeared as a sharp transition in strength observed in samples of x(sub NH3) = 0.05 and 0.01, the effect of melt was less pronounced. For any given water ice + dihydrate alloy in the subsolidus region, we observed one rheological law over the entire temperature range from 175 K to about 140 K. Below 140 K, a shear instability similar to that occurring in pure water ice under the same conditions limited our ability to measure ductile flow. The rheological laws for the several alloys vary systematically from that of pure ice to that of dihydrate. Pure dihydrate is about 4 orders of magnitude less viscous than water ice just below the peritectic temperature, but because of a very pronounced temperature dependence in dihydrate (100 kJ/mol versus 43 kJ/mol for water ice) the viscosity of dihydrate equals or exceeds that of water ice at T less than 140 K. The large variation in viscosity of dihydrate with relatively small changes in temperature may be helpful in explaining the rich variety of tectonic and volcanic features seen on the surfaces of icy moons in the outer solar system.

  19. The Effect of Excess Snow on Sea Ice in a Global Ice-Ocean Prediction System

    NASA Astrophysics Data System (ADS)

    Winter, B.; Bélair, S.; Lemieux, J. F.

    2014-12-01

    Snow cover on sea ice acts as a thermal insulator, greatly reducing the upward heat flux from the ocean through the ice, specifically through thin ice. The treatment of snow in the CICE sea ice model does not include the effects of blowing snow, thereby leading to an unrealistically thick snow layer on the ice. We investigate the consequences of this excess snow for the upward heat fluxes throughout the year, and how this impacts forecast accuracy in a global ice-ocean prediction model (GIOPS). First results will be presented, and computationally efficient solutions will be discussed.

  20. Making Technology Ready: Integrated Systems Health Management

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Oliver, Patrick J.

    2007-01-01

    This paper identifies work needed by developers to make integrated system health management (ISHM) technology ready and by programs to make mission infrastructure ready for this technology. This paper examines perceptions of ISHM technologies and experience in legacy programs. Study methods included literature review and interviews with representatives of stakeholder groups. Recommendations address 1) development of ISHM technology, 2) development of ISHM engineering processes and methods, and 3) program organization and infrastructure for ISHM technology evolution, infusion and migration.

  1. Assimilating high horizontal resolution sea ice concentration data into the US Navy's ice forecast systems: Arctic Cap Nowcast/Forecast System (ACNFS) and the Global Ocean Forecast System (GOFS 3.1)

    NASA Astrophysics Data System (ADS)

    Posey, P. G.; Metzger, E. J.; Wallcraft, A. J.; Hebert, D. A.; Allard, R. A.; Smedstad, O. M.; Phelps, M. W.; Fetterer, F.; Stewart, J. S.; Meier, W. N.; Helfrich, S. R.

    2015-04-01

    This study presents the improvement in the US Navy's operational sea ice forecast systems gained by assimilating high horizontal resolution satellite-derived ice concentration products. Since the late 1980's, the ice forecast systems have assimilated near real-time sea ice concentration derived from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSMI and then SSMIS). The resolution of the satellite-derived product was approximately the same as the previous operational ice forecast system (25 km). As the sea ice forecast model resolution increased over time, the need for higher horizontal resolution observational data grew. In 2013, a new Navy sea ice forecast system (Arctic Cap Nowcast/Forecast System - ACNFS) went into operations with a horizontal resolution of ~3.5 km at the North Pole. A method of blending ice concentration observations from the Advanced Microwave Scanning Radiometer (AMSR2) along with a sea ice mask produced by the National Ice Center (NIC) has been developed resulting in an ice concentration product with very high spatial resolution. In this study, ACNFS was initialized with this newly developed high resolution blended ice concentration product. The daily ice edge locations from model hindcast simulations were compared against independent observed ice edge locations. ACNFS initialized using the high resolution blended ice concentration data product decreased predicted ice edge location error compared to the operational system that only assimilated SSMIS data. A second evaluation assimilating the new blended sea ice concentration product into the pre-operational Navy Global Ocean Forecast System 3.1 also showed a substantial improvement in ice edge location over a system using the SSMIS sea ice concentration product alone. This paper describes the technique used to create the blended sea ice concentration product and the significant improvements to both of the Navy's sea ice forecasting systems.

  2. Engine Icing Capability Enhancements for the Propulsion Systems Laboratory

    NASA Technical Reports Server (NTRS)

    Griffin, Tom

    2010-01-01

    The AC9C is holding their biannual committee meeting in Ottawa, Ontario on 18-20 October 2010. I have been asked to provide a short presentation of the status of the icing project upgrade to the PSL test facility. I will highlight the progress made during construction the past 6 months, our approach for checkout of the facility, and an overview of the system design and its capabilities. A copy of the presentation is attached.

  3. Icing Research Tunnel (IRT) Force Measurement System (FMS)

    NASA Technical Reports Server (NTRS)

    Roberts, Paul W.

    2012-01-01

    An Electronics Engineer at the Glenn Research Center (GRC), requested the NASA Engineering and Safety Center (NESC) provide technical support for an evaluation of the existing force measurement system (FMS) at the GRC's Icing Research Tunnel (IRT) with the intent of developing conceptual designs to improve the tunnel's force measurement capability in order to better meet test customer needs. This report contains the outcome of the NESC technical review.

  4. New constraints on Greenland ice sheet dynamics during the last glacial cycle: Evidence from the Uummannaq ice stream system

    NASA Astrophysics Data System (ADS)

    Roberts, David H.; Rea, Brice R.; Lane, Tim P.; Schnabel, Christoph; RodéS, Angel

    2013-06-01

    This paper presents the first assessment of the Uummannaq ice stream system (UISS) in West Greenland. The UISS drained ~6% of the Greenland ice sheet (GrIS) at the Last Glacial Maximum (LGM). The onset of the UISS is a function of a convergent network of fjords which feed a geologically controlled trough system running offshore to the shelf break. Mapping, cosmogenic radiogenic nuclide (CRN) dating, and model output reveal that glacially scoured surfaces up to 1266 m above sea level (asl) in fjord-head areas were produced by warm-based ice moving offshore during the LGM, with the elevation of warm-based ice dropping westwards to ~700 m asl as the ice stream trunk zone developed. Marginal plateaux with allochthonous blockfields suggest that warm-based ice produced till and erratics up to ~1200 m asl, but CRN ages and weathering pits suggest this was pre-LGM, with only cold-based ice operating during the LGM. Deglaciation began on the outer shelf at ~14.8 cal. kyrs B.P., with Ubekendt Ejland becoming ice free at ~12.4 ka. The UISS then collapsed with over 100 km of retreat by ~11.4 ka-10.8 cal. kyrs B.P., a rapid and complex response to bathymetric deepening, trough widening, and sea-level rise coinciding with rapidly increasing air temperatures and solar radiation, but which occurred prior to ocean warming at ~8.4 cal. kyrs B.P. Local fjord constriction temporarily stabilized the unzipped UISS margins at the start of the Holocene before ice retreat inland of the current margin at ~8.7 ka.

  5. Enceladus: An Active Ice World in the Saturn System

    NASA Astrophysics Data System (ADS)

    Spencer, John R.; Nimmo, Francis

    2013-05-01

    Enceladus, one of the mid-sized icy moons of Saturn, has an importance to planetary science far greater than its modest 504-km diameter would suggest. Intensive exploration of Enceladus by the Cassini Saturn orbiter has revealed that it is the only known icy world in the solar system with ongoing deep-seated geological activity. Active tectonic fractures at Enceladus's south pole, dubbed “tiger stripes,” warmed by internal tidally generated heat, spew supersonic jets of water vapor, other gases, and ice particles into circum-Saturnian space. A subsurface saltwater sea probably exists under the south pole, between the ice shell and the silicate core. Because of evidence that liquid water is probably present at the jet sources, Enceladus is also of great astrobiological interest as a potential habitat for life.

  6. IceBreaker: Mars Drill and Sample Delivery System

    NASA Astrophysics Data System (ADS)

    Mellerowicz, B. L.; Paulsen, G. L.; Zacny, K.; McKay, C.; Glass, B. J.; Dave, A.; Davila, A. F.; Marinova, M.

    2012-12-01

    We report on the development and testing of a one meter class prototype Mars drill and cuttings sample delivery system. The IceBreaker drill consists of a rotary-percussive drill head, a sampling auger with a bit at the end having an integrated temperature sensor, a Z-stage for advancing the auger into the ground, and a sam-pling station for moving the augered ice shavings or soil cuttings into a sample cup. The drill is deployed from a 3 Degree of Freedom (DOF) robotic arm. The drill demonstrated drilling in ice-cemented ground, ice, and rocks at the 1-1-100-100 level; that is the drill reached 1 meter in 1 hour with 100 Watts of power and 100 Newton Weight on Bit. This cor-responds to an average energy of 100 Whr. The drill has been extensively tested in the Mars chamber to a depth of 1 meter, as well as in the Antarctic and the Arctic Mars analog sites. We also tested three sample delivery systems: 1) 4 DOF arm with a custom soil scoop at the end; 2) Pneumatic based, and 3) Drill based enabled by the 3 (DOF) drill deployment boom. In all approaches there is an air-gap between the sterilized drill (which penetrates subsurface) and the sample transfer hardware (which is not going to be sterilized). The air gap satisfies the planetary protection requirements. The scoop acquires cuttings sample once they are augered to the surface, and drops them into an in-strument inlet port. The system has been tested in the Mars chamber and in the Arctic. The pneumatic sample delivery system uses compressed gas to move the sample captured inside a small chamber inte-grated with the auger, directly into the instrument. The system was tested in the Mars chamber. In the third approach the drill auger captures the sample on its flutes, the 3 DOF boom positions the tip of the auger above the instrument, and then the auger discharges the sample into an instrument. This approach was tested in the labolatory (at STP). The above drilling and sample delivery tests have shown that drilling and sample transfer on Mars, in ice cemented ground with limited power, energy and Weight on Bit, and collecting samples in dis-crete depth intervals is possible within the given mass, power, and energy levels of a Phoenix-size lander and within the duration of a Phoenix-like mission.

  7. ICE Raids, Children, Media, and Making Sense of Latino Newcomers in Flyover Country

    ERIC Educational Resources Information Center

    Hamann, Edmund T.; Reeves, Jenelle

    2012-01-01

    Extant cultural models articulated in "Flyover Country" print media responses to ICE workplace raids showed a welcome of sorts of Latino newcomers. These models suggest a place for Latino students at school and more broadly for Latino children and parents in these communities. Thus, they index an unwillingness to see Latino newcomers in…

  8. ICE Raids, Children, Media, and Making Sense of Latino Newcomers in Flyover Country

    ERIC Educational Resources Information Center

    Hamann, Edmund T.; Reeves, Jenelle

    2012-01-01

    Extant cultural models articulated in "Flyover Country" print media responses to ICE workplace raids showed a welcome of sorts of Latino newcomers. These models suggest a place for Latino students at school and more broadly for Latino children and parents in these communities. Thus, they index an unwillingness to see Latino newcomers in

  9. Naturalistic Decision Making For Power System Operators

    SciTech Connect

    Greitzer, Frank L.; Podmore, Robin; Robinson, Marck; Ey, Pamela

    2009-06-23

    Abstract: Motivation -- As indicated by the Blackout of 2003, the North American interconnected electric system is vulnerable to cascading outages and widespread blackouts. Investigations of large scale outages often attribute the causes to the three T’s: Trees, Training and Tools. A systematic approach has been developed to document and understand the mental processes that an expert power system operator uses when making critical decisions. The approach has been developed and refined as part of a capability demonstration of a high-fidelity real-time power system simulator under normal and emergency conditions. To examine naturalistic decision making (NDM) processes, transcripts of operator-to-operator conversations are analyzed to reveal and assess NDM-based performance criteria. Findings/Design -- The results of the study indicate that we can map the Situation Awareness Level of the operators at each point in the scenario. We can also identify clearly what mental models and mental simulations are being performed at different points in the scenario. As a result of this research we expect that we can identify improved training methods and improved analytical and visualization tools for power system operators. Originality/Value -- The research applies for the first time, the concepts of Recognition Primed Decision Making, Situation Awareness Levels and Cognitive Task Analysis to training of electric power system operators. Take away message -- The NDM approach provides an ideal framework for systematic training management and mitigation to accelerate learning in team-based training scenarios with high-fidelity power grid simulators.

  10. Residential-scale ice-storage system for space cooling

    NASA Astrophysics Data System (ADS)

    Hopkinson, H. H.

    Energy load management is a necessity to electrical utilities. Thermal cool storage offers the utility a means of load management. The ice bank approach to thermal energy cool storage offers the most potential for development. Seasonal performance of both full and partial storage systems are studied using a Carrier simulation program. These results form the basis for selection of a system to be developed. A conceptual design was established, and a marketing and economic study were completed. Seasonal performance of the proposed equipment for several locations are determined by computer simulation.

  11. Event triggering in the IceCube data acquisition system

    SciTech Connect

    Kelley, J. L.; Collaboration: IceCube Collaboration

    2014-11-18

    In order to detect cosmic ray air showers and neutrinos, the software data acquisition (DAQ) system of the IceCube Neutrino Observatory forms triggers on patterns of Cherenkov light deposition in the detector based on temporal and/or spatial coincidences. Here we describe the algorithms used for triggering, as well as the fast merging algorithm used to combine the time-ordered hit streams from the optical modules. We also present recently implemented and planned modifications of the DAQ that take advantage of our newly upgraded multi-core computer systems at the South Pole.

  12. NASA Icing Remote Sensing System Comparisons From AIRS II

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Brinker, David J.; Ratvasky, Thomas P.

    2005-01-01

    NASA has an on-going activity to develop remote sensing technologies for the detection and measurement of icing conditions aloft. A multiple instrument approach is the current emphasis of this activity. Utilizing radar, radiometry, and lidar, a region of supercooled liquid is identified. If the liquid water content (LWC) is sufficiently high, then the region of supercooled liquid cloud is flagged as being an aviation hazard. The instruments utilized for the current effort are an X-band vertical staring radar, a radiometer that measures twelve frequencies between 22 and 59 GHz, and a lidar ceilometer. The radar data determine cloud boundaries, the radiometer determines the sub-freezing temperature heights and total liquid water content, and the ceilometer refines the lower cloud boundary. Data is post-processed with a LabVIEW program with a resultant supercooled LWC profile and aircraft hazard identification. Individual remotely sensed measurements gathered during the 2003-2004 Alliance Icing Research Study (AIRS II) were compared to aircraft in-situ measurements. Comparisons between the remote sensing system s fused icing product and in-situ measurements from the research aircraft are reviewed here. While there are areas where improvement can be made, the cases examined indicate that the fused sensor remote sensing technique appears to be a valid approach.

  13. JBluIce-EPICS control system for macromolecular crystallography.

    SciTech Connect

    Stepanov, S.; Makarov, O.; Hilgart, M.; Pothineni, S.; Urakhchin, A.; Devarapalli, S.; Yoder, D.; Becker, M.; Ogata, C.; Sanishvili, R.; Nagarajan, V.; Smith, J. L.; Fischetti, R. F.

    2011-01-01

    The trio of macromolecular crystallography beamlines constructed by the General Medicine and Cancer Institutes Collaborative Access Team (GM/CA-CAT) in Sector 23 of the Advanced Photon Source (APS) have been in growing demand owing to their outstanding beam quality and capacity to measure data from crystals of only a few micrometres in size. To take full advantage of the state-of-the-art mechanical and optical design of these beamlines, a significant effort has been devoted to designing fast, convenient, intuitive and robust beamline controls that could easily accommodate new beamline developments. The GM/CA-CAT beamline controls are based on the power of EPICS for distributed hardware control, the rich Java graphical user interface of Eclipse RCP and the task-oriented philosophy as well as the look and feel of the successful SSRL BluIce graphical user interface for crystallography. These beamline controls feature a minimum number of software layers, the wide use of plug-ins that can be written in any language and unified motion controls that allow on-the-fly scanning and optimization of any beamline component. This paper describes the ways in which BluIce was combined with EPICS and converted into the Java-based JBluIce, discusses the solutions aimed at streamlining and speeding up operations and gives an overview of the tools that are provided by this new open-source control system for facilitating crystallographic experiments, especially in the field of microcrystallography.

  14. Making real-time reactive systems reliable

    NASA Technical Reports Server (NTRS)

    Marzullo, Keith; Wood, Mark

    1990-01-01

    A reactive system is characterized by a control program that interacts with an environment (or controlled program). The control program monitors the environment and reacts to significant events by sending commands to the environment. This structure is quite general. Not only are most embedded real time systems reactive systems, but so are monitoring and debugging systems and distributed application management systems. Since reactive systems are usually long running and may control physical equipment, fault tolerance is vital. The research tries to understand the principal issues of fault tolerance in real time reactive systems and to build tools that allow a programmer to design reliable, real time reactive systems. In order to make real time reactive systems reliable, several issues must be addressed: (1) How can a control program be built to tolerate failures of sensors and actuators. To achieve this, a methodology was developed for transforming a control program that references physical value into one that tolerates sensors that can fail and can return inaccurate values; (2) How can the real time reactive system be built to tolerate failures of the control program. Towards this goal, whether the techniques presented can be extended to real time reactive systems is investigated; and (3) How can the environment be specified in a way that is useful for writing a control program. Towards this goal, whether a system with real time constraints can be expressed as an equivalent system without such constraints is also investigated.

  15. Transport, hysteresis and avalanches in artificial spin ice systems

    SciTech Connect

    Reichhardt, Charles; Reichhardt, Cynthia J; Libal, A

    2010-01-01

    We examine the hopping dynamics of an artificial spin ice system constructed from colloids on a kagome optical trap array where each trap has two possible states. By applying an external drive from an electric field which is analogous to a biasing applied magnetic field for real spin systems, we can create polarized states that obey the spin-ice rules of two spins in and one spin out at each vertex. We demonstrate that when we sweep the external drive and measure the fraction of the system that has been polarized, we can generate a hysteresis loop analogous to the hysteretic magnetization versus external magnetic field curves for real spin systems. The disorder in our system can be readily controlled by changing the barrier that must be overcome before a colloid can hop from one side of a trap to the other. For systems with no disorder, the effective spins all flip simultaneously as the biasing field is changed, while for strong disorder the hysteresis curves show a series of discontinuous jumps or avalanches similar to Barkhausen noise.

  16. Information Processing in Decision-Making Systems

    PubMed Central

    van der Meer, Matthijs; Kurth-Nelson, Zeb; Redish, A. David

    2015-01-01

    Decisions result from an interaction between multiple functional systems acting in parallel to process information in very different ways, each with strengths and weaknesses. In this review, the authors address three action-selection components of decision-making: The Pavlovian system releases an action from a limited repertoire of potential actions, such as approaching learned stimuli. Like the Pavlovian system, the habit system is computationally fast but, unlike the Pavlovian system permits arbitrary stimulus-action pairings. These associations are a “forward” mechanism; when a situation is recognized, the action is released. In contrast, the deliberative system is flexible but takes time to process. The deliberative system uses knowledge of the causal structure of the world to search into the future, planning actions to maximize expected rewards. Deliberation depends on the ability to imagine future possibilities, including novel situations, and it allows decisions to be taken without having previously experienced the options. Various anatomical structures have been identified that carry out the information processing of each of these systems: hippocampus constitutes a map of the world that can be used for searching/imagining the future; dorsal striatal neurons represent situation-action associations; and ventral striatum maintains value representations for all three systems. Each system presents vulnerabilities to pathologies that can manifest as psychiatric disorders. Understanding these systems and their relation to neuroanatomy opens up a deeper way to treat the structural problems underlying various disorders. PMID:22492194

  17. Ground-Based Icing Condition Remote Sensing System Definition

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Koenig, George G.

    2001-01-01

    This report documents the NASA Glenn Research Center activities to assess and down select remote sensing technologies for the purpose of developing a system capable of measuring icing condition hazards aloft. The information generated by such a remote sensing system is intended for use by the entire aviation community, including flight crews. air traffic controllers. airline dispatchers, and aviation weather forecasters. The remote sensing system must be capable of remotely measuring temperature and liquid water content (LWC), and indicating the presence of super-cooled large droplets (SLD). Technologies examined include Profiling Microwave Radiometer, Dual-Band Radar, Multi-Band Radar, Ka-Band Radar. Polarized Ka-Band Radar, and Multiple Field of View (MFOV) Lidar. The assessment of these systems took place primarily during the Mt. Washington Icing Sensors Project (MWISP) in April 1999 and the Alliance Icing Research Study (AIRS) from November 1999 to February 2000. A discussion of the various sensing technologies is included. The result of the assessment is that no one sensing technology can satisfy all of the stated project goals. Therefore a proposed system includes radiometry and Ka-band radar. A multilevel approach is proposed to allow the future selection of the fielded system based upon required capability and available funding. The most basic level system would be the least capable and least expensive. The next level would increase capability and cost, and the highest level would be the most capable and most expensive to field. The Level 1 system would consist of a Profiling Microwave Radiometer. The Level 2 system would add a Ka-Band Radar. The Level 3 system would add polarization to the Ka-Band Radar. All levels of the system would utilize hardware that is already under development by the U.S. Government. However, to meet the needs of the aviation community, all levels of the system will require further development. In addition to the proposed system, it is also recommended that NASA continue to foster the development of Multi-Band Radar and airborne microwave radiometer technologies.

  18. Naturalistic Decision Making for Power System Operators

    SciTech Connect

    Greitzer, Frank L.; Podmore, Robin; Robinson, Marck; Ey, Pamela

    2010-02-01

    Motivation – Investigations of large-scale outages in the North American interconnected electric system often attribute the causes to three T’s: Trees, Training and Tools. To document and understand the mental processes used by expert operators when making critical decisions, a naturalistic decision making (NDM) model was developed. Transcripts of conversations were analyzed to reveal and assess NDM-based performance criteria. Findings/Design – An item analysis indicated that the operators’ Situation Awareness Levels, mental models, and mental simulations can be mapped at different points in the training scenario. This may identify improved training methods or analytical/ visualization tools. Originality/Value – This study applies for the first time, the concepts of Recognition Primed Decision Making, Situation Awareness Levels and Cognitive Task Analysis to training of electric power system operators. Take away message – The NDM approach provides a viable framework for systematic training management to accelerate learning in simulator-based training scenarios for power system operators and teams.

  19. VAV systems -- What makes them succeed? What makes them fail?

    SciTech Connect

    Cappellin, T.E.

    1997-12-31

    When variable-air-volume (VAV) systems work right, they provide excellent temperature and humidity control and in addition deliver outside air to conditioned spaces in amounts sufficient to satisfy ASHRAE Standard 62 and meet all criteria required for acceptable indoor air quality. The final benefit is lower utility cost when compared to a comparable constant-air-volume system. However, the successful performance of VAV systems is often compromised by flawed conception, faulty design, defective installation, poor start-up, inaccurate operation, and inadequate maintenance. Field observations of underperforming VAV systems have uncovered problems due to mistakes that have been made through all the phases of system development. It is recommended that most VAV systems be designed, installed, started, and operated under a comprehensive commissioning process. Experience has shown that careful monitoring of all phases of development and operation will ensure that there are minimal problems to plague the building owner and operating personnel once the system is in use. This paper is written from the viewpoint of a former contractor who is now a professional engineer and who has designed, installed, started, and maintained VAV systems.

  20. The Role of Snow and Ice in the Climate System

    ScienceCinema

    Barry, Roger G.

    2009-09-01

    Global snow and ice cover (the 'cryosphere') plays a major role in global climate and hydrology through a range of complex interactions and feedbacks, the best known of which is the ice - albedo feedback. Snow and ice cover undergo marked seasonal and long term changes in extent and thickness. The perennial elements - the major ice sheets and permafrost - play a role in present-day regional and local climate and hydrology, but the large seasonal variations in snow cover and sea ice are of importance on continental to hemispheric scales. The characteristics of these variations, especially in the Northern Hemisphere, and evidence for recent trends in snow and ice extent are discussed.

  1. The Role of Snow and Ice in the Climate System

    SciTech Connect

    Barry, Roger G.

    2007-12-19

    Global snow and ice cover (the 'cryosphere') plays a major role in global climate and hydrology through a range of complex interactions and feedbacks, the best known of which is the ice - albedo feedback. Snow and ice cover undergo marked seasonal and long term changes in extent and thickness. The perennial elements - the major ice sheets and permafrost - play a role in present-day regional and local climate and hydrology, but the large seasonal variations in snow cover and sea ice are of importance on continental to hemispheric scales. The characteristics of these variations, especially in the Northern Hemisphere, and evidence for recent trends in snow and ice extent are discussed.

  2. The effect of sea ice on the solar energy budget in the astmosphere-sea ice-ocean system: A model study

    NASA Technical Reports Server (NTRS)

    Jin, Z.; Stamnes, Knut; Weeks, W. F.; Tsay, Si-Chee

    1994-01-01

    A coupled one-dimensional multilayer and multistream radiative transfer model has been developed and applied to the study of radiative interactions in the atmosphere, sea ice, and ocean system. The consistent solution of the radiative transfer equation in this coupled system automatically takes into account the refraction and reflection at the air-ice interface and allows flexibility in choice of stream numbers. The solar radiation spectrum (0.25 micron-4.0 micron) is divided into 24 spectral bands to account adequately for gaseous absorption in the atmosphere. The effects of ice property changes, including salinity and density variations, as well as of melt ponds and snow cover variations over the ice on the solar energy distribution in the entire system have been studied quantitatively. The results show that for bare ice it is the scattering, determined by air bubbles and brine pockets, in just a few centimeters of the top layer of ice that plays the most important role in the solar energy absorption and partitioning in the entire system. Ice thickness is important to the energy distribution only when the ice is thin, while the absorption in the atmosphere is not sensitive to ice thickness exceeds about 70 cm. The presence of clouds moderates all the sensitivities of the absorptive amounts in each layer to the variations in the ice properties and ice thickness. Comparisons with observational spectral albedo values for two simple ice types are also presented.

  3. A method of predicting flow rates required to achieve anti-icing performance with a porous leading edge ice protection system

    NASA Technical Reports Server (NTRS)

    Kohlman, D. L.

    1983-01-01

    A proposed method of analytically predicting the minimum fluid flow rate required to provide anti-ice protection with a porous leading edge system on a wing under a given set of flight conditions is presented. Results of the proposed method are compared with the actual results of an icing test of a real wing section in the NASA Lewis Icing Research Tunnel.

  4. Ice Thermal Storage Systems for Nuclear Power Plant Supplemental Cooling and Peak Power Shifting

    SciTech Connect

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2013-03-01

    Availability of cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. One potential solution is to use ice thermal storage (ITS) systems that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses the ice for supplemental cooling during peak demand time. ITS also provides a way to shift a large amount of electricity from off peak time to peak time. For once-through cooling plants near a limited water body, adding ITS can bring significant economic benefits and avoid forced derating and shutdown during extremely hot weather. For the new plants using dry cooling towers, adding the ITS systems can effectively reduce the efficiency loss during hot weather so that new plants could be considered in regions lack of cooling water. This paper will review light water reactor cooling issues and present the feasibility study results.

  5. Lunar South Pole ice as heat sink for Lunar cryofuel production system

    SciTech Connect

    Zuppero, A.; Stanley, M.; Modro, S.M.; Whitman, P.

    1995-03-01

    Recent Clementine bistatic radar data suggest that water ice may be present in a {open_quotes}forever shaded{close_quotes} depression or crater at the South Pole of the Moon. The ice is a feedstock for the electrolysis production of cryogenic oxygen and hydrogen rocket fuels for a transportation system on the moon and for leaving and descending on to the moon. The ice also provides a convective heat sink critical to the practical implementation of high throughput electric power generators and refrigerators that liquefy and cool the oxygen and hydrogen into cryogenic rocket fuel. This brief analysis shows that about a hundred tonnes of hardware delivered to the lunar surface can produce tens of thousands of tonnes of rocket fuel per year, on the moon. And it makes the point that if convective cooling is used instead of radiative cooling, then power and processing systems can be used that exist and have been tested already. This shortens the time by an order of magnitude to develop lunar operations. Quick deployment of a chemical cryofuel energy source is a key factor in the economics of lunar development.

  6. Lunar south pole ice as heat sink for lunar cryofuel production system

    NASA Astrophysics Data System (ADS)

    Zuppero, Anthony; Stanley, Marland; Modro, S. Michael; Whitman, Pat

    1995-01-01

    Recent Clementine bistatic radar data suggest that water ice may be present in a ``forever shaded'' depression or crater at the South Pole of the Moon. The ice is a feedstock for the electrolysis production of cryogenic oxygen and hydrogen rocket fuel for a transportation system on the moon and for leaving and descending on the moon. The ice also provides a convective heat sink critical to the practical implementation of high throughput electric power generators and refrigerators that liquefy and cool the oxyen and hydrogen into cryogenic rocket fuel. This brief analysis shows that about a hundred tonnes of hardware delivered to the lunar surface can produce tens of thousands of tonnes of rocket fuel per year, on the moon. And it makes the point that if convective cooling is used instead of radiative cooling, then power and processing systems can be used that exist and have been tested already. This shortens the time by an order of magnitude to develop lunar operations. Quick deployment of a chemical cryofuel energy source is a key factor in the economics of lunar development.

  7. Sputtering of ices in the outer solar system

    SciTech Connect

    Johnson, R.E.

    1996-01-01

    Exploration of the outer solar system has led to studies in a new area of physics: electronically induced sputtering of low-temperature, condensed-gas solids (ices). Many of the icy bodies in the outer solar system were found to be bombarded by relatively intense fluxes of ions and electrons, causing both changes in their optical reflectance and ejection (sputtering) of molecules from their surfaces. The small cohesive energies of the condensed-gas solids afford relatively large sputtering rates from the electronic excitations produced in the solid by fast ions and electrons. Such sputtering produces an ambient gas about an icy body, often the source of the local plasma. This colloquium outlines the physics of the sputtering of ices and its relevance to several outer-solar-system phenomena: the sputter-produced plasma trapped in Saturn{close_quote}s magnetosphere; the O{sub 2} atmosphere on Europa; and optical absorption features such as SO{sub 2} in the surface of Europa and O{sub 2} and, possibly, O{sub 3} in the surface of Ganymede. {copyright} {ital 1996 The American Physical Society.}

  8. The ancient heritage of water ice in the solar system.

    PubMed

    Cleeves, L Ilsedore; Bergin, Edwin A; Alexander, Conel M O'D; Du, Fujun; Graninger, Dawn; Öberg, Karin I; Harries, Tim J

    2014-09-26

    Identifying the source of Earth's water is central to understanding the origins of life-fostering environments and to assessing the prevalence of such environments in space. Water throughout the solar system exhibits deuterium-to-hydrogen enrichments, a fossil relic of low-temperature, ion-derived chemistry within either (i) the parent molecular cloud or (ii) the solar nebula protoplanetary disk. Using a comprehensive treatment of disk ionization, we find that ion-driven deuterium pathways are inefficient, which curtails the disk's deuterated water formation and its viability as the sole source for the solar system's water. This finding implies that, if the solar system's formation was typical, abundant interstellar ices are available to all nascent planetary systems. PMID:25258075

  9. On-ice vibroseis and snowstreamer systems for geoscientific research

    NASA Astrophysics Data System (ADS)

    Eisen, Olaf; Hofstede, Coen; Diez, Anja; Kristoffersen, Yngve; Lambrecht, Astrid; Mayer, Christoph; Blenkner, Rick; Hilmarsson, Sverrir

    2015-03-01

    We present implementations of vibroseis system configurations with a snowstreamer for over-ice long-distance seismic traverses (>100 km). The configurations have been evaluated in Antarctica on ice sheet and ice shelf areas in the period 2010-2014. We discuss results of two different vibroseis sources: Failing Y-1100 on skis with a peak force of 120 kN in the frequency range 10-110 Hz; IVI EnviroVibe with a nominal peak force of 66 kN in the nominal frequency range 10-300 Hz. All measurements used a well-established 60 channel 1.5 km snowstreamer for the recording. Employed forces during sweeps were limited to less than 80% of the peak force. Maximum sweep frequencies, with a typical duration of 10 s, were 100 and 250 Hz for the Failing and EnviroVibe, respectively. Three different concepts for source movement were employed: the Failing vibrator was mounted with wheels on skis and pulled by a Pistenbully snow tractor. The EnviroVibe was operated self-propelled on Mattracks on the Antarctic plateau. This lead to difficulties in soft snow. For later implementations the EnviroVibe with tracks was put on a polyethylene (PE) sled. The sled had a hole in the center to lower the vibrator baseplate directly onto the snow surface. With the latter setup, data production varied between 20 km/day for 6-fold and 40 km/day for single fold for 9 h/day of measurements. The combination of tracks with the PE-sled was especially advantageous on hard and rough surfaces because of the flexibility of each component and the relatively lose mounting. The systems presented here are suitable to obtain data of subglacial and sub-seabed sediment layers and englacial layering in comparable quality as obtained from marine geophysics and land-based explosive surveys. The large offset aperture of the streamer overcomes limitations of radar systems for imaging of steep along-track subglacial topography. With joint international scientific and logistic efforts, large-scale mapping of Antarctica's and Greenland's subglacial geology, ice-shelf cavity geometries and sea-bed strata, as well as englacial structures can be achieved.

  10. An ice-motion tracking system at the Alaska SAR facility

    NASA Technical Reports Server (NTRS)

    Kwok, Ronald; Curlander, John C.; Pang, Shirley S.; Mcconnell, Ross

    1990-01-01

    An operational system for extracting ice-motion information from synthetic aperture radar (SAR) imagery is being developed as part of the Alaska SAR Facility. This geophysical processing system (GPS) will derive ice-motion information by automated analysis of image sequences acquired by radars on the European ERS-1, Japanese ERS-1, and Canadian RADARSAT remote sensing satellites. The algorithm consists of a novel combination of feature-based and area-based techniques for the tracking of ice floes that undergo translation and rotation between imaging passes. The system performs automatic selection of the image pairs for input to the matching routines using an ice-motion estimator. It is designed to have a daily throughput of ten image pairs. A description is given of the GPS system, including an overview of the ice-motion-tracking algorithm, the system architecture, and the ice-motion products that will be available for distribution to geophysical data users.

  11. Altitude Effects on Thermal Ice Protection System Performance; A Study of an Alternative Simulation Approach

    NASA Technical Reports Server (NTRS)

    Addy, Gene; Wright, Bill; Orchard, David; Oleskiw, Myron

    2015-01-01

    The quest for more energy-efficient green aircraft, dictates that all systems, including the ice protection system (IPS), be closely examined for ways to reduce energy consumption and to increase efficiency. A thermal ice protection systems must protect the aircraft from the hazardous effects of icing, and yet it needs to do so as efficiently as possible. The system can no longer be afforded the degree of over-design in power usage they once were. To achieve these more exacting designs, a better understanding of the heat and mass transport phenomena involved during an icing encounter is needed.

  12. Design, fabrication, and testing of an ultrasonic de-icing system for helicopter rotor blades

    NASA Astrophysics Data System (ADS)

    Palacios, Jose Luis

    A low-power, non-thermal ultrasonic de-icing system is introduced as a possible substitute for current electro-thermal systems. The system generates delaminating ultrasonic transverse shear stresses at the interface of accreted ice. A PZT-4 disk driven at 28.5 KHz (radial resonance of the disk) instantaneously de-bonds 2 mm thick freezer ice layers. The ice layers are accreted to a 0.7 mm thick, 30.4 cm x 30.4 cm steel plate at an environment temperature of -20°C. A power input of 50 Watts is applied to the actuator (50 V, 19.6 KV/m), which translates to a de-icing power of 0.07 W/cm2. A finite element model of the actuator bonded to the isotropic plate is used to guide the design of the system, and predicts the transverse shear stresses at the ice interface. Wind tunnel icing tests were conducted to demonstrate the potential use of the proposed system under impact icing conditions. Both glaze ice and rime ice were generated on steel and composite plates by changing the cloud conditions of the wind tunnel. Continuous ultrasonic vibration prevented impact ice formation around the actuator location at an input power not exceeding 0.18 W/cm 2 (1.2 W/in2). As ice thickness reached a critical thickness of approximately 1.2 mm, shedding occurred on those locations where ultrasonic transverse shear stresses exceeded the shear adhesion strength of the ice. Finite element transverse shear stress predictions correlate with observed experimental impact ice de-bonding behavior. To increase the traveling distance of propagating ultrasonic waves, ultrasonic shear horizontal wave modes are studied. Wave modes providing large modal interface transverse shear stress concentration coefficients (ISCC) between the host structure (0.7 mm thick steel plate) and accreted ice (2.5 mm thick ice layer) are identified and investigated for a potential increase in the wave propagation distance. Ultrasonic actuators able to trigger these optimum wave modes are designed and fabricated. Despite exciting wave modes with high ISCC values, instantaneous ice de-bonding is not observed at input powers under 100 Watts. The two triggered ultrasonic wave modes of the structure occur at high excitation frequencies, 202 KHz and 500 KHz respectively. At these frequencies, the ultrasonic actuators do not provide large enough transverse shear stresses to exceed the shear adhesion strength of the ice layer. Neither the actuator exciting the SH1 mode (202 KHz), nor the actuator triggering the SH2 mode (500 KHz) instantaneously de-bonds ice layers with an input power under 100 Watts.

  13. Convection Models for Ice-Water System: Dynamical Investigation of Phase Transition

    NASA Astrophysics Data System (ADS)

    Allu Peddinti, D.; McNamara, A. K.

    2012-12-01

    Ever since planetary missions of Voyager and Galileo revealed a dynamically altered surface of the icy moon Europa, a possible subsurface ocean under an icy shell has been speculated and surface features have been interpreted from an interior dynamics perspective. The physics of convection in a two phase water-ice system is governed by a wide set of physical parameters that include melting viscosity of ice, the variation of viscosity due to pressure and temperature, temperature contrast across and tidal heating within the system, and the evolving thickness of each layer. Due to the extreme viscosity contrast between liquid water and solid ice, it is not feasible to model the entire system to study convection. However, using a low-viscosity proxy (higher viscosity than the liquid water but much lower than solid ice) for the liquid phase provides a convenient approximation of the system, and allows for a relatively realistic representation of convection within the ice layer while also providing a self-consistent ice layer thickness that is a function of the thermal state of the system. In order to apply this method appropriately, we carefully examine the upper bound of viscosity required for the low-viscosity proxy to adequately represent the liquid phase. We identify upper bounds on the viscosity of the proxy liquid such that convective dynamics of the ice are not affected by further reductions of viscosity. Furthermore, we investigate how the temperature contrast across the system and viscosity contrast between liquid and ice control ice layer thickness. We also investigate ice shell thickening as a function of cooling, particularly how viscosity affects the conduction-to-convection transition within the ice shell. Finally, we present initial results that investigate the effects that latent heat of fusion (due to the ice-water phase transition) has on ice convection.

  14. Implications of Arctic Sea Ice Decline for the Earth System

    NASA Technical Reports Server (NTRS)

    Bhatt, Uma S.; Walker, Donald A.; Walsh, John E.; Carmack, Eddy C.; Frey, Karen E.; Meier, Walter N.; Moore, Sue E.; Parmentier, Frans-Jan W.; Post, Eric; Romanovsky, Vladimir E.; Simpson, William R.

    2014-01-01

    Arctic sea ice decline has led to an amplification of surface warming and is projected to continue to decline from anthropogenic forcing, although the exact timing of ice-free summers is uncertain owing to large natural variability. Sea ice reductions affect surface heating patterns and the atmospheric pressure distribution, which may alter midlatitude extreme weather patterns. Increased light penetration and nutrient availability during spring from earlier ice breakup enhances primary production in the Arctic Ocean and its adjacent shelf seas. Ice-obligate marine mammals may be losers, whereas seasonally migrant species may be winners from rapid sea ice decline. Tundra greening is occurring across most of the Arctic, driven primarily by warming temperatures, and is displaying complex spatial patterns that are likely tied to other factors. Sea ice changes are affecting greenhouse gas exchanges as well as halogen chemistry in the Arctic. This review highlights the heterogeneous nature of Arctic change, which is vital for researchers to better understand.

  15. Discovery of water ice nearly everywhere in the solar system

    SciTech Connect

    Zuppero, A.

    1995-10-01

    During the last decade we have discovered sources of accessible water in some form nearly everywhere in the solar system. Water ice has been found on the planet Mercury; probably on the Earth`s Moon; on Mars; on near Earth objects; on comets whose orbits frequently come close to that of Earth`s orbit; probably on Ceres, the largest inner asteroid; and on comets previously and incorrectly considered to be out of practical reach. The comets also provide massive quantities of hydrocarbons, similar to oil shale. The masses of either water or hydrocarbons are measured in units of cubic kilometers. The water is key to space transportation because it can be used as a rocket propellant directly, and because thermal process alone can be used to convert it and hydrocarbons into hydrogen, the highest performing rocket propellant. This presentation outlines what is currently known about the locations of the water ice, and sketches the requirements and environments of missions to prospect for and assay the water sources.

  16. A novel approach to making microstructure measurements in the ice-covered Arctic Ocean.

    NASA Astrophysics Data System (ADS)

    Guthrie, J.; Morison, J.; Fer, I.

    2014-12-01

    As part of the 2014 Field Season of the North Pole Environmental Observatory, a 7-day microstructure experiment was performed. A Rockland Scientific Microrider with 2 FP07 fast response thermistors and 2 SBE-7 micro-conductivity probes was attached to a Seabird 911+ Conductivity-Temperature-Depth unit to allow for calibration of the microstructure probes against the highly accurate Seabird temperature and conductivity sensors. From a heated hut, the instrument package was lowered through a 0.75-m hole in the sea ice down to 350 m depth using a lightweight winch powered with a 3-phase, frequency-controlled motor that produced a smooth, controlled lowering speed of 25 cm s-1. Focusing on temperature and conductivity microstructure and using the special winch removed many of the complications involved with the use of free-fall microstructure profilers under the ice. The slow profiling speed permits calculation of Χ, the dissipation of thermal variance, without relying on fits to theoretical spectra to account for the unresolved variance. The dissipation rate of turbulent kinetic energy, ɛ, can then be estimated using the temperature gradient spectrum and the Ruddick et al. [2001] maximum likelihood method. Outside of a few turbulent patches, thermal diffusivity ranged between O(10-7) and O(10-6) m2s-1, resulting in negligible turbulent heat fluxes. Estimated ɛ was often at or below the noise level of most shear-based microstructure profilers. The noise level of Χ is estimated at O(10-11) °C2s-1, revealing the utility and applicability of this technique in future Arctic field work.

  17. A PHOTOMETRIC SYSTEM FOR DETECTION OF WATER AND METHANE ICES ON KUIPER BELT OBJECTS

    SciTech Connect

    Trujillo, Chadwick A.; Sheppard, Scott S.; Schaller, Emily L. E-mail: sheppard@dtm.ciw.edu

    2011-04-01

    We present a new near-infrared photometric system for detection of water ice and methane ice in the solar system. The system consists of two medium-band filters in the K-band region of the near-infrared, which are sensitive to water ice and methane ice, plus continuum observations in the J band and Y band. The primary purpose of this system is to distinguish between three basic types of Kuiper Belt Objects (KBOs)-those rich in water ice, those rich in methane ice, and those with little absorbance. In this work, we present proof-of-concept observations of 51 KBOs using our filter system, 21 of which have never been observed in the near-infrared spectroscopically. We show that our custom photometric system is consistent with previous spectroscopic observations while reducing telescope observing time by a factor of {approx}3. We use our filters to identify Haumea collisional family members, which are thought to be collisional remnants of a much larger body and are characterized by large fractions of water ice on their surfaces. We add 2009 YE{sub 7} to the Haumea collisional family based on our water ice band observations (J - H{sub 2}O = -1.03 {+-} 0.27) which indicate a high amount of water ice absorption, our calculated proper orbital elements, and the neutral optical colors we measured, V - R = 0.38 {+-} 0.04, which are all consistent with the rest of the Haumea family. We identify several objects dynamically similar to Haumea as being distinct from the Haumea family as they do not have water ice on their surfaces. In addition, we find that only the largest KBOs have methane ice, and Haumea itself has significantly less water ice absorption than the smaller Haumea family members. We find no evidence for other families in the Kuiper Belt.

  18. Icing rate meter estimation of in-cloud cable icing

    SciTech Connect

    McComber, P.; Druez, J.; Laflamme, J.

    1994-12-31

    In many northern countries, the design and reliability of power transmission lines are closely related to atmospheric icing overloads. It is becoming increasingly important to have reliable instrument systems to warn of icing conditions before icing loads become sufficient to damage the power transmission network. Various instruments are presently being developed to provide better monitoring of icing conditions. One such instrument is the icing rate meter (IRM) which counts icing and de-icing cycles per unit time on a standard probe and can be used to estimate the icing rate on nearby cables. The calibration presently used was originally based on experiments conducted in a cold room. Even though this calibration has shown that the IRM estimation already offers an improvement over model prediction based on standard meteorological parameters, it can certainly be improved further with appropriate field data. For this purpose, the instrument was tested on an icing test site at Mt. Valin (altitude 902 m) Quebec, Canada. In this paper measurements from twelve in-cloud icing events during the 1991--92 winter are divided into one hour periods of icing to provide the experimental icing rate data. The icing rates measured on a 12.5 mm and a 35 mm cables are then compared with the number of IRM signals, also for one hour periods, in relation to initial ice load, temperature, wind velocity and direction. From this analysis, a better calibration for the IRM instrument is suggested. The improvement of the IRM estimation is illustrated by making a comparison with measurements, of the icing load estimation with the old and new calibrations for two complete icing events.

  19. Effects of ice microphysics on a tropical coupled system

    NASA Astrophysics Data System (ADS)

    Ping, Fan; Luo, Zhexian; Li, Xiaofan

    2010-04-01

    The effects of ice microphysics on tropical atmospheric and oceanic variability are investigated with a two-dimensional coupled ocean-cloud resolving atmosphere model forced by the large-scale vertical velocity and zonal wind derived from Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA COARE). The experiment without ice microphysics is compared to a control experiment with ice microphysics. Compared to the control experiment, the experiment without ice microphysics generates a more humid and colder atmosphere by suppressing stratiform clouds and rainfall and associated latent heating; the experiment without ice microphysics produces a saltier mixed layer by a larger saline forcing associated with a weaker stratiform rainfall. Ocean mixed-layer temperature is insensitive to the atmospheric variability associated with ice microphysics.

  20. New Spray Bar System Installed in NASA Lewis' Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Irvine, Thomas B.

    1998-01-01

    NASA Lewis Research Center's Icing Research Tunnel (IRT) is the world's largest refrigerated wind tunnel dedicated to the study of aircraft icing. In the IRT, natural icing conditions are duplicated to test the effects of in-flight icing on actual aircraft components and on scale models of airplanes and helicopters. The IRT's ability to reproduce a natural icing cloud was significantly improved with the recent installation of a new spray bar system. It is the spray bar system that transforms the low-speed wind tunnel into an icing wind tunnel by producing microscopic droplets of water and injecting them into the wind tunnel air stream in order to accurately simulate cloud moisture.

  1. Advancing plant phenology and reduced herbivore production in a terrestrial system associated with sea ice decline.

    PubMed

    Kerby, Jeffrey T; Post, Eric

    2013-01-01

    The contribution of declining Arctic sea ice to warming in the region through Arctic amplification suggests that sea ice decline has the potential to influence ecological dynamics in terrestrial Arctic systems. Empirical evidence for such effects is limited, however, particularly at the local population and community levels. Here we identify an Arctic sea ice signal in the annual timing of vegetation emergence at an inland tundra system in West Greenland. According to the time series analyses presented here, an ongoing advance in plant phenology at this site is attributable to the accelerating decline in Arctic sea ice, and contributes to declining large herbivore reproductive performance via trophic mismatch. Arctic-wide sea ice metrics consistently outperform other regional and local abiotic variables in models characterizing these dynamics, implicating large-scale Arctic sea ice decline as a potentially important, albeit indirect, contributor to local-scale ecological dynamics on land. PMID:24084589

  2. Analysis and testing of the Diamond One wing anti-icing system

    NASA Astrophysics Data System (ADS)

    Yeoman, K. E.

    1985-01-01

    The Diamond One wing leading edge is protected against ice accretions by a bleed air anti-icing system. Three cross-sections selected for computer modeling considered the thermal mechanisms of convection, conduction, evaporation and sensible heating of impinged and runback water. With an instrumented aircraft, the model was refined using dry air and above freezing cloud flight test data. The refined model was exercised for wing surface temperature predictions for six critical icing conditions and found safe for natural icing flight testing. Measured natural icing test data was then inserted into the model to compare predicted vs. measured temperatures. Correlation was achieved and the system was accepted by FAA as safe for flight into known icing conditions.

  3. A simple video-based timing system for on-ice team testing in ice hockey: a technical report.

    PubMed

    Larson, David P; Noonan, Benjamin C

    2014-09-01

    The purpose of this study was to describe and evaluate a newly developed on-ice timing system for team evaluation in the sport of ice hockey. We hypothesized that this new, simple, inexpensive, timing system would prove to be highly accurate and reliable. Six adult subjects (age 30.4 ± 6.2 years) performed on ice tests of acceleration and conditioning. The performance times of the subjects were recorded using a handheld stopwatch, photocell, and high-speed (240 frames per second) video. These results were then compared to allow for accuracy calculations of the stopwatch and video as compared with filtered photocell timing that was used as the "gold standard." Accuracy was evaluated using maximal differences, typical error/coefficient of variation (CV), and intraclass correlation coefficients (ICCs) between the timing methods. The reliability of the video method was evaluated using the same variables in a test-retest analysis both within and between evaluators. The video timing method proved to be both highly accurate (ICC: 0.96-0.99 and CV: 0.1-0.6% as compared with the photocell method) and reliable (ICC and CV within and between evaluators: 0.99 and 0.08%, respectively). This video-based timing method provides a very rapid means of collecting a high volume of very accurate and reliable on-ice measures of skating speed and conditioning, and can easily be adapted to other testing surfaces and parameters. PMID:24936905

  4. Towards an automated lake ice monitoring system from SAR imagery

    NASA Astrophysics Data System (ADS)

    Ochilov, S.; Svacina, N. A.; Duguay, C. R.; Clausi, D. A.

    2010-12-01

    In recent years, there has been an increasing interest in monitoring ice cover on northern lakes for various purposes including winter-road transportation, weather prediction, climate modeling or simply for better understanding lake dynamics/thermodynamics. In Canada alone more than one hundred lakes are currently being monitored on a weekly basis by Canadian Ice Service (CIS) through the visual interpretation of Radarsat synthetic aperture radar (SAR) ScanSAR imagery and supported by other sources such as NOAA AVHRR data, to provide users with estimates of lake-wide ice fractional coverage (i.e. single value per lake). With more frequent satellite revisits at present and expected in the near future (e.g. ESA Sentinel missions and Radarsat constellation), the requirements are growing towards automated interpretation of SAR imagery for lake ice monitoring, including both estimates of fractional ice coverage and the production of ice maps. In this paper, the potential of using automated algorithms for SAR lake ice imagery interpretation is explored using the iterative region-growing algorithm using semantics (IRGS) and conventional segmentation techniques. IRGS effectively models the statistical and spatial characteristics of pixels in the scene and outperforms the other segmentation techniques. An ice fraction estimation scheme is introduced using the MAGIC (MAp Guided Ice-Classification), which uses the IRGS as a core segmentation algorithm. The performance of MAGIC is demonstrated using a time series of SAR images of Great Bear Lake (GBL) and Great Slave Lake (GSL) used operationally at CIS for the period 1997-2007. Results show ice fraction estimates from MAGIC to be better than those from visual interpretation and estimates provided by CIS. The framework used for GBL/GSL can be easily extended to other lakes and can be adapted for operational lake ice monitoring.

