National Library of Energy BETA

Sample records for assessing surface ice

  1. Rubber friction on ice and snow surfaces 

    E-Print Network [OSTI]

    Skouvaklis, Gerasimos

    2011-06-28

    The friction of rubber on ice and snow surfaces is complex. Deeper scientific understanding is important for optimising performance of tyres in winter. Rubber, ice and snow systems exhibit frictional behaviour which ...

  2. A direct evidence of vibrationally delocalized response at ice surface

    SciTech Connect (OSTI)

    Ishiyama, Tatsuya; Morita, Akihiro

    2014-11-14

    Surface-specific vibrational spectroscopic responses at isotope diluted ice and amorphous ice are investigated by molecular dynamics (MD) simulations combined with quantum mechanics/molecular mechanics calculations. The intense response specific to the ordinary crystal ice surface is predicted to be significantly suppressed in the isotopically diluted and amorphous ices, demonstrating the vibrational delocalization at the ordinary ice surface. The collective vibration at the ice surface is also analyzed with varying temperature by the MD simulation.

  3. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    E-Print Network [OSTI]

    2013-01-01

    Surface configuration, ice thick- ness, volume and bedrockconstruction of the ice thick- ness grids. between flightof the physical ice thick- ness, rather than an “ice-

  4. Vapor deposition of water on graphitic surfaces: Formation of amorphous ice, bilayer ice, ice I, and liquid water

    SciTech Connect (OSTI)

    Lupi, Laura; Kastelowitz, Noah; Molinero, Valeria

    2014-11-14

    Carbonaceous surfaces are a major source of atmospheric particles and could play an important role in the formation of ice. Here we investigate through molecular simulations the stability, metastability, and molecular pathways of deposition of amorphous ice, bilayer ice, and ice I from water vapor on graphitic and atomless Lennard-Jones surfaces as a function of temperature. We find that bilayer ice is the most stable ice polymorph for small cluster sizes, nevertheless it can grow metastable well above its region of thermodynamic stability. In agreement with experiments, the simulations predict that on increasing temperature the outcome of water deposition is amorphous ice, bilayer ice, ice I, and liquid water. The deposition nucleation of bilayer ice and ice I is preceded by the formation of small liquid clusters, which have two wetting states: bilayer pancake-like (wetting) at small cluster size and droplet-like (non-wetting) at larger cluster size. The wetting state of liquid clusters determines which ice polymorph is nucleated: bilayer ice nucleates from wetting bilayer liquid clusters and ice I from non-wetting liquid clusters. The maximum temperature for nucleation of bilayer ice on flat surfaces, T{sub B}{sup max} is given by the maximum temperature for which liquid water clusters reach the equilibrium melting line of bilayer ice as wetting bilayer clusters. Increasing water-surface attraction stabilizes the pancake-like wetting state of liquid clusters leading to larger T{sub B}{sup max} for the flat non-hydrogen bonding surfaces of this study. The findings of this study should be of relevance for the understanding of ice formation by deposition mode on carbonaceous atmospheric particles, including soot.

  5. Molecular simulations of heterogeneous ice nucleation. I. Controlling ice nucleation through surface hydrophilicity

    E-Print Network [OSTI]

    Stephen J. Cox; Shawn M. Kathmann; Ben Slater; Angelos Michaelides

    2015-05-29

    Ice formation is one of the most common and important processes on earth and almost always occurs at the surface of a material. A basic understanding of how the physicochemical properties of a material's surface affect its ability to form ice has remained elusive. Here, we use molecular dynamics simulations to directly probe heterogeneous ice nucleation at a hexagonal surface of a nanoparticle of varying hydrophilicity. Surprisingly, we find that structurally identical surfaces can both inhibit and promote ice formation and analogous to a chemical catalyst, it is found that an optimal interaction between the surface and the water exists for promoting ice nucleation. We use our microscopic understanding of the mechanism to design a modified surface in silico with enhanced ice nucleating ability.

  6. Heterogeneous ice nucleation controlled by the coupling of surface crystallinity and surface hydrophilicity

    E-Print Network [OSTI]

    Bi, Yuanfei; Li, Tianshu

    2015-01-01

    The microscopic mechanisms controlling heterogeneous ice nucleation are complex and remain poorly understood. Although good ice nucleators are generally believed to match ice lattice and to bind water, counter examples are often identified. Here we show, by advanced molecular simulations, that the heterogeneous nucleation of ice on graphitic surface is controlled by the coupling of surface crystallinity and surface hydrophilicity. Molecular level analysis reveals that the crystalline graphitic lattice with an appropriate hydrophilicity may indeed template ice basal plane by forming a strained ice layer, thus significantly enhancing its ice nucleation efficiency. Remarkably, the templating effect is found to transit from within the first contact layer of water to the second as the hydrophilicity increases, yielding an oscillating distinction between the crystalline and amorphous graphitic surfaces in their ice nucleation efficiencies. Our study sheds new light on the long-standing question of what constitutes ...

  7. Oil spreading in surface waters with an ice cover

    SciTech Connect (OSTI)

    Yapa, P.D.; Weerasuriya, S.A.; Belaskas, D.P.; Chowdhury, T.

    1993-02-01

    A study of oil spreading in surface waters in the presence of a floating ice cover is presented. The ice can be solid or fragmented. Both axi-symmetrical and uni-directional spreading are studied. The report describes the analytical and numerical model development, the experimental set-up, results from the laboratory experiments, and their comparison with the derived theory and the numerical simulation. To analyze the spreading of oil under solid ice, new equations are derived. These equations consider gravity (buoyancy) - inertia phase, gravity (buoyancy) - viscous phase, and the termination of spreading during the buoyancy - surface tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to termination of spreading is presented. The emphasis of the study is on the dominant spreading mechanism for oil under ice, which is the buoyancy-viscous phase.

  8. The glacier and land ice surface topography interferometer: An airborne proof-of-concept demonstration of high-precision Ka-band single-pass elevation mapping

    E-Print Network [OSTI]

    2011-01-01

    and Land Ice Surface Topography Interferometer (GLISTIN): AAND LAND ICE SURFACE TOPOGRAPHY INTERFEROMETER application,”AND LAND ICE SURFACE TOPOGRAPHY INTERFEROMETER Fig. 2.

  9. THEORETICAL MODELING OF LIDAR RETURN PHENOMENOLOGY FROM SNOW AND ICE SURFACES

    E-Print Network [OSTI]

    Kerekes, John

    THEORETICAL MODELING OF LIDAR RETURN PHENOMENOLOGY FROM SNOW AND ICE SURFACES J. Kerekes, J. Zhang the science of lidar sensing of complex ice and snow surfaces as well as in support of the upcoming ICESat- 2 from snow and ice surfaces. First, the anticipated lidar return characteristics for a sloped non

  10. A radio air shower surface detector as an extension for IceCube and IceTop

    E-Print Network [OSTI]

    J. Auffenberg; T. Gaisser; K. Helbing; T. Huege; T. Karg; A. Karle

    2007-08-24

    The IceCube neutrino detector is built into the Antarctic ice sheet at the South Pole to measure high energy neutrinos. For this, 4800 photomultiplier tubes (PMTs) are being deployed at depths between 1450 and 2450 meters into the ice to measure neutrino induced charged particles like muons. IceTop is a surface air shower detector consisting of 160 Cherenkov ice tanks located on top of IceCube. To extend IceTop, a radio air shower detector could be built to significantly increase the sensitivity at higher shower energies and for inclined showers. As air showers induced by cosmic rays are a major part of the muonic background in IceCube, IceTop is not only an air shower detector, but also a veto to reduce the background in IceCube. Air showers are detectable by radio signals with a radio surface detector. The major emission process is the coherent synchrotron radiation emitted by e+ e- shower particles in the Earths magnetic field (geosynchrotron effect). Simulations of the expected radio signals of air showers are shown. The sensitivity and the energy threshold of different antenna field configurations are estimated.

  11. Comparison of satellite-derived and in-situ observations of ice and snow surface temperatures over Greenland

    E-Print Network [OSTI]

    Box, Jason E.

    Comparison of satellite-derived and in-situ observations of ice and snow surface temperatures over temperature in the data-sparse cryosphere is by satellite remote sensing. The uncertainties in satellite-derived) records needed for climate studies. In this work we assess satellite-derived "clear-sky" LST products from

  12. Assessment of Future ICE and Fuel-Cell Powered Vehicles and Their...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Future ICE and Fuel-Cell Powered Vehicles and Their Potential Impacts Assessment of Future ICE and Fuel-Cell Powered Vehicles and Their Potential Impacts 2004 Diesel Engine...

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

    SciTech Connect (OSTI)

    Ueta, S.; Sasaki, T. E-mail: takanori@geo.titech.ac.jp

    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.

  14. Determination and Characterization of Ice Propagation Mechanisms on Surfaces Undergoing Dropwise Condensation 

    E-Print Network [OSTI]

    Dooley, Jeffrey B.

    2011-08-08

    The mechanisms responsible for ice propagation on surfaces undergoing dropwise condensation have been determined and characterized. Based on experimental data acquired non-invasively with high speed quantitative microscopy, ...

  15. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    E-Print Network [OSTI]

    Fretwell, P.; Pritchard, H. D.; Vaughan, D. G.; Bamber, J. L.; Barrand, N. E.; Bell, R.; Bianchi, C.; Bingham, R. G.; Blankenship, D. D.; Casassa, G.; Catania, G.; Callens, D.; Conway, H.; Cook, A. J.; Corr, H. F. J.; Damaske, D.; Damm, V.; Ferraccioli, F.; Forsberg, R.; Fujita, S.; Gim, Y.; Gogineni, Sivaprasad; Griggs, J. A.; Hindmarsh, R.; Holmlund, P.; Holt, J. W.; Jacobel, R. W.; Jenkins, A.; Jokat, W.; Jordan, T.; King, E. C.; Kohler, J.; Krabill, W.; Riger-Kusk, M.; Langley, K. A.; Leitchenkov, G.; Leuschen, Carl; Lyendyk, B. P.; Matsuoka, K.; Mouginot, J.; Nitsche, F. O.; Nogi, Y.; Nost, O. A.; Popov, S. V.; Rignot, E.; Rippin, D. M.; Rivera, A.; Roberts, J.; Roberts, J.; Ross, N.; Siegert, M. J.; Smith, A. M.; Steinhage, D.; Studinger, M.; Sun, B.; Tinto, B. K.; Welch, B. C.; Wilson, D.; Young, D. A.; Xiangbin, C.; Zirizzotti, A.

    2013-02-28

    We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a ...

  16. Seismicity on the western Greenland Ice Sheet: Surface fracture in the vicinity of active moulins

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carmichael, Joshua D.; Joughin, Ian; Behn, Mark D.; Das, Sarah; King, Matt A.; Stevens, Laura; Lizarralde, Dan

    2015-06-25

    We analyzed geophone and GPS measurements collected within the ablation zone of the western Greenland Ice Sheet during a ~35 day period of the 2011 melt season to study changes in ice deformation before, during, and after a supraglacial lake drainage event. During rapid lake drainage, ice flow speeds increased to ~400% of winter values, and icequake activity peaked. At times >7 days after drainage, this seismicity developed variability over both diurnal and longer periods (~10 days), while coincident ice speeds fell to ~150% of winter values and showed nightly peaks in spatial variability. Approximately 95% of all detected seismicitymore »in the lake basin and its immediate vicinity was triggered by fracture propagation within near-surface ice (« less

  17. Nanotextured Anti-Icing Surfaces | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework usesofPublications The NRELDemonstrate Promising Anti-icing Nano

  18. Biogeochemistry in Sea Ice: CICE model developments

    SciTech Connect (OSTI)

    Jeffery, Nicole; Hunke, Elizabeth; Elliott, Scott; Turner, Adrian

    2012-06-18

    Polar primary production unfolds in a dynamic sea ice environment, and the interactions of sea ice with ocean support and mediate this production. In spring, for example, fresh melt water contributes to the shoaling of the mixed layer enhancing ice edge blooms. In contrast, sea ice formation in the fall reduces light penetration to the upper ocean slowing primary production in marine waters. Polar biogeochemical modeling studies typically consider these types of ice-ocean interactions. However, sea ice itself is a biogeochemically active medium, contributing a significant and, possibly, essential source of primary production to polar regions in early spring and fall. Here we present numerical simulations using the Los Alamos Sea Ice Model (CICE) with prognostic salinity and sea ice biogeochemistry. This study investigates the relationship between sea ice multiphase physics and sea ice productivity. Of particular emphasis are the processes of gravity drainage, melt water flushing, and snow loading. During sea ice formation, desalination by gravity drainage facilitates nutrient exchange between ocean and ice maintaining ice algal blooms in early spring. Melt water flushing releases ice algae and nutrients to underlying waters limiting ice production. Finally, snow loading, particularly in the Southern Ocean, forces sea ice below the ocean surface driving an upward flow of nutrient rich water into the ice to the benefit of interior and freeboard communities. Incorporating ice microphysics in CICE has given us an important tool for assessing the importance of these processes for polar algal production at global scales.

  19. Influence of surface morphology on the immersion mode ice nucleation efficiency of hematite particles

    SciTech Connect (OSTI)

    Hiranuma, Naruki; Hoffmann, Nadine; Kiselev, Alexei; Dreyer, Axel; Zhang, Kai; Kulkarni, Gourihar R.; Koop, Thomas; Mohler, Ottmar

    2014-03-05

    In this paper, the effect of the morphological modification of aerosol particles with respect to heterogeneous ice nucleation is comprehensively investigated for laboratory-generated hematite particles as a model substrate for atmospheric dust particles. The surface area-scaled ice nucleation efficiencies of monodisperse cubic hematite particles and milled hematite particles were measured with a series of expansion cooling experiments using the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud simulation chamber. Complementary off-line characterization of physico-chemical properties of both hematite subsets were also carried out with scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, dynamic light scattering (DLS), and an electro-kinetical particle charge detector to further constrain droplet-freezing measurements of hematite particles. Additionally, an empirical parameterization derived from our laboratory measurements was implemented in the single-column version of the Community Atmospheric Model version 5 (CAM5) to investigate the model sensitivity in simulated ice crystal number concentration on different ice nucleation efficiencies. From an experimental perspective, our results show that the immersion mode ice nucleation efficiency of milled hematite particles is almost an order of magnitude higher at -35.2 ?C < T < -33.5 ?C than that of the cubic hematite particles, indicating a substantial effect of morphological irregularities on immersion mode freezing. Our modeling results similarly show that the increased droplet-freezing rates of milled hematite particles lead to about one order magnitude higher ice crystal number in the upper troposphere than cubic hematite particles. Overall, our results suggest that the surface irregularities and associated active sites lead to greater ice activation through droplet-freezing.

  20. Assessing Phosphorous Loss to Protect Surface Water 

    E-Print Network [OSTI]

    Garcia, Raul

    2005-01-01

    programs. It is an integrated approach that considers soil and landscape features in order tx H2O | pg. 10 Assessing Phosphorus Loss to Protect Surface Water to find appropriate phosphorus management practices by estimating phosphorus delivery...

  1. Mobility of D atoms on porous amorphous water ice surfaces under interstellar conditions

    E-Print Network [OSTI]

    E. Matar; E. Congiu; F. Dulieu; A. Momeni; J. L. Lemaire

    2008-10-13

    Aims. The mobility of H atoms on the surface of interstellar dust grains at low temperature is still a matter of debate. In dense clouds, the hydrogenation of adsorbed species (i.e., CO), as well as the subsequent deuteration of the accreted molecules depend on the mobility of H atoms on water ice. Astrochemical models widely assume that H atoms are mobile on the surface of dust grains even if controversy still exists. We present here direct experimental evidence of the mobility of H atoms on porous water ice surfaces at 10 K. Methods. In a UHV chamber, O2 is deposited on a porous amorphous water ice substrate. Then D atoms are deposited onto the surface held at 10 K. Temperature-Programmed Desorption (TPD) is used and desorptions of O2 and D2 are simultaneously monitored. Results. We find that the amount of O2 that desorb during the TPD diminishes if we increase the deposition time of D atoms. O2 is thus destroyed by D atoms even though these molecules have previously diffused inside the pores of thick water ice. Our results can be easily interpreted if D is mobile at 10 K on the water ice surface. A simple rate equation model fits our experimental data and best fit curves were obtained for a D atoms diffusion barrier of 22(+-)2 meV. Therefore hydrogenation can take place efficiently on interstellar dust grains. These experimental results are in line with most calculations and validate the hypothesis used in several models.

