Science.gov

Sample records for aircraft icing project

  1. Project ADIOS: Aircraft Deployable Ice Observation System

    NASA Astrophysics Data System (ADS)

    Gudmundsson, G. H.

    2013-12-01

    Regions of the Antarctic that are of scientific interest are often too heavily crevassed to enable a plane to land, or permit safe access from a field camp. We have developed an alternative strategy for instrumenting these regions: a sensor that can be dropped from an overflying aircraft. Existing aircraft deployable sensors are not suitable for long term operations in areas where snow accumulates, as they are quickly buried. We have overcome this problem by shaping the sensor like an aerodynamic mast with fins and a small parachute. After being released from the aircraft, the sensor accelerates to 42m/s and stabilizes during a 10s descent. On impact with the snow surface the sensor package buries itself to a depth of 1m then uses the large surface area of the fins to stop it burying further. This leaves a 1.5m mast protruding high above the snow surface to ensure a long operating life. The high impact kinetic energy and robust fin braking mechanism ensure that the design works in both soft and hard snow. Over the past two years we have developed and tested our design with a series of aircraft and wind tunnel tests. Last season we used this deployment strategy to successfully install a network of 31 single band GPS sensors in regions where crevassing has previously prevented science operations: Pine Island Glacier, West Antarctica, and Scar Inlet, Antarctic Peninsula. This season we intend to expand on this network by deploying a further 25 single and dual band GPS sensors on Thwaites Glacier, West Antarctica.

  2. Subsonic Aircraft Safety Icing Study

    NASA Technical Reports Server (NTRS)

    Jones, Sharon Monica; Reveley, Mary S.; Evans, Joni K.; Barrientos, Francesca A.

    2008-01-01

    NASA's Integrated Resilient Aircraft Control (IRAC) Project is one of four projects within the agency s Aviation Safety Program (AvSafe) in the Aeronautics Research Mission Directorate (ARMD). The IRAC Project, which was redesigned in the first half of 2007, conducts research to advance the state of the art in aircraft control design tools and techniques. A "Key Decision Point" was established for fiscal year 2007 with the following expected outcomes: document the most currently available statistical/prognostic data associated with icing for subsonic transport, summarize reports by subject matter experts in icing research on current knowledge of icing effects on control parameters and establish future requirements for icing research for subsonic transports including the appropriate alignment. This study contains: (1) statistical analyses of accident and incident data conducted by NASA researchers for this "Key Decision Point", (2) an examination of icing in other recent statistically based studies, (3) a summary of aviation safety priority lists that have been developed by various subject-matter experts, including the significance of aircraft icing research in these lists and (4) suggested future requirements for NASA icing research. The review of several studies by subject-matter experts was summarized into four high-priority icing research areas. Based on the Integrated Resilient Aircraft Control (IRAC) Project goals and objectives, the IRAC project was encouraged to conduct work in all of the high-priority icing research areas that were identified, with the exception of the developing of methods to sense and document actual icing conditions.

  3. 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.

  4. Remote sensing of potential aircraft icing areas

    NASA Astrophysics Data System (ADS)

    Zuev, Vladimir V.; Nakhtigalova, Daria P.; Shelekhov, Alexander P.; Shelekhova, Evgeniya A.; Baranov, Nikolay A.; Kizhner, Lubov I.

    2015-11-01

    Remote sensing technique of detection of potential aircraft icing areas based on temperature profile measurements, using meteorological temperature profiler, and the data of the Airfield Measuring and Information System (AMIS-RF), was proposed, theoretically described and experimentally validated during the field project in 2012 - 2013 in the Tomsk Bogashevo Airport. Spatial areas of potential aircraft icing were determined using the RAP algorithm and Godske formula. The equations for the reconstruction of profiles of relative humidity and dew point using data from AMIS-RF are given. Actual data on the aircraft icing for the Tomsk Bogashevo Airport on 11 October 2012 and 17 March 2013 are presented in this paper. The RAP algorithm and Godske formula show similar results for the location of spatial areas of potential icing. Though, the results obtained using the RAP algorithm are closer to the actual data on the icing known from aircraft crew reports.

  5. NASA's aircraft icing analysis program

    NASA Technical Reports Server (NTRS)

    Shaw, R. J.

    1986-01-01

    An overview of the NASA ongoing efforts to develop an aircraft icing analysis capability is presented. Discussions are included of the overall and long term objectives of the program as well as current capabilities and limitations of the various computer codes being developed. Descriptions are given of codes being developed to analyze two- and three-dimensional trajectories of water droplets, airfoil ice accretion, aerodynamic performance degradation of components and complete aircraft configurations, electrothermal deicer, fluid freezing point depressant antideicer and electro-impulse deicer. The need for bench mark and verification data to support the code development is also discussed, and selected results of experimental programs are presented.

  6. NASA's Aircraft Icing Analysis Program

    NASA Technical Reports Server (NTRS)

    Shaw, R. J.

    1986-01-01

    An overview of the NASA ongoing efforts to develop an aircraft icing analysis capability is presented. Discussions are included of the overall and long term objectives of the program as well as current capabilities and limitations of the various computer codes being developed. Descriptions are given of codes being developed to analyze two and three dimensional trajectories of water droplets, airfoil ice accretion, aerodynamic performance degradation of components and complete aircraft configurations, electrothermal deicer, fluid freezing point depressant antideicer and electro-impulse deicer. The need for bench mark and verification data to support the code development is also discussed, and selected results of experimental programs are presented.

  7. 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.

  8. Aircraft icing instrumentation: Unfilled needs. [rotary wing aircraft

    NASA Technical Reports Server (NTRS)

    Kitchens, P. F.

    1980-01-01

    A list of icing instrumentation requirements are presented. Because of the Army's helicopter orientation, many of the suggestions are specific to rotary wing aircraft; however, some of the instrumentation are also suitable for general aviation aircraft.

  9. Report on ice formation on aircraft

    NASA Technical Reports Server (NTRS)

    1939-01-01

    The physical phenomena involved in the icing of aircraft have been analyzed and measured. Recommendations on warning devices are made as well as the different types of ice and glazing that can occur on airplanes are examined and discussed.

  10. National plans for aircraft icing and improved aircraft icing forecasts and associated warning services

    NASA Technical Reports Server (NTRS)

    Pass, Ralph P.

    1988-01-01

    Recently, the United States has increased its activities related to aircraft icing in numerous fields: ice phobics, revised characterization of icing conditions, instrument development/evaluation, de-ice/anti-ice devices, simulated supercooled clouds, computer simulation and flight tests. The Federal Coordinator for Meteorology is involved in two efforts, one a National Plan on Aircraft Icing and the other a plan for Improved Aircraft Icing Forecasts and Associated Warning Services. These two plans will provide an approved structure for future U.S. activities related to aircraft icing. The recommended activities will significantly improve the position of government agencies to perform mandated activities and to enable U.S. manufacturers to be competitive in the world market.

  11. Microwave System for Detecting Ice on Aircraft

    NASA Technical Reports Server (NTRS)

    Joseph, Philip J.; Glynn, Dennis P., Jr.; Joseph, John C.

    2004-01-01

    A microwave-based system has been developed as a means of detecting ice on aircraft surfaces, with enough sensitivity to provide a warning before the ice accretes to a dangerous thickness. The system can measure the thickness of ice from a few mils (1 mil = 0.0254 mm) to about 1/4 in. (.6 mm) and can distinguish among (1) ice, (2) water (or deicing fluid), and (3) a mixture of ice and water (or deicing fluid). Sensors have been ruggedized to withstand the rain erosion environment.

  12. Continuous measurement of aircraft wing icing

    NASA Technical Reports Server (NTRS)

    Yao, Stephen S. C.

    1994-01-01

    Ice formation on the wings of aircraft is a problem that has plagued air travel since its inception. Several recent incidents have been attributed to ice formation on the lifting surfaces of wings. This paper describes a SBIR Phase 1 research effort on the use of small flat dielectric sensors in detecting a layer of ice above the sensor. The sensors are very small, lightweight, and inexpensive. The electronics package that controls the sensor is also small, and could be even smaller using commonly available miniaturization technologies. Thus, several sensors could be placed on a surface such that a representative ice thickness profile could be measured. The benefits offered by developing this technology go beyond the safety improvements realized by monitoring ice formation on the wings of an aircraft. Continuous monitoring of anti-icing fluid concentrations on the ground would warn the pilot of impending fluid failure as well as allowing the stations to use less de-icing solution per aircraft. This in turn would increase the safety of takeoffs and reduce the overall discharge of de-icing solution into the environment, thus reducing the biohazard of the de-icing procedure.

  13. Instrument for Aircraft-Icing and Cloud-Physics Measurements

    NASA Technical Reports Server (NTRS)

    Lilie, Lyle; Bouley, Dan; Sivo, Chris

    2006-01-01

    The figure shows a compact, rugged, simple sensor head that is part of an instrumentation system for making measurements to characterize the severity of aircraft-icing conditions and/or to perform research on cloud physics. The quantities that are calculated from measurement data acquired by this system and that are used to quantify the severity of icing conditions include sizes of cloud water drops, cloud liquid water content (LWC), cloud ice water content (IWC), and cloud total water content (TWC). The sensor head is mounted on the outside of an aircraft, positioned and oriented to intercept the ambient airflow. The sensor head consists of an open housing that is heated in a controlled manner to keep it free of ice and that contains four hot-wire elements. The hot-wire sensing elements have different shapes and sizes and, therefore, exhibit different measurement efficiencies with respect to droplet size and water phase (liquid, frozen, or mixed). Three of the hot-wire sensing elements are oriented across the airflow so as to intercept incoming cloud water. For each of these elements, the LWC or TWC affects the power required to maintain a constant temperature in the presence of cloud water.

  14. Simulation Tools Model Icing for Aircraft Design

    NASA Technical Reports Server (NTRS)

    2012-01-01

    Here s a simple science experiment to try: Place an unopened bottle of distilled water in your freezer. After 2-3 hours, if the water is pure enough, you will notice that it has not frozen. Carefully pour the water into a bowl with a piece of ice in it. When it strikes the ice, the water will instantly freeze. One of the most basic and commonly known scientific facts is that water freezes at around 32 F. But this is not always the case. Water lacking any impurities for ice crystals to form around can be supercooled to even lower temperatures without freezing. High in the atmosphere, water droplets can achieve this delicate, supercooled state. When a plane flies through clouds containing these droplets, the water can strike the airframe and, like the supercooled water hitting the ice in the experiment above, freeze instantly. The ice buildup alters the aerodynamics of the plane - reducing lift and increasing drag - affecting its performance and presenting a safety issue if the plane can no longer fly effectively. In certain circumstances, ice can form inside aircraft engines, another potential hazard. NASA has long studied ways of detecting and countering atmospheric icing conditions as part of the Agency s efforts to enhance aviation safety. To do this, the Icing Branch at Glenn Research Center utilizes a number of world-class tools, including the Center s Icing Research Tunnel and the NASA 607 icing research aircraft, a "flying laboratory" for studying icing conditions. The branch has also developed a suite of software programs to help aircraft and icing protection system designers understand the behavior of ice accumulation on various surfaces and in various conditions. One of these innovations is the LEWICE ice accretion simulation software. Initially developed in the 1980s (when Glenn was known as Lewis Research Center), LEWICE has become one of the most widely used tools in icing research and aircraft design and certification. LEWICE has been transformed over

  15. Advanced instrumentation for aircraft icing research

    NASA Technical Reports Server (NTRS)

    Bachalo, W.; Smith, J.; Rudoff, R.

    1990-01-01

    A compact and rugged probe based on the phase Doppler method was evaluated as a means for characterizing icing clouds using airborne platforms and for advancing aircraft icing research in large scale wind tunnels. The Phase Doppler Particle Analyzer (PDPA) upon which the new probe was based is now widely recognized as an accurate method for the complete characterization of sprays. The prototype fiber optic-based probe was evaluated in simulated aircraft icing clouds and found to have the qualities essential to providing information that will advance aircraft icing research. Measurement comparisons of the size and velocity distributions made with the standard PDPA and the fiber optic probe were in excellent agreement as were the measurements of number density and liquid water content. Preliminary testing in the NASA Lewis Icing Research Tunnel (IRT) produced reasonable results but revealed some problems with vibration and signal quality at high speeds. The cause of these problems were identified and design changes were proposed to eliminate the shortcomings of the probe.

  16. Effects of ice accretions on aircraft aerodynamics

    NASA Astrophysics Data System (ADS)

    Lynch, Frank T.; Khodadoust, Abdollah

    2001-11-01

    This article is a systematic and comprehensive review, correlation, and assessment of test results available in the public domain which address the aerodynamic performance and control degradations caused by various types of ice accretions on the lifting surfaces of fixed wing aircraft. To help put the various test results in perspective, overviews are provided first of the important factors and limitations involved in computational and experimental icing simulation techniques, as well as key aerodynamic testing simulation variables and governing flow physics issues. Following these are the actual reviews, assessments, and correlations of a large number of experimental measurements of various forms of mostly simulated in-flight and ground ice accretions, augmented where appropriate by similar measurements for other analogous forms of surface contamination and/or disruptions. In-flight icing categories reviewed include the initial and inter-cycle ice accretions inherent in the use of de-icing systems which are of particular concern because of widespread misconceptions about the thickness of such accretions which can be allowed before any serious consequences occur, and the runback/ridge ice accretions typically associated with larger-than-normal water droplet encounters which are of major concern because of the possible potential for catastrophic reductions in aerodynamic effectiveness. The other in-flight ice accretion category considered includes the more familiar large rime and glaze ice accretions, including ice shapes with rather grotesque features, where the concern is that, in spite of all the research conducted to date, the upper limit of penalties possible has probably not been defined. Lastly, the effects of various possible ground frost/ice accretions are considered. The concern with some of these is that for some types of configurations, all of the normally available operating margins to stall at takeoff may be erased if these accretions are not

  17. Antifreeze Polysaccharide Coating Study for De-icing Aircraft

    NASA Astrophysics Data System (ADS)

    Morita, Katsuaki; Sakaue, Hirotaka; Ando, Azuma; Matsuda, Yoshiyuki; Kawahara, Hidehisa

    2015-11-01

    Anti-icing or deicing of an aircraft is necessary for a safe flight operation. Mechanical processes, such as heating and deicer boot, are widely used. Deicing fluids, such as propyrene glycol and ethylene glycol, are used to coat the aircraft. However, these should be coated every time before the take-off, since the fluids come off from the aircraft while cruising. We study an antifreeze polysaccharide (AFPS) coating as a deicer for an aircraft. It is designed to coat on the aircraft without removal. Since an AFPS coating removes ice by reducing the interfacial energy, it would be an alternative way to prevent ice on the aircraft. We provide a temperature-controlled room, which can control its temperature under icing conditions (-8 and -4 °C). Ice adhesion tests are performed for AFPS coating and compared with a fundamental specimen without the coating.

  18. The influence of ice accretion physics on the forecasting of aircraft icing conditions

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.

    1990-01-01

    The physics which control aircraft ice accretion are reviewed in the context of identifying and forecasting hazardous icing conditions. The severity of aircraft icing is found to be extremely sensitive to temperature, liquid water content and droplet size distribution particularly near the transition between rime and mixed icing. The difficulty in measurement and the variability of these factors with altitude, position and time coupled with variable aircraft sensitivity make forecasting and identifying icing conditions difficult. Automated Pilot Reports (PIREPS) are suggested as one mechanism for improving the data base necessary to forecast icing conditions.

  19. 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.

  20. Contrail ice particles in aircraft wakes and their climatic importance

    NASA Astrophysics Data System (ADS)

    Schumann, Ulrich; JeßBerger, Philipp; Voigt, Christiane

    2013-06-01

    Measurements of gaseous (NO, NOy, SO2, HONO) and ice particle concentrations in young contrails in primary and secondary wakes of aircraft of different sizes (B737, A319, A340, A380) are used to investigate ice particle formation behind aircraft. The gas concentrations are largest in the primary wake and decrease with increasing altitude in the secondary wake, as expected for passive trace gases and aircraft-dependent dilution. In contrast, the measured ice particle concentrations were found larger in the secondary wake than in the primary wake. The contrails contain more ice particles than expected for previous black carbon (soot) estimates. The ice concentrations may result from soot-induced ice nucleation for a soot number emission index of 1015 kg-1. For a doubled ice particle concentration in young contrails, a contrail cirrus model computes about 60% increases of global radiative forcing by contrail cirrus because of simultaneous increases in optical depth, age, and cover.

  1. Selected bibliography of NACA-NASA aircraft icing publications

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J. (Compiler)

    1981-01-01

    A summary of NACA-NASA icing research from 1940 to 1962 is presented. It includes: the main results of the NACA icing program from 1940 to 1950; a selected bibliography of 132 NACA-NASA aircraft icing publications; a technical summary of each document cited in the selected bibliography; and a microfiche copy of each document cited in the selected bibliography.

  2. Project report: Aircraft

    SciTech Connect

    Wuebbles, D.J.; Baughcum, S.; Metwally, M.; Seals, R.

    1994-04-01

    Analyses of scenarios of past and possible future emissions are an important aspect of assessing the potential environmental effects from aircraft, including the proposed high speed civil transport (HSCT). The development of a detailed three-dimensional database that accurately represents the integration of all aircraft emissions along realistic flight paths for such scenarios requires complex computational modeling capabilities. Such a detailed data set is required for the scenarios evaluated in this interim assessment. Within the NASA High-Speed Research Program, the Emissions Scenarios Committee provides a forum for identifying the required scenarios and evaluating the resulting database being developed with the advanced emissions modeling capabilities at the Boeing Company and McDonnell Douglas Corporation.

  3. Icing Frequencies Experienced During Climb and Descent by Fighter-Interceptor Aircraft

    NASA Technical Reports Server (NTRS)

    Perkins, Porter J.

    1958-01-01

    Data and analyses are presented on the relative frequencies of occurrence and severity of icing cloud layers encountered by jet aircraft in the climb and descent phases of flights to high altitudes. Fighter-interceptor aircraft operated by the Air Defense Command (USAF) at bases in the Duluth and Seattle areas collected the data with icing meters installed for a l-year period. The project was part of an extensive program conducted by the NACA to collect Icing cloud data for evaluating the icing problem relevant to routine operations. The average frequency of occurrence of icing was found to be about 5 percent of the number of climbs and descents during 1 year of operations The icing encounters were predominantly in the low and middle cloud layers, decreasing above 15,000 feet to practically none above 25,000 feet. The greatest thickness of ice that would accumulate on any aircraft component (as indicated by the accretion on a small object) was measured with the icing meters. The ice thicknesses on a small sensing probe averaged less than 1/32 inch and did not exceed 1/2 inch. Such accumulations are relatively small when compared with those that can form during horizontal flight in icing clouds. The light accretions resulted from relatively steep angles of flight through generally thin cloud layers. Because of the limited statistical reliability of the results, an analysis was made using previous statistics on icing clouds below an altitude of 20,000 feet to determine the general icing severity probabilities. The calculations were made using adiabatic lifting as a basis to establish the liquid-water content. Probabilities of over-all ice accretions on a small object as a function of airspeed and rate of climb were computed from the derived water contents. These results were then combined with the probability of occurrence of icing in order to give the icing severity that can be expected for routine aircraft operations.

  4. Hydrophobic coating study for anti-icing aircraft

    NASA Astrophysics Data System (ADS)

    Morita, Katsuaki; Aoki, Akihito; Konno, Akihisa; Sakaue, Hirotaka

    2010-11-01

    Anti-icing or deicing of an aircraft is necessary for a safe flight operation. Mechanical processes, such as heating and deicer boot, are widely used. Deicing fluids, such as ethylene glycol type, are used to coat the aircraft. However, these should be coated every time before the take-off, since the fluids come off from the aircraft while cruising. We study a hydrophobic coating as a anti-icing for an aircraft. It is designed to coat the aircraft without removal. Since a hydrophobic coating prevents water by reducing the surface energy, it would be another way to prevent ice on the aircraft. We provide a temperature-controlled room, which can control its temperature at an icing condition (-10 to 0 degrees C). The contact angle is tested for various hydrophobic coatings. A water jet impingement on a hydrophobic-coated plate is included. The jet freezes under the icing condition. Qualitative comparison among various hydrophobic coatings as anti-icing is discussed.

  5. Ultrasonic techniques for aircraft ice accretion measurement

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.; Kirby, Mark S.; Lichtenfelts, Fred

    1990-01-01

    Results of tests to measure ice growth in natural (flight) and artificial (icing wind tunnel) icing conditions are presented. Ice thickness is measured using an ultrasonic pulse-echo technique. Two icing regimes, wet and dry ice growth, are identified and the unique ultrasonic signal characteristics associated with these different types of ice growth are described. Ultrasonic measurements of ice growth on cylinders and airfoils exposed to artificial and natural icing conditions are presented. An accuracy of plus or minus 0.5 mm is achieved for ice thickness measurement using the pulse-echo technique. The performance of two-probe type ice detectors is compared to the surface mounted ultrasonic system. The ultrasonically measured ice accretion rates and ice surface condition (wet or dry) are used to compare the heat transfer characteristics for flight and icing wind tunnel environments. In general the heat transfer coefficient is inferred to be higher in the wind tunnel environment, not likely due to higher freestream turbulence levels. Finally, preliminary results of tests to measure ice growth on airfoil using an array of ultrasonic transducers are described. Ice profiles obtained during flight in natural icing conditions are shown and compared with mechanical and stereo image measurements.

  6. Ultrasonic techniques for aircraft ice accretion measurement

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.; Kirby, Mark S.; Lichtenfelts, Fred

    1988-01-01

    Ultrasonic pulse-echo measurements of ice growth on cylinders and airfoils exposed to both artificial (icing wind tunnel) and natural (flight) icing conditions are presented. An accuracy of + or - 0.5 mm is achieved with the present method. The ultrasonic signal characteristics associated with each of the two types of icing regimes identified, wet and dry ice growth, are discussed. Heat transfer coefficients are found to be higher in the wind tunnel environment than in flight. Results for ice growth on airfoils have also been obtained using an array of ultrasonic transducers. Icing profiles obtained during flight are compared with mechanical and stereo image measurements.

  7. In-flight detection and identification and accommodation of aircraft icing

    NASA Astrophysics Data System (ADS)

    Caliskan, Fikret; Hajiyev, Chingiz

    2012-11-01

    The recent improvements and research on aviation have focused on the subject of aircraft safe flight even in the severe weather conditions. As one type of such weather conditions, aircraft icing considerably has negative effects on the aircraft flight performance. The risks of the iced aerodynamic surfaces of the flying aircraft have been known since the beginning of the first flights. Until recent years, as a solution for this event, the icing conditions ahead flight route are estimated from radars or other environmental sensors, hence flight paths are changed, or, if it exists, anti-icing/de-icing systems are used. This work aims at the detection and identification of airframe icing based on statistical properties of aircraft dynamics and reconfigurable control protecting aircraft from hazardous icing conditions. In this paper, aircraft icing identification based on neural networks is investigated. Following icing identification, reconfigurable control is applied for protecting the aircraft from hazardous icing conditions.

  8. NASA Now: Phase Change and Forces of Flight: Aircraft Icing Research

    NASA Video Gallery

    Tour the Icing Research Tunnel with Judith VanZante, aeromechanical engineer and icing specialist. VanZante explains the hazards of ice on aircraft, how it is formed, and why the research on ice pl...

  9. Experimental methodologies to support aircraft icing analysis

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.; Kirby, Mark S.

    1987-01-01

    The experimental methodologies are illustrated by graphs, charts and line drawings. Typical ultrasonic echo signals for dry and wet ice growth, ice accretion rates for various tunnel configurations, the experimental configuration for flight tests of the ultrasonic measuring system and heat balance models used to predict ice growth are among the topics that are illustrated and briefly discussed.

  10. Progress Towards the Remote Sensing of Aircraft Icing Hazards

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew; Brinker, David; Politovich, Marcia; Serke, David; Ryerson, Charles; Pazmany, Andrew; Solheim, Fredrick

    2009-01-01

    NASA has teamed with the FAA, DoD, industry, and academia for research into the remote detection and measurement of atmospheric conditions leading to aircraft icing hazards. The ultimate goal of this effort is to provide pilots, controllers, and dispatchers sufficient information to allow aircraft to avoid or minimize their exposure to the hazards of in-flight icing. Since the hazard of in-flight icing is the outcome of aircraft flight through clouds containing supercooled liquid water and strongly influenced by the aircraft s speed and configuration and by the length of exposure, the hazard cannot be directly detected, but must be inferred based upon the measurement of conducive atmospheric conditions. Therefore, icing hazard detection is accomplished through the detection and measurement of liquid water in regions of measured sub-freezing air temperatures. The icing environment is currently remotely measured from the ground with a system fusing radar, lidar, and multifrequency microwave radiometer sensors. Based upon expected ice accretion severity for the measured environment, a resultant aircraft hazard is then calculated. Because of the power, size, weight, and view angle constraints of airborne platforms, the current ground-based solution is not applicable for flight. Two current airborne concepts are based upon the use of either multifrequency radiometers or multifrequency radar. Both ground-based and airborne solutions are required for the future since groundbased systems can provide hazard detection for all aircraft in airport terminal regions while airborne systems will be needed to provide equipped aircraft with flight path coverage between terminal regions.

  11. Structural properties of impact ices accreted on aircraft structures

    NASA Technical Reports Server (NTRS)

    Scavuzzo, R. J.; Chu, M. L.

    1987-01-01

    The structural properties of ice accretions formed on aircraft surfaces are studied. The overall objectives are to measure basic structural properties of impact ices and to develop finite element analytical procedures for use in the design of all deicing systems. The Icing Research Tunnel (IRT) was used to produce simulated natural ice accretion over a wide range of icing conditions. Two different test apparatus were used to measure each of the three basic mechanical properties: tensile, shear, and peeling. Data was obtained on both adhesive shear strength of impact ices and peeling forces for various icing conditions. The influences of various icing parameters such as tunnel air temperature and velocity, icing cloud drop size, material substrate, surface temperature at ice/material interface, and ice thickness were studied. A finite element analysis of the shear test apparatus was developed in order to gain more insight in the evaluation of the test data. A comparison with other investigators was made. The result shows that the adhesive shear strength of impact ice typically varies between 40 and 50 psi, with peak strength reaching 120 psi and is not dependent on the kind of substrate used, the thickness of accreted ice, and tunnel temperature below 4 C.

  12. Aircraft measurements of microwave emission from Arctic Sea ice

    USGS Publications Warehouse

    Wilheit, T.; Nordberg, W.; Blinn, J.; Campbell, W.; Edgerton, A.

    1971-01-01

    Measurements of the microwave emission from Arctic Sea ice were made with aircraft at 8 wavelengths ranging from 0.510 to 2.81 cm. The expected contrast in emissivities between ice and water was observed at all wavelengths. Distributions of sea ice and open water were mapped from altitudes up to 11 km in the presence of dense cloud cover. Different forms of ice also exhibited strong contrasts in emissivity. Emissivity differences of up to 0.2 were observed between two types of ice at the 0.811-cm wavelength. The higher emissivity ice type is tentatively identified as having been formed more recently than the lower emissivity ice. ?? 1971.

  13. Light transport and general aviation aircraft icing research requirements

    NASA Technical Reports Server (NTRS)

    Breeze, R. K.; Clark, G. M.

    1981-01-01

    A short term and a long term icing research and technology program plan was drafted for NASA LeRC based on 33 separate research items. The specific items listed resulted from a comprehensive literature search, organized and assisted by a computer management file and an industry/Government agency survey. Assessment of the current facilities and icing technology was accomplished by presenting summaries of ice sensitive components and protection methods; and assessments of penalty evaluation, the experimental data base, ice accretion prediction methods, research facilities, new protection methods, ice protection requirements, and icing instrumentation. The intent of the research plan was to determine what icing research NASA LeRC must do or sponsor to ultimately provide for increased utilization and safety of light transport and general aviation aircraft.

  14. Progress toward the development of an aircraft icing analysis capability

    NASA Technical Reports Server (NTRS)

    Shaw, R. J.

    1984-01-01

    An overview of the NASA efforts to develop an aircraft icing analysis capability is presented. Discussions are included of the overall and long term objectives of the program as well as current capabilities and limitations of the various computer codes being developed. Descriptions are given of codes being developed to analyze two and three dimensional trajectories of water droplets, airfoil ice accretion, aerodynamic performance degradation of components and complete aircraft configurations, electrothermal deicer, and fluid freezing point depressant deicer. The need for bench mark and verification data to support the code development is also discussed.

  15. Precise Aircraft Guidance Techniques for NASA's Operation IceBridge

    NASA Astrophysics Data System (ADS)

    Sonntag, J. G.; Russell, R.

    2013-12-01

    We present a suite of novel aircraft guidance techniques we designed, developed and now operationally utilize to precisely guide large NASA aircraft and their sensor suites over polar science targets. Our techniques are based on real-time, non-differential Global Positioning System (GPS) data. They interact with the flight crew and the aircraft using a combination of yoke-mounted computer displays and an electronic interface to the aircraft's autopilot via the aircraft's Instrument Landing System (ILS). This ILS interface allows the crew to 'couple' the autopilot to our systems, which then guide the aircraft over science targets with considerably better accuracy than it can using its internal guidance. We regularly demonstrate errors in cross-track aircraft positioning of better than 4 m standard deviation and better than 2 m in mean offset over lengthy great-circle routes across the ice sheets. Our system also has a mode allowing for manual aircraft guidance down a predetermined path of arbitrary curvature, such as a sinuous glacier centerline. This mode is in general not as accurate as the coupled technique but is more versatile. We employ both techniques interchangeably and seamlessly during a typical Operation IceBridge science flight. Flight crews find the system sufficiently intuitive so that little or no familiarization is required prior to their accurately flying science lines. We regularly employ the system on NASA's P-3B and DC-8 aircraft, and since the interface to the aircraft's autopilot operates through the ILS, it should work well on any ILS-equipped aircraft. Finally, we recently extended the system to provide precise, three-dimensional landing approach guidance to the aircraft, thus transforming any approach into a precise ILS approach, even to a primitive runway. This was intended to provide a backup to the aircraft's internal landing systems in the event of a zero-visibility landing to a non-ILS equipped runway, such as the McMurdo sea ice runway

  16. Weather Features Associated with Aircraft Icing Conditions: A Case Study

    PubMed Central

    Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; López, Laura; García-Ortega, Eduardo; Merino, Andrés

    2014-01-01

    In the context of aviation weather hazards, the study of aircraft icing is very important because of several accidents attributed to it over recent decades. On February 1, 2012, an unusual meteorological situation caused severe icing of a C-212-200, an aircraft used during winter 2011-2012 to study winter cloud systems in the Guadarrama Mountains of the central Iberian Peninsula. Observations in this case were from a MP-3000A microwave radiometric profiler, which acquired atmospheric temperature and humidity profiles continuously every 2.5 minutes. A Cloud Aerosol and Precipitation Spectrometer (CAPS) was also used to study cloud hydrometeors. Finally, ice nuclei concentration was measured in an isothermal cloud chamber, with the goal of calculating concentrations in the study area. Synoptic and mesoscale meteorological conditions were analysed using the Weather Research and Forecasting (WRF) model. It was demonstrated that topography influenced generation of a mesolow and gravity waves on the lee side of the orographic barrier, in the region where the aircraft experienced icing. Other factors such as moisture, wind direction, temperature, atmospheric stability, and wind shear were decisive in the appearance of icing. This study indicates that icing conditions may arise locally, even when the synoptic situation does not indicate any risk. PMID:24701152

  17. Weather features associated with aircraft icing conditions: a case study.

    PubMed

    Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; López, Laura; García-Ortega, Eduardo; Merino, Andrés

    2014-01-01

    In the context of aviation weather hazards, the study of aircraft icing is very important because of several accidents attributed to it over recent decades. On February 1, 2012, an unusual meteorological situation caused severe icing of a C-212-200, an aircraft used during winter 2011-2012 to study winter cloud systems in the Guadarrama Mountains of the central Iberian Peninsula. Observations in this case were from a MP-3000A microwave radiometric profiler, which acquired atmospheric temperature and humidity profiles continuously every 2.5 minutes. A Cloud Aerosol and Precipitation Spectrometer (CAPS) was also used to study cloud hydrometeors. Finally, ice nuclei concentration was measured in an isothermal cloud chamber, with the goal of calculating concentrations in the study area. Synoptic and mesoscale meteorological conditions were analysed using the Weather Research and Forecasting (WRF) model. It was demonstrated that topography influenced generation of a mesolow and gravity waves on the lee side of the orographic barrier, in the region where the aircraft experienced icing. Other factors such as moisture, wind direction, temperature, atmospheric stability, and wind shear were decisive in the appearance of icing. This study indicates that icing conditions may arise locally, even when the synoptic situation does not indicate any risk. PMID:24701152

  18. Weather features associated with aircraft icing conditions: a case study.

    PubMed

    Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; López, Laura; García-Ortega, Eduardo; Merino, Andrés

    2014-01-01

    In the context of aviation weather hazards, the study of aircraft icing is very important because of several accidents attributed to it over recent decades. On February 1, 2012, an unusual meteorological situation caused severe icing of a C-212-200, an aircraft used during winter 2011-2012 to study winter cloud systems in the Guadarrama Mountains of the central Iberian Peninsula. Observations in this case were from a MP-3000A microwave radiometric profiler, which acquired atmospheric temperature and humidity profiles continuously every 2.5 minutes. A Cloud Aerosol and Precipitation Spectrometer (CAPS) was also used to study cloud hydrometeors. Finally, ice nuclei concentration was measured in an isothermal cloud chamber, with the goal of calculating concentrations in the study area. Synoptic and mesoscale meteorological conditions were analysed using the Weather Research and Forecasting (WRF) model. It was demonstrated that topography influenced generation of a mesolow and gravity waves on the lee side of the orographic barrier, in the region where the aircraft experienced icing. Other factors such as moisture, wind direction, temperature, atmospheric stability, and wind shear were decisive in the appearance of icing. This study indicates that icing conditions may arise locally, even when the synoptic situation does not indicate any risk.

  19. Diagnosing Aircraft Icing Potential from Satellite Cloud Retrievals

    NASA Technical Reports Server (NTRS)

    Smith, William L., Jr.; Minnis, Patrick; Fleeger, Cecilia; Spangenberg, Douglas

    2013-01-01

    The threat for aircraft icing in clouds is a significant hazard that routinely impacts aviation operations. Accurate diagnoses and forecasts of aircraft icing conditions requires identifying the location and vertical distribution of clouds with super-cooled liquid water (SLW) droplets, as well as the characteristics of the droplet size distribution. Traditional forecasting methods rely on guidance from numerical models and conventional observations, neither of which currently resolve cloud properties adequately on the optimal scales needed for aviation. Satellite imagers provide measurements over large areas with high spatial resolution that can be interpreted to identify the locations and characteristics of clouds, including features associated with adverse weather and storms. This paper describes new techniques for interpreting cloud products derived from satellite data to infer the flight icing threat to aircraft. For unobscured low clouds, the icing threat is determined using empirical relationships developed from correlations between satellite imager retrievals of liquid water path and droplet size with icing conditions reported by pilots (PIREPS). For deep ice over water cloud systems, ice and liquid water content (IWC and LWC) profiles are derived by using the imager cloud properties to constrain climatological information on cloud vertical structure and water phase obtained apriori from radar and lidar observations, and from cloud model analyses. Retrievals of the SLW content embedded within overlapping clouds are mapped to the icing threat using guidance from an airfoil modeling study. Compared to PIREPS and ground-based icing remote sensing datasets, the satellite icing detection and intensity accuracies are approximately 90% and 70%, respectively, and found to be similar for both low level and deep ice over water cloud systems. The satellite-derived icing boundaries capture the reported altitudes over 90% of the time. Satellite analyses corresponding to

  20. Effects of Ice Accretion on Aircraft Aerodynamics

    NASA Technical Reports Server (NTRS)

    Bragg, Michael B.

    1998-01-01

    The primary objective of this research was to support the development of a new ice accretion model by improving our physical understanding of the ice accretion process through experimental measurements. The focus was on the effect of the initial ice roughness (smooth/rough boundary) on the accretion process. This includes understanding the boundary-layer development over the roughness and especially its effect on the heat transfer which is fundamental to the ice accretion process. The research focused on acquiring the experimental data needed to formulate a new ice accretion physical model. Research was conducted to analyze boundary-layer data taken on a NACA 0012 airfoil with roughness to simulate the smooth/rough boundary. The effect of isolated roughness on boundary-layer transition was studied experimentally to determine if the classical critical roughness Reynolds number criteria could be applied to transition in the airfoil leading-edge area. The effect of simulated smooth/rough boundary roughness on convective heat transfer was studied to complete the study. During the course of this research the effect of free-stream wind tunnel turbulence on the boundary layer was measured. Since this quantity was not well known, research to accurately measure the wind tunnel turbulence in an icing cloud was undertaken. Preliminary results were attained and the final data were acquired, reduced and presented under a subsequent grant.

  1. Numerical modeling of runback water on ice protected aircraft surfaces

    NASA Technical Reports Server (NTRS)

    Al-Khalil, Kamel M.; Keith, Theo G., Jr.; Dewitt, Kenneth J.

    1992-01-01

    A numerical simulation for 'running wet' aircraft anti-icing systems is developed. The model includes breakup of the water film, which exists in regions of direct impingement, into individual rivulets. The wetness factor distribution resulting from the film breakup and the rivulet configuration on the surface are predicted in the numerical solution procedure. The solid wall is modeled as a multilayer structure and the anti-icing system used is of the thermal type utilizing hot air and/or electrical heating elements embedded with the layers. Details of the calculation procedure and the methods used are presented.

  2. Remote sensing as a research tool. [sea ice surveillance from aircraft and spacecraft

    NASA Technical Reports Server (NTRS)

    Carsey, F. D.; Zwally, H. J.

    1986-01-01

    The application of aircraft and spacecraft remote sensing techniques to sea ice surveillance is evaluated. The effects of ice in the air-sea-ice system are examined. The measurement principles and characteristics of remote sensing methods for aircraft and spacecraft surveillance of sea ice are described. Consideration is given to ambient visible light, IR, passive microwave, active microwave, and laser altimeter and sonar systems. The applications of these systems to sea ice surveillance are discussed and examples are provided. Particular attention is placed on the use of microwave data and the relation between ice thickness and sea ice interactions. It is noted that spacecraft and aircraft sensing techniques can successfully measure snow cover; ice thickness; ice type; ice concentration; ice velocity field; ocean temperature; surface wind vector field; and air, snow, and ice surface temperatures.

  3. The Greenland Ice Mapping Project

    NASA Astrophysics Data System (ADS)

    Joughin, I.; Smith, B.; Howat, I. M.; Moon, T. A.; Scambos, T. A.

    2015-12-01

    Numerous glaciers in Greenland have sped up rapidly and unpredictably during the first part of the 21st Century. We started the Greenland Ice Mapping Project (GIMP) to produce time series of ice velocity for Greenland's major outlet glaciers. We are also producing image time series to document the advance and retreat of glacier calving fronts and other changes in ice-sheet geometry (e.g., shrinking ice caps and ice shelves). When the project began, there was no digital elevation model (DEM) with sufficient accuracy and resolution to terrain-correct the SAR-derived products. Thus, we also produced the 30-m GIMP DEM, which, aside from improving our processing, is an important product in its own right. Although GIMP focuses on time series, complete spatial coverage for initializing ice sheet models also is important. There are insufficient data, however, to map the full ice sheet in any year. There is good RADARSAT coverage for many years in the north, but the C-band data decorrelate too quickly to measure velocity in the high accumulation regions of the southeast. For such regions, ALOS data usually correlate well, but speckle-tracking estimates at L-band are subject to large ionospheric artifacts. Interferometric phase data are far less sensitive to the effect of the ionosphere, but velocity estimates require results from crossing orbits. Thus, to produce a nearly complete mosaic we used data from multiple sensors, beginning with ERS-1/2 data from the mid 1990s. By using a primarily phase-only solution for much of the interior, we have reduced the velocity errors to ~1-3 m/yr. For the faster moving ice-sheet margin where phase data cannot be unwrapped, we used speckle-tracking data. In particular, we have relied on TerraSAR-X for many fast-moving glaciers because the ionosphere far less affects X-band data. This pan-Greenland velocity map as well as many of the time series would not have been possible without an extensive archive of data collected using six

  4. Detection and Analysis of High Ice Concentration Events and Supercooled Drizzle from IAGOS Commercial Aircraft

    NASA Astrophysics Data System (ADS)

    Gallagher, Martin; Baumgardner, Darrel; Lloyd, Gary; Beswick, Karl; Freer, Matt; Durant, Adam

    2016-04-01

    Hazardous encounters with high ice concentrations that lead to temperature and airspeed sensor measurement errors, as well as engine rollback and flameout, continue to pose serious problems for flight operations of commercial air carriers. Supercooled liquid droplets (SLD) are an additional hazard, especially for smaller commuter aircraft that do not have sufficient power to fly out of heavy icing conditions or heat to remove the ice. New regulations issued by the United States and European regulatory agencies are being implemented that will require aircraft below a certain weight class to carry sensors that will detect and warn of these types of icing conditions. Commercial aircraft do not currently carry standard sensors to detect the presence of ice crystals in high concentrations because they are typical found in sizes that are below the detection range of aircraft weather radar. Likewise, the sensors that are currently used to detect supercooled water do not respond well to drizzle-sized drops. Hence, there is a need for a sensor that can fill this measurement void. In addition, the forecast models that are used to predict regions of icing rely on pilot observations as the only means to validate the model products and currently there are no forecasts for the prevalence of high altitude ice crystals. Backscatter Cloud Probes (BCP) have been flying since 2011 under the IAGOS project on six Airbus commercial airliners operated by Lufthansa, Air France, China Air, Iberia and Cathay Pacific, and measure cloud droplets, ice crystals and aerosol particles larger than 5 μm. The BCP can detect these particles and measures an optical equivalent diameter (OED) but is not able to distinguish the type of particle, i.e. whether they are droplets, ice crystals, dust or ash. However, some qualification can be done based on measured temperature to discriminate between liquid water and ice. The next generation BCP (BCPD, Backscatter Cloud Probe with polarization detection) is

  5. Stress-strain state of ice cover during aircraft takeoff and landing

    NASA Astrophysics Data System (ADS)

    Pogorelova, A. V.; Kozin, V. M.; Matyushina, A. A.

    2015-09-01

    We consider the linear unsteady motion of an IL-76TD aircraft on ice. Water is treated as an ideal incompressible liquid, and the liquid motion is considered potential. Ice cover is modeled by an initially unstressed uniform isotropic elastic plate, and the load exerted by the aircraft on the ice cover with consideration of the wing lift is modeled by regions of distributed pressure of variable intensity, arranged under the aircraft landing gear. The effect of the thickness and elastic modulus of the ice plate, takeoff and landing regimes on stress-strain state of the ice cover used as a runway.

  6. The effect of ice crystal shape on aircraft contrails

    NASA Astrophysics Data System (ADS)

    Meza Castillo, Omar E.

    Aircraft contrails are a common phenomenon observed in the sky. They are formed mainly of water, from the ambient atmosphere and as a by-product of the combustion process, in the form of ice crystals. They have been identified as a potential contributor to global warming. Some contrails can be long-lived and create man-made cloud cover, thus possibly altering the radiative balance of the earth. There has been a great deal of research on various aspects of contrail development, but to date, little has been done on the influence of ice crystal shapes on the contrail evolution. In-situ studies have reported that young contrails are mainly quasi-spherical crystals while older contrails can have a much more diverse spectrum of possible shapes. The most common shapes found in contrails are quasi-spherical, hexagonal columns, hexagonal plates, and bullet rosettes. Numerical simulations of contrails to date typically have assumed "spherical" as the default ice shape. This work simulated contrail development with a large eddy simulation (LES) model that implemented both spherical and non-spherical shapes to examine the effects. The included shape effect parameters, such as capacitance coefficient, ventilation factor, Kelvin effect, fall velocity and ice crystal surface area, help to establish the shape difference in the results. This study also investigated initial sensitivities to an additional ice parameter, the ice deposition coefficient. The literature shows conflicting values for this coefficient over a wide range. In the course of this investigation a comparison of various ice metrics was made for simulations with different assumed crystal shapes (spheres, hexagonal columns, hexagonal plates, bullet rosettes and combination of shapes). The simulations were performed at early and late contrail time, with a range of ice crystal sizes, and with/without coupled radiation. In young and older contrails and without coupled radiation, the difference from the shape effect in

  7. Daedalus Project's Light Eagle - Human powered aircraft

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Michelob Light Eagle is seen here in flight over Rogers Dry Lake at the NASA Dryden Flight Research Center, Edwards, California. The Light Eagle and Daedalus human powered aircraft were testbeds for flight research conducted at Dryden between January 1987 and March 1988. These unique aircraft were designed and constructed by a group of students, professors, and alumni of the Massachusetts Institute of Technology within the context of the Daedalus project. The construction of the Light Eagle and Daedalus aircraft was funded primarily by the Anheuser Busch and United Technologies Corporations, respectively, with additional support from the Smithsonian Air and Space Museum, MIT, and a number of other sponsors. To celebrate the Greek myth of Daedalus, the man who constructed wings of wax and feathers to escape King Minos, the Daedalus project began with the goal of designing, building and testing a human-powered aircraft that could fly the mythical distance, 115 km. To achieve this goal, three aircraft were constructed. The Light Eagle was the prototype aircraft, weighing 92 pounds. On January 22, 1987, it set a closed course distance record of 59 km, which still stands. Also in January of 1987, the Light Eagle was powered by Lois McCallin to set the straight distance, the distance around a closed circuit, and the duration world records for the female division in human powered vehicles. Following this success, two more aircraft were built, the Daedalus 87 and Daedalus 88. Each aircraft weighed approximately 69 pounds. The Daedalus 88 aircraft was the ship that flew the 199 km from the Iraklion Air Force Base on Crete in the Mediterranean Sea, to the island of Santorini in 3 hours, 54 minutes. In the process, the aircraft set new records in distance and endurance for a human powered aircraft. The specific areas of flight research conducted at Dryden included characterizing the rigid body and flexible dynamics of the Light Eagle, investigating sensors for an

  8. Performance degradation of a typical twin engine commuter type aircraft in measured natural icing conditions

    NASA Technical Reports Server (NTRS)

    Ranaudo, R. J.; Mikkelsen, K. L.; Mcknight, R. C.; Perkins, P. J., Jr.

    1984-01-01

    The performance of an aircraft in various measured icing conditions was investigated. Icing parameters such as liquid water content, temperature, cloud droplet sizes and distributions were measured continuously while in icing. Flight data were reduced to provide plots of the aircraft drag polars and lift curves (CL vs. alpha) for the measured ""iced'' condition as referenced to the uniced aircraft. These data were also reduced to provide plots of thrust horsepower required vs. single engine power available to show how icing affects engine out capability. It is found that performance degradation is primarily influenced by the amount and shape of the accumulated ice. Glaze icing caused the greatest aerodynamic performance penalties in terms of increased drag and reduction in lift while aerodynamic penalties due to rime icing were significantly lower.

  9. Smart skin technology development for measuring ice accretion, stall, and high AOA aircraft performance. Part 1: Capacitive ice detector development

    NASA Technical Reports Server (NTRS)

    Pruzan, Daniel A.; Khatkhate, Ateen A.; Gerardi, Joseph J.; Hickman, Gail A.

    1993-01-01

    A reliable way to detect and measure ice accretion during flight is required to reduce the hazards of icing currently threatening present day aircraft. Many of the sensors used for this purpose are invasive (probe) sensors which must be placed in areas of the airframe where ice does not naturally form. Due to the difference in capture efficiency of the exposed surface, difficulties result in correlating the ice accretion on the probe to what is happening on a number of vastly different airfoil sections. Most flush mounted sensors in use must be integrated into the aircraft surface by cutting or drilling the aircraft surface. An alternate type of ice detector which is based on a NASA patent is currently being investigated at Innovative Dynamics, Inc. (IDI). Results of the investigation into the performance of different capacitive type sensor designs, both rigid as well as elastic, are presented.

  10. Studying Ice Formation from Aircraft: Experimental Constraints on Techniques for Sampling Ice and Ice Forming Particles

    NASA Astrophysics Data System (ADS)

    Stith, J. L.

    2015-12-01

    A major experimental pathway to study the role of ice forming particles in clouds involves evaporating ice particles in a counterflow virtual impactor (CVI), measuring the residue with airborne instrumentation to determine the IFP concentration, and then comparing these concentrations with simultaneous measurements of ice concentrations, as determined from various types of instruments designed to measure hydrometeor concentrations. In order for these types of experiments to provide meaningful results, they must consider a number of factors, such as the impact of the CVI on the ice particles and the effects of probe tip shattering on the measurement of ice concentrations. These problems can be minimized by careful selection of sampling conditions and by studying the morphology of the sampled ice particles.

  11. Influence of color coatings on aircraft surface ice detection based on multi-wavelength imaging

    NASA Astrophysics Data System (ADS)

    Zhuge, Jing-chang; Yu, Zhi-jing; Gao, Jian-shu; Zheng, Da-chuan

    2016-03-01

    In this paper, a simple aircraft surface ice detection system is proposed based on multi-wavelength imaging. Its feasibility is proved by the experimental results. The influence of color coatings of aircraft surface is investigated. The results show that the ice area can be clearly distinguished from the red, white, gray and blue coatings painted aluminum plates. Due to the strong absorption, not enough signals can be detected for the black coatings. Thus, a deep research is needed. Even though, the results of this paper are helpful to the development of aircraft surface ice detection.

  12. 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.

  13. Use of Unmanned Aircraft Systems in Observations of Glaciers, Ice Sheets, Sea Ice and Snow Fields

    NASA Astrophysics Data System (ADS)

    Herzfeld Mayer, M. U.

    2015-12-01

    Unmanned Aircraft Systems (UAS) are being used increasingly in observations of the Earth, especially as such UAS become smaller, lighter and hence less expensive. In this paper, we present examples of observations of snow fields, glaciers and ice sheets and of sea ice in the Arctic that have been collected from UAS. We further examine possibilities for instrument miniaturization, using smaller UAS and smaller sensors for collecting data. The quality and type of data is compared to that of satellite observations, observations from manned aircraft and to measurements made during field experiments on the ground. For example, a small UAS can be sent out to observe a sudden event, such as a natural catastrophe, and provide high-resolution imagery, but a satellite has the advantage of providing the same type of data over much of the Earth's surface and for several years, but the data is generally of lower resolution. Data collected on the ground typically have the best control and quality, but the survey area is usually small. Here we compare micro-topographic measurements made on snow fields the Colorado Rocky Mountains with airborne and satellite data.

  14. Analysis of Microphysics Mechanisms in Icing Aircraft Events: A Case Study

    NASA Astrophysics Data System (ADS)

    Sanchez, Jose Luis; Fernández, Sergio; Gascón, Estibaliz; Weigand, Roberto; Hermida, Lucia; Lopez, Laura; García-Ortega, Eduardo

    2013-04-01

    The appearance of Supercooled Large Drops (SLD) can give way to icing aircraft. In these cases, atmospheric icing causes an unusual loss of support on the aircraft due to the rapid accumulation of ice on the wings or measurement instruments. There are two possible ways that SLD can be formed: The first is through a process called "warm nose", followed by "resupercooling". This process is usually associated with the entrance of warm fronts. The second possibility is that drops are formed by the process of condensation, and they grow, to sizes of at least 50 µm through processes of collision-coalescence, in environments with temperatures inferior to 0°C at all times, but without being able to produce a freezing process. Some authors point out that approximately 75% of gelling precipitation events are produced as a consequence of this second situation. Within the framework of the TECOAGUA Project, a series of scientific flights were performed in order to collect data in cloud systems capable of producing precipitation during the winter period and their capacity to create environments favorable to "icing aircraft". These flights were carried out making use of a C 212-200 aircraft, belonging to the National Institute of Aerospatial Techniques (INTA), with a CAPS installed. On 1 February 2012, the C 212-200 aircraft took off from the airport in Torrejón de Ardoz (Madrid), flying about 70 km to stand upright on the northern side of the Central System, finding itself at a flight level of 3500 m, an elevated concentration of SLD at temperatures around -12°C, with liquid water content up to 0.44 g/m3, which provoked the accumulation of ice on the outline of the aircraft's wings, which required a cancellation of the flight. Surrounding the flight area, a microwave radiometer (MWR) was installed. An area of instability between 750 hPa and 600 hPa was identified in the vertical MWR profiles of temperature and humidity during the hour of the flight. It is mainly in this

  15. Development of an ultrasonic pulse-echo (UPE) technique for aircraft icing studies

    SciTech Connect

    Liu, Yang; Hu, Hui; Chen, Wen-Li; Bond, Leonard J.

    2014-02-18

    Aircraft operating in some cold weather conditions face the risk of icing. Icing poses a threat to flight safety and its management is expensive. Removing light frost on a clear day from a medium-size business jet can cost $300, heavy wet snow removal can cost $3,000 and removal of accumulated frozen/freezing rain can cost close to $10,000. Understanding conditions that lead to severe icing events is important and challenging. When an aircraft or rotorcraft flies in a cold climate, some of the super cooled droplets impinging on exposed aircraft surfaces may flow along the surface prior to freezing and give various forms and shapes of ice. The runback behavior of a water film on an aircraft affects the morphology of ice accretion and the rate of formation. In this study, we report the recent progress to develop an Ultrasonic Pulse-Echo (UPE) technique to provide real-time thickness distribution measurements of surface water flows driven by boundary layer airflows for aircraft icing studies. A series of initial experimental investigations are conducted in an ice wind tunnel employing an array of ultrasonic transducers placed underneath the surface of a flat plate. The water runback behavior on the plate is evaluated by measuring the thickness profile variation of the water film along the surface by using the UPE technique under various wind speed and flow rate conditions.

  16. Alternative aircraft anti-icing formulations with reduced aquatic toxicity and biochemical oxygen demand

    USGS Publications Warehouse

    Gold, Harris; Joback, Kevin; Geis, Steven; Bowman, George; Mericas, Dean; Corsi, Steven R.; Ferguson, Lee

    2010-01-01

    The current research was conducted to identify alternative aircraft and pavement deicer and anti-icer formulations with improved environmental characteristics compared to currently used commercial products (2007). The environmental characteristics of primary concern are the biochemical oxygen demand (BOD) and aquatic toxicity of the fully formulated products. Except when the distinction among products is necessary for clarity, “deicer” will refer to aircraft-deicing fluids (ADFs), aircraft anti-icing fluids (AAFs), and pavementdeicing materials (PDMs).

  17. Nowcasting Aircraft Icing Conditions in the Presence of Multilayered Clouds Using Meteorological Satellite Data

    NASA Technical Reports Server (NTRS)

    Spangenberg, Douglas A.; Minnis, Patrick; Smith, William L.; Chang, Fu-Lung

    2011-01-01

    Cloud properties retrieved from satellite data are used to diagnose aircraft icing threat in single layer and multilayered ice-over-liquid clouds. The algorithms are being applied in real time to the Geostationary Operational Environmental Satellite (GOES) data over the CONUS with multilayer data available over the eastern CONUS. METEOSAT data are also used to retrieve icing conditions over western Europe. The icing algorithm s methodology and validation are discussed along with future enhancements and plans. The icing risk product is available in image and digital formats on NASA Langley s Cloud and Radiation Products web site, http://wwwangler. larc.nasa.gov.

  18. Concurrent remote sensing of Arctic sea ice from submarine and aircraft

    NASA Technical Reports Server (NTRS)

    Wadhams, P.; Davis, N. R.; Comiso, J. C.; Kutz, R.; Crawford, J.; Jackson, G.; Krabill, W.; Sear, C. B.; Swift, R.; Tucker, W. B., III

    1991-01-01

    In May 1987 a concurrent remote sensing study of Arctic sea ice from above and below was carried out. A submarine equipped with sidescan and upward looking sonar collaborated with two remote sensing aircraft equipped with passive microwave, synthetic aperture radar (SAR), a laser profilometer and an infrared radiometer. By careful registration of the three tracks it has been possible to find relationships between ice type, ice morphology and thickness, SAR backscatter and microwave brightness temperatures. The key to the process has been the sidescan sonar's ability to identify ice type through differences in characteristic topography. Over a heavily ridged area of mainly multiyear ice there is a strong positive correlation between SAR backscatter and ice draft or elevation. It was also found that passive and active microwave complement each other in that SAR has a high contrast between open water and multiyear ice, while passive microwave has a high contrast between open water and first-year ice.

  19. In-situ aircraft observations of ice concentrations within clouds over the Antarctic Peninsula and Larsen Ice Shelf

    NASA Astrophysics Data System (ADS)

    Grosvenor, D. P.; Choularton, T. W.; Lachlan-Cope, T.; Gallagher, M. W.; Crosier, J.; Bower, K. N.; Ladkin, R. S.; Dorsey, J. R.

    2012-07-01

    In-situ aircraft observations of ice crystal concentrations in Antarctic clouds are presented for the first time. Orographic, layer and wave clouds around the Antarctic Peninsula and Larsen Ice shelf regions were penetrated by the British Antarctic Survey's Twin Otter Aircraft, which was equipped with modern cloud physics probes. The clouds studied were mostly in the free troposphere and hence ice crystals blown from the surface are unlikely to have been a major source for the ice phase. The temperature range covered by the experiments was 0 to -21°C. The clouds were found to contain supercooled liquid water in most regions and at heterogeneous ice formation temperatures ice crystal concentrations (60 s averages) were often less than 0.07 l-1, although values up to 0.22 l-1 were observed. Estimates of observed aerosol concentrations were used as input into the DeMott et al., 2010 ice nuclei (IN) parameterisation. The observed ice crystal number concentrations were generally in broad agreement with the IN predictions, although on the whole the predicted values were higher. Possible reasons for this are discussed and include the lack of IN observations in this region with which to characterise the parameterisation, and/or problems in relating ice concentration measurements to IN concentrations. Other IN parameterisations significantly overestimated the number of ice particles. Generally ice particle concentrations were much lower than found in clouds in middle latitudes for a given temperature. Higher ice crystal concentrations were sometimes observed at temperatures warmer than -9 °C, with values of several per litre reached. These were attributable to secondary ice particle production by the Hallett Mossop process. Even in this temperature range it was observed that there were regions with little or no ice that were dominated by supercooled liquid water. It is likely that in some cases this was due to a lack of seeding ice crystals to act as rimers to initiate

  20. In-situ aircraft observations of ice concentrations within clouds over the Antarctic Peninsula and Larsen Ice Shelf

    NASA Astrophysics Data System (ADS)

    Grosvenor, D. P.; Choularton, T. W.; Lachlan-Cope, T.; Gallagher, M. W.; Crosier, J.; Bower, K. N.; Ladkin, R. S.; Dorsey, J. R.

    2012-12-01

    In-situ aircraft observations of ice crystal concentrations in Antarctic clouds are presented for the first time. Orographic, layer and wave clouds around the Antarctic Peninsula and Larsen Ice shelf regions were penetrated by the British Antarctic Survey's Twin Otter aircraft, which was equipped with modern cloud physics probes. The clouds studied were mostly in the free troposphere and hence ice crystals blown from the surface are unlikely to have been a major source for the ice phase. The temperature range covered by the experiments was 0 to -21 °C. The clouds were found to contain supercooled liquid water in most regions and at heterogeneous ice formation temperatures ice crystal concentrations (60 s averages) were often less than 0.07 l-1, although values up to 0.22 l-1 were observed. Estimates of observed aerosol concentrations were used as input into the DeMott et al. (2010) ice nuclei (IN) parameterisation. The observed ice crystal number concentrations were generally in broad agreement with the IN predictions, although on the whole the predicted values were higher. Possible reasons for this are discussed and include the lack of IN observations in this region with which to characterise the parameterisation, and/or problems in relating ice concentration measurements to IN concentrations. Other IN parameterisations significantly overestimated the number of ice particles. Generally ice particle concentrations were much lower than found in clouds in middle latitudes for a given temperature. Higher ice crystal concentrations were sometimes observed at temperatures warmer than -9 °C, with values of several per litre reached. These were attributable to secondary ice particle production by the Hallett Mossop process. Even in this temperature range it was observed that there were regions with little or no ice that were dominated by supercooled liquid water. It is likely that in some cases this was due to a lack of seeding ice crystals to act as rimers to initiate

  1. Current Methods for Modeling and Simulating Icing Effects on Aircraft Performance, Stability and Control

    NASA Technical Reports Server (NTRS)

    Ralvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam

    2008-01-01

    Icing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to the performance changes, icing can also affect control surface effectiveness, hinge moments, and damping. These effects result in altered aircraft stability and control and flying qualities. Over the past 80 years, methods have been developed to understand how icing affects performance, stability and control. Emphasis has been on wind tunnel testing of two-dimensional subscale airfoils with various ice shapes to understand their effect on the flow field and ultimately the aerodynamics. This research has led to wind tunnel testing of subscale complete aircraft models to identify the integrated effects of icing on the aircraft system in terms of performance, stability, and control. Data sets of this nature enable pilot in the loop simulations to be performed for pilot training, or engineering evaluation of system failure impacts or control system design.

  2. Current Methods Modeling and Simulating Icing Effects on Aircraft Performance, Stability, Control

    NASA Technical Reports Server (NTRS)

    Ratvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam

    2010-01-01

    Icing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to the performance changes, icing can also affect control surface effectiveness, hinge moments, and damping. These effects result in altered aircraft stability and control and flying qualities. Over the past 80 years, methods have been developed to understand how icing affects performance, stability, and control. Emphasis has been on wind-tunnel testing of two-dimensional subscale airfoils with various ice shapes to understand their effect on the flowfield and ultimately the aerodynamics. This research has led to wind-tunnel testing of subscale complete aircraft models to identify the integrated effects of icing on the aircraft system in terms of performance, stability, and control. Data sets of this nature enable pilot-in-the-loop simulations to be performed for pilot training or engineering evaluation of system failure impacts or control system design.

  3. Analysis of surface roughness generation in aircraft ice accretion

    NASA Technical Reports Server (NTRS)

    Hansman, R. J., Jr.; Reehorst, Andrew; Sims, James

    1992-01-01

    Patterns of roughness evolution have been studied analysis of high magnification video observations of accreting ice surfaces provided by the NASA Lewis Research Center. Three distinct patterns of surface roughness generation have been identified within the parametric regions studied. They include: Rime, Multi-Zone Glaze, and Uniform Glaze. Under most icing conditions, a brief period of transient rime ice growth was observed caused by heat conduction into the body. The resulting thin rime layer explains previously observed insensitivity of some ice accretions to substrate insensitivity of some ice accretions to substrate surface chemistry and may provide justification for simplifying assumptions in ice accretion sailing and modeling effects.