  5. Automatic digital photo-book making system

    NASA Astrophysics Data System (ADS)

    Wang, Wiley; Teo, Patrick; Muzzolini, Russ

    2010-02-01

    The diversity of photo products has grown more than ever before. A group of photos are not only printed individually, but also can be arranged in specific order to tell a story, such as in a photo book, a calendar or a poster collage. Similar to making a traditional scrapbook, digital photo book tools allow the user to choose a book style/theme, layouts of pages, backgrounds and the way the pictures are arranged. This process is often time consuming to users, given the number of images and the choices of layout/background combinations. In this paper, we developed a system to automatically generate photo books with only a few initial selections required. The system utilizes time stamps, color indices, orientations and other image properties to best fit pictures into a final photo book. The common way of telling a story is to lay the pictures out in chronological order. If the pictures are proximate in time, they will coincide with each other and are often logically related. The pictures are naturally clustered along a time line. Breaks between clusters can be used as a guide to separate pages or spreads, thus, pictures that are logically related can stay close on the same page or spread. When people are making a photo book, it is helpful to start with chronologically grouped images, but time alone wont be enough to complete the process. Each page is limited by the number of layouts available. Many aesthetic rules also apply, such as, emphasis of preferred pictures, consistency of local image density throughout the whole book, matching a background to the content of the images, and the variety of adjacent page layouts. We developed an algorithm to group images onto pages under the constraints of aesthetic rules. We also apply content analysis based on the color and blurriness of each picture, to match backgrounds and to adjust page layouts. Some of our aesthetic rules are fixed and given by designers. Other aesthetic rules are statistic models trained by using customer photo book samples. We evaluate our algorithm with test photo sets, and ask participants both quantitative and qualitative questions for feedback. We have seen the improvement on the time it takes users to produce a photo book and on the satisfaction with the overall quality.

  6. Basal Drainage System Response to Increasing Surface Melt on the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Meierbachtol, T.; Harper, J.; Humphrey, N.

    2013-08-01

    Surface meltwater reaching the bed of the Greenland ice sheet imparts a fundamental control on basal motion. Sliding speed depends on ice/bed coupling, dictated by the configuration and pressure of the hydrologic drainage system. In situ observations in a four-site transect containing 23 boreholes drilled to Greenland’s bed reveal basal water pressures unfavorable to water-draining conduit development extending inland beneath deep ice. This finding is supported by numerical analysis based on realistic ice sheet geometry. Slow meltback of ice walls limits conduit growth, inhibiting their capacity to transport increased discharge. Key aspects of current conceptual models for Greenland basal hydrology, derived primarily from the study of mountain glaciers, appear to be limited to a portion of the ablation zone near the ice sheet margin.

  7. Basal drainage system response to increasing surface melt on the Greenland ice sheet.

    PubMed

    Meierbachtol, T; Harper, J; Humphrey, N

    2013-08-16

    Surface meltwater reaching the bed of the Greenland ice sheet imparts a fundamental control on basal motion. Sliding speed depends on ice/bed coupling, dictated by the configuration and pressure of the hydrologic drainage system. In situ observations in a four-site transect containing 23 boreholes drilled to Greenland's bed reveal basal water pressures unfavorable to water-draining conduit development extending inland beneath deep ice. This finding is supported by numerical analysis based on realistic ice sheet geometry. Slow meltback of ice walls limits conduit growth, inhibiting their capacity to transport increased discharge. Key aspects of current conceptual models for Greenland basal hydrology, derived primarily from the study of mountain glaciers, appear to be limited to a portion of the ablation zone near the ice sheet margin. PMID:23950535

  8. Tracking and responding to a changing Arctic sea-ice cover: How ice users can help the scientific community design better observing systems (Louis Agassiz Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Eicken, Hajo

    2010-05-01

    The Arctic sea-ice cover is undergoing a major transformation, with substantial reductions in summer ice extent reflecting changes in ice thickness, age, and circulation. These changes are impacting Arctic ecosystems and a range of human activities. Anticipating and responding to such impacts, exacerbated by increasing economic activity in parts of the Arctic, requires a foundation of environmental observations and model predictions. Recent increases in industrial activities such as shipping and resource development in parts of the Arctic have further highlighted the need for an integrated observing system. In the case of a changing sea-ice cover, how would one best design and optimize such a system? One of the challenges is to meet the information needs of the scientific community in furthering fundamental understanding of the Arctic system, as well as those of key stakeholders and society, helping them to prepare for and respond to Arctic change. This presentation focuses on how the concept of sea-ice system services, i.e., the uses and benefits (or harm) derived from sea ice, may help guide the implementation of an effective observing system. Principal service categories are (1) sea ice as climate regulator, marine hazard, and coastal buffer; (2) transportation and use of ice as a platform; (3) cultural services obtained from the "icescape"; and (4) support of food webs and biological diversity by sea ice. An analysis of the different ice services provided to different user groups can help prioritize different types of observations and determine optimal measurement strategies. Moreover, the focus on different uses of the ice cover may also help synthesize fundamental and applied research to help Arctic communities adapt in a changing environment. Alaska has experienced some of the most substantial changes in sea-ice conditions throughout the Arctic over the past three decades and is used to illustrate the concepts discussed above. Specifically, we have examined use of sea ice as a platform for travel, hunting and resource development. Observations of variables (such as ice thickness and morphology) that constrain such use can help in developing models and forecasts of ice stability which in turn are of potential value to ice users. As discussed for a seasonal ice break-up forecast, the demands with respect to the spatial and temporal resolution of data and forecast products for such applied cases is not always met by existing data sets and can help guide design and optimization of future observing systems.

  9. A New Ice Slurry-System Combined with Liquid-Dehumidifying

    NASA Astrophysics Data System (ADS)

    Li, Xiuwei; Zhang, Xiaosong

    2007-06-01

    Ice is widely used in many fields of today's life. However, we have to pay a lot of energy, in order to produce the ice we need. Since that, we propose a new ice-slurry producing system in this paper, which produces ice using the evaporating freezing method combined with liquid- dehumidifying. The system consists of three major parts, known as the pre-cooling part, the liquid-dehumidifying part and the evaporating-freezing part. We did simulating calculation on evaporating freezing process, and the result exposes the factors that have impacts on this process and how they influence it. Also, we analyze the coefficient of the performance theoretically, from which it could be concluded that this system is an energy-saving compared to a traditional ice-producing system.

  10. Ice/berm interaction study using rotary sidescan sonar and acoustic profiling systems

    SciTech Connect

    Good, R.R.; Anderson, K.G.; Lanzier, H.H.

    1984-05-01

    Tarsiut Island, in the Canadian Beaufort Sea, was the first dredged caisson retained island built for exploration drilling operations in the Arctic offshore. Due to the island's configuration location, a large first-year ice rubble pile would result from the ice/structure interaction. This paper outlines how a rotary side-scan sonar and a mechanically scanning, narrow-beam acoustic profiling system were used to determine the geometry and the contact area of the underside of heavily rubbled first-year ice. The results of this study are to be used to further the understanding of the nature and mechanism of the ice/structure interaction in Arctic offshore structures.

  11. Calving of large tabular icebergs from ice shelf rift systems

    NASA Astrophysics Data System (ADS)

    Joughin, Ian; MacAyeal, Douglas R.

    2005-01-01

    We used Interferometric Synthetic Aperture Radar to study the detachment process that allowed two large icebergs to calve from the Ross Ice Shelf, Antarctica. Time series of rift geometries indicate that rift widths increased steadily, whereas rift lengths increased episodically through several discrete rift-tip propagation events. We also conducted modeling experiments constrained by the observed rift geometry. Both the observations and model suggest that rift opening, and, thus, tabular-iceberg calving, are largely driven by ``glaciological'' stresses-stress introduced by the effect of gravity on the ice shelf-rather than by stress introduced by the ocean and atmosphere, e.g., tides and storms. This style of rift propagation is expected to determine the steady, background calving rate of ice shelves and, thus, differs significantly from styles that led to the recent disintegration of ice shelves in response to climate warming, e.g., the Larsen B Ice Shelf on the Antarctic Peninsula.

  12. Real-Time Observations of Optical Properties of Arctic Sea Ice with an Autonomous System

    NASA Astrophysics Data System (ADS)

    Wang, C.; Gerland, S.; Nicolaus, M.; Granskog, M. A.; Hudson, S. R.; Perovich, D. K.; Karlsen, T. I.; Fossan, K.

    2012-12-01

    The recent drastic changes in the Arctic sea ice cover have altered the interaction of solar radiation and sea ice. To improve our understanding of this interaction, a Spectral Radiation Buoy (SRB) for measuring sea ice optical properties was developed, based on a system used during the last International Polar Year at the drift of "Tara" across the Arctic Ocean. A first version of the SRB was deployed on drifting ice in the high Arctic in April 2012. It includes three Satlantic spectral radiometers (two in air, one under ice), covering the wavelength range from 347 nm to 804 nm with 3.3 nm spectral resolution, a bio-shutter to protect the under-ice radiometer, a data logger to handle and store collected data, and an Iridium satellite modem to transfer data in real-time. The under-ice radiometer is mounted on an adjustable under-ice arm, and the other instruments are mounted on a triangular frame frozen into the ice. The SRB measures simultaneously, autonomously and continuously the spectral fluxes of incident and reflected solar radiation, as well as under-ice irradiance, water temperature and water pressure every hour. So far, between mid April and early August 2012, the system has drifted about 600 km, from the starting position near the North Pole towards the Fram Strait. The data collected during this deployment, so far, already demonstrate that this system is suitable for autonomous and long-term observations over and under sea ice in harsh conditions. Along with the SRB, commercially available Ice Mass Balance buoys (IMB) were deployed on the same ice floe. In the vicinity of the site, manned baseline measurements of snow and sea ice physical properties have been carried out during the SRB deployment. The combined datasets allow description of the evolution of the ice floe during seasonal melt. With snow melt, the spectral surface albedo decreased and the transmittance through the snow and ice increased after mid-April, especially when melt ponds started to develop in July.

  13. Topological defects from doping and quenched disorder in artificial ice systems

    SciTech Connect

    Reichhardt, Charles; Reichhardt, Cynthia J; Libal, A

    2010-01-01

    We examine the ice-rule obeying and ice-rule breaking vertices in an artificial spin ice system created using magnetic vortices in type-II superconductors with nanostructured pinning arrays. We show that this system can be doped by changing the external field to move the number of vortices away from commensurability and create sites that contain two or zero vortices. For a square ice, the doping leads to the formation of a grain boundary of vertices that do not obey the ice rules. In commensurate systems where the ice rules are obeyed, we can introduce random disorder at the individual pinning sites to create regions where vortices may not be able to flip from one side of the trap to another. For weak disorder, all of the vertices still obey the ice rules, while at intermediate levels of disorder we find grain boundaries of vertices which do not obey the ice rules. For strong disorder it is possible to create isolated paired vertices that do not obey the ice rules. In summary, we have shown that an artificial square ice can be created using vortices in a type-II superconductor interacting with a periodic array of pinning sites where each site has a double well potential. By defining the direction of the effective spin according to the side of the double well occupied by the vortex, we find that this system obeys the ice rules for square ice. We add disorder to the system in the form of randomness of the height of the potential barrier at the center of the well, and obtain vertex configurations using a rotating drive protocol which is similar to the shaking ac magnetic field used in nanomagnetic systems. For weak disorder the entire system still obeys the square ice rules. For intermediate disorder, ice-rule breaking vertices appear and form grain boundaries, while for strong disorder there are both gain boundaries and isolated paired defects. In a system with uniform potential barrier heights, we introduce disorder by moving away from commensurability and creating Home pinning sites that contain two or zero vortices. In this case we find grain boundaries that emanate from the defect site and span the sample.

  14. Effectiveness of Thermal-Pneumatic Airfoil-Ice-Protection System

    NASA Technical Reports Server (NTRS)

    Gowan, William H., Jr.; Mulholland, Donald R.

    1951-01-01

    Icing and drag investigations were conducted in the NACA Lewis icing research tunnel employing a combination thermal-pneumatic de-icer mounted on a 42-inch-chord NACA 0018 airfoil. The de-icer consisted of a 3-inch-wide electrically heated strip symmetrically located about the leading edge with inflatable tubes on the upper and lower airfoil surfaces aft of the heated area. The entire de-icer extended to approximately 25 percent of chord. A maximum power density of 9.25 watts per square inch was required for marginal ice protection on the airfoil leading edge at an air temperature of 00 F and an airspeed of 300 miles per hour. Drag measurements indicated, that without icing, the de-icer installation increased the section drag to approximately 140 percent of that of the bare airfoil; with the tubes inflated, this value increased to a maximum of approximately 620 percent. A 2-minute tube-inflation cycle prevented excessive ice formation on the inflatable area although small scattered residual Ice formations remained after inflation and were removed intermittently during later cycles. Effects of the time lag of heater temperatures after initial application of power and the insulating effect of ice formations on heater temperatures were also determined.

  15. Ice Chemistry on Outer Solar System Bodies: Electron Radiolysis of N2-, CH4-, and CO-Containing Ices

    NASA Astrophysics Data System (ADS)

    Materese, Christopher K.; Cruikshank, Dale P.; Sandford, Scott A.; Imanaka, Hiroshi; Nuevo, Michel

    2015-10-01

    Radiation processing of the surface ices of outer Solar System bodies may be an important process for the production of complex chemical species. The refractory materials resulting from radiation processing of known ices are thought to impart to them a red or brown color, as perceived in the visible spectral region. In this work, we analyzed the refractory materials produced from the 1.2-keV electron bombardment of low-temperature N2-, CH4-, and CO-containing ices (100:1:1), which simulates the radiation from the secondary electrons produced by cosmic ray bombardment of the surface ices of Pluto. Despite starting with extremely simple ices dominated by N2, electron irradiation processing results in the production of refractory material with complex oxygen- and nitrogen-bearing organic molecules. These refractory materials were studied at room temperature using multiple analytical techniques including Fourier-transform infrared spectroscopy, X-ray absorption near-edge structure (XANES) spectroscopy, and gas chromatography coupled with mass spectrometry (GC-MS). Infrared spectra of the refractory material suggest the presence of alcohols, carboxylic acids, ketones, aldehydes, amines, and nitriles. XANES spectra of the material indicate the presence of carboxyl groups, amides, urea, and nitriles, and are thus consistent with the IR data. Atomic abundance ratios for the bulk composition of these residues from XANES analysis show that the organic residues are extremely N-rich, having ratios of N/C ∼ 0.9 and O/C ∼ 0.2. Finally, GC-MS data reveal that the residues contain urea as well as numerous carboxylic acids, some of which are of interest for prebiotic and biological chemistries.

  16. Sea Ice

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.; Cavalieri, Donald J.

    2005-01-01

    Sea ice covers vast areas of the polar oceans, with ice extent in the Northern Hemisphere ranging from approximately 7 x 10(exp 6) sq km in September to approximately 15 x 10(exp 6) sq km in March and ice extent in the Southern Hemisphere ranging from approximately 3 x 10(exp 6) sq km in February to approximately 18 x 10(exp 6) sq km in September. These ice covers have major impacts on the atmosphere, oceans, and ecosystems of the polar regions, and so as changes occur in them there are potential widespread consequences. Satellite data reveal considerable interannual variability in both polar sea ice covers, and many studies suggest possible connections between the ice and various oscillations within the climate system, such as the Arctic Oscillation, North Atlantic Oscillation, and Antarctic Oscillation, or Southern Annular Mode. Nonetheless, statistically significant long-term trends are also apparent, including overall trends of decreased ice coverage in the Arctic and increased ice coverage in the Antarctic from late 1978 through the end of 2003, with the Antarctic ice increases following marked decreases in the Antarctic ice during the 1970s. For a detailed picture of the seasonally varying ice cover at the start of the 21st century, this chapter includes ice concentration maps for each month of 2001 for both the Arctic and the Antarctic, as well as an overview of what the satellite record has revealed about the two polar ice covers from the 1970s through 2003.

  17. The Fresh Meltwater in the Sea Ice System

    NASA Astrophysics Data System (ADS)

    Polashenski, C.; Perovich, D. K.; Claffey, K.; Frey, K. E.; Trusel, L. D.; Wood, C.

    2010-12-01

    The disposition of fresh meltwater created by snowmelt at the surface of Arctic sea ice plays important roles in driving the evolution of ice melt, surface energy budget, and PAR transmitted to the upper ocean. Fresh meltwater can form pools on the surface, drain into the ocean through flaws, or percolate into the brine channel matrix of the ice. These processes, respectively, result in lowered surface albedo and enhanced PAR transmission, the creation of stable freshwater lenses and false bottoms under the ice, and, depending on timing, the displacement of brine into the ocean or creation of interposed freshwater ice which blocks permeability pathways. Each of these processes likely occurs to some extent in any given melt season, but the overall duration and relative timing of fresh meltwater transport and storage processes varies with significant impacts. Identifying ice temperature, melt stage, or other measurable thresholds which dictate the timing and mechanisms of fresh water movement will enable the use of meltwater movement processes as prognostics in modeling. This presentation will cover a series of observations from the 2010 summer melt season taken in Barrow, AK and offshore in the Chukchi Sea aboard the icebreaker Healy which track fresh meltwater movement and effects thereof. Meltwater is tracked using analysis of ice cores, surface volume shifts derived from LiDAR, and salinity profiles of the surface ocean. The synthesis of time series data from Barrow, with spatially varying observations from aboard the Healy will track the significance, timing, and critical thresholds for fresh meltwater movement between reservoirs, as well as the impacts thereof. The results enhance basic knowledge of ice melt in a way that provides conceptual framework useful for modeling both ice melt and impacts on biological activity.

  18. Inorganic carbon system dynamics in landfast Arctic sea ice during the early-melt period

    NASA Astrophysics Data System (ADS)

    Brown, Kristina A.; Miller, Lisa A.; Mundy, C. J.; Papakyriakou, Tim; Francois, Roger; Gosselin, Michel; Carnat, Gauthier; Swystun, Kyle; Tortell, Philippe D.

    2015-05-01

    We present the results of a 6 week time series of carbonate system and stable isotope measurements investigating the effects of sea ice on air-sea CO2 exchange during the early melt period in the Canadian Arctic Archipelago. Our observations revealed significant changes in sea ice and sackhole brine carbonate system parameters that were associated with increasing temperatures and the buildup of chlorophyll a in bottom ice. The warming sea-ice column could be separated into distinct geochemical zones where biotic and abiotic processes exerted different influences on inorganic carbon and pCO2 distributions. In the bottom ice, biological carbon uptake maintained undersaturated pCO2 conditions throughout the time series, while pCO2 was supersaturated in the upper ice. Low CO2 permeability of the sea ice matrix and snow cover effectively impeded CO2 efflux to the atmosphere, despite a strong pCO2 gradient. Throughout the middle of the ice column, brine pCO2 decreased significantly with time and was tightly controlled by solubility, as sea ice temperature and in situ melt dilution increased. Once the influence of melt dilution was accounted for, both CaCO3 dissolution and seawater mixing were found to contribute alkalinity and dissolved inorganic carbon to brines, with the CaCO3 contribution driving brine pCO2 to values lower than predicted from melt-water dilution alone. This field study reveals a dynamic carbon system within the rapidly warming sea ice, prior to snow melt. We suggest that the early spring period drives the ice column toward pCO2 undersaturation, contributing to a weak atmospheric CO2 sink as the melt period advances.

  19. Modelling the coupled evolution of the ice shelf/stream flow system and the oceanic circulation in the ice-shelf cavity.

    NASA Astrophysics Data System (ADS)

    Payne, A. J.; Jenkins, A.

    2004-12-01

    Recent satellite-based observations highlight the importance of coastal processes on the dynamics of the West Antarctic and Greenland ice sheets. In particular, the ice streams of the Amundsen Sea embayment, West Antarctica, as well as Jakobshavns Isbrae, Greenland, appear to be thinning in response to a recent oceanic trigger. One hypothesis is that enhanced melt from the underside of floating ice shelves and ice plains is causing the ice to thin and reducing the traction exerted by ice rises and other bedrock protrusions. This, in turn, may lead to accelerated flow over the grounding line and thinning of the ice streams. While there is a large amount of observational evidence suggesting that the ice sheets are more tightly coupled to their surrounding oceans than previously thought, the modelling of these interactions is still in its infancy. We investigate these processes by coupling a two-dimensional plume model of sub-shelf oceanic circulation with a three-dimensional, higher-order model of ice flow in the shelf/stream system. Coupling between the two systems arises in three ways. Firstly, through the basal melt rates determined by the plume model which largely control the mass balance of the ice shelf. Second, through the changing basal geometry of the ice shelf that plays an important role in the momentum balance of the plume. Finally, through the subglacial meltwater flux across the grounding line that provides the initial impetus for plume development. We conduct a series of coupled experiments in which the ice shelf/stream and plume are allowed reach equilibrium. We then assess the sensitivity of the predicted melt and freezing rates to the three primary oceanic inputs of shelf water temperature and salinity, as well as turbulent mixing coefficients. Finally, we conduct a series of perturbation experiments in which the effects of incremental changes to these parameters on the coupled system will be assessed.

  20. Modelling the coupled evolution of the ice shelf/stream flow system and the oceanic circulation in the ice-shelf cavity

    NASA Astrophysics Data System (ADS)

    Payne, A. J.; Holland, P. R.; Vieli, A.; Feltham, D. L.

    2005-12-01

    Recent satellite-based observations highlight the importance of coastal processes on the dynamics of the West Antarctic and Greenland ice sheets. In particular, the ice streams of the Amundsen Sea embayment, West Antarctica, as well as Jakobshavns Isbrae, Greenland, appear to be thinning in response to a recent oceanic trigger. One hypothesis is that enhanced melt from the underside of floating ice shelves and ice plains is causing the ice to thin and reducing the traction exerted by ice rises and other bedrock protrusions. This, in turn, may lead to accelerated flow over the grounding line and thinning of the ice streams. While there is a large amount of observational evidence suggesting that the ice sheets are more tightly coupled to their surrounding oceans than previously thought, the modelling of these interactions is still in its infancy. We investigate these processes by coupling a two-dimensional plume model of sub-shelf oceanic circulation with a three-dimensional, higher-order model of ice flow in the shelf/stream system. Coupling between the two systems arises in three ways. Firstly, through the basal melt rates determined by the plume model which largely control the mass balance of the ice shelf. Second, through the changing basal geometry of the ice shelf that plays an important role in the momentum balance of the plume. Finally, through the subglacial meltwater flux across the grounding line that provides the initial impetus for plume development. We conduct a series of coupled experiments in which the ice shelf/stream and plume are allowed to reach equilibrium. We then assess the sensitivity of the predicted melt and freezing rates to the three primary oceanic inputs of shelf water temperature and salinity, as well as turbulent mixing coefficients. Finally, we conduct a series of perturbation experiments in which the effects of incremental changes to these parameters on the coupled system will be assessed.

  1. Late Quaternary Advance and Retreat of an East Antarctic Ice Shelf System: Insights from Sedimentary Beryllium-10 Concentrations

    NASA Astrophysics Data System (ADS)

    Guitard, M. E.; Shevenell, A.; Domack, E. W.; Rosenheim, B. E.; Yokoyama, Y.

    2014-12-01

    Observed retreat of Antarctica's marine-based glaciers and the presence of warm (~2°C) modified Circumpolar Deep Water on Antarctica's continental shelves imply ocean temperatures may influence Antarctic cryosphere stability. A paucity of information regarding Late Quaternary East Antarctic cryosphere-ocean interactions makes assessing the variability, timing, and style of deglacial retreat difficult. Marine sediments from Prydz Bay, East Antarctica contain hemipelagic siliceous mud and ooze units (SMO) alternating with glacial marine sediments. The record suggests Late Quaternary variability of local outlet glacier systems, including the Lambert Glacier/Amery Ice Shelf system that drains 15% of the East Antarctic Ice Sheet. We present a refined radiocarbon chronology and beryllium-10 (10Be) record of Late Quaternary depositional history in Prydz Channel, seaward of the Amery Ice Shelf system, which provides insight into the timing and variability of this important outlet glacier system. We focus on three piston cores (NBP01-01, JPC 34, 35, 36; 750 m water depth) that contain alternating SMO and granulated units uninterrupted by glacial till; the record preserves a succession of glacial marine deposits that pre-date the Last Glacial Maximum. We utilize the ramped pyrolysis preparatory method to improve the bulk organic carbon 14C-based chronology for Prydz Channel. To determine if the SMO intervals reflect open water conditions or sub-ice shelf advection, we measured sedimentary 10Be concentrations. Because ice cover affects 10Be pathways through the water column, sedimentary concentrations should provide information on past depositional environments in Prydz Channel. In Prydz Channel sediments, 10Be concentrations are generally higher in SMO units and lower in glacial units, suggesting Late Quaternary fluctuations in the Amery Ice Shelf. Improved chronologic constraints indicate that these fluctuations occurred on millennial timescales during the Last Glacial Maximum and deglaciation (~35-10 ka). Timing and depositional history of SMO units suggest environmental forcing on ice shelf evolution. While the driver of Amery Ice Shelf retreat is uncertain, our study provides new insight into the calving history of the largest outlet glacier in East Antarctica.

  2. Laboratory Studies of Extraterrestrial Ices and PAHs: Making an Astrobiological Silk Purse Out of An Interstellar Sow's Ear

    NASA Technical Reports Server (NTRS)

    Hudgins, Douglas M.; DeVincenzi, Donald (Technical Monitor)

    2002-01-01

    Tremendous strides have been made in our understanding of interstellar material over the past twenty years thanks to significant, parallel developments in observational astronomy and laboratory astrophysics. Today, the composition of dust in the ISM is reasonably well constrained to cold, micron-sized particles of various refractory materials. Shrouded within the protective confines of cold, opaque molecular clouds--the birthplace of stars and planets--these particles secrete mantles of mixed molecular lees whose major components are also well constrained. Finally, amidst the molecular inventory of these ice mantles are likely to be found polycyclic aromatic hydrocarbons (PAHs), whose telltale infrared signature I is now recognized throughout the Universe. However, of what significance is this scenario to the origin of life in our solar system--or any other? The major components of the icy materials observed in interstellar clouds and in our own solar system are uniformly quite simple. In addition, despite the fact that PAHs likely represent the single largest molecular reservoir of organic carbon in evolving planetary systems, they are not what would be considered "biogenic" molecules. Although interesting from a chemical and astrophysical standpoint, in the absence of a mechanism by which these materials can be transformed into more biochemically significant structures, they are of little Astrobiological significance. In this talk, we will begin with a brief review of the nature and abundance of the "raw" population of PAHs and PAH-related materials in the ISM. From there, we will move on to explore our laboratory simulations of the photochemical evolution of realistic mixed molecular ices under conditions which simulate those encountered in the ISM and in evolving planetary systems. Particular attention will be paid to the surprisingly complex array of organic species that are produced in these ices from such a deceptively simple inventory of starting materials. In addition, we will explore the chemistry of PAHs under these conditions and consider its potential for transforming that rich repository of pre-biotic organic "ore" into materials of greater importance to Astrobiology.

  3. Application of thermal imagery to the development of a Great Lakes ice information system. [infrared and SLAR imagery of fresh water ice thickness

    NASA Technical Reports Server (NTRS)

    Schertler, R. J.; Raquet, C. A.; Svehla, R. A.

    1973-01-01

    Recent measurements and analysis have shown that thermal infrared imagery (wavelength, 8-14 microns) can be employed to delineate the relative thicknesses of various regions of freshwater ice, as well as, differentiate new ice from both open water areas and thicker (young)ice. Thermal imagery was observed to be generally superior to visual (0.4 - 0.7 microns) and our SLAR (3.3 cm) imagery for estimating relative ice thicknesses and delineating open water from new ice growth. In a real-time Great Lakes Ice Information System, thermal imagery can not only provide supplementary imagery but also aid in developing interpretative methods for all-weather SLAR imagery, as well as, establishing the areal extent of spot thickness measurements.

  4. High-frequency microwave anti-/de-icing system for carbon-reinforced airfoil structures

    NASA Astrophysics Data System (ADS)

    Feher, Lambert; Thumm, Manfred

    2001-08-01

    An aircraft may be subjected to icing for a variety of meteorological reasons during the flight. Ice formation on the plane and in particular on the aerodynamically carrying structures adversely affects the flight behaviour. Conventional de-icing methods for aluminum wings are characterised by a high energy consumption during the flight and slow ice melting due to thermal diffusion of the heat in the wing material. In addition to advanced turbines, novel materials and composites have to be used in order to reduce the weight and, hence, the fuel consumption. These composite materials have a far worse thermal conductivity than metals and undergo delamination when hot air systems, resistance or ohmic heating mats are used. In the paper, the unique advantages of a novel High Frequency Microwave Anti-/De-icing System for large future aircraft with carbon reinforced leading edge structures are presented.

  5. A seamless approach to understanding and predicting Arctic sea ice in Met Office modelling systems.

    PubMed

    Hewitt, Helene T; Ridley, Jeff K; Keen, Ann B; West, Alex E; Peterson, K Andrew; Rae, Jamie G L; Milton, Sean F; Bacon, Sheldon

    2015-07-13

    Recent CMIP5 models predict large losses of summer Arctic sea ice, with only mitigation scenarios showing sustainable summer ice. Sea ice is inherently part of the climate system, and heat fluxes affecting sea ice can be small residuals of much larger air-sea fluxes. We discuss analysis of energy budgets in the Met Office climate models which point to the importance of early summer processes (such as clouds and meltponds) in determining both the seasonal cycle and the trend in ice decline. We give examples from Met Office modelling systems to illustrate how the seamless use of models for forecasting on time scales from short range to decadal might help to unlock the drivers of high latitude biases in climate models. PMID:26032316

  6. Measures Earth System Data Records (ESDR) of Ice Motion in Antarctica: Status, Impact and Future Products.

    NASA Astrophysics Data System (ADS)

    Scheuchl, B.; Rignot, E. J.; Mouginot, J.

    2014-12-01

    Spaceborne Synthetic Aperture Radar (SAR) data is an extremely useful tool for providing relevant information about the ice sheet ECV: ice vector velocity, grounding line position, and ice front location. Here, we provide an overview of the SAR Earth System Data Records (ESDR) for Antarctica part of MEaSUREs that includes: the first complete map of surface ice vector velocity in Antarctica, a map of grounding line positions around Antarctica, ice velocity time series for selected regions: Ross and Ronne-Filchner Ice Shelves and associated drainage basins, the Amundsen Sea Embayment of West Antarctica which is the largest contributor to sea level rise from Antarctica and the focus of rapid ice sheet retreat, and Larsen-B and -C ice shelves which is the second largest contribution to sea level rise from Antarctica. Other products include a database of ice shelf boundaries and drainage basins based on ice motion mapping and digital elevation models generated independently. Data continuity is a crucial aspect of this work and a fundamental challenge for the continuation of these products due to the lack of a dedicated interferometric mission on the cryosphere until the SAR mission under consideration between NASA and ISRO is approved. Four SAR missions ceased operations since IPY. CSA's RADARSAT-2 has provided important bridging data between these missions in Greenland and Antarctica. In 2014, ESA launched Sentinel-1a and JAXA launched ALOS-2 PALSAR, for which we will have limited data access. The Polar Space Task Group (PSTG) created by WMO has established a mandate to support cryospheric products from scientific research using international SARs which continues to play an active role in securing key data acquisitions over ice sheets. We will provide an overview of current efforts. This work was conducted at UC Irvine, Department of Earth System Science under a contract with NASA's MEaSUREs program.

  7. Use of the X-Band Radar to Support the Detection of In-Flight Icing Hazards by the NASA Icing Remote Sensing System

    NASA Technical Reports Server (NTRS)

    Serke, David J.; Politovich, Marcia K.; Reehorst, Andrew L.; Gaydos, Andrew

    2009-01-01

    The Alliance Icing Research Study-II (AIRS-II) field program was conducted near Montreal, Canada during the winter of 2003. The NASA Icing Remote Detection System (NIRSS) was deployed to detect in-flight icing hazards and consisted of a vertically pointing multichannel radiometer, a ceilometer and an x-band cloud radar. The radiometer was used to derive atmospheric temperature soundings and integrated liquid water, while the ceilometer and radar were used only to define cloud boundaries. The purpose of this study is to show that the radar reflectivity profiles from AIRS-II case studies could be used to provide a qualitative icing hazard.

  8. Dynamics of coupled ice-ocean system in the marginal ice zone: Study of the mesoscale processes and of constitutive equations for sea ice

    NASA Technical Reports Server (NTRS)

    Hakkinen, S.

    1984-01-01

    This study is aimed at the modelling of mesoscale processed such as up/downwelling and ice edge eddies in the marginal ice zones. A 2-dimensional coupled ice-ocean model is used for the study. The ice model is coupled to the reduced gravity ocean model (f-plane) through interfacial stresses. The constitutive equations of the sea ice are formulated on the basis of the Reiner-Rivlin theory. The internal ice stresses are important only at high ice concentrations (90-100%), otherwise the ice motion is essentially free drift, where the air-ice stress is balanced by the ice-water stress. The model was tested by studying the upwelling dynamics. Winds parallel to the ice edge with the ice on the right produce upwilling because the air-ice momentum flux is much greater that air-ocean momentum flux, and thus the Ekman transport is bigger under the ice than in the open water. The upwelling simulation was extended to include temporally varying forcing, which was chosen to vary sinusoidally with a 4 day period. This forcing resembles successive cyclone passings. In the model with a thin oceanic upper layer, ice bands were formed.

  9. Semi-automated Digital Imaging and Processing System for Measuring Lake Ice Thickness

    NASA Astrophysics Data System (ADS)

    Singh, Preetpal

    Canada is home to thousands of freshwater lakes and rivers. Apart from being sources of infinite natural beauty, rivers and lakes are an important source of water, food and transportation. The northern hemisphere of Canada experiences extreme cold temperatures in the winter resulting in a freeze up of regional lakes and rivers. Frozen lakes and rivers tend to offer unique opportunities in terms of wildlife harvesting and winter transportation. Ice roads built on frozen rivers and lakes are vital supply lines for industrial operations in the remote north. Monitoring the ice freeze-up and break-up dates annually can help predict regional climatic changes. Lake ice impacts a variety of physical, ecological and economic processes. The construction and maintenance of a winter road can cost millions of dollars annually. A good understanding of ice mechanics is required to build and deem an ice road safe. A crucial factor in calculating load bearing capacity of ice sheets is the thickness of ice. Construction costs are mainly attributed to producing and maintaining a specific thickness and density of ice that can support different loads. Climate change is leading to warmer temperatures causing the ice to thin faster. At a certain point, a winter road may not be thick enough to support travel and transportation. There is considerable interest in monitoring winter road conditions given the high construction and maintenance costs involved. Remote sensing technologies such as Synthetic Aperture Radar have been successfully utilized to study the extent of ice covers and record freeze-up and break-up dates of ice on lakes and rivers across the north. Ice road builders often used Ultrasound equipment to measure ice thickness. However, an automated monitoring system, based on machine vision and image processing technology, which can measure ice thickness on lakes has not been thought of. Machine vision and image processing techniques have successfully been used in manufacturing to detect equipment failure and identify defective products at the assembly line. The research work in this thesis combines machine vision and image processing technology to build a digital imaging and processing system for monitoring and measuring lake ice thickness in real time. An ultra-compact USB camera is programmed to acquire and transmit high resolution imagery for processing with MATLAB Image Processing toolbox. The image acquisition and transmission process is fully automated; image analysis is semi-automated and requires limited user input. Potential design changes to the prototype and ideas on fully automating the imaging and processing procedure are presented to conclude this research work.

  10. Investigation of Aerodynamic and Icing Characteristics of a Flush Alternate Inlet Induction System Air Scoop

    NASA Technical Reports Server (NTRS)

    Lewis, James P.

    1953-01-01

    An investigation has been made in the NACA Lewis icing research tunnel to determine the aerodynamic and icing characteristics of a full-scale induction-system air-scoop assembly incorporating a flush alternate inlet. The flush inlet was located immediately downstream of the offset ram inlet and included a 180 deg reversal and a 90 deg elbow in the ducting between inlet and carburetor top deck. The model also had a preheat-air inlet. The investigation was made over a range of mass-air- flow ratios of 0 to 0.8, angles of attack of 0 and 4 deg airspeeds of 150 to 270 miles per hour, air temperatures of 0 and 25 F various liquid-water contents, and droplet sizes. The ram inlet gave good pressure recovery in both clear air and icing but rapid blockage of the top-deck screen occurred during icing. The flush alternate inlet had poor pressure recovery in both clear air and icing. The greatest decreases in the alternate-inlet pressure recovery were obtained at icing conditions of low air temperature and high liquid-water content. No serious screen icing was observed with the alternate inlet. Pressure and temperature distributions on the carburetor top deck were determined using the preheat-air supply with the preheat- and alternate-inlet doors in various positions. No screen icing occurred when the preheat-air system was operated in combination with alternate-inlet air flow.

  11. Summary of results from an ultrasonic in-flight wing ice detection system

    NASA Astrophysics Data System (ADS)

    Hongerholt, Derrick D.; Willms, Gary; Rose, Joseph L.

    2002-05-01

    Ultrasonic guided waves provide a convenient and reliable method to detect contaminants on the surface of the structure the wave travels in. Classifying the contaminants is possible by selecting the guided wave mode with the appropriate wave structure. An ice detection system, using this technology, designed at Sensor Systems, Goodrich Corporation is described. The system is demonstrated in-flight and is shown to be successful in detecting ice bonded to the aircraft wing leading edge.

  12. Electrometric method to determine the surface impedance of an ice-sea water bilayer system

    NASA Astrophysics Data System (ADS)

    Bashkuev, Yu. B.; Naguslaeva, I. B.; Khaptanov, V. B.; Dembelov, M. G.

    2016-02-01

    An electrometric method to determine the surface impedance of an ice-sea water bilayer system is suggested. The complex impedance (its magnitude and phase) of this system is determined at very low, low, and medium frequencies from electrometric, rather than radio, measurements. For the ice-sea water system, it is sufficient to determine the conductivity and thickness of a water sample from drilling data.

  13. Low-frequency variability in the arctic atmosphere, sea ice, and upper-ocean climate system

    SciTech Connect

    Bitz, C.M.; Battisti, D.S.; Moritz, R.E.; Beesley, J.A.

    1996-02-01

    The low-frequency natural variability of the arctic climate system is modeled using a single-column, energy balance model of the atmosphere, sea ice, and upper-ocean system. Variability in the system is induced by forcing with realistic, random perturbations in the atmospheric energy transport and cloudiness. The model predicts that the volume of perennial sea ice varies predominantly on decadal timescales, while other arctic climate variables vary mostly on intraannual and interannual timescales. The variance of the simulated sea ice volume is most sensitive to perturbations of the atmospheric forcing in late spring, at the onset of melt. The variance of the simulated sea ice volume is most sensitive to perturbations of the atmospheric forcing in the late spring, at the onset of melt. The variance of sea ice volume increases with the mean sea ice thickness and with the number of layers resolved in the sea ice model. This suggests that much of the simulated variance develops when the surface temperature decouples from the sea ice interior during the late spring, when melting snow abruptly exposes the sea ice surface and decreases the surface albedo. The minimum model requirements to simulate the natural variability in the arctic climate are identified. The implications of the low-frequency, natural variability in sea ice volume for detecting a climate change are discussed. Finally, calculations suggest that the variability in the thermodynamic forcing of the polar cap could lead to a freshening in North Atlantic that is comparable to the freshening associated with the Great Salinity Anomaly. 28 refs., 14 figs., 5 tabs.

  14. Modelling the liquid-water vein system within polar ice sheets as a potential microbial habitat

    NASA Astrophysics Data System (ADS)

    Dani, K. G. Srikanta; Mader, Heidy M.; Wolff, Eric W.; Wadham, Jemma L.

    2012-06-01

    Based on the fundamental and distinctive physical properties of polycrystalline ice Ih, the chemical and temperature profiles within the polar ice sheets, and the observed selective partitioning of bacteria into liquid water filled veins in the ice, we consider the possibility that microbial life could survive and be sustained within glacial systems. Here, we present a set of modelled vertical profiles of vein diameter, vein chemical concentration, and vein water volume variability across a range of polar ice sheets using their ice core chemical profiles. A sensitivity analysis of VeinsInIce1.0, the numerical model used in this study shows that the ice grain size and the local borehole temperature are the most significant factors that influence the intergranular liquid vein size and the amount of freeze-concentrated impurities partitioned into the veins respectively. Model results estimate the concentration and characteristics of the chemical broth in the veins to be a potential extremophilic microbial medium. The vein sizes are estimated to vary between 0.3 μm to 8 μm across the vertical length of many polar ice sheets and they may contain up to 2 μL of liquid water per litre of solid ice. The results suggest that these veins in polar ice sheets could accommodate populations of psychrophilic and hyperacidophilic ultra-small bacteria and in some regions even support the habitation of unicellular eukaryotes. This highlights the importance of understanding the potential impact of englacial microbial metabolism on polar ice core chemical profiles and provides a model for similar extreme habitats elsewhere in the universe.

  15. Active Lakes of the Recovery Ice Stream, East Antarctica: A Bedrock-Controlled Subglacial Hydrological System

    NASA Astrophysics Data System (ADS)

    Fricker, H. A.; Scambos, T. A.; Bell, R. E.; Carter, S. P.

    2014-12-01

    A connected system of active sub-glacial lakes was revealed beneath the Recovery Ice Stream, East Antarctica by ICESat laser altimetry acquired from 2003 to 2008. Here we combine repeat-track analysis of ICESat (2003-2009), Operation IceBridge laser altimetry and radio-echo sounding (RES; 2011 and 2012), and MODIS image differencing (2009-2011) to learn more about the surface and bedrock topographic setting of the lakes and the constraints on water flow through the system. IceBridge data reveal a ~1500 m deep, ~1000 km long bedrock trough under the main trunk of Recovery Ice Stream. We extend the lake activity time series to 2012 for the three lower lakes using IceBridge data: one lake underwent a large deflation between 2009 and 2011; another lake, which had been continuously filling between 2003 and 2010, started to drain after 2011. Hydrologic connections among the lakes appear to be direct and responsive. We reproduce the lake activity using a simple subglacial water model. The hydrologic system beneath Recovery Ice Stream is controlled by unusually pronounced bedrock topography (and not ice surface topography, as is the case for most Antarctic systems studied to date). We discuss potential causes of non-steady hydrologic behavior in major Antarctic catchments.

  16. Evolution of the subglacial drainage system beneath the Greenland Ice Sheet revealed by tracers

    NASA Astrophysics Data System (ADS)

    Chandler, D. M.; Wadham, J. L.; Lis, G. P.; Cowton, T.; Sole, A.; Bartholomew, I.; Telling, J.; Nienow, P.; Bagshaw, E. B.; Mair, D.; Vinen, S.; Hubbard, A.

    2013-03-01

    Predictions of the Greenland Ice Sheet's response to climate change are limited in part by uncertainty in the coupling between meltwater lubrication of the ice-sheet bed and ice flow. This uncertainty arises largely from a lack of direct measurements of water flow characteristics at the bed of the ice sheet. Previous work has been restricted to indirect observations based on seasonal and spatial variations in surface ice velocities and on meltwater flux. Here, we employ rhodamine and sulphur hexafluoride tracers, injected into the drainage system over three melt seasons, to observe subglacial drainage properties and evolution beneath the Greenland Ice Sheet, up to 57km from the margin. Tracer results indicate evolution from a slow, inefficient drainage system to a fast, efficient channelized drainage system over the course of the melt season. Further inland, evolution to efficient drainage occurs later and more slowly. An efficient routing of water was established up to 41km or more from the margin, where the ice is approximately 1km thick. Overall, our findings support previous interpretations of drainage system characteristics, thereby validating the use of surface observations as a means of investigating basal processes.

  17. Thermal design and de-icing system for the Antarctic Telescope ICE-T

    NASA Astrophysics Data System (ADS)

    Strassmeier, Klaus G.; Krcher, Hans J.; Khn, Jrgen; Divarano, Igor

    2010-07-01

    ICE-T, the International Concordia Explorer Telescope, is under final design by an international consortium led by the Astrophysical Institute Potsdam AIP, Germany, and is intended to be placed at the French-Italian Concordia Station on Dome C in Antarctica. Experience with smaller telescopes at Concordia has shown that under the weather conditions at this site - with mean outside temperatures of -60 to -80 C and temperature changes of 20 in short time intervals - the ice-accumulation on the optical components during observation is a major problem. Also, energy consumption at this site should be minimized because fuel transport to the site is very costly. The paper describes the thermal concept for the telescope where the waste energy of the instrument electronics is used for heating the front surfaces of the Schmidt optics. All other parts of the telescope are protected by an insulated smooth cladding against the harsh outside environment. The effectiveness of the thermal concept is verified by CFD (Computer Fluid Dynamics) calculations.

  18. Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

    SciTech Connect

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2010-06-01

    Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be built at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant economic benefits and avoid forced derating and shutdown during extremely hot weather. For the new plants using dry cooling towers, adding the ice thermal storage systems can effectively reduce the efficiency loss and water consumption during hot weather so that new LWRs could be considered in regions without enough cooling water. \\ This paper presents the feasibility study of using ice thermal storage systems for LWR supplemental cooling and peak power shifting. LWR cooling issues and ITS application status will be reviewed. Two ITS application case studies will be presented and compared with alternative options: one for once-through cooling without enough cooling for short time, and the other with dry cooling. Because capital cost, especially the ice storage structure/building cost, is the major cost for ITS, two different cost estimation models are developed: one based on scaling method, and the other based on a preliminary design using Building Information Modeling (BIM), an emerging technology in Architecture/Engineering/Construction, which enables design options, performance analysis and cost estimating in the early design stage.

  19. Results of a low power ice protection system test and a new method of imaging data analysis

    NASA Technical Reports Server (NTRS)

    Shin, Jaiwon; Bond, Thomas H.; Mesander, Geert A.

    1992-01-01

    Tests were conducted on a BF Goodrich De-Icing System's Pneumatic Impulse Ice Protection (PIIP) system in the NASA Lewis Icing Research Tunnel (IRT). Characterization studies were done on shed ice particle size by changing the input pressure and cycling time of the PIIP de-icer. The shed ice particle size was quantified using a newly developed image software package. The tests were conducted on a 1.83 m (6 ft) span, 0.53 m (221 in) chord NACA 0012 airfoil operated at a 4 degree angle of attack. The IRT test conditions were a -6.7 C (20 F) glaze ice, and a -20 C (-4 F) rime ice. The ice shedding events were recorded with a high speed video system. A detailed description of the image processing package and the results generated from this analytical tool are presented.

  20. Temperature Sensitivity of the Near-Infrared Spectrum of Water Ice: Application to Icy, Outer Solar System Surfices

    NASA Astrophysics Data System (ADS)

    Grundy, W. M.; Buie, M. W.; Spencer, J. R.; Stansberry, J. A.; Schmitt, B.; dalla Piazza, C.; Hilbert, B. N.

    1998-09-01

    We have obtained spectra of a large sample of outer solar system objects using the OSIRIS spectrometer, covering the wavelength range from 1.2 to 2.3 mu m. Our spectra of many of the solid objects exhibit near-IR absorptions bands characteristic of low-temperature, crystalline water ice. These objects include satellites of Jupiter, Saturn, and Uranus, as well as the rings of Saturn. We make use of new H_2O ice optical constants [Grundy and Schmitt 1998 J. Geophs. Res. in press.] to analyze our spectra to determine the physical state and temperature of H_2O ice at the surfaces of these objects. We will present the technique we have developed for determining temperatures of ice-rich surfaces from near-IR spectra, and will discuss limitations of this technique which result from effects such as multiple scattering, radiation damage, and the presence of hydrated impurities. Under some circumstances, these effects can result in errors in the derived temperature. We will also discuss the application of our technique to remote sensing of temperature changes, which are less vulnerable to errors resulting from the effects listed above.

  1. A study of carburetor/induction system icing in general aviation accidents

    NASA Technical Reports Server (NTRS)

    Obermayer, R. W.; Roe, W. T.

    1975-01-01

    An assessment of the frequency and severity of carburetor/induction icing in general-aviation accidents was performed. The available literature and accident data from the National Transportation Safety Board were collected. A computer analysis of the accident data was performed. Between 65 and 90 accidents each year involve carburetor/induction system icing as a probable cause/factor. Under conditions conducive to carburetor/induction icing, between 50 and 70 percent of engine malfunction/failure accidents (exclusive of those due to fuel exhaustion) are due to carburetor/induction system icing. Since the evidence of such icing may not remain long after an accident, it is probable that the frequency of occurrence of such accidents is underestimated; therefore, some extrapolation of the data was conducted. The problem of carburetor/induction system icing is particularly acute for pilots with less than 1000 hours of total flying time. The severity of such accidents is about the same as any accident resulting from a forced landing or precautionary landing. About 144 persons, on the average, are exposed to death and injury each year in accidents involving carburetor/induction icing as a probable cause/factor.

  2. A dynamical-systems approach for computing ice-affected streamflow

    USGS Publications Warehouse

    Holtschlag, David J.

    1996-01-01

    A dynamical-systems approach was developed and evaluated for computing ice-affected streamflow. The approach provides for dynamic simulation and parameter estimation of site-specific equations relating ice effects to routinely measured environmental variables. Comparison indicates that results from the dynamical-systems approach ranked higher than results from 11 analytical methods previously investigated on the basis of accuracy and feasibility criteria. Additional research will likely lead to further improvements in the approach.

  3. Passenger comfort technology for system decision making

    NASA Technical Reports Server (NTRS)

    Conner, D. W.

    1980-01-01

    Decisions requiring passenger comfort technology were shown to depend on: the relationship between comfort and other factors (e.g., cost, urgency, alternate modes) in traveler acceptance of the systems, serving a selected market require technology to quantify effects of comfort versus offsetting factors in system acceptance. Public predict the maximum percentage of travelers who willingly accept the overall comfort of any trip ride. One or the other of these technology requirements apply to decisions on system design, operation and maintenance.

  4. The IceCube data acquisition system: Signal capture, digitization,and timestamping

    SciTech Connect

    The IceCube Collaboration; Matis, Howard

    2009-03-02

    IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs), detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration ismaintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved.

  5. An Approach to Detect and Mitigate Ice Particle Accretion in Aircraft Engine Compression Systems

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Guo, Ten-Huei; Simon, Donald L.

    2013-01-01

    The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation sector. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. This work focuses on developing an accurate and reliable algorithm for detecting the accretion of ice in the low pressure compressor of a generic 40,000 lbf thrust class engine. The algorithm uses only the two shaft speed sensors and works regardless of engine age, operating condition, and power level. In a 10,000-case Monte Carlo simulation, the detection approach was found to have excellent capability at determining ice accretion from sensor noise with detection occurring when ice blocks an average of 6.8% of the low pressure compressor area. Finally, an initial study highlights a potential mitigation strategy that uses the existing engine actuators to raise the temperature in the low pressure compressor in an effort to reduce the rate at which ice accretes.

  6. An Approach to Detect and Mitigate Ice Particle Accretion in Aircraft Engine Compression Systems

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Guo, Ten-Huei; Simon, Donald L.

    2013-01-01

    The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation sector. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. This work focuses on developing an accurate and reliable algorithm for detecting the accretion of ice in the low pressure compressor of a generic 40,000 lbf thrust class engine. The algorithm uses only the two shaft speed sensors and works regardless of engine age, operating condition, and power level. In a 10,000-case Monte Carlo simulation, the detection approach was found to have excellent capability at determining ice accretion from sensor noise with detection occurring when ice blocks an average of 6.8 percent of the low pressure compressor area. Finally, an initial study highlights a potential mitigation strategy that uses the existing engine actuators to raise the temperature in the low pressure compressor in an effort to reduce the rate at which ice accretes.

  7. Analyses and tests for design of an electro-impulse de-icing system

    NASA Technical Reports Server (NTRS)

    Zumwalt, G. W.; Schrag, R. L.; Bernhart, W. D.; Friedberg, R. A.

    1985-01-01

    De-icing of aircraft by using the electro-magnetic impulse phenomenon was proposed and demonstrated in several European countries. However, it is not available as a developed system due to lack of research on the basic physical mechanisms and necessary design parameters. The de-icing is accomplished by rapidly discharging high voltage capacitors into a wire coil rigidly supported just inside the aircraft skin. Induced eddy currents in the skin create a repulsive force resulting in a hammer-like force which cracks, de-bonds, and expels ice on the skin surface. The promised advantages are very low energy, high reliability of de-icing, and low maintenance. Three years of Electo-Impulse De-icing (EIDI) research is summarized and the analytical studies and results of testing done in the laboratory, in the NASA Icing Research Tunnel, and in flight are presented. If properly designed, EIDI was demonstrated to be an effective and practical ice protection system for small aircraft, turbojet engine inlets, elements of transport aircraft, and shows promise for use on helicopter rotor blades. Included are practical techniques of fabrication of impulse coils and their mountings. The use of EIDI with nonmetallic surface materials is also described.

  8. 14 CFR 29.1093 - Induction system icing protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... carburetors has a preheater that can provide a heat rise of 90 °F.; (2) Each rotorcraft with sea level engines using carburetors tending to prevent icing has a preheater that can provide a heat rise of 70 °F.; (3... provide a heat rise of 120 °F.; and (4) Each rotorcraft with altitude engines using carburetors tending...