  2. Ice Surface Entropy Induction by Humidity or How Humidity Prompts Freezing

    E-Print Network [OSTI]

    Jose Luis Perez-Diaz; Marco Antonio Alvarez-Valenzuela; Juan Sanchez-Garcia-Casarrubios; Sergio Jimenez-Lopez

    2015-09-22

    In this work we measured Surface Energy and Freezing Temperature of supercooled water droplets in air. We find that freezing of water droplets is triggered at the water-air interface and that freezing progresses faster on the surface than in the bulk. The Freezing Point of water droplets is strongly depressed by dryness in air and how humidity triggers freezing. Additionally it is shown to be a Surface phenomenon related to a transfer of Entropy from water vapour to the surface of ice.

  3. Kinetics of Heterogeneous Ice Nucleation on the Surfaces of Mineral Dust Cores Inserted into Aqueous Ammonium Sulfate Particles

    E-Print Network [OSTI]

    Kinetics of Heterogeneous Ice Nucleation on the Surfaces of Mineral Dust Cores Inserted and absorb- ing terrestrial upwelling infrared radiation in the longwave.1 Unlike lower altitude clouds detailed know- ledge of both homogeneous and heterogeneous ice nucleation kinetics in the liquid phase.6

  4. Radiation damage and associated phase change effect on photodesorption rates from ices—Ly? studies of the surface behavior of CO{sub 2}(ice)

    SciTech Connect (OSTI)

    Yuan, Chunqing; Yates, John T. Jr.

    2014-01-01

    Photodesorption from a crystalline film of CO{sub 2}(ice) at 75 K has been studied using Ly? (10.2 eV) radiation. We combine quantitative mass spectrometric studies of gases evolved and transmission IR studies of species trapped in the ice. Direct CO desorption is observed from the primary CO{sub 2} photodissociation process, which occurs promptly for CO{sub 2} molecules located on the outermost surface of the ice (Process I). As the fluence of Ly? radiation increases to ?5.5 × 10{sup 17} photons cm{sup –2}, extensive damage to the crystalline ice occurs and photo-produced CO molecules from deeper regions (Process II) are found to desorb at a rapidly increasing rate, which becomes two orders of magnitude greater than Process I. It is postulated that deep radiation damage to produce an extensive amorphous phase of CO{sub 2} occurs in the 50 nm ice film and that CO (and CO{sub 2}) diffusive transport is strongly enhanced in the amorphous phase. Photodesorption in Process II is a combination of electronic and thermally activated processes. Radiation damage in crystalline CO{sub 2} ice has been monitored by its effects on the vibrational line shapes of CO{sub 2}(ice). Here the crystalline-to-amorphous phase transition has been correlated with the occurrence of efficient molecular transport over long distances through the amorphous phase of CO{sub 2}(ice). Future studies of the composition of the interstellar region, generated by photodesorption from ice layers on grains, will have to consider the significant effects of radiation damage on photodesorption rates.

  5. Water-hydroxyl phases on an open metal surface: breaking the ice rules Matthew Forster,a

    E-Print Network [OSTI]

    Alavi, Ali

    Water-hydroxyl phases on an open metal surface: breaking the ice rules Matthew Forster,a Rasmitath July 2011 DOI: 10.1039/c1sc00355k Hydroxyl is a key reaction intermediate in many surface catalyzed redox reactions, yet establishing the phase diagram for water/hydroxyl adsorption on metal

  6. An idealised experimental model of ocean surface wave transmission by an ice floe

    E-Print Network [OSTI]

    Bennetts, Luke; Meylan, Michael; Cavaliere, Claudio; Babanin, Alexander; Toffoli, Alessandro

    2015-01-01

    An experimental model of transmission of ocean waves by an ice floe is presented. Thin plastic plates with different material properties and thicknesses are used to model the floe. Regular incident waves with different periods and steepnesses are used, ranging from gently-sloping to storm-like conditions. A wave gauge is used to measure the water surface elevation in the lee of the floe. The depth of wave overwash on the floe is measured by a gauge in the centre of the floe's upper surface. Results show transmitted waves are regular for gently-sloping incident waves but irregular for storm-like incident waves. The proportion of the incident wave transmitted is shown to decrease as incident wave steepness increases, and to be at its minimum for an incident wavelength equal to the floe length. Further, a trend is noted for transmission to decrease as the mean wave height in the overwash region increases.

  7. Impact of Solvent on Photocatalytic Mechanisms: Reactions of Photodesorption Products with Ice Overlayers on the TiO2(110) Surface

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2011-04-07

    The effects of water and methanol ice overlayers on the photodecomposition of acetone on rutile TiO2(110) were evaluated in ultrahigh vacuum (UHV) using photon stimulated desorption (PSD) and temperature programmed desorption (TPD). In the absence of ice overlayers, acetone photodecomposed on TiO2(110) at 95 K by ejection of a methyl radical into the gas phase and formation of acetate on the surface. With ice overlayers, the methyl radicals are trapped at the interface between TiO2(110) and the ice. When water ice was present, these trapped methyl radicals reacted either with each other to form ethane or with other molecules in the ice (e.g., water or displaced acetone) to form methane (CH4), ethane (CH3CH3) and other products (e.g., methanol), with all of these products trapped in the ice. The new products were free to revisit the surface or depart during desorption of the ice. When methanol ice was present, methane formation came about only from reaction of trapped methyl radicals with the methanol ice. Methane and ethane slowly leaked through methanol ice overlayers into vacuum at 95 K, but not through water ice overlayers. Different degrees of site competition between water and acetone, and between methanol and acetone led to different hydrogen abstraction pathways in the two ices. These results provide new insights into product formation routes and solution-phase radical formation mechanisms that are important in heterogeneous photocatalysis.

  8. A NEW SOURCE OF CO{sub 2} IN THE UNIVERSE: A PHOTOACTIVATED ELEY-RIDEAL SURFACE REACTION ON WATER ICES

    SciTech Connect (OSTI)

    Yuan, Chunqing; Cooke, Ilsa R.; Yates, John T. Jr.

    2014-08-20

    CO{sub 2} is one of the most abundant components of ices in the interstellar medium; however, its formation mechanism has not been clearly identified. Here we report an experimental observation of an Eley-Rideal-type reaction on a water ice surface, where CO gas molecules react by direct collisions with surface OH radicals, made by photodissociation of H{sub 2}O molecules, to produce CO{sub 2} ice on the surface. The discovery of this source of CO{sub 2} provides a new mechanism to explain the high relative abundance of CO{sub 2} ice in space.

  9. The water ice rich surface of (145453) 2005 RR43: a case for a carbon-depleted population of TNOs?

    E-Print Network [OSTI]

    N. Pinilla-Alonso; J. Licandro; R. Gil-Hutton; R. Brunetto

    2007-05-26

    Recent results suggest that there is a group of TNOs (2003 EL61 being the biggest member), with surfaces composed of almost pure water ice and with very similar orbital elements. We study the surface composition of another TNO that moves in a similar orbit, 2005 RR43, and compare it with the surface composition of the other members of this group. We report visible and near-infrared spectra, obtained with the 4.2m William Herschel Telescope and the 3.58m Telescopio Nazionale Galileo at the "Roque de los Muchachos" Observatory (La Palma, Spain). The spectrum of 2005 RR43 is neutral in color in the visible and dominated by very deep water ice absorption bands in the near infrared (D= 70.3 +/- 2.1 % and 82.8 +/- 4.9 % at 1.5 \\mu and 2.0 \\mu respectively). It is very similar to the spectrum of the group of TNOs already mentioned. All of them present much deeper water ice absorption bands (D>40 %) than any other TNO except Charon. Scattering models show that its surface is covered by water ice, a significant fraction in crytalline state with no trace (5 % upper limit) of complex organics. Possible scenarios to explain the existence of this population of TNOs are discussed: a giant collision, an originally carbon depleted composition, or a common process of continuous resurfacing. We conclude that TNO 2005 RR43 is member of a group, may be a population, of TNOs clustered in the space of orbital parameters that show abundant water ice and no signs of complex organics. The lack of complex organics in their surfaces suggests a significant smaller fraction of carbonaceous volatiles like CH4 in this population than in "normal" TNOs. A carbon depleted population of TNOs could be the origin of the population of carbon depleted Jupiter family comets already noticed by A'Hearn et al. (1995).

  10. Assessing the Predictability of the Beaufort Sea Minimum Ice Extent in a Changing Arctic Climate Regime 

    E-Print Network [OSTI]

    Quirk, Laura Marie

    2014-04-25

    Understanding the climatic drivers of changes in sea ice extent in the Arctic has become increasingly important as record minima in the September sea ice extent continue to be reached. This research therefore addresses the question of which synoptic...

  11. Fluorescence Microscopy Evidence for Quasi-Permanent Attachment of Antifreeze Proteins to Ice Surfaces

    E-Print Network [OSTI]

    Wettlaufer, John S.

    Fluorescence Microscopy Evidence for Quasi-Permanent Attachment of Antifreeze Proteins to Ice ABSTRACT Many organisms are protected from freezing by the presence of extracellular antifreeze proteins (AFPs), which bind to ice, modify its morphology, and prevent its further growth. These proteins have

  12. Interannual Changes in Seasonal Ground Freezing and Near-surface Heat Flow Beneath Bottom-fast Ice in the Near-shore Zone, Mackenzie Delta, NWT, Canada

    E-Print Network [OSTI]

    Moorman, Brian

    Interannual Changes in Seasonal Ground Freezing and Near-surface Heat Flow Beneath Bottom-fast Ice Resources Canada, Dartmouth, Nova Scotia, Canada ABSTRACT Interannual changes in seasonal ground freezing. KEY WORDS: seasonal ground freezing; permafrost; bottom-fast ice; Mackenzie Delta INTRODUCTION Arctic

  13. Interstellar Ices

    E-Print Network [OSTI]

    Boogert, A C A

    2003-01-01

    Currently ~36 different absorption bands have been detected in the infrared spectra of cold, dense interstellar and circumstellar environments. These are attributed to the vibrational transitions of ~17 different molecules frozen on dust grains. We review identification issues and summarize the techniques required to extract information on the physical and chemical evolution of these ices. Both laboratory simulations and line of sight studies are essential. Examples are given for ice bands observed toward high mass protostars, fields stars and recent work on ices in disks surrounding low mass protostars. A number of clear trends have emerged in recent years. One prominent ice component consists of an intimate mixture between H2O, CH3OH and CO2 molecules. Apparently a stable balance exists between low temperature hydrogenation and oxidation reactions on grain surfaces. In contrast, an equally prominent ice component, consisting almost entirely of CO, must have accreted directly from the gas phase. Thermal proc...

  14. ICE MINERALOGY ACROSS AND INTO THE SURFACES OF PLUTO, TRITON, AND ERIS

    SciTech Connect (OSTI)

    Tegler, S. C.; Grundy, W. M.; Olkin, C. B.; Young, L. A.; Romanishin, W.; Cornelison, D. M.; Khodadadkouchaki, R. E-mail: W.Grundy@lowell.edu E-mail: layoung@boulder.swri.edu E-mail: DavidCornelison@MissouriState.edu

    2012-05-20

    We present three near-infrared spectra of Pluto taken with the Infrared Telescope Facility and SpeX, an optical spectrum of Triton taken with the MMT and the Red Channel Spectrograph, and previously published spectra of Pluto, Triton, and Eris. We combine these observations with a two-phase Hapke model and gain insight into the ice mineralogy on Pluto, Triton, and Eris. Specifically, we measure the methane-nitrogen mixing ratio across and into the surfaces of these icy dwarf planets. In addition, we present a laboratory experiment that demonstrates it is essential to model methane bands in spectra of icy dwarf planets with two methane phases-one highly diluted by nitrogen and the other rich in methane. For Pluto, we find bulk, hemisphere-averaged, methane abundances of 9.1% {+-} 0.5%, 7.1% {+-} 0.4%, and 8.2% {+-} 0.3% for sub-Earth longitudes of 10 Degree-Sign , 125 Degree-Sign , and 257 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds these small differences are statistically significant. For Triton, we find bulk, hemisphere-averaged, methane abundances of 5.0% {+-} 0.1% and 5.3% {+-} 0.4% for sub-Earth longitudes of 138 Degree-Sign and 314 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds the differences are not statistically significant. For Eris, we find a bulk, hemisphere-averaged, methane abundance of 10% {+-} 2%. Pluto, Triton, and Eris do not exhibit a trend in methane-nitrogen mixing ratio with depth into their surfaces over the few centimeter range probed by these observations. This result is contrary to the expectation that since visible light penetrates deeper into a nitrogen-rich surface than the depths from which thermal emission emerges, net radiative heating at depth would drive preferential sublimation of nitrogen leading to an increase in the methane abundance with depth.

  15. An AeroCom Assessment of Black Carbon in Arctic Snow and Sea Ice

    SciTech Connect (OSTI)

    Jiao, C.; Flanner, M. G.; Balkanski, Y.; Bauer, S.; Bellouin, N.; Berntsen, T.; Bian, Huisheng; Carslaw, K. S.; Chin, Mian; De Luca, N.; Diehl, Thomas; Ghan, Steven J.; Iversen, T.; Kirkevag, A.; Koch, Dorothy; Liu, Xiaohong; Mann, G. W.; Penner, Joyce E.; Pitari, G.; Schulz, M.; Seland, O.; Skeie, R. B.; Steenrod, Stephen D.; Stier, P.; Takemura, T.; Tsigaridis, Kostas; van Noije, T.; Yun, Yuxing; Zhang, Kai

    2014-03-07

    Though many global aerosols models prognose surface deposition, only a few models have been used to directly simulate the radiative effect from black carbon (BC) deposition to snow and sea-ice. Here, we apply aerosol deposition fields from 25 models contributing to two phases of the Aerosol Comparisons between Observations and Models (AeroCom) project to simulate and evaluate within snow BC concentrations and radiative effect in the Arctic. We accomplish this by driving the offline land and sea-ice components of the Community Earth System Model with different deposition fields and meteorological conditions from 2004-2009, during which an extensive field campaign of BC measurements in Arctic snow occurred. We find that models generally underestimate BC concentrations in snow in northern Russia and Norway, while overestimating BC amounts elsewhere in the Arctic. Although simulated BC distributions in snow are poorly correlated with measurements, mean values are reasonable. The multi-model mean (range) bias in BC concentrations, sampled over the same grid cells, snow depths, and months of measurements, are -4.4 (-13.2 to +10.7) ng g?1 for an earlier Phase of AeroCom models (Phase I), and +4.1 (-13.0 to +21.4) ng g?1 for a more recent Phase of AeroCom models (Phase II), compared to the observational mean of 19.2 ng g?1. Factors determining model BC concentrations in Arctic snow include Arctic BC emissions, transport of extra-Arctic aerosols, precipitation, deposition efficiency of aerosols within the Arctic, and meltwater removal of particles in snow. Sensitivity studies show that the model–measurement evaluation is only weakly affected by meltwater scavenging efficiency because most measurements were conducted in non-melting snow. The Arctic (60-90?N) atmospheric residence time for BC in Phase II models ranges from 3.7 to 23.2 days, implying large inter-model variation in local BC deposition efficiency. Combined with the fact that most Arctic BC deposition originates from extra-Arctic emissions, these results suggest that aerosol removal processes are a leading source of variation in model performance. The multi-model mean (full range) of Arctic radiative effect from BC in snow is 0.15 (0.07-0.25) W m?2 and 0.18 (0.06-0.28) W m?2 in Phase I and Phase II models, respectively. After correcting for model biases relative to observed BC concentrations in different regions of the Arctic, we obtain a multi-model mean Arctic radiative effect of 0.17 W m?2 for the combined AeroCom ensembles. Finally, there is a high correlation between modeled BC concentrations sampled over the observational sites and the Arctic as a whole, indicating that the field campaign provided a reasonable sample of the Arctic.