  4. National Unmanned Aircraft Systems Project Office

    USGS Publications Warehouse

    Goplen, Susan E.; Sloan, Jeff L.

    2015-01-01

    The U.S. Geological Survey (USGS) National Unmanned Aircraft Systems (UAS) Project Office leads the implementation of UAS technology in the Department of the Interior (DOI). Our mission is to support the transition of UAS into DOI as a new cost-effective tool for collecting remote-sensing data to monitor environmental conditions, respond to natural hazards, recognize the consequences and benefits of land and climate change and conduct wildlife inventories. The USGS is teaming with all DOI agencies and academia as well as local, State, and Tribal governments with guidance from the Federal Aviation Administration and the DOI Office of Aviation Services (OAS) to lead the safe, efficient, costeffective and leading-edge adoption of UAS technology into the scientific research and operational activities of the DOI.

  5. Experimental evidence for modifying the current physical model for ice accretion on aircraft surfaces

    NASA Technical Reports Server (NTRS)

    Olsen, W.; Walker, E.

    1986-01-01

    Closeup movies, still photographs, and other experimental data suggest that the current physical model for ice accretion needs significant modification. At aircraft airspeeds there was no flow of liquid over the surface of the ice after a short initial flow, even at barely subfreezing temperatures. Instead, there were very large stationary drops on the ice surface that lose water from their bottoms by freezing and replenish their liquid by catching the microscopic cloud droplets. This observation disagrees with the existing physical model, which assumes there is a thin liquid film continuously flowing over the ice surface. With no such flow, the freezing-fraction concept of the model fails when a mass balance is performed on the surface water. Rime ice does, as the model predicts, form when the air temperature is low enough to cause the cloud droplets to freeze almost immediately on impact. However, the characteristic shapes of horn-glaze ice or rime ice are primarily caused by the ice shape affecting the airflow locally and consequently the droplet catch and the resulting ice shape. Ice roughness greatly increases the heat transfer coefficient, stops the movement of drops along the surface, and may also affect the airflow initially and thereby the droplet catch. At high subreezing temperatures the initial flow and shedding of surface drops have a large effect on the ice shape. At the incipient freezing limit, no ice forms.

  6. Discrete Surface Evolution and Mesh Deformation for Aircraft Icing Applications

    NASA Technical Reports Server (NTRS)

    Thompson, David; Tong, Xiaoling; Arnoldus, Qiuhan; Collins, Eric; McLaurin, David; Luke, Edward; Bidwell, Colin S.

    2013-01-01

    Robust, automated mesh generation for problems with deforming geometries, such as ice accreting on aerodynamic surfaces, remains a challenging problem. Here we describe a technique to deform a discrete surface as it evolves due to the accretion of ice. The surface evolution algorithm is based on a smoothed, face-offsetting approach. We also describe a fast algebraic technique to propagate the computed surface deformations into the surrounding volume mesh while maintaining geometric mesh quality. Preliminary results presented here demonstrate the ecacy of the approach for a sphere with a prescribed accretion rate, a rime ice accretion, and a more complex glaze ice accretion.

  7. Catalog of Media Resources. Project ICE.

    ERIC Educational Resources Information Center

    Project I-C-E, Green Bay, WI.

    This guide is a list of available environmental education materials from the Project I-C-E Resource Materials Center. A one-page guide explaining procedures for using the Resource Center services is provided. It contains the service charges for shipping and handling, check-out periods, those who may use the resources, ordering instructions,…

  8. Ice Load Project Final Technical Report

    SciTech Connect

    McCoy, Timothy J.; Brown, Thomas; Byrne, Alex

    2014-10-30

    As interest and investment in offshore wind projects increase worldwide, some turbines will be installed in locations where ice of significant thickness forms on the water surface. This ice moves under the driving forces of wind, current, and thermal effects and may result in substantial forces on bottom-fixed support structures. The North and Baltic Seas in Europe have begun to see significant wind energy development and the Great Lakes of the United States and Canada may host wind energy development in the near future. Design of the support structures for these projects is best performed through the use of an integrated tool that can calculate the cumulative effects of forces due to turbine operations, wind, waves, and floating ice. The dynamic nature of ice forces requires that these forces be included in the design simulations, rather than added as static forces to simulation results. The International Electrotechnical Commission (IEC) standard[2] for offshore wind turbine design and the International Organization for Standardization (ISO) standard[3] for offshore structures provide requirements and algorithms for the calculation of forces induced by surface ice; however, currently none of the major wind turbine dynamic simulation codes provides the ability to model ice loads. The scope of work of the project described in this report includes the development of a suite of subroutines, collectively named IceFloe, that meet the requirements of the IEC and ISO standards and couples with four of the major wind turbine dynamic simulation codes. The mechanisms by which ice forces impinge on offshore structures generally include the forces required for crushing of the ice against vertical-sided structures and the forces required to fracture the ice as it rides up on conical-sided structures. Within these two broad categories, the dynamic character of the forces with respect to time is also dependent on other factors such as the velocity and thickness of the moving ice

  9. Sea Ice Topography Profiling using Laser Altimetry from Small Unmanned Aircraft Systems

    NASA Astrophysics Data System (ADS)

    Crocker, Roger Ian

    Arctic sea ice is undergoing a dramatic transition from a perennial ice pack with a high prevalence of old multiyear ice, to a predominantly seasonal ice pack comprised primarily of young first-year and second-year ice. This transition has brought about changes in the sea ice thickness and topography characteristics, which will further affect the evolution and survivability of the ice pack. The varying ice conditions have substantial implications for commercial operations, international affairs, regional and global climate, our ability to model climate dynamics, and the livelihood of Arctic inhabitants. A number of satellite and airborne missions are dedicated to monitoring sea ice, but they are limited by their spatial and temporal resolution and coverage. Given the fast rate of sea ice change and its pervasive implications, enhanced observational capabilities are needed to augment the current strategies. The CU Laser Profilometer and Imaging System (CULPIS) is designed specifically for collecting fine-resolution elevation data and imagery from small unmanned aircraft systems (UAS), and has a great potential to compliment ongoing missions. This altimeter system has been integrated into four different UAS, and has been deployed during Arctic and Antarctic science campaigns. The CULPIS elevation measurement accuracy is shown to be 95±25 cm, and is limited primarily by GPS positioning error (<25 cm), aircraft attitude determination error (<20 cm), and sensor misalignment error (<20 cm). The relative error is considerably smaller over short flight distances, and the measurement precision is shown to be <10 cm over a distance of 200 m. Given its fine precision, the CULPIS is well suited for measuring sea ice topography, and observed ridge height and ridge separation distributions are found to agree with theoretical distributions to within 5%. Simulations demonstrate the inability of course-resolution measurements to accurately represent the theoretical distributions

  10. Aircraft-Produced Ice Particles (APIPs): Additional Results and Further Insights.

    NASA Astrophysics Data System (ADS)

    Woodley, William L.; Gordon, Glenn; Henderson, Thomas J.; Vonnegut, Bernard; Rosenfeld, Daniel; Detwiler, Andrew

    2003-05-01

    This paper presents new results from studies of aircraft-produced ice particles (APIPs) in supercooled fog and clouds. Nine aircraft, including a Beech King Air 200T cloud physics aircraft, a Piper Aztec, a Cessna 421-C, two North American T-28s, an Aero Commander, a Piper Navajo, a Beech Turbo Baron, and a second four-bladed King Air were involved in the tests. The instrumented King Air served as the monitoring aircraft for trails of ice particles created, or not created, when the other aircraft were flown through clouds at various temperatures and served as both the test and monitoring aircraft when it itself was tested. In some cases sulfur hexafluoride (SF6) gas was released by the test aircraft during its test run and was detected by the King Air during its monitoring passes to confirm the location of the test aircraft wake. Ambient temperatures for the tests ranged between 5° and 12°C. The results confirm earlier published results and provide further insights into the APIPs phenomenon. The King Air at ambient temperatures less than 8°C can produce APIPs readily. The Piper Aztec and the Aero Commander also produced APIPs under the test conditions in which they were flown. The Cessna 421, Piper Navajo, and Beech Turbo Baron did not. The APIPs production potential of a T-28 is still indeterminate because a limited range of conditions was tested. Homogeneous nucleation in the adiabatically cooled regions where air is expanding around the rapidly rotating propeller tips is the cause of APIPs. An equation involving the propeller efficiency, engine thrust, and true airspeed of the aircraft is used along with the published thrust characteristics of the propellers to predict when the aircraft will produce APIPs. In most cases the predictions agree well with the field tests. Of all of the aircraft tested, the Piper Aztec, despite its small size and low horsepower, was predicted to be the most prolific producer of APIPs, and this was confirmed in field tests. The

  11. Near-Real Time Cloud Properties and Aircraft Icing Indices from GEO and LEO Satellites

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Smith, William L., Jr.; Nguyen, Louis; Spangenberg, D. A.; Heck, Patrick W.; Palikonda, Rabindra; Ayers, J. Kirk; Wolff, Cory; Murray, John J.

    2004-01-01

    Imagers on many of the current and future operational meteorological satellites in geostationary Earth orbit (GEO) and lower Earth orbit (LEO) have enough spectral channels to derive cloud microphysical properties useful for a variety of applications. The products include cloud amount, phase, optical depth, temperature, height and pressure, thickness, effective particle size, and ice or liquid water path, shortwave albedo, and outgoing longwave radiation for each imager pixel. Because aircraft icing depends on cloud temperature, droplet size, and liquid water content as well as aircraft variables, it is possible to estimate the potential icing conditions from the cloud phase, temperature, effective droplet size, and liquid water path. A prototype icing index is currently being derived over the contiguous USA in near-real time from Geostationary Operational Environmental Satellite (GOES-10 and 12) data on a half-hourly basis and from NOAA- 16 Advanced Very High Resolution (AVHRR) data when available. Because the threshold-based algorithm is sensitive to small errors and differences in satellite imager and icing is complex process, a new probability based icing diagnosis technique is developed from a limited set of pilot reports. The algorithm produces reasonable patterns of icing probability and intensities when compared with independent model and pilot report data. Methods are discussed for improving the technique for incorporation into operational icing products.

  12. The measurement of aircraft performance and stability and control after flight through natural icing conditions

    NASA Technical Reports Server (NTRS)

    Ranaudo, R. J.; Mikkelsen, K. L.; Mcknight, R. C.; Ide, R. F.; Reehorst, A. L.; Jordan, J. L.; Schinstock, W. C.; Platz, S. J.

    1986-01-01

    The effects of airframe icing on the performance and stability and control of a twin-engine commuter-class aircraft were measured by the NASA Lewis Research Center. This work consisted of clear air tests with artificial ice shapes attached to the horizontal tail, and natural icing flight tests in measured icing clouds. The clear air tests employed static longitudinal flight test methods to determine degradation in stability margins for four simulated ice shapes. The natural icing flight tests employed a data acquisition system, which was provided under contract to NASA by Kohlman Systems Research Incorporated. This system used a performance modeling method and modified maximum likelihood estimation (MMLE) technique to determine aircraft performance degradation and stability and control. Flight test results with artificial ice shapes showed that longitudinal, stick-fixed, static margins are reduced on the order of 5 percent with flaps up. Natural icing tests with the KSR system corroborated these results and showed degradation in the elevator control derivatives on the order of 8 to 16 percent depending on wing flap configuration. Performance analyses showed the individual contributions of major airframe components to the overall degration in lift and drag.

  13. The measurement of aircraft performance and stability and control after flight through natural icing conditions

    NASA Technical Reports Server (NTRS)

    Ranaudo, R. J.; Mikkelsen, K. L.; Mcknight, R. C.; Ide, R. F.; Reehorst, A. L.

    1986-01-01

    The effects of airframe icing on the performance and stability and control of a twin-engine commuter-class aircraft were measured by the NASA Lewis Research Center. This work consisted of clear air tests with artificial ice shapes attached to the horizontal tail, and natural icing flight tests in measured icing clouds. The clear air tests employed static longitudinal flight test methods to determine degradation in stability margins for four simulated ice shapes. The natural icing flight tests employed a data acquisition system, which was provided under contract to NASA by Kohlman Systems Research Incorporated. This system used a performance modeling method and modified maximum likelihood estimation (MMLE) technique to determine aircraft performance degradation and stability and control. Flight test results with artificial ice shapes showed that longitudinal, stick-fixed, static margins are reduced on the order of 5 percent with flaps up. Natural icing tests with the KSR system corroborated these results and showed degradation in the elevator control derivatives on the order of 8 to 16 percent depending on wing flap configuration. Performance analyses showed the individual contributions of major airframe components to the overall degradation in lift and drag.

  14. 'Scaling' analysis of the ice accretion process on aircraft surfaces

    NASA Technical Reports Server (NTRS)

    Keshock, E. G.; Tabrizi, A. H.; Missimer, J. R.

    1982-01-01

    A comprehensive set of scaling parameters is developed for the ice accretion process by analyzing the energy equations of the dynamic freezing zone and the already frozen ice layer, the continuity equation associated with supercooled liquid droplets entering into and impacting within the dynamic freezing zone, and energy equation of the ice layer. No initial arbitrary judgments are made regarding the relative magnitudes of each of the terms. The method of intrinsic reference variables in employed in order to develop the appropriate scaling parameters and their relative significance in rime icing conditions in an orderly process, rather than utilizing empiricism. The significance of these parameters is examined and the parameters are combined with scaling criteria related to droplet trajectory similitude.

  15. A NASA/University/Industry Consortium for Research on Aircraft Ice Protection

    NASA Technical Reports Server (NTRS)

    Zumwalt, Glen W.

    1989-01-01

    From 1982 through 1987, an unique consortium was functioning which involved government (NASA), academia (Wichita State Univ.) and twelve industries. The purpose was the development of a better ice protection systems for aircraft. The circumstances which brought about this activity are described, the formation and operation recounted, and the effectiveness of the ventue evaluated.

  16. 6. Looking glass aircraft in the project looking glass historic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Looking glass aircraft in the project looking glass historic district. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Avenue between Comstat Drive & Nightwatch Avenue, Offutt Air Force Base, Bellevue, Sarpy County, NE

  17. The NASA IceBridge Project Quickly Delivers Snow and Ice Elevation Measurements of Dynamic Polar Landscapes

    NASA Astrophysics Data System (ADS)

    Tressel, S. S.; Kaminski, M. L.; Brodzik, M.

    2012-12-01

    NASA's Operation IceBridge was formulated to bridge the gap between the ICESat and ICESat-2 satellite missions. IceBridge data are collected by a wide variety of instrumentation aboard aircraft that trace routes around Greenland, Alaska and Antarctica, concentrating on areas experiencing accelerated change. Data parameters such as ice surface elevation, ice bottom elevation, snow and ice depth, grounding line position, sea ice distribution and freeboard are extracted at resolutions better than what can be expected by satellite. IceBridge provides the continuity of such data until the launch of the ICESat-2 satellite, expected in 2016. NSIDC manages the data distribution and makes the data available quickly and effectively to any and all interested parties. For example, the MCoRDS L1B Geolocated Radar Echo Strength Profiles data represents one of 60 total data products available through the IceBridge project. The MCoRDS L1B data for the Greenland 2012 campaign exhibit ice surface and ice bottom information for areas of Greenland between 27 March 2012 and 17 May 2012. In July of 2012, these data were made available on the NSIDC Web site, allowing users to begin analyzing the data only a couple of months after the data collection. The data are distributed in MATLAB files with associated PDF, TIFF and PNG files. Comparable data are available starting in 2009 for periodic campaigns covering both Greenland and Antarctica. These data can be combined with an array of other parameters to track the state of the most crucial areas of the Earth's cryosphere.

  18. Close-up analysis of aircraft ice accretion

    NASA Technical Reports Server (NTRS)

    Hansman, R. John; Breuer, Kenneth S.; Hazan, Didier; Reehorst, Andrew; Vargas, Mario

    1993-01-01

    Various types of ice formation have been studied by analysis of high magnification video observations. All testing was conducted in the NASA Lewis Icing Research Tunnel (IRT). A faired 8.9 cm (3.5 in.) diameter metal-clad cylinder and a 5.1 (2 in.) aluminum cylinder were observed by close-up and overview video cameras for several wind tunnel conditions. These included close-up grazing angle, close-up side view, as well as overhead and side overview cameras. Still photographs were taken at the end of each spray along with tracings of the subsequent ice shape. While in earlier tests only the stagnation region was observed, the entire area from the stagnation line to the horn region of glaze ice shapes was observed in this test. The modes or horn formation have been identified within the range of conditions observed. In the horn region, Horn Type A ice is formed by 'dry' feather growth into the flow direction and Horn Type B is formed by a 'wet' growth normal to the surface. The feather growth occurs when the freezing fraction is near unity and roughness elements exist to provide an initial growth site.

  19. Estimation of longitudinal stability and control derivatives for an icing research aircraft from flight data

    NASA Technical Reports Server (NTRS)

    Batterson, James G.; Omara, Thomas M.

    1989-01-01

    The results of applying a modified stepwise regression algorithm and a maximum likelihood algorithm to flight data from a twin-engine commuter-class icing research aircraft are presented. The results are in the form of body-axis stability and control derivatives related to the short-period, longitudinal motion of the aircraft. Data were analyzed for the baseline (uniced) and for the airplane with an artificial glaze ice shape attached to the leading edge of the horizontal tail. The results are discussed as to the accuracy of the derivative estimates and the difference between the derivative values found for the baseline and the iced airplane. Additional comparisons were made between the maximum likelihood results and the modified stepwise regression results with causes for any discrepancies postulated.

  20. Lewis icing research tunnel test of the aerodynamic effects of aircraft ground deicing/anti-icing fluids

    NASA Technical Reports Server (NTRS)

    Runyan, L. James; Zierten, Thomas A.; Hill, Eugene G.; Addy, Harold E., Jr.

    1992-01-01

    A wind tunnel investigation of the effect of aircraft ground deicing/anti-icing fluids on the aerodynamic characteristics of a Boeing 737-200ADV airplane was conducted. The test was carried out in the NASA Lewis Icing Research Tunnel. Fluids tested include a Newtonian deicing fluid, three non-Newtonian anti-icing fluids commercially available during or before 1988, and eight new experimental non-Newtonian fluids developed by four fluid manufacturers. The results show that fluids remain on the wind after liftoff and cause a measurable lift loss and drag increase. These effects are dependent on the high-lift configuration and on the temperature. For a configuration with a high-lift leading-edge device, the fluid effect is largest at the maximum lift condition. The fluid aerodynamic effects are related to the magnitude of the fluid surface roughness, particularly in the first 30 percent chord. The experimental fluids show a significant reduction in aerodynamic effects.

  1. Development of Three-Dimensional Flow Code Package to Predict Performance and Stability of Aircraft with Leading Edge Ice Contamination

    NASA Technical Reports Server (NTRS)

    Strash, D. J.; Summa, J. M.

    1996-01-01

    In the work reported herein, a simplified, uncoupled, zonal procedure is utilized to assess the capability of numerically simulating icing effects on a Boeing 727-200 aircraft. The computational approach combines potential flow plus boundary layer simulations by VSAERO for the un-iced aircraft forces and moments with Navier-Stokes simulations by NPARC for the incremental forces and moments due to iced components. These are compared with wind tunnel force and moment data, supplied by the Boeing Company, examining longitudinal flight characteristics. Grid refinement improved the local flow features over previously reported work with no appreciable difference in the incremental ice effect. The computed lift curve slope with and without empennage ice matches the experimental value to within 1%, and the zero lift angle agrees to within 0.2 of a degree. The computed slope of the un-iced and iced aircraft longitudinal stability curve is within about 2% of the test data. This work demonstrates the feasibility of a zonal method for the icing analysis of complete aircraft or isolated components within the linear angle of attack range. In fact, this zonal technique has allowed for the viscous analysis of a complete aircraft with ice which is currently not otherwise considered tractable.

  2. The PHOCUS Project: Mesospheric Ice Particle Properties

    NASA Astrophysics Data System (ADS)

    Khaplanov, M.; Hedin, J.; Gumbel, J.

    2012-12-01

    On the morning of July 21, 2011, the PHOCUS sounding rocket was launched from Esrange, Sweden, intostrong noctilucent clouds (NLC) and polar mesosphere summer echoes (PMSE). The aim of the PHOCUS project (Particles, Hydrogen and Oxygen Chemistry in the Upper Summer mesosphere) is to study mesospheric particles (ice and meteoric smoke) and their interaction with their neutral and charged environment. Interactions of interest comprise the charging and nucleation of particles, the relationship between meteoric smoke and ice, and the influence of these particles on gas-phase chemistry. Here we will describe the optical measurements of the ice particlesand present first results including comparison to the other simultaneous measurements.Ice particle properties were probed with a set of three NLC photometers from Stockholm University. NLC photometry is currently the best technique available for determining altitude ranges of NLC in situ. At the same time, UV photometry allows a study of particle properties like size and shape by analysing the spectral dependence (colour ratio), angle dependence (phase function), and polarisation of the scattering. The set of NLC photometer flown on PHOCUS was a unique photometer package that for the first time investigated all three parameters simultaneously. Two forward-viewing photometers measured at different wavelengths (one in the UV at 220 nm and the other in the visible at 440 nm) and were both equipped with fixed linear polarisers. The payload spin was utilised to scan through the polarisation direction, thus providing us with the Stokes vectors I, Q and U at both wavelengths. The third photometer (also measured in the UV at 220 nm)was mounted sideways, viewing the overhead sky at an angle of 40°from the rocket spin axis. Due to the payload spin, the NLC was observed under varying scattering geometries as the payload approached the cloud layer. Thus, this set of NLC photometers provided a complete optical characterization of the

  3. Comparisons of cloud ice mass content retrieved from the radar-infrared radiometer method with aircraft data during the second international satellite cloud climatology project regional experiment (FIRE-II)

    SciTech Connect

    Matrosov, S.Y. |; Heymsfield, A.J.; Kropfli, R.A.; Snider, J.B.

    1996-04-01

    Comparisons of remotely sensed meteorological parameters with in situ direct measurements always present a challenge. Matching sampling volumes is one of the main problems for such comparisons. Aircraft usually collect data when flying along a horizontal leg at a speed of about 100 m/sec (or even greater). The usual sampling time of 5 seconds provides an average horizontal resolution of the order of 500 m. Estimations of vertical profiles of cloud microphysical parameters from aircraft measurements are hampered by sampling a cloud at various altitudes at different times. This paper describes the accuracy of aircraft horizontal and vertical coordinates relative to the location of the ground-based instruments.

  4. Ice Shape Scaling for Aircraft in SLD Conditions

    NASA Technical Reports Server (NTRS)

    Anderson, David N.; Tsao, Jen-Ching

    2008-01-01

    This paper has summarized recent NASA research into scaling of SLD conditions with data from both SLD and Appendix C tests. Scaling results obtained by applying existing scaling methods for size and test-condition scaling will be reviewed. Large feather growth issues, including scaling approaches, will be discussed briefly. The material included applies only to unprotected, unswept geometries. Within the limits of the conditions tested to date, the results show that the similarity parameters needed for Appendix C scaling also can be used for SLD scaling, and no additional parameters are required. These results were based on visual comparisons of reference and scale ice shapes. Nearly all of the experimental results presented have been obtained in sea-level tunnels. The currently recommended methods to scale model size, icing limit and test conditions are described.

  5. Root damage analysis of aircraft engine blade subject to ice impact

    NASA Technical Reports Server (NTRS)

    Reddy, E. S.; Abumeri, G. H.; Chamis, C. C.; Murthy, P. L. N.

    1992-01-01

    The blade root response due to ice impact on an engine blade is simulated using the NASA in-house code BLASIM. The ice piece is modeled as an equivalent spherical object impacting on the leading edge of the blade and has the velocity opposite to that of the aircraft with direction parallel to the engine axis. The effect of ice impact is considered to be an impulse load on the blade with its amplitude computed based on the momentum transfer principle. The blade response due to the impact is carried out by modal superposition using the first three modes. The maximum dynamic stresses at the blade root are computed at the quarter cycle of the first natural frequency. A combined stress failure function based on modified distortion energy is used to study the spanwise bending damage response at the blade root. That damage function reaches maximum value for very low ice speeds and increases steeply with increases in engine speed.

  6. Current Icing Potential: Algorithm Description and Comparison with Aircraft Observations.

    NASA Astrophysics Data System (ADS)

    Bernstein, Ben C.; McDonough, Frank; Politovich, Marcia K.; Brown, Barbara G.; Ratvasky, Thomas P.; Miller, Dean R.; Wolff, Cory A.; Cunning, Gary

    2005-07-01

    The “current icing potential” (CIP) algorithm combines satellite, radar, surface, lightning, and pilot-report observations with model output to create a detailed three-dimensional hourly diagnosis of the potential for the existence of icing and supercooled large droplets. It uses a physically based situational approach that is derived from basic and applied cloud physics, combined with forecaster and onboard flight experience from field programs. Both fuzzy logic and decision-tree logic are applied in this context. CIP determines the locations of clouds and precipitation and then estimates the potential for the presence of supercooled liquid water and supercooled large droplets within a given airspace. First developed in the winter of 1997/98, CIP became an operational National Weather Service and Federal Aviation Administration product in 2002, providing real-time diagnoses that allow users to make route-specific decisions to avoid potentially hazardous icing. The CIP algorithm, its individual components, and the logic behind them are described.

  7. Comparison of TWP-ICE Satellite and Field Campaign Aircraft Derived Cloud Properties

    NASA Technical Reports Server (NTRS)

    Ayers, J. K.; Minnis, Patrick; Spangenberg, Douglas A.; Nordeen, Michele L.; Khaiyer, Mandana M.; Palikonda, Rabindra; Nguyen, Louis; Phan, Dung N.

    2007-01-01

    Cloud and radiation products derived from the MTSAT-1R satellite have been developed for TWP-ICE. These include pixel-level, gridded, and ground site and aircraft matched. These products are available from the Langley website and the ARM data center. As shown in Figs 2, and 4-6, these products compare favorably with in-situ ground and aircraft based measurements. With additional quantitative validation these products can provide valuable information about tropical convection and its impact on the radiation budget and climate. As new algorithm improvements, such as multi-layer cloud detection, are implemented these products will be reprocessed and updated.

  8. Flying Qualities Evaluation of a Commuter Aircraft With an Ice Contaminated Tailplane

    NASA Technical Reports Server (NTRS)

    Ranaudo, Richard J.; Ratvasky, Thomas P.; FossVanZante, Judith

    2000-01-01

    During the NASA/FAA (Federal Aviation Administration) Tailplane Icing Program, pilot evaluations of aircraft flying qualities were conducted with various ice shapes attached to the horizontal tailplane of the NASA Twin Otter Icing Research Aircraft. Initially, only NASA pilots conducted these evaluations, assessing the differences in longitudinal flight characteristics between the baseline or clean aircraft, and the aircraft configured with an Ice Contaminated Tailplane (ICT). Longitudinal tests included Constant Airspeed Flap Transitions, Constant Airspeed Thrust Transitions, zero-G Pushovers, Repeat Elevator Doublets, and Simulated Approach and Go-Around tasks. Later in the program, guest pilots from government and industry were invited to fly the NASA Twin Otter configured with a single full-span artificial ice shape attached to the leading edge of the horizontal tailplane. This shape represented ice formed due to a 'Failed Boot' condition, and was generated from tests in the Glenn Icing Research Tunnel on a full-scale tailplane model. Guest pilots performed longitudinal handling tests, similar to those conducted by the NASA pilots, to evaluate the ICT condition. In general, all pilots agreed that longitudinal flying qualities were degraded as flaps were lowered, and further degraded at high thrust settings. Repeat elevator doublets demonstrated reduced pitch damping effects due to ICT, which is a characteristic that results in degraded flying qualities. Pilots identified elevator control force reversals (CFR) in zero-G pushovers at a 20 deg flap setting, a characteristic that fails the FAR 25 no CFR certification requirement. However, when the same pilots used the Cooper-Harper rating scale to perform a simulated approach and go-around task at the 20 deg flap setting, they rated the airplane as having Level I and Level II flying qualities respectively. By comparison, the same task conducted at the 30 deg flap setting, resulted in Level II flying qualities for

  9. Satellite and aircraft passive microwave observations during the Marginal Ice Zone Experiment in 1984

    NASA Astrophysics Data System (ADS)

    Gloersen, Per; Campbell, William J.

    1988-06-01

    During the Marginal Ice Zone Experiment in the Fram Strait in June-July 1984, a number of aircraft with microwave sensors and the scanning multichannel microwave radiometer (SMMR) on board the Nimbus 7 satellite were used to acquire large-scale and mesoscale ice-ocean observations in conjunction with local surface measurements made by experimenters based on helicopter-equipped ice-strengthened vessels. An analysis of the data acquired during six flights of one such aircraft, the NASA CV-990 airborne laboratory, is discussed in this paper. Included in the instrument complement of the CV-990 were two passive microwave imagers operating at wavelengths of 0.33 and 1.55 cm and the airborne multichannel microwave radiometer (AMMR) operating at wavelengths of 0.81, 1.4, and 1.7 cm for both horizontal and vertical polarizations. Total and multiyear sea ice concentrations calculated from the AMMR data were found to agree with similar calculations using SMMR data. This is the first check of the performance of the SMMR Team ice algorithm for near-melting point conditions. The temperature dependence of the multiyear sea ice concentration determination near the melting point was found to be the same for both airborne and spacecraft instrument data and to be correlated with presence or absence of clouds. Finally, it was found that a spectral gradient ratio using the data from both the 0.33- and 1.55-cm radiometers provides more reliable distinctions between low total ice concentrations and open water storm effects near the ice edge than does either singly.

  10. Real-Time Cloud, Radiation, and Aircraft Icing Parameters from GOES over the USA

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Nguyen, Louis; Smith, William, Jr.; Young, David; Khaiyer, Mandana; Palikonda, Rabindra; Spangenberg, Douglas; Doelling, Dave; Phan, Dung; Nowicki, Greg

    2004-01-01

    A preliminary new, physically based method for realtime estimation of the probability of icing conditions has been demonstrated using merged GOES-10 and 12 data over the continental United States and southern Canada. The algorithm produces pixel-level cloud and radiation properties as well as an estimate of icing probability with an associated intensity rating Because icing depends on so many different variables, such as aircraft size or air speed, it is not possible to achieve 100% success with this or any other type of approach. This initial algorithm, however, shows great promise for diagnosing aircraft icing and putting it at the correct altitude within 0.5 km most of the time. Much additional research must be completed before it can serve as a reliable input for the operational CIP. The delineation of the icing layer vertical boundaries will need to be improved using either the RUC or balloon soundings or ceilometer data to adjust the cloud base height, a change that would require adjustment of the cloud-top altitude also.

  11. Navier-Stokes Analysis of the Flowfield Characteristics of an Ice Contaminated Aircraft Wing

    NASA Technical Reports Server (NTRS)

    Chung, J.; Choo, Y.; Reehorst, A.; Potapczuk, M.; Slater, J.

    1999-01-01

    An analytical study was performed as part of the NASA Lewis support of a National Transportation Safety Board (NTSB) aircraft accident investigation. The study was focused on the performance degradation associated with ice contamination on the wing of a commercial turbo-prop-powered aircraft. Based upon the results of an earlier numerical study conducted by the authors, a prominent ridged-ice formation on the subject aircraft wing was selected for detailed flow analysis using 2-dimensional (2-D), as well as, 3-dimensional (3-D) Navier-Stokes computations. This configuration was selected because it caused the largest lift decrease and drag increase among all the ice shapes investigated in the earlier study. A grid sensitivity test was performed to find out the influence of grid spacing on the lift, drag, and associated angle-of-attack for the maximum lift (C(sub lmax)). This study showed that grid resolution is important and a sensitivity analysis is an essential element of the process in order to assure that the final solution is independent of the grid. The 2-D results suggested that a severe stability and control difficulty could have occurred at a slightly higher angle-of-attack (AOA) than the one recorded by the Flight Data Recorder (FDR). This stability and control problem was thought to have resulted from a decreased differential lift on the wings with respect to the normal loading for the configuration. The analysis also indicated that this stability and control problem could have occurred whether or not natural ice shedding took place. Numerical results using an assumed 3-D ice shape showed an increase of the angle at which this phenomena occurred of about 4 degrees. As it occurred with the 2-D case, the trailing edge separation was observed but started only when the AOA was very close to the angle at which the maximum lift occurred.

  12. ISMIP6: Ice Sheet Model Intercomparison Project for CMIP6

    NASA Astrophysics Data System (ADS)

    Nowicki, Sophie; Payne, Tony; Larour, Eric; Abe Ouchi, Ayako; Goelzer, Heiko; Gregory, Jonathan; Lipscomb, William; Seroussi, Helene; Shepherd, Andrew

    2015-04-01

    The sea level projections made by the glaciological community as part of the Intergovernmental Panel on Climate Change (IPCC) process have often been out of phase with the projections considered by the wider Coupled Model Intercomparison Project (CMIP) community. For instance in AR5, the ice2sea and SeaRISE (Sea-level Response to Ice Sheet Evolution) ice sheet projects predominantly worked with AR4 scenarios, while the CMIP5 community used new future scenarios. As the next phase of CMIP is being designed (CMIP6), an effort for ice sheet models to be better integrated in the CMIP6 initiative has been proposed to the CMIP panel. We present the framework for the new effort, ISMIP6, the Ice Sheet Model Intercomparison Project for CMIP6. The primary goal of ISMIP6 is to improve projections of sea level rise via improved projections of the evolution of the Greenland and Antarctic ice sheets under a changing climate, along with a quantification of associated uncertainties (including uncertainty in both climate forcing and ice-sheet response). This goal requires an evaluation of AOGCM climate over and surrounding the ice sheets; analysis of simulated ice-sheet response from standalone models forced "offline" with CMIP AOGCM outputs and, where possible, with coupled ice sheet-AOGCM models; and experiments with standalone ice sheet models targeted at exploring the uncertainty associated with ice sheets physics, dynamics and numerical implementation. A secondary goal is to investigate the role of feedbacks between ice sheets and climate in order to gain insight into the impact of increased mass loss from the ice sheets on regional and global sea level, and of the implied ocean freshening on the coupled ocean-atmosphere circulation. These goals map into both Cryosphere and Sea-Level Rise Grand Challenges relevant to Climate and Cryosphere (CliC) and the World Climate Research Program (WCRP).

  13. Evaluating and Constraining Ice Cloud Parameterizations in CAM5 using Aircraft Measurements from the SPARTICUS Campaign

    SciTech Connect

    Zhang, Kai; Liu, Xiaohong; Wang, Minghuai; Comstock, Jennifer M.; Mitchell, David; Mishra, Subhashree; Mace, Gerald G.

    2013-05-14

    This study uses aircraft measurements of relative humidity and ice crystal size distribution collected in synoptic cirrus during the SPARTICUS (Small PARTicles In CirrUS) field campaign to evaluate and constrain ice cloud parameterizations in the Community Atmosphere Model version 5. The probability density function (PDF) of ice crystal number concentration (Ni) derived from high frequency (1 Hz) measurements features a strong dependence on ambient temperature. As temperature decreases from -35°C to -62°C, the peak in the PDF shifts from 10-20 L-1 to 200-1000 L-1, while the ice crystal number concentration shows a factor of 6-7 increase. Model simulations are performed with two different insitu ice nucleation schemes. One of the schemes can reproduce a clear increase of Ni with decreasing temperature, by using either an observation based ice nuclei spectrum or a classical theory based spectrum with a relatively low (5%-10%) maximum freezing ratio for dust aerosols. The simulation with the other scheme, which assumes a high maximum freezing ratio (100%), shows much weaker temperature dependence of Ni. Simulations are also performed to test empirical parameters related to water vapor deposition and the auto-conversion of ice crystals to snow. Results show that a value between 0.05 and 0.1 for the water vapor deposition coefficient and 250 um for the critical ice crystal size can produce good agreements between model simulation and the SPARTICUS measurements in terms of ice crystal number concentration and effective radius. The climate impact of perturbing these parameters is also discussed.

  14. NASA Fixed Wing Project: Green Technologies for Future Aircraft Generation

    NASA Technical Reports Server (NTRS)

    Del Rosario, Ruben; Koudelka, John M.; Wahls, Rich; Madavan, Nateri

    2014-01-01

    Commercial aviation relies almost entirely on subsonic fixed wing aircraft to constantly move people and goods from one place to another across the globe. While air travel is an effective means of transportation providing an unmatched combination of speed and range, future subsonic aircraft must improve substantially to meet efficiency and environmental targets.The NASA Fundamental Aeronautics Fixed Wing (FW) Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. Multidisciplinary advances are required in aerodynamic efficiency to reduce drag, structural efficiency to reduce aircraft empty weight, and propulsive and thermal efficiency to reduce thrust-specific energy consumption (TSEC) for overall system benefit. Additionally, advances are required to reduce perceived noise without adversely affecting drag, weight, or TSEC, and to reduce harmful emissions without adversely affecting energy efficiency or noise.The paper will highlight the Fixed Wing project vision of revolutionary systems and technologies needed to achieve these challenging goals. Specifically, the primary focus of the FW Project is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe

  15. A novel actuator phasing method for ultrasonic de-icing of aircraft structures

    NASA Astrophysics Data System (ADS)

    Borigo, Cody J.

    Aircraft icing is a critical concern for commercial and military rotorcraft and fixed-wing aircraft. In-flight icing can lead to dramatic decreases in lift and increases in drag that have caused more than a thousand deaths and hundreds of accidents over the past three decades alone. Current ice protection technologies have substantial drawbacks due to weight, power consumption, environmental concerns, or incompatibility with certain structures. In this research, an actuator phasing method for ultrasonic de-icing of aircraft structures was developed and tested using a series of finite element models, 3D scanning laser Doppler vibrometer measurements, and experimental de-icing tests on metallic and composite structures including plates and airfoils. An independent actuator analysis method was developed to allow for practical evaluation of many actuator phasing scenarios using a limited number of finite element models by properly calculating the phased stress fields and electromechanical impedance curves using a complex coupled impedance model. A genetic algorithm was utilized in conjunction with a series of finite element models to demonstrate that phase inversion, in which only in-phase and anti-phase signal components are applied to actuators, can be utilized with a small number of phasing combinations to achieve substantial improvements in de-icing system coverage. Finite element models of a 48"-long airfoil predicted that phase inversion with frequency sweeping can provide an improvement in the shear stress coverage levels of up to 90% compared to frequency sweeping alone. Experimental evaluation of the phasing approach on an icing grid showed a 189% improvement in de-icing coverage compared to frequency sweeping alone at comparable power levels. 3D scanning laser Doppler vibrometer measurements confirmed the increased variation in the surface vibration field induced by actuator phasing compared to unphased frequency sweeping. Additional contributions were made

  16. ISMIP6: Ice Sheet Model Intercomparison Project for CMIP6

    NASA Technical Reports Server (NTRS)

    Nowicki, S.

    2015-01-01

    ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6) targets the Cryosphere in a Changing Climate and the Future Sea Level Grand Challenges of the WCRP (World Climate Research Program). Primary goal is to provide future sea level contribution from the Greenland and Antarctic ice sheets, along with associated uncertainty. Secondary goal is to investigate feedback due to dynamic ice sheet models. Experiment design uses and augment the existing CMIP6 (Coupled Model Intercomparison Project Phase 6) DECK (Diagnosis, Evaluation, and Characterization of Klima) experiments. Additonal MIP (Model Intercomparison Project)- specific experiments will be designed for ISM (Ice Sheet Model). Effort builds on the Ice2sea, SeaRISE (Sea-level Response to Ice Sheet Evolution) and COMBINE (Comprehensive Modelling of the Earth System for Better Climate Prediction and Projection) efforts.

  17. Large-area Ice Sheet and Sea Ice mapping from High-altitude Aircraft: Examples from the LVIS Sensor

    NASA Astrophysics Data System (ADS)

    Blair, J. B.; Hofton, M. A.; Rabine, D. L.

    2010-12-01

    High altitude airborne surveys of remote polar regions is a relatively recent addition to the remote sensing capabilities serving the Cryospheric science community. The NASA/GSFC-developed airborne sensor, LVIS (Land, Vegetation, and Ice Sensor) is a wide-swath, full-waveform laser altimeter system that produces large-area topographic maps with the highest levels of accuracy and precision. Recent data collections in support of NASA's Operation IceBridge over Antarctica and Greenland have demonstrated the extraordinary mapping capability of the LVIS sensor. Areal coverage is accumulated at a rate of > 1,000 sq. km/hr with repeatability of the surface elevation measurements at the decimeter level. With this new capability come new applications, new insights, the ability to fully capture the spatial extent and variability of changes occurring in highly dynamic areas, and enhanced input into ice sheet models. One example is over 7,000 sq. km collected over the Antarctic Peninsula in just 7 hours from 40,000 ft on the NASA DC-8 aircraft. The wide swath and dense coverage enabled by the LVIS sensor results in significant overlap with legacy ICESat data permitting statistically powerful comparisons and eliminate the need for interpolation or slope corrections. Several examples of ICESat comparisons and change detection between LVIS data takes and other topographic data sets will be presented . Further, a description of the LVIS waveform vector data product and examples of advanced data products and analysis techniques with be shown. A fully-autonomous version of LVIS is now under development (LVIS-GH) for use in the Global Hawk aircraft. Long duration flights over remote areas will be possible with this sensor. Testing on the Global Hawk UAV is scheduled for the Summer of 2011. The LVIS data are freely available from the NSIDC website (http://nsidc.org/data/icebridge/) and the LVIS website (https://lvis.gsfc.nasa.gov).

  18. 5. General view of looking glass aircraft in the project ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. General view of looking glass aircraft in the project looking glass historic district. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Avenue between Comstat Drive & Nightwatch Avenue, Offutt Air Force Base, Bellevue, Sarpy County, NE

  19. 2. General view of looking glass aircraft in the project ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. General view of looking glass aircraft in the project looking glass historic district. View to south. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Avenue between Comstat Drive & Nightwatch Avenue, Offutt Air Force Base, Bellevue, Sarpy County, NE

  20. 1. General view of looking glass aircraft in the project ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. General view of looking glass aircraft in the project looking glass historic district. View to southeast. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Avenue between Comstat Drive & Nightwatch Avenue, Offutt Air Force Base, Bellevue, Sarpy County, NE

  1. 3. General view of looking glass aircraft in the project ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. General view of looking glass aircraft in the project looking glass historic district. View to west. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Avenue between Comstat Drive & Nightwatch Avenue, Offutt Air Force Base, Bellevue, Sarpy County, NE

  2. 4. General view of looking glass aircraft in the project ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. General view of looking glass aircraft in the project looking glass historic district. View to west. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Avenue between Comstat Drive & Nightwatch Avenue, Offutt Air Force Base, Bellevue, Sarpy County, NE

  3. 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.

  4. Mapping of ice, snow and water using aircraft-mounted LiDAR

    NASA Astrophysics Data System (ADS)

    Church, Philip; Matheson, Justin; Owens, Brett

    2016-05-01

    Neptec Technologies Corp. has developed a family of obscurant-penetrating 3D laser scanners (OPAL 2.0) that are being adapted for airborne platforms for operations in Degraded Visual Environments (DVE). The OPAL uses a scanning mechanism based on the Risley prism pair. Data acquisition rates can go as high as 200kHz for ranges within 240m and 25kHz for ranges exceeding 240m. The scan patterns are created by rotating two prisms under independent motor control producing a conical Field-Of-View (FOV). An OPAL laser scanner with 90° FOV was installed on a Navajo aircraft, looking down through an aperture in the aircraft floor. The rotation speeds of the Risley prisms were selected to optimize a uniformity of the data samples distribution on the ground. Flight patterns simulating a landing approach over snow and ice in an unprepared Arctic environment were also performed to evaluate the capability of the OPAL LiDAR to map snow and ice elevation distribution in real-time and highlight potential obstacles. Data was also collected to evaluate the detection of wires when flying over water, snow and ice. Main results and conclusions obtained from the flight data analysis are presented.

  5. Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications

    NASA Astrophysics Data System (ADS)

    DeWeaver, Eric T.; Bitz, Cecilia M.; Tremblay, L.-Bruno

    This volume addresses the rapid decline of Arctic sea ice, placing recent sea ice decline in the context of past observations, climate model simulations and projections, and simple models of the climate sensitivity of sea ice. Highlights of the work presented here include • An appraisal of the role played by wind forcing in driving the decline; • A reconstruction of Arctic sea ice conditions prior to human observations, based on proxy data from sediments; • A modeling approach for assessing the impact of sea ice decline on polar bears, used as input to the U.S. Fish and Wildlife Service's decision to list the polar bear as a threatened species under the Endangered Species Act; • Contrasting studies on the existence of a "tipping point," beyond which Arctic sea ice decline will become (or has already become) irreversible, including an examination of the role of the small ice cap instability in global warming simulations; • A significant summertime atmospheric response to sea ice reduction in an atmospheric general circulation model, suggesting a positive feedback and the potential for short-term climate prediction. The book will be of interest to researchers attempting to understand the recent behavior of Arctic sea ice, model projections of future sea ice loss, and the consequences of sea ice loss for the natural and human systems of the Arctic.

  6. The Small Aircraft Transportation System Project: An Update

    NASA Technical Reports Server (NTRS)

    Kemmerly, Guy T.

    2006-01-01

    To all peoples in all parts of the world throughout history, the ability to move about easily is a fundamental element of freedom. The American people have charged NASA to increase their freedom and that of their children knowing that their quality of life will improve as our nation s transportation systems improve. In pursuit of this safe, reliable, and affordable personalized air transportation option, in 2000 NASA established the Small Aircraft Transportation System (SATS) Project. As the name suggests personalized air transportation would be built on smaller aircraft than those used by the airlines. Of course, smaller aircraft can operate from smaller airports and 96% of the American population is within thirty miles of a high-quality, underutilized community airport as are the vast majority of their customers, family members, and favorite vacation destinations.

  7. NASA Fixed Wing Project: Green Technologies for Future Aircraft Generation

    NASA Technical Reports Server (NTRS)

    DelRosario, Ruben

    2014-01-01

    The NASA Fundamental Aeronautics Fixed Wing (FW) Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advances in multidisciplinary technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. The presentation will highlight the FW Project vision of revolutionary systems and technologies needed to achieve the challenging goals of aviation. Specifically, the primary focus of the FW Project is on the N+3 generation that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe.

  8. Comparison of Profiling Microwave Radiometer, Aircraft, and Radiosonde Measurements From the Alliance Icing Research Study (AIRS)

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.

    2001-01-01

    Measurements from a profiling microwave radiometer are compared to measurements from a research aircraft and radiosondes. Data compared is temperature, water vapor, and liquid water profiles. Data was gathered at the Alliance Icing Research Study (AIRS) at Mirabel Airport outside Montreal, Canada during December 1999 and January 2000. All radiometer measurements were found to lose accuracy when the radome was wet. When the radome was not wetted, the radiometer was seen to indicate an inverted distribution of liquid water within a cloud. When the radiometer measurements were made at 15 deg. instead of the standard zenith, the measurements were less accurate.

  9. Five Year Changes in Surface Elevations Of The Greenland Ice Sheet Measured by Aircraft Laser Altimetry

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Frederick, E. B.; Manizade, S. M.; Martin, C. F.; Sonntag, J. G.; Swift, R. N.; Thomas, R. H.; Wright, C. W.; Yungel, J. K.

    2000-01-01

    The Arctic Ice Mapping group (Project AIM) at NASA's Wallops Flight Facility has been conducting systematic topographic surveys of the Greenland Ice Sheet since 1993, using scanning airborne laser altimeters combined with GPS positioning technology. Flight lines were planned to cover all major ice drainage basins, with the intention to repeat the surveys after a 5-year interval in order to detect changes in the ice-sheet volume. The first resurvey was completed in June/July, 1998, along flight lines in the southern half of Greenland which had been first surveyed in 1993. The northern half of the ice sheet will be resurveyed in 1999. The resulting data sets will provide the first comprehensive examination of regional changes in the the surface elevation of the World's second largest ice sheet. This analysis includes the ice sheet fringe areas, which are expected to be much more climatically sensitive than the interior. Data will be presented which demonstrate the combination of the ATM (Airborne Topographic Mapper) sensors and GPS (Global Positioning System) yields measurements which are repeatable at the 10 cm level over baselines in excess of 1000 km.

  10. Statistical Study of Aircraft Icing Probabilities at the 700- and 500- Millibar Levels over Ocean Areas in the Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    Perkins, Porter J.; Lewis, William; Mulholland, Donald R.

    1957-01-01

    A statistical study is made of icing data reported from weather reconnaissance aircraft flown by Air Weather Service (USAF). The weather missions studied were flown at fixed flight levels of 500 millibars (18,000 ft) and 700 millibars (10,000 ft) over wide areas of the Pacific, Atlantic, and Arctic Oceans. This report is presented as part of a program conducted by the NACA to obtain extensive icing statistics relevant to aircraft design and operation. The thousands of in-flight observations recorded over a 2- to 4-year period provide reliable statistics on icing encounters for the specific areas, altitudes, and seasons included in the data. The relative frequencies of icing occurrence are presented, together with the estimated icing probabilities and the relation of these probabilities to the frequencies of flight in clouds and cloud temperatures. The results show that aircraft operators can expect icing probabilities to vary widely throughout the year from near zero in the cold Arctic areas in winter up to 7 percent in areas where greater cloudiness and warmer temperatures prevail. The data also reveal a general tendency of colder cloud temperatures to reduce the probability of icing in equally cloudy conditions.

  11. Current trends in seasonal ice storage. [Compilation of projects

    SciTech Connect

    Gorski, A.J.

    1986-05-01

    This document is a compilation of modern research projects focused upon the use of naturally grown winter ice for summer cooling applications. Unlike older methods of ice-based cooling, in which ice was cut from rivers and lakes and transported to insulated icehouses, modern techniques grow ice directly in storage containers - by means of heat pipes, snow machines, and water sprays - at the site of application. This modern adaptation of an old idea was reinvented independently at several laboratories in the United States and Canada. Applications range from air conditioning and food storage to desalinization.

  12. In-situ aircraft observations of ice supersaturation and cirrus clouds in global field studies

    NASA Astrophysics Data System (ADS)

    Diao, M.; Zondlo, M. A.

    2012-12-01

    Clouds play important roles in the Earth's climate and weather system, and the net forcing of all clouds results in a cooling effect on the Earth's surface. However, clouds remain one of the largest uncertainties in climate models. The IPCC AR4 report shows that both the magnitude and sign of the changes in cloud radiative forcing in response to anthropogenic aerosols are highly uncertain. Cirrus clouds are a type of ice clouds that occur at 235-185K with a net warming effect on the Earth surface. Cirrus cloud formation requires ice supersaturation (ISS), i.e., relative humidity with respect to ice (RHi) greater than 100%. Because ISS is critically related to the ice nucleation processes, it is also an indicator of any changes of ice nucleation and cirrus cloud formation. Here we use the in-situ 1 Hz aircraft observations by the Vertical Cavity Surface Emitting Laser (VCSEL) hygrometer on board the NSF Gulfstream-V research aircraft to analyze the differences of ISS distribution between the Northern and Southern Hemispheres (NH and SH). Our dataset is based on five deployments of the NSF Hiaper Pole-to-Pole Observations (HIPPO) Global field campaigns, including nine Pole-to-Pole transects from the year of 2009 to 2011, extending from 87°N to 67°S, covering four seasons, and the Stratosphere-Troposphere Analyses of Regional Transport (START08) campaign over North America region in April-June 2008. The flight track was mostly over the mid-Pacific Ocean, and also parts of the North America and Australia. We found that the frequency of ISS is much higher in NH than SH for the clear-sky conditions, while the in-cloud conditions show no significant difference between the two hemispheres. Our conclusion is in sharp contrast to the previous aircraft observations which concluded that the SH has higher frequency of ISS for clear-sky conditions based on two flight campaigns at Prestwick, Scotland (55°N) and Punta Arenas, Chile (55°S). We propose a method to separate

  13. Project ARES 2: High-altitude battery-powered aircraft

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A high-altitude, battery-powered, propeller-driven aircraft was designed and is being built by undergraduate students at California State University, Northridge. The aircraft will fly at an altitude of 104,000 ft at Mach 0.2 (190 ft/sec) and will be instrumented to record flight performance data, including low Reynolds number propeller and airfoil information. This project will demonstrate the feasibility of electric-powered flight in a low-density, low-temperature Earth environment that models the atmosphere of Mars. Data collected will be used to design a Mars aircraft to investigate the surface of Mars prior to manned missions. The instrumented payload and the mission profile for the high-altitude Earth flight were determined. Detailed aerodynamic and structural analyses were performed. Control, tracking, and data recording subsystems were developed. Materials were obtained and fabrication begun. The aircraft has a 32-ft wing span, a wing area of 105 sq ft, is 17.5 ft long, has a 12-in payload bay, and weighs 42 lb. It is composed primarily of lightweight materials, including Mylar, and composite materials, including graphite/epoxy and aramid core honeycomb sandwich. Low-altitude flight testing to check guidance and control systems and to calibrate data-gathering instruments will take place this summer, followed shortly by the 104,000-ft flight.

  14. Observing the Arctic Ocean under melting ice - the UNDER-ICE project

    NASA Astrophysics Data System (ADS)

    Sagen, Hanne; Ullgren, Jenny; Geyer, Florian; Bergh, Jon; Hamre, Torill; Sandven, Stein; Beszczynska-Möller, Agnieszka; Falck, Eva; Gammelsrød, Tor; Worcester, Peter

    2014-05-01

    The sea ice cover of the Arctic Ocean is gradually diminishing in area and thickness. The variability of the ice cover is determined by heat exchange with both the atmosphere and the ocean. A cold water layer with a strong salinity gradient insulates the sea ice from below, preventing direct contact with the underlying warm Atlantic water. Changes in water column stratification might therefore lead to faster erosion of the ice. As the ice recedes, larger areas of surface water are open to wind mixing; the effect this might have on the water column structure is not yet clear. The heat content in the Arctic strongly depends on heat transport from other oceans. The Fram Strait is a crucial pathway for the exchange between the Arctic and the Atlantic Ocean. Two processes of importance for the Arctic heat and freshwater budget and the Atlantic meridional overturning circulation take place here: poleward heat transport by the West Spitzbergen Current and freshwater export by the East Greenland Current. A new project, Arctic Ocean under Melting Ice (UNDER-ICE), aims to improve our understanding of the ocean circulation, water mass distribution, fluxes, and mixing processes, sea ice processes, and net community primary production in ice-covered areas and the marginal ice zone in the Fram Strait and northward towards the Gakkel Ridge. The interdisciplinary project brings together ocean acoustics, physical oceanography, marine biology, and sea ice research. A new programme of observations, integrated with satellite data and state-of-the-art numerical models, will be started in order to improve the estimates of heat, mass, and freshwater transport between the North Atlantic and the Arctic Ocean. On this poster we present the UNDER-ICE project, funded by the Research Council of Norway and GDF Suez E&P Norge AS for the years 2014-2017, and place it in context of the legacy of earlier projects in the area, such as ACOBAR. A mooring array for acoustic tomography combined with

  15. EOS Aqua AMSR-E Arctic Sea-Ice Validation Program: Arctic2006 Aircraft Campaign Flight Report

    NASA Technical Reports Server (NTRS)

    Cavalieri, D. J.; Markus, T.

    2006-01-01

    In March 2006, a coordinated Arctic sea-ice validation field campaign using the NASA Wallops P-3B aircraft was successfully completed. This campaign was the second Alaskan Arctic field campaign for validating the Earth Observing System (EOS) Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sea-ice products. The first campaign was completed in March 2003. The AMSR-E, designed and built by the Japanese Space 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. The focus of this campaign was on the validation of snow depth on sea ice and sea-ice temperature. This flight report describes the suite of instruments flown on the P-3, the objectives of each of the six flights, the Arctic regions overflown, and the coordination among satellite, aircraft, and surface-based measurements.

  16. 78 FR 26103 - Proposed Standard Operating Procedure (SOP) of the Aircraft Certification Service (AIR) Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ... Service (AIR) Project Prioritization and Resource Management ACTION: Notice of availability and request... process used to prioritize certification projects and manage certification project resources when local... Operating Procedure--Aircraft Certification Service Project Prioritization. FOR FURTHER INFORMATION...

  17. 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…

  18. Ice Nuclei in Mid-Latitude Cirrus: Preliminary Results from a New Counterflow Virtual Impactor (CVI) Aircraft Inlet

    NASA Astrophysics Data System (ADS)

    Froyd, K. D.; Cziczo, D. J.; Murphy, D. M.; Kulkarni, G.; Lawson, P.

    2011-12-01

    Cirrus cloud properties are strongly governed by the mechanism of ice particle formation and by the number and effectiveness of ambient ice nuclei. Airborne measurements of ice nuclei reveal new nucleation mechanisms, provide constraints on microphysical models, and guide laboratory investigations. For over two decades the Counterflow Virtual Impactor (CVI) inlet has remained the prevailing approach for sampling cloud particles to measure ice nuclei from an aircraft platform. However, traditional CVI inlets have fundamental limitations when operating on high speed aircraft, where only a small fraction of ambient cloud particles are typically sampled. A novel 'folded' CVI was constructed and deployed during the NASA MACPEX 2011 campaign. The flow design of this inlet effectively doubles the CVI length and thereby increases the size range of captured cirrus particles. Additional design elements such as an internal vortex flow, a neon carrier gas, and an infrared laser further improve the capture and evaporation of ice crystals. Preliminary results of ice nuclei composition measured by the PALMS single-particle mass spectrometer are presented from the MACPEX campaign. Examples of ice nuclei from mid-latitude cirrus are shown, including mineral dust, organic-rich aerosol with amine and diacid components, and lead-containing aerosol.

  19. 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.

  20. HAIC/HIWC field project: characterizing the high ice water content environment

    NASA Astrophysics Data System (ADS)

    Leroy, Delphine; Coutris, Pierre; Fontaine, Emmanuel; Schwarzenboeck, Alfons; Strapp, J. Walter; Korolev, Alexei; McFarquhar, Greg; Gourbeyre, Christophe; Dupuy, Regis; Dezitter, Fabien; Calmels, Alice

    2016-04-01

    High ice water content (IWC) cloud regions in mesoscale convective systems (MCSs) are suspected to cause in-service engine power loss events and air-data probe malfunctions on commercial aircraft. In order to better document this particular environment, a multi-year international HAIC/HIWC (High Altitude Ice Crystals / High Ice Water Content) field project has been designed including two field campaigns. The first campaign was conducted in Darwin in 2014 while the second one took place in Cayenne in May 2015. The French Falcon 20 research aircraft has been deployed for the two campaigns, with an instrumental payload including an IKP-2 (isokinetic evaporator probe which provides a reference measurement of IWC), a CDP-2 (cloud droplet spectrometer probe measuring particles in the range 2-50 μm), and optical array probes 2D-S (2D-Stereo, 10-1280 μm) and PIP (precipitation imaging probe, 100-6400 μm). 23 flights were performed in Darwin, 18 in Cayenne, all sampling MCSs at different flight levels with temperatures from -10°C to -50°C. The study presented here focuses on ice crystal size properties related to IWC, 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 probes were processed in order to produce particle size distributions (PSDs) and median mass diameters (MMDs). Darwin results shows that ice crystals properties are quite different in high IWC areas compared to the surrounding cloud regions. Most of the sampled MCS reveal that the higher the measured IWC, the smaller are the corresponding crystal MMD. This effect is interfering with a temperature trend, whereby colder temperatures are leading to smaller MMD. A preliminary analysis of the Cayenne data seems to be consistent with the above trends.

  1. An Experimental Investigation on the Impingement of Water Droplets onto Superhydrophobic Surfaces Pertinent to Aircraft Icing Phenomena

    NASA Astrophysics Data System (ADS)

    Li, Haixing; Waldman, Rye; Hu, Hui

    2015-11-01

    Superhydrophobic surfaces have self-cleaning properties that make them promising candidates as anti-icing solutions for various engineering applications, including aircraft anti-/de-icing. However, under sufficient external pressure, the liquid water on the surface can transition to a wetted state, defeating the self-cleaning properties of superhydrpphobic surfaces. In the present study, an experimental investigation was conducted to quantify the transient behavior of water droplets impinging onto test surfaces with different hydrophobicity properties under different environmental icing conditions. The experiments were performed in the Icing Research Tunnel of Iowa State University (IRT-ISU) with a NACA0012 airfoil. In addition to using a high-speed imaging system to reveal transient behavior of water droplets impinging onto test surfaces with different hydrophobicity properties, an IR thermometry was also used to quantify the unsteady heat transfer and dynamic phase changing process within the water droplets after impingement onto the test plates with different frozen cold temperatures. The high-speed imaging results were correlated with the quantitatively temperature measurements to elucidate underlying physics in order to gain further insight into the underlying physics pertinent to aircraft icing phenomena. The research work is partially supported by NASA with grant number NNX12AC21A and National Science Foundation under award numbers of CBET-1064196 and CBET-1435590.

  2. Aerodynamic heating and the deflection of drops by an obstacle in an air stream in relation to aircraft icing

    NASA Technical Reports Server (NTRS)

    Kantrowitz, Arthur

    1940-01-01

    Two topics of interest to persons attempting to apply the heat method of preventing ice formation on aircraft are considered. Surfaces moving through air at high speed are shown, both theoretically and experimentally, to be subject to important aerodynamic heating effects that will materially reduce the heat required to prevent ice. Numerical calculations of the path of water drops in an air stream around a circular cylinder are given. From these calculations, information is obtained on the percentage of the swept area cleared of drops.

  3. Aircraft

    DOEpatents

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  4. Aircraft

    DOEpatents

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  5. Aircraft observations of the evolution of ice surface conditions at the onset of the melt season in the Beaufort Sea

    NASA Astrophysics Data System (ADS)

    Birnbaum, G.; Ehrlich, A.; Schwarz, P.; Lüpkes, C.; Dierking, W.; Hartmann, J.