  9. 14 CFR 25.1093 - Induction system icing protection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... using— (1) Conventional venturi carburetors have a preheater that can provide a heat rise of 120 F. with... probability of ice formation has a preheater that can provide a heat rise of 100 °F. with the engine at 60... before it enters the carburetor, the heat rise in the air caused by that supercharging at any...

  10. A Systems Model for Ethical Decision Making in Public Relations.

    ERIC Educational Resources Information Center

    Bivins, Thomas H.

    1992-01-01

    Advocates using systems theory and systems models for ethical decision making in public relations. Demonstrates how to apply systems theory (with its ability to delineate a complex process and wed it to a model of organizational decision making) to analyzing the ethical dimensions inherent in the public relations process. (SR)

  11. Decision-making in healthcare as a complex adaptive system.

    PubMed

    Kuziemsky, Craig

    2016-01-01

    Healthcare transformation requires a change in how the business of healthcare is done. Traditional decision-making approaches based on stable and predictable systems are inappropriate in healthcare because of the complex nature of healthcare delivery. This article reviews challenges to using traditional decision-making approaches in healthcare and how insight from Complex Adaptive Systems (CAS) could support healthcare management. The article also provides a system model to guide decision-making in healthcare as a CAS. PMID:26656389

  12. Young Solar System in the Making

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for larger annotated version

    This artist's diagram compares the Epsilon Eridani system to our own solar system. The two systems are structured similarly, and both host asteroids (brown), comets (blue) and planets (white dots).

    Epsilon Eridani is our closest known planetary system, located about 10 light-years away in the constellation Eridanus. Its central star is a younger, fainter version of our sun, and is about 800 million years old about the same age of our solar system when life first took root on Earth.

    Observations from NASA's Spitzer Space Telescope show that the system hosts two asteroid belts, in addition to previously identified candidate planets and an outer comet ring.

    Epsilon Eridani's inner asteroid belt is located at about the same position as ours, approximately three astronomical units from its star (an astronomical unit is the distance between Earth and the sun.). The system's second, denser belt lies at about the same place where Uranus orbits in our solar system, or 20 astronomical units from the star.

    In the same way that Jupiter lies just outside our asteroid belt, shepherding its rocky debris into a ring, Epsilon Eridani is thought to have planets orbiting near the rims of its two belts. The first of these planets was identified in 2000 via the radial velocity technique. Called Epsilon Eridani b, it orbits at an average distance of 3.4 astronomical units placing it just outside the system's inner asteroid belt.

    The second planet orbiting near the rim of the outer asteroid belt at 20 astronomical units was inferred when Spitzer discovered the belt.

    A third planet might orbit in Epsilon Eridani at the inner edge of its outermost comet ring, which lies between 35 and 90 astronomical units. This planet was first hinted at in 1998 due to observed lumpiness in the comet ring.

    The outer comet ring around Epsilon Eridani is denser than our comet ring, called the Kuiper belt, because the system is younger. Over time, Epsilon Eridani's ring will become wispier like the Kuiper Belt. Its comets will collide with each other and break up, or get pushed out of the ring by the gravitational influences of planets.

  13. Ice-ocean-atmosphere coupling in the Regional Arctic System Model

    NASA Astrophysics Data System (ADS)

    Roberts, A.; Brunke, M.; Cassano, J. J.; Craig, A.; Duvivier, A.; Hughes, M.; Maslowski, W.; Nijssen, B.; Osinski, R.

    2013-12-01

    This work demonstrates the sea ice model performance in the latest version of the Regional Arctic System Model (RASM), which is a fully coupled regional climate model developed by a group of U.S. institutions as a regional counterpart to the Community Earth System Model (CESM). RASM is comprised of the Parallel Ocean Program (POP), Los Alamos Sea Ice Model (CICE), Variable Infiltration Capacity (VIC) hydrology model and the Weather Research and Forecasting (WRF) Model. It uses the same coupling infrastructure as CESM, with important physics differences that we have found to be important in our high-resolution model. Model evaluations using SSM/I sea ice extent and concentration, ICESat sea ice thickness measurements, ice-ocean buoys, and satellite retrievals of sea ice drift and deformation, lead us to adjust the standard CESM Monin-Obukhov ice-ocean-atmospheric coupling and ice-ocean stress term used for coupling with POP-CICE at eddy-permitting resolution of 1/12 degree with the 50km resolution WRF and VIC models. Evaluation metrics based on scaling laws and wavelet techniques illustrate that 20-minute coupling produces deformation and drift statistics commensurate with high temporal and spatial resolution measurements. However, dynamical interactions are compromised when typical radiative settings are used as in stand-alone POP-CICE and WRF. This highlights the limitations of surface polar boundary conditions in stand-alone models relative to fully coupled interactions. Our results suggest that use of uncoupled models as testbeds for improved polar components of next-generation global Earth System Models may introduce biases into fully coupled systems, and these can be reduced using a regional coupled climate system model, such as RASM, as a testbed instead.

  14. Balance Mass Flux and Velocity Across the Equilibrium Line in Ice Drainage Systems of Greenland

    NASA Technical Reports Server (NTRS)

    Zwally, H. Jay; Giovinetto, Mario B.; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    Estimates of balance mass flux and the depth-averaged ice velocity through the cross-section aligned with the equilibrium line are produced for each of six drainage systems in Greenland. (The equilibrium line, which lies at approximately 1200 m elevation on the ice sheet, is the boundary between the area of net snow accumulation at higher elevations and the areas of net melting at lower elevations around the ice sheet.) Ice drainage divides and six major drainage systems are delineated using surface topography from ERS (European Remote Sensing) radar altimeter data. The net accumulation rate in the accumulation zone bounded by the equilibrium line is 399 Gt/yr and net ablation rate in the remaining area is 231 Gt/yr. (1 GigaTon of ice is 1090 kM(exp 3). The mean balance mass flux and depth-averaged ice velocity at the cross-section aligned with the modeled equilibrium line are 0.1011 Gt kM(exp -2)/yr and 0.111 km/yr, respectively, with little variation in these values from system to system. The ratio of the ice mass above the equilibrium line to the rate of mass output implies an effective exchange time of approximately 6000 years for total mass exchange. The range of exchange times, from a low of 3 ka in the SE drainage system to 14 ka in the NE, suggests a rank as to which regions of the ice sheet may respond more rapidly to climate fluctuations.

  15. What makes closed ecological systems sustainable?

    NASA Astrophysics Data System (ADS)

    Gitelson, I.; Degermendzhy, A.; Rodicheva, E.

    A closed ecosystem has some properties that an open systems lacks. Let us consider the ones that increase the sustainability of an ecosystem. The common feature of biological and physicochemical life support systems is that basically they are both catalytic. There are two fundamental properties distinguishing biological systems: 1) they are auto-catalytic: their catalysts - enzymes of protein nature - are continuously reproduced when the system functions; 2) the program of every process performed by enzymes and the program of their reproduction are inherent in the biological system itself - in the totality of genomes of the species involved in the functioning of the ecosystem. Actually, one cell with the genome capable of the phenotypic realization is enough for the self- restoration of the function performed by the cells of this species in the ecosystem. The multi-cellular organisms with stem cells are constantly ready to repair themselves by intensifying the continuous process of regeneration. We (Gitelson) have made a quantitative investigation of this process by studying the regeneration and reparation of erythrocytes in mammals. The continuous microalgal culture of Chlorella vulgaris was taken to investigate quantitatively the similar functional process of self-restoration in unicellular algae (Rodicheva). Based on the data obtained, we proposed a mathematical model of the restoration process in the cell population that has suffered an acute radiation damage. Besides these general biological mechanisms responsible for their sustainability, closed systems also possess specific features enhancing their stability. They are as follows: 1. Nutrients cannot leave the system. 2. The metabolic pathways of the material cycling are closed. 3. The rates of interlink metabolism are in conformity with each other due to their mutual limitation. We present the data obtained in the Bios-3 experiments that prove the efficiency of this mechanism as a factor of the sustainability. The factors that reduce the sustainability of a CES are as follows: the range of ambient physicochemical parameters compatible with life is rather narrow and it takes rather a long time for the system to restore itself if damage is done to its relatively long-lived species, such as higher plants. A specific property of a small CES is that humans inhabiting it must perform a deterministic control. Our experiments in Bios-3 proved that this control is quite feasible and that it effectively increases the stability of the system. Thus, we can predict that humanity may perform the function of control in the Earth's biosphere in the course of its transformation into the noosphere. * "This work was made possible in part by Award No. REC-002 of the U.S. Civilian Research &Development Foundation for the Independent States of the Former Union (CRDF) and RF Ministry of Education."

  16. Continuous Production of Ice Slurry by Control of Solute Concentration with Ultrasonic Vibration

    NASA Astrophysics Data System (ADS)

    Tada, Yukio; Takimoto, Akira; Miyamoto, Tomoaki; Mikami, Hiroko; Hayashi, Yujiro

    A method to making ice slurry is one of key technology for cold-energy Storage system. This study has been conducted to clarify continuous production of ice slurry by utilizing constitutional supercooling promoted by mixing of two aqueous solutions whose solute concentrations are different. In this technique, fine ice crystals are made under volume-catalyzed nucleation without heat transfer surface. In the experiments, cooled sucrose solution and water were mixed in the cylindrical vessel, and ultrasonic vibration was applied to promote nucleation in the supercooled solution. It was found that the ice making process is classified into three characteristic patterns; stable ice making, ice making in stratified concentration layer due to defect in solute-mixing, and no ice making due to no supercooling by mixing. The characteristics of ice making were discussed with the mixing ratio and total flow rate of solutions.

  17. Development of Measurement System for Three-Dimensional Structure of Ice Crystals in Raw Beef Samples

    NASA Astrophysics Data System (ADS)

    Do, Gab-Soo; Sagara, Yasuyuki; Tabata, Mizuho; Kudoh, Ken-Ichi; Higuchi, Toshiro

    Micro-Slicer Image Processing System (MSIPS) has been developed for measuring the three-dimensional(3-D) structure and distribution of ice crystals formed in biological materials. The system has functions to reconstruct the 3-D image based on the image data of exposed cross sections obtained by multi-slicing of a frozen sample with the minimum thickness of 1?m and to display the internal structure as well as an arbitrary cross section of the sample choosing observation angles. The effects of freezing conditions on the morphology and distribl1tion of ice crystals were demonstrated quantitatively from the observations of raw beef stained by fluorescent indicator. The 3-D image of the sample demonstrated that the growth of ice columns was restricted by the intrinsic structure of muscle fibers. The proposed method provided a new tool to investigate the effects of freezing conditions on the size, morphology and distribution of ice crystals.

  18. An Instructional System for Consumer Decision-Making: Teacher's Manual.

    ERIC Educational Resources Information Center

    Suchman, J. Richard; DiSario, Martha R.

    An instructional system is presented for building the competencies of adult basic education students in making consumer decisions, and offers a guide to teachers who wish to design their own decision-making problems for students. The first four chapters provide a brief introduction, discuss the rational consumer decision-making process and the…

  19. Quantum criticality and fractional charge excitations in itinerant ice-rule systems

    NASA Astrophysics Data System (ADS)

    Udagawa, Masafumi; Ishizuka, Hiroaki; Motome, Yukitoshi

    2013-03-01

    ``Ice rule'' is a configurational constraint on Ising-type variables defined on tetrahedron-based lattices, such as a pyrochlore lattice, so that two out of the four sites on a tetrahedron are in the opposite state to the other two. This concept plays an important role in many systems, such as water ice Ih, magnetite Fe3O4, and spin ice materials Ho(Dy)2Ti2O7. Under the ice-rule constraint, the ground state is disordered and retains macroscopic degeneracy. Nevertheless, the ice-rule configuration is not completely random but has a peculiar spatial structure with quasi-long-range correlation. It is interesting to ask how itinerant electrons change their properties by coupling to this anomalous spatial structure. To answer this problem, we adopt an extended Falicov-Kimball model as a minimal model, in which itinerant electrons interact with localized charge degrees of freedom under the ice rule. We exactly solve this model on a loop-less variant of the tetrahedron-based lattices, a tetrahedron Husimi cactus and clarify the ground-state phase diagram. The exact solution reveals a quantum critical point separating two insulating phases, where a novel non-Fermi-liquid behavior emerges. We also discuss the nature of fractional excitations breaking the ice-rule manifold.

  20. Long-term observing system for the oceanic regime of Filchner-Ronne Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Østerhus, Svein; Schröder, Michael; Hellmer, Hartmunt; Darelius, Elin; Nicholls, Keith; Makinson, Keith

    2014-05-01

    Long term observations of the flow of dense waters from their area of formation to the abyss of the World Ocean, and the return flow of warm waters, are central to climate research. For the Weddell Sea an important component of such a system entails monitoring the formation of High Salinity Shelf Water (HSSW) on the continental shelf north of Ronne Ice Front, the transformation to Ice Shelf Water (ISW) beneath the floating Filchner-Ronne ice shelf, and the flux of ISW overflowing the shelf break to the deep Weddell Sea. Equally important is the return flow of warm water toward the Filchner-Ronne Ice Shelf system. AWI, BAS and UNI/UIB operate a number of monitoring stations in the southern Weddell Sea. The systems build upon techniques and methods developed over several decades and have a proven record of high data return. Here we present plans for extending, integrating and operating the existing long term observatories to increase our knowledge of the natural variability of the ocean-ice shelf system, and to allow early identification of possible changes of regional or global importance. The S2 observatory at the Filchner sill was established in 1977 and continues to deliver the longest existing marine time series from Antarctica. As a key site for monitoring the ISW overflow S2 is a part of the global net of monitoring sites under CLIVAR Southern Ocean Observing System (SOOS) and OceanSITES. The existing S2 observatory consists of a sub-surface mooring carrying sensors for current velocity, temperature, salinity and dissolved oxygen measurements. Observations at the Filchner sill also show a seasonal inflow of relatively warm water that is able to reach Filchner Ice Front. New model results indicate that this flow of water might increase in the future and we have deployed a number of instrumented moorings in the Filchner Depression to estimate the heat flux towards the ice shelf. In 1999 we established Site 5 on Ronne Ice Shelf using a hot-water drill to access the 402 m of water underlying the 763-m thick ice. Results from the multiyear time series show the sensitivity of the sub-ice shelf circulation to changes in conditions over the continental shelf and highlight the importance of monitoring the ice shelf cavity. We will reoccupy Site 5 in the 2014/15 season to deploy a suite of observing systems for long time monitoring of the circulation below Ronne Ice Shelf. The systems will consist of sub-ice shelf oceanographic moorings instrumented with high quality sensors. They will transmit in real-time and are designed to operate for more than 10 years. In 2015/16 we will extend the observing network by deploying observatories on Filchner Ice Shelf. The Filchner-Ronne Ice Shelf and S2 observatories will provide the first ever concurrent observations from the ice-shelf cavity where ISW is formed, and the sill where it starts its descent towards the deep Weddell Sea, and will provide a unique dataset allowing us to link processes and variability within the cavity directly to overflow properties and deep water formation.

  1. JBluIce-EPICS: a fast and flexible open-source beamline control system for macromolecular crystallography

    NASA Astrophysics Data System (ADS)

    Stepanov, S.; Hilgart, M.; Makarov, O.; Pothineni, S. B.; Yoder, D.; Ogata, C.; Sanishvili, R.; Venugopalan, N.; Becker, M.; Clift, M.; Smith, J. L.; Fischetti, R. F.

    2013-03-01

    This paper overviews recent advances in the JBluIce-EPICS open-source control system designed at the macromolecular crystallography beamlines of the National Institute of General Medical Sciences and National Cancer Institute at the Advanced Photon Source (GM/CA@APS). We discuss some technical highlights of this system distinguishing it from the competition, such as reduction of software layers to only two, possibility to operate JBluIce in parallel with other beamline controls, plugin-enabled architecture where the plugins can be written in any programming language, and utilization of the whole power of the Java integrated development environment in the Graphical User Interface. Then, we demonstrate how these highlights help to make JBluIce fast, easily adaptable to new beamline developments, and intuitive for users. In particular, we discuss several recent additions to the system including a bridge between crystal rastering and data collection, automatic detection of raster polygons from optical crystal centering, background data processing, and a pathway to a fully automated pipeline from crystal screening to solving crystal structure.

  2. Experimental investigation on performance of ice storage air-conditioning system with separate heat pipe

    SciTech Connect

    Fang, Guiyin; Liu, Xu; Wu, Shuangmao

    2009-11-15

    An experimental study on operation performance of ice storage air-conditioning system with separate helical heat pipe is conducted in this paper. The experimental system of ice storage air-conditioning system with separate heat pipe is set up. The performance parameters such as the evaporation pressure and the condensation pressure of refrigeration system, the refrigeration capacity and the COP (coefficient of performance) of the system, the IPF (ice packing factor) and the cool storage capacity in the cool storage tank during charging period, and the cool discharge rate and the cool discharge capacity in the cool storage tank, the outlet water temperature in the cool storage tank and the outlet air temperature in room unit during discharging period are investigated. The experimental results show that the ice storage air-conditioning system with separate helical heat pipe can stably work during charging and discharging period. This indicates that the ice storage air-conditioning system with separate helical heat pipe is well adapted to cool storage air-conditioning systems in building. (author)

  3. Ice & Fire: Missions to the most difficult solar system destinations… on a budget

    NASA Astrophysics Data System (ADS)

    Staehle, Robert L.; Brewster, Stephen C.; Carraway, John B.; Chatterjee, Alok K.; Clark, Karla B.; Doyle, Richard J.; Henry, Paul K.; Johannesen, Jennie R.; Johnson, Torrence V.; Jorgensen, Edward J.; Kemski, Richard P.; Ludwinski, Jan M.; Maddock, Robert W.; Mondt, Jack F.; Randolph, James E.; Terrile, Richard J.; Tsurutani, Bruce T.

    1999-11-01

    Three radii from the surface of the Sun… more natural radiation around Jupiter than would be encountered immediately following a nuclear war… to the farthest planet and beyond… these challenges are faced by the three "Ice & Fire" missions: Solar Probe, Europa Orbiter, and PlutoKuiper Express. These three missions will be beneficiaries of the X2000 and related advanced technology development programs. Technology developments now in progress make these missions achievable at costs recently thought adequate only for missions of relatively short durations to "nearby" destinations. The next mission to Europa after Galileo will determine whether a global subsurface liquid water ocean is currently present, and will identify locations where the ocean, if it exists, may be most accessible to future missions. Pluto-Kuiper Express will complete the reconnaissance of the known planets in our Solar System with geological, compositional, and atmospheric mapping of Pluto and Charon while Pluto remains relatively near the Sun during its 248 year orbit. An extended mission to a Kuiper Disk object may be possible, depending on remaining sciencecraft resources. Using a unique combination of Sun shield/high gain antenna and quadrature encounter geometry, Solar Probe will deeply penetrate our nearest star's atmosphere to make local measurements of the birth of solar wind, and to remotely image features as small as 60 kilometers across on the Sun's surface. Avionics technology, leading to integration of functions among a set of multichip modules with standard interfaces, will enable lower production costs, lower power and mass, and the ability to package with modest shielding to enable survival in orbit around Europa inside Jupiter's intense radiation belts. The same avionics and software can be utilized on the other Ice & Fire missions. Each mission is characterized by a long cruise to its destination, facilitated by planetary flybys. The flight systems will represent a unique early integration of science "payload" and "spacecraft," becoming a more integrated "sciencecraft." To reduce operations and tracking costs, sciencecraft will be more autonomous. They will self-monitor and self-command, while sending a continuous beacon alerting ground receivers to general sciencecraft health and any need for immediate attention. Where solar power proves impractical for achieving mission goals, an advanced radioisotope power source may be utilized with a much smaller amount of fuel than on prior missions. The three missions described are to begin the Outer Planets/Solar Probe exploration program, as first proposed in the FY1998 Federal Budget. Sciencecraft, launch systems and mission operations must all fit within a single program, encouraging system- and program-wide tradeoffs to minimize costs. Some of the system and technological solutions utilized by these missions may find application in a variety of other science-driven missions.

  4. Gas lift systems make ideal offshore workers

    SciTech Connect

    1999-05-01

    With a low initial installation cost and small footprint, gas lift systems are well suited for offshore installations where compressed gas is usually already available. These systems are used on multiple and slimhole completions and handle sandy conditions well. They are also used to kick off wells that will flow naturally once the heavier completion fluids leave the production string. Gas lift itself is a mature workaday technology. Measurement and control of gas flow is an area of intense development in gas lift technology. One new control method involves production of multiple completions through a single wellbore. Typically, gas lift valves are opened and closed through tubing pressure. But downhole measurement technology does not yet yield information good enough for stable gas lift control of multiple completions. Gas lift is proving to be a useful AL technique in conjunction with electric submersible pumps (ESP). Located above the ESP pump, the gas lift can reduce the head and allow greater flow. This is helpful when small casing restricts the size of the downhole ESP pump. Wells can usually be produced by the gas lift alone in case of ESP failure, or by replacing the ESP where schedules, high repair costs or low prices rule out repair.

  5. Crystallization of amorphous water ice in the solar system

    NASA Technical Reports Server (NTRS)

    Jenniskens, P.; Blake, D. F.

    1996-01-01

    Electron diffraction studies of vapor-deposited water ice have characterized the dynamical structural changes during crystallization that affect volatile retention in cometary materials. Crystallization is found to occur by nucleation of small domains, while leaving a significant part of the amorphous material in a slightly more relaxed amorphous state that coexists metastably with cubic crystalline ice. The onset of the amorphous relaxation is prior to crystallization and coincides with the glass transition. Above the glass transition temperature, the crystallization kinetics are consistent with the amorphous solid becoming a "strong" viscous liquid. The amorphous component can effectively retain volatiles during crystallization if the volatile concentration is approximately 10% or less. For higher initial impurity concentrations, a significant amount of impurities is released during crystallization, probably because the impurities are trapped on the surfaces of micropores. A model for crystallization over long timescales is described that can be applied to a wide range of impure water ices under typical astrophysical conditions if the fragility factor D, which describes the viscosity behavior, can be estimated.

  6. Architecture for decision making in a home safety system

    NASA Astrophysics Data System (ADS)

    Uusitalo, Ilkka; Mantere, Matti

    2012-01-01

    We describe the requirements and architecture for decision making in the context of a home safety system. The architecture is capable of local- and network supported decision making. To develop and test the architecture in practice we define a use case of an elderly man in his daily chores. We also discuss the ethical concerns posed by such a system.

  7. Architecture for decision making in a home safety system

    NASA Astrophysics Data System (ADS)

    Uusitalo, Ilkka; Mantere, Matti

    2011-12-01

    We describe the requirements and architecture for decision making in the context of a home safety system. The architecture is capable of local- and network supported decision making. To develop and test the architecture in practice we define a use case of an elderly man in his daily chores. We also discuss the ethical concerns posed by such a system.

  8. Rapid Access Ice Drill: A New Tool for Exploration of the Deep Antarctic Ice Sheets and Subglacial Geology

    NASA Astrophysics Data System (ADS)

    Goodge, J. W.; Severinghaus, J. P.

    2014-12-01

    The Rapid Access Ice Drill (RAID) will penetrate the Antarctic ice sheets in order to core through deep ice, the glacial bed, and into bedrock below. This new technology will provide a critical first look at the interface between major ice caps and their subglacial geology. Currently in construction, RAID is a mobile drilling system capable of making several long boreholes in a single field season in Antarctica. RAID is interdisciplinary and will allow access to polar paleoclimate records in ice >1 Ma, direct observation at the base of the ice sheets, and recovery of rock cores from the ice-covered East Antarctic craton. RAID uses a diamond rock-coring system as in mineral exploration. Threaded drill-pipe with hardened metal bits will cut through ice using reverse circulation of Estisol for pressure-compensation, maintenance of temperature, and removal of ice cuttings. Near the bottom of the ice sheet, a wireline bottom-hole assembly will enable diamond coring of ice, the glacial bed, and bedrock below. Once complete, boreholes will be kept open with fluid, capped, and made available for future down-hole measurement of thermal gradient, heat flow, ice chronology, and ice deformation. RAID will also sample for extremophile microorganisms. RAID is designed to penetrate up to 3,300 meters of ice and take sample cores in less than 200 hours. This rapid performance will allow completion of a borehole in about 10 days before moving to the next drilling site. RAID is unique because it can provide fast borehole access through thick ice; take short ice cores for paleoclimate study; sample the glacial bed to determine ice-flow conditions; take cores of subglacial bedrock for age dating and crustal history; and create boreholes for use as an observatory in the ice sheets. Together, the rapid drilling capability and mobility of the drilling system, along with ice-penetrating imaging methods, will provide a unique 3D picture of the interior Antarctic ice sheets.

  9. A coupled dynamic-thermodynamic model of an ice-ocean system in the marginal ice zone

    NASA Technical Reports Server (NTRS)

    Hakkinen, Sirpa

    1987-01-01

    Thermodynamics are incorporated into a coupled ice-ocean model in order to investigate wind-driven ice-ocean processes in the marginal zone. Upswelling at the ice edge which is generated by the difference in the ice-air and air-water surface stresses is found to give rise to a strong entrainment by drawing the pycnocline closer to the surface. Entrainment is shown to be negligible outside the areas affected by the ice edge upswelling. If cooling at the top is included in the model, the heat and salt exchanges are further enhanced in the upswelling areas. It is noted that new ice formation occurs in the region not affected by ice edge upswelling, and it is suggested that the high-salinity mixed layer regions (with a scale of a few Rossby radii of deformation) will overturn due to cooling, possibly contributing to the formation of deep water.

  10. Tightly integrated single- and multi-crystal data collection strategy calculation and parallelized data processing in JBluIce beamline control system

    SciTech Connect

    Pothineni, Sudhir Babu; Venugopalan, Nagarajan; Ogata, Craig M.; Hilgart, Mark C.; Stepanov, Sergey; Sanishvili, Ruslan; Becker, Michael; Winter, Graeme; Sauter, Nicholas K.; Smith, Janet L.; Fischetti, Robert F.

    2014-11-18

    The calculation of single- and multi-crystal data collection strategies and a data processing pipeline have been tightly integrated into the macromolecular crystallographic data acquisition and beamline control software JBluIce. Both tasks employ wrapper scripts around existing crystallographic software. JBluIce executes scripts through a distributed resource management system to make efficient use of all available computing resources through parallel processing. The JBluIce single-crystal data collection strategy feature uses a choice of strategy programs to help users rank sample crystals and collect data. The strategy results can be conveniently exported to a data collection run. The JBluIce multi-crystal strategy feature calculates a collection strategy to optimize coverage of reciprocal space in cases where incomplete data are available from previous samples. The JBluIce data processing runs simultaneously with data collection using a choice of data reduction wrappers for integration and scaling of newly collected data, with an option for merging with pre-existing data. Data are processed separately if collected from multiple sites on a crystal or from multiple crystals, then scaled and merged. Results from all strategy and processing calculations are displayed in relevant tabs of JBluIce.

  11. Tightly integrated single- and multi-crystal data collection strategy calculation and parallelized data processing in JBluIce beamline control system

    DOE PAGESBeta

    Pothineni, Sudhir Babu; Venugopalan, Nagarajan; Ogata, Craig M.; Hilgart, Mark C.; Stepanov, Sergey; Sanishvili, Ruslan; Becker, Michael; Winter, Graeme; Sauter, Nicholas K.; Smith, Janet L.; et al

    2014-11-18

    The calculation of single- and multi-crystal data collection strategies and a data processing pipeline have been tightly integrated into the macromolecular crystallographic data acquisition and beamline control software JBluIce. Both tasks employ wrapper scripts around existing crystallographic software. JBluIce executes scripts through a distributed resource management system to make efficient use of all available computing resources through parallel processing. The JBluIce single-crystal data collection strategy feature uses a choice of strategy programs to help users rank sample crystals and collect data. The strategy results can be conveniently exported to a data collection run. The JBluIce multi-crystal strategy feature calculates amore » collection strategy to optimize coverage of reciprocal space in cases where incomplete data are available from previous samples. The JBluIce data processing runs simultaneously with data collection using a choice of data reduction wrappers for integration and scaling of newly collected data, with an option for merging with pre-existing data. Data are processed separately if collected from multiple sites on a crystal or from multiple crystals, then scaled and merged. Results from all strategy and processing calculations are displayed in relevant tabs of JBluIce.« less

  12. Tightly integrated single- and multi-crystal data collection strategy calculation and parallelized data processing in JBluIce beamline control system.

    PubMed

    Pothineni, Sudhir Babu; Venugopalan, Nagarajan; Ogata, Craig M; Hilgart, Mark C; Stepanov, Sergey; Sanishvili, Ruslan; Becker, Michael; Winter, Graeme; Sauter, Nicholas K; Smith, Janet L; Fischetti, Robert F

    2014-12-01

    The calculation of single- and multi-crystal data collection strategies and a data processing pipeline have been tightly integrated into the macromolecular crystallographic data acquisition and beamline control software JBluIce. Both tasks employ wrapper scripts around existing crystallographic software. JBluIce executes scripts through a distributed resource management system to make efficient use of all available computing resources through parallel processing. The JBluIce single-crystal data collection strategy feature uses a choice of strategy programs to help users rank sample crystals and collect data. The strategy results can be conveniently exported to a data collection run. The JBluIce multi-crystal strategy feature calculates a collection strategy to optimize coverage of reciprocal space in cases where incomplete data are available from previous samples. The JBluIce data processing runs simultaneously with data collection using a choice of data reduction wrappers for integration and scaling of newly collected data, with an option for merging with pre-existing data. Data are processed separately if collected from multiple sites on a crystal or from multiple crystals, then scaled and merged. Results from all strategy and processing calculations are displayed in relevant tabs of JBluIce. PMID:25484844

  13. Tightly integrated single- and multi-crystal data collection strategy calculation and parallelized data processing in JBluIce beamline control system

    PubMed Central

    Pothineni, Sudhir Babu; Venugopalan, Nagarajan; Ogata, Craig M.; Hilgart, Mark C.; Stepanov, Sergey; Sanishvili, Ruslan; Becker, Michael; Winter, Graeme; Sauter, Nicholas K.; Smith, Janet L.; Fischetti, Robert F.

    2014-01-01

    The calculation of single- and multi-crystal data collection strategies and a data processing pipeline have been tightly integrated into the macromolecular crystallographic data acquisition and beamline control software JBluIce. Both tasks employ wrapper scripts around existing crystallographic software. JBluIce executes scripts through a distributed resource management system to make efficient use of all available computing resources through parallel processing. The JBluIce single-crystal data collection strategy feature uses a choice of strategy programs to help users rank sample crystals and collect data. The strategy results can be conveniently exported to a data collection run. The JBluIce multi-crystal strategy feature calculates a collection strategy to optimize coverage of reciprocal space in cases where incomplete data are available from previous samples. The JBluIce data processing runs simultaneously with data collection using a choice of data reduction wrappers for integration and scaling of newly collected data, with an option for merging with pre-existing data. Data are processed separately if collected from multiple sites on a crystal or from multiple crystals, then scaled and merged. Results from all strategy and processing calculations are displayed in relevant tabs of JBluIce. PMID:25484844

  14. An overview of laboratory studies on the energetic processes in water-rich ices containing organic impurities at outer Solar System temperatures.

    NASA Astrophysics Data System (ADS)

    Gudipati, M. S.; Allamandola, L. J.

    2006-12-01

    Solid water-rich ice is an important constituent in our Solar System. Planets such as Earth and Mars, Moons such as Europa and Enceladus, Comets, rings of Saturn, and KBOs are covered with solid water ices. Thus, understanding the intricate physics and chemistry of these ices is a non-trivial and non-negligible task that needs both laboratory and in-situ observational work to make advances in this field. Over the past several years, we have been systematically studying VUV-radiation processing of organic impurities embedded in water-ices in the temperature range between 20 K and 180 K. Since PAHs are abundant extraterrestrial species and their optical strong absorption occurs in the UV-VIS-NIR region (0.2 -- 0.9 μ m) where water-ice is transparent, we have focused on water rich ices containing PAHs. During these in-situ studies we discovered several counter-intuitive phenomena (see for example: Gudipati {&} Allamandola, 2006, Astrophys. J. 638, 286 {&} J. Phys. Chem. A 110, 9020 and references therein): \\begin{itemize} PAHs embedded in cryogenic water-ice are easily and efficiently ionized (>80{%}, i.e., near quantitative ion yields) to the cation form by VUV photons. In water ice, PAH ionization energy is lowered by up to 2 eV compared to the gas-phase, in agreement with recent theoretical predictions. PAH cations are stabilized in water ice to temperatures as high as 120 K. Sequential photoionization leading to the formation and stabilization of doubly positively charged organic (PAH) species in water ice has also been found. Electrons are stored in these energy processed water-ices doped with organic impurities. These findings have a range of applications to understanding the geology, chemistry, and physics of icy bodies in the outer Solar System such as coloration, energy budget, outbursts and atmospheres. These and other applications to outer Solar System will be discussed. Acknowledgments: This work was supported by grants from NASA's Exobiology, Astrobiology, and Long Term Space Astrophysics Programs (Grants: 344-58-12, 344-53-92, and 399-20-40 respectively), NASA's Planetary Geology and Geophysics Program (Grant: NNG05GI01G) and a NASA - University of Maryland cooperative agreement (NCC 2-1303).

  15. Non-linear feedbacks affecting sea ice deformation in the Regional Arctic System Model (RASM)

    NASA Astrophysics Data System (ADS)

    Roberts, A.; Maslowski, W.; Mills, T.; Hunke, E. C.; Craig, A.; Osinski, R.; Cassano, J. J.; Duvivier, A.; Hughes, M.; Zeng, X.; Brunke, M.; Gutowski, W. J., Jr.; Fisel, B. J.

    2014-12-01

    We present the latest results of high-resolution sea ice simulations from the fully coupled Regional Arctic System Model (RASM), including explicit melt ponds, form drag and anisotropic sea ice rheology. RASM is a pan-Arctic model composed of the Parallel Ocean Program (POP) and Los Alamos Sea ice Model (CICE5) at ~9km resolution, coupled to the Weather Research and Forecasting Model (WRF) and Variable Infiltration Capacity (VIC) model at 50km resolution using the Community Earth System Model (CESM) coupling framework. Using RASM, we have analyzed coupled feedbacks resulting from different sea ice mechanics formulations. Strong spatial and temporal scaling of sea ice deformation has been observed in the Arctic using the Radarsat Geophysical Processing System and Global Positioning System equipped buoys. Whereas previous results from stand-alone ice-ocean simulations suggest that the established Elastic Viscous Plastic (EVP) rheology is unable to replicate these features, RASM simulates the observed scaling using EVP, with a spatial scaling fractal dimension of around -0.23, as compared to the observed range of -0.18 to -0.20. Using this metric, we extend our analysis to test for spatial scaling in sea ice deformation using a recently revised EVP formulation, as well as the new Elastic Plastic Anistropic rheology in CICE5. Our results suggest that a fundamental source of scaling stems from feedbacks associated with frequent coupling between high resolution ocean and atmospheric models, and this result serves as an example of the broader utility of limited-area, fully coupled models in isolating coupled feedbacks and evaluating them using daily in-situ and satellite measurements.

  16. An Investigation of a Thermal Ice-Prevention System for a Twin-Engine Transport Airplane

    NASA Technical Reports Server (NTRS)

    Jones, Alun R

    1946-01-01

    Several previously published reports on a comprehensive investigation of a thermal ice-prevention system for a typical twin-engine transport airplane are correlated with some unpublished data to present the entire investigation in one publication. Several previously published reports on a comprehensive investigation of a thermal ice-prevention system for a typical twin-engine transport airplane are correlated with some unpublished data to present the entire investigation in one publication. The thermal system investigated was based upon the transfer of heat from the engine exhaust gas to air, which is then caused to flow along the inner surface of any portion of the airplane for which protection is desired.

  17. Measurements of the isotopic composition of ice and vapor above a tropical convective system

    NASA Astrophysics Data System (ADS)

    O'Brien, A.; Hanisco, T. F.; Sayres, D. S.; St Clair, J.; Smith, J. B.; Weinstock, E. M.; Anderson, J.

    2011-12-01

    We present observations of the isotopic composition of condensed and vapor water in the lower tropical tropopause layer (TTL) above a large summertime tropical convective system obtained by the Hoxotope and ICOS isotope instruments flown on the NASA WB-57 during TC4. A simple ice isotopic physics model is used in conjunction with our observational data to determine the origin of the condensed phase encountered above the cloud top. Regions of ice that are characteristic of both convective lofting, where the ice is isotopically heavier than the surroundings, and in situ condensation, where the ice shows little difference in isotopic composition with respect to the vapor, are encountered above the convective cell with convective lofting being the dominant mechanism by which water is transported to this altitude. While ice lofting is an important component of water transport models in the TTL, the isotopic composition of ice has been a relatively unconstrained parameter. Observations of condensed isotopes coupled with the vertical profile of vapor in the summertime TTL suggests that there is a seasonal variation in convective timescales that needs to be accounted for in convectively-influenced trajectory models describing the transport of water in the TTL.

  18. Analysis of ice crystals occuring in the upper high levels of tropical mesoscale convective systems

    NASA Astrophysics Data System (ADS)

    Delplanque, Alexandre

    2015-04-01

    In 2010 several test flights were performed in tropical marine meso-scale convective systems at flight levels between 10.5 and 10.8 km. Ice crystals were observed with a high speed CDD camera (image pixel resolution: 15 μ m, time resolution 0.007 s) hereafter called the Airbus nephelometer. In-cloud observations were not restricted to the stratiform regions of the MCS but also convective cores were intensely sampled. High number concentrations of ice crystals (N > 1000 L-1) and IWC of more than 4 g.m-3 could be observed. The main objective of our study is the retrieval of the ice water mass from ice particle number distribution and crystal habits, both observed by the Airbus nephelometer. The shape of ice particles was supposed to correspond to the form of oblate spheroids. A statistical study of the aspect ratio of crystal images was performed comparing two different geometrical approaches for the aspect ratio of their semi axis. One uses the ratio of minimum to maximum length, the other is based on the aspect ratio which best fits the crystal image. Different regions of the MCS present different mean aspect ratios measured at small scale (200 m). Variations of the aspect ratio seem to be associated with different nucleation and growth histories for the crystals. For regions with 'young' ice crystals, an anti-correlation between the aspect ratio and ice number concentration was observed. This observation is compared with the results obtained from simple diffusional growth modeling. To better quantify the characteristics of high concentrations of small ice crystal MCS regions, we propose to use the size distribution of the mean aspect ratio (from 100 μ m to 1 mm), to distinguish quite different behaviors for 'young' and 'mature' convective regions.

  19. The CONCEPTS Global Ice-Ocean Prediction System: Establishing an Environmental Prediction Capability in Canada

    NASA Astrophysics Data System (ADS)

    Pellerin, Pierre; Smith, Gregory; Testut, Charles-Emmanuel; Surcel Colan, Dorina; Roy, Francois; Reszka, Mateusz; Dupont, Frederic; Lemieux, Jean-Francois; Beaudoin, Christiane; He, Zhongjie; Belanger, Jean-Marc; Deacu, Daniel; Lu, Yimin; Buehner, Mark; Davidson, Fraser; Ritchie, Harold; Lu, Youyu; Drevillon, Marie; Tranchant, Benoit; Garric, Gilles

    2015-04-01

    Here we describe a new system implemented recently at the Canadian Meteorological Centre (CMC) entitled the Global Ice Ocean Prediction System (GIOPS). GIOPS provides ice and ocean analyses and 10 day forecasts daily at 00GMT on a global 1/4° resolution grid. GIOPS includes a full multivariate ocean data assimilation system that combines satellite observations of sea level anomaly and sea surface temperature (SST) together with in situ observations of temperature and salinity. In situ observations are obtained from a variety of sources including: the Argo network of autonomous profiling floats, moorings, ships of opportunity, marine mammals and research cruises. Ocean analyses are blended with sea ice analyses produced by the Global Ice Analysis System.. GIOPS has been developed as part of the Canadian Operational Network of Coupled Environmental PredicTion Systems (CONCEPTS) tri-departmental initiative between Environment Canada, Fisheries and Oceans Canada and National Defense. The development of GIOPS was made through a partnership with Mercator-Océan, a French operational oceanography group. Mercator-Océan provided the ocean data assimilation code and assistance with the system implementation. GIOPS has undergone a rigorous evaluation of the analysis, trial and forecast fields demonstrating its capacity to provide high-quality products in a robust and reliable framework. In particular, SST and ice concentration forecasts demonstrate a clear benefit with respect to persistence. These results support the use of GIOPS products within other CMC operational systems, and more generally, as part of a Government of Canada marine core service. Impact of a two-way coupling between the GEM atmospheric model and NEMO-CICE ocean-ice model will also be presented.

  20. HAIC/HIWC field campaign - investigating ice microphysics in high ice water content regions of mesoscale convective systems

    NASA Astrophysics Data System (ADS)

    Leroy, Delphine; Fontaine, Emmanuel; Schwarzenboeck, Alfons; Strapp, J. Walter; Lilie, Lyle; Dezitter, Fabien; Grandin, Alice

    2015-04-01

    Despite existing research programs focusing on tropical convection, high ice water content (IWC) regions in Mesoscale Convective Systems (MCS) - potentially encountered by commercial aircraft and related to reported in-service events - remain poorly documented either because investigation of such high IWC regions was not of highest priority or because utilized instrumentation was not capable of providing accurate cloud microphysical measurements. To gather quantitative data in high IWC regions, a multi-year international HAIC/HIWC (High Altitude Ice Crystals / High Ice Water Content) field project has been designed including a first field campaign conducted out of Darwin (Australia) in 2014. The French Falcon 20 research aircraft had been equipped among others with a state-of-the-art in situ microphysics package including the IKP (isokinetic evaporator probe which provides a reference measurement of IWC and TWC), the CDP (cloud droplet spectrometer probe measuring particles in the range 2-50 µm), the 2D-S (2D-Stereo, 10-1280 µm) and PIP (precipitation imaging probe, 100-6400 µm) optical array probes. Microphysical data collection has been performed mainly at -40°C and -30°C levels, whereas little data could be sampled at -50°C and at -15C/-10°C. The study presented here focuses on ice crystal size properties, thereby analyzing in detail the 2D image data from 2D-S and PIP optical array imaging probes. 2D images recorded with 2D-S and PIP were processed in order to extract a large variety of geometrical parameters, such as maximum diameter (Dmax), 2D surface equivalent diameter (Deq), and the corresponding number particle size distribution (PSD). Using the PSD information from both probes, a composite size distribution was then built, with sizes ranging from few tens of µm to roughly 10 mm. Finally, mass-size relationships for ice crystals in tropical convection were established in terms of power laws in order to compute median mass diameters MMDmax and MMDeq. The preliminary analysis of all HAIC/HIWC flights, performed during the first flight campaign out of Darwin, demonstrate that various flights include high IWC regions mostly produced by high concentrations of small crystals while other flights with similar peak IWCs show high IWC regions nevertheless composed of primarily larger particles. This interesting result indicates that high IWC can be produced and or maintained in various environments, preferentially high concentrations of small crystals, however sometimes by smaller concentrations of larger sized crystal populations. These variations in crystal sizes producing comparable high IWC values are reflected by respective variations in MMDmax and MMDeq. Acknowledgements: The research leading to these results has received funding from the European Union's Seventh Framework Program in research, technological development and demonstration under grant agreement n°ACP2-GA-2012-314314. The research leading to these results has received funding from the European Aviation Safety Agency Research Program under service contract n° EASA.2013.FC27.

  1. Ices in the solar system; Proceedings of the Advanced Research Workshop, Nice, France, January 16-19, 1984

    NASA Astrophysics Data System (ADS)

    Klinger, J.; Benest, D.; Dollfus, A.; Smoluchowski, R.

    The physics and remote sensing of ices are discussed, taking into account some fundamentals of planetary glaciology, the water-rich region of the system NH3-H2O, phase transitions in solid methane at high pressure, clathrate hydrates in the solar system, polymorphism in vapor deposited amorphous solid water, creep of high-pressure ice VI, measurement of the extinction of water ice particles, and ices and color systematics in the case of outer solar system materials. Other topics explored are related to cosmochemistry of ices and interplanetary particles, the icy nuclei of comets, ices on Mars, and rings, icy satellites and Pluto. Attention is given to the evolution of ices from interstellar space to the solar system, the formation history and environment of cometary nuclei, the present status of the icy conglomerate model, amorphous and porous ices in cometary nuclei, the Martian polar caps, geomorphologic evidence for ground ice on Mars, icy satellites of Uranus, ices in planetary rings, and the small, icy satellites of Saturn.

  2. Ice-sheet feedbacks to freshwater perturbations on the climate system

    NASA Astrophysics Data System (ADS)

    Philippon, G.; Ramstein, G.; Charbit, S.

    2009-04-01

    Fresh water inputs in North Atlantic due to huge surge of icebergs coming from ice sheets might be responsible for drastic regional and global abrupt climatic transitions. To quantify the sensitivity of climate system to these fresh water inputs, we use a model of intermediate complexity coupled to ice-sheet models for both Northern and Southern Hemispheres. We mimic the Dansgaard-Oeschger and Heinrich events by forcing the model with appropriate fresh water perturbations. Moreover, we perform perturbations at high latitudes for both Northern (North Atlantic) and Southern (Circum Polar Ocean) hemispheres. The originality of this study is to investigate with such a global model, the response of the coupled system to freshwater discharges in three different climate contexts, the Last Maximum Glacial (LGM), the Last Glacial Inception (LGI) and the present-day (PD) climates. We show that: 1/ In all climate contexts, the stability of the North Atlantic circulation diagnosed through "hysteresis diagram is more sensitive to freshwater flux when ice sheets are considered as an interactive component of the climate system. 2/ The seesaw mechanism (swings between the Northern and Southern hemispheres) occurs mostly for the North Atlantic freshwater perturbation whereas it remains very weak for the Southern Ocean freshwater release. Moreover, in most cases, the seesaw is enhanced when ice sheets are interactive. 3/ An interesting result is that the fresh water perturbation amplifies the inception of an ice sheet at LGI. The sea-level drop is significantly increased and is in a better agreement with data.

  3. Systems for measuring thickness of temperate and polar ice from the ground or from the air.

    USGS Publications Warehouse

    Watts, R.D.; Wright, D.L.

    1981-01-01

    Equipment has been designed and tested for ground-based and airborne sounding of temperate glaciers. Echoes have been obtained from ice depths of 550m using the airborne system and about 1000m using the ground-based system. -from Authors

  4. Improving Climate Literacy Using The Ice Sheet System Model (ISSM): A Prototype Virtual Ice Sheet Laboratory For Use In K-12 Classrooms

    NASA Astrophysics Data System (ADS)

    Halkides, D. J.; Larour, E. Y.; Perez, G.; Petrie, K.; Nguyen, L.

    2013-12-01

    Statistics indicate that most Americans learn what they will know about science within the confines of our public K-12 education system and the media. Next Generation Science Standards (NGSS) aim to remedy science illiteracy and provide guidelines to exceed the Common Core State Standards that most U.S. state governments have adopted, by integrating disciplinary cores with crosscutting ideas and real life practices. In this vein, we present a prototype ';Virtual Ice Sheet Laboratory' (I-Lab), geared to K-12 students, educators and interested members of the general public. I-Lab will allow users to perform experiments using a state-of-the-art dynamical ice sheet model and provide detailed downloadable lesson plans, which incorporate this model and are consistent with NGSS Physical Science criteria for different grade bands (K-2, 3-5, 6-8, and 9-12). The ultimate goal of this website is to improve public climate science literacy, especially in regards to the crucial role of the polar ice sheets in Earth's climate and sea level. The model used will be the Ice Sheet System Model (ISSM), an ice flow model developed at NASA's Jet Propulsion Laboratory and UC Irvine, that simulates the near-term evolution of polar ice sheets (Greenland and Antarctica) and includes high spatial resolution capabilities and data assimilation to produce realistic simulations of ice sheet dynamics at the continental scale. Open sourced since 2011, ISSM is used in cutting edge cryosphere research around the globe. Thru I-Lab, students will be able to access ISSM using a simple, online graphical interface that can be launched from a web browser on a computer, tablet or smart phone. The interface will allow users to select different climate conditions and watch how the polar ice sheets evolve in time under those conditions. Lesson contents will include links to background material and activities that teach observation recording, concept articulation, hypothesis formulation and testing, and critical problem solving appropriate to grade level.

  5. Glacial ice cores: A model system for developing extraterrestrial decontamination protocols

    NASA Astrophysics Data System (ADS)

    Christner, Brent C.; Mikucki, Jill A.; Foreman, Christine M.; Denson, Jackie; Priscu, John C.

    2005-04-01

    Evidence gathered from spacecraft orbiting Mars has shown that water ice exists at both poles and may form a large subsurface reservoir at lower latitudes. The recent exploration of the martian surface by unmanned landers and surface rovers, and the planned missions to eventually return samples to Earth have raised concerns regarding both forward and back contamination. Methods to search for life in these icy environments and adequate protocols to prevent contamination can be tested with earthly analogues. Studies of ice cores on Earth have established past climate changes and geological events, both globally and regionally, but only recently have these results been correlated with the biological materials (i.e., plant fragments, seeds, pollen grains, fungal spores, and microorganisms) that are entrapped and preserved within the ice. The inclusion of biology into ice coring research brings with it a whole new approach towards decontamination. Our investigations on ice from the Vostok core (Antarctica) have shown that the outer portion of the cores have up to 3 and 2 orders of magnitude higher bacterial density and dissolved organic carbon (DOC) than the inner portion of the cores, respectively, as a result of drilling and handling. The extreme gradients that exist between the outer and inner portion of these samples make contamination a very relevant aspect of geomicrobiological investigations with ice cores, particularly when the actual numbers of ambient bacterial cells are low. To address this issue and the inherent concern it raises for the integrity of future investigations with ice core materials from terrestrial and extraterrestrial environments, we employed a procedure to monitor the decontamination process in which ice core surfaces are painted with a solution containing a tracer microorganism, plasmid DNA, and fluorescent dye before sampling. Using this approach, a simple and direct method is proposed to verify the authenticity of geomicrobiological results obtained from ice core materials. Our protocol has important implications for the design of life detection experiments on Mars and the decontamination of samples that will eventually be returned to Earth.

  6. Optimization via CFD of aircraft hot-air anti-icing systems

    NASA Astrophysics Data System (ADS)

    Pellissier, Mathieu Paul Constantin

    In-flight icing is a major concern in aircraft safety and a non-negligible source of incidents and accidents, and is still a serious hazard today. It remains consequently a design and certification challenge for aircraft manufacturers. The aerodynamic performance of an aircraft can indeed degrade rapidly when flying in icing conditions, leading to incidents or accidents. In-flight icing occurs when an aircraft passes through clouds containing supercooled water droplets at or below freezing temperature. Droplets impinge on its exposed surfaces and freeze, causing roughness and shape changes that increase drag, decrease lift and reduce the stall angle of attack, eventually inducing flow separation and stall. This hazardous ice accretion is prevented by the use of dedicated anti-icing systems, among which hot-air-types are the most common for turbofan aircraft. This work presents a methodology for the optimization of such aircraft hot-air-type anti-icing systems, known as Piccolo tubes. Having identified through 3D Computational Fluid Dynamics (CFD) the most critical in-flight icing conditions, as well as determined thermal power constraints, the objective is to optimize the heat distribution in such a way to minimize power requirements, while meeting or exceeding all safety regulation requirements. To accomplish this, an optimization method combining 3D CFD, Reduced-Order Models (ROM) and Genetic Algorithms (GA) is constructed to determine the optimal configuration of the Piccolo tube (angles of jets, spacing between holes, and position from leading edge). The methodology successfully results in increasingly optimal configurations from three up to five design variables.

  7. Personal Ice Cooling System (PICS). Innovative technology summary report

    SciTech Connect

    1998-11-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. To this end, the Deactivation and Decommissioning Focus Area (DDFA) of the DOE`s Office of Science and Technology sponsors Large-Scale Demonstration and Deployment Projects (LSDDPs) in which developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE`s projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased cost of operation. As buildings are demolished as part of the DOE Fernald Environmental Management Project`s (FEMP`s) D and D Plan, many of the activities are performed in hot weather and usually require use of various types and layers of personal protective equipment (PPE). While PPE is designed to protect the worker from contamination, it also significantly compromises the body`s ability to cool itself, leading to potentially serious heat stress situations. This report describes a comparative demonstration between the methodology currently used for heat stress management (i.e., limited stay times and cool-down rooms) and an alternative personal ice cooling suit technology. The baseline methodology for heat stress management is limited stay times when working in hot conditions. The FEMP`s Safety Performance Requirements outline the procedures and stay times to be followed and consider the temperature of the working environment, work load, and the type and amount of PPE required for the job. While these common criteria for determining stay times, other sites may have different requirements. This demonstration investigates the feasibility of using the personal ice cooling suite as a tool for managing heat stress in workers at the FEMP. This report provides a comparative analysis of the productivity of work using the baseline heat stress management approach currently used at the FEMP and the innovative personal ice cooling suit technology.