  16. Distribution of CO2 ice on the large moons of Uranus and evidence for compositional stratification of their near-surfaces

    E-Print Network [OSTI]

    Cartwright, Richard J; Rivkin, Andy S; Trilling, David E; Pinilla-Alonso, Noemi

    2015-01-01

    The surfaces of the large Uranian satellites are characterized by a mixture of H2O ice and a dark, potentially carbon-rich, constituent, along with CO2 ice. At the mean heliocentric distance of the Uranian system, native CO2 ice should be removed on timescales shorter than the age of the Solar System. Consequently, the detected CO2 ice might be actively produced. Analogous to irradiation of icy moons in the Jupiter and Saturn systems, we hypothesize that charged particles caught in Uranus' magnetic field bombard the surfaces of the Uranian satellites, driving a radiolytic CO2 production cycle. To test this hypothesis, we investigated the distribution of CO2 ice by analyzing near-infrared (NIR) spectra of these moons, gathered using the SpeX spectrograph at NASA's Infrared Telescope Facility (IRTF) (2000 - 2013). Additionally, we made spectrophotometric measurements using images gathered by the Infrared Array Camera (IRAC) onboard the Spitzer Space Telescope (2003 - 2005). We find that the detected CO2 ice is ...

  17. Sensitive response of the Greenland Ice Sheet to surface melt drainage over soft bed

    E-Print Network [OSTI]

    Bougamont, M. H.; Christoffersen, P.; Hubbard, A.. L..; Fitzpatrick, A.. A..; Doyle, S. H.; Carter, S. P.

    2014-09-29

    by frictional and geothermal heating accumulates at the 136 bed over the course of winter and is released together with the first SGL drainage 137 events. With either one of these factors included, our model was able to reproduce the 138 2010 spring... . Measurements of ice 492 deformation, temperature and cross-borehole conductivity in boreholes to the 493 bedrock. Journal Of Glaciology 48, 369-385 (2002). 494 25 Pimentel, S. & Flowers, G. E. A numerical study of hydrologically driven 495 glacier dynamics...

  18. SEISMIC SURFACE WAVE TESTING FOR TRACK SUBSTRUCTURE ASSESSMENT

    E-Print Network [OSTI]

    SEISMIC SURFACE WAVE TESTING FOR TRACK SUBSTRUCTURE ASSESSMENT Timothy D. Stark and Thomas J to evaluate track safety and to predict inspection and maintenance intervals. This paper describes the seismic track safety and inspection intervals. A new seismic wave test system is being developed under Rail

  19. Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface Radar and Satellite Data in Support of ARM SCM Activities

    SciTech Connect (OSTI)

    Liu, Guosheng

    2013-03-15

    Single-column modeling (SCM) is one of the key elements of Atmospheric Radiation Measurement (ARM) research initiatives for the development and testing of various physical parameterizations to be used in general circulation models (GCMs). The data required for use with an SCM include observed vertical profiles of temperature, water vapor, and condensed water, as well as the large-scale vertical motion and tendencies of temperature, water vapor, and condensed water due to horizontal advection. Surface-based measurements operated at ARM sites and upper-air sounding networks supply most of the required variables for model inputs, but do not provide the horizontal advection term of condensed water. Since surface cloud radar and microwave radiometer observations at ARM sites are single-point measurements, they can provide the amount of condensed water at the location of observation sites, but not a horizontal distribution of condensed water contents. Consequently, observational data for the large-scale advection tendencies of condensed water have not been available to the ARM cloud modeling community based on surface observations alone. This lack of advection data of water condensate could cause large uncertainties in SCM simulations. Additionally, to evaluate GCMsĆ¢Ā?Ā? cloud physical parameterization, we need to compare GCM results with observed cloud water amounts over a scale that is large enough to be comparable to what a GCM grid represents. To this end, the point-measurements at ARM surface sites are again not adequate. Therefore, cloud water observations over a large area are needed. The main goal of this project is to retrieve ice water contents over an area of 10 x 10 deg. surrounding the ARM sites by combining surface and satellite observations. Built on the progress made during previous ARM research, we have conducted the retrievals of 3-dimensional ice water content by combining surface radar/radiometer and satellite measurements, and have produced 3-D cloud ice water contents in support of cloud modeling activities. The approach of the study is to expand a (surface) point measurement to an (satellite) area measurement. That is, the study takes the advantage of the high quality cloud measurements (particularly cloud radar and microwave radiometer measurements) at the point of the ARM sites. We use the cloud ice water characteristics derived from the point measurement to guide/constrain a satellite retrieval algorithm, then use the satellite algorithm to derive the 3-D cloud ice water distributions within an 10Ć?Ā° (latitude) x 10Ć?Ā° (longitude) area. During the research period, we have developed, validated and improved our cloud ice water retrievals, and have produced and archived at ARM website as a PI-product of the 3-D cloud ice water contents using combined satellite high-frequency microwave and surface radar observations for SGP March 2000 IOP and TWP-ICE 2006 IOP over 10 deg. x 10 deg. area centered at ARM SGP central facility and Darwin sites. We have also worked on validation of the 3-D ice water product by CloudSat data, synergy with visible/infrared cloud ice water retrievals for better results at low ice water conditions, and created a long-term (several years) of ice water climatology in 10 x 10 deg. area of ARM SGP and TWP sites and then compared it with GCMs.

  20. Spreading of oil spilled under ice

    SciTech Connect (OSTI)

    Yapa, P.D.; Chowdhury, T. )

    1990-12-01

    A new set of equations is presented to describe the process of oil spreading under ice in clam waters. These equations consider the gravity (buoyancy)-inertia phase, the gravity (buoyancy)-viscous phase, and the termination of spreading during the buoyancy-surface-tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to the termination of spreading is presented. Laboratory experiments were conducted using both real ice covers in a cold room and artificial ice covers. The experiments included different ice-cover roughnesses from smooth to rough, oils of different viscosities, and a variety of discharge conditions. The experimental data show close agreement with the theory. These equations can be used during cleanup or environmental impact assessment to estimate the area of an oil slick with respect to time.

  1. Decadal-scale sensitivity of Northeast Greenland ice flow to errors in surface mass balance using ISSM

    E-Print Network [OSTI]

    Schlegel, N-J.; Larour, E.; Seroussi, H.; Morlighem, M.; Box, J. E

    2013-01-01

    perturbations in SMB upstream and downstream from gate 8of ice ?ow both upstream and downstream. [ 36 ] By mappingthat errors far upstream and downstream of a gate could

  2. Technology demonstration of Ka-band digitally-beamformed radar for ice topography mapping

    E-Print Network [OSTI]

    Sadowy, G; Heavey, B; Moller, D; Rignot, E; Zawadzki, M; Rengarajan, S

    2007-01-01

    Beamformed Radar for Ice Topography Mapping Gregory Sadowy,Glacier and Land Ice Surface Topography Interferometer) is aGLISTIN will collect ice topography measurements over a wide

  3. Assessment of architectural options for surface power generation and energy storage on human Mars missions

    E-Print Network [OSTI]

    de Weck, Olivier L.

    Assessment of architectural options for surface power generation and energy storage on human Mars power Nuclear Solar power Architectures a b s t r a c t The provision of power for human Mars surface analysis of surface power generation and energy storage architectures for human Mars surface missions

  4. Ice thickness measurements by Raman scattering

    E-Print Network [OSTI]

    Pershin, Sergey M; Klinkov, Vladimir K; Yulmetov, Renat N; Bunkin, Alexey F

    2014-01-01

    A compact Raman LIDAR system with a spectrograph was used for express ice thickness measurements. The difference between the Raman spectra of ice and liquid water is employed to locate the ice-water interface while elastic scattering was used for air-ice surface detection. This approach yields an error of only 2 mm for an 80-mm-thick ice sample, indicating that it is promising express noncontact thickness measurements technique in field experiments.

  5. A LARGE ROCK AVALANCHE ONTO MORSRJKULL GLACIER, SOUTH-EAST ICELAND. ITS IMPLICATIONS FOR ICE-SURFACE EVOLUTION

    E-Print Network [OSTI]

    Paris-Sud XI, UniversitƩ de

    1 A LARGE ROCK AVALANCHE ONTO MORSƁRJĆ?KULL GLACIER, SOUTH-EAST ICELAND. ITS IMPLICATIONS FOR ICE 6042, GEOLAB, F-63057 Clermont-Ferrand, France (3) Natural Research Centre of Northwestern Iceland, AĆ°algata 2, IS-550 SauĆ°Ć”rkrĆ³kur, Iceland (4) Icelandic Institute of Natural History, Borgum viĆ° NorĆ°urslĆ³Ć°

  6. Iced Coffee Iced Chai Tea Latte

    E-Print Network [OSTI]

    Iced Coffee Iced Chai Tea Latte Iced Americano Iced Cappuccino Iced Latte Iced Mocha Iced White the Cooler Canned Soda Bottled Water Arizona Teas Energy Drinks Red Bull, SF Red Bull & Bing Jones Sodas $0.50 Listed prices do not include applicable sales tax. #12;Brewed Coffee Cafe au Lait Hot Tea Chai Tea Latte

  7. Viscosity of interfacial water regulates ice nucleation

    SciTech Connect (OSTI)

    Li, Kaiyong; Chen, Jing; Zhang, Qiaolan; Zhang, Yifan; University of Chinese Academy of Sciences, Beijing 100049 ; Xu, Shun; Zhou, Xin; Cui, Dapeng; Wang, Jianjun Song, Yanlin

    2014-03-10

    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{sub 0} and ?, in the context of classical nucleation theory. From the extracted J{sub 0} and ?, we reveal the dominant role played by interfacial water. The results provide an insight into freezing mechanism on solid surfaces.

  8. Gas Migration from Closed Coal Mines to the Surface RISK ASSESSMENT METHODOLOGY AND PREVENTION MEANS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Gas Migration from Closed Coal Mines to the Surface RISK ASSESSMENT METHODOLOGY AND PREVENTION to the surface is especially significant in the context of coal mines. This is because mine gas can migrate of the scheduled closure of all coal mining operations in France, INERIS has drawn up, at the request of national

  9. Water ice in the dark dune spots of Richardson crater on Mars

    E-Print Network [OSTI]

    Kereszturi, A; Schmidt, F

    2010-01-01

    In this study we assess the presence, nature and properties of ices - in particular water ice - that occur within these spots using HIRISE and CRISM observations, as well as the LMD Global Climate Model. Our studies focus on Richardson crater (72{\\deg}S, 179{\\deg}E) and cover southern spring and summer (LS 175{\\deg} - 17 341{\\deg}). Three units have been identified of these spots: dark core, gray ring and bright halo. Each unit show characteristic changes as the season progress. In winter, the whole area is covered by CO2 ice with H2O ice contamination. Dark spots form during late winter and early spring. During spring, the dark spots are located in a 10 cm thick depression compared to the surrounding bright ice-rich layer. They are spectrally characterized by weak CO2 ice signatures that probably result from spatial mixing of CO2 ice rich and ice free regions within pixels, and from mixing of surface signatures due to aerosols scattering. The bright halo shaped by winds shows stronger CO2 absorptions than th...

  10. Satellite SAR Remote Sensing of Great Lakes Ice Cover, Part 2. Ice Classification and Mapping

    E-Print Network [OSTI]

    (look-up table) for different ice types. The library is used in the computer classifica- tion (freshwater) ice types using the Jet Propulsion Laboratory C-band scatterometer, together with surface data set, composed of over 20 variations of different ice types measured at incident angles from 0

  11. Assessing and Analyzing Near-Surface Radar Snow Accumulation Layers at Summit, Greenland

    E-Print Network [OSTI]

    Overly, Thomas Buckmaster

    2010-04-28

    High vertical-resolution 0.5&mdash2 GHz frequency-modulated continuous-wave radar data collected near Summit on the Greenland Ice Sheet reveal continuous horizons connecting the GRIP and GISP2 deep ice cores. Traced radar ...

  12. Incorporation of particulates into accreted ice above subglacial Vostok lake, Antarctica 

    E-Print Network [OSTI]

    Siegert, M. J.; Royston-Bishop, G.; Priscu, J. C.; Tranter, M.; Christner, B.; Lee, V.

    2005-01-01

    The nature of microscopic particulates in meteoric and accreted ice from the Vostok (Antarctica) ice core is assessed in conjunction with existing ice-core data to investigate the mechanism by which particulates are ...

  13. A damage mechanics assessment of the Larsen B ice shelf prior to collapse: Toward a physically-based calving law

    E-Print Network [OSTI]

    2012-01-01

    J. (1996), A Course on Damage Mechanics, Springer, New York.10.1029/2012GL053317, 2012 A damage mechanics assessment ofon con- tinuum damage mechanics coupled with the equations

  14. Importance of thermal effects and sea surface roughness for offshore wind resource assessment

    E-Print Network [OSTI]

    Heinemann, Detlev

    Importance of thermal effects and sea surface roughness for offshore wind resource assessment National Laboratory, Roskilde, Denmark Abstract The economic feasibility of offshore wind power utilisation depends on the favourable wind conditions offshore compared to sites on land, which have to compensate

  15. A reconciled estimate of ice-sheet mass balance

    E-Print Network [OSTI]

    2012-01-01

    Estimate of Ice-Sheet Mass Balance Andrew Shepherd, 1 * Erikand models of surface mass balance and glacial isostaticThis Ice Sheet Mass Balance Exercise (IMBIE) was facilitated

  16. Iced Coffee Iced Yerba Mate "Tea"

    E-Print Network [OSTI]

    Iced Coffee Iced Yerba Mate "Tea" Iced Yerba Mate Latte Iced Chai Tea Latte Original, Green Tea Canned Soda Xing Tea Bottled Water Arizona Teas Energy Drinks Red Bull, SF Red Bull & Bing Jones Sodas $0 Cafe au Lait Hot Tea Yerba Mate "Tea" Yerba Mate Latte Chai Tea Latte - Original, Green Tea, or Sugar

  17. High-Resolution Monitoring of Internal Layers Over the Greenland Ice Sheet P. Kanagaratnam, S.P. Gogineni

    E-Print Network [OSTI]

    Kansas, University of

    been attributed to the melting of mountain glaciers among other causes. The mass balance of the glacial attributed half of this rise to thermal expansion of the ocean and melting of mountain glaciers. To assess extent, intensity of summer melt, wind-generated surface roughness, ice temperature, and absolute

  18. Medical ice slurry production device

    DOE Patents [OSTI]

    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.

  19. ARM - Field Campaign - SGP Ice Nuclei Characterization Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and their impact on clouds and climate therefore remain relatively unconstrained. Soils of all types and plant surfaces are sources for ice nucleating particles that are...

  20. Glaciers and Ice Sheets Mapping Orbiter concept

    E-Print Network [OSTI]

    Jezek, Kenneth; Rodriguez, Ernesto; Gogineni, Sivaprasad; Freeman, Anthony; Curlander, John; Paden, John D.; Allen, Christopher Thomas

    2006-05-13

    We describe a concept for a spaceborne radar system designed to measure the surface and basal topography of terrestrial ice sheets and to determine the physical properties of the glacier bed. Our primary objective is to ...

  1. Conductivity Profile Determination by Eddy Current for Shot Peened Superalloy Surfaces Toward Residual Stress Assessment

    SciTech Connect (OSTI)

    Shen, Y.; Lo, C. C. H.; Frishman, A. M.; Lee, C.; Nakagawa, N. [Center for Nondestructive Evaluation, Iowa State University, Ames, Iowa 50011 (United States)

    2007-03-21

    This paper describes an eddy current model-based method for inverting near-surface conductivity deviation profiles of surface treated materials from swept-high frequency eddy current (SHFEC) data. This work forms part of our current research directed towards the development of an electromagnetic nondestructive technique for assessing residual stress of shot-peened superalloy components. The inversion procedure is based on the use of a parameterized function to describe the near-surface conductivity as a function of depth for a shot-peened surface, and the laterally uniform multi-layer theory of Cheng, Dodd and Deeds to calculate the resulting coil impedance deviations. The convergence of the inversion procedure has been tested against synthesized eddy current data. As a demonstration, the conductivity deviation profiles of a series of Inconel 718 specimens, shot peened at various Almen intensities, have been obtained by inversion. Several consistency tests were conducted to examine the reliability of the inverted conductivity profiles. The results show that conductivity deviation profiles can be reliably determined from SHFEC data within the accuracy of the current measurement system.