    2012-12-01

    At the onset of the melt season in the Arctic, the energy exchange between atmosphere, sea ice, and ocean undergoes strong changes. Caused by melting of snow and formation of melt ponds and open leads the areally averaged albedo decreases dramatically and absorption of solar radiation is enhanced. To investigate these changes, the aircraft campaign MELTEX was performed from 11 May to 7 June, 2008 over the Beaufort Sea (region 69°N-74°N, 133°W-144°W). During the campaign, the sea ice cover experienced several episodes with strong on-ice warm-air advection from the Canadian Coast. Between these warm episodes, northerly flow with cold-air advection from the inner Arctic caused an interruption of melting and melt pond evolution and even a temporary refreezing. To quantify the evolution of ice surface conditions, the aircraft POLAR 5 was equipped with a digital reflex camera, broadband radiation sensors, a spectral albedometer with active horizontal stabilization, and further meteorological instruments. Images of seven flights were analyzed by means of a supervised classification employing the maximum likelihood method to derive the areal fraction of different surface classes. Areally averaged broadband and spectral albedo was derived for clear-sky conditions only to allow for a better comparison of values. On 11 May, the ice conditions were still characteristic for late winter. The maximum broadband albedo for snow covered ice was 0.82. On 26 May, already 21,6% of the sea ice surface right north of a coastal polynya consisted of wet ice (19,4%) and shallow melt ponds (2,2%). Broadband albedo measurements indicated an average value of 0.57 for melting snow and bare ice. The most enhanced stage of melting was encountered on 6 June for fast ice in Franklin and Darnley Bay, south of the Amundsen Gulf. The total fraction of melt ponds and particle-laden sea ice amounted to 45,0±16,7% with an average broadband albedo of 0.16. The average albedo of the remaining clean

  6. Impacts of alternative fuels in aviation on microphysical aerosol properties and predicted ice nuclei concentration at aircraft cruise altitude

    NASA Astrophysics Data System (ADS)

    Weinzierl, B.; D'Ascoli, E.; Sauer, D. N.; Kim, J.; Scheibe, M.; Schlager, H.; Moore, R.; Anderson, B. E.; Ullrich, R.; Mohler, O.; Hoose, C.

    2015-12-01

    In the past decades air traffic has been substantially growing affecting air quality and climate. According to the International Civil Aviation Authority (ICAO), in the next few years world passenger and freight traffic is expected to increase annually by 6-7% and 4-5%, respectively. One possibility to reduce aviation impacts on the atmosphere and climate might be the replacement of fossil fuels by alternative fuels. However, so far the effects of alternative fuels on particle emissions from aircraft engines and their ability to form contrails remain uncertain. To study the effects of alternative fuels on particle emissions and the formation of contrails, the Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) field experiment was conducted in California. In May 2014, the DLR Falcon 20 and the NASA HU-25 jet aircraft were instrumented with an extended aerosol and trace gas payload probing different types of fuels including JP-8 and JP-8 blended with HEFA (Hydroprocessed Esters and Fatty Acids) while the NASA DC8 aircraft acted as the source aircraft for ACCESS-2. Emission measurements were taken in the DC8 exhaust plumes at aircraft cruise level between 9-12 km altitude and at distances between 50 m and 20 km behind the DC8 engines. Here, we will present results from the ACCESS-2 aerosol measurements which show a 30-60% reduction of the non-volatile (mainly black carbon) particle number concentration in the aircraft exhaust for the HEFA-blend compared to conventional JP-8 fuel. Size-resolved particle emission indices show the largest reductions for larger particle sizes suggesting that the HEFA blend contains fewer and smaller black carbon particles. We will combine the airborne measurements with a parameterization of deposition nucleation developed during a number of ice nucleation experiments at the AIDA chamber in Karlsruhe and discuss the impact of alternative fuels on the abundance of potential ice nuclei at cruise conditions.

  7. A Grand Design for Future Ice Sheet Projections

    NASA Astrophysics Data System (ADS)

    Edwards, T.

    2014-12-01

    If we are to make robust projections of the probability of sea level rise from the ice sheets, these must be founded in both glaciological theory, represented by dynamical ice sheet models, and statistical inference, i.e. formal uncertainty quantification (UQ). No such studies yet exist for either the Greenland or Antarctic ice sheet. Therefore projections risk being physically implausible, difficult to interpret, or both. More optimistically, ice sheet models have many advantages over climate models with respect to uncertainty quantification. They are computationally cheaper, simpler to understand, and have fewer input parameters and output variables. It is relatively straightforward to switch between different model structures, such as physics approximations, basal drag laws, and resolution. Moreover the ice sheet modelling community is relatively small and is not constrained methodologically or culturally by the legacy - and pitfalls - of the CMIP multi-model "ensemble of opportunity". These advantages present us with a golden opportunity to create a new vision for policy-relevant sea level projections: we can design a grand ensemble that quantifies multiple modelling uncertainties in a statistically rigorous and efficient way. Such an ensemble systematically samples model parameters and structures, initial and boundary conditions, in the most informative way given the available resources and also allows statistical inference. I will review some of the UQ steps that have been taken in ice sheet modelling, such as Bayesian calibration of parameters and projections, history matching (statistically-formalised ruling out of poor parameter values), and emulation (statistical surrogates of numerical models). I will then describe how to implement these and other techniques in a multi-model ensemble design, including: sequential experimental design, which is more efficient than the usual Latin Hypercube; quantifying uncertainty in Full Stokes and high resolution models

  8. 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.

  9. Ocean farfield response to projected Arctic sea ice loss.

    NASA Astrophysics Data System (ADS)

    Jochum, Markus; Deser, Clara; Tomas, Robert

    2016-04-01

    An ensemble of 20 fully coupled CESM simulations is used to elucidate the ocean's role in shaping the global climate response to projected Arctic sea ice loss. The ensemble allows us to separate unambiguously between internal variability and forced changes. Thus, it is possible to identify the oceanic processes by which sea ice induced changes in Arctic and North Pacific sea level pressure are transmitted across the world ocean. Of particular interest is the Kelvin wave train that connects the North Atlantic with the equatorial Pacific. Within 10 years after the loss of sea ice the oceanic signal arrives in the Pacific and leads to a slow and steady deepening of the equatorial thermocline and, after another 5 decades, the subtropical thermocline. This suggests that the current Arctic sea ice loss already set into motion changes in tropical Pacific climate that will be felt several decades from now. We will dicuss these ocean induced changes in the mean climate as well as ENSO and explore possibilities of observational verification.

  10. The CMIP6 Sea-Ice Model Intercomparison Project (SIMIP): understanding sea ice through climate-model simulations

    NASA Astrophysics Data System (ADS)

    Notz, Dirk; Jahn, Alexandra; Holland, Marika; Hunke, Elizabeth; Massonnet, François; Stroeve, Julienne; Tremblay, Bruno; Vancoppenolle, Martin

    2016-09-01

    A better understanding of the role of sea ice for the changing climate of our planet is the central aim of the diagnostic Coupled Model Intercomparison Project 6 (CMIP6)-endorsed Sea-Ice Model Intercomparison Project (SIMIP). To reach this aim, SIMIP requests sea-ice-related variables from climate-model simulations that allow for a better understanding and, ultimately, improvement of biases and errors in sea-ice simulations with large-scale climate models. This then allows us to better understand to what degree CMIP6 model simulations relate to reality, thus improving our confidence in answering sea-ice-related questions based on these simulations. Furthermore, the SIMIP protocol provides a standard for sea-ice model output that will streamline and hence simplify the analysis of the simulated sea-ice evolution in research projects independent of CMIP. To reach its aims, SIMIP provides a structured list of model output that allows for an examination of the three main budgets that govern the evolution of sea ice, namely the heat budget, the momentum budget, and the mass budget. In this contribution, we explain the aims of SIMIP in more detail and outline how its design allows us to answer some of the most pressing questions that sea ice still poses to the international climate-research community.

  11. Impact of the Projected Future Sea Ice Concentrations on the Atmospheric Circulation

    NASA Astrophysics Data System (ADS)

    Bader, J.; Seierstad, I.

    2007-12-01

    The observed decline of Arctic sea ice cover and the projected future reduction raise the question of how reduced Artic sea ice will influence/feed back on the climate. Using the projected future sea ice concentration by the coupled atmosphere ocean sea ice model ECHAM5/MPI, we investigate the impact of the changed sea ice cover on the atmospheric circulation by conducting atmospheric general circulation model (AGCM) experiments. We force the AGCM ECHAM5 by the current seasonal cycle of arctic sea ice and the projected future arctic seasonal cycle. The goal of this experiment is to determine the impact of the Artic sea ice reduction - that is projected in the next 100 years - on the atmospheric circulation. We find a significant reduction in storminess. The response to sea ice concentration changes differs strongly even on intraseasonal time scales.

  12. Pipeline under the arctic ice: the Polar Gas Project

    SciTech Connect

    Kaustinen, O.M.

    1982-06-01

    The Polar Gas Project was established in 1972 to determine the best means of moving frontier natural gas from Canada's high arctic to southern markets. Pipeline was found to be most feasible. Several pipeline routings from two major supply areas--the MacKenzie Delta/Beaufort Sea region, and the Sverdrup Basin of the Arctic Islands--have been considered. Field programs to determine the type and ice content of soils along the route have been undertaken. The most challenging engineering aspect will be two marine crossings in arctic waters at either end of Victoria Island, at Dolphin and Union Strait, and at McClure's strait. The ''Ice Hole Bottom Pull'' technique has been recommended, and is illustrated in detail. The planned pipeline demonstration would significantly enhance the current state-of-the-art for deepwater pipelining worldwide.

  13. Experimental design for three interrelated Marine Ice-Sheet and Ocean Model Intercomparison Projects

    NASA Astrophysics Data System (ADS)

    Asay-Davis, X. S.; Cornford, S. L.; Durand, G.; Galton-Fenzi, B. K.; Gladstone, R. M.; Gudmundsson, G. H.; Hattermann, T.; Holland, D. M.; Holland, D.; Holland, P. R.; Martin, D. F.; Mathiot, P.; Pattyn, F.; Seroussi, H.

    2015-11-01

    Coupled ice sheet-ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of marine ice sheets and tidewater glaciers, from process studies to future projections of ice mass loss and sea level rise. The Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP) is a community effort aimed at designing and coordinating a series of model intercomparison projects (MIPs) for model evaluation in idealized setups, model verification based on observations, and future projections for key regions in the West Antarctic Ice Sheet (WAIS). Here we describe computational experiments constituting three interrelated MIPs for marine ice sheet models and regional ocean circulation models incorporating ice shelf cavities. These consist of ice sheet experiments under the Marine Ice Sheet MIP third phase (MISMIP+), ocean experiments under the ice shelf-ocean MIP second phase (ISOMIP+) and coupled ice sheet-ocean experiments under the MISOMIP first phase (MISOMIP1). All three MIPs use a shared domain with idealized bedrock topography and forcing, allowing the coupled simulations (MISOMIP1) to be compared directly to the individual component simulations (MISMIP+ and ISOMIP+). The experiments, which have qualitative similarities to Pine Island Glacier Ice Shelf and the adjacent region of the Amundsen Sea, are designed to explore the effects of changes in ocean conditions, specifically the temperature at depth, on basal melting and ice dynamics. In future work, differences between model results will form the basis for evaluation of the participating models.

  14. Arctic sea ice decline: Projected changes in timing and extent of sea ice in the Bering and Chukchi Seas

    USGS Publications Warehouse

    Douglas, D.C.

    2010-01-01

    The Arctic region is warming faster than most regions of the world due in part to increasing greenhouse gases and positive feedbacks associated with the loss of snow and ice cover. One consequence has been a rapid decline in Arctic sea ice over the past 3 decades?a decline that is projected to continue by state-of-the-art models. Many stakeholders are therefore interested in how global warming may change the timing and extent of sea ice Arctic-wide, and for specific regions. To inform the public and decision makers of anticipated environmental changes, scientists are striving to better understand how sea ice influences ecosystem structure, local weather, and global climate. Here, projected changes in the Bering and Chukchi Seas are examined because sea ice influences the presence of, or accessibility to, a variety of local resources of commercial and cultural value. In this study, 21st century sea ice conditions in the Bering and Chukchi Seas are based on projections by 18 general circulation models (GCMs) prepared for the fourth reporting period by the Intergovernmental Panel on Climate Change (IPCC) in 2007. Sea ice projections are analyzed for each of two IPCC greenhouse gas forcing scenarios: the A1B `business as usual? scenario and the A2 scenario that is somewhat more aggressive in its CO2 emissions during the second half of the century. A large spread of uncertainty among projections by all 18 models was constrained by creating model subsets that excluded GCMs that poorly simulated the 1979-2008 satellite record of ice extent and seasonality. At the end of the 21st century (2090-2099), median sea ice projections among all combinations of model ensemble and forcing scenario were qualitatively similar. June is projected to experience the least amount of sea ice loss among all months. For the Chukchi Sea, projections show extensive ice melt during July and ice-free conditions during August, September, and October by the end of the century, with high agreement

  15. Numerical simulation of two-dimensional heat transfer in composite bodies with application to de-icing of aircraft components. Ph.D. Thesis. Final Report

    NASA Technical Reports Server (NTRS)

    Chao, D. F. K.

    1983-01-01

    Transient, numerical simulations of the de-icing of composite aircraft components by electrothermal heating were performed for a two dimensional rectangular geometry. The implicit Crank-Nicolson formulation was used to insure stability of the finite-difference heat conduction equations and the phase change in the ice layer was simulated using the Enthalpy method. The Gauss-Seidel point iterative method was used to solve the system of difference equations. Numerical solutions illustrating de-icer performance for various composite aircraft structures and environmental conditions are presented. Comparisons are made with previous studies. The simulation can also be used to solve a variety of other heat conduction problems involving composite bodies.

  16. Examination Of A Strong Downslope Warming Wind Event Over The Larsen Ice Shelf In Antarctica Through Modeling And Aircraft Observations

    NASA Astrophysics Data System (ADS)

    Grosvenor, D. P.; Choularton, T. W.; Gallagher, M. W.; Lachlan-Cope, T. A.; King, J. C.

    2009-12-01

    The high mountains of the Antarctic Peninsula (AP) provide a climatic barrier between the west and east. The east side is generally blocked from the warmer oceanic air of the west and is consequently usually under the influence of colder continental air. On occasion, however, air from the west can cross the barrier in the form of strong winds travelling down the eastern slopes, which are also very warm and dry due to adiabatic descent. They penetrate onto the Larsen ice shelves where they lead to above zero surface temperatures and are therefore likely to encourage surface melting. Crevasse propagation due to the weight of accumulated meltwater is currently thought to have been the major factor in causing the near total disintegration of the Larsen B ice shelf in 2002. In January 2006 the British Antarctic Survey performed an aircraft flight over the Larsen C ice shelf on the east side of the AP, which sampled a strong downslope wind event. Surface flux measurements over the ice shelf suggest that the sensible heat provided by the warm jets would be likely to be negated by latent heat losses from ice ablation. The main cause of any ice melting was likely to be due to shortwave radiation input. However, the warming from the jets is still likely to be important by acting as an on/off control for melting by keeping air temperatures above zero. In addition, the dryness of the winds is likely to prevent cloud cover and thus maximize exposure of the ice shelf to solar energy input. This case study has been modeled using the WRF mesoscale model. The model reproduces the strong downslope winds seen by the aircraft with good comparisons of wind speed and temperature profiles through the wind jets. Further comparisons to surface station data have allowed progress towards achieving the best set up of the model for this case. The modeling agrees with the results of the aircraft study in suggesting that solar radiation input is likely to provide the largest amount of energy for

  17. Aircraft Emission Scenarios Projected in Year 2015 for the NASA Technology Concept Aircraft (TCA) High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Henderson, Stephen C.

    1998-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from projected fleets of high speed civil transports (HSCTs) on a universal airline network. Inventories for 500 and 1000 HSCT fleets, as well as the concurrent subsonic fleets, were calculated. The HSCT scenarios are calculated using the NASA technology concept airplane (TCA) and update an earlier report. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer pressure altitude grid and delivered to NASA as electronic files.

  18. Part A: Cirrus ice crystal nucleation and growth. Part B: Automated analysis of aircraft ice particle data

    NASA Technical Reports Server (NTRS)

    Arnott, William P.; Hallett, John; Hudson, James G.

    1995-01-01

    Specific measurement of cirrus crystals by aircraft and temperature modified CN are used to specify measurements necessary to provide a basis for a conceptual model of cirrus particle formation. Key to this is the ability to measure the complete spectrum of particles at cirrus levels. The most difficult regions for such measurement is from a few to 100 microns, and uses a replicator. The details of the system to automate replicator data analysis are given, together with an example case study of the system provided from a cirrus cloud in FIRE 2, with particles detectable by replicator and FSSP, but not 2DC.

  19. Application of a cost/performance measurement system on a research aircraft project

    NASA Technical Reports Server (NTRS)

    Diehl, J. J.

    1978-01-01

    The fundamentals of the cost/performance management system used in the procurement of two tilt rotor aircraft for a joint NASA/Army research project are discussed. The contractor's reporting system and the GPO's analyses are examined. The use of this type of reporting system is assessed. Recommendations concerning the use of like systems on future projects are included.

  20. 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.

  1. 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.

  2. Over Ice

    NASA Video Gallery

    All about NASA's IceBridge P-3B plane and its IceBridge retrofit. Upgraded with 21st century "special modifications", the aircraft is less a cold war relic and more like the Space Agency's Millenni...

  3. Structural tailoring of aircraft engine blade subject to ice impact constraints

    NASA Technical Reports Server (NTRS)

    Reddy, E. S.; Abumeri, G. H.; Murthy, P. L. N.; Chamis, C. C.

    1993-01-01

    Results are presented for the minimum weight design of SR2 unswept blade made of (titanium/graphite-epoxy/titanium) sub s fiber composite. The blade which is rotating at high RPM is subject to ice impact. The root chord length, blade thicknesses at five stations, and graphite-epoxy ply orientation are chosen as design variables. Design constraints are placed on the behavior variables: local leading edge strain and root damage parameter (combined stress failure criteria) as a function due to ice impact, maximum spanwise centrifugal stress at the root of the deformed blade due to local damage, first three natural frequencies, and resonance margin after impact. The method of feasible directions is employed to solve the inequality constrained minimization problem. The effect of ice speed and the ice impact location on the final design are discussed.

  4. Low Energy Nuclear Reaction Aircraft- 2013 ARMD Seedling Fund Phase I Project

    NASA Technical Reports Server (NTRS)

    Wells, Douglas P.; McDonald, Robert; Campbell, Robbie; Chase, Adam; Daniel, Jason; Darling, Michael; Green, Clayton; MacGregor, Collin; Sudak, Peter; Sykes, Harrison; Waddington, Michael; Fredericks, William J.; Lepsch, Roger A.; Martin, John G.; Moore, Mark D.; Zawodny, Joseph M.; Felder, James L.; Snyder, Christopher A.

    2014-01-01

    This report serves as the final written documentation for the Aeronautic Research Mission Directorate (ARMD) Seedling Fund's Low Energy Nuclear Reaction (LENR) Aircraft Phase I project. The findings presented include propulsion system concepts, synergistic missions, and aircraft concepts. LENR is a form of nuclear energy that potentially has over 4,000 times the energy density of chemical energy sources. It is not expected to have any harmful emissions or radiation which makes it extremely appealing. There is a lot of interest in LENR, but there are no proven theories. This report does not explore the feasibility of LENR. Instead, it assumes that a working system is available. A design space exploration shows that LENR can enable long range and high speed missions. Six propulsion concepts, six missions, and four aircraft concepts are presented. This report also includes discussion of several issues and concerns that were uncovered during the study and potential research areas to infuse LENR aircraft into NASA's aeronautics research.

  5. Jet engine exhaust emissions of high altitude commercial aircraft projected to 1990

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Ingebo, R. D.

    1974-01-01

    Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high-altitude cruise conditions are presented. The forecasts are based on:(1) current knowledge of emission characteristics of combustors and augmentors; (2) the status of combustion research in emission reduction technology; and (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft fueled by either JP fuel, liquefied natural gas, or hydrogen. Results are presented for cruise conditions in terms of both an emission index (g constituent/kg fuel) and an emission rate (g constituent/hr).

  6. Theoretical analysis of the electrical aspects of the basic electro-impulse problem in aircraft de-icing applications

    NASA Technical Reports Server (NTRS)

    Henderson, Robert A.; Schrag, Robert L.

    1987-01-01

    A method of modelling a system consisting of a cylindrical coil with its axis perpendicular to a metal plate of finite thickness, and a simple electrical circuit for producing a transient current in the coil, is discussed in the context of using such a system for de-icing aircraft surfaces. A transmission line model of the coil and metal plate is developed as the heart of the system model. It is shown that this transmission model is central to calculation of the coil impedance, the coil current, the magnetic fields established on the surfaces of the metal plate, and the resultant total force between the coil and the plate. FORTRAN algorithms were developed for numerical calculation of each of these quantities, and the algorithms were applied to an experimental prototype system in which these quantities had been measured. Good agreement is seen to exist between the predicted and measured results.

  7. An efficient finite element method for aircraft de-icing problems

    NASA Technical Reports Server (NTRS)

    Huang, J. R.; Keith, Theo G., Jr.; De Witt, Kenneth J.

    1992-01-01

    In this paper, a finite element formulation based on an assumed states method is proposed for the solution of heat conduction problems with phase change at a fixed temperature. Attention is directed toward reduction of computer cost through the use of an efficient formulation, solver and algorithm. The procedure is applied to the analysis of an electrothermally deiced aircraft surface.

  8. Integrated Resilient Aircraft Control Project Full Scale Flight Validation

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.

    2009-01-01

    Objective: Provide validation of adaptive control law concepts through full scale flight evaluation. Technical Approach: a) Engage failure mode - destabilizing or frozen surface. b) Perform formation flight and air-to-air tracking tasks. Evaluate adaptive algorithm: a) Stability metrics. b) Model following metrics. Full scale flight testing provides an ability to validate different adaptive flight control approaches. Full scale flight testing adds credence to NASA's research efforts. A sustained research effort is required to remove the road blocks and provide adaptive control as a viable design solution for increased aircraft resilience.

  9. Snow Cover on the Arctic Sea Ice: Model Validation, Sensitivity, and 21st Century Projections

    NASA Astrophysics Data System (ADS)

    Blazey, Benjamin Andrew

    The role of snow cover in controlling Arctic Ocean sea ice thickness and extent is assessed with a series of models. Investigations with the stand alone Community Ice CodE (CICE) show, first, a reduction in snow depth triggers a decrease in ice volume and area, and, second, that the impact of increased snow is heavily dependent on ice and atmospheric conditions. Hindcast snow depths on the Arctic ice, simulated by the fully coupled Community Climate System Model (CCSM) are validated with 20th century in situ snow depth measurements. The snow depths in CCSM are found to be deeper than observed, likely due to excessive precipitation produced by the component atmosphere model. The sensitivity of the ice to the thermal barrier imposed by the biased snow depth is assessed. The removal of the thermodynamic impact of the exaggerated snow depth increases ice area and volume. The initial increases in ice due to enhanced conductive flux triggers feedback mechanisms with the atmosphere and ocean, reinforcing the increase in ice. Finally, the 21st century projections of decreased Arctic Ocean snow depth in CCSM are reported and diagnosed. The changes in snow are dominated by reduced accumulation due to the lack of autumn ice cover. Without this platform, much of the early snowfall is lost directly to the ocean. While this decrease in snow results in enhanced conductive flux through the ice as in the validation sensitivity experiment, the decreased summer albedo is found to dominate, as in the CICE stand alone sensitivity experiment. As such, the decrease in snow projected by CCSM in the 21st century presents a mechanism to continued ice loss. These negative (ice growth due decreased insulation) and positive (ice melt due to decreased albedo) feedback mechanisms highlight the need for an accurate representation snow cover on the ice in order to accurately simulate the evolution of Arctic Ocean sea ice.

  10. Evaluation of Arctic Sea Ice Thickness Simulated by Arctic Ocean Model Intercomparison Project Models

    NASA Technical Reports Server (NTRS)

    Johnson, Mark; Proshuntinsky, Andrew; Aksenov, Yevgeny; Nguyen, An T.; Lindsay, Ron; Haas, Christian; Zhang, Jinlun; Diansky, Nikolay; Kwok, Ron; Maslowski, Wieslaw; Hakkinen, Sirpa; Ashik, Igor; De Cuevas, Beverly

    2012-01-01

    Six Arctic Ocean Model Intercomparison Project model simulations are compared with estimates of sea ice thickness derived from pan-Arctic satellite freeboard measurements (2004-2008); airborne electromagnetic measurements (2001-2009); ice draft data from moored instruments in Fram Strait, the Greenland Sea, and the Beaufort Sea (1992-2008) and from submarines (1975-2000); and drill hole data from the Arctic basin, Laptev, and East Siberian marginal seas (1982-1986) and coastal stations (1998-2009). Despite an assessment of six models that differ in numerical methods, resolution, domain, forcing, and boundary conditions, the models generally overestimate the thickness of measured ice thinner than approximately 2 mand underestimate the thickness of ice measured thicker than about approximately 2m. In the regions of flat immobile landfast ice (shallow Siberian Seas with depths less than 25-30 m), the models generally overestimate both the total observed sea ice thickness and rates of September and October ice growth from observations by more than 4 times and more than one standard deviation, respectively. The models do not reproduce conditions of fast ice formation and growth. Instead, the modeled fast ice is replaced with pack ice which drifts, generating ridges of increasing ice thickness, in addition to thermodynamic ice growth. Considering all observational data sets, the better correlations and smaller differences from observations are from the Estimating the Circulation and Climate of the Ocean, Phase II and Pan-Arctic Ice Ocean Modeling and Assimilation System models.

  11. Ice Prevention on Aircraft by Means of Impregnated Leather Covers, Special Report

    NASA Technical Reports Server (NTRS)

    Clay, William C.

    1935-01-01

    The National Advisory Committee for Aeronautics is testing the effectiveness of a method to prevent the formation of ice on airplanes. The system makes use of a leather cover that is attached to the leading edge of the wing. A small tube, attached to the inner surface of the leather, distributes to the leading edge a solution that permeates throughout the leather and inhibits the formation of ice on the surface. About 25 pounds of the liquid per hour would be sufficient to prevent ice from forming on a wing of 50-foot span. The additional gross weight of the system will not be excessive. The tests are not yet completed but the method is thought to be practicable for the wing and it may also be adaptable to the propeller.

  12. NASA's Operation IceBridge: using instrumented aircraft to bridge the observational gap between ICESat and ICESat-2 laser altimeter measurements (Invited)

    NASA Astrophysics Data System (ADS)

    Studinger, M.; Koenig, L.; Martin, S.; Sonntag, J. G.

    2010-12-01

    In 2009, the NASA satellite laser altimeter mission ICESat (Ice, Cloud and Land Elevation Satellite), which was launched in 2003, ceased to operate. To bridge the gap in polar laser observations between ICESat and its replacement ICESat-2, which is not scheduled for launch until 2015, Operation IceBridge, a six-year NASA airborne mission, was initiated in 2009. From a series of yearly polar flights, Operation IceBridge uses airborne instruments to map rapidly changing areas in the Arctic and Antarctic, building on two decades of repeat airborne and satellite measurements. Combined with previous aircraft observations, as well as ICESat, CryoSat-2 and the forthcoming ICESat-2 observations, Operation IceBridge will produce a cross-calibrated 17-year time series of ice sheet and sea-ice elevation data over Antarctica, as well as a 27-year time series over Greenland. These time series will be a critical resource for predictive models of sea ice and ice sheet behavior. In addition to laser altimetry, Operation IceBridge is using a comprehensive suite of instruments to produce a three-dimensional view of the Arctic and Antarctic ice sheets, ice shelves and the sea ice. The suite includes two NASA laser altimeters, the Airborne Topographic Mapper (ATM) and the Land, Vegetation and Ice Sensor (LVIS); four radar systems from the University of Kansas’ Center for Remote Sensing of Ice Sheets (CReSIS), a Ku-band radar altimeter, accumulation radar, snow radar and the Multichannel Coherent Radar Depth Sounder (MCoRDS); a Sander Geophysics airborne gravimeter (AIRGrav) and a high resolution stereographic camera (DMS). The first Operation IceBridge flights were conducted between March and May 2009 over the Arctic and between October and November 2009 over Antarctica. Since its start in 2009, Operation IceBridge has flown 69 science missions, 580 flight hours and collected more than 350,000 km of data. All Operation IceBridge data are available at NSDIC: http

  13. The examination of a downslope warming wind event over the Larsen Ice Shelf in Antarctica through modeling and aircraft observations.

    NASA Astrophysics Data System (ADS)

    Grosvenor, Daniel; Choularton, Thomas; King, John; Lachlan-Cope, Thomas

    2010-05-01

    During the last 50-60 years temperatures over the Antarctic Peninsula region have increased more rapidly than anywhere else in the southern hemisphere, at several times the global average rate. At one station, the near-surface warming between 1951 and 2004 was 2.94 oC compared to a global average of 0.52 oC. However, the seasonal pattern of this regional warming has varied with location, with the east side having warmed more than the west in the autumn and summer seasons. This is important since the process of surface melting on the Larsen ice shelves, which are located on the east side, predominately occurs in summer. Crevasse propagation due to the weight of accumulated melt water is currently thought to have been the major factor in causing the catastrophic near-total disintegration of the Larsen B ice shelf in 2002, representing a loss of ice of area 3200 km2. The larger and more southerly Larsen C ice shelf could also suffer a similar fate if the warming continues, with consequences for the ecology and for increased glacier flow, leading to sea level rise. The difference in warming between the east and west side in these seasons is thought to have been driven by circulation changes that have led to increases in the strength of westerly winds. The high mountains of the Antarctic Peninsula provide a climatic barrier between the warmer oceanic air of the west and the cold continental air of the east. It has been suggested that increased westerlies allow warm winds to cross to the east side more frequently. The warming of westerly flow can also be enhanced by latent heat release on the upslope side and/or adiabatic descent of air from above, on the downslope side. In January 2006 the British Antarctic Survey performed an aircraft flight over the Larsen C ice shelf on the east side of the Peninsula, which sampled a strong downslope warming wind event. Surface flux measurements over the ice shelf suggest that the sensible heat provided by the warm jets would be

  14. Surface micro-grooves for near-wall exergy and flow control: application to aircraft intake de-icing

    NASA Astrophysics Data System (ADS)

    Naterer, G. F.; Glockner, P. S.; Thiele, D.; Chomokovski, S.; Venn, G.; Richardson, G.

    2005-03-01

    This paper develops a new surface micro-profiling technique for reducing exergy losses and controlling near-wall flow processes, particularly for anti-icing of a helicopter surface. Fabrication of embedded surface microchannels entails surface etching with KOH and XeF2 gas, so that the interspersed microchannels can be assembled into a surface layer of silicon. Testing of the micro-profiled surfaces is performed with particle image velocimetry in a water tunnel. Experimental data indicate that converging open microchannels lead to certain differences of flow patterns on the downstream side of an engine cooling bay. Furthermore, exergy losses for external flow past the parallel embedded microchannels are shown to be lower than previous benchmark results without microchannels. Analytical results are presented for these losses of available energy and exergy destruction. Reduced drag of slip-flow conditions within each microchannel offsets the added friction irreversibility of larger surface area. By altering the near-wall flow patterns, it is anticipated that embedded surface microchannels can provide a useful new approach for dealing with flow-related problems of aircraft icing.

  15. Overview of the Small Aircraft Transportation System Project Four Enabling Operating Capabilities

    NASA Technical Reports Server (NTRS)

    Viken, Sally A.; Brooks, Frederick M.; Johnson, Sally C.

    2005-01-01

    It has become evident that our commercial air transportation system is reaching its peak in terms of capacity, with numerous delays in the system and the demand still steadily increasing. NASA, FAA, and the National Consortium for Aviation Mobility (NCAM) have partnered to aid in increasing the mobility throughout the United States through the Small Aircraft Transportation System (SATS) project. The SATS project has been a five-year effort to provide the technical and economic basis for further national investment and policy decisions to support a small aircraft transportation system. The SATS vision is to enable people and goods to have the convenience of on-demand point-to-point travel, anywhere, anytime for both personal and business travel. This vision can be obtained by expanding near all-weather access to more than 3,400 small community airports that are currently under-utilized throughout the United States. SATS has focused its efforts on four key operating capabilities that have addressed new emerging technologies, procedures, and concepts to pave the way for small aircraft to operate in nearly all weather conditions at virtually any runway in the United States. These four key operating capabilities are: Higher Volume Operations at Non-Towered/Non-Radar Airports, En Route Procedures and Systems for Integrated Fleet Operations, Lower Landing Minimums at Minimally Equipped Landing Facilities, and Increased Single Pilot Performance. The SATS project culminated with the 2005 SATS Public Demonstration in Danville, Virginia on June 5th-7th, by showcasing the accomplishments achieved throughout the project and demonstrating that a small aircraft transportation system could be viable. The technologies, procedures, and concepts were successfully demonstrated to show that they were safe, effective, and affordable for small aircraft in near all weather conditions. The focus of this paper is to provide an overview of the technical and operational feasibility of the

  16. ICEPOD - Developing Ice Imaging Capabilities for the New York Air National Guard's LC-130 Aircraft

    NASA Astrophysics Data System (ADS)

    Detemple, J.; Frearson, N.; Zappa, C. J.; Turrin, M.; Bell, R. E.

    2010-12-01

    The ICEPOD program is a 5-year development effort to develop a polar instrumentation suite for the New York Air National Guard’s (NYANG) LC-130’s supported by the NSF American Reinvestment and Recovery Act (ARRA) Major Research Instrumentation program. The fundamental goal of the ICEPOD program is to develop an instrumentation package that can capture the dynamics of the changing polar regions, focusing on ice and ocean targets. The vision is for this instrumentation to be operated both on routine flights of the NYANG in the polar regions, such as missions between McMurdo and South Pole Station and on targeted science missions, such as mapping the sea ice and outlet glaciers surrounding Ross Island or the draining systems from large subglacial lakes in East Antarctica. We are in the process of finalizing the science requirements for the system. To provide support to the ICEPOD development, we are defining the goals for imaging the surface of the ice sheet with a scanning laser system and stereo-photogrammetry, the temperature of the ice surface using an IR camera and the internal structure of the ice sheet using a depth-sounding radar and an accumulation radar. The instrumentation will be positioned using an IMU and differential GPS. We also are working toward two operational modes - low-altitude flight operations to optimize the surface imaging systems, specifically the scanning laser, and a high-altitude flight operation to facilitate wide use of the instrumentation suite during a routine NYANG support mission flight envelope. The ICEPOD program is seeking input on the science goals of the instrumentation suite to ensure the system meets the community’s need for observations. The ultimate goal of the ICEPOD program is to provide the community with a facility for dedicated and routine measurements over the polar regions using the suite of instruments. The final ICEPOD system will also be capable of supporting instrumentation developed by other groups. The

  17. Prediction of ice accretion on a swept NACA 0012 airfoil and comparisons to flight test results

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.

    1992-01-01

    In the winter of 1989-90, an icing research flight project was conducted to obtain swept wing ice accretion data. Utilizing the NASA Lewis Research Center's DHC-6 DeHavilland Twin Otter aircraft, research flights were made into known icing conditions in Northeastern Ohio. The icing cloud environment and aircraft flight data were measured and recorded by an onboard data acquisition system. Upon entry into the icing environment, a 24 inch span, 15 inch chord NACA 0012 airfoil was extended from the aircraft and set to the desired sweep angle. After the growth of a well defined ice shape, the airfoil was retracted into the aircraft cabin for ice shape documentation. The ice accretions were recorded by ice tracings and photographs. Ice accretions were mostly of the glaze type and exhibited scalloping. The ice was accreted at sweep angles of 0, 30, and 45 degrees. A 3-D ice accretion prediction code was used to predict ice profiles for five selected flight test runs, which include sweep angle of zero, 30, and 45 degrees. The code's roughness input parameter was adjusted for best agreement. A simple procedure was added to the code to account for 3-D ice scalloping effects. The predicted ice profiles are compared to their respective flight test counterparts. This is the first attempt to predict ice profiles on swept wings with significant scalloped ice formations.

  18. Ice saturation at the tropopause observed from the ER-2 aircraft

    NASA Technical Reports Server (NTRS)

    Murphy, D. M.; Kelly, K. K.; Tuck, A. F.; Proffitt, M. H.; Kinne, S.

    1990-01-01

    Ice saturation at or just above the tropopause was frequently observed during the ER-2 vertical profiles over Stavanger (59 deg N) during the Airborne Arctic Stratospheric Expedition (AASE). On occasion, ice saturation extended as much as 500 m above the tropopause. Saturation was not observed over Punta Arenas (53 deg S) during the Airborne Antarctic Ozone Experiment. Saturation extending just above the tropopause was observed at Moffett Field (38 deg N) in winter but not in summer. The top of a thick cirrus layer at the tropopause will be very strongly cooled, and a thin cloud layer at the tropopause will either be strongly heated or cooled depending on the presence of lower level clouds. Some ER-2 data suggests removal of water and nitrogen species from the tropopause.

  19. Uncertainty in climate model projections of Arctic sea ice decline: An evaluation relevant to polar bears

    USGS Publications Warehouse

    DeWeaver, Eric

    2007-01-01

    This report describes uncertainties in climate model simulations of Arctic sea ice decline, and proposes a selection criterion for models to be used in projecting polar bear (Ursus maritimus) habitat loss. Uncertainties in model construction are discussed first, both for climate models in general and for their sea ice component models. A key point in the discussion is that the inherent climate sensitivity of sea ice leads inevitably to uncertainty in simulations of sea ice decline. The ability of climate models to simulate gross properties of Arctic ice cover, including the annual mean, seasonal cycle, and recent trends, is then assessed, followed by a review of model projections of 21st Century decline. The proposed selection criterion selects models with less than 20% error in their simulations of present-day September sea ice extent, where extent is defined as the area of the Arctic with at least 50% ice cover. Of the 10 models satisfying this criterion, all lose at least 30% of their September ice extent, and 4 lose over 80% of their September ice by the middle of the 21st Century (years 2045 to 2055). By the end of the 21st Century (years 2090 to 2099), seven of the models are essentially ice free in September.

  20. Impacts of projected sea ice changes on trans-Arctic navigation

    NASA Astrophysics Data System (ADS)

    Stephenson, S. R.; Smith, L. C.

    2012-12-01

    Reduced Arctic sea ice continues to be a palpable signal of global change. Record lows in September sea ice extent from 2007 - 2011 have fueled speculation that trans-Arctic navigation routes may become physically viable in the 21st century. General Circulation Models project a nearly ice-free Arctic Ocean in summer by mid-century; however, how reduced sea ice will realistically impact navigation is not well understood. Using the ATAM (Arctic Transportation Accessibility Model) we present simulations of 21st-century trans-Arctic voyages as a function of climatic (ice) conditions and vessel class. Simulations are based on sea ice projections for three climatic forcing scenarios (RCP 4.5, 6.0, and 8.5 W/m^2) representing present-day and mid-century conditions, assuming Polar Class 6 (PC6) and open-water vessels (OW) with medium and no ice-breaking capability, respectively. Optimal least-cost routes (minimizing travel time while avoiding ice impassible to a given vessel class) between the North Atlantic and the Bering Strait were calculated for summer months of each time window. While Arctic navigation depends on other factors besides sea ice including economics, infrastructure, bathymetry, current, and weather, these projections should be useful for strategic planning by governments, regulatory and environmental agencies, and the global maritime industry to assess potential changes in the spatial and temporal ranges of Arctic marine operations.

  1. Simulating the Antarctic ice sheet in the late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project

    NASA Astrophysics Data System (ADS)

    de Boer, B.; Dolan, A. M.; Bernales, J.; Gasson, E.; Goelzer, H.; Golledge, N. R.; Sutter, J.; Huybrechts, P.; Lohmann, G.; Rogozhina, I.; Abe-Ouchi, A.; Saito, F.; van de Wal, R. S. W.

    2015-05-01

    In the context of future climate change, understanding the nature and behaviour of ice sheets during warm intervals in Earth history is of fundamental importance. The late Pliocene warm period (also known as the PRISM interval: 3.264 to 3.025 million years before present) can serve as a potential analogue for projected future climates. Although Pliocene ice locations and extents are still poorly constrained, a significant contribution to sea-level rise should be expected from both the Greenland ice sheet and the West and East Antarctic ice sheets based on palaeo sea-level reconstructions. Here, we present results from simulations of the Antarctic ice sheet by means of an international Pliocene Ice Sheet Modeling Intercomparison Project (PLISMIP-ANT). For the experiments, ice-sheet models including the shallow ice and shelf approximations have been used to simulate the complete Antarctic domain (including grounded and floating ice). We compare the performance of six existing numerical ice-sheet models in simulating modern control and Pliocene ice sheets by a suite of five sensitivity experiments. We include an overview of the different ice-sheet models used and how specific model configurations influence the resulting Pliocene Antarctic ice sheet. The six ice-sheet models simulate a comparable present-day ice sheet, considering the models are set up with their own parameter settings. For the Pliocene, the results demonstrate the difficulty of all six models used here to simulate a significant retreat or re-advance of the East Antarctic ice grounding line, which is thought to have happened during the Pliocene for the Wilkes and Aurora basins. The specific sea-level contribution of the Antarctic ice sheet at this point cannot be conclusively determined, whereas improved grounding line physics could be essential for a correct representation of the migration of the grounding-line of the Antarctic ice sheet during the Pliocene.

  2. Reducing Spread in Climate Model Projections of a September Ice-Free Arctic

    NASA Technical Reports Server (NTRS)

    Liu, Jiping; Song, Mirong; Horton, Radley M.; Hu, Yongyun

    2013-01-01

    This paper addresses the specter of a September ice-free Arctic in the 21st century using newly available simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5). We find that large spread in the projected timing of the September ice-free Arctic in 30 CMIP5 models is associated at least as much with different atmospheric model components as with initial conditions. Here we reduce the spread in the timing of an ice-free state using two different approaches for the 30 CMIP5 models: (i) model selection based on the ability to reproduce the observed sea ice climatology and variability since 1979 and (ii) constrained estimation based on the strong and persistent relationship between present and future sea ice conditions. Results from the two approaches show good agreement. Under a high-emission scenario both approaches project that September ice extent will drop to approx. 1.7 million sq km in the mid 2040s and reach the ice-free state (defined as 1 million sq km) in 2054-2058. Under a medium-mitigation scenario, both approaches project a decrease to approx.1.7 million sq km in the early 2060s, followed by a leveling off in the ice extent.

  3. Effect of drop size on the impact thermodynamics for supercooled large droplet in aircraft icing

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Liu, Hong

    2016-06-01

    Supercooled large droplet (SLD), which can cause abnormal icing, is a well-known issue in aerospace engineering. Although efforts have been exerted to understand large droplet impact dynamics and the supercooled feature in the film/substrate interface, respectively, the thermodynamic effect during the SLD impact process has not received sufficient attention. This work conducts experimental studies to determine the effects of drop size on the thermodynamics for supercooled large droplet impingement. Through phenomenological reproduction, the rapid-freezing characteristics are observed in diameters of 400, 800, and 1300 μm. The experimental analysis provides information on the maximum spreading rate and the shrinkage rate of the drop, the supercooled diffusive rate, and the freezing time. A physical explanation of this unsteady heat transfer process is proposed theoretically, which indicates that the drop size is a critical factor influencing the supercooled heat exchange and effective heat transfer duration between the film/substrate interface. On the basis of the present experimental data and theoretical analysis, an impinging heating model is developed and applied to typical SLD cases. The model behaves as anticipated, which underlines the wide applicability to SLD icing problems in related fields.

  4. Effects of postdepositional processing on nitrogen isotopes of nitrate in the Greenland Ice Sheet Project 2 ice core

    NASA Astrophysics Data System (ADS)

    Geng, Lei; Zatko, Maria C.; Alexander, Becky; Fudge, T. J.; Schauer, Andrew J.; Murray, Lee T.; Mickley, Loretta J.

    2015-07-01

    Records of ice core nitrate and its isotopes hold the potential to assess past atmospheric conditions regarding NOx and oxidant levels. However, relating such records to past atmospheric conditions requires a site-specific understanding of the postdepositional processing of snow nitrate. We report δ15N(NO3-) records from the Greenland Ice Sheet Project 2 (GISP2) ice core over major climate transitions. Model calculations and comparison with records of parameters influencing UV-driven postdepositional processing of snow nitrate suggest that the observed variability in GISP2 δ15N(NO3-) over major climate transitions is primarily driven by changes in the degree of postdepositional loss of snow nitrate. Estimates of the fractional loss of snow nitrate is (16-23)% in the Holocene and (45-53)% in the glacial period, suggesting a (41 ± 32)% lower nitrate depositional flux to Greenland during the glacial period relative to the Holocene.

  5. Regional variability of a projected sea ice-free Arctic during the summer months

    NASA Astrophysics Data System (ADS)

    Laliberté, F.; Howell, S. E. L.; Kushner, P. J.

    2016-01-01

    Climate projections of sea ice retreat under anthropogenic climate change at the regional scale and in summer months other than September have largely not been evaluated. Information at this level of detail is vital for future planning of safe Arctic marine activities. Here the timing of when Arctic waters will be reliably ice free across Arctic regions from June to October is presented. It is shown that during this century regions along the Northern Sea Route and Arctic Bridge will be more reliably ice free than regions along the Northwest Passage and the Transpolar Sea Route, which will retain substantial sea ice cover past midcentury. Moreover, ice-free conditions in the Arctic will likely be confined to September for several decades to come in many regions. Projections using a selection of models that accounts for agreement of models in each region and calendar month with observations yield similar conclusions.

  6. Dynamics of molecules in a supercooled water nanoparticle during the ice accretion on the aircraft surface

    NASA Astrophysics Data System (ADS)

    Amelyushkin, I. A.; Stasenko, A. L.

    2015-06-01

    The principal aim of this work is to elaborate a robust physical model and the corresponding numerical code for prediction of the icing startup due to numerous water nanoparticles in the supercooled humid air. For this purpose, a scientified approach was used which is based not on the quantum-mechanics considerations but on the information about intermolecular potentials (especially, Lennard-Jones (LJ), etc.) tightly connected with the state equations of the corresponding specie (e. g., van der Waals for air and water and Mie-Grünaisen for circumfluent body). u In other words, the principal idea of this work is to adequately ascribe certain macroscopic characteristics of a water nanoparticle which may significantly differ from those indicated in physical reference books for bulk materials.

  7. Toward Unanimous Projections for Sea Ice Using CMIP5 Multi-model Simulations

    NASA Astrophysics Data System (ADS)

    Yang, S.; Christensen, J. H.; Langen, P. P.; Thejll, P.

    2015-12-01

    Coupled global climate models have been used to provide future climate projections as major objective tools based on physical laws that govern the dynamics and thermodynamics of the climate system. However, while climate models in general predict declines in Arctic sea ice cover (i.e., ice extent and volume) from late 20th century through the next decades in response to increase of anthropogenic forcing, the model simulated Arctic sea ice demonstrates considerable biases in both the mean and the declining trend in comparison with the observations over the satellite era (1979-present). The models also show wide inter-model spread in hindcast and projected sea ice decline, raising the question of uncertainty in model predicted polar climate. In order to address the model uncertainty in the Arctic sea ice projection, we analyze the Arctic sea ice extent under the context of surface air temperature (SAT) as simulated in the historical, RCP4.5 and RCP8.5 experiments by 27 CMIP5 models. These 27 models are all we could obtain from the CMIP5 archive with sufficient gird information for processing the sea ice data. Unlike many previous studies in which only limited number of models were selected based on metrics of modeled sea ice characteristics for getting projected ice with reduced uncertainty, our analysis is applied to all model simulations with no discrimination. It is found that the changes in total Arctic sea ice in various seasons from one model are closely related to the changes in global mean SAT in the corresponding model. This relationship appears very similar in all models and agrees well with that in the observational data. In particular, the ratio of the total Arctic sea ice changes in March, September and annual mean with respect to the baseline climatology (1979-2008) are seen to linearly correlate to the global mean annual SAT anomaly, suggesting unanimous projection of the sea ice extent may be possible with this relationship. Further analysis is

  8. Coulman High Project Site Survey Interdisciplinary Outcomes: What Lies Beneath The Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    Rack, F. R.; Zook, R.; Mahacek, P.; Carroll, D.; Levy, R. H.; Limeburner, R.; Williams, M.; Stewart, C.; C/O Andrill Smo, A.

    2011-12-01

    The ANDRILL Coulman High (CH) Project Site Surveys were an international effort conducted from November 2010 through January 2011. These surveys achieved all their primary and secondary objectives and resulted in an unexpected biological discovery at the lower boundary of the Ross Ice Shelf (RIS), which demonstrates the role of serendipity in scientific research. The surveys followed a safe traverse route to CH across the RIS using a ground-penetrating radar system supplemented by previously collected airborne radar. Four GPS stations and a weather station were established to monitor lateral and vertical ice motions and environmental conditions. A series of combined US-NZ field camps on the RIS were occupied and the ANDRILL hot water drill (HWD) system was used to melt numerous holes through 250-275 meters of ice shelf. Oceanographic moorings comprised of inductive sensors were deployed through the RIS at two sites and were recovered to the ice surface after two months. The NZ mooring was redeployed to conduct long-term observations through the water column at CH. Video camera observations of the interior and basal surface of the ice shelf and benthic observations of the seafloor were integrated with conductivity-temperature-depth (CTD) measurements at each site. The Submersible Capable of under-Ice Navigation and Imaging (SCINI) underwater remotely operated vehicle (ROV) was deployed at two sites through 260 meters of ice to explore the underside of the ice shelf while conducting operational testing. This was the first time that SCINI was deployed through an ice shelf. SCINI discovered an unusual biological community living in the ice at the lower surface of the ice shelf and recovered biological samples using an improvised suction pump sampler. These samples and extensive imagery are being further investigated to determine the nature of this newly discovered ecosystem. The biological discovery at the base of the RIS highlights the importance of continued

  9. Aircraft engine hot section technology: An overview of the HOST Project

    NASA Technical Reports Server (NTRS)

    Sokolowski, Daniel E.; Hirschberg, Marvin H.

    1990-01-01

    NASA sponsored the Turbine Engine Hot Section (HOST) project to address the need for improved durability in advanced aircraft engine combustors and turbines. Analytical and experimental activities aimed at more accurate prediction of the aerothermal environment, the thermomechanical loads, the material behavior and structural responses to loads, and life predictions for cyclic high temperature operation were conducted from 1980 to 1987. The project involved representatives from six engineering disciplines who are spread across three work disciplines - industry, academia, and NASA. The HOST project not only initiated and sponsored 70 major activities, but also was the keystone in joining the multiple disciplines and work sectors to focus on critical research needs. A broad overview of the project is given along with initial indications of the project's impact.

  10. Cost and schedule management on the quiet short-haul research aircraft project

    NASA Technical Reports Server (NTRS)

    Wilcox, D. E.; Patterakis, P.

    1979-01-01

    The Quiet Short-Haul Research Aircraft (QSRA) Project, one of the largest aeronautical programs undertaken by NASA to date, achieved a significant cost underrun. This is attributed to numerous factors, not the least of which were the contractual arrangement and the system of cost and schedule management employed by the contractor. This paper summarizes that system and the methods used for cost/performance measurement by the contractor and by the NASA project management. Recommendations are made for the use of some of these concepts in particular for future programs of a similar nature.

  11. Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP

    NASA Astrophysics Data System (ADS)

    Pattyn, F.; Schoof, C.; Perichon, L.; Hindmarsh, R. C. A.; Bueler, E.; de Fleurian, B.; Durand, G.; Gagliardini, O.; Gladstone, R.; Goldberg, D.; Gudmundsson, G. H.; Lee, V.; Nick, F. M.; Payne, A. J.; Pollard, D.; Rybak, O.; Saito, F.; Vieli, A.

    2012-01-01

    Predictions of marine ice-sheet behaviour require models that are able to robustly simulate grounding line migration. We present results of an intercomparison exercise for marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no effects of lateral buttressing). Unique steady-state grounding line positions exist for ice sheets on a downward sloping bed, while hysteresis occurs across an overdeepened bed, and stable steady state grounding line positions only occur on the downward-sloping sections. Models based on the shallow ice approximation, which does not resolve extensional stresses, do not reproduce the approximate analytical results unless appropriate parameterizations for ice flux are imposed at the grounding line. For extensional-stress resolving "shelfy stream" models, differences between model results were mainly due to the choice of spatial discretization. Moving grid methods were found to be the most accurate at capturing grounding line evolution, since they track the grounding line explicitly. Adaptive mesh refinement can further improve accuracy, including in fixed-grid models that generally perform poorly at coarse resolution. Fixed grid models with nested grid representations of the grounding line are able to generate accurate steady-state positions, but can be inaccurate over transients. Only one full Stokes model was included in the intercomparison, and consequently the accuracy of shelfy stream models as approximations of full Stokes models remains to be determined in detail, especially during transients.

  12. Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP

    NASA Astrophysics Data System (ADS)

    Pattyn, F.; Schoof, C.; Perichon, L.; Hindmarsh, R. C. A.; Bueler, E.; de Fleurian, B.; Durand, G.; Gagliardini, O.; Gladstone, R.; Goldberg, D.; Gudmundsson, G. H.; Huybrechts, P.; Lee, V.; Nick, F. M.; Payne, A. J.; Pollard, D.; Rybak, O.; Saito, F.; Vieli, A.

    2012-05-01

    Predictions of marine ice-sheet behaviour require models that are able to robustly simulate grounding line migration. We present results of an intercomparison exercise for marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no effects of lateral buttressing). Unique steady state grounding line positions exist for ice sheets on a downward sloping bed, while hysteresis occurs across an overdeepened bed, and stable steady state grounding line positions only occur on the downward-sloping sections. Models based on the shallow ice approximation, which does not resolve extensional stresses, do not reproduce the approximate analytical results unless appropriate parameterizations for ice flux are imposed at the grounding line. For extensional-stress resolving "shelfy stream" models, differences between model results were mainly due to the choice of spatial discretization. Moving grid methods were found to be the most accurate at capturing grounding line evolution, since they track the grounding line explicitly. Adaptive mesh refinement can further improve accuracy, including fixed grid models that generally perform poorly at coarse resolution. Fixed grid models, with nested grid representations of the grounding line, are able to generate accurate steady state positions, but can be inaccurate over transients. Only one full-Stokes model was included in the intercomparison, and consequently the accuracy of shelfy stream models as approximations of full-Stokes models remains to be determined in detail, especially during transients.

  13. Arctic spring ozone reduction associated with projected sea ice loss

    NASA Astrophysics Data System (ADS)

    Deser, C.; Sun, L.; Tomas, R. A.; Polvani, L. M.

    2013-12-01

    The impact of Arctic sea ice loss on the stratosphere is investigated using the Whole-Atmosphere Community Climate Model (WACCM), by prescribing the sea ice in the late 20th century and late 21st century, respectively. The localized Sea Surface Temperature (SST) change associated with sea ice melt is also included in the future run. Overall, the model simulates a negative annular-mode response in the winter and spring. In the stratosphere, polar vortex strengthens from February to April, peaking in March. Consistent with it, there is an anomalous cooling in the high-latitude stratosphere, and polar cap ozone reduction is up to 20 DU. Since the difference between these two runs lies only in the sea ice and localized SST in the Arctic, the stratospheric circulation and ozone changes can be attributed to the surface forcing. Eliassen-Palm analysis reveals that the upward propagation of planetary waves is suppressed in the spring as a consequence of sea ice loss. The reduction in propagation causes less wave dissipation and thus less zonal wind deceleration in the extratropical stratosphere.

  14. Software Released by LEWICE 2.0 Ice Accretion Software Development Project

    NASA Technical Reports Server (NTRS)

    Potapczuk, Mark G.

    2000-01-01

    Computational icing simulation methods are making the transition from the realm of research to commonplace use in design and certification. As such, standards of software management, design, validation, and documentation must be adjusted to accommodate the increased expectations of the user community with respect to accuracy, reliability, capability, and usability. With this in mind, in collaboration with Glenn's Engineering Design and Analysis Division, the Icing Branch of the NASA Glenn Research Center at Lewis Field began a software improvement project focused on the two-dimensional ice accretion simulation tool LEWICE. This project is serving as an introduction to the concepts of software management and is intended to serve as a pilot project for future icing simulation code development. The LEWICE 2.0 Software Development Project consisted of two major elements: software management and software validation. The software management element consisted of identifying features of well-designed and well-managed software that are appropriate for an analytical prediction tool such as LEWICE and applying them to a revised version of the code. This element included tasks such as identification of software requirements, development and implementation of coding standards, and implementation of software revision control practices. With the application of these techniques, the LEWICE ice accretion code became a more stable and reliable software product. In addition, the lessons learned about software development and maintenance can be factored into future software projects at the outset. The software validation activity was an integral part of our effort to make LEWICE a more accurate and reliable analysis tool. Because of the efforts taken to extensively validate this software, LEWICE 2.0 is more robust than previous releases and can reproduce results accurately across several computing platforms. It also differs from previous versions in the extensive quantitative

  15. Improved Arctic Sea Ice Thickness Projections Using Bias Corrected CMIP5 Simulations

    NASA Astrophysics Data System (ADS)

    Melia, N.; Hawkins, E.; Haines, K.

    2015-12-01

    Projections of Arctic sea ice thickness (SIT) have the potential to inform stakeholders about accessibility to the region, but are currently rather uncertain. The latest suite of CMIP5 Global Climate Models (GCMs) produce a wide range of simulated SIT in the historical period (1979-2014) and exhibit various spatial and temporal biases when compared with the Pan-Arctic Ice Ocean Modelling and Assimilation System (PIOMAS) sea ice reanalysis. We present a new method to constrain such GCM simulations of SIT to narrow projection uncertainty via a statistical bias correction technique. The bias correction successfully constrains the spatial SIT distribution and temporal variability in the CMIP5 projections whilst retaining the climatic fluctuations from individual ensemble members. The bias correction acts to reduce the uncertainty in projections of SIT and reveals the significant contributions of sea ice internal variability in the first half of the century and of scenario uncertainty from mid-century onwards. The projected date of ice-free conditions in the Arctic under the RCP8.5 high emission scenario occurs in the 2050s, which is a decade earlier than without the bias correction, with potentially significant implications for stakeholders in the Arctic such as the shipping industry. The bias correction methodology developed could be similarly applied to other variables to narrow uncertainty in climate projections more generally.

  16. The Winter 2010 and 2011 FRONT/NIRSS In-Flight Icing Hazard Detection Project

    NASA Technical Reports Server (NTRS)

    Serke, David; Hubbert, John; Reehorst, Andrew; Kennedy, Patrick; Politovich, Marcia

    2011-01-01

    The NASA Icing Remote Sensing System (NIRSS) deploys a vertically-pointing K-band radar, a lidar ceiliometer, and a profiling microwave radiometer to obtain measurements for diagnosing local inflight icing conditions. RAL is working with NASA GRC to develop algorithms and data ingest and display software for the system. NASA has an ongoing activity to develop remote sensing technologies for the detection and measurement of icing conditions aloft. As part of that effort NASA teamed with NCAR to develop software that fuses data from multiple instruments into a single detected icing condition product. The multiple instrument approach, which is the current emphasis of this activity, utilizes a K-band vertical staring radar, a microwave radiometer that detects 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 in C++ program with a Java-based web display of resultant supercooled LWC profile and aircraft hazard identification. In 2010, a multi-channel scanning radiometer, designed and built by Radiometrics, Inc. under a SBIR grant,,was added to the system to assess its utility in improving icing diagnoses.

  17. Ice crystal ingestion by turbofans

    NASA Astrophysics Data System (ADS)

    Rios Pabon, Manuel A.

    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.

  18. Future ice ages and the challenges related to final disposal of nuclear waste: The Greenland Ice Sheet Hydrology Project

    NASA Astrophysics Data System (ADS)

    Lehtinen, A.; Claesson-Liljedahl, L.; Näslund, J.-O.; Ruskeeniemi, T.

    2009-04-01

    ) provides a good analogue for this purpose due to similarities in geology (in the selected study area), and the climate conditions and ice sheet size in Kangerlussuaq resemble the expected conditions in Fennoscandia during future glaciations. In 2005 and 2008 reconnaissance field trips were made to Kangerlussuaq, which confirmed the suitability of the area for the planned studies. According to the present Work Programme the investigations will be carried out in 2009-2012. The project is divided into four subprojects (SPA, SPB, SPC and SPD) addressing specific and different topics at or in relation to the ice margin: SPA (ice sheet hydrology and glacial groundwater formation); SPB (subglacial ice sheet hydrology), SPC (hydrogeochemistry and hydrogeology) and SPD (periglacial environment: biosphere and permafrost). The main objectives of SPA and SPB are to gain a better process understanding of supra- and subglacial hydrology. Qualitative and quantitative knowledge of the mechanisms, rates and distribution of the melt water recharge through the ice down to the bed, location and extension of warm-based areas and hydraulic pressure conditions at the base are the key issues to be studied. This will be made by meteorological observations, GPS measurements, radar surveys, drilling through the ice sheet and by ice sheet modelling. SPC will further study the fate of melt water by extending the investigations into the bedrock. It is assumed that the high hydraulic pressures at the ice sheet bed force water into the fracture network prevailing in the bedrock. However, it is not known how the fracture network behaves under loading, what is the proportion of recharging water compared to the drainage through the bed sediments, what is the intrusion depth, how long the meltwater can sustain its oxic nature and what chemical composition the recharging water has when and if it reaches repository depth (400-700 m). SPC seeks to answer these questions by drilling and instrumenting boreholes

  19. Simulating the Antarctic ice sheet in the Late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project

    NASA Astrophysics Data System (ADS)

    de Boer, Bas; Dolan, Aisling; Bernales, Jorge; Gasson, Edward; Goelzer, Heiko; Golledge, Nick; Sutter, Johannes; Huybrechts, Phillipe; Lohmann, Gerrit; Rogozhina, Irina; Abe-Ouchi, Ayako; Saito, Fuyuki; van de Wal, Roderik

    2015-04-01

    In the context of future climate change, understanding the nature and behaviour of ice sheets during warm intervals in Earth history is of fundamental importance. The Late-Pliocene warm period (also known as the PRISM interval: 3.264 to 3.025 million years before present) can serve as a potential analogue for projected future climates. Although Pliocene ice locations and extents are still poorly constrained, a significant contribution to sea-level rise should be expected from both the Greenland ice sheet and the West and East Antarctic ice sheets based on palaeo sea-level reconstructions. Here, we present results from simulations of the Antarctic ice sheet by means of an international Pliocene Ice Sheet Modeling Intercomparison Project (PLISMIP-ANT). For the experiments, ice-sheet models including the shallow ice and shelf approximations have been used to simulate the complete Antarctic domain (including grounded and floating ice). We compare the performance of six existing numerical ice-sheet models in simulating modern control and Pliocene ice sheets by a suite of four sensitivity experiments. Ice-sheet model forcing fields are taken from the HadCM3 atmosphere-ocean climate model runs for the pre-industrial and the Pliocene. We include an overview of the different ice-sheet models used and how specific model configurations influence the resulting Pliocene Antarctic ice sheet. The six ice-sheet models simulate a comparable present-day ice sheet, although the models are setup with their own parameter settings. For the Pliocene simulations using the Bedmap1 bedrock topography, some models show a small retreat of the East Antarctic ice sheet, which is thought to have happened during the Pliocene for the Wilkes and Aurora basins. This can be ascribed to either the surface mass balance, as the HadCM3 Pliocene climate shows a significant increase over the Wilkes and Aurora basin, or the initial bedrock topography. For the latter, our simulations with the recently

  20. The Roosevelt Island Climate Evolution (RICE) Project - Did the Ross Ice Shelf Collapse During MIS 5e?

    NASA Astrophysics Data System (ADS)

    Bertler, N. A. N.; Conway, H.; Dahl-Jensen, D.; Blunier, T.; Brook, E.; Dadic, R.; Delmonte, B.; Dongqi, Z.; Edwards, R.; Emanuelsson, D. B.; Fudge, T. J.; Golledge, N.; Hindmarsh, R. C. A.; Hawley, R. L.; Kipfstuhl, S.; Kjær, H. A.; Kurbatov, A.; Lee, J.; Mayewski, P. A.; Naish, T.; Neff, P. D.; Scherer, R. P.; Severinghaus, J. P.; Simonsen, M. F.; Steig, E. J.; Tuohy, A.; Vallelonga, P. T.; Waddington, E. D.

