WorldWideScience

Sample records for international ice patrol

  1. International Ice Patrol (IIP) Iceberg Sightings Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The International Ice Patrol (IIP) has been collecting information on iceberg activity in the North Atlantic since 1911. This database contains the data from these...

  2. Report of the International Ice Patrol in the North Atlantic. 1986 Season Bulletin Number 72

    Science.gov (United States)

    1986-01-01

    business transac-tions from the season. Flight The Intemnational Ice Patrol Month Sooe these nhos requested that all ships transiting -Month Sorties hours...GERMANY 1 EASTERN SHELL UNKNOWN 1 EASTERN UNICORN PANAMA 1 1 ESPANA 1 FEDERAL REPUBLIC OF GERMANY 1 EUROPE BELGIUM 5 EVA FRANCE 1 1 EVERGREEN USA 15 1...when flown at 8000 ft similar pattern, but a winch failure computed using an algorithm (2438 m), maps a 50 km wide after 28 CTD stations resulted in

  3. Report of the International Ice Patrol in the North Atlantic. Bulletin Number 76

    Science.gov (United States)

    1990-01-01

    lIP’s iceberg predictions. Ice were updated by Scobie dynamic height, resulting in a and Schultz (1976). Figure low estimate of the current Page 78 I...0. - 9 *460 460 440 1. 4 40 I42*N 9 .’I...........1 442*N 53OW 510 490 470 450W Figure C-2. Mean Dynamic Topography Relative to 1000 db ( Scobie and...Schultz, 1976). Paqle 79 MI magnitude. Scobie and PREVIOUS CHANGES TO Kassler and Shuhy I Schultz (1976) substantially THE 1979 CURRENT FILE also

  4. Civil Air Patrol Proposed Agreements With the Air Force Are Intended to Address Identified Problems

    National Research Council Canada - National Science Library

    2000-01-01

    The Air Force and Civil Air Patrol relationship is usually cooperative. The Air Force includes the Patrol in its internal budget process to determine what the Patrol needs and how much money will be available to support the Patrol...

  5. Report of the International Ice Patrol Service in the North Atlantic Ocean. Season of 1979.

    Science.gov (United States)

    1979-01-01

    used is ( Scobie and Schultz, 1976) and it is basically these the sum of a mean value and a wind driven compo- updated currents which were used during...direction REFERENCES and U (east-west) and V (north-south) components Scobie , R. W. and R. H. Schultz (1976). Oceanography of on a printout and plots

  6. Report of the International Ice Patrol in the North Atlantic. 1984 Season Bulletin Number 70

    Science.gov (United States)

    1984-01-01

    directed 300 to the right of area has a high degree of the middle of the thermocline. downwind. Measured winds from variability (Soule, 1964; Scobie ...geostrophic flow as long as the in the area north of 430 N ( Scobie conducted in both 1983 and Figure B-10. Actual iceberg and TOD drift from 17-22 July...before next season. lIP 8030. plans to evaluate the drift model using the drift data obtained from Scobie , R.W. and R.H., Schultz HORNBEAM, data from

  7. Report of the International Ice Patrol Services in the North Atlantic Ocean, Season of 1985

    Science.gov (United States)

    1987-03-17

    drift to a hydroahic surveys ( Scobie AscresuleIPmt ofthis re lyconna e constant 90-150km drift error In and Schultz, 1976). It is on a grid schedule,l...D.G., 1980. On Predicting Iceberg Drift, Cold Regions Science and Technology, Vol 1 (3/4): 273-282. Scobie , R.W., and R.H. Schultz, 1976. Oceanographyof

  8. International Conference on Environment Science (ICES 2012)

    CERN Document Server

    Advances in Computational Environment Science

    2012-01-01

    2012 International Conference on Environment Science and 2012 International Conference on Computer Science (ICES 2012/ICCS 2012) will be held in Australia, Melbourne, 15‐16 March, 2012.Volume 1 contains some new results in computational environment science. There are 47 papers were selected as the regular paper in this volume. It contains the latest developments and reflects the experience of many researchers working in different environments (universities, research centers or even industries), publishing new theories and solving new technological problems on computational environment science.   The purpose of volume 1 is interconnection of diverse scientific fields, the cultivation of every possible scientific collaboration, the exchange of views and the promotion of new research targets as well as the further dissemination, the dispersion, the diffusion of the environment science, including but not limited to Ecology, Physics, Chemistry, Biology, Soil Science, Geology, Atmospheric Science and Geography �...

  9. DNR Division of Enforcement Officer Patrol Areas

    Data.gov (United States)

    Minnesota Department of Natural Resources — This theme shows the DNR Division of Enforcement Office Patrol Areas as of January 1, 2003. Patrol areas were defined and verified by Patrol Officers during the fall...

  10. Ultraviolet spectrophotometry of comet Giacobini-Zinner during the ICE encounter. [International Cometary Explorer (ICE)

    Science.gov (United States)

    Ahearn, Michael F.; Mcfadden, Lucy A.; Feldman, Paul D.; Boehnhardt, Hermann; Rahe, Juergen; Festou, Michael; Brandt, John C.; Maran, Stephen P.; Niedner, Malcom B.; Smith, Andrew M.

    1986-01-01

    The IUE spectrophotometry of Comet P/Giacobini-Zinner was acquired in support of the International Cometary Explorer (ICE) mission. The abundances (or upper limits) of UV-active species were calculated. During the ICE encounter the H2O production rate was 3 times 10 to the 28th power/sec, + or - 50%, consistent with values derived from the ICE experiments. Comparison of the abundance of CO2(+) ions with the total electron density measured by the plasma electron experiment on ICE indicates a deficiency of ions relative to electrons indicating a population of ions not detected by remote sensing. The absence of detectable Mg(+) rules out this species as a possible ion of M/Q = 24 detected by the Ion Composition Instrument, part of the ICE complement of instruments.

  11. Solar Features - Solar Flares - Patrol

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The H-alpha Flare Patrol identifies time periods each day when the sun is being continuously monitored by select ground-based solar observatories.

  12. Ice crystallization in ultrafine water-salt aerosols: nucleation, ice-solution equilibrium, and internal structure.

    Science.gov (United States)

    Hudait, Arpa; Molinero, Valeria

    2014-06-04

    Atmospheric aerosols have a strong influence on Earth's climate. Elucidating the physical state and internal structure of atmospheric aqueous aerosols is essential to predict their gas and water uptake, and the locus and rate of atmospherically important heterogeneous reactions. Ultrafine aerosols with sizes between 3 and 15 nm have been detected in large numbers in the troposphere and tropopause. Nanoscopic aerosols arising from bubble bursting of natural and artificial seawater have been identified in laboratory and field experiments. The internal structure and phase state of these aerosols, however, cannot yet be determined in experiments. Here we use molecular simulations to investigate the phase behavior and internal structure of liquid, vitrified, and crystallized water-salt ultrafine aerosols with radii from 2.5 to 9.5 nm and with up to 10% moles of ions. We find that both ice crystallization and vitrification of the nanodroplets lead to demixing of pure water from the solutions. Vitrification of aqueous nanodroplets yields nanodomains of pure low-density amorphous ice in coexistence with vitrified solute rich aqueous glass. The melting temperature of ice in the aerosols decreases monotonically with an increase of solute fraction and decrease of radius. The simulations reveal that nucleation of ice occurs homogeneously at the subsurface of the water-salt nanoparticles. Subsequent ice growth yields phase-segregated, internally mixed, aerosols with two phases in equilibrium: a concentrated water-salt amorphous mixture and a spherical cap-like ice nanophase. The surface of the crystallized aerosols is heterogeneous, with ice and solution exposed to the vapor. Free energy calculations indicate that as the concentration of salt in the particles, the advance of the crystallization, or the size of the particles increase, the stability of the spherical cap structure increases with respect to the alternative structure in which a core of ice is fully surrounded by

  13. Internal friction and microplasticity of ice Isub(h)

    International Nuclear Information System (INIS)

    Perez, J.; Mai, C.; Tatibouet, J.; Vassoille, R.

    1976-01-01

    This study is concerned with internal-friction measurements made at low frequency (torsion pendulum) on specimens of ice Isub(h). In the case of a single crystal, the spectrum of internal friction vs. temperature exhibits the classical relaxation peak. This peak is followed by an increase of damping above 260 K. Furthermore, in this temperature range, the internal friction delta is shown to be amplitude dependent: delta increases with shear strain γ as long as the temperature T is high. These features are strongly modified by plastic deformation of ice in particular i) high-temperature internal friction is increased as long as the plastic defomation ratio is important, ii) high-temperature internal friction becomes more amplitude dependent. In the high-temperature range the mobility of dislocations in ice increase quickly. During the internal-friction measurements the cyclic stress causes movement of linear defects and, hence, damping phenomena. Then, the theoretical analysis of the dynamic behaviour of dislocations in ice has been used to interpret the preceding results. This interpretation allows us to connect our damping data with the microplastic behaviour of ice

  14. Promoting Academic Development: A History of the International Consortium for Educational Development (ICED)

    Science.gov (United States)

    Mason O'Connor, Kristine

    2016-01-01

    This essay traces the history of the International Consortium for Educational Development (ICED) through document analysis and email interviews with founding and prominent ICED members. It also provides a summary of the themes and locations of all the ICED conferences.

  15. Tracing Internal Radar Layers in the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Panton, Christian

    Internal layers in radio-echograms from the sounding of ice sheets have long been a valuable resource in glaciology, but their usefulness have been limited by availability of traced (digitized) layers. To speed up this process, we have developed an algorithm for semi-automatic tracing the internal...... layers and a fully automated algorithm for mapping the layer slope. The layer slope is inferred by the intensity response to a slanted Gaussian filter, whereafter layers can be traced using an active contour model. With these techniques we show that it possible to trace internal layers over distances...... of hundreds kilometers with minimal operator intervention, and the methods have been successfully validated between two Greenland deep ice cores with internal match points. In order to remove any operator assistance, we show how the layer slope can be used to detect disturbances in the deep radiostratigraphy...

  16. Connectivity for underway Coast Guard patrol boats

    OpenAIRE

    Busch, Gregory C.

    1997-01-01

    Approved for public release; distribution is unlimited This thesis examines the US Coast Guard patrol boat's ability to effectively exchange operational data while underway. The patrol boat is currently unable to obtain tactical law enforcement information from the central Law Enforcement Information System 2 (LEIS 2) database while on patrol. LEIS 2 provides access to law enforcement information from Coast Guard, FBI, and state and local law enforcement agencies. Availability of this info...

  17. International Workshop on Comparing Ice Nucleation Measuring Systems 2014

    Energy Technology Data Exchange (ETDEWEB)

    Cziczo, Daniel [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2016-04-30

    The relationship of ambient aerosol particles to the formation of ice-containing clouds is one of the largest uncertainties in understanding the Earth’s climate. The uncertainty is due to several poorly understood processes and measurements including, but not limited to: (1) the microphysics of how particles nucleate ice, (2) the number of ice forming particles as a function of atmospheric properties such as temperature and relative humidity, (3) the atmospheric distribution of ice forming particles and (4) the role of anthropogenic activities in producing or changing the behavior of ice forming particles. The ways in which ice forming particles can impact climate is also multi-faceted. More ice forming particles can lead to clouds with more ice crystals and different optical properties than clouds with less ice forming particles. More effective ice forming particles can lead to ice at higher temperature and/or lower saturation, resulting in clouds at lower altitude or latitude which also changes the Earth’s radiative balance. Ice nucleation also initiates most of the Earth’s precipitation, even in the mid- and low-latitudes, since cloud-top temperatures are often below freezing. The limited measurements and lack of understanding directly translates to restrictions in our ability to model atmospheric ice formation and project changes into the future. The importance of ice nucleation research is further exemplified by Figure 1 which shows the publications per decade and citations per year on the topic of ice nucleation [DeMott et al., 2011]. After a lull at the end of the last century, there has been a dramatic increase in both publications and citations related to ice nucleation; this directly corresponds to the importance of ice nucleation on the Earth’s climate and the uncertainty in this area noted by the Solomon [2007].

  18. Civil Air Patrol (CAP) Aircraft Requirement Study

    National Research Council Canada - National Science Library

    Mercher, Christopher

    1999-01-01

    The Air Force Audit Agency (AFAA) concluded in its Report of Audit EB0980013 (13 May 98), Air Force Oversight of CY 1996 Civil Air Patrol Corporation Activities, CAP-USAF, Maxwell AFB, AL 36112-6323...

  19. Relative influences of the metocean forcings on the drifting ice pack and estimation of internal ice stress gradients in the Labrador Sea

    Science.gov (United States)

    Turnbull, I. D.; Torbati, R. Z.; Taylor, R. S.

    2017-07-01

    Understanding the relative influences of the metocean forcings on the drift of sea ice floes is a crucial component to the overall characterization of an ice environment and to developing an understanding of the factors controlling the ice dynamics. In addition, estimating the magnitude of the internal stress gradients on drifting sea ice floes generated by surrounding ice cover is important for modeling operations, informing the design of offshore structures and vessels in ice environments, and for the proper calibration of Discrete Element Models (DEM) of fields of drifting ice floes. In the spring of 2015 and 2016, four sea ice floes offshore Makkovik, Labrador were tagged with satellite-linked ice tracking buoys along with one satellite-linked weather station on each floe to transmit wind speed and direction. Twenty satellite-linked Lagrangian surface ocean current tracking buoys were also deployed in the open water adjacent to the targeted ice floes. In this paper, the dynamics of the four ice floes are explored in terms of the relative proportions which were forced by the wind, current, sea surface topography, Coriolis, and internal stress gradients. The internal ice stress gradients are calculated as residuals between the observed accelerations of the floes as measured by the tracking buoys and the sums of the other metocean forcings. Results show that internal ice stress gradients accounted for up to 50% of the observed forcing on the floes, and may have reached up to around 0.19 kPa.

  20. Internal Combustion Engine (ICE) bottoming with Organic Rankine Cycles (ORCs)

    International Nuclear Information System (INIS)

    Vaja, Iacopo; Gambarotta, Agostino

    2010-01-01

    This paper describes a specific thermodynamic analysis in order to efficiently match a vapour cycle to that of a stationary Internal Combustion Engine (ICE). Three different working fluids are considered to represent the main classes of fluids, with reference to the shape of the vapour lines in the T-s diagram: overhanging, nearly isoentropic and bell shaped. First a parametric analysis is conducted in order to determine optimal evaporating pressures for each fluid. After which three different cycles setups are considered: a simple cycle with the use of only engine exhaust gases as a thermal source, a simple cycle with the use of exhaust gases and engine cooling water and a regenerated cycle. A second law analysis of the cycles is performed, with reference to the available heat sources. This is done in order to determine the best fluid and cycle configuration to be employed, the main parameters of the thermodynamic cycles and the overall efficiency of the combined power system. The analysis demonstrates that a 12% increase in the overall efficiency can be achieved with respect to the engine with no bottoming; nevertheless it has been observed that the Organic Rankine Cycles (ORCs) can recover only a small fraction of the heat released by the engine through the cooling water.

  1. Proceedings of the 19. IAHR international symposium on ice : using new technology to understand water-ice interaction

    International Nuclear Information System (INIS)

    Jasek, M.; Andrishak, R.; Siddiqui, A.

    2008-01-01

    This conference provided a venue for scientists, engineers and researchers an opportunity to expand their knowledge of water-ice interactions with reference to water resources, river and coastal hydraulics, risk analysis, energy and the environment. The the theme of new technology falls into 3 basic groups, notably measurement and instrumentation; remote sensing; and numerical simulation. The thermal regime of rivers was discussed along with ice mechanics, ice hydraulics, ice structures and modelling ice phenomena. The titles of the sessions were: river ice, glaciers and climate change; freeze-up processes on rivers and oceans; river ice-structure interactions; numerical simulations in ice engineering; river-ice break-up and ice jam formation; ice measurement; Grasse River ice evaluation; evaluation of structural ice control alternatives; remote sensing; hydropower and dam decommissioning; mechanical behaviour of river ice, ice covered flow and thermal modelling; mathematical and computer model formulations for ice friction and sea ice; ice bergs and ice navigation; ice crushing processes; sea ice and shore/structure interactions; ice properties, testing and physical modelling; ice actions on compliant structures; oil spills in ice; desalination, ice thickness and climate change; and, sea ice ridges. The conference featured 123 presentations, of which 20 have been catalogued separately for inclusion in this database. refs., tabs., figs

  2. The IceCube Collaboration: contributions to the 30th International Cosmic Ray Conference (ICRC 2007)

    International Nuclear Information System (INIS)

    IceCube Collaboration; Ackermann, M.

    2007-01-01

    This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial ν e , ν μ and ν τ signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends IceCube's reach to lower energies. Before the deployment of IceTop, cosmic air showers were registered with the 30 station SPASE-2 surface array. IceCube's low noise Digital Optical Modules are very reliable, show a uniform response and record waveforms of arriving photons that are resolvable with nanosecond precision over a large dynamic range. Data acquisition, reconstruction and simulation software are running in production mode and the analyses, profiting from the improved data quality and increased overall sensitivity, are well under way

  3. 32 CFR 700.922 - Shore patrol.

    Science.gov (United States)

    2010-07-01

    ... area that can absorb them without danger of disturbance or disorder, the senior officer present shall cause to be established, temporarily or permanently, in charge of an officer, a sufficient patrol of officers, petty officers, and noncommissioned officers to maintain order and suppress any unseemly conduct...

  4. Rapid grounding line migration induced by internal variability of a marine-terminating ice stream

    Science.gov (United States)

    Robel, A.; Schoof, C.; Tziperman, E.

    2013-12-01

    Numerous studies have found significant variability in the velocity of ice streams to be a prominent feature of geomorphologic records in the Siple Coast (Catania et al. 2012) and other regions in West Antarctica (Dowdeswell et al. 2008). Observations indicate that grounding line position is strongly influenced by ice stream variability, producing rapid grounding line migration in the recent past (Catania et al. 2006) and the modern (Joughin & Tulaczyk 2002). We analyze the interaction of grounding line mass flux and position in a marine-terminating ice stream using a stretch-coordinate flowline model. This model is based on that described in Schoof (2007), with a mesh refined near the grounding line to ensure accurate resolution of the mechanical transition zone. Here we have added lateral shear stress (Dupont & Alley 2005) and an undrained plastic bed (Tulaczyk et al. 2000). The parameter dependence of ice stream variability seen in this model compares favorably to both simpler (Robel et al. 2013) and more complex (van der Wel et al. 2013) models, though with some key differences. We find that thermally-induced internal ice stream variability can cause very rapid grounding line migration even in the absence of retrograde bed slopes or external forcing. Activation waves propagate along the ice stream length and trigger periods of rapid grounding line migration. We compare the behavior of the grounding line due to internal ice stream variability to changes triggered externally at the grounding line such as the rapid disintegration of buttressing ice shelves. Implications for Heinrich events and the Marine Ice Sheet Instability are discussed.

  5. Ganymede's internal structure including thermodynamics of magnesium sulfate oceans in contact with ice

    Science.gov (United States)

    Vance, Steve; Bouffard, Mathieu; Choukroun, Mathieu; Sotin, Christophe

    2014-06-01

    The large icy moons of Jupiter contain vast quantities of liquid water, a key ingredient for life. Ganymede and Callisto are weaker candidates for habitability than Europa, in part because of the model-based assumption that high-pressure ice layers cover their seafloors and prevent significant water-rock interaction. Water-rock interactions may occur, however, if heating at the rock-ice interface melts the high pressure ice. Highly saline fluids would be gravitationally stable, and might accumulate under the ice due to upward migration, refreezing, and fractionation of salt from less concentrated liquids. To assess the influence of salinity on Ganymede's internal structure, we use available phase-equilibrium data to calculate activity coefficients and predict the freezing of water ice in the presence of aqueous magnesium sulfate. We couple this new equation of state with thermal profiles in Ganymede's interior-employing recently published thermodynamic data for the aqueous phase-to estimate the thicknesses of layers of ice I, III, V, and VI. We compute core and silicate mantle radii consistent with available constraints on Ganymede's mass and gravitational moment of inertia. Mantle radii range from 800 to 900 km for the values of salt and heat flux considered here (4-44 mW m-2 and 0 to 10 wt% MgSO4). Ocean concentrations with salinity higher than 10 wt% have little high pressure ice. Even in a Ganymede ocean that is mostly liquid, achieving such high ocean salinity is permissible for the range of likely S/Si ratios. However, elevated salinity requires a smaller silicate mantle radius to satisfy mass and moment-of-inertia constraints, so ice VI is always present in Ganymede's ocean. For lower values of heat flux, oceans with salinity as low as 3 wt% can co-exist with ice III. Available experimental data indicate that ice phases III and VI become buoyant for salinity higher than 5 wt% and 10 wt%, respectively. Similar behavior probably occurs for ice V at salinities

  6. Hanford Patrol Academy demolition sites closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-30

    The Hanford Site is owned by the U.S. Government and operated by the U.S. Department of Energy, Richland Operations Office. Westinghouse Hanford Company is a major contractor to the U.S. Department of Energy, Richland Operations Office and serves as co-operator of the Hanford Patrol Academy Demolition Sites, the unit addressed in this paper. This document consists of a Hanford Facility Dangerous Waste Part A Permit Application, Form 3 (Revision 4), and a closure plan for the site. An explanation of the Part A Form 3 submitted with this closure plan is provided at the beginning of the Part A section. This Hanford Patrol Academy Demolition Sites Closure Plan submittal contains information current as of December 15, 1994.

  7. Ultraviolet spectrophotometry of Comet Giacobini-Zinner during the ICE encounter. [International Cometary Explorer

    Science.gov (United States)

    Mcfadden, Lucy A.; Ahearn, Michael F.; Feldman, Paul D.; Boehnhardt, Hermann; Rahe, Juergen; Festou, Michel C.; Brandt, John C.; Maran, Stephen P.; Niedner, Malcolm B.; Smith, Andrew M.

    1987-01-01

    The IUE's UV spectrophotometer was used to monitor Comet Giacobini-Zinner's H2O production rate from June to October, 1985, in support of the International Cometary Explorer (ICE) mission. Observation results for the spatial and temporal variation and the abundance or upper limits of C, CO, CO(+), CO2(+), CS, H, Mg(+), O, OH, and S, between September 9 and 12, included the time of the ICE encounter: at this time, the H2O production rate obtained was consistent with a number of gas production rates derived indirectly from the ICE experiments. A comparison of the CO2(+) ion abundance with the total electron density measured by the plasma electron and radio science experiments on ICE implies an ion deficiency relative to electrons, so that the satisfaction of charge balance criteria requires the presence of a major ion population not detected by remote sensing.

  8. Managing organizational change in an international scientific network: A study of ICES reform processes

    NARCIS (Netherlands)

    Stange, K.; Olssen, P.; Österblom, H.

    2012-01-01

    Organizations involved in the governance of natural resources are challenged to adjust to the call for more holistic management approaches. This often necessitates organizational change. Here change processes in the International Council for the Exploration of the Sea (ICES) during the years

  9. ICE-B 2008 : International Conference on e-Business: Proceedings

    NARCIS (Netherlands)

    Filipe, Joaquim; Marca, David A.; Shishkov, Boris; van Sinderen, Marten J.

    2008-01-01

    The purpose of ICE-B 2008, the International Conference on e-Business, is to bring together researchers, engineers and practitioners interested in information systems methods and applications in the context of e-business. e-Business is a research area of growing importance, encompassing several

  10. Feelings of Safety: Ironic Consequences of Police Patrolling

    NARCIS (Netherlands)

    Veer, van de E.; Lange, de M.A.; Haar, van der E.; Karremans, J.C.

    2012-01-01

    Increasing police patrolling is often assumed to be an effective means of enhancing general feelings of safety. This relationship between perceiving police and feelings of safety was tested by having police officers patrol during a field experiment (Study 1) and by manipulating the police presence

  11. Review of Anti-Icing/Ice Release Systems

    Science.gov (United States)

    2014-01-29

    walkways, and superstructure which the US Navy has shown 1 for a Green Arctic Patrol Vessel can be supplied by waste heat recovery from engine...adhesion strength than the ice does, thus facilitating shear. It has been found that such treatments depend on the chemical nature and condition of...application. • Ablative or Depletion Coatings: where the coating fails cohesively as ice is sheared away, or where low surface energy or oily additives

  12. Hanford Patrol Academy Demolition Sites Closure Plan

    International Nuclear Information System (INIS)

    1992-11-01

    From 1975 to 1991 the Hanford Patrol Academy Demolition Sites (HPADS) were used for demolition events. These demolition events were a form of thermal treatment for spent or abandoned chemical waste. Because the HPADS will no longer be used for this thermal activity, the sites will be closed. Closure will be conducted pursuant to the requirements of the Washington State Department of Ecology (Ecology) Dangerous Waste Regulations, Washington Administrative Code (WAC) 173-303-610 and 40 CFR 270.1. Closure also will satisfy closure requirements of WAC 173-303-680 and for the thermal treatment closure requirements of 40 CFR 265.381. This closure plan presents a description of the HPADS, the history of the waste treated, and the approach that will be followed to close the HPADS. Because dangerous waste does not include the source, special nuclear, and by-product material components of mixed waste, radionuclides are not within the scope of WAC 173-303 or of this closure plan. The information on radionuclides is provided only for general knowledge where appropriate. Only dangerous constituents derived from HPADS operations will be addressed in this closure plan in accordance with WAC 173-303-610(2)(b)(i). The HPADS are actually two distinct soil closure areas within the Hanford Patrol Academy training area

  13. A "continuity-index" for assessing ice-sheet dynamics from radar-sounded internal layers

    DEFF Research Database (Denmark)

    Karlsson, Nanna Bjørnholt; Rippin, David; Bingham, Robert G.

    2012-01-01

    Radio-echo sounding (RES) of polar icesheets reveals extensive internal layering. The degree of continuity of internal layering holds critical information about the ice-flow field, but previous analyses of this parameter have been limited to qualitative classifications. Here we present a new...... further support that the main trunk and tributaries are unlikely to have undergone substantial migration since the deposition of the internal layering. Significantly, our new method for analyzing internallayers is readily transferable across RES datasets, offering promise for data-led assessments of past...

  14. 4th International Conference on Energy and Environment 2013 (ICEE 2013)

    Science.gov (United States)

    Chakrabarty, Chandan Kumar; Shamsuddin, Abd Halim Bin; Ahmad, Ibrahim Bin; Desa, Mohamed Nor Bin Mohamed; Din, Norashidah Bte Md; Bte Mohd, Lariyah; Hamid, Nasri A.; See, Ong Hang; Hafiz Nagi, Farrukh; Yong, Lee Choon; Pasupuleti, Jagadeesh; Mei, Goh Su; Abdullah, Fairuz Bin; Satgunam, Meenaloshini

    2013-06-01

    The 4th International Conference on Energy & Environment 2013 (ICEE2013) was organized by the Universiti Tenaga Nasional (UNITEN) to provide a platform for creating and sharing ideas among engineers, researchers, scientists, industrialists and students in sustainable green energy and technologies. The theme 'Shaping a Sustainable Future through Advancement in Green Energy Technology' is in line with the University's vision to be a leading global energy university that shapes a sustainable future. The general scopes of the conference are renewable energy, smart grid, green technology, energy policies and economics, sustainable green energy and environment, sustainable education, international cooperation and innovation and technology transfer. Five international keynote speakers delivered their speeches in specialized areas of green energy technology and sustainability. In addition, the conference highlights several special parallel sessions by notable invited presenters in their niche areas, which are: Hybrid Energy Power Quality & Distributed Energy Smart Grid Nuclear Power & Technologies Geohazard Management Greener Environment for Sustainability Advances in Computational Fluid Dynamics The research papers presented in ICEE2013 are included in this volume of IOP Conference Series: Earth and Environmental Science (EES). EES is abstracted and indexed in SCOPUS, GeoBase, GeoRef, Compendex, Inspec, Chemical Abstracts Service, NASA Astrophysics Data System, and International Nuclear Information System (INIS). With the comprehensive programme outline, the organizing committee hopes that the ICEE2013 was a notable intellectual sharing session for the research and academic community in Malaysia and regionally. The organizing committee expresses gratitude to the ICEE2013 delegates for their great support and contributions to the event.

  15. For a Greater Horn of Africa Sea Patrol

    DEFF Research Database (Denmark)

    Struwe, Lars Bangert

    Patrol. The capacity and resources devoted by the individual states, alliances and organisations to combating piracy could be used more efficiently by establishing a regional unit: a Greater Horn of Africa Sea Patrol (GHASP). GHASP could be built up on a regional basis founded on the states in and around...... of Somalia. Experience from the Absalon and Thetis missions shows that the use of helicopters combined with boarding and landing elements from the Danish Navy Frogman Corps are effective in combating attacks by pirates. Irrespective of whether there is a decision to act or react, the boarding and landing...... elements in particular should be strengthened. This would also strengthen participation in future international operations, such as controlling ships, for instance. A final recommendation is to: • Initiate research into the generic characteristics of piracy. This report also shows that we know too little...

  16. DESIGNING DAILY PATROL ROUTES FOR POLICING BASED ON ANT COLONY ALGORITHM

    Directory of Open Access Journals (Sweden)

    H. Chen

    2015-07-01

    Full Text Available In this paper, we address the problem of planning police patrol routes to regularly cover street segments of high crime density (hotspots with limited police forces. A good patrolling strategy is required to minimise the average time lag between two consecutive visits to hotspots, as well as coordinating multiple patrollers and imparting unpredictability in patrol routes. Previous studies have designed different police patrol strategies for routing police patrol, but these strategies have difficulty in generalising to real patrolling and meeting various requirements. In this research we develop a new police patrolling strategy based on Bayesian method and ant colony algorithm. In this strategy, virtual marker (pheromone is laid to mark the visiting history of each crime hotspot, and patrollers continuously decide which hotspot to patrol next based on pheromone level and other variables. Simulation results using real data testifies the effective, scalable, unpredictable and extensible nature of this strategy.

  17. Integrated Design of Semi-Displacement Patrol Crafts

    National Research Council Canada - National Science Library

    Gillespy, Andrew J

    2008-01-01

    ... of any one change on the entire system. The initial design of smaller patrol craft is especially difficult due to the lack of design tools able to deal with ships of small size operating in the semi-planing region...

  18. Patrol Detection for Replica Attacks on Wireless Sensor Networks

    OpenAIRE

    Wang, Liang-Min; Shi, Yang

    2011-01-01

    Replica attack is a critical concern in the security of wireless sensor networks. We employ mobile nodes as patrollers to detect replicas distributed in different zones in a network, in which a basic patrol detection protocol and two detection algorithms for stationary and mobile modes are presented. Then we perform security analysis to discuss the defense strategies against the possible attacks on the proposed detection protocol. Moreover, we show the advantages of the proposed protocol by d...

  19. Application of autonomous mobile patrol system for nuclear power plants

    International Nuclear Information System (INIS)

    Kanemoto, S.; Hattori, Y.; Ochiai, M.; Tai, I.; Ozaki, O.; Shimada, H.; Okano, H.

    1995-01-01

    The integrity of the components of an operating nuclear power plant (NPP) is usually monitored daily by an operator patrol. Currently, there is a great need to replace such human patrol activities by automated remote monitoring in order to reduce radiation exposure and severe workload. From this perspective, we started an R and D project with the objective of developing an autonomous mobile patrol system for NPPs. The project started in 1991 and is scheduled to be completed in 1996. The main targets of this project are as follows. (1) Development of an autonomous and independent mobile robot, (2) Development of a transportable compact remote sensing system for plant component inspection, (3) Development of a patrol guidance and sensing data evaluation system. The remote sensing system has the capability of detecting video image, sound, temperature and vibration distribution of component surfaces. A laser Doppler vibrometer is newly developed to measure a wide range of vibration distribution remotely. Also, in order to integrate and recognize various kinds of remote sensing data, a 3-dimensional (3D) computer aided design database and 3D graphics technology is extensively used. Operators can interpret the measured image data by mapping their textures onto the 3-dimensional model surface. In this paper, we describe the concept of the entire patrol system and its three main component technologies, that is, mobile robot, remote sensing and inspected data evaluations. (author)

  20. Development of nuclear power plant automated remote patrol system

    International Nuclear Information System (INIS)

    Nakayama, R.; Kubo, K.; Sato, K.; Taguchi, J.

    1984-01-01

    An Automated Remote Patrol System was developed for a remote inspection, observation and monitoring of nuclear power plant's components. This automated remote patrol system consists of; a vehicle moving along a monorail; three rails mounted in a monorail for data transmission and for power supply; an image fiber connected to a TV camera; an arm type mechanism (manipulator) for moving image fiber; a computer for control and data processing and operator's console. Special features of this Automated Remote Patrol System are as follows: The inspection vehicle runs along horizontal and vertical (up/down) monorails. The arm type mechanism (manipulator) on the vehicle is used to move image fiber. Slide type electric collectors are used for data transmission and power supply. Time-division multiplexing is adapted for data transmission. Voice communication is used for controlling mechanisms. Pattern recognition is used for data processing. The experience that has been obtained from a series of various tests is summarized. (author)

  1. The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007),

    Energy Technology Data Exchange (ETDEWEB)

    IceCube Collaboration; Ackermann, M.

    2007-11-02

    This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial {nu}{sub e}, {nu}{sub {mu}} and {nu}{sub {tau}} signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends IceCube's reach to lower energies. Before the deployment of IceTop, cosmic air showers were registered with the 30 station SPASE-2 surface array. IceCube's low noise Digital Optical Modules are very reliable, show a uniform response and record waveforms of arriving photons that are resolvable with nanosecond precision over a large dynamic range. Data acquisition, reconstruction and simulation software are running in production mode and the analyses, profiting from the improved data quality and increased overall sensitivity, are well under way.

  2. Patrol Detection for Replica Attacks on Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yang Shi

    2011-02-01

    Full Text Available Replica attack is a critical concern in the security of wireless sensor networks. We employ mobile nodes as patrollers to detect replicas distributed in different zones in a network, in which a basic patrol detection protocol and two detection algorithms for stationary and mobile modes are presented. Then we perform security analysis to discuss the defense strategies against the possible attacks on the proposed detection protocol. Moreover, we show the advantages of the proposed protocol by discussing and comparing the communication cost and detection probability with some existing methods.

  3. 49 CFR 192.705 - Transmission lines: Patrolling.

    Science.gov (United States)

    2010-10-01

    ... adjacent to the transmission line right-of-way for indications of leaks, construction activity, and other factors affecting safety and operation. (b) The frequency of patrols is determined by the size of the line, the operating pressures, the class location, terrain, weather, and other relevant factors, but...

  4. A Bayesian Retrieval of Greenland Ice Sheet Internal Temperature from Ultra-wideband Software-defined Microwave Radiometer (UWBRAD) Measurements

    Science.gov (United States)

    Duan, Y.; Durand, M. T.; Jezek, K. C.; Yardim, C.; Bringer, A.; Aksoy, M.; Johnson, J. T.

    2017-12-01

    The ultra-wideband software-defined microwave radiometer (UWBRAD) is designed to provide ice sheet internal temperature product via measuring low frequency microwave emission. Twelve channels ranging from 0.5 to 2.0 GHz are covered by the instrument. A Greenland air-borne demonstration was demonstrated in September 2016, provided first demonstration of Ultra-wideband radiometer observations of geophysical scenes, including ice sheets. Another flight is planned for September 2017 for acquiring measurements in central ice sheet. A Bayesian framework is designed to retrieve the ice sheet internal temperature from simulated UWBRAD brightness temperature (Tb) measurements over Greenland flight path with limited prior information of the ground. A 1-D heat-flow model, the Robin Model, was used to model the ice sheet internal temperature profile with ground information. Synthetic UWBRAD Tb observations was generated via the partially coherent radiation transfer model, which utilizes the Robin model temperature profile and an exponential fit of ice density from Borehole measurement as input, and corrupted with noise. The effective surface temperature, geothermal heat flux, the variance of upper layer ice density, and the variance of fine scale density variation at deeper ice sheet were treated as unknown variables within the retrieval framework. Each parameter is defined with its possible range and set to be uniformly distributed. The Markov Chain Monte Carlo (MCMC) approach is applied to make the unknown parameters randomly walk in the parameter space. We investigate whether the variables can be improved over priors using the MCMC approach and contribute to the temperature retrieval theoretically. UWBRAD measurements near camp century from 2016 was also treated with the MCMC to examine the framework with scattering effect. The fine scale density fluctuation is an important parameter. It is the most sensitive yet highly unknown parameter in the estimation framework

  5. What About Sea Ice? People, animals, and climate change in the polar regions: An online resource for the International Polar Year and beyond

    Science.gov (United States)

    Renfrow, S.; Meier, W. N.; Wolfe, J.; Scott, D.; Leon, A.; Weaver, R.

    2005-12-01

    Decreasing Arctic sea ice has been one of the most noticeable changes on Earth over the past quarter-century. The years 2002 through 2005 have had much lower summer sea ice extents than the long-term (1979-2000). Reduced sea ice extent has a direct impact on Arctic wildlife and people, as well as ramifications for regional and global climate. Students, educators, and the general public want and need to have a better understanding of sea ice. Most of us are unfamiliar with sea ice: what it is, where it occurs, and how it affects global climate. The upcoming International Polar Year will provide an opportunity for the public to learn about sea ice. Here, we provide an overview of sea ice, the changes that the sea ice is undergoing, and information about the relation between sea ice and climate. The information presented here is condensed from the National Snow and Ice Data Center's new 'All About Sea Ice' Web site (http://www.nsidc.org/seaice/), a comprehensive resource of information for sea ice.

  6. Advancing Diversity and Inclusion within the IceCube Collaboration: Lessons from an International Particle Astrophysics Research Collaboration

    Science.gov (United States)

    Knackert, J.

    2017-12-01

    The IceCube Collaboration is comprised of 300 scientists, engineers, students, and support staff at 48 institutions in 12 countries. IceCube recognizes the value of increased diversity within STEM fields and is committed to improving this situation both within the collaboration and more broadly. The process of establishing and maintaining a focus on diversity and inclusion within an international research collaboration has yielded many lessons and best practices relevant for broader STEM diversity efforts. Examples of events, training activities, and workshops to promote diversity both internally and within the broader STEM community will be provided. We will outline strategies to promote an environment of inclusivity and increase diversity in hiring within IceCube. We will describe collaborations with local networks and advocacy groups that have helped to guide our efforts and maximize their impact. We will also discuss methods for getting community members interested, informed, and invested, while helping them better understand the benefits associated with increased STEM diversity. This work has been informed by the American Association for the Advancement of Science's inaugural cohort of the Community Engagement Fellows Program. The author has made this submission on behalf of the IceCube Collaboration Diversity Task Force.

  7. Securing the Borders: Creation of the Border Patrol Auxiliary

    Science.gov (United States)

    2007-05-05

    DATES COVERED 00-00-2007 to 00-00-2007 4. TITLE AND SUBTITLE Securing the Borders: Creation of the Border Patrol Auxillary 5a. CONTRACT NUMBER...Substantial work experience which demonstrates an ability to (1) take charge, make sound decisions , and maintain composure in stressful situations; (2...applicable laws, court decisions , and law enforcement procedures; and 4. Develop and maintain contact with the network of informants. ¾ To qualify at

  8. High Seas Buffer: The Taiwan Patrol Force, 1950-1979

    Science.gov (United States)

    2012-04-01

    It is prohibited to use NWC’s logo on any republication of this book without the express, written permission of the Editor, Naval War College Press, or...watches and developed an English–Chinese signal book to be used in communications between American and Nationalist ships. With the help of foreign... secondhand from Belgium, Canada, Denmark, Germany, and Japan. One of their primary missions was to patrol the strait. On 13 January 1967, Maj. Shih-Lin Hu

  9. Contract Administration of the Ice Delivery Contract between International American Products, Worldwide Services and the U.S. Army Corps of Engineers during the Hurricane Katrina Recovery Effort

    National Research Council Canada - National Science Library

    Jolliffe, Richard B; Burton, Bruce A; Culp, Deborah L; Wan, Bobbie S; Dutton, Gary B; Steinbauer, Jeffrey L; Herman, Rachel L; Kistler, Jonathan M; Johnson, Meredith H

    2007-01-01

    The U.S. Army Corps of Engineers Principal Assistant Responsible for Contracting requested a review on the administration of the ice delivery process between International American Products, Worldwide Services and the U.S...

  10. Getting around Antarctica: new high-resolution mappings of the grounded and freely-floating boundaries of the Antarctic ice sheet created for the International Polar Year

    Directory of Open Access Journals (Sweden)

    R. Bindschadler

    2011-07-01

    Full Text Available Two ice-dynamic transitions of the Antarctic ice sheet – the boundary of grounded ice features and the freely-floating boundary – are mapped at 15-m resolution by participants of the International Polar Year project ASAID using customized software combining Landsat-7 imagery and ICESat/GLAS laser altimetry. The grounded ice boundary is 53 610 km long; 74 % abuts to floating ice shelves or outlet glaciers, 19 % is adjacent to open or sea-ice covered ocean, and 7 % of the boundary ice terminates on land. The freely-floating boundary, called here the hydrostatic line, is the most landward position on ice shelves that expresses the full amplitude of oscillating ocean tides. It extends 27 521 km and is discontinuous. Positional (one-sigma accuracies of the grounded ice boundary vary an order of magnitude ranging from ±52 m for the land and open-ocean terminating segments to ±502 m for the outlet glaciers. The hydrostatic line is less well positioned with errors over 2 km. Elevations along each line are selected from 6 candidate digital elevation models based on their agreement with ICESat elevation values and surface shape inferred from the Landsat imagery. Elevations along the hydrostatic line are converted to ice thicknesses by applying a firn-correction factor and a flotation criterion. BEDMAP-compiled data and other airborne data are compared to the ASAID elevations and ice thicknesses to arrive at quantitative (one-sigma uncertainties of surface elevations of ±3.6, ±9.6, ±11.4, ±30 and ±100 m for five ASAID-assigned confidence levels. Over one-half of the surface elevations along the grounded ice boundary and over one-third of the hydrostatic line elevations are ranked in the highest two confidence categories. A comparison between ASAID-calculated ice shelf thicknesses and BEDMAP-compiled data indicate a thin-ice bias of 41.2 ± 71.3 m for the ASAID ice thicknesses. The relationship between the seaward offset of the hydrostatic line

  11. Getting around Antarctica: New High-Resolution Mappings of the Grounded and Freely-Floating Boundaries of the Antarctic Ice Sheet Created for the International Polar Year

    Science.gov (United States)

    Bindschadler, R.; Choi, H.; Wichlacz, A.; Bingham, R.; Bohlander, J.; Brunt, K.; Corr, H.; Drews, R.; Fricker, H.; Hall, M.; hide

    2011-01-01

    Two ice-dynamic transitions of the Antarctic ice sheet - the boundary of grounded ice features and the freely-floating boundary - are mapped at 15-m resolution by participants of the International Polar Year project ASAID using customized software combining Landsat-7 imagery and ICESat/GLAS laser altimetry. The grounded ice boundary is 53 610 km long; 74% abuts to floating ice shelves or outlet glaciers, 19% is adjacent to open or sea-ice covered ocean, and 7% of the boundary ice terminates on land. The freely-floating boundary, called here the hydrostatic line, is the most landward position on ice shelves that expresses the full amplitude of oscillating ocean tides. It extends 27 521 km and is discontinuous. Positional (one-sigma) accuracies of the grounded ice boundary vary an order of magnitude ranging from +/- 52m for the land and open-ocean terminating segments to +/- 502m for the outlet glaciers. The hydrostatic line is less well positioned with errors over 2 km. Elevations along each line are selected from 6 candidate digital elevation models based on their agreement with ICESat elevation values and surface shape inferred from the Landsat imagery. Elevations along the hydrostatic line are converted to ice thicknesses by applying a firn-correction factor and a flotation criterion. BEDMAP-compiled data and other airborne data are compared to the ASAID elevations and ice thicknesses to arrive at quantitative (one-sigma) uncertainties of surface elevations of +/-3.6, +/-9.6, +/-11.4, +/-30 and +/-100m for five ASAID-assigned confidence levels. Over one-half of the surface elevations along the grounded ice boundary and over one-third of the hydrostatic line elevations are ranked in the highest two confidence categories. A comparison between ASAID-calculated ice shelf thicknesses and BEDMAP-compiled data indicate a thin-ice bias of 41.2+/-71.3m for the ASAID ice thicknesses. The relationship between the seaward offset of the hydrostatic line from the grounded ice

  12. An Ultra-Wideband, Microwave Radar for Measuring Snow Thickness on Sea Ice and Mapping Near-Surface Internal Layers in Polar Firn

    Science.gov (United States)

    Panzer, Ben; Gomez-Garcia, Daniel; Leuschen, Carl; Paden, John; Rodriguez-Morales, Fernando; Patel, Azsa; Markus, Thorsten; Holt, Benjamin; Gogineni, Prasad

    2013-01-01

    Sea ice is generally covered with snow, which can vary in thickness from a few centimeters to >1 m. Snow cover acts as a thermal insulator modulating the heat exchange between the ocean and the atmosphere, and it impacts sea-ice growth rates and overall thickness, a key indicator of climate change in polar regions. Snow depth is required to estimate sea-ice thickness using freeboard measurements made with satellite altimeters. The snow cover also acts as a mechanical load that depresses ice freeboard (snow and ice above sea level). Freeboard depression can result in flooding of the snow/ice interface and the formation of a thick slush layer, particularly in the Antarctic sea-ice cover. The Center for Remote Sensing of Ice Sheets (CReSIS) has developed an ultra-wideband, microwave radar capable of operation on long-endurance aircraft to characterize the thickness of snow over sea ice. The low-power, 100mW signal is swept from 2 to 8GHz allowing the air/snow and snow/ ice interfaces to be mapped with 5 c range resolution in snow; this is an improvement over the original system that worked from 2 to 6.5 GHz. From 2009 to 2012, CReSIS successfully operated the radar on the NASA P-3B and DC-8 aircraft to collect data on snow-covered sea ice in the Arctic and Antarctic for NASA Operation IceBridge. The radar was found capable of snow depth retrievals ranging from 10cm to >1 m. We also demonstrated that this radar can be used to map near-surface internal layers in polar firn with fine range resolution. Here we describe the instrument design, characteristics and performance of the radar.

  13. Proceedings of the 18th International Conference on Engineering Design (ICED11)

    DEFF Research Database (Denmark)

    Maier, Anja; Mougaard, Krestine; Howard, Thomas J.

    The ICED series of conferences is the Design Society's "flagship" event. ICED11 took place on August 15-18, 2011, at the campus of the Danish Technical University in Lyngby/Copenhagen, Denmark. The Proceedings of the conference are published in 10 individual volumes, arranged according to topics....... All volumes of the Proceedings may be purchased individually through Amazon and other on-line booksellers. For members of the Design Society, all papers are available on this website. The Programme and Abstract Book is publically available for download....

  14. Prowling proboscises promise probity in anti-pollution patrol

    Energy Technology Data Exchange (ETDEWEB)

    Mackay, B B

    1980-11-01

    The Louisiana Environmental Control Commission (ECC) has required that Rollins Environmental Services, a multi-million dollar waste disposal facility, prevent odors from leaving the property. Failure could result in a penalty of $2000/day and possible closing of the facility. To enforce this mandate, ECC has appointed seven people to serve on a special task force, known as the Nose Patrol. Using their sense of smell, these seven people will determine compliance or non-compliance with the odor edict. Problems with using untrained people to detect odors from a particular facility, especially when the entire area is filled with industrial facilities, are identified. (1 drawing)

  15. GATEWAY Demonstrations: Trial Demonstration of Area Lighting Retrofit, Yuma Border Patrol, Yuma, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, A. M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McCullough, J. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-31

    Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial demonstration in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations at the Yuma Sector Border Patrol Area in Yuma, Arizona. The retrofit was documented to better understand LED technology performance in high-temperature environments.

  16. Propagation of Uncertainties in Sea Ice Thickness Calculations From Basin-Scale Operational Observations: A Report Prepared for the International Ice Charting Working Group and the National/Naval Ice Center

    National Research Council Canada - National Science Library

    Geiger, Cathleen A

    2006-01-01

    Sea ice serves as a natural flux monitor of the global heat balance. This capability is attributed to the unique location of sea ice at the interface of the world's two largest circulation systems the air and ocean...

  17. A STUDY ON INTERNATIONAL BRAND ICE CREAM IN INDIAN MARKET SPECIAL REFERENCE TO COIMBATORE

    OpenAIRE

    R. Belliraj; Dr. D. Santhanakrishnan

    2018-01-01

    The brand awareness place a big role in influencing the customers purchase decision. Best marketing and brand awareness activity in current scenario is advertisement therefore effective advertisement should be made to attract more customers. In Indian ice cream industry where switching cost is negligible a product can’t be placed in the market on the basis of brand alone, but it should match the spending power of the customers and cordial relationship. The manager of the outlet has to adopt v...

  18. High-speed railway signal trackside equipment patrol inspection system

    Science.gov (United States)

    Wu, Nan

    2018-03-01

    High-speed railway signal trackside equipment patrol inspection system comprehensively applies TDI (time delay integration), high-speed and highly responsive CMOS architecture, low illumination photosensitive technique, image data compression technique, machine vision technique and so on, installed on high-speed railway inspection train, and achieves the collection, management and analysis of the images of signal trackside equipment appearance while the train is running. The system will automatically filter out the signal trackside equipment images from a large number of the background image, and identify of the equipment changes by comparing the original image data. Combining with ledger data and train location information, the system accurately locate the trackside equipment, conscientiously guiding maintenance.

  19. Remote Control of a Mobile Robot for Indoor Patrol

    Directory of Open Access Journals (Sweden)

    Shih-Yao Juang

    2016-03-01

    Full Text Available This study applies smartphone, Bluetooth, and Wi-Fi wireless network to control a wheeled mobile robot (WMR remotely. The first part of this study demonstrates that the WMR can be controlled manually by a smartphone. The smartphone can remotely control the WMR for forward, backward, left-turn, and right-turn operations. The second part of this article presents object tracking. The WMR can follow a moving object through the use of image processing for object tracking and distance detection. In the third part, infrared sensor and fuzzy system algorithms are integrated into the control scheme. Through wall-following and obstacle-avoidance control, the WMR can successfully perform indoor patrol.

  20. Path Planning Algorithms for Autonomous Border Patrol Vehicles

    Science.gov (United States)

    Lau, George Tin Lam

    This thesis presents an online path planning algorithm developed for unmanned vehicles in charge of autonomous border patrol. In this Pursuit-Evasion game, the unmanned vehicle is required to capture multiple trespassers on its own before any of them reach a target safe house where they are safe from capture. The problem formulation is based on Isaacs' Target Guarding problem, but extended to the case of multiple evaders. The proposed path planning method is based on Rapidly-exploring random trees (RRT) and is capable of producing trajectories within several seconds to capture 2 or 3 evaders. Simulations are carried out to demonstrate that the resulting trajectories approach the optimal solution produced by a nonlinear programming-based numerical optimal control solver. Experiments are also conducted on unmanned ground vehicles to show the feasibility of implementing the proposed online path planning algorithm on physical applications.

  1. Forensic science information needs of patrol officers: The perceptions of the patrol officers, their supervisors and administrators, detectives, and crime scene technicians

    Science.gov (United States)

    Aydogdu, Eyup

    Thanks to the rapid developments in science and technology in recent decades, especially in the past two decades, forensic sciences have been making invaluable contributions to criminal justice systems. With scientific evaluation of physical evidence, policing has become more effective in fighting crime and criminals. On the other hand, law enforcement personnel have made mistakes during the detection, protection, collection, and evaluation of physical evidence. Law enforcement personnel, especially patrol officers, have been criticized for ignoring or overlooking physical evidence at crime scenes. This study, conducted in a large American police department, was aimed to determine the perceptions of patrol officers, their supervisors and administrators, detectives, and crime scene technicians about the forensic science needs of patrol officers. The results showed no statistically significant difference among the perceptions of the said groups. More than half of the respondents perceived that 14 out of 16 areas of knowledge were important for patrol officers to have: crime scene documentation, evidence collection, interviewing techniques, firearm evidence, latent and fingerprint evidence, blood evidence, death investigation information, DNA evidence, document evidence, electronically recorded evidence, trace evidence, biological fluid evidence, arson and explosive evidence, and impression evidence. Less than half of the respondents perceived forensic entomology and plant evidence as important for patrol officers.

  2. The initiative of the ICES MR: Children teach their parents[International Center for Environmental Safety of Minatom of Russia (ICES MR)

    Energy Technology Data Exchange (ETDEWEB)

    Krupenina, Faina [International Center for Environmental Safety of Minatom of Russia, (ICES MR), 26, Staromonetny per., 109180 Moscow (Russian Federation)

    2002-07-01

    Air and soil pollution, increased water discharge and energy consumption, forest and plant fires are often caused by low general and ecological culture. Nuclear power has long been a main target of environmental campaigners, in Europe as well as America. The past 200 years have seemed to reinforce their case: the Chernobyl accident was compounded by fears that a similar disaster could occur in any of the antiquated graphite-cooled reactors, revelations that leaks and mishaps from Windscale/Sellafield were far worse than originally reported, campaigns against reprocessing in Germany and Japan and alarming data on nuclear hazards from sunken Russian submarines and leaking waste storage tanks. The International Center for Environmental Safety of Minatom of Russia (ICES MR) is an autonomous non-commercial organisation. The mission of the Center is to assist in environment improving and consolidation of international contacts in environmental safety, to assist in development of te positive public perception of nuclear power. We attach great significance to interaction with the public, administrations of regions and State Duma deputies. Very often a dread of radiation and protests against nuclear power development are caused by lack or insufficiency of information concerning what is radiation, how it influences a human being and nature, where is real and not made-up danger. Here it is very important to organize work with the youth. Our first experience was a Children Ecological Olympiad 'Sozvezdie'. The Olympiad was held in the Russian Cosmonauts Training Center in Zvezdny gorodok in May 2001. It has a success and showed the strong interest of schoolchildren, their parents and teachers in environmental problems, in the nuclear power as an environment friendly energy production. Together with the UNESCO department and the Youth Department of Russian Nuclear Society for youth interaction we have prepared proposals concerning establishing Youth Environmental Centers in

  3. Scenario-based Analysis: Scheduling Activities for the Patrol Boat Force

    National Research Council Canada - National Science Library

    2003-01-01

    The objectives of these briefing charts were to discuss the understanding and the implications of the current government guidance for new patrol boat fleet and find better ways to manage the new fleet...

  4. Barrier Patrol and Air Defense System: Developing and Integrating Flight Profiles

    National Research Council Canada - National Science Library

    Bianchi, Luiz

    2002-01-01

    ...) This aircraft and the types of missions it can support are innovative in the Brazilian Air Force, The R-99 will be used for patrolling the Brazilian borders and interception control of illicit air...

  5. Evaluation of Personal Chemical Vapor Protection for Patrol and Tactical Law Enforcement

    National Research Council Canada - National Science Library

    Fedele, Paul D; Lake, William L; Arca, Victor J; Marshall, Stephen M; Mitchell, David B

    2002-01-01

    In Domestic Preparedness efforts, the US Army Soldier and Biological Chemical Command and the Maryland State Police, have evaluated personal chemical protective systems for use in patrol and tactical...

  6. Design of Power Cable UAV Intelligent Patrol System Based on Adaptive Kalman Filter Fuzzy PID Control

    Directory of Open Access Journals (Sweden)

    Chen Siyu

    2017-01-01

    Full Text Available Patrol UAV has poor aerial posture stability and is largely affected by anthropic factors, which lead to some shortages such as low power cable tracking precision, captured image loss and inconvenient temperature measurement, etc. In order to solve these disadvantages, this article puts forward a power cable intelligent patrol system. The core innovation of the system is a 360° platform. This collects the position information of power cables by using far infrared sensors and carries out real-time all-direction adjustment of UAV lifting platform through the adaptive Kalman filter fuzzy PID control algorithm, so that the precise tracking of power cables is achieved. An intelligent patrol system is established to detect the faults more accurately, so that a high intelligence degree of power cable patrol system is realized.

  7. Keeping pace with criminals: An extended study of designing patrol allocation against adaptive opportunistic criminals

    OpenAIRE

    Zhang, Chao; Gholami, Shahrzad; Kar, Debarun; Sinha, Arunesh; Jain, Manish; Goyal, Ripple; Tambe, Milind

    2016-01-01

    Game theoretic approaches have recently been used to model the deterrence effect of patrol officers’ assignments on opportunistic crimes in urban areas. One major challenge in this domain is modeling the behavior of opportunistic criminals. Compared to strategic attackers (such as terrorists) who execute a well-laid out plan, opportunistic criminals are less strategic in planning attacks and more flexible in executing well-laid plans based on their knowledge of patrol officers’ assignments. I...

  8. Indoor Surveillance Security Robot with a Self-Propelled Patrolling Vehicle

    Directory of Open Access Journals (Sweden)

    Hou-Tsan Lee

    2011-01-01

    Full Text Available Self-propelled patrolling vehicles can patrol periodically in the designed area to ensure the safety like men do. The proposed vehicle cannot only save manpower, but also ensure the performance without mistakes caused by man. It is different from the traditional patrolling system which is limited by the manpower and the fixed camera positions. To improve such situation, this paper proposes a self-propelled patrolling vehicle which can move automatically to a wider range and record the monitored image by IPCAM within a predefined patrolling route. Besides, the user can use the mobile device or website to connect to the vehicle at anytime and anywhere and control it to move to the position to get the indoor image user wants. The position of self-propelled vehicles can be detected by the RFID reader as a feedback and be shown on the PC screen and smart phone. The recorded images can be also transmitted back to the server via WiFi system for face tracking and discriminating analysis. On the other hand, the self-propelled vehicle patrolling routes can be modified by the Android smart-phone remote-control module. When some defined events occur, the build-in MSN module will notice users by sending messages to PC and smart phone. Experimental results are given in the paper to validate its performance.

  9. Proceedings of ICETECH 2008 : the 8. international conference and exhibition on performance of ships and structures in ice. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Bercha, F. (ed.) [Bercha Group, Calgary, AB (Canada); Bercha, S. (comp.) [Bercha Group, Calgary, AB (Canada); Pilkington, R. [CANATEC Associates International Ltd., Calgary, AB (Canada)

    2008-09-15

    The rapid growth and renewed interest in oil and gas exploration and production in Arctic offshore regions has resulted in an increase in maritime transport through northern sea routes, including the Canadian Northwest Passage. This conference included both plenary and technical sessions which addressed issues facing offshore resource development in ice-covered areas, such as construction of offshore platforms; pipelines and facilities; and ice-structure interactions in terms of ice loads and ice mechanics. New offshore developments in ice-covered areas were discussed with reference to potential damage caused by dynamic ice loads, risk assessment, personnel safety, and emergency evacuation rescue. The global warming implications to the Arctic were also discussed along with Arctic geopolitics. The technical session on ships addressed ship performance in ice; propulsion systems; offshore operations; ice loads and hull strength; and icebreaker designs. Ice properties and observations were reviewed along with ice detection and mapping techniques. Developments in the Sakhalin Sea were reviewed along with codes, regulations and standards. Other technical sessions included ice scour and gouging; Arctic escape, evacuation and rescue (EER) operations; oil spill protection and response; and a special session on Arctic marine shipping assessment (AMSA). The conference featured 63 presentations, of which 24 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  10. Proceedings of ICETECH 2008 : the 8. international conference and exhibition on performance of ships and structures in ice. 2. ed.