  8. An Investigation of the Icing and Heated-air De-icing Characteristics of the R-2600-13 Induction System

    NASA Technical Reports Server (NTRS)

    Chapman, Gilbert E.

    1946-01-01

    A laboratory investigation was made on a Holley 1685-HB carburetor mounted on an R-2600-13 supercharger assembly to determine the icing characteristics and the heated-air de-icing requirements of this portion of the B-25D airplane induction system. Icing has been found to be most prevalent at relatively small throttle openings and, consequently, all runs were made at simulated 60-percent normal rated power condition. Icing characteristics were determined during a series of 15-minute runs over a range of inlet-air conditions. For the de-icing investigation severe impact ice was allowed to form in the induction system and the time required for the recovery of 95 percent of the maximum possible air flow at the original throttle setting was then determined for a range of wet-bulb temperatures. Results of these runs showed that ice on the walls of the carburetor adapter and on the rim of the impeller-shroud portion of the supercharger diffuser plate did not affect engine operation at 60-percent normal rated power. Ice that adversely affected the air flow and the fuel-air ratio was formed only on the central web of the carburetor and then only when the inlet air was saturated or contained free moisture in excess of saturation. No serious ice formations were observed at inlet-air temperatures above 66 0 F or with an inlet-air enthalpy greater than 34 Btu per pound. The maximum temperature at. which any trace of icing could be detected was 1110 F with a relative humidity of approximately 28 percent, The air-flow recovery time for emergency de-icing was 0.3 minute for.an enthalpy of 35 Btu per pound or wet-bulb temperature of 68 0 F. Further increase in enthalpy and wet-bulb temperature above these values resulted in very slight improvement in recovery time. The fuel-air ratio restored by a 5-Minute application of heated air was approximately 7 percent less than the initial value for cold-air conditions.

  9. Strategic Decision Making and Group Decision Support Systems.

    ERIC Educational Resources Information Center

    McGrath, Michael Robert

    1986-01-01

    Institutional strategic decisions require the participation of every individual with a significant stake in the solution, and group decision support systems are being developed to respond to the political and consensual problems of collective decision-making. (MSE)

  10. All-weather ice information system for Alaskan arctic coastal shipping

    NASA Technical Reports Server (NTRS)

    Gedney, R. T.; Jirberg, R. J.; Schertler, R. J.; Mueller, R. A.; Chase, T. L.; Kramarchuk, I.; Nagy, L. A.; Hanlon, R. A.; Mark, H.

    1977-01-01

    A near real-time ice information system designed to aid arctic coast shipping along the Alaskan North Slope is described. The system utilizes a X-band Side Looking Airborne Radar (SLAR) mounted aboard a U.S. Coast Guard HC-130B aircraft. Radar mapping procedures showing the type, areal distribution and concentration of ice cover were developed. In order to guide vessel operational movements, near real-time SLAR image data were transmitted directly from the SLAR aircraft to Barrow, Alaska and the U.S. Coast Guard icebreaker Glacier. In addition, SLAR image data were transmitted in real time to Cleveland, Ohio via the NOAA-GOES Satellite. Radar images developed in Cleveland were subsequently facsimile transmitted to the U.S. Navy's Fleet Weather Facility in Suitland, Maryland for use in ice forecasting and also as a demonstration back to Barrow via the Communications Technology Satellite.

  11. Replicating the Ice-Volume Signal of the Early Pleistocene with a Complex Earth System Model

    NASA Astrophysics Data System (ADS)

    Tabor, C. R.; Poulsen, C. J.; Pollard, D.

    2013-12-01

    Milankovitch theory proposes high-latitude summer insolation intensity paces the ice ages by controlling perennial snow cover amounts (Milankovitch, 1941). According to theory, the ~21 kyr cycle of precession should dominate the ice-volume records since it has the greatest influence on high-latitude summer insolation. Modeling experiments frequently support Milankovitch theory by attributing the majority of Northern Hemisphere high-latitude summer snowmelt to changes in the cycle of precession (e.g. Jackson and Broccoli, 2003). However, ice-volume proxy records, especially those of the Early Pleistocene (2.6-0.8 Ma), display variability with a period of ~41 kyr (Raymo and Lisiecki, 2005), indicative of insolation forcing from obliquity, which has a much smaller influence on summer insolation intensity than precession. Several hypotheses attempt to explain the discrepancies between Milkankovitch theory and the proxy records by invoking phenomena such as insolation gradients (Raymo and Nisancioglu, 2003), hemispheric offset (Raymo et al., 2006; Lee and Poulsen, 2009), and integrated summer energy (Huybers, 2006); however, all of these hypotheses contain caveats (Ruddiman, 2006) and have yet to be supported by modeling studies that use a complex GCM. To explore potential solutions to this '41 kyr problem,' we use an Earth system model composed of the GENESIS GCM and Land Surface model, the BIOME4 vegetation model, and the Pennsylvania State ice-sheet model. Using an asynchronous coupling technique, we run four idealized transient combinations of obliquity and precession, representing the orbital extremes of the Pleistocene (Berger and Loutre, 1991). Each experiment is run through several complete orbital cycles with a dynamic ice domain spanning North America and Greenland, and fixed preindustrial greenhouse-gas concentrations. For all orbital configurations, model results produce greater ice-volume spectral power at the frequency of obliquity despite significantly greater summer insolation variability from the cycle of precession. We find obliquity enhances the climate sensitivity to direct insolation forcing through positive high-latitude surface feedbacks between vegetation, sea-ice, and mean-annual insolation while the seasonal dichotomy of precessional forcing leads to climate counterbalancing that dampens the annual ice-volume response. Longer cycle duration further amplifies the ice-volume response to obliquity. Our results help remedy the discrepancies between Milankovitch theory and the ice-volume proxy records. However, summer insolation intensity remains the most important factor for determining ice-volume rate-of-change in our experiments. Consequently, we still find a significant ice-volume response to precession, which is inconsistent with the Early Pleistocene records. The disconnect is likely attributable to climate phenomena not accounted for in the model or our choice of initial conditions, which are poorly constrained for the Early Pleistocene and ice-sheet modeling in general. Future work will examine the importance of initial climate conditions on ice-volume response.

  12. 76 FR 7238 - Pipeline Safety: Dangers of Abnormal Snow and Ice Build-Up on Gas Distribution Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ... distribution system facilities appear to have been related to either the stress of snow and ice or the... distribution system facilities that appear to have been related to either the stress of snow and ice or... piping at metering and pressure regulating stations, at service regulators, and at propane tanks, are...

  13. Sensitivity of the Regional Arctic System Model surface climate to ice-ocean state

    NASA Astrophysics Data System (ADS)

    Roberts, A.; Maslowski, W.; Osinski, R.; Cassano, J. J.; Craig, A.; Duvivier, A.; Fisel, B. J.; Gutowski, W. J.; Higgins, M.; Hughes, M. R.; Lettenmaier, D. P.; Nijssen, B.

    2012-12-01

    The Regional Arctic System Model (RASM) is a high-resolution Earth System model extending across the Arctic Ocean, its marginal seas, the Arctic drainage basin, and including the Coordinated Regional Downscaling Experiment (CORDEX) Arctic domain. RASM uses the flux coupler (CPL7) within the Community Earth System Model framework to couple regional configurations of the Weather Research and Forecasting model (WRF), Parallel Ocean Program (POP), Los Alamos sea ice model (CICE), and Variable Infiltration Capacity land hydrology model (VIC). Work is also underway to incorporate the Community Ice Sheet Model (CISM) as well as glacier, ice cap and dynamic vegetation models. As part of RASM development, coupled simulations are being prepared for the CORDEX Arctic domain, which is unique among CORDEX regions by being centered over the ocean. Up to this point, there has been uncertainty over how much initial and surface conditions in the ice-ocean boundary layer influence the surface climate of the Arctic in RASM, relative to regional atmospheric model constraints, such as spectral nudging and boundary conditions. We present results that suggest there is a significant dependency on the initial sea ice conditions on decadal timescales within RASM. This has important implications for (i) how results from different regional artic models may be combined and compared in CORDEX and (ii) appropriate methods for ensemble generation in regional polar models. We will also present results illustrating the influence of sub-hourly sea ice deformation on decadal climate in RASM, highlighting an important reason why fully coupled and high-resolution regional models are essential for regional Arctic downscaling.

  14. Simulations of ice shelves in the Parallel Ocean Program (POP), the ocean model of the Community Earth System Model (CESM)

    NASA Astrophysics Data System (ADS)

    Asay-Davis, Xylar

    2013-04-01

    We present a series of simulations using POP2X, a modified version of the LANL Parallel Ocean Program version 2 (POP2) that includes circulations in ice-shelf cavities. The geometry of the ice-shelf/ocean interface is represented using the partial-top cells, following the approach developed by Losch (2008) for the Massachusetts Institute of Technology General Circulation Model (MITgcm). The model domain is an idealized domain reminiscent of the Ronne-Filchner Ice Shelf cavity. Our simulations show relatively warm circumpolar deep water (CDW) flowing into the Filchner trough, causing a large increase in melting under the ice shelf. Using more realistic geometry and climate forcing, Helmer et al. (2012) saw a drastic increase in melting in the late twenty-first century as a result of similar processes. We show that vertical model resolution can have a strong impact on the melt rate and circulation in the vicinity of the ice shelf. The results suggest that a resolution-conscious parameterization of the buoyancy-driven plume under ice shelves is needed. This work is an early step toward coupling POP2X to the Community Ice Sheet Model (CISM) in order to perform more advanced modeling of ice-sheet/ocean interactions. Remarkable advances in ice-sheet model physics and numerical methods in recent years mean that a number of these models (e.g. the CISM; the Ice Sheet System Model; the Elmer Ice Sheet Model) have both sufficient physical accuracy and numerical scalability to be ready for inclusion in Earth System Models (ESMs). A significant stumbling block preventing full ice-sheet/ocean coupling is the inability of ocean models to handle ice-shelf cavity geometries that change in time. This is a major focus of our ongoing research.

  15. Defining Mesoscale Convective Systems by Their 85-GHz Ice-Scattering Signatures.

    NASA Astrophysics Data System (ADS)

    Mohr, Karen I.; Zipser, Edward J.

    1996-06-01

    Mesoseale Convective systems are composed of numerous deep convective cells with varying amounts of large, convectively produced ice particles aloft. The magnitude of the 85-GHz brightness temperature depression resulting from scattering by large ice is believed to be related to the convective intensity and to the magnitude of the convective fluxes through a deep layer. The 85-GHz ice-scattering signature can be used to map the distribution of organized mesoscale regions of convectively produced large ice particles. The purpose of this article is to demonstrate the usefulness of the 85-GHz ice-scattering signature for describing the frequency, convective intensity, and geographic distribution of mesoscale convective systems.Objective criteria were developed to identify mesoscale convective systems from raw data from January, April, July, and October 1993. To minimize the effects of background contamination and to ensure that bounded areas contained convective elements, a "mesoscale convective system" was defined as an area bounded by 250 K of at least 2000 km2 of 85 GHz, with a minimum brightness temperature 225 K. Mesoscale convective systems extracted from the raw data were sorted and plotted by their areas and by their minimum brightness temperatures. Four area and brightness temperature classes were used to account for a spectrum of organized convection ranging from small to very large and from less organized to highly organized. The populations of mesoscale convective systems by this study's definition were consistent with infrared-based climatologies and large-scale seasonal dynamics. Land/water differences were high-lighted by the plots of minimum brightness temperature. Most of the intense mesoscale convective systems were located on or near land and seemed to occur most frequently in particular areas in North America, South America, Africa, and India.

  16. NASA Glenn Propulsion Systems Lab: 2012 Inaugural Ice Crystal Cloud Calibration Procedure and Results

    NASA Technical Reports Server (NTRS)

    VanZante, Judith F.; Rosine, Bryan M.

    2014-01-01

    The inaugural calibration of the ice crystal and supercooled liquid water clouds generated in NASA Glenn's engine altitude test facility, the Propulsion Systems Lab (PSL) is reported herein. This calibration was in support of the inaugural engine ice crystal validation test. During the Fall of 2012 calibration effort, cloud uniformity was documented via an icing grid, laser sheet and cloud tomography. Water content was measured via multi-wire and robust probes, and particle sizes were measured with a Cloud Droplet Probe and Cloud Imaging Probe. The environmental conditions ranged from 5,000 to 35,000 ft, Mach 0.15 to 0.55, temperature from +50 to -35 F and relative humidities from less than 1 percent to 75 percent in the plenum.

  17. Comparison of two droplet sizing systems in an icing wind tunnel

    NASA Technical Reports Server (NTRS)

    Oldenburg, J. R.; Ide, R. F.

    1990-01-01

    A comparison between the Phase Doppler Analyzer and the combined measurements from the Particle Measuring Systems Forward Scattering Spectrometer Probe and the Optical Array Probe was conducted in an icing wind tunnel using NASA Icing Research Tunnel spray nozzles to produce the icing cloud. Clouds with a range of volume median diameters from 10 to greater than 50 microns were used for the instrument comparisons. A comparison of the volume median diameter from the Phase Doppler Particle Analyzer and only the Forward Scattering Spectrometer Probe indicated agreement up to 18 microns. A combined volume median diameter was calculated from the droplet distribution of the Optical Array Probe and the Forward Scattering Spectrometer Probe. A comparison of the combined volume median diameters and the Phase Doppler Particle Analyzer volume median diameters showed agreement up to 30 microns with the agreement deteriorating rapidly above 30 microns. Droplet distributions from the Phase Doppler Particle Analyzer, the Forward Scattering Spectrometer Probe, and Optical Array Probe are presented.

  18. Magnetostatic bias in Kagome artificial spin ice systems

    NASA Astrophysics Data System (ADS)

    Panagiotopoulos, I.

    2016-04-01

    The magnetostatic bias in elongated nanomagnetic elements arranged in artificial Kagome spin ice arrays is studied by micromagnetic simulations. Using the Nmag package the reversal of a given element has been simulated under the influence of its four nearest neighbors with their magnetic states fixed in all possible configurations, which amount to 24=16 states that can be classified under five distinct cases. The hysteresis loop of each element is greatly influenced by the magnetic state of the nearest neighbors, not only by the expected shift due to dipolar interaction bias, but as it regards the loop shape and width itself. This presents a correction to the usual macrospin calculation based on the assumption that the loop is shifted by a biasing field (equal to the local dipole field) but the loop width (and shape in general) does not change. Although coercive and biasing fields depend strongly on the dimensions their relative strength has only weak thickness dependence for a fixed length to width aspect ratio. Therefore the behavior of such arrays is expected to be to a large degree size invariant apart from an appropriate maximum external applied field scaling.

  19. Volume of Ice Crystal Growing in Supercooled Water

    NASA Astrophysics Data System (ADS)

    Teraoka, Yoshikazu; Saito, Akio; Okawa, Seiji

    Recently, dynamic type of ice storage system has been high lightened, since it gives a solution to the problem of peak electrical load. The deferent types of the method of ice making produce the different types of ice, and the selection of the type of ice influence the coefficient of performance of ice storage system. Hence studying the shape of ice and its behavior such as stickiness are important. The shape of ice crystal depends on various factors such as concentration of solution, temperature, convection, time and so on. There are various types of ice exists, such as frazil ice, dendrite, needle ice, solid ice, slurry ice. However, there is no report measuring the volume of the crystal, yet, because the shape of the crystal is too complicated to measure. In this report, pure water was used and single crystal ice was formed in supercooled water. The shape of the crystal was measured in three-dimensions using Mach-Zehnder spectro-interferometer. Volume of the crystal was measured. It was found that the volume depends upon time and the degree of supercooling, and experimental equation was derived. Furthermore, projected area normal to c-axis was measured. It was found that the area depends not only on time but also the degree of supercooling.

  20. Creating future fit between ice and society: The institutionalization of a refuge in the Arctic to preserve sea ice system services in a changing North

    NASA Astrophysics Data System (ADS)

    Lovecraft, A. L.; Meek, C. L.

    2010-12-01

    The Arctic sea ice system can be holistically characterized as a social-ecological system that provides not only vital geophysical and biological services to climate and oceans but also provisioning services to people and industry. These services are under threat from the three major interconnected global forces of increasing traffic for shipping, security, and tourism; contaminant accumulation primarily from distant, but also related to some local marine activities, industrial production; and climatic changes, especially the warming at the poles which is diminishing the earth’s cryosphere. As the Arctic becomes more open due to sea ice loss the current strategies to preserve individual species or sea ice system functions may become obsolete in the next several decades. Concurrent to this will be the rise of traffic in areas currently not passable and an increase in exploitation of natural resources (biological and mineral) further north. This expansion of human activity does not have a suite of institutions in place that comprehensively address a future open Arctic Ocean and the coasts of the circumpolar north. Consequently, as the amount of space that can preserve a diversity of sea ice system services shrinks and the use of that space becomes crowded with interests, governments across scales need to be able to plan to balance the increase in use with preservation of services valuable both in terms of regulating and supporting planetary processes and the cultural and provisioning services more immediately tied to human flourishing. In short, it is a race between stressors and human capacity to manage them through rules minimizing their direct impact on the ice or preventing them from entering an eventual “ice shed” boundaries of a minimum summer sea ice cover. This poster explores the potential for the creation of a system of governance that would provide a refuge based on the projected summer sea ice to remain in the Arctic even as the climate shifts in the coming decades. The authors propose the institutionalization of rule sets based on adaptive governance principles which take advantage of several sets of international and national or subnational arrangements for protecting places. Respectively these could include World Heritage Sites, Marine Protected Areas, and state or provincial level management. However, current governance systems may not be adequately linked across interrelated services and the people who depend on them for their livelihoods. We propose an adaptive cross-scalar system of monitoring and governance focused on the sea ice services tied to marine and coastal areas. The design would account for the special properties of sea ice (e.g. creating uniform legal categories tied to ice rather than either land or sea) so that the system can continue to provide diverse services in a holistic fashion rather than piecemeal in isolated locations. Hence the need for a continuous refuge governing a singular “ice shed” in spite of national boundaries.

  1. Evaluation of a new Gulf of St. Lawrence coupled environmental prediction system based on the GEM atmospheric model and on the NEMO-CICE ocean-ice model

    NASA Astrophysics Data System (ADS)

    Pellerin, Pierre; Roy, François; Dick, Sarah; Smith, Greg; Dupont, Fred; Pilon, Mark; Senneville, Simon; Chanut, Jerome

    2015-04-01

    The Canadian operational Gulf of St. Lawrence (GSL) coupled environmental forecast system has been updated with a new ocean-ice component (NEMO-CICE) and coupling methodology. The use of NEMO-CICE will facilitate future advances toward an increase in resolution and the introduction of new scientific developments. Indeed NEMO and CICE are supported by a large scientific community and are based on more efficient computing technologies than the current system. An ensemble of hindcasts over previous years demonstrate that recent developments in the NEMO-CICE model make it possible to meet the high quality standards of the ocean model by Saucier et al. (2009) used in the previous operational system in terms of the tides, circulation and water mass properties. We present results from these hindcasts as well as from an experimental run for the winter of 2014 and compare them with the operational system. The experimental run includes a pseudo-analysis cycle producing daily initial ice-ocean conditions and their subsequent coupled atmosphere-ice-ocean 48 hr forecasts. We first examine extreme weather event cases, and then present results from a subjective evaluation as well as objective skill scores for SST analyses and for ice, surface air temperature and wind forecasts. The importance of the two-way coupling will also be assessed.

  2. Development of a one-dimensional electro-thermophysical model of the snow sea-ice system: Arctic climate processes and microwave remote sensing applications

    NASA Astrophysics Data System (ADS)

    Hanesiak, John Michael

    Snow covered sea ice plays a crucial role in the earth's climate. This includes polar biology, local, regional and world weather and ocean circulations as well as indigenous people's way of life. Recent research has indicated significant climate change in the polar regions, especially the Canadian arctic. Polar climate processes are also among the most poorly misrepresented within global circulation models (GCMs). The goal of this thesis is to improve our understanding and capability to simulate arctic climate processes in a predictive sense. An electro-thermophysical relationship exists between the thermophysical characteristics (climate variables and processes) and electrical properties (dielectrics) that control microwave remote sensing of snow-covered first- year sea ice (FYI). This work explicitly links microwave dielectrics and a thermodynamic model of snow and sea ice by addressing four key issues. These includes: (1)ensure the existing one-dimensional sea ice models treat the surface energy balance (SEB) and snow/ice thermodynamics in the appropriate time scales we see occurring in field experiments, (2)ensure the snow/ice thermodynamics are not compromised by differences in environmental and spatial representation within components of the SEB, (3)ensure the snow layer is properly handled in the modeling environment, and (4)how we can make use of satellite microwave remote sensing data within the model environment. Results suggest that diurnal processes are critical and need to be accounted for in modeling snow-covered FYI, similar to time scales acting in microwave remote sensing signatures. Output from the coupled snow sea-ice model provides the required input to microwave dielectric models of snow and sea ice to predict microwave penetration depths within the snow and sea ice (an Electro-Thermophysical model of the Snow Sea Ice System (ETSSIS)). Results suggest ETSSIS can accurately simulate microwave penetration depths in the cold dry snow season and wet snow season (funicular snow regime). Simulated penetration depths become too large in the pendular snow regime since liquid water is not generated soon enough within the snow pack in the spring season. The inclusion of salinity in the mass balance of ETSSIS will improve the simulation of penetration depths in the pendular snow regime in future implementations of the model. (Abstract shortened by UMI.)

  3. TOPAZ4: an ocean-sea ice data assimilation system for the North Atlantic and Arctic

    NASA Astrophysics Data System (ADS)

    Sakov, P.; Counillon, F.; Bertino, L.; Lisæter, K. A.; Oke, P. R.; Korablev, A.

    2012-04-01

    We present a detailed description of TOPAZ4, the latest version of TOPAZ - a coupled ocean-sea ice data assimilation system for the North Atlantic Ocean and Arctic. It is the only operational, large-scale ocean data assimilation system that uses the ensemble Kalman filter. This means that TOPAZ features a time-evolving, state-dependent estimate of the state error covariance. Based on results from the pilot MyOcean reanalysis for 2003-2008, we demonstrate that TOPAZ4 produces a realistic estimate of the ocean circulation and the sea ice. We find that the ensemble spread for temperature and sea-level remains fairly constant throughout the reanalysis demonstrating that the data assimilation system is robust to ensemble collapse. Moreover, the ensemble spread for ice concentration is well correlated with the actual errors. This indicates that the ensemble statistics provide reliable state-dependent error estimates - a feature that is unique to ensemble-based data assimilation systems. We demonstrate that the quality of the reanalysis changes when different sea surface temperature products are assimilated, or when in situ profiles below the ice in the Arctic Ocean are assimilated. We find that data assimilation improves the match to independent observations compared to a free model. Improvements are particularly noticeable for ice thickness, salinity in the Arctic, and temperature in the Fram Strait, but not for transport estimates or underwater temperature. At the same time, the pilot reanalysis has revealed several flaws in the system that have degraded its performance. Finally, we show that a simple bias estimation scheme can effectively detect the seasonal or constant bias in temperature and sea-level.

  4. TOPAZ4: an ocean-sea ice data assimilation system for the North Atlantic and Arctic

    NASA Astrophysics Data System (ADS)

    Sakov, P.; Counillon, F.; Bertino, L.; Lisæter, K. A.; Oke, P. R.; Korablev, A.

    2012-08-01

    We present a detailed description of TOPAZ4, the latest version of TOPAZ - a coupled ocean-sea ice data assimilation system for the North Atlantic Ocean and Arctic. It is the only operational, large-scale ocean data assimilation system that uses the ensemble Kalman filter. This means that TOPAZ features a time-evolving, state-dependent estimate of the state error covariance. Based on results from the pilot MyOcean reanalysis for 2003-2008, we demonstrate that TOPAZ4 produces a realistic estimate of the ocean circulation in the North Atlantic and the sea-ice variability in the Arctic. We find that the ensemble spread for temperature and sea-level remains fairly constant throughout the reanalysis demonstrating that the data assimilation system is robust to ensemble collapse. Moreover, the ensemble spread for ice concentration is well correlated with the actual errors. This indicates that the ensemble statistics provide reliable state-dependent error estimates - a feature that is unique to ensemble-based data assimilation systems. We demonstrate that the quality of the reanalysis changes when different sea surface temperature products are assimilated, or when in-situ profiles below the ice in the Arctic Ocean are assimilated. We find that data assimilation improves the match to independent observations compared to a free model. Improvements are particularly noticeable for ice thickness, salinity in the Arctic, and temperature in the Fram Strait, but not for transport estimates or underwater temperature. At the same time, the pilot reanalysis has revealed several flaws in the system that have degraded its performance. Finally, we show that a simple bias estimation scheme can effectively detect the seasonal or constant bias in temperature and sea-level.

  5. Functional evaluation of candidate ice structuring proteins using cell-free expression systems.

    PubMed

    Brödel, A K; Raymond, J A; Duman, J G; Bier, F F; Kubick, S

    2013-02-10

    Ice structuring proteins (ISPs) protect organisms from damage or death by freezing. They depress the non-equilibrium freezing point of water and prevent recrystallization, probably by binding to the surface of ice crystals. Many ISPs have been described and it is likely that many more exist in nature that have not yet been identified. ISPs come in many forms and thus cannot be reliably identified by their structure or consensus ice-binding motifs. Recombinant protein expression is the gold standard for proving the activity of a candidate ISP. Among existing expression systems, cell-free protein expression is the simplest and gives the fastest access to the protein of interest, but selection of the appropriate cell-free expression system is crucial for functionality. Here we describe cell-free expression methods for three ISPs that differ widely in structure and glycosylation status from three organisms: a fish (Macrozoarces americanus), an insect (Dendroides canadensis) and an alga (Chlamydomonas sp. CCMP681). We use both prokaryotic and eukaryotic expression systems for the production of ISPs. An ice recrystallization inhibition assay is used to test functionality. The techniques described here should improve the success of cell-free expression of ISPs in future applications. PMID:23195406

  6. Making intelligent systems team players: Overview for designers

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Schreckenghost, Debra L.

    1992-01-01

    This report is a guide and companion to the NASA Technical Memorandum 104738, 'Making Intelligent Systems Team Players,' Volumes 1 and 2. The first two volumes of this Technical Memorandum provide comprehensive guidance to designers of intelligent systems for real-time fault management of space systems, with the objective of achieving more effective human interaction. This report provides an analysis of the material discussed in the Technical Memorandum. It clarifies what it means for an intelligent system to be a team player, and how such systems are designed. It identifies significant intelligent system design problems and their impacts on reliability and usability. Where common design practice is not effective in solving these problems, we make recommendations for these situations. In this report, we summarize the main points in the Technical Memorandum and identify where to look for further information.

  7. A high velocity impact experiment of micro-scale ice particles using laser-driven system

    NASA Astrophysics Data System (ADS)

    Yu, Hyeonju; Kim, Jungwook; Yoh, Jack J.

    2014-11-01

    A jet engine for high speed air breathing propulsion is subject to continuous wear as a result of impacts of micro-scale ice particles during a flight in the atmosphere. The inlet duct and compressor blades are exposed to on-coming frozen moisture particles that may result in the surface damage and significantly shorten the designed lifetime of the aircraft. Under such prolonged high-speed impact loading, the performance parameters such as flight instability and power loss of a jet engine can be significantly degraded. In this work, a laser-driven system was designed to accelerate micro-scale ice particles to the velocity up to Mach 2 using a Q-switched Nd:YAG laser beam at 100-600 mJ with 1064 nm wavelength and 9 ns pulse duration. The high speed images (Phantom v711) and double exposure shadowgraphs were used to calculate the average velocity of ice particles and their deceleration. Velocity Interferometer System for Any Reflector measurements were also utilized for the analysis of free surface velocity of a metal foil in order to understand the interfacial dynamics between the impacting particles and accepting metal target. The velocity of our ice particles is sufficiently fast for studying the effect of moisture particle collision on an air-breathing duct of high speed aircraft, and thus the results can provide insight into how minute space debris or micrometeorites cause damage to the orbiting spacecraft at large.

  8. How do the physical properties of ice influence the habitability of outer solar system satellites? (Invited)

    NASA Astrophysics Data System (ADS)

    Nimmo, F.

    2009-12-01

    A possible definition of a habitable environment is one that has liquid water, a range of suitable prebiotic compounds (however defined), and a source of energy. An ocean-bearing icy satellite can provide the first two quite easily, as well as giving protection from radiation. The third requirement is most readily provided by redox reactants, which may arise from hydrothermal activity, solar ultraviolet radiation, or impacts [1-4]. Reactants produced at the surface must thus be transported through the ice shell to the underlying liquid, while hydrothermal activity requires contact between hot silicates and the ocean. Large satellites, such as Ganymede, possessing denser ice phases beneath the ocean are thus less plausibly habitable. As far as ice properties are concerned, there are two key issues. The first is the ability of ice to insulate an underlying ocean, thus controlling its lifetime. This depends on whether the ice is convecting (which in turn depends on grain size, shell thickness, basal temperature etc. [5]), the extent to which the ice shell is tidally heated, and the thermal conductivity of the ice (clathrates are good insulators [6]). For instance, Enceladus is sufficiently small that its putative ocean is expected to freeze on timescales of tens of Myr [7], reducing its potential habitability. On the other hand, ice shells above ammonia-rich oceans are likely to have lower basal temperatures and thus freeze more slowly [8]. The second issue is the extent to which the ice allows communication between the surface and subsurface. Getting material from the surface to the ocean, or vice versa, is difficult because convecting ice typically has a thick, stagnant lid [9]. But there may be situations in which this stagnant lid does not occur, for instance if the ice has a low yield strength. Brittle failure might also allow communication between the ocean and the surface [9] (as appears to happen at Enceladus [10]), while melt production due to shear heating [11] might enhance downwards transportation rates. A less obvious issue is the extent to which the silicate portion of the satellites can be heated. This is because 1) hot silicates prolong the life of an overlying ocean and 2) hydrothermal circulation is a source of reactants. Europa [12] and Enceladus [13] may both possess hot, partially-molten silicate interiors. However, at least for Enceladus the temperatures inferred by [13] cannot be explained by conventional tidal heating [7]. One possibility is that the conventional Maxwell viscoelastic rheological model does not adequately describe dissipation in real geological materials [14], and that more complicated descriptions are required. [1] Gaidos EJ, Science 284, 1631-33, 1999. [2] Hand KP et al., Astrobiology 7, 1006-22, 2007. [3] Zolotov MY Shock EL, JGR 109, E06003, 2004. [4] Schulze-Makuch D, Irwin LN Astrobiology 2, 105-21, 2002. [5] Barr AC, McKinnon WB, JGR 112, E02012, 2007. [6] Ross RG, Kargel JS, in Solar System Ices, 33-62, 1998. [7] Roberts JH, Nimmo F, Icarus 194, 675-89, 2008. [8] Deschamps F, Sotin C, JGR 106, 5107-21, 2001. [9] Barr AC et al., LPSC 33, 1545, 2002. [10] Postberg F et al., Nature 459, 1098-1101, 2009. [11] Nimmo F, Gaidos E, JGR 107, 5021, 2002. [12] Greenberg R et al., Rev. Geophys. 40, 1004, 2002. [13] Matson DL et al., Icarus 187, 569-73, 2007. [14] McCarthy C et al., LPSC 39, 2512, 2008.

  9. Use of a new high-speed digital data acquisition system in airborne ice-sounding

    USGS Publications Warehouse

    Wright, David L.; Bradley, Jerry A.; Hodge, Steven M.

    1989-01-01

    A high-speed digital data acquisition and signal averaging system for borehole, surface, and airborne radio-frequency geophysical measurements was designed and built by the US Geological Survey. The system permits signal averaging at rates high enough to achieve significant signal-to-noise enhancement in profiling, even in airborne applications. The first field use of the system took place in Greenland in 1987 for recording data on a 150 by 150-km grid centered on the summit of the Greenland ice sheet. About 6000-line km were flown and recorded using the new system. The data can be used to aid in siting a proposed scientific corehole through the ice sheet.

  10. Decision making algorithm for development strategy of information systems

    NASA Astrophysics Data System (ADS)

    Derman, Galyna Y.; Nikitenko, Olena D.; Kotyra, Andrzej; Bazarova, Madina; Kassymkhanova, Dana

    2015-12-01

    The paper presents algorithm of decision making for development strategy of information systems. The process of development is planned taking into account the internal and external factors of the enterprise which affect the prospects of development of both the information system and the whole enterprise. The initial state of the system must be taken into account. The total risk is the criterion for selecting the strategy. The risk is calculated using statistical and fuzzy data of system's parameters. These data are summarized by means of the function of uncertainty. The software for the realization of the algorithm of decision making on choosing the development strategy of information system is developed and created in this paper.

  11. Extraction and characterization of gelatin from two edible Sudanese insects and its applications in ice cream making.

    PubMed

    Mariod, Abdalbasit Adam; Fadul, Hadia

    2015-07-01

    Three methods were used for extraction of gelatin from two insects, melon bug (Coridius viduatus) and sorghum bug (Agonoscelis versicoloratus versicoloratus). Extraction of insect gelatin using hot water gave higher yield reached up to 3.0%, followed by mild acid extraction which gave 1.5% and distilled water extraction which gave only 1.0%, respectively. The obtained gelatins were characterized by FTIR and the spectra of insect's gelatin seem to be similar when compared with commercial gelatin. Amide II bands of gelatins from melon and sorghum bug appeared around at 1542-1537 cm(-1). Slight differences in the amino acid composition of gelatin extracted from the two insects were observed. Ice cream was made by using 0.5% insect's gelatin and compared with that made using 0.5% commercial gelatin as stabilizing agent. The properties of the obtained ice cream produced using insects gelatin were significantly different when compared with that made using commercial gelatin. PMID:24958775

  12. Monitoring and decision making by people in man machine systems

    NASA Technical Reports Server (NTRS)

    Johannsen, G.

    1979-01-01

    The analysis of human monitoring and decision making behavior as well as its modeling are described. Classic and optimal control theoretical, monitoring models are surveyed. The relationship between attention allocation and eye movements is discussed. As an example of applications, the evaluation of predictor displays by means of the optimal control model is explained. Fault detection involving continuous signals and decision making behavior of a human operator engaged in fault diagnosis during different operation and maintenance situations are illustrated. Computer aided decision making is considered as a queueing problem. It is shown to what extent computer aids can be based on the state of human activity as measured by psychophysiological quantities. Finally, management information systems for different application areas are mentioned. The possibilities of mathematical modeling of human behavior in complex man machine systems are also critically assessed.

  13. Experimental and analytical investigation of a freezing point depressant fluid ice protection system. M.S. Thesis. Final Report

    NASA Technical Reports Server (NTRS)

    Albright, A. E.

    1984-01-01

    A glycol-exuding porous leading edge ice protection system was tested in the NASA Icing Research Tunnel. Stainless steel mesh, laser drilled titanium, and composite panels were tested on two general aviation wing sections. Two different glycol-water solutions were evaluated. Minimum glycol flow rates required for anti-icing were obtained as a function of angle of attack, liquid water content, volume median drop diameter, temperature, and velocity. Ice accretions formed after five minutes of icing were shed in three minutes or less using a glycol fluid flow equal to the anti-ice flow rate. Two methods of predicting anti-ice flow rates are presented and compared with a large experimental data base of anti-ice flow rates over a wide range of icing conditions. The first method presented in the ADS-4 document typically predicts flow rates lower than the experimental flow rates. The second method, originally published in 1983, typically predicts flow rates up to 25 percent higher than the experimental flow rates. This method proved to be more consistent between wing-panel configurations. Significant correlation coefficients between the predicted flow rates and the experimental flow rates ranged from .867 to .947.

  14. Ice-Free Arctic Ocean?

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    The current warming trends in the Arctic may shove the Arctic system into a seasonally ice-free state not seen for more than one million years, according to a new report. The melting is accelerating, and researchers were unable to identify any natural processes that might slow the deicing of the Arctic. "What really makes the Arctic different from

  15. Ice-Free Arctic Ocean?

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    The current warming trends in the Arctic may shove the Arctic system into a seasonally ice-free state not seen for more than one million years, according to a new report. The melting is accelerating, and researchers were unable to identify any natural processes that might slow the deicing of the Arctic. "What really makes the Arctic different from…

  16. The Fate of De-icing Salts in Stormwater Management Systems

    NASA Astrophysics Data System (ADS)

    Ballestero, T. P.; Roseen, R. M.; Houle, J. J.

    2005-05-01

    The traditional paradigm behind the design of stormwater management systems is to minimize the water quantity and water quality impacts resulting from land modification. The intent is to yield post-development hydrology similar to pre-development hydrology. The water quality aspect has been primarily focused on sediment removal, however, rarely are stormwater management systems designed for removal of de-icing salt. Chloride toxicity effects upon aquatic organisms resulting from snowmelt runoff are pronounced, routine, and problematic in northern climates. The capacity of current management strategies to treat chloride is in question. This paper explores the fate of de-icing salt through 13 different stormwater management systems. The systems include swales, retention pond, infiltration systems, bioretention systems, wetlands, manufactured devices, and porous asphalt. All systems exist at a field site and are delivered the same runoff (quantity and quality). The devices were designed and installed in accordance with existing drainage manual recommendations. None were designed for salt removal. As expected, devices with minimal water storage do not remove salt. Devices that do have significant amounts of storage do not remove salt, however the effluent concentrations are not as high as the influent concentrations: the peak influent salt concentration is attenuated similar to how the peak inflow discharge is attenuated by storage routing. The porous asphalt has displayed some remarkable characteristics. This surface has remained permeable throughout the winter, even though in addition to the de-icing chemicals, sand is applied. It appears that very little de-icing salt is needed on the surface, which has enormous economic and environmental implications.

  17. Pavlovian valuation systems in learning and decision making

    PubMed Central

    Clark, Jeremy J.; Hollon, Nick G.; Phillips, Paul E. M.

    2012-01-01

    Environmental stimuli guide value-based decision making, but can do so through cognitive representation of outcomes or through general-incentive properties attributed to the cues themselves. We assert that these differences are conferred through the use of alternative associative structures differing in computational intensity. Using this framework, we review scientific evidence to discern the neural substrates of these assumed separable processes. We suggest that the contribution of the mesolimbic dopamine system to Pavlovian valuation is restricted to an affective system that is only updated through experiential feedback of stimulus-outcome pairing, whereas the orbitofrontal cortex contributes to an alternative system capable of inferential reasoning. Finally we discuss the interactions and convergence of these systems and their implications for decision making and its pathology. PMID:22749132

  18. A safety-based decision making architecture for autonomous systems

    NASA Technical Reports Server (NTRS)

    Musto, Joseph C.; Lauderbaugh, L. K.

    1991-01-01

    Engineering systems designed specifically for space applications often exhibit a high level of autonomy in the control and decision-making architecture. As the level of autonomy increases, more emphasis must be placed on assimilating the safety functions normally executed at the hardware level or by human supervisors into the control architecture of the system. The development of a decision-making structure which utilizes information on system safety is detailed. A quantitative measure of system safety, called the safety self-information, is defined. This measure is analogous to the reliability self-information defined by McInroy and Saridis, but includes weighting of task constraints to provide a measure of both reliability and cost. An example is presented in which the safety self-information is used as a decision criterion in a mobile robot controller. The safety self-information is shown to be consistent with the entropy-based Theory of Intelligent Machines defined by Saridis.

  19. Making Geographic Information Systems (GIS) Sustainable in Schools

    ERIC Educational Resources Information Center

    Dascombe, Brett

    2006-01-01

    Spatial technologies, particularly Geographic Information Systems (GIS), have become invaluable and persuasive tools in society today. These technologies have also made their way into classrooms around the world and Australian teachers are leaders in implementing GIS technology into their classrooms. There is still a way to go in order to make

  20. Making the System Work for Your Child with ADHD

    ERIC Educational Resources Information Center

    Jensen, Peter S.

    2004-01-01

    Even for parents who "do everything right," the road to successful management of ADHD is seldom smooth. Now leading child psychiatrist Dr. Peter Jensen guides parents over the rough patches and around the hairpin curves in this empowering, highly informative book. Readers learn the "whats," "whys," and "how-tos" of making the system work-getting

  1. Decision Making Methods in Space Economics and Systems Engineering

    NASA Technical Reports Server (NTRS)

    Shishko, Robert

    2006-01-01

    This viewgraph presentation reviews various methods of decision making and the impact that they have on space economics and systems engineering. Some of the methods discussed are: Present Value and Internal Rate of Return (IRR); Cost-Benefit Analysis; Real Options; Cost-Effectiveness Analysis; Cost-Utility Analysis; Multi-Attribute Utility Theory (MAUT); and Analytic Hierarchy Process (AHP).

  2. Laboratory Studies of Ethane Ice Relevant to Outer Solar System Surfaces

    NASA Technical Reports Server (NTRS)

    Moore, Marla H.; Hudson, Reggie; Raines, Lily

    2009-01-01

    Oort Cloud comets, as well as TNOs Makemake (2045 FYg), Quaoar, and Pluto, are known to contain ethane. However, even though this molecule is found on several outer Solar System objects relatively little information is available about its amorphous and crystalline phases. In new experiments, we have prepared ethane ices at temperatures applicable to the outer Solar System, and have heated and ion-irradiated these ices to study phase changes and ethane's radiation chemistry using mid-IR spectroscopy (2.2 - 16.6 microns). Included in our work is the meta-stable phase that exists at 35 - 55 K. These results, including newly obtained optical constants, are relevant to ground-based observational campaigns, the New Horizons mission, and supporting laboratory work. An improved understanding of solid-phase ethane may contribute to future searches for this and other hydrocarbons in the outer Solar System.

  3. Evaluation of a solar intermittent refrigeration system for ice production operating with ammonia/lithium nitrate

    SciTech Connect

    Rivera, W.; Moreno-Quintanar, G.; Best, R.; Rivera, C.O.; Martinez, F.

    2011-01-15

    A novel solar intermittent refrigeration system for ice production developed in the Centro de Investigacion en Energia of the Universidad Nacional Autonoma de Mexico is presented. The system operates with the ammonia/lithium nitrate mixture. The system developed has a nominal capacity of 8 kg of ice/day. It consists of a cylindrical parabolic collector acting as generator-absorber. Evaporator temperatures as low as -11 C were obtained for several hours with solar coefficients of performance up to 0.08. It was found that the coefficient of performance increases with the increment of solar radiation and the solution concentration. A dependency of the coefficient of performance was not founded against the cooling water temperature. Also it was found that the maximum operating pressure increases meanwhile the generation temperature decreases with an increase of the solution concentration. (author)

  4. A sectional stock tray system for making impressions.

    PubMed

    Ohkubo, Chikahiro; Ohkubo, Chika; Hosoi, Toshio; Kurtz, Kenneth S

    2003-08-01

    This article describes a sectional stock tray system developed by the authors for making preliminary impressions. It may be used not only for individual dental arches but also for patients with microstomia or constricted oral openings. This system allows many combinations of right and left tray sizes and forms to be assembled into a well-fitted anatomically-conforming tray in spite of individual anatomic discrepancies. PMID:12886215

  5. Modeling the 20th century Arctic Ocean/Sea ice system: Reconstruction of surface forcing

    NASA Astrophysics Data System (ADS)

    Kauker, Frank; KöBerle, Cornelia; Gerdes, Rüdiger; Karcher, Michael

    2008-09-01

    The ability to simulate the past variability of the sea ice-ocean system is of fundamental interest for the identification of key processes and the evaluation of scenarios of future developments. To achieve this goal atmospheric surface fields are reconstructed by statistical means for the period 1900 to 1997 and applied to a coupled sea ice-ocean model of the North Atlantic/Arctic Ocean. We devised a statistical model using a redundancy analysis to reconstruct the atmospheric fields. Several sets of predictor and predictand fields are used for reconstructions on different time scales. The predictor fields are instrumental records available as gridded or station data sets of sea level pressure and surface air temperature. The predictands are surface fields from the NCAR/NCEP reanalysis. Spatial patterns are selected by maximizing predictand variance during a "learning" period. The reliability of these patterns is tested in a validation period. The ensemble of reconstructions is checked for robustness by mutual comparison and an "optimal" reconstruction is selected. Results of the simulations with the sea ice-ocean model are compared with historical sea ice extent observations for the Arctic and Nordic Seas. The results obtained with the "optimal" reconstruction are shown to be highly consistent with these historical data. An analysis of simulated trends of the "early 20th century warming" and the recent warming in the Arctic complete the manuscript.

  6. The IceCube data acquisition system for galactic core collapse supernova searches

    SciTech Connect

    Baum, Volker; Collaboration: IceCube Collaboration

    2014-11-18

    The IceCube Neutrino Observatory was designed to detect highly energetic neutrinos. The detector was built as a lattice of 5160 photomultiplier tubes monitoring one cubic kilometer of clear Antarctic ice. Due to low photomultiplier dark noise rates in the cold and radio-pure ice, IceCube is also able to detect bursts of O(10MeV) neutrinos expected to be emitted from core collapse supernovae. The detector will provide the world’s highest statistical precision for the lightcurves of galactic supernovae by observing an induced collective rise in all photomultiplier rates [1]. This paper presents the supernova data acquisition system, the search algorithms for galactic supernovae, as well as the recently implemented HitSpooling DAQ extension. HitSpooling will overcome the current limitation of transmitting photomultiplier rates in intervals of 1.6384 ms by storing all recorded time-stamped hits for supernova candidate triggers. From the corresponding event-based information, the average neutrino energy can be estimated and the background induced by detector noise and atmospheric muons can be reduced.

  7. Development and Implementation of a Model-Driven Envelope Protection System for In-Flight Ice Contamination

    NASA Technical Reports Server (NTRS)

    Gingras, David R.; Barnhart, Billy P.; Martos, Borja; Ratvasky, Thomas P.; Morelli, Eugene

    2011-01-01

    Fatal loss-of-control (LOC) accidents have been directly related to in-flight airframe icing. The prototype system presented in this paper directly addresses the need for real-time onboard envelope protection in icing conditions. The combinations of a-priori information and realtime aerodynamic estimations are shown to provide sufficient input for determining safe limits of the flight envelope during in-flight icing encounters. The Icing Contamination Envelope Protection (ICEPro) system has been designed and implemented to identify degradations in airplane performance and flying qualities resulting from ice contamination and provide safe flight-envelope cues to the pilot. Components of ICEPro are described and results from preliminary tests are presented.

  8. Detection of the Impact of Ice Crystal Accretion in an Aircraft Engine Compression System During Dynamic Operation

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

    2014-01-01

    The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation community. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. Here a detection algorithm is developed which has the capability to detect the impact of ice accretion in the Low Pressure Compressor of an aircraft engine during steady flight as well as during changes in altitude. Unfortunately, the algorithm as implemented was not able to distinguish throttle changes from ice accretion and thus more work remains to be done.

  9. Experimental Shock Synthesis of Pre-Biotic Compounds from Outer Solar System Surface Ice Analogues (Invited)

    NASA Astrophysics Data System (ADS)

    Price, M. C.; Martins, Z.; Miljkovic, K.; Burchell, M.; Kearsley, A. T.; Cole, M. J.

    2010-12-01

    One of the most exciting discoveries from NASA’s recent Stardust mission has been the detection of glycine on the spacecraft’s cometary dust collector [1, 2]. This discovery prompts two important questions: “where did it come from?” and “how widespread are such amino acids in the outer solar system?” One of the possible formation routes for complex organic compounds is through shock synthesis of simple ice mixtures. Recent ab initio molecular dynamics simulations [3] and experimental laser ablation techniques [4] indicate it is possible to create complex organics molecules (including glycine) from shock synthesis of a mixture of H20, CH3OH, NH3, CO and CO2 ices. These ices are present in the outer solar system. For example, according to observations made by Cassini’s Visual and Infrared Mapping Spectrometer (VIMS) instrument, Enceladus’ south polar region contains a mix of light organics, CO2, and water ice. The absorptions near 3.44 and 3.53 μm could be due to short-chain organics and there are other features in the spectrum that are still unidentified [5]. Tethys, Dione, Rhea, Iapetus, Hyperion, and Phoebe could also contain organic material in the surface water ice [6]. It thus seems probable that there are conditions on the surfaces of bodies in the Saturnian system where ammonium compounds, CO2 and water ice co-exist in a solid form. Impact of a bolide traveling with sufficiently high velocity (5-20 km/sec) onto such a surface, should impart enough energy to promote shock synthesis of more complex organic compounds, including amino acids, from these ices. We have performed such shock experiments using a light gas gun by impacting a mixture of CO2, NH3OH, CH3OH and H20 ices with a 1.5 mm stainless steel sphere at 6 km/sec and a solid nylon sabot at 7.5 km/sec. The residues were then analysed using FTIR and Raman spectroscopy and GCMS for the presence of complex organics. Preliminary results are encouraging and organic compounds were detected in the residues after evaporation of the main ice constituents [7]. In order to verify that the organic signatures we observed were due solely to the shock, and not background contamination, we have repeated these initial experiments using deuterated, where possible, ices in order to synthesis deuterated complex organics for which there should be no equivalent background contaminant. Analysis of these residues is currently being undertaken, and the results will be presented at the AGU meeting in December 2010. [1] J. E. Elsila et. al., MAPS, 2009, 44, 1323-1330 [2] D. P. Glavin et. al., MAPS, 2008, 43, 399-413 [3] N. Goldman et. al., Nature Chemistry, 2010 (in press). [4] D. Nna Mvondo et al. Icarus, 2008, 194(2): 822-835 [5] R. H. Brown et. al., Science, 2006, 311, 5766, 1425-1428 [6] Ostro et al., Icarus, 2006, 183, 479-490. [7] M. C. Price et. al., LSPC XXXXI, 2010, Abstract # 1830

  10. Advanced Optical Diagnostics for Ice Crystal Cloud Measurements in the NASA Glenn Propulsion Systems Laboratory

    NASA Technical Reports Server (NTRS)

    Bencic, Timothy J.; Fagan, Amy; Van Zante, Judith F.; Kirkegaard, Jonathan P.; Rohler, David P.; Maniyedath, Arjun; Izen, Steven H.

    2013-01-01

    A light extinction tomography technique has been developed to monitor ice water clouds upstream of a direct connected engine in the Propulsion Systems Laboratory (PSL) at NASA Glenn Research Center (GRC). The system consists of 60 laser diodes with sheet generating optics and 120 detectors mounted around a 36-inch diameter ring. The sources are pulsed sequentially while the detectors acquire line-of-sight extinction data for each laser pulse. Using computed tomography algorithms, the extinction data are analyzed to produce a plot of the relative water content in the measurement plane. To target the low-spatial-frequency nature of ice water clouds, unique tomography algorithms were developed using filtered back-projection methods and direct inversion methods that use Gaussian basis functions. With the availability of a priori knowledge of the mean droplet size and the total water content at some point in the measurement plane, the tomography system can provide near real-time in-situ quantitative full-field total water content data at a measurement plane approximately 5 feet upstream of the engine inlet. Results from ice crystal clouds in the PSL are presented. In addition to the optical tomography technique, laser sheet imaging has also been applied in the PSL to provide planar ice cloud uniformity and relative water content data during facility calibration before the tomography system was available and also as validation data for the tomography system. A comparison between the laser sheet system and light extinction tomography resulting data are also presented. Very good agreement of imaged intensity and water content is demonstrated for both techniques. Also, comparative studies between the two techniques show excellent agreement in calculation of bulk total water content averaged over the center of the pipe.

  11. Arctic ice islands

    SciTech Connect

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  12. Modeling the Effects of Ice Accretion on the Low Pressure Compressor and the Overall Turbofan Engine System Performance

    NASA Technical Reports Server (NTRS)

    Veres, Joseph P.; Jorgenson, Philip C. E.; Wright, William B.