    2014-12-01

    Geological evidence and modelling experiments suggest that the removal of ice shelves from marine based ice sheets can lead to catastrophic collapse. Roosevelt and Ross Islands are thought to be key stabilization anchors for the Ross Ice Shelf and thus the West Antarctic Ice Sheet. As part of the Roosevelt Island Climate Evolution (RICE) project, a 763m deep ice core was recovered during 2011-2013 from Roosevelt Island, at the northern edge of the Ross Ice Shelf. The ice at Roosevelt Island is grounded 210m below sea level and accumulates in situ, with the Ross Ice Shelf flowing around the rise. High resolution radar surveys show a well developed Raymond Bump at the divide of the ice dome. With the conclusion of the RICE core processing campaign in July 2014, a preliminary age model is developed using annual layer count, volcanic ash layers; and high resolution methane data tied to the WAIS Divide ice core record, and a glacial flow model. Here we show preliminary data spanning over 100 ka including evidence of ice from the Eemian period (MIS 5e) at the base of the core. The presence of Eemian ice in the RICE record raises the question: how much of the Ross Ice Shelf and West Antarctic Ice Sheet collapsed during the last interglacial, when global sea level was 4-8m higher than today? We discuss reconstructions of sea surface and air temperature, sea ice extent, atmospheric circulation patterns, and ice shelf retreat. An ensemble of sensitivity modelling experiments is used to determine thresholds for the removal of ice on Roosevelt Island and correlated grounding line and ice volume changes of the Ross Ice Shelf and the West Antarctic Ice Sheet.

  1. Simulating the Antarctic ice sheet in the Late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project

    NASA Astrophysics Data System (ADS)

    de Boer, Bas; Dolan, Aisling M.; Hill, Daniel J.; van de Wal, Roderik S. W.

    2014-05-01

    In the context of future climate change, understanding the nature and behaviour of ice sheets during warm intervals in Earth history is of fundamental importance. The Late-Pliocene Warm Period (also known as the PRISM interval: 3.29 to 2.97 million years before present) can serve as a potential analogue for projected future climates, with a global annual mean surface-air temperature warming of 1.76 °C. Although Pliocene ice locations and surface extents are still poorly constrained, a significant contribution to sea-level rise should be expected from Greenland and West and, possibly, East Antarctica based on palaeo sea-level reconstructions. Here, we present results from simulations of the Antarctic ice sheet by means of an international Pliocene Ice Sheet Modeling Intercomparison Project (PLISMIP-ANT). We include an overview of the different ice-sheet models used and how specific model configurations influence the resulting Pliocene Antarctic ice sheet. For the experiments, ice-sheet models including the shallow ice and shelf approximations have been used to simulate the complete Antarctic domain (including grounded and floating ice). We compare the performance of the ice-sheet models in simulating modern control and Pliocene ice sheets by a suite of sensitivity experiments. Ice-sheet model forcing fields are taken from the PlioMIP results incorporating multiple coupled atmosphere-ocean general circulation models (GCM). We show that ice-sheet models simulate a present-day ice sheet which is comparable to the observations, and find no systematic biases introduced when using different GCM forcing relative to observational climate forcing. This project includes multiple ice-sheet models forced with multiple climate model output, from which a comprehensive assessment can be made as to the uncertainties of ice-sheet extent on Antarctica. These results may eventually serve as a new constraint on the extent of the Antarctic ice sheet during the Late-Pliocene Warm Period

  2. Simulating the Antarctic ice sheet in the Late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project

    NASA Astrophysics Data System (ADS)

    de Boer, B.; Dolan, A. M.; Bernales, J.; Gasson, E.; Goelzer, H.; Golledge, N. R.; Sutter, J.; Huybrechts, P.; Lohmann, G.; Rogozhina, I.; Abe-Ouchi, A.; Saito, F.; van de Wal, R. S. W.

    2014-11-01

    In the context of future climate change, understanding the nature and behaviour of ice sheets during warm intervals in Earth history is of fundamental importance. The Late-Pliocene warm period (also known as the PRISM interval: 3.264 to 3.025 million years before present) can serve as a potential analogue for projected future climates. Although Pliocene ice locations and extents are still poorly constrained, a significant contribution to sea-level rise should be expected from both the Greenland ice sheet and the West and East Antarctic ice sheets based on palaeo sea-level reconstructions. Here, we present results from simulations of the Antarctic ice sheet by means of an international Pliocene Ice Sheet Modeling Intercomparison Project (PLISMIP-ANT). For the experiments, ice-sheet models including the shallow ice and shelf approximations have been used to simulate the complete Antarctic domain (including grounded and floating ice). We compare the performance of six existing numerical ice-sheet models in simulating modern control and Pliocene ice sheets by a suite of four sensitivity experiments. Ice-sheet model forcing fields are taken from the HadCM3 atmosphere-ocean climate model runs for the pre-industrial and the Pliocene. We include an overview of the different ice-sheet models used and how specific model configurations influence the resulting Pliocene Antarctic ice sheet. The six ice-sheet models simulate a comparable present-day ice sheet, although the models are setup with their own parameter settings. For the Pliocene simulations using the Bedmap1 bedrock topography, some models show a small retreat of the East Antarctic ice sheet, which is thought to have happened during the Pliocene for the Wilkes and Aurora basins. This can be ascribed to either the surface mass balance, as the HadCM3 Pliocene climate shows a significant increase over the Wilkes and Aurora basin, or the initial bedrock topography. For the latter, our simulations with the recently

  3. Overview of ICE Project: Integration of Computational Fluid Dynamics and Experiments

    NASA Technical Reports Server (NTRS)

    Stegeman, James D.; Blech, Richard A.; Babrauckas, Theresa L.; Jones, William H.

    2001-01-01

    Researchers at the NASA Glenn Research Center have developed a prototype integrated environment for interactively exploring, analyzing, and validating information from computational fluid dynamics (CFD) computations and experiments. The Integrated CFD and Experiments (ICE) project is a first attempt at providing a researcher with a common user interface for control, manipulation, analysis, and data storage for both experiments and simulation. ICE can be used as a live, on-tine system that displays and archives data as they are gathered; as a postprocessing system for dataset manipulation and analysis; and as a control interface or "steering mechanism" for simulation codes while visualizing the results. Although the full capabilities of ICE have not been completely demonstrated, this report documents the current system. Various applications of ICE are discussed: a low-speed compressor, a supersonic inlet, real-time data visualization, and a parallel-processing simulation code interface. A detailed data model for the compressor application is included in the appendix.

  4. Meeting of Experts on NASA's Unmanned Aircraft System (UAS) Integration in the National Airspace Systems (NAS) Project

    NASA Technical Reports Server (NTRS)

    Wolfe, Jean; Bauer, Jeff; Bixby, C.J.; Lauderdale, Todd; Shively, Jay; Griner, James; Hayhurst, Kelly

    2010-01-01

    Topics discussed include: Aeronautics Research Mission Directorate Integrated Systems Research Program (ISRP) and UAS Integration in the NAS Project; UAS Integration into the NAS Project; Separation Assurance and Collision Avoidance; Pilot Aircraft Interface Objectives/Rationale; Communication; Certification; and Integrated Tests and Evaluations.

  5. Polar Bear Conservation Status in Relation to Projected Sea-ice Conditions

    NASA Astrophysics Data System (ADS)

    Regehr, E. V.

    2015-12-01

    The status of the world's 19 subpopulations of polar bears (Ursus maritimus) varies as a function of sea-ice conditions, ecology, management, and other factors. Previous methods to project the response of polar bears to loss of Arctic sea ice—the primary threat to the species—include expert opinion surveys, Bayesian Networks providing qualitative stressor assessments, and subpopulations-specific demographic analyses. Here, we evaluated the global conservation status of polar bears using a data-based sensitivity analysis. First, we estimated generation length for subpopulations with available data (n=11). Second, we developed standardized sea-ice metrics representing habitat availability. Third, we projected global population size under alternative assumptions for relationships between sea ice and subpopulation abundance. Estimated generation length (median = 11.4 years; 95%CI = 9.8 to 13.6) and sea-ice change (median = loss of 1.26 ice-covered days per year; 95%CI = 0.70 to 3.37) varied across subpopulations. Assuming a one-to-one proportional relationship between sea ice and abundance, the median percent change in global population size over three polar bear generations was -30% (95%CI = -35% to -25%). Assuming a linear relationship between sea ice and normalized estimates of subpopulation abundance, median percent change was -4% (95% CI = -62% to +50%) or -43% (95% CI = -76% to -20%), depending on how subpopulations were grouped and how inference was extended from relatively well-studied subpopulations (n=7) to those with little or no data. Our findings suggest the potential for large reductions in polar bear numbers over the next three polar bear generations if sea-ice loss due to climate change continues as forecasted.

  6. Extreme Access & Lunar Ice Mining in Permanently Shadowed Craters Project

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.

    2014-01-01

    Results from the recent LCROSS mission in 2010, indicate that H2O ice and other useful volatiles such as CO, He, and N are present in the permanently shadowed craters at the poles of the moon. However, the extreme topography and steep slopes of the crater walls make access a significant challenge. In addition temperatures have been measured at 40K (-233 C) so quick access and exit is desirable before the mining robot cold soaks. The Global Exploration Roadmap lists extreme access as a necessary technology for Lunar Exploration.

  7. Improved Arctic sea ice thickness projections using bias-corrected CMIP5 simulations

    NASA Astrophysics Data System (ADS)

    Melia, N.; Haines, K.; Hawkins, E.

    2015-12-01

    Projections of Arctic sea ice thickness (SIT) have the potential to inform stakeholders about accessibility to the region, but are currently rather uncertain. The latest suite of CMIP5 global climate models (GCMs) produce a wide range of simulated SIT in the historical period (1979-2014) and exhibit various biases when compared with the Pan-Arctic Ice-Ocean Modelling and Assimilation System (PIOMAS) sea ice reanalysis. We present a new method to constrain such GCM simulations of SIT via a statistical bias correction technique. The bias correction successfully constrains the spatial SIT distribution and temporal variability in the CMIP5 projections whilst retaining the climatic fluctuations from individual ensemble members. The bias correction acts to reduce the spread in projections of SIT and reveals the significant contributions of climate internal variability in the first half of the century and of scenario uncertainty from the mid-century onwards. The projected date of ice-free conditions in the Arctic under the RCP8.5 high emission scenario occurs in the 2050s, which is a decade earlier than without the bias correction, with potentially significant implications for stakeholders in the Arctic such as the shipping industry. The bias correction methodology developed could be similarly applied to other variables to reduce spread in climate projections more generally.

  8. Investigation of Meteorological Conditions Associated with Aircraft Icing in Layer-Type Clouds for 1947-48 Winter

    NASA Technical Reports Server (NTRS)

    Kline, Dwight B

    1949-01-01

    Rotating-cylinder measurements of the icing conditions encountered in flight during the winter of 1947-48 are presented. Liquid water content, drop size, and temperature data are shown to be consistent with previously measured conditions and with proposed maximum icing conditions in supercooled layer-type clouds. Cumulative frequency graphs of meteorological parameters indicate the frequency with which various icing conditions have been encountered in the Great Lakes area and surrounding states.

  9. Exposure-effect relations between aircraft and road traffic noise exposure at school and reading comprehension: the RANCH project.

    PubMed

    Clark, Charlotte; Martin, Rocio; van Kempen, Elise; Alfred, Tamuno; Head, Jenny; Davies, Hugh W; Haines, Mary M; Lopez Barrio, Isabel; Matheson, Mark; Stansfeld, Stephen A

    2006-01-01

    Transport noise is an increasingly prominent feature of the urban environment, making noise pollution an important environmental public health issue. This paper reports on the 2001-2003 RANCH project, the first cross-national epidemiologic study known to examine exposure-effect relations between aircraft and road traffic noise exposure and reading comprehension. Participants were 2,010 children aged 9-10 years from 89 schools around Amsterdam Schiphol, Madrid Barajas, and London Heathrow airports. Data from The Netherlands, Spain, and the United Kingdom were pooled and analyzed using multilevel modeling. Aircraft noise exposure at school was linearly associated with impaired reading comprehension; the association was maintained after adjustment for socioeconomic variables (beta = -0.008, p = 0.012), aircraft noise annoyance, and other cognitive abilities (episodic memory, working memory, and sustained attention). Aircraft noise exposure at home was highly correlated with aircraft noise exposure at school and demonstrated a similar linear association with impaired reading comprehension. Road traffic noise exposure at school was not associated with reading comprehension in either the absence or the presence of aircraft noise (beta = 0.003, p = 0.509; beta = 0.002, p = 0.540, respectively). Findings were consistent across the three countries, which varied with respect to a range of socioeconomic and environmental variables, thus offering robust evidence of a direct exposure-effect relation between aircraft noise and reading comprehension.

  10. Insights into Spatial Sensitivities of Ice Mass Response to Environmental Change from the SeaRISE Ice Sheet Modeling Project I: Antarctica

    NASA Technical Reports Server (NTRS)

    Nowicki, Sophie; Bindschadler, Robert A.; Abe-Ouchi, Ayako; Aschwanden, Andy; Bueler, Ed; Choi, Hyengu; Fastook, Jim; Granzow, Glen; Greve, Ralf; Gutowski, Gail; Herzfeld, Ute; Jacskon, Charles; Johnson, Jesse; Khroulev, Constantine; Larour, Eric; Levermann, Anders; Lipscomb, William H.; Martin, Maria A.; Morlighem, Mathieu; Parizek, Byron R; Pollard, David; Price, Stephen F.; Seroussi, Helene; Walker, Ryan; Wang, Wei Li

    2013-01-01

    Atmospheric, oceanic, and subglacial forcing scenarios from the Sea-level Response to Ice Sheet Evolution (SeaRISE) project are applied to six three-dimensional thermomechanical ice-sheet models to assess Antarctic ice sheet sensitivity over a 500 year timescale and to inform future modeling and field studies. Results indicate (i) growth with warming, except within low-latitude basins (where inland thickening is outpaced by marginal thinning); (ii) mass loss with enhanced sliding (with basins dominated by high driving stresses affected more than basins with low-surface-slope streaming ice); and (iii) mass loss with enhanced ice shelf melting (with changes in West Antarctica dominating the signal due to its marine setting and extensive ice shelves; cf. minimal impact in the Terre Adelie, George V, Oates, and Victoria Land region of East Antarctica). Ice loss due to dynamic changes associated with enhanced sliding and/or sub-shelf melting exceeds the gain due to increased precipitation. Furthermore, differences in results between and within basins as well as the controlling impact of sub-shelf melting on ice dynamics highlight the need for improved understanding of basal conditions, grounding-zone processes, ocean-ice interactions, and the numerical representation of all three.

  11. Sea-level feedback lowers projections of future Antarctic Ice-Sheet mass loss.

    PubMed

    Gomez, Natalya; Pollard, David; Holland, David

    2015-11-10

    The stability of marine sectors of the Antarctic Ice Sheet (AIS) in a warming climate has been identified as the largest source of uncertainty in projections of future sea-level rise. Sea-level fall near the grounding line of a retreating marine ice sheet has a stabilizing influence on the ice sheets, and previous studies have established the importance of this feedback on ice age AIS evolution. Here we use a coupled ice sheet-sea-level model to investigate the impact of the feedback mechanism on future AIS retreat over centennial and millennial timescales for a range of emission scenarios. We show that the combination of bedrock uplift and sea-surface drop associated with ice-sheet retreat significantly reduces AIS mass loss relative to a simulation without these effects included. Sensitivity analyses show that the stabilization tends to be greatest for lower emission scenarios and Earth models characterized by a thin elastic lithosphere and low-viscosity upper mantle, as is the case for West Antarctica.

  12. Sea-level feedback lowers projections of future Antarctic Ice-Sheet mass loss.

    PubMed

    Gomez, Natalya; Pollard, David; Holland, David

    2015-01-01

    The stability of marine sectors of the Antarctic Ice Sheet (AIS) in a warming climate has been identified as the largest source of uncertainty in projections of future sea-level rise. Sea-level fall near the grounding line of a retreating marine ice sheet has a stabilizing influence on the ice sheets, and previous studies have established the importance of this feedback on ice age AIS evolution. Here we use a coupled ice sheet-sea-level model to investigate the impact of the feedback mechanism on future AIS retreat over centennial and millennial timescales for a range of emission scenarios. We show that the combination of bedrock uplift and sea-surface drop associated with ice-sheet retreat significantly reduces AIS mass loss relative to a simulation without these effects included. Sensitivity analyses show that the stabilization tends to be greatest for lower emission scenarios and Earth models characterized by a thin elastic lithosphere and low-viscosity upper mantle, as is the case for West Antarctica. PMID:26554381

  13. Impacts of sea ice / SST changes for the observed climate change -GREENICE project-

    NASA Astrophysics Data System (ADS)

    Ogawa, Fumiaki; Gao, Yongqi; Keenlyside, Noel; Koenigk, Torben; Semenov, Vladimir; Suo, Lingling; Yang, Shuting; Wang, Tao

    2016-04-01

    Under the recent global warming, melting of arctic sea-ice in recent decades could have contributed to recent climate changes including its long-term trend and extreme weather events. While the climatic response to the sea-ice loss have been studied recently, it is still an open question to what extent the sea-ice change has influenced recent climate change. Other factors, such as for example, SST could also have had an influence. A main objective of GREENICE research project is to show what extent of the observed climate trend as well as observed weather extremes could be explained by the change and variability in sea ice and SST, respectively. In this project, we designed two atmospheric general circulation model experiments: In both experiments observed daily sea ice cover variations are prescribed, while for SST, one experiment uses observed daily variations and the other the observed climatology. The experiment is performed by several different state-of-the-art AGCMs. Our preliminary results show that the observed wintertime temperature trend near the surface is poorly reproduced in our hindcast experiments using observed SIC and SST. The impact of SIC variation seems to be confined near the surface, while SST variation seems a key for temperature trend above. It suggests a necessity to consider the atmospheric poleward energy transport associated with SST variation to understand the observed arctic amplification. Other aspects of SIC/SST impact on the observed circulation change such as NAO shall also be discussed.

  14. Impact of a projected future Antarctic sea-ice reduction on the West African Monsoon

    NASA Astrophysics Data System (ADS)

    Bader, Juergen; Voigt, Aiko; Zanchettin, Davide

    2013-04-01

    Several model and observational studies have demonstrated a strong relationship between Sahel rainfall variability and sea-surface temperatures anomalies during the 20th century. However, this relationship does not explain Sahel rainfall changes in model projections of the 21st century. This raises the possibility that other forcing factors might become predominant at the end of the 21st century. Here, simulations with the atmosphere general circulaton model ECHAM5 are performed to investigate to which extent reductions in Antarctic sea ice affect Sahel rainfall during boreal summer. To this end, the model is forced by the present and a projected future seasonal cycle of Antarctic sea ice with sea-surface temperatures outside tha Antarctic sea-ice region kept constant. Reducing the Antarctic sea ice leads to an equatorward shift of the tropical rainbelt over sub-Saharan Africa. The shift entails a strong decline of summer Sahel rainfall and a substantial rainfall increase along the Guinea Coast. The shift is associated with an atmospheric bridge that does not require changes in tropical sea-surface temperatures. While Antarctic sea-ice reductions clearly impact Sahel rainfall in our idealized ECHAM5 simulatons, they do not seem to substantially influence Sahel rainfall in the ECHAM5 CMIP3 A1B simulation.

  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: Accretion, Detection, Protection

    NASA Technical Reports Server (NTRS)

    Reinmann, John J.

    1994-01-01

    The global aircraft industry and its regulatory agencies are currently involved in three major icing efforts: ground icing; advanced technologies for in-flight icing; and tailplane icing. These three major icing topics correspondingly support the three major segments of any aircraft flight profile: takeoff; cruise and hold; and approach and land. This lecture addressess these three topics in the same sequence as they appear in flight, starting with ground deicing, followed by advanced technologies for in-flight ice protection, and ending with tailplane icing.

  17. Monitoring Snow and Land Ice Using Satellite data in the GMES Project CryoLand

    NASA Astrophysics Data System (ADS)

    Bippus, Gabriele; Nagler, Thomas

    2013-04-01

    The main objectives of the project "CryoLand - GMES Service Snow and Land Ice" are to develop, implement and validate services for snow, glaciers and lake and river ice products as a Downstream Service within the Global Monitoring for Environment and Security (GMES) program of the European Commission. CryoLand exploits Earth Observation data from current optical and microwave sensors and of the upcoming GMES Sentinel satellite family. The project prepares also the basis for the cryospheric component of the GMES Land Monitoring services. The CryoLand project team consists of 10 partner organisations from Austria, Finland, Norway, Sweden, Switzerland and Romania and is funded by the 7th Framework Program of the European Commission. The CryoLand baseline products for snow include fractional snow extent from optical satellite data, the extent of melting snow from SAR data, and coarse resolution snow water equivalent maps from passive microwave data. Experimental products include maps of snow surface wetness and temperature. The products range from large scale coverage at medium resolution to regional products with high resolution, in order to address a wide user community. Medium resolution optical data (e.g. MODIS, in the near future Sentinel-3) and SAR (ENVISAT ASAR, in the near future Sentinel-1) are the main sources of EO data for generating large scale products in near real time. For generation of regional products high resolution satellite data are used. Glacier products are based on high resolution optical (e.g. SPOT-5, in the near future Sentinel-2) and SAR (TerraSAR-X, in the near future Sentinel-1) data and include glacier outlines, mapping of glacier facies, glacier lakes and ice velocity. The glacier products are generated on users demand. Current test areas are located in the Alps, Norway, Greenland and the Himalayan Mountains. The lake and river ice products include ice extent and its temporal changes and snow extent on ice. The algorithms for these

  18. Laboratory Investigation of Ice Formation and Elimination in the Induction System of a Large Twin-engine Cargo Aircraft

    NASA Technical Reports Server (NTRS)

    Colis, William D

    1947-01-01

    The icing characteristics, the de-icing rate with hot air, and the effect of impact ice on fuel metering and mixture distribution have been determined in a laboratory investigation of that part of the engine induction system consisting of a three-barrel injection-type carburetor and a supercharger housing with spinner-type fuel injection from an 18-cylinder radial engine used on a large twin-engine cargo airplane. The induction system remained ice-free at carburetor-air temperatures above 36 F regardless of the moisture content of the air. Between carburetor-air temperatures of 32 F and 36 F with humidity ratios in excess of saturation, serious throttling ice formed in the carburetor because of expansion cooling of the air; at carburetor-air temperatures below 32 F with humidity ratios in excess of saturation, serious impact-ice formations occurred, Spinner-type fuel injection at the entrance to the supercharger and heating of the supercharger-inlet elbow and the guide vanes by the warn oil in the rear engine housing are design features that proved effective in eliminating fuel-evaporation icing and minimized the formation of throttling ice below the carburetor. Air-flow recovery time with fixed throttle was rapidly reduced as the inlet -air wet -bulb temperature was increased to 55 F; further temperature increase produced negligible improvement in recovery time. Larger ice formations and lower icing temperatures increased the time required to restore proper air flow at a given wet-bulb temperature. Impact-ice formations on the entrance screen and the top of the carburetor reduced the over-all fuel-air ratio and increased the spread between the over-all ratio and the fuel-air ratio of the individual cylinders. The normal spread of fuel-air ratio was increased from 0.020 to 0.028 when the left quarter of the entrance screen was blocked in a manner simulating the blocking resulting from ice formations released from upstream duct walls during hot-air de-icing.

  19. AMOC projections driven by global warming and Greenland Ice Sheet melt

    NASA Astrophysics Data System (ADS)

    Bakker, Pepijn; Schmittner, Andreas; Lenaerts, Jan; Abe-Ouchi, Ayako; Bi, Dave; van den Broeke, Michiel; Hu, Aixue; Beadling, Rebecca Lynn; Marsland, Simon; Mernhild, Sebastian H.; Ohgaito, Rumi; Rodehacke, Christian; Saenko, Oleg; Swingedouw, Didier; Yang, Shuting; Yin, Jianjun

    2016-04-01

    The evolution of the Atlantic meridional overturning circulation (AMOC) is one of the key uncertainties of future climate projections. State-of-art climate models that took part in the CMIP5 project show that over the 21st century the AMOC might reduce by 20-30% under the intermediate RCP4.5 scenario and by 36-44% under the high end RCP8.5 scenario relative to preindustrial values. However, these projections neglect enhanced meltwater input from the Greenland Ice Sheet and lack a thorough uncertainty assessment. We present results of a community effort to use state-of-the-science climate models to simulate the impact of the partial melt of the Greenland Ice Sheet on the AMOC under future global warming up to the year 2300 (AMOCMIP). A probabilistic uncertainty assessment is presented based on a physics-based AMOC emulator and includes uncertainties in the AMOC's sensitivity to temperature and salinity changes, as well as uncertainties of future global warming, regional temperature amplification and melt rates of the Greenland Ice Sheet. We find that the impact of increased Greenland Ice Sheet melt on the AMOC strength is non-negligible, albeit strongly model dependent. The uncertainty analysis shows that the chance of an collapse of the AMOC is negligible if global temperature change remains below 2°C, but becomes more probable for larger warming.

  20. Investigation of ice cloud microphysical properties of DCSs using aircraft in situ measurements during MC3E over the ARM SGP site

    NASA Astrophysics Data System (ADS)

    Wang, Jingyu; Dong, Xiquan; Xi, Baike

    2015-04-01

    Six deep convective systems (DCSs) with a total of 5589 five-second samples and a range of temperatures from -41°C to 0°C during the Midlatitude Continental Convective Clouds Experiment (MC3E) were selected to investigate the ice cloud microphysical properties of DCSs over the Department of Energy Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site. The ice cloud measurements of the DCS cases were made by the University of North Dakota Citation II research aircraft, and the ice cloud properties were derived through the following processes. First, the instances of supercooled liquid water in the ice-dominated cloud layers of DCSs have been eliminated using multisensor detection, including the Rosemount Icing Detector, King and Cloud Droplet Probes, as well as 2DC and Cloud Imaging Probe images. Then the Nevzorov-measured ice water contents (IWCs) at maximum diameter Dmax < 4000 µm are used as the best estimation to determine a new mass-dimensional relationship. Finally, the newly derived mass-dimensional relationship (a = 0.00365, b = 2.1) has been applied to a full spectrum of particle size distributions (PSDs, 120-30,000 µm) constructed from both 2DC and High-Volume Precipitation Spectrometer measurements to calculate the best-estimated IWCs of DCSs during MC3E. The averages of the total number concentrations (Nt), median mass diameter (Dm), maximum diameter (Dmax), and IWC from six selected cases are 0.035 cm-3, 1666 µm, 8841 µm, and 0.45 g m-3, respectively. The gamma-type-size distributions are then generated matching the observed PSDs (120-30,000 µm), and the fitted gamma parameters are compared with the observed PSDs through multimoment assessments including first moment (Dm), third moment (IWC), and sixth moment (equivalent radar reflectivity, Ze). For application of observed PSDs to the remote sensing community, a series of empirical relationships between fitted parameters and Ze values has been derived, and the bullet rosette

  1. Millimeter-Wave Radar Field Measurements and Inversion of Cloud Parameters for the 1999 Mt. Washington Icing Sensors Project

    NASA Technical Reports Server (NTRS)

    Pazmany, Andrew L.; Reehorst, Andrew (Technical Monitor)

    2001-01-01

    The Mount Washington Icing Sensors Project (MWISP) was a multi-investigator experiment with participants from Quadrant Engineering, NOAA Environmental Technology Laboratory (NOAA/ETL), the Microwave Remote Sensing Laboratory (MIRSL) of the University of Massachusetts (UMass), and others. Radar systems from UMass and NOAA/ETL were used to measure X-, Ka-, and W-band backscatter data from the base of Mt. Washington, while simultaneous in-situ particle measurements were made from aircraft and from the observatory at the summit. This report presents range and time profiles of liquid water content and particle size parameters derived from range profiles of radar reflectivity as measured at X-, Ka-, and W-band (9.3, 33.1, and 94.9 GHz) using an artificial neural network inversion algorithm. In this report, we provide a brief description of the experiment configuration, radar systems, and a review of the artificial neural network used to extract cloud parameters from the radar data. Time histories of liquid water content (LWC), mean volume diameter (MVD) and mean Z diameter (MZD) are plotted at 300 m range intervals for slant ranges between 1.1 and 4 km. Appendix A provides details on the extraction of radar reflectivity from measured radar power, and Appendix B provides summary logs of the weather conditions for each day in which we processed data.

  2. Remote sensing and GIS technology in the Global Land Ice Measurements from Space (GLIMS) Project

    USGS Publications Warehouse

    Raup, B.; Kaab, Andreas; Kargel, J.S.; Bishop, M.P.; Hamilton, G.; Lee, E.; Paul, F.; Rau, F.; Soltesz, D.; Khalsa, S.J.S.; Beedle, M.; Helm, C.

    2007-01-01

    Global Land Ice Measurements from Space (GLIMS) is an international consortium established to acquire satellite images of the world's glaciers, analyze them for glacier extent and changes, and to assess these change data in terms of forcings. The consortium is organized into a system of Regional Centers, each of which is responsible for glaciers in their region of expertise. Specialized needs for mapping glaciers in a distributed analysis environment require considerable work developing software tools: terrain classification emphasizing snow, ice, water, and admixtures of ice with rock debris; change detection and analysis; visualization of images and derived data; interpretation and archival of derived data; and analysis to ensure consistency of results from different Regional Centers. A global glacier database has been designed and implemented at the National Snow and Ice Data Center (Boulder, CO); parameters have been expanded from those of the World Glacier Inventory (WGI), and the database has been structured to be compatible with (and to incorporate) WGI data. The project as a whole was originated, and has been coordinated by, the US Geological Survey (Flagstaff, AZ), which has also led the development of an interactive tool for automated analysis and manual editing of glacier images and derived data (GLIMSView). This article addresses remote sensing and Geographic Information Science techniques developed within the framework of GLIMS in order to fulfill the goals of this distributed project. Sample applications illustrating the developed techniques are also shown. ?? 2006 Elsevier Ltd. All rights reserved.

  3. About uncertainties in sea ice thickness retrieval from satellite radar altimetry: results from the ESA-CCI Sea Ice ECV Project Round Robin Exercise

    NASA Astrophysics Data System (ADS)

    Kern, S.; Khvorostovsky, K.; Skourup, H.; Rinne, E.; Parsakhoo, Z. S.; Djepa, V.; Wadhams, P.; Sandven, S.

    2014-03-01

    One goal of the European Space Agency Climate Change Initiative sea ice Essential Climate Variable project is to provide a quality controlled 20 year long data set of Arctic Ocean winter-time sea ice thickness distribution. An important step to achieve this goal is to assess the accuracy of sea ice thickness retrieval based on satellite radar altimetry. For this purpose a data base is created comprising sea ice freeboard derived from satellite radar altimetry between 1993 and 2012 and collocated observations of snow and sea ice freeboard from Operation Ice Bridge (OIB) and CryoSat Validation Experiment (CryoVEx) air-borne campaigns, of sea ice draft from moored and submarine Upward Looking Sonar (ULS), and of snow depth from OIB campaigns, Advanced Microwave Scanning Radiometer aboard EOS (AMSR-E) and the Warren Climatology (Warren et al., 1999). An inter-comparison of the snow depth data sets stresses the limited usefulness of Warren climatology snow depth for freeboard-to-thickness conversion under current Arctic Ocean conditions reported in other studies. This is confirmed by a comparison of snow freeboard measured during OIB and CryoVEx and snow freeboard computed from radar altimetry. For first-year ice the agreement between OIB and AMSR-E snow depth within 0.02 m suggests AMSR-E snow depth as an appropriate alternative. Different freeboard-to-thickness and freeboard-to-draft conversion approaches are realized. The mean observed ULS sea ice draft agrees with the mean sea ice draft computed from radar altimetry within the uncertainty bounds of the data sets involved. However, none of the realized approaches is able to reproduce the seasonal cycle in sea ice draft observed by moored ULS satisfactorily. A sensitivity analysis of the freeboard-to-thickness conversion suggests: in order to obtain sea ice thickness as accurate as 0.5 m from radar altimetry, besides a freeboard estimate with centimetre accuracy, an ice-type dependent sea ice density is as mandatory

  4. Demand for large freighter aircraft as projected by the NASA cargo/logistics airlift system studies

    NASA Technical Reports Server (NTRS)

    Whitehead, A. H., Jr.; Kuhlman, W. H.

    1979-01-01

    The market conditions are examined up through the year 2008 to provide a preliminary assessment of the potential for and the characteristics of an advanced, all-cargo transport aircraft. Any new freighter must compete with current wide-body aircraft and their derivatives. Aircraft larger than the wide-bodies may incur economic penalties and operational problems. A lower direct operating cost is not a sufficient criterion to base a decision for the initiation of a new aircraft development or to select aircraft characteristics. Other factors of equal importance that are reviewed in this paper include considerations of the system infrastructure, the economics of the airlines, and the aircraft manufacturer return on investment. The results of the market forecast and a computer simulation show that an advanced long range aircraft with a payload between 68 to 181 tonnes (75 to 200 tons) could generate a solid foothold beginning around 1994.

  5. A multi-year monitoring project of the high-altitude Cenote ice cave, Dolomites, Italy

    NASA Astrophysics Data System (ADS)

    Sauro, Francesco; Santagata, Tommaso; Spötl, Christoph; Festi, Daniela; Oeggl, Klaus; Dal Molin, Luca; De Waele, Jo

    2016-04-01

    The Cenote ice cave hosts one of the most voluminous cave glaciers of the Dolomites. This 280 m-deep abyss was discovered in 1994 after the entrance had opened as a result of the abrupt emptying of a small lake at 2940 m a.s.l. in the Regional Park of Fanes, Sennes and Braies. The cave consists of a massive, 130 m-thick layered ice deposit carved by meltwater tunnels and chimneys excavated from below by ascending air. At the lower limit of the cave glacier a shaft opens - ice-free and 165 m deep - leading into a dome occupied by a cave rock glacier with typical terminal tongue embankments. A research project was launched to monitor long-term movements and volume changes of this ice deposit as well as to understand the cave microclimate and the potential for future palaeoclimate studies. During October 2015 a first expedition performed a complete survey of the final chamber using a Leica HDS7000, a phase difference laser scanner equipped with a dual axis compensator, on-board control, a wavelenght of 1.5 microns, a laser "CLASS 1" with a flow rate of 187 m and a resolution of 0.1 mm. A scan station was performed also at 110 m above the bottom of the shaft to map in detail the lower side of the hanging ice glacier. This survey has provided the detailed volume of the chamber (420,000 m3) as well as a first record of the position of the ice masses hanging on the ceiling and of the rock glacier at the bottom. Barometric, temperature and humidity dataloggers have been installed in the cave to record the microclimate. In addition pollen traps have been installed to study the present flux of pollen at the surface and inside the cave, while preliminary analyses on pollen grains preserved in the ice are being carried out. The Cenote ice cave research project aims to shed light on the climate evolution of the Dolomites during the last hundreds or possibly thousands of years, as well as on the more recent environmental changes that lead to the upward melting of the cave

  6. Early and Middle Miocene Antarctic Ice Sheet Behavior: results from the ANDRILL SMS Project

    NASA Astrophysics Data System (ADS)

    Harwood, D. M.; Florindo, F.; Levy, R. H.; SMS Project Science Team http://andrill. org/projects/sms/team. html

    2011-12-01

    A 1138-meter sediment drillcore (AND-2A) recovered by the SMS Project of the ANDRILL Program from the McMurdo Sound sector of the western Ross Sea contains a near-continuous, coastal record of Antarctic climate and ice sheet variability through the early Miocene (20.2 to ~14.5 million years ago), including an interval of global warmth known as the Mid-Miocene Climatic Optimum (MMCO). The AND-2A drillcore was deposited in the subsiding Victoria Land Basin, during a period of relatively steady thermal subsidence, on the coastal plain and continental shelf seaward of the rising Transantarctic Mountains. Analysis of this drillcore indicates prolonged periods when the ice sheet margin remained retreated from the coastline, and other periods when the ice sheet was highly dynamic, advancing and retreating on orbital timescales. It preserves a record of the pace and scale of climate and ice sheet variation, and allows for the evaluation of climate sensitivity through data and numerical modeling integration. Stratigraphic sequences and facies interpretations reveal a cyclical history of climate changes, glacial advance and retreat cycles. Under warm, equable climate conditions recorded in a variety of climate indicators, the behavior of the early Miocene Antarctic ice sheet evident in the AND-2A core was varied, ranging between two modes: (1) persistent absence/retreat of low elevation ice sheets from coastal regions, and (2) periods of dynamic but subdued fluctuations with the ice margin of larger volume ice sheets entering across the coastal zone. The glacial regime varied from sub-polar with significant meltwater through proximal and distal high-latitude temperate glacial conditions with abundant meltwater. A well-developed chronostratigraphic framework allows for the comparison of events recognized in this drillcore with events identified in distal proxy records from deep-sea stable isotope studies. This dynamic response of Antarctic climate during times when CO2 levels

  7. Projected future duration of the sea-ice-free season in the Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Wang, Muyin; Overland, James E.

    2015-08-01

    Global warming and continued reduction in sea ice cover will result in longer open water duration in the Arctic, which is important for the shipping industry, marine mammals, and other components of the regional ecosystem. In this study we assess the length of open water duration in the Alaskan Arctic over the next few decades using the set of latest coupled climate models (CMIP5). The Alaskan Arctic, including the Chukchi and the Beaufort Sea, has been a major region of summer sea ice retreat since 2007. Thirty five climate models from CMIP5 are evaluated and twelve are selected for composite projections based on their historical simulation performance. In the regions north of the Bering Strait (north of 70° N), future open-water duration shifts from a current 3-4 months to a projected near 5 months by 2040 based on the mean of the twelve selected climate models. There is considerable north-south gradient in projected durations. Open water duration is about 1 month shorter along the same latitudes in the Beaufort Sea compared with that in the Chukchi Sea. Uncertainty is generally ±1 month estimated from the range of model results. Open-water duration in the Alaskan Arctic expands quickly in these models over the next decades which will impact regional economic access and potentially alter ecosystems. Yet the northern Alaskan Arctic from January through May will remain sea ice covered into the second half of the century due to normal lack of sunlight.

  8. Projected Demand and Potential Impacts to the National Airspace System of Autonomous, Electric, On-Demand Small Aircraft

    NASA Technical Reports Server (NTRS)

    Smith, Jeremy C.; Viken, Jeffrey K.; Guerreiro, Nelson M.; Dollyhigh, Samuel M.; Fenbert, James W.; Hartman, Christopher L.; Kwa, Teck-Seng; Moore, Mark D.

    2012-01-01

    Electric propulsion and autonomy are technology frontiers that offer tremendous potential to achieve low operating costs for small-aircraft. Such technologies enable simple and safe to operate vehicles that could dramatically improve regional transportation accessibility and speed through point-to-point operations. This analysis develops an understanding of the potential traffic volume and National Airspace System (NAS) capacity for small on-demand aircraft operations. Future demand projections use the Transportation Systems Analysis Model (TSAM), a tool suite developed by NASA and the Transportation Laboratory of Virginia Polytechnic Institute. Demand projections from TSAM contain the mode of travel, number of trips and geographic distribution of trips. For this study, the mode of travel can be commercial aircraft, automobile and on-demand aircraft. NASA's Airspace Concept Evaluation System (ACES) is used to assess NAS impact. This simulation takes a schedule that includes all flights: commercial passenger and cargo; conventional General Aviation and on-demand small aircraft, and operates them in the simulated NAS. The results of this analysis projects very large trip numbers for an on-demand air transportation system competitive with automobiles in cost per passenger mile. The significance is this type of air transportation can enhance mobility for communities that currently lack access to commercial air transportation. Another significant finding is that the large numbers of operations can have an impact on the current NAS infrastructure used by commercial airlines and cargo operators, even if on-demand traffic does not use the 28 airports in the Continental U.S. designated as large hubs by the FAA. Some smaller airports will experience greater demand than their current capacity allows and will require upgrading. In addition, in future years as demand grows and vehicle performance improves other non-conventional facilities such as short runways incorporated into

  9. NASA's program on icing research and technology

    NASA Technical Reports Server (NTRS)

    Reinmann, John J.; Shaw, Robert J.; Ranaudo, Richard J.

    1989-01-01

    NASA's program in aircraft icing research and technology is reviewed. The program relies heavily on computer codes and modern applied physics technology in seeking icing solutions on a finer scale than those offered in earlier programs. Three major goals of this program are to offer new approaches to ice protection, to improve our ability to model the response of an aircraft to an icing encounter, and to provide improved techniques and facilities for ground and flight testing. This paper reviews the following program elements: (1) new approaches to ice protection; (2) numerical codes for deicer analysis; (3) measurement and prediction of ice accretion and its effect on aircraft and aircraft components; (4) special wind tunnel test techniques for rotorcraft icing; (5) improvements of icing wind tunnels and research aircraft; (6) ground de-icing fluids used in winter operation; (7) fundamental studies in icing; and (8) droplet sizing instruments for icing clouds.

  10. NASA's program on icing research and technology

    NASA Technical Reports Server (NTRS)

    Reinmann, John J.; Shaw, Robert J.; Ranaudo, Richard J.

    1989-01-01

    NASA's program in aircraft icing research and technology is reviewed. The program relies heavily on computer codes and modern applied physics technology in seeking icing solutions on a finer scale than those offered in earlier programs. Three major goals of this program are to offer new approaches to ice protection, to improve the ability to model the response of an aircraft to an icing encounter, and to provide improved techniques and facilities for ground and flight testing. The following program elements are reviewed: (1) new approaches to ice protection; (2) numerical codes for deicer analysis; (3) measurement and prediction of ice accretion and its effect on aircraft and aircraft components; (4) special wind tunnel test techniques for rotorcraft icing; (5) improvements of icing wind tunnels and research aircraft; (6) ground de-icing fluids used in winter operation; (7) fundamental studies in icing; and (8) droplet sizing instruments for icing clouds.

  11. The Horizon: A blended wing aircraft configuration design project, volume 3

    NASA Technical Reports Server (NTRS)

    Keidel, Paul; Gonda, Mark; Freeman, Darnon; Kim, Jay; Hsu, Yul

    1988-01-01

    The results of a study to design a High-Speed Civilian Transport (HSCT) using the blended wing-body configuration are presented. The HSCT is a Mach 2 to 5 transport aircraft designed to compete with current commercial aircraft. The subjects discussed are sizing, configuration, aerodynamics, stability and control, propulsion, performance, structures and pollution effects.

  12. The Darkening of the Greenland Ice Sheet: Trends, Drivers and Projections (1981-2100)

    NASA Technical Reports Server (NTRS)

    Tedesco, Marco; Doherty, Sarah; Fettweis, Xavier; Alexander, Patrick; Jeyaratnam, Jeyavinoth; Stroeve, Julienne

    2016-01-01

    The surface energy balance and meltwater production of the Greenland ice sheet (GrIS) are modulated by snow and ice albedo through the amount of absorbed solar radiation. Here we show, using space-borne multispectral data collected during the 3 decades from 1981 to 2012, that summertime surface albedo over the GrIS decreased at a statistically significant (99 %) rate of 0.02 decade(sup -1) between 1996 and 2012. Over the same period, albedo modelled by the Modele Atmospherique Regionale (MAR) also shows a decrease, though at a lower rate (approximately -0.01 decade(sup -1)) than that obtained from space-borne data. We suggest that the discrepancy between modelled and measured albedo trends can be explained by the absence in the model of processes associated with the presence of light-absorbing impurities. The negative trend in observed albedo is confined to the regions of the GrIS that undergo melting in summer, with the dry snow zone showing no trend. The period 1981-1996 also showed no statistically significant trend over the whole GrIS. Analysis of MAR outputs indicates that the observed albedo decrease is attributable to the combined effects of increased near-surface air temperatures, which enhanced melt and promoted growth in snow grain size and the expansion of bare ice areas, and to trends in light-absorbing impurities (LAI) on the snow and ice surfaces. Neither aerosol models nor in situ and remote sensing observations indicate increasing trends in LAI in the atmosphere over Greenland. Similarly, an analysis of the number of fires and BC emissions from fires points to the absence of trends for such quantities. This suggests that the apparent increase of LAI in snow and ice might be related to the exposure of a "dark band" of dirty ice and to increased consolidation of LAI at the surface with melt, not to increased aerosol deposition. Albedo projections through to the end of the century under different warming scenarios consistently point to continued

  13. The darkening of the Greenland ice sheet: trends, drivers, and projections (1981-2100)

    NASA Astrophysics Data System (ADS)

    Tedesco, Marco; Doherty, Sarah; Fettweis, Xavier; Alexander, Patrick; Jeyaratnam, Jeyavinoth; Stroeve, Julienne

    2016-03-01

    The surface energy balance and meltwater production of the Greenland ice sheet (GrIS) are modulated by snow and ice albedo through the amount of absorbed solar radiation. Here we show, using space-borne multispectral data collected during the 3 decades from 1981 to 2012, that summertime surface albedo over the GrIS decreased at a statistically significant (99 %) rate of 0.02 decade-1 between 1996 and 2012. Over the same period, albedo modelled by the Modèle Atmosphérique Régionale (MAR) also shows a decrease, though at a lower rate ( ˜ -0.01 decade-1) than that obtained from space-borne data. We suggest that the discrepancy between modelled and measured albedo trends can be explained by the absence in the model of processes associated with the presence of light-absorbing impurities. The negative trend in observed albedo is confined to the regions of the GrIS that undergo melting in summer, with the dry-snow zone showing no trend. The period 1981-1996 also showed no statistically significant trend over the whole GrIS. Analysis of MAR outputs indicates that the observed albedo decrease is attributable to the combined effects of increased near-surface air temperatures, which enhanced melt and promoted growth in snow grain size and the expansion of bare ice areas, and to trends in light-absorbing impurities (LAI) on the snow and ice surfaces. Neither aerosol models nor in situ and remote sensing observations indicate increasing trends in LAI in the atmosphere over Greenland. Similarly, an analysis of the number of fires and BC emissions from fires points to the absence of trends for such quantities. This suggests that the apparent increase of LAI in snow and ice might be related to the exposure of a "dark band" of dirty ice and to increased consolidation of LAI at the surface with melt, not to increased aerosol deposition. Albedo projections through to the end of the century under different warming scenarios consistently point to continued darkening, with albedo

  14. Experimental design for three interrelated marine ice sheet and ocean model intercomparison projects: MISMIP v. 3 (MISMIP +), ISOMIP v. 2 (ISOMIP +) and MISOMIP v. 1 (MISOMIP1)

    NASA Astrophysics Data System (ADS)

    Asay-Davis, Xylar S.; Cornford, Stephen L.; Durand, Gaël; Galton-Fenzi, Benjamin K.; Gladstone, Rupert M.; Hilmar Gudmundsson, G.; Hattermann, Tore; Holland, David M.; Holland, Denise; Holland, Paul R.; Martin, Daniel F.; Mathiot, Pierre; Pattyn, Frank; Seroussi, Hélène

    2016-07-01

    Coupled ice sheet-ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of marine ice sheets and tidewater glaciers, from process studies to future projections of ice mass loss and sea level rise. The Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP) is a community effort aimed at designing and coordinating a series of model intercomparison projects (MIPs) for model evaluation in idealized setups, model verification based on observations, and future projections for key regions of the West Antarctic Ice Sheet (WAIS). Here we describe computational experiments constituting three interrelated MIPs for marine ice sheet models and regional ocean circulation models incorporating ice shelf cavities. These consist of ice sheet experiments under the Marine Ice Sheet MIP third phase (MISMIP+), ocean experiments under the Ice Shelf-Ocean MIP second phase (ISOMIP+) and coupled ice sheet-ocean experiments under the MISOMIP first phase (MISOMIP1). All three MIPs use a shared domain with idealized bedrock topography and forcing, allowing the coupled simulations (MISOMIP1) to be compared directly to the individual component simulations (MISMIP+ and ISOMIP+). The experiments, which have qualitative similarities to Pine Island Glacier Ice Shelf and the adjacent region of the Amundsen Sea, are designed to explore the effects of changes in ocean conditions, specifically the temperature at depth, on basal melting and ice dynamics. In future work, differences between model results will form the basis for the evaluation of the participating models.

  15. Development, Implementation, and Pilot Evaluation of a Model-Driven Envelope Protection System to Mitigate the Hazard of In-Flight Ice Contamination on a Twin-Engine Commuter Aircraft

    NASA Technical Reports Server (NTRS)

    Martos, Borja; Ranaudo, Richard; Norton, Billy; Gingras, David; Barnhart, Billy

    2014-01-01

    Fatal loss-of-control accidents have been directly related to in-flight airframe icing. The prototype system presented in this report directly addresses the need for real-time onboard envelope protection in icing conditions. The combination of prior information and real-time aerodynamic parameter estimations are shown to provide sufficient information for determining safe limits of the flight envelope during inflight icing encounters. The Icing Contamination Envelope Protection (ICEPro) system was 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. The utility of the ICEPro system for mitigating a potentially hazardous icing condition was evaluated by 29 pilots using the NASA Ice Contamination Effects Flight Training Device. 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 awareness of a hazardous aircraft state. The performance of ICEPro system was further evaluated by various levels of sensor noise and atmospheric turbulence.

  16. The Idea of an Innovated Concept of the Košice Geothermal Project

    NASA Astrophysics Data System (ADS)

    Bujanská, Alena; Böszörményi, László

    2015-11-01

    Slovakia has very limited amounts of fossil resources. However, it has a relatively high potential of geothermal energy which use is far below its possibilities. The most abundant geothermal resource, not only in Slovakia but throughout the central Europe, is Košice basin. Since the publication of the first ideas about the ambitious goal to exploit the geothermal potential of this site, 20 years has passed and three geothermal wells has been made but without any progress. In the article the authors present the idea of a fundamental change in the approach to improve the energy and economic efficiency of the project.

  17. The interaction of radio frequency electromagnetic fields with atmospheric water droplets and applications to aircraft ice prevention. Thesis

    NASA Technical Reports Server (NTRS)

    Hansman, R. J., Jr.

    1982-01-01

    The feasibility of computerized simulation of the physics of advanced microwave anti-icing systems, which preheat impinging supercooled water droplets prior to impact, was investigated. Theoretical and experimental work performed to create a physically realistic simulation is described. The behavior of the absorption cross section for melting ice particles was measured by a resonant cavity technique and found to agree with theoretical predictions. Values of the dielectric parameters of supercooled water were measured by a similar technique at lambda = 2.82 cm down to -17 C. The hydrodynamic behavior of accelerated water droplets was studied photograhically in a wind tunnel. Droplets were found to initially deform as oblate spheroids and to eventually become unstable and break up in Bessel function modes for large values of acceleration or droplet size. This confirms the theory as to the maximum stable droplet size in the atmosphere. A computer code which predicts droplet trajectories in an arbitrary flow field was written and confirmed experimentally. The results were consolidated into a simulation to study the heating by electromagnetic fields of droplets impinging onto an object such as an airfoil. It was determined that there is sufficient time to heat droplets prior to impact for typical parameter values. Design curves for such a system are presented.

  18. Mapping Ice with Airborne Lasers

    NASA Video Gallery

    Determining whether polar ice quantities are growing or shrinking requires accurate and detailed measurements, year over year. To help make those measurements, IceBridge mission aircraft fire 3,000...

  19. Progress of Aircraft System Noise Assessment with Uncertainty Quantification for the Environmentally Responsible Aviation Project

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Burley, Casey L.; Guo, Yueping

    2016-01-01

    Aircraft system noise predictions have been performed for NASA modeled hybrid wing body aircraft advanced concepts with 2025 entry-into-service technology assumptions. The system noise predictions developed over a period from 2009 to 2016 as a result of improved modeling of the aircraft concepts, design changes, technology development, flight path modeling, and the use of extensive integrated system level experimental data. In addition, the system noise prediction models and process have been improved in many ways. An additional process is developed here for quantifying the uncertainty with a 95% confidence level. This uncertainty applies only to the aircraft system noise prediction process. For three points in time during this period, the vehicle designs, technologies, and noise prediction process are documented. For each of the three predictions, and with the information available at each of those points in time, the uncertainty is quantified using the direct Monte Carlo method with 10,000 simulations. For the prediction of cumulative noise of an advanced aircraft at the conceptual level of design, the total uncertainty band has been reduced from 12.2 to 9.6 EPNL dB. A value of 3.6 EPNL dB is proposed as the lower limit of uncertainty possible for the cumulative system noise prediction of an advanced aircraft concept.

  20. Resilient Propulsion Control Research for the NASA Integrated Resilient Aircraft Control (IRAC) Project

    NASA Technical Reports Server (NTRS)

    Guo, Ten-Huei; Litt, Jonathan S.

    2007-01-01

    Gas turbine engines are designed to provide sufficient safety margins to guarantee robust operation with an exceptionally long life. However, engine performance requirements may be drastically altered during abnormal flight conditions or emergency maneuvers. In some situations, the conservative design of the engine control system may not be in the best interest of overall aircraft safety; it may be advantageous to "sacrifice" the engine to "save" the aircraft. Motivated by this opportunity, the NASA Aviation Safety Program is conducting resilient propulsion research aimed at developing adaptive engine control methodologies to operate the engine beyond the normal domain for emergency operations to maximize the possibility of safely landing the damaged aircraft. Previous research studies and field incident reports show that the propulsion system can be an effective tool to help control and eventually land a damaged aircraft. Building upon the flight-proven Propulsion Controlled Aircraft (PCA) experience, this area of research will focus on how engine control systems can improve aircraft safe-landing probabilities under adverse conditions. This paper describes the proposed research topics in Engine System Requirements, Engine Modeling and Simulation, Engine Enhancement Research, Operational Risk Analysis and Modeling, and Integrated Flight and Propulsion Controller Designs that support the overall goal.

  1. Development of a Low-Cost Sub-Scale Aircraft for Flight Research: The FASER Project

    NASA Technical Reports Server (NTRS)

    Owens, Donald B.; Cox, David E.; Morelli, Eugene A.

    2006-01-01

    An inexpensive unmanned sub-scale aircraft was developed to conduct frequent flight test experiments for research and demonstration of advanced dynamic modeling and control design concepts. This paper describes the aircraft, flight systems, flight operations, and data compatibility including details of some practical problems encountered and the solutions found. The aircraft, named Free-flying Aircraft for Sub-scale Experimental Research, or FASER, was outfitted with high-quality instrumentation to measure aircraft inputs and states, as well as vehicle health parameters. Flight data are stored onboard, but can also be telemetered to a ground station in real time for analysis. Commercial-off-the-shelf hardware and software were used as often as possible. The flight computer is based on the PC104 platform, and runs xPC-Target software. Extensive wind tunnel testing was conducted with the same aircraft used for flight testing, and a six degree-of-freedom simulation with nonlinear aerodynamics was developed to support flight tests. Flight tests to date have been conducted to mature the flight operations, validate the instrumentation, and check the flight data for kinematic consistency. Data compatibility analysis showed that the flight data are accurate and consistent after corrections are made for estimated systematic instrumentation errors.

  2. The ENDURANCE (Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer) project. (Invited)

    NASA Astrophysics Data System (ADS)

    Doran, P. T.; Stone, B.; Priscu, J. C.

    2010-12-01

    ENDURANCE (Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer) has completed two field seasons working in perennially ice-covered Lake Bonney. Our new data set for West Lake Bonney includes unprecedented hi-resolution sonar maps of the entire lake including through the connecting channel and into East Lake Bonney, 3D (at 100 m xy and subcentimeter z resolution) temperature, conductivity, pH, REDOX, photosynthetically-active radiation, chl-a fluorometry, turbidity and dissolved organic matter. The drop sonde science package also includes a bottom imager which collected 100’s of images of the benthic microbial community. An upward looking camera on the vehicle itself captured information on sediment distribution in the ice cover, which in conjunction with the PAR measurements will be used to generate whole lake photosynthesis models. Variation in ice thickness across the lake was acquired both by sonar and pressure transducer readings while the vehicle was at rest under the ice. A forward looking camera in conjunction with swath sonar was used to confirm the location of the grounding line of Taylor Glacier at the west end of the lake. Our preliminary assessment of the data suggests that the depth of the grounding line coincides with anomalous water characteristics near the glacier face, suggesting either a subglacial discharge or some previously undocumented mixing phenomenon. Our project tested two central hypotheses: H1: The low kinetic energy of the system (diffusion dominates the spatial transport of constituents) produces an ecosystem and ecosystem limits that vary significantly in three dimensions. H2: The whole-lake physical and biogeochemical structure remains static from year to year. Our results can be used to accept H1, and reject H2. Addressing either of these hypotheses would have been near impossible without the ENDURANCE vehicle. The data generated and conclusions drawn have advanced our knowledge of the lake ecosystems in the dry

  3. Top/bottom multisensor remote sensing of Arctic sea ice

    NASA Technical Reports Server (NTRS)

    Comiso, J. C.; Wadhams, P.; Krabill, W. B.; Swift, R. N.; Crawford, J. P.

    1991-01-01

    Results are presented on the Aircraft/Submarine Sea Ice Project experiment carried out in May 1987 to investigate concurrently the top and the bottom features of the Arctic sea-ice cover. Data were collected nearly simultaneously by instruments aboard two aircraft and a submarine, which included passive and active (SAR) microwave sensors, upward looking and sidescan sonars, a lidar profilometer, and an IR sensor. The results described fall into two classes of correlations: (1) quantitative correlations between profiles, such as ice draft (sonar), ice elevation (laser), SAR backscatter along the track line, and passive microwave brightness temperatures; and (2) qualitative and semiquantitative correlations between corresponding areas of imagery (i.e., passive microwave, AR, and sidescan sonar).

  4. A 94/183 GHz aircraft radiometer system for Project Storm Fury

    NASA Technical Reports Server (NTRS)

    Gagliano, J. A.; Stratigos, J. A.; Forsythe, R. E.; Schuchardt, J. M.; Welch, J. M.; Gallentine, D. O.

    1980-01-01

    A radiometer design suitable for use in NASA's WB-57F aircraft to collect data from severe storm regions was developed. The design recommended was a 94/183 GHz scanning radiometer with 3 IF channels on either side of the 183.3 GHz water vapor line and a single IF channel for a low loss atmospheric window channel at 94 GHz. The development and construction of the 94/183 GHz scanning radiometer known as the Advanced Microwave Moisture Sounder (AMMS) is presented. The radiometer scans the scene below the aircraft over an angle of + or - 45 degrees with the beamwidth of the scene viewed of approximately 2 degrees at 94 GHz and 1 degree at 183 GHz. The AMMS data collection system consists of a microcomputer used to store the radiometer data on the flight cartridge recorder, operate the stepper motor driven scanner, and collect housekeeping data such as thermistor temperature readings and aircraft time code.

  5. Assessment of a demonstration project to supply near real-time sea ice information to end users

    NASA Astrophysics Data System (ADS)

    Blackford, C.; Howes, Sally; Whitelaw, Alan S.; Laxon, S.; Mantripp, D.

    1994-12-01

    Sea ice maps are required by a diverse range of users for scientific research and operational activities. Satellite remote sensing provides opportunities for monitoring and producing sea ice maps at a range of scales, in near real time. During March 1994 ESYS Limited and the University College London Mullard Space Science Laboratory (MSSL) operated a sea ice demonstration project to supply near real time sea ice maps in the southern ocean. The sea ice information was derived from a number of data sources: DMSP SSM/I data; ERS-1 SAR and Radar Altimeter fast delivery data; NOAA AVHRR data; and PoSAT-1 imagery. The maps were supplied to three users, two involved in yacht races in the southern ocean and a ship on an oceanographic research cruise in the waters of the Princess Elizabeth Trough region of Antarctica. The demonstration was successful, supplying the users with sea ice information which they had previously not received and combining data from various sources to produce sea ice maps. The demonstration also developed operational skills within ESYS and enabled the transfer of knowledge from MSSL to ESYS.

  6. The Leading Edge 250: Oblique wing aircraft configuration project, volume 4

    NASA Technical Reports Server (NTRS)

    Schmidt, Andre; Moore, Peri; Nguyen, Dan; Oganesyan, Petros; Palmer, Charles

    1988-01-01

    The design of a high speed transport aircraft using the oblique wing concept as a part of the High Speed Civil Transport (HSCT) aircraft study is the Leading Edge 250 capable of travelling at Mach 4 with 250 passengers and has a 6,500 nautical mile range. Its innovation lies within its use of the unconventional oblique wing to provide efficient flight at any Mach number. Wave drag is kept to a minimum at high speed, while high lift is attained during critical takeoff and landing maneuvers by varying the sweep of the wing.

  7. On ISSM and leveraging the Cloud towards faster quantification of the uncertainty in ice-sheet mass balance projections

    NASA Astrophysics Data System (ADS)

    Larour, E.; Schlegel, N.