    International Nuclear Information System (INIS)

    Bercha, F.; Bercha, S.; Pilkington, R.

    2008-09-01

    The rapid growth and renewed interest in oil and gas exploration and production in Arctic offshore regions has resulted in an increase in maritime transport through northern sea routes, including the Canadian Northwest Passage. This conference included both plenary and technical sessions which addressed issues facing offshore resource development in ice-covered areas, such as construction of offshore platforms; pipelines and facilities; and ice-structure interactions in terms of ice loads and ice mechanics. New offshore developments in ice-covered areas were discussed with reference to potential damage caused by dynamic ice loads, risk assessment, personnel safety, and emergency evacuation rescue. The global warming implications to the Arctic were also discussed along with Arctic geopolitics. The technical session on ships addressed ship performance in ice; propulsion systems; offshore operations; ice loads and hull strength; and icebreaker designs. Ice properties and observations were reviewed along with ice detection and mapping techniques. Developments in the Sakhalin Sea were reviewed along with codes, regulations and standards. Other technical sessions included ice scour and gouging; Arctic escape, evacuation and rescue (EER) operations; oil spill protection and response; and a special session on Arctic marine shipping assessment (AMSA). The conference featured 63 presentations, of which 24 have been catalogued separately for inclusion in this database. refs., tabs., figs

  11. Internal combustion engine report: Spark ignited ICE GenSet optimization and novel concept development

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; Blarigan, P. Van [Sandia National Labs., Livermore, CA (United States)

    1998-08-01

    In this manuscript the authors report on two projects each of which the goal is to produce cost effective hydrogen utilization technologies. These projects are: (1) the development of an electrical generation system using a conventional four-stroke spark-ignited internal combustion engine generator combination (SI-GenSet) optimized for maximum efficiency and minimum emissions, and (2) the development of a novel internal combustion engine concept. The SI-GenSet will be optimized to run on either hydrogen or hydrogen-blends. The novel concept seeks to develop an engine that optimizes the Otto cycle in a free piston configuration while minimizing all emissions. To this end the authors are developing a rapid combustion homogeneous charge compression ignition (HCCI) engine using a linear alternator for both power take-off and engine control. Targeted applications include stationary electrical power generation, stationary shaft power generation, hybrid vehicles, and nearly any other application now being accomplished with internal combustion engines.

  12. Proceedings of ICES 2015 International Conference : Asian Economy at the Crossroad : China, India, and ASEAN

    OpenAIRE

    Xu, Peng; Esho, Hideki

    2015-01-01

    There are conflicting views on the impact of political conflict on economic relations from the literature of international political economics. We use quarterly data to investigate the effects of political relation on export flows between China and certain countries in East Asia from 1980 to 2013 while controlling the role of the economic power of China. The results suggest that the political relations between China and East Asia countries impact their trade volume significantly which support...

  13. On guard - Ice patrol out to make sure oil platform is no Titanic

    Energy Technology Data Exchange (ETDEWEB)

    Harvie, W.

    1997-12-01

    For offshore oil operations floating icebergs represent a formidable danger. Hibernia is the only one among major offshore sites that faces this particular problem. Accordingly, an elaborate system of iceberg surveillance has been set up. The four-part strategy in place, consisting of surveillance, monitoring, deflection and the iceberg protection features designed into the platform itself, are described in this paper. The essence of the plans is that every iceberg that moves south of the 48th parallel is reported to the St. John`s based Seaborne Information Technologies Ltd., an iceberg information clearinghouse on contract to Hibernia, by passing aircraft, fishing vessels, freighters and others at sea or over the sea. Each occurrence is plotted and monitored. If any of them enters Hibernia`s `tactical zone`, a ring extending 24 nautical miles around the platform, surveillance is intensified and wind and drift patterns are plotted. Deflection becomes a real option when the iceberg enters a ring six nautical miles from the platform. Although icebergs can weigh anywhere up to 5 million tonnes, a slight nudge can cause a degree or two of deflection, enough to send the iceberg sailing past the platform. Smaller icebergs are pushed with prop wash or water cannon aboard the Hibernia supply ships. Larger bergs are lassoed with ropes and dragged a short distance to head them on a different course. The platform itself has a 1.4 metre thick icewall, equipped with 16 teeth to distribute the force on the entire structure should an iceberg actually manage to hit the platform itself. The teeth are designed to withstand a direct hit from a one million tonne iceberg without damage. Statistically, such an event can be expected to occur once every 500 years.

  14. Ice Sheets & Ice Cores

    DEFF Research Database (Denmark)

    Mikkelsen, Troels Bøgeholm

    Since the discovery of the Ice Ages it has been evident that Earth’s climate is liable to undergo dramatic changes. The previous climatic period known as the Last Glacial saw large oscillations in the extent of ice sheets covering the Northern hemisphere. Understanding these oscillations known....... The first part concerns time series analysis of ice core data obtained from the Greenland Ice Sheet. We analyze parts of the time series where DO-events occur using the so-called transfer operator and compare the results with time series from a simple model capable of switching by either undergoing...

  15. Ice, Ice, Baby!

    Science.gov (United States)

    Hamilton, C.

    2008-12-01

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

  16. CLUSTERING ANALYSIS OF OFFICER'S BEHAVIOURS IN LONDON POLICE FOOT PATROL ACTIVITIES

    Directory of Open Access Journals (Sweden)

    J. Shen

    2015-07-01

    Full Text Available In this small paper we aim at presenting a framework of conceptual representation and clustering analysis of police officers’ patrol pattern obtained from mining their raw movement trajectory data. This have been achieved by a model developed to accounts for the spatio-temporal dynamics human movements by incorporating both the behaviour features of the travellers and the semantic meaning of the environment they are moving in. Hence, the similarity metric of traveller behaviours is jointly defined according to the stay time allocation in each Spatio-temporal region of interests (ST-ROI to support clustering analysis of patrol behaviours. The proposed framework enables the analysis of behaviour and preferences on higher level based on raw moment trajectories. The model is firstly applied to police patrol data provided by the Metropolitan Police and will be tested by other type of dataset afterwards.

  17. Pregnancy outcomes after paternal radiofrequency field exposure aboard fast patrol boats.

    Science.gov (United States)

    Baste, Valborg; Moen, Bente E; Oftedal, Gunnhild; Strand, Leif Age; Bjørge, Line; Mild, Kjell Hansson

    2012-04-01

    To investigate adverse reproductive outcomes among male employees in the Royal Norwegian Navy exposed to radiofrequency electromagnetic fields aboard fast patrol boats. Cohort study of Royal Norwegian Navy servicemen linked to the Medical Birth Registry of Norway, including singleton offspring born between 1967 and 2008 (n = 37,920). Exposure during the last 3 months before conception (acute) and exposure more than 3 months before conception (nonacute) were analyzed. Perinatal mortality and preeclampsia increased after service aboard fast patrol boats during an acute period and also after increased estimated radiofrequency exposure during an acute period, compared with service aboard other vessels. No associations were found between nonacute exposure and any of the reproductive outcomes. Paternal work aboard fast patrol boats during an acute period was associated with perinatal mortality and preeclampsia, but the cause is not clear.

  18. Keeping Pace with Criminals: An Extended Study of Designing Patrol Allocation against Adaptive Opportunistic Criminals

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2016-06-01

    Full Text Available Game theoretic approaches have recently been used to model the deterrence effect of patrol officers’ assignments on opportunistic crimes in urban areas. One major challenge in this domain is modeling the behavior of opportunistic criminals. Compared to strategic attackers (such as terrorists who execute a well-laid out plan, opportunistic criminals are less strategic in planning attacks and more flexible in executing well-laid plans based on their knowledge of patrol officers’ assignments. In this paper, we aim to design an optimal police patrolling strategy against opportunistic criminals in urban areas. Our approach is comprised by two major parts: learning a model of the opportunistic criminal (and how he or she responds to patrols and then planning optimal patrols against this learned model. The planning part, by using information about how criminals responds to patrols, takes into account the strategic game interaction between the police and criminals. In more detail, first, we propose two categories of models for modeling opportunistic crimes. The first category of models learns the relationship between defender strategy and crime distribution as a Markov chain. The second category of models represents the interaction of criminals and patrol officers as a Dynamic Bayesian Network (DBN with the number of criminals as the unobserved hidden states. To this end, we: (i apply standard algorithms, such as Expectation Maximization (EM, to learn the parameters of the DBN; (ii modify the DBN representation that allows for a compact representation of the model, resulting in better learning accuracy and the increased speed of learning of the EM algorithm when used for the modified DBN. These modifications exploit the structure of the problem and use independence assumptions to factorize the large joint probability distributions. Next, we propose an iterative learning and planning mechanism that periodically updates the adversary model. We

  19. Research on Line Patrol Strategy of 110kV Transmission Line after Lightning Strike

    Directory of Open Access Journals (Sweden)

    Li Mingjun

    2016-01-01

    Full Text Available Lightning faults occupy in the majority of instantaneous fault and reclosing can usually be successful, so power supply can be restored without immediate patrol in many cases. Firstly, this paper introduces the lightning fault positioning and identifying method. Then test electrical performance of insulators after lightning strike from 110kV lines. Data shows that lightning strike has little effect on the electric performance of insulator. Finally, illustrating disposal process of the 110 kV transmission line after lightning fault, certifying that the power supply reliability be ensured without line patrol.

  20. Patrol car and agent tracking/suspect tagging and tracking

    Science.gov (United States)

    Wilkins, Steven C.

    1997-01-01

    Emerging technologies in the field of law enforcement are providing today's law enforcement personnel with the advantage of an innovative and faster means of providing safety and service to the public. The use of open such technology, the Automatic Vehicle Locator (AVL) tracking device, is fast becoming a commonplace and cost-effective solution for agencies to efficiently command and control their 'officer' assets. Through the use of AVL's global positioning satellite-based system, the response time of law enforcement is greatly enhanced by permitting a dispatcher to visually identify and assign the officer closest to the location of an accident or incident. The system is effective in reducing delays due to highway blockages, improving the level of protection to the motoring public, and promoting the flow of traffic on busy freeways. Likewise, an officer or agent in distress can be assured that a dispatcher will be constantly aware of his or her location in the field. In the 1990's the demands on law enforcement agencies have grown tremendously. this is due primarily to population increases, limited funding or resources, and increases in drug, property and violent crimes. Frequently, the automobile is used for escape after the commission of these crimes. This often results in high speed pursuits involving law enforcement agencies. In California, by statute, the California Highway Patrol is the central repository for data regarding all pursuits involving state and local law enforcement agencies. Statistics show that more than 10 percent of pursuits result in injuries to the violator and/or innocent bystanders. Most pursuits last less than 10 minutes, and the AVL system provides a tremendous advantage to law enforcement's ability to immediately deploy and direct units into pursuits for rapid closure of the incident. AVL systems not only reduce the risk of personal injury by minimizing public exposure to the unsafe incident, but also enhance officer safety during the

  1. Space Solar Patrol data and changes in weather and climate, including global warming

    Science.gov (United States)

    Avakyan, S. V.; Baranova, L. A.; Leonov, N. B.; Savinov, E. P.; Voronin, N. A.

    2010-08-01

    In this paper, the results obtained during the execution of several ISTC projects are presented. The general aim of these projects has been the study of global changes in the environment, connected with solar activity. A brief description of the optical apparatus of the Space Solar Patrol (SSP) developed and built in the framework of the ISTC projects 385, 385.2, 1523 and 2500 is given. The SSP is intended for permanent monitoring of spectra and absolute fluxes of soft x-ray and extreme ultraviolet (x-ray/EUV) radiation from the full disk of the Sun which ionizes the upper atmosphere of the Earth. Permanent solar monitoring in the main part of the ionizing radiation spectra 0.8-115 (119) nm does not exist. The apparatus of the SSP was developed in the years 1996-2005 with multiyear experience of developing such apparatus in S I Vavilov State Optical Institute. The basis of this apparatus is the use of unique detectors of ionizing radiation—open secondary electron multipliers, which are 'solar blind' to near UV, visible and IR radiation from the Sun, and new methodology of these solar spectroradiometric absolute measurements. The prospects are discussed of using the SSP data for the investigation and forecast of the influence of solar variability on the weather and climate including global warming and also on the biosphere including human beings (proposal 3878). This article was originally submitted for inclusion with the papers from the 9th International Symposium on Measurement Science and Intelligent Instruments (ISMTII-2009), published in the May 2010 issue.

  2. A design of toxic gas detecting security robot car based on wireless path-patrol

    Directory of Open Access Journals (Sweden)

    Cheng Ho-Chih

    2017-01-01

    Full Text Available Because a toxic gas detecting/monitoring system in a chemical plant is not movable, a gas detecting/monitoring system will be passive and the detecting range will also be constrained. This invention is an active multi-functional wireless patrol car that can substitute for humans that inspect a plant's security. In addition, to widen the monitoring vision within the environment, two motors used to rotate a wireless IPCAM with two axes are presented. Also, to control the robot car's movement, two axis motors used to drive the wheel of the robot car are also installed. Additionally, a toxic gas detector is linked to the microcontroller of the patrol car. The detected concentration of the gas will be fed back to the server pc. To enhance the robot car's patrolling duration, a movable electrical power unit in conjunction with a wireless module is also used. Consequently, this paper introduces a wireless path-patrol and toxic gas detecting security robot car that can assure a plant's security and protect workers when toxic gases are emitted.

  3. 78 FR 21610 - Expansion Funds for the Support of the Senior Medicare Patrol (SMP) Program

    Science.gov (United States)

    2013-04-11

    ... Grants. Announcement Type: Health Care Fraud Prevention Program Expansion Capacity. Funding Opportunity... DEPARTMENT OF HEALTH AND HUMAN SERVICES Administration for Community Living Expansion Funds for the Support of the Senior Medicare Patrol (SMP) Program ACTION: Notice of intent to provide expansion...

  4. 76 FR 41260 - Supplemental Funding for the Senior Medicare Patrol (SMP) Program

    Science.gov (United States)

    2011-07-13

    ... additional funding to double the size of the SMP program. The SMP program expansion has resulted in... DEPARTMENT OF HEALTH AND HUMAN SERVICES Administration on Aging Supplemental Funding for the Senior Medicare Patrol (SMP) Program ACTION: Notice of intent to provide supplemental funding to the...

  5. EXPOSURE TO PARTICULATE MATTER, VOLATILE ORGANIC COMPOUNDS, AND OTHER AIR POLLUTANTS INSIDE PATROL CARS

    Science.gov (United States)

    People driving in a vehicle might receive an enhanced dose of mobile source pollutants that are considered a potential risk for cardiovascular diseases. The exposure to components of air pollution in highway patrol vehicles, at an ambient, and a roadside location was determined d...

  6. Tracking Object Existence From an Autonomous Patrol Vehicle

    Science.gov (United States)

    Wolf, Michael; Scharenbroich, Lucas

    2011-01-01

    An autonomous vehicle patrols a large region, during which an algorithm receives measurements of detected potential objects within its sensor range. The goal of the algorithm is to track all objects in the region over time. This problem differs from traditional multi-target tracking scenarios because the region of interest is much larger than the sensor range and relies on the movement of the sensor through this region for coverage. The goal is to know whether anything has changed between visits to the same location. In particular, two kinds of alert conditions must be detected: (1) a previously detected object has disappeared and (2) a new object has appeared in a location already checked. For the time an object is within sensor range, the object can be assumed to remain stationary, changing position only between visits. The problem is difficult because the upstream object detection processing is likely to make many errors, resulting in heavy clutter (false positives) and missed detections (false negatives), and because only noisy, bearings-only measurements are available. This work has three main goals: (1) Associate incoming measurements with known objects or mark them as new objects or false positives, as appropriate. For this, a multiple hypothesis tracker was adapted to this scenario. (2) Localize the objects using multiple bearings-only measurements to provide estimates of global position (e.g., latitude and longitude). A nonlinear Kalman filter extension provides these 2D position estimates using the 1D measurements. (3) Calculate the probability that a suspected object truly exists (in the estimated position), and determine whether alert conditions have been triggered (for new objects or disappeared objects). The concept of a probability of existence was created, and a new Bayesian method for updating this probability at each time step was developed. A probabilistic multiple hypothesis approach is chosen because of its superiority in handling the

  7. Risk factors for dermatitis in submariners during a submerged patrol: an observational cohort study.

    Science.gov (United States)

    Flaxman, Amy; Allen, Elizabeth; Lindemann, Claudia; Yamaguchi, Yuko; O'Shea, Matthew K; Fallowfield, Joanne L; Lindsay, Michael; Gunner, Frances; Knox, Kyle; Wyllie, David H

    2016-06-02

    The aim of this pilot study was to determine risk factors, including Staphylococcus aureus nasal carriage, for dermatitis in submariners during a submarine patrol. 36 submariners undertaking a submerged 6-week patrol participated in the study. Severity of dermatitis and its impact was assessed using visual analogue scales and questionnaires at baseline and weekly throughout the patrol. S. aureus carriage levels in submariners were determined by nasal swabbing at baseline and shortly before disembarking the submarine. Occurrence of any skin or soft tissue infections (SSTI) were reported to the medical officer and swabs of the area were taken for subsequent analysis. S. aureus carriers were significantly more likely than non-carriers to have previously received treatment for a cutaneous abscess (39% vs 5%, OR=13 (95% CI 1.3 to 130)) with a trend to being submariners longer (p=0.051). Skin scores at baseline and on patrol were not significantly associated with carriage status. Higher dermatitis scores were observed in those who had been submariners longer (p=0.045). Smoking and allergies were not found to be linked to carriage status or skin health score in this cohort. This small pilot study investigates S. aureus carriage status and skin health in submariners. Length of submarine service but not S. aureus carriage was identified as a risk factor for worsening skin health in this small cohort during a 6-week patrol. This does not support S. aureus decolonisation to improve skin health in this population. Further investigation into causes of dermatitis in submariners is required. This data supports a better understanding of the potential impact of exposure to environmental factors that could affect skin health in submariners. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  8. A century of variation in the dependence of Greenland iceberg calving on ice sheet surface mass balance and regional climate change.

    Science.gov (United States)

    Bigg, G R; Wei, H L; Wilton, D J; Zhao, Y; Billings, S A; Hanna, E; Kadirkamanathan, V

    2014-06-08

    Iceberg calving is a major component of the total mass balance of the Greenland ice sheet (GrIS). A century-long record of Greenland icebergs comes from the International Ice Patrol's record of icebergs (I48N) passing latitude 48° N, off Newfoundland. I48N exhibits strong interannual variability, with a significant increase in amplitude over recent decades. In this study, we show, through a combination of nonlinear system identification and coupled ocean-iceberg modelling, that I48N's variability is predominantly caused by fluctuation in GrIS calving discharge rather than open ocean iceberg melting. We also demonstrate that the episodic variation in iceberg discharge is strongly linked to a nonlinear combination of recent changes in the surface mass balance (SMB) of the GrIS and regional atmospheric and oceanic climate variability, on the scale of the previous 1-3 years, with the dominant causal mechanism shifting between glaciological (SMB) and climatic (ocean temperature) over time. We suggest that this is a change in whether glacial run-off or under-ice melting is dominant, respectively. We also suggest that GrIS calving discharge is episodic on at least a regional scale and has recently been increasing significantly, largely as a result of west Greenland sources.

  9. Are ranger patrols effective in reducing poaching-related threats within protected areas?

    Science.gov (United States)

    Moore, Jennnifer F.; Mulindahabi, Felix; Masozera, Michel K.; Nichols, James; Hines, James; Turikunkiko, Ezechiel; Oli, Madan K.

    2018-01-01

    Poaching is one of the greatest threats to wildlife conservation world-wide. However, the spatial and temporal patterns of poaching activities within protected areas, and the effectiveness of ranger patrols and ranger posts in mitigating these threats, are relatively unknown.We used 10 years (2006–2015) of ranger-based monitoring data and dynamic multi-season occupancy models to quantify poaching-related threats, to examine factors influencing the spatio-temporal dynamics of these threats and to test the efficiency of management actions to combat poaching in Nyungwe National Park (NNP), Rwanda.The probability of occurrence of poaching-related threats was highest at lower elevations (1,801–2,200 m), especially in areas that were close to roads and tourist trails; conversely, occurrence probability was lowest at high elevation sites (2,601–3,000 m), and near the park boundary and ranger posts. The number of ranger patrols substantially increased the probability that poaching-related threats disappear at a site if threats were originally present (i.e. probability of extinction of threats). Without ranger visits, the annual probability of extinction of poaching-related threats was an estimated 7%; this probability would increase to 20% and 57% with 20 and 50 ranger visits per year, respectively.Our results suggest that poaching-related threats can be effectively reduced in NNP by adding ranger posts in areas where they do not currently exist, and by increasing the number of patrols to sites where the probability of poaching activities is high.Synthesis and applications. Our application of dynamic occupancy models to predict the probability of presence of poaching-related threats is novel, and explicitly considers imperfect detection of illegal activities. Based on the modelled relationships, we identify areas that are most vulnerable to poaching, and offer insights regarding how ranger patrols can be optimally deployed to reduce poaching-related threats and

  10. GATEWAY Demonstrations: LED System Performance in a Trial Installation--Two Years Later, Yuma Border Patrol, Yuma, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sullivan, Gregory P. [Efficiency Solutions, Inc., Richland, WA (United States); Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-04-01

    Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial demonstration in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations at the Yuma Sector Border Patrol Area in Yuma, Arizona. The retrofit was documented to better understand LED technology performance in high-temperature environments. This report follows the GATEWAY Yuma Phase 1.1 Report and reflects LED system results documented two years after the demonstration began.

  11. Trial Demonstration of Area Lighting Retrofit: Yuma Border Patrol, Yuma Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McCullough, Jeffrey J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    The Yuma Sector Border Patrol Area is a high flux lighting application in a high temperature environment, presenting a formidable challenge for light-emitting diodes (LEDs). This retrofit is an Energy Savings Performance Contract ENABLE project under the U.S. Department of Energy (DOE) Federal Energy Management Program. If high flux LED technology performs well in a region with high ambient temperature and solar radiation, it can perform well in most outdoor environments. The design process for the Yuma retrofit has already provided valuable knowledge to CBP and DOE. The LED lighting system selected for the retrofit is expected to reduce energy consumption 69% compared to the incumbent quartz metal halide (QMH) lighting system. If the LED lighting system is installed, GATEWAY will continue to document and disseminate information regarding the installation and long-term performance so that others may also gain valuable knowledge from the Yuma Sector Border Patrol Area lighting retrofit.

  12. Design of γ-ray vehicle patrol system based on GPS

    International Nuclear Information System (INIS)

    Zhang Wen; Li Changjin

    2011-01-01

    In order to detect the radiation in the surrounding environment of Nuclear facilities in a wide range, the γ-Ray vehicle patrol system based radiation on GPS and composed of γ-Ray detection terminal and PC is designed. The γ-Ray detection terminal uses controller ATmega128L as control core, detecting the radiation intensity of γ-Ray with G-M counter tube and getting the location with GPS module LR9548S, packing a data frame with γ-Ray radiation and location information according to the agreed protocol which will be sent to PC through UART interface; The PC can processes, display and analyze the data, backup to database Access2003, also can paint the measuring track and distributed picture of radiation intensity. The system can be equipped with a variety of vehicles for mobile patrol to use in the fields of searching radioactive sources, emergency monitoring and measurement of environmental radiation levels. (authors)

  13. Changes in water quality along the course of a river - Classic monitoring versus patrol monitoring

    Science.gov (United States)

    Absalon, Damian; Kryszczuk, Paweł; Rutkiewicz, Paweł

    2017-11-01

    Monitoring of water quality is a tool necessary to assess the condition of waterbodies in order to properly formulate water management plans. The paper presents the results of patrol monitoring of a 40-kilometre stretch of the Oder between Racibórz and Koźle. It has been established that patrol monitoring is a good tool for verifying the distribution of points of classic stationary monitoring, particularly in areas subject to varied human impact, where tributaries of the main river are very diversified as regards hydrochemistry. For this reason the results of operational monitoring carried out once every few years may not be reliable and the presented condition of the monitored waterbodies may be far from reality.

  14. A New Catalog of Contact Binary Stars from ROTSE-I Sky Patrols

    Science.gov (United States)

    Gettel, S. J.; McKay, T. A.; Geske, M. T.

    2005-05-01

    Over 65,000 variable stars have been detected in the data from the ROTSE-I Sky Patrols. Using period-color and light curve selection techniques, about 5000 objects have been identified as contact binaries. This selection is tested for completeness against EW objects in the GCVS. By utilizing infrared color data from 2MASS, we fit a period-color-luminosity relation to these stars and estimate their distances.

  15. METHODOLOGY OF THE HYBRID PROPULSION SYSTEM (DMP & DEP FOR TRIMARAN TYPE FAST PATROL BOAT

    Directory of Open Access Journals (Sweden)

    Aulia Widyandari

    2012-04-01

    Full Text Available There are lot of research done to develop a patrol boat, from the modification of hull model until propulsion system equipment. For example the model ship type AMV (Advanced Marine Vehicle was developed starting from the Catamaran, Trimaran and  Pentamaran model. Everything is aimed at obtaining the ship design that has the speed and stability. In addition to achieving high-speed vessel must be equipped with propulsion (Main Power is great, that means the main engine dimensions, auxiliary equipments and fuel tanks is too large. Many Limitations of space on the ship's engine room trimaran vessel is the main obstacle in designing propulsion system. Beside that Patrol boat should have many missions speed, so propulsion system should be designed at that conditions.   Hybrid propulsion is a combination of Diesel Mechanical Propulsion (DMP with Diesel Electric Propulsion (DEP. DMP system is connected directly to the propeller shaft (or through a reduction-gear. DMP has provide more efficiency rate of 95%. While DEP is only able to provide efficiency by 85% - 89% is slightly lower than DMP, but the DEP offers many advantages such as simplicity and suitability in the rotational speed settings, control systems, engine power production Redundancy, Flexibility in the design of equipments layout in engine rooms, noise, vibration and fuel consumption efficiency which affects the lower pollution.   Design of Hybrid Propulsion system can be satisfied and achieved the Power requirements and optimally at all speed condition of patrol boat. Therefore the author made using modeling Maxsurf-11.12 software and carried out various optimization of the choice of main engine, propeller and system conditions for fast patrol boat cruise. 

  16. Development of freeway service patrol program in china: a new Perspective from funds and institutional management

    OpenAIRE

    Sun, Zhentian; Xuhong, Li; Ruoxi, Wu

    2013-01-01

    This paper analyzed institutional issues especially on funding sources and institutional management that are very critical to successful building up and operating freeway service patrols (FSPs) Programs. The goal of this research was to determine the suitable funding sources and institutional management structures for FSPs considering the real institutional situation in different provinces. To achieve this objective, we first classified the freeway financial and investment institutional struc...

  17. Predictors of patrol officer interest in cybercrime training and investigation in selected United States police departments.

    Science.gov (United States)

    Holt, Thomas J; Bossler, Adam M

    2012-09-01

    Cybercrime has created substantial challenges for law enforcement, particularly at the local level. Most scholars and police administrators believe that patrol officers need to become more effective first responders to cybercrime calls. The evidence illustrates, however, that many patrol officers are neither adequately prepared nor strongly interested in taking an active role in addressing cybercrime at the local level. This study, therefore, examined the factors that predicted patrol officer interest in cybercrime training and investigations in two southeastern U.S. cities. The study specifically examined the relationship between demographics, cybercrime exposure, computer training, computer proficiency, Internet and cybercrime perceptions, and views on policing cybercrime with officer interest in cybercrime investigation training and conducting cybercrime investigations in the future. Officer views on policing cybercrime, particularly whether they valued cybercrime investigations and believed that cybercrime would dramatically change policing, along with their computer skills, were the strongest predictors of interest in cybercrime efforts. Officers who had received previous computer training were less interested in additional training and conducting investigations. These findings support the argument that more command and departmental meetings focusing on the value of investigating these types of crime need to be held in order to increase officer interest.

  18. RxPATROL: a Web-based tool for combating pharmacy theft.

    Science.gov (United States)

    Smith, Meredith Y; Graham, J Aaron; Haddox, J David; Steffey, Amy

    2009-01-01

    To report the incidence of pharmacy-related burglaries and robberies and characteristics of pharmacies where such crimes have occurred using recent data from Rx Pattern Analysis Tracking Robberies & Other Losses (RxPATROL), a national Web-based information clearinghouse on pharmacy-related theft of prescription medications and over-the-counter products. Descriptive, nonexperimental study. United States between 2005 and 2006. Not applicable. Not applicable. Number of pharmacy theft reports received; incident type, date, and location; point of entry; and pharmacy security features. Between 2005 and 2006, 202 pharmacy burglary and 299 pharmacy robbery reports from 45 different states were filed with RxPATROL. More than 70% of pharmacies reporting such crimes lacked a security camera. Among those reporting a burglary, 60% lacked dead bolt locks, a solid exterior door, a motion detector device, or a safe or vault for storage of controlled substances. Burglars most often obtained access to the pharmacy via the front door. RxPATROL is a Web-based tool that can assist pharmacies and law enforcement in collaborating more effectively to combat and prevent pharmacy-related crimes.

  19. Ice Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice...

  20. Ice Cream

    NARCIS (Netherlands)

    Scholten, E.

    2014-01-01

    Ice cream is a popular dessert, which owes its sensorial properties (mouth feel) to its complex microstructure. The microstructure is a result of the combination of the ingredients and the production process. Ice cream is produced by simultaneous freezing and shearing of the ice cream mix, which

  1. Ice targets

    International Nuclear Information System (INIS)

    Pacheco, C.; Stark, C.; Tanaka, N.; Hodgkins, D.; Barnhart, J.; Kosty, J.

    1979-12-01

    This report presents a description of ice targets that were constructed for research work at the High Resolution Spectrometer (HRS) and at the Energetic Pion Channel and Spectrometer (EPICS). Reasons for using these ice targets and the instructions for their construction are given. Results of research using ice targets will be published at a later date

  2. Proposing an International Collaboration on Lightweight Autonomous Vehicles to Conduct Scientific Traverses and Surveys over Antarctica and the Surrounding Sea Ice

    Science.gov (United States)

    Carsey, Frank; Behar, Alberto

    2004-01-01

    We have continued to develop a concept for use of autonomous rovers, originally developed for use in planetary exploration, in polar science on Earth; the concept was the subject of a workshop, and this report summarizes and extends that workshop. The workshop on Antarctic Autonomous Scientific Vehicles and Traverses met at the National Geographic Society on February 14 and 15, 2001 to discuss scientific objectives and benefits of the use of autonomous rovers. The participants enthusiastically viewed rovers as being uniquely valuable for such tasks as data taking on tedious or repetitive routes, traverses in polar night, difficult or hazardous routes, extremely remote regions, routes requiring only simple instrumentation, traverses that must be conducted at low speed, augments of manned traverses, and scientific procedures not compatible with human presence or combustion engines. The workshop has concluded that instrumented autonomous vehicles, of the type being developed for planetary exploration, have the potential to contribute significantly to the way science in conducted in Antarctica while also aiding planetary technology development, and engaging the public's interest. Specific objectives can be supported in understanding ice sheet mass balance, sea ice heat and momentum exchange, and surface air chemistry processes. In the interval since the workshop, we have concluded that organized program to employ such rovers to perform scientific tasks in the Fourth International Polar Year would serve the objectives of that program well.

  3. Sea ice-albedo climate feedback mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, J.L.; Curry, J.A. [Univ. of Colorado, Boulder, CO (United States); Ebert, E.E. [Bureau of Meterology Research Center, Melbourne (Australia)

    1995-02-01

    The sea ice-albedo feedback mechanism over the Arctic Ocean multiyear sea ice is investigated by conducting a series of experiments using several one-dimensional models of the coupled sea ice-atmosphere system. In its simplest form, ice-albedo feedback is thought to be associated with a decrease in the areal cover of snow and ice and a corresponding increase in the surface temperature, further decreasing the area cover of snow and ice. It is shown that the sea ice-albedo feedback can operate even in multiyear pack ice, without the disappearance of this ice, associated with internal processes occurring within the multiyear ice pack (e.g., duration of the snow cover, ice thickness, ice distribution, lead fraction, and melt pond characteristics). The strength of the ice-albedo feedback mechanism is compared for several different thermodynamic sea ice models: a new model that includes ice thickness distribution., the Ebert and Curry model, the Mayjut and Untersteiner model, and the Semtner level-3 and level-0 models. The climate forcing is chosen to be a perturbation of the surface heat flux, and cloud and water vapor feedbacks are inoperative so that the effects of the sea ice-albedo feedback mechanism can be isolated. The inclusion of melt ponds significantly strengthens the ice-albedo feedback, while the ice thickness distribution decreases the strength of the modeled sea ice-albedo feedback. It is emphasized that accurately modeling present-day sea ice thickness is not adequate for a sea ice parameterization; the correct physical processes must be included so that the sea ice parameterization yields correct sensitivities to external forcing. 22 refs., 6 figs., 1 tab.

  4. Sea Ice

    Science.gov (United States)

    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.

  5. Moving Object Tracking and Its Application to an Indoor Dual-Robot Patrol

    Directory of Open Access Journals (Sweden)

    Cheng-Han Shih

    2016-11-01

    Full Text Available This paper presents an application of image tracking using an omnidirectional wheeled mobile robot (WMR. The objective of this study is to integrate image processing of hue, saturation, and lightness (HSL for fuzzy color space, and use mean shift tracking for object detection and a Radio Frequency Identification (RFID reader for confirming destination. Fuzzy control is applied to omnidirectional WMR for indoor patrol and intruder detection. Experimental results show that the proposed control scheme can make the WMRs perform indoor security service.

  6. The Role of Subscription-Based Patrol and Restitution in the Future of Liberty

    Directory of Open Access Journals (Sweden)

    Gil Guillory

    2009-02-01

    Full Text Available Market anarchists are often keen to know how we might rid ourselves of the twin evils institutionalized in the state: taxation and monopoly. A possible future history for North America is suggested, focusing upon the implications of the establishment of a subscription-based patrol and restitution business sector. We favor Rothbard over Higgs regarding crises and liberty. We favor Barnett over Rothbard regarding vertical integration of security. We examine derived demand for adjudication, mediation and related goods; and we advance the thesis that private adjudication will tend to libertarianly just decisions. We show how firms will actively build civil society, strengthening and coordinating Nisbettian intermediating institutions.

  7. More Eyes, (No Guns,) Less Crime: Estimating the Effects of Unarmed Private Patrols on Crime Using a Bayesian Structural Time-Series Model

    NARCIS (Netherlands)

    P.P. Liu (Paul); M. Fabbri (Marco)

    2016-01-01

    textabstractThis work studies the effect of unarmed private security patrols on crime. We make use of a initiative, triggered by an arguably exogenous events, consisting in hiring unarmed private security agents to patrol, observe and report to ordinary police criminal activities within a

  8. Effects of seasonal vitamin D deficiency and respiratory acidosis on bone metabolism markers in submarine crewmembers during prolonged patrols.

    Science.gov (United States)

    Holy, Xavier; Collombet, Jean-Marc; Labarthe, Frédéric; Granger-Veyron, Nicolas; Bégot, Laurent

    2012-02-01

    The aim of the study was to determine the seasonal influence of vitamin D status on bone metabolism in French submariners over a 2-mo patrol. Blood samples were collected as follows: prepatrol and patrol days 20, 41, and 58 on crewmembers from both a winter (WP; n = 20) and a summer patrol (SP; n = 20), respectively. Vitamin D status was evaluated for WP and SP. Moreover, extended parameters for acid-base balance (Pco(2), pH, and bicarbonate), bone metabolism (bone alkaline phosphatase and COOH-terminal telopeptide of type I collagen), and mineral homeostasis (parathyroid hormone, ionized calcium and phosphorus) were scrutinized. As expected, SP vitamin D status was higher than WP vitamin D status, regardless of the considered experimental time. A mild chronic respiratory acidosis (CRA) was identified in both SP and WP submariners, up to patrol day 41. Such an occurrence paired up with an altered bone remodeling coupling (decreased bone alkaline phosphatase-to-COOH-terminal telopeptide of type I collagen ratio). At the end of the patrol (day 58), a partial compensation of CRA episode, combined with a recovered normal bone remodeling coupling, was observed in SP, not, however, in WP submariners. The mild CRA episode displayed over the initial 41-day submersion period was mainly induced by a hypercapnia resulting from the submarine-enriched CO(2) level. The correlated impaired bone remodeling may imply a physiological attempt to compensate this acidosis via bone buffering. On patrol day 58, the discrepancy observed in terms of CRA compensation between SP and WP may result from the seasonal influence on vitamin D status.

  9. Preface: Proceedings of the 11th International Conference on Magnetic Fluids (ICMF 11) (Košice, Slovakia, 23 27 July 2007)

    Science.gov (United States)

    Kopčanský, Peter; Timko, Milan; Kováč, Josef; Václavíková, Miroslava; Odenbach, Stefan

    2008-05-01

    The 11th International Conference on Magnetic Fluids (ICMF 11) was held in Košice, Slovakia between 23-27 July 2007. Attendance at the conference was high and its motivation was in line with the ten previous ICMF conferences organized in Udine, Orlando, Bangor, Sendai-Tokyo, Riga, Paris, Bhavnagar, Timisoara, Bremen and Guarujá. The conference in Slovakia reflected the scientific community's enthusiasm and worldwide support, with 256 participants, from 30 countries attending.The main objective of ICMF 11 was to promote progress and knowledge in the field of magnetic fluids regarding their chemistry, physical and magnetic properties, heat and mass transfer, surface phenomena, as well as their technological and biomedical applications. As research on magnetic fluids is essentially interdisciplinary, experts from related areas were invited to present their contributions with a view to increasing knowledge in the field and highlighting new trends. Submitted communications were refereed by members of the Scientific Organizing Committee and abstracts were assembled in a book of abstracts. Participants presented 180 posters in two poster sessions and 56 oral presentations. All presentations contributed to a greater understanding of the area, and helped to bridge the gap between physics, chemistry, technology, biology and medical sciences. Contributions to this conference are presented in 115 scientific papers, with some published in Journal of Physics: Condensed Matter and the rest in Magnetohydrodynamics. The organization of the conference was made possible by generous support from the Institute of Experimental Physics and Institute of Geotechnics of the Slovak Academy of Sciences, the University of Pavol Jozef Šafárik and the Slovak Physical Society. Financial support from Ferrotec, Cryosoft Ltd, Mikrochem, Liquids Research Ltd, Askony and US Steel Košice, is also gratefully acknowledged.

  10. Proceedings of the 11th International Conference on Magnetic Fluids (ICMF 11) (Košice, Slovakia, 23-27 July 2007).

    Science.gov (United States)

    Kopčanský, Peter; Timko, Milan; Kováč, Josef; Václavíková, Miroslava; Odenbach, Stefan

    2008-05-21

    The 11th International Conference on Magnetic Fluids (ICMF 11) was held in Košice, Slovakia between 23-27 July 2007. Attendance at the conference was high and its motivation was in line with the ten previous ICMF conferences organized in Udine, Orlando, Bangor, Sendai-Tokyo, Riga, Paris, Bhavnagar, Timisoara, Bremen and Guarujá. The conference in Slovakia reflected the scientific community's enthusiasm and worldwide support, with 256 participants, from 30 countries attending.The main objective of ICMF 11 was to promote progress and knowledge in the field of magnetic fluids regarding their chemistry, physical and magnetic properties, heat and mass transfer, surface phenomena, as well as their technological and biomedical applications. As research on magnetic fluids is essentially interdisciplinary, experts from related areas were invited to present their contributions with a view to increasing knowledge in the field and highlighting new trends. Submitted communications were refereed by members of the Scientific Organizing Committee and abstracts were assembled in a book of abstracts. Participants presented 180 posters in two poster sessions and 56 oral presentations. All presentations contributed to a greater understanding of the area, and helped to bridge the gap between physics, chemistry, technology, biology and medical sciences. Contributions to this conference are presented in 115 scientific papers, with some published in Journal of Physics: Condensed Matter and the rest in Magnetohydrodynamics. The organization of the conference was made possible by generous support from the Institute of Experimental Physics and Institute of Geotechnics of the Slovak Academy of Sciences, the University of Pavol Jozef Šafárik and the Slovak Physical Society. Financial support from Ferrotec, Cryosoft Ltd, Mikrochem, Liquids Research Ltd, Askony and US Steel Košice, is also gratefully acknowledged.

  11. Intravascular Immune Surveillance by CXCR6+ NKT Cells Patrolling Liver Sinusoids

    Directory of Open Access Journals (Sweden)

    Geissmann Frederic

    2005-01-01

    Full Text Available We examined the in vivo behavior of liver natural killer T cells (NKT cells by intravital fluorescence microscopic imaging of mice in which a green fluorescent protein cDNA was used to replace the gene encoding the chemokine receptor CXCR6. NKT cells, which account for most CXCR6+ cells in liver, were found to crawl within hepatic sinusoids at 10-20 µm/min and to stop upon T cell antigen receptor activation. CXCR6-deficient mice exhibited a selective and severe reduction of CD1d-reactive NKT cells in the liver and decreased susceptibility to T-cell-dependent hepatitis. CXCL16, the cell surface ligand for CXCR6, is expressed on sinusoidal endothelial cells, and CXCR6 deficiency resulted in reduced survival, but not in altered speed or pattern of patrolling of NKT cells. Thus, NKT cells patrol liver sinusoids to provide intravascular immune surveillance, and CXCR6 contributes to liver-based immune responses by regulating their abundance.

  12. Effector CD4+ T cells recognize intravascular antigen presented by patrolling monocytes.

    Science.gov (United States)

    Westhorpe, Clare L V; Norman, M Ursula; Hall, Pam; Snelgrove, Sarah L; Finsterbusch, Michaela; Li, Anqi; Lo, Camden; Tan, Zhe Hao; Li, Songhui; Nilsson, Susan K; Kitching, A Richard; Hickey, Michael J

    2018-02-21

    Although effector CD4 + T cells readily respond to antigen outside the vasculature, how they respond to intravascular antigens is unknown. Here we show the process of intravascular antigen recognition using intravital multiphoton microscopy of glomeruli. CD4 + T cells undergo intravascular migration within uninflamed glomeruli. Similarly, while MHCII is not expressed by intrinsic glomerular cells, intravascular MHCII-expressing immune cells patrol glomerular capillaries, interacting with CD4 + T cells. Following intravascular deposition of antigen in glomeruli, effector CD4 + T-cell responses, including NFAT1 nuclear translocation and decreased migration, are consistent with antigen recognition. Of the MHCII + immune cells adherent in glomerular capillaries, only monocytes are retained for prolonged durations. These cells can also induce T-cell proliferation in vitro. Moreover, monocyte depletion reduces CD4 + T-cell-dependent glomerular inflammation. These findings indicate that MHCII + monocytes patrolling the glomerular microvasculature can present intravascular antigen to CD4 + T cells within glomerular capillaries, leading to antigen-dependent inflammation.

  13. Animals and ICE

    DEFF Research Database (Denmark)

    van Hemmen, J Leo; Christensen-Dalsgaard, Jakob; Carr, Catherine E

    2016-01-01

    experimental and mathematical foundation, it is known that there is a low-frequency regime where the internal time difference (iTD) as perceived by the animal may well be 2-5 times higher than the external ITD, the interaural time difference, and that there is a frequency plateau over which the fraction i......TD/ITD is constant. There is also a high-frequency regime where the internal level (amplitude) difference iLD as perceived by the animal is much higher than the interaural level difference ILD measured externally between the two ears. The fundamental tympanic frequency segregates the two regimes. The present special...... issue devoted to "internally coupled ears" provides an overview of many aspects of ICE, be they acoustic, anatomical, auditory, mathematical, or neurobiological. A focus is on the hotly debated topic of what aspects of ICE animals actually exploit neuronally to localize a sound source....

  14. The IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope Array : Joint Contribution to the 34th International Cosmic Ray Conference (ICRC 2015)

    NARCIS (Netherlands)

    Collaboration, IceCube; Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Ansseau, I.; Archinger, M.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Tjus, J. Becker; Becker, K. H.; Beiser, E.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H. -P.; Buzinsky, N.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Cowen, D. F.; Silva, A. H. Cruz; Daughhetee, J.; Davis, J. C.; Day, M.; André, J. P. A. M. de; Clercq, C. De; Rosendo, E. del Pino; Dembinski, H.; Ridder, S. De; Desiati, P.; Vries, K. D. de; Wasseige, G. de; With, M. de; DeYoung, T.; Díaz-Vélez, J. C.; Lorenzo, V. di; Dumm, J. P.; Dunkman, M.; Eagan, R.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fahey, S.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Fösig, C. -C.; Fuchs, T.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Gier, D.; Gladstone, L.; Glagla, M.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Góra, D.; Grant, D.; Groh, J. C.; Groß, A.; Ha, C.; Haack, C.; Ismail, A. Haj; Hallgren, A.; Halzen, F.; Hansmann, B.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hellwig, D.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Holzapfel, K.; Homeier, A.; Hoshina, K.; Huang, F.; Huber, M.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jero, K.; Jurkovic, M.; Kaminsky, B.; Kappes, A.; Karg, T.; Karle, A.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kemp, J.; Kheirandish, A.; Kiryluk, J.; Kläs, J.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Koob, A.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, G.; Kroll, M.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Leuner, J.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Maruyama, R.; Mase, K.; Matis, H. S.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meli, A.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Middell, E.; Middlemas, E.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Paul, L.; Pepper, J. A.; Heros, C. Pérez de los; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Pütz, J.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Richter, S.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Saba, S. M.; Sabbatini, L.; Sander, H. -G.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Schatto, K.; Scheriau, F.; Schimp, M.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schulte, L.; Seckel, D.; Seunarine, S.; Shanidze, R.; Smith, M. W. E.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stahlberg, M.; Stamatikos, M.; Stanev, T.; Stanisha, N. A.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Turcati, A.; Unger, E.; Usner, M.; Vallecorsa, S.; Vandenbroucke, J.; Eijndhoven, N. van; Vanheule, S.; Santen, J. van; Veenkamp, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Weaver, Ch; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Whitehorn, N.; Wichary, C.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.; Collaboration, Pierre Auger; Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allison, P.; Almela, A.; Castillo, J. Alvarez; Alvarez-Muñiz, J.; Batista, R. Alves; Ambrosio, M.; Aminaei, A.; Anastasi, G. A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Awal, N.; Badescu, A. M.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, A.; Blanco, M.; Blazek, J.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Brogueira, P.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; Almeida, R. M. de; Jong, S. J. de; Mauro, G. De; Neto, J. R. T. de Mello; Mitri, I. De; Oliveira, J. de; Souza, V. de; Peral, L. del; Deligny, O.; Dhital, N.; Giulio, C. Di; Matteo, A. Di; Diaz, J. C.; Castro, M. L. Díaz; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Hasankiadeh, Q. Dorosti; Anjos, R. C. dos; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; García, B.; García-Gámez, D.; Garcia-Pinto, D.; Gate, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Glass, H.; Golup, G.; Berisso, M. Gómez; Vitale, P. F. Gómez; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Hervé, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Mezek, G. Kukec; Kunka, N.; Awad, A. W. Kuotb; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Coz, S. Le; Lebrun, D.; Lebrun, P.; Oliveira, M. A. Leigui de; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; Casado, A. López; Louedec, K.; Lucero, A.; Malacari, M.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Bravo, O. Martínez; Martraire, D.; Meza, J. J. Masías; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Mello, V. B. B.; Melo, D.; Menshikov, A.; Messina, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Müller, G.; Muller, M. A.; Müller, S.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Reinert, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Carvalho, W. Rodrigues de; Rojo, J. Rodriguez; Rodríguez-Frías, M. D.; Rogozin, D.; Rosado, J.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Greus, F. Salesa; Salina, G.; Gomez, J. D. Sanabria; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sarmiento-Cano, C.; Sato, R.; Scarso, C.; Schauer, M.; Scherini, V.; Schieler, H.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanca, D.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Durán, M. Suarez; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Tibolla, O.; Timmermans, C.; Peixoto, C. J. Todero; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Elipe, G. Torralba; Machado, D. Torres; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Galicia, J. F. Valdés; Valiño, I.; Valore, L.; Aar, G. van; Bodegom, P. van; Berg, A. M. van den; Velzen, S. van; Vliet, A. van; Varela, E.; Cárdenas, B. Vargas; Varner, G.; Vasquez, R.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Welling, C.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yang, L.; Yapici, T.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zuccarello, F.; Collaboration, Telescope Array; Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, Y.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, H. S.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

    2015-01-01

    We have conducted three searches for correlations between ultra-high energy cosmic rays detected by the Telescope Array and the Pierre Auger Observatory, and high-energy neutrino candidate events from IceCube. Two cross-correlation analyses with UHECRs are done: one with 39 cascades from the IceCube

  15. Melting ice, growing trade?

    Directory of Open Access Journals (Sweden)

    Sami Bensassi

    2016-05-01

    Full Text Available Abstract Large reductions in Arctic sea ice, most notably in summer, coupled with growing interest in Arctic shipping and resource exploitation have renewed interest in the economic potential of the Northern Sea Route (NSR. Two key constraints on the future viability of the NSR pertain to bathymetry and the future evolution of the sea ice cover. Climate model projections of future sea ice conditions throughout the rest of the century suggest that even under the most “aggressive” emission scenario, increases in international trade between Europe and Asia will be very low. The large inter-annual variability of weather and sea ice conditions in the route, the Russian toll imposed for transiting the NSR, together with high insurance costs and scarce loading/unloading opportunities, limit the use of the NSR. We show that even if these obstacles are removed, the duration of the opening of the NSR over the course of the century is not long enough to offer a consequent boost to international trade at the macroeconomic level.

  16. MULTI-VEHICLE COVERING TOUR PROBLEM: BUILDING ROUTES FOR URBAN PATROLLING

    Directory of Open Access Journals (Sweden)

    Washington Alves de Oliveira

    2015-12-01

    Full Text Available ABSTRACT In this paper we study a particular aspect of the urban community policing: routine patrol route planning. We seek routes that guarantee visibility, as this has a sizable impact on the community perceived safety, allowing quick emergency responses and providing surveillance of selected sites (e.g., hospitals, schools. The planning is restricted to the availability of vehicles and strives to achieve balanced routes. We study an adaptation of the model for the multi-vehicle covering tour problem, in which a set of locations must be visited, whereas another subset must be close enough to the planned routes. It constitutes an NP-complete integer programming problem. Suboptimal solutions are obtained with several heuristics, some adapted from the literature and others developed by us. We solve some adapted instances from TSPLIB and an instance with real data, the former being compared with results from literature, and latter being compared with empirical data.

  17. Design of Electric Patrol UAVs Based on a Dual Antenna System

    Directory of Open Access Journals (Sweden)

    Yongjie Zhai

    2018-04-01

    Full Text Available China completed the construction of more than 1.15 million kilometers of transmission lines with conventional voltage levels spanning its vast territory in 2014. This large and complicated power grid structure relies mainly on manual operation and maintenance of lines. Unmanned aerial vehicles (UAVs equipped with high-definition digital video cameras and cameras and GPS positioning systems can conduct autonomous patrols along the grid. However, the presence of electromagnetic fields around high-voltage transmission lines can affect the UAV’s magnetometer, resulting in a wrong heading and thus unsafe flight. In this paper, the traditional method of UAV heading calculation using a magnetometer was analyzed, and a novel method for calculating UAV heading based on dual antennas was proposed. Experimental data showed that the proposed method improves the anti-magnetic interference characteristics of UAVs and increases UAV security and stability for power inspection applications.

  18. Yuma Border Patrol Lighting Retrofit: Final LED System Performance Assessment of Trial and Full Installation

    Energy Technology Data Exchange (ETDEWEB)

    Andrea Wilkerson, Gregory P Sullivan, Robert G Davis, Sarah Safranek

    2018-04-30

    Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial evaluation in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations, and illuminance measurements were recorded initially and at 2500 hours, 5000 hours, 7000, and 11,000 hours of operation. Additionally, four second-generation LED luminaires installed as part of the full installation were evaluated initially and again after 4,000 hours of operation. While the initial energy, lighting quality, and maintenance benefits relative to the incumbent high-pressure sodium system were very satisfactory, the study raises important questions regarding the long-term performance of LED lighting systems in high-temperature environments.

  19. Sea Ice, Climate and Fram Strait

    Science.gov (United States)

    Hunkins, K.

    1984-01-01

    When sea ice is formed the albedo of the ocean surface increases from its open water value of about 0.1 to a value as high as 0.8. This albedo change effects the radiation balance and thus has the potential to alter climate. Sea ice also partially seals off the ocean from the atmosphere, reducing the exchange of gases such as carbon dioxide. This is another possible mechanism by which climate might be affected. The Marginal Ice Zone Experiment (MIZEX 83 to 84) is an international, multidisciplinary study of processes controlling the edge of the ice pack in that area including the interactions between sea, air and ice.

  20. Car engine breather icing

    OpenAIRE

    Horoufi, Aryan

    2012-01-01

    Icing in an engine breather system can block the engine breather pipe, cause excessive crankcase pressure and degrade the engine performance. In this project, a numerical study, experimental tests and CFD analysis are employed in order to understand condensation and the extent of freezing inside a vertical pipe, a horizontal pipe and a T-joint pipe which are exposed to an external convective cooling. The pipe internal flow is assumed to be a vapour/air mixture. This study has l...

  1. Modeling an HF NVIS Towel-Bar Antenna on a Coast Guard Patrol Boat. A Comparison of WIPL-D and the Numerical Electromagnetics Code (NEC)

    National Research Council Canada - National Science Library

    Mora, Darla; Weiser, Christopher; McKaughan, Michael

    2005-01-01

    A Coast Guard patrol boat high-frequency (HF) near-vertical incident skywave (NVIS) antenna is selected as a test case to compare the electromagnetic modeling programs Numerical Electromagnetics Code, NEC and WIPL-D code...

  2. Ice Ages

    Indian Academy of Sciences (India)

    that the precession of the earth's orbit caused ice ages. The precession of the earth's orbit leads to changes in the time of the year at which ... than in the southern hemisphere. ..... small increase in ocean temperature implies a large increase in.

  3. Response timescales for martian ice masses and implications for ice flow on Mars

    DEFF Research Database (Denmark)

    Koutnik, Michelle Rebecca; Waddington, E.D.; Winebrener, D.P.

    2013-01-01

    a predictable shape, which is a function of ice temperature, ice rheology, and surface mass-exchange rate. In addition, the time for surface-shape adjustment is shorter than the characteristic time for significant deformation or displacement of internal layers within a flowing ice mass; as a result, surface......On Earth and on Mars, ice masses experience changes in precipitation, temperature, and radiation. In a new climate state, flowing ice masses will adjust in length and in thickness, and this response toward a new steady state has a characteristic timescale. However, a flowing ice mass has...... topography is more diagnostic of flow than are internal-layer shapes. Because the shape of Gemina Lingula, North Polar Layered Deposits indicates that it flowed at some time in the past, we use its current topography to infer characteristics of those past ice conditions, or past climate conditions, in which...

  4. Structures of twilight patrol in the "Churyumov's Unified network" to ensure continuous monitoring

    Science.gov (United States)

    Churyumov, K. I.; Steklov, A. F.; Vidmachenko, A. P.; Dashkiev, G. N.; Steklov, E. A.; Slipchenko, A. S.; Romaniuk, Ya. O.; Nevodovskyi, P. V.

    2016-10-01

    calibrating control of facts and traces of all kinds of dangerous invasions. 3. Twilight patrol of "Churyumov Unified Network" and the study of invasions of fragments of cometary nuclei in the Earth's atmosphere. The costs of the study of the comet Churyumov-Gerasimenko 67P and its nuclei, on all mission of Rosetta-Philae, amounted to about EUR 2 billion [6]. Its results have significantly improved our understanding of the physics of cometary phenomena have further exacerbated problems of asteroid and comet hazard. In 2016, astronomers a lot of effort and time allocated for study of the disintegration of cometary nucleus of Ikeya - Murakami (P / 2010 V1) at least 17 of fragments. The authors have created a twilight patrol of "United Network Churyumov" to implement of daytime and twilight observations

  5. Eulerian Method for Ice Crystal Icing

    NARCIS (Netherlands)

    Norde, Ellen; van der Weide, Edwin Theodorus Antonius; Hoeijmakers, Hendrik Willem Marie

    In this study, an ice accretion method aimed at ice crystal icing in turbofan engines is developed and demonstrated for glaciated as well as mixed-phase icing conditions. The particle trajectories are computed by an Eulerian trajectory method. The effects of heat transfer and phase change on the

  6. Sea ice - Multiyear cycles and white ice

    Science.gov (United States)

    Ledley, T. S.

    1985-01-01

    The multiyear thickness cycles represent one of the interesting features of the sea ice studies performed by Semtner (1976) and Washington et al. (1976) with simple thermodynamic models of sea ice. In the present article, a description is given of results which show that the insulating effect of snow on the surface of the sea ice is important in producing these multiyear cycles given the physics included in the model. However, when the formation of white ice is included, the cycles almost disappear. White ice is the ice which forms at the snow-ice interface when the snow layer becomes thick enough to depress the ice below the water level. Water infiltrates the snow by coming through the ice at leads and generally freezes there, forming white ice.

  7. Uncertainties in the Antarctic Ice Sheet Contribution to Sea Level Rise: Exploration of Model Response to Errors in Climate Forcing, Boundary Conditions, and Internal Parameters

    Science.gov (United States)

    Schlegel, N.; Seroussi, H. L.; Boening, C.; Larour, E. Y.; Limonadi, D.; Schodlok, M.; Watkins, M. M.

    2017-12-01

    The Jet Propulsion Laboratory-University of California at Irvine Ice Sheet System Model (ISSM) is a thermo-mechanical 2D/3D parallelized finite element software used to physically model the continental-scale flow of ice at high resolutions. Embedded into ISSM are uncertainty quantification (UQ) tools, based on the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) software. ISSM-DAKOTA offers various UQ methods for the investigation of how errors in model input impact uncertainty in simulation results. We utilize these tools to regionally sample model input and key parameters, based on specified bounds of uncertainty, and run a suite of continental-scale 100-year ISSM forward simulations of the Antarctic Ice Sheet. Resulting diagnostics (e.g., spread in local mass flux and regional mass balance) inform our conclusion about which parameters and/or forcing has the greatest impact on century-scale model simulations of ice sheet evolution. The results allow us to prioritize the key datasets and measurements that are critical for the minimization of ice sheet model uncertainty. Overall, we find that Antartica's total sea level contribution is strongly affected by grounding line retreat, which is driven by the magnitude of ice shelf basal melt rates and by errors in bedrock topography. In addition, results suggest that after 100 years of simulation, Thwaites glacier is the most significant source of model uncertainty, and its drainage basin has the largest potential for future sea level contribution. This work is performed at and supported by the California Institute of Technology's Jet Propulsion Laboratory. Supercomputing time is also supported through a contract with the National Aeronautics and Space Administration's Cryosphere program.

  8. Portable Gas Analyzer Based on Fourier Transform Infrared Spectrometer for Patrolling and Examining Gas Exhaust

    Directory of Open Access Journals (Sweden)

    Yuntao Liang

    2015-01-01

    Full Text Available Aimed at monitoring emission of organic gases such as CH4, C2H6, C3H8, iso-C4H10, n-C4H10, C2H4, C3H6, C2H2, CO, and CO2, from coal mines, petroleum refineries, and other plants, a Fourier Transform Infrared (FT-IR spectrometer was used to develop a portable gas analyzer for patrolling and examining gas exhaust. Firstly, structure of the instrument was introduced. Then, a spectral analysis approach was presented. Finally, instrument was tested with standard gases and with actual gases emitted from a petroleum refinery. For the latter test, a gas chromatograph (GC was used as a reference instrument. The test results showed that the detection limit of every component of analyte was less than 10 × 10−6. The maximum test error of every analyte was less than 15 × 10−6 when its practical concentration was no more than 500 × 10−6. A final comparison showed that the result curves of analytes obtained with FT-IR spectrometer almost overlapped with those obtained with GC, and their resulting noise was less than 6.4% when the practical gas concentration was above 100 × 10−6. As a result, our instrument was suitable to be used as a portable instrument for monitoring exhaust gases.