  2. Use of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research

    E-Print Network [OSTI]

    cancer and environmental contaminants, focusing primarily on agricultural chemical exposure assessmentUse of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research SUSAN K. MAXWELLa , JAYMIE R. MELIKERb AND PIERRE GOOVAERTSc a U.S. Geological

  3. Incorporation of a physically based melt pond scheme into the sea ice component of a climate model

    E-Print Network [OSTI]

    Feltham, Daniel

    Incorporation of a physically based melt pond scheme into the sea ice component of a climate model and evolution of melt ponds. Melt ponds accumulate on the surface of sea ice from snow and sea ice melt, melt ponds cover up to 50% of the sea ice surface. We have developed a melt pond evolution theory. Here

  4. Smoothed particle hydrodynamics Non-Newtonian model for ice-sheet and ice-shelf dynamics

    SciTech Connect (OSTI)

    Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

    2013-06-01

    Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) non-Newtonian model for coupled ice sheet and ice shelf dynamics. SPH, a fully Lagrangian particle method, is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface ?ows, large material deformation, and material fragmentation. In this paper, SPH is used to study 3D ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios, similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is veri?ed by simulating Poiseuille ?ow, plane shear ?ow with free surface and the propagation of a blob of ice along a horizontal surface. In the laboratory experiment, the ice was represented with a viscous Newtonian ?uid. In the present work, however, the ice is modeled as both viscous Newtonian ?uid and non-Newtonian ?uid, such that the e?ect of non-Newtonian rheology on the dynamics of grounding line was examined. The non-Newtonian constitutive relation is prescribed to be Glen’s law for the creep of polycrystalline ice. A V-shaped bedrock ramp is further introduced to model the real geometry of bedrock slope.

  5. ELECTRON IRRADIATION OF KUIPER BELT SURFACE ICES: TERNARY N{sub 2}-CH{sub 4}-CO MIXTURES AS A CASE STUDY

    SciTech Connect (OSTI)

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

    2012-10-10

    The space weathering of icy Kuiper Belt Objects was investigated in this case study by exposing methane (CH{sub 4}) and carbon monoxide (CO) doped nitrogen (N{sub 2}) ices at 10 K to ionizing radiation in the form of energetic electrons. Online and in situ Fourier transform infrared spectroscopy was utilized to monitor the radiation-induced chemical processing of these ices. Along with isocyanic acid (HNCO), the products could be mainly derived from those formed in irradiated binary ices of the N{sub 2}-CH{sub 4} and CO-CH{sub 4} systems: nitrogen-bearing products were found in the form of hydrogen cyanide (HCN), hydrogen isocyanide (HNC), diazomethane (CH{sub 2}N{sub 2}), and its radical fragment (HCN{sub 2}); oxygen-bearing products were of acetaldehyde (CH{sub 3}CHO), formyl radical (HCO), and formaldehyde (H{sub 2}CO). As in the pure ices, the methyl radical (CH{sub 3}) and ethane (C{sub 2}H{sub 6}) were also detected, as were carbon dioxide (CO{sub 2}) and the azide radical (N{sub 3}). Based on the temporal evolution of the newly formed products, kinetic reaction schemes were then developed to fit the temporal profiles of the newly formed species, resulting in numerical sets of rate constants. The current study highlights important constraints on the preferential formation of isocyanic acid (HNCO) over hydrogen cyanide (HCN) and hydrogen isocyanide (HNC), thus guiding the astrobiological and chemical evolution of those distant bodies.

  6. Assessing the cleanliness of surfaces: Innovative molecular approaches vs. standard spore assays

    SciTech Connect (OSTI)

    Cooper, M.; Duc, M.T. La; Probst, A.; Vaishampayan, P.; Stam, C.; Benardini, J.N.; Piceno, Y.M.; Andersen, G.L.; Venkateswaran, K.

    2011-04-01

    A bacterial spore assay and a molecular DNA microarray method were compared for their ability to assess relative cleanliness in the context of bacterial abundance and diversity on spacecraft surfaces. Colony counts derived from the NASA standard spore assay were extremely low for spacecraft surfaces. However, the PhyloChip generation 3 (G3) DNA microarray resolved the genetic signatures of a highly diverse suite of microorganisms in the very same sample set. Samples completely devoid of cultivable spores were shown to harbor the DNA of more than 100 distinct microbial phylotypes. Furthermore, samples with higher numbers of cultivable spores did not necessarily give rise to a greater microbial diversity upon analysis with the DNA microarray. The findings of this study clearly demonstrated that there is not a statistically significant correlation between the cultivable spore counts obtained from a sample and the degree of bacterial diversity present. Based on these results, it can be stated that validated state-of-the-art molecular techniques, such as DNA microarrays, can be utilized in parallel with classical culture-based methods to further describe the cleanliness of spacecraft surfaces.

  7. Community Ice Sheet Model (CISM2) Development and Marine Ice...

    Office of Scientific and Technical Information (OSTI)

    Conference: Community Ice Sheet Model (CISM2) Development and Marine Ice Sheet Simulations Citation Details In-Document Search Title: Community Ice Sheet Model (CISM2) Development...

  8. Arctic ice islands

    SciTech Connect (OSTI)

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

    1988-01-01

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

  9. A Bayesian Approach to Assess the Importance of Crustal Corrections in Global Anisotropic Surface Wave Tomography

    E-Print Network [OSTI]

    Xing, Z; Beghein, C

    2015-01-01

    from measurements of surface wave phase velocity anomalies,boundary from surface wave dispersion data, J. Geophys.radially anisotropic surface wave tomography, J. Geophys.

  10. A Smoothed Particle Hydrodynamics Model for Ice Sheet and Ice Shelf Dynamics

    SciTech Connect (OSTI)

    Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

    2012-02-08

    Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) model for coupled ice sheet and ice shelf dynamics. SPH is a fully Lagrangian particle method. It is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface flows, large material deformation, and material fragmentation. In this paper SPH is used to study ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from the SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is further verified by simulating the plane shear flow of two immiscible fluids and the propagation of a highly viscous blob of fluid along a horizontal surface. In the experiment, the ice was represented with a viscous newtonian fluid. For consistency, in the described SPH model the ice is also modeled as a viscous newtonian fluid. Typically, ice sheets are modeled as a non-Newtonian fluid, accounting for the changes in the mechanical properties of ice. Implementation of a non-Newtonian rheology in the SPH model is the subject of our ongoing research.

  11. Surface water drainage system. Environmental assessment and finding of no significant impact

    SciTech Connect (OSTI)

    1996-05-01

    This Environmental Assessment (EA) is written pursuant to the National Environmental Policy Act (NEPA). The document identifies and evaluates the action proposed to correct deficiencies in, and then to maintain, the surface water drainage system serving the Department of Energy`s Rocky Flats Environmental Technology Site (Site), located north of Golden, Colorado. Many of the activities proposed would not normally be subject to this level of NEPA documentation. However, in many cases, maintenance of the system has been deferred to the point that wetlands vegetation has become established in some ditches and culverts, creating wetlands. The proposed activities would damage or remove some of these wetlands in order to return the drainage system to the point that it would be able to fully serve its intended function - stormwater control. The Department of Energy (DOE) regulations require that activities affecting environmentally sensitive areas like wetlands be the subject of an EA. Most portions of the surface water drainage system are presently inadequate to convey the runoff from a 100-year storm event. As a result, such an event would cause flooding across much of the Site and possibly threaten the integrity of the dams at the terminal ponds. Severe flooding would not only cause damage to facilities and equipment, but could also facilitate the transport of contaminants from individual hazardous substance sites (IHSSs). Uncontrolled flow through the A- and B-series ponds could cause contaminated sediments to become suspended and carried downstream. Additionally, high velocity flood flows significantly increase erosion losses.

  12. A model of the threedimensional evolution of Arctic melt ponds on firstyear and multiyear sea ice

    E-Print Network [OSTI]

    Feltham, Daniel

    A model of the threedimensional evolution of Arctic melt ponds on firstyear and multiyear sea ice F in Arctic melt ponds on the surface of sea ice. An accurate estimate of the fraction of the sea ice surface covered in melt ponds is essential for a realistic estimate of the albedo for global climate models. We

  13. Test Plan to Assess Fire Effects on the Function of an Engineered Surface Barrier

    SciTech Connect (OSTI)

    Ward, Anderson L.; Berlin, Gregory T.; Cammann, Jerry W.; Leary, Kevin D.; Link, Steven O.

    2008-09-29

    Wildfire is a frequent perturbation in shrub steppe ecosystems, altering the flora, fauna, atmosphere, and soil of these systems. Research on the fire effects has focused mostly on natural ecosystems with essentially no attention on engineered systems like surface barriers. The scope of the project is to use a simulated wildfire to induce changes in an engineered surface barrier and document the effects on barrier performance. The main objective is to quantify the effects of burning and the resulting post-fire conditions on alterations in soil physical properties; hydrologic response, particularly the water balance; geochemical properties; and biological properties. A secondary objective is to use the lessons learned to maximize fire protection in the design of long-term monitoring systems based on electronic sensors. A simulated wildfire will be initiated, controlled and monitored at the 200-BP-1 barrier in collaboration with the Hanford Fire Department during the fall of 2008. The north half of the barrier will be divided into nine 12 x 12 m plots, each of which will be randomly assigned a fuel load of 2 kg m-2 or 4 kg m-2. Each plot will be ignited around the perimeter and flames allowed to carry to the centre. Any remaining unburned vegetation will be manually burned off using a drip torch. Progress of the fire and its effects will be monitored using point measurements of thermal, hydrologic, and biotic variables. Three measures of fire intensity will be used to characterize fire behavior: (1) flame height, (2) the maximum temperature at three vertical profile levels, and (3) total duration of elevated temperature at these levels. Pre-burn plant information, including species diversity, plant height, and canopy diameter will be measured on shrubs from the plots to be burned and from control plots at the McGee ranch. General assessments of shrub survival, recovery, and recruitment will be made after the fire. Near-surface soil samples will be collected pre- and post-burn to determine changes in the gravel content of the surface layer so as to quantify inflationary or deflationary responses to fire and to reveal the ability of the surface to resist post-fire erosive stresses. Measures of bulk density, water repellency, water retention, and hydraulic conductivity will be used to characterize changes in infiltration rates and water storage capacity following the fire. Samples will also be analyzed to quantify geochemical changes including changes in soil pH, cation exchange capacity, specific surface area, and the concentration of macro nutrients (e.g. N, P, K) and other elements such as Na, Mg, Ca, that are critical to the post-fire recovery revegetation. Soil CO2 emissions will be measured monthly for one year following the burn to document post-fire stimulation of carbon turnover and soil biogenic emissions. Surface and subsurface temperature measurements at and near monitoring installations will be used to document fire effects on electronic equipment. The results of this study will be used to bridge the gaps in knowledge on the effects of fire on engineered ecosystems (e.g. surface barriers), particularly the hydrologic and biotic characteristics that govern the water and energy balance. These results will also support the development of practical fire management techniques for barriers that are compatible with wildfire suppression strategies. Furthermore, lessons learned will be use to develop installation strategies needed to protect electronic monitoring equipment from the intense heat of fire and the potential damaging effects of smoke and fire extinguishing agents. Such information is needed to better understand long-term barrier performance under extreme conditions, especially if site maintenance and operational funding is lost for activities such as barrier revegetation.

  14. Mass balance of the Greenland ice sheet from 1958 to 2007

    E-Print Network [OSTI]

    Rignot, E; Rignot, E; Box, JE; Burgess, E; Hanna, E

    2008-01-01

    ice sheet surface mass balance varia- bility (1988 – 2004)5 L20502 RIGNOT ET AL. : MASS BALANCE GREENLAND 1958 – 20072005), Runoff and mass balance of the Greenland ice sheet:

  15. Ice electrode electrolytic cell

    DOE Patents [OSTI]

    Glenn, D.F.; Suciu, D.F.; Harris, T.L.; Ingram, J.C.

    1993-04-06

    This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

  16. Ice electrode electrolytic cell

    DOE Patents [OSTI]

    Glenn, David F. (Idaho Falls, ID); Suciu, Dan F. (Idaho Falls, ID); Harris, Taryl L. (Idaho Falls, ID); Ingram, Jani C. (Idaho Falls, ID)

    1993-01-01

    This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

  17. Assessment of Zero Power Critical Experiments and Needs for a Fission Surface Power System

    SciTech Connect (OSTI)

    Jim R Parry; John Darrell bess; Brad T. Rearden; Gary A. Harms

    2009-06-01

    The National Aeronautics and Space Administration (NASA) is providing funding to the Department of Energy (DOE) to assess, develop, and test nuclear technologies that could provide surface power to a lunar outpost. Sufficient testing of this fission surface power (FSP) system will need to be completed to enable a decision by NASA for flight development. The near-term goal for the FSP work is to conduct the minimum amount of testing needed to validate the system performance within an acceptable risk. This report attempts to assess the current modeling capabilities and quantify any bias associated with the modeling methods for designing the nuclear reactor. The baseline FSP system is a sodium-potassium (NaK) cooled, fast spectrum reactor with 93% 235U enriched HEU-O2 fuel, SS316 cladding, and beryllium reflectors with B4C control drums. The FSP is to produce approximately 40 kWe net power with a lifetime of at least 8 years at full power. A flight-ready FSP is to be ready for launch and deployment by 2020. Existing benchmarks from the International Criticality Safety Benchmark Evaluation Program (ICSBEP) were reviewed and modeled in MCNP. An average bias of less than 0.6% was determined using the ENDF/B-VII cross-section libraries except in the case of subcritical experiments, which exhibited an average bias of approximately 1.5%. The bias increases with increasing reflector worth of the beryllium. The uncertainties and sensitivities in cross section data for the FSP model and ZPPR-20 configurations were assessed using TSUNAMI-3D. The cross-section covariance uncertainty in the FSP model was calculated as 2.09%, which was dominated by the uncertainty in the 235U(n,?) reactions. Global integral indices were generated in TSUNAMI-IP using pre-release SCALE 6 cross-section covariance data. The ZPPR-20 benchmark models exhibit strong similarity with the FSP model. A penalty assessment was performed to determine the degree of which the FSP model could not be characterized by available ZPPR-20 benchmark data. The uncertainty in the FSP covariance data was reduced from 2.09% to 0.29%, where the bulk of the uncertainty was from the Be(n,n) reaction. Advanced analysis techniques using ZPPR-20C data should provide sufficient information to preclude the necessity of a cold critical of the FSP. Further testing to reduce uncertainties in the beryllium and uranium cross-section data should reduce the overall uncertainty in the computational models. The utilization of parameterization analysis software with perturbation techniques can help in understanding the computational uncertainty and relative systematic effects of parameters such as control drum, reflector, and material worth, temperature effects, and reaction rate measurements.

  18. Assessing surface water consumption using remotely-sensed groundwater, evapotranspiration, and precipitation

    E-Print Network [OSTI]

    Anderson, Ray G; Lo, Min-Hui; Famiglietti, James S

    2012-01-01

    Fernandez (2010), The surface water and ocean topographyObserving terrestrial surface water and oceanic submesoscaleof trends in streamflow and water availability in a changing

  19. Digital processing of SEM images for the assessment of evaluation indexes of cleaning interventions on Pentelic marble surfaces

    SciTech Connect (OSTI)

    Moropoulou, A. Delegou, E.T.; Vlahakis, V.; Karaviti, E.

    2007-11-15

    In this work, digital processing of scanning-electron-microscopy images utilized to assess cleaning interventions applied on the Pentelic marble surfaces of the National Archaeological Museum and National Library in Athens, Greece. Beside mineralogical and chemical characterization that took place by scanning-electron-microscopy with Energy Dispersive X-ray Spectroscopy, the image-analysis program EDGE was applied for estimating three evaluation indexes of the marble micro-structure. The EDGE program was developed by the U.S. Geological Survey for the evaluation of cleaning interventions applied on Philadelphia City Hall. This computer program analyzes scanning-electron-microscopy images of stone specimens cut in cross-section for measuring the fractal dimension of the exposed surfaces, the stone near-surface fracture density, the shape factor (a surface roughness factor) and the friability index which represents the physico-chemical and physico-mechanical stability of the stone surface. The results indicated that the evaluation of the marble surface micro-structure before and after cleaning is achieved by the suggested indexes, while the performance of cleaning interventions on the marble surfaces can be assessed.

  20. Ising model for melt ponds on Arctic sea ice

    E-Print Network [OSTI]

    Ma, Y -P; Golden, K M

    2014-01-01

    The albedo of melting Arctic sea ice, a key parameter in climate modeling, is determined by pools of water on the ice surface. Recent observations show an onset of pond complexity at a critical area of about 100 square meters, attended by a transition in pond fractal dimension. To explain this behavior and provide a statistical physics approach to sea ice modeling, we introduce a two dimensional Ising model for pond evolution which incorporates ice-albedo feedback and the underlying thermodynamics. The binary magnetic spin variables in the Ising model correspond to the presence of melt water or ice on the sea ice surface. The model exhibits a second-order phase transition from isolated to clustered melt ponds, with the evolution of pond complexity in the clustered phase consistent with the observations.