    2016-11-01

    With the Amazon EC2 Cloud becoming available as a viable platform for parallel computing, Earth System Models are increasingly interested in leveraging its capabilities towards improving climate projections. In particular, faced with long wait periods on high-end clusters, the elasticity of the Cloud presents a unique opportunity of potentially "infinite" availability of small-sized clusters running on high-performance instances. Among specific applications of this new paradigm, we show here how uncertainty quantification in climate projections of polar ice sheets (Antarctica and Greenland) can be significantly accelerated using the Cloud. Indeed, small-sized clusters are very efficient at delivering sensitivity and sampling analysis, core tools of uncertainty quantification. We demonstrate how this approach was used to carry out an extensive analysis of ice-flow projections on one of the largest basins in Greenland, the North-East Greenland Glacier, using the Ice Sheet System Model, the public-domain NASA-funded ice-flow modeling software. We show how errors in the projections were accurately quantified using Monte-Carlo sampling analysis on the EC2 Cloud, and how a judicious mix of high-end parallel computing and Cloud use can best leverage existing infrastructures, and significantly accelerate delivery of potentially ground-breaking climate projections, and in particular, enable uncertainty quantification that were previously impossible to achieve.

  8. Projections of 21st Century Sea Level Rise From the Melt of Mountain Glaciers and Ice Caps

    NASA Astrophysics Data System (ADS)

    Radic, V.; Hock, R.

    2008-12-01

    An ensemble of 21st century volume projections for all mountain glaciers and ice caps from the World Glacier Inventory is derived by modeling the surface mass balance coupled with volume--area--length scaling and forced with temperature and precipitation scenarios with A1B emission scenario from ensemble of GCMs. By upscaling the volume projections through a regionally differentiated approach to all mountain glaciers and ice caps outside Greenland and Antarctica (514,380~km2) we estimated total volume change to range from -0.039~m to -0.150~m of sea level equivalent for the time period 2001--2100. A major source of uncertainty in the methodology is the temperature forcing in the mass balance model which depends on bias correction of ERA-40 temperatures in order to simulate the local temperatures on a mountain glacier or ice cap. Other major sources of uncertainties are the volume-area scaling in deriving initial glacier volume and upscaling the volume changes with assumptions on glacier-size distributions in each glacierized region. Our projected 21st century volume loss is probably a lower bound since no calving is modeled and no mountain glaciers and ice caps surrounding Antarctica and Greenland are included due to a lack of glacier inventory data. Nevertheless, the large range of our projections depends on the choice of GCM emphasizing the importance of ensemble projections.

  9. Downhole measurements in the AND-1B borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica

    USGS Publications Warehouse

    Morin, R.; Williams, T.; Henrys, S.; Crosby, T.; Hansaraj, D.

    2007-01-01

    A comprehensive set of downhole measurements was collected in the AND-1B drillhole as part of the on-ice scientific programme defined for the McMurdo Ice Shelf (MIS) Project. Geophysical logs were recorded over two operation phases and consisted of calliper, temperature, fluid conductivity, induction resistivity, magnetic susceptibility, natural gamma activity, acoustic televiewer, borehole deviation, and dipmeter. In addition, two standard vertical seismic profiles (VSP) and one walk-away VSP were obtained. Radioactive logs (porosity and density) were not run because of unstable borehole conditions. Although the total depth of the hole is 1285 metres below seafloor (mbsf), the depth range for in situ measurements was limited by the length of the wireline (1018 mbsf) and by the nullification of some geophysical logs due to the presence of steel casing. A depth correction was derived to account for systematic discrepancies in depth between downhole measurements and cores; consequently, log responses can be directly compared to core properties. The resulting data are amenable to studies of cyclicity and climate, heat flux and fluid flow, and stricture and stress. When integrated with physical properties and fractures measured on the core, this information should play a significant role in addressing many of the scientific objectives of the ANDRILL programme.

  10. Effect of advanced aircraft noise reduction technology on the 1990 projected noise environment around Patrick Henry Airport. [development of noise exposure forecast contours for projected traffic volume and aircraft types

    NASA Technical Reports Server (NTRS)

    Cawthorn, J. M.; Brown, C. G.

    1974-01-01

    A study has been conducted of the future noise environment of Patric Henry Airport and its neighboring communities projected for the year 1990. An assessment was made of the impact of advanced noise reduction technologies which are currently being considered. These advanced technologies include a two-segment landing approach procedure and aircraft hardware modifications or retrofits which would add sound absorbent material in the nacelles of the engines or which would replace the present two- and three-stage fans with a single-stage fan of larger diameter. Noise Exposure Forecast (NEF) contours were computed for the baseline (nonretrofitted) aircraft for the projected traffic volume and fleet mix for the year 1990. These NEF contours are presented along with contours for a variety of retrofit options. Comparisons of the baseline with the noise reduction options are given in terms of total land area exposed to 30 and 40 NEF levels. Results are also presented of the effects on noise exposure area of the total number of daily operations.

  11. Contrasting current and projected changes in surface mass balance components across the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Langen, Peter L.; Mottran, Ruth H.; Christensen, Jens H.; Olesen, Martin

    2016-04-01

    Comparison of the last decade's low surface mass balance (SMB) on the Greenland ice sheet to the changes that are projected for a warming future allows the current mass loss to be placed in a broader perspective. We compare changes in SMB components in HIRHAM5 regional climate model experiments forced by current ERA-Interim reanalysis data and by future projections with the EC-Earth general circulation model. The EC-Earth-forced experiments run over time slices 1991-2010, 2031-2050 and 2081-2100 for both RCP4.5 and RCP8.5. SMB decreases considerably in the in the last decades of the ERA-Interim experiment. The changes between the early and later part of this experiment are therefore compared to changes in the future scenarios relative to the baseline 1991-2010 EC-Earth-forced experiment. A major increase in melting and runoff, particularly along the western margin, is common to both the current and projected situations. Over the reanalysis period, accumulation has decreased in many places, particularly in the south. This is linked to the dominant circulation pattern in the last decade and enhances the effect of increased melt and runoff in producing the recent low SMB. In the projections, however, accumulation increases and thereby partially offsets the mass loss. This offset is so efficient that only in the warmest scenario in the latest time slice is the SMB decline significantly stronger than the current one. In the mid-term in the RCP4.5 experiment, central East Greenland sees an increase in accumulation which is not yet countered by increased melt and runoff. Consequently, this basin even has an increased SMB. The increase in accumulation (both rain and snow) is projected to lead to significant SMB increase in the interior parts of the ice sheet. Rain fractions tend to increase, as seen already in reanalysis period. As melting intensifies in the ablation zone and the percolation zone migrates upward into areas that see increased snowfall, the refreezing rate

  12. [Tail Plane Icing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Aviation Safety Program initiated by NASA in 1997 has put greater emphasis in safety related research activities. Ice-contaminated-tailplane stall (ICTS) has been identified by the NASA Lewis Icing Technology Branch as an important activity for aircraft safety related research. The ICTS phenomenon is characterized as a sudden, often uncontrollable aircraft nose- down pitching moment, which occurs due to increased angle-of-attack of the horizontal tailplane resulting in tailplane stall. Typically, this phenomenon occurs when lowering the flaps during final approach while operating in or recently departing from icing conditions. Ice formation on the tailplane leading edge can reduce tailplane angle-of-attack range and cause flow separation resulting in a significant reduction or complete loss of aircraft pitch control. In 1993, the Federal Aviation Authority (FAA) and NASA embarked upon a four-year research program to address the problem of tailplane stall and to quantify the effect of tailplane ice accretion on aircraft performance and handling characteristics. The goals of this program, which was completed in March 1998, were to collect aerodynamic data for an aircraft tail with and without ice contamination and to develop analytical methods for predicting the effects of tailplane ice contamination. Extensive dry air and icing tunnel tests which resulted in a database of the aerodynamic effects associated with tailplane ice contamination. Although the FAA/NASA tailplane icing program generated some answers regarding ice-contaminated-tailplane stall (ICTS) phenomena, NASA researchers have found many open questions that warrant further investigation into ICTS. In addition, several aircraft manufacturers have expressed interest in a second research program to expand the database to other tail configurations and to develop experimental and computational methodologies for evaluating the ICTS phenomenon. In 1998, the icing branch at NASA Lewis initiated a second

  13. Project Ice Storm: Prenatal Maternal Stress Affects Cognitive and Linguistic Functioning in 5 1/2-Year-Old Children

    ERIC Educational Resources Information Center

    Laplante, David P.; Brunet, Alain; Schmitz, Norbert; Ciampi, Antonio; King, Suzanne

    2008-01-01

    The study used data from Project Ice Storm to determine the extent to which exposure to prenatal maternal stress due to a natural disaster can explain variance in the intellectual and language performance of offspring at age 5 1/2.

  14. Aircraft Emission Inventories Projected in Year 2015 for a High Speed Civil Transport (HSCT) Universal Airline Network. Final report

    SciTech Connect

    Baughcum, S.L.; Henderson, S.C.

    1995-07-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from projected fleets of high speed civil transports (HSCT`s) on a universal airline network. Inventories for 500 and 1000 HSCT fleets, as well as the concurrent subsonic fleets, were calculated. The objective of this work was to evaluate the changes in geographical distribution of the HSCT emissions as the fleet size grew from 500 to 1000 HSCT`s. For this work, a new expanded HSCT network was used and flights projected using a market penetration analysis rather than assuming equal penetration as was done in the earlier studies. Emission inventories on this network were calculated for both Mach 2.0 and Mach 2.4 HSCT fleets with NOx cruise emission indices of approximately 5 and 15 grams NOx/kg fuel. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer attitude grid and delivered to NASA as electronic files.

  15. Aircraft Emission Inventories Projected in Year 2015 for a High Speed Civil Transport (HSCT) Universal Airline Network

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Henderson, Stephen C.

    1995-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from projected fleets of high speed civil transports (HSCT's) on a universal airline network.Inventories for 500 and 1000 HSCT fleets, as well as the concurrent subsonic fleets, were calculated. The objective of this work was to evaluate the changes in geographical distribution of the HSCT emissions as the fleet size grew from 500 to 1000 HSCT's. For this work, a new expanded HSCT network was used and flights projected using a market penetration analysis rather than assuming equal penetration as was done in the earlier studies. Emission inventories on this network were calculated for both Mach 2.0 and Mach 2.4 HSCT fleets with NOx cruise emission indices of approximately 5 and 15 grams NOx/kg fuel. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer attitude grid and delivered to NASA as electronic files.

  16. A perspective on 15 years of proof-of-concept aircraft development and flight research at Ames-Moffett by the Rotorcraft and Powered-Lift Flight Projects Division, 1970-1985

    NASA Technical Reports Server (NTRS)

    Few, David D.

    1987-01-01

    A proof-of-concept (POC) aircraft is defined and the concept of interest described for each of the six aircraft developed by the Ames-Moffet Rotorcraft and Powered-Lift Flight Projects Division from 1970 through 1985; namely, the OV-10, the C-8A Augmentor Wing, the Quiet Short-Haul Research Aircraft (QSRA), the XV-15 Tilt Rotor Research Aircraft (TRRA), the Rotor Systems Research Aircraft (RSRA)-compound, and the yet-to-fly RSRA/X-Wing Aircraft. The program/project chronology and most noteworthy features of the concepts are reviewed. The paper discusses the significance of each concept and the project demonstrating it; it briefly looks at what concepts are on the horizon as potential POC research aircraft and emphasizes that no significant advanced concept in aviation technology has ever been accepted by civilian or military users without first completing a demonstration through flight testing.

  17. Coast Guard/NOAA/NASA Great Lakes Project Icewarn. [ice mapping for winter navigation

    NASA Technical Reports Server (NTRS)

    Brennan, T. D.; Gedney, R. T.

    1975-01-01

    The operational feasibility of using remote sensing to provide all weather ice formation for Great Lakes winter navigation is explored. A combination airborne pulsed radar system to measure actual ice thickness, a satellite data link system, and a hand drawn interpretive ice chart proved valuable for extending winter navigation through the icepack.

  18. European Space Agency Campaign Activities in Support of Earth Observation Projects: Examples for Snow and Ice

    NASA Astrophysics Data System (ADS)

    Schüttemeyer, D.; Davidson, M.; Casal, T.; Perrera, A.; Bianchi, R.; Kern, M.; Scipal, K.

    2012-04-01

    In the framework of its Earth Observation Programmes the European Space Agency (ESA) carries out groundbased and airborne campaigns to support geophysical algorithm development, calibration/validation, simulation of future spaceborne earth observation missions, and applications development related to land, oceans and atmosphere. Campaigns in support of future mission development have technological, geophysical and simulation objectives while exploitation projects need validation for the assessment of the quality of the earth observation products and of the service provision. ESA has been conducting airborne and ground measurements campaigns since 1981 by deploying a broad range of active and passive instrumentation in both the optical and microwave regions of the electromagnetic spectrum such as lidars, limb/nadir sounding interferometers/spectrometers, high-resolution spectral imagers, advanced synthetic aperture radars, altimeters and radiometers. These campaigns take place inside and outside Europe in collaboration with national research organisations in the ESA member states as well as with international organisations harmonising European campaign activities. For the different activities a rich variety of datasets has been recorded, are archived and users can access campaign data through the EOPI web portal [http://eopi.esa.int]. In 2005, ESA released a call for the next Earth Explorer Core Mission Ideas with the aim to select a 7th Earth Explorer (EE7) mission to be launched in the next decade. Twenty-four proposals were received and subject to detailed scientific and technical assessment. During the so-called Phase 0, six concepts were selected and further investigated. A down-selection was made after the User Consultation Meeting held in Lisbon, Portugal in January 2009. Three candidate mission concepts were selected for further feasibility phase (phase A) investigation. Each of the candidate missions are being elaborated through two parallel industrial

  19. Waterway Ice Thickness Measurements

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The ship on the opposite page is a U. S. Steel Corporation tanker cruising through the ice-covered waters of the Great Lakes in the dead of winter. The ship's crew is able to navigate safely by plotting courses through open water or thin ice, a technique made possible by a multi-agency technology demonstration program in which NASA is a leading participant. Traditionally, the Great Lakes-St. Lawrence Seaway System is closed to shipping for more than three months of winter season because of ice blockage, particularly fluctuations in the thickness and location of ice cover due to storms, wind, currents and variable temperatures. Shippers have long sought a system of navigation that would allow year-round operation on the Lakes and produce enormous economic and fuel conservation benefits. Interrupted operations require that industrial firms stockpile materials to carry them through the impassable months, which is costly. Alternatively, they must haul cargos by more expensive overland transportation. Studies estimate the economic benefits of year-round Great Lakes shipping in the hundreds of millions of dollars annually and fuel consumption savings in the tens of millions of gallons. Under Project Icewarn, NASA, the U.S. Coast Guard and the National Oceanic Atmospheric Administration collaborated in development and demonstration of a system that permits safe year-round operations. It employs airborne radars, satellite communications relay and facsimile transmission to provide shippers and ships' masters up-to-date ice charts. Lewis Research Center contributed an accurate methods of measuring ice thickness by means of a special "short-pulse" type of radar. In a three-year demonstration program, Coast Guard aircraft equipped with Side-Looking Airborne Radar (SLAR) flew over the Great Lakes three or four times a week. The SLAR, which can penetrate clouds, provided large area readings of the type and distribution of ice cover. The information was supplemented by short

  20. Icing flight research: Aerodynamic effects of ice and ice shape documentation with stereo photography

    NASA Technical Reports Server (NTRS)

    Mikkelsen, K. L.; Mcknight, R. C.; Ranaudo, R. J.; Perkins, P. J., Jr.

    1985-01-01

    Aircraft icing flight research was performed in natural icing conditions. A data base consisting of icing cloud measurements, ice shapes, and aerodynamic measurements is being developed. During research icing encounters the icing cloud was continuously measured. After the encounter, the ice accretion shapes on the wing were documented with a stereo camera system. The increase in wing section drag was measured with a wake survey probe. The overall aircraft performance loss in terms of lift and drag coefficient changes was obtained by steady level speed/power measurements. Selective deicing of the airframe components was performed to determine their contributions to the total drag increase. Engine out capability in terms of power available was analyzed for the iced aircraft. It was shown that the stereo photography system can be used to document ice shapes in flight and that the wake survey probe can measure increases in wing section drag caused by ice. On one flight, the wing section drag coefficient (c sub d) increased approximately 120 percent over the uniced baseline at an aircraft angle of attack of 6 deg. On another flight, the aircraft darg coefficient (c sub d) increased by 75 percent over the uniced baseline at an aircraft lift coefficient (C sub d) of 0.5.

  1. The EUMETSAT ocean and sea ice SAF (OSI SAF) : Overview on the project and the products

    NASA Astrophysics Data System (ADS)

    Guevel, Guenole

    The EUMETSAT OSI SAF (www.osi-saf.org) was created in 1997 as an answer to requirements for a comprehensive information derived from meteorological satellites at the ocean-atmosphere interface. The OSI SAF consortium is constituted of Météo-France as leading entity, and Met.no (Norske ee Meteorologiske Institutt), DMI (Danish Meteorological Institute), SMHI (Swedish Meteorolog-ical and Hydrological Institute), KNMI (Koninklijk Nederlands Meteorologisch Instituut) and IFREMER (Institut Français de Recherche pour l'Exploitation de la MER) as co-operating c entities. The two previous phases of the EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI SAF), the Development phase (1997-2002) and the IOP (initial Operations Phase, 2002-2007) met the main target which was to develop, validate and then produce operationally quality controlled satellite-derived products related to four key parameters of the sea surface (Sea Surface Temperature, Radiative Fluxes, Sea Ice, Wind) over various geographical coverage from regional to global. These products are currently available in near real time both through EUMETCAST and local FTP servers, and off line from local archive. Archiving at EUMETSAT Data Center is also being implemented. The current phase of the EUMETSAT OSI SAF, the CDOP (Continuous Development and Operations Phase, 2007-2012) has taken into account new requirements expressed in particular in the context of GODAE, GHRSST and GCOS at international level, and GMES (through MyOcean) at European level, with in particular a strong need for increasing the temporal and geographical resolution of the products and user friendly interfaces allowing access to high level allowing flexible extraction An overview on the OSI SAF project and its current and future production in the time frame of the CDOP will be presented, as well as first glance on the following phase, the CDOP-2, that will cover 2012 to 2017.

  2. Aircraft measurements over Fennoscandia during the MAMM project - highlights from 2012-2014

    NASA Astrophysics Data System (ADS)

    Allen, Grant

    2015-04-01

    This paper will present highlights and conclusions from a 3-year campaign of summer airborne measurements across the Fennoscandian region and over the Barents Sea and Svalbard during the Methane in the Arctic Measurements and Modelling (MAMM) campaign. Beginning in July 2012, the UK Facility for Airborne Atmospheric Measurement (FAAM) Bae-146 Atmospheric Research Aircraft has conducted more than 150 hours of sampling over this Arctic domain in a series of tailored process-driven case studies in the period July to September in each year between 2012 and 2014. High precision, continuous measurements of methane concentration and its isotopologues were collected on the FAAM aircraft along with measurements of a wide range of other gases (such as CO2, N2O, O3, CO, HCOOH), aerosol, and thermodynamic parameters. Together, such measurements provide a dataset from which to assess physico-chemical airmass history and specific local and regional emission processes. The FAAM platform complemented a longer term ground-based measurement deployment to collect data for measurement-led case studies, and regional and global model evaluation. In this study we will present highlights from case studies of regionally-averaged snapshots of Arctic wetland methane and formic acid net surface flux and we will present conclusions from airborne methane measurements over potential gas seepage areas on the continental shelf off the coast of Svalbard. We will also present the first airborne remote sensing measurements of methane over the region from the FAAM aircraft and we will present a summer climatology of greenhouse measurements across the MAMM campaign. We will conclude by discussing the next steps in completing the Arctic methane picture and what this might mean for the global methane conundrum.

  3. Enhancing Icing Training for Pilots Through Web-Based Multimedia

    NASA Technical Reports Server (NTRS)

    Fletcher, William; Nolan, Gary; Adanich, Emery; Bond, Thomas H.

    2006-01-01

    The Aircraft Icing Project of the NASA Aviation Safety Program has developed a number of in-flight icing education and training aids designed to increase pilot awareness about the hazards associated with various icing conditions. The challenges and advantages of transitioning these icing training materials to a Web-based delivery are discussed. Innovative Web-based delivery devices increased course availability to pilots and dispatchers while increasing course flexibility and utility. These courses are customizable for both self-directed and instructor-led learning. Part of our goal was to create training materials with enough flexibility to enable Web-based delivery and downloadable portability while maintaining a rich visual multimedia-based learning experience. Studies suggest that using visually based multimedia techniques increases the effectiveness of icing training materials. This paper describes these concepts, gives examples, and discusses the transitional challenges.

  4. Greenhouse gas fluxes for the UK and Ireland using aircraft sampling during the GAUGE project

    NASA Astrophysics Data System (ADS)

    Pitt, Joseph; Allen, Grant; Percival, Carl; Rigby, Matt; Ganesan, Anita; Levy, Peter; Bauguitte, Stephane; Le Breton, Michael; Lee, James; Mead, Iqbal; Cain, Michelle; Palmer, Paul

    2016-04-01

    As part of the GAUGE campaign (Greenhouse gAs UK and Global Emissions) the UK's FAAM (Facility for Airborne Atmospheric Measurement) aircraft was deployed to measure atmospheric composition around the UK and Ireland. Overall 15 flights were flown during the summers of 2014 and 2015; here we focus on a case study from two of these flights conducted upwind and downwind of the UK mainland on a single day in May 2015. During these two flights the prevailing meteorology brought maritime air from the Atlantic Ocean across the region, providing an upwind background conducive to the calculation of bulk regional greenhouse gas fluxes. We employ the NAME (Numerical Atmospheric dispersion Modelling Environment) dispersion model to generate air history maps for discrete sampling segments of the flight tracks. These are convolved with spatially disaggregated fluxes from bottom-up emission inventories to produce a modelled time series of concentration enhancements along the sampling path of the aircraft. By comparing modelled concentration enhancements to the measured time series it is possible to assess the overall inventory performance, and by looking at the scale factor between measured and modelled enhancements we can estimate the weighted greenhouse gas fluxes over the sample footprint. We also assess the sampling strategy used during these flights, and provide recommendations for future studies using this technique.

  5. A Contribution to the Sea-Ice Model Intercomparison Project 2 (SIMIP2) Thermodynamic Sea-Ice Models Assessment : Impact of Vertical Resolution, Vertical Salinity Profile, and Salinity- and Temperature-Dependent Thermal Properties

    NASA Astrophysics Data System (ADS)

    Fichefet, T.; Vancoppenolle, M.

    2004-12-01

    Results from a sophisticated thermodynamic sea-ice model are presented. The model has the following peculiarities. First, the sea-ice pack is represented by several layers of snow on top of several layers of ice, and different ways of specifying the number and thickness of vertical layers are possible. Second, the heat-diffusion equation and its boundary conditions explicitly take into account the thermal damping effect of the brine pockets trapped into the ice through temperature- and salinity-dependent thermal properties, but density is nevertheless a constant. The main experiment consists in an almost-one-year integration of the model following the SIMIP2 (Sea-Ice Model Intercomparision Project) specifications, i.e., a Lagrangian multiyear undeformed ice floe forced by observed hourly atmospheric and monthly oceanic data fields. Model results are compared to weekly observations of ice and snow thicknesses. Snow precipitations have to be increased by 50% for the snow thickness to be correctly reproduced, supporting gauge problems already reported in the past. Ice thickness shows good overall agreement, especially in winter, and an underestimation of around 10 cm of surface melting in summer. Sensitivity experiments show that the effect of salinity and temperature through thermal properties is significant. The non-linear vertical salinity profile can be replaced by a linear profile with same mean salinity. Finally, the simplest resolution which conserves the main features of the results gathers one layer in the snow and between 5 and 10 layers in the ice.

  6. UAV applications for thermodynamic profiling: Emphasis on ice fog research

    NASA Astrophysics Data System (ADS)

    Gultepe, Ismail; Heymsfield, Andrew J.; Fernando, Harindra J. S.; Hoch, Sebastian W.; Ware, Randolph

    2016-04-01

    Ice fog occurs often over the Arctic, cold climatic, and mountainous regions for about 30% of time where temperature (T) can go down to -10°C or below. Ice Nucleation (IN) and cooling processes play an important role by the controlling the intensity of ice fog conditions that affect aviation application, transportation, and local climate. Ice fog can also occur at T above -10°C but close to 0°C it occurs due to freezing of supercooled droplets that include an IN. To better document ice fog conditions, observations from the ice fog events of the Indirect and Semi-Direct Aerosol effects on Climate (ISDAC) project, Barrow, Alaska, Fog Remote Sensing And Modeling (FRAM) project Yellowknife, Northwest Territories, and the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) project, Heber City, Utah, were analyzed.. Measurements difficulties of small ice fog particles at cold temperatures and low-level flying restrictions prevent observations from aircraft within the surface boundary layer. However, unmanned Aerial Vehicles (UAVs) can be operated safely to measure IN number concentration, Relative Humidity with respect to ice (RHi), T, horizontal wind speed (Uh) and direction, and ice crystal spectra less than about 500 micron. Thermodynamic profiling by a Radiometrics Profiling Microwave Radiometer (PMWR) and Vaisala CL51 ceilometer was used to describe ice fog conditions in the vertical and its time development. In this presentation, ice fog characteristics and its thermodynamic environment will be presented using both ground-based and airborne platforms such as a UAV with new sensors. Some examples of measurements from the UAV for future research, and challenges related to both ice fog measurements and visibility parameterization will also be presented.

  7. Preliminary design study of advanced composite blade and hub and nonmechanical control system for the tilt-rotor aircraft. Volume 2: Project planning data

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Project planning data for a rotor and control system procurement and testing program for modifications to the XV-15 tilt-rotor research demonstrator aircraft is presented. The design, fabrication, and installation of advanced composite blades compatible with the existing hub, an advanced composite hub, and a nonmechanical control system are required.

  8. Lobster Tail Ice Formation on Aerosurface

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Glace Ice formation commonly refered to as 'Lobster Tail' by scientists and engineers, is caused to form on the leading edge of a aircraft tail section in the icing research tunnel at the NASA Glenn Research Center, Cleveland, Ohio.

  9. Ice Accretions and Full-Scale Iced Aerodynamic Performance Data for a Two-Dimensional NACA 23012 Airfoil

    NASA Technical Reports Server (NTRS)

    Addy, Harold E., Jr.; Broeren, Andy P.; Potapczuk, Mark G.; Lee, Sam; Guffond, Didier; Montreuil, Emmanuel; Moens, Frederic

    2016-01-01

    This report documents the data collected during the large wind tunnel campaigns conducted as part of the SUNSET project (StUdies oN Scaling EffecTs due to ice) also known as the Ice-Accretion Aerodynamics Simulation study: a joint effort by NASA, the Office National d'Etudes et Recherches Aérospatiales (ONERA), and the University of Illinois. These data form a benchmark database of full-scale ice accretions and corresponding ice-contaminated aerodynamic performance data for a two-dimensional (2D) NACA 23012 airfoil. The wider research effort also included an analysis of ice-contaminated aerodynamics that categorized ice accretions by aerodynamic effects and an investigation of subscale, low- Reynolds-number ice-contaminated aerodynamics for the NACA 23012 airfoil. The low-Reynolds-number investigation included an analysis of the geometric fidelity needed to reliably assess aerodynamic effects of airfoil icing using artificial ice shapes. Included herein are records of the ice accreted during campaigns in NASA Glenn Research Center's Icing Research Tunnel (IRT). Two different 2D NACA 23012 airfoil models were used during these campaigns; an 18-in. (45.7-cm) chord (subscale) model and a 72-in. (182.9-cm) chord (full-scale) model. The aircraft icing conditions used during these campaigns were selected from the Federal Aviation Administration's (FAA's) Code of Federal Regulations (CFR) Part 25 Appendix C icing envelopes. The records include the test conditions, photographs of the ice accreted, tracings of the ice, and ice depth measurements. Model coordinates and pressure tap locations are also presented. Also included herein are the data recorded during a wind tunnel campaign conducted in the F1 Subsonic Pressurized Wind Tunnel of ONERA. The F1 tunnel is a pressured, high- Reynolds-number facility that could accommodate the full-scale (72-in. (182.9-cm) chord) 2D NACA 23012 model. Molds were made of the ice accreted during selected test runs of the full-scale model

  10. Projected Arctic warming, rapid sea ice loss, and snow state changes: Influence on near- surface permafrost degradation

    NASA Astrophysics Data System (ADS)

    Lawrence, D. M.; Slater, A. G.

    2008-12-01

    Projected climatic changes in the Arctic associated with increasing greenhouse gas concentrations are varied. Global climate models suggest that warming in the Arctic will be considerably stronger than the rest of the world. In the Community Climate System Model (CCSM3), 21st century terrestrial Arctic warming ranges from ~+4 to +8° C depending on emission scenario. This warming is non-linear, due in part, to periods of accelerated sea ice loss. Along with the warming, CCSM3 (and other global models) project an increase in winter snowfall and concomitant changes in snow depth, snow density, and snow-season length. Here, we evaluate the roles of Arctic warming, accelerated sea ice loss, and snow state changes on the rate and extent of soil warming and permafrost degradation. We utilize the Community Land Model (CLM) with improved permafrost dynamics to evaluate and compare the large-scale near-surface permafrost response to these climatic forcings. The strong projected warming is, not surprisingly the biggest contributor to permafrost degradation. However, we can attribute roughly 18 percent of the permafrost degradation to increasing snowfall and the resulting maintenance of the insulating snowpack even in the face of strong warming. We also find that a period of accelerated warming associated with rapid sea ice loss can accelerate soil warming and lead to rapid thaw of warmer permafrost and to increased vulnerability of colder permafrost.

  11. Freezing Rain as an In-Flight Icing Hazard

    NASA Technical Reports Server (NTRS)

    Bernstein, Ben C.; Ratvasky, Thomas P.; Miller, Dean R.; McDonough, Frank

    2000-01-01

    Exposure to supercooled large drops (SLD-subfreezing water droplets with diameters greater than approx. 50 microns) can pose a significant threat to the safety of some aircraft. Although SLD includes both freezing drizzle (FZDZ) and freezing rain (FZRA), much of the SLD research and development of operational SLD forecast tools has focused on FZDZ and ignored FZRA, regarding is as less of a hazard to aviation. This paper provides a counterpoint case study that demonstrates FZRA as a significant in-flight icing hazard. The case study is based on flight and meteorological data from a joint NASA/FAA/NCAR SLD icing research project collected on February 4, 1998. The NASA Twin Otter Icing Research Aircraft experienced a prolonged exposure to "classical" FZRA that formed extensive ice formations including ridges and nodules on the wing and tail, and resulted in a substantial performance penalty. Although the case study provides only a singular FZRA event with one aircraft type, it is clear that classical FZRA can pose a significant in-flight icing hazard, and should not be ignored when considering SLD issues.

  12. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Subcommittee Final

    NASA Technical Reports Server (NTRS)

    Johnson, Chuck; Griner, James H.; Hayhurst, Kelly J.; Shively, Robert J.; Consiglio, Maria; Muller, Eric; Murphy, James; Kim, Sam

    2012-01-01

    UAS Integration in the NAS Project overview with details from each of the subprojects. Subprojects include: Communications, Certification, Integrated Test and Evaluation, Human Systems Integration, and Separation Assurance/Sense and Avoid Interoperability.

  13. 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.

  14. Aircraft Measurements of Convective System Vertical Structure and Coldpools during the DYNAMO Project

    NASA Astrophysics Data System (ADS)

    Guy, N.; Jorgensen, D. P.; Chen, S. S.; Wang, Q.

    2012-12-01

    The DYNAMO (Dynamics of the Madden-Julian Oscillation) field experiment employed a large number of measurement platforms with which to study environmental and convective cloud system characteristics of the MJO initiation region in the Indian Ocean. One such platform, the NOAA P-3 instrumented aircraft, provided mobility to sample convective cloud systems along with the surrounding environment. The tail-mounted, X-band Doppler radar allowed a pseudo-dual-Doppler analysis technique to study system kinematics and derive vertical wind motion. GPS dropwindsondes provided a robust means for thermodynamic characterization both in and around the sampled convective cloud systems. This presentation will focus on the relationships between coldpool strength and depth (along with other environmental characteristics) and the vertical structure of convective systems. In addition, a comparison of the DYNAMO observations to previous results in the region (e.g. TOGA COARE) will be presented. Differences in organizational aspects of convective clouds into mesoscale convective systems between the studies will provide a context of regional differences, which may serve as a basis for future model simulations.

  15. The Flying Diamond: A joined aircraft configuration design project, volume 1

    NASA Technical Reports Server (NTRS)

    Ball, Chris; Czech, Joe; Lentz, Bryan; Kobashigawa, Daryl; Oishi, Curtis; Poladian, David

    1988-01-01

    The results of the analysis conducted on the Joined Wing Configuration study are presented. The joined wing configuration employs a conventional fuselage and incorporates two wings joined together near their tips to form a diamond shape in both plan view and front view. The arrangement of the lifting surfaces uses the rear wing as a horizontal tail and as a forward wing strut. The rear wing has its root at the tip of the vertical stabilizer and is structurally attached to the trailing edge of the forward wing. This arrangement of the two wings forms a truss structure which is inherently resistant to the aerodynamic bending loads generated during flight. This allows for a considerable reduction in the weight of the lifting surfaces. With smaller internal wing structures needed, the Joined Wing may employ thinner wings which are more suitable for supersonic and hypersonic flight, having less induced drag than conventional cantilever winged aircraft. Inherent in the Joined Wing is the capability of the generation of direct lift and side force which enhance the performance parameters.

  16. Aircraft-type dependency of contrail evolution

    NASA Astrophysics Data System (ADS)

    Unterstrasser, S.; Görsch, N.

    2014-12-01

    The impact of aircraft type on contrail evolution is assessed using a large eddy simulation model with Lagrangian ice microphysics. Six different aircraft ranging from the small regional airliner Bombardier CRJ to the largest aircraft Airbus A380 are taken into account. Differences in wake vortex properties and fuel flow lead to considerable variations in the early contrail geometric depth and ice crystal number. Larger aircraft produce contrails with more ice crystals (assuming that the number of initially generated ice crystals per kilogram fuel is constant). These initial differences are reduced in the first minutes, as the ice crystal loss during the vortex phase is stronger for larger aircraft. In supersaturated air, contrails of large aircraft are much deeper after 5 min than those of small aircraft. A parameterization for the final vertical displacement of the wake vortex system is provided, depending only on the initial vortex circulation and stratification. Cloud resolving simulations are used to examine whether the aircraft-induced initial differences have a long-lasting mark. These simulations suggest that the synoptic scenario controls the contrail cirrus evolution qualitatively. However, quantitative differences between the contrail cirrus properties of the various aircraft remain over the total simulation period of 6 h. The total extinctions of A380-produced contrails are about 1.5 to 2.5 times higher than those from contrails of a Bombardier CRJ.

  17. Icing simulation: A survey of computer models and experimental facilities

    NASA Technical Reports Server (NTRS)

    Potapczuk, M. G.; Reinmann, J. J.

    1991-01-01

    A survey of the current methods for simulation of the response of an aircraft or aircraft subsystem to an icing encounter is presented. The topics discussed include a computer code modeling of aircraft icing and performance degradation, an evaluation of experimental facility simulation capabilities, and ice protection system evaluation tests in simulated icing conditions. Current research focussed on upgrading simulation fidelity of both experimental and computational methods is discussed. The need for increased understanding of the physical processes governing ice accretion, ice shedding, and iced airfoil aerodynamics is examined.

  18. Chemical Characterization of Individual Particles and Residuals of Cloud Droplets and Ice Crystals Collected On Board Research Aircraft in the ISDAC 2008 Study

    SciTech Connect

    Hiranuma, Naruki; Brooks, Sarah D.; Moffet, Ryan C.; Glen, Andrew; Laskin, Alexander; Gilles, Marry K.; Liu, Peter; MacDonald, A. M.; Strapp, J. Walter; McFarquhar, Greg

    2013-06-24

    Although it has been shown that size of atmospheric particles has a direct correlation with their ability to act as cloud droplet and ice nuclei, the influence of composition of freshly emitted and aged particles in nucleation processes is poorly understood. In this work we combine data from field measurements of ice nucleation with chemical imaging of the sampled particles to link aerosol composition with ice nucleation ability. Field measurements and sampling were conducted during the Indirect and Semidirect Aerosols Campaign (ISDAC) over Barrow, Alaska, in the springtime of 2008. In-situ ice nucleation measurements were conducted using a Continuous Flow Diffusion Chamber (CFDC). Measured number concentrations of ice nuclei (IN) varied from frequent values of 0.01 per liter to more than 10 per liter. Residuals of airborne droplets and ice crystals were collected through a counterflow virtual impactor (CVI). The compositions of individual atmospheric particles and the residuals were studied using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis (CCSEM/EDX) and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy (STXM/NEXAFS). Chemical analysis of cloud particle residuals collected during an episode of high ice nucleation suggests that both size and composition may influence aerosol's ability to act as IN. The STXM/NEXAFS chemical composition maps of individual residuals have characteristic structures of either inorganic or black carbon cores coated by organic materials. In a separate flight, particle samples from a biomass burning plume were collected. Although it has previously been suggested that episodes of biomass burning contribute to increased numbers of highly effective ice nuclei, in this episode we observed that only a small fraction were effective ice nuclei. Most of the particles from the biomass plume episode were smaller in size and were composed of

  19. Future projections of Greenland's ice loss accounting for changes in surface mass balance and dynamic discharge

    NASA Astrophysics Data System (ADS)

    Fürst, J. J.; Goelzer, H.; Huybrechts, P.

    2012-04-01

    Under future climate change, the Greenland Ice Sheet (GrIS) is highly vulnerable as its margins are relatively warm compared to Antarctica making them relatively prone for summer melting. A rise of about three degrees in annual average temperature over Greenland is expected to lead to irreversible ice sheet melting, which makes the GrIS a sensitive element in the Earth's climate system. Moreover, extended coverage and improved observation techniques have revealed high variations in dynamical ice discharge from outlet glaciers around the entire ice sheet. During the last decade, this dynamic discharge has contributed to almost half of the total mass loss. Since variations of the dynamic discharge are limited to the GrIS margin, direct inland transmission of these perturbations is necessary to significantly alter the overall GIS evolution on short time scales. Gradients in membrane stresses hold the potential for direct horizontal coupling and thus concerns are raised whether direct signal transmission has a significant impact on the ice interior. Because of strong mutual feedbacks between surface mass balance and marginal ice dynamics, our aim is to account for changes in both to assess the future GrIS contribution to sea level rise. For this purpose, we use a three-dimensional ice sheet model with a Blatter/Pattyn dynamic core that allows for direct signal transmission in ice flow. The surface mass balance is calculated by a positive degree-day model, which accounts for internal accumulation and temporary water storage in the snow cover. The model is initialised by calibrating a glacial cycle spin-up to the present day geometry. For the last half of the 20th century we force the ice sheet model with reanalysis data of surface temperature and precipitation. Future climate scenarios are taken from general circulation models and used in anomaly mode in the positive degree-day model. These scenarios are based on the representative concentration pathways that were

  20. Nimbus Satellite Data Rescue Project for Sea Ice Extent: Data Processing

    NASA Astrophysics Data System (ADS)

    Campbell, G. G.; Sandler, M.; Moses, J. F.; Gallaher, D. W.

    2011-12-01

    scanning and simple quality control of more than 200,000 pictures. Preliminary results from September 1964, 1966 and 1969 data analysis will be discussed in this presentation. Our scientific use of the data will focus on recovering the sea ice extent around the poles. We especially welcome new users interested in the meteorology from 50N to 50S in the 1960's. Lessons and examples of the scanning and quality control procedures will be highlighted in the presentation. Illustrations will include mapped and reformatted data. When the project is finished a public archive from September 1964, April to November 1966 and May to December 1969 will be available for general use.

  1. Deicing and Anti-Icing Unite

    NASA Technical Reports Server (NTRS)

    2002-01-01

    With funding from Glenn's Small Business Innovation Research (SBIR) program, Cox & Company, Inc., built an ice protection system that combines thermal anti-icing and mechanical deicing to keep airfoils (wings and other lifting surfaces) clear of ice. Cox's concept was to combine an anti-icing system with NASA's Electro-Mechanical Expulsion Deicing System, a mechanical deicer. The anti-icing element of this hybrid would reduce the aerodynamic losses associated with deicing systems. The Cox Low Power Ice Protection System is the first new aircraft ice protection system that has been approved by the Federal Aviation Administration for use on a business jet in 40 years. While the system is currently sized for Premier class aircraft, there are no apparent constraints prohibiting its use on aircraft of any size. The company is investigating further applications, such as adapting the system for unmanned aerial vehicles and other military aircraft.

  2. Swept wing ice accretion modeling

    NASA Technical Reports Server (NTRS)

    Potapczuk, Mark G.; Bidwell, Colin S.

    1990-01-01

    An effort to develop a three-dimensional modeling method was initiated. This first step towards creation of a complete aircraft icing simulation code builds on previously developed methods for calculating three-dimensional flow fields and particle trajectories combined with a two-dimensional ice accretion calculation along coordinate locations corresponding to streamlines. This work is a demonstration of the types of calculations necessary to predict a three-dimensional ice accretion. Results of calculations using the 3-D method for a MS-317 swept wing geometry are projected onto a 2-D plane normal to the wing leading edge and compared to 2-D results for the same geometry. It is anticipated that many modifications will be made to this approach, however, this effort will lay the groundwork for future modeling efforts. Results indicate that the flow field over the surface and the particle trajectories differed for the two calculations. This led to lower collection efficiencies, convective heat transfer coefficients, freezing fractions, and ultimately ice accumulation for the 3-D calculation.

  3. Aircraft surface coatings

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Liquid, spray on elastomeric polyurethanes are selected and investigated as best candidates for aircraft external protective coatings. Flight tests are conducted to measure drag effects of these coatings compared to paints and a bare metal surface. The durability of two elastometric polyurethanes are assessed in airline flight service evaluations. Laboratory tests are performed to determine corrosion protection properties, compatibility with aircraft thermal anti-icing systems, the effect of coating thickness on erosion durability, and the erosion characteristics of composite leading edges-bare and coated. A cost and benefits assessment is made to determine the economic value of various coating configurations to the airlines.

  4. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

    NASA Technical Reports Server (NTRS)

    Griner, James H.

    2013-01-01

    NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication system prototype radio, operating on recently allocated UAS frequency spectrum bands. The prototype radio will be used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current status of the design, development, and flight test planning for this prototype radio.

  5. Projected Duration of the Sea-Ice-Free Season in the Future Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Wang, M.; Overland, J. E.

    2014-12-01

    The change in the Arctic climate is fast and broad. Among many changes that have been observed, the reduction of sea ice coverage has been one of the most significant factors. Continued reduction in sea ice cover will probably result in longer open water duration, which is important for the shipping industry, marine mammals as well as other component of the local ecosystem. In this study we are to assess future sea ice conditions, particularly the length of open water duration in the Alaskan Arctic over the next few decades using the latest coupled climate models (CMIP5). The Alaskan Arctic, including the Chukchi and the Beaufort Sea, has been a major region of summer sea ice retreat since 2007. Based on the mean of 12 climate models, for the region north of the Bering Strait (70° N), future open-water duration may extend from a current 3-4 months to around five months by 2050. It is about one month shorter along the same latitude over the Beaufort Sea. The difference in the length of ice-free season between the north and the south will remain, but will be smaller in the 21st century compared with current condition. Open-water duration in the Alaskan Arctic expands quickly in these models over the next decades, in contrast to model under-predictions of sea ice loss for the summer minimum over the Arctic wide domain. Uncertainty is generally ±one month estimated from the range of model results. Continued increases in open-water duration over the next two decades will impact regional economic access and potentially alter ecosystems, yet we need to keep in mind that from December through May most of the northern Alaskan Arctic will remain sea ice covered into the second half of the century.

  6. FINAL REPORT FOR THE DOE/ARM PROJECT TITLED Representation of the Microphysical and Radiative Properties of Ice Clouds in SCMs and GCMs

    SciTech Connect

    Mitchell, David L.

    2005-08-08

    The broad goal of this research is to improve climate prediction through better representation of cirrus cloud microphysical and radiative properties in global climate models (GCMs). Clouds still represent the greatest source of uncertainty in climate prediction, and the representation of ice clouds is considerably more challenging than liquid water clouds. While about 40% of cloud condensate may be in the form of ice by some estimates, there have been no credible means of representing the ice particle size distribution and mass removal rates from ice clouds in GCMs. Both factors introduce large uncertainties regarding the global net flux, the latter factor alone producing a change of 10 W/m2 in the global net flux due to plausible changes in effective ice particle fallspeed. In addition, the radiative properties of ice crystals themselves are in question. This research provides GCMs with a credible means of representing the full (bimodal) ice particle size distribution (PSD) in ice clouds, including estimates of the small crystal (D < 65 microns) mode of the PSD. It also provides realistic estimates of mass sedimentation rates from ice clouds, which have a strong impact on their ice contents and radiative properties. This can be done through proper analysis of ice cloud microphysical data from ARM and other field campaigns. In addition, this research tests the ice cloud radiation treatment developed under two previous ARM projects by comparing it against laboratory measurements of ice cloud extinction efficiency and by comparing it with explicit theoretical calculations of ice crystal optical properties. The outcome of this project includes two PSD schemes for ice clouds; one appropriate for mid-latitude cirrus clouds and another for tropical anvil cirrus. Cloud temperature and ice water content (IWC) are the inputs for these PSD schemes, which are based on numerous PSD observations. The temperature dependence of the small crystal mode of the PSD for tropical

  7. Research on the Application of Life Cycle Cost Management in the Civil Aircraft Assembly Line Project

    NASA Astrophysics Data System (ADS)

    Dawei, Lian; Xuefeng, Zhao

    Based on the investigation of airplane enterprises, the paper defines the life cycle of the airplane's assembly line in a reasonable way. It takes the model of project list in the stage of bidding to make it more actual. Regarding the airplane's assembly line, it also applies the equipments life cycle management theory into the using stage so that we can control the using cost more effectively. The paper uses the Crystal Ball to analyze the risk factors of the airplane's assembly line and improves the investment budget's accuracy.

  8. 14 CFR 33.68 - Induction system icing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.68 Induction system icing. Each engine, with all icing protection systems operating, must— (a) Operate throughout its flight...

  9. 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

  10. Web-based Tools for Educators: Outreach Activities of the Polar Radar for Ice Sheet Measurements (PRISM) Project

    NASA Astrophysics Data System (ADS)

    Braaten, D. A.; Holvoet, J. F.; Gogineni, S.

    2003-12-01

    The Radar Systems and Remote Sensing Laboratory at the University of Kansas (KU) has implemented extensive outreach activities focusing on Polar Regions as part of the Polar Radar for Ice Sheet Measurements (PRISM) project. The PRISM project is developing advanced intelligent remote sensing technology that involves radar systems, an autonomous rover, and communications systems to measure detailed ice sheet characteristics, and to determine bed conditions (frozen or wet) below active ice sheets in both Greenland and Antarctica. These measurements will provide a better understanding of the response of polar ice sheets to global climate change and the resulting impact the ice sheets will have on sea level rise. Many of the research and technological development aspects of the PRISM project, such as robotics, radar systems, climate change and exploration of harsh environments, can kindle an excitement and interest in students about science and technology. These topics form the core of our K-12 education and training outreach initiatives, which are designed to capture the imagination of young students, and prompt them to consider an educational path that will lead them to scientific or engineering careers. The K-12 PRISM outreach initiatives are being developed and implemented in a collaboration with the Advanced Learning Technology Program (ALTec) of the High Plains Regional Technology in Education Consortium (HPR*TEC). ALTec is associated with the KU School of Education, and is a well-established educational research center that develops and hosts web tools to enable teachers nationwide to network, collaborate, and share resources with other teachers. An example of an innovative and successful web interface developed by ALTec is called TrackStar. Teachers can use TrackStar over the Web to develop interactive, resource-based lessons (called tracks) on-line for their students. Once developed, tracks are added to the TrackStar database and can be accessed and modified

  11. A layout designer's data projection reticle. [for optimum indicator instrument location in aircraft

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1977-01-01

    The designer's projection reticle is a modified surplus weapons sighting device consisting of a 3.5 cm diameter, 8.9 focal length coated objective lens. It is placed 1.5 cm in front of a clear flat glass plate on which the aluminized reflective pattern has been deposited. Reflected light passes through the objective lens, off the front surface of the coating, and off the rear coated surface of the objective lens. Several reticle patterns have been designed and tested, and other patterns are in the planning stage. The device may be used for a variety of applications including determining the optimum locations on a cockpit panel for luminous warning indicators requiring rapid manual responses.

  12. Overview of Icing Research at NASA Glenn

    NASA Technical Reports Server (NTRS)

    Kreeger, Richard E.

    2013-01-01

    The aviation industry continues to deal with icing-related incidents and accidents on a regular basis. Air traffic continues to increase, placing more aircraft in adverse icing conditions more frequently and for longer periods. Icing conditions once considered rare or of little consequence, such as super-cooled large droplet icing or high altitude ice crystals, have emerged as major concerns for modern aviation. Because of this, there is a need to better understand the atmospheric environment, the fundamental mechanisms and characteristics of ice growth, and the aerodynamic effects due to icing, as well as how best to protect these aircraft. The icing branch at NASA Glenn continues to develop icing simulation methods and engineering tools to address current aviation safety issues in airframe, engine and rotorcraft icing.

  13. The formation of ice on airplanes

    NASA Technical Reports Server (NTRS)

    Noth, H; Polte, W

    1936-01-01

    The present report examines the problem of ice formation from the point of view of the pilot and the meteorologist. Their experiences prove the ice deposit to be first and foremost a navigational problem and only secondarily a question of de-icing devices. With correct utilization of the meteorological information by the flyer, ice hazard can in many cases be minimized or avoided. Ice formation and the different types of ice deposits are listed and discussed. Weather formation during these ice deposits are also discussed as well as the effect of ice formation on aircraft.

  14. Ice Prevention on Aircraft by Means of Engine Exhaust Heat and a Technical Study of Heat Transmission from a Clark Y Airfoil

    NASA Technical Reports Server (NTRS)

    Theodorsen, Theodore; Clay, William C

    1933-01-01

    This investigation was conducted to study the practicability of employing heat as a means of preventing the formation of ice on airplane wings. The report relates essentially to technical problems regarding the extraction of heat from the exhaust gases and its proper distribution over the exposed surfaces. In this connection a separate study has been made to determine the variation of the coefficient of heat transmission along the chord of a Clark Y airfoil. Experiments on ice prevention both in the laboratory and in flight show conclusively that it is necessary to heat only the front portion of the wing surface to effect complete prevention. Experiments in flight show that a vapor-heating system which extracts heat from the exhaust and distributes it to the wings is an entirely practical and efficient method for preventing ice formation.

  15. The microphysical properties of small ice particles measured during MACPEX

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; Schnaiter, M.; Heymsfield, A.; Bansemer, A.; Hirst, E.

    2012-12-01

    During the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) field campaign, the Small Ice Detector version 3 (SID-3) and the NCAR Video Ice Particle Sampler (VIPS) probes were operated onboard the NASA WB-57 aircraft to measure the microphysical properties of small ice particles in midlatitude cirrus clouds. The VIPS was optimized to measure the particle size distribution and projected area properties of ice particles between 20 and 200 microns and measurements agreed well with other microphysical probes. SID-3 measures the forward light scattering pattern from ice particles in the 1 to 100 micron size range. Forward scattering patterns can be used to characterize ice particle shape as well as surface roughness. Scattering patterns appear to be 'speckled' when particles have surface roughness and/or are polycrystalline. Scattering patterns can be used to identify quasi-spherical ice particles as well as particles which are sublimating. Sublimating crystals, spherical ice particles, and particles with surface roughness were all observed by SID-3 during MACPEX. Observed particle properties will be correlated to concurrent atmospheric observations. Measurements from the controlled environment of the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud chamber will be related to atmospheric particle measurements.

  16. Lake Michigan and Lake Superior air quality: The 1994-2003 LADCO Aircraft Project (LAP)

    NASA Astrophysics Data System (ADS)

    Foley, T. A.; Betterton, E. A.; Jacko, R.; Hillery, J.

    2011-12-01

    The goal of the 1994 to 2003 LADCO Airplane Project (LAP) was to study ozone formation over Lake Michigan so that equitable regional control strategies could be devised. During the ten year LAP campaign, a total of 328 flights were flown on 81 days over Lake Michigan and its southern and western boundaries. LAP also monitored air quality over Lake Superior and other areas in the Midwestern and southern United States. From 2001 to 2003, 117 flights were conducted over Lake Superior, Isle Royale National Park, Painted Rocks National Lakeshore and the Seeney National Wildlife Refuge in Michigan. 63 flights were conducted over St. Louis and 58 flights over the Dolly Sods Wilderness Area in West Virginia. We are looking for collaborators to help us analyze this vast data archive. Our first paper (Atmospheric Environment 45 (2011) 3192-3202) documented the project and presented results of our ozone analysis. Our results support the hypothesis of Dye et al. (1995), who found that the atmosphere over Lake Michigan is stable in the summer due to the air water temperature difference, which creates an efficient reaction chamber for ozone formation. They also hypothesized that the southwest winds characteristic of ozone-conducive conditions transport ozone further north over the lake before it crosses the shoreline onto land. We found that below 200 m above the lake, ozone formation is VOC-limited in the morning and becomes NOx limited in the afternoon. Above 200 m, ozone formation is NOx-limited throughout the day. The onshore NOx and VOC diurnal cycles peak during the early morning rush hour and are clearly linked to traffic patterns. Over the lake, VOC and NOy concentrations peak during the mid-morning rather than the early morning, supporting the hypothesis that the land breeze transports VOC and NOy over the lake. The diurnal NOx pattern over Lake Michigan is less clearly defined than the VOC pattern possibly as a result of emissions from five coal-burning power plants

  17. Fuel conservative aircraft engine technology

    NASA Technical Reports Server (NTRS)

    Nored, D. L.

    1978-01-01

    Technology developments for more fuel-efficiency subsonic transport aircraft are reported. Three major propulsion projects were considered: (1) engine component improvement - directed at current engines; (2) energy efficient engine - directed at new turbofan engines; and (3) advanced turboprops - directed at technology for advanced turboprop-powered aircraft. Each project is reviewed and some of the technologies and recent accomplishments are described.

  18. The Antarctic Ice.

    ERIC Educational Resources Information Center

    Radok, Uwe

    1985-01-01

    The International Antarctic Glaciological Project has collected information on the East Antarctic ice sheet since 1969. Analysis of ice cores revealed climatic history, and radar soundings helped map bedrock of the continent. Computer models of the ice sheet and its changes over time will aid in predicting the future. (DH)

  19. BRITICE-CHRONO: A multi-method project to determine the timing and rates of change of a marine-influenced ice sheet

    NASA Astrophysics Data System (ADS)

    Fabel, Derek; Clark, Chris; Chiverrell, Richard; O'Cofaigh, Colm; Scourse, James; Hindmarsh, Richard

    2016-04-01

    BRITICE-CHRONO is a five-year Natural Environment Research Council (NERC) funded consortium of more than 44 researchers comprising glaciologists, marine and terrestrial Quaternary scientists and ice sheet-modellers, with the specific aim to systematically collect and date material to constrain the timing and rates of change of the marine-influenced sectors of the collapsing British Irish Ice Sheet (http://britice-chrono.org/). At the halfway point of the project we have collected over 400 cores during two 40-day research cruises circumnavigating the British Isles and Ireland, and completed over 300 person-days of terrestrial fieldwork, yielding around 15 tonnes of samples for dating by optically stimulated luminescence-, surface exposure-, and radiocarbon methods. By end 2016 we expect to have generated about 850 new dates from landforms associated with the deglaciation of the last British and Irish ice-sheet. The success of the project will in part depend on the team being able to provide ice-sheet modellers with robust chronological markers against which the ice-sheet models can be tested. The decision-making process in deciding robustness of ages derived from multiple samples and different Quaternary geochronological methods will be discussed. Some geochronological highlights thus far are that deglaciation of the northwest sector of the ice-sheet was in progress at 28ka, well before the global LGM, and the northern tip of mainland Scotland was ice free by 25ka. At the same time the Irish Sea ice stream in the south appears to have been advancing towards its maximum extend. Although deglaciation in the south commences much later, both the main southern and northern ice streams appear to have persisted for at least 10ka with final retreat onto the mainland occurring at approximately the same time (16ka).

  20. The impact of snow depth, snow density and ice density on sea ice thickness retrieval from satellite radar altimetry: results from the ESA-CCI Sea Ice ECV Project Round Robin Exercise

    NASA Astrophysics Data System (ADS)

    Kern, S.; Khvorostovsky, K.; Skourup, H.; Rinne, E.; Parsakhoo, Z. S.; Djepa, V.; Wadhams, P.; Sandven, S.

    2015-01-01

    We assess different methods and input parameters, namely snow depth, snow density and ice density, used in freeboard-to-thickness conversion of Arctic sea ice. This conversion is an important part of sea ice thickness retrieval from spaceborne altimetry. A data base is created comprising sea ice freeboard derived from satellite radar altimetry between 1993 and 2012 and co-locate observations of total (sea ice + snow) and sea ice freeboard from the Operation Ice Bridge (OIB) and CryoSat Validation Experiment (CryoVEx) airborne campaigns, of sea ice draft from moored and submarine upward looking sonar (ULS), and of snow depth from OIB campaigns, Advanced Microwave Scanning Radiometer (AMSR-E) and the Warren climatology (Warren et al., 1999). We compare the different data sets in spatiotemporal scales where satellite radar altimetry yields meaningful results. An inter-comparison of the snow depth data sets emphasizes the limited usefulness of Warren climatology snow depth for freeboard-to-thickness conversion under current Arctic Ocean conditions reported in other studies. We test different freeboard-to-thickness and freeboard-to-draft conversion approaches. The mean observed ULS sea ice draft agrees with the mean sea ice draft derived from radar altimetry within the uncertainty bounds of the data sets involved. However, none of the approaches are able to reproduce the seasonal cycle in sea ice draft observed by moored ULS. A sensitivity analysis of the freeboard-to-thickness conversion suggests that sea ice density is as important as snow depth.

  1. Dual-Polarised Doppler X-band Radar Observations of Mixed Phased Clouds from the UK's Ice in Clouds Experiment-Dust (ICE-D)

    NASA Astrophysics Data System (ADS)

    Neely, R. R., III; Blyth, A. M.; Bennett, L.; Dufton, D.; Cui, Z.; Huang, Y.

    2015-12-01

    Here we present dual-polarised Doppler X-band radar observations of convective, altocumulus and altostratus clouds relatively close to the Sahara desert in order to examine the impact of dust on the formation of ice and precipitation. These initial results come the UK's Ice in Clouds Experiment - Dust (UK ICE-D). UK ICE-D was an aircraft and ground-based project based in Cape Verde off the coast of Senegal, Africa during August 2015. The overall goal of this experiment was to determine how desert dust affects primary nucleation of ice particles in convective and layer clouds as well as the subsequent development of precipitation and glaciation of the clouds. This was accomplished by making focused observations when dust was present in high concentrations and when almost no dust was present. Here we focus on examining the differences in hydrometeor types derived from the dual-polarised X-band radar observations observed in the high and low dust loadings with specific emphasis on the role of supercooled rain drops in these two situations.

  2. Dual-Polarised Doppler X-band Radar Observations of Mixed Phased Clouds from the UK's Ice in Clouds Experiment-Dust (ICE-D)

    NASA Astrophysics Data System (ADS)

    Neely, Ryan; Blyth, Alan; Bennett, Lindsay; Dufton, David; Cui, Zhiqiang; McQuaid, Jim; Price, Hannah; Murray, Benjamin; Huang, Yahui

    2016-04-01

    Here we present dual-polarised X-band radar and in situ observations of convective, altocumulus and altostratus clouds relatively close to the Sahara desert in order to examine the impact of dust on the formation of ice and precipitation. These initial results come the UK's Ice in Clouds Experiment - Dust (UK ICE-D). UK ICE-D was an aircraft and ground-based project based in Cape Verde off the coast of Senegal, Africa during August 2015. The overall goal of this experiment was to determine how desert dust affects primary nucleation of ice particles in convective and layer clouds as well as the subsequent development of precipitation and glaciation of the clouds. This was accomplished by making focused observations when dust was present in high concentrations and when almost no dust was present. Here we focus on examining the differences in hydrometeor types derived from the dual-polarised X-band radar observations observed in the high and low dust loadings with specific emphasis on the role of supercooled rain drops in these two situations.

  3. 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.

  4. Aircraft Contrails

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Captured in this scene is a series of aircraft contrails in a high traffic region over the northern Gulf of Mexico (27.0N, 85.5W). Contrails are caused by the hot engine exhaust of high flying aircraft interacting with moisture in the cold upper atmosphere and are common occurrances of high flying aircraft.

  5. Integration of Satellite-Derived Cloud Phase, Cloud Top Height, and Liquid Water Path into an Operational Aircraft Icing Nowcasting System

    NASA Technical Reports Server (NTRS)

    Haggerty, Julie; McDonough, Frank; Black, Jennifer; Landott, Scott; Wolff, Cory; Mueller, Steven; Minnis, Patrick; Smith, William, Jr.

    2008-01-01

    Operational products used by the U.S. Federal Aviation Administration to alert pilots of hazardous icing provide nowcast and short-term forecast estimates of the potential for the presence of supercooled liquid water and supercooled large droplets. The Current Icing Product (CIP) system employs basic satellite-derived information, including a cloud mask and cloud top temperature estimates, together with multiple other data sources to produce a gridded, three-dimensional, hourly depiction of icing probability and severity. Advanced satellite-derived cloud products developed at the NASA Langley Research Center (LaRC) provide a more detailed description of cloud properties (primarily at cloud top) compared to the basic satellite-derived information used currently in CIP. Cloud hydrometeor phase, liquid water path, cloud effective temperature, and cloud top height as estimated by the LaRC algorithms are into the CIP fuzzy logic scheme and a confidence value is determined. Examples of CIP products before and after the integration of the LaRC satellite-derived products will be presented at the conference.