  9. Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

    Science.gov (United States)

    McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

    2015-02-01

    Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe-/-Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP+ macrophages "dancing on the spot" and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells.

  10. Perencanaan Simulasi Pengaturan Pembangkitan Daya Pada Kapal Fast Patrol Boat 60 M dengan Propulsi Hybrid

    Directory of Open Access Journals (Sweden)

    Fikri Nuruddin Muzakki

    2017-01-01

    Full Text Available Sistem propulsi hybrid yang memberikan berbagai keuntungan untuk pengoperasian kapal, seperti pertimbangan konsumsi bahan bakar yang rendah, pengaturan kecepatan dengan penggunaan propulsi yang optimal ataupun khusus untuk jenis kapal tertentu. Tentunya sistem propulsi hybrid memiliki kelamahan pula, salah satunya adalah pengaturan pembangkitan daya yang kompleks dibandingkan dengan system propulsi lain. Setiap kecepatan membutuhkan daya yang berbeda dan bahan bakar yang berbeda pula. Keputusan yang kurang tepat dapat mengurangi keunggulan dari pemasangan sistem propulsi hybrid. Oleh karena itu dibutuhkan Decision Support System untuk membantu nahkoda menentukan pengaturan propulsi yang optimal pada kecepatan yang diinginkan dan pada kondisi yang ada pada perairan yang dilalui. Dalam makalah ini dibuat Decision Support System dengan input utama berupa kecepatan dalam knot, service margin, dan kebutuhan listrik. Kecepatan dan sevice margin digunakan untuk menentukan kebutuhan tenaga penggerak dan selanjutnya digunakan untuk analisa alat penggerak. Untuk digunakan referensi nahkoda dapat memilih propulsi yang optimal dengan konsumsi bahan bakar yang minimum, dan dengan jumlah daya yang diperlukan untuk pengoperaian tersebut. Berdasarkan hasil simulasi penggunaan Decision Support System pada kapal Fast Patrol Boat 60 m ini menujukkan pemakaian terbaik pada kecepatan 20 knot dengan menggunakan sistem Shaft Generator pada daya 1181 kW disertai pengoperasian genset pada daya 0 kW dan jumlah pemakaian bahan bakar 482,99 kg per jam.

  11. Space Solar Patrol data and changes in weather and climate, including global warming

    International Nuclear Information System (INIS)

    Avakyan, S V; Leonov, N B; Voronin, N A; Baranova, L A; Savinov, E P

    2010-01-01

    In this paper, the results obtained during the execution of several ISTC projects are presented. The general aim of these projects has been the study of global changes in the environment, connected with solar activity. A brief description of the optical apparatus of the Space Solar Patrol (SSP) developed and built in the framework of the ISTC projects 385, 385.2, 1523 and 2500 is given. The SSP is intended for permanent monitoring of spectra and absolute fluxes of soft x-ray and extreme ultraviolet (x-ray/EUV) radiation from the full disk of the Sun which ionizes the upper atmosphere of the Earth. Permanent solar monitoring in the main part of the ionizing radiation spectra 0.8–115 (119) nm does not exist. The apparatus of the SSP was developed in the years 1996–2005 with multiyear experience of developing such apparatus in S I Vavilov State Optical Institute. The basis of this apparatus is the use of unique detectors of ionizing radiation—open secondary electron multipliers, which are 'solar blind' to near UV, visible and IR radiation from the Sun, and new methodology of these solar spectroradiometric absolute measurements. The prospects are discussed of using the SSP data for the investigation and forecast of the influence of solar variability on the weather and climate including global warming and also on the biosphere including human beings (proposal 3878)

  12. [Stress as an occupational risk factor among policemen of road patrol service].

    Science.gov (United States)

    Fedotova, I V; Chernikova, E F

    The hygienic evaluation of occupational factors which characterized working conditions of traffic policemen of road patrol service was performed. The authors found that along with high neuro-emotional occupational stress in traffic policemen, they exposed to unfavorable microclimate, higher level of noise, vibration and their work was classified as heavy. Also, traffic policemen presented subjective complaints about negative impact of polluted air of motorways on their health status. Prevalence of chronic diseases was analyzed in group of 431 traffic policemen. The authors revealed a leading role of the following diseases: musculoskeletal diseases, diseases of connective tissue, digestive diseases, diseases of the nerve system, circulation system; their portion in the morbidity structure was 86.0%. The association of these diseases with occupation was confirmed by the increasing of their incidence with increasing of length of duration of service. Calculation of indices of relative occupational risk showed (that especially important) the increase of the length of service led to the increase in the risk ofpathologies, in which stress played a significant role. In examined group, the authors revealed such diseases as hypertension, autonomous-vascular dystonia, gastric and duodenal ulcer. Risk of the development of these diseases in some age/length of service groups is classified as high and very high. Obtained results provide the evidence that measures aimed to the decrease of the exposure to occupational factors will promote prevention of stress-stipulated diseases among traffic policemen.

  13. Application of an automated patrol-type monitoring system in the reinforced concrete containment vessel at Kashiwazaki-Kariwa Nuclear Power Plant Units 6 and 7

    International Nuclear Information System (INIS)

    Kimoto, T.; Senoh, M.; Hirakawa, H.; Tanaka, K.; Takahashi, M.

    1996-01-01

    An automated patrol-type monitoring system was applied to the first Advanced Boiling Water Reactor (ABWR) plants in the world, Kashiwazaki-Kariwa Nuclear Power Plant Units 6 and 7. The system consists of two robots traveling along monorail and several ITV systems. This monitoring system is used to watch the operating incident of key components of ABWR, such as water leakage from packing in Fine Motion Control Rod Drive (FM-CRD), Reactor Internal Pump (RIP) etc. which are located in the reinforced concrete containment and usually could not be accessible under operation. The traveling robots are equipped with the three kinds of sensors, an infrared camera, a color TV camera and a microphone, and have a capability to inspect the pre-determined inspection points guided by the monorail. This monitoring system is automatically turned on to start inspection at a scheduled time. For Units 6 and 7, this monitoring system, two robots and several ITV systems, can be controlled from one common control desk and one handy-type remote control panel. Since this monitoring system was installed at Kashiwazaki-Kariwa Nuclear Power Plant Units 6 and 7, this system has been operating successfully. (The installation and testing of the system for Unit 6 was finished completely and the testing the system for Unit 7 has been carrying out.) (author)

  14. Forecasting Turbine Icing Events

    DEFF Research Database (Denmark)

    Davis, Neil; Hahmann, Andrea N.; Clausen, Niels-Erik

    2012-01-01

    In this study, we present a method for forecasting icing events. The method is validated at two European wind farms in with known icing events. The icing model used was developed using current ice accretion methods, and newly developed ablation algorithms. The model is driven by inputs from the WRF...... mesoscale model, allowing for both climatological estimates of icing and short term icing forecasts. The current model was able to detect periods of icing reasonably well at the warmer site. However at the cold climate site, the model was not able to remove ice quickly enough leading to large ice...

  15. Determining the ice-binding planes of antifreeze proteins by fluorescence-based ice plane affinity.

    Science.gov (United States)

    Basu, Koli; Garnham, Christopher P; Nishimiya, Yoshiyuki; Tsuda, Sakae; Braslavsky, Ido; Davies, Peter

    2014-01-15

    Antifreeze proteins (AFPs) are expressed in a variety of cold-hardy organisms to prevent or slow internal ice growth. AFPs bind to specific planes of ice through their ice-binding surfaces. Fluorescence-based ice plane affinity (FIPA) analysis is a modified technique used to determine the ice planes to which the AFPs bind. FIPA is based on the original ice-etching method for determining AFP-bound ice-planes. It produces clearer images in a shortened experimental time. In FIPA analysis, AFPs are fluorescently labeled with a chimeric tag or a covalent dye then slowly incorporated into a macroscopic single ice crystal, which has been preformed into a hemisphere and oriented to determine the a- and c-axes. The AFP-bound ice hemisphere is imaged under UV light to visualize AFP-bound planes using filters to block out nonspecific light. Fluorescent labeling of the AFPs allows real-time monitoring of AFP adsorption into ice. The labels have been found not to influence the planes to which AFPs bind. FIPA analysis also introduces the option to bind more than one differently tagged AFP on the same single ice crystal to help differentiate their binding planes. These applications of FIPA are helping to advance our understanding of how AFPs bind to ice to halt its growth and why many AFP-producing organisms express multiple AFP isoforms.

  16. Ecology of southern ocean pack ice.

    Science.gov (United States)

    Brierley, Andrew S; Thomas, David N

    2002-01-01

    Around Antarctica the annual five-fold growth and decay of sea ice is the most prominent physical process and has a profound impact on marine life there. In winter the pack ice canopy extends to cover almost 20 million square kilometres--some 8% of the southern hemisphere and an area larger than the Antarctic continent itself (13.2 million square kilometres)--and is one of the largest, most dynamic ecosystems on earth. Biological activity is associated with all physical components of the sea-ice system: the sea-ice surface; the internal sea-ice matrix and brine channel system; the underside of sea ice and the waters in the vicinity of sea ice that are modified by the presence of sea ice. Microbial and microalgal communities proliferate on and within sea ice and are grazed by a wide range of proto- and macrozooplankton that inhabit the sea ice in large concentrations. Grazing organisms also exploit biogenic material released from the sea ice at ice break-up or melt. Although rates of primary production in the underlying water column are often low because of shading by sea-ice cover, sea ice itself forms a substratum that provides standing stocks of bacteria, algae and grazers significantly higher than those in ice-free areas. Decay of sea ice in summer releases particulate and dissolved organic matter to the water column, playing a major role in biogeochemical cycling as well as seeding water column phytoplankton blooms. Numerous zooplankton species graze sea-ice algae, benefiting additionally because the overlying sea-ice ceiling provides a refuge from surface predators. Sea ice is an important nursery habitat for Antarctic krill, the pivotal species in the Southern Ocean marine ecosystem. Some deep-water fish migrate to shallow depths beneath sea ice to exploit the elevated concentrations of some zooplankton there. The increased secondary production associated with pack ice and the sea-ice edge is exploited by many higher predators, with seals, seabirds and whales

  17. Control of a nonlinear ice cream crystallization process

    OpenAIRE

    Casenave, Céline; Dochain, Denis; Alvarez, Graciela; Arellano, Marcela; Benkhelifa, Hayat; Leducq, Denis

    2013-01-01

    International audience; In the ice cream industry, the type of final desired product (large cartons (sqrounds) or ice creams on a stick) determine the viscosity at which the ice cream has to be produced. One of the objectives of the ice cream crystallization processes is therefore to produce an ice cream of specified viscosity. In this paper, a nonlinear control strategy is proposed for the control of the viscosity of the ice cream in a continuous crystallizer. It has been designed on the bas...

  18. Life in Ice: Implications to Astrobiology

    Science.gov (United States)

    Hoover, Richard B.

    2009-01-01

    During the 2008 Tawani International Expedition Schirmacher Oasis/Lake Untersee Antarctica Expedition, living and instantly motile bacteria were found in freshly thawed meltwater from ice of the Schirmacher Oasis Lakes, the Anuchin Glacier ice and samples of the that perennial ice sheet above Lake Untersee. This phenomenon of living bacteria encased in ice had previously been observed in the 32,000 year old ice of the Fox Tunnel. The bacteria found in this ice included the strain FTR1T which was isolated and published as valid new species (Carnobacterium pleistocenium) the first validly published living Pleistocene organism still alive today. Living bacteria were also extracted from ancient ice cores from Vostok, Antarctica. The discovery that many strains of bacteria are able to survive and remain alive while frozen in ice sheets for long periods of time may have direct relevance to Astrobiology. The abundance of viable bacteria in the ice sheets of Antarctica suggests that the presence of live bacteria in ice is common, rather than an isolated phenomenon. This paper will discuss the results of recent studies at NSSTC of bacteria cryopreserved in ice. This paper advances the hypothesis that cryopreserved cells, and perhaps even viable bacterial cells, may exist today--frozen in the water-ice of lunar craters, the Polar Caps or craters of Mars; or in the permafrost of Mars; ice and rocks of comets or water bearing asteroids; or in the frozen crusts of the icy moons of Jupiter and Saturn. The existence of bacterial life in ice suggests that it may not be necessary to drill through a thick ice crust to reach liquid water seas deep beneath the icy crusts of Europa, Ganymede and Enceladus. The presence of viable bacteria in the ice of the Earth s Polar Caps suggests that the possibility that cryo-panspermia (i.e., the trans-planetary transfer of microbial life by impact ejection/spallation of bacteria-rich polar ice masses) deserves serious consideration and study as a

  19. Thick or Thin Ice Shell on Europa?

    Science.gov (United States)

    2007-01-01

    Scientists are all but certain that Europa has an ocean underneath its icy surface, but they do not know how thick this ice might be. This artist concept illustrates two possible cut-away views through Europa's ice shell. In both, heat escapes, possibly volcanically, from Europa's rocky mantle and is carried upward by buoyant oceanic currents. If the heat from below is intense and the ice shell is thin enough (left), the ice shell can directly melt, causing what are called 'chaos' on Europa, regions of what appear to be broken, rotated and tilted ice blocks. On the other hand, if the ice shell is sufficiently thick (right), the less intense interior heat will be transferred to the warmer ice at the bottom of the shell, and additional heat is generated by tidal squeezing of the warmer ice. This warmer ice will slowly rise, flowing as glaciers do on Earth, and the slow but steady motion may also disrupt the extremely cold, brittle ice at the surface. Europa is no larger than Earth's moon, and its internal heating stems from its eccentric orbit about Jupiter, seen in the distance. As tides raised by Jupiter in Europa's ocean rise and fall, they may cause cracking, additional heating and even venting of water vapor into the airless sky above Europa's icy surface. (Artwork by Michael Carroll.)

  20. Great Lakes Ice Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the 2001/2002...

  1. Injury Prevention for Ski-Area Employees: A Physiological Assessment of Lift Operators, Instructors, and Patrollers

    Directory of Open Access Journals (Sweden)

    Delia Roberts

    2013-01-01

    Full Text Available Background. Momentary lapses in concentration contribute to workplace accidents. Given that blood glucose (BG and hydration levels have been shown to affect vigilance, this study proposed to investigate these parameters and functional movement patterns of ski-resort workers and to determine whether an educational program to stabilize BG and hydration and encourage joint stability had an effect in decreasing occupational injuries. Methods. Seventy-five instructors, patrollers and, lift-operators at five snowsport resorts were evaluated for BG, vigilance, workload, dietary/hydration practices, and functional-movement patterns. Injury rates were tabulated before and after an educational program for nutrition and functional-movement awareness and compared to other resorts. Results. Workers showed poor stability at the lumbar spine, knee, and shoulder. BG levels were normal but variable (%CV = 14±6. Diets were high in sugar and fat and low in water and many nutrients. Medical Aid and Lost Time claims declined significantly by 65.1±20.0% (confidence interval −90.0% ≤μ≤−40.2% in resorts that used the educational program whereas four control resorts not using the program experienced increases of 33.4±42.9% (confidence interval −19.7% ≤μ≤−86.7%; F[2,12] = 21.35, P<0.0001 over the same season. Conclusion. Provision of snowsport resort workers with educational programs encouraging hydration, diet to stabilize BG, and functional-movement awareness was effective in reducing worksite injuries in this population.

  2. Autonomous mobile platform with simultaneous localisation and mapping system for patrolling purposes

    Science.gov (United States)

    Mitka, Łukasz; Buratowski, Tomasz

    2017-10-01

    This work describes an autonomous mobile platform for supervision and surveillance purposes. The system can be adapted for mounting on different types of vehicles. The platform is based on a SLAM navigation system which performs a localization task. Sensor fusion including laser scanners, inertial measurement unit (IMU), odometry and GPS lets the system determine its position in a certain and precise way. The platform is able to create a 3D model of a supervised area and export it as a point cloud. The system can operate both inside and outside as the navigation algorithm is resistant to typical localization errors caused by wheel slippage or temporal GPS signal loss. The system is equipped with a path-planning module which allows operating in two modes. The first mode is for periodical observation of points in a selected area. The second mode is turned on in case of an alarm. When it is called, the platform moves with the fastest route to the place of the alert. The path planning is always performed online with use of the most current scans, therefore the platform is able to adjust its trajectory to the environment changes or obstacles that are in the motion. The control algorithms are developed under the Robot Operating System (ROS) since it comes with drivers for many devices used in robotics. Such a solution allows for extending the system with any type of sensor in order to incorporate its data into a created area model. Proposed appliance can be ported to other existing robotic platforms or used to develop a new platform dedicated to a specific kind of surveillance. The platform use cases are to patrol an area, such as airport or metro station, in search for dangerous substances or suspicious objects and in case of detection instantly inform security forces. Second use case is a tele-operation in hazardous area for an inspection purposes.

  3. How ice shelf morphology controls basal melting

    Science.gov (United States)

    Little, Christopher M.; Gnanadesikan, Anand; Oppenheimer, Michael

    2009-12-01

    The response of ice shelf basal melting to climate is a function of ocean temperature, circulation, and mixing in the open ocean and the coupling of this external forcing to the sub-ice shelf circulation. Because slope strongly influences the properties of buoyancy-driven flow near the ice shelf base, ice shelf morphology plays a critical role in linking external, subsurface heat sources to the ice. In this paper, the slope-driven dynamic control of local and area-integrated melting rates is examined under a wide range of ocean temperatures and ice shelf shapes, with an emphasis on smaller, steeper ice shelves. A 3-D numerical ocean model is used to simulate the circulation underneath five idealized ice shelves, forced with subsurface ocean temperatures ranging from -2.0°C to 1.5°C. In the sub-ice shelf mixed layer, three spatially distinct dynamic regimes are present. Entrainment of heat occurs predominately under deeper sections of the ice shelf; local and area-integrated melting rates are most sensitive to changes in slope in this "initiation" region. Some entrained heat is advected upslope and used to melt ice in the "maintenance" region; however, flow convergence in the "outflow" region limits heat loss in flatter portions of the ice shelf. Heat flux to the ice exhibits (1) a spatially nonuniform, superlinear dependence on slope and (2) a shape- and temperature-dependent, internally controlled efficiency. Because the efficiency of heat flux through the mixed layer decreases with increasing ocean temperature, numerical simulations diverge from a simple quadratic scaling law.

  4. The IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope Array: Joint Contribution to the 34th International Cosmic Ray Conference (ICRC 2015)

    Energy Technology Data Exchange (ETDEWEB)

    Aartsen, M.G.; et al.

    2015-11-06

    We have conducted three searches for correlations between ultra-high energy cosmic rays detected by the Telescope Array and the Pierre Auger Observatory, and high-energy neutrino candidate events from IceCube. Two cross-correlation analyses with UHECRs are done: one with 39 cascades from the IceCube `high-energy starting events' sample and the other with 16 high-energy `track events'. The angular separation between the arrival directions of neutrinos and UHECRs is scanned over. The same events are also used in a separate search using a maximum likelihood approach, after the neutrino arrival directions are stacked. To estimate the significance we assume UHECR magnetic deflections to be inversely proportional to their energy, with values $3^\\circ$, $6^\\circ$ and $9^\\circ$ at 100 EeV to allow for the uncertainties on the magnetic field strength and UHECR charge. A similar analysis is performed on stacked UHECR arrival directions and the IceCube sample of through-going muon track events which were optimized for neutrino point-source searches.

  5. [Risk for environment-induced diseases due to air pollution from motor vehicles in road-patrol officers].

    Science.gov (United States)

    Mikhaĭlichenko, K Iu; Kas'ianenko, A A; Shchelkunova, I G; Grechko, A V

    2010-01-01

    The paper describes risk factors for environment-induced diseases in road-patrol (RP) officers under the existing working conditions: noise and chemical ambient air pollution from motor vehicles. There is evidence for a significant increase in the incidence of diseases of the cardiovascular and nervous system, sense organs, digestive and endocrine metabolic systems in the State Road Safety Inspectorate officers who are directly engaged in traffic management. Potential and real risks from motor transport to the health of RP roads have been estimated. Recommendations on optimizing the working conditions are given.

  6. Development of automated patrol-type monitoring and inspection system for nuclear power plant and application to actual plant

    International Nuclear Information System (INIS)

    Senoo, Makoto; Koga, Kazunori; Hirakawa, Hiroshi; Tanaka, Keiji

    1996-01-01

    An automated patrol-type monitoring and inspection system was developed and applied in a nuclear power plant. This system consists of a monorail, a monitoring robot and an operator's console. The monitoring robot consists of a sensor unit and a control unit. Three kinds of sensor, a color ITV camera, an infrared camera and a microphone are installed in the sensor unit. The features of this monitoring robot are; (1) Weights 15 kg with a cross-sectional dimensions of 152 mm width and 290 mm height. (2) Several automatic monitoring functions are installed using image processing and frequency analysis for three sensor signals. (author)

  7. Yuma Border Patrol Area Lighting Retrofit LED System Performance in a Trial Installation – Two Years Later

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sullivan, Gregory P. [Efficiency Solutions, Inc, Richland, WA (United States); Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-05-21

    Documentation of the Yuma Sector Border Patrol Area lighting LED trial demonstration continues to provide a better understanding of LED technology performance in a high ambient temperature and high solar radiation environment. Measured data at the project site showed illuminances changing more rapidly than anticipated. As previously predicted, the causes for these observed changes are mostly if not completely explained by dirt accumulation. The laboratory measurements showed not only the effect of dirt on lumen output, but also on the distribution of light exiting the luminaire.

  8. Switch of flow direction in an Antarctic ice stream.

    Science.gov (United States)

    Conway, H; Catania, G; Raymond, C F; Gades, A M; Scambos, T A; Engelhardt, H

    2002-10-03

    Fast-flowing ice streams transport ice from the interior of West Antarctica to the ocean, and fluctuations in their activity control the mass balance of the ice sheet. The mass balance of the Ross Sea sector of the West Antarctic ice sheet is now positive--that is, it is growing--mainly because one of the ice streams (ice stream C) slowed down about 150 years ago. Here we present evidence from both surface measurements and remote sensing that demonstrates the highly dynamic nature of the Ross drainage system. We show that the flow in an area that once discharged into ice stream C has changed direction, now draining into the Whillans ice stream (formerly ice stream B). This switch in flow direction is a result of continuing thinning of the Whillans ice stream and recent thickening of ice stream C. Further abrupt reorganization of the activity and configuration of the ice streams over short timescales is to be expected in the future as the surface topography of the ice sheet responds to the combined effects of internal dynamics and long-term climate change. We suggest that caution is needed when using observations of short-term mass changes to draw conclusions about the large-scale mass balance of the ice sheet.

  9. Surface ice flow velocity and tide retrieval of the amery ice shelf using precise point positioning

    DEFF Research Database (Denmark)

    Zhang, X.H.; Andersen, Ole Baltazar

    2006-01-01

    Five days of continuous GPS observation data were collected in the frontal zone of the Amery ice shelf and subsequently post-processed using precise point position (PPP) technology based on precise orbit and clock products from the International GNSS service. The surface ice flow velocity of the ...

  10. Dead-ice environments

    DEFF Research Database (Denmark)

    Krüger, Johannes; Kjær, Kurt H.; Schomacker, Anders

    2010-01-01

    glacier environment. The scientific challenges are to answer the key questions. What are the conditions for dead-ice formation? From which sources does the sediment cover originate? Which melting and reworking processes act in the ice-cored moraines? What is the rate of de-icing in the ice-cored moraines...

  11. Rate of ice accumulation during ice storms

    Energy Technology Data Exchange (ETDEWEB)

    Feknous, N. [SNC-Lavalin, Montreal, PQ (Canada); Chouinard, L. [McGill Univ., Montreal, PQ (Canada); Sabourin, G. [Hydro-Quebec, Montreal, PQ (Canada)

    2005-07-01

    The rate of glaze ice accumulation is the result of a complex process dependent on numerous meteorological and physical factors. The aim of this paper was to estimate the distribution rate of glaze ice accumulation on conductors in southern Quebec for use in the design of mechanical and electrical de-icing devices. The analysis was based on direct observations of ice accumulation collected on passive ice meters. The historical database of Hydro-Quebec, which contains observations at over 140 stations over period of 25 years, was used to compute accumulation rates. Data was processed so that each glaze ice event was numbered in a chronological sequence. Each event consisted of the time series of ice accumulations on each of the 8 cylinders of the ice meters, as well as on 5 of its surfaces. Observed rates were converted to represent the average ice on a 30 mm diameter conductor at 30 m above ground with a span of 300 m. Observations were corrected to account for the water content of the glaze ice as evidenced by the presence of icicles. Results indicated that despite significant spatial variations in the expected severity of ice storms as a function of location, the distribution function for rates of accumulation were fairly similar and could be assumed to be independent of location. It was concluded that the observations from several sites could be combined in order to obtain better estimates of the distribution of hourly rates of ice accumulation. However, the rates were highly variable. For de-icing strategies, it was suggested that average accumulation rates over 12 hour periods were preferable, and that analyses should be performed for other time intervals to account for the variability in ice accumulation rates over time. In addition, accumulation rates did not appear to be highly correlated with average wind speed for maximum hourly accumulation rates. 3 refs., 2 tabs., 10 figs.

  12. Phototherapy and orange-tinted goggles for night-shift adaptation of police officers on patrol.

    Science.gov (United States)

    Boivin, Diane B; Boudreau, Philippe; Tremblay, Geneviève M

    2012-06-01

    The aim of the present combined field and laboratory study was to assess circadian entrainment in two groups of police officers working seven consecutive 8/8.5-h night shifts as part of a rotating schedule. Eight full-time police officers on patrol (mean age ± SD: 29.8 ± 6.5 yrs) were provided an intervention consisting of intermittent exposure to wide-spectrum bright light at night, orange-tinted goggles at sunrise, and maintenance of a regular sleep/darkness episode in the day. Orange-tinted goggles have been shown to block the melatonin-suppressing effect of light significantly more than neutral gray density goggles. Nine control group police officers (mean age ± SD: 30.3 ± 4.1 yrs) working the same schedule were enrolled. Police officers were studied before, after (in the laboratory), and during (ambulatory) a series of seven consecutive nights. Urine samples were collected at wake time and bedtime throughout the week of night work and during laboratory visits (1 × /3 h) preceding and following the work week to measure urinary 6-sulfatoxymelatonin (UaMT6s) excretion rate. Subjective alertness was assessed at the start, middle, and end of night shifts. A 10-min psychomotor vigilance task was performed at the start and end of each shift. Both laboratory visits consisted of two 8-h sleep episodes based on the prior schedule. Saliva samples were collected 2 × /h during waking episodes to assay their melatonin content. Subjective alertness (3 × /h) and performance (1 × /2 h) were assessed during wake periods in the laboratory. A mixed linear model was used to analyze the progression of UaMt6s excreted during daytime sleep episodes at home, as well as psychomotor performance and subjective alertness during night shifts. Two-way analysis of variance (ANOVA) (factors: laboratory visit and group) were used to compare peak salivary melatonin and UaMT6s excretion rate in the laboratory. In both groups of police officers, the excretion rate of UaMT6s at home was

  13. The conceptual design of the sensing system for patrolling and inspecting a nuclear facility by the intelligent robot

    International Nuclear Information System (INIS)

    Ebihara, Ken-ichi

    1993-11-01

    Supposing that an intelligent robot, instead of a human worker, patrols and inspects nuclear facilities, it is indispensable for such robot to be capable of moving with avoiding obstacles and recognizing various abnormal conditions, carrying out some ordered works based on information from sensors mounted on the robot. The present robots being practically used in nuclear facilities, however, have the limited capability such as identifying a few specific abnormal conditions using data detected by specific sensors on them. Hence, a conceptual design of a sensor-fusion-based system, which is named 'sensing system', has been performed to collect various kinds of information required for patrol and inspection. This sensing system combines a visual sensor, which consists of a monocular camera and a range finder by the active stereopsis method, an olfactory, acoustic and dose sensors. This report describes the hardware configuration and the software function for processing sensed data. An idea of sensor fusion and the preliminary consideration in respect of applying the neural network to image data processing are also described. (author)

  14. The IceCube Neutrino Observatory - Contributions to ICRC 2017 Part VI: IceCube-Gen2, the Next Generation Neutrino Observatory

    OpenAIRE

    Collaboration, IceCube-Gen2; :; Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Samarai, I. Al; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Argüelles, C.

    2017-01-01

    Papers on research & development towards IceCube-Gen2, the next generation neutrino observatory at South Pole, submitted to the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the IceCube-Gen2 Collaboration.

  15. Stochastic ice stream dynamics.

    Science.gov (United States)

    Mantelli, Elisa; Bertagni, Matteo Bernard; Ridolfi, Luca

    2016-08-09

    Ice streams are narrow corridors of fast-flowing ice that constitute the arterial drainage network of ice sheets. Therefore, changes in ice stream flow are key to understanding paleoclimate, sea level changes, and rapid disintegration of ice sheets during deglaciation. The dynamics of ice flow are tightly coupled to the climate system through atmospheric temperature and snow recharge, which are known exhibit stochastic variability. Here we focus on the interplay between stochastic climate forcing and ice stream temporal dynamics. Our work demonstrates that realistic climate fluctuations are able to (i) induce the coexistence of dynamic behaviors that would be incompatible in a purely deterministic system and (ii) drive ice stream flow away from the regime expected in a steady climate. We conclude that environmental noise appears to be crucial to interpreting the past behavior of ice sheets, as well as to predicting their future evolution.

  16. Sea Ice Ecosystems

    Science.gov (United States)

    Arrigo, Kevin R.

    2014-01-01

    Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters.

  17. Ross Ice Shelf, Antarctic Ice and Clouds

    Science.gov (United States)

    1991-01-01

    In this view of Antarctic ice and clouds, (56.5S, 152.0W), the Ross Ice Shelf of Antarctica is almost totally clear, showing stress cracks in the ice surface caused by wind and tidal drift. Clouds on the eastern edge of the picture are associated with an Antarctic cyclone. Winds stirred up these storms have been known to reach hurricane force.

  18. Sea ice dynamics across the Mid-Pleistocene transition in the Bering Sea.

    Science.gov (United States)

    Detlef, H; Belt, S T; Sosdian, S M; Smik, L; Lear, C H; Hall, I R; Cabedo-Sanz, P; Husum, K; Kender, S

    2018-03-05

    Sea ice and associated feedback mechanisms play an important role for both long- and short-term climate change. Our ability to predict future sea ice extent, however, hinges on a greater understanding of past sea ice dynamics. Here we investigate sea ice changes in the eastern Bering Sea prior to, across, and after the Mid-Pleistocene transition (MPT). The sea ice record, based on the Arctic sea ice biomarker IP 25 and related open water proxies from the International Ocean Discovery Program Site U1343, shows a substantial increase in sea ice extent across the MPT. The occurrence of late-glacial/deglacial sea ice maxima are consistent with sea ice/land ice hysteresis and land-glacier retreat via the temperature-precipitation feedback. We also identify interactions of sea ice with phytoplankton growth and ocean circulation patterns, which have important implications for glacial North Pacific Intermediate Water formation and potentially North Pacific abyssal carbon storage.

  19. Arctic Sea Ice Trafficability - New Strategies for a Changing Icescape

    Science.gov (United States)

    Dammann, Dyre Oliver

    substantial thickness variability results in the need to raise thickness thresholds by 50%. If sea ice is thick enough for safe travel, then the efficiency of travel is relevant and is influenced by the roughness of the ice surface. Here, I develop a technique to derive trafficability measures from ice roughness using polarimetric and interferometric synthetic aperture radar (SAR). Validated using Structure-from-Motion analysis of imagery obtained from an unmanned aerial system near Utqiagvik, Alaska, I demonstrate the ability of these SAR techniques to map both topography and roughness with potential to guide trail construction efforts towards more trafficable ice. Even when the ice is sufficiently thick to ensure safe travel, potential for fracturing can be a serious hazard through the ability of cracks to compromise load-bearing capacity. Therefore, I have created a state-of-the-art technique using interferometric SAR to assess ice stability with capability of assessing internal ice stress and potential for failure. In an analysis of ice deformation and potential hazards for the Northstar Island ice road near Prudhoe Bay on Alaska's North Slope I have identified a zone of high relative fracture intensity potential that conformed with road inspections and hazard assessments by the operator. Through this work I have investigated the intersection between ice use and geophysics, demonstrating that quantitative evaluation of a given region in the ice use assessment framework developed here can aid in tactical routing of ice trails and roads as well as help inform long-term strategic decision-making regarding the future of Arctic operations on or near sea ice.

  20. A natural ice boom

    Energy Technology Data Exchange (ETDEWEB)

    Hopper, H.R. [Manitoba Hydro, Winnipeg, MB (Canada)

    1998-10-01

    Planning for ice jams and ice movements are critical on the Nelson River in northern Manitoba in designing cofferdams. Experience on the St. Lawrence River demonstrated the possibility of exercising some control over ice action by judicious placement of log booms or ice control structures. The success of experiments with man-made controls led to field tests in which an ice sheet of sufficient magnitude and competence was introduced into the open water stream of the Nelson River. The ice sheet was subsequently jammed in a narrow channel, thereby creating a natural ice bridge or boom upstream of a proposed hydro development. Under favourable conditions, this boom would initiate the progression of the ice cover from its location upstream, cutting off the downstream reach from the ice producing potential of the upstream reach. Although ice would still be generated downstream, the length of the reach between the ice boom and the development site would be short enough that ice jamming at the development site would never occur. Although problems in blasting prevented the introduction of a competent ice sheet into the main stream of the river at the location chosen, sufficient confidence in the theory was gained to warrant further consideration. 4 refs., 1 tab., 10 figs.

  1. Ice Segregation and Frost Heaving.

    Science.gov (United States)

    1984-01-01

    to a buried chilled gas pipeline by continual frost ’. ’- heave during the service life or to a buried liquefied gas tank is a more _ recent concern...M). Lule en: Uiversity of Lulea. Pehner, E., 1982. Aspects of ice lens fornmation. P ing of the Third International Syvosium on Ground Freezi, Hanover...Soils. Lalea, Sweden: Uiversity ofLulea. . Berg, R. L., G. Guymon and J. Ingersoll, 1979. Conference on soil-water . problems in cold regions. Cold

  2. Forecast Icing Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Forecast Icing Product (FIP) is an automatically-generated index suitable for depicting areas of potentially hazardous airframe icing. The FIP algorithm uses...

  3. Current Icing Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Current Icing Product (CIP) is an automatically-generated index suitable for depicting areas of potentially hazardous airframe icing. The CIP algorithm combines...

  4. Radiofrequency exposure on fast patrol boats in the Royal Norwegian Navy--an approach to a dose assessment.

    Science.gov (United States)

    Baste, Valborg; Mild, Kjell Hansson; Moen, Bente E

    2010-07-01

    Epidemiological studies related to radiofrequency (RF) electromagnetic fields (EMF) have mainly used crude proxies for exposure, such as job titles, distance to, or use of different equipment emitting RF EMF. The Royal Norwegian Navy (RNoN) has measured RF field emitted from high-frequency antennas and radars on several spots where the crew would most likely be located aboard fast patrol boats (FPB). These boats are small, with short distance between the crew and the equipment emitting RF field. We have described the measured RF exposure aboard FPB and suggested different methods for calculations of total exposure and annual dose. Linear and spatial average in addition to percentage of ICNIRP and squared deviation of ICNIRP has been used. The methods will form the basis of a job exposure matrix where relative differences in exposure between groups of crew members can be used in further epidemiological studies of reproductive health. 2010 Wiley-Liss, Inc.

  5. Sputtering of water ice

    International Nuclear Information System (INIS)

    Baragiola, R.A.; Vidal, R.A.; Svendsen, W.; Schou, J.; Shi, M.; Bahr, D.A.; Atteberrry, C.L.

    2003-01-01

    We present results of a range of experiments of sputtering of water ice together with a guide to the literature. We studied how sputtering depends on the projectile energy and fluence, ice growth temperature, irradiation temperature and external electric fields. We observed luminescence from the decay of H(2p) atoms sputtered by heavy ion impact, but not bulk ice luminescence. Radiolyzed ice does not sputter under 3.7 eV laser irradiation

  6. Medical ice slurry production device

    Science.gov (United States)

    Kasza, Kenneth E [Palos Park, IL; Oras, John [Des Plaines, IL; Son, HyunJin [Naperville, IL

    2008-06-24

    The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

  7. Creation of a strategic framework for global development of ice hockey

    OpenAIRE

    Nieminen, Aku

    2016-01-01

    The International Ice Hockey Federation (IIHF) is the international governing body of ice hockey and inline hockey. Among many responsibilities and objectives, one of the main tasks of the IIHF is to develop ice hockey on a global scale. The IIHF has 74 Member National Associations which can benefit from the development programs of the IIHF. These development programs have the purpose of assisting and supporting the National Association in the domestic development of ice hockey in their count...

  8. Helicopter Icing Review.

    Science.gov (United States)

    1980-09-01

    helicopter (i.e. in an icing tunnel or engine test cell ) and therefore can be subjected to controlled icing where spe- cific problems can be safely...evaluation. 69 2.2.5.2 Ice Protection Systems Demonstration Many of the systems noted in 2.2.5.1 can be evaluated in icing test cells or icing wind tunnels...Figure 2-32 illustrates a typical rotor deice system control arrangement. 104 (N >4 A.dO INaH -E- C4) uo U En 9 E-1 H m I ~z O 04 04iH U 0 El4 E-f C E

  9. Processes driving sea ice variability in the Bering Sea in an eddying ocean/sea ice model: Mean seasonal cycle

    Science.gov (United States)

    Li, Linghan; McClean, Julie L.; Miller, Arthur J.; Eisenman, Ian; Hendershott, Myrl C.; Papadopoulos, Caroline A.

    2014-12-01

    The seasonal cycle of sea ice variability in the Bering Sea, together with the thermodynamic and dynamic processes that control it, are examined in a fine resolution (1/10°) global coupled ocean/sea-ice model configured in the Community Earth System Model (CESM) framework. The ocean/sea-ice model consists of the Los Alamos National Laboratory Parallel Ocean Program (POP) and the Los Alamos Sea Ice Model (CICE). The model was forced with time-varying reanalysis atmospheric forcing for the time period 1970-1989. This study focuses on the time period 1980-1989. The simulated seasonal-mean fields of sea ice concentration strongly resemble satellite-derived observations, as quantified by root-mean-square errors and pattern correlation coefficients. The sea ice energy budget reveals that the seasonal thermodynamic ice volume changes are dominated by the surface energy flux between the atmosphere and the ice in the northern region and by heat flux from the ocean to the ice along the southern ice edge, especially on the western side. The sea ice force balance analysis shows that sea ice motion is largely associated with wind stress. The force due to divergence of the internal ice stress tensor is large near the land boundaries in the north, and it is small in the central and southern ice-covered region. During winter, which dominates the annual mean, it is found that the simulated sea ice was mainly formed in the northern Bering Sea, with the maximum ice growth rate occurring along the coast due to cold air from northerly winds and ice motion away from the coast. South of St Lawrence Island, winds drive the model sea ice southwestward from the north to the southwestern part of the ice-covered region. Along the ice edge in the western Bering Sea, model sea ice is melted by warm ocean water, which is carried by the simulated Bering Slope Current flowing to the northwest, resulting in the S-shaped asymmetric ice edge. In spring and fall, similar thermodynamic and dynamic

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

    Science.gov (United States)

    Oliver, Michael J.

    2014-01-01

    The Propulsion Systems Laboratory (PSL) is an existing altitude simulation jet engine test facility located at NASA Glenn Research Center in Cleveland, OH. It was modified in 2012 with the integration of an ice crystal cloud generation system. This paper documents the inaugural ice crystal cloud test in PSL--the first ever full scale, high altitude ice crystal cloud turbofan engine test to be conducted in a ground based facility. The test article was a Lycoming ALF502-R5 high bypass turbofan engine, serial number LF01. The objectives of the test were to validate the PSL ice crystal cloud calibration and engine testing methodologies by demonstrating the capability to calibrate and duplicate known flight test events that occurred on the same LF01 engine and to generate engine data to support fundamental and computational research to investigate and better understand the physics of ice crystal icing in a turbofan engine environment while duplicating known revenue service events and conducting test points while varying facility and engine parameters. During PSL calibration testing it was discovered than heated probes installed through tunnel sidewalls experienced ice buildup aft of their location due to ice crystals impinging upon them, melting and running back. Filtered city water was used in the cloud generation nozzle system to provide ice crystal nucleation sites. This resulted in mineralization forming on flow path hardware that led to a chronic degradation of performance during the month long test. Lacking internal flow path cameras, the response of thermocouples along the flow path was interpreted as ice building up. Using this interpretation, a strong correlation between total water content (TWC) and a weaker correlation between median volumetric diameter (MVD) of the ice crystal cloud and the rate of ice buildup along the instrumented flow path was identified. For this test article the engine anti-ice system was required to be turned on before ice crystal

  11. Ice slurry applications

    Energy Technology Data Exchange (ETDEWEB)

    Kauffeld, M. [Karlsruhe University of Applied Sciences, Moltkestr. 30, 76133 Karlsruhe (Germany); Wang, M.J.; Goldstein, V. [Sunwell Technologies Inc., 180 Caster Avenue, Woodbridge, L4L 5Y (Canada); Kasza, K.E. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2010-12-15

    The role of secondary refrigerants is expected to grow as the focus on the reduction of greenhouse gas emissions increases. The effectiveness of secondary refrigerants can be improved when phase changing media are introduced in place of single-phase media. Operating at temperatures below the freezing point of water, ice slurry facilitates several efficiency improvements such as reductions in pumping energy consumption as well as lowering the required temperature difference in heat exchangers due to the beneficial thermo-physical properties of ice slurry. Research has shown that ice slurry can be engineered to have ideal ice particle characteristics so that it can be easily stored in tanks without agglomeration and then be extractable for pumping at very high ice fraction without plugging. In addition ice slurry can be used in many direct contact food and medical protective cooling applications. This paper provides an overview of the latest developments in ice slurry technology. (author)

  12. Export of Ice-Cavity Water from Pine Island Ice Shelf, West Antarctica

    Science.gov (United States)

    Thurnherr, Andreas; Jacobs, Stanley; Dutrieux, Pierre

    2013-04-01

    Stability of the West Antarctic Ice Sheet is sensitive to changes in melting at the bottom of floating ice shelves that form the seaward extensions of Antarctic glaciers flowing into the ocean. Not least because observations in the cavities beneath ice shelves are difficult, heat fluxes and melt rates have been inferred from oceanographic measurements obtained near the ice edge (calving fronts). Here, we report on a set of hydrographic and velocity data collected in early 2009 near the calving front of the Amundsen Sea's fast-moving and (until recently) accelerating Pine Island Glacier and its associated ice shelf. CTD profiles collected along the southern half of the meridionally-trending ice front show clear evidence for export of ice-cavity water. That water was carried in the upper ocean along the ice front by a southward current that is possibly related to a striking clockwise gyre that dominated the (summertime) upper-ocean circulation in Pine Island Bay. Signatures of ice-cavity water appear unrelated to current direction along most of the ice front, suggesting that cross-frontal exchange is dominated by temporal variability. However, repeated hydrographic and velocity measurements in a small "ice cove" at the southern end of the calving front show a persistent strong (mean velocity peaking near 0.5 ms-1) outflow of ice-cavity water in the upper 500 m. While surface features (boils) suggested upwelling from deep below the ice shelf, vertical velocity measurements reveal 1) that the mean upwelling within the confines of the cove was too weak to feed the observed outflow, and 2) that large high-frequency internal waves dominated the vertical motion of water inside the cove. These observations indicate that water exchange between the Pine Island Ice Shelf cavity and the Amundsen sea is strongly asymmetric with weak broad inflow at depth and concentrated surface-intensified outflow of melt-laden deep water at the southern edge of the calving front. The lack of

  13. Autonomous Aerial Ice Observation for Ice Defense

    Directory of Open Access Journals (Sweden)

    Joakim Haugen

    2014-10-01

    Full Text Available One of the tasks in ice defense is to gather information about the surrounding ice environment using various sensor platforms. In this manuscript we identify two monitoring tasks known in literature, namely dynamic coverage and target tracking, and motivate how these tasks are relevant in ice defense using RPAS. An optimization-based path planning concept is outlined for solving these tasks. A path planner for the target tracking problem is elaborated in more detail and a hybrid experiment, which consists of both a real fixed-wing aircraft and simulated objects, is included to show the applicability of the proposed framework.

  14. Corporate social responsibility concept in the ice cream industry

    OpenAIRE

    Jílková, Andrea

    2015-01-01

    The bachelor thesis is focused on the corporate social responsibility concept in the ice cream industry and in Ben & Jerry's company. Ben & Jerry's ice cream is Vermont- based company and subsidiary of Unilever and produces high quality ice cream while striving to serve to greater good. Collected data about the company that were used in analyses of the internal environment and CSR environment revealed some unique techniques of how company Ben & Jerry's deals with CSR. These analyses were equa...

  15. Arctic landfast sea ice

    Science.gov (United States)

    Konig, Christof S.

    Landfast ice is sea ice which forms and remains fixed along a coast, where it is attached either to the shore, or held between shoals or grounded icebergs. Landfast ice fundamentally modifies the momentum exchange between atmosphere and ocean, as compared to pack ice. It thus affects the heat and freshwater exchange between air and ocean and impacts on the location of ocean upwelling and downwelling zones. Further, the landfast ice edge is essential for numerous Arctic mammals and Inupiat who depend on them for their subsistence. The current generation of sea ice models is not capable of reproducing certain aspects of landfast ice formation, maintenance, and disintegration even when the spatial resolution would be sufficient to resolve such features. In my work I develop a new ice model that permits the existence of landfast sea ice even in the presence of offshore winds, as is observed in mature. Based on viscous-plastic as well as elastic-viscous-plastic ice dynamics I add tensile strength to the ice rheology and re-derive the equations as well as numerical methods to solve them. Through numerical experiments on simplified domains, the effects of those changes are demonstrated. It is found that the modifications enable landfast ice modeling, as desired. The elastic-viscous-plastic rheology leads to initial velocity fluctuations within the landfast ice that weaken the ice sheet and break it up much faster than theoretically predicted. Solving the viscous-plastic rheology using an implicit numerical method avoids those waves and comes much closer to theoretical predictions. Improvements in landfast ice modeling can only verified in comparison to observed data. I have extracted landfast sea ice data of several decades from several sources to create a landfast sea ice climatology that can be used for that purpose. Statistical analysis of the data shows several factors that significantly influence landfast ice distribution: distance from the coastline, ocean depth, as

  16. International

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  17. Workshop on wave-ice interaction

    Science.gov (United States)

    Wadhams, Peter; Squire, Vernon; Rottier, Philip; Liu, Antony; Dugan, John; Czipott, Peter; Shen, Hayley

    The subject of wave-ice interaction has been advanced in recent years by small groups of researchers working on a similar range of topics in widely separated geographic locations. Their recent studies inspired a workshop on wave-ice interaction held at the Scott Polar Research Institute, University of Cambridge, England, December 16-18, 1991, where theories in all aspects of the physics of wave-ice interaction were compared.Conveners of the workshop hoped that plans for future observational and theoretical work dealing with outstanding issues in a collaborative way would emerge. The workshop, organized by the Commission on Sea Ice of the International Association for Physical Sciences of the Ocean (IAPSO), was co-chaired by Vernon Squire, professor of mathematics and statistics at the University of Otago, New Zealand, and Peter Wadhams, director of the Scott Polar Research Institute. Participants attended from Britain, Finland, New Zealand, Norway, and the United States.

  18. Removable cruciform for ice condenser ice basket

    International Nuclear Information System (INIS)

    Scrabis, C.M.; Mazza, G.E.; Golick, L.R.; Pomaibo, P.

    1987-01-01

    A removable cruciform for use in an ice basket having a generally cylindrical sidewall defining a central, vertical axis of the ice basket and plural, generally annular retaining rings secured to the interior of the cylindrical sidewall of the ice basket at predetermined, spaced elevations throughout the axial height of the ice basket is described comprising: a pair of brackets, each comprising a central, base portion having parallel longitudinal edges and a pair of integral legs extending at corresponding angles relative to the base portion from the perspective parallel longitudinal edges thereof; a pair of support plate assemblies secured to and extending in parallel, spaced relationship from one of the pair of brackets; a pair of slide support plates secured to the other of the pair of brackets and extending therefrom in spaced, parallel relationship; and spring means received within the housing and engaging the base portions of the brackets and applying a resilient biasing force thereto for maintaining the spaced relationship thereof

  19. Ice cream structure modification by ice-binding proteins.

    Science.gov (United States)

    Kaleda, Aleksei; Tsanev, Robert; Klesment, Tiina; Vilu, Raivo; Laos, Katrin

    2018-04-25

    Ice-binding proteins (IBPs), also known as antifreeze proteins, were added to ice cream to investigate their effect on structure and texture. Ice recrystallization inhibition was assessed in the ice cream mixes using a novel accelerated microscope assay and the ice cream microstructure was studied using an ice crystal dispersion method. It was found that adding recombinantly produced fish type III IBPs at a concentration 3 mg·L -1 made ice cream hard and crystalline with improved shape preservation during melting. Ice creams made with IBPs (both from winter rye, and type III IBP) had aggregates of ice crystals that entrapped pockets of the ice cream mixture in a rigid network. Larger individual ice crystals and no entrapment in control ice creams was observed. Based on these results a model of ice crystals aggregates formation in the presence of IBPs was proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Free Energy and Internal Combustion Engine Cycles

    OpenAIRE

    Harris, William D.

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  1. Aircraft Icing Handbook. (Update)

    Science.gov (United States)

    1993-01-01

    Report 1946-1947, U. S. Air Material Command Tech. Rept. 5676. Findeisen , W., *Meteorological Commentary of D (air) 1209, Icing,* Germany, Reichsamt fur...Wetterdienst, Forschungs-und Krfahrungsberichte, Ser. a, No. 29, 1943. Findeisen , W., *Meteorological-Physical Limitations of Icing on the Atmosphere...Apparatus for Measurement,’ Harvard - Mt. Washington Icing Research Report 1946-1947, U. S. Air Material Command Tech. Rept. 5676.. Findeisen , W., "The

  2. Safe Loads on Ice Sheets (Ice Engineering. Number 13)

    National Research Council Canada - National Science Library

    Haynes, F. D; Carey, Kevin L; Cattabriga, Gioia

    1996-01-01

    Every winter, ice sheets that grow on lakes and rivers in northern states are used for ice roads, ice bridges, construction platforms, airstrips, and recreational activities, It becomes very important...

  3. Preliminary Results From a Heavily Instrumented Engine Ice Crystal Icing Test in a Ground Based Altitude Test Facility

    Science.gov (United States)

    Flegel, Ashlie B.; Oliver, Michael J.

    2016-01-01

    Preliminary results from the heavily instrumented ALF502R-5 engine test conducted in the NASA Glenn Research Center Propulsion Systems Laboratory are discussed. The effects of ice crystal icing on a full scale engine is examined and documented. This same model engine, serial number LF01, was used during the inaugural icing test in the Propulsion Systems Laboratory facility. The uncommanded reduction of thrust (rollback) events experienced by this engine in flight were simulated in the facility. Limited instrumentation was used to detect icing on the LF01 engine. Metal temperatures on the exit guide vanes and outer shroud and the load measurement were the only indicators of ice formation. The current study features a similar engine, serial number LF11, which is instrumented to characterize the cloud entering the engine, detect/characterize ice accretion, and visualize the ice accretion in the region of interest. Data were acquired at key LF01 test points and additional points that explored: icing threshold regions, low altitude, high altitude, spinner heat effects, and the influence of varying the facility and engine parameters. For each condition of interest, data were obtained from some selected variations of ice particle median volumetric diameter, total water content, fan speed, and ambient temperature. For several cases the NASA in-house engine icing risk assessment code was used to find conditions that would lead to a rollback event. This study further helped NASA develop necessary icing diagnostic instrumentation, expand the capabilities of the Propulsion Systems Laboratory, and generate a dataset that will be used to develop and validate in-house icing prediction and risk mitigation computational tools. The ice accretion on the outer shroud region was acquired by internal video cameras. The heavily instrumented engine showed good repeatability of icing responses when compared to the key LF01 test points and during day-to-day operation. Other noticeable

  4. Coherent Surface Clutter Suppression Techniques with Topography Estimation for Multi-Phase-Center Radar Ice Sounding

    DEFF Research Database (Denmark)

    Nielsen, Ulrik; Dall, Jørgen; Kristensen, Steen Savstrup

    2012-01-01

    Radar ice sounding enables measurement of the thickness and internal structures of the large ice sheets on Earth. Surface clutter masking the signal of interest is a major obstacle in ice sounding. Algorithms for surface clutter suppression based on multi-phase-center radars are presented. These ...

  5. A Backscattering and Propagation Model for Radar Sounding of Ice Sheets

    DEFF Research Database (Denmark)

    Dall, Jørgen

    2016-01-01

    . The scattering and propagation properties of the icesheets are characterized using an empirical approach. The model comprises surface scattering from the air/ice interfaceand the ice/bed interface as well as volume scattering from the firn and the ice. Also specular reflection from the internal layers is modeled...

  6. Ice and ocean velocity in the Arctic marginal ice zone: Ice roughness and momentum transfer

    Directory of Open Access Journals (Sweden)

    Sylvia T. Cole

    2017-09-01

    Full Text Available The interplay between sea ice concentration, sea ice roughness, ocean stratification, and momentum transfer to the ice and ocean is subject to seasonal and decadal variations that are crucial to understanding the present and future air-ice-ocean system in the Arctic. In this study, continuous observations in the Canada Basin from March through December 2014 were used to investigate spatial differences and temporal changes in under-ice roughness and momentum transfer as the ice cover evolved seasonally. Observations of wind, ice, and ocean properties from four clusters of drifting instrument systems were complemented by direct drill-hole measurements and instrumented overhead flights by NASA operation IceBridge in March, as well as satellite remote sensing imagery about the instrument clusters. Spatially, directly estimated ice-ocean drag coefficients varied by a factor of three with rougher ice associated with smaller multi-year ice floe sizes embedded within the first-year-ice/multi-year-ice conglomerate. Temporal differences in the ice-ocean drag coefficient of 20–30% were observed prior to the mixed layer shoaling in summer and were associated with ice concentrations falling below 100%. The ice-ocean drag coefficient parameterization was found to be invalid in September with low ice concentrations and small ice floe sizes. Maximum momentum transfer to the ice occurred for moderate ice concentrations, and transfer to the ocean for the lowest ice concentrations and shallowest stratification. Wind work and ocean work on the ice were the dominant terms in the kinetic energy budget of the ice throughout the melt season, consistent with free drift conditions. Overall, ice topography, ice concentration, and the shallow summer mixed layer all influenced mixed layer currents and the transfer of momentum within the air-ice-ocean system. The observed changes in momentum transfer show that care must be taken to determine appropriate parameterizations

  7. Airborne observations of changes of ice sheet and sea ice in the Arctic using CryoVEx campaign data

    DEFF Research Database (Denmark)

    Hvidegaard, Sine Munk; Skourup, Henriette; Forsberg, René

    measurements of ice sheet changes. The majority of the campaigns have been sponsored by the European Space Agency, ESA, as part of the CryoSat Validation Experiments – CryoVEx. These have been internationally coordinated efforts to collect coincident space‐borne, airborne, and in‐situ data for pre‐ and post...... cap (Svalbard), the EGIG line crossing the Greenland Ice Sheet, as well as the sea ice north of Alert and sea ice around Svalbard in the Fram Strait. Selected tracks were planned to match CryoSat‐2 passes and a few of them were flown in formation flight with the Alfred Wegener Institute (AWI) Polar‐5...

  8. Temporal dynamics of ikaite in experimental sea ice

    DEFF Research Database (Denmark)

    Rysgaard, Søren; Wang, F.; Galley, R.J.

    2014-01-01

    Ikaite (CaCO3·6H2O) is a metastable phase of calcium carbonate that normally forms in a cold environment and/or under high pressure. Recently, ikaite crystals have been found in sea ice, and it has been suggested that their precipitation may play an important role in air–sea CO2 exchange in ice......-covered seas. Little is known, however, of the spatial and temporal dynamics of ikaite in sea ice. Here we present evidence for highly dynamic ikaite precipitation and dissolution in sea ice grown at an outdoor pool of the Sea-ice Environmental Research Facility (SERF) in Manitoba, Canada. During...... the experiment, ikaite precipitated in sea ice when temperatures were below −4 C, creating three distinct zones of ikaite concentrations: (1) a millimeter-to-centimeter-thin surface layer containing frost flowers and brine skim with bulk ikaite concentrations of > 2000 μmol kg−1, (2) an internal layer...

  9. Bacterial Ice Crystal Controlling Proteins

    Science.gov (United States)

    Lorv, Janet S. H.; Rose, David R.; Glick, Bernard R.

    2014-01-01

    Across the world, many ice active bacteria utilize ice crystal controlling proteins for aid in freezing tolerance at subzero temperatures. Ice crystal controlling proteins include both antifreeze and ice nucleation proteins. Antifreeze proteins minimize freezing damage by inhibiting growth of large ice crystals, while ice nucleation proteins induce formation of embryonic ice crystals. Although both protein classes have differing functions, these proteins use the same ice binding mechanisms. Rather than direct binding, it is probable that these protein classes create an ice surface prior to ice crystal surface adsorption. Function is differentiated by molecular size of the protein. This paper reviews the similar and different aspects of bacterial antifreeze and ice nucleation proteins, the role of these proteins in freezing tolerance, prevalence of these proteins in psychrophiles, and current mechanisms of protein-ice interactions. PMID:24579057

  10. Greenland ice sheet mass balance: a review.

    Science.gov (United States)

    Khan, Shfaqat A; Aschwanden, Andy; Bjørk, Anders A; Wahr, John; Kjeldsen, Kristian K; Kjær, Kurt H

    2015-04-01

    Over the past quarter of a century the Arctic has warmed more than any other region on Earth, causing a profound impact on the Greenland ice sheet (GrIS) and its contribution to the rise in global sea level. The loss of ice can be partitioned into processes related to surface mass balance and to ice discharge, which are forced by internal or external (atmospheric/oceanic/basal) fluctuations. Regardless of the measurement method, observations over the last two decades show an increase in ice loss rate, associated with speeding up of glaciers and enhanced melting. However, both ice discharge and melt-induced mass losses exhibit rapid short-term fluctuations that, when extrapolated into the future, could yield erroneous long-term trends. In this paper we review the GrIS mass loss over more than a century by combining satellite altimetry, airborne altimetry, interferometry, aerial photographs and gravimetry data sets together with modelling studies. We revisit the mass loss of different sectors and show that they manifest quite different sensitivities to atmospheric and oceanic forcing. In addition, we discuss recent progress in constructing coupled ice-ocean-atmosphere models required to project realistic future sea-level changes.