    2011-01-01

    The focus of this study is on utilizing a mean line compressor flow analysis code coupled to an engine system thermodynamic code, to estimate the effects of ice accretion on the low pressure compressor, and quantifying its effects on the engine system throughout a notional flight trajectory. In this paper a temperature range in which engine icing would occur was assumed. This provided a mechanism to locate potential component icing sites and allow the computational tools to add blockages due to ice accretion in a parametric fashion. Ultimately the location and level of blockage due to icing would be provided by an ice accretion code. To proceed, an engine system modeling code and a mean line compressor flow analysis code were utilized to calculate the flow conditions in the fan-core and low pressure compressor and to identify potential locations within the compressor where ice may accrete. In this study, an "additional blockage" due to the accretion of ice on the metal surfaces, has been added to the baseline aerodynamic blockage due to boundary layer, as well as the blade metal blockage. Once the potential locations of ice accretion are identified, the levels of additional blockage due to accretion were parametrically varied to estimate the effects on the low pressure compressor blade row performance operating within the engine system environment. This study includes detailed analysis of compressor and engine performance during cruise and descent operating conditions at several altitudes within the notional flight trajectory. The purpose of this effort is to develop the computer codes to provide a predictive capability to forecast the onset of engine icing events, such that they could ultimately help in the avoidance of these events.

  13. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Rouse, W. B.; Chu, Y. Y.; Greenstein, J. S.; Walden, R. S.

    1976-01-01

    An investigation was made of interaction between a human pilot and automated on-board decision making systems. Research was initiated on the topic of pilot problem solving in automated and semi-automated flight management systems and attempts were made to develop a model of human decision making in a multi-task situation. A study was made of allocation of responsibility between human and computer, and discussed were various pilot performance parameters with varying degrees of automation. Optimal allocation of responsibility between human and computer was considered and some theoretical results found in the literature were presented. The pilot as a problem solver was discussed. Finally the design of displays, controls, procedures, and computer aids for problem solving tasks in automated and semi-automated systems was considered.

  14. Earth Observing System (EOS) Snow and Ice Products for Observation and Modeling

    NASA Technical Reports Server (NTRS)

    Hall, D.; Kaminski, M.; Cavalieri, D.; Dickinson, R.; Marquis, M.; Riggs, G.; Robinson, D.; VanWoert, M.; Wolfe, R.

    2005-01-01

    Snow and ice are the key components of the Earth's cryosphere, and their influence on the Earth's energy balance is very significant due at least in part to the large areal extent and high albedo characterizing these features. Large changes in the cryosphere have been measured over the last century and especially over the past decade, and remote sensing plays a pivotal role in documenting these changes. Many of NASA's Earth Observing System (EOS) products derived from instruments on the Terra, Aqua, and Ice, Cloud and land Elevation Satellite (ICESat) satellites are useful for measuring changes in features that are associated with climate change. The utility of the products is continually enhanced as the length of the time series increases. To gain a more coherent view of the cryosphere and its historical and recent changes, the EOS products may be employed together, in conjunction with other sources of data, and in models. To further this goal, the first EOS Snow and Ice Products Workshop was convened. The specific goals of the workshop were to provide current and prospective users of EOS snow and ice products up-to-date information on the products, their validation status and future enhancements, to help users utilize the data products through hands-on demonstrations, and to facilitate the integration of EOS products into models. Oral and poster sessions representing a wide variety of snow and ice topics were held; three panels were also convened to discuss workshop themes. Panel discussions focused on data fusion and assimilation of the products into models. Approximately 110 people attended, representing a wide array of interests and organizations in the cryospheric community.

  15. Acetals and ketals of reduced sugars as fuel system icing inhibitor additives

    SciTech Connect

    Mushrush, G.W.; Stalick, W.M.; Basu, S.

    1996-10-01

    Currently the fuel system icing inhibitor additives ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethyl ether (DiEGME) are mandatory in all military aircraft fuels. These additives are optional for use in all worldwide commercial aviation fuels depending on routes, flight lengths, and season. These deicing compounds are toxic at the concentrations that are required for effective deicing. The additives are leached out of the fuel and into tank water bottoms; glycols exert high oxygen demand. In addition, water drained from fuel system pumps, filters and storage tanks contain EGME/DiEGME and creates a personnel hazard. Acetals and ketals of reduced sugars represent viable alternatives to glycol based additives. They are inexpensive, fuel stable for at least one year and show the similar icing inhibitor characteristics. The synthesis and fuel studies for these compounds will be presented.

  16. Regional Earth System Prediction for Policy Decision-Making

    NASA Astrophysics Data System (ADS)

    Murtugudde, R. G.; Cbfs Team

    2010-12-01

    While the IPCC will continue to lead Earth System projections for global issues such as greenhouse gas levels and global temperature increase, high-resolution regional Earth System predictions will be crucial for producing effective decision-making tools for day-to-day, sustainable Earth System management and adaptive management of resources. Regional Earth System predictions and projections at the order of a few meters resolution from days to decades must be validated and provide uncertainties and skill scores to be usable. While the task is daunting, it would be criminally negligent of the global human not to embark on this task immediately. The observational needs for the integrated natural-human system for the regional Earth System are distinct from the global needs even though there are many overlaps. The process understanding of the Earth System at the micro-scale can be translated into predictive understanding and skillful predictions for sustainable management and adaptation by merging these observations with Earth System models to go from global scale predictions and projections to regional environmental manifestations and mechanistic depiction of human interactions with the Earth System and exploitation of its resources. Regional Earth System monitoring and predictions thus will continuously take the pulse of the planet to prescribe appropriate actions for participatory decision-making for sustainable and adaptive management of the Earth System and to avoid catastrophic domains of potential outcomes. An example of a regional Earth System prediction system over the Chesapeake Bay with detailed interactions with users is discussed. Routine forecasts of atmospheric and hydrodynamic forecasts are used to produce linked prediction products for water quality, hypoxia, sea nettles, harmful algal blooms, striped bass, pathogens, etc.

  17. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Hammer, John M.

    1990-01-01

    Ways in which computers can aid the decision making of an human operator of an aerospace system are investigated. The approach taken is to aid rather than replace the human operator, because operational experience has shown that humans can enhance the effectiveness of systems. As systems become more automated, the role of the operator has shifted to that of a manager and problem solver. This shift has created the research area of how to aid the human in this role. Published research in four areas is described. A discussion is presented of the DC-8 flight simulator at Georgia Tech.

  18. A high-resolution ocean and sea-ice modelling system for the Arctic and North Atlantic oceans

    NASA Astrophysics Data System (ADS)

    Dupont, F.; Higginson, S.; Bourdallé-Badie, R.; Lu, Y.; Roy, F.; Smith, G. C.; Lemieux, J.-F.; Garric, G.; Davidson, F.

    2015-05-01

    As part of the CONCEPTS (Canadian Operational Network of Coupled Environmental PredicTion Systems) initiative, a high-resolution (1/12°) ice-ocean regional model is developed covering the North Atlantic and the Arctic oceans. The long-term objective is to provide Canada with short-term ice-ocean predictions and hazard warnings in ice-infested regions. To evaluate the modelling component (as opposed to the analysis - or data-assimilation - component, which is not covered in this contribution), a series of hindcasts for the period 2003-2009 is carried out, forced at the surface by the Canadian GDPS reforecasts (Smith et al., 2014). These hindcasts test how the model represents upper ocean characteristics and ice cover. Each hindcast implements a new aspect of the modelling or the ice-ocean coupling. Notably, the coupling to the multi-category ice model CICE is tested. The hindcast solutions are then assessed using a verification package under development, including in situ and satellite ice and ocean observations. The conclusions are as follows: (1) the model reproduces reasonably well the time mean, variance and skewness of sea surface height; (2) the model biases in temperature and salinity show that while the mean properties follow expectations, the Pacific Water signature in the Beaufort Sea is weaker than observed; (3) the modelled freshwater content of the Arctic agrees well with observational estimates; (4) the distribution and volume of the sea ice are shown to be improved in the latest hindcast due to modifications to the drag coefficients and to some degree to the ice thickness distribution available in CICE; (5) nonetheless, the model still overestimates the ice drift and ice thickness in the Beaufort Gyre.

  19. Remote Pulsed Laser Raman Spectroscopy System for Detecting Qater, Ice, and Hydrous Minerals

    NASA Technical Reports Server (NTRS)

    Garcia, Christopher S.; Abedin, M. Nuraul; Sharma, Shiv K.; Misra, Anupam K.; Ismail, Syed; Singh, Upendra; Refaat, Tamer F.; Elsayed-Ali, Hani; Sandford, Steve

    2006-01-01

    For exploration of planetary surfaces, detection of water and ice is of great interest in supporting existence of life on other planets. Therefore, a remote Raman spectroscopy system was demonstrated at NASA Langley Research Center in collaboration with University of Hawaii for detecting ice-water and hydrous minerals on planetary surfaces. In this study, a 532 nm pulsed laser is utilized as an excitation source to allow detection in high background radiation conditions. The Raman scattered signal is collected by a 4-inch telescope positioned in front of a spectrograph. The Raman spectrum is analyzed using a spectrograph equipped with a holographic super notch filter to eliminate Rayleigh scattering, and a holographic transmission grating that simultaneously disperses two spectral tracks onto the detector for higher spectral range. To view the spectrum, the spectrograph is coupled to an intensified charge-coupled device (ICCD), which allows detection of very weak Stokes line. The ICCD is operated in gated mode to further suppress effects from background radiation and long-lived fluorescence. The sample is placed at 5.6 m from the telescope, and the laser is mounted on the telescope in a coaxial geometry to achieve maximum performance. The system was calibrated using the spectral lines of a Neon lamp source. To evaluate the system, Raman standard samples such as calcite, naphthalene, acetone, and isopropyl alcohol were analyzed. The Raman evaluation technique was used to analyze water, ice and other hydrous minerals and results from these species are presented.

  20. The evaluation of the east Greenland Sea Odden ice feature using the Community Climate System Model3.0 (CCSM3.0)

    NASA Astrophysics Data System (ADS)

    Hung, Meng-Pai

    The Odden event is a dominant mode of the Arctic sea ice variability, which is very important for the Arctic climate. The Odden sea ice feature extends northeastward from the Arctic pack ice of the east Greenland Sea during winter and spring, typically covering an area between 8°W and 5°E, and between 73° and 77°N. The key causes and forcing of Odden sea ice variability in the atmosphere and ocean is examined using the Community Sea Ice Model5.0 (CSIM5) within a Slab Ocean Model (SOM) called the M configuration of Community Climate System Model3.0 (CCSM3) provided by the National Center for Atmospheric Research (NCAR). A 26 year control run is made with the T62 NCEP/NCAR Reanalysis (NNR) atmospheric data from 1979--2004, and the simulated northern Atlantic sea ice is compared with that from the Hadley Center Sea ice and Sea Surface Temperature (HadISST) observational dataset in order to evaluate the model's capabilities. The control run sea ice data were subjected to a rotated principal component analysis (RPCA) that revealed a component (#3) mode of variability that exhibited Odden-like variability similar to that obtained in observational data. To further investigate the single or multiple effects from the atmospheric and oceanic parameters associating with the Odden sea ice, 18 experiments are conducted with the NNR and a 1°x 1° Simple Ocean Data Assimilation (SODA) for the atmospheric and oceanic forcing, respectively. In one set of experiments the atmosphere and ocean model are run simultaneously in efforts to simulate the Odden while other experiments evaluate Odden forcing of individual atmospheric parameters with other parameter forcing being held in a non-Odden state. Model forcing data for Odden ice conditions are from 1997 (January--December) while those from 1994 are used as the forcing for non-Odden conditions, in keeping with observational studies. Results show that the model sea ice concentration (SIC) and ice thickness exhibit large variability in an area on the eastern end of the Odden region found in observational data. It does so particularly in response to air temperature and surface wind and ocean current forcing when the model output is averaged from February through April and May through July. The annual cycle of model parameter output shows that SIC peaks from March through May in experiments with full atmospheric forcing in the Odden and non-Odden years and where the ocean is held to climatological forcing. Parameters such as air temperature, overlying winds, longwave radiation, specific humidity and surface ocean currents make some of the larger contributions to SIC and ice thickness variations through the model year. At the time of peak model SIC and thickness (e.g., April, May) the wind forcing and that of surface currents appear to be larger than the SIC/thickness contribution by air temperature. In other words, the Odden mode in the model is mainly produced by dynamical effects of atmospheric winds and ocean currents.

  1. Tracer gauge: an automated dye dilution gauging system for ice-affected streams

    USGS Publications Warehouse

    Clow, D.W.; Fleming, A.C.

    2008-01-01

    In-stream flow protection programs require accurate, real-time streamflow data to aid in the protection of aquatic ecosystems during winter base flow periods. In cold regions, however, winter streamflow often can only be estimated because in-channel ice causes variable backwater conditions and alters the stage-discharge relation. In this study, an automated dye dilution gauging system, a tracer gauge, was developed for measuring discharge in ice-affected streams. Rhodamine WT is injected into the stream at a constant rate, and downstream concentrations are measured with a submersible fluorometer. Data loggers control system operations, monitor key variables, and perform discharge calculations. Comparison of discharge from the tracer gauge and from a Cipoletti weir during periods of extensive ice cover indicated that the root-mean-square error of the tracer gauge was 0.029 m3 s−1, or 6.3% of average discharge for the study period. The tracer gauge system can provide much more accurate data than is currently available for streams that are strongly ice affected and, thus, could substantially improve management of in-stream flow protection programs during winter in cold regions. Care must be taken, however, to test for the validity of key assumptions, including complete mixing and conservative behavior of dye, no changes in storage, and no gains or losses of water to or from the stream along the study reach. These assumptions may be tested by measuring flow-weighted dye concentrations across the stream, performing dye mass balance analyses, and evaluating breakthrough curve behavior.

  2. Making intelligent systems team players: Additional case studies

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Schreckenghost, Debra L.; Rhoads, Ron W.

    1993-01-01

    Observations from a case study of intelligent systems are reported as part of a multi-year interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. A series of studies were conducted to investigate issues in designing intelligent fault management systems in aerospace applications for effective human-computer interaction. The results of the initial study are documented in two NASA technical memoranda: TM 104738 Making Intelligent Systems Team Players: Case Studies and Design Issues, Volumes 1 and 2; and TM 104751, Making Intelligent Systems Team Players: Overview for Designers. The objective of this additional study was to broaden the investigation of human-computer interaction design issues beyond the focus on monitoring and fault detection in the initial study. The results of this second study are documented which is intended as a supplement to the original design guidance documents. These results should be of interest to designers of intelligent systems for use in real-time operations, and to researchers in the areas of human-computer interaction and artificial intelligence.

  3. Facts and fiction of learning systems. [decision making intelligent control

    NASA Technical Reports Server (NTRS)

    Saridis, G. N.

    1975-01-01

    The methodology that will provide the updated precision for the hardware control and the advanced decision making and planning in the software control is called learning systems and intelligent control. It was developed theoretically as an alternative for the nonsystematic heuristic approaches of artificial intelligence experiments and the inflexible formulation of modern optimal control methods. Its basic concepts are discussed and some feasibility studies of some practical applications are presented.

  4. Recent Greenland Ice Mass Loss by Drainage System from Satellite Gravity Observations

    NASA Astrophysics Data System (ADS)

    Luthcke, S. B.; Zwally, H. J.; Abdalati, W.; Rowlands, D. D.; Ray, R. D.; Nerem, R. S.; Lemoine, F. G.; McCarthy, J. J.; Chinn, D. S.

    2006-11-01

    Mass changes of the Greenland Ice Sheet resolved by drainage system regions were derived from a local mass concentration analysis of NASA Deutsches Zentrum für Luft- und Raumfahrt Gravity Recovery and Climate Experiment (GRACE mission) observations. From 2003 to 2005, the ice sheet lost 101 ± 16 gigaton/year, with a gain of 54 gigaton/year above 2000 meters and a loss of 155 gigaton/year at lower elevations. The lower elevations show a large seasonal cycle, with mass losses during summer melting followed by gains from fall through spring. The overall rate of loss reflects a considerable change in trend ( 113 ± 17 gigaton/year) from a near balance during the 1990s but is smaller than some other recent estimates.

  5. Recent Greenland ice mass loss by drainage system from satellite gravity observations.

    PubMed

    Luthcke, S B; Zwally, H J; Abdalati, W; Rowlands, D D; Ray, R D; Nerem, R S; Lemoine, F G; McCarthy, J J; Chinn, D S

    2006-11-24

    Mass changes of the Greenland Ice Sheet resolved by drainage system regions were derived from a local mass concentration analysis of NASA-Deutsches Zentrum fr Luftund Raumfahrt Gravity Recovery and Climate Experiment (GRACE mission) observations. From 2003 to 2005, the ice sheet lost 101 +/- 16 gigaton/year, with a gain of 54 gigaton/year above 2000 meters and a loss of 155 gigaton/year at lower elevations. The lower elevations show a large seasonal cycle, with mass losses during summer melting followed by gains from fall through spring. The overall rate of loss reflects a considerable change in trend (-113 +/- 17 gigaton/year) from a near balance during the 1990s but is smaller than some other recent estimates. PMID:17053112

  6. THE RADIAL DISTRIBUTION OF WATER ICE AND CHROMOPHORES ACROSS SATURN'S SYSTEM

    SciTech Connect

    Filacchione, G.; Capaccioni, F.; Cerroni, P.; Tosi, F.; Ciarniello, M.; Clark, R. N.; Nicholson, P. D.; Lunine, J. I.; Hedman, M. M.; Cruikshank, D. P.; Cuzzi, J. N.; Brown, R. H.; Buratti, B. J.; Flamini, E.

    2013-04-01

    Over the past eight years, the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini orbiter has returned hyperspectral images in the 0.35-5.1 {mu}m range of the icy satellites and rings of Saturn. These very different objects show significant variations in surface composition, roughness, and regolith grain size as a result of their evolutionary histories, endogenic processes, and interactions with exogenic particles. The distributions of surface water ice and chromophores, i.e., organic and non-icy materials, across the Saturnian system, are traced using specific spectral indicators (spectral slopes and absorption band depths) obtained from rings mosaics and disk-integrated satellites observations by VIMS. Moving from the inner C ring to Iapetus, we found a marking uniformity in the distribution of abundance of water ice. On the other hand, the distribution of chromophores is much more concentrated in the rings particles and on the outermost satellites (Rhea, Hyperion, and Iapetus). A reduction of red material is observed on the satellites' surfaces orbiting within the E ring environment likely due to fine particles from Enceladus' plumes. Once the exogenous dark material covering the Iapetus' leading hemisphere is removed, the texture of the water ice-rich surfaces, inferred through the 2 {mu}m band depth, appears remarkably uniform across the entire system.

  7. Economic Decision Making: Application of the Theory of Complex Systems

    NASA Astrophysics Data System (ADS)

    Kitt, Robert

    In this chapter the complex systems are discussed in the context of economic and business policy and decision making. It will be showed and motivated that social systems are typically chaotic, non-linear and/or non-equilibrium and therefore complex systems. It is discussed that the rapid change in global consumer behaviour is underway, that further increases the complexity in business and management. For policy making under complexity, following principles are offered: openness and international competition, tolerance and variety of ideas, self-reliability and low dependence on external help. The chapter contains four applications that build on the theoretical motivation of complexity in social systems. The first application demonstrates that small economies have good prospects to gain from the global processes underway, if they can demonstrate production flexibility, reliable business ethics and good risk management. The second application elaborates on and discusses the opportunities and challenges in decision making under complexity from macro and micro economic perspective. In this environment, the challenges for corporate management are being also permanently changed: the balance between short term noise and long term chaos whose attractor includes customers, shareholders and employees must be found. The emergence of chaos in economic relationships is demonstrated by a simple system of differential equations that relate the stakeholders described above. The chapter concludes with two financial applications: about debt and risk management. The non-equilibrium economic establishment leads to additional problems by using excessive borrowing; unexpected downturns in economy can more easily kill companies. Finally, the demand for quantitative improvements in risk management is postulated. Development of the financial markets has triggered non-linearity to spike in prices of various production articles such as agricultural and other commodities that has added market risk management to the business model of many companies.

  8. Autonomous perception and decision making in cyber-physical systems

    NASA Astrophysics Data System (ADS)

    Sarkar, Soumik

    2011-07-01

    The cyber-physical system (CPS) is a relatively new interdisciplinary technology area that includes the general class of embedded and hybrid systems. CPSs require integration of computation and physical processes that involves the aspects of physical quantities such as time, energy and space during information processing and control. The physical space is the source of information and the cyber space makes use of the generated information to make decisions. This dissertation proposes an overall architecture of autonomous perception-based decision & control of complex cyber-physical systems. Perception involves the recently developed framework of Symbolic Dynamic Filtering for abstraction of physical world in the cyber space. For example, under this framework, sensor observations from a physical entity are discretized temporally and spatially to generate blocks of symbols, also called words that form a language. A grammar of a language is the set of rules that determine the relationships among words to build sentences. Subsequently, a physical system is conjectured to be a linguistic source that is capable of generating a specific language. The proposed technology is validated on various (experimental and simulated) case studies that include health monitoring of aircraft gas turbine engines, detection and estimation of fatigue damage in polycrystalline alloys, and parameter identification. Control of complex cyber-physical systems involve distributed sensing, computation, control as well as complexity analysis. A novel statistical mechanics-inspired complexity analysis approach is proposed in this dissertation. In such a scenario of networked physical systems, the distribution of physical entities determines the underlying network topology and the interaction among the entities forms the abstract cyber space. It is envisioned that the general contributions, made in this dissertation, will be useful for potential application areas such as smart power grids and buildings, distributed energy systems, advanced health care procedures and future ground and air transportation systems.

  9. Vibroseismic-Streamer Systems to Image Sub-Ice Properties and Englacial Layering on Large Scales

    NASA Astrophysics Data System (ADS)

    Diez, A.; Eisen, O.; Lambrecht, A.; Christoph, M.; Hofstede, C. M.; Kristoffersen, Y.; Blenkner, R.; Hilmarsson, S.

    2014-12-01

    After testing different vibroseismic systems on firn from small scale vibrators to heavy trucks we now established an operational vibroseis system, excellent to image englacial layering and sub-ice conditions below ice sheets and shelves. This allowed the longest vibroseismic traverse with continuous data acquisition in Antarctica, along a route from the Ekströmisen over the grounding line onto the ice sheet. We covered about 500 km distance within three weeks including 407 km seismic profile. 110 km of 6-fold data were acquired with 125 m shot spacing and 25 km of 3-fold data with 250 m shot spacing. The remaining distance was covered with 1-fold data. The operational vibroseismic system consists of a vibroseis Buggy 'EnviroVibe' in combination with a 1.5 km long snow streamer towed behind a Pistenbully. The vibroseis on Mattracks was set onto a polyethylene sled to distribute the load of the vibroseis on the surface and allow flexibility on rough surfaces. The highest production was reached for an operation speed of 6 km/h ensuring minimal damage to the 1.5 km streamer, consisting of 60 channels with 8 geophones each. Still the setup allowed for the measurement of 20 km of seismic 6-fold data per day or 40 km/day for 1-fold data. This survey allowed covering the bathymetry below the Ekströmisen, the bed topography within the catchment area of the Ekstömisen as well as englacial features. It was possible to map the ice shelf bottom and produce a clear image of the sea bed. The production speed allowed for high fold-coverage increasing image quality compared to 1-fold seismic data. Especially, the imaging of deepenings within the bed topography and their steep sidewalls shows the advantages and the additional information that can be gained from these seismic surveys compared to airborne or ground-penetrating radar data. We present the overall characteristics of the different vibroseis sources and mounting set-ups investigated over the last six years and provide recommendation which set-up to use for which scientific questions and areas of interest. Our surveys demonstrate the potential to image englacial layering and sub-ice features and, thus, help increase our understanding of subglacial and englacial properties by the application of such an operational vibroseismic system.

  10. Examination of Icing Induced Loss of Control and Its Mitigations

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Addy, Harold E., Jr.; Colantonio, Renato O.

    2010-01-01

    Factors external to the aircraft are often a significant causal factor in loss of control (LOC) accidents. In today s aviation world, very few accidents stem from a single cause and typically have a number of causal factors that culminate in a LOC accident. Very often the "trigger" that initiates an accident sequence is an external environment factor. In a recent NASA statistical analysis of LOC accidents, aircraft icing was shown to be the most common external environmental LOC causal factor for scheduled operations. When investigating LOC accident or incidents aircraft icing causal factors can be categorized into groups of 1) in-flight encounter with super-cooled liquid water clouds, 2) take-off with ice contamination, or 3) in-flight encounter with high concentrations of ice crystals. As with other flight hazards, icing induced LOC accidents can be prevented through avoidance, detection, and recovery mitigations. For icing hazards, avoidance can take the form of avoiding flight into icing conditions or avoiding the hazard of icing by making the aircraft tolerant to icing conditions. Icing detection mitigations can take the form of detecting icing conditions or detecting early performance degradation caused by icing. Recovery from icing induced LOC requires flight crew or automated systems capable of accounting for reduced aircraft performance and degraded control authority during the recovery maneuvers. In this report we review the icing induced LOC accident mitigations defined in a recent LOC study and for each mitigation describe a research topic required to enable or strengthen the mitigation. Many of these research topics are already included in ongoing or planned NASA icing research activities or are being addressed by members of the icing research community. These research activities are described and the status of the ongoing or planned research to address the technology needs is discussed

  11. An update on land-ice modeling in the CESM

    SciTech Connect

    Lipscomb, William H

    2011-01-18

    Mass loss from land ice, including the Greenland and Antarctic ice sheets as well as smaller glacier and ice caps, is making a large and growing contribution to global sea-level rise. Land ice is only beginning to be incorporated in climate models. The goal of the Land Ice Working Group (LIWG) is to develop improved land-ice models and incorporate them in CESM, in order to provide useful, physically-based sea-level predictions. LJWG efforts to date have led to the inclusion of a dynamic ice-sheet model (the Glimmer Community Ice Sheet Model, or Glimmer-CISM) in the Community Earth System Model (CESM), which was released in June 2010. CESM also includes a new surface-mass-balance scheme for ice sheets in the Community Land Model. Initial modeling efforts are focused on the Greenland ice sheet. Preliminary results are promising. In particular, the simulated surface mass balance for Greenland is in good agreement with observations and regional model results. The current model, however, has significant limitations: The land-ice coupling is one-way; we are using a serial version of Glimmer-CISM with the shallow-ice approximation; and there is no ice-ocean coupling. During the next year we plan to implement two-way coupling (including ice-ocean coupling with a dynamic Antarctic ice sheet) with a parallel , higher-order version of Glimmer-CISM. We will also add parameterizations of small glaciers and ice caps. With these model improvements, CESM will be able to simulate all the major contributors to 21st century global sea-level rise. Results of the first round of simulations should be available in time to be included in the Fifth Assessment Report (ARS) of the Intergovernmental Panel on Climate Change.

  12. Physical Chemical Controls of Methane and other Hydrocarbon gases in Outer Solar System Water-Ice Systems

    NASA Astrophysics Data System (ADS)

    Osegovic, J. P.; Max, M. D.

    2012-12-01

    Saturn's moon Enceladus appear to have liquid water under its thin icy surface that has venting water and complex hydrocarbons. Jupiter's moon Europa is locked under a very thick layer of surface ice. Because Saturn's moon Titan contains abundant hydrocarbon gasses and liquids and both Saturn and Jupiter contain abundant hydrocarbon gases, it is likely that Europa also may have significant quantities of hydrocarbon gases in their water-ice systems. Both of these moons have the potential for life. We have begun to explore the impact that gas hydrate, which is a crystalline material composed of water and gas molecules, has on the availability of liquid water on a planet's surface: what conditions need to be present to initiate hydrate formation from a primordial selection of gases, salts, and water, how isolated hydrate systems evolve under the condition of mass transfer from ex-hydrate stability conditions to pro-hydrate stability conditions, the timespan of conditions that hydrate formation can host liquid solutions in an otherwise cooling regime; and the impact that additional chemistry, such as primitive chemosynthesis, may have on the sequestered hydrocarbon gases in hydrate. The analog for gas hydrate on these moons is the Permafrost hydrate system of Earth. Gas hydrate and water ice are stable in a compound cryosphere with ice extending downward from cold surface conditions to about the 273 K isotherm. Hydrate, depending on the mixture of gases in it, is stable from some depth below the surface to some isotherm that could be considerably in excess of 273 K. Salinity may strongly affect stability conditions. In order to estimate the thickness of the gas hydrate stability zone and its effect on 'planetary' heat flow, we model heat production as a function of mass flow. Variables are gravity, ice thickness, temperature of the surrounding medium (space, ice, and water), the thickness of the "ocean", the and the thermophysical properties of the gas being transferred. The model is constrained by the molecular diffusion rate of gas approaching the hydrate phase boundary. The heat produced or consumed by the hydrate system will affect the ice system and phase boundary. Fick's law can be used to model steady state diffusion. Flux is related to the diffusivity of the component and as a function of concentration and the distance over which the reactions take place. Initial model calculations indicate that in some cases, methane (ΔH = -56 kJ/mol for small molecules (CH4, N2, CO2, H2S) may affect the water-ice energy balance sufficiently to contribute to the maintenance of a deep ocean below ice. The effect of the presence of higher density hydrocarbons (ΔH = -72 kJ/mol for ethane and -126 kJ/mol for propane) accentuate the thermal transfer effect but may diffuse too slowly to be a thermal forcing agent in the hydrate system.

  13. Geospatial decision support systems for societal decision making

    USGS Publications Warehouse

    Bernknopf, R.L.

    2005-01-01

    While science provides reliable information to describe and understand the earth and its natural processes, it can contribute more. There are many important societal issues in which scientific information can play a critical role. Science can add greatly to policy and management decisions to minimize loss of life and property from natural and man-made disasters, to manage water, biological, energy, and mineral resources, and in general, to enhance and protect our quality of life. However, the link between science and decision-making is often complicated and imperfect. Technical language and methods surround scientific research and the dissemination of its results. Scientific investigations often are conducted under different conditions, with different spatial boundaries, and in different timeframes than those needed to support specific policy and societal decisions. Uncertainty is not uniformly reported in scientific investigations. If society does not know that data exist, what the data mean, where to use the data, or how to include uncertainty when a decision has to be made, then science gets left out -or misused- in a decision making process. This paper is about using Geospatial Decision Support Systems (GDSS) for quantitative policy analysis. Integrated natural -social science methods and tools in a Geographic Information System that respond to decision-making needs can be used to close the gap between science and society. The GDSS has been developed so that nonscientists can pose "what if" scenarios to evaluate hypothetical outcomes of policy and management choices. In this approach decision makers can evaluate the financial and geographic distribution of potential policy options and their societal implications. Actions, based on scientific information, can be taken to mitigate hazards, protect our air and water quality, preserve the planet's biodiversity, promote balanced land use planning, and judiciously exploit natural resources. Applications using the GDSS have demonstrated the benefits of utilizing science for policy decisions. Investment in science reduces decision-making uncertainty and reducing that uncertainty has economic value.

  14. Top Sounder Ice Penetration

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Goemmer, S. A.; Sweeney, J. H.

    2014-12-01

    Ice draft measurements are made as part of normal operations for all US Navy submarines operating in the Arctic Ocean. The submarine ice draft data are unique in providing high resolution measurements over long transects of the ice covered ocean. The data has been used to document a multidecadal drop in ice thickness, and for validating and improving numerical sea-ice models. A submarine upward-looking sonar draft measurement is made by a sonar transducer mounted in the sail or deck of the submarine. An acoustic beam is transmitted upward through the water column, reflecting off the bottom of the sea ice and returning to the transducer. Ice thickness is estimated as the difference between the ship's depth (measured by pressure) and the acoustic range to the bottom of the ice estimated from the travel time of the sonar pulse. Digital recording systems can provide the return off the water-ice interface as well as returns that have penetrated the ice. Typically, only the first return from the ice hull is analyzed. Information regarding ice flow interstitial layers provides ice age information and may possibly be derived with the entire return signal. The approach being investigated is similar to that used in measuring bottom sediment layers and will involve measuring the echo level from the first interface, solving the reflection loss from that transmission, and employing reflection loss versus impedance mismatch to ascertain ice structure information.

  15. Commercial aviation icing research requirements

    NASA Technical Reports Server (NTRS)

    Koegeboehn, L. P.

    1981-01-01

    A short range and long range icing research program was proposed. A survey was made to various industry and goverment agencies to obtain their views of needs for commercial aviation ice protection. Through these responsed, other additional data, and Douglas Aircraft icing expertise; an assessment of the state-of-the-art of aircraft icing data and ice protection systems was made. The information was then used to formulate the icing research programs.

  16. Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Chennault, Jonathan

    2004-01-01

    The Icing Research Tunnel in Building 11 at the NASA Glenn Research Center is committed to researching the effects of in flight icing on aircraft and testing ways to stop the formation of hazardous icing conditions on planes. During this summer, I worked here with Richard DelRosa, the lead engineer for this area. address one of the major concerns of aviation: icing conditions. During the war, many planes crashed (especially supply planes going over the.Himalayas) because ice built up in their wings and clogged the engines. To this day, it remains the largest ice tunnel in the world, with a test section that measures 6 feet high, 9 feet long, and 20 feet wide. It can simulate airspeeds from 50 to 300 miles per hour at temperatures as low as -50 Fahrenheit. Using these capabilities, IRT can simulate actual conditions at high altitudes. The first thing I did was creating a cross reference in Microsoft Excel. It lists commands for the DPU units that control the pressure and temperature variations in the tunnel, as well as the type of command (keyboard, multiplier, divide, etc). The cross reference also contains the algorithm for every command, and which page it is listed in on the control sheet (visual Auto-CAD graphs, which I helped to make). I actually spent most of the time on the computer using Auto-CAD. I drew a diagram of the entire icing tunnel and then drew diagrams of its various parts. Between my mentor and me, we have drawings of every part of it, from the spray bars to the thermocouples, power cabinets, input-output connectors for power systems, and layouts of various other machines. I was also responsible for drawing schematics for the Escort system (which controls the spray bars), the power system, DPUs, and other electrical systems. In my spare time, I am attempting to build and program the "toddler". Toddler is a walking robot that I have to program in PBASIC language. When complete, it should be able to walk on level terrain while avoiding obstacles in real-time. It features an infrared detector that can keep it from falling over edges, as well as follow or avoid a light source. The toddler is giving me a much better understanding of the basics of electronic circuitry and computer programming.

  17. A Procedure for the Design of Air-Heated Ice-Prevention Systems

    NASA Technical Reports Server (NTRS)

    Neel, C. B.

    1954-01-01

    A procedure proposed for use in the design of air-heated systems for the continuous prevention of ice formation on airplane components is set forth. Required heat-transfer and air-pressure-loss equations are presented, and methods of selecting appropriate meteorological conditions for flight over specified geographical areas and for the calculation of water-drop-impingement characteristics are suggested. In order to facilitate the design, a simple electrical analogue was devised which solves the complex heat-transfer relationships existing in the thermal-system analysis. The analogue is described and an illustration of its application to design is given.

  18. Optimizing the performance of Ice-storage Systems in Electricity Load Management through a credit mechanism. An analytical work for Jiangsu, China

    DOE PAGESBeta

    Han, Yafeng; Shen, Bo; Hu, Huajin; Fan, Fei

    2015-01-12

    Ice-storage air-conditioning is a technique that uses ice for thermal energy storage. Replacing existing air conditioning systems with ice storage has the advantage of shifting the load from on-peak times to off-peak times that often have excess generation. However, increasing the use of ice-storage faces significant challenges in China. One major barrier is the inefficiency in the current electricity tariff structure. There is a lack of effective incentive mechanism that induces ice-storage systems from achieving optimal load-shifting results. This study presents an analysis that compares the potential impacts of ice-storage systems on load-shifting under a new credit-based incentive scheme andmore » the existing incentive arrangement in Jiangsu, China. The study indicates that by changing how ice-storage systems are incentivized in Jiangsu, load-shifting results can be improved.« less

  19. Optimizing the performance of Ice-storage Systems in Electricity Load Management through a credit mechanism. An analytical work for Jiangsu, China

    SciTech Connect

    Han, Yafeng; Shen, Bo; Hu, Huajin; Fan, Fei

    2015-01-12

    Ice-storage air-conditioning is a technique that uses ice for thermal energy storage. Replacing existing air conditioning systems with ice storage has the advantage of shifting the load from on-peak times to off-peak times that often have excess generation. However, increasing the use of ice-storage faces significant challenges in China. One major barrier is the inefficiency in the current electricity tariff structure. There is a lack of effective incentive mechanism that induces ice-storage systems from achieving optimal load-shifting results. This study presents an analysis that compares the potential impacts of ice-storage systems on load-shifting under a new credit-based incentive scheme and the existing incentive arrangement in Jiangsu, China. The study indicates that by changing how ice-storage systems are incentivized in Jiangsu, load-shifting results can be improved.

  20. The effects of arctic stratus clouds on the solar energy budget in the atmosphere-sea ice-ocean system

    SciTech Connect

    Jin, Z.; Stamnes, K.; Zak, B.D.

    1995-04-01

    This article describes a comprehensive radiative transfer model pertinent to the atmosphere-sea ice-ocean system. The main features of the model include: The atmosphere, sea ice, and ocean each represented by a sufficient number of layers to resolve the change in the optical properties of each stratum; An appropriate quadrature structure to take into account the total reflection at the air-ice or air-water interface, as well as to solve the radiative transfer equation in the coupled system consistently; Provision for a different number of streams (quadrature points) in the atmosphere, ice, and ocean, chosen based on the optical properties in each stratum and the computational accuracy method.

  1. Continuous ice core melter system with discrete sampling for major ion, trace element and stable isotope analyses.

    PubMed

    Osterberg, Erich C; Handley, Michael J; Sneed, Sharon B; Mayewski, Paul A; Kreutz, Karl J

    2006-05-15

    We present a novel ice/firn core melter system that uses fraction collectors to collect discrete, high-resolution (<1 cm/sample possible), continuous, coregistered meltwater samples for analysis of eight major ions by ion chromatography (IC), >32 trace elements by inductively coupled plasma sectorfield mass spectrometry (ICP-SMS), and stable oxygen and hydrogen isotopes by isotope ratio mass spectrometry (IRMS). The new continuous melting with discrete sampling (CMDS) system preserves an archive of each sample, reduces the problem of incomplete particle dissolution in ICP-SMS samples, and provides more precise trace element data than previous ice melter models by using longer ICP-SMS scan times and washing the instrument between samples. CMDS detection limits are similar to or lower than those published for ice melter systems coupled directly to analytical instruments and are suitable for analyses of polar and mid-low-latitude ice cores. Analysis of total calcium and sulfur by ICP-SMS and calcium ion, sulfate, and methanesulfonate by IC from the Mt. Logan Prospector-Russell Col ice core confirms data accuracy and coregistration of the split fractions from each sample. The reproducibility of all data acquired by the CMDS system is confirmed by replicate analyses of parallel sections of the GISP2 D ice core. PMID:16749705

  2. Technology for Ice Rinks

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Ron Urban's International Ice Shows set up portable ice rinks for touring troupes performing on temporary rinks at amusement parks, sports arenas, dinner theaters, shopping malls and civic centers. Key to enhanced rink portability, fast freezing and maintaining ice consistency is a mat of flexible tubing called ICEMAT, an offshoot of a solar heating system developed by Calmac, Mfg. under contract with Marshall.

  3. Multi objective decision making in hybrid energy system design

    NASA Astrophysics Data System (ADS)

    Merino, Gabriel Guillermo

    The design of grid-connected photovoltaic wind generator system supplying a farmstead in Nebraska has been undertaken in this dissertation. The design process took into account competing criteria that motivate the use of different sources of energy for electric generation. The criteria considered were 'Financial', 'Environmental', and 'User/System compatibility'. A distance based multi-objective decision making methodology was developed to rank design alternatives. The method is based upon a precedence order imposed upon the design objectives and a distance metric describing the performance of each alternative. This methodology advances previous work by combining ambiguous information about the alternatives with a decision-maker imposed precedence order in the objectives. Design alternatives, defined by the photovoltaic array and wind generator installed capacities, were analyzed using the multi-objective decision making approach. The performance of the design alternatives was determined by simulating the system using hourly data for an electric load for a farmstead and hourly averages of solar irradiation, temperature and wind speed from eight wind-solar energy monitoring sites in Nebraska. The spatial variability of the solar energy resource within the region was assessed by determining semivariogram models to krige hourly and daily solar radiation data. No significant difference was found in the predicted performance of the system when using kriged solar radiation data, with the models generated vs. using actual data. The spatial variability of the combined wind and solar energy resources was included in the design analysis by using fuzzy numbers and arithmetic. The best alternative was dependent upon the precedence order assumed for the main criteria. Alternatives with no PV array or wind generator dominated when the 'Financial' criteria preceded the others. In contrast, alternatives with a nil component of PV array but a high wind generator component, dominated when the 'Environment' objective or the 'User/System compatibility' objectives were more important than the 'Financial' objectives and they also dominated when the three criteria were considered equally important.

  4. Using Multimodal Input for Autonomous Decision Making for Unmanned Systems

    NASA Technical Reports Server (NTRS)

    Neilan, James H.; Cross, Charles; Rothhaar, Paul; Tran, Loc; Motter, Mark; Qualls, Garry; Trujillo, Anna; Allen, B. Danette

    2016-01-01

    Autonomous decision making in the presence of uncertainly is a deeply studied problem space particularly in the area of autonomous systems operations for land, air, sea, and space vehicles. Various techniques ranging from single algorithm solutions to complex ensemble classifier systems have been utilized in a research context in solving mission critical flight decisions. Realized systems on actual autonomous hardware, however, is a difficult systems integration problem, constituting a majority of applied robotics development timelines. The ability to reliably and repeatedly classify objects during a vehicles mission execution is vital for the vehicle to mitigate both static and dynamic environmental concerns such that the mission may be completed successfully and have the vehicle operate and return safely. In this paper, the Autonomy Incubator proposes and discusses an ensemble learning and recognition system planned for our autonomous framework, AEON, in selected domains, which fuse decision criteria, using prior experience on both the individual classifier layer and the ensemble layer to mitigate environmental uncertainty during operation.

  5. Development and evaluation of a rule-based control strategy for ice storage systems

    SciTech Connect

    Drees, K.H.; Braun, J.E.

    1997-12-31

    This paper describes the development and evaluation of a near-optimal control strategy for ice storage systems. The strategy is based upon simple heuristics that were developed from daily and monthly simulations of cooling systems with internal melt, area-constrained ice storage tanks. Dynamic programming was used to obtain the optimal control trajectories which minimized an integrated energy and demand cost function for both the daily and monthly simulations. In addition to leading to simple heuristics, the monthly optimal control results were used as benchmarks to evaluate the performance of both conventional and the new control strategy. For a range of partial-storage systems, load profiles, and utility rate structures, the monthly electrical costs for the rule-based control strategy were, on average, within about 3% of the optimal costs. In contrast, the monthly electrical costs associated with the most common conventional control strategy, chiller-priority control, were as much as 20% greater than optimal, whereas a simple storage-priority strategy yielded costs that were within about 6% of optimal. The rule-based strategy can be easily implemented within a small micro-processor controller and only requires measurements of the system cooling requirement, building electrical usage, and state-of-charge of storage.

  6. Viscoelastic Relaxation of Tidally Induced Stresses in the Ice Shells of Outer Solar System Satellites

    NASA Astrophysics Data System (ADS)

    Crawford, Z. A.; Mullen, M.; Wahr, J.; Pappalardo, R. T.; Stempel, M. M.; Barr, A. C.; Collins, G.

    2006-12-01

    A significant fraction of icy satellites appear to have an ice shell decoupled from the moon's solid interior by a global ocean. Such satellites when in an eccentric orbit will experience diurnal tidal deformation and stresses within the shell. Further, non-synchronous rotation (NSR) of decoupled ice shells has been suggested as a potential source of large surface stresses. These stresses may be stored elastically, released through brittle failure, or relaxed away viscously. Prior work has focused on elastic behavior, since the surface temperatures in the outer solar system are so low. However, much of a convecting ice shell may be warm enough to behave viscously on NSR timescales. Near the melting point it may even be possible for some diurnal stress to relax away. We model an ice shell as two Maxwell viscoelastic layers with independent viscosities. Frequency dependent degree-two Love numbers are calculated assuming a silicate core, global ocean, and the two layer ice shell for both NSR and diurnal forcing frequencies. When orbital eccentricity is set to zero, we find that surface stresses due to NSR depend on the ratio of the NSR forcing period to the shell's relaxation time: γ = \\frac{PNSR}{τMaxwell} When γ >> 1 the shell behaves viscously, and when γ << 1 the shell behaves elastically. Since the upper and lower shells have different relaxation times, assuming the surface is colder than the interior there are three possible regimes: when both layers behave elastically, the resulting stresses are similar to previously published results. When both layers behave viscously, surface stresses are greatly reduced. When the upper layer behaves elastically, and the lower layer behaves viscously NSR stresses are effectively concentrated in the upper layer, and are somewhat larger than if the entire shell is elastic. As the elastic proportion of the shell is reduced, the magnitude of the surface stresses increases. When the lower shell behaves viscously and the upper shell behaves elastically, the surface stresses are very similar to those resulting from a thin elastic shell floating directly on a liquid ocean. If orbital eccentricity is non-zero and γ >> 1 for the upper layer, then the shorter period results in the diurnal stresses dominating. The existence of surface features on Europa that apparently stem from diurnal stresses suggests that at some point in the recent geologic past the upper shell has behaved viscously on the timescale of NSR. We would like to thank PG&G and OPR for their support of this research.

  7. Bench Scale Test of Absorption Slurry-ice Maker

    NASA Astrophysics Data System (ADS)

    Sasao, Hiroyuki; Yoshida, Takashi

    Slurry ice system is desirable as cold heat source for air conditioning, because it requires less conveyance power or less pipe size. On the other hand, recently absorption refrigerator is reevaluated because it can utilize various types of waste heat and it does not use fluorocarbon refrigerant. But it had been regarded to be difficult to make ice by absorption refrigerator because the refrigerant is water. However making slurry ice is possible, of cource, if the slurry ice generated by partial freezing of water is continuously taken away from the evaporator. This method was certified experimentally with a bench scale model. For ice making continuously, ice had not to be frozen stiff at water surface or inside wall of the evaporator. Then refrigerant water in the evaporator was raised swirl flow. And inside wall of the evaporator was finished by water repellent coating, and heated from outside wall. This slurry ice was adaptable to hydraulic transportation, because ice was needle crystal with about 5 mm length and ice temperature was 0°C.

  8. The Met Office Coupled Atmosphere/Land/Ocean/Sea-Ice Data Assimilation System

    NASA Astrophysics Data System (ADS)

    Lea, Daniel; Mirouze, Isabelle; King, Robert; Martin, Matthew; Hines, Adrian

    2015-04-01

    The Met Office has developed a weakly-coupled data assimilation (DA) system using the global coupled model HadGEM3 (Hadley Centre Global Environment Model, version 3). At present the analysis from separate ocean and atmosphere DA systems are combined to produced coupled forecasts. The aim of coupled DA is to produce a more consistent analysis for coupled forecasts which may lead to less initialisation shock and improved forecast performance. The HadGEM3 coupled model combines the atmospheric model UM (Unified Model) at 60 km horizontal resolution on 85 vertical levels, the ocean model NEMO (Nucleus for European Modelling of the Ocean) at 25 km (at the equator) horizontal resolution on 75 vertical levels, and the sea-ice model CICE at the same resolution as NEMO. The atmosphere and the ocean/sea-ice fields are coupled every 1-hour using the OASIS coupler. The coupled model is corrected using two separate 6-hour window data assimilation systems: a 4D-Var for the atmosphere with associated soil moisture content nudging and snow analysis schemes on the one hand, and a 3D-Var FGAT for the ocean and sea-ice on the other hand. The background information in the DA systems comes from a previous 6-hour forecast of the coupled model. To isolate the impact of the coupled DA, 13-month experiments have been carried out, including 1) a full atmosphere/land/ocean/sea-ice coupled DA run, 2) an atmosphere-only run forced by OSTIA SSTs and sea-ice with atmosphere and land DA, and 3) an ocean-only run forced by atmospheric fields from run 2 with ocean and sea-ice DA. In addition, 5-day and 10-day forecast runs, have been produced from initial conditions generated by either run 1 or a combination of runs 2 and 3. The different results have been compared to each other and, whenever possible, to other references such as the Met Office atmosphere and ocean operational analyses or the OSTIA SST data. The performance of the coupled DA is similar to the existing separate ocean and atmosphere DA systems. This is despite the fact that the assimilation error covariances have not yet been tuned for coupled DA. In addition, the coupled model also exhibits some biases which do not affect the uncoupled models. An example is precipitation and run off errors affecting the ocean salinity. This of course impacts the performance of the ocean data assimilation. This does, however, highlight a particular benefit of data assimilation in that it can help to identify short term model biases by using, for example, the differences between the observations and model background (innovations) and the mean increments. Coupled DA has the distinct advantage that this gives direct information about the coupled model short term biases. By identifying the biases and developing solutions this will improve the short range coupled forecasts, and may also improve the coupled model on climate timescales.

  9. Vortex ice in nanostructured superconductors

    SciTech Connect

    Reichhardt, Charles; Reichhardt, Cynthia J; Libal, Andras J

    2008-01-01

    We demonstrate using numerical simulations of nanostructured superconductors that it is possible to realize vortex ice states that are analogous to square and kagome ice. The system can be brought into a state that obeys either global or local ice rules by applying an external current according to an annealing protocol. We explore the breakdown of the ice rules due to disorder in the nanostructure array and show that in square ice, topological defects appear along grain boundaries, while in kagome ice, individual defects appear. We argue that the vortex system offers significant advantages over other artificial ice systems.

  10. Laboratory Studies of Ethane Ice Relevant to Outer Solar System Surfaces

    NASA Astrophysics Data System (ADS)

    Moore, Marla H.; Hudson, R. L.; Raines, L.

    2009-09-01

    Oort Cloud comets, as well as TNOs Makemake (2005 FY9), Quaoar, and Pluto, are known to contain ethane. However, even though this molecule is found on several outer Solar System objects relatively little information is available about its amorphous and crystalline phases. In new experiments, we have prepared ethane ices at temperatures applicable to the outer Solar System, and have heated and ion-irradiated these ices to study phase changes and ethane's radiation chemistry using mid-IR spectroscopy (2.2 - 16.6 microns). Included in our work is the meta-stable phase that exists at 35 - 55 K. These results, including newly obtained optical constants, are relevant to ground-based observational campaigns, the New Horizons mission, and supporting laboratory work. An improved understanding of solid-phase ethane may contribute to future searches for this and other hydrocarbons in the outer Solar System. This work was funded by NASA's Planetary Geology and Geophysics, Planetary Atmospheres, and Outer Planets programs. LR was supported by a summer research internship at the NASA Astrobiology Institute's Goddard Center for Astrobiology.

  11. An ice nucleation reporter gene system: identification of inducible pathogenicity genes in Pseudomonas syringae pv. phaseolicola.

    PubMed Central

    Lindgren, P B; Frederick, R; Govindarajan, A G; Panopoulos, N J; Staskawicz, B J; Lindow, S E

    1989-01-01

    We have constructed derivatives of the transposon Tn3 that allow an ice nucleation gene (inaZ) to be used as 'reporter' of the transcriptional activity of genes into which it is inserted. In these derivatives (Tn3-Ice and Tn3-Spice), the lacZYA sequences of transposon Tn3-HoHo1 were replaced with inaZ lacking its native promoter. The ice nucleation activity of virB::inaZ fusions in the correct transcriptional orientation was inducible by acetosyringone, a plant metabolite which activates the vir operon of Agrobacterium tumefaciens Ti plasmids, while fusions in the opposite orientation were unresponsive to the inducer. Tn3-Spice was also used to investigate the expression of a cluster of genes (hrp) which control pathogenicity and hypersensitivity elicited by Pseudomonas syringae pv. phaseolicola. An inducible region was identified which is expressed at low levels in vitro but becomes activated when the bacteria come into contact with the susceptible host, bean. Activation of this region occurred within 2 h post-inoculation and was nearly complete by the time the bacteria began to multiply in the leaf tissue. The inaZ reporter appears to be at least 10(5)-fold more sensitive than lacZ in P.s.phaseolicola. Thus, the inaZ fusion system provides a sensitive, convenient and inexpensive tool for the study of bacterial gene expression, particularly during plant pathogenesis, and should be generally useful as a reporter gene system in Gram-negative bacteria. PMID:2548841

  12. Modelling the response of the Lambert Glacier-Amery Ice Shelf system, East Antarctica, to uncertain climate forcing over the 21st and 22nd centuries

    NASA Astrophysics Data System (ADS)

    Gong, Y.; Cornford, S. L.; Payne, A. J.