  6. The importance of sea ice area biases in 21st century multimodel projections of Antarctic temperature and precipitation

    NASA Astrophysics Data System (ADS)

    Bracegirdle, Thomas J.; Stephenson, David B.; Turner, John; Phillips, Tony

    2015-12-01

    Climate models exhibit large biases in sea ice area (SIA) in their historical simulations. This study explores the impacts of these biases on multimodel uncertainty in Coupled Model Intercomparison Project phase 5 (CMIP5) ensemble projections of 21st century change in Antarctic surface temperature, net precipitation, and SIA. The analysis is based on time slice climatologies in the Representative Concentration Pathway 8.5 future scenario (2070-2099) and historical (1970-1999) simulations across 37 different CMIP5 models. Projected changes in net precipitation, temperature, and SIA are found to be strongly associated with simulated historical mean SIA (e.g., cross-model correlations of r = 0.77, 0.71, and -0.85, respectively). Furthermore, historical SIA bias is found to have a large impact on the simulated ratio between net precipitation response and temperature response. This ratio is smaller in models with smaller-than-observed SIA. These strong emergent relationships on SIA bias could, if found to be physically robust, be exploited to give more precise climate projections for Antarctica.

  7. Operation IceBridge/ESA Collaboration Benefits All

    NASA Video Gallery

    For the second straight year, NASA's Operation IceBridge is collaborating with the European Space Agency's CryoVEx program, flying aircraft low over Arctic sea ice while ESA's CryoSat satellite orb...

  8. Scientists as Correspondents: Exploratorium "Ice Stories" for International Polar Year Project Educational Outreach

    NASA Astrophysics Data System (ADS)

    McGillivary, P. A.; Fall, K. R.; Miller, M.; Higdon, R.; Andrews, M.; O'Donnell, K.

    2008-12-01

    As part of the 2007-2009 International Polar Year (IPY), an educational outreach developed by the Exploratorium science museum of San Francisco builds on prior high latitude programs to: 1) create public awareness of IPY research; 2) increase public understanding of the scientific process; and, 3) stimulate a new relationship between scientists and outreach. Funded by the National Science Foundation, a key "Ice Stories" innovation is to facilitate "scientist correspondents" reporting directly to the public. To achieve this, scientists were furnished multimedia equipment and training to produce material for middle school students to adults. Scientists submitted blogs of text, images, and video from the field which were edited, standardized for format, and uploaded by Exploratorium staff, who coordinated website content and management. Online links to educational partner institutions and programs from prior Exploratorium high latitude programs will extend "Ice Stories" site visits beyond the @250,000 unique in-house users/year to more than 28 million webpage users/year overall. We review relevant technical issues, the variety of scientist participation, and what worked best and recommendations for similar efforts in the future as a legacy for the IPY.

  9. Airframe Icing Research Gaps: NASA Perspective

    NASA Technical Reports Server (NTRS)

    Potapczuk, Mark

    2009-01-01

    qCurrent Airframe Icing Technology Gaps: Development of a full 3D ice accretion simulation model. Development of an improved simulation model for SLD conditions. CFD modeling of stall behavior for ice-contaminated wings/tails. Computational methods for simulation of stability and control parameters. Analysis of thermal ice protection system performance. Quantification of 3D ice shape geometric characteristics Development of accurate ground-based simulation of SLD conditions. Development of scaling methods for SLD conditions. Development of advanced diagnostic techniques for assessment of tunnel cloud conditions. Identification of critical ice shapes for aerodynamic performance degradation. Aerodynamic scaling issues associated with testing scale model ice shape geometries. Development of altitude scaling methods for thermal ice protections systems. Development of accurate parameter identification methods. Measurement of stability and control parameters for an ice-contaminated swept wing aircraft. Creation of control law modifications to prevent loss of control during icing encounters. 3D ice shape geometries. Collection efficiency data for ice shape geometries. SLD ice shape data, in-flight and ground-based, for simulation verification. Aerodynamic performance data for 3D geometries and various icing conditions. Stability and control parameter data for iced aircraft configurations. Thermal ice protection system data for simulation validation.

  10. Aircraft type influence on contrail properties

    NASA Astrophysics Data System (ADS)

    Jeßberger, P.; Voigt, C.; Schumann, U.; Sölch, I.; Schlager, H.; Kaufmann, S.; Petzold, A.; Schäuble, D.; Gayet, J.-F.

    2013-12-01

    The investigation of the impact of aircraft parameters on contrail properties helps to better understand the climate impact from aviation. Yet, in observations, it is a challenge to separate aircraft and meteorological influences on contrail formation. During the CONCERT campaign in November 2008, contrails from 3 Airbus passenger aircraft of types A319-111, A340-311 and A380-841 were probed at cruise under similar meteorological conditions with in situ instruments on board DLR research aircraft Falcon. Within the 2 min-old contrails detected near ice saturation, we find similar effective diameters Deff (5.2-5.9 μm), but differences in particle number densities nice (162-235 cm-3) and in vertical contrail extensions (120-290 m), resulting in large differences in contrail optical depths τ at 550 nm (0.25-0.94). Hence larger aircraft produce optically thicker contrails. Based on the observations, we apply the EULAG-LCM model with explicit ice microphysics and, in addition, the Contrail and Cirrus Prediction (CoCiP) model to calculate the aircraft type impact on young contrails under identical meteorological conditions. The observed increase in τ for heavier aircraft is confirmed by the models, yet for generally smaller τ. CoCiP model results suggest that the aircraft dependence of climate-relevant contrail properties persists during contrail lifetime, adding importance to aircraft-dependent model initialization. We finally derive an analytical relationship between contrail, aircraft and meteorological parameters. Near ice saturation, contrail width × τ scales linearly with the fuel flow rate, as confirmed by observations. For higher relative humidity with respect to ice (RHI), the analytical relationship suggests a non-linear increase in the form (RHI-12/3. Summarized, our combined results could help to more accurately assess the climate impact from aviation using an aircraft-dependent contrail parameterization.

  11. Advanced hypersonic aircraft design

    NASA Technical Reports Server (NTRS)

    Utzinger, Rob; Blank, Hans-Joachim; Cox, Craig; Harvey, Greg; Mckee, Mike; Molnar, Dave; Nagy, Greg; Petersen, Steve

    1992-01-01

    The objective of this design project is to develop the hypersonic reconnaissance aircraft to replace the SR-71 and to complement existing intelligence gathering devices. The initial design considerations were to create a manned vehicle which could complete its mission with at least two airborne refuelings. The aircraft must travel between Mach 4 and Mach 7 at an altitude of 80,000 feet for a maximum range of 12,000 nautical miles. The vehicle should have an air breathing propulsion system at cruise. With a crew of two, the aircraft should be able to take off and land on a 10,000 foot runway, and the yearly operational costs were not to exceed $300 million. Finally, the aircraft should exhibit stealth characteristics, including a minimized radar cross-section (RCS) and a reduced sonic boom. The technology used in this vehicle should allow for production between the years 1993 and 1995.

  12. A Database of Supercooled Large Droplet Ice Accretions

    NASA Technical Reports Server (NTRS)

    VanZante, Judith Foss

    2007-01-01

    A unique, publicly available database regarding supercooled large droplet ice accretions has been developed in NASA Glenn's Icing Research Tunnel. Identical cloud and flight conditions were generated for five different airfoil models. The models chosen represent a variety of aircraft types from the horizontal stabilizer of a large trans-port aircraft to the wings of regional, business, and general aviation aircraft. In addition to the standard documentation methods of 2D ice shape tracing and imagery, ice mass measurements were also taken. This database will also be used to validate and verify the extension of the ice accretion code, LEWICE, into the SLD realm.

  13. A Database of Supercooled Large Droplet Ice Accretions [Supplement

    NASA Technical Reports Server (NTRS)

    VanZante, Judith Foss

    2007-01-01

    A unique, publicly available database regarding supercooled large droplet (SLD) ice accretions has been developed in NASA Glenn's Icing Research Tunnel. Identical cloud and flight conditions were generated for five different airfoil models. The models chosen represent a variety of aircraft types from the horizontal stabilizer of a large transport aircraft to the wings of regional, business, and general aviation aircraft. In addition to the standard documentation methods of 2D ice shape tracing and imagery, ice mass measurements were also taken. This database will also be used to validate and verify the extension of the ice accretion code, LEWICE, into the SLD realm.

  14. Simulating Arctic clouds during Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE)

    NASA Astrophysics Data System (ADS)

    Bromwich, D. H.; Hines, K. M.; Wang, S. H.

    2015-12-01

    The representation within global and regional models of the extensive low-level cloud cover over polar oceans remains a critical challenge for quantitative studies and forecasts of polar climate. In response, the polar-optimized version of the Weather Research and Forecasting model (Polar WRF) is used to simulate the meteorology, boundary layer, and Arctic clouds during the September-October 2014 Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE) project. Polar WRF was developed with several adjustments to the sea ice thermodynamics in WRF. ARISE was based out of Eielson Air Force Base near Fairbanks, Alaska and included multiple instrumented C-130 aircraft flights over open water and sea ice of the Beaufort Sea. Arctic boundary layer clouds were frequently observed within cold northeasterly flow over the open ocean and ice. Preliminary results indicate these clouds were primarily liquid water, with characteristics differing between open water and sea ice surfaces. Simulated clouds are compared to ARISE observations. Furthermore, Polar WRF simulations are run for the August-September 2008 Arctic Summer Cloud Ocean Study (ASCOS) for comparison to the ARISE. Preliminary analysis shows that simulated low-level water clouds over the sea ice are too extensive during the the second half of the ASCOS field program. Alternatives and improvements to the Polar WRF cloud schemes are considered. The goal is to use the ARISE and ASCOS observations to achieve an improved polar supplement to the WRF code for open water and sea ice that can be provided to the Polar WRF community.

  15. Project VAHIIA: Volatile Analysis coming from the heating of interstellar/cometary ice analogs

    NASA Astrophysics Data System (ADS)

    Abou Mrad, Ninette; Duvernay, Fabrice; Chiavassa, Thierry; Danger, Grégoire

    2015-04-01

    Studying organic volatile compounds (VOC) coming from the heating of cometary ice analogs through laboratory simulations is of great interest in understanding the reactivity that leads to the formation of the organic refractory residues available in interplanetary objects. They will enlighten us on conditions prevailing on the primitive nebula and during the formation of the Solar system and will support understanding and interpreting space mission data for comet surveys such as the ongoing Rosetta mission. Experimental simulations consist of irradiating and warming-up an ice analog under ultrahigh vaccum conditions reproducing astrophysical environments. To analyze the VOC formed in these conditions by gas chromatography (GC) coupled to mass spectrometry (MS), different analytical challenges need to be addressed such as: the low pressure under which the VOC are formed in the vacuum chamber (10-8 mbar) since their analysis by GC-MS is conducted at atmospheric or close to atmospheric pressures; and the low sensitivities due to slow desorption kinetics in the vaccum chamber while a narrow injection is needed to ensure the best GC efficiency. To overcome these challenges, we have developed an analytical interface called VAHIIA that links directly the cryogenic chamber where the VOC sublime to the GC-MS where they are analyzed (Figure 1). By this means, an online transfer of the compounds to the analytical instrument is ensured, maintaining the representativeness of the sample and avoiding compound losses, a common problem in multi-procedural methodologies for VOC analysis. This interface is constituted by a preconcentration unit allowing VOC enrichment and sample pressure increase in order to facilitate its transfer to the GC-MS, and of an injection unit allowing online gaseous sample introduction into the GC injector. The VAHIIA interface has been calibrated, optimized and validated and its performance is very satisfactory regarding trace VOC analysis from gaseous

  16. 14 CFR 25.1403 - Wing icing detection lights.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wing icing detection lights. 25.1403... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1403 Wing icing... ice on the parts of the wings that are critical from the standpoint of ice accumulation....

  17. 14 CFR 25.1403 - Wing icing detection lights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing icing detection lights. 25.1403... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1403 Wing icing... ice on the parts of the wings that are critical from the standpoint of ice accumulation....

  18. Flight test report of the NASA icing research airplane: Performance, stability, and control after flight through natural icing conditions

    NASA Technical Reports Server (NTRS)

    Jordan, J. L.; Platz, S. J.; Schinstock, W. C.

    1986-01-01

    Flight test results are presented documenting the effect of airframe icing on performance and stability and control of a NASA DHC-6 icing research aircraft. Kohlman System Research, Inc., provided the data acquisition system and data analysis under contract to NASA. Performance modeling methods and MMLE techniques were used to determine the effects of natural ice on the aircraft. Results showed that ice had a significant effect on the drag coefficient of the aircraft and a modest effect on the MMLE derived longitudinal stability coefficients (code version MMLE). Data is also presented on asymmetric power sign slip maneuvers showing rudder floating characteristics with and without ice on the vertical stabilizer.

  19. Airborne geophysical survey of ice caps in the Queen Elizabeth Islands, Arctic Canada

    NASA Astrophysics Data System (ADS)

    Palmer, S. J.; Dowdeswell, J. A.; Christoffersen, P.; Benham, T. J.; Young, D. A.; Blankenship, D. D.; Richter, T.; Ng, G.; Grima, C.; Habbal, F.; Sharp, M. J.; Rutishauser, A.

    2014-12-01

    Previous studies have shown that between 2003 and 2009, 60 ± 6 Gt of ice was lost each year from the Canadian Arctic (Gardner et al., 2013), making the region the largest cryospheric contributor to global sea level rise outside of the great ice sheets. Glacier ice in the Queen Elizabeth Islands (QEI) currently covers more than 100,000 km2, representing 20% of Earth's ice-covered land area outside of Greenland and Antarctica. The vast majority of this ice is stored within six ice caps located on Ellesmere, Devon and Axel Heiberg islands. Recent satellite observations of the outlet glaciers draining these ice caps have revealed significant velocity variability on inter-annual and multi-year timescales (Van Wychen et al., 2014), though the drivers of these dynamics are not yet understood. Here we present results obtained in May 2014 during an airborne geophysical survey of the ice caps of Axel Heiberg, Ellesmere and Devon islands, including Agassiz Ice Cap (17,300 km2), Prince of Wales Icefield (19,300 km2) and Devon Ice Cap (14,000 km2). We used a Basler BT-67 aircraft equipped with a suite of geophysical instruments, including a phase-coherent VHF ice-penetrating radar, to measure ice thickness and investigate ice basal conditions along outlet glacier flow lines and in the interior of the ice caps. We reveal that the glaciers draining the ice caps of the QEI exhibit diverse characteristics over short spatial scales, and that fast-flowing tidewater glaciers are located adjacent to previously fast-flowing areas that have subsequently stagnated. Our results show that many ice cap outlet glaciers on Ellesmere and Devon islands are between 700 and 1000 m thick and flow through deep bedrock troughs whose beds lie below sea-level. Some of the outlet glaciers also have floating tongues of ice which extend into the adjacent fjord waters. We intend to use our results to characterize the substrate beneath the ice, and to reveal any variations in conditions at the ice

  20. In-Flight Icing Training for Pilots Using Multimedia Technology

    NASA Technical Reports Server (NTRS)

    Burke, Kevin M.; VanZante, Judith Foss; Bond, Thomas H.

    2004-01-01

    Over the last five years, the Aircraft Icing Project of the NASA Aviation Safety Program has developed a number of in-flight icing education and training aids to support increased awareness for pilots of the hazards associated with atmospheric icing conditions. Through the development of this work, a number of new instructional design approaches and media delivery methods have been introduced to enhance the learning experience, expand user interactivity and participation, and, hopefully, increase the learner retention rates. The goal of using these multimedia techniques is to increase the effectiveness of the training materials. This paper will describe the mutlimedia technology that has been introduced and give examples of how it was used.

  1. WHIPICE. [Computer Program for Analysis of Aircraft Deicing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This video documents efforts by NASA Lewis Research Center researchers to improve ice protection for aircraft. A new system of deicing aircraft by allowing a thin sheet of ice to develop, then breaking it into particles, is being examined, particularly to determine the extent of shed ice ingestion by jet engines that results. The process is documented by a high speed imaging system that scans the breakup and flow of the ice particles at 1000 frames per second. This data is then digitized and analyzed using a computer program called WHIPICE, which analyzes grey scale images of the ice particles. Detailed description of the operation of this computer program is provided.

  2. Intelligent aircraft/airspace systems

    NASA Technical Reports Server (NTRS)

    Wangermann, John P.

    1995-01-01

    Projections of future air traffic predict at least a doubling of the number of revenue passenger miles flown by the year 2025. To meet this demand, an Intelligent Aircraft/Airspace System (IAAS) has been proposed. The IAAS operates on the basis of principled negotiation between intelligent agents. The aircraft/airspace system today consists of many agents, such as airlines, control facilities, and aircraft. All the agents are becoming increasingly capable as technology develops. These capabilities should be exploited to create an Intelligent Aircraft/Airspace System (IAAS) that would meet the predicted traffic levels of 2005.

  3. Marquardt's Mach 4.5 Supercharged Ejector Ramjet (SERJ) High-Performance Aircraft Engine Project: Unfulfilled Aspirations Ca.1970

    NASA Technical Reports Server (NTRS)

    Escher, William J. D.; Roddy, Jordan E.; Hyde, Eric H.

    2000-01-01

    The Supercharged Ejector Ramjet (SERJ) engine developments of the 1960s, as pursued by The Marquardt Corporation and its associated industry team members, are described. In just three years, engineering work on this combined-cycle powerplant type evolved, from its initial NASA-sponsored reusable space transportation system study status, into a U.S. Air Force/Navy-supported exploratory development program as a candidate 4.5 high-performance military aircraft engine. Bridging a productive transition from the spaceflight to the aviation arena, this case history supports the expectation that fully-integrated airbreathing/rocket propulsion systems hold high promise toward meeting the demanding propulsion requirements of tomorrow's aircraft-like Spaceliner class transportation systems. Lessons to be learned from this "SERJ Story" are offered for consideration by today's advanced space transportation and combined-cycle propulsion researchers and forward-planning communities.

  4. Capability Description for NASA's F/A-18 TN 853 as a Testbed for the Integrated Resilient Aircraft Control Project

    NASA Technical Reports Server (NTRS)

    Hanson, Curt

    2009-01-01

    The NASA F/A-18 tail number (TN) 853 full-scale Integrated Resilient Aircraft Control (IRAC) testbed has been designed with a full array of capabilities in support of the Aviation Safety Program. Highlights of the system's capabilities include: 1) a quad-redundant research flight control system for safely interfacing controls experiments to the aircraft's control surfaces; 2) a dual-redundant airborne research test system for hosting multi-disciplinary state-of-the-art adaptive control experiments; 3) a robust reversionary configuration for recovery from unusual attitudes and configurations; 4) significant research instrumentation, particularly in the area of static loads; 5) extensive facilities for experiment simulation, data logging, real-time monitoring and post-flight analysis capabilities; and 6) significant growth capability in terms of interfaces and processing power.

  5. The rapid disintegration of projections: the West Antarctic Ice Sheet and the intergovernmental panel on climate change.

    PubMed

    O'Reilly, Jessica; Oreskes, Naomi; Oppenheimer, Michael

    2012-10-01

    How and why did the scientific consensus about sea level rise due to the disintegration of the West Antarctic Ice Sheet (WAIS), expressed in the third Intergovernmental Panel on Climate Change (IPCC) assessment, disintegrate on the road to the fourth? Using ethnographic interviews and analysis of IPCC documents, we trace the abrupt disintegration of the WAIS consensus. First, we provide a brief historical overview of scientific assessments of the WAIS. Second, we provide a detailed case study of the decision not to provide a WAIS prediction in the Fourth Assessment Report. Third, we discuss the implications of this outcome for the general issue of scientists and policymakers working in assessment organizations to make projections. IPCC authors were less certain about potential WAIS futures than in previous assessment reports in part because of new information, but also because of the outcome of cultural processes within the IPCC, including how people were selected for and worked together within their writing groups. It became too difficult for IPCC assessors to project the range of possible futures for WAIS due to shifts in scientific knowledge as well as in the institutions that facilitated the interpretations of this knowledge.

  6. Prenatal maternal stress predicts autism traits in 6½ year-old children: Project Ice Storm.

    PubMed

    Walder, Deborah J; Laplante, David P; Sousa-Pires, Alexandra; Veru, Franz; Brunet, Alain; King, Suzanne

    2014-10-30

    Research implicates prenatal maternal stress (PNMS) as a risk factor for neurodevelopmental disorders; however few studies report PNMS effects on autism risk in offspring. We examined, prospectively, the degree to which objective and subjective elements of PNMS explained variance in autism-like traits among offspring, and tested moderating effects of sex and PNMS timing in utero. Subjects were 89 (46F/43M) children who were in utero during the 1998 Quebec Ice Storm. Soon after the storm, mothers completed questionnaires on objective exposure and subjective distress, and completed the Autism Spectrum Screening Questionnaire (ASSQ) for their children at age 6½. ASSQ scores were higher among boys than girls. Greater objective and subjective PNMS predicted higher ASSQ independent of potential confounds. An objective-by-subjective interaction suggested that when subjective PNMS was high, objective PNMS had little effect; whereas when subjective PNMS was low, objective PNMS strongly affected ASSQ scores. A timing-by-objective stress interaction suggested objective stress significantly affected ASSQ in first-trimester exposed children, though less so with later exposure. The final regression explained 43% of variance in ASSQ scores; the main effect of sex and the sex-by-PNMS interactions were not significant. Findings may help elucidate neurodevelopmental origins of non-clinical autism-like traits from a dimensional perspective.

  7. Prenatal maternal stress predicts childhood asthma in girls: project ice storm.

    PubMed

    Turcotte-Tremblay, Anne-Marie; Lim, Robert; Laplante, David P; Kobzik, Lester; Brunet, Alain; King, Suzanne

    2014-01-01

    Little is known about how prenatal maternal stress (PNMS) influences risks of asthma in humans. In this small study, we sought to determine whether disaster-related PNMS would predict asthma risk in children. In June 1998, we assessed severity of objective hardship and subjective distress in women pregnant during the January 1998 Quebec Ice Storm. Lifetime asthma symptoms, diagnoses, and corticosteroid utilization were assessed when the children were 12 years old (N = 68). No effects of objective hardship or timing of the exposure were found. However, we found that, in girls only, higher levels of prenatal maternal subjective distress predicted greater lifetime risk of wheezing (OR = 1.11; 90% CI = 1.01-1.23), doctor-diagnosed asthma (OR = 1.09; 90% CI = 1.00-1.19), and lifetime utilization of corticosteroids (OR = 1.12; 90% CI = 1.01-1.25). Other perinatal and current maternal life events were also associated with asthma outcomes. Findings suggest that stress during pregnancy opens a window for fetal programming of immune functioning. A sex-based approach may be useful to examine how prenatal and postnatal environments combine to program the immune system. This small study needs to be replicated with a larger, more representative sample.

  8. Aircraft Design

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H. (Inventor); Uden, Edward (Inventor)

    2016-01-01

    The present invention is an aircraft wing design that creates a bell shaped span load, which results in a negative induced drag (induced thrust) on the outer portion of the wing; such a design obviates the need for rudder control of an aircraft.

  9. Aircraft Cabin Environmental Quality Sensors

    SciTech Connect

    Gundel, Lara; Kirchstetter, Thomas; Spears, Michael; Sullivan, Douglas

    2010-05-06

    The Indoor Environment Department at Lawrence Berkeley National Laboratory (LBNL) teamed with seven universities to participate in a Federal Aviation Administration (FAA) Center of Excellence (COE) for research on environmental quality in aircraft. This report describes research performed at LBNL on selecting and evaluating sensors for monitoring environmental quality in aircraft cabins, as part of Project 7 of the FAA's COE for Airliner Cabin Environmental Research (ACER)1 effort. This part of Project 7 links to the ozone, pesticide, and incident projects for data collection and monitoring and is a component of a broader research effort on sensors by ACER. Results from UCB and LBNL's concurrent research on ozone (ACER Project 1) are found in Weschler et al., 2007; Bhangar et al. 2008; Coleman et al., 2008 and Strom-Tejsen et al., 2008. LBNL's research on pesticides (ACER Project 2) in airliner cabins is described in Maddalena and McKone (2008). This report focused on the sensors needed for normal contaminants and conditions in aircraft. The results are intended to complement and coordinate with results from other ACER members who concentrated primarily on (a) sensors for chemical and biological pollutants that might be released intentionally in aircraft; (b) integration of sensor systems; and (c) optimal location of sensors within aircraft. The parameters and sensors were selected primarily to satisfy routine monitoring needs for contaminants and conditions that commonly occur in aircraft. However, such sensor systems can also be incorporated into research programs on environmental quality in aircraft cabins.

  10. Neogene ice sheet, paleoclimatic and geological history of the McMurdo Sound region, Victoria Land Basin, Antarctica: overview of ANDRILL's first two drilling projects

    NASA Astrophysics Data System (ADS)

    Powell, R.; Naish, T.; Harwood, D.; Florindo, F.; Levy, R.; Teams, M. S.

    2008-12-01

    The ANtarctic geological DRILLing Program (ANDRILL), an international collaboration within IPY, has recovered 2 cores: from under the Ross Ice Shelf (McMurdo Ice Shelf Project (MIS) - AND-1B), and from the land-fast sea-ice of McMurdo Sound (Southern McMurdo Sound Project (SMS) - AND-2A). Drill cores reached respective total depths of 1285mbsf in c. 850m of water (MIS) and 1138.54mbsf in c. 380m of water (SMS). Repetitive facies successions in AND-1B core imply at least 60 fluctuations, of probable Milankovitch- duration, between subglacial, ice proximal and ice distal open marine environments. These are grouped into 3 types of facies cycles corresponding to glacial-interglacial variability during climatically distinct periods of Late Neogene: (1) cold-polar climate and ice (late Miocene and Pleistocene); (2) relatively warmer climate, polythermal ice and interglacials dominated by pelagic diatomite (Pliocene); (3) warmer climate, polythermal ice with interglacials dominated by hemipelagites (early late Miocene). A c. 80m-thick interval of diatomite of mid to late Pliocene age shows no apparent glacial cyclicity and represents an extended period of ice-free conditions indicating reduced or absent WAIS. Late Pliocene glacial-interglacial cycles characterized by abrupt alternations between subglacial/ice-proximal facies and open marine diatomite units imply significant WAIS dynamism, and contribution to global ice volume changes coeval with the initiation of Northern Hemisphere glaciations. A c. 4m-thick interval of diatomaceous mudstone in the mid-Pleistocene also represents warm-interglacial ice-free conditions. Intriguingly, glacial deposits interrupted by periodic, small- scale grounding-line retreats dominate the last 1m.y. Inter-hemispheric ice sheet coupling was probably controlled by Northern Hemispheric insolation and consequent glacial eustasy to account for much of the orbital-scale WAIS variability since 2.5Ma. A further expansion of WAIS occurred across

  11. Ice Accretions and Icing Effects for Modern Airfoils

    NASA Technical Reports Server (NTRS)

    Addy, Harold E., Jr.

    2000-01-01

    Icing tests were conducted to document ice shapes formed on three different two-dimensional airfoils and to study the effects of the accreted ice on aerodynamic performance. The models tested were representative of airfoil designs in current use for each of the commercial transport, business jet, and general aviation categories of aircraft. The models were subjected to a range of icing conditions in an icing wind tunnel. The conditions were selected primarily from the Federal Aviation Administration's Federal Aviation Regulations 25 Appendix C atmospheric icing conditions. A few large droplet icing conditions were included. To verify the aerodynamic performance measurements, molds were made of selected ice shapes formed in the icing tunnel. Castings of the ice were made from the molds and placed on a model in a dry, low-turbulence wind tunnel where precision aerodynamic performance measurements were made. Documentation of all the ice shapes and the aerodynamic performance measurements made during the icing tunnel tests is included in this report. Results from the dry, low-turbulence wind tunnel tests are also presented.

  12. High altitude reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Yazdo, Renee Anna; Moller, David

    1990-01-01

    At the equator the ozone layer ranges from 65,000 to 130,000 plus feet, which is beyond the capabilities of the ER-2, NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozone layer at the equator. This aircraft must be able to cruise at 130,000 feet for six hours at Mach 0.7, while carrying 3,000 lbs. of payload. In addition, the aircraft must have a minimum range of 6,000 miles. In consideration of the novel nature of this project, the pilot must be able to take control in the event of unforeseen difficulties. Three aircraft configurations were determined to be the most suitable - a joined-wing, a biplane, and a twin-boom conventional airplane. The performance of each configuration was analyzed to investigate the feasibility of the project.

  13. Life Detection and Characterization of Subsurface Ice and Brine in the McMurdo Dry Valleys Using an Ultrasonic Gopher: A NASA ASTEP Project

    NASA Technical Reports Server (NTRS)

    Doran, P. T.; Bar-Cohen, Y.; Fritsen, C.; Kenig, F.; McKay, C. P.; Murray, A.; Sherrit, S.

    2003-01-01

    Evidence for the presence of ice and fluids near the surface of Mars in both the distant and recent past is growing with each new mission to the Planet. One explanation for fluids forming springlike features on Mars is the discharge of subsurface brines. Brines offer potential refugia for extant Martian life, and near surface ice could preserve a record of past life on the planet. Proven techniques to get underground to sample these environments, and get below the disruptive influence of the surface oxidant and radiation regime, will be critical for future astrobiology missions to Mars. Our Astrobiology for Science and Technology for Exploring Planets (ASTEP) project has the goal to develop and test a novel ultrasonic corer in a Mars analog environment, the McMurdo Dry valleys, Antarctica, and to detect and describe life in a previously unstudied extreme ecosystem; Lake Vida (Fig. 1), an ice-sealed lake.

  14. Aircraft type influence on contrail properties

    NASA Astrophysics Data System (ADS)

    Jeßberger, P.; Voigt, C.; Schumann, U.; Sölch, I.; Schlager, H.; Kaufmann, S.; Petzold, A.; Schäuble, D.; Gayet, J.-F.

    2013-05-01

    The investigation of the impact of aircraft parameters on contrail properties helps to better understand the climate impact from aviation. Yet, in observations, it is a challenge to separate aircraft and meteorological influences on contrail formation. During the CONCERT campaign in November 2008, contrails from 3 Airbus passenger aircraft of type A319-111, A340-311 and A380-841 were probed at cruise under similar meteorological conditions with in-situ instruments on board the DLR research aircraft Falcon. Within the 2 min old contrails detected near ice saturation, we find similar effective diameters Deff (5.2-5.9 μm), but differences in particle number densities nice (162-235 cm-3) and in vertical contrail extensions (120-290 m), resulting in large differences in contrail optical depths τ (0.25-0.94). Hence larger aircraft produce optically thicker contrails. Based on the observations, we apply the EULAG-LCM model with explicit ice microphysics and in addition the Contrail and Cirrus Prediction model CoCiP to calculate the aircraft type impact on young contrails under identical meteorological conditions. The observed increase in τ for heavier aircraft is confirmed by the models, yet for generally smaller τ. An aircraft dependence of climate relevant contrail properties persists during contrail lifetime, adding importance to aircraft dependent model initialization. We finally derive an analytical relationship between contrail, aircraft and meteorological parameters. Near ice saturation, contrail width × τ scales linearly with fuel flow rate as confirmed by observations. For higher saturation ratios approximations from theory suggest a non-linear increase in the form (RHI-1)2/3. Summarized our combined results could help to more accurately assess the climate impact from aviation using an aircraft dependent contrail parameterization.

  15. Chemical characterization of individual particles and residuals of cloud droplets and ice crystals collected on board research aircraft in the ISDAC 2008 study

    NASA Astrophysics Data System (ADS)

    Hiranuma, N.; Brooks, S. D.; Moffet, R. C.; Glen, A.; Laskin, A.; Gilles, M. K.; Liu, P.; MacDonald, A. M.; Strapp, J. W.; McFarquhar, G. M.

    2013-06-01

    Ambient particles and the dry residuals of mixed-phase cloud droplets and ice crystals were collected during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) near Barrow, Alaska, in spring of 2008. The collected particles were analyzed using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy to identify physico-chemical properties that differentiate cloud-nucleating particles from the total aerosol population. A wide range of individually mixed components was identified in the ambient particles and residuals including organic carbon compounds, inorganics, carbonates, and black carbon. Our results show that cloud droplet residuals differ from the ambient particles in both size and composition, suggesting that both properties may impact the cloud-nucleating ability of aerosols in mixed-phase clouds. The percentage of residual particles which contained carbonates (47%) was almost four times higher than those in ambient samples. Residual populations were also enhanced in sea salt and black carbon and reduced in organic compounds relative to the ambient particles. Further, our measurements suggest that chemical processing of aerosols may improve their cloud-nucleating ability. Comparison of results for various time periods within ISDAC suggests that the number and composition of cloud-nucleating particles over Alaska can be influenced by episodic events bringing aerosols from both the local vicinity and as far away as Siberia.

  16. (Reduce uncertainty in projection of future sea-level change due to ice wastage)

    SciTech Connect

    Meier, M.F.

    1991-01-01

    Three basic goals were stated in the original proposal. These were: (1) develop an understanding of the heat and mass flow into subfreezing snow and firn, in order to model the evolution of the temperature distribution and the infiltration rates through the firn; (2) relate changes in climate, as given by general circulation model predictions, to changes in the surface mass and energy balances of glaciers; and (3) use the above results to analyze the effects of changed surface mass and energy balances on the flow of meltwater through snow and firn, and on the runoff from these glaciers, in a CO{sub 2}-affected climate. This final report summarizes our progress toward these goals. The primary product of this research program has been the communication of this progress in the form of publications in the scientific literature and presentations at scientific meetings. Our research activities in the past three years have provided a new basis for modeling of multiphase flow in subfreezing snow, new field data on the structural properties of arctic firn pertinent to hydrological modeling, and estimates of sea level change in response to changing patterns of runoff from the Greenland Ice Sheet. We conclude that forecasts of future sea level changes from all glacier runoff sources may be in error by amounts on the order of +8 cm over the next 150 years, due to the lag in generating runoff to the sea. Our specific research products include two distributed-parameter models of water flow through snow with melting and freezing, a theoretical model of wetting-front advance into subfreezing snow for inclusion in a future model, and a simple large-scale model of the response of Greenland runoff in a changing climate which provides estimates of the effect of melt water refreezing phenomena on sea level changes in response to a range of possible future climates.

  17. Projected decline in spring snow depth on Arctic sea ice caused by progressively later autumn open ocean freeze-up this century

    NASA Astrophysics Data System (ADS)

    Hezel, P. J.; Zhang, X.; Bitz, C. M.; Kelly, B. P.; Massonnet, F.

    2012-09-01

    We present the first analysis of snow depth on Arctic sea ice in the Coupled Model Intercomparison Project 5 (CMIP5) because of its importance for sea ice thermodynamics and ringed seal (Phoca hispida) habitat. Snow depths in April on Arctic sea ice decrease over the 21st century in RCP2.6, RCP4.5, and RCP8.5 scenarios. The chief cause is loss of sea ice area in autumn and, to a lesser extent, winter. By the end of the 21st century in the RCP8.5 scenario, snowfall accumulation is delayed by about three months compared to the late 20th century in the multi-model mean. Mean April snow depth north of 70°N declines from about 28 cm to 16 cm. Precipitation increases as expected in a warmer climate, but much of this increase in the Arctic occurs as rainfall. The seasonality of snowfall rate grows, with increasing rates in winter and decreasing rates in summer and autumn, but the cumulative snowfall from September to April does not change. Ringed seals depend on spring snow cover on Arctic sea ice to create subnivean birth lairs. The area with snow depths above 20 cm — a threshold needed for ringed seals to build snow caves — declines by 70%.

  18. Detection and Monitoring of Stratigraphic Markers and Temperature Trends at the Greenland Ice Sheet Project 2 Using Passive-Microwave Remote-Sensing Data

    NASA Technical Reports Server (NTRS)

    Shuman, C. A.; Alley, R. B.; Fahnestock, M. A.; Fawcett, P. J.; Bondschadler, R. A.; White, J. W. C.; Grootes, P. M.; Anandakrishnan, S.; Stearns, C. R.

    1997-01-01

    Satellite passive-microwave sensors provide a sensitive means of studying ice-sheet surface processes that assists ice-core interpretation and can extend local observations across regional scales. Analysis of special sensor microwave/imager (SSM/I) brightness temperature (TB) data supports ice-core research in two specific ways. First, the summer hoar complex layers used to date the Holocene portion of the Greenland Ice Sheet Project 2 ice core can be defined temporally and spatially by SSM/I 37-GHz vertically (V) and horizontally (H) polarized B ratio (V/H) trends. Second, comparison of automatic weather station temperatures to SSM/I 37-GHz V TB data shows that they are an effective proxy temperature record in this region. Also, the TB data can be correlated with proxy temperature trends from stable-isotope-ratio (delta O-18 and delta-D) profiles from snow pits and this allows the assignment of dates to specific snow depths.

  19. 14 CFR 121.629 - Operation in icing conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... safety of the flight. (b) No person may take off an aircraft when frost, ice, or snow is adhering to the... the takeoff would not be in compliance with paragraph (c) of this section. Takeoffs with frost under... conditions are such that frost, ice, or snow may reasonably be expected to adhere to the aircraft, unless...

  20. 14 CFR 121.629 - Operation in icing conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... safety of the flight. (b) No person may take off an aircraft when frost, ice, or snow is adhering to the... the takeoff would not be in compliance with paragraph (c) of this section. Takeoffs with frost under... conditions are such that frost, ice, or snow may reasonably be expected to adhere to the aircraft, unless...

  1. 14 CFR 121.629 - Operation in icing conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... safety of the flight. (b) No person may take off an aircraft when frost, ice, or snow is adhering to the... the takeoff would not be in compliance with paragraph (c) of this section. Takeoffs with frost under... conditions are such that frost, ice, or snow may reasonably be expected to adhere to the aircraft, unless...

  2. 14 CFR 121.629 - Operation in icing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... safety of the flight. (b) No person may take off an aircraft when frost, ice, or snow is adhering to the... the takeoff would not be in compliance with paragraph (c) of this section. Takeoffs with frost under... conditions are such that frost, ice, or snow may reasonably be expected to adhere to the aircraft, unless...

  3. 14 CFR 121.629 - Operation in icing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... safety of the flight. (b) No person may take off an aircraft when frost, ice, or snow is adhering to the... the takeoff would not be in compliance with paragraph (c) of this section. Takeoffs with frost under... conditions are such that frost, ice, or snow may reasonably be expected to adhere to the aircraft, unless...

  4. Microwave and physical properties of sea ice in the winter marginal ice zone

    NASA Technical Reports Server (NTRS)

    Tucker, W. B., III; Perovich, D. K.; Gow, A. J.; Grenfell, T. C.; Onstott, R. G.

    1991-01-01

    Surface-based active and passive microwave measurements were made in conjunction with ice property measurements for several distinct ice types in the Fram Strait during March and April 1987. Synthesis aperture radar imagery downlinked from an aircraft was used to select study sites. The surface-based radar scattering cross section and emissivity spectra generally support previously inferred qualitative relationships between ice types, exhibiting expected separation between young, first-year and multiyear ice. Gradient ratios, calculated for both active and passive data, appear to allow clear separation of ice types when used jointly. Surface flooding of multiyear floes, resulting from excessive loading and perhaps wave action, causes both active and passive signatures to resemble those of first-year ice. This effect could possibly cause estimates of ice type percentages in the marginal ice zone to be in error when derived from aircraft- or satellite-born sensors.

  5. 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

  6. 150 Passenger Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Bucovsky, Adrian; Romli, Fairuz I.; Rupp, Jessica

    2002-01-01

    It has been projected that the need for a short-range mid-sized, aircraft is increasing. The future strategy to decrease long-haul flights will increase the demand for short-haul flights. Since passengers prefer to meet their destinations quickly, airlines will increase the frequency of flights, which will reduce the passenger load on the aircraft. If a point-to-point flight is not possible, passengers will prefer only a one-stop short connecting flight to their final destination. A 150-passenger aircraft is an ideal vehicle for these situations. It is mid-sized aircraft and has a range of 3000 nautical miles. This type of aircraft would market U.S. domestic flights or inter-European flight routes. The objective of the design of the 150-passenger aircraft is to minimize fuel consumption. The configuration of the aircraft must be optimized. This aircraft must meet CO2 and NOx emissions standards with minimal acquisition price and operating costs. This report contains all the work that has been performed for the completion of the design of a 150 passenger commercial aircraft. The methodology used is the Technology Identification, Evaluation, and Selection (TIES) developed at Georgia Tech Aerospace Systems Design laboratory (ASDL). This is an eight-step conceptual design process to evaluate the probability of meeting the design constraints. This methodology also allows for the evaluation of new technologies to be implemented into the design. The TIES process begins with defining the problem with a need established and a market targeted. With the customer requirements set and the target values established, a baseline concept is created. Next, the design space is explored to determine the feasibility and viability of the baseline aircraft configuration. If the design is neither feasible nor viable, new technologies can be implemented to open up the feasible design space and allow for a plausible solution. After the new technologies are identified, they must be evaluated

  7. Skylab floating ice experiment

    NASA Technical Reports Server (NTRS)

    Campbell, W. J. (Principal Investigator); Ramseier, R. O.; Weaver, R. J.; Weeks, W. F.

    1975-01-01

    The author has identified the following significant results. Coupling of the aircraft data with the ground truth observations proved to be highly successful with interesting results being obtained with IR and SLAR passive microwave techniques, and standard photography. Of particular interest were the results of the PMIS system which operated at 10.69 GHz with both vertical and horizontal polarizations. This was the first time that dual polarized images were obtained from floating ice. In both sea and lake ice, it was possible to distinguish a wide variety of thin ice types because of their large differences in brightness temperatures. It was found that the higher brightness temperature was invariably obtained in the vertically polarized mode, and as the age of the ice increases the brightness temperature increases in both polarizations. Associated with this change in age, the difference in temperature was observed as the different polarizations decreased. It appears that the horizontally polarized data is the most sensitive to variations in ice type for both fresh water and sea ice. The study also showed the great amount of information on ice surface roughness and deformation patterns that can be obtained from X-band SLAR observations.

  8. 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...

  9. 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...

  10. 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...

  11. 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...

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

    NASA Technical Reports Server (NTRS)

    Addy, Harold E., Jr.; Oleskiw, Myron; Broeren, Andy P.; Orchard, Andy P.

    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.

  13. Aircraft Operations Classification System

    NASA Technical Reports Server (NTRS)

    Harlow, Charles; Zhu, Weihong

    2001-01-01

    Accurate data is important in the aviation planning process. In this project we consider systems for measuring aircraft activity at airports. This would include determining the type of aircraft such as jet, helicopter, single engine, and multiengine propeller. Some of the issues involved in deploying technologies for monitoring aircraft operations are cost, reliability, and accuracy. In addition, the system must be field portable and acceptable at airports. A comparison of technologies was conducted and it was decided that an aircraft monitoring system should be based upon acoustic technology. A multimedia relational database was established for the study. The information contained in the database consists of airport information, runway information, acoustic records, photographic records, a description of the event (takeoff, landing), aircraft type, and environmental information. We extracted features from the time signal and the frequency content of the signal. A multi-layer feed-forward neural network was chosen as the classifier. Training and testing results were obtained. We were able to obtain classification results of over 90 percent for training and testing for takeoff events.

  14. EOS Aqua AMSR-E Arctic Sea Ice Validation Program

    NASA Technical Reports Server (NTRS)

    Cavalieri, D. J.; Markus, T.; Gasiewski, A.; Klein, M.; Maslanik, J.; Sturm, M.; Stroeve, J.; Heinrichs, J.

    2004-01-01

    A coordinated Arctic sea ice validation field campaign using the NASA Wallops P-3B aircraft was successfully completed in March 2003. 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 include sea ice concentration, sea ice temperature, and snow depth on sea ice. The primary instrument on the P-3B aircraft was the NOAA ETL Polarimetric Scanning Radiometer (PSR) covering the same frequencies and polarizations as the AMSR-E. This paper describes 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. The remaining flights covered portions of the Bering Sea ice edge, the Chukchi Sea, and Norton Sound. Comparisons among the satellite and aircraft PSR data sets are presented.

  15. Improving and Assessing Aircraft-based Greenhouse Gas Emission Rate Measurements at Indianapolis as part of the INFLUX project.

    NASA Astrophysics Data System (ADS)

    Heimburger, A. M. F.; Shepson, P. B.; Stirm, B. H.; Susdorf, C.; Cambaliza, M. O. L.

    2015-12-01

    Since the Copenhagen accord in 2009, several countries have affirmed their commitment to reduce their greenhouse gas emissions. The United States and Canada committed to reduce their emissions by 17% below 2005 levels, by 2020, Europe by 14% and China by ~40%. To achieve such targets, coherent and effective strategies in mitigating atmospheric carbon emissions must be implemented in the next decades. Whether such goals are actually achieved, they require that reductions are "measurable", "reportable", and "verifiable". Management of greenhouse gas emissions must focus on urban environments since ~74% of CO2 emissions worldwide will be from cities, while measurement approaches are highly uncertain (~50% to >100%). The Indianapolis Flux Experiment (INFLUX) was established to develop, assess and improve top-down and bottom-up quantifications of urban greenhouse gas emissions. Based on an aircraft mass balance approach, we performed a series of experiments focused on the improvement of CO2, CH4 and CO emission rates quantification from Indianapolis, our final objective being to drastically improve the method overall uncertainty from the previous estimate of 50%. In November-December 2014, we conducted nine methodologically identical mass balance experiments in a short period of time (24 days, one downwind distance) for assumed constant total emission rate conditions, as a means to obtain an improved standard deviation of the mean determination. By averaging the individual emission rate determinations, we were able to obtain a method precision of 17% and 16% for CO2 and CO, respectively, at the 95%C.L. CH4 emission rates are highly variable day to day, leading to precision of 60%. Our results show that repetitive sampling can enable improvement in precision of the aircraft top-down methods through averaging.

  16. The LARsen Ice Shelf System, Antarctica, LARISSA a Model for Antarctic Integrated System Science (AISS) Investigations using Marine Platforms

    NASA Astrophysics Data System (ADS)

    Domack, E. W.; Huber, B. A.; Vernet, M.; Leventer, A.; Scambos, T. A.; Mosley-Thompson, E. S.; Smith, C. R.; de Batist, M. A.; Yoon, H.; Larissa

    2010-12-01

    The LARISSA program is the first interdisciplinary project funded in the AISS program of the NSF Office of Polar Programs and was officially launched in the closing days of the IPY. This program brings together investigators, students, and media to address the rapid and fundamental changes taking place in the region of the Larsen Ice Shelf and surrounding areas. Scientific foci include: glaciologic and oceanographic interactions, the response of pelagic and benthic ecosystems to ice shelf decay, sedimentary record of ice shelf break disintegration, the geologic evolution of ice shelf systems over the last 100,000 years, paleoclimate/environmental records from marine sediment and ice cores, and the crustal response to ice mass loss at decade to millennial time scales. The first major field season took place this past austral summer aboard the NB Palmer (cruise NBP10-01) which deployed with a multi-layered logistical infrastructure that included: two Bell 220 aircraft, a multifunctional deep water ROV, video guided sediment corer, jumbo piston core, and an array of oceanographic and biological sensors and instruments. In tandem with this ship based operation Twin Otter aircraft supported an ice core team upon the crest of the Bruce Plateau with logistic support provided by the BAS at Rothera Station. Although unusually heavy sea ice prevented much of the original work from being completed in the Larsen Embayment the interdisciplinary approach proved useful. Further the logistical model of ship based aircraft to support interdisciplinary work proved viable, again despite an unusually severe summer meterologic pattern across the northern Antarctic Peninsula. As the program moves forward other vessels will come into play and the model can be applied to interdisciplinary objectives in other regions of Antarctica which are remote and lack land based infrastructure to support coastal field programs in glaciology, geology, or meteorology. This work could then be completed

  17. Analytical ice shape predictions for flight in natural icing conditions

    NASA Technical Reports Server (NTRS)

    Berkowitz, Brian M.; Riley, James T.

    1988-01-01

    LEWICE is an analytical ice prediction code that has been evaluated against icing tunnel data, but on a more limited basis against flight data. Ice shapes predicted by LEWICE is compared with experimental ice shapes accreted on the NASA Lewis Icing Research Aircraft. The flight data selected for comparison includes liquid water content recorded using a hot wire device and droplet distribution data from a laser spectrometer; the ice shape is recorded using stereo photography. The main findings are as follows: (1) An equivalent sand grain roughness correlation different from that used for LEWICE tunnel comparisons must be employed to obtain satisfactory results for flight; (2) Using this correlation and making no other changes in the code, the comparisons to ice shapes accreted in flight are in general as good as the comparisons to ice shapes accreted in the tunnel (as in the case of tunnel ice shapes, agreement is least reliable for large glaze ice shapes at high angles of attack); (3) In some cases comparisons can be somewhat improved by utilizing the code so as to take account of the variation of parameters such as liquid water content, which may vary significantly in flight.

  18. 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.

  19. NASA Lewis Research Center's Program on Icing Research

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Shaw, R. J.; Olsen, W. A., Jr.

    1982-01-01

    The helicopter and general aviation, light transport, and commercial transport aircraft share common icing requirements: highly effective, lightweight, low power consuming deicing systems, and detailed knowledge of the aeropenalties due to ice on aircraft surfaces. To meet current and future needs, NASA has a broadbased icing research program which covers both research and engineering applications, and is well coordinated with the FAA, DOD, universities, industry, and some foreign governments. Research activity in ice protection systems, icing instrumentation, experimental methods, analytical modeling, and in-flight research are described.

  20. Icing Sensor Probe

    NASA Technical Reports Server (NTRS)

    Emery, Edward; Kok, Gregory L.

    2002-01-01

    Aircraft icing is a serious safety problem for the general aviation and some commuter transport airplanes. There has been tremendous growth in the commuter aviation industry in the last few years, Since these type of aircraft generally operate at lower altitudes they consequently spend a far greater proportion of their time operating in icing conditions. For the past thirty years airborne and ground based facilities have relied primarily on two types of cloud physics instrumentation to measure the characteristics of icing clouds: hot wire liquid water content probes and laser based particle sizing probes for the measurement of water droplet size. The instrumentation is severely limited by the technology that was developed during the 1970's and is quite large in size. The goal of this research is to develop one instrument with a wide bandwidth, better response time, higher resolution, user selectability, and small and lightweight. NASA Glenn Research Center, Droplet Measurement Technology, and Meteorology Society of Canada have developed a collaborative effort to develop such an instrument. This paper describes the development and test results of the prototype Icing Sensor Probe.

  1. Ice formation and development in aged, wintertime cumulus over the UK: observations and modelling

    NASA Astrophysics Data System (ADS)

    Crawford, I.; Bower, K. N.; Choularton, T. W.; Dearden, C.; Crosier, J.; Westbrook, C.; Capes, G.; Coe, H.; Connolly, P. J.; Dorsey, J. R.; Gallagher, M. W.; Williams, P.; Trembath, J.; Cui, Z.; Blyth, A.

    2012-06-01

    In situ high resolution aircraft measurements of cloud microphysical properties were made in coordination with ground based remote sensing observations of a line of small cumulus clouds, using Radar and Lidar, as part of the Aerosol Properties, PRocesses And InfluenceS on the Earth's climate (APPRAISE) project. A narrow but extensive line (~100 km long) of shallow convective clouds over the southern UK was studied. Cloud top temperatures were observed to be higher than -8 °C, but the clouds were seen to consist of supercooled droplets and varying concentrations of ice particles. No ice particles were observed to be falling into the cloud tops from above. Current parameterisations of ice nuclei (IN) numbers predict too few particles will be active as ice nuclei to account for ice particle concentrations at the observed, near cloud top, temperatures (-7.5 °C). The role of mineral dust particles, consistent with concentrations observed near the surface, acting as high temperature IN is considered important in this case. It was found that very high concentrations of ice particles (up to 100 L-1) could be produced by secondary ice particle production providing the observed small amount of primary ice (about 0.01 L-1) was present to initiate it. This emphasises the need to understand primary ice formation in slightly supercooled clouds. It is shown using simple calculations that the Hallett-Mossop process (HM) is the likely source of the secondary ice. Model simulations of the case study were performed with the Aerosol Cloud and Precipitation Interactions Model (ACPIM). These parcel model investigations confirmed the HM process to be a very important mechanism for producing the observed high ice concentrations. A key step in generating the high concentrations was the process of collision and coalescence of rain drops, which once formed fell rapidly through the cloud, collecting ice particles which caused them to freeze and form instant large riming particles. The

  2. 14 CFR 25.1403 - Wing icing detection lights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing icing detection lights. 25.1403... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1403 Wing icing detection lights. Unless operations at night in known or forecast icing conditions are prohibited by...

  3. 14 CFR 25.1403 - Wing icing detection lights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wing icing detection lights. 25.1403... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1403 Wing icing detection lights. Unless operations at night in known or forecast icing conditions are prohibited by...

  4. 14 CFR 25.1403 - Wing icing detection lights.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing icing detection lights. 25.1403... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1403 Wing icing detection lights. Unless operations at night in known or forecast icing conditions are prohibited by...

  5. Pathfinder aircraft in flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pathfinder research aircraft's solar cell arrays are prominently displayed as it touches down on the bed of Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, following a test flight. The solar arrays covered more than 75 percent of Pathfinder's upper wing surface, and provided electricity to power its six electric motors, flight controls, communications links and a host of scientific sensors. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  6. Pathfinder aircraft in flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The unique Pathfinder solar-powered flying wing, is shown during a checkout flight from the Dryden Flight Research Center, Edwards, California. This two-hour low-altitude flight over Rogers Dry Lake, Nov. 19, 1996, served to test aircraft systems and functional procedures, according to officials of AeroVironment, Inc., Pathfinder's developer and operator. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  7. Pathfinder aircraft in flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pathfinder solar-powered research aircraft heads for landing on the bed of Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, after a successful test flight Nov. 19, 1996. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  8. Pathfinder aircraft in flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pathfinder solar-powered research aircraft is silhouetted against a clear blue sky as it soars aloft during a checkout flight from the Dryden Flight Research Center, Edwards, California, November, 1996. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  9. Pathfinder aircraft flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pathfinder research aircraft's wing structure is clearly defined as it soars under a clear blue sky during a test flight from Dryden Flight Research Center, Edwards, California, in November of 1996. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  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. 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.

  12. Sampling the composition of cirrus ice residuals

    NASA Astrophysics Data System (ADS)

    Cziczo, Daniel J.; Froyd, Karl D.

    2014-06-01

    Cirrus are high altitude clouds composed of ice crystals. They are the first tropospheric clouds that can scatter incoming solar radiation and the last which can trap outgoing terrestrial heat. Considering their extensive global coverage, estimated at between 25 and 33% of the Earth's surface, cirrus exert a measurable climate forcing. The global radiative influence depends on a number of properties including their altitude, ice crystal size and number density, and vertical extent. These properties in turn depend on the ability of upper tropospheric aerosol particles to initiate ice formation. Because aerosol populations, and therefore cirrus formation mechanisms, may change due to human activities, the sign of cirrus forcing (a net warming or cooling) due to anthropogenic effects is not universally agreed upon although most modeling studies suggest a positive effect. Cirrus also play a major role in the water cycle in the tropopause region, affecting not only redistribution in the troposphere but also the abundance of vapor entering the stratosphere. Both the current lack of understanding of cirrus properties and the need to improve our ability to project changes due to human activities in the future highlight the critical need to determine the aerosol particles on which cirrus form. This review addresses what is currently known about the abundance, size and composition of cirrus-forming particles. We review aircraft-based field studies which have either collected cirrus ice residuals for off-line analysis or determined their size, composition and other properties in situ by capturing ice crystals and sublimating/removing the condensed phase water. This review is predominantly restricted to cirrus clouds. Limited comparisons are made to other ice-containing (e.g., mixed-phase) cloud types. The findings of recent reviews on laboratory measurements that mimic upper tropospheric cirrus formation are briefly summarized. The limitations of the current state of the art

  13. Commercial transport aircraft composite structures

    NASA Technical Reports Server (NTRS)

    Mccarty, J. E.

    1983-01-01

    The role that analysis plays in the development, production, and substantiation of aircraft structures is discussed. The types, elements, and applications of failure that are used and needed; the current application of analysis methods to commercial aircraft advanced composite structures, along with a projection of future needs; and some personal thoughts on analysis development goals and the elements of an approach to analysis development are discussed.

  14. Predicting the future distribution of Polar Bear Habitat in the polar basin from resource selection functions applied to 21st century general circulation model projections of sea ice

    USGS Publications Warehouse

    Durner, George M.; Douglas, David C.; Nielson, Ryan M.; Amstrup, Steven C.; McDonald, Trent L.

    2007-01-01

    Predictions of polar bear (Ursus maritimus) habitat distribution in the Arctic polar basin during the 21st century were developed to help understand the likely consequences of anticipated sea ice reductions on polar bear populations. We used location data from satellite-collared polar bears and environmental data (e.g., bathymetry, coastlines, and sea ice) collected between 1985–1995 to build habitat use models called Resource Selection Functions (RSF). The RSFs described habitats polar bears preferred in each of four seasons: summer (ice minimum), autumn (growth), winter (ice maximum) and spring (melt). When applied to the model source data and to independent data (1996–2006), the RSFs consistently identified habitats most frequently used by polar bears. We applied the RSFs to monthly maps of 21st century sea ice concentration predicted by 10 general circulation models (GCM) described in the International Panel of Climate Change Fourth Assessment Report. The 10 GCMs we used had high concordance between their simulations of 20th century summer sea ice extent and the actual ice extent derived from passive microwave satellite observations. Predictions of the amount and rate of change in polar bear habitat varied among GCMs, but all GCMs predicted net habitat losses in the polar basin during the 21st century. Projected losses in the highest-valued RSF habitat (optimal habitat) were greatest in the peripheral seas of the polar basin, especially the Chukchi Sea and Barents Sea. Losses were least in high-latitude regions where RSFs predicted an initial increase in optimal habitat followed by a modest decline. The largest seasonal reductions in habitat were predicted for spring and summer. Average area of optimal polar bear habitat during summer in the polar basin declined from an observed 1.0 million km2 in 1985–1995 (baseline) to a projected multi-model average of 0.58 million km2 in 2045–2054 (-42% change), 0.36 million km2 in 2070–2079 (-64% change), and 0

  15. Nimbus Satellite Data Rescue Project for Sea Ice Extent: Preliminary results from September 1964, 1966, and 1969

    NASA Astrophysics Data System (ADS)

    Gallaher, D. W.; Meier, W.; Campbell, G.; Moses, J. F.

    2011-12-01

    The earliest satellite data available to obtain estimates of total sea ice extent date back to 1972, based on passive microwave sensors. Earlier estimates, available from operational ice charts, provide incomplete coverage in the Arctic and virtually no coverage in the Antarctic. Recovered data from 1960s Nimbus satellite sensor now provides the potential to obtain estimates from as early as 1964. There are a number of challenges in using data from the 1960's to estimate sea ice extent. We are organizing visible and window channel infrared data from Nimbus I, II and III to attack this problem from old archive tapes (IR) and satellite based images on film (visible). There were over 7000 infrared files for just Nimbus II. We estimate there are over 200,000 images from the AVCS and IDCS from just the 1960s Nimbus missions. All this data will be recovered, scanned and rectified (Image 1). We will discuss the errors resulting from the limited spatial and temporal coverage and calibration issues using observations from the Advanced Vidicon Camera System (N1+N2), Image Dissection Camera System (N3) and the High Resolution Infrared Radiometer (HRIR) instrument onboard these early NASA satellites. The first ice detection technique involves determining the rolling minimum reflectivity over a period of 7-10 days. This effectively removes the clouds in the composite of observations from.multiple orbits. This data was then compared to the IR data covering the same period to derive an IR ice extent algorithm for the particular IR window collected by the Nimbus satellites. For the most part the IR data was collected only at night; however there were a few exceptions, which provided an opportunity for a direct temporal comparison. We will have preliminary estimates of the sea ice extent and an error estimate for 3 selected months (September 1964, 1966 and 1969) for comparison to modern ice extent measurements for both the Arctic and Antarctic. The Arctic sea ice minimums and

  16. The NASA Altitude Wind Tunnel (AWT): Its role in advanced icing research and development

    NASA Technical Reports Server (NTRS)

    Blaha, B. J.; Shaw, R. J.

    1985-01-01

    Currently experimental aircraft icing research is severely hampered by limitations of ground icing simulation facilities. Existing icing facilities do not have the size, speed, altitude, and icing environment simulation capabilities to allow accurate studies to be made of icing problems occurring for high speed fixed wing aircraft and rotorcraft. Use of the currently dormant NASA Lewis Altitude Wind Tunnel (AWT), as a proposed high speed propulsion and adverse weather facility, would allow many such problems to be studied. The characteristics of the AWT related to adverse weather simulation and in particular to icing simulation are discussed, and potential icing research programs using the AWT are also included.

  17. Comparison of LEWICE and GlennICE in the SLD Regime

    NASA Technical Reports Server (NTRS)

    Wright, William B.; Potapczuk, Mark G.; Levinson, Laurie H.

    2008-01-01

    A research project is underway at the NASA Glenn Research Center (GRC) to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. This report will present results from two different computer programs. The first program, LEWICE version 3.2.2, has been reported on previously. The second program is GlennICE version 0.1. An extensive comparison of the results in a quantifiable manner against the database of ice shapes that have been generated in the GRC Icing Research Tunnel (IRT) has also been performed, including additional data taken to extend the database in the Super-cooled Large Drop (SLD) regime. This paper will show the differences in ice shape between LEWICE 3.2.2, GlennICE, and experimental data. This report will also provide a description of both programs. Comparisons are then made to recent additions to the SLD database and selected previous cases. Quantitative comparisons are shown for horn height, horn angle, icing limit, area, and leading edge thickness. The results show that the predicted results for both programs are within the accuracy limits of the experimental data for the majority of cases.

  18. Aircraft cybernetics

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

  19. Ices in the Solar Nebula

    NASA Astrophysics Data System (ADS)

    Robinson, Sarah

    2008-05-01

    The centerpiece of this proposal is my hypothesis that other ices besides H2O help build giant planet cores. I propose a theory project on the ice composition of planet-forming regions and a related observing project on ice detection and mineralogy in debris disks. Together, the theory and observing projects will answer two questions: 1. Where are the condensation fronts of abundant volatiles located in relation to giant planet feeding zones? 2. How much does the presence of CHON ices in planetesimals speed up giant planet formation?