  1. Theoretical and kinetic assessment of the mechanism of ethane hydrogenolysis on metal surfaces saturated with chemisorbed hydrogen

    E-Print Network [OSTI]

    Iglesia, Enrique

    Theoretical and kinetic assessment of the mechanism of ethane hydrogenolysis on metal surfaces Hydrogenation Ring opening a b s t r a c t Ethane hydrogenolysis involves C­C bond rupture in unsaturated predominantly via an a,b-bound Ć CHCHĆ species that forms via sequential dehydrogenation of adsorbed ethane; all

  2. Development of a Laser-Produced Plasma X-ray source for Phase-Contrast Radiography of DT Ice layers

    SciTech Connect (OSTI)

    Izumi, N; Dewald, E; Kozioziemski, B; Landen, O L; Koch, J A

    2008-07-21

    Refraction enhanced x-ray phase contrast imaging is crucial for characterization of deuterium-tritium (DT) ice layer roughness in optically opaque inertial confinement fusion capsules. To observe the time development of DT ice roughness over {approx} second timescales, we need a bright x-ray source that can produce an image faster than the evolution of the ice surface roughness. A laser produced plasma x-ray source is one of the candidates that can meet this requirement. We performed experiments at the Janus laser facility at Lawrence Livermore National Laboratory and assessed the characteristics of the laser produced plasma x-ray source as a potential backlight for in situ target characterization.

  3. Ice chemistry in starless molecular cores

    E-Print Network [OSTI]

    Kalvans, Juris

    2015-01-01

    Starless molecular cores are natural laboratories for interstellar molecular chemistry research. The chemistry of ices in such objects was investigated with a three-phase (gas, surface, and mantle) model. We considered the center part of five starless cores, with their physical conditions derived from observations. The ice chemistry of oxygen, nitrogen, sulfur, and complex organic molecules (COMs) was analyzed. We found that an ice-depth dimension, measured, e.g., in monolayers, is essential for modeling of chemistry in interstellar ices. Particularly, the H2O:CO:CO2:N2:NH3 ice abundance ratio regulates the production and destruction of minor species. It is suggested that photodesorption during core collapse period is responsible for high abundance of interstellar H2O2 and O2H, and other species synthesized on the surface. The calculated abundances of COMs in ice were compared to observed gas-phase values. Smaller activation barriers for CO and H2CO hydrogenation may help explain the production of a number of...

  4. IceVeto: Extended PeV neutrino astronomy in the Southern Hemisphere with IceCube

    SciTech Connect (OSTI)

    Auffenberg, Jan; Collaboration: IceCube Collaboration

    2014-11-18

    IceCube, the world's largest high-energy neutrino observatory, built at the South Pole, recently reported evidence of an astrophysical neutrino flux extending to PeV energies in the Southern Hemisphere. This observation raises the question of how the sensitivity in this energy range could be further increased. In the down-going sector, in IceCube's case the Southern Hemisphere, backgrounds from atmospheric muons and neutrinos pose a challenge to the identification of an astrophysical neutrino flux. The IceCube analysis, that led to the evidence for astrophysical neutrinos, is based on an in-ice veto strategy for background rejection. One possibility available to IceCube is the concept of an extended surface detector, IceVeto, which could allow the rejection of a large fraction of atmospheric backgrounds, primarily for muons from cosmic ray (CR) air showers as well as from neutrinos in the same air showers. Building on the experience of IceTop/IceCube, possibly the most cost-effective and sensitive way to build IceVeto is as an extension of the IceTop detector, with simple photomultiplier based detector modules for CR air shower detection. Initial simulations and estimates indicate that such a veto detector will significantly increase the sensitivity to an astrophysical flux of ?{sub ?} induced muon tracks in the Southern Hemisphere compared to current analyses. Here we present the motivation and capabilities based on initial simulations. Conceptual ideas for a simplified surface array will be discussed briefly.

  5. WATER ICE IN THE KUIPER BELT

    SciTech Connect (OSTI)

    Brown, M. E.; Fraser, W. C. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Schaller, E. L., E-mail: mbrown@caltech.edu [NASA Dryden Aircraft Operations Facility, Palmdale, CA 93550 (United States)

    2012-06-15

    We examine a large collection of low-resolution near-infrared spectra of Kuiper Belt objects (KBOs) and centaurs in an attempt to understand the presence of water ice in the Kuiper Belt. We find that water ice on the surface of these objects occurs in three separate manners: (1) Haumea family members uniquely show surfaces of nearly pure water ice, presumably a consequence of the fragmentation of the icy mantle of a larger differentiated proto-Haumea; (2) large objects with absolute magnitudes of H < 3 (and a limited number to H = 4.5) have surface coverings of water ice-perhaps mixed with ammonia-that appears to be related to possibly ancient cryovolcanism on these large objects; and (3) smaller KBOs and centaurs which are neither Haumea family members nor cold-classical KBOs appear to divide into two families (which we refer to as 'neutral' and 'red'), each of which is a mixture of a common nearly neutral component and either a slightly red or very red component that also includes water ice. A model suggesting that the difference between neutral and red objects due to formation in an early compact solar system either inside or outside, respectively, of the {approx}20 AU methanol evaporation line is supported by the observation that methanol is only detected on the reddest objects, which are those which would be expected to have the most of the methanol containing mixture.

  6. Ethanol adsorbed on ice: A first-principles study C. Thierfelder*

    E-Print Network [OSTI]

    Schmidt, Wolf Gero

    Ethanol adsorbed on ice: A first-principles study C. Thierfelder* Centre of Theoretical Chemistry of ethanol molecules on the ice Ih basal plane. Apart from smooth surfaces, also substrate models simulation for ethanol adsorbed on ice using the TIP4P potential16 for the water-water interaction. Recent

  7. Mass balance of the Greenland ice sheet from 1958 to 2007 E. Rignot,1,2

    E-Print Network [OSTI]

    Box, Jason E.

    Mass balance of the Greenland ice sheet from 1958 to 2007 E. Rignot,1,2 J. E. Box,3 E. Burgess,4 October 2008. [1] We combine estimates of the surface mass balance, SMB, of the Greenland ice sheet the total ice sheet mass balance. During that time period, we find a robust correlation (R2 = 0.83) between

  8. THE STICKINESS OF MICROMETER-SIZED WATER-ICE PARTICLES

    SciTech Connect (OSTI)

    Gundlach, B.; Blum, J.

    2015-01-01

    Water ice is one of the most abundant materials in dense molecular clouds and in the outer reaches of protoplanetary disks. In contrast to other materials (e.g., silicates), water ice is assumed to be stickier due to its higher specific surface energy, leading to faster or more efficient growth in mutual collisions. However, experiments investigating the stickiness of water ice have been scarce, particularly in the astrophysically relevant micrometer-sized region and at low temperatures. In this work, we present an experimental setup to grow aggregates composed of ?m-sized water-ice particles, which we used to measure the sticking and erosion thresholds of the ice particles at different temperatures between 114 K and 260 K. We show with our experiments that for low temperatures (below ?210 K), ?m-sized water-ice particles stick below a threshold velocity of 9.6 m s{sup –1}, which is approximately 10 times higher than the sticking threshold of ?m-sized silica particles. Furthermore, erosion of the grown ice aggregates is observed for velocities above 15.3 m s{sup –1}. A comparison of the experimentally derived sticking threshold with model predictions is performed to determine important material properties of water ice, i.e., the specific surface energy and the viscous relaxation time. Our experimental results indicate that the presence of water ice in the outer reaches of protoplanetary disks can enhance the growth of planetesimals by direct sticking of particles.

  9. Safety Assessment for a Surface Repository in the Chernobyl Exclusion Zone - Methodology for Assessing Disposal under Intervention Conditions - 13476

    SciTech Connect (OSTI)

    Haverkamp, B.; Krone, J.; Shybetskyi, I.

    2013-07-01

    The Radioactive Waste Disposal Facility (RWDF) Buryakovka was constructed in 1986 as part of the intervention measures after the accident at Chernobyl NPP (ChNPP). Today, RWDF Buryakovka is still being operated but its maximum capacity is nearly reached. Plans for enlargement of the facility exist since more than 10 years but have not been implemented yet. In the framework of an European Commission Project DBE Technology GmbH prepared a safety analysis report of the facility in its current state (SAR) and a preliminary safety analysis report (PSAR) based on the planned enlargement. Due to its history RWDF Buryakovka does not fully comply with today's best international practices and the latest Ukrainian regulations in this area. The most critical aspects are its inventory of long-lived radionuclides, and the non-existent multi-barrier waste confinement system. A significant part of the project was dedicated, therefore, to the development of a methodology for the safety assessment taking into consideration the facility's special situation and to reach an agreement with all stakeholders involved in the later review and approval procedure of the safety analysis reports. Main aspect of the agreed methodology was to analyze the safety, not strictly based on regulatory requirements but on the assessment of the actual situation of the facility including its location within the Exclusion Zone. For both safety analysis reports, SAR and PSAR, the assessment of the long-term safety led to results that were either within regulatory limits or within the limits allowing for a specific situational evaluation by the regulator. (authors)

  10. Global Simulations of Ice nucleation and Ice Supersaturation...

    Office of Scientific and Technical Information (OSTI)

    Article: Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model Citation Details In-Document Search Title:...

  11. IceCube: Performance, Status, and Future

    E-Print Network [OSTI]

    Carsten Rott; for the IceCube Collaboration

    2006-11-28

    High-energy neutrinos are uniquely suited to study a large variety of physics as they traverse the universe almost untouched, in contrast to conventional astronomical messengers like photons or cosmic rays which are limited by interactions with radiation and matter at high energies or deflected by ambient magnetic fields. Located at the South Pole, IceCube combined with its predecessor AMANDA comprise the world's largest neutrino telescope. IceCube currently consists of nine strings, each containing 60 digital optical modules, deployed at depths of 1.5 to 2.5km in the ice and an array of 16 surface air-shower stations. IceCube is expected to be completed in early 2011 at which time it will instrument a volume of one km^3 below the IceTop air-shower array covering an area of one km^2. The current IceCube detector performance is described and an outlook given into the large variety of physics that it can address, with an emphasis on the search for ultra-high-energy neutrinos which may shed light on the origins of the highest energy cosmic rays.

  12. IceCube: Performance, Status, and Future

    E-Print Network [OSTI]

    Rott, C

    2006-01-01

    High-energy neutrinos are uniquely suited to study a large variety of physics as they traverse the universe almost untouched, in contrast to conventional astronomical messengers like photons or cosmic rays which are limited by interactions with radiation and matter at high energies or deflected by ambient magnetic fields. Located at the South Pole, IceCube combined with its predecessor AMANDA comprise the world's largest neutrino telescope. IceCube currently consists of nine strings, each containing 60 digital optical modules, deployed at depths of 1.5 to 2.5km in the ice and an array of 16 surface air-shower stations. IceCube is expected to be completed in early 2011 at which time it will instrument a volume of one km^3 below the IceTop air-shower array covering an area of one km^2. The current IceCube detector performance is described and an outlook given into the large variety of physics that it can address, with an emphasis on the search for ultra-high-energy neutrinos which may shed light on the origins ...

  13. Assessing surface water consumption using remotely-sensed groundwater, evapotranspiration, and precipitation

    E-Print Network [OSTI]

    Anderson, Ray G; Lo, Min-Hui; Famiglietti, James S

    2012-01-01

    model of land surface water and energy fluxes for generalin our water balance. One is a daily, 0.05 ET energy balance

  14. Equations of state of ice VI and ice VII at high pressure and high temperature

    SciTech Connect (OSTI)

    Bezacier, Lucile; Hanfland, Michael; Journaux, Baptiste; Perrillat, Jean-Philippe; Cardon, Hervé; Daniel, Isabelle

    2014-09-14

    High-pressure H{sub 2}O polymorphs among which ice VI and ice VII are abundant in the interiors of large icy satellites and exo-planets. Knowledge of the elastic properties of these pure H{sub 2}O ices at high-temperature and high-pressure is thus crucial to decipher the internal structure of icy bodies. In this study we assess for the first time the pressure-volume-temperature (PVT) relations of both polycrystalline pure ice VI and ice VII at high pressures and temperatures from 1 to 9 GPa and 300 to 450 K, respectively, by using in situ synchrotron X-ray diffraction. The PVT data are adjusted to a second-order Birch-Murnaghan equation of state and give V{sub 0} = 14.17(2) cm{sup 3}?mol{sup ?1}, K{sub 0} = 14.05(23) GPa, and ?{sub 0} = 14.6(14) × 10{sup ?5} K{sup ?1} for ice VI and V{sub 0} = 12.49(1) cm{sup 3}?mol{sup ?1}, K{sub 0} = 20.15(16) GPa, and ?{sub 0} = 11.6(5) × 10{sup ?5} K{sup ?1} for ice VII.

  15. A Surface Water Protection Assessment Tool that uses Digital Elevation Models1 Darwin L. Sorensen

    E-Print Network [OSTI]

    Tarboton, David

    . A first approximation estimate of pollutant concentration reaching the drinking water treatment plant of surface water supplies to pollution from current and future activities in the watershed. Surface water of pollution under various storm intensities can be analyzed. The influences of shallow ground water quality (e

  16. Field demonstration of the ICE 250{trademark} Cleaning System

    SciTech Connect (OSTI)

    Johnston, J.L.; Jackson, L.M.

    1999-10-05

    The ICE 250{trademark} Cleaning System was engineered to convert water into small ice particles for use in cleaning and decontamination applications. Ice crystals are produced in a special icemaker and pressured through a hose-nozzle onto the surface to be cleaned. The Rocky Mountain Oilfield Testing Center and Ice Cleaning Systems, Inc., conducted a test of this system at Naval Petroleum Reserve No. 3 to evaluate the system's cleaning capabilities in an oil field environment. Equipment cleaned included an oil storage tank, a rod pumping unit, a road grader, and a wellhead. Contaminants were unrefined sour crude oil, hydraulic fluid, paraffin, and dirt, occurring separately and as mixtures. In all four demonstration cleaning tasks, the ICE 250 System effectively removed surface contaminant mixtures in a timely manner and left no oily residue. A minimal amount of waste moisture was generated, thereby reducing cleanup and disposal costs.

  17. Turbulent heat exchange between water and ice at an evolving ice-water interface

    E-Print Network [OSTI]

    Ramudu, Eshwan; Olson, Peter; Gnanadesikan, Anand

    2015-01-01

    We conduct laboratory experiments on the time evolution of an ice layer cooled from below and subjected to a turbulent shear flow of warm water from above. Our study is motivated by observations of warm water intrusion into the ocean cavity under Antarctic ice shelves, accelerating the melting of their basal surfaces. The strength of the applied turbulent shear flow in our experiments is represented in terms of its Reynolds number $\\textit{Re}$, which is varied over the range $2.0\\times10^3 \\le \\textit{Re} \\le 1.0\\times10^4$. Depending on the water temperature, partial transient melting of the ice occurs at the lower end of this range of $\\textit{Re}$ and complete transient melting of the ice occurs at the higher end. Following these episodes of transient melting, the ice reforms at a rate that is independent of $\\textit{Re}$. We fit our experimental measurements of ice thickness and temperature to a one-dimensional model for the evolution of the ice thickness in which the turbulent heat transfer is parameter...

  18. Prediction of lake ice in the Netherlands

    E-Print Network [OSTI]

    Haak, Hein

    by HARMONIE ·Flake driven by ECMWF ensembles ·Conclusions and Outlook #12;Lake workshop sept 2012 Motivation Operational Observations ECMWF model #12;Lake workshop sept 2012 h D Air Water Ice ·Surface energy ·Radiative fluxes (Qs, Ql, absorbed solar radiation) ·Turbulent fluxes (sensible and latent heat fluxes

  19. Arctic Sea ice model sensitivities.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  20. Risk assessment of surface vs subsea blowout preventers (bops) on mobile offshore drilling units focusing on riser failure and the use of subsea shear rams 

    E-Print Network [OSTI]

    Melendez, Jorge Luis

    2006-08-16

    The use of a slim, high-pressure drilling riser for surface blowout preventer operations in the deepwater Gulf of Mexico was assessed as an alternative to conventional drilling procedures from floating units. Comparison ...