  11. Development of a Data Reduction Algorithm for Optical Wide Field Patrol (OWL) II: Improving Measurement of Lengths of Detected Streaks

    Science.gov (United States)

    Park, Sun-Youp; Choi, Jin; Roh, Dong-Goo; Park, Maru; Jo, Jung Hyun; Yim, Hong-Suh; Park, Young-Sik; Bae, Young-Ho; Park, Jang-Hyun; Moon, Hong-Kyu; Choi, Young-Jun; Cho, Sungki; Choi, Eun-Jung

    2016-09-01

    As described in the previous paper (Park et al. 2013), the detector subsystem of optical wide-field patrol (OWL) provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time) data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.

  12. Sensor data fusion of radar, ESM, IFF, and data LINK of the Canadian Patrol Frigate and the data alignment issues

    Science.gov (United States)

    Couture, Jean; Boily, Edouard; Simard, Marc-Alain

    1996-05-01

    The research and development group at Loral Canada is now at the second phase of the development of a data fusion demonstration model (DFDM) for a naval anti-air warfare to be used as a workbench tool to perform exploratory research. This project has emphatically addressed how the concepts related to fusion could be implemented within the Canadian Patrol Frigate (CPF) software environment. The project has been designed to read data passively on the CPF bus without any modification to the CPF software. This has brought to light important time alignment issues since the CPF sensors and the CPF command and control system were not important time alignment issues since the CPF sensors and the CPF command and control system were not originally designed to support a track management function which fuses information. The fusion of data from non-organic sensors with the tactical Link-11 data has produced stimulating spatial alignment problems which have been overcome by the use of a geodetic referencing coordinate system. Some benchmark scenarios have been selected to quantitatively demonstrate the capabilities of this fusion implementation. This paper describes the implementation design of DFDM (version 2), and summarizes the results obtained so far when fusing the scenarios simulated data.

  13. SEDNA: Sea ice Experiment - Dynamic Nature of the Arctic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Ice Experiment - Dynamic Nature of the Arctic (SEDNA) is an international collaborative effort to improve the understanding of the interaction between sea...

  14. Women of Ice and Fire

    DEFF Research Database (Denmark)

    challenges, exploits, yet also changes how we think of women and gender, not only in fantasy, but in Western culture in general. Divided into three sections addressing questions of adaptation from novel to television, female characters, and politics and female audience engagement within the GoT universe......, the interdisciplinary and international lineup of contributors analyze gender in relation to female characters and topics such as genre, sex, violence, adaptation, as well as fan reviews. The genre of fantasy was once considered a primarily male territory with male heroes. Women of Ice and Fire shows how the GoT...

  15. Sputtering of water ice

    DEFF Research Database (Denmark)

    Baragiola, R.A.; Vidal, R.A.; Svendsen, W.

    2003-01-01

    We present results of a range of experiments of sputtering of water ice together with a guide to the literature. We studied how sputtering depends on the projectile energy and fluence, ice growth temperature, irradiation temperature and external electric fields. We observed luminescence from...

  16. Ice sheet in peril

    DEFF Research Database (Denmark)

    Hvidberg, Christine Schøtt

    2016-01-01

    Earth's large ice sheets in Greenland and Antarctica are major contributors to sea level change. At present, the Greenland Ice Sheet (see the photo) is losing mass in response to climate warming in Greenland (1), but the present changes also include a long-term response to past climate transitions...

  17. Turning into Ice

    Science.gov (United States)

    Pietsch, Renée B.; Hanlon, Regina; Bohland, Cynthia; Schmale, David G., III

    2016-01-01

    This article describes an interdisciplinary unit in which students explore biological "ice nucleation"--by particles that cause water to freeze at temperatures above -38°C--through the lens of the microbial ice nucleator "Pseudomonas syringae." Such This activity, which aligns with the "Next Generation Science…

  18. A Volunteer program guidebook for sport managers organizing large scale ice hockey tournaments

    OpenAIRE

    Frison, Logan

    2010-01-01

    The guidebook is a tool to assist the tournament coordinator when recruting, training, and leading the best possible team of ice hockey volunteers to work at International Ice Hockey Federation (IIHF) tournaments and within the Sport Function - Ice Hockey events at Olympic Winter Games. The select volunteers are termed the ‘Ice Hockey Volunteers’ and consist of the six crews that make up the ‘Sport Team’ which work closely with the National Teams (athletes and team staff) and Officials (re...

  19. Multi-scale modeling of the mechanical behavior of polycrystalline ice under transient creep.

    OpenAIRE

    Suquet , Pierre; Moulinec , Hervé; Castelnau , O.; Montagnat , Maurine; Lahellec , Noël; Grennerat , Fanny; Duval , Paul; Brenner , Renald

    2012-01-01

    International audience; Ice is a challenging material for understanding the overall behavior of polycrystalline materials and more specifically the coupling between elastic and viscous effects during transient creep. At the single crystal level, ice is an hexagonal material with a rather weak elastic anisotropy but with a strong viscoplastic anisotropy. The strain-stress curve of ice single crystals shows a softening behavior depending on the strain-rate. The strong viscous anisotropy of ice ...

  20. Review of Ice-Induced Scour Impacts to Navigation and Structures

    Science.gov (United States)

    2017-07-17

    Channel Responses to River Ice. Journal of Cold Regions Engineering 164:191–217. ———. 2008. Ice Effects on Sediment Transport in Rivers. In...Chichester, UK: Wiley-Blackwell. Ettema, R., F. Braileanu, and M. Muste. 2000. Method for Estimating Sediment Transport in Ice-Covered Channels ... Sediment Transport in Ice-Covered Channels . International Journal of Sediment Research 301:63–67. ERDC SR-17-3 35 Knack, I. M., A. M. Tuthill

  1. The Relationship Between Debris and Grain Growth in Polycrystalline Ice

    Science.gov (United States)

    Rivera, A.; McCarthy, C.

    2017-12-01

    An understanding of the mechanisms of ice flow, as well as the factors that affect it, must be improved in order to make more accurate predictions of glacial melting rates, and hence, sea level rise. Both field and laboratory studies have made an association between smaller grain sizes of ice and more rapid deformation. Therefore, it is essential to understand the different factors that affect grain size. Observations from ice cores have shown a correlation between debris content in layers of ice with smaller grain sizes, whereas layers with very little debris have larger grain sizes. Static grain growth rates for both pure ice and ice containing bubbles are well constrained, but the effect of small rock/dust particles has received less attention. We tested the relationship between debris and grain growth in polycrystalline ice with controlled annealing at -5°C and microstructural characterization. Three samples, two containing fine rock powder and one without, were fabricated, annealed, and imaged over time. The samples containing powder had different initial grain sizes due to solidification temperature during fabrication. Microstructural analysis was done on all samples after initial fabrication and at various times during the anneal using a light microscope housed in a cold room. Microstructural images were analyzed by the linear-intercept method. When comparing average grain size over time between pure ice and ice with debris, it was found that the rate of growth for the pure ice was larger than the rate of growth for the ice with debris at both initial grain sizes. These results confirm the observations seen in nature, and suggest that small grain size is indeed influenced by debris content. By understanding this, scientists could gain a more in-depth understanding of internal ice deformation and the mechanisms of ice flow. This, in turn, helps improve the accuracy of glacial melting predictions, and sea level rise in the future.

  2. Aircraft Surveys of the Beaufort Sea Seasonal Ice Zone

    Science.gov (United States)

    Morison, J.

    2016-02-01

    The Seasonal Ice Zone Reconnaissance Surveys (SIZRS) is a program of repeated ocean, ice, and atmospheric measurements across the Beaufort-Chukchi sea seasonal sea ice zone (SIZ) utilizing US Coast Guard Arctic Domain Awareness (ADA) flights of opportunity. The SIZ is the region between maximum winter sea ice extent and minimum summer sea ice extent. As such, it contains the full range of positions of the marginal ice zone (MIZ) where sea ice interacts with open water. The increasing size and changing air-ice-ocean properties of the SIZ are central to recent reductions in Arctic sea ice extent. The changes in the interplay among the atmosphere, ice, and ocean require a systematic SIZ observational effort of coordinated atmosphere, ice, and ocean observations covering up to interannual time-scales, Therefore, every year beginning in late Spring and continuing to early Fall, SIZRS makes monthly flights across the Beaufort Sea SIZ aboard Coast Guard C-130H aircraft from USCG Air Station Kodiak dropping Aircraft eXpendable CTDs (AXCTD) and Aircraft eXpendable Current Profilers (AXCP) for profiles of ocean temperature, salinity and shear, dropsondes for atmospheric temperature, humidity, and velocity profiles, and buoys for atmosphere and upper ocean time series. Enroute measurements include IR imaging, radiometer and lidar measurements of the sea surface and cloud tops. SIZRS also cooperates with the International Arctic Buoy Program for buoy deployments and with the NOAA Earth System Research Laboratory atmospheric chemistry sampling program on board the aircraft. Since 2012, SIZRS has found that even as SIZ extent, ice character, and atmospheric forcing varies year-to-year, the pattern of ocean freshening and radiative warming south of the ice edge is consistent. The experimental approach, observations and extensions to other projects will be discussed.

  3. GLERL Radiation Transfer Through Freshwater Ice

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Radiation transmittance (ratio of transmitted to incident radiation) through clear ice, refrozen slush ice and brash ice, from ice surface to ice-water interface in...

  4. THE STRUCTURE OF SURFACE H{sub 2}O LAYERS OF ICE-COVERED PLANETS WITH HIGH-PRESSURE ICE

    Energy Technology Data Exchange (ETDEWEB)

    Ueta, S.; Sasaki, T., E-mail: ueta@geo.titech.ac.jp, E-mail: takanori@geo.titech.ac.jp [Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2013-10-01

    Many extrasolar (bound) terrestrial planets and free-floating (unbound) planets have been discovered. While the existence of bound and unbound terrestrial planets with liquid water is an important question, of particular importance is the question of these planets' habitability. Even for a globally ice-covered planet, geothermal heat from the planetary interior may melt the interior ice, creating an internal ocean covered by an ice shell. In this paper, we discuss the conditions that terrestrial planets must satisfy for such an internal ocean to exist on the timescale of planetary evolution. The question is addressed in terms of planetary mass, distance from a central star, water abundance, and abundance of radiogenic heat sources. In addition, we investigate the structure of the surface H{sub 2}O layers of ice-covered planets by considering the effects of ice under high pressure (high-pressure ice). As a fiducial case, a 1 M{sub ⊕} planet at 1 AU from its central star and with 0.6-25 times the H{sub 2}O mass of the Earth could have an internal ocean. We find that high-pressure ice layers may appear between the internal ocean and the rock portion on a planet with an H{sub 2}O mass over 25 times that of the Earth. The planetary mass and abundance of surface water strongly restrict the conditions under which an extrasolar terrestrial planet may have an internal ocean with no high-pressure ice under the ocean. Such high-pressure ice layers underlying the internal ocean are likely to affect the habitability of the planet.

  5. Torque and Axial Loading Physics for Measuring Atmospheric Icing Load and Icing Rate

    OpenAIRE

    Mughal, Umair Najeeb; Virk, Muhammad Shakeel

    2015-01-01

    Measuring icing load and icing rate are important parameters for an atmospheric icing sensor. A new icing sensor has recently been designed and developed at Narvik University College for measuring atmospheric icing rate, icing load and icing type. Unlike the existing atmospheric icing sensors commercially available in market, which uses the axial loading for measuring icing load and icing rate, this new sensory system measures icing load and icing rate using the torque loading physics. The pe...

  6. Investigations of the form and flow of ice sheets and glaciers using radio-echo sounding

    Energy Technology Data Exchange (ETDEWEB)

    Dowdeswell, J A; Evans, S [Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER (United Kingdom)

    2004-10-01

    Radio-echo sounding (RES), utilizing a variety of radio frequencies, was developed to allow glaciologists to measure the thickness of ice sheets and glaciers. We review the nature of electromagnetic wave propagation in ice and snow, including the permittivity of ice, signal attenuation and volume scattering, along with reflection from rough and specular surfaces. The variety of instruments used in RES of polar ice sheets and temperate glaciers is discussed. The applications and insights that a knowledge of ice thickness, and the wider nature of the form and flow of ice sheets, provides are also considered. The thickest ice measured is 4.7 km in East Antarctica. The morphology of the Antarctic and Greenland ice sheets, and many of the smaller ice caps and glaciers of the polar regions, has been investigated using RES. These findings are being used in three-dimensional numerical models of the response of the cryosphere to environmental change. In addition, the distribution and character of internal and basal reflectors within ice sheets contains information on, for example, ice-sheet layering and its chrono-stratigraphic significance, and has enabled the discovery and investigation of large lakes beneath the Antarctic Ice Sheet. Today, RES from ground-based and airborne platforms remains the most effective tool for measuring ice thickness and internal character.

  7. Modelling snow ice and superimposed ice on landfast sea ice in Kongsfjorden, Svalbard

    Directory of Open Access Journals (Sweden)

    Caixin Wang

    2015-08-01

    Full Text Available Snow ice and superimposed ice formation on landfast sea ice in a Svalbard fjord, Kongsfjorden, was investigated with a high-resolution thermodynamic snow and sea-ice model, applying meteorological weather station data as external forcing. The model shows that sea-ice formation occurs both at the ice bottom and at the snow/ice interface. Modelling results indicated that the total snow ice and superimposed ice, which formed at the snow/ice interface, was about 14 cm during the simulation period, accounting for about 15% of the total ice mass and 35% of the total ice growth. Introducing a time-dependent snow density improved the modelled results, and a time-dependent oceanic heat flux parameterization yielded reasonable ice growth at the ice bottom. Model results suggest that weather conditions, in particular air temperature and precipitation, as well as snow thermal properties and surface albedo are the most critical factors for the development of snow ice and superimposed ice in Kongsfjorden. While both warming air and higher precipitation led to increased snow ice and superimposed ice forming in Kongsfjorden in the model runs, the processes were more sensitive to precipitation than to air temperature.

  8. The Mobilization of Effort: Sergeants, Patrol Officers, and Productivity in an American Agency.

    Science.gov (United States)

    1982-02-01

    the precinct captain complaining about the sergeant’s notorious "mandatory car stop" policies. After the sergeant’s words about "those fucking fools...internal investigations by 16 telling IID to "not go after my men" or to " fuck off" have a formidable ally and guardian. Of course, the price officers...sector covering a small, almost rural, lightly populated region where it was thought only the " fuck -ups were assigned -- an assignment from which it

  9. Coulombic charge ice

    Science.gov (United States)

    McClarty, P. A.; O'Brien, A.; Pollmann, F.

    2014-05-01

    We consider a classical model of charges ±q on a pyrochlore lattice in the presence of long-range Coulomb interactions. This model first appeared in the early literature on charge order in magnetite [P. W. Anderson, Phys. Rev. 102, 1008 (1956), 10.1103/PhysRev.102.1008]. In the limit where the interactions become short ranged, the model has a ground state with an extensive entropy and dipolar charge-charge correlations. When long-range interactions are introduced, the exact degeneracy is broken. We study the thermodynamics of the model and show the presence of a correlated charge liquid within a temperature window in which the physics is well described as a liquid of screened charged defects. The structure factor in this phase, which has smeared pinch points at the reciprocal lattice points, may be used to detect charge ice experimentally. In addition, the model exhibits fractionally charged excitations ±q/2 which are shown to interact via a 1/r potential. At lower temperatures, the model exhibits a transition to a long-range ordered phase. We are able to treat the Coulombic charge ice model and the dipolar spin ice model on an equal footing by mapping both to a constrained charge model on the diamond lattice. We find that states of the two ice models are related by a staggering field which is reflected in the energetics of these two models. From this perspective, we can understand the origin of the spin ice and charge ice ground states as coming from a dipolar model on a diamond lattice. We study the properties of charge ice in an external electric field, finding that the correlated liquid is robust to the presence of a field in contrast to the case of spin ice in a magnetic field. Finally, we comment on the transport properties of Coulombic charge ice in the correlated liquid phase.

  10. Ice Load Project Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Timothy J. [DNV GL, Seattle, WA (United States); Brown, Thomas [IFC Engineering, Calgary, AB (Canada); Byrne, Alex [DNV GL, Seattle, WA (United States)

    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

  11. Creep of ice: further studies

    International Nuclear Information System (INIS)

    Heard, H.C.; Durham, W.B.; Kirby, S.H.

    1987-01-01

    Detailed studies have been done of ice creep as related to the icy satellites, Ganymede and Callisto. Included were: (1) the flow of high-pressure water ices II, III, and V, and (2) frictional sliding of ice I sub h. Work was also begun on the study of the effects of impurities on the flow of ice. Test results are summarized

  12. Cardiovascular effects in patrol officers are associated with fine particulate matter from brake wear and engine emissions

    Directory of Open Access Journals (Sweden)

    Herbst Margaret C

    2004-12-01

    Full Text Available Abstract Background Exposure to fine particulate matter air pollutants (PM2.5 affects heart rate variability parameters, and levels of serum proteins associated with inflammation, hemostasis and thrombosis. This study investigated sources potentially responsible for cardiovascular and hematological effects in highway patrol troopers. Results Nine healthy young non-smoking male troopers working from 3 PM to midnight were studied on four consecutive days during their shift and the following night. Sources of in-vehicle PM2.5 were identified with variance-maximizing rotational principal factor analysis of PM2.5-components and associated pollutants. Two source models were calculated. Sources of in-vehicle PM2.5 identified were 1 crustal material, 2 wear of steel automotive components, 3 gasoline combustion, 4 speed-changing traffic with engine emissions and brake wear. In one model, sources 1 and 2 collapsed to a single source. Source factors scores were compared to cardiac and blood parameters measured ten and fifteen hours, respectively, after each shift. The "speed-change" factor was significantly associated with mean heart cycle length (MCL, +7% per standard deviation increase in the factor score, heart rate variability (+16%, supraventricular ectopic beats (+39%, % neutrophils (+7%, % lymphocytes (-10%, red blood cell volume MCV (+1%, von Willebrand Factor (+9%, blood urea nitrogen (+7%, and protein C (-11%. The "crustal" factor (but not the "collapsed" source was associated with MCL (+3% and serum uric acid concentrations (+5%. Controlling for potential confounders had little influence on the effect estimates. Conclusion PM2.5 originating from speed-changing traffic modulates the autonomic control of the heart rhythm, increases the frequency of premature supraventricular beats and elicits pro-inflammatory and pro-thrombotic responses in healthy young men.

  13. Vortex ice in nanostructured superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, Cynthia J [Los Alamos National Laboratory; Libal, Andras J [Los Alamos National Laboratory

    2008-01-01

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

  14. Influence of sea ice on Arctic coasts

    Science.gov (United States)

    Barnhart, K. R.; Kay, J. E.; Overeem, I.; Anderson, R. S.

    2017-12-01

    Coasts form the dynamic interface between the terrestrial and oceanic systems. In the Arctic, and in much of the world, the coast is a focal point for population, infrastructure, biodiversity, and ecosystem services. A key difference between Arctic and temperate coasts is the presence of sea ice. Changes in sea ice cover can influence the coast because (1) the length of the sea ice-free season controls the time over which nearshore water can interact with the land, and (2) the location of the sea ice edge controls the fetch over which storm winds can interact with open ocean water, which in turn governs nearshore water level and wave field. We first focus on the interaction of sea ice and ice-rich coasts. We combine satellite records of sea ice with a model for wind-driven storm surge and waves to estimate how changes in the sea ice-free season have impacted the nearshore hydrodynamic environment along Alaska's Beaufort Sea Coast for the period 1979-2012. This region has experienced some of the greatest changes in both sea ice cover and coastal erosion rates in the Arctic: the median length of the open-water season has expanded by 90 percent, while coastal erosion rates have more than doubled from 8.7 to 19 m yr-1. At Drew Point, NW winds increase shoreline water levels that control the incision of a submarine notch, the rate-limiting step of coastal retreat. The maximum water-level setup at Drew Point has increased consistently with increasing fetch. We extend our analysis to the entire Arctic using both satellite-based observations and global coupled climate model output from the Community Earth System Model Large Ensemble (CESM-LE) project. This 30-member ensemble employs a 1-degree version of the CESM-CAM5 historical forcing for the period 1920-2005, and RCP 8.5 forcing from 2005-2100. A control model run with constant pre-industrial (1850) forcing characterizes internal variability in a constant climate. Finally, we compare observations and model results to

  15. Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone

    Science.gov (United States)

    Cooper, Matthew G.; Smith, Laurence C.; Rennermalm, Asa K.; Miège, Clément; Pitcher, Lincoln H.; Ryan, Jonathan C.; Yang, Kang; Cooley, Sarah W.

    2018-03-01

    We document the density and hydrologic properties of bare, ablating ice in a mid-elevation (1215 m a.s.l.) supraglacial internally drained catchment in the Kangerlussuaq sector of the western Greenland ice sheet. We find low-density (0.43-0.91 g cm-3, μ = 0.69 g cm-3) ice to at least 1.1 m depth below the ice sheet surface. This near-surface, low-density ice consists of alternating layers of water-saturated, porous ice and clear solid ice lenses, overlain by a thin (sheet ablation zone surface. A conservative estimate for the ˜ 63 km2 supraglacial catchment yields 0.009-0.012 km3 of liquid meltwater storage in near-surface, porous ice. Further work is required to determine if these findings are representative of broader areas of the Greenland ice sheet ablation zone, and to assess the implications for sub-seasonal mass balance processes, surface lowering observations from airborne and satellite altimetry, and supraglacial runoff processes.

  16. Prediction of ice accretion and anti-icing heating power on wind turbine blades using standard commercial software

    International Nuclear Information System (INIS)

    Villalpando, Fernando; Reggio, Marcelo; Ilinca, Adrian

    2016-01-01

    An approach to numerically simulate ice accretion on 2D sections of a wind turbine blade is presented. The method uses standard commercial ANSYS-Fluent and Matlab tools. The Euler-Euler formulation is used to calculate the water impingement on the airfoil, and a UDF (Used Defined Function) has been devised to turn the airfoil's solid wall into a permeable boundary. Mayer's thermodynamic model is implemented in Matlab for computing ice thickness and for updating the airfoil contour. A journal file is executed to systematize the procedure: meshing, droplet trajectory calculation, thermodynamic model application for computing ice accretion, and the updating of airfoil contours. The proposed ice prediction strategy has been validated using iced airfoil contours obtained experimentally in the AMIL refrigerated wind tunnel (Anti-icing Materials International Laboratory). Finally, a numerical prediction method has been generated for anti-icing assessment, and its results compared with data obtained in this laboratory. - Highlights: • A methodology for ice accretion prediction using commercial software is proposed. • Euler model gives better prediction of airfoil water collection with detached flow. • A source term is used to change from a solid wall to a permeable wall in Fluent. • Energy needed for ice-accretion mitigation system is predicted.

  17. Ice Engineering Research Area

    Data.gov (United States)

    Federal Laboratory Consortium — Refrigerated Physical Modeling of Waterways in a Controlled EnvironmentThe Research Area in the Ice Engineering Facility at the Cold Regions Research and Engineering...

  18. Ice Cream Stick Math.

    Science.gov (United States)

    Paddock, Cynthia

    1992-01-01

    Described is a teaching technique which uses the collection of ice cream sticks as a means of increasing awareness of quantity in a self-contained elementary special class for students with learning disabilities and mild mental retardation. (DB)

  19. Global ice sheet modeling

    International Nuclear Information System (INIS)

    Hughes, T.J.; Fastook, J.L.

    1994-05-01

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed

  20. The Antartic Ice Borehole Probe

    Science.gov (United States)

    Behar, A.; Carsey, F.; Lane, A.; Engelhardt, H.

    2000-01-01

    The Antartic Ice Borehole Probe mission is a glaciological investigation, scheduled for November 2000-2001, that will place a probe in a hot-water drilled hole in the West Antartic ice sheet. The objectives of the probe are to observe ice-bed interactions with a downward looking camera, and ice inclusions and structure, including hypothesized ice accretion, with a side-looking camera.

  1. On the Arctic Ocean ice thickness response to changes in the external forcing

    Energy Technology Data Exchange (ETDEWEB)

    Stranne, Christian; Bjoerk, Goeran [University of Gothenburg, Department of Earth Sciences, Box 460, Goeteborg (Sweden)

    2012-12-15

    Submarine and satellite observations show that the Arctic Ocean ice cover has undergone a large thickness reduction and a decrease in the areal extent during the last decades. Here the response of the Arctic Ocean ice cover to changes in the poleward atmospheric energy transport, F{sub wall}, is investigated using coupled atmosphere-ice-ocean column models. Two models with highly different complexity are used in order to illustrate the importance of different internal processes and the results highlight the dramatic effects of the negative ice thickness - ice volume export feedback and the positive surface albedo feedback. The steady state ice thickness as a function of F{sub wall} is determined for various model setups and defines what we call ice thickness response curves. When a variable surface albedo and snow precipitation is included, a complex response curve appears with two distinct regimes: a perennial ice cover regime with a fairly linear response and a less responsive seasonal ice cover regime. The two regimes are separated by a steep transition associated with surface albedo feedback. The associated hysteresis is however small, indicating that the Arctic climate system does not have an irreversible tipping point behaviour related to the surface albedo feedback. The results are discussed in the context of the recent reduction of the Arctic sea ice cover. A new mechanism related to regional and temporal variations of the ice divergence within the Arctic Ocean is presented as an explanation for the observed regional variation of the ice thickness reduction. Our results further suggest that the recent reduction in areal ice extent and loss of multiyear ice is related to the albedo dependent transition between seasonal and perennial ice i.e. large areas of the Arctic Ocean that has previously been dominated by multiyear ice might have been pushed below a critical mean ice thickness, corresponding to the above mentioned transition, and into a state dominated

  2. The De-Icing Comparison Experiment (D-ICE): A campaign for improving data retention rates of radiometric measurements under icing conditions in cold regions

    Science.gov (United States)

    Cox, C. J.; Morris, S. M.

    2017-12-01

    Longwave and shortwave radiative fluxes are fundamental quantities regularly observed globally using broadband radiometers. In cold climates, frost, rime, snow and ice (collectively, "icing") frequently builds up on sensor windows, contaminating measurements. Since icing occurs under particular meteorological conditions, associated data losses constitutes a climatological bias. Furthermore, the signal caused by ice is difficult to distinguish from that of clouds, hampering efforts to identify contaminated from real data in post-processing. Because of the sensitivity of radiometers to internal temperature instabilities, there are limitations to using heat as a de-icing method. The magnitude of this problem is indicated by the large number of research institutions and commercial vendors that have developed various de-icing strategies. The D-ICE campaign has been designed to bring together a large number of currently available systems to quantitatively evaluate and compare ice-migration strategies and also to characterize the potentially adverse effects of the techniques themselves. For D-ICE, a variety of automated approaches making use of ventilation, heating, modified housings and alcohol spray are being evaluated alongside standard units operating with only the regularly scheduled manual cleaning by human operators at the NOAA Baseline Surface Radiation Network (BSRN) station in Utqiaġvik (formerly Barrow), Alaska. Previous experience within the BSRN community suggests that aspiration of ambient air alone may be sufficient to maintain ice-free radiometers without increasing measurement uncertainty during icing conditions, forming the main guiding hypothesis of the experiment. Icing on the sensors is monitored visually using cameras recording images every 15 minutes and quantitatively using an icing probe and met station. The effects of applied heat on infrared loss in pyranometers will be analyzed and the integrated effect of icing on monthly averages will be

  3. Ice recrystallization inhibition in ice cream by propylene glycol monostearate.

    Science.gov (United States)

    Aleong, J M; Frochot, S; Goff, H D

    2008-11-01

    The effectiveness of propylene glycol monostearate (PGMS) to inhibit ice recrystallization was evaluated in ice cream and frozen sucrose solutions. PGMS (0.3%) dramatically reduced ice crystal sizes in ice cream and in sucrose solutions frozen in a scraped-surface freezer before and after heat shock, but had no effect in quiescently frozen solutions. PGMS showed limited emulsifier properties by promoting smaller fat globule size distributions and enhanced partial coalescence in the mix and ice cream, respectively, but at a much lower level compared to conventional ice cream emulsifier. Low temperature scanning electron microscopy revealed highly irregular crystal morphology in both ice cream and sucrose solutions frozen in a scraped-surface freezer. There was strong evidence to suggest that PGMS directly interacts with ice crystals and interferes with normal surface propagation. Shear during freezing may be required for its distribution around the ice and sufficient surface coverage.

  4. Method for maintenance of ice beds of ice condenser containment

    International Nuclear Information System (INIS)

    Scrabis, C.M.; Hardin, R.T. Jr.

    1987-01-01

    This patent describes a method of maintaining ice baskets associated with a nuclear reactor system and disposed in an array of plural such ice baskets, supported in generally vertically oriented and parallel relationship by a lattice support structure which extends between the individual ice baskets and includes lateral supports adjacent the tops of the comprising: selecting an ice basket of the array requiring replenishment of the ice therewithin due to sublimation voids within the ice charges in the basket; isolating the selected ice basket; drilling a hole downwardly through the ice charges in the ice basket in general parallel axial relationship with respect to the cylindrical sidewall of the ice basket, utilizing a rotary drill bit connected through an auger to a rotary drive means; maintaining the rotary drive means in a fixed axial position and reversing the direction of rotation thereof for driving the auger in reverse rotation; and supplying ice in particulate form to the vicinity of the auger and conveying the particulate ice through the drilled hole by continued, reverse rotation of the auger so as to fill the sublimated voids in communication with the drilled hole, from the lowest and through successively higher such voids in the ice charges within the ice basket, and withdrawing the auger from the drilled hole as the voids are filled

  5. Upper Ocean Evolution Across the Beaufort Sea Marginal Ice Zone

    Science.gov (United States)

    Lee, C.; Rainville, L.; Gobat, J. I.; Perry, M. J.; Freitag, L. E.; Webster, S.

    2016-12-01

    The observed reduction of Arctic summertime sea ice extent and expansion of the marginal ice zone (MIZ) have profound impacts on the balance of processes controlling sea ice evolution, including the introduction of several positive feedback mechanisms that may act to accelerate melting. Examples of such feedbacks include increased upper ocean warming though absorption of solar radiation, elevated internal wave energy and mixing that may entrain heat stored in subsurface watermasses (e.g., the relatively warm Pacific Summer and Atlantic waters), and elevated surface wave energy that acts to deform and fracture sea ice. Spatial and temporal variability in ice properties and open water fraction impact these processes. To investigate how upper ocean structure varies with changing ice cover, how the balance of processes shift as a function of ice fraction and distance from open water, and how these processes impact sea ice evolution, a network of autonomous platforms sampled the atmosphere-ice-ocean system in the Beaufort, beginning in spring, well before the start of melt, and ending with the autumn freeze-up. Four long-endurance autonomous Seagliders occupied sections that extended from open water, through the marginal ice zone, deep into the pack during summer 2014 in the Beaufort Sea. Gliders penetrated up to 200 km into the ice pack, under complete ice cover for up to 10 consecutive days. Sections reveal strong fronts where cold, ice-covered waters meet waters that have been exposed to solar warming, and O(10 km) scale eddies near the ice edge. In the pack, Pacific Summer Water and a deep chlorophyll maximum form distinct layers at roughly 60 m and 80 m, respectively, which become increasingly diffuse late in the season as they progress through the MIZ and into open water. Stratification just above the Pacific Summer Water rapidly weakens near the ice edge and temperature variance increases, likely due to mixing or energetic vertical exchange associated with strong

  6. Icing losses on wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, T.; Fotsing, I.; Pearson, S. [Garrad Hassan Canada Inc., Ottawa, ON (Canada)

    2010-07-01

    This PowerPoint presentation discussed some of the energy losses that can occur as a result of icing on wind turbines. Airfoil deterioration can occur in the presence of rime and glaze ice. Anemometers are also impacted by ice, and shut-downs can occur as a result of icing events. Availability deficits that occur during the winter months can lead to annual energy losses of 0.5 percent. The impact of icing events on total wind power energy production in Quebec is estimated at between 1.3 percent to 2.7 percent. Ice loss estimates are considered during the pre-construction phases of wind power projects. However, ice loss prediction methods are often inaccurate. Studies have demonstrated that preconstruction masts show a reasonable correlation with wind turbine icing, and that icing losses are site-specific. tabs., figs.

  7. A Detailed Geophysical Investigation of the Grounding of Henry Ice Rise, with Implications for Holocene Ice-Sheet Extent.

    Science.gov (United States)

    Wearing, M.; Kingslake, J.

    2017-12-01

    It is generally assumed that since the Last Glacial Maximum the West Antarctic Ice Sheet (WAIS) has experienced monotonic retreat of the grounding line (GL). However, recent studies have cast doubt on this assumption, suggesting that the retreat of the WAIS grounding line may have been followed by a significant advance during the Holocene in the Weddell and Ross Sea sectors. Constraining this evolution is important as reconstructions of past ice-sheet extent are used to spin-up predictive ice-sheet models and correct mass-balance observations for glacial isostatic adjustment. Here we examine in detail the formation of the Henry Ice Rise (HIR), which ice-sheet model simulations suggest played a key role in Holocene ice-mass changes in the Weddell Sea sector. Observations from a high-resolution ground-based, ice-penetrating radar survey are best explained if the ice rise formed when the Ronne Ice Shelf grounded on a submarine high, underwent a period of ice-rumple flow, before the GL migrated outwards to form the present-day ice rise. We constrain the relative chronology of this evolution by comparing the alignment and intersection of isochronal internal layers, relic crevasses, surface features and investigating the dynamic processes leading to their complex structure. We also draw analogies between HIR and the neighbouring Doake Ice Rumples. The date of formation is estimated using vertical velocities derived with a phase-sensitive radio-echo sounder (pRES). Ice-sheet models suggest that the formation of the HIR and other ice rises may have halted and reversed large-scale GL retreat. Hence the small-scale dynamics of these crucial regions could have wide-reaching consequences for future ice-sheet mass changes and constraining their formation and evolution further would be beneficial. One stringent test of our geophysics-based conclusions would be to drill to the bed of HIR to sample the ice for isotopic analysis and the bed for radiocarbon analysis.

  8. Ice flow Modelling of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Nielsen, Lisbeth Tangaa

    Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others. In t...... a steady state with respect to the reference climate at the end of the simulation and that the mass balance of the ice sheet at this time was more sensitive to recent climate fluctuations than the temperature forcing in the early or mid-Holocene.......Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others....... In this PhD project, the use of ice flow models for the interpretation of the age-structure of the Greenland ice sheet, i.e. the depth within the ice, at which ice deposited at given times are found at present day. Two different observational data sets of this archive were investigated. Further, paleo...

  9. Modeling Commercial Turbofan Engine Icing Risk With Ice Crystal Ingestion

    Science.gov (United States)

    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

  10. Some Results on Sea Ice Rheology for the Seasonal Ice Zone, Obtained from the Deformation Field of Sea Ice Drift Pattern

    Science.gov (United States)

    Toyota, T.; Kimura, N.

    2017-12-01

    Sea ice rheology which relates sea ice stress to the large-scale deformation of the ice cover has been a big issue to numerical sea ice modelling. At present the treatment of internal stress within sea ice area is based mostly on the rheology formulated by Hibler (1979), where the whole sea ice area behaves like an isotropic and plastic matter under the ordinary stress with the yield curve given by an ellipse with an aspect ratio (e) of 2, irrespective of sea ice area and horizontal resolution of the model. However, this formulation was initially developed to reproduce the seasonal variation of the perennial ice in the Arctic Ocean. As for its applicability to the seasonal ice zones (SIZ), where various types of sea ice are present, it still needs validation from observational data. In this study, the validity of this rheology was examined for the Sea of Okhotsk ice, typical of the SIZ, based on the AMSR-derived ice drift pattern in comparison with the result obtained for the Beaufort Sea. To examine the dependence on a horizontal scale, the coastal radar data operated near the Hokkaido coast, Japan, were also used. Ice drift pattern was obtained by a maximum cross-correlation method with grid spacings of 37.5 km from the 89 GHz brightness temperature of AMSR-E for the entire Sea of Okhotsk and the Beaufort Sea and 1.3 km from the coastal radar for the near-shore Sea of Okhotsk. The validity of this rheology was investigated from a standpoint of work rate done by deformation field, following the theory of Rothrock (1975). In analysis, the relative rates of convergence were compared between theory and observation to check the shape of yield curve, and the strain ellipse at each grid cell was estimated to see the horizontal variation of deformation field. The result shows that the ellipse of e=1.7-2.0 as the yield curve represents the observed relative conversion rates well for all the ice areas. Since this result corresponds with the yield criterion by Tresca and

  11. Border patrol: insights into the unique role of perlecan/heparan sulfate proteoglycan 2 at cell and tissue borders.

    Science.gov (United States)

    Farach-Carson, Mary C; Warren, Curtis R; Harrington, Daniel A; Carson, Daniel D

    2014-02-01

    suggested, to that of a critical agent for establishing and patrolling tissue borders in complex tissues in metazoans. We also propose that understanding these unique functions of the individual portions of the perlecan molecule can provide new insights and tools for engineering of complex multi-layered tissues including providing the necessary cues for establishing neotissue borders. © 2013.

  12. The ICES system

    International Nuclear Information System (INIS)

    Inzaghi, A.

    1983-01-01

    ICES is an integrated system used in the various engineering fields. It is made up of the Basic System and the applied Subsystems. ICES is controlled by the Operating System of the computer, from which it calls for suitable services: space allocation, loading of the modules etc... To be able to use software of this type on a computer the Operating System should be made more general. The Subsystems are developed with special programs included in the ICES Basic System. Each Subsystem is associated with an area of application. In other words, a Subsystem can only treat a previously defined ''class of problems''. The engineer (user) communicates with the Subsystem using a language oriented towards the problem (POL) also previously defined using the CDL language. The use of the (POL) language makes the engineer-computer contact much easier. The applied programs written in ICETRAN, once supplied as input to the ICETRAN Precompiler, become Fortran programs with special characteristics. A Fortran compiler produces the corresponding object programs with which, using the ICES ''Link-edit'' procedures, one obtains the modules which can be executed by an ICES Subsystem

  13. Ice Engineering. Number 25, September 2000. Remote Ice Motion Detection

    National Research Council Canada - National Science Library

    2000-01-01

    .... Government agencies, and the engineering community in general. The potential exists for property damage, serious injury, and fatalities during ice-related flooding, evacuations, and other ice mitigation operations...

  14. On the Ice Nucleation Spectrum

    Science.gov (United States)

    Barahona, D.

    2012-01-01

    This work presents a novel formulation of the ice nucleation spectrum, i.e. the function relating the ice crystal concentration to cloud formation conditions and aerosol properties. The new formulation is physically-based and explicitly accounts for the dependency of the ice crystal concentration on temperature, supersaturation, cooling rate, and particle size, surface area and composition. This is achieved by introducing the concepts of ice nucleation coefficient (the number of ice germs present in a particle) and nucleation probability dispersion function (the distribution of ice nucleation coefficients within the aerosol population). The new formulation is used to generate ice nucleation parameterizations for the homogeneous freezing of cloud droplets and the heterogeneous deposition ice nucleation on dust and soot ice nuclei. For homogeneous freezing, it was found that by increasing the dispersion in the droplet volume distribution the fraction of supercooled droplets in the population increases. For heterogeneous ice nucleation the new formulation consistently describes singular and stochastic behavior within a single framework. Using a fundamentally stochastic approach, both cooling rate independence and constancy of the ice nucleation fraction over time, features typically associated with singular behavior, were reproduced. Analysis of the temporal dependency of the ice nucleation spectrum suggested that experimental methods that measure the ice nucleation fraction over few seconds would tend to underestimate the ice nuclei concentration. It is shown that inferring the aerosol heterogeneous ice nucleation properties from measurements of the onset supersaturation and temperature may carry significant error as the variability in ice nucleation properties within the aerosol population is not accounted for. This work provides a simple and rigorous ice nucleation framework where theoretical predictions, laboratory measurements and field campaign data can be

  15. Arctic and Antarctic Sea Ice Changes and Impacts (Invited)

    Science.gov (United States)

    Nghiem, S. V.

    2013-12-01

    The extent of springtime Arctic perennial sea ice, important to preconditioning summer melt and to polar sunrise photochemistry, continues its precipitous reduction in the last decade marked by a record low in 2012, as the Bromine, Ozone, and Mercury Experiment (BROMEX) was conducted around Barrow, Alaska, to investigate impacts of sea ice reduction on photochemical processes, transport, and distribution in the polar environment. In spring 2013, there was further loss of perennial sea ice, as it was not observed in the ocean region adjacent to the Alaskan north coast, where there was a stretch of perennial sea ice in 2012 in the Beaufort Sea and Chukchi Sea. In contrast to the rapid and extensive loss of sea ice in the Arctic, Antarctic sea ice has a trend of a slight increase in the past three decades. Given the significant variability in time and in space together with uncertainties in satellite observations, the increasing trend of Antarctic sea ice may arguably be considered as having a low confidence level; however, there was no overall reduction of Antarctic sea ice extent anywhere close to the decreasing rate of Arctic sea ice. There exist publications presenting various factors driving changes in Arctic and Antarctic sea ice. After a short review of these published factors, new observations and atmospheric, oceanic, hydrological, and geological mechanisms contributed to different behaviors of sea ice changes in the Arctic and Antarctic are presented. The contribution from of hydrologic factors may provide a linkage to and enhance thermal impacts from lower latitudes. While geological factors may affect the sensitivity of sea ice response to climate change, these factors can serve as the long-term memory in the system that should be exploited to improve future projections or predictions of sea ice changes. Furthermore, similarities and differences in chemical impacts of Arctic and Antarctic sea ice changes are discussed. Understanding sea ice changes and

  16. Rheology of planetary ices

    Energy Technology Data Exchange (ETDEWEB)

    Durham, W.B. [Lawrence Livermore National Lab., CA (United States); Kirby, S.H.; Stern, L.A. [Geological Survey, Menlo Park, CA (United States)

    1996-04-24

    The brittle and ductile rheology of ices of water, ammonia, methane, and other volatiles, in combination with rock particles and each other, have a primary influence of the evolution and ongoing tectonics of icy moons of the outer solar system. Laboratory experiments help constrain the rheology of solar system ices. Standard experimental techniques can be used because the physical conditions under which most solar system ices exist are within reach of conventional rock mechanics testing machines, adapted to the low subsolidus temperatures of the materials in question. The purpose of this review is to summarize the results of a decade-long experimental deformation program and to provide some background in deformation physics in order to lend some appreciation to the application of these measurements to the planetary setting.

  17. Ice accreditation vs wind

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, G. [Hydro-Quebec, PQ (Canada). TransEnergie Div.; Chouinard, L. [McGill Univ., Montreal, PQ (Canada); Feknous, N. [SNC-Lavalin, Montreal, PQ (Canada)

    2002-07-01

    Wind and ice data from Hydro Quebec and Environment Canada indicates that winds during ice storms are in the general direction of the St. Lawrence River. This observation is important for upgrading existing power transmission lines from the Manicouagan and Churchill generation system because they are parallel to the St. Lawrence and they were designed with lower criteria than is currently accepted. ASCE 74 suggests an accumulation ratio based on thickness of 0.70 for winds parallel to the line. The Goodwin model was used to calculate this ratio. The presentation includes illustrations showing the accumulation ratio for a north wind, as well as the accumulation ratios and wind roses at Quebec. A table showing a comparison of ratios from passive ice meters shows that results are similar to mean values from the theoretical model.

  18. Ice cores and palaeoclimate

    International Nuclear Information System (INIS)

    Krogh Andersen, K.; Ditlevsen, P.; Steffensen, J.P.

    2001-01-01

    Ice cores from Greenland give testimony of a highly variable climate during the last glacial period. Dramatic climate warmings of 15 to 25 deg. C for the annual average temperature in less than a human lifetime have been documented. Several questions arise: Why is the Holocene so stable? Is climatic instability only a property of glacial periods? What is the mechanism behind the sudden climate changes? Are the increased temperatures in the past century man-made? And what happens in the future? The ice core community tries to attack some of these problems. The NGRIP ice core currently being drilled is analysed in very high detail, allowing for a very precise dating of climate events. It will be possible to study some of the fast changes on a year by year basis and from this we expect to find clues to the sequence of events during rapid changes. New techniques are hoped to allow for detection of annual layers as far back as 100,000 years and thus a much improved time scale over past climate changes. It is also hoped to find ice from the Eemian period. If the Eemian layers confirm the GRIP sequence, the Eemian was actually climatically unstable just as the glacial period. This would mean that the stability of the Holocene is unique. It would also mean, that if human made global warming indeed occurs, we could jeopardize the Holocene stability and create an unstable 'Eemian situation' which ultimately could start an ice age. Currenlty mankind is changing the composition of the atmosphere. Ice cores document significant increases in greenhouse gases, and due to increased emissions of sulfuric and nitric acid from fossil fuel burning, combustion engines and agriculture, modern Greenland snow is 3 - 5 times more acidic than pre-industrial snow (Mayewski et al., 1986). However, the magnitude and abruptness of the temperature changes of the past century do not exceed the magnitude of natural variability. It is from the ice core perspective thus not possible to attribute the

  19. ICE Online Detainee Locator System

    Data.gov (United States)

    Department of Homeland Security — The Online Detainee Locator datasets provide the location of a detainee who is currently in ICE custody, or who was release from ICE custody for any reason with the...

  20. Ice recrystallization inhibition in ice cream as affected by ice structuring proteins from winter wheat grass.

    Science.gov (United States)

    Regand, A; Goff, H D

    2006-01-01

    Ice recrystallization in quiescently frozen sucrose solutions that contained some of the ingredients commonly found in ice cream and in ice cream manufactured under commercial conditions, with or without ice structuring proteins (ISP) from cold-acclimated winter wheat grass extract (AWWE), was assessed by bright field microscopy. In sucrose solutions, critical differences in moisture content, viscosity, ionic strength, and other properties derived from the presence of other ingredients (skim milk powder, corn syrup solids, locust bean gum) caused a reduction in ice crystal growth. Significant ISP activity in retarding ice crystal growth was observed in all solutions (44% for the most complex mix) containing 0.13% total protein from AWWE. In heat-shocked ice cream, ice recrystallization rates were significantly reduced 40 and 46% with the addition of 0.0025 and 0.0037% total protein from AWWE. The ISP activity in ice cream was not hindered by its inclusion in mix prior to pasteurization. A synergistic effect between ISP and stabilizer was observed, as ISP activity was reduced in the absence of stabilizer in ice cream formulations. A remarkably smoother texture for ice creams containing ISP after heat-shock storage was evident by sensory evaluation. The efficiency of ISP from AWWE in controlling ice crystal growth in ice cream has been demonstrated.

  1. The IceProd Framework

    DEFF Research Database (Denmark)

    Aartsen, M.G.; Abbasi, R.; Ackermann, M.

    2015-01-01

    of computational resources. IceProd is a distributed management system based on Python, XML-RPC and GridFTP. It is driven by a central database in order to coordinate and admin- ister production of simulations and processing of data produced by the IceCube detector. IceProd runs as a separate layer on top of other...

  2. 2006 Program of Study: Ice

    Science.gov (United States)

    2007-03-01

    form a debris flow. One such debris flow, initiated by a glacial lake flood in Peru in 1941, devastated the city of Huaraz, killing over 6000 people [5...ice, a series of’ prototype interlocking fingers is formed which grow ats the ice floes areI compressed and the ice floes plough through one another

  3. Circulation and Respiration in Ice-covered Alaskan Arctic Lakes

    Science.gov (United States)

    MacIntyre, S.; Cortés, A.

    2016-12-01

    Arctic lakes are ice-covered 9 months of the year. For some of this time, the sediments heat the overlying water, and respiration in the sediments increases specific conductivity, depletes oxygen, and produces greenhouse gases (GHG). Whether anoxia forms and whether the greenhouse gases are sequestered at depth depends on processes inducing circulation and upward fluxes. Similarly, whether the GHG are released at ice off depends on the extent of vertical mixing at that time. Using time series meteorological data and biogeochemical arrays with temperature, specific conductivity, and optical oxygen sensors in 5 lakes ranging from 1 to 150 ha, we illustrate the connections between meteorological forcing and within lake processes including gravity currents resulting from increased density just above the sediment water interface and internal waves including those induced by winds acting on the surface of the ice and at ice off. CO2 production was well predicted by the initial rate of oxygen drawdown near the bottom at ice on and that the upward density flux depended on lake size, with values initially high in all lakes but near molecular in lakes of a few hectares in size by mid-winter. Both CO2 production and within lake vertical fluxes were independent of the rate of cooling in fall and subsequent within lake temperatures under the ice. Anoxia formed near the sediments in all 5 lakes with the concentration of CH4 dependent, in part, on lake size and depth. Twenty to fifty percent of the greenhouse gases produced under the ice remained in the lakes by the time thermal stratification was established in summer despite considerable internal wave induced mixing at the time of ice off. These observations and analysis lay a framework for understanding the links between within lake hydrodynamics, within year variability, and the fraction of greenhouse gases produced over the winter which evade at ice off.

  4. Polar Ice Caps: a Canary for the Greenland Ice Sheet

    Science.gov (United States)

    Honsaker, W.; Lowell, T. V.; Sagredo, E.; Kelly, M. A.; Hall, B. L.

    2010-12-01

    Ice caps are glacier masses that are highly sensitive to climate change. Because of their hypsometry they can have a binary state. When relatively slight changes in the equilibrium line altitude (ELA) either intersect or rise above the land the ice can become established or disappear. Thus these upland ice masses have a fast response time. Here we consider a way to extract the ELA signal from independent ice caps adjacent to the Greenland Ice Sheet margin. It may be that these ice caps are sensitive trackers of climate change that also impact the ice sheet margin. One example is the Istorvet Ice Cap located in Liverpool Land, East Greenland (70.881°N, 22.156°W). The ice cap topography and the underlying bedrock surface dips to the north, with peak elevation of the current ice ranging in elevation from 1050 to 745 m.a.s.l. On the eastern side of the ice mass the outlet glaciers extending down to sea level. The western margin has several small lobes in topographic depressions, with the margin reaching down to 300 m.a.s.l. Topographic highs separate the ice cap into at least 5 main catchments, each having a pair of outlet lobes toward either side of the ice cap. Because of the regional bedrock slope each catchment has its own elevation range. Therefore, as the ELA changes it is possible for some catchments of the ice cap to experience positive mass balance while others have a negative balance. Based on weather observations we estimate the present day ELA to be ~1000 m.a.s.l, meaning mass balance is negative for the majority of the ice cap. By tracking glacier presence/absence in these different catchments, we can reconstruct small changes in the ELA. Another example is the High Ice Cap (informal name) in Milne Land (70.903°N, 25.626°W, 1080 m), East Greenland. Here at least 4 unconformities in ice layers found near the southern margin of the ice cap record changing intervals of accumulation and ablation. Therefore, this location may also be sensitive to slight

  5. Polar Stereographic Valid Ice Masks Derived from National Ice Center Monthly Sea Ice Climatologies, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — These valid ice masks provide a way to remove spurious ice caused by residual weather effects and land spillover in passive microwave data. They are derived from the...

  6. User's guide for ICE

    International Nuclear Information System (INIS)

    Fraley, S.K.

    1976-07-01

    ICE is a cross-section mixing code which will accept cross sections from an AMPX working library and produce mixed cross sections in the AMPX working library format, ANISN format, and the group-independent ANISN format. User input is in the free-form or fixed-form FIDO structure. The code is operable as a module in the AMPX system

  7. Autosub under ice

    OpenAIRE

    Griffiths, G.

    2005-01-01

    Autosub made headlines recently when it became trapped under 200m of ice in Antarctica.Here we explore the ideas behind the £5.86 million research programme, and look back at an earlier expedition which took place last summer off the coast of Greenland.

  8. Ecology under lake ice

    NARCIS (Netherlands)

    Hampton, Stephanie E.; Galloway, Aaron W. E.; Powers, Stephen M.; Ozersky, Ted; Woo, Kara H.; Batt, Ryan D.; Labou, Stephanie G.; O'Reilly, Catherine M.; Sharma, Sapna; Lottig, Noah R.; Stanley, Emily H.; North, Rebecca L.; Stockwell, Jason D.; Adrian, Rita; Weyhenmeyer, Gesa A.; Arvola, Lauri; Baulch, Helen M.; Bertani, Isabella; Bowman, Larry L., Jr.; Carey, Cayelan C.; Catalan, Jordi; Colom-Montero, William; Domine, Leah M.; Felip, Marisol; Granados, Ignacio; Gries, Corinna; Grossart, Hans-Peter; Haberman, Juta; Haldna, Marina; Hayden, Brian; Higgins, Scott N.; Jolley, Jeff C.; Kahilainen, Kimmo K.; Kaup, Enn; Kehoe, Michael J.; MacIntyre, Sally; Mackay, Anson W.; Mariash, Heather L.; Mckay, Robert M.; Nixdorf, Brigitte; Noges, Peeter; Noges, Tiina; Palmer, Michelle; Pierson, Don C.; Post, David M.; Pruett, Matthew J.; Rautio, Milla; Read, Jordan S.; Roberts, Sarah L.; Ruecker, Jacqueline; Sadro, Steven; Silow, Eugene A.; Smith, Derek E.; Sterner, Robert W.; Swann, George E. A.; Timofeyev, Maxim A.; Toro, Manuel; Twiss, Michael R.; Vogt, Richard J.; Watson, Susan B.; Whiteford, Erika J.; Xenopoulos, Marguerite A.

    Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experi-ence periods of snow and ice cover. Relatively little is known of winter ecology in these systems,due to a historical research focus on summer ‘growing seasons’. We executed the first global

  9. Ice shelf fracture parameterization in an ice sheet model

    Directory of Open Access Journals (Sweden)

    S. Sun

    2017-11-01

    Full Text Available Floating ice shelves exert a stabilizing force onto the inland ice sheet. However, this buttressing effect is diminished by the fracture process, which on large scales effectively softens the ice, accelerating its flow, increasing calving, and potentially leading to ice shelf breakup. We add a continuum damage model (CDM to the BISICLES ice sheet model, which is intended to model the localized opening of crevasses under stress, the transport of those crevasses through the ice sheet, and the coupling between crevasse depth and the ice flow field and to carry out idealized numerical experiments examining the broad impact on large-scale ice sheet and shelf dynamics. In each case we see a complex pattern of damage evolve over time, with an eventual loss of buttressing approximately equivalent to halving the thickness of the ice shelf. We find that it is possible to achieve a similar ice flow pattern using a simple rule of thumb: introducing an enhancement factor ∼ 10 everywhere in the model domain. However, spatially varying damage (or equivalently, enhancement factor fields set at the start of prognostic calculations to match velocity observations, as is widely done in ice sheet simulations, ought to evolve in time, or grounding line retreat can be slowed by an order of magnitude.

  10. Ice shelf fracture parameterization in an ice sheet model

    Science.gov (United States)

    Sun, Sainan; Cornford, Stephen L.; Moore, John C.; Gladstone, Rupert; Zhao, Liyun

    2017-11-01

    Floating ice shelves exert a stabilizing force onto the inland ice sheet. However, this buttressing effect is diminished by the fracture process, which on large scales effectively softens the ice, accelerating its flow, increasing calving, and potentially leading to ice shelf breakup. We add a continuum damage model (CDM) to the BISICLES ice sheet model, which is intended to model the localized opening of crevasses under stress, the transport of those crevasses through the ice sheet, and the coupling between crevasse depth and the ice flow field and to carry out idealized numerical experiments examining the broad impact on large-scale ice sheet and shelf dynamics. In each case we see a complex pattern of damage evolve over time, with an eventual loss of buttressing approximately equivalent to halving the thickness of the ice shelf. We find that it is possible to achieve a similar ice flow pattern using a simple rule of thumb: introducing an enhancement factor ˜ 10 everywhere in the model domain. However, spatially varying damage (or equivalently, enhancement factor) fields set at the start of prognostic calculations to match velocity observations, as is widely done in ice sheet simulations, ought to evolve in time, or grounding line retreat can be slowed by an order of magnitude.

  11. Autonomous Ice Mass Balance Buoys for Seasonal Sea Ice

    Science.gov (United States)

    Whitlock, J. D.; Planck, C.; Perovich, D. K.; Parno, J. T.; Elder, B. C.; Richter-Menge, J.; Polashenski, C. M.

    2017-12-01

    The ice mass-balance represents the integration of all surface and ocean heat fluxes and attributing the impact of these forcing fluxes on the ice cover can be accomplished by increasing temporal and spatial measurements. Mass balance information can be used to understand the ongoing changes in the Arctic sea ice cover and to improve predictions of future ice conditions. Thinner seasonal ice in the Arctic necessitates the deployment of Autonomous Ice Mass Balance buoys (IMB's) capable of long-term, in situ data collection in both ice and open ocean. Seasonal IMB's (SIMB's) are free floating IMB's that allow data collection in thick ice, thin ice, during times of transition, and even open water. The newest generation of SIMB aims to increase the number of reliable IMB's in the Arctic by leveraging inexpensive commercial-grade instrumentation when combined with specially developed monitoring hardware. Monitoring tasks are handled by a custom, expandable data logger that provides low-cost flexibility for integrating a large range of instrumentation. The SIMB features ultrasonic sensors for direct measurement of both snow depth and ice thickness and a digital temperature chain (DTC) for temperature measurements every 2cm through both snow and ice. Air temperature and pressure, along with GPS data complete the Arctic picture. Additionally, the new SIMB is more compact to maximize deployment opportunities from multiple types of platforms.

  12. Improved ice loss estimate of the northwestern Greenland ice sheet

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup; Khan, Shfaqat Abbas; Wahr, J.

    2013-01-01

    We estimate ice volume change rates in the northwest Greenland drainage basin during 2003–2009 using Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Elevation changes are often reported to be largest near the frontal portion of outlet glaciers. To improve the volume change...... estimate, we supplement the ICESat data with altimeter surveys from NASA's Airborne Topographic Mapper from 2002 to 2010 and NASA's Land, Vegetation and Ice Sensor from 2010. The Airborne data are mainly concentrated along the ice margin and thus have a significant impact on the estimate of the volume...... change. Our results show that adding Airborne Topographic Mapper and Land, Vegetation and Ice Sensor data to the ICESat data increases the catchment-wide estimate of ice volume loss by 11%, mainly due to an improved volume loss estimate along the ice sheet margin. Furthermore, our results show...

  13. Heterogeneous ice nucleation

    Energy Technology Data Exchange (ETDEWEB)

    Bogdan, A. [Helsinki Univ. (Finland). Dept. of Physics

    1994-12-31

    The classical theory of heterogenous ice nucleation is reviewed in detail. The modelling of ice nucleation in the adsorbed water films on natural particles by analogous ice nucleation in adsorbed water films on the walls of porous media is discussed. Ice nucleation in adsorbed films of purewater and the HNO{sub 3}/H{sub 2}0 binary system on the surface of porous aerosol (SiO{sub 2}) was investigated using the method of NMR spectroscopy. The median freezing temperature and freezing temperature region were shown to be highly sensitive both to the average thickness of the adsorbed films and to the amount of adsorbed nitric acid. The character of the ice phase formation tends to approach that of bulk liquid with increasing adsorbed film thickness. Under the given conditions the thickness of the adsorbed films decreases with an increasing amount of adsorbed nitric acid molecules The molar concentration of nitric acid in the adsorbed films is very small (of the order of 10{sup -}3 10{sup -}2 (M/l)). Nitric acid molecules tend to adsorb on the surface of aerosol to a greater extent than in subsequent layers. The concentration is greatest in layers situated close to the surface and sharply decreases with the distance from the surface. The difference between the median freezing temperatures for adsorbed pure water and for the binary system was found to be about 9 K for films of equal thickness. This is about 150 times greater than the difference between the median freezing temperatures of bulk pure water and a solution with the same concentration of nitric acid. (orig.)