  20. Sea Ice Mapping using Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Solbø, S.; Storvold, R.

    2011-12-01

    Mapping of sea ice extent and sea ice features is an important task in climate research. Since the arctic coastal and oceanic areas have a high probability of cloud coverage, aerial platforms are superior to satellite measurements for high-resolution optical measurements. However, routine observations of sea ice conditions present a variety of problems using conventional piloted aircrafts. Specially, the availability of suitable aircrafts for lease does not cover the demand in major parts of the arctic. With the recent advances in unmanned aerial systems (UAS), there is a high possibility of establishing routine, cost effective aerial observations of sea ice conditions in the near future. Unmanned aerial systems can carry a wide variety of sensors useful for characterizing sea-ice features. For instance, the CryoWing UAS, a system initially designed for measurements of the cryosphere, can be equipped with digital cameras, surface thermometers and laser altimeters for measuring freeboard of ice flows. In this work we will present results from recent CryoWing sea ice flights on Svalbard, Norway. The emphasis will be on data processing for stitching together images acquired with the non-stabilized camera payload, to form high-resolution mosaics covering large spatial areas. These data are being employed to map ice conditions; including ice and lead features and melt ponds. These high-resolution mosaics are also well suited for sea-ice mechanics, classification studies and for validation of satellite sea-ice products.

  1. Ultrasonic guided wave tomography for ice detection.

    PubMed

    Zhao, Xiang; Rose, Joseph L

    2016-04-01

    Of great concern for many structures, particularly critical sections of rotary and fixed wing aircrafts, is the ability to detect ice either on grounded or in-flight vehicles. As a consequence, some work is reported here that could be useful for a variety of different industries where ice formation is an important problem. This paper presents experimental validations of a probability-based reconstruction algorithm (PRA) on ice detection of plate-like structures. The ice detection tests are performed for three different specimens: a single layer aluminum plate with a circular ice sensing array, a titanium plate with a sparse rectangular ice sensing array, and a carbon-fiber-reinforced titanium plate with an embedded ice sensing array mounted on a carbon fiber back plate. Cases from the simple to the more challenging exemplify that special modes can be used to differentiate ice from water, a sparse rectangular array could also be used for ice detection, and an ice sensing array could be further used to detect the ice on the sensor free side, a very useful application of ice sensing for aircraft wings, for example. Ice detection images for the respective cases are reconstructed to investigate the feasibility of ice sensing with ultrasonic guided wave tomography technology. The results show that the PRA based ultrasonic guided wave tomography method successfully detected and showed ice spots correctly for all three cases. This corroborates the fact that ultrasonic guided wave imaging technology could be a potential useful ice sensing tool in plate-like structures. PMID:26746159

  2. 3. General view showing rear of looking glass aircraft. View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. General view showing rear of looking glass aircraft. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  3. 5. Headon view of looking glass aircraft. View to southwest. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Head-on view of looking glass aircraft. View to southwest. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  4. 4. View showing underside of wing, looking glass aircraft. View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View showing underside of wing, looking glass aircraft. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  5. Aircraft vortex marking program

    NASA Technical Reports Server (NTRS)

    Pompa, M. F.

    1979-01-01

    A simple, reliable device for identifying atmospheric vortices, principally as generated by in-flight aircraft and with emphasis on the use of nonpolluting aerosols for marking by injection into such vortex (-ices) is presented. The refractive index and droplet size were determined from an analysis of aerosol optical and transport properties as the most significant parameters in effecting vortex optimum light scattering (for visual sighting) and visual persistency of at least 300 sec. The analysis also showed that a steam-ejected tetraethylene glycol aerosol with droplet size near 1 micron and refractive index of approximately 1.45 could be a promising candidate for vortex marking. A marking aerosol was successfully generated with the steam-tetraethylene glycol mixture from breadboard system hardware. A compact 25 lb/f thrust (nominal) H2O2 rocket chamber was the key component of the system which produced the required steam by catalytic decomposition of the supplied H2O2.

  6. Climatic implications of ice microphysics

    SciTech Connect

    Liou, K.N.

    1995-09-01

    Based on aircraft measurements of mid-latitude cirrus clouds, ice crystal size distribution and ice water content (IWC) are shown to be dependent on temperature. This dependence is also evident from the theoretical consideration of ice crystal growth. Using simple models of the diffusion and accretion growth of ice particles, the computed mean ice crystal size and IWC compare reasonably well with the measured mean values. The temperature dependence of ice crystal size and IWC has important climatic implications in that the temperature field perturbed by external radiative forcings, such as greenhouse warming, can alter the composition of ice crystal clouds. Through radiative transfer, ice microphysics can in turn affect the temperature field. Higher IWC would increase cloud solar albedo and infrared emissivity, while for a given IWC, larger crystals would reduce cloud albedo and emissivity. The competing effects produced by greenhouse temperature perturbations via ice micro-physics and radiation interactions and feedbacks are assessed by a one-dimensional radiative-convective climate model that includes an advanced radiation parameterization program. 3 figs.

  7. A scheme for parameterizing ice cloud water content in general circulation models

    NASA Technical Reports Server (NTRS)

    Heymsfield, Andrew J.; Donner, Leo J.

    1989-01-01

    A method for specifying ice water content in GCMs is developed, based on theory and in-cloud measurements. A theoretical development of the conceptual precipitation model is given and the aircraft flights used to characterize the ice mass distribution in deep ice clouds is discussed. Ice water content values derived from the theoretical parameterization are compared with the measured values. The results demonstrate that a simple parameterization for atmospheric ice content can account for ice contents observed in several synoptic contexts.

  8. Climate condition in the Central Europe during the Weichselian Ice Sheet according to the Educational Global Climate Modeling Project

    NASA Astrophysics Data System (ADS)

    Szuman, Izabela; Czernecki, Bartosz

    2010-05-01

    The expansion and retreat of the ice sheet is controlled by climate changes, and from the other hand, a huge ice mass influences on the climate in the regional scale. This mechanism is commonly known as the fact but often without making reconstruction by using climatological modeling. The purpose of our study is to reconstruct the climate condition during the Weichselian Ice Sheet in the Central Europe, especially for Poland and surrounded countries. The Global Climate Model (GCM) is made for predicting climate, but simplified version can be useful for reconstructing paleoclimate. Hence, the simple initial conditions and surface data proposed by the Educational version of the GCM was applied. In our study we used a simplified version of the GCM to calculate main climate characteristics within the time limits c. 21 000 BP - 18 000 BP, which has been previously invented on Columbia University. The model is constructed on grid with a horizontal resolution 8° latitude by 10° longitude and was establish for modeling most of weather conditions based on available paleoclimate data. It is possible to estimate the probable climate condition along the southern ice sheets margin on the basis of output from the GCM and GIS modeling techniques. Above the ice mass occurs local high pressure area, which seriously interfered on atmospheric circulation. Whereas the low pressure systems in the southern part of continent may caused permanent barometric situation, which stimulates wind directions as well as the precipitable water available in the mass of air. The climate on the east-south border of ice margin was colder and drier than on the west-south region, where it was more ocean-reliable and gentle with higher temperatures. The differences in temperature between the western and eastern part of the Central Europe reached few centigrade. Against a background of the mean paleoclimatic situation in the Central Europe there is coming out a question about the particular paleoclimate

  9. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project - Gen-4 and Gen-5 Radio Plans

    NASA Technical Reports Server (NTRS)

    Griner, James H.

    2014-01-01

    NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication (CNPC) system prototype radio, operating on recently allocated UAS frequency spectrum bands. This prototype radio is being used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current plans for the prototype radio development.

  10. Microwave de-/anti-icing using the midas-technology.

    PubMed

    Feher, L; Seitz, T; Nuss, V

    2009-01-01

    For aviation, a suitable alternative for currently used in-flight anti-/de-icing technologies for today's aircrafts with metal structures and future aircrafts with replaced composite structures is necessary. Intense investigations performed at FZK have been together in collaboration with aircraft manufacturers to design and develop a new avionic microwave technology for monolithic composite structures.The full system integration has been evaluated for several airplanes considering the structural and efficiency demands. The concept of this MIDAS (MIcrowave De-icing Anti-icing System) technology as well their recent results will be presented. A full system integration has been tested and is visualized in the paper. PMID:21384724

  11. Mixed-Phase Icing Simulation and Testing at the Cox Icing Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Al-Khalil, Kamel; Irani, Eddie; Miller, Dean

    2003-01-01

    A new capability was developed for indoor simulation of snow and mixed-phase icing conditions. This capability is useful for year-round testing in the Cox closed-loop Icing Wind Tunnel. Certification of aircraft for flight into these types of icing conditions is only required by the JAA in Europe. In an effort to harmonize certification requirements, the FAA in the US sponsored a preliminary program to study the effects of mixed-phase and fully glaciated icing conditions on the performance requirements of thermal ice protection systems. This paper describes the test program and the associated results.

  12. Eclipse program QF-106 aircraft

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This photo shows two QF-106 aircraft that were used for the Eclipse project, both parked at the Mojave Airport in Mojave, California. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator -01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  13. Technologies for Aircraft Noise Reduction

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.

    2006-01-01

    Technologies for aircraft noise reduction have been developed by NASA over the past 15 years through the Advanced Subsonic Technology (AST) Noise Reduction Program and the Quiet Aircraft Technology (QAT) project. This presentation summarizes highlights from these programs and anticipated noise reduction benefits for communities surrounding airports. Historical progress in noise reduction and technologies available for future aircraft/engine development are identified. Technologies address aircraft/engine components including fans, exhaust nozzles, landing gear, and flap systems. New "chevron" nozzles have been developed and implemented on several aircraft in production today that provide significant jet noise reduction. New engines using Ultra-High Bypass (UHB) ratios are projected to provide about 10 EPNdB (Effective Perceived Noise Level in decibels) engine noise reduction relative to the average fleet that was flying in 1997. Audio files are embedded in the presentation that estimate the sound levels for a 35,000 pound thrust engine for takeoff and approach power conditions. The predictions are based on actual model scale data that was obtained by NASA. Finally, conceptual pictures are shown that look toward future aircraft/propulsion systems that might be used to obtain further noise reduction.

  14. Air pollution from aircraft

    NASA Technical Reports Server (NTRS)

    Heywood, J. B.; Fay, J. A.; Chigier, N. A.

    1979-01-01

    Forty-one annotated abstracts of reports generated at MIT and the University of Sheffield are presented along with summaries of the technical projects undertaken. Work completed includes: (1) an analysis of the soot formation and oxidation rates in gas turbine combustors, (2) modelling the nitric oxide formation process in gas turbine combustors, (3) a study of the mechanisms causing high carbon monoxide emissions from gas turbines at low power, (4) an analysis of the dispersion of pollutants from aircraft both around large airports and from the wakes of subsonic and supersonic aircraft, (5) a study of the combustion and flow characteristics of the swirl can modular combustor and the development and verification of NO sub x and CO emissions models, (6) an analysis of the influence of fuel atomizer characteristics on the fuel-air mixing process in liquid fuel spray flames, and (7) the development of models which predict the stability limits of fully and partially premixed fuel-air mixtures.

  15. Preliminary ice shelf-ocean simulation results from idealized standalone-ocean and coupled model intercomparison projects (MIPs)

    NASA Astrophysics Data System (ADS)

    Asay-Davis, Xylar; Martin, Daniel

    2016-04-01

    The second Ice Shelf-Ocean MIP (ISOMIP+) and the first Marine Ice Sheet-Ocean MIP (MISOMIP1) prescribe a set of idealized experiments for ocean models with ice-shelf cavities and coupled ice sheet-ocean models, respectively. ISOMIP+ and MISOMIP1 were designed together with the third Marine Ice Sheet MIP (MISMIP+) with three main goals, namely that the MIPs should provide: a controlled forum for researchers to compare their model results with those from other models during model development. a path for testing components in the process of developing coupled ice sheet-ocean models. a basic setup from which a large variety of parameter and process studies can usefully be performed. The experimental design for the three MIPs is currently under review in Geoscientific Model Development (Asay-Davis et al. 2015, doi:10.5194/gmdd-8-9859-2015). We present preliminary results from ISOMIP+ and MISOMIP1 experiments using several ocean-only and coupled ice sheet-ocean models. Among ocean models, we show that differences in model behavior are significant enough that similar results can only be achieved by tuning model parameters (e.g. boundary-layer transfer coefficients, drag coefficients, vertical mixing parameterizations) for each models. This tuning is constrained by a desired mean melt rate in quasi-steady state under specified forcing conditions, akin to how models would be tuned based on observations for non-idealized simulations. We also present a number of parameter studies based the MIP experiments. Again, using several models, we show that melt rates respond sub-linearly to both changes in the square root of the drag coefficient and the heat-transfer coefficient, and that melting is relatively insensitive to horizontal-mixing coefficients (perhaps because the resolution is sufficient to permit eddies) but more sensitive to vertical-mixing coefficients. We show that the choice of the equation of state (linear or nonlinear) does not have a significant impact as long as

  16. ICOARE: Impacts on Climate and Ozone from Aircraft and Rocket Emissions

    NASA Astrophysics Data System (ADS)

    Toohey, D. W.; Ross, M.

    2009-12-01

    This presentation will provide an overview of an Earth Venture proposal for a series of in situ measurements in the exhaust plumes of aircraft and rockets with the following objectives: to obtain information that is critical for reducing the uncertainties in assessments (e.g., WMO and IPCC) of the impacts of aviation and aerospace activities on regional and global climate; to assess the viability of a climate engineering scheme that employs injection of reflective particles into the lower stratosphere; and to initiate the development of an operational modeling tool that can be used by the aviation and aerospace industries to guide design of new transporation systems that minimize the impact on Earth’s climate. The ICOARE mission will deploy instruments to measure water vapor, ice water content, tracers, reactive species, particles, and radiation fields on a high-altitude aircraft to characterize the variability of water vapor in aircraft and rocket contrails, determine accurate emission indices for initialization of plume-wake and regional scale models, investigate the microphysical properties of cirrus particles in and out of aircraft corridors, and examine the light scattering properties of contrail ice crystals and small alumina particles. Focused campaigns will be timed to occur around the launch schedules of a variety of rocket types in order to characterize the range of emissions from the current launch suite. There will be special emphasis on characterizing the emissions from rockets employing new propellants, in particular those that may produce soot and nitrogen oxides. Observations in aircraft exhaust, and examinations of cirrus cloud properties and persistent contrails, will occur on flights that are not dedicated to studies of rockets (e.g., test, transit, and rocket-scrub flights). ICOARE will offer a unique opportunities for training students and postdoctorates, especially those from underrepresented groups, in areas of project management, logistics

  17. Mixed Phase Modeling in GlennICE with Application to Engine Icing

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    A capability for modeling ice crystals and mixed phase icing has been added to GlennICE. Modifications have been made to the particle trajectory algorithm and energy balance to model this behavior. This capability has been added as part of a larger effort to model ice crystal ingestion in aircraft engines. Comparisons have been made to four mixed phase ice accretions performed in the Cox icing tunnel in order to calibrate an ice erosion model. A sample ice ingestion case was performed using the Energy Efficient Engine (E3) model in order to illustrate current capabilities. Engine performance characteristics were supplied using the Numerical Propulsion System Simulation (NPSS) model for this test case.

  18. NASA Now: Operation IceBridge

    NASA Video Gallery

    During this NASA Now program, you'€™ll meet Michael Studinger, Project Scientist for Operation IceBridge. He'€™ll describe the purpose of the IceBridge campaign and how the campaign objectives will...

  19. Progress on low altitude cloud icing research

    NASA Technical Reports Server (NTRS)

    Jeck, R. K.

    1981-01-01

    The icing environment at altitudes below 10,000 feet were studied. The following questions are asked, are: (1) existing aircraft certification criteria applicable; (2) too stringent on icing for helos; (3) based on accurate data; (4) appropriate for low (10,000 ft) altitudes? The research plan is outlined: review historical icing data, obtain new measurements, collect modern icing data from other groups, and recommend LWC, OAT, and MVD criteria for helicopters. Estimated accuracies and known sources of error are included. It is concluded that the net effect of possible sources of error of both signs is uncertain.

  20. The 2012 melting record and 21st century sea level rise projections for major drainage systems of the Greenland ice sheet

    NASA Astrophysics Data System (ADS)

    Tedesco, M.; Fettweis, X.

    2012-12-01

    At the time of the submission of this abstract melting over the Greenland ice sheet estimated from spaceborne microwave observations and modeled by the regional climate model MAR (Modèle Atmosphérique Régional) are close to previously breaking-record values set in 2010 and 2011 (for the period 1979 - 2011). With August still to come, 2012 is very likely going to set a new record for the whole season. For the period June - July, melting detected from spaceborne observations was already above two standard deviations the 1979 - 2011 mean, setting a new record for that period. In this study, we compare the 2012 melting season with those previously setting a new record and analyze some of the potential drivers for the new record. To put things in the context of future projections, we analyze MAR outputs to study 21st century projected surface mass balance (SMB) over six major drainage basins of the Greenland Ice Sheet (GrIS). The regional model is forced with the outputs of three different Earth System Models (CanESM2, NorESM1 and MIROC5) obtained when considering two greenhouse gas future scenarios with levels of CO2 equivalent of, respectively, 850 and > 1370 ppm by 2100. First, we study whether the MAR future projections starting in 2006 (using the historical period 1980 - 2005) are capable of identifying the recently observed melting records. We also find that, by the end of the century, the increase in runoff due to warming will exceed the increased precipitation deriving from the increase in evaporation for all basins, with the amount of net loss of mass at the surface varying spatially. Basins along the southwest and north coast are projected to have the highest sensitivity of SMB to increasing temperatures. For these basins, the global temperature anomaly corresponding to a decrease of the SMB below the 1980 - 1999 average (when the ice sheet was near the equilibrium) ranges between +0.60 deg C and +2.16 deg C. For the basins along the northwest and northeast

  1. Calcareous nannofossil evidence for Marine Isotope Stage 31 (1 Ma) in the AND-1B Core, ANDRILL McMurdo Ice Shelf Project (Antarctica).

    NASA Astrophysics Data System (ADS)

    Villa, G.; Persico, D.; Wise, S. W.; Gadaleta, A.

    2009-04-01

    During the austral summer 2006 the ANDRILL Program recovered a 1285 m-long succession of cyclic glacimarine sediments from the McMurdo Ice Shelf (MIS). The aim of the MIS Project was to obtain continuous Neogene (c. 0-10 Ma) glacial, glacimarine, volcanic, and biogenic sediments that have accumulated in the region of the McMurdo Ice Shelf (Ross Sea) nourished by ice flowing from East Antarctic Ice Sheet (EAIS) outlet glaciers in the Transantarctic Mountains (TAM). The MIS AND-1B drill core represents the longest and most complete (98% recovery) geological record from the Antarctic continental margin to date, and will provide a key reference record of climate and ice-sheet variability through the Late Neogene; detailed investigations of this record will contribute for improving our knowledge of Antarctica's influence on global climate. Preliminary on-ice analysis of the smear slides of the Andrill core revealed calcareous microfossils (dinoflagellates, calciosponge spicula and small foraminifera) occurring with variable concentrations. The presence of thoracosphaerid fragments in the smear slides of the first 600 mbsf (Quaternary), probably belong to the species Thoracosphaera saxea (Stradner 1961), and Thoracosphaera heimi (Kamptner, 1941) and other, potentially undescribed species (Villa & Wise 1998), suggests either a peculiar adaptation to this environment, due to their ability to develop cysts or warmer conditions at the time of their deposition, or a combination of both. However, they represent an additional element to use with the other proxies for inferring palaeoenvironmental conditions of the core. Subsequent shore-based analyses of 100 samples from 86-96 mbsf revealed for the first time the presence of Pleistocene coccolithophorids at these high southern latitudes (77° S), including: Coccolithus pelagicus, small Gephyrocapsa, Reticulofenestra asanoi, Pseudoemiliania lacunosa, Dictyoccocites productus, Reticulofenestra sp., Reticulofenestra minutula

  2. Hydrogeochemistry of Groundwater as Part of the Greenland Analogue Project in an Area of Continuous Permafrost Adjacent to the Greenland Ice Sheet, Kangerlussuaq, West Greenland

    NASA Astrophysics Data System (ADS)

    Henkemans, E.; Frape, S.; Ruskeeniemi, T.; Claesson-Liljedahl, L.; Lehtinen, A.; Annable, W. K.

    2011-12-01

    Studying groundwater in areas of continuous permafrost is often limited to studies of springs and open pingos (eg. Pollard et al. 1999 and Allen et al. 1976). Boreholes in such locations are expensive, risky and logistically challenging (eg. Stotler et al. 2011) resulting in a limited understanding of the interaction between continental scale ice sheets and groundwater. Continental ice sheet models are often coupled to groundwater flow systems; however, there is a lack of modern field data with which to compare the results of models and their treatment of groundwater flow systems under the influence of glaciation. The Greenland Analogue Project (GAP) aims to eliminate some of the uncertainties in modeling ice sheets by using the Greenland ice sheet as a modern analogue for past glaciations. Since 2009, 3 boreholes have been drilled, 2 of which contain sampling systems. DH-GAP01 is a 191 m deep borehole drilled at an angle into a talik and has been sampled and studied since 2009. DH-GAP04 is a 632 m deep, angled borehole that intersects the groundwater flow system directly beneath Isunguata Sermia and is producing preliminary groundwater samples. Additional information on groundwater in the Kangerlussuaq area comes from a spring located directly in front of the Leverett ice lobe. Geochemical and isotopic (δ18O, δ2H, δ37Cl, 87Sr/86Sr, and δ34S and δ18O of SO4) tools are used to interpret geochemical processes acting on groundwaters and provide insight into groundwater flow. Analyses of δ18O and δ2H in groundwaters from DH-GAP01 show the borehole waters fall along the Global Meteoric Water Line (GMWL). Evaporation is an important process affecting the δ18O-δ2H of surface waters in the region causing lakes to plot along a local evaporation line (Leng and Anderson, 2003). The waters from the Leverett spring plot to the right of the GMWL as possibly a mixture of groundwater and surface evaporated fluids. However, both the waters from DH-GAP01 and the Leverett

  3. Simulation Model Development for Icing Effects Flight Training

    NASA Technical Reports Server (NTRS)

    Barnhart, Billy P.; Dickes, Edward G.; Gingras, David R.; Ratvasky, Thomas P.

    2003-01-01

    A high-fidelity simulation model for icing effects flight training was developed from wind tunnel data for the DeHavilland DHC-6 Twin Otter aircraft. First, a flight model of the un-iced airplane was developed and then modifications were generated to model the icing conditions. The models were validated against data records from the NASA Twin Otter Icing Research flight test program with only minimal refinements being required. The goals of this program were to demonstrate the effectiveness of such a simulator for training pilots to recognize and recover from icing situations and to establish a process for modeling icing effects to be used for future training devices.

  4. Systems and Techniques for Identifying and Avoiding Ice

    NASA Technical Reports Server (NTRS)

    Hansman, R. John

    1995-01-01

    In-flight icing is one of the most difficult aviation weather hazards facing general aviation. Because most aircraft in the general aviation category are not certified for flight into known icing conditions, techniques for identifying and avoiding in-flight ice are important to maintain safety while increasing the utility and dispatch capability which is part of the AGATE vision. This report summarizes a brief study effort which: (1) Reviewed current ice identification, forecasting, and avoidance techniques; (2) Assessed feasibility of improved forecasting and ice avoidance procedures; and (3) Identified key issues for the development of improved capability with regard to in-flight icing.

  5. 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.

  6. Does traffic-related air pollution explain associations of aircraft and road traffic noise exposure on children's health and cognition? A secondary analysis of the United Kingdom sample from the RANCH project.

    PubMed

    Clark, Charlotte; Crombie, Rosanna; Head, Jenny; van Kamp, Irene; van Kempen, Elise; Stansfeld, Stephen A

    2012-08-15

    The authors examined whether air pollution at school (nitrogen dioxide) is associated with poorer child cognition and health and whether adjustment for air pollution explains or moderates previously observed associations between aircraft and road traffic noise at school and children's cognition in the 2001-2003 Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) project. This secondary analysis of a subsample of the United Kingdom RANCH sample examined 719 children who were 9-10 years of age from 22 schools around London's Heathrow airport for whom air pollution data were available. Data were analyzed using multilevel modeling. Air pollution exposure levels at school were moderate, were not associated with a range of cognitive and health outcomes, and did not account for or moderate associations between noise exposure and cognition. Aircraft noise exposure at school was significantly associated with poorer recognition memory and conceptual recall memory after adjustment for nitrogen dioxide levels. Aircraft noise exposure was also associated with poorer reading comprehension and information recall memory after adjustment for nitrogen dioxide levels. Road traffic noise was not associated with cognition or health before or after adjustment for air pollution. Moderate levels of air pollution do not appear to confound associations of noise on cognition and health, but further studies of higher air pollution levels are needed.

  7. The Role of Turbulence in Chemical and Dynamical Processes in the Near-Field Wake of Subsonic Aircraft

    NASA Technical Reports Server (NTRS)

    Lewellen, D. C.; Lewellen, W. Steve

    2002-01-01

    During this grant, covering the period from September 1998 to December 2001, we continued the investigation of the role of turbulent mixing in the wake of subsonic aircraft initiated in 1994 for NASA's Atmospheric Effects of Aviation Project. The goal of the research has been to provide sufficient understanding and quantitative analytical capability to assess the dynamical, chemical, and microphysical interactions in the near-field wake that have the greatest potential to influence the global atmospheric impact of the projected fleet of subsonic aircraft. Through large-eddy simulations we have shown that turbulence in the early wake dynamics can have a strong effect on both the ice microphysics of contrail evolution and on wake chemistry. The wake vortex dynamics are the primary determinant of the vertical extent of the contrail; this together with the local wind shear largely determines the horizontal extent. The fraction of the initial ice crystals surviving the wake vortex dynamics, their spatial distribution, and the ice mass distribution are all sensitive to the aircraft type, assumed initial ice crystal number, and ambient humidity and turbulence conditions. Our model indicates that there is a significant range of conditions for which a smaller aircraft such as a B737 produces as significant a persistent contrail as a larger aircraft such as a B747, even though the latter consumes almost five times as much fuel. Large-eddy simulations of the near wake of a B757 provided a fine-grained chemical-dynamical representation of simplified NOx - HOx chemistry in wakes of ages from a few seconds to several minutes. By sampling the simulated data in a manner similar to that of in situ aircraft measurements it was possible to provide a likely explanation for a puzzle uncovered in the 1996 SUCCESS flight measurements of OH and HO2 The results illustrate the importance of considering fluid dynamics effects in interpreting chemistry results when mixing rates and species

  8. The NASA Aircraft Energy Efficiency Program

    NASA Technical Reports Server (NTRS)

    Klineberg, J. M.

    1978-01-01

    The objective of the NASA Aircraft Energy Efficiency Program is to accelerate the development of advanced technology for more energy-efficient subsonic transport aircraft. This program will have application to current transport derivatives in the early 1980s and to all-new aircraft of the late 1980s and early 1990s. Six major technology projects were defined that could result in fuel savings in commercial aircraft: (1) Engine Component Improvement, (2) Energy Efficient Engine, (3) Advanced Turboprops, (4) Energy Efficiency Transport (aerodynamically speaking), (5) Laminar Flow Control, and (6) Composite Primary Structures.

  9. The lift-fan aircraft: Lessons learned

    NASA Technical Reports Server (NTRS)

    Deckert, Wallace H.

    1995-01-01

    This report summarizes the highlights and results of a workshop held at NASA Ames Research Center in October 1992. The objective of the workshop was a thorough review of the lessons learned from past research on lift fans, and lift-fan aircraft, models, designs, and components. The scope included conceptual design studies, wind tunnel investigations, propulsion systems components, piloted simulation, flight of aircraft such as the SV-5A and SV-5B and a recent lift-fan aircraft development project. The report includes a brief summary of five technical presentations that addressed the subject The Lift-Fan Aircraft: Lessons Learned.

  10. Educating with Aircraft Models

    ERIC Educational Resources Information Center

    Steele, Hobie

    1976-01-01

    Described is utilization of aircraft models, model aircraft clubs, and model aircraft magazines to promote student interest in aerospace education. The addresses for clubs and magazines are included. (SL)

  11. High-altitude reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Yazdi, Renee Anna

    1991-01-01

    At the equator the ozone layer ranges from 65,000 to 130,000+ ft, which is beyond the capabilities of the ER-2, NASA's current high-altitude reconnaissance aircraft. This project is geared to designing an aircraft that can study the ozone layer. The aircraft must be able to satisfy four mission profiles. The first is a polar mission that ranges from Chile to the South Pole and back to Chile, a total range of 6000 n.m. at 100,000 ft with a 2500-lb payload. The second mission is also a polar mission with a decreased altitude and an increased payload. For the third mission, the aircraft will take off at NASA Ames, cruise at 100,000 ft, and land in Chile. The final mission requires the aircraft to make an excursion to 120,000 ft. All four missions require that a subsonic Mach number be maintained because of constraints imposed by the air sampling equipment. Three aircraft configurations were determined to be the most suitable for meeting the requirements. The performance of each is analyzed to investigate the feasibility of the mission requirements.

  12. Design Methods and Optimization for Morphing Aircraft

    NASA Technical Reports Server (NTRS)

    Crossley, William A.

    2005-01-01

    This report provides a summary of accomplishments made during this research effort. The major accomplishments are in three areas. The first is the use of a multiobjective optimization strategy to help identify potential morphing features that uses an existing aircraft sizing code to predict the weight, size and performance of several fixed-geometry aircraft that are Pareto-optimal based upon on two competing aircraft performance objectives. The second area has been titled morphing as an independent variable and formulates the sizing of a morphing aircraft as an optimization problem in which the amount of geometric morphing for various aircraft parameters are included as design variables. This second effort consumed most of the overall effort on the project. The third area involved a more detailed sizing study of a commercial transport aircraft that would incorporate a morphing wing to possibly enable transatlantic point-to-point passenger service.

  13. Computational Fluid Dynamics-Icing: a Predictive Tool for In-Flight Icing Risk Management

    NASA Astrophysics Data System (ADS)

    Zeppetelli, Danial

    In-flight icing is a hazard that continues to afflict the aviation industry, despite all the research and efforts to mitigate the risks. The recurrence of these types of accidents has given renewed impetus to the development of advanced analytical predictive tools to study both the accretion of ice on aircraft components in flight, and the aerodynamic consequences of such ice accumulations. In this work, an in-depth analysis of the occurrence of in-flight icing accidents and incidents was conducted to identify high-risk flight conditions. To investigate these conditions more thoroughly, a computational fluid dynamics model of a representative airfoil was developed to recreate experiments from the icing wind tunnel that occurred in controlled flight conditions. The ice accumulations and resulting aerodynamic performance degradations of the airfoil were computed for a range or pitch angles and flight speeds. These simulations revealed substantial performance losses such as reduced maximum lift, and decreased stall angle. From these results, an icing hazard analysis tool was developed, using risk management principles, to evaluate the dangers of in-flight icing for a specific aircraft based on the atmospheric conditions it is expected to encounter, as well as the effectiveness of aircraft certification procedures. This method is then demonstrated through the simulation of in-flight icing scenarios based on real flight data from accidents and incidents. The risk management methodology is applied to the results of the simulations and the predicted performance degradation is compared to recorded aircraft performance characteristics at the time of the occurrence. The aircraft performance predictions and resulting risk assessment are found to correspond strongly to the pilot's comments as well as to the severity of the incident.

  14. Commercial Aircraft Emission Scenario for 2020: Database Development and Analysis

    NASA Technical Reports Server (NTRS)

    Sutkus, Donald J., Jr.; Baughcum, Steven L.; DuBois, Douglas P.; Wey, Chowen C. (Technical Monitor)

    2003-01-01

    This report describes the development of a three-dimensional database of aircraft fuel use and emissions (NO(x), CO, and hydrocarbons) for the commercial aircraft fleet projected to 2020. Global totals of emissions and fuel burn for 2020 are compared to global totals from previous aircraft emission scenario calculations.

  15. Dual-Mission Large Aircraft Feasibility Study and Aerodynamic Investigation

    NASA Technical Reports Server (NTRS)

    Mavris, Dimitri

    1997-01-01

    A Dual-Mission Large Aircraft, or DMLA, represents the possibility of a single aircraft capable of fulfilling both a Global Reach Aircraft (GRA) and Very Large Transport (VLT) roles. The DMLA, by combining the GRA and VLT into a single new aircraft, could possibly lower the aircraft manufacturer's production costs through the resulting increase in production quantity. This translates into lower aircraft acquisition costs, a primary concern for both the Air Force and commercial airlines. This report outlines the first steps taken in this study, namely the assessment of technical and economic feasibility of the DMLA concept. In the course of this project, specialized GRA and VLT aircraft were sized for their respective missions, using baseline conventional (i.e., lacking advanced enabling technologies) aircraft models from previous work for the Air Force's Wright Laboratory and NASA-Langley. DMLA baseline aircraft were then also developed, by first sizing the aircraft for the more critical of the two missions and then analyzing the aircraft's performance over the other mission. The resulting aircraft performance values were then compared to assess technical feasibility. Finally, the life-cycle costs of each aircraft (GRA, VLT, and DMLA) were analyzed to quantify economic feasibility. These steps were applied to both a two-engine aircraft set, and a four-engine aircraft set.

  16. IcePod: Imaging Ice-Ocean Process from Top to Bottom

    NASA Astrophysics Data System (ADS)

    Bell, R. E.; Frearson, N.; Zappa, C. J.; Tinto, K. J.; Das, I.; Dhakal, T.; Bertinato, C.; Dong, L.; Brown, S.; Le Bel, D. A.

    2014-12-01

    Resolving the future of the ice in the polar regions requires understanding of the changing ice from top to bottom from the center of the ice sheets to the margin where ice interacts with the polar oceans. The IcePod is an imaging system developed to study the ice sheets and polar oceans in a comprehensive fashion from an LC-130. The system has been developed for initial deployment on the New York National Guard's ski-equipped LC-130s. The IcePod can resolve high resolution surface elevation with a scanning laser and visual cameras, the temperature of the surface with an infrared camera, the thickness and layering of the shallow snow and ice with a high frequency radar and the thickness of the ice sheet with an ice penetrating radar. The IcePod can be moved between aircraft in less than four hours and can be operated on aircraft on routine cargo missions to skiways. Here we present IcePod ice-ocean imaging from the top to the bottom of several major outlet glaciers in western Greenland. The data, acquired in July 2014, demonstrates the broad capabilities of the IcePod instrumentation suite. The IcePod resolved the structure of the ice sheet from the accumulation zone to the calving front of Eqip Glacier and 4 adjacent outlet glacier systems. High resolution mapping of the calving front and the upwelling meltwater plumes provides new insights into the structure and dynamics of the turbulent mixing at the ice-ocean interface. Mapping of the ice sheet margin provides insights into the connections between the surface meltwater and the fate of the subglacial water at the ice sheet base. The Greenland data includes airport passes in every flight for calibration of both the lidar and camera systems. An expanded IcePod instrumentation suite will include a gravity meter and a magnetometer. The gravity meter can be used to determine the bathymetry beneath ice shelves. Together the gravimeter and the magnetometer can be used to constrain the regional tectonic frameworks. In

  17. Microwave remote sensing of sea ice

    NASA Technical Reports Server (NTRS)

    Comiso, J. C.

    1988-01-01

    The long term objectives are: (1) to understand the physics of the multispectral microwave radiative characteristics of sea ice as it goes through different phases; (2) to improve characterization of sea ice cover using satellite microwave sensors; and (3) to study ice/ocean physical and biological processes associated with polynya formations and variability of the marginal sea ice region. Two field experiments were conducted to pursue these objectives. One involved measurements of radiative and physical characteristics of sea ice from a ship during a 3-month long cruise through the Weddell Sea ice pack during the Austral winter of 1986. The other involved similar measurements from two aircrafts and a submarine over the Central Arctic and Greenland Sea region. Preliminary results have already led to an enhanced understanding of the microwave signatures of pancake ice, nilas, first year ice, multiyear ice and effects of snow cover. Coastal and deep ocean polynyas and their role in bottom water formation and ocean circulation were studied using a time series of ice images from SMMR. An unsupervised cluster analysis of Arctic sea ice using SMMR and THIR emissivity and brightness temperature data was implemented. The analysis indicates the existence of several unique and persistent clusters in the Central Arctic region during winter and that the sum of the area of these clusters excluding those of first year ice is about 20 percent less than minimum ice cover area inferred from a previous summer data. This result is consistent with saline surface for some multiyear ice floes as observed during MIZEZ and suggests that a significant fraction of multiyear ice floes in the Arctic have first year ice signatures.

  18. An Overview of NASA Engine Ice-Crystal Icing Research

    NASA Technical Reports Server (NTRS)

    Addy, Harold E., Jr.; Veres, Joseph P.

    2011-01-01

    Ice accretions that have formed inside gas turbine engines as a result of flight in clouds of high concentrations of ice crystals in the atmosphere have recently been identified as an aviation safety hazard. NASA s Aviation Safety Program (AvSP) has made plans to conduct research in this area to address the hazard. This paper gives an overview of NASA s engine ice-crystal icing research project plans. Included are the rationale, approach, and details of various aspects of NASA s research.

  19. Ice Shelf-Ocean Interactions Near Ice Rises and Ice Rumples

    NASA Astrophysics Data System (ADS)

    Lange, M. A.; Rückamp, M.; Kleiner, T.

    2013-12-01

    , focusing on the floating ice parts of the Brunt and Riiser-Larsen ice shelves. The major response of the ice is observed instantaneously and is caused by the time independent nature of the Stokes equations and the used Glen-type rheology. The influence of ice temperatures and therefore the time-dependent effect on the flow-rate are small, given a 100 year time frame and applying a fixed-geometry setting.. A particularly important result of the current project lies in the fact that we have numerically simulated the three-dimensional stress fields in an ice shelf. Common numerical models that utilize a vertically integrated Shallow Shelf Approximation (SSA-models), do not provide that information. Due to the detailed horizontal resolution of 1km in our models, we were able to also model the observed heavily fractured areas in the vicinity of McDonald Ice Rise, a region that is characterized by simulated tensile stresses reaching maximum vertical extension in the ice column.

  20. Aircraft Electric Secondary Power

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

  1. World commercial aircraft accidents

    SciTech Connect

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accident is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.

  2. The importance of sea-ice area biases in 21st century multi-model projections of Antarctic net precipitation and temperature and their relative change

    NASA Astrophysics Data System (ADS)

    Bracegirdle, T.

    2015-12-01

    Climate models exhibit large biases in sea ice area (SIA) in their historical simulations. This study has explored the impacts of these biases on multi-model uncertainty in CMIP5 ensemble projections of 21st century change in Antarctic surface temperature, net precipitation and SIA. The analysis is based on time slice climatologies in the RCP8.5 future scenario (2070-2099) and historical (1970-1999) simulations across 37 different CMIP5 models. Projected changes in net precipitation, temperature and SIA are found to be strongly associated with simulated historical mean SIA (e.g. cross-model correlations of r = 0.77, 0.70 and -0.86, respectively). Furthermore, historical SIA bias is found to have a large impact on the simulated ratio between net precipitation response and temperature response. This ratio is smaller in models with smaller-than-observed historical SIA. These findings are particularly relevant to quantifying and reducing model uncertainty in projections of Antarctic surface mass balance and associated contributions to sea level change.

  3. Aircraft soot indirect effect on large-scale cirrus clouds: Is the indirect forcing by aircraft soot positive or negative?

    NASA Astrophysics Data System (ADS)

    Zhou, Cheng; Penner, Joyce E.

    2014-10-01

    The indirect effect of aircraft soot on cirrus clouds is subject to large uncertainties due to uncertainty in the effectiveness of aircraft soot acting as heterogeneous ice nuclei (IN) and the complexity caused by background ice nucleation, which introduces two major competing ice nucleation mechanisms: homogeneous freezing that generally produces more abundant ice particles and heterogeneous nucleation that generally produces fewer ice particles. In this paper, we used the coupled Community Atmosphere Model version 5.2 (CAM5)/IMPACT model to estimate the climate impacts of aircraft soot acting as IN in large-scale cirrus clouds. We assume that only the aircraft soot particles that are preactivated in persistent contrail cirrus clouds are efficient IN. Further, we assume that these particles lose their ability to act as efficient IN when they become coated with three monolayers of sulfate. We varied the background number concentration of sulfate aerosols allowed to act as homogeneous ice nucleation sites as well as the dust concentrations that act as heterogeneous ice nuclei to examine the sensitivity of the forcing by aircraft soot to the background atmosphere. The global average effect can range from a high negative (cooling) rate, -0.35 W m-2, for the high sulfate/low dust case to a positive (warming) rate, +0.09 W m-2, for the low sulfate/low dust case (default CAM5 setup) when approximately 0.6% of total aviation soot acts as IN. The net negative forcing is caused by the addition of IN to a background atmosphere that is dominated by homogeneous nucleation (mainly in the tropic Indian Ocean, Central America, and North Atlantic Ocean). The forcings can be all positive, about +0.11 to +0.21 W m-2, when the background atmosphere is dominated by pure heterogeneous ice nucleation.

  4. Characteristics of future air cargo demand and impact on aircraft development: A report on the Cargo/Logistic Airlift Systems Study (CLASS) project

    NASA Technical Reports Server (NTRS)

    Whitehead, A. H., Jr.

    1978-01-01

    Current domestic and international air cargo operations are studied and the characteristics of 1990 air cargo demand are postulated from surveys conducted at airports and with shippers, consignees, and freight forwarders as well as air, land, and ocean carriers. Simulation and route optimization programs are exercised to evaluate advanced aircraft concepts. The results show that proposed changes in the infrastructure and improved cargo loading efficiencies are as important enhancing the prospects of air cargo growth as is the advent of advanced freighter aircraft. Potential reductions in aircraft direct operating costs are estimated and related to future total revenue. Service and cost elasticities are established and utilized to estimate future potential tariff reductions that may be realized through direct and indirect operating cost reductions and economies of scale.

  5. 14 CFR 25.1093 - 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. 25.1093... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Induction System § 25.1093 Induction system icing protection. (a) Reciprocating engines. Each reciprocating engine air induction...

  6. 14 CFR 139.313 - Snow and ice control.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Positioning snow off the movement area surfaces so all air carrier aircraft propellers, engine pods, rotors... portion of the movement area; (3) Selection and application of authorized materials for snow and ice... contain methods and procedures for snow and ice control equipment, materials, and removal that...

  7. 14 CFR 139.313 - Snow and ice control.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) Positioning snow off the movement area surfaces so all air carrier aircraft propellers, engine pods, rotors... portion of the movement area; (3) Selection and application of authorized materials for snow and ice... contain methods and procedures for snow and ice control equipment, materials, and removal that...

  8. 14 CFR 139.313 - Snow and ice control.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) Positioning snow off the movement area surfaces so all air carrier aircraft propellers, engine pods, rotors... portion of the movement area; (3) Selection and application of authorized materials for snow and ice... contain methods and procedures for snow and ice control equipment, materials, and removal that...

  9. 14 CFR 139.313 - Snow and ice control.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) Positioning snow off the movement area surfaces so all air carrier aircraft propellers, engine pods, rotors... portion of the movement area; (3) Selection and application of authorized materials for snow and ice... contain methods and procedures for snow and ice control equipment, materials, and removal that...

  10. 14 CFR 139.313 - Snow and ice control.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Positioning snow off the movement area surfaces so all air carrier aircraft propellers, engine pods, rotors... portion of the movement area; (3) Selection and application of authorized materials for snow and ice... contain methods and procedures for snow and ice control equipment, materials, and removal that...

  11. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... frost under the wing in the area of the fuel tanks if authorized by the FAA. (b) No certificate holder... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot...

  12. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... frost under the wing in the area of the fuel tanks if authorized by the FAA. (b) No certificate holder... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot...

  13. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... frost under the wing in the area of the fuel tanks if authorized by the FAA. (b) No certificate holder... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot...

  14. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... limitations. (a) No pilot may take off an aircraft that has frost, ice, or snow adhering to any rotor blade... frost under the wing in the area of the fuel tanks if authorized by the FAA. (b) No certificate holder... such that frost, ice, or snow may reasonably be expected to adhere to the airplane unless the pilot...

  15. Method to Generate Full-Span Ice Shape on Swept Wing Using Icing Tunnel Data

    NASA Technical Reports Server (NTRS)

    Lee, Sam; Camello, Stephanie

    2015-01-01

    There is a collaborative research program by NASA, FAA, ONERA, and university partners to improve the fidelity of experimental and computational simulation methods for swept-wing ice accretion formulations and resultant aerodynamic effects on large transport aircraft. This research utilizes a 65 scale Common Research Model as the baseline configuration. In order to generate the ice shapes for the aerodynamic testing, ice-accretion testing will be conducted in the NASA Icing Research Tunnel utilizing hybrid model from the 20, 64, and 83 spanwise locations. The models will have full-scale leading edges with truncated chord in order to fit the IRT test section. The ice shapes from the IRT tests will be digitized using a commercially available articulated-arm 3D laser scanning system. The methodology to acquire 3D ice shapes using a laser scanner was developed and validated in a previous research effort. Each of these models will yield a 1.5ft span of ice than can be used. However, a full-span ice accretion will require 75 ft span of ice. This means there will be large gaps between these spanwise ice sections that must be filled, while maintaining all of the important aerodynamic features. A method was developed to generate a full-span ice shape from the three 1.5 ft span ice shapes from the three models.

  16. Sea Ice

    NASA Technical Reports Server (NTRS)

    Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.

    2013-01-01

    During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.

  17. Aircraft de-icer: Recycling can cut carbon emissions in half

    SciTech Connect

    Johnson, Eric P.

    2012-01-15

    Flight-safety regulations in most countries require aircraft to be ice-free upon takeoff. In icy weather, this means that the aircraft usually must be de-iced (existing ice is removed) and sometimes anti-iced (to protect against ice-reformation). For both processes, aircraft typically are sprayed with an 'antifreeze' solution, consisting mainly of glycol diluted with water. This de/anti-icing creates an impact on the environment, of which environmental regulators have grown increasingly conscious. The US Environmental Protection Agency (EPA), for example, recently introduced stricter rules that require airports above minimum size to collect de-icing effluents and send them to wastewater treatment. De-icer collection and treatment is already done at most major airports, but a few have gone one step further: rather than putting the effluent to wastewater, they recycle it. This study examines the carbon savings that can be achieved by recycling de-icer. There are two key findings. One, recycling, as opposed to not recycling, cuts the footprint of aircraft de-icing by 40-50% - and even more, in regions where electricity-generation is cleaner. Two, recycling petrochemical-based de-icer generates a 15-30% lower footprint than using 'bio' de-icer without recycling. - Highlights: Black-Right-Pointing-Pointer Carbon footprint of aircraft de-icing can be measured. Black-Right-Pointing-Pointer Recycling aircraft de-icer cuts the footprint of aircraft de-icing by 40-50%. Black-Right-Pointing-Pointer Recycling 'fossil' de-icer is lower carbon than not recycling 'bio' de-icer.

  18. Smart aircraft routing - a possibility for mitigation?

    NASA Astrophysics Data System (ADS)

    Mannstein, H.; Gierens, K.; Graf, K.; Waibel, A.; Meilinger, S.; Seifert, A.; Köhler, C.

    2009-12-01

    Air traffic affects the energy balance of the earth in various ways. Emission of CO2 with atmospheric residence times measured in decades contributes to the greenhouse effect as well as emission of nitrous oxides, with their impact on ozone and methane chemistry. Soot has a direct effect on the net radiation and, much more important, is involved in the production of contrails and the triggering of contrail cirrus, which can be visible for several hours. These artificial clouds are initiated when flying in sufficiently cold and moist air. In total, their net radiative forcing is of the same order of magnitude as the forcing by the emitted CO2. The impact of contrail cirrus on net radiation results from the conversion of ambient moisture in ice super-saturated regions into ice crystals and depends strongly on the conditions of the ambient radiation field. It ranges from a warming at night or over bright low clouds to cooling during daytime over dark surfaces like the ocean. For the time being these effects are not at all taken into consideration in aircraft routing: the production of contrails and contrail cirrus happens by chance. The dependency of the radiative forcing by contrail cirrus clouds on the weather conditions opens the possibility for mitigation: Avoiding warming (and perhaps also producing cooling) contrails and contrail cirrus by changes of the flight routes has the potential to reduce the man-made imbalance in radiative forcing. As contrails are produced only in 10%- 20% of the flown distances and only the warming contrails should be avoided, the impact on the traffic system is likely to be limited. The basic idea of the project ’Environmentally compatible flight route optimisation’, funded by the German Ministry for Research and Education is, to predict the time integrated radiative forcing of a potential contrail cirrus based on the information given by a weather forecast model. This information is used in relation to total forcing of the

  19. Dynamic Wind-Tunnel Testing of a Sub-Scale Iced Business Jet

    NASA Technical Reports Server (NTRS)

    Lee, Sam; Barnhart, Billy P.; Ratvasky, Thomas P.; Dickes, Edward; Thacker, Michael

    2006-01-01

    The effect of ice accretion on a 1/12-scale complete aircraft model of a business jet was studied in a rotary-balance wind tunnel. Three types of ice accretions were considered: ice protection system failure shape, pre-activation roughness, and runback shapes that form downstream of the thermal ice protection system. The results were compared with those from a 1/12-scale semi-span wing of the same aircraft at similar Reynolds number. The data showed that the full aircraft and the semi-span wing models showed similar characteristics, especially post stall behavior under iced configuration. However, there were also some discrepancies, such as the magnitude in the reductions in the maximum lift coefficient. Most of the ice-induced effects were limited to longitudinal forces. Rotational and forced oscillation studies showed that the effects of ice on lateral forces were relatively minor.

  20. Development and test of a Microwave Ice Accretion Measurement Instrument (MIAMI)

    NASA Technical Reports Server (NTRS)

    Magenheim, B.; Rocks, J. K.

    1982-01-01

    The development of an ice accretion measurement instrument that is a highly sensitive, accurate, rugged and reliable microprocessor controlled device using low level microwave energy for non-instrusive real time measurement and recording of ice growth history, including ice thickness and accretion rate is discussed. Data is displayed and recorded digitally. New experimental data is presented, obtained with the instrument, which demonstrates its ability to measure ice growth on a two-dimensional airfoil. The device is suitable for aircraft icing protection. It may be mounted flush, non-intrusively, on any part of an aircraft skin including rotor blades and engine inlets.

  1. Under-ice noise generated from diamond exploration in a Canadian sub-arctic lake and potential impacts on fishes.

    PubMed

    Mann, D; Cott, P; Horne, B

    2009-11-01

    Mineral exploration is increasing in Canada, particularly in the north where extensive diamond mining and exploration are occurring. This study measured the under-ice noise produced by a variety of anthropogenic sources (drilling rigs, helicopters, aircraft landing and takeoff, ice-road traffic, augers, snowmobiles, and chisels) at a winter-based diamond exploration project on Kennady Lake in the Northwest Territories, Canada to infer the potential impact of noise on fishes in the lake. The root-mean-square noise level measured 5 m from a small diameter drill was approximately 46 dB greater (22 kHz bandwidth) than ambient noise, while the acoustic particle velocity was approximately 40 dB higher than ambient levels. The loudest sounds at the exploration site were produced by ice cracking, both natural and during landing and takeoff of a C130 Hercules aircraft. However, even walking on the snow above the ice raised ambient sound levels by approximately 30 dB. Most of the anthropogenic sounds are likely detectable by fishes with hearing specializations, such as chubs and suckers. Other species without specialized hearing adaptations will detect these sounds only close to the source. The greatest potential impact of noise from diamond exploration is likely to be the masking of sounds for fishes with sensitive hearing.

  2. BABOC: A new project aimed at analysing geological boundary conditions for the East Antarctic Ice Sheet in the Wilkes Subglacial Basin

    NASA Astrophysics Data System (ADS)

    Armadillo, Egidio; Ferraccioli, Fausto; Balbi, Pietro; Jordan, Tom; Young, Duncan; Blankenship, Don; Bozzo, Emanuele; Siegert, Martin

    2013-04-01

    The Wilkes Subglacial Basin extends for ca 1,400 km from George V Land into the interior of East Antarctica and hosts several major glaciers that drain a large sector of the East Antarctic Ice Sheet (EAIS). The region is of major significance for assessing the long-term stability of the EAIS, as it lies well below sea level and its bedrock deepens inland. This makes it potentially prone to marine ice sheet instability, much like areas of the West Antarctic Ice Sheet (WAIS) that are presently experiencing significant mass loss. This sector of the EAIS has also recently become a major focus of research within IODP Leg 318 that aims to better comprehend the initial stages of glaciation in East Antarctica and the subsequent history and stability of the ice sheet in response to major paleoclimatic changes (Escutia et al., 2010 IODP Rep.). Understanding geological boundary conditions in this region is therefore important to assess their influence on ice sheet dynamics and stability. Early geophysical models inferred the existence of a major extensional sedimentary basin beneath the region, which if true, could be similar to some areas of the WAIS, There thick subglacial sediments deposited within deep rift basins or forming thin marine sedimentary drapes have been inferred to exert a key influence on the onset and maintenance of fast-glacial flow. However, later geophysical models indicated that the Wilkes Basin contains little or no sediment, is not rift-related and formed in response to Cenozoic flexural uplift of the Transantarctic Mountains (TAM). A major joint Italian-UK aerogeophysical exploration campaign over parts of the Wilkes Basin is super-seeding these earlier geophysical views of the basin: i) Precambrian and Paleozoic basement faults can now be recognised as exerting fundamental controls on the location of the topographic margins of the basin; ii) the crust underlying the basin is thinner compared to the TAM, but is unlikely to be Cretaceous or Cenozoic

  3. An experimental evaluation of the tensile strength of impact ice

    NASA Technical Reports Server (NTRS)

    Xian, X.; Chu, M. L.; Scavuzzo, R. J.; Srivatsan, T. S.

    1989-01-01

    The evaluation of the tensile strength of impact built-up ice on structural components has been prompted by such problems as electrical transmission line losses and catastrophic failures in Arctic regions, deicing problems with fixed-wing and rotary-wing aircraft, etc. It is demonstrated that the conventional tensile-testing technique furnishes adequate data on artificially refrigerated ice, and helps establish the influence of extrinsic factors on ice tensile strength.

  4. NASA Airframe Icing Research Overview Past and Current

    NASA Technical Reports Server (NTRS)

    Potapczuk, Mark

    2009-01-01

    This slide presentation reviews the past and current research that NASA has done in the area of airframe icing. Both the history experimental efforts and model development to understand the process and problem of ice formation are reviewed. This has resulted in the development of new experimental methods, advanced icing simulation software, flight dynamics and experimental databases that have an impact on design, testing, construction and certification and qualification of the aircraft and its sub-systems.

  5. Ice Particle Impacts on a Flat Plate

    NASA Technical Reports Server (NTRS)

    Vargas, Mario; Ruggeri, Charles; Struk, Peter M.; Pereira, Mike; Revilock, Duane; Kreeger, Richard E.

    2015-01-01

    An experimental study was conducted at the Ballistic Laboratory of NASA Glenn Research Center to study the impact of ice particles on a stationary flat surface target set at 45 degrees with respect to the direction of motion of the impinging particle (Figure 1). The experiment is part of NASA efforts to study the physics involved in engine power-loss events due to ice-crystal ingestion and ice accretion formation inside engines. These events can occur when aircraft encounter high-altitude convective weather.

  6. Aircraft-Induced Hole Punch and Canal Clouds

    NASA Astrophysics Data System (ADS)

    Heymsfield, A. J.; Kennedy, P.; Massie, S. T.; Schmitt, C. G.; Wang, Z.; Haimov, S.; Rangno, A.

    2009-12-01

    The production of holes and channels in altocumulus clouds by two commercial turboprop aircraft is documented for the first time. An unprecedented data set combining in situ measurements from microphysical probes with remote sensing measurements from cloud radar and lidar, all operating from the NSF/NCAR C130 aircraft, as well as ground-based NOAA and CSU radars, is used to describe the radar/lidar properties of a hole punch cloud and channel and the ensuing ice microphysical properties and structure of the ice column that subsequently developed. Ice particle production by commercial turboprop aircraft climbing through clouds much warmer than the regions where contrails are produced has the potential to modify significantly the cloud microphysical properties and effectively seed them under some conditions. Jet aircraft may also be producing hole punch clouds when flying through altocumulus with supercooled droplets at heights lower than their normal cruise altitudes where contrails can form. Commercial aircraft therefore can generate ice and affect the clouds at temperatures as much as 30°C warmer than the -40°C contrail formation threshold temperature.

  7. The 1996 Subsonic Aircraft: Contrail and Cloud Effects Special Study

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Condon, Estelle P. (Technical Monitor)

    1996-01-01

    During April 1996 NASA, in conjunction with the DOE, will sponsor a multi-aircraft field campaign to better understand the microphysical and radiative properties of cirrus clouds, the origins of ice nuclei and cloud condensation nuclei in the upper troposphere, and the possible role that the commercial subsonic aircraft fleet might play in altering cloud or aerosol properties. The NASA ER-2 aircraft will be used as a remote sensing platform, while the NASA DC-8 aircraft will be used as an in situ measurement platform. In situ observations will include a full set of size distribution measurements from nano-meter to millimeter sizes, ice water content measurements, gas phase and condensed phase chemical measurements, ice crystal optical phase function measurements, lidar observations of cloud top and cloud base, and atmospheric state measurement. The ER-2 will have lidar, microwave ice water path measurements, as well as visible and infrared spectral measurement. In this presentation the highlights of the mission will be presented. The goal will be to address fundamental questions such as the mode of nucleation of cirrus clouds, the composition of the nuclei on which cirrus form, the degree to which aircraft impact cirrus cloud properties.

  8. Comparing Aircraft Observations of Snowfall to Forecasts Using Single or Two Moment Bulk Water Microphysics Schemes

    NASA Technical Reports Server (NTRS)

    Molthan, Andrew L.

    2010-01-01

    High resolution weather forecast models with explicit prediction of hydrometeor type, size distribution, and fall speed may be useful in the development of precipitation retrievals, by providing representative characteristics of frozen hydrometeors. Several single or double-moment microphysics schemes are currently available within the Weather Research and Forecasting (WRF) model, allowing for the prediction of up to three ice species. Each scheme incorporates different assumptions regarding the characteristics of their ice classes, particularly in terms of size distribution, density, and fall speed. In addition to the prediction of hydrometeor content, these schemes must accurately represent the vertical profile of water vapor to account for possible attenuation, along with the size distribution, density, and shape characteristics of ice crystals that are relevant to microwave scattering. An evaluation of a particular scheme requires the availability of field campaign measurements. The Canadian CloudSat/CALIPSO Validation Project (C3VP) obtained measurements of ice crystal shapes, size distributions, fall speeds, and precipitation during several intensive observation periods. In this study, C3VP observations obtained during the 22 January 2007 synoptic-scale snowfall event are compared against WRF model output, based upon forecasts using four single-moment and two double-moment schemes available as of version 3.1. Schemes are compared against aircraft observations by examining differences in size distribution, density, and content. In addition to direct measurements from aircraft probes, simulated precipitation can also be converted to equivalent, remotely sensed characteristics through the use of the NASA Goddard Satellite Data Simulator Unit. Outputs from high resolution forecasts are compared against radar and satellite observations emphasizing differences in assumed crystal shape and size distribution characteristics.

  9. Aircraft Lightning Electromagnetic Environment Measurement

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.

    2011-01-01

    This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.

  10. Electro-impulse de-icing testing analysis and design

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    Electro-Impulse De-Icing (EIDI) is a method of ice removal by sharp blows delivered by a transient electromagnetic field. Detailed results are given for studies of the electrodynamic phenomena. Structural dynamic tests and computations are described. Also reported are ten sets of tests at NASA's Icing Research Tunnel and flight tests by NASA and Cessna Aircraft Company. Fabrication of system components are described and illustrated. Fatigue and electromagnetic interference tests are reported. Here, the necessary information for the design of an EIDI system for aircraft is provided.

  11. Aerodynamic Performance Degradation Induced by Ice Accretion. PIV Technique Assessment in Icing Wind Tunnel

    NASA Astrophysics Data System (ADS)

    Gregorio, Fabrizio De

    The aim of the present chapter is to consider the use of PIV technique in an industrial icing wind tunnel (IWT) and the potentiality/advantages of applying the PIV technique to this specific field. The purpose of icing wind tunnels is to simulate the aircraft flight condition through cloud formations. In this operational condition ice accretions appear on the aircraft exposed surfaces due to the impact of the water droplets present in the clouds and the subsequent solidification. The investigation of aircraft aerodynamic performances and flight safety in icing condition is a fundamental aspect in the phase of design, development and certification of new aircrafts. The description of this unusual ground testing facility is reported. The assessment of PIV in CIRA-IWT has been investigated. Several technological problems have been afforded and solved by developing the components of the measurement system, such as the laser system and the recording apparatus, both fully remotely controlled, equipped with several traversing mechanism and protected by the adverse environment conditions (temperature and pressure). The adopted solutions are described. Furthermore, a complete test campaign on a full-scale aircraft wing tip, equipped with moving slat and deicing system has been carried out by PIV. Two regions have been investigated. The wing leading-edge (LE) area has been studied with and without ice accretion and for different cloud characteristics. The second activitiy was aimed at the investigation of the wing-wake behavior. The measurements were aimed to characterize the wake for the model in cruise condition without ice formation and during the ice formation.

  12. NASA/FAA Tailplane Icing Program: Flight Test Report

    NASA Technical Reports Server (NTRS)

    Ratvasky, Thomas P.; VanZante, Judith Foss; Sim, Alex

    2000-01-01

    This report presents results from research flights that explored the characteristics of an ice-contaminated tailplane using various simulated ice shapes attached to the leading edge of the horizontal tailplane. A clean leading edge provided the baseline case, then three ice shapes were flown in order of increasing severity. Flight tests included both steady state and dynamic maneuvers. The steady state points were 1G wings level and steady heading sideslips. The primary dynamic maneuvers were pushovers to various G-levels; elevator doublets; and thrust transitions. These maneuvers were conducted for a full range of flap positions and aircraft angle of attack where possible. The analysis of this data set has clearly demonstrated the detrimental effects of ice contamination on aircraft stability and controllability. Paths to tailplane stall were revealed through parameter isolation and transition studies. These paths are (1) increasing ice shape severity, (2) increasing flap deflection, (3) high or low speeds, depending on whether the aircraft is in a steady state (high speed) or pushover maneuver (low speed), and (4) increasing thrust. The flight research effort was very comprehensive, but did not examine effects of tailplane design and location, or other aircraft geometry configuration effects. However, this effort provided the role of some of the parameters in promoting tailplane stall. The lessons learned will provide guidance to regulatory agencies, aircraft manufacturers, and operators on ice-contaminated tailplane stall in the effort to increase aviation safety and reduce the fatal accident rate.