  1. Interface limited growth of heterogeneously nucleated ice in supercooled water

    E-Print Network [OSTI]

    Razvan A. Nistor; Thomas E. Markland; B. J. Berne

    2013-12-30

    Heterogeneous ice growth exhibits a maximum in freezing rate arising from the competition between kinetics and the thermodynamic driving force between the solid and liquid states. Here, we use molecular dynamics simulations to elucidate the atomistic details of this competition, focusing on water properties in the interfacial region along the secondary prismatic direction. The crystal growth velocity is maximized when the efficiency of converting interfacial water molecules to ice, collectively known as the attachment kinetics, is greatest. We find water molecules that contact the intermediate ice layer in concave regions along the atomistically roughened surface are more likely to freeze directly. The increased roughening of the solid surface at large undercoolings consequently plays an important limiting role on the rate of ice growth, as water molecules are unable to integrate into increasingly deeper surface pockets. These results provide insights into the molecular mechanisms for self-assembly of solid phases that are important in many biological and atmospheric processes.

  2. Ice Nuclei in Marine Air: Biogenic Particles or Dust?

    SciTech Connect (OSTI)

    Burrows, Susannah M.; Hoose, C.; Poschl, U.; Lawrence, M.

    2013-01-11

    Ice nuclei impact clouds, but their sources and distribution in the atmosphere are still not well known. Particularly little attention has been paid to IN sources in marine environments, although evidence from field studies suggests that IN populations in remote marine regions may be dominated by primary biogenic particles associated with sea spray. In this exploratory model study, we aim to bring attention to this long-neglected topic and identify promising target regions for future field campaigns. We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated marine biogenic immersion IN distributions and dust immersion IN distributions, we predict strong regional differences in the importance of marine biogenic IN relative to dust IN. Our analysis suggests that marine biogenic IN are most likely to play a dominant role in determining IN concentrations in near-surface-air over the Southern Ocean, so future field campaigns aimed at investigating marine biogenic IN should target that region. Climate related changes in the abundance and emission of biogenic marine IN could affect marine cloud properties, thereby introducing previously unconsidered feedbacks that influence the hydrological cycle and the Earth’s energy balance. Furthermore, marine biogenic IN may be an important aspect to consider in proposals for marine cloud brightening by artificial sea spray production.

  3. THE PHASES OF WATER ICE IN THE SOLAR NEBULA

    SciTech Connect (OSTI)

    Ciesla, Fred J.

    2014-03-20

    Understanding the phases of water ice that were present in the solar nebula has implications for understanding cometary and planetary compositions as well as the internal evolution of these bodies. Here we show that amorphous ice formed more readily than previously recognized, with formation at temperatures <70 K being possible under protoplanetary disk conditions. We further argue that photodesorption and freeze-out of water molecules near the surface layers of the solar nebula would have provided the conditions needed for amorphous ice to form. This processing would be a natural consequence of ice dynamics and would allow for the trapping of noble gases and other volatiles in water ice in the outer solar nebula.

  4. Ice Bear® Storage Module | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Ice Bear Storage Module Ice Bear Storage Module Thermal Energy Storage for Light Commercial Refrigerant-Based Air Conditioning Units The Ice Bear storage technology was...

  5. Large Scale Ice Water Path and 3-D Ice Water Content

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Liu, Guosheng

    2008-01-15

    Cloud ice water concentration is one of the most important, yet poorly observed, cloud properties. Developing physical parameterizations used in general circulation models through single-column modeling is one of the key foci of the ARM program. In addition to the vertical profiles of temperature, water vapor and condensed water at the model grids, large-scale horizontal advective tendencies of these variables are also required as forcing terms in the single-column models. Observed horizontal advection of condensed water has not been available because the radar/lidar/radiometer observations at the ARM site are single-point measurement, therefore, do not provide horizontal distribution of condensed water. The intention of this product is to provide large-scale distribution of cloud ice water by merging available surface and satellite measurements. The satellite cloud ice water algorithm uses ARM ground-based measurements as baseline, produces datasets for 3-D cloud ice water distributions in a 10 deg x 10 deg area near ARM site. The approach of the study is to expand a (surface) point measurement to an (satellite) areal measurement. That is, this study takes the advantage of the high quality cloud measurements at the point of ARM site. We use the cloud characteristics derived from the point measurement to guide/constrain satellite retrieval, then use the satellite algorithm to derive the cloud ice water distributions within an area, i.e., 10 deg x 10 deg centered at ARM site.

  6. Large Scale Ice Water Path and 3-D Ice Water Content

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Liu, Guosheng

    Cloud ice water concentration is one of the most important, yet poorly observed, cloud properties. Developing physical parameterizations used in general circulation models through single-column modeling is one of the key foci of the ARM program. In addition to the vertical profiles of temperature, water vapor and condensed water at the model grids, large-scale horizontal advective tendencies of these variables are also required as forcing terms in the single-column models. Observed horizontal advection of condensed water has not been available because the radar/lidar/radiometer observations at the ARM site are single-point measurement, therefore, do not provide horizontal distribution of condensed water. The intention of this product is to provide large-scale distribution of cloud ice water by merging available surface and satellite measurements. The satellite cloud ice water algorithm uses ARM ground-based measurements as baseline, produces datasets for 3-D cloud ice water distributions in a 10 deg x 10 deg area near ARM site. The approach of the study is to expand a (surface) point measurement to an (satellite) areal measurement. That is, this study takes the advantage of the high quality cloud measurements at the point of ARM site. We use the cloud characteristics derived from the point measurement to guide/constrain satellite retrieval, then use the satellite algorithm to derive the cloud ice water distributions within an area, i.e., 10 deg x 10 deg centered at ARM site.

  7. Final Report DE-EE0005380: Assessment of Offshore Wind Farm Effects on Sea Surface, Subsurface and Airborne Electronic Systems

    SciTech Connect (OSTI)

    Ling, Hao; Hamilton, Mark F.; Bhalla, Rajan; Brown, Walter E.; Hay, Todd A.; Whitelonis, Nicholas J.; Yang, Shang-Te; Naqvi, Aale R.

    2013-09-30

    Offshore wind energy is a valuable resource that can provide a significant boost to the US renewable energy portfolio. A current constraint to the development of offshore wind farms is the potential for interference to be caused by large wind farms on existing electronic and acoustical equipment such as radar and sonar systems for surveillance, navigation and communications. The US Department of Energy funded this study as an objective assessment of possible interference to various types of equipment operating in the marine environment where offshore wind farms could be installed. The objective of this project was to conduct a baseline evaluation of electromagnetic and acoustical challenges to sea surface, subsurface and airborne electronic systems presented by offshore wind farms. To accomplish this goal, the following tasks were carried out: (1) survey electronic systems that can potentially be impacted by large offshore wind farms, and identify impact assessment studies and research and development activities both within and outside the US, (2) engage key stakeholders to identify their possible concerns and operating requirements, (3) conduct first-principle modeling on the interactions of electromagnetic signals with, and the radiation of underwater acoustic signals from, offshore wind farms to evaluate the effect of such interactions on electronic systems, and (4) provide impact assessments, recommend mitigation methods, prioritize future research directions, and disseminate project findings. This report provides a detailed description of the methodologies used to carry out the study, key findings of the study, and a list of recommendations derived based the findings.

  8. CO diffusion into amorphous H2O ices

    E-Print Network [OSTI]

    Lauck, Trish; Shulenberger, Katherine; Rajappan, Mahesh; Oberg, Karin I; Cuppen, Herma M

    2015-01-01

    The mobility of atoms, molecules and radicals in icy grain mantles regulate ice restructuring, desorption, and chemistry in astrophysical environments. Interstellar ices are dominated by H2O, and diffusion on external and internal (pore) surfaces of H2O-rich ices is therefore a key process to constrain. This study aims to quantify the diffusion kinetics and barrier of the abundant ice constituent CO into H2O dominated ices at low temperatures (15-23 K), by measuring the mixing rate of initially layered H2O(:CO2)/CO ices. The mixed fraction of CO as a function of time is determined by monitoring the shape of the infrared CO stretching band. Mixing is observed at all investigated temperatures on minute time scales, and can be ascribed to CO diffusion in H2O ice pores. The diffusion coefficient and final mixed fraction depend on ice temperature, porosity, thickness and composition. The experiments are analyzed by applying Fick's diffusion equation under the assumption that mixing is due to CO diffusion into an i...

  9. The Relative Importance of Clouds and Sea Ice for the Solar Energy Budget of the Southern Ocean

    E-Print Network [OSTI]

    Warren, Stephen

    The Relative Importance of Clouds and Sea Ice for the Solar Energy Budget of the Southern Ocean) ABSTRACT The effects of clouds and sea ice on the solar radiation budget are determined for the Southern and for altered surface and cloud conditions. Poleward of 68°S in spring, ice causes a greater reduction of solar

  10. Piezoresistive Effect for Near-Surface Eddy Current Residual Stress Assessment

    SciTech Connect (OSTI)

    Yu, F.; Nagy, P.B. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, Ohio 45221-0070 (United States)

    2005-04-09

    This paper discusses the relationship between isothermal and adiabatic piezoresistive properties of metals. The piezoresistive effect, i.e., stress-dependence of the electrical resistivity, can be exploited for nondestructive residual stress assessment using eddy current measurements. First, the paper establishes the relationship between the familiar isothermal piezoresistivity coefficients measured under uniaxial tension and hydrostatic pressure and the relevant isothermal electroelastic coefficients measured under uniaxial and biaxial stress conditions either by non-directional circular or directional elliptical eddy current coils. In order to quantitatively assess the prevailing residual stress from eddy current conductivity measurements, the electroelastic coefficients must be first determined. These calibration measurements are usually conducted on a reference specimen of the material to be tested using cyclic uniaxial loads between 0.1 and 10 Hz, which is fast enough to produce adiabatic conditions. It is demonstrated that in high-conductivity metals such calibration measurements must be corrected for the thermoelastic effect, which is always positive, i.e., it increases the conductivity in tension, when the material cools down, and reduces it in compression, when the material heats up.

  11. SU-E-J-171: Surface Imaging Based Intrafraction Motion Assessments for Whole Brain Radiotherapy

    SciTech Connect (OSTI)

    Wiant, D; Vanderstraeten, C; Maurer, J; Pursley, J; Terrell, J; Sintay, B

    2014-06-01

    Purpose: To quantify and characterize intrafraction motion for whole brain radiotherapy treatments in open face masks using 3D surface imaging. Methods: Fifteen whole brain patients were monitored with 3D surface imaging over a total of 202 monitoring sessions. Mean translations and rotations were calculated over each minute, each session, and over all sessions combined. The percentage of each session that the root mean square (RMS) of the linear translations were outside of 2 mm, 3 mm, 4 mm, and 5 mm were determined for each patient. Correlations between mean translations per minute and time and between standard deviation per minute and time were evaluated using Pearson's r value. Results: The mean RMS translation averaged over all patients was 1.45 mm +/? 1.52 mm. The patients spent an average of 18%, 10%, 6%, and 3% of the monitoring time outside of 2 mm, 3 mm, 4 mm, and 5 mm RMS tolerances, respectively. The RMS values averaged over all patients were 1.31 mm +/? 0.98 mm, 1.52 +/- 1.04, and 1.30 mm +/? 0.71 mm over the 1th, 5th, and 10th minutes of monitoring, respectively. Neither, the RMS values (p = 0.15) or the standard deviations of the RMS values (p = 0.16) showed significant correlations with time. Conclusion: The patients were positioned within 2 mm of isocenter, which was the initial set-up tolerance, for the majority of their treatments. The average position changed by < 0.3 mm over 10 minutes of monitoring. Short term movements, reflected by the standard deviations, where on the order of 1 mm. This immobilization system provides adequate immobilization over a course of treatment for whole brain radiotherapy. This system may also be suitable for head and neck or stereotactic radiosurgery treatments as well.

  12. IceCube: The state of the art

    E-Print Network [OSTI]

    Teresa Montaruli

    2006-08-09

    In this paper we describe the performance of the 9 instrumented IceCube strings and 16 surface IceTop stations taking data at the Geographical South Pole after 2 deployment seasons. We will focus on the description of the array and on the construction and data analysis status. The expected full array performance is discussed and compared to other results for the relevant physics studies using high energy neutrinos for astrophysical neutrino searches.

  13. Carbon dioxide effects research and assessment program. Environmental and societal consequences of a possible CO/sub 2/-induced climate change: volume II, part I. Response of the West Antarctic ice sheet to CO/sub 2/-induced climatic warming

    SciTech Connect (OSTI)

    Bentley, C.

    1982-04-01

    The paper proposes a research plan to deal with the question of what the response of the West Antarctic Ice Sheet would be to a rise in global temperatures caused by an anthropogenic CO/sub 2/ buildup in the atmosphere. The plan is designed to answer the following questions: (1) how fast is the ice mass changing now, and why; (2) how will the boundary conditions that affect the ice sheet respond to an atmospheric temperature change and how are those boundary conditions changing now; (3) what will be the response of the ice sheet to changes in boundary conditions; and (4) what can be learned by analogy with what has happened in the past. (ACR)

  14. Reprocessing of Ices in Turbulent Protoplanetary Disks: Carbon and Nitrogen Chemistry

    E-Print Network [OSTI]

    Furuya, Kenji

    2014-01-01

    We study the influence of the turbulent transport on ice chemistry in protoplanetary disks, focusing on carbon and nitrogen bearing molecules. Chemical rate equations are solved with the diffusion term, mimicking the turbulent mixing in the vertical direction. Turbulence can bring ice-coated dust grains from the midplane to the warm irradiated disk surface, and the ice mantles are reprocessed by photoreactions, thermal desorption, and surface reactions. The upward transport decreases the abundance of methanol and ammonia ices at r reprocessing could explain the smaller abundances of carbon and nitrogen bearing molecules in cometary coma than those in low-mass protostellar envelopes. We also show the effect of mixing on the synthesis of complex organic molecules (COMs) are two ways: (1) transport of ices from the midplane to the disk surface and (2) transport of atomic hydrogen from the surface to the midplane. The fo...

  15. Photodesorption of ices I: CO, N2 and CO2

    E-Print Network [OSTI]

    Karin I. Oberg; Ewine F. van Dishoeck; Harold Linnartz

    2009-01-23

    A longstanding problem in astrochemistry is how molecules can be maintained in the gas phase in dense inter- and circumstellar regions. Photodesorption is a non-thermal desorption mechanism, which may explain the small amounts of observed cold gas in cloud cores and disk mid-planes. This paper aims to determine the UV photodesorption yields and to constrain the photodesorption mechanisms of three astrochemically relevant ices: CO, N2 and CO2. In addition, the possibility of co-desorption in mixed and layered CO:N2 ices is explored. The ice photodesorption is studied experimentally under ultra high vacuum conditions and at 15-60 K using a hydrogen discharge lamp (7-10.5 eV). The ice desorption during irradiation is monitored by reflection absorption infrared spectroscopy of the ice and simultaneous mass spectrometry of the desorbed molecules. Both the UV photodesorption yields per incident photon and the photodesorption mechanisms are molecule specific. CO photodesorbs without dissociation from the surface layer of the ice. N2, which lacks an electronic transition in this wavelength range, has a photodesorption yield that is more than an order of magnitude lower. This yield increases significantly due to co-desorption when N2 is mixed in with or layered on top of CO ice. CO2 photodesorbs through dissociation and subsequent recombination from the top 10 layers of the ice. At low temperatures (15-18 K) the derived photodesorption yields are 2.7x10^-3 and CO2 photodesorption yield is 1.2x10^-3x(1-e^(-X/2.9)) + 1.1x10^-3x(1-e^(-X/4.6)) molecules photon-1, where X is the ice thickness in monolayers and the two parts of the expression represent a CO2 and CO photodesorption pathway.

  16. Hidden force floating ice

    E-Print Network [OSTI]

    Chang Q. Sun

    2015-01-17

    Because of the segmental specific-heat disparity of the hydrogen bond (O:H-O) and the Coulomb repulsion between oxygen ions, cooling elongates the O:H-O bond at freezing by stretching its containing angle and shortening the H-O bond with an association of larger O:H elongation, which makes ice less dense than water, allowing it to float.

  17. Ice Storm Supercomputer

    ScienceCinema (OSTI)

    None

    2013-05-28

    "A new Idaho National Laboratory supercomputer is helping scientists create more realistic simulations of nuclear fuel. Dubbed 'Ice Storm,' this 2048-processor machine allows researchers to model and predict the complex physics behind nuclear reactor behavior. And with a new visualization lab, the team can see the results of its simulations on the big screen." For more information about INL research, visit http://www.facebook.com/idahonationallaboratory.