  14. Evaluation of the limit ice thickness for the hull of various Finnish-Swedish ice class vessels navigating in the Russian Arctic

    Directory of Open Access Journals (Sweden)

    Pentti Kujala

    2018-05-01

    Full Text Available Selection of suitable ice class for ships operation is an important but not simple task. The increased exploitation of the Polar waters, both seasonal periods and geographical areas, as well as the introduction of new international design standards such as Polar Code, reduces the relevancy of using existing experience as basis for the selection, and new methods and knowledge have to be developed. This paper will analyse what can be the limiting ice thickness for ships navigating in the Russian Arctic and designed according to the Finnish-Swedish ice class rules. The permanent deformations of ice-strengthened shell structures for various ice classes is determined using MT Uikku as the typical size of a vessel navigating in ice. The ice load in various conditions is determined using the ARCDEV data from the winter 1998 as the basic database. By comparing the measured load in various ice conditions with the serviceability limit state of the structures, the limiting ice thickness for various ice classes is determined. The database for maximum loads includes 3-weeks ice load measurements during April 1998 on the Kara Sea mainly by icebreaker assistance. Gumbel 1 distribution is fitted on the measured 20 min maximum values and the data is divided into various classes using ship speed, ice thickness and ice concentration as the main parameters. Results encouragingly show that present designs are safer than assumed in the Polar Code suggesting that assisted operation in Arctic conditions is feasible in rougher conditions than indicated in the Polar Code. Keywords: Loads, Serviceability, Limit ice thickness, Polar code

  15. Bibliography of Ice Properties and Forecasting Related to Transportation in Ice-Covered Waters.

    Science.gov (United States)

    1980-09-01

    N. and Tabata , T., Ice study in the Gulf of Peschanskii, I.S., Ice science and ice technology, Bothnia, III: observations on large grains of ice...ice and by Sterrett, K.F., The arctic environment and the hitting ice floes. Results of these measurements have arctic surface effect vehicle, Cold...ice growth, temperature 26-3673 effects, ice cover thickness. 28-557 Determining contact stresses when a ship’s stem hits the ice, Kheisin, D.E

  16. Employee quality, monitoring environment and internal control

    OpenAIRE

    Chunli Liu; Bin Lin; Wei Shu

    2017-01-01

    We investigate the effect of internal control employees (ICEs) on internal control quality. Using special survey data from Chinese listed firms, we find that ICE quality has a significant positive influence on internal control quality. We examine the effect of monitoring on this result and find that the effect is more pronounced for firms with strict monitoring environments, especially when the firms implement the Chinese internal control regulation system (CSOX), have higher institutional ow...

  17. Automatic ice-cream characterization by impedance measurements for optimal machine setting

    OpenAIRE

    Grossi , Marco; Lanzoni , Massimo; Lazzarini , Roberto; Riccò , Bruno

    2012-01-01

    International audience; Electrical characterization of products is gaining increasing interest in the food industry for quality monitoring and control. In particular, this is the case in the ice-cream industry, where machines dedicated to store ice-cream mixes are programmed ''ad hoc'' for different groups of products. To this purpose, the present work shows that essential product classification (discrimination between milk based and fruit based ice-cream mixes) can be done by means of a tech...

  18. Is there 1.5-million-year-old ice near Dome C, Antarctica?

    Directory of Open Access Journals (Sweden)

    F. Parrenin

    2017-11-01

    Full Text Available Ice sheets provide exceptional archives of past changes in polar climate, regional environment and global atmospheric composition. The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC, reaching ∼ 800 000 years. Obtaining an older paleoclimatic record from Antarctica is one of the greatest challenges of the ice core community. Here, we use internal isochrones, identified from airborne radar coupled to ice-flow modelling to estimate the age of basal ice along transects in the Dome C area. Three glaciological properties are inferred from isochrones: surface accumulation rate, geothermal flux and the exponent of the Lliboutry velocity profile. We find that old ice (> 1.5 Myr, 1.5 million years likely exists in two regions: one ∼ 40 km south-west of Dome C along the ice divide to Vostok, close to a secondary dome that we name Little Dome C (LDC, and a second region named North Patch (NP located 10–30 km north-east of Dome C, in a region where the geothermal flux is apparently relatively low. Our work demonstrates the value of combining radar observations with ice flow modelling to accurately represent the true nature of ice flow, and understand the formation of ice-sheet architecture, in the centre of large ice sheets.

  19. Experimental provocation of 'ice-cream headache' by ice cubes and ice water.

    Science.gov (United States)

    Mages, Stephan; Hensel, Ole; Zierz, Antonia Maria; Kraya, Torsten; Zierz, Stephan

    2017-04-01

    Background There are various studies on experimentally provoked 'ice-cream headache' or 'headache attributed to ingestion or inhalation of a cold stimulus' (HICS) using different provocation protocols. The aim of this study was to compare two provocation protocols. Methods Ice cubes pressed to the palate and fast ingestion of ice water were used to provoke HICS and clinical features were compared. Results The ice-water stimulus provoked HICS significantly more often than the ice-cube stimulus (9/77 vs. 39/77). Ice-water-provoked HICS had a significantly shorter latency (median 15 s, range 4-97 s vs. median 68 s, range 27-96 s). There was no difference in pain localisation. Character after ice-cube stimulation was predominantly described as pressing and after ice-water stimulation as stabbing. A second HICS followed in 10/39 (26%) of the headaches provoked by ice water. Lacrimation occurred significantly more often in volunteers with than in those without HICS. Discussion HICS provoked by ice water was more frequent, had a shorter latency, different pain character and higher pain intensity than HICS provoked by ice cubes. The finding of two subsequent HICS attacks in the same volunteers supports the notion that two types of HICS exist. Lacrimation during HICS indicates involvement of the trigeminal-autonomic reflex.

  20. GPR capabilities for ice thickness sampling of low salinity ice and for detecting oil in ice

    Energy Technology Data Exchange (ETDEWEB)

    Lalumiere, Louis [Sensors by Design Ltd. (Canada)

    2011-07-01

    This report discusses the performance and capabilities test of two airborne ground-penetrating radar (GPR) systems of the Bedford Institute of Oceanography (BIO), Noggin 1000 and Noggin 500, for monitoring low salinity snow and ice properties which was used to measure the thickness of brackish ice on Lake Melville in Labrador and on a tidal river in Prince Edward Island. The work of other researchers is documented and the measurement techniques proposed are compared to the actual GPR approach. Different plots of GPR data taken over snow and freshwater ice and over ice with changing salinity are discussed. An interpretation of brackish ice GPR plots done by the Noggin 1000 and Noggin 500 systems is given based on resolution criterion. Additionally, the capability of the BIO helicopter-borne GPR to detect oil-in-ice has been also investigated, and an opinion on the likelihood of the success of GPR as an oil-in-ice detector is given.

  1. Skating on slippery ice

    Directory of Open Access Journals (Sweden)

    J. M. J. van Leeuwen

    2017-12-01

    Full Text Available The friction of a stationary moving skate on smooth ice is investigated, in particular in relation to the formation of a thin layer of water between skate and ice. It is found that the combination of ploughing and sliding gives a friction force that is rather insensitive for parameters such as velocity and temperature. The weak dependence originates from the pressure adjustment inside the water layer. For instance, high velocities, which would give rise to high friction, also lead to large pressures, which, in turn, decrease the contact zone and so lower the friction. The theory is a combination and completion of two existing but conflicting theories on the formation of the water layer.

  2. Theory of amorphous ices.

    Science.gov (United States)

    Limmer, David T; Chandler, David

    2014-07-01

    We derive a phase diagram for amorphous solids and liquid supercooled water and explain why the amorphous solids of water exist in several different forms. Application of large-deviation theory allows us to prepare such phases in computer simulations. Along with nonequilibrium transitions between the ergodic liquid and two distinct amorphous solids, we establish coexistence between these two amorphous solids. The phase diagram we predict includes a nonequilibrium triple point where two amorphous phases and the liquid coexist. Whereas the amorphous solids are long-lived and slowly aging glasses, their melting can lead quickly to the formation of crystalline ice. Further, melting of the higher density amorphous solid at low pressures takes place in steps, transitioning to the lower-density glass before accessing a nonequilibrium liquid from which ice coarsens.

  3. Arctic Ice Studies

    Science.gov (United States)

    1993-02-01

    i heoriotlscale wace s 50 kin wthe11 aii vertical leadi tof M o.ChrlesA Lcur the siir-ai’.orc~5 . ~ ~G. RLI Lt(lWA~S II I Shuchln P A P Ut alI 9...can be utilized msccesafully. distinguish between these two major ice types and open I. INTRODUCTION water. S THE geophysical and economic importance of

  4. Marginal Ice Zone Bibliography.

    Science.gov (United States)

    1985-06-01

    Tsunamis, Gravimetry , Earth Tides, World Data Center A: Oceanography Recent Movements of the Earth’s National Oceanographic Data Center Crust...sufficiently low, the dissolved salts precipitate out in the form of solid hydrates. It has been proposed that these solid hydrates add to the overall...strength of the ice. The first salt hydrate to precipitate should be that of sodium sul- * fate, Na2SO4IOH2O (the sulfate ion is the second most

  5. Ice condenser experimental plan

    International Nuclear Information System (INIS)

    Kannberg, L.D.; Piepel, G.F.; Owczarski, P.C.; Liebetrau, A.M.

    1986-01-01

    An experimental plan is being developed to validate the computer code ICEDF. The code was developed to estimate the extent of aerosol retention in the ice compartments of pressurized water reactor ice condenser containment systems during severe accidents. The development of the experimental plan began with review of available information on the conditions under which the code will be applied. Computer-generated estimates of thermohydraulic and aerosol conditions entering the ice condenser were evaluated and along with other information, used to generate design criteria. The design criteria have been used for preliminary test assembly design and for generation of statistical test designs. Consideration of the phenomena to be evaluated in the testing program, as well as equipment and measurement limitations, have led to changes in the design criteria and to subsequent changes in the test assembly design and statistical test design. The overall strategy in developing the experimental plan includes iterative generation and evaluation of candidate test designs using computer codes for statistical test design and ICEDF for estimation of experimental results. Estimates of experimental variability made prior to actual testing will be verified by replicate testing at preselected design points

  6. Visualizing Glaciers and Sea Ice via Google Earth

    Science.gov (United States)

    Ballagh, L. M.; Fetterer, F.; Haran, T. M.; Pharris, K.

    2006-12-01

    The NOAA team at NSIDC manages over 60 distinct cryospheric and related data products. With an emphasis on data rescue and in situ data, these products hold value for both the scientific and non-scientific user communities. The overarching goal of this presentation is to promote products from two components of the cryosphere (glaciers and sea ice). Our Online Glacier Photograph Database contains approximately 3,000 photographs taken over many decades, exemplifying change in the glacier terminus over time. The sea ice product shows sea ice extent and concentration along with anomalies and trends. This Sea Ice Index product, which starts in 1979 and is updated monthly, provides visuals of the current state of sea ice in both hemispheres with trends and anomalies. The long time period covered by the data set means that many of the trends in ice extent and concentration shown in this product are statistically significant despite the large natural variability in sea ice. The minimum arctic sea ice extent has been a record low in September 2002 and 2005, contributing to an accelerated trend in sea ice reduction. With increasing world-wide interest in indicators of global climate change, and the upcoming International Polar Year, these data products are of interest to a broad audience. To further extend the impact of these data, we have made them viewable through Google Earth via the Keyhole Markup Language (KML). This presents an opportunity to branch out to a more diverse audience by using a new and innovative tool that allows spatial representation of data of significant scientific and educational interest.

  7. Uncertainty Quantification for Ice Sheet Science and Sea Level Projections

    Science.gov (United States)

    Boening, C.; Schlegel, N.; Limonadi, D.; Schodlok, M.; Seroussi, H. L.; Larour, E. Y.; Watkins, M. M.

    2017-12-01

    In order to better quantify uncertainties in global mean sea level rise projections and in particular upper bounds, we aim at systematically evaluating the contributions from ice sheets and potential for extreme sea level rise due to sudden ice mass loss. Here, we take advantage of established uncertainty quantification tools embedded within the Ice Sheet System Model (ISSM) as well as sensitivities to ice/ocean interactions using melt rates and melt potential derived from MITgcm/ECCO2. With the use of these tools, we conduct Monte-Carlo style sampling experiments on forward simulations of the Antarctic ice sheet, by varying internal parameters and boundary conditions of the system over both extreme and credible worst-case ranges. Uncertainty bounds for climate forcing are informed by CMIP5 ensemble precipitation and ice melt estimates for year 2100, and uncertainty bounds for ocean melt rates are derived from a suite of regional sensitivity experiments using MITgcm. Resulting statistics allow us to assess how regional uncertainty in various parameters affect model estimates of century-scale sea level rise projections. The results inform efforts to a) isolate the processes and inputs that are most responsible for determining ice sheet contribution to sea level; b) redefine uncertainty brackets for century-scale projections; and c) provide a prioritized list of measurements, along with quantitative information on spatial and temporal resolution, required for reducing uncertainty in future sea level rise projections. Results indicate that ice sheet mass loss is dependent on the spatial resolution of key boundary conditions - such as bedrock topography and melt rates at the ice-ocean interface. This work is performed at and supported by the California Institute of Technology's Jet Propulsion Laboratory. Supercomputing time is also supported through a contract with the National Aeronautics and Space Administration's Cryosphere program.

  8. Rapid formation of a sea ice barrier east of Svalbard

    Science.gov (United States)

    Nghiem, S. V.; van Woert, M. L.; Neumann, G.

    2005-11-01

    Daily SeaWinds scatterometer images acquired by the QuikSCAT satellite show an elongated sea ice feature that formed very rapidly (˜1-2 days) in November 2001 east of Svalbard over the Barents Sea. This sea ice structure, called "the Svalbard sea ice barrier," spanning approximately 10° in longitude and 2° in latitude, restricts the sea route and poses a significant navigation hazard. The secret of its formation appears to lie in the bottom of the sea: A comparison between bathymetry from the International Bathymetric Chart of the Arctic Ocean data and the pattern of sea ice formation from scatterometer data reveals that the sea ice barrier conforms well with and stretches above a deep elongated channel connecting the Franz Josef-Victoria Trough to the Hinlopen Basin between Svalbard and Franz Josef Land. Historic hydrographic data from this area indicate that this sea channel contains cold Arctic water less than 50 m below the surface. Strong and persistent cold northerly winds force strong heat loss from this shallow surface layer, leading to the rapid formation of the sea ice barrier. Heat transfer rates estimated from European Centre for Medium-Range Weather Forecasts temperature and wind data over this region suggest that the surface water along the deep channel can be rapidly cooled to the freezing point. Scatterometer results in 1999-2003 show that sea ice forms in this area between October and December. Understanding the ice formation mechanisms helps to select appropriate locations for deployment of buoys measuring wind and air-sea temperature profile and to facilitate ice monitoring, modeling, and forecasting.

  9. Temporal dynamics of ikaite in experimental sea ice

    Science.gov (United States)

    Rysgaard, S.; Wang, F.; Galley, R. J.; Grimm, R.; Notz, D.; Lemes, M.; Geilfus, N.-X.; Chaulk, A.; Hare, A. A.; Crabeck, O.; Else, B. G. T.; Campbell, K.; Sørensen, L. L.; Sievers, J.; Papakyriakou, T.

    2014-08-01

    Ikaite (CaCO3 · 6H2O) is a metastable phase of calcium carbonate that normally forms in a cold environment and/or under high pressure. Recently, ikaite crystals have been found in sea ice, and it has been suggested that their precipitation may play an important role in air-sea CO2 exchange in ice-covered seas. Little is known, however, of the spatial and temporal dynamics of ikaite in sea ice. Here we present evidence for highly dynamic ikaite precipitation and dissolution in sea ice grown at an outdoor pool of the Sea-ice Environmental Research Facility (SERF) in Manitoba, Canada. During the experiment, ikaite precipitated in sea ice when temperatures were below -4 °C, creating three distinct zones of ikaite concentrations: (1) a millimeter-to-centimeter-thin surface layer containing frost flowers and brine skim with bulk ikaite concentrations of >2000 μmol kg-1, (2) an internal layer with ikaite concentrations of 200-400 μmol kg-1, and (3) a bottom layer with ikaite concentrations of ikaite crystals to dissolve. Manual removal of the snow cover allowed the sea ice to cool and brine salinities to increase, resulting in rapid ikaite precipitation. The observed ikaite concentrations were on the same order of magnitude as modeled by FREZCHEM, which further supports the notion that ikaite concentration in sea ice increases with decreasing temperature. Thus, varying snow conditions may play a key role in ikaite precipitation and dissolution in sea ice. This could have a major implication for CO2 exchange with the atmosphere and ocean that has not been accounted for previously.

  10. Identifikasi Bakteri pada Rumput Laut Euchema spinosum yang terserang penyakit Ice-ice di Perairan Pantai Kutuh

    Directory of Open Access Journals (Sweden)

    Suprabadevi Ayumayasari Saraswati

    2016-01-01

    Full Text Available The main causes of ice-ice disease that seaweed production will decline. Bacterial infections occur due to fluctuations in climate change resulted in a decrease in water quality resulting in the durability of seaweed. When seaweed stress will facilitate pathogen infection. Disease pathogens cause damage to internal organs. The spread of bacterial disease in seaweed is generally very fast and can lead to death, so that the loss caused by this disease is quite large. Ice-ice disease occurrence is seasonal and contagious, so the impact on the selling price low. The results showed that there are two types of pathogenic bacteria that can potentially cause disease in which bacteria Vibrio alginoliticus and Pseudomonas aeruginosa. Climate change affects the spatial distribution of micro seaweed bacterial pathogens.

  11. Using ice melting and ice rolling technologies to remove ice from sub-transmission and transmission lines at Manitoba Hydro

    International Nuclear Information System (INIS)

    Farias, A. R.

    1999-01-01

    Development of an of an Ice Storm Management program by Manitoba Hydro to reduce ice storm damage to its 8 kV feeders to 115 kV transmission lines, is discussed. The program consists of the de-icing of overhead lines, either by ice melting, or ice rolling. Ice melting involves the placement of a three-phase short at a calculated point. The term ice rolling denotes a process of mechanically stripping the ice from conductors. The most recent major ice storm experienced by Manitoba Hydro was in the winter of 1997/1998. During the period from February 6 to February 17, 1998, a total of 83 'ice melt' procedures were performed to melt the ice from 2,628 km of overhead line (7,883 km of conductor), in addition to 'ice rolling'. This paper describes Manitoba Hydro's 25-years' experience with ice melting and it also describes the advantages and disadvantages of both ice melting and ice rolling. Although not a panacea to combat the effects of ice storms, ice melting was found to be the most effective way of removing ice from overhead transmission and sub-transmission lines. Ice rolling was also found to be effective. Other tools that have been found to be useful by various utilities in combating ice storm damage include improved structure and line design, system design that provide more redundancies and emergency sources, and standby generators at critical load points

  12. Remote Sensing of Crystal Shapes in Ice Clouds

    Science.gov (United States)

    van Diedenhoven, Bastiaan

    2017-01-01

    Ice crystals in clouds exist in a virtually limitless variation of geometries. The most basic shapes of ice crystals are columnar or plate-like hexagonal prisms with aspect ratios determined by relative humidity and temperature. However, crystals in ice clouds generally display more complex structures owing to aggregation, riming and growth histories through varying temperature and humidity regimes. Crystal shape is relevant for cloud evolution as it affects microphysical properties such as fall speeds and aggregation efficiency. Furthermore, the scattering properties of ice crystals are affected by their general shape, as well as by microscopic features such as surface roughness, impurities and internal structure. To improve the representation of ice clouds in climate models, increased understanding of the global variation of crystal shape and how it relates to, e.g., location, cloud temperature and atmospheric state is crucial. Here, the remote sensing of ice crystal macroscale and microscale structure from airborne and space-based lidar depolarization observations and multi-directional measurements of total and polarized reflectances is reviewed. In addition, a brief overview is given of in situ and laboratory observations of ice crystal shape as well as the optical properties of ice crystals that serve as foundations for the remote sensing approaches. Lidar depolarization is generally found to increase with increasing cloud height and to vary with latitude. Although this variation is generally linked to the variation of ice crystal shape, the interpretation of the depolarization remains largely qualitative and more research is needed before quantitative conclusions about ice shape can be deduced. The angular variation of total and polarized reflectances of ice clouds has been analyzed by numerous studies in order to infer information about ice crystal shapes from them. From these studies it is apparent that pristine crystals with smooth surfaces are generally

  13. IceCube systematic errors investigation: Simulation of the ice

    Energy Technology Data Exchange (ETDEWEB)

    Resconi, Elisa; Wolf, Martin [Max-Planck-Institute for Nuclear Physics, Heidelberg (Germany); Schukraft, Anne [RWTH, Aachen University (Germany)

    2010-07-01

    IceCube is a neutrino observatory for astroparticle and astronomy research at the South Pole. It uses one cubic kilometer of Antartica's deepest ice (1500 m-2500 m in depth) to detect Cherenkov light, generated by charged particles traveling through the ice, with an array of phototubes encapsulated in glass pressure spheres. The arrival time as well as the charge deposited of the detected photons represent the base measurements that are used for track and energy reconstruction of those charged particles. The optical properties of the deep antarctic ice vary from layer to layer. Measurements of the ice properties and their correct modeling in Monte Carlo simulation is then of primary importance for the correct understanding of the IceCube telescope behavior. After a short summary about the different methods to investigate the ice properties and to calibrate the detector, we show how the simulation obtained by using this information compares to the measured data and how systematic errors due to uncertain ice properties are determined in IceCube.

  14. Ice exposures and landscape evolution in the Martian mid-latitudes

    Science.gov (United States)

    Dundas, C. M.; Bramson, A. M.; Ojha, L.; Wray, J. J.; Mellon, M. T.; Byrne, S.; McEwen, A. S.; Putzig, N. E.; Viola, D.; Sutton, S.

    2017-12-01

    The large-scale geographic distribution of Martian shallow ground ice is now relatively well-known, but the vertical structure of the ice is not as well understood. Here we report on erosional scarps in kilometer-scale pits near ±55-60 degrees latitude that expose cross-sections through ice-rich mantling deposits covering much of the mid-latitudes. HiRISE images of the scarps reveal ice-rich deposits (i.e., not regolith-pore-filling ice) that are >100 m thick and occur within 1 m of the top of the scarps. CRISM spectra confirm the presence of water ice through late summer, implying exposed ground ice rather than seasonal frost. SHARAD sounding radar data show some candidate reflectors similar to those inferred to be from the base of excess ice deposits elsewhere on Mars, but no internal structure is resolved. Ice-exposing impacts and thermokarst landforms convey information about excess ice abundance in the upper few meters, but not its deeper structure. The overall structure of the ice table is simple, with massive ice (sometimes layered) under a relatively thin lithic mantle, plus a boulder-rich interior lens in one scarp. The latter may be partly ice-cemented. The ice is commonly fractured. These observations demonstrate how deep ice sheets link with the shallow ice table, at least locally. The likely origin of the ice is accumulation of snow with some admixed dust during a different climate. This snow accumulation could be related to 370 ka changes observed at the poles [1] but some ice sheets may be tens of Myr old [2]. the origin of superposed boulder-sized rocks is puzzling; possible explanations include glacial flow, impact gardening, or some form of frost heave or cryoturbation. Repeat HiRISE observations demonstrate that the scarps are actively retreating, as boulders have fallen from one scarp and there are albedo changes elsewhere. This activity demonstrates that local sublimation is contributing to present-day Martian landscape evolution and is an

  15. Arctic continental shelf morphology related to sea-ice zonation, Beaufort Sea, Alaska

    Science.gov (United States)

    Reimnitz, E.; Toimil, L.; Barnes, P.

    1978-01-01

    Landsat-1 and NOAA satellite imagery for the winter 1972-1973, and a variety of ice and sea-floor data were used to study sea-ice zonation and dynamics and their relation to bottom morphology and geology on the Beaufort Sea continental shelf of arctic Alaska. In early winter the location of the boundary between undeformed fast ice and westward-drifting pack ice of the Pacific Gyre is controlled by major coastal promontories. Pronounced linear pressure- and shear-ridges, as well as hummock fields, form along this boundary and are stabilized by grounding, generally between the 10- and 20-m isobaths. Slippage along this boundary occurs intermittently at or seaward of the grounded ridges, forming new grounded ridges in a widening zone, the stamukhi zone, which by late winter extends out to the 40-m isobath. Between intermittent events along the stamukhi zone, pack-ice drift and slippage is continuous along the shelf edge, at average rates of 3-10 km/day. Whether slippage occurs along the stamukhi zone or along the shelf edge, it is restricted to a zone several hundred meters wide, and ice seaward of the slip face moves at uniform rates without discernible drag effects. A causal relationship is seen between the spatial distribution of major ice-ridge systems and offshore shoals downdrift of major coastal promontories. The shoals appear to have migrated shoreward under the influence of ice up to 400 m in the last 25 years. The sea floor seaward of these shoals within the stamukhi zone shows high ice-gouge density, large incision depths, and a high degree of disruption of internal sedimentary structures. The concentration of large ice ridges and our sea floor data in the stamukhi zone indicate that much of the available marine energy is expended here, while the inner shelf and coast, where the relatively undeformed fast ice grows, are sheltered. There is evidence that anomalies in the overall arctic shelf profile are related to sea-ice zonation, ice dynamics, and bottom

  16. Multi-Decadal Averages of Basal Melt for Ross Ice Shelf, Antarctica Using Airborne Observations

    Science.gov (United States)

    Das, I.; Bell, R. E.; Tinto, K. J.; Frearson, N.; Kingslake, J.; Padman, L.; Siddoway, C. S.; Fricker, H. A.

    2017-12-01

    Changes in ice shelf mass balance are key to the long term stability of the Antarctic Ice Sheet. Although the most extensive ice shelf mass loss currently is occurring in the Amundsen Sea sector of West Antarctica, many other ice shelves experience changes in thickness on time scales from annual to ice age cycles. Here, we focus on the Ross Ice Shelf. An 18-year record (1994-2012) of satellite radar altimetry shows substantial variability in Ross Ice Shelf height on interannual time scales, complicating detection of potential long-term climate-change signals in the mass budget of this ice shelf. Variability of radar signal penetration into the ice-shelf surface snow and firn layers further complicates assessment of mass changes. We investigate Ross Ice Shelf mass balance using aerogeophysical data from the ROSETTA-Ice surveys using IcePod. We use two ice-penetrating radars; a 2 GHz unit that images fine-structure in the upper 400 m of the ice surface and a 360 MHz radar to identify the ice shelf base. We have identified internal layers that are continuous along flow from the grounding line to the ice shelf front. Based on layer continuity, we conclude that these layers must be the horizons between the continental ice of the outlet glaciers and snow accumulation once the ice is afloat. We use the Lagrangian change in thickness of these layers, after correcting for strain rates derived using modern day InSAR velocities, to estimate multidecadal averaged basal melt rates. This method provides a novel way to quantify basal melt, avoiding the confounding impacts of spatial and short-timescale variability in surface accumulation and firn densification processes. Our estimates show elevated basal melt rates (> -1m/yr) around Byrd and Mullock glaciers within 100 km from the ice shelf front. We also compare modern InSAR velocity derived strain rates with estimates from the comprehensive ground-based RIGGS observations during 1973-1978 to estimate the potential magnitude of

  17. Effect of ice surface size on collision rates and head impacts at the World Junior Hockey Championships, 2002 to 2004.

    Science.gov (United States)

    Wennberg, Richard

    2005-03-01

    To determine if collision rates and head impacts in elite junior hockey differed between games played on the small North American ice surface (85 ft wide), an intermediate-size Finnish ice surface (94 ft wide), and the large standard international ice surface (100 ft wide). Videotape analysis of all games involving Team Canada from the 2002 (large ice, Czech Republic), 2003 (small ice, Canada), and 2004 (intermediate ice, Finland) World Junior Championships. All collisions were counted and separated into various categories (volitional player/player bodychecks, into boards or open ice, plus accidental/incidental player/boards, player/ice, head/stick, head/puck). Further subdivisions included collisions involving the head directly or indirectly and notably severe head impacts. Small, intermediate, and large ice surface mean collisions/game, respectively, were 295, 258, 222, total collisions; 251, 220, 181, volitional bodychecks; 126, 115, 88, into boards; 125, 106, 93, open ice; 71, 52, 44, total head; 44, 36, 30, indirect head; 26, 16, 13, direct head; and 1.3, 0.5, 0.3, severe head (P < 0.05 for small-intermediate ice and intermediate-large ice differences in total collisions; P < 0.005 for small-large ice difference; P < 0.05 for small-intermediate ice differences in head impacts; P < 0.01 for small-large ice differences in total and severe head impacts). There is a significant inverse correlation between ice size and collision rates in elite hockey, including direct, indirect, and severe head impacts. These findings suggest that uniform usage of the larger international rinks could reduce the risk of injury, and specifically, concussions in elite hockey by decreasing the occurrence of collisions and head impacts.

  18. Radiation effects in ice: New results

    International Nuclear Information System (INIS)

    Baragiola, R.A.; Fama, M.; Loeffler, M.J.; Raut, U.; Shi, J.

    2008-01-01

    Studies of radiation effects in ice are motivated by intrinsic interest and by applications in astronomy. Here we report on new and recent results on radiation effects induced by energetic ions in ice: amorphization of crystalline ice, compaction of microporous amorphous ice, electrostatic charging and dielectric breakdown and correlated structural/chemical changes in the irradiation of water-ammonia ices

  19. Antarctic ice sheet thickness estimation based on P-receiver function and waveform inversion

    Science.gov (United States)

    Yan, P.; Li, F.; LI, Z.; Li, J.; Yang, Y.; Hao, W.

    2016-12-01

    Antarctic ice sheet thickness is key parameter and boundary condition for ice sheet model construction, which has great significance for glacial isostatic adjustment, ice sheet mass balance and global change study. Ice thickness acquired utilizing seismological receiver function method can complement and verify with results obtained by radar echo sounding method. In this paper, P-receiver functions(PRFs) are extracted for stations deployed on Antarctic ice sheet, then Vp/Vs ratio and ice thickness are obtained using H-Kappa stacking. Comparisons are made between Bedmap2 dataset and the ice thickness from PRFs, most of the absolute value of the differences are less than 200 meters, only a few reach 600 meters. Taking into account of the intensity of Bedmap2 dataset survey lines and the uncertainty of radio echo sounding, as well as the inherit complexity of the internal ice structure beneath some stations, the ice thickness obtained from receiver function method is reliable. However limitation exists when using H-Kappa stacking method for stations where sediment squeezed between the ice and the bed rock layer. For better verifying the PRF result, a global optimizing method-Neighbourhood algotithm(NA) and spline interpolation are used to modeling PRFs assuming an isotropic layered ice sheet with depth varied densities and velocities beneath the stations. Then the velocity structure and ice sheet thickness are obtained through nonlinear searching by optimally fitting the real and the theoretical PRFs. The obtained ice sheet thickness beneath the stations agree well with the former H-Kappa method, but further detailed study are needed to constrain the inner ice velocity structure.

  20. Dynamics and Structural Details of Amorphous Phases of Ice Determined by Incoherent Inelastic Neutron Scattering

    International Nuclear Information System (INIS)

    Klug, D.D.; Tulk, C.A.; Svensson, E.C.; Loong, C.

    1999-01-01

    Incoherent-inelastic neutron scattering data are obtained over the energy range of lattice and internal vibrations of water molecules in phases of ice prepared by pressure-induced amorphization (high-density amorphous ice, hda), by thermal annealing of hda (low-density amorphous ice, lda), and by rapidly cooling water, as well as in ice Ih and Ic . Hydrogen bonding interactions in lda differ significantly from those in the glass obtained by rapid quenching, which has hydrogen-bond interactions characteristic of highly supercooled water. Hydrogen-bond interactions in hda are weaker than in the low-density phases. copyright 1999 The American Physical Society

  1. The making of salty ice

    International Nuclear Information System (INIS)

    Bove, L.E.

    2009-01-01

    Full text: It is widely accepted that ice, no matter what phase, is unable to incorporate large amount of salt into its structure. This conclusion is based on the observation that upon freezing of saltwater, ice expels the salt almost entirely into brine, a fact which can be exploited to desalinate seawater. Here we show, by neutron diffraction under high pressure, that this behaviour is not an intrinsic physico-chemical property of ice phases. We demonstrate that substantial am mounts of dissolved LiCl can be built homogeneously into the ice VII structure if it is produced by recrystallisation of its glassy state under pressure [1]. Such highly doped or alloyed ice VII has significantly different structural properties compared to pure ice VII, such as a 8% larger unit cell volume, 5 times larger displacement factors, an absence of a transition to an ordered ice VIII structure, plasticity, and most likely ionic conductivity. Our study suggests that there could be a whole new class of salty ices based on various kinds of solutes and high pressure ice forms. (author)

  2. Diffuse scattering in Ih ice

    International Nuclear Information System (INIS)

    Wehinger, Björn; Krisch, Michael; Bosak, Alexeï; Chernyshov, Dmitry; Bulat, Sergey; Ezhov, Victor

    2014-01-01

    Single crystals of ice Ih, extracted from the subglacial Lake Vostok accretion ice layer (3621 m depth) were investigated by means of diffuse x-ray scattering and inelastic x-ray scattering. The diffuse scattering was identified as mainly inelastic and rationalized in the frame of ab initio calculations for the ordered ice XI approximant. Together with Monte-Carlo modelling, our data allowed reconsidering previously available neutron diffuse scattering data of heavy ice as the sum of thermal diffuse scattering and static disorder contribution. (paper)

  3. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    to sea level high stands during past interglacial periods. A number of AIS models have been developed and applied to try to understand the workings of the AIS and to form a robust basis for future projections of the AIS contribution to sea level change. The recent DCESS (Danish Center for Earth System......The Antarctic ice sheet is a major player in the Earth’s climate system and is by far the largest depository of fresh water on the planet. Ice stored in the Antarctic ice sheet (AIS) contains enough water to raise sea level by about 58 m, and ice loss from Antarctica contributed significantly...

  4. Improved ice loss estimate of the northwestern Greenland ice sheet

    NARCIS (Netherlands)

    Kjeldsen, K.K.; Khan, S.A.; van den Broeke, M.R.; van Angelen, J.H.

    2013-01-01

    We estimate ice volume change rates in the northwest Greenland drainage basin during 2003–2009 using Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Elevation changes are often reported to be largest near the frontal portion of outlet glaciers. To improve the volume change

  5. Eulerian method for ice crystal icing in turbofan engines

    NARCIS (Netherlands)

    Norde, Ellen

    2017-01-01

    The newer generations of high-bypass-ratio engines are susceptible to the ingestion of small ice crystals which may cause engine power loss or damage. The research presented in this thesis focusses on the development of a computational method for in-engine ice crystal accretion. The work has been

  6. Tropospheric characteristics over sea ice during N-ICE2015

    Science.gov (United States)

    Kayser, Markus; Maturilli, Marion; Graham, Robert; Hudson, Stephen; Cohen, Lana; Rinke, Annette; Kim, Joo-Hong; Park, Sang-Jong; Moon, Woosok; Granskog, Mats

    2017-04-01

    Over recent years, the Arctic Ocean region has shifted towards a younger and thinner sea-ice regime. The Norwegian young sea ICE (N-ICE2015) expedition was designed to investigate the atmosphere-snow-ice-ocean interactions in this new ice regime north of Svalbard. Here we analyze upper-air measurements made by radiosondes launched twice daily together with surface meteorology observations during N-ICE2015 from January to June 2015. We study the multiple cyclonic events observed during N-ICE2015 with respect to changes in the vertical thermodynamic structure, sudden increases in moisture content and temperature, temperature inversions and boundary layer dynamics. The influence of synoptic cyclones is strongest under polar night conditions, when radiative cooling is most effective and the moisture content is low. We find that transitions between the radiatively clear and opaque state are the largest drivers of changes to temperature inversion and stability characteristics in the boundary layer during winter. In spring radiative fluxes warm the surface leading to lifted temperature inversions and a statically unstable boundary layer. The unique N-ICE2015 dataset is used for case studies investigating changes in the vertical structure of the atmosphere under varying synoptic conditions. The goal is to deepen our understanding of synoptic interactions within the Arctic climate system, to improve model performance, as well as to identify gaps in instrumentation, which precludes further investigations.

  7. Glacitectonic deformation around the retreating margin of the last Irish ice sheet

    Science.gov (United States)

    Knight, J.

    2008-12-01

    Evidence for ice-marginal glacitectonic shunting and deformation of bedrock slabs is described from three sites around the west coast of Ireland. These sites (Brandon Bay, County Kerry; Pigeon Point, County Mayo; Inishcrone, County Sligo) are all locations where the late Devensian ice margin retreated on land and was confined to within limestone bedrock embayments. At these sites, flat-lying bedrock slabs (bedrock slabs have been variously stacked, rotated, deformed into open folds, and brecciated. Separating the bedrock slabs is either a thin layer (bedrock that shows internal folding; or a thicker (bedrock fractures and bedding planes and away from the ice margin, and that bedrock slabs were moved in part by hydraulic lift as well as thrust-style ice-marginal tectonics. The presence of a mosaic of warm and frozen ice-bed patches, in combination with strong geologic control and meltwater generation from behind the ice margin, can help explain formation of these unusual bedrock slab features.

  8. Single-particle characterization of ice-nucleating particles and ice particles residuals sampled by three different techniques

    Science.gov (United States)

    Kandler, Konrad; Worringen, Annette; Benker, Nathalie; Dirsch, Thomas; Mertes, Stephan; Schenk, Ludwig; Kästner, Udo; Frank, Fabian; Nillius, Björn; Bundke, Ulrich; Rose, Diana; Curtius, Joachim; Kupiszewski, Piotr; Weingartner, Ernest; Vochezer, Paul; Schneider, Johannes; Schmidt, Susan; Weinbruch, Stephan; Ebert, Martin

    2015-04-01

    During January/February 2013, at the High Alpine Research Station Jungfraujoch a measurement campaign was carried out, which was centered on atmospheric ice-nucleating particles (INP) and ice particle residuals (IPR). Three different techniques for separation of INP and IPR from the non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed phase clouds and allow for the analysis of the residuals. The combination of the Fast Ice Nucleus Chamber (FINCH) and the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated INP for analysis. Collected particles were analyzed by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine size, chemical composition and mixing state. All INP/IPR-separating techniques had considerable abundances (median 20 - 70 %) of instrumental contamination artifacts (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH+IN-PCVI: steel particles). Also, potential sampling artifacts (e.g., pure soluble material) occurred with a median abundance of separated by all three techniques. Soot was a minor contributor. Lead was detected in less than 10 % of the particles, of which the majority were internal mixtures with other particle types. Sea-salt and sulfates were identified by all three methods as INP/IPR. Most samples showed a maximum of the INP/IPR size distribution at 400 nm geometric diameter. In a few cases, a second super-micron maximum was identified. Soot/carbonaceous material and metal oxides were present mainly in the submicron range. ISI and FINCH yielded silicates and Ca-rich particles mainly with diameters above 1 µm, while the Ice-CVI also separated many submicron IPR. As strictly parallel sampling could not be performed, a part of the discrepancies between the different techniques may result from

  9. Observing Arctic Sea Ice from Bow to Screen: Introducing Ice Watch, the Data Network of Near Real-Time and Historic Observations from the Arctic Shipborne Sea Ice Standardization Tool (ASSIST)

    Science.gov (United States)

    Orlich, A.; Hutchings, J. K.; Green, T. M.

    2013-12-01

    The Ice Watch Program is an open source forum to access in situ Arctic sea ice conditions. It provides the research community and additional stakeholders a convenient resource to monitor sea ice and its role in understanding the Arctic as a system by implementing a standardized observation protocol and hosting a multi-service data portal. International vessels use the Arctic Shipborne Sea Ice Standardization Tool (ASSIST) software to report near-real time sea ice conditions while underway. Essential observations of total ice concentration, distribution of multi-year ice and other ice types, as well as their respective stage of melt are reported. These current and historic sea ice conditions are visualized on interactive maps and in a variety of statistical analyses, and with all data sets available to download for further investigation. The summer of 2012 was the debut of the ASSIST software and the Ice Watch campaign, with research vessels from six nations reporting from a wide spatio-temporal scale spanning from the Beaufort Sea, across the North Pole and Arctic Basin, the coast of Greenland and into the Kara and Barents Seas during mid-season melt and into the first stages of freeze-up. The 2013 summer field season sustained the observation and data archiving record, with participation from some of the same cruises as well as other geographic and seasonal realms covered by new users. These results are presented to illustrate the evolution of the program, increased participation and critical statistics of ice regime change and record of melt and freeze processes revealed by the data. As an ongoing effort, Ice Watch/ASSIST aims to standardize observations of Arctic-specific sea ice features and conditions while utilizing nomenclature and coding based on the World Meteorological Organization (WMO) standards and the Antarctic Sea Ice and Processes & Climate (ASPeCt) protocol. Instigated by members of the CliC Sea Ice Working Group, the program has evolved with

  10. Arctic Sea Ice Freeboard and Thickness

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides measurements of sea ice freeboard and sea ice thickness for the Arctic region. The data were derived from measurements made by from the Ice,...

  11. Assessing deformation and morphology of Arctic landfast sea ice using InSAR to support use and management of coastal ice

    Science.gov (United States)

    Dammann, D. O.; Eicken, H.; Meyer, F. J.; Mahoney, A. R.

    2016-12-01

    Arctic landfast sea ice provides important services to people, including coastal communities and industry, as well as key marine biota. In many regions of the Arctic, the use of landfast sea ice by all stakeholders is increasingly limited by reduced stability of the ice cover, which results in more deformation and rougher ice conditions as well as reduced extent and an increased likelihood of detachment from the shore. Here, we use Synthetic Aperture Radar Interferometry (InSAR) to provide stakeholder-relevant data on key constraints for sea ice use, in particular ice stability and morphology, which are difficult to assess using conventional SAR. InSAR has the capability to detect small-scale landfast ice displacements, which are linked to important coastal hazards, including the formation of cracks, ungrounding of ice pressure ridges, and catastrophic breakout events. While InSAR has previously been used to identify the extent of landfast ice and regions of deformation within, quantitative analysis of small-scale ice motion has yet to be thoroughly validated and its potential remains largely underutilized in sea ice science. Using TanDEM-X interferometry, we derive surface displacements of landfast ice within Elson Lagoon near Barrow, Alaska, which we validate using in-situ DGPS data. We then apply an inverse model to estimate rates and patterns of shorefast ice deformation in other regions of landfast ice using interferograms generated with long-temporal baseline L-band ALOS-1 PALSAR-1 data. The model is able to correctly identify deformation modes and proxies for the associated relative internal elastic stress. The derived potential for fractures corresponds well with large-scale sea ice patterns and local in-situ observations. The utility of InSAR to quantify sea ice roughness has also been explored using TanDEM-X bistatic interferometry, which eliminates the effects of temporal changes in the ice cover. The InSAR-derived DEM shows good correlation with a high

  12. Climate Impacts of Ice Nucleation

    Science.gov (United States)

    Gettelman, Andrew; Liu, Xiaohong; Barahona, Donifan; Lohmann, Ulrike; Chen, Celia

    2012-01-01

    Several different ice nucleation parameterizations in two different General Circulation Models (GCMs) are used to understand the effects of ice nucleation on the mean climate state, and the Aerosol Indirect Effects (AIE) of cirrus clouds on climate. Simulations have a range of ice microphysical states that are consistent with the spread of observations, but many simulations have higher present-day ice crystal number concentrations than in-situ observations. These different states result from different parameterizations of ice cloud nucleation processes, and feature different balances of homogeneous and heterogeneous nucleation. Black carbon aerosols have a small (0.06 Wm(exp-2) and not statistically significant AIE when included as ice nuclei, for nucleation efficiencies within the range of laboratory measurements. Indirect effects of anthropogenic aerosols on cirrus clouds occur as a consequence of increasing anthropogenic sulfur emissions with different mechanisms important in different models. In one model this is due to increases in homogeneous nucleation fraction, and in the other due to increases in heterogeneous nucleation with coated dust. The magnitude of the effect is the same however. The resulting ice AIE does not seem strongly dependent on the balance between homogeneous and heterogeneous ice nucleation. Regional effects can reach several Wm2. Indirect effects are slightly larger for those states with less homogeneous nucleation and lower ice number concentration in the base state. The total ice AIE is estimated at 0.27 +/- 0.10 Wm(exp-2) (1 sigma uncertainty). This represents a 20% offset of the simulated total shortwave AIE for ice and liquid clouds of 1.6 Wm(sup-2).

  13. Extracellular ice phase transitions in insects.

    Science.gov (United States)

    Hawes, T C

    2014-01-01

    At temperatures below their temperature of crystallization (Tc), the extracellular body fluids of insects undergo a phase transition from liquid to solid. Insects that survive the transition to equilibrium (complete freezing of the body fluids) are designated as freeze tolerant. Although this phenomenon has been reported and described in many Insecta, current nomenclature and theory does not clearly delineate between the process of transition (freezing) and the final solid phase itself (the frozen state). Thus freeze tolerant insects are currently, by convention, described in terms of the temperature at which the crystallization of their body fluids is initiated, Tc. In fact, the correct descriptor for insects that tolerate freezing is the temperature of equilibrium freezing, Tef. The process of freezing is itself a separate physical event with unique physiological stresses that are associated with ice growth. Correspondingly there are a number of insects whose physiological cryo-limits are very specifically delineated by this transitional envelope. The distinction also has considerable significance for our understanding of insect cryobiology: firstly, because the ability to manage endogenous ice growth is a fundamental segregator of cryotype; and secondly, because our understanding of internal ice management is still largely nascent.

  14. Carbon Monoxide Exposure in Youth Ice Hockey.

    Science.gov (United States)

    Macnow, Theodore; Mannix, Rebekah; Meehan, William P

    2017-11-01

    To examine the effect of ice resurfacer type on carboxyhemoglobin levels in youth hockey players. We hypothesized that players in arenas with electric resurfacers would have normal, stable carboxyhemoglobin levels during games, whereas those in arenas with internal combustion engine (IC) resurfacers would have an increase in carboxyhemoglobin levels. Prospective cohort study. Enclosed ice arenas in the northeastern United States. Convenience sample of players aged 8 to 18 years old in 16 games at different arenas. Eight arenas (37 players) used an IC ice resurfacer and 8 arenas (36 players) an electric resurfacer. Carboxyhemoglobin levels (SpCO) were measured using a pulse CO-oximeter before and after the game. Arena air was tested for carbon monoxide (CO) using a metered gas detector. Players completed symptom questionnaires. The change in SpCO from pregame to postgame was compared between players at arenas with electric versus IC resurfacers. Carbon monoxide was present at 6 of 8 arenas using IC resurfacers, levels ranged from 4 to 42 parts per million. Carbon monoxide was not found at arenas with electric resurfacers. Players at arenas with IC resurfacers had higher median pregame SpCO levels compared with those at electric arenas (4.3% vs 1%, P carboxyhemoglobin during games and have elevated baseline carboxyhemoglobin levels compared with players at arenas with electric resurfacers. Electric resurfacers decrease the risk of CO exposure.

  15. Deglaciation of the Eurasian ice sheet complex

    Science.gov (United States)

    Patton, Henry; Hubbard, Alun; Andreassen, Karin; Auriac, Amandine; Whitehouse, Pippa L.; Stroeven, Arjen P.; Shackleton, Calvin; Winsborrow, Monica; Heyman, Jakob; Hall, Adrian M.

    2017-08-01

    The Eurasian ice sheet complex (EISC) was the third largest ice mass during the Last Glacial Maximum with a span of over 4500 km and responsible for around 20 m of eustatic sea-level lowering. Whilst recent terrestrial and marine empirical insights have improved understanding of the chronology, pattern and rates of retreat of this vast ice sheet, a concerted attempt to model the deglaciation of the EISC honouring these new constraints is conspicuously lacking. Here, we apply a first-order, thermomechanical ice sheet model, validated against a diverse suite of empirical data, to investigate the retreat of the EISC after 23 ka BP, directly extending the work of Patton et al. (2016) who modelled the build-up to its maximum extent. Retreat of the ice sheet complex was highly asynchronous, reflecting contrasting regional sensitivities to climate forcing, oceanic influence, and internal dynamics. Most rapid retreat was experienced across the Barents Sea sector after 17.8 ka BP when this marine-based ice sheet disintegrated at a rate of ∼670 gigatonnes per year (Gt a-1) through enhanced calving and interior dynamic thinning, driven by oceanic/atmospheric warming and exacerbated by eustatic sea-level rise. From 14.9 to 12.9 ka BP the EISC lost on average 750 Gt a-1, peaking at rates >3000 Gt a-1, roughly equally partitioned between surface melt and dynamic losses, and potentially contributing up to 2.5 m to global sea-level rise during Meltwater Pulse 1A. Independent glacio-isostatic modelling constrained by an extensive inventory of relative sea-level change corroborates our ice sheet loading history of the Barents Sea sector. Subglacial conditions were predominately temperate during deglaciation, with over 6000 subglacial lakes predicted along with an extensive subglacial drainage network. Moreover, the maximum EISC and its isostatic footprint had a profound impact on the proglacial hydrological network, forming the Fleuve Manche mega-catchment which had an area of

  16. Ford's E-450 H2ICE program

    International Nuclear Information System (INIS)

    Williams, R.

    2006-01-01

    In 4th quarter of 2006, Ford delivered the first Hydrogen powered Internal Combustion Engine (ICE) vehicles to customers. Ford is a leader in alternative fuels and engine strategies for future applications, and these vehicles serve as a bridge to Fuel Cell Vehicle acceptance and continued development of the hydrogen economy. This program also supports continued growth in hydrogen fueling infrastructure and vehicle hydrogen storage development. This presentation provided a program summary and discuss some of the lessons learned in dealing with placements of hydrogen powered vehicles. (author)

  17. Ice hockey injuries.

    Science.gov (United States)

    Benson, Brian W; Meeuwisse, Willem H

    2005-01-01

    This article reviews the distribution and determinants of injuries reported in the pediatric ice hockey literature, and suggests potential injury prevention strategies and directions for further research. Thirteen electronic databases, the ISI Web of Science, and 'grey literature' databases were searched using a combination of Medical Subject Headings and text words to identify potentially relevant articles. The bibliographies of selected studies were searched to identify additional articles. Studies were selected for review based on predetermined inclusion and exclusion criteria. A comparison between studies on this topic area was difficult due to the variability in research designs, definition of injury, study populations, and measurements used to assess injury. The majority of injuries were sustained during games compared with practices. The two most commonly reported injuries were sprains/strains and contusions. Players competing at the Minor hockey, High School, and Junior levels of competition sustained most of their injuries to the upper extremity, head, and lower extremity, respectively. The primary mechanism of injury was body checking, followed by stick and puck contact. The frequency of catastrophic eye injuries has been significantly reduced with the world-wide mandation of full facial protection for all Minor hockey players. Specific hockey-related injury risk factors are poorly delineated and rarely studied among pediatric ice hockey players leaving large gaps in the knowledge of appropriate prevention strategies. Risk management strategies should be focused at avoiding unnecessary foreseeable risk, and controlling the risks inherent to the sport. Suggestions for injury prevention and future research are discussed.

  18. The physics of ice cream

    Science.gov (United States)

    Clarke, Chris

    2003-05-01

    Almost everybody likes ice cream, so it can provide an excellent vehicle for discussing and demonstrating a variety of physical phenomena, such as Newton's law of cooling, Boyle's law and the relationship between microstructure and macroscopic properties (e.g. Young's modulus). Furthermore, a demonstration of freezing point depression can be used to make ice cream in the classroom!

  19. Snow, ice and solar radiation

    NARCIS (Netherlands)

    Kuipers Munneke, P.

    2009-01-01

    The snow-covered ice sheets of Antarctica and Greenland reflect most of the incoming solar radiation. The reflectivity, commonly called the albedo, of snow on these ice sheets has been observed to vary in space and time. In this thesis, temporal and spatial changes in snow albedo is found to depend

  20. Ice as a Construction Material

    Science.gov (United States)

    Zuppero, Anthony; Lewis, Joseph

    1998-01-01

    The use of ice as a construction material is discussed. A model of an ice tire torus space ship, which slowly spins to produce artificial gravity is proposed. The size of the ship, needed to support a given number of people and the required envelope mass is presented.

  1. A global, high-resolution data set of ice sheet topography, cavity geometry, and ocean bathymetry

    Science.gov (United States)

    Schaffer, Janin; Timmermann, Ralph; Arndt, Jan Erik; Savstrup Kristensen, Steen; Mayer, Christoph; Morlighem, Mathieu; Steinhage, Daniel

    2016-10-01

    The ocean plays an important role in modulating the mass balance of the polar ice sheets by interacting with the ice shelves in Antarctica and with the marine-terminating outlet glaciers in Greenland. Given that the flux of warm water onto the continental shelf and into the sub-ice cavities is steered by complex bathymetry, a detailed topography data set is an essential ingredient for models that address ice-ocean interaction. We followed the spirit of the global RTopo-1 data set and compiled consistent maps of global ocean bathymetry, upper and lower ice surface topographies, and global surface height on a spherical grid with now 30 arcsec grid spacing. For this new data set, called RTopo-2, we used the General Bathymetric Chart of the Oceans (GEBCO_2014) as the backbone and added the International Bathymetric Chart of the Arctic Ocean version 3 (IBCAOv3) and the International Bathymetric Chart of the Southern Ocean (IBCSO) version 1. While RTopo-1 primarily aimed at a good and consistent representation of the Antarctic ice sheet, ice shelves, and sub-ice cavities, RTopo-2 now also contains ice topographies of the Greenland ice sheet and outlet glaciers. In particular, we aimed at a good representation of the fjord and shelf bathymetry surrounding the Greenland continent. We modified data from earlier gridded products in the areas of Petermann Glacier, Hagen Bræ, and Sermilik Fjord, assuming that sub-ice and fjord bathymetries roughly follow plausible Last Glacial Maximum ice flow patterns. For the continental shelf off Northeast Greenland and the floating ice tongue of Nioghalvfjerdsfjorden Glacier at about 79° N, we incorporated a high-resolution digital bathymetry model considering original multibeam survey data for the region. Radar data for surface topographies of the floating ice tongues of Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm have been obtained from the data centres of Technical University of Denmark (DTU), Operation Icebridge (NASA

  2. Ice sheet hydrology from observations

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ-, Stockholm (Sweden)

    2010-11-15

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  3. Ice sheet hydrology from observations

    International Nuclear Information System (INIS)

    Jansson, Peter

    2010-11-01

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  4. L-band radiometry for sea ice applications

    Science.gov (United States)

    Heygster, G.; Hedricks, S.; Mills, P.; Kaleschke, L.; Stammer, D.; Tonboe, R.

    2009-04-01

    Although sea ice remote sensing has reached the level of operational exploitation with well established retrieval methods, several important tasks are still unsolved. In particular during freezing and melting periods with mixed ice and water surfaces, estimates of ice concentration with passive and active microwave sensors remain challenging. Newly formed thin ice is also hard to distinguish from open water with radiometers for frequencies above 8 GHz. The SMOS configuration (planned launch 2009) with a radiometer at 1.4 GHz is a promising technique to complement observations at higher microwave frequencies. ESA has initiated a project to investigate the possibilities for an additional Level-2 sea ice data product based on SMOS. In detail, the project objectives are (1) to model the L band emission of sea ice, and to assess the potential (2) to retrieve sea ice parameters, especially concentration and thickness, and (3) to use cold water regions for an external calibration of SMOS. Modelling of L band emission: Several models have are investigated. All of them work on the same basic principles and have a vertically-layered, plane-parallel geometry. They are comprised of three basic components: (1) effective permittivities are calculated for each layer based on ice bulk and micro-structural properties; (2) these are integrated across the total depth to derive emitted brightness temperature; (3) scattering terms can also be added because of the granular structure of ice and snow. MEMLS (Microwave Emission Model of Layered Snowpacks (Wiesmann and Matzler 1999)) is one such model that contains all three elements in a single Matlab program. In the absence of knowledge about the internal structure of the sea ice, three-layer (air, ice and water) dielectric slab models which take as input a single effective permittivity for the ice layer are appropriate. By ignoring scattering effects one can derive a simple analytic expression for a dielectric slab as shown by Apinis and

  5. Multiple climate and sea ice states on a coupled Aquaplanet

    Science.gov (United States)

    Rose, B.; Ferreira, D.; Marshall, J.

    2010-12-01

    A fully coupled atmosphere-ocean-sea ice GCM is used to explore the climates of Earth-like planets with no continents and idealized ocean basin geometries. We find three qualitatively different stable equilibria under identical external forcing: an equable ice-free climate, a cold climate with ice caps extending into mid-latitudes, and a completely ice-covered "Snowball" state. These multiple states persist for millennia with no drift despite a full seasonal cycle and vigorous internal variability of the system on all time scales. The behavior of the coupled system is rationalized through an extension of the Budyko-Sellers model to include explicit ocean heat transport (OHT), and the insulation of the ice-covered sea surface. Sensitivity tests are also conducted with a slab ocean GCM with prescribed OHT. From these we conclude that albedo feedback and ocean circulation both play essential roles in the maintenance of the multiple states. OHT in the coupled system is dominated by a wind-driven subtropical cell carrying between 2 and 3 PW of thermal energy out of the deep tropics, most of which converges in the subtropics to lower mid-latitudes. This convergence pattern (similar to modern Earth) is robust to changes in the ocean basin geometry, and is directly responsible for the stabilization of the large ice cap. OHT also plays an essential but indirect role in the maintenance of the ice-free pole in the warm states, by driving an enhanced poleward atmospheric latent heat flux. The hysteresis loop for transitions between the warm and large ice cap states spans a much smaller range of parameter space (e.g. ±1.8% variations in solar constant) than the transitions in and out of the Snowball. Three qualitatively different climate states for the same external forcing in a coupled GCM: ice-free, large ice cap, and Snowball. SST and sea ice thickness are plotted. Similar results are found in a pure Aquaplanet (lower) and a "RidgeWorld" with a global-scale ocean basin

  6. Advances in river ice hydrology 1999-2003

    Science.gov (United States)

    Morse, Brian; Hicks, Faye

    2005-01-01

    In the period 1999 to 2003, river ice has continued to have important socio-economic impacts in Canada and other Nordic countries. Concurrently, there have been many important advances in all areas of Canadian research into river ice engineering and hydrology. For example: (1) River ice processes were highlighted in two special journal issues (Canadian Journal of Civil Engineering in 2003 and Hydrological Processes in 2002) and at five conferences (Canadian Committee on River Ice Processes and the Environment in 1999, 2001 and 2003, and International Association of Hydraulic Research in 2000 and 2002). (2) A number of workers have clearly advanced our understanding of river ice processes by bringing together disparate information in comprehensive review articles. (3) There have been significant advances in river ice modelling. For example, both one-dimensional (e.g. RIVICE, RIVJAM, ICEJAM, HEC-RAS, etc.) and two-dimensional (2-D; www.river2d.ca) public-domain ice-jam models are now available. Work is ongoing to improve RIVER2D, and a commercial 2-D ice-process model is being developed. (4) The 1999-2003 period is notable for the number of distinctly hydrological and ecological studies. On the quantitative side, many are making efforts to determine streamflow during the winter period. On the ecological side, some new publications have addressed the link to water quality (temperature, dissolved oxygen, nutrients and pollutants), and others have dealt with sediment transport and geomorphology (particularly as it relates to break-up), stream ecology (plants, food cycle, etc.) and fish habitat.There is the growing recognition, that these types of study require collaborative efforts. In our view, the main areas requiring further work are: (1) to interface geomorphological and habitat models with quantitative river ice hydrodynamic models; (2) to develop a manager's toolbox (database management, remote sensing, forecasting, intervention methodologies, etc.) to enable

  7. The IceProd (IceCube Production) Framework

    International Nuclear Information System (INIS)

    Díaz-Vélez, J C

    2014-01-01

    IceProd is a data processing and management framework developed by the IceCube Neutrino Observatory for processing of Monte Carlo simulations and data. IceProd runs as a separate layer on top of middleware or cluster job schedulers and can take advantage of a variety of computing resources including grids such as EGI, OSG, and NorduGrid as well as local clusters running batch systems like HT Condor, PBS, and SGE. This is accomplished by a set of dedicated daemons which process job submission in a coordinated fashion through the use of middleware plug-ins that serve to abstract the details of job submission and job management. IceProd can also manage complex workflow DAGs across distributed computing grids in order to optimize usage of resources. We describe several aspects of IceProd's design and it's applications in collaborative computing environments. We also briefly discuss design aspects of a second generation IceProd, currently being tested in IceCube.