    2014-06-01

    The interaction between the climate system and the large polar ice sheet regions is a key process in global environmental change. We carried out dynamic ice simulations of one of the largest drainage systems in East Antarctica: the Lambert Glacier-Amery Ice Shelf system, with an adaptive mesh ice sheet model. The ice sheet model is driven by surface accumulation and basal melt rates computed by the FESOM (Finite-Element Sea-Ice Ocean Model) ocean model and the RACMO2 (Regional Atmospheric Climate Model) and LMDZ4 (Laboratoire de Météorologie Dynamique Zoom) atmosphere models. The change of ice thickness and velocity in the ice shelf is mainly influenced by the basal melt distribution, but, although the ice shelf thins in most of the simulations, there is little grounding line retreat. We find that the Lambert Glacier grounding line can retreat as much as 40 km if there is sufficient thinning of the ice shelf south of Clemence Massif, but the ocean model does not provide sufficiently high melt rates in that region. Overall, the increased accumulation computed by the atmosphere models outweighs ice stream acceleration so that the net contribution to sea level rise is negative.

  13. Ice, Ice, Baby!

    NASA Astrophysics Data System (ADS)

    Hamilton, C.

    2008-12-01

    The Center for Remote Sensing of Ice Sheets (CReSIS) has developed an outreach program based on hands-on activities called "Ice, Ice, Baby". These lessons are designed to teach the science principles of displacement, forces of motion, density, and states of matter. These properties are easily taught through the interesting topics of glaciers, icebergs, and sea level rise in K-8 classrooms. The activities are fun, engaging, and simple enough to be used at science fairs and family science nights. Students who have participated in "Ice, Ice, Baby" have successfully taught these to adults and students at informal events. The lessons are based on education standards which are available on our website www.cresis.ku.edu. This presentation will provide information on the activities, survey results from teachers who have used the material, and other suggested material that can be used before and after the activities.

  14. Thermophysical, Rheological and Mechanical Measurements on Icy Compositions with Application to Solar System Ices

    NASA Astrophysics Data System (ADS)

    Hays, C. C.; Barmatz, M. B.; Zhong, F. V.; Mitchell, K. L.; Castillo, J. C.; Weilert, M.; Lopes, R. M.; Matson, D. L.; Pappalardo, R. T.; Wall, S.; Smythe, W.

    2006-12-01

    In this talk, we will discuss objectives and preliminary results for a research effort that uses a combined experimental and theoretical approach to: 1) determine fundamental physical properties of icy moon materials (ices and candidate cryomagmas) at small scales through cryogenic laboratory experiments; and 2) through modeling, extend these experimental results to explain observations at planetary length scales. These data will be used to help model the observed properties of planetary icy moons, in two important areas: 1) cryovolcanism; and 2) geophysical and tectonic processes, including mechanical response at tidal frequencies. New data from cryogenic laboratory experiments, on relevant icy systems, are needed to improve our ability to model these phenomena. Our experimental work will focus on three areas: 1) calorimetric studies of water-ice systems to construct relevant phase diagrams; 2) measurements of the bulk rheology (stress vs. strain rate) for cryovolcanic candidate fluids and mixed-phase (slurry) materials at different temperatures and crystal/solid fractions; and 3) mechanical property measurements (under compression) for solid specimens to obtain the Young's modulus at cryogenic temperatures. These experimental results will enable improved interpretations of the geophysical processes operant on Enceladus, Titan and Europa, i.e., crack propagation, crustal cycling, and band formation. This work was carried out at the Jet Propulsion Laboratory-California Institute of Technology, under contract to NASA.

  15. Transport and transformation of de-icing urea from airport runways in a constructed wetland system.

    PubMed

    Thorén, A K; Legrand, C; Herrmann, J

    2003-01-01

    Urea, NH2-CO-NH2, is used as a de-icing agent at Kalmar Airport, southeast Sweden. During 1998-2001, urea contributed on average 30% of the yearly nitrogen (N) transport of 41,000 kg via Törnebybäcken stream to the coastal zone of the Baltic Sea. In order to reduce stream transport of N from airport, agricultural and other diffuse sources, a wetland was constructed in 1996. Annual wetland retention of total-N varied in the range of 2,500-8,100 kg (6-36% of influent) during 1998-2001, according to mass balances calculated from monthly sampling. During airport de-icing, January-March 2001,660 kg urea-N out of 2,600 kg applied urea-N reached the wetland according to daily sampling. This indicated that 75% of the urea was transformed before entering the wetland. Urea was found to be only a minor part (8%) of total-N in the wetland influent. Calculations of cumulative urea-N loads at the wetland inlet and outlet respectively, showed a significant urea transformation during February 2001 with approximately 40% of the incoming urea-N being transformed in the wetland system. These results show that significant amounts of urea can be transformed in a wetland system at air temperatures around 0 degree C. PMID:14621175

  16. Constraints on ice volume changes of the WAIS and Ross Ice Shelf since the LGM based on cosmogenic exposure ages in the Darwin-Hatherton glacial system of the Transantarctic Mountains

    NASA Astrophysics Data System (ADS)

    Fink, David; Storey, Bryan; Hood, David; Joy, Kurt; Shulmeister, James

    2010-05-01

    Quantitative assessment of the spatial and temporal scale of ice volume change of the West Antarctic ice sheet (WAIS) and Ross Ice Shelf since the last glacial maximum (LGM) ~20 ka is essential to accurately predict ice sheet response to current and future climate change. Although global sea level rose by approximately 120 metres since the LGM, the contribution of polar ice sheets is uncertain and the timing of any such contribution is controversial. Mackintosh et al (2007) suggest that sectors of the EAIS, similar to those studied at Framnes Mountains where the ice sheet slowly calves at coastal margins, have made marginal contributions to global sea-level rise between 13 and 7 ka. In contrast, Stone et al (2003) document continuing WAIS decay during the mid-late Holocene, raising the question of what was the response of the WAIS since LGM and into the Holocene. Terrestrial evidence is restricted to sparse coastal oasis and ice free mountains which archive limits of former ice advances. Mountain ranges flanking the Darwin-Hatherton glaciers exhibit well-defined moraines, weathering signatures, boulder rich plateaus and glacial tills, which preserve the evidence of advance and retreat of the ice sheet during previous glacial cycles. Previous studies suggest a WAIS at the LGM in this location to be at least 1,000 meters thicker than today. As part of the New Zealand Latitudinal Gradient Project along the Transantarctic, we collected samples for cosmogenic exposure dating at a) Lake Wellman area bordering the Hatherton Glacier, (b) Roadend Nunatak at the confluence of the Darwin and Hatherton glaciers and (c) Diamond Hill which is positioned at the intersection of the Ross Ice Shelf and Darwin Glacier outlet. While the technique of exposure dating is very successful in mid-latitude alpine glacier systems, it is more challenging in polar ice-sheet regions due to the prevalence of cold-based ice over-riding events and absence of outwash processes which removes glacially transported debris. Our glacial geomorphic survey from ice sheet contact edge (~850 masl) to mountain peak at 1600 masl together with a suite of 10Be and 26Al exposure ages, documents a pre-LGM ice volume at least 800 meters thicker than current ice levels which was established at least 2 million years ago. However a complex history of exposure and re-exposure of the ice free regions in this area is seen in accordance with advance and retreat of the ice sheets that feeds into the Darwin -Hatherton system. A cluster of mid-altitude boulders, located below a prominent moraine feature mapped previously as demarcating the LGM ice advance limits, have exposure ages ranging from 30 to 40 ka. Exposure ages for boulders just above the ice contact range from 1to 19 ka and allow an estimate of inheritance. Hence, we conclude that LGM ice volume was not as large as previously estimated and actually little different from what is observed today. These results raise rather serious questions about the implications of a reduced WAIS at the LGM, its effect on the development of the Ross Ice Shelf, and how the Antarctic ice sheets respond to global warming. J. O. Stone et al., Science v299, 99 (2003). A. Mackintosh, D. White, D. Fink, D. Gore et al, Geology, v 35; 551-554 (2007).

  17. Radiolysis of Amino Acids in Outer Solar-System Ice Analogs

    NASA Technical Reports Server (NTRS)

    Gerakines, Perry A.; Hudson, Reggie L.

    2011-01-01

    Amino acids have been found in cometary dust particles and in the organic component of meteorites. These molecules, important for pre-biotic chemistry and for active biological systems, might be formed in cold planetary or interstellar environments and then delivered to H20-rich surfaces in the outer solar system. Many models for the availability of organic species on Earth and elsewhere depend on the ability of these molecules to survive in radiation-rich space environments. This poster presents results of O.8-MeV proton radiolysis of ice films at lS-140K. using infrared spectroscopy, the destruction rates of glycine, alanine, and phenylalanine have been determined for both pure films and those containing amino acids diluted in H2o. our results are discussed in terms of the survivability of these molecules in the icy surfaces present in the outer solar system and the possibility of their detection by instruments on board the New Horizons spacecraft

  18. Present-day and future Antarctic ice sheet climate and surface mass balance in the Community Earth System Model

    NASA Astrophysics Data System (ADS)

    Lenaerts, Jan T. M.; Vizcaino, Miren; Fyke, Jeremy; van Kampenhout, Leo; van den Broeke, Michiel R.

    2016-02-01

    We present climate and surface mass balance (SMB) of the Antarctic ice sheet (AIS) as simulated by the global, coupled ocean-atmosphere-land Community Earth System Model (CESM) with a horizontal resolution of ˜1° in the past, present and future (1850-2100). CESM correctly simulates present-day Antarctic sea ice extent, large-scale atmospheric circulation and near-surface climate, but fails to simulate the recent expansion of Antarctic sea ice. The present-day Antarctic ice sheet SMB equals 2280 ± 131 {Gt year^{-1}} , which concurs with existing independent estimates of AIS SMB. When forced by two CMIP5 climate change scenarios (high mitigation scenario RCP2.6 and high-emission scenario RCP8.5), CESM projects an increase of Antarctic ice sheet SMB of about 70 {Gt year^{-1}} per degree warming. This increase is driven by enhanced snowfall, which is partially counteracted by more surface melt and runoff along the ice sheet's edges. This intensifying hydrological cycle is predominantly driven by atmospheric warming, which increases (1) the moisture-carrying capacity of the atmosphere, (2) oceanic source region evaporation, and (3) summer AIS cloud liquid water content.

  19. Systemic Data-Based Decision Making: A Systems Approach for Using Data in Schools

    ERIC Educational Resources Information Center

    Walser, Tamara M.

    2009-01-01

    No Child Left Behind has increased data collection and reporting, the development of data systems, and interest in using data for decision-making in schools and classrooms. Ends-driven decision making has become common educational practice, where the ends justify the means at all costs, and short-term results trump longer-term outcomes and the…

  20. ABIOTIC FORMATION OF CARBOXYLIC ACIDS (RCOOH) IN INTERSTELLAR AND SOLAR SYSTEM MODEL ICES

    SciTech Connect

    Kim, Y. S.; Kaiser, R. I.

    2010-12-10

    The present laboratory study simulated the abiotic formation of carboxylic acids (RCOOH) in interstellar and solar system model ices of carbon dioxide (CO{sub 2})-hydrocarbon mix C{sub n} H{sub 2n+2} (n = 1-6). The pristine model ices were irradiated at 10 K under contamination-free, ultrahigh vacuum conditions with energetic electrons generated in the track of galactic cosmic-ray particles. The chemical processing of the ices was monitored by a Fourier transform infrared spectrometer and a quadrupole mass spectrometer during the irradiation phase and subsequent warm-up phases on line and in situ in order to extract qualitative (carriers) and quantitative (rate constants and yields) information on the newly synthesized species. Carboxylic acids were identified to be the main carrier, together with carbon monoxide (CO) and a trace of formyl (HCO) and hydroxycarbonyl (HOCO) radicals at 10 K. The upper limit of acid column density at 10 K was estimated as much as (1.2 {+-} 0.1) x 10{sup 17} molecules cm{sup -2} at doses of 17 {+-} 2 eV molecule{sup -1}, or the yield of 39% {+-} 4% from the initial column density of carbon dioxide. The temporal column density profiles of the products were then numerically fit using two independent kinetic schemes of reaction mechanisms. Finally, we transfer this laboratory simulation to star-forming regions of the interstellar medium, wherein cosmic-ray-induced processing of icy grains at temperatures as low as 10 K could contribute to the current level of chemical complexity as evidenced in astronomical observations and in extracts of carbonaceous meteorites.

  1. Ikaite crystal distribution in Arctic winter sea ice and implications for CO2 system dynamics

    NASA Astrophysics Data System (ADS)

    Rysgaard, S.; Søgaard, D. H.; Cooper, M.; Pućko, M.; Lennert, K.; Papakyriakou, T. N.; Wang, F.; Geilfus, N. X.; Glud, R. N.; Ehn, J.; McGinnnis, D. F.; Attard, K.; Sievers, J.; Deming, J. W.; Barber, D.

    2012-12-01

    The precipitation of ikaite (CaCO3·6H2O) in polar sea ice is critical to the efficiency of the sea ice-driven carbon pump and potentially important to the global carbon cycle, yet the spatial and temporal occurrence of ikaite within the ice is poorly known. We report unique observations of ikaite in unmelted ice and vertical profiles of ikaite abundance and concentration in sea ice for the crucial season of winter. Ice was examined from two locations: a 1 m thick land-fast ice site and a 0.3 m thick polynya site, both in the Young Sound area (74° N, 20° W) of NE Greenland. Ikaite crystals, ranging in size from a few µm to 700 µm were observed to concentrate in the interstices between the ice platelets in both granular and columnar sea ice. In vertical sea-ice profiles from both locations, ikaite concentration determined from image analysis, decreased with depth from surfaceice values of 700-900 µmol kg-1 ice (~ 25 × 106 crystals kg-1) to bottom-layer values of 100-200 µmol kg-1 ice (1-7 × 106 kg-1), all of which are much higher (4-10 times) than those reported in the few previous studies. Direct measurements of total alkalinity (TA) in surface layers fell within the same range as ikaite concentration whereas TA concentrations in bottom layers were twice as high. This depth-related discrepancy suggests interior ice processes where ikaite crystals form in surface sea ice layers and partly dissolved in bottom layers. From these findings and model calculations we relate sea ice formation and melt to observed pCO2 conditions in polar surface waters, and hence, the air-sea CO2 flux.

  2. Effect of Sublimation of Ice on Evaporation Phenomenon of Ethanol Solution

    NASA Astrophysics Data System (ADS)

    Asaoka, Tatsunori; Okada, Masashi; Aida, Kazuki

    Ice making method using evaporation of ethanol solution is useful to ice thermal storage system. In the method, ethanol solution is evaporated under low pressure condition, and ice is produced in it due to the latent heat of evaporation. From our previous experiment, it was found that ethanol concentration of vapor decreases when ice particles floats on the surface of the solution. In this study, the effect of sublimation of ice on the evaporation phenomenon of ethanol solution was investigated. In the experiment, the ethanol concentration of vapor in ice producing chamber was measured under the various conditions. As a result, it was found that the ethanol concentration of vapor significantly decreases due to formation of ice layer, which covers surface of the ethanol solution. It was also found that the amount of decrease in ethanol concentration of vapor mainly depends on thesurface area of the covering ice.

  3. Regular network model for the sea ice-albedo feedback in the Arctic.

    PubMed

    Müller-Stoffels, Marc; Wackerbauer, Renate

    2011-03-01

    The Arctic Ocean and sea ice form a feedback system that plays an important role in the global climate. The complexity of highly parameterized global circulation (climate) models makes it very difficult to assess feedback processes in climate without the concurrent use of simple models where the physics is understood. We introduce a two-dimensional energy-based regular network model to investigate feedback processes in an Arctic ice-ocean layer. The model includes the nonlinear aspect of the ice-water phase transition, a nonlinear diffusive energy transport within a heterogeneous ice-ocean lattice, and spatiotemporal atmospheric and oceanic forcing at the surfaces. First results for a horizontally homogeneous ice-ocean layer show bistability and related hysteresis between perennial ice and perennial open water for varying atmospheric heat influx. Seasonal ice cover exists as a transient phenomenon. We also find that ocean heat fluxes are more efficient than atmospheric heat fluxes to melt Arctic sea ice. PMID:21456825

  4. Calmac Ice Storage Test report

    SciTech Connect

    Stovall, T.K.

    1991-08-01

    The Ice Storage Test Facility (ISTF) is designed to test commercial ice storage systems. Calmac provided a storage tank equipped with coils designed for use with a secondary fluid system. The Calmac ice storage system was tested over a wide range of operating conditions. Measured system performance during charging was similar to that reported by the manufacturer. Both the measured average and minimum brine temperatures were in close agreement with Calmac's literature values, and the ability to fully charge the tank was relatively unaffected by charging rate and brine flow rate. During discharge cycles, the storage tank outlet temperature was strongly affected by the discharge rate. The discharge capacity was dependent upon both the selected discharge rate and maximum allowable tank outlet temperature. Based on these tests, storage tank selection must depend most strongly on the discharge conditions required to serve the load. This report describes Calmac system performance fully under both charging and discharging conditions. Companion reports describe ISTF test procedures and ice-making efficiency test results that are common to many of the units tested. 11 refs., 31 figs., 9 tabs.

  5. MUSE - Mission to the Uranian system: Unveiling the evolution and formation of ice giants

    NASA Astrophysics Data System (ADS)

    Bocanegra-Bahamón, Tatiana; Bracken, Colm; Costa Sitjà, Marc; Dirkx, Dominic; Gerth, Ingo; Konstantinidis, Kostas; Labrianidis, Christos; Laneuville, Matthieu; Luntzer, Armin; MacArthur, Jane L.; Maier, Andrea; Morschhauser, Achim; Nordheim, Tom A.; Sallantin, Renaud; Tlustos, Reinhard

    2015-05-01

    The planet Uranus, one of the two ice giants in the Solar System, has only been visited once by the Voyager 2 spacecraft in 1986. Ice giants represent a fundamental class of planets, and many known exoplanets fall within this category. Therefore, a dedicated mission to an ice giant is crucial to improve the understanding of the formation, evolution and current characteristics of such planets in order to extend the knowledge of both the Solar System and exoplanetary systems. In the study at hand, the rationale, selection, and conceptual design for a mission to investigate the Uranian system, as an archetype for ice giants, is presented. A structured analysis of science questions relating to the Uranian system is performed, categorized by the themes atmosphere, interior, moons and rings, and magnetosphere. In each theme, science questions are defined, with their relative importance in the theme quantified. Additionally, top-level weights for each theme are defined, with atmosphere and interior weighted the strongest, as they are more related to both exoplanetary systems and the Uranian system, than the other two themes (which are more specific for the planet itself). Several top level mission architecture aspects have been defined, from which the most promising concepts were generated using heuristic methods. A trade-off analysis of these concepts is presented, separately, for engineering aspects, such as cost, complexity, and risk, and for science aspects. The science score for each mission is generated from the capability of each mission concept to answer the science questions. The trade-off results in terms of relative science and engineering weight are presented, and competitive mission concepts are analyzed based on the preferred mission type. A mission design point for a typical flagship science mission is selected from the trade space. It consists of a Uranus orbiter with a dry mass of 2073 kg including 402 kg of payload and a Uranus entry probe, which is to perform measurements down 100 bar atmospheric pressure. The orbiter science phase will consist of a Uranus orbit phase of approximately 2 years in a highly elliptical orbit, during which 36 Uranus orbits are performed. Subsequently, a moon phase is performed, during which the periapsis will be raised in five steps, facilitating 9 flybys of each of Uranus' major moons. A preliminary vehicle design is presented, seeking the best compromise between the design drivers, which basically derive from the large distance between Uranus and the Earth (e.g., high thermal load during Venus flyby, low thermal load during Uranus science phase, low data-rate during Uranus science phase, the need of radioisotope power source, etc). This paper is the result of a study carried out during the Alpbach Summer School 2012 "Exploration of the icy planets and their systems" and a one-week follow-up meeting in Graz, Austria. The results of this study show that a flagship ESA L-class mission - consisting of an orbiter with a single atmospheric entry probe and flybys of the main satellites - would be able to address the set of science questions which are identified in the study at hand as the most essential for the understanding of Uranus and its system. The spacecraft, as currently designed, could be launched with an Ariane 5, in 2026, arriving at Uranus in 2044, and operating until 2050. The development of a radioactive power source is the main requirement for feasibility for this mission.

  6. The NASA aircraft icing research program

    NASA Technical Reports Server (NTRS)

    Shaw, Robert J.; Reinmann, John J.

    1990-01-01

    The objective of the NASA aircraft icing research program is to develop and make available to industry icing technology to support the needs and requirements for all-weather aircraft designs. Research is being done for both fixed wing and rotary wing applications. The NASA program emphasizes technology development in two areas, advanced ice protection concepts and icing simulation. Reviewed here are the computer code development/validation, icing wind tunnel testing, and icing flight testing efforts.

  7. Reducing uncertainty in high-resolution sea ice models.

    SciTech Connect

    Peterson, Kara J.; Bochev, Pavel Blagoveston

    2013-07-01

    Arctic sea ice is an important component of the global climate system, reflecting a significant amount of solar radiation, insulating the ocean from the atmosphere and influencing ocean circulation by modifying the salinity of the upper ocean. The thickness and extent of Arctic sea ice have shown a significant decline in recent decades with implications for global climate as well as regional geopolitics. Increasing interest in exploration as well as climate feedback effects make predictive mathematical modeling of sea ice a task of tremendous practical import. Satellite data obtained over the last few decades have provided a wealth of information on sea ice motion and deformation. The data clearly show that ice deformation is focused along narrow linear features and this type of deformation is not well-represented in existing models. To improve sea ice dynamics we have incorporated an anisotropic rheology into the Los Alamos National Laboratory global sea ice model, CICE. Sensitivity analyses were performed using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) to determine the impact of material parameters on sea ice response functions. Two material strength parameters that exhibited the most significant impact on responses were further analyzed to evaluate their influence on quantitative comparisons between model output and data. The sensitivity analysis along with ten year model runs indicate that while the anisotropic rheology provides some benefit in velocity predictions, additional improvements are required to make this material model a viable alternative for global sea ice simulations.

  8. EOS Aqua AMSR-E Arctic Sea Ice Validation Program: Arctic2003 Aircraft Campaign Flight Report

    NASA Technical Reports Server (NTRS)

    Cavalieri, D. J.; Markus,T.

    2003-01-01

    In March 2003 a coordinated Arctic sea ice validation field campaign using the NASA Wallops P-3B aircraft was successfully completed. This campaign was part of the program for validating the Earth Observing System (EOS) Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sea ice products. The AMSR-E, designed and built by the Japanese National Space Development Agency for NASA, was launched May 4, 2002 on the EOS Aqua spacecraft. The AMSR-E sea ice products to be validated include sea ice concentration, sea ice temperature, and snow depth on sea ice. This flight report describes the suite of instruments flown on the P-3, the objectives of each of the seven flights, the Arctic regions overflown, and the coordination among satellite, aircraft, and surface-based measurements. Two of the seven aircraft flights were coordinated with scientists making surface measurements of snow and ice properties including sea ice temperature and snow depth on sea ice at a study area near Barrow, AK and at a Navy ice camp located in the Beaufort Sea. Two additional flights were dedicated to making heat and moisture flux measurements over the St. Lawrence Island polynya to support ongoing air-sea-ice processes studies of Arctic coastal polynyas. The remaining flights covered portions of the Bering Sea ice edge, the Chukchi Sea, and Norton Sound.

  9. Modeling the response of Lambert Glacier-Amery Ice Shelf system, East Antarctic, to uncertain climate forcing over the 21st and 22nd centuries

    NASA Astrophysics Data System (ADS)

    Gong, Yongmei; Cornford, Steph; Payne, Tony

    2014-05-01

    The interaction between the climate system and the large polar ice sheets regions is a key process in global environmental change. We carried out ice dynamic simulations of one of the largest drainage systems in East Antarctica: the Lambert Glacier-Amery Ice Shelf system, with an adaptive mesh ice sheet model. The ice sheet model is driven by surface accumulation and basal melt rates computed by two ocean and two atmosphere models. The change of the ice thickness and velocity in the ice shelf is mainly influenced by the basal melt distribution, but, although the ice shelf thins in the most of the simulations, there is little grounding line retreat. We find that the Lambert Glacier grounding line can retreat as much as 30 km if there is sufficient thinning of the ice shelf south of Clemence Massif, but none of the ocean models provide sufficiently high melt rates in that region. Overall, the increased accumulation computed by the atmosphere models outweighs ice stream acceleration so that the net contribution to sea level rise is negative.

  10. Modeling the response of Lambert Glacier-Amery Ice Shelf system, East Antarctic, to uncertain climate forcing over the 21st and 22nd centuries

    NASA Astrophysics Data System (ADS)

    Gong, Y.; Cornford, S. L.; Payne, A. J.

    2013-12-01

    The interaction between the climate system and the large polar ice sheets regions is a key process in global environmental change. We carried out ice dynamic simulations of one of the largest drainage systems in East Antarctica: the Lambert Glacier-Amery Ice Shelf system, with an adaptive mesh ice sheet model. The ice sheet model is driven by surface accumulation and basal melt rates computed by two ocean and two atmosphere models. The change of the ice thickness and velocity in the ice shelf is mainly influenced by the basal melting distribution, but, although the ice shelf thins in the most of the simulations, there is little grounding line retreat. We find that the Lambert Glacier grounding line can retreat as much as 30 km if there is sufficient thinning of the ice shelf south of Clemence Massif, but none of the ocean models provide sufficiently high melt rates in that region. Overall, the increased accumulation computed by the atmosphere models outweighs ice stream acceleration so that the net contribution to sea level rise is negative.

  11. Application of new GPS aircraft control/display system to topographic mapping of the Greenland ice cap

    NASA Technical Reports Server (NTRS)

    Wright, C. W.

    1992-01-01

    A new PC-based GPS flight management display system (GFMS) was developed for Greenland ice cap mapping during the NASA Greenland Ice Sheet mapping experiment, when a total of nine flights were made over four different flight tracks, of which two coincided with ground tracks of the ERS altimeter satellite. In this system, the GFMS inputs the GPS position data to a PC, which generates aircraft automatic pilot steering commands and a cockpit display. The display includes (1) the course deviation indicators for cross-track error and altitude, (2) the flight plan and waypoint map overlay oriented to the aircraft, and (3) various other mission-pertinent numerical data.

  12. Hydrographer on the Ice

    Scott Bendtson, a hydrologic technician with the Maine Office of the New England Water Science Center, is seen here making a discharge measurement through the ice on the St. John River at Ninemile Bridge, USGS station number 01010000....

  13. Implications of Contingency Planning Support for Weather and Icing Information

    NASA Technical Reports Server (NTRS)

    Vigeant-Langlois, Laurence; Hansman, R. John, Jr.

    2003-01-01

    A human-centered systems analysis was applied to the adverse aircraft weather encounter problem in order to identify desirable functions of weather and icing information. The importance of contingency planning was identified as emerging from a system safety design methodology as well as from results of other aviation decision-making studies. The relationship between contingency planning support and information on regions clear of adverse weather was investigated in a scenario- based analysis. A rapid prototype example of the key elements in the depiction of icing conditions was developed in a case study, and the implications for the components of the icing information system were articulated.

  14. Ice Observatory

    NASA Astrophysics Data System (ADS)

    blugerman, n.

    2015-10-01

    My project is to make ice observatories to perceive astral movements as well as light phenomena in the shape of cosmic rays and heat, for example.I find the idea of creating an observation point in space, that in time will change shape and eventually disappear, in consonance with the way we humans have been approaching the exploration of the universe since we started doing it. The transformation in the elements we use to understand big and small transformations, within the universe elements.

  15. Space Launch System Complex Decision-Making Process

    NASA Technical Reports Server (NTRS)

    Lyles, Garry; Flores, Tim; Hundley, Jason; Monk, Timothy; Feldman,Stuart

    2012-01-01

    The Space Shuttle program has ended and elements of the Constellation Program have either been cancelled or transitioned to new NASA exploration endeavors. The National Aeronautics and Space Administration (NASA) has worked diligently to select an optimum configuration for the Space Launch System (SLS), a heavy lift vehicle that will provide the foundation for future beyond low earth orbit (LEO) large-scale missions for the next several decades. From Fall 2010 until Spring 2011, an SLS decision-making framework was formulated, tested, fully documented, and applied to multiple SLS vehicle concepts at NASA from previous exploration architecture studies. This was a multistep process that involved performing figure of merit (FOM)-based assessments, creating Pass/Fail gates based on draft threshold requirements, performing a margin-based assessment with supporting statistical analyses, and performing sensitivity analysis on each. This paper focuses on the various steps and methods of this process (rather than specific data) that allowed for competing concepts to be compared across a variety of launch vehicle metrics in support of the successful completion of the SLS Mission Concept Review (MCR) milestone.

  16. Mechanisms of ice gouging

    SciTech Connect

    Kioka, Shinji; Saeki, Hiroshi

    1995-12-31

    Sea ice is carried to the cost of Hokkaido by wind and water currents every year. In low pressure systems or when there is much sea ice, it drifts out toward the Pacific Ocean. When sea ice moves in shallow water areas, the sandy subgrade on the sea bottom is gouged by the sea ice. This phenomenon is generally called ``ice gouging``. Substantial damage to sea food i.e. (shellfish) and to structures embedded in the seabed is reported every year. However, the mechanisms and behavior of ice gouging is not known sufficiently enough for discussion. Therefore, the authors have conducted a suitable experiment to clarify this phenomenon and have suggested formulas to measure ice gouging.

  17. Decision making strategies for probabilistic aerospace systems design

    NASA Astrophysics Data System (ADS)

    Borer, Nicholas Keith

    Modern aerospace systems design problems are often characterized by the necessity to identify and enable multiple tradeoffs. This can be accomplished by transformation of the design problem to a multiple objective optimization formulation. However, existing multiple criteria techniques can lead to unattractive solutions due to their basic assumptions; namely that of monotonically increasing utility and independent decision criteria. Further, it can be difficult to quantify the relative importance of each decision metric, and it is very difficult to view the pertinent tradeoffs for large-scale problems. This thesis presents a discussion and application of Multiple Criteria Decision Making (MCDM) to aerospace systems design and quantifies the complications associated with switching from single to multiple objectives. It then presents a procedure to tackle these problems by utilizing a two-part relative importance model for each criterion. This model contains a static and dynamic portion with respect to the current value of the decision metric. The static portion is selected based on an entropy analogy of each metric within the decision space to alleviate the problems associated with quantifying basic (monotonic) relative importance. This static value is further modified by examination of the interdependence of the decision metrics. The dynamic contribution uses a penalty function approach for any constraints and further reduces the importance of any metric approaching a user-specified threshold level. This reduces the impact of the assumption of monotonically increasing utility by constantly updating the relative importance of a given metric based on its current value. A method is also developed to determine a linearly independent subset of the original requirements, resulting in compact visualization techniques for large-scale problems.

  18. Massively parallel molecular-dynamics simulation of ice crystallisation and melting: The roles of system size, ensemble, and electrostatics

    NASA Astrophysics Data System (ADS)

    English, Niall J.

    2014-12-01

    Ice crystallisation and melting was studied via massively parallel molecular dynamics under periodic boundary conditions, using approximately spherical ice nano-particles (both "isolated" and as a series of heterogeneous "seeds") of varying size, surrounded by liquid water and at a variety of temperatures. These studies were performed for a series of systems ranging in size from ˜1 × 106 to 8.6 × 106 molecules, in order to establish system-size effects upon the nano-clusters" crystallisation and dissociation kinetics. Both "traditional" four-site and "single-site" and water models were used, with and without formal point charges, dipoles, and electrostatics, respectively. Simulations were carried out in the microcanonical and isothermal-isobaric ensembles, to assess the influence of "artificial" thermo- and baro-statting, and important disparities were observed, which declined upon using larger systems. It was found that there was a dependence upon system size for both ice growth and dissociation, in that larger systems favoured slower growth and more rapid melting, given the lower extent of "communication" of ice nano-crystallites with their periodic replicae in neighbouring boxes. Although the single-site model exhibited less variation with system size vis-à-vis the multiple-site representation with explicit electrostatics, its crystallisation-dissociation kinetics was artificially fast.

  19. The TetR-Type MfsR Protein of the Integrative and Conjugative Element (ICE) ICEclc Controls both a Putative Efflux System and Initiation of ICE Transfer

    PubMed Central

    Pradervand, Nicolas; Delavat, François; Sulser, Sandra; Miyazaki, Ryo

    2014-01-01

    Integrative and conjugating elements (ICE) are self-transferable DNAs widely present in bacterial genomes, which often carry a variety of auxiliary genes of potential adaptive benefit. One of the model ICE is ICEclc, an element originally found in Pseudomonas knackmussii B13 and known for its propensity to provide its host with the capacity to metabolize chlorocatechols and 2-aminophenol. In this work, we studied the mechanism and target of regulation of MfsR, a TetR-type repressor previously found to exert global control on ICEclc horizontal transfer. By using a combination of ICEclc mutant and transcriptome analysis, gene reporter fusions, and DNA binding assays, we found that MfsR is a repressor of both its own expression and that of a gene cluster putatively coding for a major facilitator superfamily efflux system on ICEclc (named mfsABC). Phylogenetic analysis suggests that mfsR was originally located immediately adjacent to the efflux pump genes but became displaced from its original cis target DNA by a gene insertion. This resulted in divergence of the original bidirectional promoters into two separated individual regulatory units. Deletion of mfsABC did not result in a strong phenotype, and despite screening a large number of compounds and conditions, we were unable to define the precise current function or target of the putative efflux pump. Our data reconstruct how the separation of an ancestor mfsR-mfsABC system led to global control of ICEclc transfer by MfsR. PMID:25182498

  20. Universal Dynamic Calving Law implies Potential for Abrupt Ice-Shelf Retreat

    NASA Astrophysics Data System (ADS)

    Levermann, Anders; Albrecht, Torsten; Winkelmann, Ricarda; Martin, Maria A.; Haseloff, Marianne

    2010-05-01

    Recently observed large-scale disintegration of Antarctic ice shelves has moved their fronts closer towards grounded ice. In response, ice-sheet discharge into the ocean has accelerated, contributing to global sea-level rise and emphasizing the importance of calving-front dynamics. The position of the ice front strongly influences the stress field within the entire sheet-shelf-system and thereby the mass flow across the grounding line. While theories for an advance of the ice-front are readily available, no general rule exists for its retreat, making the study of ice-front motion inaccessible. Here we present a universal dynamic calving law which (1) combines observations into a mathematically simple first-order relation, (2) depends only on local ice-flow properties, (3) naturally incorporates the stabilizing effect of pinning points and (4) inhibits shelf-ice growth outside of embayments. In numerical simulations it reproduces multiple stable fronts as observed for the Larsen A and B Ice Shelves including rapid transitions between them caused by localized ice weaknesses. We also observe an abrupt retreat of Ross Ice Shelf at the gateway of the West Antarctic Ice Sheet which reduces back stresses onto the sheet by up to 40%. Our results thus enable the study of ice-front motion and have strong implications for global sea level rise.

  1. Ice pack heat sink subsystem, phase 2. [astronaut life support cooling system

    NASA Technical Reports Server (NTRS)

    Roebelen, G. J., Jr.; Kellner, J. D.

    1975-01-01

    The report describes the design, development, fabrication, and test at one gravity of a prototype ice pack heat sink subsystem to be used eventually for astronaut cooling during manned space missions; the investigation of thermal storage material with the objective of uncovering materials with heats of fusion and/or solution in the range of 300 Btu/lb (700 kilojoules/kilogram); and the planned procedure for implementing an ice pack heat sink subsystem flight experiment. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

  2. Subaqueous ice-contact fans: Depositional systems characterised by highly aggradational supercritical flow conditions

    NASA Astrophysics Data System (ADS)

    Lang, Joerg; Winsemann, Jutta

    2015-04-01

    Subaqueous ice-contact fans are deposited by high-energy plane-wall jets from subglacial conduits into standing water bodies. Highly aggradational conditions during flow expansion and deceleration allow for the preservation of bedforms related to supercritical flows, which are commonly considered rare in the depositional record. We present field examples from gravelly and sandy subaqueous ice-contact fan successions, which indicate that deposition by supercritical flows might be considered as a characteristic feature of these depositional systems. The studied successions were deposited in deep ice-dammed lakes, which formed along the margins of the Middle Pleistocene Scandinavian ice sheets across Northern Germany. The gravel-rich subaqueous fan deposits are dominated by large scour-fills (up to 25 m wide and 3 m) deep and deposits of turbulent hyperconcentrated flows, which are partly attributed to supercritical flow conditions (Winsemann et al., 2009). Scours (up to 4.5 m wide and 0.9 m deep) infilled by gravelly backsets are observed above laterally extensive erosional surfaces and are interpreted as deposits of cyclic steps. Laterally discontinuous beds of low-angle cross-stratified gravel are interpreted as antidune deposits. Downflow and up-section the gravel-rich deposits pass into sand-rich successions, which include deposits of chutes-and-pools, breaking antidunes, stationary antidunes and humpback dunes (Lang and Winsemann, 2013). Deposits of chutes-and-pools and breaking antidunes are characterised by scour-fills (up to 4 m wide and 1.2 m deep) comprising backsets or gently dipping sigmoidal foresets. Stationary antidune deposits consist of laterally extensive sinusoidal waveforms with long wavelengths (1-12 m) and low amplitudes (0.1-0.5 m), which formed under quasi-steady flows at the lower limit of the supercritical flow stage and high rates of sedimentation. Humpback dunes are characterised by divergent sigmoidal foresets and are interpreted as bedforms related to transcritical flow conditions. Deposits of aggrading stationary antidunes and humpback dunes represent a characteristic facies association of the distal zone of flow transition. Downflow the succession passes into deposits of large 3D dunes and climbing ripples. The large-scale lateral and vertical successions of bedforms are interpreted as representing the temporal and spatial evolution of the supercritical meltwater jets, which was affected by hydraulic jumps. Small-scale facies changes and the formation of individual bedforms are interpreted as controlled by fluctuating discharge, pulsating unstable flows and bed topography. References: Lang, J., Winsemann, J. (2013) Lateral and vertical facies relationships of bedforms deposited by aggrading supercritical flows: from cyclic steps to humpback dunes. Sedimentary Geology 296, 36-54. Winsemann, J., Hornung, J.J., Meinsen, J., Asprion, U., Polom, U., Brandes, C., Bussmann, M., Weber, C., (2009) Anatomy of a subaqueous ice-contact fan and delta complex, Middle Pleistocene, North-west Germany, Sedimentology 56, 1041-1076.

  3. Aircraft Icing Sensor

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Simmonds Precision's ice system consists of an ultrasonic sensor and a signal conditioner. The sensor has a piezoelectric ceramic crystal (PCC) that sends an ultrasonic pulse into an ice layer and detects an echo returning from the ice; the time elapsed in the pulse-echo round trip provides a basis for calculating ice thickness. Simmonds offers an alternative system with two PCCs, one a transmitter and the other a receiver for picking up the return echo. This technique offers detection of ice at much smaller thickness values, but at the cost of some ability to detect thicker ice. Among the advantages of the system are the small size of the sensor, which allows its placement in areas previously inaccessible. Other sensor advantages include high accuracy and insensitivity to salt spray, fog, chemicals and abrasion. Both sensor and signal conditioner offer high reliability, light weight and low power consumption.

  4. Decision making support system for emergency shutdown of gas lifeline system

    SciTech Connect

    Takada, Shiro; Fukui, Shinji

    1995-12-31

    Quick recovery of the lifeline function and serviceability after big earthquakes is very important to avoid a secondary disaster. Emergency shutdown of the lifeline systems is a possible way for this purpose. The present paper proposes a computer aided decision making system for a proper timing of an emergency shutdown. The AHP (Analytical Hierarchy Process) method has been employed to consider relative evaluation of the various factors associated with the decision making. The proposed method is useful especially for an emergency shutdown of the gas supply system which would cause severe effects due to the shutdown.

  5. Arctic Sea ice model sensitivities.

    SciTech Connect

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  6. Ice Protection of Turbojet Engines by Inertia Separation of Water I : Alternate-duct System

    NASA Technical Reports Server (NTRS)

    Von Glahn, Uwe

    1948-01-01

    Aerodynamic and icing investigations of internal water-inertia separation inlets designed to prevent automatically entrance of large quantities of water into a turbojet engine in icing conditions was conducted on a one-half scale model. A simplified analytical approach to the design of internal water-inertia separation inlets is included. Results show that in order to be effective in preventing screen and guide-vane icing for an inlet of this type, a ram-pressure recovery of 75 percent was attained at design inlet-velocity ratio in an icing condition. For nonicing operation, ram-pressure recovery is comparable to direct-ram inlet.

  7. Glacier Land Ice Measurements from Space (GLIMS) and the GLIMS Information Management System at NSIDC

    NASA Astrophysics Data System (ADS)

    Machado, A. E.; Scharfen, G. R.; Barry, R. G.; Khalsa, S. S.; Raup, B.; Swick, R.; Troisi, V. J.; Wang, I.

    2001-12-01

    GLIMS (Global Land Ice Measurements from Space) is an international project to survey a majority of the world's glaciers with the accuracy and precision needed to assess recent changes and determine trends in glacial environments. This will be accomplished by: comprehensive periodic satellite measurements, coordinated distribution of screened image data, analysis of images at worldwide Regional Centers, validation of analyses, and a publicly accessible database. The primary data source will be from the ASTER (Advanced Spaceborne Thermal Emission and reflection Radiometer) instrument aboard the EOS Terra spacecraft, and Landsat ETM+ (Enhanced Thematic Mapper Plus), currently in operation. Approximately 700 ASTER images have been acquired with GLIMS gain settings as of mid-2001. GLIMS is a collaborative effort with the United States Geological Survey (USGS), the National Aeronautics Space Adminstration (NASA), other U.S. Federal Agencies and a group of internationally distributed glaciologists at Regional Centers of expertise. The National Snow and Ice Data Center (NSIDC) is developing the information management system for GLIMS. We will ingest and maintain GLIMS-analyzed glacier data from Regional Centers and provide access to the data via the World Wide Web. The GLIMS database will include measurements (over time) of glacier length, area, boundaries, topography, surface velocity vectors, and snowline elevation, derived primarily from remote sensing data. The GLIMS information management system at NSIDC will provide an easy to use and widely accessible service for the glaciological community and other users needing information about the world's glaciers. The structure of the international GLIMS consortium, status of database development, sample imagery and derived analyses and user search and order interfaces will be demonstrated. More information on GLIMS is available at: http://www.glims.org/.

  8. Microbial activity inhibition in chilled mackerel (Scomber scombrus) by employment of an organic acid-icing system.

    PubMed

    Sanjuás-Rey, Minia; Gallardo, José M; Barros-Velázquez, Jorge; Aubourg, Santiago P

    2012-05-01

    The present study concerns Atlantic mackerel (Scomber scombrus) traded as a chilled product. The study was aimed to investigate the effect of including a mixture of organic acids (citric, ascorbic, and lactic) in the icing medium employed during the fish chilled storage. To this end and according to preliminary trials results, an aqueous solution including 0.050% (w/v) of each acid was employed as icing medium; its effect on the microbial activity development in mackerel muscle was monitored for up to 13 d of chilled storage and compared to a counterpart-fish batch kept under traditional water ice considered as control. Results indicated a lower bacterial growth in mackerel muscle subjected to storage in the organic acid-icing system by comparison with control fish. Thus, statistically-significant (P < 0.05) differences between both batches for all 6 microbial groups investigated (aerobes, anaerobes, psychrotrophes, Enterobacteriaceae, lipolytics, and proteolytics) and for 2 chemical indices related to microbial activity development (total volatile bases and trimethylamine) were obtained. The surface wash caused by the melting of the ice during storage and the subsequent antimicrobial effect of such acids on skin microflora of the fish can be invoked as the main reasons for the limited bacterial growth found in the corresponding mackerel muscle. PMID:22510040

  9. Numerical Modeling of Anti-icing Systems and Comparison to Test Results on a NACA 0012 Airfoil

    NASA Technical Reports Server (NTRS)

    Al-Khalil, Kamel M.; Potapczuk, Mark G.

    1993-01-01

    A series of experimental tests were conducted in the NASA Lewis IRT on an electro-thermally heated NACA 0012 airfoil. Quantitative comparisons between the experimental results and those predicted by a computer simulation code were made to assess the validity of a recently developed anti-icing model. An infrared camera was utilized to scan the instantaneous temperature contours of the skin surface. Despite some experimental difficulties, good agreement between the numerical predictions and the experiment results were generally obtained for the surface temperature and the possibility for each runback to freeze. Some recommendations were given for an efficient operation of a thermal anti-icing system.

  10. An ice lithography instrument

    PubMed Central

    Han, Anpan; Chervinsky, John; Branton, Daniel; Golovchenko, J. A.

    2011-01-01

    We describe the design of an instrument that can fully implement a new nanopatterning method called ice lithography, where ice is used as the resist. Water vapor is introduced into a scanning electron microscope (SEM) vacuum chamber above a sample cooled down to 110 K. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice is removed by the SEM electron beam (e-beam) guided by an e-beam lithography system. Without breaking vacuum, the sample with the ice mask is then transferred into a metal deposition chamber where metals are deposited by sputtering. The cold sample is then unloaded from the vacuum system and immersed in isopropanol at room temperature. As the ice melts, metal deposited on the ice disperses while the metals deposited on the sample where the ice had been removed by the e-beam remains. The instrument combines a high beam-current thermal field emission SEM fitted with an e-beam lithography system, cryogenic systems, and a high vacuum metal deposition system in a design that optimizes ice lithography for high throughput nanodevice fabrication. The nanoscale capability of the instrument is demonstrated with the fabrication of nanoscale metal lines. PMID:21721733

  11. Influence of Icing Information on Pilot Strategies for Operating in Icing Conditions

    NASA Technical Reports Server (NTRS)

    Vigeant-Langlois, Laurence; Hansman, R. John, Jr.

    2003-01-01

    The influence of potential remoteice-deteetion system features on pilot decision making was investigated through a Web-based experiment. Display features including a graphical plan view depiction of icing severity, vertical view depiction, single and multiple icing Severity levels as well as sensor range were varied in a part-task simulation experiment. Using information from each display, pilots were presented with a set of four flight scenarios and probed on their routing decisions and comfort level with those decisions. The experiment also included a subjective display preference evaluation. Results show that all of the displays improved pilot decision making over existing text-based icing information. The three-dimensional displays that included vertical depiction of icing conditions were found to support improved decision making. Range was not found to be a strong factor in the experiment; however, the minimum range tested was 25 n miles, which may be in excess of current technical capabilities. The depiction of the severity of icing conditions was not found to be as important as accurate information on the location of icing conditions.

  12. Organic solids produced from simple C/H/O/N ices by charged particles - Applications to the outer solar system

    NASA Technical Reports Server (NTRS)

    Khare, B. N.; Thompson, W. R.; Chyba, C. F.; Sagan, C.; Arakawa, E. T.

    1989-01-01

    The effects of charged particle irradiation by cold plasma discharge on surfaces of H2O:CH4 clathrate with a 200:1 ratio and on ices composed of H2O and C2H6 or C2H2 are examined. The molecules studies are found in Comet Halley and are plausible constituents in icy outer solar system objects. The IR transmission spectra of four ice-tholin residues obtained in the laboratory are compared with spectra produced by irradiation of gases and ices containing simple hydrocarbons. The similarities between CH4 clathrate residue and Halley organic grains, and the surface transport or atmospheric replenishment activity on Triton and Pluto are discussed.

  13. Organic solids produced from simple C/H/O/N ices by charged particles - Applications to the outer solar system

    SciTech Connect

    Khare, B.N.; Thompson, W.R.; Chyba, C.F.; Sagan, C.; Arakawa, E.T.

    1989-01-01

    The effects of charged particle irradiation by cold plasma discharge on surfaces of H2O:CH4 clathrate with a 200:1 ratio and on ices composed of H2O and C2H6 or C2H2 are examined. The molecules studies are found in Comet Halley and are plausible constituents in icy outer solar system objects. The IR transmission spectra of four ice-tholin residues obtained in the laboratory are compared with spectra produced by irradiation of gases and ices containing simple hydrocarbons. The similarities between CH4 clathrate residue and Halley organic grains, and the surface transport or atmospheric replenishment activity on Triton and Pluto are discussed. 56 refs.

  14. Aircraft Landing Gear, Ice and Rain Control Systems (Course Outline), Aviation Mechanics 3 (Air Frame):9067.02.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to familiarize the student with operation, inspection, troubleshooting, and repair of aircraft landing gear, ice and rain control systems. It is designed to help the trainee master the knowledge and skills necessary to become an aviation airframe mechanic. The aviation airframe…

  15. Modeling South Pacific Ice-Ocean Interactions in the Global Climate System

    NASA Technical Reports Server (NTRS)

    Holland, David M.; Jenkins, Adrian; Jacobs, Stanley S.

    2001-01-01

    The objective of this project has been to improve the modeling of interactions between large Antarctic ice shelves and adjacent regions of the Southern Ocean. Our larger goal is to gain a better understanding of the extent to which the ocean controls ice shelf attrition, thereby influencing the size and dynamics of the Antarctic Ice Sheet. Melting and freezing under ice shelves also impacts seawater properties, regional upwelling and sinking and the larger-scale ocean circulation. Modifying an isopycnal coordinate general circulation model for use in sub-ice shelf cavities, we found that the abrupt change in water column thickness at an ice shelf front does not form a strong barrier to buoyancy-driven circulation across the front. Outflow along the ice shelf base, driven by melting of the thickest ice, is balanced by deep inflow. Substantial effort was focused on the Filchner-Ronne cavity, where other models have been applied and time-series records are available from instruments suspended beneath the ice. A model comparison indicated that observed changes in the production of High Salinity Shelf Water could have a major impact on circulation within the cavity. This water propagates into the cavity with an asymmetric seasonal signal that has similar phasing and shape in the model and observations, and can be related to winter production at the sea surface. Even remote parts of the sub-ice shelf cavity are impacted by external forcing on sub-annual time scales. This shows that cavity circulations and products, and therefore cavity shape, will respond to interannual variability in sea ice production and longer-term climate change. The isopycnal model gives generally lower net melt rates than have been obtained from other models and oceanographic data, perhaps due to its boundary layer formulation, or the lack of tidal forcing. Work continues on a manuscript describing the Ross cavity results.

  16. Seasonal Evolution and Interannual Variability of the Local Solar Energy Absorbed by the Arctic Sea Ice-Ocean System

    NASA Technical Reports Server (NTRS)

    Perovich, Donald K.; Nghiem, Son V.; Markus, Thorsten; Schwieger, Axel

    2007-01-01

    The melt season of the Arctic sea ice cover is greatly affected by the partitioning of the incident solar radiation between reflection to the atmosphere and absorption in the ice and ocean. This partitioning exhibits a strong seasonal cycle and significant interannual variability. Data in the period 1998, 2000-2004 were analyzed in this study. Observations made during the 1997-1998 SHEBA (Surface HEat Budget of the Arctic Ocean) field experiment showed a strong seasonal dependence of the partitioning, dominated by a five-phase albedo evolution. QuikSCAT scatterometer data from the SHEBA region in 1999-2004 were used to further investigate solar partitioning in summer. The time series of scatterometer data were used to determine the onset of melt and the beginning of freezeup. This information was combined with SSM/I-derived ice concentration, TOVS-based estimates of incident solar irradiance, and SHEBA results to estimate the amount of solar energy absorbed in the ice-ocean system for these years. The average total solar energy absorbed in the ice-ocean system from April through September was 900 MJ m(sup -2). There was considerable interannual variability, with a range of 826 to 1044 MJ m(sup -2). The total amount of solar energy absorbed by the ice and ocean was strongly related to the date of melt onset, but only weakly related to the total duration of the melt season or the onset of freezeup. The timing of melt onset is significant because the incident solar energy is large and a change at this time propagates through the entire melt season, affecting the albedo every day throughout melt and freezeup.