  18. ICE SHEETS, GLOBAL WARMING, AND ARTICLE 2 OF THE UNFCCC An Editorial Essay

    E-Print Network [OSTI]

    Oppenheimer, Michael

    in area and perhaps in mass since the Last Glacial Maximum (Bindschadler, 1998; Huybrechts, 2002) provides of ice loss by altering the mass balance between precipitation rates on the one hand, and melting and ice site has been tied to the availability of surface melt water, which percolates to and lubricates

  19. Electromagnetic and physical properties of sea ice formed in the presence of wave action

    E-Print Network [OSTI]

    Onstott, R. G.; Gogineni, Sivaprasad; Gow, A. J.; Grenfell, T. C.; Jezek, K. C.; Perovich, D. K.; Swift, C. T.

    1998-09-01

    of continuous sheets of newly formed ice. In addi- tion, because of the filtering action of frazil and ice pans, high wave energy and long ocean wavelengths are required to form large ice pans, and pans formed under these conditions have more complex surfaces... based on existing and future satellite technology is required. In this investigation, a wide range of sensor parameters are used to support the development of a ?broad spectral approach? to the problem of inverting sensor signal data to sea ice form...

  20. Light-absorbing Particles in Snow and Ice: Measurement and Modeling of Climatic and Hydrological Impact

    SciTech Connect (OSTI)

    Qian, Yun; Yasunari, Teppei J.; Doherty, Sarah J.; Flanner, M. G.; Lau, William K.; Ming, J.; Wang, Hailong; Wang, Mo; Warren, Stephen G.; Zhang, Rudong

    2015-01-01

    Light absorbing particles (LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance (a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice (LAPSI) has been identified as one of major forcings affecting climate change, e.g. in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this review paper, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the mass concentrations, albedo reduction, radiative forcing, andclimatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle.

  1. Climate Impacts of Ice Nucleation

    SciTech Connect (OSTI)

    Gettelman, A.; Liu, Xiaohong; Barahona, Donifan; Lohmann, U.; Chen, Chih-Chieh

    2012-10-27

    Several different ice nucleation parameterizations in two different General Circulation Models are used to understand the effects of ice nucleation on the mean climate state, and the climate effect of aerosol perturbations to ice clouds. The simulations have different ice microphysical states that are consistent with the spread of observations. These different states occur from different parameterizations of the ice cloud nucleation processes, and feature different balances of homogeneous and heterogeneous nucleation. At reasonable efficiencies, consistent with laboratory measurements and constrained by the global radiative balance, black carbon has a small (-0.06 Wm?2) and not statistically significant climate effect. Indirect effects of anthropogenic aerosols on cirrus clouds occur mostly due to increases in homogeneous nucleation fraction as a consequence of anthropogenic sulfur emissions. The resulting ice indirect effects do not seem strongly dependent on the ice micro-physical balance, but are slightly larger for those states with less homogeneous nucleation in the base state. The total ice AIE is estimated at 0.26±0.09 Wm?2 (1? uncertainty). This represents an offset of 20-30% of the simulated total Aerosol Indirect Effect for ice and liquid clouds.

  2. arXiv:1408.2487v2[physics.ao-ph]22Aug2014 Ising model for melt ponds on Arctic sea ice

    E-Print Network [OSTI]

    Golden, Kenneth M.

    arXiv:1408.2487v2[physics.ao-ph]22Aug2014 Ising model for melt ponds on Arctic sea ice Yi-Ping Ma,1 of water on the ice surface. Recent observations show an onset of pond complexity at a critical area modeling, we introduce a two dimensional Ising model for pond evolution which incorporates ice

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

    SciTech Connect (OSTI)

    Liu, Yang; Hu, Hui [Department of Aerospace Engineering, Iowa State University, 2271 Howe Hall, Room 1200, Ames, IA 50011 (United States); Chen, Wen-Li [Department of Aerospace Engineering, Iowa State University, 2271 Howe Hall, Room 1200, Ames, IA 50011 (United States); School of Civil Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150090 (China); Bond, Leonard J. [Department of Aerospace Engineering, Iowa State University, 2271 Howe Hall, Room 1200, Ames, IA 50011 (United States); Center for Nondestructive Evaluation, Iowa State University, 1915 Scholl Road, 151 ASC II, Ames, IA 50011 (United States)

    2014-02-18

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

  4. Sputtering of Oxygen Ice by Low Energy Ions

    E-Print Network [OSTI]

    Muntean, E A; Field, T A; Fitzsimmons, A; Hunniford, C A; McCullough, R W

    2015-01-01

    Naturally occurring ices lie on both interstellar dust grains and on celestial objects, such as those in the outer solar system. These ices are continu- ously subjected to irradiation by ions from the solar wind and/or cosmic rays, which modify their surfaces. As a result, new molecular species may form which can be sputtered off into space or planetary atmospheres. We determined the experimental values of sputtering yields for irradiation of oxygen ice at 10 K by singly (He+, C+, N+, O+ and Ar+) and doubly (C2+, N2+ and O2+) charged ions with 4 keV kinetic energy. In these laboratory experiments, oxygen ice was deposited and irradiated by ions in an ultra high vacuum chamber at low temperature to simulate the environment of space. The number of molecules removed by sputtering was observed by measurement of the ice thickness using laser interferometry. Preliminary mass spectra were taken of sputtered species and of molecules formed in the ice by temperature programmed desorption (TPD). We find that the experi...

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

    SciTech Connect (OSTI)

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

    2011-04-01

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

  6. Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics

    E-Print Network [OSTI]

    Anderson, M. L.; Larsen, T. B.; Nettles, M.; Elosegui, P.; van As, D.; Hamilton, Gordon S.; Stearns, Leigh; Davis, J. L.; Ahlstrom, A. P.; de Juan, J.; Ekstrom, G.; Stenseng, L.; Khan, S. A.; Forsberg, R.; Dahl-Jensen, D.

    2010-12-29

    [1] Understanding the behavior of large outlet glaciers draining the Greenland Ice Sheet is critical for assessing the impact of climate change on sea level rise. The flow of marine-terminating outlet glaciers is partly governed by calving...

  7. ARM - Ice Cores

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments? WeDatastreamstps DocumentationAtlanticENAField ParticipantsField Campaign StatisticsPastIce Cores

  8. Tuesday, March 24, 2009 MARS: GROUND ICE AND CLIMATE CHANGE

    E-Print Network [OSTI]

    Rathbun, Julie A.

    Tuesday, March 24, 2009 MARS: GROUND ICE AND CLIMATE CHANGE 1:30 p.m. Waterway Ballroom 1 Chairs.-B. Fastook J. L. Deciphering the Late Amazonian Climate History of Mars: Assessing Obliquity Predictions climate history of Mars; extended periods of consistently high or low obliquity are unlikely during

  9. 2 Internal melting in Antarctic sea ice: Development of ``gap layers'' 3 S. F. Ackley,1

    E-Print Network [OSTI]

    Texas at San Antonio, University of

    accelerate melting by 63increasing the absorption of solar radiation within the sea 64ice. Algal blooms only in the Antarctic to date. 48 In contrast, massive surface melt, resulting in the complete 49 loss

  10. Therapeutic Hypothermia: Protective Cooling Using Medical Ice...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Therapeutic Hypothermia: Protective Cooling Using Medical Ice Slurry Technology available for licensing: Proprietary method and equipment for making an ice slurry coolant to induce...

  11. Light propagation in the South Pole ice

    SciTech Connect (OSTI)

    Williams, Dawn; Collaboration: IceCube Collaboration

    2014-11-18

    The IceCube Neutrino Observatory is located in the ice near the geographic South Pole. Particle showers from neutrino interactions in the ice produce light which is detected by IceCube modules, and the amount and pattern of deposited light are used to reconstruct the properties of the incident neutrino. Since light is scattered and absorbed by ice between the neutrino interaction vertex and the sensor, IceCube event reconstruction depends on understanding the propagation of light through the ice. This paper presents the current status of modeling light propagation in South Pole ice, including the recent observation of an azimuthal anisotropy in the scattering.

  12. OBSERVATIONAL CONSTRAINTS ON METHANOL PRODUCTION IN INTERSTELLAR AND PREPLANETARY ICES

    SciTech Connect (OSTI)

    Whittet, D. C. B.; Cook, A. M.; Herbst, Eric; Chiar, J. E.; Shenoy, S. S.

    2011-11-20

    Methanol (CH{sub 3}OH) is thought to be an important link in the chain of chemical evolution that leads from simple diatomic interstellar molecules to complex organic species in protoplanetary disks that may be delivered to the surfaces of Earthlike planets. Previous research has shown that CH{sub 3}OH forms in the interstellar medium predominantly on the surfaces of dust grains. To enhance our understanding of the conditions that lead to its efficient production, we assemble a homogenized catalog of published detections and limiting values in interstellar and preplanetary ices for both CH{sub 3}OH and the other commonly observed C- and O-bearing species, H{sub 2}O, CO, and CO{sub 2}. We use this catalog to investigate the abundance of ice-phase CH{sub 3}OH in environments ranging from dense molecular clouds to circumstellar envelopes around newly born stars of low and high mass. Results show that CH{sub 3}OH production arises during the CO freezeout phase of ice-mantle growth in the clouds, after an ice layer rich in H{sub 2}O and CO{sub 2} is already in place on the dust, in agreement with current astrochemical models. The abundance of solid-phase CH{sub 3}OH in this environment is sufficient to account for observed gas-phase abundances when the ices are subsequently desorbed in the vicinity of embedded stars. CH{sub 3}OH concentrations in the ices toward embedded stars show order-of-magnitude object-to-object variations, even in a sample restricted to stars of low mass associated with ices lacking evidence of thermal processing. We hypothesize that the efficiency of CH{sub 3}OH production in dense cores and protostellar envelopes is mediated by the degree of prior CO depletion.

  13. Acceleration of Greenland ice mass loss in spring 2004

    E-Print Network [OSTI]

    Chen, Zhongping

    of increased melting at the ice sheet surface and increased glacial discharge at the coasts. All these trends, suggest that both accumulation and melting have increased during the past decade, with melting increasing thinning in the 1990s at low elevations8 where increased melting is probably more important than increased

  14. MEAT, POULTRY, Still contains ice

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    MEAT, POULTRY, SEAFOOD Still contains ice crystals and feels as cold, and ground meats Refreeze Discard Poultry and ground poultry Refreeze Discard Variety meats may safely re-freeze foods that s:ll contain ice crystals or that have been

  15. Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    de la Peńa, S.; Howat, I. M.; Nienow, P. W.; van den Broeke, M. R.; Mosley-Thompson, E.; Price, S. F.; Mair, D.; Noėl, B.; Sole, A. J.

    2015-06-11

    Atmospheric warming over the Greenland Ice Sheet during the last 2 decades has increased the amount of surface meltwater production, resulting in the migration of melt and percolation regimes to higher altitudes and an increase in the amount of ice content from refrozen meltwater found in the firn above the superimposed ice zone. Here we present field and airborne radar observations of buried ice layers within the near-surface (0–20 m) firn in western Greenland, obtained from campaigns between 1998 and 2014. We find a sharp increase in firn-ice content in the form of thick widespread layers in the percolation zone,more »which decreases the capacity of the firn to store meltwater. The estimated total annual ice content retained in the near-surface firn in areas with positive surface mass balance west of the ice divide in Greenland reached a maximum of 74 ± 25 Gt in 2012, compared to the 1958–1999 average of 13 ± 2 Gt, while the percolation zone area more than doubled between 2003 and 2012. Increased melt and column densification resulted in surface lowering averaging –0.80 ± 0.39 m yr?¹ between 1800 and 2800 m in the accumulation zone of western Greenland. Since 2007, modeled annual melt and refreezing rates in the percolation zone at elevations below 2100 m surpass the annual snowfall from the previous year, implying that mass gain in the region is retained after melt in the form of refrozen meltwater. If current melt trends over high elevation regions continue, subsequent changes in firn structure will have implications for the hydrology of the ice sheet and related abrupt seasonal densification could become increasingly significant for altimetry-derived ice sheet mass balance estimates.« less

  16. Impacts of ocean albedo alteration on Arctic sea ice restoration and Northern Hemisphere climate

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Cvijanovic, Ivana; Caldeira, Ken; MacMartin, Douglas G.

    2015-04-01

    The Arctic Ocean is expected to transition into a seasonally ice-free state by mid-century, enhancing Arctic warming and leading to substantial ecological and socio-economic challenges across the Arctic region. It has been proposed that artificially increasing high latitude ocean albedo could restore sea ice, but the climate impacts of such a strategy have not been previously explored. Motivated by this, we investigate the impacts of idealized high latitude ocean albedo changes on Arctic sea ice restoration and climate. In our simulated 4xCO? climate, imposing surface albedo alterations over the Arctic Ocean leads to partial sea ice recovery and a modestmore »reduction in Arctic warming. With the most extreme ocean albedo changes, imposed over the area 70°–90°N, September sea ice cover stabilizes at ~40% of its preindustrial value (compared to ~3% without imposed albedo modifications). This is accompanied by an annual mean Arctic surface temperature decrease of ~2 °C but no substantial global mean temperature decrease. Imposed albedo changes and sea ice recovery alter climate outside the Arctic region too, affecting precipitation distribution over parts of the continental United States and Northeastern Pacific. For example, following sea ice recovery, wetter and milder winter conditions are present in the Southwest United States while the East Coast experiences cooling. We conclude that although ocean albedo alteration could lead to some sea ice recovery, it does not appear to be an effective way of offsetting the overall effects of CO? induced global warming.« less

  17. Winter Driving Tips Driving in Ice & Snow

    E-Print Network [OSTI]

    Capogna, Luca

    Winter Driving Tips Driving in Ice & Snow: When you must drive, clear the ice and snow from your in ice and snow, other drivers will be traveling cautiously. Don't disrupt the flow of traffic by driving handle better in ice and snow, but they do not have flawless traction, and skids can occur unexpectedly

  18. The sticking of atomic hydrogen on amorphous water ice

    SciTech Connect (OSTI)

    Veeraghattam, Vijay K.; Manrodt, Katie; Lewis, Steven P.; Stancil, P. C. E-mail: lewis@physast.uga.edu

    2014-07-20

    Using classical molecular dynamics, we have simulated the sticking and scattering process of a hydrogen atom on an amorphous ice film to predict the sticking probability of hydrogen on ice surfaces. A wide range of initial kinetic energies of the incident hydrogen atom (10 K-600 K) and two different ice temperatures (10 K and 70 K) were used to investigate this fundamental process in interstellar chemistry. We report here the sticking probability of atomic hydrogen as a function of incident kinetic energy, gas temperature, and substrate temperature, which can be used in astrophysical models. The current results are compared to previous theoretical and experimental studies that have reported a wide range in the sticking coefficient.

  19. Journal of Nondestructive Evaluation, Vol. 23, No. 3, September 2004 ( C 2004) Eddy Current Assessment of Near-Surface Residual

    E-Print Network [OSTI]

    Nagy, Peter B.

    Journal of Nondestructive Evaluation, Vol. 23, No. 3, September 2004 ( C 2004) Eddy Current in eddy current conductivity at increasing inspection frequencies, which can be exploited components, lend themselves easily for eddy current residual stress assessment lies in their favorable

  20. Method of forming calthrate ice

    DOE Patents [OSTI]

    Hino, T.; Gorski, A.J.

    1985-09-30

    A method of forming clathrate ice in a supercooled water-based liquid contained in a vessel is disclosed. Initially, an oscillator device is located in the liquid in the vessel. The oscillator device is then oscillated ultransonically so that small crystals are formed in the liquid. Thes small crystals serve as seed crystals for ice formation in the liquid and thereby prevent supercooling of the liquid. Preferably, the oscillating device is controlled by a thermostat which initiates operation of the oscillator device when the temperature of the liquid is lowered to the freezing point. Thereafter, the operation of the oscillator device is terminated when ice is sensed in the liquid by an ice sensor.

  1. Method of forming clathrate ice

    DOE Patents [OSTI]

    Hino, Toshiyuki (Tokyo, JP); Gorski, Anthony J. (Lemont, IL)

    1987-01-01

    A method of forming clathrate ice in a supercooled water-based liquid contained in a vessel is disclosed. Initially, an oscillator device is located in the liquid in the vessel. The oscillator device is then oscillated ultrasonically so that small crystals are formed in the liquid. These small crystals serve as seed crystals for ice formation in the liquid and thereby prevent supercooling of the liquid. Preferably, the oscillating device is controlled by a thermostat which initiates operation of the oscillator device when the temperature of the liquid is lowered to the freezing point. Thereafter, the operation of the oscillator device is terminated when ice is sensed in the liquid by an ice sensor.