  8. Little Ice Age Fluctuations of Quelccaya Ice Cap, Peru

    Science.gov (United States)

    Stroup, J. S.; Kelly, M. A.; Lowell, T.

    2009-12-01

    A record of the past extents of Quelccaya Ice Cap (QIC) provides valuable information about tropical climate change from late glacial to recent time. Here, we examine the timing and regional significance of fluctuations of QIC during the Little Ice Age (LIA; ~1300-1850 AD). One prominent set of moraines, known as the Huancane I moraines, is located ~1 km from the present-day western ice cap margin and provides a near-continuous outline of the most recent advance of QIC. This moraine set was radiocarbon dated (~298 ± 134 and 831 ± 87 yr BP) by Mercer and Palacios (1977) and presented as some of the first evidence for cooling in the tropics during the Little Ice Age. Recent field investigations in the QIC region focused on refining the chronology of the Huancane I moraines. In 2008, new stratigraphic sections exposed by local lake-flooding events revealed multiple layers of peat within the Huancane I moraines. In both 2008 and 2009, samples were obtained for 10Be dating of boulders on Huancane I moraines. A combination of radiocarbon and 10Be ages indicate that the Huancane I moraines were deposited by ice cap expansion after ~3800 yr BP and likely by multiple advances at approximately 1000, 600, 400, and 200 yr BP. Radiocarbon and 10Be chronologies of the Huancane I moraines are compared with the Quelccaya ice core records (Thompson et al., 1985; 1986; 2006). Accumulation data from the ice core records are interpreted to indicate a significant wet period at ~1500-1700 AD followed by a significant drought at ~1720-1860 AD. We examine ice marginal fluctuations during these times to determine influence of such events on the ice cap extent.

  9. Arctic sea-ice ridges—Safe heavens for sea-ice fauna during periods of extreme ice melt?

    Science.gov (United States)

    Gradinger, Rolf; Bluhm, Bodil; Iken, Katrin

    2010-01-01

    The abundances and distribution of metazoan within-ice meiofauna (13 stations) and under-ice fauna (12 stations) were investigated in level sea ice and sea-ice ridges in the Chukchi/Beaufort Seas and Canada Basin in June/July 2005 using a combination of ice coring and SCUBA diving. Ice meiofauna abundance was estimated based on live counts in the bottom 30 cm of level sea ice based on triplicate ice core sampling at each location, and in individual ice chunks from ridges at four locations. Under-ice amphipods were counted in situ in replicate ( N=24-65 per station) 0.25 m 2 quadrats using SCUBA to a maximum water depth of 12 m. In level sea ice, the most abundant ice meiofauna groups were Turbellaria (46%), Nematoda (35%), and Harpacticoida (19%), with overall low abundances per station that ranged from 0.0 to 10.9 ind l -1 (median 0.8 ind l -1). In level ice, low ice algal pigment concentrations (Turbellaria, Nematoda and Harpacticoida also were observed in pressure ridges (0-200 ind l -1, median 40 ind l -1), although values were highly variable and only medians of Turbellaria were significantly higher in ridge ice than in level ice. Median abundances of under-ice amphipods at all ice types (level ice, various ice ridge structures) ranged from 8 to 114 ind m -2 per station and mainly consisted of Apherusa glacialis (87%), Onisimus spp. (7%) and Gammarus wilkitzkii (6%). Highest amphipod abundances were observed in pressure ridges at depths >3 m where abundances were up to 42-fold higher compared with level ice. We propose that the summer ice melt impacted meiofauna and under-ice amphipod abundance and distribution through (a) flushing, and (b) enhanced salinity stress at thinner level sea ice (less than 3 m thickness). We further suggest that pressure ridges, which extend into deeper, high-salinity water, become accumulation regions for ice meiofauna and under-ice amphipods in summer. Pressure ridges thus might be crucial for faunal survival during periods of

  10. Evaluating the Duration and Continuity of Potential Climate Records From the Allan Hills Blue Ice Area, East Antarctica

    Science.gov (United States)

    Kehrl, Laura; Conway, Howard; Holschuh, Nicholas; Campbell, Seth; Kurbatov, Andrei V.; Spaulding, Nicole E.

    2018-05-01

    The current ice core record extends back 800,000 years. Geologic and glaciological evidence suggests that the Allan Hills Blue Ice Area, East Antarctica, may preserve a continuous record that extends further back in time. In this study, we use ice-penetrating radar and existing age constraints to map the internal stratigraphy and age structure of the Allan Hills Main Ice Field. The dated isochrones provide constraints for an ice flow model to estimate the age of ice near the bed. Previous drilling in the region recovered stratigraphically disturbed sections of ice up to 2.7 million years old. Our study identifies a site 5 km upstream, which likely preserves a continuous record through Marine Isotope Stage 11 with the possibility that the record extends back 1 million years. Such records would provide new insight into the past climate and glacial history of the Ross Sea Sector.

  11. Employee quality, monitoring environment and internal control

    Directory of Open Access Journals (Sweden)

    Chunli Liu

    2017-03-01

    Full Text Available We investigate the effect of internal control employees (ICEs on internal control quality. Using special survey data from Chinese listed firms, we find that ICE quality has a significant positive influence on internal control quality. We examine the effect of monitoring on this result and find that the effect is more pronounced for firms with strict monitoring environments, especially when the firms implement the Chinese internal control regulation system (CSOX, have higher institutional ownership or attach greater importance to internal control. Our findings suggest that ICEs play an important role in the design and implementation of internal control systems. Our study should be of interest to both top managers who wish to improve corporate internal control quality and regulators who wish to understand the mechanisms of internal control monitoring.

  12. Documentation and analysis for packaging limited quantity ice chests

    International Nuclear Information System (INIS)

    Nguyen, P.M.

    1995-01-01

    The purpose of this Documentation and Analysis for Packaging (DAP) is to document that ice chests meet the intent of the International Air Transport Association (IATA) and the U.S. Department of Transportation (DOT) Code of Federal Regulations as strong, tight containers for the packaging of limited quantities for transport. This DAP also outlines the packaging method used to protect the sample bottles from breakage. Because the ice chests meet the DOT requirements, they can be used to ship LTD QTY on the Hanford Site

  13. City under the Ice

    DEFF Research Database (Denmark)

    Nielsen, Kristian Hvidtfelt

    : The public image of Camp Century was one of technological comfort and military-scientific control. Amidst the raging Cold War and up against the harsh environment, the construction of the camp would prove to the public that the combined forces of the US military-technology-science complex would prevail......This paper uses Paul Edwards’ closed world metaphor to understand US involvement in Greenland during the Cold War. Closed worlds mark military-techno-scientific geographies of conflict: They refer to sealed techno-spaces of observation, containment, and control, but also to the settings in which....... However, the military logic of Camp Century was self-referential and closed in the sense that the very idea of constructing the city under ice emerged from Cold War strategy. The closed world of Camp Century established a temporary boundary between, on the one hand, the comfortable space controlled by US...

  14. Ice-skating injuries.

    Science.gov (United States)

    Williamson, D M; Lowdon, I M

    1986-05-01

    The range of injuries sustained at an ice-rink and presented to an Accident Service department is described. A total of 203 patients with 222 injuries presented themselves during a 2-month period. There were 103 noteworthy injuries, including 61 fractures, 2 dislocations and 2 severed tendons, but the commonest injuries were wounds, sprains and bruises. Beginners appear to be more prone to injury than experienced skaters. In addition to using well-fitting skate-boots to protect the ankle, some injuries could be avoided by wearing elbow and knee pads, and a thick pair of gloves. The number of injuries compared with the total number of skaters was small but produced a noteworthy increase in the workload of the Accident Service.

  15. A model of the ice-d electron metal interface

    International Nuclear Information System (INIS)

    Painter, K.R.; Grout, P.J.; March, N.H.; Tosi, M.P.

    1981-10-01

    A qualitative explanation of the different orientations of the growth of ice on Pt (111) and Ag (111) surfaces is proposed. Other physical consequences which follow are discussed and experiments are suggested to test these. (author)

  16. VT Ice Damage Assessment from the 1998 Ice Storm

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This dataset (ICEDAMAG98) depicts the extent and severity of tree damage caused by the 1998 ice storm, which resulted in extensive tree damage in...

  17. Influence of winter sea-ice motion on summer ice cover in the Arctic

    Directory of Open Access Journals (Sweden)

    Noriaki Kimura

    2013-11-01

    Full Text Available Summer sea-ice cover in the Arctic varies largely from year to year owing to several factors. This study examines one such factor, the relationship between interannual difference in winter ice motion and ice area in the following summer. A daily-ice velocity product on a 37.5-km resolution grid is prepared using the satellite passive microwave sensor Advanced Microwave Scanning Radiometer—Earth Observing System data for the nine years of 2003–2011. Derived daily-ice motion reveals the dynamic modification of the winter ice cover. The winter ice divergence/convergence is strongly related to the summer ice cover in some regions; the correlation coefficient between the winter ice convergence and summer ice area ranges between 0.5 and 0.9 in areas with high interannual variability. This relation implies that the winter ice redistribution controls the spring ice thickness and the summer ice cover.

  18. The evolution of the western rift area of the Fimbul Ice Shelf, Antarctica

    Directory of Open Access Journals (Sweden)

    A. Humbert

    2011-10-01

    Full Text Available This paper studies the evolution of a zone in the Fimbul Ice Shelf that is characterised by large crevasses and rifts west of Jutulstraumen, an outlet glacier flowing into Fimbulisen. High-resolution radar imagery and radio echo sounding data were used to study the surface and internal structure of this rift area and to define zones of similar characteristics. The western rift area is dominated by two factors: a small ice rumple that leads to basal crevasses and disturbs the homogeneity of the ice, and a zone with fibre-like blocks. Downstream of the rumple we found down-welling of internal layers and local thinning, which we explain as a result of basal crevasses due to the basal drag at the ice rumple. North of Ahlmannryggen the ice loses its lateral constraint and forms individual blocks, which are deformed like fibres under shear, where the ice stream merges with slower moving ice masses of the western side. There, the ice loses its integrity, which initiates the western rift system. The velocity difference between the slow moving western part and the fast moving extension of Jutulstraumen produces shear stress that causes the rifts to form tails and expand them to the major rifts of up to 30 km length.

  19. EROTYPE IDENTIFICATION OF VIBRIO CHOLERAE BACTERIAWHICH ISOLATED FROM ICE AMONGTUBE AND CUBE ICE TYPE IN FOOD AND BEVERAGES SELLER AT DENPASAR CITY, BALI

    Directory of Open Access Journals (Sweden)

    IGP Dhinarananta

    2014-01-01

    Full Text Available Cholera is a type of watery diarrhea with specific sign stool containing mucus which resembles rice water. Cholera caused by gram negative bacteria Vibrio cholerae (V.Cholerae. The transmissions of bacteria were through a contaminated food or water.Bali is an international tourism destination with tropical weather where ice is widelyused in food and beverage which bring a risk of cholera through a contaminated ice.Iceshave a risk of bacterial contamination whether from the making and the usage process.Type of ice that widely used were cube and tube ice which each of them have a differentin making and usage process. The purpose of this study is to obtain the contamination ofV.cholera in cube and tube ice. The method of this study is descriptive observationalstudy with quota sampling technique. Sample were obtained from a restaurants andstreet vendor which use a block and tube ice with total 10 sample and 5 for each type ofice.Sample then cultured in Alkaline Peptone Water(APW and Thiosulfate Citrate Bilesalt Sucrose(TCBS agar. Bacteriacolony then identified using a gram staining andLatex Serotyping. The result are 3 over 5 (60% sample of cube ice contaminated byV.cholera O1 Inaba serotype and 3 over 5 (60% sample of tube ice contaminated byV.cholera O1 Inaba serotype.

  20. Intermittent ice sheet discharge events in northeastern North America during the last glacial period

    Energy Technology Data Exchange (ETDEWEB)

    Papa, Brian D.; Mysak, Lawrence A.; Wang, Zhaomin [McGill University, Earth System Modelling Group, Department of Atmospheric and Oceanic Sciences, Montreal, QC (Canada)

    2006-02-01

    The 3D ice sheet model of Marshall and Clarke, which includes both dynamics and thermodynamics, is used to successfully simulate millennial-scale oscillations within an ice sheet under steady external forcing. Such internal oscillations are theorized to be the main cause of quasi-periodic large-scale ice discharges known as Heinrich Events. An analysis of the mechanisms associated with multi-millennial oscillations of the Laurentide Ice Sheet, including the initiation and termination of sliding events, is performed. This analysis involves an examination of the various heat sources and sinks that affect the basal ice temperature, which in turn determines the nature of the ice sheet movement. The ice sheet thickness and surface slope, which affect the pressure-melting point and strain heating, respectively, are found to be critical for the formation and development of fast moving ice streams, which lead to large iceberg calving. Although the main provenance for Heinrich Events is thought to be from Hudson Bay and Hudson Strait, we show that the more northerly regions around Lancaster Strait and Baffin Island may also be important sources for ice discharges during the last glacial period. (orig.)

  1. 14 CFR 23.1419 - Ice protection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ice protection. 23.1419 Section 23.1419... Ice protection. If certification with ice protection provisions is desired, compliance with the... performed to establish, on the basis of the airplane's operational needs, the adequacy of the ice protection...

  2. Airframe Icing Research Gaps: NASA Perspective

    Science.gov (United States)

    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.

  3. Comparison of ATHENA/RELAP results against ice experimental data

    CERN Document Server

    Moore-Richard, L

    2002-01-01

    In order to demonstrate the adequacy of the International Thermonuclear Experimental Reactor design from a safety stand point as well as investigating the behavior of two-phase flow phenomena during an ingress of coolant event, an integrated ICE test facility was constructed in Japan. The data generated from the ICE facility offers a valuable means to validate computer codes such as ATHENA /RELAP5, which is one of the codes used at the Idaho National Engineering And Environmental Laboratory (INEEL) to evaluate the safety of various fusion reactor concepts. In this paper we compared numerical results generated by the ATHENA code with corresponding test data from the ICE facility. Overall we found good agreement between the test data and the predicted results.

  4. Structural integrity investigations of feeder pipe ice plugging procedures

    International Nuclear Information System (INIS)

    Flaman, M.T.; Shah, N.N.

    1985-03-01

    A procedure involving the use of a liquid nitrogen cooled heat exchanger to form internal ice plugs in feeder pipes is routinely used in nuclear generating stations. The use of this procedure has caused concerns with regard to the safety of station maintenance personnel, and in regard to the integrity of the feeder pipes. This report describes the results of laboratory stress and pressure measurements which were performed on a feeder pipe section during ice plugging operations to investigate these concerns. From the results of this study, and from the results of previous studies of material behaviour at low temperatures, it has been determined that the ice plugging procedure can be performed on feeder pipes in a safe and effective manner

  5. Crevasse-squeeze ridge corridors: Diagnostic features of late-stage palaeo-ice stream activity

    Science.gov (United States)

    Evans, David J. A.; Storrar, Robert D.; Rea, Brice R.

    2016-04-01

    A 200-km-long and 10-km-wide linear assemblage of till-filled geometrical ridges on the bed of the Maskwa palaeo-ice stream of the late Wisconsinan southwest Laurentide Ice Sheet are interpreted as crevasse-squeeze ridges (CSR) developed during internal flow unit reorganization, immediately prior to ice stream shutdown. Ridge orientations are predominantly orientated WNW-ESE, with a subordinate WSW-ENE alignment, both indicative of ice fracture development transverse to former ice stream flow, as indicated by NNE-SSW aligned MSGL. Subglacial till injection into basal and/or full depth, mode I and II crevasses occurred at the approximate centreline of the ice stream, in response to extension and fracturing. Landform preservation indicates that this took place during the final stages of ice streaming, immediately prior to ice stream shutdown. This linear zone of ice fracturing therefore likely represents the narrowing of the fast-flowing trunk, similar to the plug flow identified in some surging valley glaciers. Lateral drag between the final active flow unit and the slower moving ice on either side is likely recorded by the up-ice bending of the CSR limbs. The resulting CSR corridor, here related to an individual ice stream flow unit, constitutes a previously unreported style of crevasse infilling and contrasts with two existing CSR patterns: (1) wide arcuate zones of CSRs related to widespread fracturing within glacier surge lobes; and (2) narrow concentric arcs of CSRs and recessional push moraines related to submarginal till deformation at active temperate glacier lobes.

  6. Dynamics of the ice mass in Antarctica in the time of warming

    Directory of Open Access Journals (Sweden)

    V. M. Kotlyakov

    2017-01-01

    Full Text Available The modern age of global warming affect the general state of the Antarctic ice sheet and its mass balance. Studies of the Southern polar region of the Earth during the International Geophysical Year  (1957–1958 called the assumption of growth in the modern ice mass in East Antarctica. However, with the development of new methods, this conclusion has been questioned. At the turn of the century the study of global processes Earth started to use the satellite radar or laser altimetry and satellite gravimetry, which allows determining change of different masses on the Earth, including ice bodies. From the beginning of the XXI century, these methods have been used to calculate the continental ice balance. In our study, we analyze different data of recent years, supporting the earlier conclusion on continued growth of the ice mass in East Antarctica. How‑ ever, in West Antarctica and the Antarctic Peninsula, on the contrary, there is increased loss of ice, leveling the increased income of ice mass of in the Central Antarctica. So all in all in the modern era of global warm‑ ing, the ice mass in Antarctica appears to be decreasing despite some growth of the East Antarctic ice sheet. Fluctuations of land ice mass reflect in the sea level variations, but in comparison with the scale of the Ant‑ arctic ice sheet its contribution to sea‑level rise is not so significant. The main reason for this is that the mass accumulation in East Antarctica with significant probability prevails over the ice outflow.

  7. Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover and fast ice decay

    Directory of Open Access Journals (Sweden)

    P. Itkin

    2017-10-01

    Full Text Available Ice retreat in the eastern Eurasian Arctic is a consequence of atmospheric and oceanic processes and regional feedback mechanisms acting on the ice cover, both in winter and summer. A correct representation of these processes in numerical models is important, since it will improve predictions of sea ice anomalies along the Northeast Passage and beyond. In this study, we highlight the importance of winter ice dynamics for local summer sea ice anomalies in thickness, volume and extent. By means of airborne sea ice thickness surveys made over pack ice areas in the south-eastern Laptev Sea, we show that years of offshore-directed sea ice transport have a thinning effect on the late-winter sea ice cover. To confirm the preconditioning effect of enhanced offshore advection in late winter on the summer sea ice cover, we perform a sensitivity study using a numerical model. Results verify that the preconditioning effect plays a bigger role for the regional ice extent. Furthermore, they indicate an increase in volume export from the Laptev Sea as a consequence of enhanced offshore advection, which has far-reaching consequences for the entire Arctic sea ice mass balance. Moreover we show that ice dynamics in winter not only preconditions local summer ice extent, but also accelerate fast-ice decay.

  8. Loss of sea ice in the Arctic.

    Science.gov (United States)

    Perovich, Donald K; Richter-Menge, Jacqueline A

    2009-01-01

    The Arctic sea ice cover is in decline. The areal extent of the ice cover has been decreasing for the past few decades at an accelerating rate. Evidence also points to a decrease in sea ice thickness and a reduction in the amount of thicker perennial sea ice. A general global warming trend has made the ice cover more vulnerable to natural fluctuations in atmospheric and oceanic forcing. The observed reduction in Arctic sea ice is a consequence of both thermodynamic and dynamic processes, including such factors as preconditioning of the ice cover, overall warming trends, changes in cloud coverage, shifts in atmospheric circulation patterns, increased export of older ice out of the Arctic, advection of ocean heat from the Pacific and North Atlantic, enhanced solar heating of the ocean, and the ice-albedo feedback. The diminishing Arctic sea ice is creating social, political, economic, and ecological challenges.

  9. Charge Transfer Scheme for Atmospheric Ice Sensing

    Directory of Open Access Journals (Sweden)

    Umair Najeeb MUGHAL

    2015-01-01

    Full Text Available The atmospheric icing parameters are being measured nowadays with the aid of more customized yet limited commercial equipment. The parameters include atmospheric ice detection, icing load and icing rate. The robustness of such equipment is usually under scrutiny when it comes to cold/harsh environment operations. This phenomenon was experienced consistently by the atmospheric Icing Research Team at Narvik University College during data retrieval exercises from its atmospheric icing stations installed at Fargnesfjellet during 2012-13. In this paper it is aimed to address the potential feasibility to produce a robust hardware addressing the icing measurements signals, which includes instrumentation hardware giving icing indications, icing type and de- icing rate measurements in a single platform (not commercially available till date.

  10. Evaluation of the limit ice thickness for the hull of various Finnish-Swedish ice class vessels navigating in the Russian Arctic

    OpenAIRE

    Pentti Kujala; Mihkel Kõrgesaar; Jorma Kämäräinen

    2018-01-01

    Selection of suitable ice class for ships operation is an important but not simple task. The increased exploitation of the Polar waters, both seasonal periods and geographical areas, as well as the introduction of new international design standards such as Polar Code, reduces the relevancy of using existing experience as basis for the selection, and new methods and knowledge have to be developed. This paper will analyse what can be the limiting ice thickness for ships navigating in the Russia...

  11. Greenland Ice Sheet Mass Balance

    Science.gov (United States)

    Reeh, N.

    1984-01-01

    Mass balance equation for glaciers; areal distribution and ice volumes; estimates of actual mass balance; loss by calving of icebergs; hydrological budget for Greenland; and temporal variations of Greenland mass balance are examined.

  12. Sticking properties of ice grains

    Directory of Open Access Journals (Sweden)

    Jongmanns M.

    2017-01-01

    Full Text Available We study the size dependence of pull-off forces of water ice in laboratory experiments and numerical simulations. To determine the pull-off force in our laboratory experiments, we use a liquid nitrogen cooled centrifuge. Depending on its rotation frequency, spherical ice grains detach due to the centrifugal force which is related to the adhesive properties. Numerical simulations are conducted by means of molecular dynamics simulations of hexagonal ice using a standard coarse-grained water potential. The pull-off force of a single contact between two spherical ice grains is measured due to strain controlled simulations. Both, the experimental study and the simulations reveal a dependence between the pull-off force and the (reduced particle radii, which differ significantly from the linear dependence of common contact theories.

  13. Sticking properties of ice grains

    Science.gov (United States)

    Jongmanns, M.; Kumm, M.; Wurm, G.; Wolf, D. E.; Teiser, J.

    2017-06-01

    We study the size dependence of pull-off forces of water ice in laboratory experiments and numerical simulations. To determine the pull-off force in our laboratory experiments, we use a liquid nitrogen cooled centrifuge. Depending on its rotation frequency, spherical ice grains detach due to the centrifugal force which is related to the adhesive properties. Numerical simulations are conducted by means of molecular dynamics simulations of hexagonal ice using a standard coarse-grained water potential. The pull-off force of a single contact between two spherical ice grains is measured due to strain controlled simulations. Both, the experimental study and the simulations reveal a dependence between the pull-off force and the (reduced) particle radii, which differ significantly from the linear dependence of common contact theories.

  14. Radiative properties of ice clouds

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, D.L.; Koracin, D.; Carter, E. [Desert Research Institute, Reno, NV (United States)

    1996-04-01

    A new treatment of cirrus cloud radiative properties has been developed, based on anomalous diffraction theory (ADT), which does not parameterize size distributions in terms of an effective radius. Rather, is uses the size distribution parameters directly, and explicitly considers the ice particle shapes. There are three fundamental features which characterize this treatment: (1) the ice path radiation experiences as it travels through an ice crystal is parameterized, (2) only determines the amount of radiation scattered and absorbed, and (3) as in other treatments, the projected area of the size distribution is conserved. The first two features are unique to this treatment, since it does not convert the ice particles into equivalent volume or area spheres in order to apply Mie theory.

  15. Microfabricated Ice-Detection Sensor

    National Research Council Canada - National Science Library

    DeAnna, Russell

    1997-01-01

    .... The sensor is capable of distinguishing between an ice covered and a clean surface. It employs a bulk micromachined wafer with a 7 micrometers thick, boron doped, silicon diaphragm which serves as one plate of a parallel plate capacitor...

  16. 2006 Program of Study: Ice

    National Research Council Canada - National Science Library

    Balmforth, Neil J; Wettlaufer, John S; Worster, Grae

    2007-01-01

    .... Towards the end of Grae's lectures, we also held the 2006 GFD Public Lecture. This was given by Greg Dash of the University of Washington, on matters of ice physics and a well known popularization...

  17. Let's Make Metric Ice Cream

    Science.gov (United States)

    Zimmerman, Marianna

    1975-01-01

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

  18. Geophysical Investigations of Habitability in Ice-Covered Ocean Worlds

    Science.gov (United States)

    Vance, Steven D.; Panning, Mark P.; Stähler, Simon; Cammarano, Fabio; Bills, Bruce G.; Tobie, Gabriel; Kamata, Shunichi; Kedar, Sharon; Sotin, Christophe; Pike, William T.; Lorenz, Ralph; Huang, Hsin-Hua; Jackson, Jennifer M.; Banerdt, Bruce

    2018-01-01

    Geophysical measurements can reveal the structures and thermal states of icy ocean worlds. The interior density, temperature, sound speed, and electrical conductivity thus characterize their habitability. We explore the variability and correlation of these parameters using 1-D internal structure models. We invoke thermodynamic consistency using available thermodynamics of aqueous MgSO4, NaCl (as seawater), and NH3; pure water ice phases I, II, III, V, and VI; silicates; and any metallic core that may be present. Model results suggest, for Europa, that combinations of geophysical parameters might be used to distinguish an oxidized ocean dominated by MgSO4 from a more reduced ocean dominated by NaCl. In contrast with Jupiter's icy ocean moons, Titan and Enceladus have low-density rocky interiors, with minimal or no metallic core. The low-density rocky core of Enceladus may comprise hydrated minerals or anhydrous minerals with high porosity. Cassini gravity data for Titan indicate a high tidal potential Love number (k2>0.6), which requires a dense internal ocean (ρocean>1,200 kg m-3) and icy lithosphere thinner than 100 km. In that case, Titan may have little or no high-pressure ice, or a surprisingly deep water-rock interface more than 500 km below the surface, covered only by ice VI. Ganymede's water-rock interface is the deepest among known ocean worlds, at around 800 km. Its ocean may contain multiple phases of high-pressure ice, which will become buoyant if the ocean is sufficiently salty. Callisto's interior structure may be intermediate to those of Titan and Europa, with a water-rock interface 250 km below the surface covered by ice V but not ice VI.

  19. Autonomous Sea-Ice Thickness Survey

    Science.gov (United States)

    2016-06-01

    the conductivity of an infinitely thick slab of sea ice. Ice thickness, Hice, is then obtained by subtracting the height of the ...Thickness Survey of Sea Ice Runway” ERDC/CRREL SR-16-4 ii Abstract We conducted an autonomous survey of sea -ice thickness using the Polar rover Yeti...efficiency relative to manual surveys routinely con- ducted to assess the safety of roads and runways constructed on the sea ice. Yeti executed the

  20. Multiscale Models of Melting Arctic Sea Ice

    Science.gov (United States)

    2014-09-30

    Sea ice reflectance or albedo , a key parameter in climate modeling, is primarily determined by melt pond and ice floe configurations. Ice - albedo ...determine their albedo - a key parameter in climate modeling. Here we explore the possibility of a conceptual sea ice climate model passing through a...bifurcation points. Ising model for melt ponds on Arctic sea ice Y. Ma, I. Sudakov, and K. M. Golden Abstract: The albedo of melting

  1. International Coordination of Lunar Polar Volatiles Exploration

    Science.gov (United States)

    Gruener, J. E.; Suzuki, N. H.; Carpenter, J. D.

    2015-10-01

    The International Space Exploration Coordination Group (ISECG) has established a study team to coordinate the worldwide interest in lunar polar volatiles, and in particular water ice, in an effort to stimulate cooperation and collaboration.

  2. Ice sheet hydrology - a review

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter; Naeslund, Jens-Ove [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden); Rodhe, Lars [Geological Survey of Sweden, Uppsala (Sweden)

    2007-03-15

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  3. Ice sheet hydrology - a review

    International Nuclear Information System (INIS)

    Jansson, Peter; Naeslund, Jens-Ove; Rodhe, Lars

    2007-03-01

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  4. Endmembers of Ice Shelf Melt

    Science.gov (United States)

    Boghosian, A.; Child, S. F.; Kingslake, J.; Tedesco, M.; Bell, R. E.; Alexandrov, O.; McMichael, S.

    2017-12-01

    Studies of surface melt on ice shelves have defined a spectrum of meltwater behavior. On one end the storage of meltwater in persistent surface ponds can trigger ice shelf collapse as in the 2002 event leading to the disintegration of the Larsen B Ice Shelf. On the other, meltwater export by rivers can stabilize an ice shelf as was recently shown on the Nansen Ice Shelf. We explore this dichotomy by quantifying the partitioning between stored and transported water on two glaciers adjacent to floating ice shelves, Nimrod (Antarctica) and Peterman (Greenland). We analyze optical satellite imagery (LANDSAT, WorldView), airborne imagery (Operation IceBridge, Trimetrogon Aerial Phototography), satellite radar (Sentinel-1), and digital elevation models (DEMs) to categorize surface meltwater fate and map the evolution of ice shelf hydrology and topographic features through time. On the floating Peterman Glacier tongue a sizable river exports water to the ocean. The surface hydrology of Nimrod Glacier, geometrically similar to Peterman but with ten times shallower surface slope, is dominated by storage in surface lakes. In contrast, the Nansen has the same surface slope as Nimrod but transports water through surface rivers. Slope alone is not the sole control on ice shelf hydrology. It is essential to track the storage and transport volumes for each of these systems. To estimate water storage and transport we analyze high resolution (40 cm - 2 m) modern and historical DEMs. We produce historical (1957 onwards) DEMs with structure-from-motion photogrammetry. The DEMs are used to constrain water storage potential estimates of observed basins and water routing/transport potential. We quantify the total volume of water stored seasonally and interannually. We use the normalize difference water index to map meltwater extent, and estimate lake water depth from optical data. We also consider the role of stored water in subsurface aquifers in recharging surface water after

  5. Assessing concentration uncertainty estimates from passive microwave sea ice products

    Science.gov (United States)

    Meier, W.; Brucker, L.; Miller, J. A.

    2017-12-01

    Sea ice concentration is an essential climate variable and passive microwave derived estimates of concentration are one of the longest satellite-derived climate records. However, until recently uncertainty estimates were not provided. Numerous validation studies provided insight into general error characteristics, but the studies have found that concentration error varied greatly depending on sea ice conditions. Thus, an uncertainty estimate from each observation is desired, particularly for initialization, assimilation, and validation of models. Here we investigate three sea ice products that include an uncertainty for each concentration estimate: the NASA Team 2 algorithm product, the EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI-SAF) product, and the NOAA/NSIDC Climate Data Record (CDR) product. Each product estimates uncertainty with a completely different approach. The NASA Team 2 product derives uncertainty internally from the algorithm method itself. The OSI-SAF uses atmospheric reanalysis fields and a radiative transfer model. The CDR uses spatial variability from two algorithms. Each approach has merits and limitations. Here we evaluate the uncertainty estimates by comparing the passive microwave concentration products with fields derived from the NOAA VIIRS sensor. The results show that the relationship between the product uncertainty estimates and the concentration error (relative to VIIRS) is complex. This may be due to the sea ice conditions, the uncertainty methods, as well as the spatial and temporal variability of the passive microwave and VIIRS products.

  6. Volcanic Eruptions as the Cause of the Little Ice Age

    Science.gov (United States)

    Zambri, B.; Robock, A.

    2017-12-01

    Both external forcing (solar radiation, volcanic eruptions) and internal fluctuations have been proposed to explain such multi-centennial perturbations as the Little Ice Age. Confidence in these hypotheses is limited due to the limited number of proxies, as well as only one observed realization of the Last Millennium. Here, we evaluate different hypotheses on the origin of Little Ice Age-like anomalies, focusing in particular on the long-term response of North Atlantic and Arctic climate perturbations to solar and volcanic perturbations. For that, we conduct a range of sensitivity tests carried out with the Community Earth System Model (CESM) at the National Center for Atmospheric Research, focusing in particular on the sensitivity to initial conditions and the strength of solar and volcanic forcing. By comparing the climate response to various combinations of external perturbations, we demonstrate nonlinear interactions that are necessary to explain trends observed in the fully coupled system and discuss physical mechanisms through which these external forcings can trigger multidecadal modes of the Atlantic Multidecadal Oscillation and subsequently lead to a Little-Ice-Age-like regime. For that, we capture and compare patterns of the coupled atmosphere-sea-ice-ocean response as revealed through a range of data analysis techniques. We show that the large 1257 Samalas, 1452 Kuwae, and 1600 Huaynaputina volcanic eruptions were the main causes of the multi-centennial glaciation associated with the Little Ice Age.

  7. Atmospheric Icing on Sea Structures,

    Science.gov (United States)

    1984-04-01

    results. ESTIMATION OF ICING INTENSITY Freezing process When supercooled water drops fall or move with wind, hit a structure, and freeze, the...a collision with another drop- let, with the ground, or with a structure. When a supercooled droplet hits a solid obstacle, it spreads and turns to...accretion is likely. The meteorological conditions that prevail during ship icing have been studied widely (Shektman 1968, Tabata 1968, Borisenkov and

  8. STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

    Directory of Open Access Journals (Sweden)

    Yurij K. Vasil’chuk

    2016-01-01

    Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

  9. NASA Iced Aerodynamics and Controls Current Research

    Science.gov (United States)

    Addy, Gene

    2009-01-01

    This slide presentation reviews the state of current research in the area of aerodynamics and aircraft control with ice conditions by the Aviation Safety Program, part of the Integrated Resilient Aircraft Controls Project (IRAC). Included in the presentation is a overview of the modeling efforts. The objective of the modeling is to develop experimental and computational methods to model and predict aircraft response during adverse flight conditions, including icing. The Aircraft icing modeling efforts includes the Ice-Contaminated Aerodynamics Modeling, which examines the effects of ice contamination on aircraft aerodynamics, and CFD modeling of ice-contaminated aircraft aerodynamics, and Advanced Ice Accretion Process Modeling which examines the physics of ice accretion, and works on computational modeling of ice accretions. The IRAC testbed, a Generic Transport Model (GTM) and its use in the investigation of the effects of icing on its aerodynamics is also reviewed. This has led to a more thorough understanding and models, both theoretical and empirical of icing physics and ice accretion for airframes, advanced 3D ice accretion prediction codes, CFD methods for iced aerodynamics and better understanding of aircraft iced aerodynamics and its effects on control surface effectiveness.

  10. Canadian Ice Service Arctic Regional Sea Ice Charts in SIGRID-3 Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Canadian Ice Service (CIS) produces digital Arctic regional sea ice charts for marine navigation, climate research, and input to the Global Digital Sea Ice Data...

  11. Momentum Exchange Near Ice Keels in the Under Ice Ocean Boundary Layer

    National Research Council Canada - National Science Library

    Bleidorn, John C

    2008-01-01

    .... Understanding ice-ocean momentum exchange is important for accurate predictive ice modeling. Due to climate change, increased naval presence in the Arctic region is anticipated and ice models will become necessary for tactical and safety reasons...

  12. Meteorites, Ice, and Antarctica

    Science.gov (United States)

    Cassidy, William A.

    2003-08-01

    Bill Cassidy led meteorite recovery expeditions in the Antarctic for fifteen years and his searches have resulted in the collection of thousands of meteorite specimens from the ice. This personal account of his field experiences on the U.S. Antarctic Search for Meteorites Project reveals the influence the work has had on our understanding of the moon, Mars and the asteroid belt. Cassidy describes the hardships and dangers of fieldwork in a hostile environment, as well as the appreciation he developed for its beauty. William Cassidy is Emeritus Professor of Geology and Planetary Science at the University of Pittsburgh. He initiated the U.S. Antarctic Search for Meteorites (ANSMET) nroject and led meteorite recovery expeditions in Antarctica in1976. His name is found attached to a mineral (cassidyite), on the map of Antarctica (Cassidy Glacier), and in the Catalog of Asteroids (3382 Cassidy). Profiled in "American Men of Science," and "Who's Who in America," he is also a recipient of The Antarctic Service Medal from the United States and has published widely in Science, Meteoritics and Planetary Science, and The Journal of Geophysical Research.

  13. Fire in the ice

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, Graham

    2011-10-15

    Research is ongoing to investigate the feasibility of unlocking about 85 trillion cubic feet of pure methane gas from hydrates on Alaska's North Slope while sequestering CO2 to combat global warming. When the well reaches a depth of 2,597 feet, the wireline well logs will be registered. The well site was chosen for its multiplicity of test horizons, that is, varying porosity sandstones. The CO2 injection scheme should be tested before the hydrate experiment is carried out. Lab tests and numerical modeling developed by ConocoPhillips and the University of Bergen have demonstrated the feasibility of exchanging CH4 (methane) for CO2 in porous and permeable sandstone reservoirs. However, the challenge is that that field situation is more complex than a lab test. So a new, smaller ice pad around the well is planne, starting with a nitrogen and CO2 mix injection and adjusting the mix as the experiment progresses. Canada did not participate in this test project, because it is difficult to scale up from idealized lab-scale studies and theoretical modeling to the field scale. The U.S Gulf of Mexico also has important gas hydrates reserves which may be less expensive to research and operate.

  14. Acquisition of Ice Thickness and Ice Surface Characteristics in the Seasonal Ice Zone by CULPIS-X during the US Coast Guard’s Arctic Domain Awareness Program

    Science.gov (United States)

    2014-09-30

    OBJECTIVES • What is the volume of sea ice in the Beaufort Sea Seasonal Ice Zone (SIZ) and how does this evolve during summer as the ice edge...retreats? Recent observations suggest that the remaining ice in the Beaufort Sea is younger and thinner in recent years in part because even the oldest...surrounding ice . Recent analyses have indicated that ponds on thinner ice are often darker, accelerating the ice - albedo feedback over thin ice in summer

  15. Auroral spectrograph data annals of the international geophysical year, v.25

    CERN Document Server

    Carrigan, Anne; Norman, S J

    1964-01-01

    Annals of the International Geophysical Year, Volume 25: Auroral Spectrograph Data is a five-chapter text that contains tabulations of auroral spectrograph data. The patrol spectrograph built by the Perkin-Elmer Corporation for the Aurora and Airglow Program of the IGY is a high-speed, low-dispersion, automatic instrument designed to photograph spectra of aurora occurring along a given magnetic meridian of the sky. Data from each spectral frame were recorded on an IBM punched card. The data recorded on the cards are printed onto the tabulations in this volume. These tabulations are available

  16. Mixed ice accretion on aircraft wings

    Science.gov (United States)

    Janjua, Zaid A.; Turnbull, Barbara; Hibberd, Stephen; Choi, Kwing-So

    2018-02-01

    Ice accretion is a problematic natural phenomenon that affects a wide range of engineering applications including power cables, radio masts, and wind turbines. Accretion on aircraft wings occurs when supercooled water droplets freeze instantaneously on impact to form rime ice or runback as water along the wing to form glaze ice. Most models to date have ignored the accretion of mixed ice, which is a combination of rime and glaze. A parameter we term the "freezing fraction" is defined as the fraction of a supercooled droplet that freezes on impact with the top surface of the accretion ice to explore the concept of mixed ice accretion. Additionally we consider different "packing densities" of rime ice, mimicking the different bulk rime densities observed in nature. Ice accretion is considered in four stages: rime, primary mixed, secondary mixed, and glaze ice. Predictions match with existing models and experimental data in the limiting rime and glaze cases. The mixed ice formulation however provides additional insight into the composition of the overall ice structure, which ultimately influences adhesion and ice thickness, and shows that for similar atmospheric parameter ranges, this simple mixed ice description leads to very different accretion rates. A simple one-dimensional energy balance was solved to show how this freezing fraction parameter increases with decrease in atmospheric temperature, with lower freezing fraction promoting glaze ice accretion.

  17. Ice nucleation activity of polysaccharides

    Science.gov (United States)

    Bichler, Magdalena; Felgitsch, Laura; Haeusler, Thomas; Seidl-Seiboth, Verena; Grothe, Hinrich

    2015-04-01

    Heterogeneous ice nucleation is an important process in the atmosphere. It shows direct impact on our climate by triggering ice cloud formation and therefore it has much influence on the radiation balance of our planet (Lohmann et al. 2002; Mishchenko et al. 1996). The process itself is not completely understood so far and many questions remain open. Different substances have been found to exhibit ice nucleation activity (INA). Due to their vast differences in chemistry and morphology it is difficult to predict what substance will make good ice nuclei and which will not. Hence simple model substances must be found and be tested regarding INA. Our work aims at gaining to a deeper understanding of heterogeneous ice nucleation. We intend to find some reference standards with defined chemistry, which may explain the mechanisms of heterogeneous ice nucleation. A particular focus lies on biological carbohydrates in regards to their INA. Biological carbohydrates are widely distributed in all kingdoms of life. Mostly they are specific for certain organisms and have well defined purposes, e.g. structural polysaccharides like chitin (in fungi and insects) and pectin (in plants), which has also water-binding properties. Since they are widely distributed throughout our biosphere and mostly safe to use for nutrition purposes, they are well studied and easily accessible, rendering them ideal candidates as proxies. In our experiments we examined various carbohydrates, like the already mentioned chitin and pectin, as well as their chemical modifications. Lohmann U.; A Glaciation Indirect Aerosol Effect Caused by Soot Aerosols; J. Geoph. Res.; Vol. 24 No.4; pp 11-1 - 11-4; 2002 Mishchenko M.I., Rossow W.B., Macke A., Lacis A. A.; Sensitivity of Cirrus Cloud Albedo, Bidirectional Reflectance and Optical Thickness Retrieval Accuracy to Ice Particle Shape, J. Geoph. Res.; Vol. 101, No D12; pp. 16,973 - 16,985; 1996

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

    Science.gov (United States)

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

    2014-12-01

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

  19. Sensitivity of open-water ice growth and ice concentration evolution in a coupled atmosphere-ocean-sea ice model

    Science.gov (United States)

    Shi, Xiaoxu; Lohmann, Gerrit

    2017-09-01

    A coupled atmosphere-ocean-sea ice model is applied to investigate to what degree the area-thickness distribution of new ice formed in open water affects the ice and ocean properties. Two sensitivity experiments are performed which modify the horizontal-to-vertical aspect ratio of open-water ice growth. The resulting changes in the Arctic sea-ice concentration strongly affect the surface albedo, the ocean heat release to the atmosphere, and the sea-ice production. The changes are further amplified through a positive feedback mechanism among the Arctic sea ice, the Atlantic Meridional Overturning Circulation (AMOC), and the surface air temperature in the Arctic, as the Fram Strait sea ice import influences the freshwater budget in the North Atlantic Ocean. Anomalies in sea-ice transport lead to changes in sea surface properties of the North Atlantic and the strength of AMOC. For the Southern Ocean, the most pronounced change is a warming along the Antarctic Circumpolar Current (ACC), owing to the interhemispheric bipolar seasaw linked to AMOC weakening. Another insight of this study lies on the improvement of our climate model. The ocean component FESOM is a newly developed ocean-sea ice model with an unstructured mesh and multi-resolution. We find that the subpolar sea-ice boundary in the Northern Hemisphere can be improved by tuning the process of open-water ice growth, which strongly influences the sea ice concentration in the marginal ice zone, the North Atlantic circulation, salinity and Arctic sea ice volume. Since the distribution of new ice on open water relies on many uncertain parameters and the knowledge of the detailed processes is currently too crude, it is a challenge to implement the processes realistically into models. Based on our sensitivity experiments, we conclude a pronounced uncertainty related to open-water sea ice growth which could significantly affect the climate system sensitivity.

  20. Ice-condenser aerosol tests

    International Nuclear Information System (INIS)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K.

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between ∼0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m 3 /s resulted in stable thermal stratification whereas flows less than 0.1 m 3 /s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs

  1. ICeE an interface for C. elegans experiments.

    Science.gov (United States)

    Montañana, Frédéric; Julien, Renaud A; Vaglio, Philippe; Matthews, Lisa R; Tichit, Laurent; Ewbank, Jonathan J

    2014-01-01

    An increasing number of laboratories are using the COPAS Biosort™ to implement high-throughput approaches to tackle diverse biological problems. While providing a powerful tool for generating quantitative data, the utility of the Biosort is currently limited by the absence of resources for data management. We describe a simple electronic database designed to allow easy storage and retrieval of Biosort data for C. elegans, but that has a wide potential application for organizing electronic files and data sets. ICeE is an Open Source application. The code and accompanying documentation are freely available via the web at http://www.ciml.univ-mrs.fr/EWBANK_jonathan/software.html.

  2. Participation of Women in the International Conferences on Education, 1934-2001

    Science.gov (United States)

    Cortez, David Sifuentes

    2004-01-01

    This article examines the participation of women in decision-making processes in the field of education, from a global perspective, through their roles and positions in International Conferences on Education (ICEs). This analysis is based on a sample of sixteen of the forty-six ICEs held from 1934 to this day. All of the ICEs that took place over…

  3. Open-Source Python Modules to Estimate Level Ice Thickness from Ice Charts

    Science.gov (United States)

    Geiger, C. A.; Deliberty, T. L.; Bernstein, E. R.; Helfrich, S.

    2012-12-01

    A collaborative research effort between the University of Delaware (UD) and National Ice Center (NIC) addresses the task of providing open-source translations of sea ice stage-of-development into level ice thickness estimates on a 4km grid for the Interactive Multisensor Snow and Ice Mapping System (IMS). The characteristics for stage-of-development are quantified from remote sensing imagery with estimates of level ice thickness categories originating from World Meteorological Organization (WMO) egg coded ice charts codified since the 1970s. Conversions utilize Python scripting modules which transform electronic ice charts with WMO egg code characteristics into five level ice thickness categories, in centimeters, (0-10, 10-30, 30-70, 70-120, >120cm) and five ice types (open water, first year pack ice, fast ice, multiyear ice, and glacial ice with a reserve slot for deformed ice fractions). Both level ice thickness categories and ice concentration fractions are reported with uncertainties propagated based on WMO ice stage ranges which serve as proxy estimates for standard deviation. These products are in preparation for use by NCEP, CMC, and NAVO by 2014 based on their modeling requirements for daily products in near-real time. In addition to development, continuing research tests the value of these estimated products against in situ observations to improve both value and uncertainty estimates.

  4. Characterization of an IceTop tank for the IceCube surface extension IceVeto

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Julian; Auffenberg, Jan; Hansmann, Bengt; Rongen, Martin; Stahlberg, Martin; Wiebusch, Christopher [III. Physikalisches Institut B, RWTH Aachen University (Germany); Collaboration: IceCube-Collaboration

    2015-07-01

    IceTop is an air-shower detector located at the South Pole on the surface above the IceCube detector. It consists of 81 detector stations with two Cherenkov tanks each. The tanks are filled with clear ice and instrumented with two photomultipliers. IceTop detects cosmic-ray induced air-showers above an energy threshold of ∝300 TeV. Muons and neutrinos from these air-showers are the main background for astrophysical neutrino searches with IceCube. The usage of IceTop to veto air-showers largely reduces this background in the field of view. To enlarge the field of view an extension of the surface detector, IceVeto, is planned. Therefore, we investigate the properties of an original IceTop tank as a laboratory reference for the development of new detection module designs. First results of these measurements are presented.

  5. Thermodynamic and Dynamic Aspects of Ice Nucleation

    Science.gov (United States)

    Barahona, Donifan

    2018-01-01

    It is known that ice nucleating particles (INP) immersed within supercooled droplets promote the formation of ice. Common theoretical models used to represent this process assume that the immersed particle lowers the work of ice nucleation without significantly affecting the dynamics of water in the vicinity of the particle. This is contrary to evidence showing that immersed surfaces significantly affect the viscosity and diffusivity of vicinal water. To study how this may affect ice formation this work introduces a model linking the ice nucleation rate to the modification of the dynamics and thermodynamics of vicinal water by immersed particles. It is shown that INP that significantly reduce the work of ice nucleation also pose strong limitations to the growth of the nascent ice germs. This leads to the onset of a new ice nucleation regime, called spinodal ice nucleation, where the dynamics of ice germ growth instead of the ice germ size determines the nucleation rate. Nucleation in this regime is characterized by an enhanced sensitivity to particle area and cooling rate. Comparison of the predicted ice nucleation rate against experimental measurements for a diverse set of species relevant to cloud formation suggests that spinodal ice nucleation may be common in nature.

  6. The safety band of Antarctic ice shelves

    Science.gov (United States)

    Fürst, Johannes Jakob; Durand, Gaël; Gillet-Chaulet, Fabien; Tavard, Laure; Rankl, Melanie; Braun, Matthias; Gagliardini, Olivier

    2016-05-01

    The floating ice shelves along the seaboard of the Antarctic ice sheet restrain the outflow of upstream grounded ice. Removal of these ice shelves, as shown by past ice-shelf recession and break-up, accelerates the outflow, which adds to sea-level rise. A key question in predicting future outflow is to quantify the extent of calving that might precondition other dynamic consequences and lead to loss of ice-shelf restraint. Here we delineate frontal areas that we label as `passive shelf ice’ and that can be removed without major dynamic implications, with contrasting results across the continent. The ice shelves in the Amundsen and Bellingshausen seas have limited or almost no `passive’ portion, which implies that further retreat of current ice-shelf fronts will yield important dynamic consequences. This region is particularly vulnerable as ice shelves have been thinning at high rates for two decades and as upstream grounded ice rests on a backward sloping bed, a precondition to marine ice-sheet instability. In contrast to these ice shelves, Larsen C Ice Shelf, in the Weddell Sea, exhibits a large `passive’ frontal area, suggesting that the imminent calving of a vast tabular iceberg will be unlikely to instantly produce much dynamic change.

  7. Inelastic neutron scattering of amorphous ice

    International Nuclear Information System (INIS)

    Fukazawa, Hiroshi; Ikeda, Susumu; Suzuki, Yoshiharu

    2001-01-01

    We measured the inelastic neutron scattering from high-density amorphous (HDA) and low-density amorphous (LDA) ice produced by pressurizing and releasing the pressure. We found a clear difference between the intermolecular vibrations in HDA and those in LDA ice: LDA ice has peaks at 22 and 33 meV, which are also seen in the spectrum of lattice vibrations in ice crystal, but the spectrum of HDA ice does not have these peaks. The excitation energy of librational vibrations in HDA ice is 10 meV lower than that in LDA ice. These results imply that HDA ice includes 2- and 5-coordinated hydrogen bonds that are created by breakage of hydrogen bonds and migration of water molecules into the interstitial site, while LDA ice contains mainly 4-coordinated hydrogen bonds and large cavities. Furthermore, we report the dynamical structure factor in the amorphous ice and show that LDA ice is more closely related to the ice crystal structure than to HDA ice. (author)

  8. Triple Isotope Water Measurements of Lake Untersee Ice using Off-Axis ICOS

    Science.gov (United States)

    Berman, E. S.; Huang, Y. W.; Andersen, D. T.; Gupta, M.; McKay, C. P.

    2015-12-01

    Lake Untersee (71.348°S, 13.458°E) is the largest surface freshwater lake in the interior of the Gruber Mountains of central Queen Maud Land in East Antarctica. The lake is permanently covered with ice, is partly bounded by glacier ice and has a mean annual air temperature of -10°C. In contrast to other Antarctic lakes the dominating physical process controlling ice-cover dynamics is low summer temperatures and high wind speeds resulting in sublimation rather than melting as the main mass-loss process. The ice-cover of the lake is composed of lake-water ice formed during freeze-up and rafted glacial ice derived from the Anuchin Glacier. The mix of these two fractions impacts the energy balance of the lake, which directly affects ice-cover thickness. Ice-cover is important if one is to understand the physical, chemical, and biological linkages within these unique, physically driven ecosystems. We have analyzed δ2H, δ18O, and δ17O from samples of lake and glacier ice collected at Lake Untersee in Dec 2014. Using these data we seek to answer two specific questions: Are we able to determine the origin and history of the lake ice, discriminating between rafted glacial ice and lake water? Can isotopic gradients in the surface ice indicate the ablation (sublimation) rate of the surface ice? The triple isotope water analyzer developed by Los Gatos Research (LGR 912-0032) uses LGR's patented Off-Axis ICOS (Integrated Cavity Output Spectroscopy) technology and incorporates proprietary internal thermal control for high sensitivity and optimal instrument stability. This analyzer measures δ2H, δ18O, and δ17O from water, as well as the calculated d-excess and 17O-excess. The laboratory precision in high performance mode for both δ17O and δ18O is 0.03 ‰, and for δ2H is 0.2 ‰. Methodology and isotope data from Lake Untersee samples are presented. Figure: Ice samples were collected across Lake Untersee from both glacial and lake ice regions for this study.

  9. Heavy Metal Presence in Two Different Types of Ice Cream: Artisanal Ice Cream (Italian Gelato) and Industrial Ice Cream.

    Science.gov (United States)

    Conficoni, D; Alberghini, L; Bissacco, E; Ferioli, M; Giaccone, V

    2017-03-01

    Ice cream, a popular product worldwide, is usually a milk-based product with other types of ingredients (fruit, eggs, cocoa, dried fruit, additives, and others). Different materials are used to obtain the desired taste, texture, consistency, and appearance of the final product. This study surveyed ice cream products available in Italy for heavy metals (lead, cadmium, chromium, tin, and arsenic). The differences between artisanal and industrial ice cream were also investigated because of the importance in the Italian diet and the diffusion of this ready-to-eat food. Ice cream sampling was performed between October 2010 and February 2011 in the northeast of Italy. A total of 100 samples were randomly collected from different sources: 50 industrial samples produced by 19 different brands were collected in coffee bars and supermarkets; 50 artisanal ice cream samples were gathered at nine different artisanal ice cream shops. Ten wooden sticks of industrial ice cream were analyzed in parallel to the ice cream. All samples were negative for arsenic and mercury. None of the artisanal ice cream samples were positive for lead and tin; 18% of the industrial ice cream samples were positive. All positive lead samples were higher than the legal limit stated for milk (0.02 mg/kg). All industrial ice cream samples were negative for cadmium, but cadmium was present in 10% of the artisanal ice cream samples. Chromium was found in 26% of the artisanal and in 58% of the industrial ice cream samples. The heavy metals found in the wooden sticks were different from the corresponding ice cream, pointing out the lack of cross-contamination between the products. Considering the results and the amount of ice cream consumed during the year, contamination through ice cream is a low risk for the Italian population, even though there is need for further analysis.

  10. PU-ICE Summary Information.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    The Generator Knowledge Report for the Plutonium Isentropic Compression Experiment Containment Systems (GK Report) provides information for the Plutonium Isentropic Compression Experiment (Pu- ICE) program to support waste management and characterization efforts. Attachment 3-18 presents generator knowledge (GK) information specific to the eighteenth Pu-ICE conducted in August 2015, also known as ‘Shot 18 (Aug 2015) and Pu-ICE Z-2841 (1).’ Shot 18 (Aug 2015) was generated on August 28, 2015 (1). Calculations based on the isotopic content of Shot 18 (Aug 2015) and the measured mass of the containment system demonstrate the post-shot containment system is low-level waste (LLW). Therefore, this containment system will be managed at Sandia National Laboratory/New Mexico (SNL/NM) as LLW. Attachment 3-18 provides documentation of the TRU concentration and documents the concentration of any hazardous constituents.

  11. Disorder and Quantum Spin Ice

    Science.gov (United States)

    Martin, N.; Bonville, P.; Lhotel, E.; Guitteny, S.; Wildes, A.; Decorse, C.; Ciomaga Hatnean, M.; Balakrishnan, G.; Mirebeau, I.; Petit, S.

    2017-10-01

    We report on diffuse neutron scattering experiments providing evidence for the presence of random strains in the quantum spin-ice candidate Pr2Zr2O7 . Since Pr3 + is a non-Kramers ion, the strain deeply modifies the picture of Ising magnetic moments governing the low-temperature properties of this material. It is shown that the derived strain distribution accounts for the temperature dependence of the specific heat and of the spin-excitation spectra. Taking advantage of mean-field and spin-dynamics simulations, we argue that the randomness in Pr2Zr2O7 promotes a new state of matter, which is disordered yet characterized by short-range antiferroquadrupolar correlations, and from which emerge spin-ice-like excitations. Thus, this study gives an original research route in the field of quantum spin ice.

  12. An integrated approach to the remote sensing of floating ice

    Science.gov (United States)

    Campbell, W. J.; Ramseier, R. O.; Weeks, W. F.; Gloersen, P.

    1976-01-01

    Review article on remote sensing applications to glaciology. Ice parameters sensed include: ice cover vs open water, ice thickness, distribution and morphology of ice formations, vertical resolution of ice thickness, ice salinity (percolation and drainage of brine; flushing of ice body with fresh water), first-year ice and multiyear ice, ice growth rate and surface heat flux, divergence of ice packs, snow cover masking ice, behavior of ice shelves, icebergs, lake ice and river ice; time changes. Sensing techniques discussed include: satellite photographic surveys, thermal IR, passive and active microwave studies, microwave radiometry, microwave scatterometry, side-looking radar, and synthetic aperture radar. Remote sensing of large aquatic mammals and operational ice forecasting are also discussed.

  13. Weather and forecasting at Wilkins ice runway, Antarctica

    International Nuclear Information System (INIS)

    Carpentier, Scott

    2010-01-01

    Aviation forecasts for Wilkins ice runway in East Antarctica are developed within the conceptual framework of flow against a single dome shaped hill. Forecast challenges include the sudden onset of blizzards associated with the formation of an internal gravity wave; frontal weather; transient wake vortices and mesoscale lows; temperature limitations on runway use; and snow and fog events. These key weather aspects are presented within the context of synoptic to local scale climatologies and numerical weather prediction models.