  17. Thermal and Electron Irradiation Processing of Outer SolarSystem Ice Simulants: Chemical and Spectroscopic Laboratory Characterization

    NASA Astrophysics Data System (ADS)

    Poston, Michael; Mahjoub, Ahmed; Hand, Kevin; Carlson, Robert; Brown, Mike; Blacksberg, Jordana; Eiler, John; Hodyss, Robert; Carey, Elizabeth; Ehlmann, Bethany

    2014-11-01

    Our team is examining the effects of energetic radiation and thermal cycling on pure and mixed solar system ices under ultra-high vacuum conditions. These ices are being examined in search of markers that are unique to a specific thermal or radiation history, with specific interest in simulating histories believed to be relevant to Jupiter Trojan asteroids and Kuiper Belt Objects. A key telescopic observation of the Trojan asteroids is that they have a bimodal distribution of spectral slopes in the visible and near infrared regions. One population exhibits very red spectral slopes, while the other moderately red slopes. This distribution may point to differing formation locations and dynamical histories between the two populations. The ices are deposited on a cryogenic stage at temperatures appropriate to outer solar system objects. Of specific interest are water, methanol, hydrogen sulfide, and ammonia, which are simple ice constituents that together contain the most common reactive elements found in ices. Electron irradiation has been conducted, with plans to irradiate with other particle sources as well. The ices are examined by reflectance spectroscopy in the visible through mid infrared while a quadrapole mass spectrometer monitors the vacuum chamber background for any desorbed or sputtered neutral products. All mixtures analyzed thus far have shown the appearance of new bands and disappearance of others during irradiation and formation of a residue that did not sublime upon heating to 300 Kelvin. This work has been supported by the Keck Institute for Space Studies (KISS). The research described here was carried out at the Jet Propulsion Laboratory, Caltech, under a contract with the National Aeronautics and Space Administration (NASA) and at the Caltech Division of Geological and Planetary Sciences.

  18. Cryogenic Property Measurements on Icy Compositions with Application to Solar System Ices

    NASA Astrophysics Data System (ADS)

    Hays, C.; Castillo-Rogez, J.; Barmatz, M.; Mitchell, K.

    2007-08-01

    Introduction and Science Motivation:We present the motivations, objectives, and preliminary experimental results for a new experimental cryo-ices initiative launched at JPL. The main motivation for this work is to fully appreciate the discoveries made by the Cassini-Huygens and Galileo missions, to prepare for the Dawn and New Horizons missions, and to look forward to potential missions to Europa, Enceladus, and Titan. This work is a joint effort among experimentalists and theorists at JPL, in collaboration with specialists in icy material properties the world over. Experimental Approach: A range of experiments are being devised which will improve our ability to model ice-rock body internal evolution and geological processes using modern synthesis and characterization techniques under cryogenic conditions. Initial experiments will involve pure water, methanol-water, ammonia-water, and ammoniawater- methanol mixtures, relevant to a range of icy satellites and processes. Ammonia is considered to play an important role in Titan cryovolcanism, whereas methanol is chosen as an experimental analog due to its ease-of-use in the laboratory. Where beneficial, we will determine basic thermophysical properties and phase diagrams using a Differential Scanning Calorimeter. Solids.We plan to analyze samples from terrestrial glaciers, which are relevant to both the terrestrial and planetary geology and geophysical communities. Terrestrial glaciers appear as realistic analogs for modeling processes taking place in the outer icy shells of icy satellites. These results will better enable us to predict the long-term evolution of terrestrial glaciers and ice shelves. Also, we will synthesize specimens with controlled microstructures by using equilibrium and non-equilibrium synthesis methods. Equilibrium methods, e.g., conventional (slow) freezing in a mold, will provide microstructural length scales in the range 0.2 to 1 mm (with and without preferred orientation, e.g., columnar grains). Post-synthesis microstructural characterization will be performed using Cryogenic Optical Microscopy integrating a cross-polarizer to analyze thin sections, and a Cryogenic Scanning Electron Microscope. Mechanical property measurements on solid specimens will be performed between 80 and 270 K with a cryogenically cooled Instron measurement system. Compression measurements will be conducted as a function of temperature, strain-rate, microstructural length scale and orientation. The time dependent viscous response will be measured by performing creep measurements over the same range of temperatures. Using low-frequency cyclic loading, the dissipation factor will be measured at frequencies approaching satellite orbital frequencies. We will report preliminary mechanical property measurements of Antarctic glacial specimens at cryogenic temperatures. Fluids. In order to improve our understanding of effusive cryovolcanism, the rheological properties of liquid and mixed (slurry) materials will be measured between 80 and 300 K using a cryogenically cooled Brookfield rotational rheometer. We will report preliminary measurements of the temperature dependence of the viscous response for several compositions in the Methanol-Water System. Also, we will describe an experiment designed to measure methane wetting on water ice. These experiments will be carried out in order to explore the effects of the presence of methane lakes on Titan's surface. We are developing the capability to investigate more complex materials relevant to surface processes on Titan, including methane-ethane phase studies, hydrocarbons such as acetylene and benzene, as well as tholins and clathrates, which should exhibit a range of rheological and mechanical properties from fast-moving fluids to glacial creep. Acknowledgements: Most of the research described in this presentation was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. KLM is supported by a NASA Postdoctoral Fellowship, administered by Oak Ridge Associated Universities. JCC is a postdoctoral researcher of the California Institute of Technology.

  19. Layered Ice

    An ice jam on the East Branch Wesserunsett Stream in Athens, Maine in January 2014 left 3-5 ft ice walls on the riverbanks. On a January 21, 2014 site visit Nick Stasulis and Charlie Culbertson chisled away some of the ice wall so a discharge measurement could be made. The ice walls showed the ...

  20. A System of Conservative Regridding for Ice-Atmosphere Coupling in a General Circulation Model (GCM)

    NASA Technical Reports Server (NTRS)

    Fischer, R.; Nowicki, S.; Kelley, M.; Schmidt, G. A.

    2014-01-01

    The method of elevation classes, in which the ice surface model is run at multiple elevations within each grid cell, has proven to be a useful way for a low-resolution atmosphere inside a general circulation model (GCM) to produce high-resolution downscaled surface mass balance fields for use in one-way studies coupling atmospheres and ice flow models. Past uses of elevation classes have failed to conserve mass and energy because the transformation used to regrid to the atmosphere was inconsistent with the transformation used to downscale to the ice model. This would cause problems for two-way coupling. A strategy that resolves this conservation issue has been designed and is presented here. The approach identifies three grids between which data must be regridded and five transformations between those grids required by a typical coupled atmosphere-ice flow model. This paper develops a theoretical framework for the problem and shows how each of these transformations may be achieved in a consistent, conservative manner. These transformations are implemented in Glint2, a library used to couple atmosphere models with ice models. Source code and documentation are available for download. Confounding real-world issues are discussed, including the use of projections for ice modeling, how to handle dynamically changing ice geometry, and modifications required for finite element ice models.

  1. Proceedings of the Airframe Icing Workshop

    NASA Technical Reports Server (NTRS)

    Colantonio, Ron O. (Editor)

    2009-01-01

    The NASA Glenn Research Center (GRC) has a long history of working with its partners towards the understanding of ice accretion formation and its associated degradation of aerodynamic performance. The June 9, 2009, Airframe Icing Workshop held at GRC provided an opportunity to examine the current NASA airframe icing research program and to dialogue on remaining and emerging airframe icing issues and research with the external community. Some of the airframe icing gaps identified included, but are not limited to, ice accretion simulation enhancements, three-dimensional benchmark icing database development, three-dimensional iced aerodynamics modeling, and technology development for a smart icing system.

  2. Experimental study of performance degradation of a rotating system in the NASA Lewis RC icing tunnel

    NASA Technical Reports Server (NTRS)

    Korkan, Kenneth

    1992-01-01

    The Helicopter Icing Consortium (HIC) conducted one of the first U.S. tests of a heavily instrumented model in the controlled environment of a refrigerated tunnel. In the Icing Research Tunnel (IRT) at NASA LeRC, ice was accreted on the main rotor blade of the BMTR-1 Sikorsky model helicopter under a variety of environmental conditions, such that liquid water content (LWC) and volume mean droplet diameter (VMD) ranges reflected the Federal Aviation Agency and Department of Defence icing condition envelopes. This report gives the correlated results of the data provided by NASA LeRC. The method of statistical analysis is discussed. Lift, thrust, and torque coefficients are presented as a function of icing time, as correlated with changes in ambient temperature, LWC, and VMD. The physical significance of these forces is discussed.

  3. Analysis and design of an ice wall framing system for an arctic drilling structure

    SciTech Connect

    Schlechten, J.R.; Bivens, H.R.; Dolan, D.K.; Fernandes, R.L.

    1984-05-01

    The exterior shell of a concrete base structure for an arctic oil drilling platform must be designed to resist extremely high local ice pressures. Stringent draft criteria for deployment of these structures in shallow waters require that the exterior shells, commonly called ice walls, have minimal weight in conjunction with maximum strength. These conflicting requirements are satisfactorily balanced by the selection of an arch shape on the interior face of the wall. This geometry induces arching action within the ice wall plate to resist ice loads in compression, thereby minimizing principal tension within the concrete. The development of principal tension in a concrete structure limits its ability to resist external forces. This paper describes the design of a prestressed concrete ice wall which satisfies these load, weight, and material constraints.

  4. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

    PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 µm) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 µm), known as the “small mode”. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 µm wavelength relative to 11 µm wavelength due to the process of wave resonance or photon tunneling more active at 12 µm. This makes the 12/11 µm absorption optical depth ratio (or equivalently the 12/11 µm Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

  5. Ice rule correlations in stuffed spin ice

    NASA Astrophysics Data System (ADS)

    Aldus, R. J.; Fennell, T.; Deen, P. P.; Ressouche, E.; Lau, G. C.; Cava, R. J.; Bramwell, S. T.

    2013-01-01

    Stuffed spin ice is a chemical variation of a spin ice material like Ho2Ti2O7 in which extra magnetic ions are inserted into the crystal structure. Previous studies have shown that the degree of stuffing has very little effect on the residual entropy in the system, which takes a value very close to the spin ice entropy. We argue, however, that the observation of this entropy does not imply long range coherence of the ice rules, that determine the local spin configurations. We have characterized deviations from the ice rules by means of a polarized neutron diffraction study of a single crystal of Ho2+δTi2-δO7-δ/2 with δ = 0.3. Our results demonstrate that the ice rules in stuffed spin ice are strictly valid only over a relatively short range, and that at longer range stuffed spin ice exhibits some characteristics of a ‘cluster glass’, with a tendency to more conventional ferromagnetic correlations.

  6. NASA's rotorcraft icing research program

    NASA Technical Reports Server (NTRS)

    Shaw, Robert J.; Reinmann, John J.; Miller, Thomas L.

    1988-01-01

    The objective of the NASA aircraft icing research program is to develop and make available icing technology to support the needs and requirements of industry for all weather aircraft designs. While a majority of the technology being developed is viewed to be generic (i.e., appropriate to all vehicle classes), vehicle specific emphasis is being placed on the helicopter due to its unique icing problems. In particular, some of the considerations for rotorcraft icing are indicated. The NASA icing research program emphasizes technology development in two key areas: ice protection concepts and icing simulation (analytical and experimental). The NASA research efforts related to rotorcraft icing in these two technology areas will be reviewed.

  7. How Activity Systems Evolve: Making / Saving Salmon in British Columbia

    ERIC Educational Resources Information Center

    Lee, Yew-Jin; Roth, Wolff-Michael

    2008-01-01

    The purpose of this article is to describe the history of a state-sponsored salmon enhancement project in British Columbia and to explicate the development of the former using cultural historical activity theory. We make thematic the notion of inner contradictions, which express themselves outwardly as a function of both quantitative and…

  8. Application of GRACE to the Evaluation of an Ice Flow Model of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Schlegel, N.; Wiese, D. N.; Watkins, M. M.; Larour, E. Y.; Box, J. E.; Fettweis, X.; van den Broeke, M. R.; Morlighem, M.; Boening, C.; Seroussi, H. L.

    2014-12-01

    Quantifying Greenland's future contribution to sea level rise is a challenging task and requires accurate estimates of ice flow sensitivity to climate change. Transient ice flow models are promising tools for estimating future ice sheet behavior. However, confidence in these types of future projections is low, especially because evaluation of model historical runs is so challenging due to the scarcity of continental-wide data for validation. For more than a decade, NASA's GRACE has continuously acquired time-variable measurements of the Earth's gravity field and has provided unprecedented surveillance of mass balance of the ice sheets, offering an opportunity for ice sheet model evaluation. Here, we take advantage of a new high-resolution (~300 km) monthly mascon solution for the purpose of mass balance comparison with an independent, historical ice flow model simulation using the Ice Sheet System Model (ISSM). The comparison highlights which regions of the ice sheet differ most from GRACE. Investigation of regional differences in trends and seasonal amplitudes between simulations forced with three different Regional Climate Model (RCM)-based estimates of surface mass balance (SMB) allows us to make conclusions about the relative contributions of various error sources in the model hindcast. This study constitutes the first regional comparison of GRACE data and an ice sheet model. Conclusions will aid in the improvement of RCM SMB estimates as well as ice sheet simulation estimates of present and future rates of sea level rise. This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Program and President's and Director's Fund Program.

  9. Surface Composition of the Non-Ice Component on Icy Satellites and Ring Particles in the Saturn System

    NASA Astrophysics Data System (ADS)

    Clark, R. N.; Pearson, N.; Perlman, Z. S.; Bradley, E. T.; Hendrix, A.; Cuzzi, J. N.; Cruikshank, D. P.; Filacchione, G.; Nicholson, P. D.; Hedman, M. M.; Brown, R. H.; Buratti, B. J.; Baines, K. H.; Sotin, C.; Nelson, R.

    2013-12-01

    Saturn's icy satellites and ring particle surfaces have long been known to be composed mostly of frozen water. However, all surfaces show an absorption due to a non-water-ice component whose identity has not been well understood. In the near infrared, water ice has strong absorptions which limit detectability of other trace components. Similarly, at wavelengths less than about 0.18 microns, water is very absorbing. However, in the ~0.2 to ~1 micron range, water ice has low absorption and trace components are readily detected. Classical interpretations of the UV absorber and dark material on outer Solar System satellites have been varying amounts of tholins and carbon. However, tholins have spectral structure not seen in the icy spectra in the Saturn System. Many silicates also have UV spectral structure that reject them from contributing significantly to the observed spectral signatures. We have constructed a new UV spectrometer and a new environment chamber for studying the spectral properties of materials from 0.1 to 15 microns. In our survey of the spectral properties of materials so far, we find that small amounts of metallic iron and iron oxides in the icy surfaces are compatible with and can explain the UV, visible and near-infrared spectra of icy surfaces in the Saturn system (0.12 to 5.1 microns) using data from the Cassini UltraViolet Imaging Spectrograph (UVIS) and the Visual and Infrared Mapping Spectrometer (VIMS). The wide range of observed UV-NIR (0.1-5 micron) spectral signatures provide strong constraints on composition and grain size distribution, including grain sizes of the ice. Spectra of the Saturnian rings and icy satellites indicate they have a large range of ice grain sizes, from tens of microns to sub-micron. Sub-micron ice grains create unusual spectral properties, which are seen in the spectra of the rings and satellites of Saturn and on satellites further out in the Solar System. Clark et al. (2012, Icarus v218, p831) showed that VIMS spectra were explained by combinations ! of water ice, CO2, nano-sized grains of metallic iron and iron oxide and trace amounts of other compounds. The new UV lab data are providing further evidence for this interpretation and placing further constraints on grain size distributions and abundances of the components.

  10. Subsurface Ice Probe

    NASA Technical Reports Server (NTRS)

    Hecht, Michael; Carsey, Frank

    2005-01-01

    The subsurface ice probe (SIPR) is a proposed apparatus that would bore into ice to depths as great as hundreds of meters by melting the ice and pumping the samples of meltwater to the surface. Originally intended for use in exploration of subsurface ice on Mars and other remote planets, the SIPR could also be used on Earth as an alternative to coring, drilling, and melting apparatuses heretofore used to sample Arctic and Antarctic ice sheets. The SIPR would include an assembly of instrumentation and electronic control equipment at the surface, connected via a tether to a compact assembly of boring, sampling, and sensor equipment in the borehole (see figure). Placing as much equipment as possible at the surface would help to attain primary objectives of minimizing power consumption, sampling with high depth resolution, and unobstructed imaging of the borehole wall. To the degree to which these requirements would be satisfied, the SIPR would offer advantages over the aforementioned ice-probing systems.

  11. Electronic "Expert Systems" Make Light Work of Paperwork.

    ERIC Educational Resources Information Center

    Trotter, Andrew

    1990-01-01

    Expert systems offer school possibilities beyond relieving employees of routine work. In the future, expert systems will become tools for budgeting, staff training, and teaching. Describes a system developed at Utah State University, "Mandate Consultant," that helps school staff review the legally mandated steps in developing individualized…

  12. Making adaptable systems work for mission operations: A case study

    NASA Technical Reports Server (NTRS)

    Holder, Barbara E.; Levesque, Michael E.

    1993-01-01

    The Advanced Multimission Operations System (AMMOS) at NASA's Jet Propulsion Laboratory is based on a highly adaptable multimission ground data system (MGDS) for mission operations. The goal for MGDS is to support current flight project science and engineering personnel and to meet the demands of future missions while reducing associated operations and software development costs. MGDS has become a powerful and flexible mission operations system by using a network of heterogeneous workstations, emerging open system standards, and selecting an adaptable tools-based architecture. Challenges in developing adaptable systems for mission operations and the benefits of this approach are described.

  13. neXtSIM: a new Lagrangian sea ice model

    NASA Astrophysics Data System (ADS)

    Rampal, P.; Bouillon, S.; Ólason, E.; Morlighem, M.

    2015-10-01

    The Arctic sea ice cover has changed drastically over the last decades. Associated with these changes is a shift in dynamical regime seen by an increase of extreme fracturing events and an acceleration of sea ice drift. The highly non-linear dynamical response of sea ice to external forcing makes modelling these changes, and the future evolution of Arctic sea ice a challenge for current models. It is, however, increasingly important that this challenge be better met, both because of the important role of sea ice in the climate system and because of the steady increase of industrial operations in the Arctic. In this paper we present a new dynamical/thermodynamical sea ice model, called neXtSIM in order to address this. neXtSIM is a continuous and fully Lagrangian model, and the equations are discretised with the finite-element method. In this model, sea ice physics are driven by a synergic combination of two core components: a model for sea ice dynamics built on a new mechanical framework using an elasto-brittle rheology, and a model for sea ice thermodynamics providing damage healing for the mechanical framework. The results of a thorough evaluation of the model performance for the Arctic are presented for the period September 2007 to October 2008. They show that observed multi-scale statistical properties of sea ice drift and deformation are well captured as well as the seasonal cycles of ice volume, area, and extent. These results show that neXtSIM is a very promising tool for simulating the sea ice over a wide range of spatial and temporal scales.

  14. Linking Sea Ice Physical Properties with Under-Ice and In-Ice Ecosystems

    NASA Astrophysics Data System (ADS)

    Lange, B. A.; Flores, H.; David, C. L.; Nicolaus, M.

    2012-12-01

    Impacts of climate change have been most pronounced in Polar Regions. Most alarming is the accelerating decline in Arctic sea ice cover. The changing ice cover is likely to have implications for sea ice-associated ecosystems because they rely largely on carbon produced by ice-associated algae. In order to fully understand these ecosystems and to be able to accurately represent them in models there is a need to understand both the physical and biological components of the system. The study presented here is part of AWI's research group Iceflux which takes an interdisciplinary approach to quantify the trophic carbon flux within sea ice associated ecosystems in the Arctic and Antarctic. Here we will present preliminary results from the ARK XXVII/3 Polarstern Cruise (Aug-Oct, 2012) to the Central Arctic Ocean. Biological samples will be acquired from the under-ice surface waters using the Surface and Under-Ice Trawl (SUIT) and from within the sea ice by extracting ice cores. To characterize the biophysical properties of the sea ice and under-ice environments several sensors were mounted on the SUIT including: spectral radiometer, ADCP, CTD, fluorometer, altimeter (distance to ice bottom) and video camera. Observations include ice thickness, biological diversity, biomass, light transmission, under-ice water properties and chlorophyll a content (in- and under-ice). Preliminary results will provide a description of the local- to meso-scale spatial variability of biological abundance in and under the ice and the relationship with different sea ice characteristics. The SUIT system will be deployed, for the first time, under MYI; including extensively surveyed ice station floes. The effectiveness and efficiency of the SUIT system under MYI will be presented and compared to results from previous deployments.

  15. Characterization and first results of an ice nucleating particle measurement system based on counterflow virtual impactor technique

    NASA Astrophysics Data System (ADS)

    Schenk, L. P.; Mertes, S.; Kästner, U.; Frank, F.; Nillius, B.; Bundke, U.; Rose, D.; Schmidt, S.; Schneider, J.; Worringen, A.; Kandler, K.; Bukowiecki, N.; Ebert, M.; Curtius, J.; Stratmann, F.

    2014-10-01

    A specific instrument combination was developed to achieve a better microphysical and chemical characterization of atmospheric aerosol particles that have the potential to act as ice nucleating particles (INP). For this purpose a pumped counterflow virtual impactor system called IN-PCVI was set up and characterized to separate ice particles that had been activated on INP in the Fast Ice Nucleus Chamber (FINCH) from interstitial, non-activated particles. This coupled setup consisting of FINCH (ice particle activation and counting), IN-PCVI (INP separation and preparation), and further aerosol instrumentation (INP characterization) had been developed for the application in field experiments. The separated INP were characterized on-line with regard to their total number concentration, number size distribution and chemical composition, especially with the Aircraft-based Laser Ablation Aerosol Mass Spectrometer ALABAMA. Moreover, impactor samples for electron microscopy were taken. Due to the coupling the IN-PCVI had to be operated with different flow settings than known from literature, which required a further characterization of its cut-off-behavior. Taking the changed cut-off-behavior into account, the INP number concentration measured by the IN-PCVI system was in good agreement with the one detected by the FINCH optics for water saturation ratios up to 1.01 (ice saturation ratios between 1.21-1.34 and temperatures between -18 and -26 °C). First field results of INP properties are presented which were gained during the INUIT-JFJ/CLACE 2013 campaign at the high altitude research station Jungfraujoch in the Bernese Alps, Switzerland (3580 m a.s.l.).

  16. Modeling Commercial Turbofan Engine Icing Risk With Ice Crystal Ingestion

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Veres, Joseph P.

    2013-01-01

    The occurrence of ice accretion within commercial high bypass aircraft turbine engines has been reported under certain atmospheric conditions. Engine anomalies have taken place at high altitudes that have been attributed to ice crystal ingestion, partially melting, and ice accretion on the compression system components. The result was degraded engine performance, and one or more of the following: loss of thrust control (roll back), compressor surge or stall, and flameout of the combustor. As ice crystals are ingested into the fan and low pressure compression system, the increase in air temperature causes a portion of the ice crystals to melt. It is hypothesized that this allows the ice-water mixture to cover the metal surfaces of the compressor stationary components which leads to ice accretion through evaporative cooling. Ice accretion causes a blockage which subsequently results in the deterioration in performance of the compressor and engine. The focus of this research is to apply an engine icing computational tool to simulate the flow through a turbofan engine and assess the risk of ice accretion. The tool is comprised of an engine system thermodynamic cycle code, a compressor flow analysis code, and an ice particle melt code that has the capability of determining the rate of sublimation, melting, and evaporation through the compressor flow path, without modeling the actual ice accretion. A commercial turbofan engine which has previously experienced icing events during operation in a high altitude ice crystal environment has been tested in the Propulsion Systems Laboratory (PSL) altitude test facility at NASA Glenn Research Center. The PSL has the capability to produce a continuous ice cloud which are ingested by the engine during operation over a range of altitude conditions. The PSL test results confirmed that there was ice accretion in the engine due to ice crystal ingestion, at the same simulated altitude operating conditions as experienced previously in flight. The computational tool was utilized to help guide a portion of the PSL testing, and was used to predict ice accretion could also occur at significantly lower altitudes. The predictions were qualitatively verified by subsequent testing of the engine in the PSL. The PSL test has helped to calibrate the engine icing computational tool to assess the risk of ice accretion. The results from the computer simulation identified prevalent trends in wet bulb temperature, ice particle melt ratio, and engine inlet temperature as a function of altitude for predicting engine icing risk due to ice crystal ingestion.

  17. Piloted Simulation to Evaluate the Utility of a Real Time Envelope Protection System for Mitigating In-Flight Icing Hazards

    NASA Technical Reports Server (NTRS)

    Ranaudo, Richard J.; Martos, Borja; Norton, Bill W.; Gingras, David R.; Barnhart, Billy P.; Ratvasky, Thomas P.; Morelli, Eugene

    2011-01-01

    The utility of the Icing Contamination Envelope Protection (ICEPro) system for mitigating a potentially hazardous icing condition was evaluated by 29 pilots using the NASA Ice Contamination Effects Flight Training Device (ICEFTD). ICEPro provides real time envelope protection cues and alerting messages on pilot displays. The pilots participating in this test were divided into two groups; a control group using baseline displays without ICEPro, and an experimental group using ICEPro driven display cueing. Each group flew identical precision approach and missed approach procedures with a simulated failure case icing condition. Pilot performance, workload, and survey questionnaires were collected for both groups of pilots. Results showed that real time assessment cues were effective in reducing the number of potentially hazardous upset events and in lessening exposure to loss of control following an incipient upset condition. Pilot workload with the added ICEPro displays was not measurably affected, but pilot opinion surveys showed that real time cueing greatly improved their situation awareness of a hazardous aircraft state.

  18. All Systems Go for Engine Icing Test - Duration: 2 minutes, 2 seconds.

    NASA Video Gallery

    All the pieces came together to recently produce a successful first run of a ground test investigating how ice can accumulate inside a hot jet engine. A full-size engine, spray bars to create the i...

  19. Stability domains of water ices in the NH3 - H2O system: experimental results and thermodynamic modelling

    NASA Astrophysics Data System (ADS)

    Grasset, O.; Choukroun, M.

    2009-12-01

    The ammonia compound decreases very significantly the melting curve of water ices. This property is of fundamental importance in planetology because it constrains the nature of the icy mantle within icy moons of the giant planets (1,2). That is why many experimental studies have been conducted for understanding the binary system H2O - NH3 in the temperature - pressure space (1-6). The most surprising effect of the ammonia compound is that it decreases the melting temperature of the ice polymorphs down to 180 K at the eutectic temperature (1,2). This effect has been observed throughout the pressure domain relevant for icy moons from 0 to 1 GPa. In this paper, a review of these efforts, in addition to new results, obtained by the authors with a sapphire anvil cell in the domains where experimental data were lacking (8), will be presented. A thermodynamic description that uses the chemical potential approach can be used for describing the pure water system (7,9). However, most studies that have used this approach were clearly focused on describing the melting curves of the water phase diagram. A new formulation has recently been proposed (9), which allows to compute phase equilibria in the whole P-T domain where ice polymorphs are encountered. In this work, the model has been improved by incorporating the ice II polymorph, and by describing more accurately the behaviour of the binary liquid mixture which is close to a regular symmetric solution (10). This model has been validated in the pure water domain by checking that all stability domains of the ice polymorphs (Ih, II, III, V, and VI) were predicted with an accuracy better than 1%. A very good reproduction of the stability domain of ice Ih in the H2O-NH3 phase diagram is also achieved. It will be shown that the thermodynamic approach allows to predict the stability of each ice polymorphs whatever the pressure and temperature are, in very good agreement with the available experimental data. It appears that the stability domain of some polymorphs, such as ice II and ice V, enlarges with the ammonia concentration, whereas that of ice III diminishes with NH3 concentration, and this phase is expected to disappear above 10 %wt of ammonia in the system. For each polymorph, a whole description of stability domains and melting surfaces will be presented. Implications for the occurrence of liquid oceans within the largest moons will also be briefly discussed. Ref. : 1. Hogenboom et al., Icarus, 1997. 2. Grasset and Pargamin, Planet. Space Sci., 2005. 3. Croft et al., Icarus, 1988. 4. Johnson and Nicol, J. Geoph. Res., 1987. 5Kargel, Icarus, 1992. 6. Leliwa-Kopystynski et al., Icarus, 2002. 7. Chizhov and Nagornov, J. Appl. Mech. Techn. Phys. 1991. 8. Choukroun M., PhD thesis, 2007. 9. Choukroun and Grasset, J. Chem. Phys, 2007. 10.Wood and Fraser, Oxford Univ. Press, 1977.

  20. Sedimentary record of a Scandinavian Ice Sheet drainage system and till deposition over subglacial obstacles promoting basal sliding (an example from southern Poland)

    NASA Astrophysics Data System (ADS)

    Salamon, Tomasz

    2015-12-01

    Subglacial obstacles occurring in the path of advancing ice sheets generally generate higher longitudinal compression and higher frictional drag than a flat substrate. However, in the case of a soft sediment substratum, they can have a very different effect on ice sheet behaviour. This study concerns a substrate composed of very fine-grained sediments with low permeability. The relationship between subglacial obstacles and the overriding Scandinavian Ice Sheet was studied in an area of southern Poland where a small intervalley Neogene clay ridge (40 m high) was present. Based on sedimentological and structural analysis of subglacial till and gravelly-sandy sediments, the basal depositional processes and subglacial conditions and their influence on ice sheet behaviour were analysed. The till and related deposits within the ridge reflecting high water pressure conditions and lack of glacitectonic deformations indicate that the clay ridge did not generate much resistance against the advancing ice sheet, but instead favoured basal slip: the impermeable substratum weakened the ice/bed coupling and promoted ice detachment from the substratum. Gravelly sandy inclusions at the till/clay contact indicate that during the first stage of ice sheet overriding, a canal drainage system developed at the ice/substrate interface. Varied geometry, size and location of inclusions of sorted sediments suggest periodic instability of the canal system, which could lead to its transformation from initially uniform to being composed of conduits of different sizes. During later stages of ice sheet overriding, a traction till was deposited and occasional drainage through a water film was sufficient to evacuate basal meltwater. The resulting change in the character of subglacial drainage was probably related to variations in water pressure gradient during progressive ice sheet advance.

  1. Two-way coupled ice sheet-earth system simulations: Consequences of raising CO2 concentration for Greenland and the interacting climate system

    NASA Astrophysics Data System (ADS)

    Rodehacke, Christian; Vizcaino, Miren; Mikolajewicz, Uwe

    2013-04-01

    The observed distinct warming in the Arctic and the northward flow of tropical water masses seem to trigger enhanced melting of the Greenland ice sheet, which adds more fresh water into the ambient ocean. A continuation of the observed accelerated melting during the last decade would stabilize the water column in the adjacent deep water formation sides. With our fully coupled ice sheet-earth system model we approach the questions if this weakens the formation of deep water masses and reduces the thermohaline driven meridional overturning circulation (MOC). We have performed idealized future projections to investigate the response of the interaction under raising atmospheric carbon dioxide concentration with our two-way coupled ice sheet-earth system model system. We will present the building blocks of our fully coupled system, which includes a physical based calculation of the ice sheet's surface mass balance and ice sheet-ocean interaction; The ESM instead is subject to orographic changes and receives fresh water fluxes, for example. Since the behavior of an ice sheet in the near future is controlled by both the external forcing and by its initial conditions, we have performed Latin Hyper Cube (LHC) simulations with the ice sheet model over more than one glacial-interglacial cycle utilizing standard techniques to obtain a reasonable initial state. According to several quantities the best performing LHC member is exposed afterwards to boundary conditions determined from energy balance calculations again obtained from simulated forcing fields. Finally the fully coupled system is brought into a quasi-equilibrium under pre-industrial conditions before idealized scenarios have been started. In contrast to commonly used strategies, our coupled ice sheet inherits the memory of a glacial cycle simulations obtain exclusively from ESM fields. Furthermore we use a mass conserving scheme, do neither apply flux corrections nor utilize anomaly coupling. Under different CO2 forcing scenarios - for example, raising CO2 by 1%/year until four times the pre-industrial concentration (4xCO2) has reached, abrupt raise to 4xCO2 - the response of the coupled system is analyzed. For instance, an abrupt CO2 forcing leads to an immediate response of the Greenlandic ice sheet. The surface mass balance turns strongly negative within a couple of years, causing skyrocketing melting rates and sea level rise. The contribution of the ocean-ice sheet interaction decreases instead, because the ice sheets retreats from the coast and is therefore less susceptible to an eroding ocean. The additionally released fresh water and the heat both have to potential to stifle the MOC. However sensitivity experiments indicate that the additional fresh water has a negligible influence on the MOC with a time scale of a century or more in our model system. For the study we have used the current CMIP5 earth system model MPI-ESM that comprises the atmosphere model ECHAM6 (T63L47), the vegetation model JSBACH and the ocean biogeochemical model MPIOM / HAMOCC (GR15L40, nominal horizontal resolution of 1.5° with one pole over Greenland). The ESM is coupled to the Parallel Ice Sheet Model (PISM) covering Greenland, where PISM has a horizontal resolution 10 km.

  2. Energy conservation in ice skating rinks

    SciTech Connect

    Dietrich, B.K.; McAvoy, T.J.

    1980-01-01

    An economic and energy analysis of ice rinks was made to examine the areas in which energy could be profitably conserved. The areas where new equipment could make a major reduction in energy use are: the use of waste heat for space heating, the installation of a low emissivity false ceiling to reduce radiant heat, the use of a load cycling controller to reduce refrigeration costs, and the installation of more efficient lighting systems. Changes in rink operating procedure that could cut energy use are: higher refrigerant temperatures, thinner ice, the use of colder resurfacing water, turning the compressors and pumps off at night, and reducing ventilation.

  3. Electronic Performance Support Systems (EPSS): Making the Transition.

    ERIC Educational Resources Information Center

    Des Jardins, Susan; Davis, Harry, Jr.

    An electronic performance support system (EPSS) is a computerized system designed to increase productivity by supporting the performance of the worker on demand at the time of need. This way, workers are allowed to perform with a minimum of intervention from others. Popular examples of performance support tools, or partially implemented EPSSs,…

  4. Transmission line icing measurement on photogrammetry method

    NASA Astrophysics Data System (ADS)

    Huang, Huan; Ma, Xiaohong; Zhao, Lijin; Du, Hao; Luo, Hong; Mao, Xianyin; Tang, Min; Liu, Yawen

    2015-12-01

    Icing thickness parameter is the basic data for power sector to make decision for icing accident prevention. In this paper, a transmission line icing measurement method is proposed. It used the photogrammetry method to realize icing parameters measurement through the integration of high resolution camera, laser range finder and inertial measurement unit. Compared with traditional icing measurement method, this method is flexible and is the effective supplement of the fixed icing detection terminal. And its high accuracy measurement guarantees the reliability of the icing thickness parameters.

  5. The NASA aircraft icing research program

    NASA Technical Reports Server (NTRS)

    Shaw, Robert J.; Reinmann, John J.

    1987-01-01

    The objective of the NASA aircraft icing research program is to develop and make available to industry icing technology to support the needs and requirements for all weather aircraft designs. Research is being done for both fixed and rotary wing applications. The NASA program emphasizes technology development in two key areas: advanced ice protection concepts and icing simulation (analytical and experimental). The computer code development/validation, icing wind tunnel testing, and icing flight testing efforts which were conducted to support the icing technology development are reviewed.

  6. Evaluating a decision making system for cardiovascular dysautonomias diagnosis.

    PubMed

    Idri, Ali; Kadi, Ilham

    2016-01-01

    Autonomic nervous system (ANS) is the part of the nervous system that is involved in homeostasis of the whole body functions. A malfunction in this system can lead to a cardiovascular dysautonomias. Hence, a set of dynamic tests are adopted in ANS units to diagnose and treat patients with cardiovascular dysautonomias. The purpose of this study is to develop and evaluate a decision tree based cardiovascular dysautonomias prediction system on a dataset collected from the ANS unit of the Moroccan university hospital Avicenne. We collected a dataset of 263 records from the ANS unit of the Avicenne hospital. This dataset was split into three subsets: training set (123 records), test set (55 records) and validation set (85 records). C4.5 decision tree algorithm was used in this study to develop the prediction system. Moreover, Java Enterprise Edition platform was used to implement a prototype of the developed system which was deployed in the Avicenne ANS unit so as to be clinically validated. The performance of the decision tree-based prediction system was evaluated by means of the error rate criterion. The error rates were measured for each classifier and have achieved an average value of 1.46, 2.24 and 0.89 % in training, test, and validation sets respectively. The results obtained were encouraging but further replicated studies are still needed to be performed in order to confirm the findings of this study. PMID:26844028

  7. Universal access: making health systems work for women

    PubMed Central

    2012-01-01

    Universal coverage by health services is one of the core obligations that any legitimate government should fulfil vis-à-vis its citizens. However, universal coverage may not in itself ensure universal access to health care. Among the many challenges to ensuring universal coverage as well as access to health care are structural inequalities by caste, race, ethnicity and gender. Based on a review of published literature and applying a gender-analysis framework, this paper highlights ways in which the policies aimed at promoting universal coverage may not benefit women to the same extent as men because of gender-based differentials and inequalities in societies. It also explores how ‘gender-blind’ organisation and delivery of health care services may deny universal access to women even when universal coverage has been nominally achieved. The paper then makes recommendations for addressing these. PMID:22992384

  8. Aircraft icing research at NASA

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Shaw, R. J.; Olsen, W. A., Jr.

    1982-01-01

    Research activity is described for: ice protection systems, icing instrumentation, experimental methods, analytical modeling for the above, and in flight research. The renewed interest in aircraft icing has come about because of the new need for All-Weather Helicopters and General Aviation aircraft. Because of increased fuel costs, tomorrow's Commercial Transport aircraft will also require new types of ice protection systems and better estimates of the aeropenalties caused by ice on unprotected surfaces. The physics of aircraft icing is very similar to the icing that occurs on ground structures and structures at sea; all involve droplets that freeze on the surfaces because of the cold air. Therefore all icing research groups will benefit greatly by sharing their research information.

  9. The ISS Increments 3 and 4 Test Report: For the Active Rack Isolation System ISS Characterization Experiment (ARIS-ICE)

    NASA Technical Reports Server (NTRS)

    Quraishi, Naveed; Allen, Jim; Bushnell, Glenn; Fialho, Ian

    2003-01-01

    The purpose of ARIS-ICE is to improve, optimize then operationally test and document the performance of the ARIS system on the International Space Station. The ICE program required testing across a full 3 increments (2 through 4). This paper represents the operational report summarizing our accomplishments through the third and fourth increment of testing. The main objectives and results of the increment two testing are discussed in The Increment two Operational Report. This report can be obtained from the ISS Payloads Office or from (http://iss-www.isc.nasa.gov/sslissapt/payofc/OZ3/ARIS.html). In summary these were to ensure the smooth and successful activation of the system and correct operational issues related to long term testing. Then the follow on increment 3 & 4 testing encompassed the majority of the on orbit performance assessments and improvements made to the ARIS system. The intent here is to report these preliminary results of the increment 3 & 4 ARIS-ICE testing as well as the ARIS system improvements made for our users and customers.

  10. Application of new GPS aircraft control/display system to topographic mapping of the Greenland ice cap

    SciTech Connect

    Wright, C.W.; Swift, R.N.

    1996-10-01

    NASA has completed an accurate baseline map of the elevation of the Greenland ice sheet using a scanning airborne lidar in combination with differential kinematic Global Positioning System (GPS) techniques. The present plan is to reoccupy these survey lines which are spread over the major regions of the ice sheet beginning in 1997. The results are expected to provide a quantitative answer on how the ice sheet is responding to regional climatic changes. Navigation to within +-100 m of the desired track over lengths of up to 1,000 km are a requirement for the success of the program. To meet this navigational requirement, NASA developed the GPS Flight Management System (GFMS). GFMS is a PC based system that uses the real-time position update from a single GPS receiver located on the aircraft to calculate a cross-track error and generates aircraft steering commands which are converted into analog Instrument Landing System (OM) signals using an RF generator. TU GFMS also updates a cockpit display. 4 refs., 6 figs.

  11. Binding Energies Of N2, CH4, And H2O-ice Systems

    NASA Astrophysics Data System (ADS)

    Mastrapa, Rachel M.; Sandford, S.; Cadarette, T.

    2007-10-01

    We will present measurements of binding energies of the following systems: CH4-CH4, CH4-H2O, N2-N2, and N2-H2O determined from measurements made in a cryo-vacuum system following the methods of Sandford and Allamandola (1, 2). Briefly, for the N2-N2 and CH4-CH4 measurements, we monitored the area of relevant infrared features with time at three different temperatures (<50 K) and use the results to estimate sublimation rates. For the mixtures H2O/CH4 = 20 and H2O/N2= 20, we carried out a series of experiments in which we deposited the mixtures at increasingly higher temperatures (starting at 15 K) until the infrared features of the more volatile component are no longer seen (usually at > 50 K). We then use the deposition rate of H2O to estimate the residence time of the more volatile species (N2 or CH4). In previous measurements (3), binding energies of several volatile molecules (CO, CO2, H2) to H2O-ice were found to be considerably higher than the binding energies of these molecules to themselves. For example, the binding energy of CO on CO is ΔHs/k = 960 K, while that of CO on H2O is ΔHs/k = 1740 K. These results have implications for the condensation, residence time, and sublimation of volatile species on icy surfaces inside and outside of the Solar System. 1. S. A. Sandford, L. Allamandola, Icarus 87 (1990). 2. S. A. Sandford, L. Allamandola, Icarus 76, 201 (1998). 3. S. A. Sandford, L. J. Allamandola, Astrophysical Journal 417, 815 (1993).

  12. Surface Binding Energies Of N2, CH4, And H2O-ice Systems

    NASA Astrophysics Data System (ADS)

    Mastrapa, R. M.; Cadarette, T.; Sandford, S. A.

    2007-12-01

    We will present measurements of binding energies of the following systems: CH4-CH4, CH4- H2O, N2-N2, and N2-H2O determined from measurements made in a cryo-vacuum system following the methods of Sandford and Allamandola (1, 2). Briefly, for the N2-N2 and CH4-CH4 measurements, we monitored the area of relevant infrared features with time at three different temperatures (<50 K) and use the results to estimate sublimation rates. For the mixtures H2O/CH4 = 20 and H2O/N2= 20, we carried out a series of experiments in which we deposited the mixtures at increasingly higher temperatures (starting at 15 K) until the infrared features of the more volatile component are no longer seen (usually at > 50 K). We then use the deposition rate of H2O to estimate the residence time of the more volatile species (N2 or CH4). In previous measurements (3), binding energies of several volatile molecules (CO, CO2, H2) to H2O-ice were found to be considerably higher than the binding energies of these molecules to themselves. For example, the binding energy of CO on CO is ΔHs/k = 960 K, while that of CO on H2O is ΔHs/k = 1740 K. These results have implications for the condensation, residence time, and sublimation of volatile species on icy surfaces inside and outside of the Solar System. 1. S. A. Sandford, L. Allamandola, Icarus 87 (1990). 2. S. A. Sandford, L. Allamandola, Icarus 76, 201 (1998). 3. S. A. Sandford, L. J. Allamandola, Astrophysical Journal 417, 815 (1993).

  13. NASA's Earth Observing System (EOS): Observing the Atmosphere, Land, Oceans, and Ice from Space

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2004-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During this year, the last of the first series of EOS missions, Aura, was launched. Aura is designed exclusively to conduct research on the composition, chemistry, and dynamics of the Earth's upper and lower atmosphere, employing multiple instruments on a single spacecraft. Aura is the third in a series of major Earth observing satellites to study the environment and climate change and is part of NASA's Earth Science Enterprise. The first and second missions, Terra and Aqua, are designed to study the land, oceans, atmospheric constituents (aerosols, clouds, temperature, and water vapor), and the Earth's radiation budget. The other seven EOS spacecraft include satellites to study (i) land cover & land use change, (ii) solar irradiance and solar spectral variation, (iii) ice volume, (iv) ocean processes (vector wind and sea surface topography), and (v) vertical variations of clouds, water vapor, and aerosols up to and including the stratosphere. Aura's chemistry measurements will also follow up on measurements that began with NASA's Upper Atmosphere Research Satellite and continue the record of satellite ozone data collected from the TOMS missions. In this presentation I will describe how scientists are using EOS data to examine the health of the earth's atmosphere, including atmospheric chemistry, aerosol properties, and cloud properties, with a special but not exclusive look at the latest earth observing mission, Aura.

  14. NASA's Earth Observing System (EOS): Observing the Atmosphere, Land, Oceans, and Ice from Space

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2005-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by whch scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During this year, the last of the first series of EOS missions, Aura, was launched. Aura is designed exclusively to conduct research on the composition, chemistry, and dynamics of the Earth's upper and lower atmosphere, employing multiple instruments on a single spacecraft. Aura is the third in a series of major Earth observing satellites to study the environment and climate change and is part of NASA's Earth Science Enterprise. The first and second missions, Terra and Aqua, are designed to study the land, oceans, atmospheric constituents (aerosols, clouds, temperature, and water vapor), and the Earth's radiation budget. The other seven EOS spacecraft include satellites to study (i) land cover & land use change, (ii) solar irradiance and solar spectral variation, (iii) ice volume, (iv) ocean processes (vector wind and sea surface topography), and (v) vertical variations of clouds, water vapor, and aerosols up to and including the stratosphere. Aura's chemistry measurements will also follow up on measurements that began with NASA's Upper Atmosphere Research Satellite and continue the record of satellite ozone data collected from the TOMS missions. In this presentation I will describe how scientists are using EOS data to examine the health of the earth's atmosphere, including atmospheric chemistry, aerosol properties, and cloud properties, with a special look at the latest earth observing mission, Aura.

  15. Use of Ground Imagery to Study Wood Raft and Ice Dynamics in Fluvial Systems: Potential and Challenges.

    NASA Astrophysics Data System (ADS)

    Benacchio, V.; Piegay, H.; Buffin-Belanger, T. K.; Vaudor, L.; Michel, K.

    2014-12-01

    Automatic cameras allow acquisition of large amounts of information at high resolution in both temporal and spatial dimensions, with a roughly close range. Recently, ground cameras have been used to study the morphological evolution of fluvial environments (e.g. bank erosion, bar mobility, braided pattern changes) or to quantify components of fluvial dynamics (e.g. flow velocity, wood transport or river ice development). As the amount of information increases, automation of the data processing becomes essential, but many challenges arise to improve features detection, taking into account light contrasts, shadow and reflection, or to calculate surfaces and volumes from image orthorectification. This study illustrates the high potential of ground cameras to observe and quantify rapid, stochastic or complex events in fluvial systems and the numerous challenges we have to face. In order to automatically monitor such key fluvial processes, two ground cameras were installed. The first one was placed on the Genissiat dam (Rhône River, France) focusing on the reservoir where pieces of wood are trapped, creating a large raft. The objective is to survey wood raft area over time as a surrogate of the basin wood production. The second camera was installed along the St Jean River (Gaspesia, Québec) focusing on a pool section. The objective here is to characterize the evolution of ice cover, in terms of growing rate and ice types. The snowy environment is particularly challenging because of brightness or fairly homogeneous radiometric conditions amongst ice types. In both cases, remote sensing technics, especially feature based classification are used. Radiometric and texture indexes are used to discriminate both wood and water and ice types.

  16. Proton and Electron Irradiation of Solid Nitrous Oxide at Different Temperatures and Implications to the Solar System Ices

    NASA Astrophysics Data System (ADS)

    Sivaraman, Bhalamurugan; Moore, Marla; Mason, Nigel

    N2 O was the third molecule to be detected in space that contains the NO bond therefore demonstrating the universality of basic chemistry that, on Earth at least, led to evolution of life. Significant concentrations of nitrous oxide (a relative fractional abundance of 10-9 to molecular hydrogen, H2 ) have been observed in the SgrB2(M) and is believed to have been produced by neutral-neutral reactions. Although N2 O has not yet been detected in any of the outer solar system planets/satellites it is nevertheless likely that it will be formed by irradiation of common ices like N2 , CO2 and CO. Indeed irradiation of N2 and carbon dioxide (CO2 ) ice by energetic electrons at 5 keV (Jamieson et al., 2005) and N2 + CO ice by protons at 0.8 MeV (Moore and Hudson, 2003) have shown that N2 O will be easily formed in astrochemical ices. Therefore it is important to study irradiation of N2 O ices in order to determine subsequent chemical products. Earlier experiments (Liang et al., 1984) using 4 keV argon atoms/ions and (Sivaraman et al., 2008) using 1 keV electrons have revealed that, contrary to expectations, ozone is formed when solid nitrogen oxides are bombarded by energetic particles. Since ozone is widely suggested as a biomarker in extrasolar planets, the mechanisms and probability of ozone being formed at different temperatures by such abiotic processes should therefore be investigated. References: C. S. Jamieson, C. J. Bennett, A. M. Mebel, R. I. Kaiser, ApJ 624 (2005) 436. M. H. Moore, R. L. Hudson, Icarus 161 (2003) 486. J. Liang, J. Michl, J. Am. Chem. Soc. 106 (1984) 5039. B. Sivaraman, S. Ptasinska, S. Jheeta, N. J. Mason, Submitted to Chem Phys Lett (2008).

  17. The evolution of a Pluto-like system during the migration of the ice giants

    NASA Astrophysics Data System (ADS)

    Pires, Pryscilla; Giuliatti Winter, Silvia M.; Gomes, Rodney S.

    2015-01-01

    The planetary migration of the Solar System giant planets in the framework of the Nice model (Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F. [2005]. Nature 435,459-461; Morbidelli, A., Levison, H.F., Tsiganis, K., Gomes, R. [2005]. Nature 435, 462-465; Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A. [2005]. Nature 435, 466-469) creates a dynamical mechanism which can be used to explain the distribution of objects currently observed in the Kuiper belt (e.g., Levison, H.F., Morbidelli, A., Vanlaerhoven, C., Gomes, R., Tsiganis, K. [2008]. Icarus 196, 258-273). Through this mechanism the planetesimals within the disk, heliocentric distance ranging from beyond Neptune's orbit to approximately 34 AU, are delivered to the belt after a temporary eccentric phase of Uranus and Neptune's orbits. We reproduced the mechanism proposed by Levison et al. to implant bodies into the Kuiper belt. The capture of Pluto into the external 3:2 mean motion resonance with Neptune is associated with this gravitational scattering model. We verified the existence of several close encounters between the ice giants and the planetesimals during their outward radial migration, then we believe that the analysis of the dynamical history of the plutonian satellites during this kind of migration is important, and would provide some constrains about their place of formation - within the primordial planetesimal disk or in situ. We performed N-body simulations and recorded the trajectories of the planetesimals during close approaches with Uranus and Neptune. Close encounters with Neptune are the most common, reaching approximately 1200 in total. A Pluto similarly sized body assumed the hyperbolic trajectories of the former primordial planetesimal with respect to those giant planets. We assumed the current mutual orbital configuration and sizes for Pluto's satellites, then we found that the rate of destruction of systems similar to that of Pluto with closest approaches to Uranus or Neptune <0.10 AU is 40%, i.e. these close approaches can lead to ejections of satellites or to changes in the satellites eccentricities at least 1 order of magnitude larger than the currently observed. However, we also found that the number of closest approaches which the minimum separation to Uranus or Neptune <0.10 AU is negligible, reaching 6%. In the other 60% of close encounter histories with closest approaches >0.10 AU, none of the systems have been destroyed. The latter sample concentrates 94% of closest approaches with the ice giants. Recall that throughout the early history of the Solar System giant impacts were common (McKinnon, W.B. [1989]. Astrophys. J. 344, L41-L44; Stern, A. [1991]. Icarus 90; Canup, R.M. [2005]. Science 307, 546-550). Also, impacts capable of forming a binary like Pluto-Charon can occur possibly prior to 0.5-1 Gyr (Kenyon, S.J., Bromley, B.C. [2014]. Astron. J. 147, 8), and small satellites such as Nix and Hydra can grow in debris from the giant impact (e.g., Canup, R.M. [2011]. Astron. J. 141, 35). Thus, we conclude that if Pluto and its satellites were emplaced into the KB from lower heliocentric orbits, then the Pluto system could survive the encounters that may have happened for emplacement of the Plutinos through the mechanism proposed by Levison et al.

  18. Change Detection of the Amery Ice Shelf Front (2004-2012) Using ENVISAT ASAR Data

    NASA Astrophysics Data System (ADS)

    Zhao, C.; Cheng, X.; Liu, Y.