  13. Propulsion controlled aircraft computer

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  14. Pregnant women's cognitive appraisal of a natural disaster affects DNA methylation in their children 13 years later: Project Ice Storm.

    PubMed

    Cao-Lei, L; Elgbeili, G; Massart, R; Laplante, D P; Szyf, M; King, S

    2015-01-01

    Prenatal maternal stress (PNMS) can impact a variety of outcomes in the offspring throughout childhood and persisting into adulthood as shown in human and animal studies. Many of the effects of PNMS on offspring outcomes likely reflect the effects of epigenetic changes, such as DNA methylation, to the fetal genome. However, no animal or human research can determine the extent to which the effects of PNMS on DNA methylation in human offspring is the result of the objective severity of the stressor to the pregnant mother, or her negative appraisal of the stressor or her resulting degree of negative stress. We examined the genome-wide DNA methylation profile in T cells from 34 adolescents whose mothers had rated the 1998 Québec ice storm's consequences as positive or negative (that is, cognitive appraisal). The methylation levels of 2872 CGs differed significantly between adolescents in the positive and negative maternal cognitive appraisal groups. These CGs are affiliated with 1564 different genes and with 408 different biological pathways, which are prominently featured in immune function. Importantly, there was a significant overlap in the differentially methylated CGs or genes and biological pathways that are associated with cognitive appraisal and those associated with objective PNMS as we reported previously. Our study suggests that pregnant women's cognitive appraisals of an independent stressor may have widespread effects on DNA methylation across the entire genome of their unborn children, detectable during adolescence. Therefore, cognitive appraisals could be an important predictor variable to explore in PNMS research. PMID:25710121

  15. Pregnant women's cognitive appraisal of a natural disaster affects DNA methylation in their children 13 years later: Project Ice Storm

    PubMed Central

    Cao-Lei, L; Elgbeili, G; Massart, R; Laplante, D P; Szyf, M; King, S

    2015-01-01

    Prenatal maternal stress (PNMS) can impact a variety of outcomes in the offspring throughout childhood and persisting into adulthood as shown in human and animal studies. Many of the effects of PNMS on offspring outcomes likely reflect the effects of epigenetic changes, such as DNA methylation, to the fetal genome. However, no animal or human research can determine the extent to which the effects of PNMS on DNA methylation in human offspring is the result of the objective severity of the stressor to the pregnant mother, or her negative appraisal of the stressor or her resulting degree of negative stress. We examined the genome-wide DNA methylation profile in T cells from 34 adolescents whose mothers had rated the 1998 Québec ice storm's consequences as positive or negative (that is, cognitive appraisal). The methylation levels of 2872 CGs differed significantly between adolescents in the positive and negative maternal cognitive appraisal groups. These CGs are affiliated with 1564 different genes and with 408 different biological pathways, which are prominently featured in immune function. Importantly, there was a significant overlap in the differentially methylated CGs or genes and biological pathways that are associated with cognitive appraisal and those associated with objective PNMS as we reported previously. Our study suggests that pregnant women's cognitive appraisals of an independent stressor may have widespread effects on DNA methylation across the entire genome of their unborn children, detectable during adolescence. Therefore, cognitive appraisals could be an important predictor variable to explore in PNMS research. PMID:25710121

  16. Hypersonic transport aircraft

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A hypersonic transport aircraft design project was selected as a result of interactions with NASA Lewis Research Center personnel and fits the Presidential concept of the Orient Express. The Graduate Teaching Assistant (GTA) and an undergraduate student worked at the NASA Lewis Research Center during the 1986 summer conducting a literature survey, and relevant literature and useful software were collected. The computer software was implemented in the Computer Aided Design Laboratory of the Mechanical and Aerospace Engineering Department. In addition to the lectures by the three instructors, a series of guest lectures was conducted. The first of these lectures 'Anywhere in the World in Two Hours' was delivered by R. Luidens of NASA Lewis Center. In addition, videotaped copies of relevant seminars obtained from NASA Lewis were also featured. The first assignment was to individually research and develop the mission requirements and to discuss the findings with the class. The class in consultation with the instructors then developed a set of unified mission requirements. Then the class was divided into three design groups (1) Aerodynamics Group, (2) Propulsion Group, and (3) Structures and Thermal Analyses Group. The groups worked on their respective design areas and interacted with each other to finally come up with an integrated conceptual design. The three faculty members and the GTA acted as the resource persons for the three groups and aided in the integration of the individual group designs into the final design of a hypersonic aircraft.

  17. Dumbo heavy lifter aircraft

    NASA Technical Reports Server (NTRS)

    Riester, Peter; Ellis, Colleen; Wagner, Michael; Orren, Scott; Smith, Byron; Skelly, Michael; Zgraggen, Craig; Webber, Matt

    1992-01-01

    The world is rapidly changing from one with two military superpowers, with which most countries were aligned, to one with many smaller military powers. In this environment, the United States cannot depend on the availability of operating bases from which to respond to crises requiring military intervention. Several studies (e.g. the SAB Global Reach, Global Power Study) have indicated an increased need to be able to rapidly transport large numbers of troops and equipment from the continental United States to potential trouble spots throughout the world. To this end, a request for proposals (RFP) for the concept design of a large aircraft capable of 'projecting' a significant military force without reliance on surface transportation was developed. These design requirements are: minimum payload of 400,000 pounds at 2.5 g maneuver load factor; minimum unfueled range of 6,000 nautical miles; and aircraft must operate from existing domestic air bases and use existing airbases or sites of opportunity at the destination.

  18. Ice Accretions on a Swept GLC-305 Airfoil

    NASA Technical Reports Server (NTRS)

    Vargas, Mario; Papadakis, Michael; Potapczuk, Mark; Addy, Harold; Sheldon, David; Giriunas, Julius

    2002-01-01

    An experiment was conducted in the Icing Research Tunnel (IRT) at NASA Glenn Research Center to obtain castings of ice accretions formed on a 28 deg. swept GLC-305 airfoil that is representative of a modern business aircraft wing. Because of the complexity of the casting process, the airfoil was designed with three removable leading edges covering the whole span. Ice accretions were obtained at six icing conditions. After the ice was accreted, the leading edges were detached from the airfoil and moved to a cold room. Molds of the ice accretions were obtained, and from them, urethane castings were fabricated. This experiment is the icing test of a two-part experiment to study the aerodynamic effects of ice accretions.

  19. Ice adhesion on lubricant-impregnated textured surfaces.

    PubMed

    Subramanyam, Srinivas Bengaluru; Rykaczewski, Konrad; Varanasi, Kripa K

    2013-11-01

    Ice accretion is an important problem and passive approaches for reducing ice-adhesion are of great interest in various systems such as aircrafts, power lines, wind turbines, and oil platforms. Here, we study the ice-adhesion properties of lubricant-impregnated textured surfaces. Force measurements show ice adhesion strength on textured surfaces impregnated with thermodynamically stable lubricant films to be higher than that on surfaces with excess lubricant. Systematic ice-adhesion measurements indicate that the ice-adhesion strength is dependent on texture and decreases with increasing texture density. Direct cryogenic SEM imaging of the fractured ice surface and the interface between ice and lubricant-impregnated textured surface reveal stress concentrators and crack initiation sites that can increase with texture density and result in lowering adhesion strength. Thus, lubricant-impregnated surfaces have to be optimized to outperform state-of-the-art icephobic treatments.

  20. Neutrons for probing the ice nucleation on atmospheric soot particles

    NASA Astrophysics Data System (ADS)

    Demirdjian, B.; Tishkova, V.; Ferry, D.

    2012-11-01

    Soot resulting from combustion of kerosene in aircraft engines can act as condensation nuclei for water/ice in the atmosphere and promote the formation of contrails that turn into artificial cirrus clouds and affect the climate. The mechanisms of nucleation of water/ice particles are not well identified. Studies "in situ" are difficult to realize, so we try to determine by neutron diffraction the nucleation of water/ice adsorbed on soot collected at the outlet of an aircraft engine combustor within the conditions of the upper troposphere. The results are compared with those obtained on model laboratory soot. The comparison highlights the role of chemical impurities and structural defects of original aircraft engine soot on the nucleation of water/ice in atmospheric conditions.

  1. An experimental and numerical study on the effect of some properties of non-metallic materials on the ice adhesion level

    NASA Astrophysics Data System (ADS)

    Piles Moncholi, Eduardo

    The rise of environmentalism in every sector of industry has led aircraft and engine manufacturing companies to develop new generations of more environmentally friendly engines. Companies are in a constant search for new manufacturing and production techniques in order to improve their products, from the environmental point of view, by gaining efficiency in manufacturing techniques and reduce the fuel consumption and emissions in-flight. Having this scenario in mind, the sponsor of this project is interested in understanding how changing the blade materials, currently titanium alloys, for other lighter materials, such as composites, is going to have an effect on overall gas turbine efficiency. In this Project the influence of the stiffness and coating thickness of those non-metallic materials suitable to be employed as coatings on gas turbine fan blades, from the icing point of view, are studied. The methodology is based on a study of linear elastic fracture mechanics of bi-material junctions and will extrapolate the general problem to the ice-coatings case, by obtaining experimental data from tests carried out in an icing tunnel. It was observed that the coating stiffness has an influence on the adhesion level of ice to less stiff materials, if compared with the adhesion level of ice to metals. We also describe how a 0.5 millimetre thin polymeric coating placed over a metallic substrate is enough to reduce the adhesion level of ice, hiding any effect that the underneath materials might have on the adhesion level..

  2. A review of advanced turboprop transport aircraft

    NASA Astrophysics Data System (ADS)

    Lange, Roy H.

    The application of advanced technologies shows the potential for significant improvement in the fuel efficiency and operating costs of future transport aircraft envisioned for operation in the 1990s time period. One of the more promising advanced technologies is embodied in an advanced turboprop concept originated by Hamilton Standard and NASA and known as the propfan. The propfan concept features a highly loaded multibladed, variable pitch propeller geared to a high pressure ratio gas turbine engine. The blades have high sweepback and advanced airfoil sections to achieve 80 percent propulsive efficiency at M=0.80 cruise speed. Aircraft system studies have shown improvements in fuel efficiency of 15-20 percent for propfan advanced transport aircraft as compared to equivalent turbofan transports. Beginning with the Lockheed C-130 and Electra turboprop aircraft, this paper presents an overview of the evolution of propfan aircraft design concepts and system studies. These system studies include possible civil and military transport applications and data on the performance, community and far-field noise characteristics and operating costs of propfan aircraft design concepts. NASA Aircraft Energy Efficiency (ACEE) program propfan projects with industry are reviewed with respect to system studies of propfan aircraft and recommended flight development programs.

  3. Aircraft towing feasibility study. Final report

    SciTech Connect

    Not Available

    1980-09-01

    Energy costs and availability are major concerns in most parts of the world. Many ways of increasing energy supply and reducing consumption are being proposed and investigated. One that holds considerable promise is the extended towing of aircraft between airport runways and terminal gate areas with engines shut down. This study provides a preliminary assessment of the constraints on and feasibility of extended aircraft towing. Past aircraft towing experience and the state-of-the-art in towing equipment are reviewed. Safety and operational concerns associated with aircraft towing are identified, and the benefits and costs of implementing aircraft towing at 20 major US airports are analyzed. It was concluded that extended aircraft towing is technically feasible and that substantial reductions in aircraft fuel consumption and air pollutant emissions can be achieved through its implementation. It was also concluded that, although capital and operating costs associated with towing would be increased, net savings could generally be attained at these airports. Because of the lack of past experience and the necessity of proving the cost effectiveness of the towing concept, a demonstration of the feasibility of large-scale aircraft towing is necessary. The study evaluates the suitability of the 20 study airports as potential demonstration sites and makes recommendations for the first demonstration project.

  4. Engineering Encounters: Designing Healthy Ice Pops. A STEM Enrichment Project for Second Graders Incorporates Nutrition and Design Principles

    ERIC Educational Resources Information Center

    Bubnick, Laura; Enneking, Katie; Egbers, Julie

    2016-01-01

    Science, technology, engineering, and math (STEM) education piques students' innate curiosity and opens their eyes to hundreds of career possibilities. This column presents ideas and techniques to enhance your science teaching. This month's issue shares information about a STEM enrichment project for second graders that incorporates nutrition and…

  5. Assessment of the AMSR-E Sea Ice Concentration Product at the Ice Edge Using RADARSAT-1 and MODIS Imagery

    NASA Technical Reports Server (NTRS)

    Henrichs, John F.; Cavalieri, Donald J.; Markus, Thorsten

    2006-01-01

    Imagery from the C-band synthetic aperture radar (SAR) aboard RADARSAT-1 and the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to evaluate the performance of the Advanced Microwave Scanning Radiometer- EOS (AMSR-E) ice concentration product near the sea ice edge in the Bering Sea for four days during March 2003, which is concurrent with the AMSR-Ice03 field/aircraft campaign. The AMSR-E products were observed to perform very well in identifying open-water and pack-ice areas, although the AMSR-E products occasionally underestimate ice concentration in areas with thin ice. The position of the ice edge determined from AMSR-E data using a 15% concentration threshold was found to be, on average, within one AMSR-E grid square (12.5 km) of the ice edge determined from the SAR data, with the AMSR-E edge tending to be outside the SAR-derived edge

  6. Steering Aircraft Clear of Choppy Air

    NASA Technical Reports Server (NTRS)

    2006-01-01

    AeroTech Research (U.S.A.), Inc., a leader in turbulence-detection and warning systems, has been involved with NASA Aviation Safety research since 1998. AeroTech served as a contractor for the TPAWS government/industry development project, and was funded by NASA to develop the E-Turb Mode Radar algorithms and the TAPS software. (Other contributors to this project include the National Center for Atmospheric Research, the FAA, North Carolina State University, and the Research Triangle Institute.) The radar algorithms combine an aircraft's turbulenceresponse characteristics with radar measurements to determine the predicted turbulence loads the aircraft will experience, and present this information to the pilot. The TAPS software monitors and processes onboard aircraft sensor data; generates automatic reports when an aircraft encounters turbulence and a set turbulence threshold is exceeded; and then displays the reports and underlying information to ground personnel to improve situational awareness of the location and the severity of the turbulence encounter.

  7. Heat Flow and Hydrologic Characteristics at the AND-1B borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica

    USGS Publications Warehouse

    Morin, Roger H.; Williams, Trevor; Henry, Stuart; ,; Hansaraj, Dhiresh

    2010-01-01

    The Antarctic Drilling Program (ANDRILL) successfully drilled and cored a borehole, AND-1B, beneath the McMurdo Ice Shelf and into a flexural moat basin that surrounds Ross Island. Total drilling depth reached 1285 m below seafloor (mbsf) with 98 percent core recovery for the detailed study of glacier dynamics. With the goal of obtaining complementary information regarding heat flow and permeability, which is vital to understanding the nature of marine hydrogeologic systems, a succession of three temperature logs was recorded over a five-day span to monitor the gradual thermal recovery toward equilibrium conditions. These data were extrapolated to true, undisturbed temperatures, and they define a linear geothermal gradient of 76.7 K/km from the seafloor to 647 mbsf. Bulk thermal conductivities of the sedimentary rocks were derived from empirical mixing models and density measurements performed on core, and an average value of 1.5 W/mK ± 10 percent was determined. The corresponding estimate of heat flow at this site is 115 mW/m2. This value is relatively high but is consistent with other elevated heat-flow data associated with the Erebus Volcanic Province. Information regarding the origin and frequency of pathways for subsurface fluid flow is gleaned from drillers' records, complementary geophysical logs, and core descriptions. Only two prominent permeable zones are identified and these correspond to two markedly different features within the rift basin; one is a distinct lithostratigraphic subunit consisting of a thin lava flow and the other is a heavily fractured interval within a single thick subunit.

  8. 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.

  9. Aircraft Energy Efficiency (ACEE) status report

    NASA Technical Reports Server (NTRS)

    Nored, D. L.; Dugan, J. F., Jr.; Saunders, N. T.; Ziemianski, J. A.

    1979-01-01

    Fuel efficiency in aeronautics, for fuel conservation in general as well as for its effect on commercial aircraft operating economics is considered. Projects of the Aircraft Energy Efficiency Program related to propulsion are emphasized. These include: (1) engine component improvement, directed at performance improvement and engine diagnostics for prolonged service life; (2) energy efficient engine, directed at proving the technology base for the next generation of turbofan engines; and (3) advanced turboprop, directed at advancing the technology of turboprop powered aircraft to a point suitable for commercial airline service. Progress in these technology areas is reported.

  10. Effective Training for Flight in Icing Conditions

    NASA Technical Reports Server (NTRS)

    Barnhart, Billy P.; Ratvasky, Thomas P.

    2007-01-01

    The development of a piloted flight simulator called the Ice Contamination Effects Flight Training Device (ICEFTD) was recently completed. This device demonstrates the ability to accurately represent an iced airplane s flight characteristics and is utilized to train pilots in recognizing and recovering from aircraft handling anomalies that result from airframe ice formations. The ICEFTD was demonstrated at three recent short courses hosted by the University of Tennessee Space Institute. It was also demonstrated to a group of pilots at the National Test Pilot School. In total, eighty-four pilots and flight test engineers from industry and the regulatory community spent approximately one hour each in the ICEFTD to get a "hands on" lesson of an iced airplane s reduced performance and handling qualities. Additionally, pilot cues of impending upsets and recovery techniques were demonstrated. The purpose of this training was to help pilots understand how ice contamination affects aircraft handling so they may apply that knowledge to the operations of other aircraft undergoing testing and development. Participant feedback on the ICEFTD was very positive. Pilots stated that the simulation was very valuable, applicable to their occupations, and provided a safe way to explore the flight envelope. Feedback collected at each demonstration was also helpful to define additional improvements to the ICEFTD; many of which were then implemented in subsequent demonstrations.

  11. 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.

  12. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 59: Japanese Technological Innovation. Implications for Large Commercial Aircraft and Knowledge Diffusion

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Kotler, Mindy L.

    1997-01-01

    This paper explores three factors-public policy, the Japanese (national) innovation system, and knowledge-that influence technological innovation in Japan. To establish a context for the paper, we examine Japanese culture and the U.S. and Japanese patent systems in the background section. A brief history of the Japanese aircraft industry as a source of knowledge and technology for other industries is presented. Japanese and U.S. alliances and linkages in three sectors-biotechnology, semiconductors, and large commercial aircraft (LCA)-and the importation, absorption, and diffusion of knowledge and technology are examined next. The paper closes with implications for diffusing knowledge and technology, U.S. public policy, and LCA.

  13. Smart aircraft routing - a possibility for mitigation?

    NASA Astrophysics Data System (ADS)

    Mannstein, H.; Gierens, K.; Waibel, A.; Meilinger, S.; Seifert, A.; Köhler, C.; Kühne, H.

    2009-04-01

    Air traffic affects the energy balance of the earth in various ways. Emission of CO2 with atmospheric residence times measured in decades contributes to the greenhouse effect as well as emission of nitrous oxides, with their impact on ozone and methane chemistry. Soot has a direct effect on the net radiation and, much more important, is involved the production of contrails and the triggering of contrail cirrus, which can be visible for several hours. These artificial clouds are initiated when flying in sufficiently cold and moist air. In total their net radiative forcing is of the same order of magnitude as the forcing by the emitted CO2. The impact of contrail cirrus on net radiation results from the conversion of ambient moisture in ice super-saturated regions into ice crystals and depends strongly on the conditions of the ambient radiation field. It ranges from a warming at night or over bright low clouds to cooling during daytime over dark surfaces like the ocean. For the time being these effects are not at all taken into consideration in aircraft routing: the production of contrails and contrail cirrus happens by chance. in. The dependency of the radiative forcing by contrail cirrus clouds on the weather conditions opens the possibility for a soft version of geo-engineering: Avoiding warming (and perhaps also producing cooling) contrails and contrail cirrus by small changes of the flight routes has the potential to reduce the man-made imbalance in radiative forcing by a few percent - not much compared to other geo-engineering strategies, but without any adverse consequences. With the exception of a small amount of additional fuel usage no other substances have to be brought into the atmosphere. As contrails are produced only in 10%-20% of the flown distances and only the warming contrails should be avoided, the impact on the traffic system is limited. The basic idea of the project 'Environmentally compatible flight route optimisation', funded by the German

  14. Cueing light configuration for aircraft navigation

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K. (Inventor); Johnson, Walter J. (Inventor)

    1994-01-01

    A pattern of light is projected from multiple sources located on an aircraft to form two clusters. The pattern of each cluster changes as the aircraft flies above and below a predetermined nominal altitude. The initial patterns are two horizontal, spaced apart lines. Each is capable of changing to a delta formation as either the altitude or the terrain varies. The direction of the delta cues the pilot as to the direction of corrective action.

  15. Fiber optic sensor technology for air conformal ice detection

    NASA Astrophysics Data System (ADS)

    Ikiades, Aris A.; Armstrong, David J.; Hare, George G.; Konstantaki, Mary; Crossley, Samuel D.

    2004-03-01

    Ice accretion on flying surfaces affects the aerodynamic performance and handling qualities of aircraft, and may require different pilot corrective action, dependent upon the surface that ice is accreting onto. The current methodology for ice detection usually relies on an indirect method, normally based on ambient air temperature, and liquid water content. When a pre-set threshold level is reached, the ice protection system is activated, whether or not ice is accreting on critical surfaces. This method is not cost effective or efficient for an ice protection system. Air Conformal Ice Detection System (ACIDS) obviates these problems by using a 'direct" method of detection and measurement the presence and thickness of ice. This paper outlines some of the preliminary experimental work done on the optical properties of ice grown in an icing tunnel on the leading edge of an aerofoil leading to the development of a Fibre Optic Direct Ice Detector sensor (DID) with emphasis. The result of this studies have shown that with suitable processing it is possible to use fibre optic sensors to determine the thickness of ice and texture of the ice accreted in the vicinity of the sensor. In the latter part of this paper basic fibre optic architecture is discussed and together with some preliminary results for representative icing runs.

  16. International Satellite Cloud Climatology Project (ISCCP) Ice Snow Product in Native (NAT) Format (ISCCP_ICESNOW_NAT)

    NASA Technical Reports Server (NTRS)

    Rossow, William B. (Principal Investigator)

    Since 1983 an international group of institutions has collected and analyzed satellite radiance measurements from up to five geostationary and two polar orbiting satellites to infer the global distribution of cloud properties and their diurnal, seasonal and interannual variations. The primary focus of the first phase of the project (1983-1995) was the elucidation of the role of clouds in the radiation budget (top of the atmosphere and surface). In the second phase of the project (1995 onwards) the analysis also concerns improving understanding of clouds in the global hydrological cycle. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1983-07-01; Stop_Date=] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Latitude_Resolution=112 Km; Longitude_Resolution=112 Km; Temporal_Resolution=5-day].

  17. 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…

  18. Unmanned aircraft systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unmanned platforms have become increasingly more common in recent years for acquiring remotely sensed data. These aircraft are referred to as Unmanned Airborne Vehicles (UAV), Remotely Piloted Aircraft (RPA), Remotely Piloted Vehicles (RPV), or Unmanned Aircraft Systems (UAS), the official term used...

  19. Ice-sheet response to oceanic forcing.

    PubMed

    Joughin, Ian; Alley, Richard B; Holland, David M

    2012-11-30

    The ice sheets of Greenland and Antarctica are losing ice at accelerating rates, much of which is a response to oceanic forcing, especially of the floating ice shelves. Recent observations establish a clear correspondence between the increased delivery of oceanic heat to the ice-sheet margin and increased ice loss. In Antarctica, most of these processes are reasonably well understood but have not been rigorously quantified. In Greenland, an understanding of the processes by which warmer ocean temperatures drive the observed retreat remains elusive. Experiments designed to identify the relevant processes are confounded by the logistical difficulties of instrumenting ice-choked fjords with actively calving glaciers. For both ice sheets, multiple challenges remain before the fully coupled ice-ocean-atmosphere models needed for rigorous sea-level projection are available.

  20. Collaborative Project. Understanding the effects of tides and eddies on the ocean dynamics, sea ice cover and decadal/centennial climate prediction using the Regional Arctic Climate Model (RACM)

    SciTech Connect

    Hutchings, Jennifer; Joseph, Renu

    2013-09-14

    The goal of this project is to develop an eddy resolving ocean model (POP) with tides coupled to a sea ice model (CICE) within the Regional Arctic System Model (RASM) to investigate the importance of ocean tides and mesoscale eddies in arctic climate simulations and quantify biases associated with these processes and how their relative contribution may improve decadal to centennial arctic climate predictions. Ocean, sea ice and coupled arctic climate response to these small scale processes will be evaluated with regard to their influence on mass, momentum and property exchange between oceans, shelf-basin, ice-ocean, and ocean-atmosphere. The project will facilitate the future routine inclusion of polar tides and eddies in Earth System Models when computing power allows. As such, the proposed research addresses the science in support of the BER’s Climate and Environmental Sciences Division Long Term Measure as it will improve the ocean and sea ice model components as well as the fully coupled RASM and Community Earth System Model (CESM) and it will make them more accurate and computationally efficient.

  1. Airborne measurement of tropospheric ice nuclei aerosols using the Portable Ice Nucleation Chamber (PINC)

    NASA Astrophysics Data System (ADS)

    Chou, C.; Stetzer, O.; Sierau, B.; Lohmann, U.

    2009-04-01

    Ice clouds and mixed phase clouds have different microphysical and radiative properties that need to be assessed in order to understand their impact on the climate. Indeed, on one hand ice crystals found in the ice phase have the ability to scatter incoming solar radiation and absorb terrestrial radiation. On the other hand, about 70% of the tropical precipitation forms via the ice-phase, this means an impact on the hydrological cycle. Investigation of the ability of an aerosol to act as Ice Nuclei (IN) requires knowledge of the thermodynamics conditions, i.e. relative humidity and temperature at which this aerosol form ice crystal. The PerformPINC project was a research campaign within the Education & Training program of the EUropean Fleet for Airborne Research (EUFAR). The project objectives were to measure the number concentration of IN in free and upper troposphere using the Portable Ice Nucleation Chamber (PINC) recently developed by the Institute for Atmospheric Climate Sciences at the ETH Zürich, and thus as a primary objective, testing the technical performance of the instrument during in-situ airborne measurements at different conditions within the chamber. The PINC is the portable version of the Zurich Ice Nucleation Chamber (ZINC) (Stetzer et al., 2008) and is meant for in-situ measurements. Both ZINC and PINC follow the same principle as the Continuous Flow Diffusion Chamber of the Colorado University (Rogers, 1988) that has proven to be of good performance in previous airborne in-situ campaigns (DeMott et al., 2003a). Unlike the CFDC, the PINC has a flat design composed of a main chamber, and an evaporation part. The cooling system of the PINC is also different and consists for the warm side of two BD120 compressors mounted in parallel. For the cold side, it is four BD120 compressors in parallel mounted to another BD120 compressor in serial, thus allowing us to reach lower temperature than the warm side. Aerosols are collected through an inlet where

  2. Airborne measurement of tropospheric ice nuclei aerosols using the Portable Ice Nucleation Chamber (PINC)

    NASA Astrophysics Data System (ADS)

    Chou, C.; Stetzer, O.; Sierau, B.; Lohmann, U.

    2009-04-01

    Ice clouds and mixed phase clouds have different microphysical and radiative properties that need to be assessed in order to understand their impact on the climate. Indeed, on one hand ice crystals found in the ice phase have the ability to scatter incoming solar radiation and absorb terrestrial radiation. On the other hand, about 70% of the tropical precipitation forms via the ice-phase, this means an impact on the hydrological cycle. Investigation of the ability of an aerosol to act as Ice Nuclei (IN) requires knowledge of the thermodynamics conditions, i.e. relative humidity and temperature at which this aerosol form ice crystal. The PerformPINC project was a research campaign within the Education & Training program of the EUropean Fleet for Airborne Research (EUFAR). The project objectives were to measure the number concentration of IN in free and upper troposphere using the Portable Ice Nucleation Chamber (PINC) recently developed by the Institute for Atmospheric Climate Sciences at the ETH Zürich, and thus as a primary objective, testing the technical performance of the instrument during in-situ airborne measurements at different conditions within the chamber. The PINC is the portable version of the Zurich Ice Nucleation Chamber (ZINC) (Stetzer et al., 2008) and is meant for in-situ measurements. Both ZINC and PINC follow the same principle as the Continuous Flow Diffusion Chamber of the Colorado University (Rogers, 1988) that has proven to be of good performance in previous airborne in-situ campaigns (DeMott et al., 2003a). Unlike the CFDC, the PINC has a flat design composed of a main chamber, and an evaporation part. The cooling system of the PINC is also different and consists for the warm side of two BD120 compressors mounted in parallel. For the cold side, it is four BD120 compressors in parallel mounted to another BD120 compressor in serial, thus allowing us to reach lower temperature than the warm side. Aerosols are collected through an inlet where

  3. Another look at aircraft-triggered lightning

    NASA Technical Reports Server (NTRS)

    Clifford, D. W.

    1980-01-01

    There is positive evidence that a rapidly moving aircraft charged to high potentials by triboelectric processes can trigger lightning discharges by passage through freezing precipitation. The freezing zone in a nonstormy rain cloud is shown to be an electrically volatile region because of the potent charge exchange mechanisms which are active in agitated mixtures of supercooled water droplet and ice. Several intensifying effects are suggested which can be produced by the passage of an aircraft through this precipitation, resulting in a highly-ionized wake which acts like a trailing conductor. If weak charge centers are present in the cloud, the ionized wake acts to short out the gradient field resulting in very high potentials at the aircraft. The high potentials explain the electrical activity at the aircraft described by pilots, including intense corona, sparks and radio interference terminating in a loud discharge. Lightning strikes to naval aircraft towing gunnery targets at the end of long steel cables are described, showing that the same triggering mechanism may be involved in those cases. Recommendations are made to include triggering experiments in government flight programs now in progress.

  4. 1. General view of Boeing EC135 looking aircraft. View to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. General view of Boeing EC-135 looking aircraft. View to west. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  5. Depth, ice thickness, and ice-out timing cause divergent hydrologic responses among Arctic lakes

    USGS Publications Warehouse

    Arp, Christopher D.; Jones, Benjamin M.; Liljedahl, Anna K.; Hinkel, Kenneth M.; Welker, Jeffery A.

    2015-01-01

    Lakes are prevalent in the Arctic and thus play a key role in regional hydrology. Since many Arctic lakes are shallow and ice grows thick (historically 2-m or greater), seasonal ice commonly freezes to the lake bed (bedfast ice) by winter's end. Bedfast ice fundamentally alters lake energy balance and melt-out processes compared to deeper lakes that exceed the maximum ice thickness (floating ice) and maintain perennial liquid water below floating ice. Our analysis of lakes in northern Alaska indicated that ice-out of bedfast ice lakes occurred on average 17 days earlier (22-June) than ice-out on adjacent floating ice lakes (9-July). Earlier ice-free conditions in bedfast ice lakes caused higher open-water evaporation, 28% on average, relative to floating ice lakes and this divergence increased in lakes closer to the coast and in cooler summers. Water isotopes (18O and 2H) indicated similar differences in evaporation between these lake types. Our analysis suggests that ice regimes created by the combination of lake depth relative to ice thickness and associated ice-out timing currently cause a strong hydrologic divergence among Arctic lakes. Thus understanding the distribution and dynamics of lakes by ice regime is essential for predicting regional hydrology. An observed regime shift in lakes to floating ice conditions due to thinner ice growth may initially offset lake drying because of lower evaporative loss from this lake type. This potential negative feedback caused by winter processes occurs in spite of an overall projected increase in evapotranspiration as the Arctic climate warms.

  6. Depth, ice thickness, and ice-out timing cause divergent hydrologic responses among Arctic lakes

    NASA Astrophysics Data System (ADS)

    Arp, Christopher D.; Jones, Benjamin M.; Liljedahl, Anna K.; Hinkel, Kenneth M.; Welker, Jeffery A.

    2015-12-01

    Lakes are prevalent in the Arctic and thus play a key role in regional hydrology. Since many Arctic lakes are shallow and ice grows thick (historically 2 m or greater), seasonal ice commonly freezes to the lake bed (bedfast ice) by winter's end. Bedfast ice fundamentally alters lake energy balance and melt-out processes compared to deeper lakes that exceed the maximum ice thickness (floating ice) and maintain perennial liquid water below floating ice. Our analysis of lakes in northern Alaska indicated that ice-out of bedfast ice lakes occurred on average 17 days earlier (22 June) than ice-out on adjacent floating ice lakes (9 July). Earlier ice-free conditions in bedfast ice lakes caused higher open-water evaporation, 28% on average, relative to floating ice lakes and this divergence increased in lakes closer to the coast and in cooler summers. Water isotopes (18O and 2H) indicated similar differences in evaporation between these lake types. Our analysis suggests that ice regimes created by the combination of lake depth relative to ice thickness and associated ice-out timing currently cause a strong hydrologic divergence among Arctic lakes. Thus, understanding the distribution and dynamics of lakes by ice regime is essential for predicting regional hydrology. An observed regime shift in lakes to floating ice conditions due to thinner ice growth may initially offset lake drying because of lower evaporative loss from this lake type. This potential negative feedback caused by winter processes occurs in spite of an overall projected increase in evapotranspiration as the Arctic climate warms.

  7. Eclipse program C-141A aircraft

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. The project used a QF-106 interceptor aircraft to simulate a future orbiter, which would be towed to a high altitude and released to fire its own engines and carry a payload into space. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  8. 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.

  9. Measure of Arctic Sea ice characteristics using microwave scatterometry

    NASA Technical Reports Server (NTRS)

    Jackson, B. L.; Stanley, W. D.; Jones, W. L., Jr.

    1979-01-01

    Results from a radar scatterometer used in the NASA microwave remote sensing experiment off the Alaska north shore are presented. The experiment was performed to determine whether various radars could be used from aircraft to provide definitive measurement of ice parameters such as pressure ridge height and direction, ice age, and ice type. With the aircraft at 300 m altitude, the 13.9 GHz scatterometer measured the normalized radar cross section of the ice using a pencil beam horizontally polarized antenna which pointed at either nadir or 50 deg incidence angle. Simultaneous laser altimeter and stereo photography measurements are presented as the 'surface truth' for comparison with the radar measurements. The results demonstrate that the scatterometer backscattered power is modulated by ice features and that a correlation exists between the radar cross section and the 'surface truth' derived from these ancillary instruments.

  10. Spatial patterns in backscatter strength across the Greenland Ice Sheet

    NASA Technical Reports Server (NTRS)

    Jezek, K. C.

    1993-01-01

    The relationship between the physical properties of the Greenland ice sheet and Synthetic Aperture Radar (SAR) data collected from aircraft and from ERS-1 is addressed. Limited aircraft data are combined with a description of the glacier surface to predict qualitatively the spatial and seasonal variation in backscatter strength across the ice sheet. In particular the model predicts relatively low backscatter near the ice edge where scattering is dominated by rough surface effects. Backscatter increases through the lake zone as volume scattering becomes important. Strongest backscatter is found in the percolation facies where volume scatter from snow grains and volume scatter from large, buried ice bodies becomes important. Backscatter weakens in the interior ice sheet where fine grained snow is the only mechanism producing backscatter.

  11. Aircraft landing gear systems

    NASA Technical Reports Server (NTRS)

    Tanner, John A. (Editor)

    1990-01-01

    Topics presented include the laboratory simulation of landing gear pitch-plane dynamics, a summary of recent aircraft/ground vehicle friction measurement tests, some recent aircraft tire thermal studies, and an evaluation of critical speeds in high-speed aircraft. Also presented are a review of NASA antiskid braking research, titanium matrix composite landing gear development, the current methods and perspective of aircraft flotation analysis, the flow rate and trajectory of water spray produced by an aircraft tire, and spin-up studies of the Space Shuttle Orbiter main gear tire.

  12. The 27-28 October 1986 FIRE IFO Cirrus case study: Comparison of radiative transfer theory with observations by satellite and aircraft

    NASA Technical Reports Server (NTRS)

    Wielicki, Bruce A.; Suttles, J. T.; Heymsfield, Andrew J.; Welch, Ronald M.; Spinhirne, James D.; Wu, Man-Li C.; Starr, David OC.; Parker, Lindsay; Arduini, Robert F.

    1989-01-01

    Observations of cirrus and altocumulus clouds during the First International Satellite Cloud Climatology Project Regional Experiment (FIRE) are compared to theoretical models of cloud radiative properties. Three tests are performed. First, LANDSAT radiances are used to compare the relationship between nadir reflectance ot 0.83 micron and beam emittance at 11.5 microns with that predicted for model calculations using spherical and nonspherical phase functions. Good agreement is found between observations and theory when water droplets dominate. Poor agreement is found when ice particles dominate, especially using scattering phase functions for spherical particles. Even when compared to a laboratory measured ice particle phase function, the observations show increased side scattered radiation relative to the theoretical calculations. Second, the anisotropy of conservatively scattered radiation is examined using simultaneous multiple angle views of the cirrus from LANDSAT and ER-2 aircraft radiometers. Observed anisotropy gives good agreement with theoretical calculations using the laboratory measured ice particle phase function and poor agreement with a spherical particle phase function. Third, Landsat radiances at 0.83, 1.65, and 2.21 microns are used to infer particle phase and particle size. For water droplets, good agreement is found with King Air FSSP particle probe measurements in the cloud. For ice particles, the LANDSAT radiance observations predict an effective radius of 60 microns versus aircraft observations of about 200 microns. It is suggested that this descrepancy may be explained by uncertainty in the imaginary index of ice and by inadequate measurements of small ice particles by microphysical probes.

  13. Contrail Formation in Aircraft Wakes Using Large-Eddy Simulations

    NASA Technical Reports Server (NTRS)

    Paoli, R.; Helie, J.; Poinsot, T. J.; Ghosal, S.

    2002-01-01

    In this work we analyze the issue of the formation of condensation trails ("contrails") in the near-field of an aircraft wake. The basic configuration consists in an exhaust engine jet interacting with a wing-tip training vortex. The procedure adopted relies on a mixed Eulerian/Lagrangian two-phase flow approach; a simple micro-physics model for ice growth has been used to couple ice and vapor phases. Large eddy simulations have carried out at a realistic flight Reynolds number to evaluate the effects of turbulent mixing and wake vortex dynamics on ice-growth characteristics and vapor thermodynamic properties.

  14. Protection of drinking water reservoirs in buried glacial valleys in the ice-marginal landscape for securing future demand in the European perspective (ENCORE-Project).

    NASA Astrophysics Data System (ADS)

    Smit, F. W. H.; Bregman, E. P. H.

    2012-04-01

    Quaternary glaciations have left a significant sedimentological fingerprint in the subsurface of north Europe, in the form of buried glacial valleys. These structures are important drinking water reservoirs for millions of people in the ice-marginal landscape, but are increasingly threatened by anthropogenic pollution (nitrate, sulphate and organic pollutants) and geogenic pollution (salinization). That is one of the conclusion of a recent overview study in the IML of northern Europe from the North Sea to the southern Baltic area. Adequate policy making is yet not possible for several reasons: - Large amounts of data are needed to get a good grip on the lateral continuity of the complex infill. - The BurVal Working Group (2006) has shown that a combination of high resolution seismic survey, together with transient electromagnetic (TEM) surveys can provide realistic data for 3D hydrogeological models. However, these data have not yet been retrieved on a European scale. - Available borehole data can only be used as control points in 3D hydrological models, since the infill of buried glacial valleys is often lateral too complex to make sound interpolations possible. Pollution in buried glacial valleys crosses national borders in northern Europe and therefore national geological surveys have to cooperate in a newly formed European project on protection of these structures. The ENCORE - project (Environmental Conference of the European Regions) has shown in the past that it can facilitate fruitful European cooperation, which is urgently needed due to the costs of gathering data and due to knowledge gaps between different countries. By working together in a European context, these problems can be reduced so that better policy making is possible in order to secure our future drinking water availability.

  15. Energy Efficiency of an Integral Anti-Ice System Based on Fluoroplastic Films

    NASA Astrophysics Data System (ADS)

    Bogoslov, E. A.; Danilaev, M. P.; Mikhailov, S. A.; Pol‧skii, Yu. E.

    2016-07-01

    Results of theoretical and experimental investigations of the efficiency of an integral electrothermal anti-ice system based on fluoroplastic films are presented. It is shown that the use of this system makes it possible to decrease the energy expended for the de-icing by 30% as compared to the existing electrothermal anti-ice systems and that an integral electrothermal anti-ice system can be used in small and midget aircrafts including unmanned ones.

  16. Ice Accretion Formations on a NACA 0012 Swept Wing Tip in Natural Icing Conditions

    NASA Technical Reports Server (NTRS)

    Vargas, Mario; Giriunas, Julius A.; Ratvasky, Thomas P.

    2002-01-01

    An experiment was conducted in the DeHavilland DHC-6 Twin Otter Icing Research Aircraft at NASA Glenn Research Center to study the formation of ice accretions on swept wings in natural icing conditions. The experiment was designed to obtain ice accretion data to help determine if the mechanisms of ice accretion formation observed in the Icing Research Tunnel are present in natural icing conditions. The experiment in the Twin Otter was conducted using a NACA 0012 swept wing tip. The model enabled data acquisition at 0 deg, 15 deg, 25 deg, 30 deg, and 45 deg sweep angles. Casting data, ice shape tracings, and close-up photographic data were obtained. The results showed that the mechanisms of ice accretion formation observed in-flight agree well with the ones observed in the Icing Research Tunnel. Observations on the end cap of the airfoil showed the same strong effect of the local sweep angle on the formation of scallops as observed in the tunnel.

  17. Microwave signature of sea-ice for GCOM-W1/AMSR2

    NASA Astrophysics Data System (ADS)

    Naoki, K.; Nishio, F.; Yoshikawa, M.

    2011-12-01

    The lowest Arctic sea-ice cover has been recorded in September 2007. After that, though it has increased in 2008 and 2009, it has decreased again in 2010. The factor of the sea-ice change is researched in various fields. Monitoring of a thin sea-ice thickness is important as these researches because the sea-ice thickness has influences for the heat budget. However the retrieval of thin sea-ice thickness is difficult because thin sea-ice brightness temperature (TB) depends on the salinity and temperature, and there exist the snow over the thin sea-ice. In order to know the relationship between sea-ice TB and sea-ice parameters, we observed thin sea-ice TB using Polarimetric Scanning Radiometer (PSR) and measured ice thickness by ship. The effect of sea-ice parameters on the TB was examined by model. The brightness temperature of the thin sea-ice was observed using PSR on board an aircraft in the Okhotsk on February 7, 2003. The sea-ice thickness was measured from the icebreaker synchronizing with the aircraft. The TB calculated the variation at the sea-ice with/without of the snow, thickness, and the density of the snow. The calculated result was consistent with the observed one in the 18GHz-Hpol. We show the snow density influenced the increased brightness temperature.

  18. Small transport aircraft technology

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1983-01-01

    Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

  19. Aircraft measurements of wave clouds

    NASA Astrophysics Data System (ADS)

    Cui, Z.; Blyth, A. M.; Bower, K. N.; Crosier, J.; Choularton, T.

    2012-10-01

    In this paper, aircraft measurements are presented of liquid phase (ice-free) wave clouds made at temperatures greater than -5°C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15-45 μm. A small proportion of the drops were drizzle. The measurements presented here and in previous recent studies suggest a different interaction of dynamics and microphysics in wave clouds from the accepted model. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and cloud.

  20. Aircraft measurements of wave cloud

    NASA Astrophysics Data System (ADS)

    Cui, Z.; Blyth, A. M.; Bower, K. N.; Crosier, J.; Choularton, T.

    2012-05-01

    In this paper, aircraft measurements are presented of liquid phase (ice-free) wave clouds made at temperatures greater than -5 °C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15-45 μm. A small proportion of the drops were drizzle. A new definition of a mountain-wave cloud is given, based on the measurements presented here and previous studies. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and clouds.

  1. SUCCESS Evidence for Cirrus Cloud Ice Nucleation Mechanisms

    NASA Technical Reports Server (NTRS)

    Jensen, Eric; Gore, Warren J. Y. (Technical Monitor)

    1997-01-01

    During the SUCCESS mission, several measurements were made which should improve our understanding of ice nucleation processes in cirrus clouds. Temperature and water vapor concentration were made with a variety of instruments on the NASA DC-8. These observations should provide accurate upper tropospheric humidities. In particular, we will evaluate what humidities are required for ice nucleation. Preliminary results suggest that substantial supersaturations frequently exist in the upper troposphere. The leading-edge region of wave-clouds (where ice nucleation occurs) was sampled extensively at temperatures near -40 and -60C. These observations should give precise information about conditions required for ice nucleation. In addition, we will relate the observed aerosol composition and size distributions to the ice formation observed to evaluate the role of soot or mineral particles on ice nucleation. As an alternative technique for determining what particles act as ice nuclei, numerous samples of aerosols inside ice crystals were taken. In some cases, large numbers of aerosols were detected in each crystal, indicating that efficient scavenging occurred. Analysis of aerosols in ice crystals when only one particle per crystal was detected should help with the ice nucleation issue. Direct measurements of the ice nucleating activity of ambient aerosols drawn into airborne cloud chambers were also made. Finally, measurements of aerosols and ice crystals in contrails should indicate whether aircraft exhaust soot particles are effective ice nuclei.

  2. Recent summer sea ice thickness surveys in Fram Strait and associated ice volume fluxes

    NASA Astrophysics Data System (ADS)

    Krumpen, T.; Gerdes, R.; Haas, C.; Hendricks, S.; Herber, A.; Selyuzhenok, V.; Smedsrud, L.; Spreen, G.

    2016-03-01

    Fram Strait is the main gateway for sea ice export out of the Arctic Ocean, and therefore observations there give insight into the composition and properties of Arctic sea ice in general and how it varies over time. A data set of ground-based and airborne electromagnetic ice thickness measurements collected during summer between 2001 and 2012 is presented here, including long transects well into the southern part of the Transpolar Drift obtained using fixed-wing aircrafts. The primary source of the surveyed sea ice leaving Fram Strait is the Laptev Sea and its age has decreased from 3 to 2 years between 1990 and 2012. The thickness data consistently also show a general thinning of sea ice for the last decade, with a decrease in modal thickness of second year and multiyear ice, and a decrease in mean thickness and fraction of ice thicker than 3 m. Local melting in the strait was investigated in two surveys performed in the downstream direction, showing a decrease in sea ice thickness of 0.19 m degree-1 latitude south of 81° N. Further north variability in ice thickness is more related to differences in age and deformation. The thickness observations were combined with ice area export estimates to calculate summer volume fluxes of sea ice. While satellite data show that monthly ice area export had positive trends since 1980 (10.9 × 103 km2 decade-1), the summer (July and August) ice area export is low with high uncertainties. The average volume export amounts to 16.78 km3. Naturally, the volume flux estimates are limited to the period when airborne thickness surveys are available. Nevertheless, we could show that the combination of satellite data and airborne observations can be used to determine volume fluxes through Fram Strait and as such, can be used to bridge the lack of satellite-based sea ice thickness information in summer.

  3. Structural risk assessment and aircraft fleet maintenance

    NASA Technical Reports Server (NTRS)

    Smith, Herb, Jr.; Saff, C. R.; Christian, Tom F.

    1990-01-01

    In the present analysis, deterministic flaw growth analysis is used to project the failure distributions from inspection data. Inspection data is reported for each critical point in the aircraft. The data will indicate either a crack of a specific size or no crack. The crack length may be either less than, equal to, or greater than critical size for that location. Non-critical length cracks are projected to failure using the crack growth characteristics for that location to find the life when it will be at critical length. Greater-than-critical length cracks are projected back to determine the life at failure, that is, when it was at critical length. The same process is used as in the case of a non-critical crack except that the projection goes the other direction. These points, along with the critical length cracks are used to determine the failure distribution. To be able to use data from different aircraft to build a common failure distribution, a consistent life variable must be used. Aircraft life varies with the severity of the usage; therefore the number of flight hours for a particular aircraft must be modified by its usage factor to obtain a normalized life which can be compared with that from other aircraft.

  4. Separation and sampling of ice nucleation chamber generated ice particles by means of the counterflow virtual impactor technique for the characterization of ambient ice nuclei.

    NASA Astrophysics Data System (ADS)

    Schenk, Ludwig; Mertes, Stephan; Kästner, Udo; Schmidt, Susan; Schneider, Johannes; Frank, Fabian; Nillius, Björn; Worringen, Annette; Kandler, Konrad; Ebert, Martin; Stratmann, Frank

    2014-05-01

    In 2011, the German research foundation (DFG) research group called Ice Nuclei Research Unit (INUIT (FOR 1525, project STR 453/7-1) was established with the objective to achieve a better understanding concerning heterogeneous ice formation. The presented work is part of INUIT and aims for a better microphysical and chemical characterization of atmospheric aerosol particles that have the potential to act as ice nuclei (IN). For this purpose a counterflow virtual impactor (Kulkarni et al., 2011) system (IN-PCVI) was developed and characterized in order to separate and collect ice particles generated in the Fast Ice Nucleus Chamber (FINCH; Bundke et al., 2008) and to release their IN for further analysis. Here the IN-PCVI was used for the inertial separation of the IN counter produced ice particles from smaller drops and interstitial particles. This is realized by a counterflow that matches the FINCH output flow inside the IN-PCVI. The choice of these flows determines the aerodynamic cut-off diameter. The collected ice particles are transferred into the IN-PCVI sample flow where they are completely evaporated in a particle-free and dry carrier air. In this way, the aerosol particles detected as IN by the IN counter can be extracted and distributed to several particle sensors. This coupled setup FINCH, IN-PCVI and aerosol instrumentation was deployed during the INUIT-JFJ joint measurement field campaign at the research station Jungfraujoch (3580m asl). Downstream of the IN-PCVI, the Aircraft-based Laser Ablation Aerosol Mass Spectrometer (ALABAMA; Brands et al., 2011) was attached for the chemical analysis of the atmospheric IN. Also, number concentration and size distribution of IN were measured online (TROPOS) and IN impactor samples for electron microscopy (TU Darmstadt) were taken. Therefore the IN-PCVI was operated with different flow settings than known from literature (Kulkarni et al., 2011), which required a further characterisation of its cut

  5. Use of ERTS data for mapping Arctic sea ice

    NASA Technical Reports Server (NTRS)

    Barnes, J. C. (Principal Investigator); Bowley, C. J.

    1973-01-01

    The author has identified the following significant results. Data from ERTS passes crossing the Bering Sea in early March have been correlated with ice observations collected in the Bering Sea Experiment (BESEX). On two flights of the NASA CV-990 aircraft, the ice conditions in the vicinity of St. Lawrence Island reported by the onboard observer are in close agreement with the ice conditions mapped from the corresponding ERTS imagery. The ice features identified in ERTS imagery and substantiated by the aerial observer include the locations of boundaries between areas consisting of mostly grey ice and of mostly first and multi-year ice, the existence of shearing leads, and the occurrence of open water with the associated development of stratus cloud streaks. The BESEX correlative ice formation verifies the potential of practical applications of ERTS data.

  6. SmaggIce User Guide. 1.0

    NASA Technical Reports Server (NTRS)

    Baez, Marivell; Vickerman, Mary; Choo, Yung

    2000-01-01

    SmaggIce (Surface Modeling And Grid Generation for Iced Airfoils) is one of NASNs aircraft icing research codes developed at the Glenn Research Center. It is a software toolkit used in the process of aerodynamic performance prediction of iced airfoils. It includes tools which complement the 2D grid-based Computational Fluid Dynamics (CFD) process: geometry probing; surface preparation for gridding: smoothing and re-discretization of geometry. Future releases will also include support for all aspects of gridding: domain decomposition; perimeter discretization; grid generation and modification.

  7. Jet aircraft emissions during cruise: Present and future

    NASA Technical Reports Server (NTRS)

    Grobman, J. S.

    1975-01-01

    Forecasts of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are compared to cruise emission for present day aircraft. The forecasts are based on: (1) knowledge of emission characteristics of combustors and augmentors; (2) combustion research in emission reduction technology, and (3) trends in projected engine designs for advanced subsonic or supersonic commercial aircraft. Recent progress that was made in the evolution of emissions reduction technology is discussed.

  8. Study of unconventional aircraft engines designed for low energy consumption

    NASA Technical Reports Server (NTRS)

    Gray, D. E.

    1976-01-01

    Declining U.S. oil reserves and escalating energy costs underline the need for reducing fuel consumption in aircraft engines. The most promising unconventional aircraft engines based on their potential for fuel savings and improved economics are identified. The engines installed in both a long-range and medium-range aircraft were evaluated. Projected technology advances are identified and evaluated for their state-of-readiness for application to a commercial transport. Programs are recommended for developing the necessary technology.

  9. Operational Performance of Sensor Systems Used to Determine Atmospheric Boundary Layer Properties as Part of the NASA Aircraft Vortex Spacing System Project

    NASA Technical Reports Server (NTRS)

    Zak, J. Allen; Rodgers, William G., Jr.; Nolf, Scott; McKissick, Burnell T. (Technical Monitor)

    2001-01-01

    There has been a renewed interest in the application of remote sensor technology to operational aviation and airport-related activities such as Aircraft Vortex Spacing System (AVOSS). Radio Acoustic Sounding Systems (RASS), Doppler-acoustic sodars, Ultrahigh Frequencies (UHF) profilers and lidars have many advantages in measuring wind and temperature profiles in the lower atmospheric boundary layer since they can operate more or less continuously and unattended; however, there are limitations in their operational use at airports. For example, profilers deteriorate (limited altitude coverage or missing) in moderate or greater rain and can be affected by airplane targets in their field of view. Sodars can handle precipitation better but are affected by the high noise environments of airports and strong winds. Morning temperature inversions typically limit performance of RASS, sodars and profilers. Fog affects sonic anemometers. Lidars can have difficulties in clouds, fog or heavy precipitation. Despite their limitations these sensors have proven useful to provide wind and temperature profiles for AVOSS. Capabilities and limitations of these and other sensors used in the AVOSS program are discussed, parameter settings for the sensor systems are documented, and recommendations are made for the most cost-effective group of sensors for the future. The potential use of specially tuned dynamic forecast models and measurements from landing and departing aircraft are addressed.

  10. Dry Ice Etches Terrain

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1

    Every year seasonal carbon dioxide ice, known to us as 'dry ice,' covers the poles of Mars. In the south polar region this ice is translucent, allowing sunlight to pass through and warm the surface below. The ice then sublimes (evaporates) from the bottom of the ice layer, and carves channels in the surface.

    The channels take on many forms. In the subimage shown here (figure 1) the gas from the dry ice has etched wide shallow channels. This region is relatively flat, which may be the reason these channels have a different morphology than the 'spiders' seen in more hummocky terrain.

    Observation Geometry Image PSP_003364_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 15-Apr-2007. The complete image is centered at -85.4 degrees latitude, 104.0 degrees East longitude. The range to the target site was 251.5 km (157.2 miles). At this distance the image scale is 25.2 cm/pixel (with 1 x 1 binning) so objects 75 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel . The image was taken at a local Mars time of 06:57 PM and the scene is illuminated from the west with a solar incidence angle of 75 degrees, thus the sun was about 15 degrees above the horizon. At a solar longitude of 219.6 degrees, the season on Mars is Northern Autumn.

  11. Formation and spread of aircraft-induced holes in clouds.

    PubMed

    Heymsfield, Andrew J; Thompson, Gregory; Morrison, Hugh; Bansemer, Aaron; Rasmussen, Roy M; Minnis, Patrick; Wang, Zhien; Zhang, Damao

    2011-07-01

    Hole-punch and canal clouds have been observed for more than 50 years, but the mechanisms of formation, development, duration, and thus the extent of their effect have largely been ignored. The holes have been associated with inadvertent seeding of clouds with ice particles generated by aircraft, produced through spontaneous freezing of cloud droplets in air cooled as it flows around aircraft propeller tips or over jet aircraft wings. Model simulations indicate that the growth of the ice particles can induce vertical motions with a duration of 1 hour or more, a process that expands the holes and canals in clouds. Global effects are minimal, but regionally near major airports, additional precipitation can be induced. PMID:21719676

  12. Formation and Spread of Aircraft-Induced Holes in Clouds

    NASA Astrophysics Data System (ADS)

    Heymsfield, Andrew J.; Thompson, Gregory; Morrison, Hugh; Bansemer, Aaron; Rasmussen, Roy M.; Minnis, Patrick; Wang, Zhien; Zhang, Damao

    2011-07-01

    Hole-punch and canal clouds have been observed for more than 50 years, but the mechanisms of formation, development, duration, and thus the extent of their effect have largely been ignored. The holes have been associated with inadvertent seeding of clouds with ice particles generated by aircraft, produced through spontaneous freezing of cloud droplets in air cooled as it flows around aircraft propeller tips or over jet aircraft wings. Model simulations indicate that the growth of the ice particles can induce vertical motions with a duration of 1 hour or more, a process that expands the holes and canals in clouds. Global effects are minimal, but regionally near major airports, additional precipitation can be induced.

  13. Formation and spread of aircraft-induced holes in clouds.

    PubMed

    Heymsfield, Andrew J; Thompson, Gregory; Morrison, Hugh; Bansemer, Aaron; Rasmussen, Roy M; Minnis, Patrick; Wang, Zhien; Zhang, Damao

    2011-07-01

    Hole-punch and canal clouds have been observed for more than 50 years, but the mechanisms of formation, development, duration, and thus the extent of their effect have largely been ignored. The holes have been associated with inadvertent seeding of clouds with ice particles generated by aircraft, produced through spontaneous freezing of cloud droplets in air cooled as it flows around aircraft propeller tips or over jet aircraft wings. Model simulations indicate that the growth of the ice particles can induce vertical motions with a duration of 1 hour or more, a process that expands the holes and canals in clouds. Global effects are minimal, but regionally near major airports, additional precipitation can be induced.

  14. Experimental ice shape and performance characteristics for a multi-element airfoil in the NASA Lewis Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Berkowitz, Brian M.; Potapczuk, Mark G.; Namdar, Bahman S.; Langhals, Tammy J.

    1991-01-01

    A study of the ice accretion patterns and performance of characteristics of a multi-element airfoil was undertaken at the NASA-Lewis Icing Research Tunnel. Several configurations were examined to determine the ice shape and performance characteristics. The testing included glaze, rime, and mixed icing regimes. Tunnel cloud conditions were set to correspond to those typical of the operating environment for commercial transport aircraft. Measurements acquired included ice profile tracings and aerodynamic forces both during the accretion process and in a post-accretion evaluation over a range of angle of attack. Substantial ice accretions developed on the main wing, flaps, and slat surfaces. Force measurements indicate severe performance degradation, especially near CL max, for both light and heavy ice accretion. Frost was seen on the lower surface of the airfoil which was found to contribute significantly to the force components.

  15. 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.

  16. User Manual for the NASA Glenn Ice Accretion Code LEWICE. Version 2.2.2

    NASA Technical Reports Server (NTRS)

    Wright, William B.

    2002-01-01

    A research project is underway at NASA Glenn to produce a computer code which can accurately predict ice growth under a wide range of meteorological conditions for any aircraft surface. This report will present a description of the code inputs and outputs from version 2.2.2 of this code, which is called LEWICE. This version differs from release 2.0 due to the addition of advanced thermal analysis capabilities for de-icing and anti-icing applications using electrothermal heaters or bleed air applications. An extensive effort was also undertaken to compare the results against the database of electrothermal results which have been generated in the NASA Glenn Icing Research Tunnel (IRT) as was performed for the validation effort for version 2.0. This report will primarily describe the features of the software related to the use of the program. Appendix A of this report has been included to list some of the inner workings of the software or the physical models used. This information is also available in the form of several unpublished documents internal to NASA. This report is intended as a replacement for all previous user manuals of LEWICE. In addition to describing the changes and improvements made for this version, information from previous manuals may be duplicated so that the user will not need to consult previous manuals to use this code.

  17. Ice Accretion with Varying Surface Tension

    NASA Technical Reports Server (NTRS)

    Bilanin, Alan J.; Anderson, David N.

    1995-01-01

    During an icing encounter of an aircraft in flight, super-cooled water droplets impinging on an airfoil may splash before freezing. This paper reports tests performed to determine if this effect is significant and uses the results to develop an improved scaling method for use in icing test facilities. Simple laboratory tests showed that drops splash on impact at the Reynolds and Weber numbers typical of icing encounters. Further confirmation of droplet splash came from icing tests performed in the NaSA Lewis Icing Research Tunnel (IRT) with a surfactant added to the spray water to reduce the surface tension. The resulting ice shapes were significantly different from those formed when no surfactant was added to the water. These results suggested that the droplet Weber number must be kept constant to properly scale icing test conditions. Finally, the paper presents a Weber-number-based scaling method and reports results from scaling tests in the IRT in which model size was reduced up to a factor of 3. Scale and reference ice shapes are shown which confirm the effectiveness of this new scaling method.

  18. Investigation of radar discrimination of sea ice

    NASA Technical Reports Server (NTRS)

    Parashar, S. K.; Biggs, A. W.; Fung, A. K.; Moore, R. K.

    1974-01-01

    The ability of radar to discriminate sea ice types and their thickness was studied. Radar backscatter measurements at 400 MHz (multi-polarization) and 13.3 GHz (VV polarization) obtained from NASA Earth Resources Aircraft Program Mission 126 were analyzed in detail. The scatterometer data were separated into seven categories of sea ice according to age and thickness as interpreted from stereo aerial photographs. The variations of radar backscatter cross-section with sea ice thickness at various angles are presented at the two frequencies. There is a reversal of angular character of radar return from sea ice less than 18 cm thick at the two frequencies. Multi-year ice (sea ice greater than 180 cm thick) gives strongest return at 13.3 GHz. First-year ice (30 cm to 90 cm thick) gives strongest return at 400 MHz. Open water can be differentiated at both the frequencies. Four-polarization 16.5 GHz radar imagery was also obtained. Open water and three categories of sea ice can be identified on the images. The results of the imagery analysis are consistent with the radar scatterometer results.

  19. Aircraft Fuel Cell Power Systems

    NASA Technical Reports Server (NTRS)

    Needham, Robert

    2004-01-01

    In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results

  20. Operation IceBridge: Sea Ice Interlude

    NASA Video Gallery

    Sea ice comes in an array of shapes and sizes and has its own ephemeral beauty. Operation IceBridge studies sea ice at both poles, and also runs across interesting formations en route to other targ...