  14. Solving the riddle of interglacial temperatures over the last 1.5 million years with a future IPICS "Oldest Ice" ice core

    Science.gov (United States)

    Fischer, Hubertus

    2014-05-01

    The sequence of the last 8 glacial cycles is characterized by irregular 100,000 year cycles in temperature and sea level. In contrast, the time period between 1.5-1.2 million years ago is characterized by more regular cycles with an obliquity periodicity of 41,000 years. Based on a deconvolution of deep ocean temperature and ice volume contributions to benthic δ18O (Elderfield et al., Science, 2012), it is suggested that glacial sea level became progressively lower over the last 1.5 Myr, while glacial deep ocean temperatures were very similar. At the same time many interglacials prior to the Mid Brunhes event showed significantly cooler deep ocean temperatures than the Holocene, while at the same time interglacial ice volume remained essentially the same. In contrast, interglacial sea surface temperatures in the tropics changed little (Herbert et al., Science,2010) and proxy reconstructions of atmospheric CO2 using δ11B in planktic foraminifera (Hönisch et al., Science, 2009) suggest that prior to 900,000 yr before present interglacial CO2 levels did not differ substantially from those over the last 450,000 years. Accordingly, the conundrum arises how interglacials can differ in deep ocean temperature without any obvious change in ice volume or greenhouse gas forcing and what caused the change in cyclicity of glacial interglacial cycles over the Mid Pleistocene Transition. Probably the most important contribution to solve this riddle is the recovery of a 1.5 Myr old ice core from Antarctica, which among others would provide an unambiguous, high-resolution record of the greenhouse gas history over this time period. Accordingly, the international ice core community, as represented by the International Partnership for Ice Core Science (IPICS), has identified such an 'Oldest Ice' ice core as one of the most important scientific targets for the future (http://www.pages.unibe.ch/ipics/white-papers). However, finding stratigraphically undisturbed ice, which covers this

  15. Correlating Ice Cores from Quelccaya Ice Cap with Chronology from Little Ice Age Glacial Extents

    Science.gov (United States)

    Stroup, J. S.; Kelly, M. A.; Lowell, T. V.

    2010-12-01

    Proxy records indicate Southern Hemisphere climatic changes during the Little Ice Age (LIA; ~1300-1850 AD). In particular, records of change in and around the tropical latitudes require attention because these areas are sensitive to climatic change and record the dynamic interplay between hemispheres (Oerlemans, 2005). Despite this significance, relatively few records exist for the southern tropics. Here we present a reconstruction of glacial fluctuations of Quelccaya Ice Cap (QIC), Peruvian Andes, from pre-LIA up to the present day. In the Qori Kalis valley, extensive sets of moraines exist beginning with the 1963 AD ice margin (Thompson et al., 2006) and getting progressively older down valley. Several of these older moraines can be traced and are continuous with moraines in the Challpa Cocha valley. These moraines have been dated at chronology of past ice cap extents are correlated with ice core records from QIC which show an accumulation increase during ~1500-1700 AD and an accumulation decrease during ~1720-1860 AD (Thompson et al., 1985; 1986; 2006). In addition, other proxy records from Peru and the tropics are correlated with the records at QIC as a means to understand climate conditions during the LIA. This work forms the basis for future modeling of the glacial system during the LIA at QIC and for modeling of past temperature and precipitation regimes at high altitude in the tropics.

  16. Changes on the ice plain of Ice Stream B and Ross Ice Shelf

    Science.gov (United States)

    Shabtaie, Sion

    1993-01-01

    During the 1970's and 1980's, nearly 200 stations from which accurate, three dimensional position fixes have been obtained from TRANSIT satellites were occupied throughout the Ross Ice Shelf. We have transformed the elevations obtained by satellite altimetry to the same geodetic datum, and then applied a second transformation to reduce the geodetic heights to elevations above mean sea level using the GEM-10C geoidal height. On the IGY Ross Ice Shelf traverse between Oct. 1957 and Feb. 1958, an accurate method of barometric altimetry was used on a loop around the ice shelf that was directly tied to the sea at both ends of the travel route, thus providing absolute elevations. Comparisons of the two sets of data at 32 station pairs on floating ice show a mean difference of 0 +/- 1 m. The elevation data were also compared with theoretical values of elevations for a hydrostatically floating ice shelf. The mean difference between theoretical and measured values of elevations is -2 +/- 1 m.

  17. Pneumatic Tire Performance on Ice

    OpenAIRE

    Kishore Bhoopalam, Anudeep

    2015-01-01

    The evolution of vehicle safety systems, from the earliest brakes to today's accident avoidance systems, has led vehicles to have very high passenger safety. Driving on ice, though, still happens to be one of the driving conditions of low safety. A multitude of factors were identified by various studies to contribute to the complex frictional mechanism at the tire-ice interface. The tire is only force transmitting element of the vehicle, to the surface. Thus it is very essential to have in de...

  18. The formation of ice sails

    Science.gov (United States)

    Fowler, A. C.; Mayer, C.

    2017-11-01

    Debris-covered glaciers are prone to the formation of a number of supraglacial geomorphological features, and generally speaking, their upper surfaces are far from level surfaces. Some of these features are due to radiation screening or enhancing properties of the debris cover, but theoretical explanations of the consequent surface forms are in their infancy. In this paper we consider a theoretical model for the formation of "ice sails", which are regularly spaced bare ice features which are found on debris-covered glaciers in the Karakoram.

  19. Continuous Chemistry in Ice Cores

    DEFF Research Database (Denmark)

    Kjær, Helle Astrid

    on parameters involved in the study of photolysis as a source of in situ CO2. The concentration of organic substances in Greenland ice is poorly known due to their low levels and the fact that only a few studies evaluate the concentrations of specific organic compounds. Light does not penetrate deep...... depth was found as a function of wavelength. Further, by computational chemistry hybrid density functional methods (DFT), the four most common conformers of pyruvic acid were investigated in both gas, water and ice using the DFT model CAM-B3LYP with dielectric medium methods. A de rease of the energy...

  20. Greenland Radar Ice Sheet Thickness Measurements

    Data.gov (United States)

    National Aeronautics and Space Administration — Two 150-MHz coherent radar depth sounders were developed and flown over the Greenland ice sheet to obtain ice thickness measurements in support of PARCA...

  1. IceBridge Mission Flight Reports

    Data.gov (United States)

    National Aeronautics and Space Administration — The IceBridge Mission Flight Reports data set contains flight reports from NASA Operation IceBridge Greenland, Arctic, Antarctic, and Alaska missions. Flight reports...

  2. Arctic Landfast Sea Ice 1953-1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The files in this data set contain landfast sea ice data (monthly means) gathered from both Russian Arctic and Antarctic Research Institute (AARI) and Canadian Ice...

  3. Global Lake and River Ice Phenology Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Lake and River Ice Phenology Database contains freeze and thaw/breakup dates as well as other descriptive ice cover data for 865 lakes and rivers in the...

  4. Southern Hemisphere Ice Limits, 1973-1978

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weekly Southern Ocean ice limits, have been digitized from U.S. Navy Fleet Weather Facility ice charts, at the Max-Planck Institut fur Meteorologie, Hamburg....

  5. History of sea ice in the Arctic

    DEFF Research Database (Denmark)

    Polyak, Leonid; Alley, Richard B.; Andrews, John T.

    2010-01-01

    Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past. This inf......Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past...... Optimum, and consistently covered at least part of the Arctic Ocean for no less than the last 13–14 million years. Ice was apparently most widespread during the last 2–3 million years, in accordance with Earth’s overall cooler climate. Nevertheless, episodes of considerably reduced sea ice or even...

  6. Ice sheet anisotropy measured with polarimetric ice sounding radar

    DEFF Research Database (Denmark)

    Dall, Jørgen

    2010-01-01

    For polar ice sheets, valuable stress and strain information can be deduced from crystal orientation fabrics (COF) and their prevailing c-axis alignment. Polarimetric radio echo sounding is a promising technique to measure the anisotropic electromagnetic propagation and reflection properties asso...

  7. Seasonal ice dynamics of the Northeast Greenland Ice Stream

    DEFF Research Database (Denmark)

    Vijay, Saurabh; Khan, Shfaqat Abbas; Simonsen, Sebastian Bjerregaard

    2018-01-01

    and temporal details. This study focus on the Northeast Greenland Ice Stream (NEGIS), which consists of three main outlets, 79 North glacier (79N), Zachariae Isstrøm (ZI) and Storstrømmen Glacier (SG). While both 79 North and Storstrømmen have floating tongues, Zachariae Isstrøm is mostly grounded...

  8. Delicious ice cream, why does salt thaw ice?

    Science.gov (United States)

    Bagnoli, Franco

    2016-03-01

    Plain Awful is an imaginary valley on the Andes populated by a highly-imitative, cubical people for which the most criminal offence is to exhibit round objects. The duck family (Scrooge, Donald and nephews) are teaming against Scrooge's worst enemy, Flintheart Glomgold, trying to buy the famous Plain Awful square eggs. Inadvertently, Scrooge violates the taboo, showing his Number One Dime, and is imprisoned in the stone quarries. He can be released only after the presentation of an ice cream soda to the President of Plain Awful. Donald and his nephews fly with Flintheart to deliver it, but Scrooge's enemy, of course, betrays the previous agreement after getting the ice cream, forcing the ducks into making an emergence replacement on the spot. Using dried milk, sugar and chocolate from their ration packs, plus some snow and salt for cooling they are able make the ice cream, and after dressing it with the carbonated water from a fire extinguisher they finally manage to produce the desired dessert. This comic may serve as an introduction to the "mysterious" phenomenon that added salt melts the ice and, even more surprising, does it by lowering the temperature of the mixture.

  9. Got Ice? Teaching Ice-Skating as a Lifelong Activity

    Science.gov (United States)

    Tarkinton, Brenda C.; Karp, Grace Goc

    2010-01-01

    With today's focus on the importance of lifelong physical activity, educators are increasingly offering a variety of such activities in their classes, as well as in before- and after-school programs. This article describes the benefits of offering ice skating as a challenging and rewarding lifetime activity, either before or after school or in…

  10. Seasonal Ice Zone Reconnaissance Surveys Coordination

    Science.gov (United States)

    2016-03-30

    Chukchi sea seasonal sea ice zone (SIZ) utilizing US Coast Guard Arctic Domain Awareness ( ADA ) flights of opportunity in the summers of 2012- 2014. In...measurements across the Beaufort-Chukchi sea seasonal sea ice zone (SIZ) utilizing US Coast Guard Arctic Domain Awareness ( ADA ) flights of...such, it contains the full range of positions of the marginal ice zone (MIZ) where sea ice interacts with open water. In addition to SIZRS

  11. Antarctic krill under sea ice: elevated abundance in a narrow band just south of ice edge.

    Science.gov (United States)

    Brierley, Andrew S; Fernandes, Paul G; Brandon, Mark A; Armstrong, Frederick; Millard, Nicholas W; McPhail, Steven D; Stevenson, Peter; Pebody, Miles; Perrett, James; Squires, Mark; Bone, Douglas G; Griffiths, Gwyn

    2002-03-08

    We surveyed Antarctic krill (Euphausia superba) under sea ice using the autonomous underwater vehicle Autosub-2. Krill were concentrated within a band under ice between 1 and 13 kilometers south of the ice edge. Within this band, krill densities were fivefold greater than that of open water. The under-ice environment has long been considered an important habitat for krill, but sampling difficulties have previously prevented direct observations under ice over the scale necessary for robust krill density estimation. Autosub-2 enabled us to make continuous high-resolution measurements of krill density under ice reaching 27 kilometers beyond the ice edge.

  12. An Ice Protection and Detection Systems Manufacturer's Perspective

    Science.gov (United States)

    Sweet, Dave

    2009-01-01

    Accomplishments include: World Class Aircraft Icing Research Center and Facility. Primary Sponsor/Partner - Aircraft Icing Consortia/Meetings. Icing Research Tunnel. Icing Test Aircraft. Icing Codes - LEWICE/Scaling, et al. Development of New Technologies (SBIR, STTR, et al). Example: Look Ahead Ice Detection. Pilot Training Materials. Full Cooperation with Academia, Government and Industry.

  13. Constraining ice sheet history in the Weddell Sea, West Antarctica, using ice fabric at Korff Ice Rise

    Science.gov (United States)

    Brisbourne, A.; Smith, A.; Kendall, J. M.; Baird, A. F.; Martin, C.; Kingslake, J.

    2017-12-01

    The grounding history of ice rises (grounded area of independent flow regime within a floating ice shelf) can be used to constrain large scale ice sheet history: ice fabric, resulting from the preferred orientation of ice crystals due to the stress regime, can be used to infer this grounding history. With the aim of measuring the present day ice fabric at Korff Ice Rise, West Antarctica, a multi-azimuth wide-angle seismic experiment was undertaken. Three wide-angle common-midpoint gathers were acquired centred on the apex of the ice rise, at azimuths of 60 degrees to one another, to measure variation in seismic properties with offset and azimuth. Both vertical and horizontal receivers were used to record P and S arrivals including converted phases. Measurements of the variation with offset and azimuth of seismic traveltimes, seismic attenuation and shear wave splitting have been used to quantify seismic anisotropy in the ice column. The observations cannot be reproduced using an isotropic ice column model. Anisotropic ray tracing has been used to test likely models of ice fabric by comparison with the data. A model with a weak girdle fabric overlying a strong cluster fabric provides the best fit to the observations. Fabric of this nature is consistent with Korff Ice Rise having been stable for the order of 10,000 years without any ungrounding or significant change in the ice flow configuration across the ice rise for this period. This observation has significant implications for the ice sheet history of the Weddell Sea sector.

  14. Assessing, understanding, and conveying the state of the Arctic sea ice cover

    Science.gov (United States)

    Perovich, D. K.; Richter-Menge, J. A.; Rigor, I.; Parkinson, C. L.; Weatherly, J. W.; Nghiem, S. V.; Proshutinsky, A.; Overland, J. E.

    2003-12-01

    Recent studies indicate that the Arctic sea ice cover is undergoing significant climate-induced changes, affecting both its extent and thickness. Satellite-derived estimates of Arctic sea ice extent suggest a reduction of about 3% per decade since 1978. Ice thickness data from submarines suggest a net thinning of the sea ice cover since 1958. Changes (including oscillatory changes) in atmospheric circulation and the thermohaline properties of the upper ocean have also been observed. These changes impact not only the Arctic, but the global climate system and are likely accelerated by such processes as the ice-albedo feedback. It is important to continue and expand long-term observations of these changes to (a) improve the fundamental understanding of the role of the sea ice cover in the global climate system and (b) use the changes in the sea ice cover as an early indicator of climate change. This is a formidable task that spans a range of temporal and spatial scales. Fortunately, there are numerous tools that can be brought to bear on this task, including satellite remote sensing, autonomous buoys, ocean moorings, field campaigns and numerical models. We suggest the integrated and coordinated use of these tools during the International Polar Year to monitor the state of the Arctic sea ice cover and investigate its governing processes. For example, satellite remote sensing provides the large-scale snapshots of such basic parameters as ice distribution, melt zone, and cloud fraction at intervals of half a day to a week. Buoys and moorings can contribute high temporal resolution and can measure parameters currently unavailable from space including ice thickness, internal ice temperature, and ocean temperature and salinity. Field campaigns can be used to explore, in detail, the processes that govern the ice cover. Numerical models can be used to assess the character of the changes in the ice cover and predict their impacts on the rest of the climate system. This work

  15. Development of a Capacitive Ice Sensor to Measure Ice Growth in Real Time

    Directory of Open Access Journals (Sweden)

    Xiang Zhi

    2015-03-01

    Full Text Available This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

  16. Development of a capacitive ice sensor to measure ice growth in real time.

    Science.gov (United States)

    Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

    2015-03-19

    This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

  17. Balance of the West Antarctic Ice Sheet

    Science.gov (United States)

    2002-01-01

    For several decades, measurements of the West Antarctic Ice Sheet showed it to be retreating rapidly. But new data derived from satellite-borne radar sensors show the ice sheet to be growing. Changing Antarctic ice sheets remains an area of high scientific interest, particularly in light of recent global warming concerns. These new findings are significant because scientists estimate that sea level would rise 5-6 meters (16-20 feet) if the ice sheet collapsed into the sea. Do these new measurements signal the end of the ice sheet's 10,000-year retreat? Or, are these new satellite data simply much more accurate than the sparse ice core and surface measurements that produced the previous estimates? Another possibility is that the ice accumulation may simply indicate that the ice sheet naturally expands and retreats in regular cycles. Cryologists will grapple with these questions, and many others, as they examine the new data. The image above depicts the region of West Antarctica where scientists measured ice speed. The fast-moving central ice streams are shown in red. Slower tributaries feeding the ice streams are shown in blue. Green areas depict slow-moving, stable areas. Thick black lines depict the areas that collect snowfall to feed their respective ice streams. Reference: Ian Joughin and Slawek Tulaczyk Science Jan 18 2002: 476-480. Image courtesy RADARSAT Antarctic Mapping Project

  18. CICE, The Los Alamos Sea Ice Model

    Energy Technology Data Exchange (ETDEWEB)

    2017-05-12

    The Los Alamos sea ice model (CICE) is the result of an effort to develop a computationally efficient sea ice component for a fully coupled atmosphere–land–ocean–ice global climate model. It was originally designed to be compatible with the Parallel Ocean Program (POP), an ocean circulation model developed at Los Alamos National Laboratory for use on massively parallel computers. CICE has several interacting components: a vertical thermodynamic model that computes local growth rates of snow and ice due to vertical conductive, radiative and turbulent fluxes, along with snowfall; an elastic-viscous-plastic model of ice dynamics, which predicts the velocity field of the ice pack based on a model of the material strength of the ice; an incremental remapping transport model that describes horizontal advection of the areal concentration, ice and snow volume and other state variables; and a ridging parameterization that transfers ice among thickness categories based on energetic balances and rates of strain. It also includes a biogeochemical model that describes evolution of the ice ecosystem. The CICE sea ice model is used for climate research as one component of complex global earth system models that include atmosphere, land, ocean and biogeochemistry components. It is also used for operational sea ice forecasting in the polar regions and in numerical weather prediction models.

  19. On the origin of the ice ages

    NARCIS (Netherlands)

    Oerlemans, J.

    1984-01-01

    Ice sheet dynamics provide a possible explanation for the 100 kyr power in climatic records. Some numerical experiments presented here show that even the transition from an essentially ice-free earth to a glacial can be produced by a northern hemisphere ice-sheet model, provided that a

  20. 14 CFR 29.1419 - Ice protection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ice protection. 29.1419 Section 29.1419... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Safety Equipment § 29.1419 Ice protection. (a) To obtain... of the ice protection system for the various components of the rotorcraft. (c) In addition to the...

  1. 14 CFR 25.1419 - Ice protection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ice protection. 25.1419 Section 25.1419... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Safety Equipment § 25.1419 Ice protection. If the...) An analysis must be performed to establish that the ice protection for the various components of the...

  2. 14 CFR 27.1419 - Ice protection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ice protection. 27.1419 Section 27.1419... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Safety Equipment § 27.1419 Ice protection. (a) To obtain..., the adequacy of the ice protection system for the various components of the rotorcraft. (c) In...

  3. Plant ice-binding (antifreeze) proteins

    Science.gov (United States)

    Proteins that determine the temperature at which ice crystals will form in water-based solutions in cells and tissues, that bind to growing ice crystals, thus affecting their size, and that impact ice re-crystallization have been widely-documented and studied in many plant, bacterial, fungal, insect...

  4. Tree recovery from ice storm injury

    Science.gov (United States)

    Kevin T. Smith

    2015-01-01

    Ice storms are part of nature, particularly in northeastern North America. The combination of air and surface temperatures, precipitation, and wind that result in damaging layers of ice is very specific, occurring infrequently at any given location. Across the region however, damaging ice is formed in fragmented areas every year. Occasionally as in December 2013 and...

  5. Glacial Cycles and ice-sheet modelling

    NARCIS (Netherlands)

    Oerlemans, J.

    1982-01-01

    An attempt is made to simulate the Pleistocene glacial cycles with a numerical model of the Northern Hemisphere ice sheets. This model treats the vertically-integrated ice flow along a meridian, including computation of bedrock adjustment and temperature distribution in the ice. Basal melt water is

  6. Ice targets for use at NTOF

    International Nuclear Information System (INIS)

    Mercer, D.J.

    1992-12-01

    This report describes ice targets which were used during an experiment at the Neutron Time of Flight facility (NTOF) at LAMPF. Reasons for using the ice targets are given, and the construction, refrigeration system, and target preparation are detailed. Results of the research using these ice targets will be published at a later date

  7. 21 CFR 135.160 - Water ices.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Water ices. 135.160 Section 135.160 Food and Drugs... CONSUMPTION FROZEN DESSERTS Requirements for Specific Standardized Frozen Desserts § 135.160 Water ices. (a) Description. Water ices are the foods each of which is prepared from the same ingredients and in the same...

  8. Tropically driven and externally forced patterns of Antarctic sea ice change: reconciling observed and modeled trends

    Science.gov (United States)

    Schneider, David P.; Deser, Clara

    2017-09-01

    Recent work suggests that natural variability has played a significant role in the increase of Antarctic sea ice extent during 1979-2013. The ice extent has responded strongly to atmospheric circulation changes, including a deepened Amundsen Sea Low (ASL), which in part has been driven by tropical variability. Nonetheless, this increase has occurred in the context of externally forced climate change, and it has been difficult to reconcile observed and modeled Antarctic sea ice trends. To understand observed-model disparities, this work defines the internally driven and radiatively forced patterns of Antarctic sea ice change and exposes potential model biases using results from two sets of historical experiments of a coupled climate model compared with observations. One ensemble is constrained only by external factors such as greenhouse gases and stratospheric ozone, while the other explicitly accounts for the influence of tropical variability by specifying observed SST anomalies in the eastern tropical Pacific. The latter experiment reproduces the deepening of the ASL, which drives an increase in regional ice extent due to enhanced ice motion and sea surface cooling. However, the overall sea ice trend in every ensemble member of both experiments is characterized by ice loss and is dominated by the forced pattern, as given by the ensemble-mean of the first experiment. This pervasive ice loss is associated with a strong warming of the ocean mixed layer, suggesting that the ocean model does not locally store or export anomalous heat efficiently enough to maintain a surface environment conducive to sea ice expansion. The pervasive upper-ocean warming, not seen in observations, likely reflects ocean mean-state biases.

  9. Tropically driven and externally forced patterns of Antarctic sea ice change: reconciling observed and modeled trends

    Science.gov (United States)

    Schneider, David P.; Deser, Clara

    2018-06-01

    Recent work suggests that natural variability has played a significant role in the increase of Antarctic sea ice extent during 1979-2013. The ice extent has responded strongly to atmospheric circulation changes, including a deepened Amundsen Sea Low (ASL), which in part has been driven by tropical variability. Nonetheless, this increase has occurred in the context of externally forced climate change, and it has been difficult to reconcile observed and modeled Antarctic sea ice trends. To understand observed-model disparities, this work defines the internally driven and radiatively forced patterns of Antarctic sea ice change and exposes potential model biases using results from two sets of historical experiments of a coupled climate model compared with observations. One ensemble is constrained only by external factors such as greenhouse gases and stratospheric ozone, while the other explicitly accounts for the influence of tropical variability by specifying observed SST anomalies in the eastern tropical Pacific. The latter experiment reproduces the deepening of the ASL, which drives an increase in regional ice extent due to enhanced ice motion and sea surface cooling. However, the overall sea ice trend in every ensemble member of both experiments is characterized by ice loss and is dominated by the forced pattern, as given by the ensemble-mean of the first experiment. This pervasive ice loss is associated with a strong warming of the ocean mixed layer, suggesting that the ocean model does not locally store or export anomalous heat efficiently enough to maintain a surface environment conducive to sea ice expansion. The pervasive upper-ocean warming, not seen in observations, likely reflects ocean mean-state biases.

  10. Hindcasting to measure ice sheet model sensitivity to initial states

    Directory of Open Access Journals (Sweden)

    A. Aschwanden

    2013-07-01

    Full Text Available Validation is a critical component of model development, yet notoriously challenging in ice sheet modeling. Here we evaluate how an ice sheet system model responds to a given forcing. We show that hindcasting, i.e. forcing a model with known or closely estimated inputs for past events to see how well the output matches observations, is a viable method of assessing model performance. By simulating the recent past of Greenland, and comparing to observations of ice thickness, ice discharge, surface speeds, mass loss and surface elevation changes for validation, we find that the short term model response is strongly influenced by the initial state. We show that the thermal and dynamical states (i.e. the distribution of internal energy and momentum can be misrepresented despite a good agreement with some observations, stressing the importance of using multiple observations. In particular we identify rates of change of spatially dense observations as preferred validation metrics. Hindcasting enables a qualitative assessment of model performance relative to observed rates of change. It thereby reduces the number of admissible initial states more rigorously than validation efforts that do not take advantage of observed rates of change.

  11. Arctic multiyear ice classification and summer ice cover using passive microwave satellite data

    Science.gov (United States)

    Comiso, J. C.

    1990-08-01

    The ability to classify and monitor Arctic multiyear sea ice cover using multispectral passive microwave data is studied. Sea ice concentration maps during several summer minima have been analyzed to obtain estimates of ice surviving the summer. The results are compared with multiyear ice concentrations derived from data the following winter, using an algorithm that assumes a certain emissivity for multiyear ice. The multiyear ice cover inferred from the winter data is approximately 25 to 40% less than the summer ice cover minimum, suggesting that even during winter when the emissivity of sea ice is most stable, passive microwave data may account for only a fraction of the total multiyear ice cover. The difference of about 2×106 km2 is considerably more than estimates of advection through Fram Strait during the intervening period. It appears that as in the Antarctic, some multiyear ice floes in the Arctic, especially those near the summer marginal ice zone, have first-year ice or intermediate signatures in the subsequent winter. A likely mechanism for this is the intrusion of seawater into the snow-ice interface, which often occurs near the marginal ice zone or in areas where snow load is heavy. Spatial variations in melt and melt ponding effects also contribute to the complexity of the microwave emissivity of multiyear ice. Hence the multiyear ice data should be studied in conjunction with the previous summer ice data to obtain a more complete characterization of the state of the Arctic ice cover. The total extent and actual areas of the summertime Arctic pack ice were estimated to be 8.4×106 km2 and 6.2×106 km2, respectively, and exhibit small interannual variability during the years 1979 through 1985, suggesting a relatively stable ice cover.

  12. Airfields on Antarctic Glacier Ice

    Science.gov (United States)

    1989-12-01

    that depends on compacting the thin 3350 true. There was also a crosswind runway snow cover on the hard ice. aligned with the storm wind direction. No...expire onl 31 December 1991.) flights. It Is suggested that the USAP should adopt tile The place known to us as lte Peg .-asus site can concept of

  13. Isolating the atmospheric circulation response to Arctic sea-ice loss in the coupled climate system

    Science.gov (United States)

    Kushner, Paul; Blackport, Russell

    2017-04-01

    In the coupled climate system, projected global warming drives extensive sea-ice loss, but sea-ice loss drives warming that amplifies and can be confounded with the global warming process. This makes it challenging to cleanly attribute the atmospheric circulation response to sea-ice loss within coupled earth-system model (ESM) simulations of greenhouse warming. In this study, many centuries of output from coupled ocean/atmosphere/land/sea-ice ESM simulations driven separately by sea-ice albedo reduction and by projected greenhouse-dominated radiative forcing are combined to cleanly isolate the hemispheric scale response of the circulation to sea-ice loss. To isolate the sea-ice loss signal, a pattern scaling approach is proposed in which the local multidecadal mean atmospheric response is assumed to be separately proportional to the total sea-ice loss and to the total low latitude ocean surface warming. The proposed approach estimates the response to Arctic sea-ice loss with low latitude ocean temperatures fixed and vice versa. The sea-ice response includes a high northern latitude easterly zonal wind response, an equatorward shift of the eddy driven jet, a weakening of the stratospheric polar vortex, an anticyclonic sea level pressure anomaly over coastal Eurasia, a cyclonic sea level pressure anomaly over the North Pacific, and increased wintertime precipitation over the west coast of North America. Many of these responses are opposed by the response to low-latitude surface warming with sea ice fixed. However, both sea-ice loss and low latitude surface warming act in concert to reduce storm track strength throughout the mid and high latitudes. The responses are similar in two related versions of the National Center for Atmospheric Research earth system models, apart from the stratospheric polar vortex response. Evidence is presented that internal variability can easily contaminate the estimates if not enough independent climate states are used to construct them

  14. Chemical composition and mixing-state of ice residuals sampled within mixed phase clouds

    Science.gov (United States)

    Ebert, M.; Worringen, A.; Benker, N.; Mertes, S.; Weingartner, E.; Weinbruch, S.

    2010-10-01

    During an intensive campaign at the high alpine research station Jungfraujoch, Switzerland, in February/March 2006 ice particle residuals within mixed-phase clouds were sampled using the Ice-counterflow virtual impactor (Ice-CVI). Size, morphology, chemical composition, mineralogy and mixing state of the ice residual and the interstitial (i.e., non-activated) aerosol particles were analyzed by scanning and transmission electron microscopy. Ice nuclei (IN) were identified from the significant enrichment of particle groups in the ice residual (IR) samples relative to the interstitial aerosol. In terms of number lead-bearing particles are enriched by a factor of approximately 25, complex internal mixtures with silicates or metal oxides as major components by a factor of 11, and mixtures of secondary aerosol and soot (C-O-S particles) by a factor of 2. Other particle groups (sulfates, sea salt, Ca-rich particles, external silicates) observed in the ice-residual samples cannot be assigned unambiguously as IN. Between 9 and 24% of all IR are Pb-bearing particles. Pb was found as major component in around 10% of these particles (PbO, PbCl2). In the other particles, Pb was found as some 100 nm sized agglomerates consisting of 3-8 nm sized primary particles (PbS, elemental Pb). C-O-S particles are present in the IR at an abundance of 17-27%. The soot component within these particles is strongly aged. Complex internal mixtures occur in the IR at an abundance of 9-15%. Most IN identified at the Jungfraujoch station are internal mixtures containing anthropogenic components (either as main or minor constituent), and it is concluded that admixture of the anthropogenic component is responsible for the increased IN efficiency within mixed phase clouds. The mixing state appears to be a key parameter for the ice nucleation behaviour that cannot be predicted from the separate components contained within the individual particles.

  15. Modeling and Grid Generation of Iced Airfoils

    Science.gov (United States)

    Vickerman, Mary B.; Baez, Marivell; Braun, Donald C.; Hackenberg, Anthony W.; Pennline, James A.; Schilling, Herbert W.

    2007-01-01

    SmaggIce Version 2.0 is a software toolkit for geometric modeling and grid generation for two-dimensional, singleand multi-element, clean and iced airfoils. A previous version of SmaggIce was described in Preparing and Analyzing Iced Airfoils, NASA Tech Briefs, Vol. 28, No. 8 (August 2004), page 32. To recapitulate: Ice shapes make it difficult to generate quality grids around airfoils, yet these grids are essential for predicting ice-induced complex flow. This software efficiently creates high-quality structured grids with tools that are uniquely tailored for various ice shapes. SmaggIce Version 2.0 significantly enhances the previous version primarily by adding the capability to generate grids for multi-element airfoils. This version of the software is an important step in streamlining the aeronautical analysis of ice airfoils using computational fluid dynamics (CFD) tools. The user may prepare the ice shape, define the flow domain, decompose it into blocks, generate grids, modify/divide/merge blocks, and control grid density and smoothness. All these steps may be performed efficiently even for the difficult glaze and rime ice shapes. Providing the means to generate highly controlled grids near rough ice, the software includes the creation of a wrap-around block (called the "viscous sublayer block"), which is a thin, C-type block around the wake line and iced airfoil. For multi-element airfoils, the software makes use of grids that wrap around and fill in the areas between the viscous sub-layer blocks for all elements that make up the airfoil. A scripting feature records the history of interactive steps, which can be edited and replayed later to produce other grids. Using this version of SmaggIce, ice shape handling and grid generation can become a practical engineering process, rather than a laborious research effort.

  16. Ice formation and growth shape bacterial community structure in Baltic Sea drift ice.

    Science.gov (United States)

    Eronen-Rasimus, Eeva; Lyra, Christina; Rintala, Janne-Markus; Jürgens, Klaus; Ikonen, Vilma; Kaartokallio, Hermanni

    2015-02-01

    Drift ice, open water and under-ice water bacterial communities covering several developmental stages from open water to thick ice were studied in the northern Baltic Sea. The bacterial communities were assessed with 16S rRNA gene terminal-restriction fragment length polymorphism and cloning, together with bacterial abundance and production measurements. In the early stages, open water and pancake ice were dominated by Alphaproteobacteria and Actinobacteria, which are common bacterial groups in Baltic Sea wintertime surface waters. The pancake ice bacterial communities were similar to the open-water communities, suggesting that the parent water determines the sea-ice bacterial community in the early stages of sea-ice formation. In consolidated young and thick ice, the bacterial communities were significantly different from water bacterial communities as well as from each other, indicating community development in Baltic Sea drift ice along with ice-type changes. The thick ice was dominated by typical sea-ice genera from classes Flavobacteria and Gammaproteobacteria, similar to those in polar sea-ice bacterial communities. Since the thick ice bacterial community was remarkably different from that of the parent seawater, results indicate that thick ice bacterial communities were recruited from the rarer members of the seawater bacterial community. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Single-particle characterization of ice-nucleating particles and ice particle residuals sampled by three different techniques

    Science.gov (United States)

    Worringen, A.; Kandler, K.; Benker, N.; Dirsch, T.; Mertes, S.; Schenk, L.; Kästner, U.; Frank, F.; Nillius, B.; Bundke, U.; Rose, D.; Curtius, J.; Kupiszewski, P.; Weingartner, E.; Vochezer, P.; Schneider, J.; Schmidt, S.; Weinbruch, S.; Ebert, M.

    2015-04-01

    In the present work, three different techniques to separate ice-nucleating particles (INPs) as well as ice particle residuals (IPRs) from non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed-phase clouds and allow after evaporation in the instrument for the analysis of the residuals. The Fast Ice Nucleus Chamber (FINCH) coupled with the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated particles for analysis. The instruments were run during a joint field campaign which took place in January and February 2013 at the High Alpine Research Station Jungfraujoch (Switzerland). INPs and IPRs were analyzed offline by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine their size, chemical composition and mixing state. Online analysis of the size and chemical composition of INP activated in FINCH was performed by laser ablation mass spectrometry. With all three INP/IPR separation techniques high abundances (median 20-70%) of instrumental contamination artifacts were observed (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH + IN-PCVI: steel particles). After removal of the instrumental contamination particles, silicates, Ca-rich particles, carbonaceous material and metal oxides were the major INP/IPR particle types obtained by all three techniques. In addition, considerable amounts (median abundance mostly a few percent) of soluble material (e.g., sea salt, sulfates) were observed. As these soluble particles are often not expected to act as INP/IPR, we consider them as potential measurement artifacts. Minor types of INP/IPR include soot and Pb-bearing particles. The Pb-bearing particles are mainly present as an internal mixture with other particle types. Most samples showed a maximum of the INP/IPR size distribution at 200

  18. Structural Instability in Ice VIII under Pressure

    International Nuclear Information System (INIS)

    Besson, J.; Klotz, S.; Hamel, G.; Marshall, W.; Nelmes, R.; Loveday, J.

    1997-01-01

    Below 125K, tetragonal ice VIII remains in a metastable form at ambient pressure. This form has long been considered to be identical to ice VIII, although unexplained discrepancies exist between their vibrational spectra. Neutron diffraction studies reveal an isostructural phase transformation below 2GPa related to a weakening of the bonds between the two D 2 O sublattices of ice VIII. In this new phase, ice VIII ' , the tetragonal distortion is 20% larger than in ice VIII, which accounts for the differences between the vibrational frequencies of the two phases. copyright 1997 The American Physical Society

  19. NASA/FAA Tailplane Icing Program Overview

    Science.gov (United States)

    Ratvasky, Thomas P.; VanZante, Judith Foss; Riley, James T.

    1999-01-01

    The effects of tailplane icing were investigated in a four-year NASA/FAA Tailplane Icing, Program (TIP). This research program was developed to improve the understanding, of iced tailplane aeroperformance and aircraft aerodynamics, and to develop design and training aides to help reduce the number of incidents and accidents caused by tailplane icing. To do this, the TIP was constructed with elements that included icing, wind tunnel testing, dry-air aerodynamic wind tunnel testing, flight tests, and analytical code development. This paper provides an overview of the entire program demonstrating the interconnectivity of the program elements and reports on current accomplishments.

  20. There goes the sea ice: following Arctic sea ice parcels and their properties.

    Science.gov (United States)

    Tschudi, M. A.; Tooth, M.; Meier, W.; Stewart, S.

    2017-12-01

    Arctic sea ice distribution has changed considerably over the last couple of decades. Sea ice extent record minimums have been observed in recent years, the distribution of ice age now heavily favors younger ice, and sea ice is likely thinning. This new state of the Arctic sea ice cover has several impacts, including effects on marine life, feedback on the warming of the ocean and atmosphere, and on the future evolution of the ice pack. The shift in the state of the ice cover, from a pack dominated by older ice, to the current state of a pack with mostly young ice, impacts specific properties of the ice pack, and consequently the pack's response to the changing Arctic climate. For example, younger ice typically contains more numerous melt ponds during the melt season, resulting in a lower albedo. First-year ice is typically thinner and more fragile than multi-year ice, making it more susceptible to dynamic and thermodynamic forcing. To investigate the response of the ice pack to climate forcing during summertime melt, we have developed a database that tracks individual Arctic sea ice parcels along with associated properties as these parcels advect during the summer. Our database tracks parcels in the Beaufort Sea, from 1985 - present, along with variables such as ice surface temperature, albedo, ice concentration, and convergence. We are using this database to deduce how these thousands of tracked parcels fare during summer melt, i.e. what fraction of the parcels advect through the Beaufort, and what fraction melts out? The tracked variables describe the thermodynamic and dynamic forcing on these parcels during their journey. This database will also be made available to all interested investigators, after it is published in the near future. The attached image shows the ice surface temperature of all parcels (right) that advected through the Beaufort Sea region (left) in 2014.

  1. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Arctic Sea Ice Cover

    Science.gov (United States)

    2015-09-30

    fraction product and the remotely sensed albedo product in the context of understanding the surface radiation budget. Particular attention is paid to...Stamnes, Chapter 2 The Polar Environment: Sun, Clouds, and Ice, in Ocean Colour Remote Sensing in Polar Seas, p 5-25, in press. Istomina, L, G

  2. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Artic Sea Ice Cover

    Science.gov (United States)

    2015-11-30

    the remotely sensed albedo product in the context of understanding the surface radiation budget. Particular attention is paid to the infrequent...Chapter 2 The Polar Environment: Sun, Clouds, and Ice, in Ocean Colour Remote Sensing in Polar Seas, p 5-25, in press. Istomina, L, G. Heygster, M

  3. Multi-decadal Arctic sea ice roughness.

    Science.gov (United States)

    Tsamados, M.; Stroeve, J.; Kharbouche, S.; Muller, J. P., , Prof; Nolin, A. W.; Petty, A.; Haas, C.; Girard-Ardhuin, F.; Landy, J.

    2017-12-01

    The transformation of Arctic sea ice from mainly perennial, multi-year ice to a seasonal, first-year ice is believed to have been accompanied by a reduction of the roughness of the ice cover surface. This smoothening effect has been shown to (i) modify the momentum and heat transfer between the atmosphere and ocean, (ii) to alter the ice thickness distribution which in turn controls the snow and melt pond repartition over the ice cover, and (iii) to bias airborne and satellite remote sensing measurements that depend on the scattering and reflective characteristics over the sea ice surface topography. We will review existing and novel remote sensing methodologies proposed to estimate sea ice roughness, ranging from airborne LIDAR measurement (ie Operation IceBridge), to backscatter coefficients from scatterometers (ASCAT, QUICKSCAT), to multi angle maging spectroradiometer (MISR), and to laser (Icesat) and radar altimeters (Envisat, Cryosat, Altika, Sentinel-3). We will show that by comparing and cross-calibrating these different products we can offer a consistent multi-mission, multi-decadal view of the declining sea ice roughness. Implications for sea ice physics, climate and remote sensing will also be discussed.

  4. Ice-Cliff Failure via Retrogressive Slumping

    Science.gov (United States)

    Parizek, B. R.; Christianson, K.; Alley, R. B.; Voytenko, D.; Vankova, I.; Dixon, T. H.; Holland, D.

    2016-12-01

    The magnitude and rate of future sea-level rise from warming-induced ice-sheet shrinkage remain notably uncertain. Removal of most of an ice sheet by surface melting alone requires centuries to millennia. Oceanic warming may accelerate loss by removing buttressing ice shelves and thereby speeding flow of non-floating ice into the ocean, but, until recently, modeled timescales for major dynamic ice-sheet shrinkage were centuries or longer. Beyond certain thresholds, however, observations show that warming removes floating ice shelves, leaving grounded ice cliffs from which icebergs break off directly. Cliffs higher than some limit experience rapid structural failure. Recent parameterization of this process in a comprehensive ice-flow model produced much faster sea-level rise from future rapid warming than in previous modeling studies, through formation and retreat of tall ice cliffs. Fully physical representations of this process are not yet available, however. Here, we use modeling guided by terrestrial radar data from Helheim Glacier, Greenland to show that cliffs will fail by slumping and trigger rapid retreat at a threshold height that, in crevassed ice with surface melting, may be only slightly above the 100-m maximum observed today, but may be roughly twice that (180-275 m) in mechanically-competent ice under well-drained or low-melt conditions.

  5. Evidence for radionuclide transport by sea ice

    International Nuclear Information System (INIS)

    Meese, D.A.; Tucker, W.B.; Gow, A.J.; Reimnitz, E.; Bischof, J.; Darby, D.

    1997-01-01

    Ice and ice-borne sediments were collected across the Arctic Basin during the Arctic Ocean Section, 1994 (AOS-94), a recent US/Canada trans-Arctic expedition. Sediments were analysed for 137 Cs, clay mineralogy and carbon. Concentrations of 137 Cs ranged from 5 to 73 Bq kg -1 in the ice-borne sediments. Concentrations of ice samples without sediment were all less than 1 Bq m -3 . The sediment sample with the highest 137 Cs concentration (73 Bq kg -1 ) was collected in the Beaufort Sea. This concentration was significantly higher than in bottom sediments collected in the same area, indicating an ice transport mechanism from an area with correspondingly higher concentrations. Recent results from the application of ice transport models and sediment analyses indicate that it is very likely that sediments are transported by ice, from the Siberian shelf areas to the Beaufort Sea

  6. Ice Accretion on Wind Turbine Blades

    DEFF Research Database (Denmark)

    Hudecz, Adriána; Koss, Holger; Hansen, Martin Otto Laver

    2013-01-01

    In this paper, both experimental and numerical simulations of the effects of ice accretion on a NACA 64-618 airfoil section with 7° angle of attack are presented. The wind tunnel tests were conducted in a closed-circuit climatic wind tunnel at Force Technology in Denmark. The changes of aerodynamic...... forces were monitored as ice was building up on the airfoil for glaze, rime and mixed ice. In the first part of the numerical analysis, the resulted ice profiles of the wind tunnel tests were compared to profiles estimated by using the 2D ice accretion code TURBICE. In the second part, Ansys Fluent...... of the rime iced ice profile follows the streamlines quite well, disturbing the flow the least. The TURBICE analysis agrees fairly with the profiles produced during the wind tunnel testing....

  7. Simulation of the European ice sheet through the last glacial cycle and prediction of future glaciation

    International Nuclear Information System (INIS)

    Boulton, G.S.; Payne, A.

    1992-12-01

    Global climates of the recent past appear to correlate with patterns of variation in the earths orbit round the sun. As such orbital changes can be predicted into the future, it is argued that the pattern of natural long-term future change can also be estimated. From this, future trends of glaciation can be inferred. The physical and mathematical basis of a time-dependent, thermo mechanically coupled, three dimensional ice sheet model is described. The model is driven by changes in the equilibrium line altitude (ELA) on its surface. This causes flexure of the underlying lithosphere. The model is tuned to the maximum extension of the last (Weichselian) ice sheet and driven by an ELA fluctuation which reflects the NE Atlantic sea surface temperature fluctuation pattern during the last glacial cycle in such a way that the model reproduces the ice sheet margin at the glacial maximum. The distribution of internal ice sheet velocity, temperature, basal melting rate and sub glacial permafrost penetration are all computed. The model is then tested against its predictions of the areal pattern of ice sheet expansion and decay, the pattern of crustal flexure and relative sea level change, and the distribution of till produced by the last European ice sheet. The tested model is then driven by predictions of future climate change to produce simulations of future ice sheet glaciation in northern Europe

  8. Snow and Ice Applications of AVHRR in Polar Regions: Report of a Workshop

    Science.gov (United States)

    Steffen, K.; Bindschadler, R.; Casassa, G.; Comiso, J.; Eppler, D.; Fetterer, F.; Hawkins, J.; Key, J.; Rothrock, D.; Thomas, R.; hide

    1993-01-01

    The third symposium on Remote Sensing of Snow and Ice, organized by the International Glaciological Society, took place in Boulder, Colorado, 17-22 May 1992. As part of this meeting a total of 21 papers was presented on snow and ice applications of Advanced Very High Resolution Radiometer (AVHRR) satellite data in polar regions. Also during this meeting a NASA sponsored Workshop was held to review the status of polar surface measurements from AVHRR. In the following we have summarized the ideas and recommendations from the workshop, and the conclusions of relevant papers given during the regular symposium sessions. The seven topics discussed include cloud masking, ice surface temperature, narrow-band albedo, ice concentration, lead statistics, sea-ice motion and ice-sheet studies with specifics on applications, algorithms and accuracy, following recommendations for future improvements. In general, we can affirm the strong potential of AVHRR for studying sea ice and snow covered surfaces, and we highly recommend this satellite data set for long-term monitoring of polar process studies. However, progress is needed to reduce the uncertainty of the retrieved parameters for all of the above mentioned topics to make this data set useful for direct climate applications such as heat balance studies and others. Further, the acquisition and processing of polar AVHRR data must become better coordinated between receiving stations, data centers and funding agencies to guarantee a long-term commitment to the collection and distribution of high quality data.

  9. Ice nucleation and cloud microphysical properties in tropical tropopause layer cirrus

    Directory of Open Access Journals (Sweden)

    E. J. Jensen

    2010-02-01

    Full Text Available In past modeling studies, it has generally been assumed that the predominant mechanism for nucleation of ice in the uppermost troposphere is homogeneous freezing of aqueous aerosols. However, recent in situ and remote-sensing measurements of the properties of cirrus clouds at very low temperatures in the tropical tropopause layer (TTL are broadly inconsistent with theoretial predictions based on the homogeneous freezing assumption. The nearly ubiquitous occurence of gravity waves in the TTL makes the predictions from homogeneous nucleation theory particularly difficult to reconcile with measurements. These measured properties include ice number concentrations, which are much lower than theory predicts; ice crystal size distributions, which are much broader than theory predicts; and cloud extinctions, which are much lower than theory predicts. Although other explanations are possible, one way to limit ice concentrations is to have on the order of 50 L−1 effective ice nuclei (IN that could nucleate ice at relatively low supersaturations. We suggest that ammonium sulfate particles, which would be dry much of the time in the cold TTL, are a potential IN candidate for TTL cirrus. However, this mechanism remains to be fully quantified for the size distribution of ammonium sulfate (possibly internally mixed with organics actually present in the upper troposphere. Possible implications of the observed cloud microphysical properties for ice sedimentation, dehydration, and cloud persistence are also discussed.

  10. Microshear in the deep EDML ice core analyzed using cryogenic EBSD

    Science.gov (United States)

    Kuiper, Ernst-Jan; Pennock, Gill; Drury, Martyn; Kipfstuhl, Sepp; Faria, Sérgio; Weikusat, Ilka

    2017-04-01

    Ice sheets play an important role in sea level evolution by storing large amounts of fresh water on land. The ice in an ice sheet flows from the interior of the ice sheet to the edges where it either melts or calves into the ocean. This flow of ice results from internal deformation of the ice aggregate. Dislocation creep is assumed to be the dominant deformation mechanism for polar ice and is grain size insensitive. Recently, a different deformation mechanism was identified in the deeper part of the EDML ice core (Antarctica) where, at a depth of 2385 meters, the grain size strongly decreases, the grain aspect ratio increase and, the inclination of the grain elongation changes (Faria et al., 2006; Weikusat et al., 2017). At this depth the borehole displacement increases strongly (Weikusat et al., 2017), which indicates a relatively high strain rate. Part of this EDML ice core section was studied using cryogenic electron backscattered diffraction (cryo-EBSD) (Weikusat et al, 2011). EBSD produces high resolution, full crystallographic (a-axis and c-axis) maps of the ice core samples. EBSD samples were taken from an ice core section at 2392.2 meter depth. This section was chosen for its very small grain size and the strongly aligned grain boundaries. The EBSD maps show a very low orientation gradient of <0.3° per millimetre inside the grains, which is 5-10 times lower than the orientation gradients found in other parts of the ice core. Furthermore, close to some grain boundaries, a relatively strong orientation gradient of 1°-2° per millimetre was found. The subgrain boundaries developed such that they elongate the sliding boundaries in order to accommodate the incompatibilities and maintain the strongly aligned grain boundary network. We identify the dominant deformation mechanism in this part of the ice core as grain boundary sliding accommodated by localized dislocation creep, which is a process similar to microshear (Drury and Humpreys, 1988). The existence of

  11. Role of stacking disorder in ice nucleation.

    Science.gov (United States)

    Lupi, Laura; Hudait, Arpa; Peters, Baron; Grünwald, Michael; Gotchy Mullen, Ryan; Nguyen, Andrew H; Molinero, Valeria

    2017-11-08

    The freezing of water affects the processes that determine Earth's climate. Therefore, accurate weather and climate forecasts hinge on good predictions of ice nucleation rates. Such rate predictions are based on extrapolations using classical nucleation theory, which assumes that the structure of nanometre-sized ice crystallites corresponds to that of hexagonal ice, the thermodynamically stable form of bulk ice. However, simulations with various water models find that ice nucleated and grown under atmospheric temperatures is at all sizes stacking-disordered, consisting of random sequences of cubic and hexagonal ice layers. This implies that stacking-disordered ice crystallites either are more stable than hexagonal ice crystallites or form because of non-equilibrium dynamical effects. Both scenarios challenge central tenets of classical nucleation theory. Here we use rare-event sampling and free energy calculations with the mW water model to show that the entropy of mixing cubic and hexagonal layers makes stacking-disordered ice the stable phase for crystallites up to a size of at least 100,000 molecules. We find that stacking-disordered critical crystallites at 230 kelvin are about 14 kilojoules per mole of crystallite more stable than hexagonal crystallites, making their ice nucleation rates more than three orders of magnitude higher than predicted by classical nucleation theory. This effect on nucleation rates is temperature dependent, being the most pronounced at the warmest conditions, and should affect the modelling of cloud formation and ice particle numbers, which are very sensitive to the temperature dependence of ice nucleation rates. We conclude that classical nucleation theory needs to be corrected to include the dependence of the crystallization driving force on the size of the ice crystallite when interpreting and extrapolating ice nucleation rates from experimental laboratory conditions to the temperatures that occur in clouds.

  12. Observed ices in the Solar System

    Science.gov (United States)

    Clark, Roger N.; Grundy, Will; Carlson, Robert R.; Noll, Keith; Gudipati, Murthy; Castillo-Rogez, Julie C.

    2013-01-01

    Ices have been detected and mapped on the Earth and all planets and/or their satellites further from the sun. Water ice is the most common frozen volatile observed and is also unambiguously detected or inferred in every planet and/or their moon(s) except Venus. Carbon dioxide is also extensively found in all systems beyond the Earth except Pluto although it sometimes appears to be trapped rather than as an ice on some objects. The largest deposits of carbon dioxide ice is on Mars. Sulfur dioxide ice is found in the Jupiter system. Nitrogen and methane ices are common beyond the Uranian system. Saturn’s moon Titan probably has the most complex active chemistry involving ices, with benzene (C6H6) and many tentative or inferred compounds including ices of Cyanoacetylene (HC3N), Toluene (C7H8), Cyanogen (C2N2), Acetonitrile (CH3CN), H2O, CO2, and NH3. Confirming compounds on Titan is hampered by its thick smoggy atmosphere. Ammonia was predicted on many icy moons but is notably absent among the definitively detected ices with the possible exception of Enceladus. Comets, storehouses of many compounds that could exist as ices in their nuclei, have only had small amounts of water ice definitively detected on their surfaces. Only one asteroid has had a direct detection of surface water ice, although its presence can be inferred in others. This chapter reviews some of the properties of ices that lead to their detection, and surveys the ices that have been observed on solid surfaces throughout the Solar System.

  13. Multiyear ice transport and small scale sea ice deformation near the Alaska coast measured by air-deployable Ice Trackers

    Science.gov (United States)

    Mahoney, A. R.; Kasper, J.; Winsor, P.

    2015-12-01

    Highly complex patterns of ice motion and deformation were captured by fifteen satellite-telemetered GPS buoys (known as Ice Trackers) deployed near Barrow, Alaska, in spring 2015. Two pentagonal clusters of buoys were deployed on pack ice by helicopter in the Beaufort Sea between 20 and 80 km offshore. During deployment, ice motion in the study region was effectively zero, but two days later the buoys captured a rapid transport event in which multiyear ice from the Beaufort Sea was flushed into the Chukchi Sea. During this event, westward ice motion began in the Chukchi Sea and propagated eastward. This created new openings in the ice and led to rapid elongation of the clusters as the westernmost buoys accelerated away from their neighbors to the east. The buoys tracked ice velocities of over 1.5 ms-1, with fastest motion occurring closest to the coast indicating strong current shear. Three days later, ice motion reversed and the two clusters became intermingled, rendering divergence calculations based on the area enclosed by clusters invalid. The data show no detectable difference in velocity between first year and multiyear ice floes, but Lagrangian timeseries of SAR imagery centered on each buoy show that first year ice underwent significant small-scale deformation during the event. The five remaining buoys were deployed by local residents on prominent ridges embedded in the landfast ice within 16 km of Barrow in order to track the fate of such features after they detached from the coast. Break-up of the landfast ice took place over a period of several days and, although the buoys each initially followed a similar eastward trajectory around Point Barrow into the Beaufort Sea, they rapidly dispersed over an area more than 50 km across. With rapid environmental and socio-economic change in the Arctic, understanding the complexity of nearshore ice motion is increasingly important for predict future changes in the ice and the tracking ice-related hazards

  14. EBSD in Antarctic and Greenland Ice

    Science.gov (United States)

    Weikusat, Ilka; Kuiper, Ernst-Jan; Pennock, Gill; Sepp, Kipfstuhl; Drury, Martyn

    2017-04-01

    Ice, particularly the extensive amounts found in the polar ice sheets, impacts directly on the global climate by changing the albedo and indirectly by supplying an enormous water reservoir that affects sea level change. The discharge of material into the oceans is partly controlled by the melt excess over snow accumulation, partly by the dynamic flow of ice. In addition to sliding over bedrock, an ice body deforms gravitationally under its own weight. In order to improve our description of this flow, ice microstructure studies are needed that elucidate the dominant deformation and recrystallization mechanisms involved. Deformation of hexagonal ice is highly anisotropic: ice is easily sheared in the basal plane and is about two orders of magnitude harder parallel to the c-axis. As dislocation creep is the dominant deformation mechanism in polar ice this strong anisotropy needs to be understood in terms of dislocation activity. The high anisotropy of the ice crystal is usually ascribed to a particular behaviour of dislocations in ice, namely the extension of dislocations into partials on the basal plane. Analysis of EBSD data can help our understanding of dislocation activity by characterizing subgrain boundary types thus providing a tool for comprehensive dislocation characterization in polar ice. Cryo-EBSD microstructure in combination with light microscopy measurements from ice core material from Antarctica (EPICA-DML deep ice core) and Greenland (NEEM deep ice core) are presented and interpreted regarding substructure identification and characterization. We examined one depth for each ice core (EDML: 656 m, NEEM: 719 m) to obtain the first comparison of slip system activity from the two ice sheets. The subgrain boundary to grain boundary threshold misorientation was taken to be 3-5° (Weikusat et al. 2011). EBSD analyses suggest that a large portion of edge dislocations with slip systems basal gliding on the basal plane were indeed involved in forming subgrain

  15. The effect of ice-cream-scoop water on the hygiene of ice cream.

    Science.gov (United States)

    Wilson, I. G.; Heaney, J. C.; Weatherup, S. T.

    1997-01-01

    A survey of unopened ice cream, ice cream in use, and ice-cream-scoop water (n = 91) was conducted to determine the effect of scoop water hygiene on the microbiological quality of ice cream. An aerobic plate count around 10(6) c.f.u. ml-1 was the modal value for scoop waters. Unopened ice creams generally had counts around 10(3)-10(4) c.f.u. ml-1 and this increased by one order of magnitude when in use. Many scoop waters had low coliform counts, but almost half contained > 100 c.f.u. ml-1. E. coli was isolated in 18% of ice creams in use, and in 10% of unopened ice creams. S. aureus was not detected in any sample. Statistical analysis showed strong associations between indicator organisms and increased counts in ice cream in use. EC guidelines for indicator organisms in ice cream were exceeded by up to 56% of samples. PMID:9287941

  16. The future of ice sheets and sea ice: between reversible retreat and unstoppable loss.

    Science.gov (United States)

    Notz, Dirk

    2009-12-08

    We discuss the existence of cryospheric "tipping points" in the Earth's climate system. Such critical thresholds have been suggested to exist for the disappearance of Arctic sea ice and the retreat of ice sheets: Once these ice masses have shrunk below an anticipated critical extent, the ice-albedo feedback might lead to the irreversible and unstoppable loss of the remaining ice. We here give an overview of our current understanding of such threshold behavior. By using conceptual arguments, we review the recent findings that such a tipping point probably does not exist for the loss of Arctic summer sea ice. Hence, in a cooler climate, sea ice could recover rapidly from the loss it has experienced in recent years. In addition, we discuss why this recent rapid retreat of Arctic summer sea ice might largely be a consequence of a slow shift in ice-thickness distribution, which will lead to strongly increased year-to-year variability of the Arctic summer sea-ice extent. This variability will render seasonal forecasts of the Arctic summer sea-ice extent increasingly difficult. We also discuss why, in contrast to Arctic summer sea ice, a tipping point is more likely to exist for the loss of the Greenland ice sheet and the West Antarctic ice sheet.

  17. Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine

    Science.gov (United States)

    Maselli, Olivia J.; Chellman, Nathan J.; Grieman, Mackenzie; Layman, Lawrence; McConnell, Joseph R.; Pasteris, Daniel; Rhodes, Rachael H.; Saltzman, Eric; Sigl, Michael

    2017-01-01

    Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH3SO3H) and bromine, covering the time period 1750-2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA levels decrease as a result of declining sea ice extent but bromine levels increase. We consider several possible explanations and ultimately suggest that increased acidity, specifically nitric acid, of snow on sea ice stimulates the release of reactive Br from sea ice, resulting in increased transport and deposition on the Greenland ice sheet.