    2012-12-01

    Antarctic ice shelves are prominent constituent parts of ice sheets due to their ice-ocean-atmosphere interface and their vulnerability to regional and global changes in atmospheric and oceanic temperatures. The majority of mass loss from the Antarctic ice sheet occurs at the ice shelves via either iceberg calving or basal melting. To fully understand the complex process of ice shelf mass balance, it is necessary to monitor the ice shelf changes over an extended period of time. The Amery Ice Shelf is the largest ice shelf in East Antarctica. Understanding the changes of the Amery Ice Shelf front are crucial for making accurate predictions about the response of ice sheets to global climate change. Here we use the time series of ENVISAT images from 2004 to 2012 and the ice flow lines in Antarctic to monitor the changes of 11 test areas in the Amery Ice Shelf front (Fig. 1). Each image was linearly stretched to enhance the edges and then filtered according to an efficient image denoising scheme. We then extracted the coastlines semi-automatically by combining an artificial drawing method with an improved watershed algorithm. The 11 test areas are chosen according to the ice flow lines of the Antarctic. The results show that the Amery Ice Shelf has been expanding obviously. The rate in the middle of the Amery Ice Shelf front is higher than that on both sides of the front. The highest average propagation rate is 3.36 m/day and the lowest rate is 1.65 m/day in the past 9 years. The rates of 11 test areas during 2009 and 2010 are generally lower than those in other periods. It indicates that the propagation rate would be influenced by the climate environment. Additionally, the short-term environmental forces, such as calving events, tidal bending, ocean swell and so on would influence the ice shelf propagation. In conclusion, the rapid propagation of the Amery Ice Shelf has confirmed the fact that the East Antarctic has been expanding. Once some large iceberg calving events occurred, there would be more mass loss in the whole Lambert Ice Sheet system, which would accelerate the global sea level rise. Figure 1. The 11 test areas in the Amery Ice Shelf front. The colorized solid lines are the coastlines of the Amery Ice Shelf extracted from ENVISAT ASAR (2004~2012) with the background image of ENVISAT ASAR on February 17, 2012. The black dash line is the ice flow lines of the Antarctic.

  19. Quantification of Ice Accretions for Icing Scaling Evaluations

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.; Anderson, David N.

    2003-01-01

    The comparison of ice accretion characteristics is an integral part of aircraft icing research. It is often necessary to compare an ice accretion obtained from a flight test or numerical simulation to one produced in an icing wind tunnel or for validation of an icing scaling method. Traditionally, this has been accomplished by overlaying two-dimensional tracings of ice accretion shapes. This paper addresses the basic question of how to compare ice accretions using more quantitative methods. For simplicity, geometric characteristics of the ice accretions are used for the comparison. One method evaluated is a direct comparison of the percent differences of the geometric measurements. The second method inputs these measurements into a fuzzy inference system to obtain a single measure of the goodness of the comparison. The procedures are demonstrated by comparing ice shapes obtained in the Icing Research Tunnel at NASA Glenn Research Center during recent icing scaling tests. The results demonstrate that this type of analysis is useful in quantifying the similarity of ice accretion shapes and that the procedures should be further developed by expanding the analysis to additional icing data sets.

  20. Use of geographic data in emergency response decision making system

    SciTech Connect

    Walker, H.

    1997-07-01

    Geographic data have a number of key roles in emergency response systems focused on releases of hazardous material to the environment. Maps are a key element in allowing emergency response personnel to become oriented during a response and in presenting status information effectively to these personnel. Geographic data are essential for modeling to predict dispersal patterns during a release. It is also necessary to integrate model and measurement data with demographic information in order to assess the consequences of a release. Appropriate support for such capabilities is based on a number of evolving technologies including fast computers, large databases, network technology, remote sensing and geographic information systems.

  1. FERC offers new system of gas carriage, rate making

    SciTech Connect

    Hume, M.

    1985-06-03

    A new four-part rule affecting natural gas transportation and proposed by the Federal Energy Regulatory Commission (FERC) calls for rate regulation that unleashes competition and contract carriage that is non-discriminatory. The rule would create a voluntary carriage program for end users and all others, would let pipelines buy out of their take-or-pay obligations, would offer each pipeline more flexibility to expand its markets or retrench, and would institute a new billing system with separate components for cheap, regulated gas and costlier, unregulated gas. The billing system could be a problem if some state regulators flow the cheap gas directly to residential users, excluding larger users.

  2. How to Make a Critical Analysis of Your Transportation System.

    ERIC Educational Resources Information Center

    Comeau, Lee F.

    An outline of questions is provided for evaluating student transportation systems. Questions are listed under the following topics: board of education policy, legal compliance, routing, contract transportation, special transportation, finance, purchasing, personnel, safety, vehicles, garage, maintenance, insurance, and energy conservation. (MLF)

  3. Making Geographic Information Systems (GIS) Sustainable in Schools

    ERIC Educational Resources Information Center

    Dascombe, Brett

    2006-01-01

    Spatial technologies, particularly Geographic Information Systems (GIS), have become invaluable and persuasive tools in society today. These technologies have also made their way into classrooms around the world and Australian teachers are leaders in implementing GIS technology into their classrooms. There is still a way to go in order to make…

  4. Patterns of Teacher Participation in School System Decision Making

    ERIC Educational Resources Information Center

    Alutto, Joseph A.; Belasco, James A.

    1972-01-01

    Examines the correlates of three separate configurations of teacher participation in school system decisionmaking. Defining decisional participation in terms of differences in the number of decisional instances in which they actually participate, the identified decisional patterns are Deprivation, Equilibrium, and Saturation. Four hypotheses…

  5. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Rouse, W. B.; Hammer, J. M.; Morris, N. M.; Brown, E. N.; Yoon, W. C.

    1983-01-01

    The use of advanced software engineering methods (e.g., from artificial intelligence) to aid aircraft crews in procedure selection and execution is investigated. Human problem solving in dynamic environments as effected by the human's level of knowledge of system operations is examined. Progress on the development of full scale simulation facilities is also discussed.

  6. Modeling and Detection of Ice Particle Accretion in Aircraft Engine Compression Systems

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

    2012-01-01

    The accretion of ice particles in the core of commercial aircraft engines has been an ongoing aviation safety challenge. While no accidents have resulted from this phenomenon to date, numerous engine power loss events ranging from uneventful recoveries to forced landings have been recorded. As a first step to enabling mitigation strategies during ice accretion, a detection scheme must be developed that is capable of being implemented on board modern engines. In this paper, a simple detection scheme is developed and tested using a realistic engine simulation with approximate ice accretion models based on data from a compressor design tool. These accretion models are implemented as modified Low Pressure Compressor maps and have the capability to shift engine performance based on a specified level of ice blockage. Based on results from this model, it is possible to detect the accretion of ice in the engine core by observing shifts in the typical sensed engine outputs. Results are presented in which, for a 0.1 percent false positive rate, a true positive detection rate of 98 percent is achieved.

  7. Risk intelligence: making profit from uncertainty in data processing system.

    PubMed

    Zheng, Si; Liao, Xiangke; Liu, Xiaodong

    2014-01-01

    In extreme scale data processing systems, fault tolerance is an essential and indispensable part. Proactive fault tolerance scheme (such as the speculative execution in MapReduce framework) is introduced to dramatically improve the response time of job executions when the failure becomes a norm rather than an exception. Efficient proactive fault tolerance schemes require precise knowledge on the task executions, which has been an open challenge for decades. To well address the issue, in this paper we design and implement RiskI, a profile-based prediction algorithm in conjunction with a riskaware task assignment algorithm, to accelerate task executions, taking the uncertainty nature of tasks into account. Our design demonstrates that the nature uncertainty brings not only great challenges, but also new opportunities. With a careful design, we can benefit from such uncertainties. We implement the idea in Hadoop 0.21.0 systems and the experimental results show that, compared with the traditional LATE algorithm, the response time can be improved by 46% with the same system throughput. PMID:24883392

  8. Risk Intelligence: Making Profit from Uncertainty in Data Processing System

    PubMed Central

    Liao, Xiangke; Liu, Xiaodong

    2014-01-01

    In extreme scale data processing systems, fault tolerance is an essential and indispensable part. Proactive fault tolerance scheme (such as the speculative execution in MapReduce framework) is introduced to dramatically improve the response time of job executions when the failure becomes a norm rather than an exception. Efficient proactive fault tolerance schemes require precise knowledge on the task executions, which has been an open challenge for decades. To well address the issue, in this paper we design and implement RiskI, a profile-based prediction algorithm in conjunction with a riskaware task assignment algorithm, to accelerate task executions, taking the uncertainty nature of tasks into account. Our design demonstrates that the nature uncertainty brings not only great challenges, but also new opportunities. With a careful design, we can benefit from such uncertainties. We implement the idea in Hadoop 0.21.0 systems and the experimental results show that, compared with the traditional LATE algorithm, the response time can be improved by 46% with the same system throughput. PMID:24883392

  9. Impact of the ice phase on a mesoscale convective system: Implication of cloud parameterization and cloud radiative properties

    SciTech Connect

    Chin, H.N.S.; Bradley, M.M.; Molenkamp, C.R.; Grant, K.E.; Chuang, C.

    1991-08-01

    This study attempts to provide further understanding of the effect of the ice phase on cloud ensemble features which are useful for improving GCM cumulus parameterization. In addition, cloud model results are used to diagnose the radiative properties of anvils in order to assess cloud/radiation interaction and its feedback on the larger-scale climate for the future work. The heat, moisture and mass budget analyses of a simulated squall line system indicate that, at least for this type of system, the inclusion of the ice phase in the microphysics does not considerably change the net cloud heating and drying effects and the feedback on the large-scale motion. Nonetheless, its impact on the radiative properties of clouds significantly influences not only the squall line system itself, but also the larger-scale circulation due to the favorable stratification for long-lasting anvil clouds. The water budget suggests a simple methodology to parameterize the microphysical effect without considering it as a model physics module. Further application of the water budget might also be used to parameterize the cloud transport of condensates in the anvil cloud region, which allows the GCM columns to interact with each other. The findings of this study suggest that the ice phase could be ignored in the cloud parameterization in order to save significant amounts of computational resources and to simplify the model physics. More scientific effort should, however, be focused on the effect of the ice phase to further explore cloud feedback on the large-scale climate through the radiative process. The cloud/radiation interaction and its feedback on the larger-scale climate will be addressed in a companion study by coupling the radiative transfer model with the cloud model. 19 refs., 13 figs.

  10. A Thermal Melt Probe System for Extensive, Low-Cost Instrument Deployment Within and Beneath Ice Sheets

    NASA Astrophysics Data System (ADS)

    Winebrenner, D. P.; Elam, W. T.; Carpenter, M.; Kintner, P., III

    2014-12-01

    More numerous observations within and beneath ice sheets are needed to address a broad variety of important questions concerning ice sheets and climate. However, emplacement of instruments continues to be constrained by logistical burdens, especially in cold ice a kilometer or more thick. Electrically powered thermal melt probes are inherently logistically light and efficient, especially for reaching greater depths in colder ice. They therefore offer a means of addressing current measurement problems, but have been limited historically by a lack of technology for reliable operation at the necessary voltages and powers. Here we report field tests in Greenland of two new melt probes. We operated one probe at 2.2 kilowatts (kW) and 1050 volts (V), achieving a depth of 400 m in the ice in ~ 120 hours, without electrical failure. That depth is the second greatest achieved thus far with a thermal melt probe, exceeded only by one deployment to 1005 m in Greenland in 1968, which ended in an electrical failure. Our test run took place in two intervals separated by a year, with the probe frozen at 65 m depth during the interim, after which we re-established communication, unfroze the probe, and proceeded to the greater depth. During the second field test we operated a higher-power probe, initially at 2.5 kW and 1500 V and progressing to 4.5 kW and 2000 V. Initial data indicate that this probe achieved a descent rate of 8 m/hr, which if correct would be the fastest rate yet achieved for such probes. Moreover, we observed maintenance of vertical probe travel using pendulum steering throughout both tests, as well as autonomous descent without operator-intervention after launch. The latter suggests potential for crews of 1-2 to operate several melt probes concurrently. However, the higher power probe did suffer electrical failure of a heating element after 7 hours of operation at 2000 V (24 hours after the start of the test), contrary to expectations based on laboratory component and system testing. We are therefore revising the probe heaters using a newer but more development-intensive technology. With probe systems now validated in our tests, this will result in a reliable means to emplace instruments for studies of subglacial hydrology, ice dynamics, and possible subglacial ecologies.

  11. Neogene Tectonic Events in the Marie Byrd Land Sector of the West Antarctic Rift System: Their Potential Impact on Ice Sheet Evolution and Stability.

    NASA Astrophysics Data System (ADS)

    Le Masurier, W. E.

    2007-12-01

    The West Antarctic rift system is buried beneath 1-4 km of ice over much of its extent, obscuring vast areas that could provide clues about the potential for active volcanism beneath the ice sheet, and whether significant tectonic movement has taken place in Cenozoic time. This study explores the consequences of viewing the ice as basin fill, and of approximating the mass equivalent of ice as unconsolidated sediment. It then compares the results with active rift systems elsewhere in the world. The results suggest (1) that the interior rift trough is relatively cool, and the potential there for destabilizing subglacial eruptions is low, (2) that extension and over- deepening of interior basins, like the Bentley Subglacial Trench, have taken place beneath the ice sheet in Neogene time, and (3) that dome uplift and the growth of large volcanoes along the Marie Byrd Land coast, together with the subsidence of interior basins, have greatly increased the topographic relief of the rift system in Neogene time. Recent studies suggest that West Antarctic glaciation first appeared during the Oligocene. The implication of this study is that the Oligocene ice sheet originated on a low relief landscape near sea level, adjacent to a much shallower inland sea, and has since evolved in an environment of progressive basin deepening, dome uplift, and volcanism, unlike that of any other ice sheet in the recent past.

  12. Make pipeline systems more immune to seismic activity

    SciTech Connect

    1995-09-01

    To minimize the likelihood of pipe leaks or ruptures, design engineers routinely consider the effects of thermal expansion, weight and even the vibration and torque produced by rotating equipment nearby. For pipelines destined for installation in earthquake-prone regions of the world, system design becomes even more challenging, particularly if the contained fluids are hot, toxic or valuable. PipePlus software allows engineers to model the piping system directly on a computer screen with interactive graphics. Using the menu-driven program, the engineer first draws the entire piping system and then specifies all piping components, such as valves, hinges and flanges, and pipe size, wall thickness and material. First, the computer performs a conventional stress analysis of the piping, taking into consideration reasonably anticipated weight, vibration and thermal expansion associated with normal operations,a nd calculating the forces and thermal expansion associated with normal operations, and calculation the forces and moments at all support locations and connections. This allows the designers to compare these values to the manufacturer`s recommended maximums, and if necessary, modify the piping design at this stage, to better handle these conventional stresses. Then, the program subjects the design to a series of simulated earthquakes, of the type that may occur in the vicinity of the plant. The simulation produces two types of results: Stress calculations and an illustration of the pipe deflection caused by the simulated earthquake. The deflection illustration alerts the design engineer to areas of potential failure, so that the design can be modified accordingly. After design changes are made, the earthquake is simulated again to see how the revised design performs.

  13. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Hammer, John M.; Wan, C. Yoon; Vasandani, Vijay

    1987-01-01

    The current research is focused on detection of human error and protection from its consequences. A program for monitoring pilot error by comparing pilot actions to a script was described. It dealt primarily with routine errors (slips) that occurred during checklist activity. The model to which operator actions were compared was a script. Current research is an extension along these two dimensions. The ORS fault detection aid uses a sophisticated device model rather than a script. The newer initiative, the model-based and constraint-based warning system, uses an even more sophisticated device model and is to prevent all types of error, not just slips or bad decision.

  14. Predicting Land-Ice Retreat and Sea-Level Rise with the Community Earth System Model

    SciTech Connect

    Lipscomb, William

    2012-06-19

    Coastal stakeholders need defensible predictions of 21st century sea-level rise (SLR). IPCC assessments suggest 21st century SLR of {approx}0.5 m under aggressive emission scenarios. Semi-empirical models project SLR of {approx}1 m or more by 2100. Although some sea-level contributions are fairly well constrained by models, others are highly uncertain. Recent studies suggest a potential large contribution ({approx}0.5 m/century) from the marine-based West Antarctic Ice Sheet, linked to changes in Southern Ocean wind stress. To assess the likelihood of fast retreat of marine ice sheets, we need coupled ice-sheet/ocean models that do not yet exist (but are well under way). CESM is uniquely positioned to provide integrated, physics based sea-level predictions.

  15. Putting practice into theory: making the training analyst system coherent.

    PubMed

    Wilson, Mitchell

    2010-04-01

    The question of the training analysis demands a complicated set of answers that engage the issue at different levels of human organization. Historically, the training analysis has been the central feature of the tripartite model of psychoanalytic education. Internal and external pressures have burdened the training analysis and called its legitimacy into question. This problem of legitimacy amounts to a lack of coherence in the training analyst (TA) system. This lack engenders idealized fantasies of the role of the TA, in which the TA embodies special talents and attributes, and of the system that sanctions that role. This idealization is haunted by its opposite: a melancholic devaluation of psychoanalysis and a fear that it will collapse. Recent literature on the analyst's position in the psychoanalytic process emphasizes the analyst's position as decentered and conflicted. The analyst's decentered, conflicted status goes against this idealizing impulse. An attempt is made to wed analytic values, and what we know about the analyst's role in the analytic process, into a more coherent, consistent position regarding the analysis of candidates. PMID:20538578

  16. Point measurements of mass balance of the Greenland Ice Sheet using precision vertical Global Positioning System (GPS) surveys

    NASA Astrophysics Data System (ADS)

    Hamilton, Gordon S.; Whillans, Ian M.

    2000-07-01

    Rates of ice sheet thickening or thinning in Greenland are measured using the coffee-can technique. This entails computing the difference in the vertical velocity of markers anchored in firn and the long-term rate of snow accumulation. The velocities are obtained from repeat surveys using the Global Positioning System (GPS). With corrections for densification and along-slope flow, this difference is the local mass balance. For two sites in western Greenland (Camp Century and a site just south of the EGIG line (Crawford Point)) results show ice sheet thinning. A third west Greenland site (inland from Upernavik) is close to balance. Two sites, Dye-2 in western Greenland and Summit, are thickening slowly.

  17. The volume- and surface-binding energies of ice systems containing CO, CO2, and H2O

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; Allamandola, Louis J.

    1990-01-01

    Laboratory-measured, temperature-dependent sticking efficiencies are presently used to derive the surface-binding energies of CO and CO2 on H2O-rich ices, with a view to determining the condensation and vaporization properties of these systems as well as to the measured energies' implications for both cometary behavior and the evolution of interstellar ices. The molecular volume and the surface binding energies are not found to be necessarily related on the basis of simple nearest-neighbor scaling in surface and bulk sites; this may be due to the physical constraints associated with matrix structure-associated physical constraints, which sometimes dominate the volume-binding energies.

  18. Making intelligent systems team players. A guide to developing intelligent monitoring systems

    NASA Technical Reports Server (NTRS)

    Land, Sherry A.; Malin, Jane T.; Thronesberry, Carroll; Schreckenghost, Debra L.

    1995-01-01

    This reference guide for developers of intelligent monitoring systems is based on lessons learned by developers of the DEcision Support SYstem (DESSY), an expert system that monitors Space Shuttle telemetry data in real time. DESSY makes inferences about commands, state transitions, and simple failures. It performs failure detection rather than in-depth failure diagnostics. A listing of rules from DESSY and cue cards from DESSY subsystems are included to give the development community a better understanding of the selected model system. The G-2 programming tool used in developing DESSY provides an object-oriented, rule-based environment, but many of the principles in use here can be applied to any type of monitoring intelligent system. The step-by-step instructions and examples given for each stage of development are in G-2, but can be used with other development tools. This guide first defines the authors' concept of real-time monitoring systems, then tells prospective developers how to determine system requirements, how to build the system through a combined design/development process, and how to solve problems involved in working with real-time data. It explains the relationships among operational prototyping, software evolution, and the user interface. It also explains methods of testing, verification, and validation. It includes suggestions for preparing reference documentation and training users.

  19. American juvenile justice system: history in the making.

    PubMed

    Meng, Aaron; Segal, Roland; Boden, Eric

    2013-01-01

    The original theory behind separating juvenile offenders from adult offenders was to provide care and direction for youngsters instead of isolation and punishment. This idea took hold in the 19th century and became mainstream by the early 20th century. In the 1950s and 1960s, public concern grew because of a perceived lack of effectiveness and lack of rights. The Supreme Court made a series of rulings solidifying juvenile rights including the right to receive notice of charges, the right to have an attorney and the right to have charges proven beyond a reasonable doubt. In the 1980s, the public view was that the juvenile court system was too lenient and that juvenile crimes were on the rise. In the 1990s, many states passed punitive laws, including mandatory sentencing and blanket transfers to adult courts for certain crimes. As a result, the pendulum is now swinging back toward the middle from rehabilitation toward punishment. PMID:23843574

  20. Update on nephrogenic systemic fibrosis: are we making progress?

    PubMed

    Haemel, Anna K; Sadowski, Elizabeth A; Shafer, Martin M; Djamali, Arjang

    2011-06-01

    Nephrogenic systemic fibrosis is a rare fibrosing disorder associated with the use of gadolinium-based contrast agents in patients with renal dysfunction. However, only a small proportion of at-risk patients develops the disorder, and the exact determinants of disease are still not completely clear. Here, we present an update on emerging evidence for the role of gadolinium-based contrast agents, renal dysfunction, and background inflammation in disease expression, with a focus on current experimental models. Based on these findings, significant progress has been made in our understanding of the pathophysiology of this disorder over the last few years. This review provides a summary of these developments with discussion of the implications for clinical practice and directions for additional study. PMID:21595657

  1. Coated armor system and process for making the same

    SciTech Connect

    Chu, Henry S.; Lillo, Thomas M.; McHugh, Kevin M.

    2010-11-23

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  2. Geoengineering by cloud seeding: influence on sea ice and climate system

    SciTech Connect

    Rasch, Philip J.; Latham, John; Chen, Chih-Chieh

    2009-12-18

    GCM computations using a fully coupled ocean atmosphere model indicate that increasing cloud reflectivity by seeding maritime boundary layer clouds with particles made from seawater may compensate for some of the effects on climate of increasing greenhouse gas concentrations. The chosen seeding strategy (one of many possible scenarios) can restore global averages of temperature, precipitation and sea ice to present day values, but not simultaneously. The response varies nonlinearly with extent of the seeding, and geoengineering generates local changes to important climatic features. The global tradeoffs of restoring ice cover and cooling the planet must be assessed alongside the local changes to climate features.

  3. ON THE FORMATION OF OZONE IN SOLAR SYSTEM OXYGEN ICES EXPOSED TO HEAVY IONS

    SciTech Connect

    Ennis, Courtney; Kaiser, Ralf I.

    2012-02-01

    Mimicking the bombardment of icy surfaces with heavy ions from solar system radiation fields, solid-phase molecular oxygen ({sup 32}O{sub 2}) and its isotope labeled analogue ({sup 36}O{sub 2}) were irradiated with monoenergetic carbon (C{sup +}), nitrogen (N{sup +}), and oxygen (O{sup +}) ions in laboratory experiments simulating the interaction of ions from the solar wind and those abundant in planetary magnetospheres. Online Fourier-transform infrared spectroscopy of the irradiated oxygen ices (12 K) showed that the yields of molecular ozone monomer (O{sub 3} {approx} 2 Multiplication-Sign 10{sup -3} molecules eV{sup -1} in {sup 32}O{sub 2}) were independent of the mass of the implanted C{sup +}, N{sup +}, and O{sup +} ions ({Phi}{sub max} = 4.0 Multiplication-Sign 10{sup 14} ions cm{sup -2}). The production of oxygen atoms in the solid was observed in the mid-IR stabilized via the [O{sub 3}...O] van der Waals complex. We expand on this inference by comparing the ozone yields induced by light particles (e{sup -}, H{sup +}, and He{sup +}) to the heavy ions (C{sup +}, N{sup +}, and O{sup +}) to provide compelling evidence that the abundance of radiolytic products in an oxygen-bearing solid is primarily dependent on electronic stopping regimes, which supersedes the contribution of nuclear stopping processes irrespective of the mass of the particle irradiation in the kinetic energy regime of solar wind and magnetospheric particles.

  4. Record Sea Ice Minimum

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Arctic sea ice reached a record low in September 2007, below the previous record set in 2005 and substantially below the long-term average. This image shows the Arctic as observed by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA's Aqua satellite on September 16, 2007. In this image, blue indicates open water, white indicates high sea ice concentration, and turquoise indicates loosely packed sea ice. The black circle at the North Pole results from an absence of data as the satellite does not make observations that far north. Three contour lines appear on this image. The red line is the 2007 minimum, as of September 15, about the same time the record low was reached, and it almost exactly fits the sea ice observed by AMSR-E. The green line indicates the 2005 minimum, the previous record low. The yellow line indicates the median minimum from 1979 to 2000.

  5. Patterns, Probabilities, and People: Making Sense of Quantitative Change in Complex Systems

    ERIC Educational Resources Information Center

    Wilkerson-Jerde, Michelle Hoda; Wilensky, Uri J.

    2015-01-01

    The learning sciences community has made significant progress in understanding how people think and learn about complex systems. But less is known about how people make sense of the quantitative patterns and mathematical formalisms often used to study these systems. In this article, we make a case for attending to and supporting connections…

  6. Patterns, Probabilities, and People: Making Sense of Quantitative Change in Complex Systems

    ERIC Educational Resources Information Center

    Wilkerson-Jerde, Michelle Hoda; Wilensky, Uri J.

    2015-01-01

    The learning sciences community has made significant progress in understanding how people think and learn about complex systems. But less is known about how people make sense of the quantitative patterns and mathematical formalisms often used to study these systems. In this article, we make a case for attending to and supporting connections

  7. Ice crystal ingestion by turbofans

    NASA Astrophysics Data System (ADS)

    Rios Pabon, Manuel A.

    This Thesis will present the problem of inflight icing in general and inflight icing caused by the ingestion of high altitude ice crystals produced by high energy mesoscale convective complexes in particular, and propose a new device to prevent it based on dielectric barrier discharge plasma. Inflight icing is known to be the cause of 583 air accidents and more than 800 deaths in more than a decade. The new ice crystal ingestion problem has caused more than 100 flights to lose engine power since the 1990's, and the NTSB identified it as one of the causes of the Air France flight 447 accident in 1-Jun2008. The mechanics of inflight icing not caused by ice crystals are well established. Aircraft surfaces exposed to supercooled liquid water droplets will accrete ice in direct proportion of the droplet catch and the freezing heat transfer process. The multiphase flow droplet catch is predicted by the simple sum of forces on each spherical droplet and a droplet trajectory calculation based on Lagrangian or Eulerian analysis. The most widely used freezing heat transfer model for inflight icing caused by supercooled droplets was established by Messinger. Several computer programs implement these analytical models to predict inflight icing, with LEWICE being based on Lagrangian analysis and FENSAP being based on Eulerian analysis as the best representatives among them. This Thesis presents the multiphase fluid mechanics particular to ice crystals, and explains how it differs from the established droplet multiphase flow, and the obstacles in implementing the former in computational analysis. A new modification of the Messinger thermal model is proposed to account for ice accretion produced by ice crystal impingement. Because there exist no computational and experimental ways to fully replicate ice crystal inflight icing, and because existing ice protections systems consume vast amounts of energy, a new ice protection device based on dielectric barrier discharge plasma is proposed and built in this Thesis, called DBDAIS, with a complete description of the anti-ice cycle. Contrary to existing ice protection systems, which either heat the aircraft surfaces, or mechanically remove the accreted ice, the DBDAIS employs non-thermal plasma discharges to prevent ice accretion. A new apparatus that mimics inflight icing based on combining the liquid sprays of liquid nitrogen and water was designed and fabricated, named LNITA. The apparatus produces ice similar to glaze ice and rime ice, the two characteristic types of ice from inflight icing, at the cost of 1% of similar tests in icing wind tunnels. Nineteen experiments of the DBDAIS were performed in the LNITA. The results from the experiments point to 32 kV and 4 kHz being adequate to prevent ice accretion, with a power consumption of 1 W/cm2. This compares favorably to existing ice protection systems, which typically run at 10 W/cm2, and to the power consumption of a typical electric stove burner at maximum power, which is 5 W/cm2. To complete this Thesis, a design and development project is proposed to implement the DBDAIS in Unmanned Aircraft Systems (UAS), with the selection of standard FAA inflight icing conditions, the run of 240 LEWICE simulations, and an analysis of the run results. The computational results lead to the design of a wing boot covering the airfoil from 20% of the lower pressure surface to 4% of the upper suction surface as the optimal protection for a UAS.

  8. Metal-insulator transition caused by coupling to localized charge-frustrated systems under ice-rule local constraint

    NASA Astrophysics Data System (ADS)

    Ishizuka, Hiroaki; Udagawa, Masafumi; Motome, Yukitoshi

    2011-03-01

    We report the results of our theoretical and numerical study on electronic and transport properties of fermion systems with charge frustration. We consider an extended Falicov-Kimball model in which itinerant spinless fermions interact repulsively by U with localized particles whose distribution satisfies a local constraint under geometrical frustration, the so-called ice rule. Electronic states of the itinerant fermions are studied by approximating the statistical average by the arithmetic mean over different configurations of localized particles under the constraint. We numerically calculate the density of states, optical conductivity, and inverse participation ratio for models on the pyrochlore, checkerboard, and kagome lattices, and discuss the nature of metal-insulator transitions at commensurate fillings. The results are compared with exact solutions for models on Husimi cacti as well as with numerical results for completely random distributions of localized particles. As a result, we show that the ice-rule local constraint leads to several universal features in the electronic structure common to different lattice structures; a charge gap opens at a considerably small U compared to the bandwidth, and the energy spectrum approaches a characteristic form in the large-U limit, that is, the noninteracting tight-binding form in one dimension or a δ-functional peak. In the large-U region, the itinerant fermions are confined in the macroscopically degenerate ice-rule configurations, which consist of a bunch of one-dimensional loops: We call this insulating state the charge ice. On the other hand, transport properties are much affected by the geometry and dimensionality of the lattices; e.g., the pyrochlore lattice model exhibits a transition from a metallic to the charge-ice insulating state with increasing U, while the checkerboard lattice model appears to show Anderson localization before opening a gap. Meanwhile, in the kagome lattice case, we do not obtain clear evidence of Anderson localization. Our results elucidate the universality and diversity of phase transitions to the charge-ice insulator in fully frustrated lattices.

  9. Outgassing of icy bodies in the Solar System - I. The sublimation of hexagonal water ice through dust layers

    NASA Astrophysics Data System (ADS)

    Gundlach, B.; Skorov, Yu. V.; Blum, J.

    2011-06-01

    Our knowledge about the physical processes determining the activity of comets were mainly influenced by several extremely successful space missions (Giotto, Deep Space I, Stardust, Deep Impact and EPOXI), the predictions of theoretical models and the results of laboratory experiments. However, novel computer models should not be treated in isolation but should be based on experimental results and should be verified and calibrated by experimental work. Therefore, a new experimental setup was constructed to investigate the temperature dependent sublimation properties of hexagonal water ice and the gas diffusion through a dry dust layer covering the ice surface. We show that this experimental setup is capable to reproduce known gas production rates of pure hexagonal water ice. The reduction of the gas production rate due to an additional dust layer on top of the ice surface was measured and compared to the results of another experimental setup in which the gas diffusion through dust layers at room temperature was investigated. We found that the relative permeability of the dust layer is inversely proportional to its thickness, which is also predicted by theoretical models. However, the measured absolute weakening of the gas flow was smaller than predicted by models. This lack of correspondence between model and experiment may be caused by an ill-determination of the boundary condition in the theoretical models, which further demonstrates the necessity of laboratory investigations. Furthermore, the impedance of the dust layer to the ice evaporation was found to be similar to the impedance at room temperature, which means that the temperature profile of the dust layer is not influencing the reduction of the gas production. Finally, we present the results of an extended investigation of the sublimation coefficient, which is an important factor for the description of the sublimation rate of water ice and, thus, an important value for thermophysical modeling of icy bodies in the Solar System. The achieved results of this laboratory investigations demonstrate that experimental works are essential for the understanding of the origin of cometary activity.

  10. A transportable hemispherical illumination system for making reflectance factor measurements

    NASA Technical Reports Server (NTRS)

    Williams, Darrel L.; Wood, Frank M., Jr.

    1987-01-01

    An artificial source of stable, hemispherical illumination has been developed to facilitate the collection of reflectance factor measurements of targets of interest in a laboratory environment. The light source consists of a 76 cm (30 in.) aluminum hemisphere which has been coated internally with barium sulfate paint. Illumination is provided by two banks of lamps, each consisting of eight 62-W quartz halogen bulbs which have tungsten filaments. An internal baffle precludes the viewing of any direct beam of light. A simple metal structure has been developed to hold the hemisphere and all peripheral equipment, such as spectrometers, radiometers, and cameras, in place during data collection. The entire setup can be easily disassembled and packed in airline approved shipping cases to facilitate transportation to remote laboratory facilities. This illumination system has been used during the past three years to collect spectral reflectance factor data of tree branch samples and seedlings in support of an on-going study to investigate the effect of acidic deposition on forest vegetation.

  11. AV control system which makes use of environment stabilizations

    NASA Astrophysics Data System (ADS)

    Stojanov, Georgi; Bozinovski, Stevo; Bozinovska, Liljana

    1997-01-01

    In the present paper we propose a new, biologically inspired conceptual scheme for introducing parallelism, redundancy and learning in control systems for autonomous vehicles (AV). AV are regarded as a special class of autonomous agents (AA). Most generally stated, an AA is defined with the set of its percepts (S), the set of its elementary actions (A), and its internal structure. Within our scheme expectation is the key concept, and an agent is said to be aware of its environment if it can anticipate the effects of the actions (A) it applies in particular situations (S). If the environment stabilizes for awhile, the effects of application of a particular action will remain same for particular situation. We can take advantage of this fact and avoid recomputation of the optical action in that situation by applying instead, the action generated by the stored anticipations for that situation. In the introduction we give a brief overview of the present AA architectures in the domain of autonomous vehicles and outline the basics of our architecture. In the next section the expecting agent is described in more details. The last section is devoted to an example of implementation of this scheme within the domain of obstacle avoiding path finding autonomous vehicles control. The implementation details and the simulation results of three experiments are discussed.

  12. CBSIT 2009: Airborne Validation of Envisat Radar Altimetry and In Situ Ice Camp Measurements Over Arctic Sea Ice

    NASA Technical Reports Server (NTRS)

    Connor, Laurence; Farrell, Sinead; McAdoo, David; Krabill, William; Laxon, Seymour; Richter-Menge, Jacqueline; Markus, Thorsten

    2010-01-01

    The past few years have seen the emergence of satellite altimetry as valuable tool for taking quantitative sea ice monitoring beyond the traditional surface extent measurements and into estimates of sea ice thickness and volume, parameters that arc fundamental to improved understanding of polar dynamics and climate modeling. Several studies have now demonstrated the use of both microwave (ERS, Envisat/RA-2) and laser (ICESat/GLAS) satellite altimeters for determining sea ice thickness. The complexity of polar environments, however, continues to make sea ice thickness determination a complicated remote sensing task and validation studies remain essential for successful monitoring of sea ice hy satellites. One such validation effort, the Arctic Aircraft Altimeter (AAA) campaign of2006. included underflights of Envisat and ICESat north of the Canadian Archipelago using NASA's P-3 aircraft. This campaign compared Envisat and ICESat sea ice elevation measurements with high-resolution airborne elevation measurements, revealing the impact of refrozen leads on radar altimetry and ice drift on laser altimetry. Continuing this research and validation effort, the Canada Basin Sea Ice Thickness (CBSIT) experiment was completed in April 2009. CBSIT was conducted by NOAA. and NASA as part of NASA's Operation Ice Bridge, a gap-filling mission intended to supplement sea and land ice monitoring until the launch of NASA's ICESat-2 mission. CBIST was flown on the NASA P-3, which was equipped with a scanning laser altimeter, a Ku-band snow radar, and un updated nadir looking photo-imaging system. The CB5IT campaign consisted of two flights: an under flight of Envisat along a 1000 km track similar to that flown in 2006, and a flight through the Nares Strait up to the Lincoln Sea that included an overflight of the Danish GreenArc Ice Camp off the coast of northern Greenland. We present an examination of data collected during this campaign, comparing airborne laser altimeter measurements with (1) Envisat RA-2 returns retracked optimally for sea ice and (2) in situ measurements of sea ice thickness and snow depth gathered from ice camp surveys. Particular attention is given to lead identification and classification using the continuous photo-imaging system along the Envisat underflight as well as the performance of the snow radar over the ice camp survey lines.

  13. Cryosphere: Warming ocean erodes ice sheets

    NASA Astrophysics Data System (ADS)

    Kusahara, Kazuya

    2016-01-01

    Antarctic ice sheets are a key player in sea-level rise in a warming climate. Now an ice-sheet modelling study clearly demonstrates that an Antarctic ice sheet/shelf system in the Atlantic Ocean will be regulated by the warming of the surrounding Southern Ocean, not by marine-ice-sheet instability.

  14. North American Ice Sheet build-up during the last glacial cycle, 115-21 kyr

    NASA Astrophysics Data System (ADS)

    Kleman, Johan; Jansson, Krister; De Angelis, Hernán; Stroeven, Arjen P.; Hättestrand, Clas; Alm, Göran; Glasser, Neil

    2010-08-01

    The last glacial maximum (LGM) outline and subsequent retreat pattern (21-7 kyr) of North American ice sheets are reasonably well established. However, the evolution of the ice sheets during their build-up phase towards the LGM between 115 and 21 kyr has remained elusive, making it difficult to verify numerical ice sheet models for this important time interval. In this paper we outline the pre-LGM ice sheet evolution of the Laurentide and Cordilleran ice sheets by using glacial geological and geomorphological records to make a first-order reconstruction of ice sheet extent and flow pattern. We mapped the entire area covered by the Laurentide and Cordilleran ice sheets in Landsat MSS images and approximately 40% of this area in higher resolution Landsat ETM+ images. Mapping in aerial photographs added further detail primarily in Quebec-Labrador, the Cordilleran region, and on Baffin Island. Our analysis includes the recognition of approximately 500 relative-age relationships from crosscutting lineations. Together with previously published striae and till fabric data, these are used as the basis for relative-age assignments of regional flow patterns. For the reconstruction of the most probable ice sheet evolution sequence we employ a stepwise inversion scheme with a clearly defined strategy for delineating coherent landforms swarms (reflecting flow direction and configuration), and linking these to previously published constraints on relative and absolute chronology. Our results reveal that ice-dispersal centres in Keewatin and Quebec were dynamically independent for most of pre-LGM time and that a massive Quebec dispersal centre, rivalling the LGM in extent, existed at times when the SW sector of the ice sheet had not yet developed. The oldest flow system in eastern Quebec-Labrador (Atlantic swarm had an ice divide closer to the Labrador coast than later configurations). A northern Keewatin-Central Arctic Ice Sheet existed prior to the LGM, but is poorly chronologically constrained. There is also evidence for older and more easterly Cordilleran Ice Sheet divide locations than those that prevailed during the Late Wisconsinan. In terms of ice sheet build-up dynamics, it appears that "residual" ice caps after warming phases may have played an important role. In particular, the location and size of remnant ice masses at the end of major interstadials, i.e. OIS 5c and 5a, must have been critical for subsequent build-up patterns, because such remnant "uplands" may have fostered much more rapid ice sheet growth than what would have occurred on a fully deglaciated terrain. The ice-sheet configuration during stadials would also be governed largely by the additional topography that such "residual" ice constitutes because of inherent mass balance-topography feedbacks.

  15. The physics of ice cream

    NASA Astrophysics Data System (ADS)

    Clarke, Chris

    2003-05-01

    Almost everybody likes ice cream, so it can provide an excellent vehicle for discussing and demonstrating a variety of physical phenomena, such as Newton's law of cooling, Boyle's law and the relationship between microstructure and macroscopic properties (e.g. Young's modulus). Furthermore, a demonstration of freezing point depression can be used to make ice cream in the classroom!

  16. Ice as an Abrading Agent

    NASA Technical Reports Server (NTRS)

    Blow, R. K.

    1984-01-01

    Grit-blasting method makes unnecessary to disassemble equipment for cleaning. Stream of small, frozen pellets directed at assembly to be cleaned. Pellets consist of deionized-water ice, carbon dioxide ice, or another substance that does not react chemically with parts to be cleaned and leaves no residue. Method suited to cleaning titanium and parts that touch liquid oxygen.

  17. Characterizing the Siple Coast Ice Stream System using Satellite Images, Improved Topography, and Integrated Aerogeophysical Measurements

    NASA Technical Reports Server (NTRS)

    Scambos, Ted

    2003-01-01

    A technique for improving elevation maps of the polar ice sheets has been developed using AVHRR images. The technique is based on 'photoclinometry' or 'shape from shading', a technique used in the past for mapping planetary surfaces where little elevation information was available. The fundamental idea behind photoclinometry is using the brightness of imaged areas to infer their surface slope in the sun-illuminated direction. Our version of the method relies on a calibration of the images based on an existing lower-resolution digital elevation model (DEM), and then using the images to improve the input DEM resolution to the scale of the image data. Most current DEMs covering the ice sheets are based on Radar altimetry data, and have an inherent resolution of 10 to 25 km at best - although the grid scale of the DEM is often finer. These DEMs are highly accurate (to less than 1 meter); but they report the mean elevation of a broad area, thus erasing smaller features of glaciological interest. AVHRR image data, when accurately geolocated and calibrated, provides surface slope measurements (based on the pixel brightness under known lighting conditions) every approximately 1.1 km. The limitations of the technique are noisiness in the image data, small variations in the albedo of the snow surface, and the integration technique used to create an elevation field from the image-derived slopes. Our study applied the technique to several ice sheet areas having some elevation data; Greenland, the Amery Ice Shelf, the Institute Ice Stream, and the Siple Coast. For the latter, the input data set was laser-altimetry data collected under NSF's SOAR Facility (Support Office for Aerogeophysical Research) over the onset area of the Siple Coast. Over the course of the grant, the technique was greatly improved and modified, significantly improving accuracy and reducing noise from the images. Several publications resulted from the work, and a follow-on proposal to NASA has been submitted to apply the same method to MODIS data using ICESat and other elevation input information. This follow-on grant will explore two applications that are facilitated by the improved surface morphology characterizations of the ice sheets: accumulation and temperature variations near small undulations in the ice.

  18. Coloration and darkening of methane clathrate and other ices by charged particle irradiation - Applications to the outer solar system

    NASA Technical Reports Server (NTRS)

    Thompson, W. Reid; Murray, B. G. J. P. T.; Khare, B. N.; Sagan, Carl

    1987-01-01

    The results of laboratory experiments simulating the irradiation of hydrocarbon-H2O or hydrocarbon-H2O/NH3 clathrates by charged particles in the outer solar system are reported. Ices produced by condensing and boiling liquid CH4 on an H2O frost surface at 100 K or by cocondensing frosts from gaseous mixtures were exposed to coronal-discharge electron irradiation at 77 K, and the spectral properties of the irradiated surfaces were determined. Significant darkening of the initially white ices was observed at doses of 1 Gerg/sq cm, corresponding to 8-500 yrs of irradiation by Uranian magnetospheric electrons on the surfaces of the principal Uranian satellites, or to total destruction of CH4 in the upper 1 mm of the satellite surfaces after 0.05-3.0 Myr. It is estimated that 10 m or more of icy satellite or comet surfaces would be radiation-hardened to a CH4-free ice-tholin mixture over 4 Gyr.

  19. A Flight Investigation of Exhaust-Heat De-Icing, Special Report

    NASA Technical Reports Server (NTRS)

    Rodert, Lewis A.; Jones, Alun R.

    1940-01-01

    The National Advisory Committee for Aeronautics has conducted exhaust-heat de-icing tests inflight t o provide data needed in the application of this method of ice prevention. Thc capacity to extract heat from the exhaust gas for de-icing purposes, the quantity of heat required, and other factors were examined. The results indicate that a wing-heating system employing a spanwise exhaust tube within the leading edge of the wing will make available for de-icing purposes between 30 and 35 percent of the exhaust-gas heat. Data are given by which the heat required for ice prevention can be calculated. Sample calculations have been made, on a basis of existing engine power over wing area ratios, to show that sufficient heating can be obtained for ice protection on modern transport airplanes,

  20. Arctic Sea Ice Model Sensitivities

    NASA Astrophysics Data System (ADS)

    Peterson, K. J.; Bochev, P.; Paskaleva, B.

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U. S. Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94-AL85000.

  1. The role of pinning-points, marine ice and subglacial channeling in defining the buttressing strength of the Roi Baudouin Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Drews, Reinhard; Matsuoka, Kenichi; Berger, Sophie; Callens, Denis; Favier, Lionel; Pattyn, Frank

    2014-05-01

    Within the coastal belt of Dronning Maud Land, many ice shelves, which are freely floating otherwise, reattach to localized highs in the bathymetry on the ice-shelf front. These localized pinning-points exert a buttressing force, which typically slows down the ice shelves farther upstream. Our interest is to quantify this buttressing effect, and to determine as to whether or not, the comparatively small pinning-points can play a decisive role in defining the mass balance of tributary glaciers. We consider the Roi Baudouin ice shelf, which is laterally confined by two large ice rises, and pinned on the ice-shelf front by a small ice rumple. It buttresses the western Ragnhild glacier. On the ice-shelf surface, satellite imagery reveals a number of elongated surface depressions, which are aligned along-flow and which correspond to a sub-ice shelf channeling system. We present the results of two consecutive field seasons which were geared at unraveling the combined effect of ice rumple and subice-shelf channels on the ice shelf's buttressing strength. Around 130 km of multi-frequency radar profiles map the channeling as well as the basal interface of the pinning-point. We observe strongly dipping internal layers within the surface depressions and a firmly grounded ice rumple. Data from a 20 x 25 km wide GNSS strain net is extended spatially on a 50 m grid with the help of satellite derived surface velocities. Six wide-angle radar surveys within the research grid show that the depth-averaged density varies spatially on scales that are smaller than the grid size in commonly applied Antarctic-wide firn densification models. The density variations are significant, and need to be taken into account when comparing the hydrostatically inverted GPS thickness with the measured radar thickness. Notwithstanding the ice-rumple's small extent (1-2 km), the combined strain rates show a shear zone which extends all the way back to the grounding line and emphasizes the importance of pinning points in ice-shelf dynamics. The comparison of GPS heights with radar thickness reveals a marine ice layer, with a variable thickness, particularly in the pinning-point's vicinity. The sub-ice shelf channels extend vertically more than half of the ice thickness, which potentially makes the channels more susceptible to horizontal shearing as they approach the pinning point. The combined data set illustrates that the ice-shelf properties are non-homogeneous, and we hypothesize that this results in a spatially variable effective viscosity which needs to be taken into account in ice-flow modeling.

  2. GPS PWV Information System of the Decision Making Support System Prototype for Typhoon-Flood Disaster

    NASA Astrophysics Data System (ADS)

    Sohn, D. H.; Shin, Y. H.; Cho, J. H.; Park, J. U.

    2009-04-01

    Under the frame of the Global Earth Observation System of Systems (GEOSS), we are developing a GPS Precipitable Water Vapor (PWV) Information System (IS) of the Decision Making Support System (DMSS) Prototype for Typhoon-Flood Disaster, funded by the Korea Research Council of Fundamental Science and Technology. The system is highly demanded because most, about 90%, of natural disasters happening in Korea have been caused by water, i.e. typhoon, flood, heavy rain and snow, etc. The DMSS prototype, developed mainly by the Korea Information Science and Technology Institute, consists of three sub-systems: observation, prediction, and assessment systems, which are based on the technology of data grid, computation grid, and access grid, respectively. With the augmented reality technology applied, the DMSS web portal that integrates the sub-systems will help the decision makers to access to the DMSS effectively. The GPS PWV IS is being developed as a component of the DMSS prototype for Typhoon-Flood Disaster. PWV estimated from GPS signal delay could be useful to enhance the reliability in numerical weather prediction, nowcasting, climate change monitoring, and so on. As a leading group on GPS Meteorology, the Korea Astronomy and Space Science Institute (KASI) is taking a charge of the GPS PWV IS development. The system will provide the near-real time PWV information based on the nine permanent GPS stations of KASI. Each GPS station of KASI equipped digital weather sensor and provided their own data to the center of KASI in real time. They are expected to be used for operational weather forecasting, researches, instrument validation, etc. Here we introduce the current and future status of our GPS PWV IS, presenting its detailed structures such as Meta Data and Data Base structure, data processing strategy and procedure, flow of information, and application of augmented reality technology.

  3. The comparative exploration of the ice giant planets with twin spacecraft: Unveiling the history of our Solar System

    NASA Astrophysics Data System (ADS)

    Turrini, Diego; Politi, Romolo; Peron, Roberto; Grassi, Davide; Plainaki, Christina; Barbieri, Mauro; Lucchesi, David M.; Magni, Gianfranco; Altieri, Francesca; Cottini, Valeria; Gorius, Nicolas; Gaulme, Patrick; Schmider, François-Xavier; Adriani, Alberto; Piccioni, Giuseppe

    2014-12-01

    In the course of the selection of the scientific themes for the second and third L-class missions of the Cosmic Vision 2015-2025 program of the European Space Agency, the exploration of the ice giant planets Uranus and Neptune was defined “a timely milestone, fully appropriate for an L class mission”. Among the proposed scientific themes, we presented the scientific case of exploring both planets and their satellites in the framework of a single L-class mission and proposed a mission scenario that could allow to achieve this result. In this work we present an updated and more complete discussion of the scientific rationale and of the mission concept for a comparative exploration of the ice giant planets Uranus and Neptune and of their satellite systems with twin spacecraft. The first goal of comparatively studying these two similar yet extremely different systems is to shed new light on the ancient past of the Solar System and on the processes that shaped its formation and evolution. This, in turn, would reveal whether the Solar System and the very diverse extrasolar systems discovered so far all share a common origin or if different environments and mechanisms were responsible for their formation. A space mission to the ice giants would also open up the possibility to use Uranus and Neptune as templates in the study of one of the most abundant type of extrasolar planets in the galaxy. Finally, such a mission would allow a detailed study of the interplanetary and gravitational environments at a range of distances from the Sun poorly covered by direct exploration, improving the constraints on the fundamental theories of gravitation and on the behavior of the solar wind and the interplanetary magnetic field.

  4. Ice chemistry on outer solar system bodies: Carboxylic acids, nitriles, and urea detected in refractory residues produced from the UV photolysis of N{sub 2}:CH{sub 4}:CO-containing ices

    SciTech Connect

    Materese, Christopher K.; Cruikshank, Dale P.; Sandford, Scott A.; Imanaka, Hiroshi; Nuevo, Michel; White, Douglas W.

    2014-06-20

    Radiation processing of the surface ices of outer solar system bodies may result in the production of new chemical species even at low temperatures. Many of the smaller, more volatile molecules that are likely produced by the photolysis of these ices have been well characterized by laboratory experiments. However, the more complex refractory material formed in these experiments remains largely uncharacterized. In this work, we present a series of laboratory experiments in which low-temperature (15-20 K) N{sub 2}:CH{sub 4}:CO ices in relative proportions 100:1:1 are subjected to UV irradiation, and the resulting materials are studied with a variety of analytical techniques including infrared spectroscopy, X-ray absorption near-edge structure spectroscopy, gas chromatography coupled with mass spectrometry, and high-resolution mass spectroscopy. Despite the simplicity of the reactants, these experiments result in the production of a highly complex mixture of molecules from relatively low-mass volatiles (tens of daltons) to high-mass refractory materials (hundreds of daltons). These products include various carboxylic acids, nitriles, and urea, which are also expected to be present on the surface of outer solar system bodies, including Pluto and other transneptunian objects. If these compounds occur in sufficient concentrations in the ices of outer solar system bodies, their characteristic bands may be detectable in the near-infrared spectra of these objects.

  5. Coating Reduces Ice Adhesion

    NASA Technical Reports Server (NTRS)

    Smith, Trent; Prince, Michael; DwWeese, Charles; Curtis, Leslie

    2008-01-01

    The Shuttle Ice Liberation Coating (SILC) has been developed to reduce the adhesion of ice to surfaces on the space shuttle. SILC, when coated on a surface (foam, metal, epoxy primer, polymer surfaces), will reduce the adhesion of ice by as much as 90 percent as compared to the corresponding uncoated surface. This innovation is a durable coating that can withstand several cycles of ice growth and removal without loss of anti-adhesion properties. SILC is made of a binder composed of varying weight percents of siloxane(s), ethyl alcohol, ethyl sulfate, isopropyl alcohol, and of fine-particle polytetrafluoroethylene (PTFE). The combination