  18. CO{sub 2} ICE TOWARD LOW-LUMINOSITY EMBEDDED PROTOSTARS: EVIDENCE FOR EPISODIC MASS ACCRETION VIA CHEMICAL HISTORY

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Jeong; Evans, Neal J. II [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400 Austin, TX 78712-1205 (United States); Dunham, Michael M. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Lee, Jeong-Eun [Department of Astronomy and Space Science, Kyung Hee University, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Pontoppidan, Klaus M., E-mail: hyojeong@astro.as.utexas.edu [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

    2012-10-10

    We present Spitzer IRS spectroscopy of CO{sub 2} ice bending mode spectra at 15.2 {mu}m toward 19 young stellar objects (YSOs) with luminosity lower than 1 L{sub Sun} (3 with luminosity lower than 0.1 L{sub Sun }). Ice on dust grain surfaces can encode the history of heating because pure CO{sub 2} ice forms only at elevated temperature, T > 20 K, and thus around protostars of higher luminosity. Current internal luminosities of YSOs with L < 1L{sub Sun} do not provide the conditions needed to produce pure CO{sub 2} ice at radii where typical envelopes begin. The presence of detectable amounts of pure CO{sub 2} ice would signify a higher past luminosity. Many of the spectra require a contribution from a pure, crystalline CO{sub 2} component, traced by the presence of a characteristic band splitting in the 15.2 {mu}m bending mode. About half of the sources (9 out of 19) in the low-luminosity sample have evidence for pure CO{sub 2} ice, and 6 of these have significant double-peaked features, which are very strong evidence of pure CO{sub 2} ice. The presence of the pure CO{sub 2} ice component indicates that the dust temperature, and hence luminosity of the central star/accretion disk system, must have been higher in the past. An episodic accretion scenario, in which mixed CO-CO{sub 2} ice is converted to pure CO{sub 2} ice during each high-luminosity phase, explains the presence of pure CO{sub 2} ice, the total amount of CO{sub 2} ice, and the observed residual C{sup 18}O gas.

  19. Evidence for middle Eocene Arctic sea ice from diatoms and ice-rafted debris.

    Science.gov (United States)

    Stickley, Catherine E; St John, Kristen; Koç, Nalân; Jordan, Richard W; Passchier, Sandra; Pearce, Richard B; Kearns, Lance E

    2009-07-16

    Oceanic sediments from long cores drilled on the Lomonosov ridge, in the central Arctic, contain ice-rafted debris (IRD) back to the middle Eocene epoch, prompting recent suggestions that ice appeared in the Arctic about 46 million years (Myr) ago. However, because IRD can be transported by icebergs (derived from land-based ice) and also by sea ice, IRD records are restricted to providing a history of general ice-rafting only. It is critical to differentiate sea ice from glacial (land-based) ice as climate feedback mechanisms vary and global impacts differ between these systems: sea ice directly affects ocean-atmosphere exchanges, whereas land-based ice affects sea level and consequently ocean acidity. An earlier report assumed that sea ice was prevalent in the middle Eocene Arctic on the basis of IRD, and although somewhat preliminary supportive evidence exists, these data are neither comprehensive nor quantified. Here we show the presence of middle Eocene Arctic sea ice from an extraordinary abundance of a group of sea-ice-dependent fossil diatoms (Synedropsis spp.). Analysis of quartz grain textural characteristics further supports sea ice as the dominant transporter of IRD at this time. Together with new information on cosmopolitan diatoms and existing IRD records, our data strongly suggest a two-phase establishment of sea ice: initial episodic formation in marginal shelf areas approximately 47.5 Myr ago, followed approximately 0.5 Myr later by the onset of seasonally paced sea-ice formation in offshore areas of the central Arctic. Our data establish a 2-Myr record of sea ice, documenting the transition from a warm, ice-free environment to one dominated by winter sea ice at the start of the middle Eocene climatic cooling phase.

  20. Modelling the viscoplastic behavior and the heterogeneous intracrystalline deformation of columnar ice polycrystals

    Energy Technology Data Exchange (ETDEWEB)

    Lebensohn, Ricardo A [Los Alamos National Laboratory; Montagnat, Maurine [LGGE (FRANCE); Mansuy, Philippe [MICHELIN (FRANCE); Duval, Paul [LGGE (FRANCE); Philip, A [LGGE (FRANCE)

    2008-01-01

    A full-field formulation based on Fast Fourier Transforms (FFT) has been adapted and used to predict the micromechanical fields that develop in columnar Ih ice polycrystals deforming in compression by dislocation creep. The predicted intragranular mechanical fields are in qualitative good agreement with experimental observations, in particular those involving the formation of shear and kink bands. These localization bands are associated with the large internal stresses that develop during creep in such anisotropic material, and their location, intensity, morphology and extension are found to depend strongly on the crystallographic orientation of the grains and on their interaction with neighbor crystals. The predictions of the model are also discussed in relation with the deformation of columnar sea and lake ice, and with the mechanical behavior of granular ice of glaciers and polar ice sheets, as well.

  1. Sentinel-1 provides ice drift observations for Copernicus Marine Environment Monitoring Service (CMEMS)

    DEFF Research Database (Denmark)

    Toudal Pedersen, Leif; Saldo, Roberto

    are matched every month in the processing system.The quality of the ice drift vectors are routinely verified against GPS locations of drift buoys and the RMS difference between the baseline product available through the Copernicus Marine Environment Monitoring Service data portal and GPS drifters is ~500......Sea ice drift information with an accuracy that allows also ice deformation (divergence, shear, vorticity) to be derived is being operationally generated in the Copernicus Marine Environment Monitoring Service (CMEMS).The method is based on 2-dimensional digital cross correlation where subsections......View project in 2007 when large volumes of ENVISAT ASAR images of the Polar regions became available during the International Polar Year. A dataset of daily ice drift vectors of the Polar Regions (North and South) is now available covering the time period from 2007 to the present time.In 2009 the processing...

  2. Organic Chemistry in Interstellar Ices: Connection to the Comet Halley Results

    Science.gov (United States)

    Schutte, W. A.; Agarwal, V. K.; deGroot, M. S.; Greenberg, J. M.; McCain, P.; Ferris, J. P.; Briggs, R.

    1997-01-01

    Mass spectroscopic measurements on the gas and dust in the coma of Comet Halley revealed the presence of considerable amounts of organic species. Greenberg (1973) proposed that prior to the formation of the comet UV processing of the ice mantles on grains in dense clouds could lead to the formation of complex organic molecules. Theoretical predictions of the internal UV field in dense clouds as well as the discovery in interstellar ices of species like OCS and OCN- which have been formed in simulation experiments by photoprocessing of interstellar ice analogues point to the importance of such processing. We undertook a laboratory simulation study of the formation of organic molecules in interstellar ices and their possible relevance to the Comet Halley results.

  3. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from EVERGREEN in the Greenland Sea from 1986-04-26 to 1986-05-14 (NODC Accession 8700182)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains CTD data taken during the International Ice Patrol's cruise IIP-1-86 on a front south of the Flemish Cap during April-May 1986. The data were...

  4. Pressure melting and ice skating

    Science.gov (United States)

    Colbeck, S. C.

    1995-10-01

    Pressure melting cannot be responsible for the low friction of ice. The pressure needed to reach the melting temperature is above the compressive failure stress and, if it did occur, high squeeze losses would result in very thin films. Pure liquid water cannot coexist with ice much below -20 °C at any pressure and friction does not increase suddenly in that range. If frictional heating and pressure melting contribute equally, the length of the wetted contact could not exceed 15 μm at a speed of 5 m/s, which seems much too short. If pressure melting is the dominant process, the water films are less than 0.08 μm thick because of the high pressures.

  5. Controls on Arctic sea ice from first-year and multi-year ice survival rates

    Science.gov (United States)

    Armour, K.; Bitz, C. M.; Hunke, E. C.; Thompson, L.

    2009-12-01

    The recent decrease in Arctic sea ice cover has transpired with a significant loss of multi-year (MY) ice. The transition to an Arctic that is populated by thinner first-year (FY) sea ice has important implications for future trends in area and volume. We develop a reduced model for Arctic sea ice with which we investigate how the survivability of FY and MY ice control various aspects of the sea-ice system. We demonstrate that Arctic sea-ice area and volume behave approximately as first-order autoregressive processes, which allows for a simple interpretation of September sea-ice in which its mean state, variability, and sensitivity to climate forcing can be described naturally in terms of the average survival rates of FY and MY ice. This model, used in concert with a sea-ice simulation that traces FY and MY ice areas to estimate the survival rates, reveals that small trends in the ice survival rates explain the decline in total Arctic ice area, and the relatively larger loss of MY ice area, over the period 1979-2006. Additionally, our model allows for a calculation of the persistence time scales of September area and volume anomalies. A relatively short memory time scale for ice area (~ 1 year) implies that Arctic ice area is nearly in equilibrium with long-term climate forcing at all times, and therefore observed trends in area are a clear indication of a changing climate. A longer memory time scale for ice volume (~ 5 years) suggests that volume can be out of equilibrium with climate forcing for long periods of time, and therefore trends in ice volume are difficult to distinguish from its natural variability. With our reduced model, we demonstrate the connection between memory time scale and sensitivity to climate forcing, and discuss the implications that a changing memory time scale has on the trajectory of ice area and volume in a warming climate. Our findings indicate that it is unlikely that a “tipping point” in September ice area and volume will be

  6. Observation and modeling of snow melt and superimposed ice formation on sea ice

    OpenAIRE

    Nicolaus, Marcel; Haas, Christian

    2004-01-01

    Sea ice plays a key role within the global climate system. It covers some 7% of earths surface and processes a strong seasonal cycle. Snow on sea ice even amplifies the importance of sea ice in the coupled atmosphere-ice-ocean system, because it dominates surface properties and energy balance (incl. albedo).Several quantitative observations of summer sea ice and its snow cover show the formation of superimposed ice and a gap layer underneath, which was found to be associated to high standing ...

  7. Q-space analysis of light scattering by ice crystals

    Science.gov (United States)

    Heinson, Yuli W.; Maughan, Justin B.; Ding, Jiachen; Chakrabarti, Amitabha; Yang, Ping; Sorensen, Christopher M.

    2016-12-01

    Q-space analysis is applied to extensive simulations of the single-scattering properties of ice crystals with various habits/shapes over a range of sizes. The analysis uncovers features common to all the shapes: a forward scattering regime with intensity quantitatively related to the Rayleigh scattering by the particle and the internal coupling parameter, followed by a Guinier regime dependent upon the particle size, a complex power law regime with incipient two dimensional diffraction effects, and, in some cases, an enhanced backscattering regime. The effects of significant absorption on the scattering profile are also studied. The overall features found for the ice crystals are similar to features in scattering from same sized spheres.

  8. The 3 micron ice band

    International Nuclear Information System (INIS)

    Greenberg, J.M.; Bult, C.E.P.M. van de

    1984-01-01

    Ever since it was proposed that H 2 O could be a dominant constituent of interstellar grains, its detection, or lack thereof, has played a large role in theories of grains and their evolution. It now appears possible to provide a basic theoretical structure for the evolution of grains in molecular clouds based on current observational evidence and laboratory experiments on the ice band. Both band strengths and shapes can be reasonably predicted by grain models. (U.K.)

  9. Solar ice; Sonne und Eis

    Energy Technology Data Exchange (ETDEWEB)

    Rolland, Simon

    2012-07-01

    Fishing and fish marketing are the major sources of income at Santo Antao, the biggest of the Cape Verde Islands off Africa's west coast. In the coastal village of Monte Trigo, ice for keeping the fish fresh is now produced by a photovoltaic plant. As the Alliance for Rural Electrification recently reported, the community now gets its power from a 27.3 kW local power grid.

  10. Ice storm 1998 : lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    McCready, J. [Eastern Ontario Model Forest, Kemptville, ON (Canada)

    2006-07-01

    This paper presented details of a partnership formed in response to the ice storm of 1998, which caused extensive damage to trees in woodlots and urban settings in eastern Ontario and western Quebec. The aim of the Ice Storm Forest Recovery Group was to assist in the recovery of eastern forests, collect information on the extent of the damage to trees as well as contribute to the development of assistance programs for woodlot owners and municipalities. In response to the group's request, an initial aerial survey was conducted by the Ontario Ministry of Natural Resources to map the extent of the damage in eastern Ontario, which was followed by a more scientific survey with the Canadian Forest Service through the development of a flying grid pattern to observe the status of trees, followed by extensive ground checks. Damage was variable, depending on tree species, stand age and composition, management practices, wind direction, topography and ice deposition patterns. A summary of the severity of damage indicated that conifers suffered less than hardwoods. Consultants were hired to prepare news releases and extension notes to the public in order to provide information for the caring of trees. Various educational workshops were held which attracted large numbers of landowners and homeowners. A literature review was undertaken to produce a summary of current published knowledge covering the effects of storms and ice damage to trees and forests. Science efforts were published in a series of papers, and financial assistance programs were then organized by governmental agencies. It was concluded that cooperation between all agencies, groups and levels of government is needed in order to coordinate effective emergency strategies. 7 refs., 1 tab., 1 fig.

  11. Simulating Extraterrestrial Ices in the Laboratory

    Science.gov (United States)

    Berisford, D. F.; Carey, E. M.; Hand, K. P.; Choukroun, M.

    2017-12-01

    Several ongoing experiments at JPL attempt to simulate the ice environment for various regimes associated with icy moons. The Europa Penitent Ice Experiment (EPIX) simulates the surface environment of an icy moon, to investigate the physics of ice surface morphology growth. This experiment features half-meter-scale cryogenic ice samples, cryogenic radiative sink environment, vacuum conditions, and diurnal cycling solar simulation. The experiment also includes several smaller fixed-geometry vacuum chambers for ice simulation at Earth-like and intermediate temperature and vacuum conditions for development of surface morphology growth scaling relations. Additionally, an ice cutting facility built on a similar platform provides qualitative data on the mechanical behavior of cryogenic ice with impurities under vacuum, and allows testing of ice cutting/sampling tools relevant for landing spacecraft. A larger cutting facility is under construction at JPL, which will provide more quantitative data and allow full-scale sampling tool tests. Another facility, the JPL Ice Physics Laboratory, features icy analog simulant preparation abilities that range icy solar system objects such as Mars, Ceres and the icy satellites of Saturn and Jupiter. In addition, the Ice Physics Lab has unique facilities for Icy Analog Tidal Simulation and Rheological Studies of Cryogenic Icy Slurries, as well as equipment to perform thermal and mechanical properties testing on icy analog materials and their response to sinusoidal tidal stresses.

  12. Coordinated Mapping of Sea Ice Deformation Features with Autonomous Vehicles

    Science.gov (United States)

    Maksym, T.; Williams, G. D.; Singh, H.; Weissling, B.; Anderson, J.; Maki, T.; Ackley, S. F.

    2016-12-01

    Decreases in summer sea ice extent in the Beaufort and Chukchi Seas has lead to a transition from a largely perennial ice cover, to a seasonal ice cover. This drives shifts in sea ice production, dynamics, ice types, and thickness distribution. To examine how the processes driving ice advance might also impact the morphology of the ice cover, a coordinated ice mapping effort was undertaken during a field campaign in the Beaufort Sea in October, 2015. Here, we present observations of sea ice draft topography from six missions of an Autonomous Underwater Vehicle run under different ice types and deformation features observed during autumn freeze-up. Ice surface features were also mapped during coordinated drone photogrammetric missions over each site. We present preliminary results of a comparison between sea ice surface topography and ice underside morphology for a range of sample ice types, including hummocked multiyear ice, rubble fields, young ice ridges and rafts, and consolidated pancake ice. These data are compared to prior observations of ice morphological features from deformed Antarctic sea ice. Such data will be useful for improving parameterizations of sea ice redistribution during deformation, and for better constraining estimates of airborne or satellite sea ice thickness.

  13. Demonstration of Sparse Signal Reconstruction for Radar Imaging of Ice Sheets

    Science.gov (United States)

    Heister, Anton; Scheiber, Rolf

    2017-04-01

    Conventional processing of ice-sounder data produces 2-D images of the ice sheet and bed, where the two dimensions are along-track and depth, while the across-track direction is fixed to nadir. The 2-D images contain information about the topography and radar reflectivity of the ice sheet's surface, bed, and internal layers in the along-track direction. Having multiple antenna phase centers in the across-track direction enables the production of 3-D images of the ice sheet and bed. Compared to conventional 2-D images, these contain additional information about the surface and bed topography, and orientation of the internal layers over a swath in the across-track direction. We apply a 3-D SAR tomographic ice-sounding method based on sparse signal reconstruction [1] to the data collected by Center for Remote Sensing of Ice Sheets (CReSIS) in 2008 in Greenland [2] using their multichannel coherent radar depth sounder (MCoRDS). The MCoRDS data have 16 effective phase centers which allows us to better understand the performance of the method. Lastly we offer sparsity improvement by including wavelet dictionaries into the reconstruction.The results show improved scene feature resolvability in across-track direction compared to MVDR beamformer. References: [1] A. Heister, R. Scheiber, "First Analysis of Sparse Signal Reconstruction for Radar Imaging of Ice Sheets". In: Proceedings of EUSAR, pp. 788-791, June 2016. [2] X. Wu, K. C. Jezek, E. Rodriguez, S. Gogineni, F. Rodriguez-Morales, and A. Freeman, "Ice sheet bed mapping with airborne SAR tomography". IEEE Transactions on Geoscience and Remote Sensing, vol. 49, no. 10 Part 1, pp. 3791-3802, 2011.

  14. Sintering and microstructure of ice: a review

    International Nuclear Information System (INIS)

    Blackford, Jane R

    2007-01-01

    Sintering of ice is driven by the thermodynamic requirement to decrease surface energy. The structural morphology of ice in nature has many forms-from snowflakes to glaciers. These forms and their evolution depend critically on the balance between the thermodynamic and kinetic factors involved. Ice is a crystalline material so scientific understanding and approaches from more conventional materials can be applied to ice. The early models of solid state ice sintering are based on power law models originally developed in metallurgy. For pressure sintering of ice, these are based on work on hot isostatic pressing of metals and ceramics. Recent advances in recognizing the grain boundary groove geometry between sintering ice particles require models that use new approaches in materials science. The newer models of sintering in materials science are beginning to incorporate more realistic processing conditions and microstructural complexity, and so there is much to be gained from applying these to ice in the future. The vapour pressure of ice is high, which causes it to sublime readily. The main mechanism for isothermal sintering of ice particles is by vapour diffusion; however other transport mechanisms certainly contribute. Plastic deformation with power law creep combined with recrystallization become important mechanisms in sintering with external pressure. Modern experimental techniques, low temperature scanning electron microscopy and x-ray tomography, are providing new insights into the evolution of microstructures in ice. Sintering in the presence of a small volume fraction of the liquid phase causes much higher bond growth rates. This may be important in natural snow which contains impurities that form a liquid phase. Knowledge of ice microstructure and sintering is beneficial in understanding mechanical behaviour in ice friction and the stability of snow slopes prone to avalanches. (topical review)

  15. Theory of ice-skating

    Science.gov (United States)

    Le Berre, Martine; Pomeau, Yves

    2015-10-01

    Almost frictionless skating on ice relies on a thin layer of melted water insulating mechanically the blade of the skate from ice. Using the basic equations of fluid mechanics and Stefan law, we derive a set of two coupled equations for the thickness of the film and the length of contact, a length scale which cannot be taken as its value at rest. The analytical study of these equations allows to define a small a-dimensional parameter depending on the longitudinal coordinate which can be neglected everywhere except close to the contact points at the front and the end of the blade, where a boundary layer solution is given. This solution provides without any calculation the order of magnitude of the film thickness, and its dependence with respect to external parameters like the velocity and mass of the skater and the radius of profile and bite angle of the blade, in good agreement with the numerical study. Moreover this solution also shows that a lubricating water layer of macroscopic thickness always exists for standard values of ice skating data, contrary to what happens in the case of cavitation of droplets due to thermal heating (Leidenfrost effect).

  16. ICE-DIP kicks off

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Last month, Marie Curie Actions* added a new member to its ranks: ICE-DIP (the Intel-CERN European Doctorate Industrial Program). The programme held its kick-off meeting on 18-19 February in Leixlip near Dublin, Ireland, at Intel’s premises.   Building on CERN’s long-standing relationship with Intel in the CERN openlab project, ICE-DIP brings together CERN and industrial partners, Intel and Xena Networks, to train five Early Stage ICT Researchers. These researchers will be funded by the European Commission and granted a CERN Fellow contract while enrolled in the doctoral programmes at partner universities Dublin City University and National University of Ireland Maynooth. The researchers will go on extended secondments to Intel Labs Europe locations across Europe during their three-year training programme. The primary focus of the ICE-DIP researchers will be the development of techniques for acquiring and processing data that are relevant for the trigger a...

  17. Ice/Bedrock Feedbacks as a Principle Contributor to Glacial-Interglacial Oscillations

    Science.gov (United States)

    Kimmel, J.; Lee, K.; Jackson, C. H.

    2014-12-01

    Since the mid-Pleistocene, the oscillation between glacial and interglacial climate states occurs with a period of approximately 100 kyr. Each cycle is comprised of a slow glaciation with a subsequent rapid deglaciation. While the solar forcing is clearly an important driver for these transitions, the power spectrum of the solar forcing is quite different from the subsequent climate response and, in general, does not have a noticeable correlation with global ice volume. Instead, previous studies have shown that internal climate processes and their interactions (e.g., CO2, water vapor, isostatic bed response) play a significant role in producing these global climate cycles. The rapid retreat of large ice sheets at the start of an interglacial is often attributed to the interaction between surface and atmospheric processes. While calving is thought to amplify this retreat, it is not typically considered a principle driver of the ice sheet response. Our study investigates the potential for ice/bedrock feedbacks to be a principle contributor in shaping the glacial-interglacial climate oscillation -- particularly the rapid deglaciation that precedes an interglacial. The ice sheet model we develop includes a piecewise linear ice/bedrock feedback while atmospheric and surface processes are taken to be as simple as possible. Due to the long timescale of the bedrock response and the rapid mass loss due to calving, the model ice sheet exhibits rapid deglaciation from a stable maximum when it retreats through an overdeepening. However, ice sheet advance is also shown to be as rapid unless a more complex bedrock response is considered. In particular, we show that a forebulge created by the displacement of the mantle adds a new stable branch to the volume/equilibrium line bifurcation diagram that results in slower growth of the ice sheet during glaciation.

  18. Microwave single-scattering properties of randomly oriented soft-ice hydrometeors

    Directory of Open Access Journals (Sweden)

    D. Casella

    2008-11-01

    Full Text Available Large ice hydrometeors are usually present in intense convective clouds and may significantly affect the upwelling radiances that are measured by satellite-borne microwave radiometers – especially, at millimeter-wavelength frequencies. Thus, interpretation of these measurements (e.g., for precipitation retrieval requires knowledge of the single scattering properties of ice particles. On the other hand, shape and internal structure of these particles (especially, the larger ones is very complex and variable, and therefore it is necessary to resort to simplifying assumptions in order to compute their single-scattering parameters.

    In this study, we use the discrete dipole approximation (DDA to compute the absorption and scattering efficiencies and the asymmetry factor of two kinds of quasi-spherical and non-homogeneous soft-ice particles in the frequency range 50–183 GHz. Particles of the first kind are modeled as quasi-spherical ice particles having randomly distributed spherical air inclusions. Particles of the second kind are modeled as random aggregates of ice spheres having random radii. In both cases, particle densities and dimensions are coherent with the snow hydrometeor category that is utilized by the University of Wisconsin – Non-hydrostatic Modeling System (UW-NMS cloud-mesoscale model. Then, we compare our single-scattering results for randomly-oriented soft-ice hydrometeors with corresponding ones that make use of: a effective-medium equivalent spheres, b solid-ice equivalent spheres, and c randomly-oriented aggregates of ice cylinders. Finally, we extend to our particles the scattering formulas that have been developed by other authors for randomly-oriented aggregates of ice cylinders.

  19. On the Predictability of Sea Ice

    Science.gov (United States)

    Blanchard-Wrigglesworth, Edward

    We investigate the persistence and predictability of sea ice in numerical models and observations. We first use the 3rd generation Community Climate System Model (CCSM3) General Circulation Model (GCM) to investigate the inherent persistence of sea-ice area and thickness. We find that sea-ice area anomalies have a seasonal decay timescale, exhibiting an initial decorrelation similar to a first order auto-regressive (AR1, or red noise) process. Beyond this initial loss of memory, there is a re-emergence of memory at certain times of the year. There are two distinct modes of re-emergence in the model, one driven by the seasonal coupling of area and thickness anomalies in the summer, the other by the persistence of upper ocean temperature anomalies that originate from ice anomalies in the melt season and then influence ice anomalies in the growth season. Comparison with satellite observations where available indicate these processes appear in nature. We then use the 4th generation CCSM (CCSM4) to investigate the partition of Arctic sea-ice predictability into its initial-value and boundary forced components under present day forcing conditions. We find that initial-value predictability lasts for 1-2 years for sea-ice area, and 3-4 years for sea-ice volume. Forced predictability arises after just 4-5 years for both area and volume. Initial-value predictability of sea-ice area during the summer hinges on the coupling between thickness and area anomalies during that season. We find that the loss of initial-value predictability with time is not uniform --- there is a rapid loss of predictability of sea-ice volume during the late spring early summer associated with snow melt and albedo feedbacks. At the same time, loss of predictability is not uniform across different regions. Given the usefulness of ice thickness as a predictor of summer sea-ice area, we obtain a hindcast of September sea-ice area initializing the GCM on May 1with an estimate of observed sea-ice thickness

  20. Study of the functinal characteristics and of the boot use by military policeman and its influence in the performance in the activity of patrol

    Directory of Open Access Journals (Sweden)

    Ana Claudia Vieira Martins

    2005-06-01

    Full Text Available This descriptive diagnosis study had the objective to evaluate the functional characteristics and the use of the boots worn by the police officers while they are on duty patrol walking on Florianópolis streets, as well as the influency of the boots in this activity. Selected by not-probabilistic sampling in a casual-systematic way, 234 police officers volunteered to take part in this study. The instrument used was a questionnaire assorted with clarity level of 0.93, validity of 0.85 and reliability of 0.95. According to the results, most police officers have only a pair of boots, which were worn on average 11 hours daily. To the boot usage was attributed the incidence of foot injuries such as callosity, chilblain, embedded nails and blisters. For these police officers the discomforts (overheating, pain and humidity on the feet as well as pain in the body caused by the boot interfered in their work routine taking them to classified their shoes as inappropriate, following the criteria of comfort, safety and durability. Therefore, it was concluded that the boots seemed not to be the ideal shoes in terms of comfort and job performance, because they interfered in their daily routine, causing functional and structural adaptations in the human body during the performance of motor tasks. RESUMO Este estudo descritivo diagnóstico teve como objetivo avaliar as características funcionais e de uso do coturno utilizado pelos policiais militares que realizam a tarefa de locomoção a pé durante as rondas nas ruas de Florianópolis, bem como sua influência nesta atividade. Selecionados por amostragem não-probabilística, casualsistemática por voluntariado, participaram 234 policiais militares. O instrumento utilizado foi um questionário misto com índice de clareza de 0,93, validade de 0,85 e fidedignidade de 0,95. De acordo com os resultados, a maioria dos policiais possui apenas um par de coturnos, permanecendo em média 11 horas diárias com este

  1. Understanding Ice Shelf Basal Melting Using Convergent ICEPOD Data Sets: ROSETTA-Ice Study of Ross Ice Shelf

    Science.gov (United States)

    Bell, R. E.; Frearson, N.; Tinto, K. J.; Das, I.; Fricker, H. A.; Siddoway, C. S.; Padman, L.

    2017-12-01

    The future stability of the ice shelves surrounding Antarctica will be susceptible to increases in both surface and basal melt as the atmosphere and ocean warm. The ROSETTA-Ice program is targeted at using the ICEPOD airborne technology to produce new constraints on Ross Ice Shelf, the underlying ocean, bathymetry, and geologic setting, using radar sounding, gravimetry and laser altimetry. This convergent approach to studying the ice-shelf and basal processes enables us to develop an understanding of the fundamental controls on ice-shelf evolution. This work leverages the stratigraphy of the ice shelf, which is detected as individual reflectors by the shallow-ice radar and is often associated with surface scour, form close to the grounding line or pinning points on the ice shelf. Surface accumulation on the ice shelf buries these reflectors as the ice flows towards the calving front. This distinctive stratigraphy can be traced across the ice shelf for the major East Antarctic outlet glaciers and West Antarctic ice streams. Changes in the ice thickness below these reflectors are a result of strain and basal melting and freezing. Correcting the estimated thickness changes for strain using RIGGS strain measurements, we can develop decadal-resolution flowline distributions of basal melt. Close to East Antarctica elevated melt-rates (>1 m/yr) are found 60-100 km from the calving front. On the West Antarctic side high melt rates primarily develop within 10 km of the calving front. The East Antarctic side of Ross Ice Shelf is dominated by melt driven by saline water masses that develop in Ross Sea polynyas, while the melting on the West Antarctic side next to Hayes Bank is associated with modified Continental Deep Water transported along the continental shelf. The two sides of Ross Ice Shelf experience differing basal melt in part due to the duality in the underlying geologic structure: the East Antarctic side consists of relatively dense crust, with low amplitude

  2. Duality of Ross Ice Shelf systems: crustal boundary, ice sheet processes and ocean circulation from ROSETTA-Ice surveys

    Science.gov (United States)

    Tinto, K. J.; Siddoway, C. S.; Padman, L.; Fricker, H. A.; Das, I.; Porter, D. F.; Springer, S. R.; Siegfried, M. R.; Caratori Tontini, F.; Bell, R. E.

    2017-12-01

    Bathymetry beneath Antarctic ice shelves controls sub-ice-shelf ocean circulation and has a major influence on the stability and dynamics of the ice sheets. Beneath the Ross Ice Shelf, the sea-floor bathymetry is a product of both tectonics and glacial processes, and is influenced by the processes it controls. New aerogeophysical surveys have revealed a fundamental crustal boundary bisecting the Ross Ice Shelf and imparting a duality to the Ross Ice Shelf systems, encompassing bathymetry, ocean circulation and ice flow history. The ROSETTA-Ice surveys were designed to increase the resolution of Ross Ice Shelf mapping from the 55 km RIGGS survey of the 1970s to a 10 km survey grid, flown over three years from New York Air National Guard LC130s. Radar, LiDAR, gravity and magnetic instruments provide a top to bottom profile of the ice shelf and the underlying seafloor, with 20 km resolution achieved in the first two survey seasons (2015 and 2016). ALAMO ocean-profiling floats deployed in the 2016 season are measuring the temperature and salinity of water entering and exiting the sub-ice water cavity. A significant east-west contrast in the character of the magnetic and gravity fields reveals that the lithospheric boundary between East and West Antarctica exists not at the base of the Transantarctic Mountains (TAM), as previously thought, but 300 km further east. The newly-identified boundary spatially coincides with the southward extension of the Central High, a rib of shallow basement identified in the Ross Sea. The East Antarctic side is characterized by lower amplitude magnetic anomalies and denser TAM-type lithosphere compared to the West Antarctic side. The crustal structure imparts a fundamental duality on the overlying ice and ocean, with deeper bathymetry and thinner ice on the East Antarctic side creating a larger sub-ice cavity for ocean circulation. The West Antarctic side has a shallower seabed, more restricted ocean access and a more complex history of

  3. Bimodal SLD Ice Accretion on a NACA 0012 Airfoil Model

    Science.gov (United States)

    Potapczuk, Mark; Tsao, Jen-Ching; King-Steen, Laura

    2016-01-01

    This presentation describes the results of ice accretion measurements on a NACA 0012 airfoil model, from the NASA Icing Research Tunnel, using an icing cloud composed of a bimodal distribution of Supercooled Large Droplets. The data consists of photographs, laser scans of the ice surface, and measurements of the mass of ice for each icing condition. The results of ice shapes accumulated as a result of exposure to an icing cloud with a bimodal droplet distribution were compared to the ice shapes resulting from an equivalent cloud composed of a droplet distribution with a standard bell curve shape.

  4. On Wave-Ice Interaction in the Arctic Marginal Ice Zone: Dispersion, Attenuation, and Ice Response

    Science.gov (United States)

    2016-06-01

    described in Thorndike et al. [1975]. Waves have not played a role in CICE because their influence is limited to the MIZ which was traditionally a... Thorndike et al, [1979] d(p) is area conserving, so that the integral over all ranges of ice property, p, is unity. � ()...most effected by lateral melt < O(30 m). Observations of FSD [Rothrock and Thorndike , 1984; Toyota et al., 2006], done through analysis of aerial

  5. Road icing forecasting and detecting system

    Science.gov (United States)

    Xu, Hongke; Zheng, Jinnan; Li, Peiqi; Wang, Qiucai

    2017-05-01

    Regard for the facts that the low accuracy and low real-time of the artificial observation to determine the road icing condition, and it is difficult to forecast icing situation, according to the main factors influencing the road-icing, and the electrical characteristics reflected by the pavement ice layer, this paper presents an innovative system, that is, ice-forecasting of the highway's dangerous section. The system bases on road surface water salinity measurements and pavement temperature measurement to calculate the freezing point of water and temperature change trend, and then predicts the occurrence time of road icing; using capacitance measurements to verdict the road surface is frozen or not; This paper expounds the method of using single chip microcomputer as the core of the control system and described the business process of the system.

  6. MODIS Snow and Sea Ice Products

    Science.gov (United States)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.

    2004-01-01

    In this chapter, we describe the suite of Earth Observing System (EOS) Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua snow and sea ice products. Global, daily products, developed at Goddard Space Flight Center, are archived and distributed through the National Snow and Ice Data Center at various resolutions and on different grids useful for different communities Snow products include binary snow cover, snow albedo, and in the near future, fraction of snow in a 5OO-m pixel. Sea ice products include ice extent determined with two different algorithms, and sea ice surface temperature. The algorithms used to develop these products are described. Both the snow and sea ice products, available since February 24,2000, are useful for modelers. Validation of the products is also discussed.

  7. IceProd 2 Usage Experience

    Science.gov (United States)

    Delventhal, D.; Schultz, D.; Diaz Velez, J. C.

    2017-10-01

    IceProd is a data processing and management framework developed by the IceCube Neutrino Observatory for processing of Monte Carlo simulations, detector data, and data driven analysis. It runs as a separate layer on top of grid and batch systems. This is accomplished by a set of daemons which process job workflow, maintaining configuration and status information on the job before, during, and after processing. IceProd can also manage complex workflow DAGs across distributed computing grids in order to optimize usage of resources. IceProd has recently been rewritten to increase its scaling capabilities, handle user analysis workflows together with simulation production, and facilitate the integration with 3rd party scheduling tools. IceProd 2, the second generation of IceProd, has been running in production for several months now. We share our experience setting up the system and things we’ve learned along the way.

  8. Design of an airborne P-band ice sounding radar

    DEFF Research Database (Denmark)

    Dall, Jørgen; Skou, Niels; Kusk, Anders

    2006-01-01

    is to test new ice sounding techniques, e.g. polarimetry, synthetic aperture processing, and coherent clutter suppression. A system analysis involving ice scattering models confirms that it is feasible to detect the bedrock through 4 km of ice and to detect deep ice layers. The ice sounder design features...

  9. National Ice Center Arctic Sea Ice Charts and Climatologies in Gridded Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Ice Center (NIC) is an inter-agency sea ice analysis and forecasting center comprised of the Department of Commerce/NOAA, the Department of...

  10. SmaggIce 2.0: Additional Capabilities for Interactive Grid Generation of Iced Airfoils

    Science.gov (United States)

    Kreeger, Richard E.; Baez, Marivell; Braun, Donald C.; Schilling, Herbert W.; Vickerman, Mary B.

    2008-01-01

    The Surface Modeling and Grid Generation for Iced Airfoils (SmaggIce) software toolkit has been extended to allow interactive grid generation for multi-element iced airfoils. The essential phases of an icing effects study include geometry preparation, block creation and grid generation. SmaggIce Version 2.0 now includes these main capabilities for both single and multi-element airfoils, plus an improved flow solver interface and a variety of additional tools to enhance the efficiency and accuracy of icing effects studies. An overview of these features is given, especially the new multi-element blocking strategy using the multiple wakes method. Examples are given which illustrate the capabilities of SmaggIce for conducting an icing effects study for both single and multi-element airfoils.

  11. Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes ice motion and topography measurements that were taken by measuring movement and altitude of poles set in the West Antarctic Ice Shelf. The...

  12. Cook Inlet and Kenai Peninsula, Alaska ESI: ICE (Ice Extent Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains locations of ice extent in Cook Inlet, Alaska. Vector lines in the data set represent 50 percent ice coverage. Location-specific type and...

  13. A review of the physics of ice surface friction and the development of ice skating.

    Science.gov (United States)

    Formenti, Federico

    2014-01-01

    Our walking and running movement patterns require friction between shoes and ground. The surface of ice is characterised by low friction in several naturally occurring conditions, and compromises our typical locomotion pattern. Ice skates take advantage of this slippery nature of ice; the first ice skates were made more than 4000 years ago, and afforded the development of a very efficient form of human locomotion. This review presents an overview of the physics of ice surface friction, and discusses the most relevant factors that can influence ice skates' dynamic friction coefficient. It also presents the main stages in the development of ice skating, describes the associated implications for exercise physiology, and shows the extent to which ice skating performance improved through history. This article illustrates how technical and materials' development, together with empirical understanding of muscle biomechanics and energetics, led to one of the fastest forms of human powered locomotion.

  14. IceBridge Radar L3 Tomographic Ice Thickness V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Level-3 tomographic ice thickness measurements derived from data captured by the Center for Remote Sensing of Ice Sheets (CReSIS) Multichannel...

  15. Arctic sea ice decline contributes to thinning lake ice trend in northern Alaska

    Science.gov (United States)

    Alexeev, Vladimir; Arp, Christopher D.; Jones, Benjamin M.; Cai, Lei

    2016-01-01

    Field measurements, satellite observations, and models document a thinning trend in seasonal Arctic lake ice growth, causing a shift from bedfast to floating ice conditions. September sea ice concentrations in the Arctic Ocean since 1991 correlate well (r = +0.69,p Research and Forecasting model output produced a 7% decrease in lake ice growth when 2007/08 sea ice was imposed on 1991/92 climatology and a 9% increase in lake ice growth for the opposing experiment. Here, we clearly link early winter 'ocean-effect' snowfall and warming to reduced lake ice growth. Future reductions in sea ice extent will alter hydrological, biogeochemical, and habitat functioning of Arctic lakes and cause sub-lake permafrost thaw.

  16. Ice Draft and Ice Velocity Data in the Beaufort Sea, 1990-2003, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides measurement of sea ice draft (m) and the movement of sea ice (cm/s) over the continental shelf of the Eastern Beaufort Sea. The data set spans...

  17. Ice nucleation properties of mineral dusts

    OpenAIRE

    Steinke, Isabelle

    2013-01-01

    Ice nucleation in clouds has a significant impact on the global hydrological cycle as well as on the radiative budget of the Earth. The AIDA cloud chamber was used to investigate the ice nucleation efficiency of various atmospherically relevant mineral dusts. From experiments with Arizona Test Dust (ATD) a humidity and temperature dependent ice nucleation active surface site density parameterization was developed to describe deposition nucleation at temperatures above 220 K. Based...

  18. Elevator deflections on the icing process

    Science.gov (United States)

    Britton, Randall K.

    1990-01-01

    The effect of elevator deflection of the horizontal stabilizer for certain icing parameters is investigated. Elevator deflection can severely change the lower and upper leading-edge impingement limits, and ice can accrete on the elevator itself. Also, elevator deflection had practically no effect on the maximum local collection efficiency. It is shown that for severe icing conditions (large water droplets), elevator deflections that increase the projected height of the airfoil can significantly increase the total collection efficiency of the airfoil.

  19. 21 CFR 880.6050 - Ice bag.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ice bag. 880.6050 Section 880.6050 Food and Drugs....6050 Ice bag. (a) Identification. An ice bag is a device intended for medical purposes that is in the... the body. The device may include a holder that keeps the bag in place against an external area of the...

  20. Ice Storms in a Changing Climate

    Science.gov (United States)

    2016-06-01

    CHANGING CLIMATE by Jennifer M. McNitt June 2016 Thesis Advisor: Wendell Nuss Co-Advisor: David W. Titley THIS PAGE INTENTIONALLY LEFT...SUBTITLE ICE STORMS IN A CHANGING CLIMATE 5. FUNDING NUMBERS 6. AUTHOR(S) Jennifer M. McNitt 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS...increase in global temperatures, due to climate change, could affect the frequency, intensity, and geographic location of ice storms. Three known ice

  1. On the origin of the ice ages

    OpenAIRE

    Oerlemans, J.

    1984-01-01

    Ice sheet dynamics provide a possible explanation for the 100 kyr power in climatic records. Some numerical experiments presented here show that even the transition from an essentially ice-free earth to a glacial can be produced by a northern hemisphere ice-sheet model, provided that a slow general cooling on the northern hemisphere continents is imposed. Such a cooling could for example be the result of continental drift.

  2. Greenland Ice Shelves and Ice Tongues

    DEFF Research Database (Denmark)

    Reeh, Niels

    2017-01-01

    literature and physical properties are reviewed. There exists a difference between: (1) Floating glaciers in northern Greenland (>77°N) which experience bottom melting as their dominant ablation mechanism and calve relatively thin, but large (km-sized) tabular icebergs (‘ice islands’), and (2) Grounded...... glaciers further south (iceberg calving provides the dominant ablation mechanism. The relatively smaller iceberg discharge in northern Greenland is closely related to the occurrence of extended floating glacier sections, allowing bottom melting estimated at up to 10 m year−1 for locations...

  3. Icing Branch Current Research Activities in Icing Physics

    Science.gov (United States)

    Vargas, Mario

    2009-01-01

    Current development: A grid block transformation scheme which allows the input of grids in arbitrary reference frames, the use of mirror planes, and grids with relative velocities has been developed. A simple ice crystal and sand particle bouncing scheme has been included. Added an SLD splashing model based on that developed by William Wright for the LEWICE 3.2.2 software. A new area based collection efficiency algorithm will be incorporated which calculates trajectories from inflow block boundaries to outflow block boundaries. This method will be used for calculating and passing collection efficiency data between blade rows for turbo-machinery calculations.

  4. Possible Mechanisms for Turbofan Engine Ice Crystal Icing at High Altitude

    Science.gov (United States)

    Tsao, Jen-Ching; Struk, Peter M.; Oliver, Michael J.

    2016-01-01

    A thermodynamic model is presented to describe possible mechanisms of ice formation on unheated surfaces inside a turbofan engine compression system from fully glaciated ice crystal clouds often formed at high altitude near deep convective weather systems. It is shown from the analysis that generally there could be two distinct types of ice formation: (1) when the "surface freezing fraction" is in the range of 0 to 1, dominated by the freezing of water melt from fully or partially melted ice crystals, the ice structure is formed from accretion with strong adhesion to the surface, and (2) when the "surface melting fraction" is the range of 0 to 1, dominated by the further melting of ice crystals, the ice structure is formed from accumulation of un-melted ice crystals with relatively weak bonding to the surface. The model captures important qualitative trends of the fundamental ice-crystal icing phenomenon reported earlier (Refs. 1 and 2) from the research collaboration work by NASA and the National Research Council (NRC) of Canada. Further, preliminary analysis of test data from the 2013 full scale turbofan engine ice crystal icing test (Ref. 3) conducted in the NASA Glenn Propulsion Systems Laboratory (PSL) has also suggested that (1) both types of ice formation occurred during the test, and (2) the model has captured some important qualitative trend of turning on (or off) the ice crystal ice formation process in the tested engine low pressure compressor (LPC) targeted area under different icing conditions that ultimately would lead to (or suppress) an engine core roll back (RB) event.

  5. Sea ice roughness: the key for predicting Arctic summer ice albedo

    Science.gov (United States)

    Landy, J.; Ehn, J. K.; Tsamados, M.; Stroeve, J.; Barber, D. G.

    2017-12-01

    Although melt ponds on Arctic sea ice evolve in stages, ice with smoother surface topography typically allows the pond water to spread over a wider area, reducing the ice-albedo and accelerating further melt. Building on this theory, we simulated the distribution of meltwater on a range of statistically-derived topographies to develop a quantitative relationship between premelt sea ice surface roughness and summer ice albedo. Our method, previously applied to ICESat observations of the end-of-winter sea ice roughness, could account for 85% of the variance in AVHRR observations of the summer ice-albedo [Landy et al., 2015]. Consequently, an Arctic-wide reduction in sea ice roughness over the ICESat operational period (from 2003 to 2008) explained a drop in ice-albedo that resulted in a 16% increase in solar heat input to the sea ice cover. Here we will review this work and present new research linking pre-melt sea ice surface roughness observations from Cryosat-2 to summer sea ice albedo over the past six years, examining the potential of winter roughness as a significant new source of sea ice predictability. We will further evaluate the possibility for high-resolution (kilometre-scale) forecasts of summer sea ice albedo from waveform-level Cryosat-2 roughness data in the landfast sea ice zone of the Canadian Arctic. Landy, J. C., J. K. Ehn, and D. G. Barber (2015), Albedo feedback enhanced by smoother Arctic sea ice, Geophys. Res. Lett., 42, 10,714-10,720, doi:10.1002/2015GL066712.

  6. Windows in Arctic sea ice: Light transmission and ice algae in a refrozen lead

    Science.gov (United States)

    Kauko, Hanna M.; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C. J.; Duarte, Pedro; Fernández-Méndez, Mar; Olsen, Lasse M.; Hudson, Stephen R.; Johnsen, Geir; Elliott, Ashley; Wang, Feiyue; Granskog, Mats A.

    2017-06-01

    The Arctic Ocean is rapidly changing from thicker multiyear to thinner first-year ice cover, with significant consequences for radiative transfer through the ice pack and light availability for algal growth. A thinner, more dynamic ice cover will possibly result in more frequent leads, covered by newly formed ice with little snow cover. We studied a refrozen lead (≤0.27 m ice) in drifting pack ice north of Svalbard (80.5-81.8°N) in May-June 2015 during the Norwegian young sea ICE expedition (N-ICE2015). We measured downwelling incident and ice-transmitted spectral irradiance, and colored dissolved organic matter (CDOM), particle absorption, ultraviolet (UV)-protecting mycosporine-like amino acids (MAAs), and chlorophyll a (Chl a) in melted sea ice samples. We found occasionally very high MAA concentrations (up to 39 mg m-3, mean 4.5 ± 7.8 mg m-3) and MAA to Chl a ratios (up to 6.3, mean 1.2 ± 1.3). Disagreement in modeled and observed transmittance in the UV range let us conclude that MAA signatures in CDOM absorption spectra may be artifacts due to osmotic shock during ice melting. Although observed PAR (photosynthetically active radiation) transmittance through the thin ice was significantly higher than that of the adjacent thicker ice with deep snow cover, ice algal standing stocks were low (≤2.31 mg Chl a m-2) and similar to the adjacent ice. Ice algal accumulation in the lead was possibly delayed by the low inoculum and the time needed for photoacclimation to the high-light environment. However, leads are important for phytoplankton growth by acting like windows into the water column.

  7. Determining the ice seasons severity during 1982-2015 using the ice extents sum as a new characteristic

    Science.gov (United States)

    Rjazin, Jevgeni; Pärn, Ove

    2016-04-01

    Sea ice is a key climate factor and it restricts considerably the winter navigation in sever seasons on the Baltic Sea. So determining ice conditions severity and describing ice cover behaviour at severe seasons interests scientists, engineers and navigation managers. The present study is carried out to determine the ice seasons severity degree basing on the ice seasons 1982 to 2015. A new integrative characteristic is introduced to describe the ice season severity. It is the sum of ice extents of the ice season id est the daily ice extents of the season are summed. The commonly used procedure to determine the ice season severity degree by the maximal ice extent is in this research compared to the new characteristic values. The remote sensing data on the ice concentrations on the Baltic Sea published in the European Copernicus Programme are used to obtain the severity characteristic values. The ice extents are calculated on these ice concentration data. Both the maximal ice extent of the season and a newly introduced characteristic - the ice extents sum are used to classify the winters with respect of severity. The most severe winter of the reviewed period is 1986/87. Also the ice seasons 1981/82, 1984/85, 1985/86, 1995/96 and 2002/03 are classified as severe. Only three seasons of this list are severe by both the criteria. They are 1984/85, 1985/86 and 1986/87. We interpret this coincidence as the evidence of enough-during extensive ice cover in these three seasons. In several winters, for example 2010/11 ice cover extended enough for some time, but did not endure. At few other ice seasons as 2002/03 the Baltic Sea was ice-covered in moderate extent, but the ice cover stayed long time. At 11 winters the ice extents sum differed considerably (> 10%) from the maximal ice extent. These winters yield one third of the studied ice seasons. The maximal ice extent of the season is simple to use and enables to reconstruct the ice cover history and to predict maximal ice

  8. Icing Impacts on Wind Energy Production

    DEFF Research Database (Denmark)

    Davis, Neil

    was developed for the identification of icing periods from the turbine power data and the nacelle wind speeds. This method was based on the spread of power production observations at cold temperatures that was not seen during warmer periods. Using the insights gained through the observational analysis...... and the turbine power loss. The model took the shape of a hierarchal model that combined a decision tree model, based on the existence of ice on the turbine blade, and two Generalized Additive Models (GAM). The GAM for periods where icing was forecast was found to include the terms wind speed, total ice mass...

  9. Ice nucleation triggered by negative pressure.

    Science.gov (United States)

    Marcolli, Claudia

    2017-11-30

    Homogeneous ice nucleation needs supercooling of more than 35 K to become effective. When pressure is applied to water, the melting and the freezing points both decrease. Conversely, melting and freezing temperatures increase under negative pressure, i.e. when water is stretched. This study presents an extrapolation of homogeneous ice nucleation temperatures from positive to negative pressures as a basis for further exploration of ice nucleation under negative pressure. It predicts that increasing negative pressure at temperatures below about 262 K eventually results in homogeneous ice nucleation while at warmer temperature homogeneous cavitation, i. e. bubble nucleation, dominates. Negative pressure occurs locally and briefly when water is stretched due to mechanical shock, sonic waves, or fragmentation. The occurrence of such transient negative pressure should suffice to trigger homogeneous ice nucleation at large supercooling in the absence of ice-nucleating surfaces. In addition, negative pressure can act together with ice-inducing surfaces to enhance their intrinsic ice nucleation efficiency. Dynamic ice nucleation can be used to improve properties and uniformity of frozen products by applying ultrasonic fields and might also be relevant for the freezing of large drops in rainclouds.

  10. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2015-01-01

    crustal model can be modelled. A crucial challenge for applying the technique is to control the sources. Here, we present data that describe the efficiency of explosive sources in the ice cover. Analysis of the data shows, that the ice cap traps a significant amount of energy, which is observed......Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full...

  11. Ice load reducer for dams : laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Lupien, R.; Cote, A.; Robert, A. [Institut de Recherche d' Hydro-Quebec, Varennes, PQ (Canada)

    2009-07-01

    Many studies have focused on measuring static ice loads on various hydraulic structures in Canada. This paper discussed a Hydro-Quebec research project whose main purpose was to harmonize the ice thrust value in load combinations for use in general hydraulic works or for specific cases. The objectives of the project were to obtain a better understanding of existing data and to characterize sites and their influence on ice thrust; study the structural mechanisms involved in the generation of ice thrust, their consequences on the structural behaviour of ice and the natural mitigating circumstances that may be offered by ice properties or site operating procedures; and examine the relevance of developing an ice load reducer for works that might not fit the harmonized design value. The paper presented the main research goals and ice load reducer goals, with particular focus on the four pipe samples that were planned, built and tested. The experimental program involved checking the pipe shape behaviour in terms of flexibility-stiffness; maximum deformations; maximum load reduction; permanent deformations; and, ability to shape recovering. The testing also involved examining the strength versus strain rate; creep versus strain rate; and creep capacity under biaxial state of tension and compression. It was concluded that the two phenomena involved in generation of ice thrust, notably thermal expansion and water level changes, had very low strain rates. 8 refs., 2 tabs., 16 figs.

  12. [Reflectance of sea ice in Liaodong Bay].

    Science.gov (United States)

    Xu, Zhan-tang; Yang, Yue-zhong; Wang, Gui-fen; Cao, Wen-xi; Kong, Xiang-peng

    2010-07-01

    In the present study, the relationships between sea ice albedo and the bidirectional reflectance distribution in Liaodong Bay were investigated. The results indicate that: (1) sea ice albedo alpha(lambda) is closely related to the components of sea ice, the higher the particulate concentration in sea ice surface is, the lower the sea ice albedo alpha(lambda) is. On the contrary, the higher the bubble concentration in sea ice is, the higher sea ice albedo alpha(lambda) is. (2) Sea ice albedo alpha(lambda) is similar to the bidirectional reflectance factor R(f) when the probe locates at nadir. The R(f) would increase with the increase in detector zenith theta, and the correlation between R(f) and the detector azimuth would gradually increase. When the theta is located at solar zenith 63 degrees, the R(f) would reach the maximum, and the strongest correlation is also shown between the R(f) and the detector azimuth. (3) Different types of sea ice would have the different anisotropic reflectance factors.

  13. Dynamics of colloidal particles in ice

    KAUST Repository

    Spannuth, Melissa

    2011-01-01

    We use x-ray photon correlation spectroscopy (XPCS) to probe the dynamics of colloidal particles in polycrystalline ice. During freezing, the dendritic ice morphology and rejection of particles from the ice created regions of high particle density, where some of the colloids were forced into contact and formed disordered aggregates. The particles in these high density regions underwent ballistic motion, with a characteristic velocity that increased with temperature. This ballistic motion is coupled with both stretched and compressed exponential decays of the intensity autocorrelation function. We suggest that this behavior could result from ice grain boundary migration. © 2011 American Institute of Physics.

  14. Viscosity of interfacial water regulates ice nucleation

    International Nuclear Information System (INIS)

    Li, Kaiyong; Chen, Jing; Zhang, Qiaolan; Zhang, Yifan; Xu, Shun; Zhou, Xin; Cui, Dapeng; Wang, Jianjun; Song, Yanlin

    2014-01-01

    Ice formation on solid surfaces is an important phenomenon in many fields, such as cloud formation and atmospheric icing, and a key factor for applications in preventing freezing. Here, we report temperature-dependent nucleation rates of ice for hydrophilic and hydrophobic surfaces. The results show that hydrophilic surface presents a lower ice nucleation rate. We develop a strategy to extract the thermodynamic parameters, J 0 and Γ, in the context of classical nucleation theory. From the extracted J 0 and Γ, we reveal the dominant role played by interfacial water. The results provide an insight into freezing mechanism on solid surfaces

  15. The IceCube Computing Infrastructure Model

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Besides the big LHC experiments a number of mid-size experiments is coming online which need to define new computing models to meet the demands on processing and storage requirements of those experiments. We present the hybrid computing model of IceCube which leverages GRID models with a more flexible direct user model as an example of a possible solution. In IceCube a central datacenter at UW-Madison servers as Tier-0 with a single Tier-1 datacenter at DESY Zeuthen. We describe the setup of the IceCube computing infrastructure and report on our experience in successfully provisioning the IceCube computing needs.

  16. On general principles of supplying safe operation of sea objects of Russian Federation oil and gas complex in ice conditions

    Directory of Open Access Journals (Sweden)

    Kukui Firmin Jeevo

    2016-12-01

    Full Text Available Ice sheet exerts a force on the hydraulic structures and vessels with developing and transporting hydrocarbons in the offshore waters of the Arctic causing to strengthen their design and/or provide additional measures against ice loads. The risk of ice impacts on objects of offshore oil and gas fields of the Arctic region determines the existence of the problem of ensuring the sustainability of these objects in terms of iceberg danger and ice formations. Reducing these risks involves the development of organizational and technical measures for improving the sustainability of the facilities in terms of iceberg danger through the use of international experience and development of advanced technologies to prevent dangerous effects of ice formations. Based on the fact that ice management is a specific activity that requires special effort and funds which as part of the rescue security (RS forces at sea are missing, as well as on the basis of the fact that the system of RS at sea is not assigned to prevent accidents and to ensure the smooth operation of offshore facilities, an ice management is seen as an independent kind of ensuring the proper functioning objects of hydrocarbons production and marine transportation. The paper considers the analysis and synthesis of domestic and foreign experience of ice and iceberg management. A system of security measures for functioning marine oil and gas facilities in icy conditions on the basis of technology of preventing dangerous effects of ice formations has been worked out. It has been shown that the system of ice and iceberg management of marine objects of hydrocarbon production and marine transportation should be a practical mechanism for reducing deposits' operation risks in ice conditions. The work relates to the safe operation of mining platforms in the Arctic seas, and more particularly, to methods and means of influence on the icebergs in order to prevent collisions with fixed or floating production

  17. International Trade. International Business

    OpenAIRE

    Мохнюк, А. М.; Mokhniuk, A. M.

    2015-01-01

    Work programme of the study course “International Trade. International Business” was prepared in accordance with educational and vocational training program for bachelors of training direction 6.030601 “Management”.

  18. Deformation and failure of the ice bridge on the Wilkins Ice Shelf, Antarctica

    NARCIS (Netherlands)

    Humbert, A.; Gross, D.; Müller, R.; Braun, M.; van de Wal, R.S.W.; van den Broeke, M.R.; Vaughan, D.G.; van de Berg, W.J.

    2010-01-01

    A narrow bridge of floating ice that connected the Wilkins Ice Shelf, Antarctica, to two confining islands eventually collapsed in early April 2009. In the month preceding the collapse, we observed deformation of the ice bridge by means of satellite imagery and from an in situ GPS station.

  19. Assimilation of ice and water observations from SAR imagery to improve estimates of sea ice concentration

    Directory of Open Access Journals (Sweden)

    K. Andrea Scott

    2015-09-01

    Full Text Available In this paper, the assimilation of binary observations calculated from synthetic aperture radar (SAR images of sea ice is investigated. Ice and water observations are obtained from a set of SAR images by thresholding ice and water probabilities calculated using a supervised maximum likelihood estimator (MLE. These ice and water observations are then assimilated in combination with ice concentration from passive microwave imagery for the purpose of estimating sea ice concentration. Due to the fact that the observations are binary, consisting of zeros and ones, while the state vector is a continuous variable (ice concentration, the forward model used to map the state vector to the observation space requires special consideration. Both linear and non-linear forward models were investigated. In both cases, the assimilation of SAR data was able to produce ice concentration analyses in closer agreement with image analysis charts than when assimilating passive microwave data only. When both passive microwave and SAR data are assimilated, the bias between the ice concentration analyses and the ice concentration from ice charts is 19.78%, as compared to 26.72% when only passive microwave data are assimilated. The method presented here for the assimilation of SAR data could be applied to other binary observations, such as ice/water information from visual/infrared sensors.

  20. Inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate.

    Science.gov (United States)

    Damodaran, Srinivasan

    2007-12-26

    The inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate produced by papain action was studied. The ice crystal growth was monitored by thermal cycling between -14 and -12 degrees C at a rate of one cycle per 3 min. It is shown that the hydrolysate fraction containing peptides in the molecular weight range of about 2000-5000 Da exhibited the highest inhibitory activity on ice crystal growth in ice cream mix, whereas fractions containing peptides greater than 7000 Da did not inhibit ice crystal growth. The size distribution of gelatin peptides formed in the hydrolysate was influenced by the pH of hydrolysis. The optimum hydrolysis conditions for producing peptides with maximum ice crystal growth inhibitory activity was pH 7 at 37 degrees C for 10 min at a papain to gelatin ratio of 1:100. However, this may depend on the type and source of gelatin. The possible mechanism of ice crystal growth inhibition by peptides from gelatin is discussed. Molecular modeling of model gelatin peptides revealed that they form an oxygen triad plane at the C-terminus with oxygen-oxygen distances similar to those found in ice nuclei. Binding of this oxygen triad plane to the prism face of ice nuclei via hydrogen bonding appears to be the mechanism by which gelatin hydrolysate might be inhibiting ice crystal growth in ice cream mix.