  2. An experimental and theoretical study of the ice accretion process during artificial and natural icing conditions

    E-Print Network [OSTI]

    Kirby, Mark Samuel

    1986-01-01

    Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an ultrasonic pulse-echo technique. This technique allows ice thickness to be measured with an accuracy of ?0.5 mm; ...

  3. Data-Driven Low-Dimensional Modeling and Uncertainty Quantification for Airfoil Icing

    E-Print Network [OSTI]

    DeGennaro, Anthony M; Martinelli, Luigi

    2015-01-01

    The formation and accretion of ice on the leading edge of an airfoil can be detrimental to aerodynamic performance. Furthermore, the geometric shape of leading edge ice profiles can vary significantly depending on a wide range of physical parameters, which can translate into a wide variability in aerodynamic performance. The purpose of this work is to explore the variability in airfoil aerodynamic performance that results from variability in leading edge ice shape profile. First, we demonstrate how to identify a low-dimensional set of parameters that governs ice shape from a database of ice shapes using Proper Orthogonal Decomposition (POD). Then, we investigate the effects of uncertainty in the POD coefficients. This is done by building a global response surface surrogate using Polynomial Chaos Expansions (PCE). To construct this surrogate efficiently, we use adaptive sparse grid sampling of the POD parameter space. We then analyze the data from a statistical standpoint.

  4. Warming of the arctic ice-ocean system is faster than the global average since the 1960s

    E-Print Network [OSTI]

    Zhang, Jinlun

    Warming of the arctic ice-ocean system is faster than the global average since the 1960s Jinlun.203°C. The warming of the world ocean is associated with an increase in global surface air temperature heat flux. Citation: Zhang, J. (2005), Warming of the arctic ice-ocean system is faster than the global

  5. First-Principles Assessment of H[subscript 2]S and H[subscript 2]O Reaction Mechanisms and the Subsequent Hydrogen Absorption on the CeO[subscript 2](111) Surface

    E-Print Network [OSTI]

    Marrocchelli, Dario

    The main goal of this study is to assess the resistance of ceria against hydrogen penetration into its bulk, in the context of its application as a protective surface coating against hydrogen embrittlement in metals. We ...

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

    SciTech Connect (OSTI)

    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.

  7. Importance of aerosol composition, mixing state, and morphology for heterogeneous ice nucleation: A combined field and laboratory approach

    SciTech Connect (OSTI)

    Baustian, Kelly J.; Cziczo, Daniel J.; Wise, M. A.; Pratt, Kerri; Kulkarni, Gourihar R.; Hallar, Anna G.; Tolbert, Margaret A.

    2012-03-30

    In this study chemical compositions of background aerosol and ice nuclei were examined through laboratory investigations using Raman spectroscopy and field measurements by single-particle mass spectrometry. Aerosol sampling took place at Storm Peak Laboratory in Steamboat Springs, Colorado (elevation of 3210 m). A cascade impactor was used to collect coarse-mode aerosol particles for laboratory analysis by Raman spectroscopy; the composition, mixing state, and heterogeneous ice nucleation activity of individual particles were examined. For in situ analysis of fine-mode aerosol, ice nucleation on ambient particles was observed using a compact ice nucleation chamber. Ice crystals were separated from unactivated aerosol using a pumped counterflow virtual impactor, and ice nuclei were analyzed using particle analysis by laser mass spectrometry. For both fine and coarse modes, the ice nucleating particle fractions were enriched in minerals and depleted in sulfates and nitrates, compared to the background aerosol sampled. The vast majority of particles in both the ambient and ice active aerosol fractions contained a detectable amount of organic material. Raman spectroscopy showed that organic material is sometimes present in the form of a coating on the surface of inorganic particles. We find that some organic-containing particles serve as efficient ice nuclei while others do not. For coarse-mode aerosol, organic particles were only observed to initiate ice formation when oxygen signatures were also present in their spectra.

  8. Molecular interactions with ice: Molecular embedding, adsorption, detection, and release

    SciTech Connect (OSTI)

    Gibson, K. D.; Langlois, Grant G.; Li, Wenxin; Sibener, S. J.; Killelea, Daniel R.

    2014-11-14

    The interaction of atomic and molecular species with water and ice is of fundamental importance for chemistry. In a previous series of publications, we demonstrated that translational energy activates the embedding of Xe and Kr atoms in the near surface region of ice surfaces. In this paper, we show that inert molecular species may be absorbed in a similar fashion. We also revisit Xe embedding, and further probe the nature of the absorption into the selvedge. CF{sub 4} molecules with high translational energies (?3 eV) were observed to embed in amorphous solid water. Just as with Xe, the initial adsorption rate is strongly activated by translational energy, but the CF{sub 4} embedding probability is much less than for Xe. In addition, a larger molecule, SF{sub 6}, did not embed at the same translational energies that both CF{sub 4} and Xe embedded. The embedding rate for a given energy thus goes in the order Xe > CF{sub 4} > SF{sub 6}. We do not have as much data for Kr, but it appears to have a rate that is between that of Xe and CF{sub 4}. Tentatively, this order suggests that for Xe and CF{sub 4}, which have similar van der Waals radii, the momentum is the key factor in determining whether the incident atom or molecule can penetrate deeply enough below the surface to embed. The more massive SF{sub 6} molecule also has a larger van der Waals radius, which appears to prevent it from stably embedding in the selvedge. We also determined that the maximum depth of embedding is less than the equivalent of four layers of hexagonal ice, while some of the atoms just below the ice surface can escape before ice desorption begins. These results show that energetic ballistic embedding in ice is a general phenomenon, and represents a significant new channel by which incident species can be trapped under conditions where they would otherwise not be bound stably as surface adsorbates. These findings have implications for many fields including environmental science, trace gas collection and release, and the chemical composition of astrophysical icy bodies in space.

  9. Laboratory Investigation of Contact Freezing and the Aerosol to Ice Crystal Transformation Process

    SciTech Connect (OSTI)

    Shaw, Raymond A.

    2014-10-28

    This project has been focused on the following objectives: 1. Investigations of the physical processes governing immersion versus contact nucleation, specifically surface-induced crystallization; 2. Development of a quadrupole particle trap with full thermodynamic control over the temperature range 0 to –40 °C and precisely controlled water vapor saturation ratios for continuous, single-particle measurement of the aerosol to ice crystal transformation process for realistic ice nuclei; 3. Understanding the role of ice nucleation in determining the microphysical properties of mixed-phase clouds, within a framework that allows bridging between laboratory and field measurements.

  10. Electrothermal Icing Protection of Aerosurfaces Using Conductive Polymer Nanocomposites

    E-Print Network [OSTI]

    Buschhorn, Samuel T.

    Ice protection systems (IPS) are critical components for many aerospace flight vehicles, including commercial transports and unmanned aerial systems (UAS), and can include anti-icing, de-icing, ice sensing, etc. Here, an ...

  11. Coherent radar ice thickness measurements over the Greenland ice sheet

    E-Print Network [OSTI]

    Gogineni, S. Prasad; Tammana, Dilip; Braaten, David A.; Leuschen, C.; Legarsky, J.; Kanagaratnam, P.; Stiles, J.; Allen, C.; Jezek, K.; Akins, T. L.

    2001-12-27

    averaged over a distance covered by aircraft in 1 s (-130 m).) tt(X, g = -d) = Sice(t: T, x). (6) The value t = - can be interpreted as the time when S ice(t, x) represents the wave energy due to scattering specifically from depth d, as opposed... of the Greenland ice sheet produced by Mark Fahnestock (Department of Meteorology, University of Maryland, College Park) and Ron Kwok (Jet Propulsion Laboratory, California Institute of Technology, Pasa- dena). The helpful suggestions and comments of two...

  12. Water Ice on the Satellite of Kuiper Belt Object 2003 EL61

    E-Print Network [OSTI]

    K. M Barkume; M. E. Brown; E. L. Schaller

    2006-01-24

    We have obtained a near infrared spectrum of the brightest satellite of the large Kuiper Belt Object, 2003 EL61. The spectrum has absorption features at 1.5 and 2.0 microns, indicating that water ice is present on the surface. We find that the satellite's absorption lines are much deeper than water ice features typically found on Kuiper Belt Objects. We argue that the unusual spectrum indicates that the satellite was likely formed by impact and not by capture.

  13. Implementation and Initial Evaluation of the Glimmer Community Ice Sheet Model in the Community Earth System Model

    E-Print Network [OSTI]

    Born, Andreas

    2013) ABSTRACT The Glimmer Community Ice Sheet Model (Glimmer-CISM) has been implemented in the Community Earth System Model (CESM). Glimmer-CISM is forced by a surface mass balance (SMB) computed

  14. Heavy ion irradiation of crystalline water ice

    E-Print Network [OSTI]

    Dartois, E; Boduch, P; Brunetto, R; Chabot, M; Domaracka, A; Ding, J J; Kamalou, O; Lv, X Y; Rothard, H; da Silveira, E F; Thomas, J C

    2015-01-01

    Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic ...

  15. Thermal Storage with Ice Harvesting Systems 

    E-Print Network [OSTI]

    Knebel, D. E.

    1986-01-01

    Application of Harvesting Ice Storage Systems. Thermal storage systems are becoming widely accepted techniques for utility load management. This paper discusses the principles of ice harvesting equipment and their application to the multi...

  16. The convective desalination of sea ice

    E-Print Network [OSTI]

    Rees Jones, David

    2014-07-01

    in the interstices of an ice matrix. My focus is on one of the processes by which the salt content of sea ice decreases, namely convective desalination, which is also often called gravity drainage by geophysicists. Modelling convective desalination requires...

  17. Electrical properties of saline ices and ice-silicate mixtures: geophysical and astrobiological consequences (Invited)

    E-Print Network [OSTI]

    Stillman, David E.

    MR22A-05 Electrical properties of saline ices and ice-silicate mixtures: geophysical) electrical-properties measurements of laboratory- produced saline ice, salt hydrates, and ice of interior properties, and habitability. The electrical properties of saline H2O are controlled by the binary

  18. Experimental study of surface erosion processes of the icy moons of Jupiter

    E-Print Network [OSTI]

    Galli, A; Wurz, P; Jost, B; Scheer, J A; Vorburger, A; Tulej, M; Thomas, N; Wieser, M; Barabash, S

    2015-01-01

    We use an existing laboratory facility for space hardware calibration in vacuum to study the impact of energetic ions on water ice. The experiment is intended to simulate the conditions on the surface of Jupiter's icy moons. We present first results of ion sputtering in a sample of porous ice, including the first experimental results for sulphur ion sputtering of ice. The results confirm theoretical predictions and extrapolations from previous sputtering experiments obtained at different impact angles for non-porous water ice.

  19. Calibration and Characterization of the IceCube Photomultiplier Tube

    SciTech Connect (OSTI)

    IceCube Collaboration; Abbasi, R.; al., et

    2010-02-11

    Over 5,000 PMTs are being deployed at the South Pole to compose the IceCube neutrino observatory. Many are placed deep in the ice to detect Cherenkov light emitted by the products of high-energy neutrino interactions, and others are frozen into tanks on the surface to detect particles from atmospheric cosmic ray showers. IceCube is using the 10-inch diameter R7081-02 made by Hamamatsu Photonics. This paper describes the laboratory characterization and calibration of these PMTs before deployment. PMTs were illuminated with pulses ranging from single photons to saturation level. Parameterizations are given for the single photoelectron charge spectrum and the saturation behavior. Time resolution, late pulses and afterpulses are characterized. Because the PMTs are relatively large, the cathode sensitivity uniformity was measured. The absolute photon detection efficiency was calibrated using Rayleigh-scattered photons from a nitrogen laser. Measured characteristics are discussed in the context of their relevance to IceCube event reconstruction and simulation efforts.

  20. Assessment of the applicability of an anoxic limestone drain for a surface mine in east central Tennessee

    SciTech Connect (OSTI)

    Schmidt, T.W. [Skelly and Loy, Inc., Harrisburg, PA (United States); Hedin, R.S. [Hedin Environmental, Pittsburgh, PA (United States); Lorello, P.R. [Kennecott Energy Company, Gillette, WY (United States)

    1996-12-31

    Anoxic limestone drains (ALDs) are a cost-effective technique for adding alkalinity to acid mine drainage. However, the applicability of an ALD is limited to a rather narrow range of mine drainage chemical conditions due to concerns about the armoring of limestone with ferric hydroxide, the plugging of flow paths with aluminum hydroxide, and the limited solubility of calcite. While the armoring and plugging potentials can be assessed with careful water quality analyses, the solubility of limestone in a particular mine water cannot, at this time, be predicted from mine water chemistry. Thus, the danger always exists that the ALD will generate insufficient alkalinity to completely neutralize the acidic water, resulting in either insufficiently treated discharge or a need for additional treatment. In order to remove uncertainty from the design of a 4,000-ton ALD, we conducted limestone incubation tests and pilot-scale ALD tests. Incubation tests were done using a modified version of the {open_quotes}cubitainer{close_quotes} procedure developed by the United States Bureau of Mines. The pilot ALD consisted of 65 tons of limestone. Hydrologic loading experiments were conducted that provided an assessment of the ALD performance under design flow conditions and flow rates four times higher than the design flow. Under design flow conditions, the pilot ALD discharged water with alkalinity concentrations similar to that predicted by the cubitainer tests (360 parts per million). With increased flow, concentrations of alkalinity in the pilot ALD effluent decreased, with the water becoming net acidic at a flow rate of 15 gallons per minute. The results of the pilot ALD were used to size a full-scale ALD and model ALD performance under a variety of flow conditions.

  1. Assessing the nonlinear response of fine particles to precursor emissions: Development and application of an extended response surface modeling technique v1.0

    SciTech Connect (OSTI)

    Zhao, B.; Wang, S. X.; Xing, J.; Fu, K.; Fu, J. S.; Jang, C.; Zhu, Y.; Dong, X. Y.; Gao, Y.; Wu, W. J.; Wang, J. D.; Hao, J. M.

    2015-01-30

    An innovative extended response surface modeling technique (ERSM v1.0) is developed to characterize the nonlinear response of fine particles (PM???) to large and simultaneous changes of multiple precursor emissions from multiple regions and sectors. The ERSM technique is developed based on the conventional response surface modeling (RSM) technique; it first quantifies the relationship between PM??? concentrations and the emissions of gaseous precursors from each single region using the conventional RSM technique, and then assesses the effects of inter-regional transport of PM??? and its gaseous precursors on PM??? concentrations in the target region. We apply this novel technique with a widely used regional chemical transport model (CTM) over the Yangtze River delta (YRD) region of China, and evaluate the response of PM??? and its inorganic components to the emissions of 36 pollutant–region–sector combinations. The predicted PM??? concentrations agree well with independent CTM simulations; the correlation coefficients are larger than 0.98 and 0.99, and the mean normalized errors (MNEs) are less than 1 and 2% for January and August, respectively. It is also demonstrated that the ERSM technique could reproduce fairly well the response of PM??? to continuous changes of precursor emission levels between zero and 150%. Employing this new technique, we identify the major sources contributing to PM??? and its inorganic components in the YRD region. The nonlinearity in the response of PM??? to emission changes is characterized and the underlying chemical processes are illustrated.

  2. Assessing the nonlinear response of fine particles to precursor emissions: Development and application of an extended response surface modeling technique v1.0

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhao, B.; Wang, S. X.; State Environmental Protection Key Lab. of Sources and Control of Air Pollution Complex, Beijing; Xing, J.; Fu, K.; Fu, J. S.; Jang, C.; Zhu, Y.; Dong, X. Y.; Gao, Y.; et al

    2015-01-30

    An innovative extended response surface modeling technique (ERSM v1.0) is developed to characterize the nonlinear response of fine particles (PM???) to large and simultaneous changes of multiple precursor emissions from multiple regions and sectors. The ERSM technique is developed based on the conventional response surface modeling (RSM) technique; it first quantifies the relationship between PM??? concentrations and the emissions of gaseous precursors from each single region using the conventional RSM technique, and then assesses the effects of inter-regional transport of PM??? and its gaseous precursors on PM??? concentrations in the target region. We apply this novel technique with a widelymore »used regional chemical transport model (CTM) over the Yangtze River delta (YRD) region of China, and evaluate the response of PM??? and its inorganic components to the emissions of 36 pollutant–region–sector combinations. The predicted PM??? concentrations agree well with independent CTM simulations; the correlation coefficients are larger than 0.98 and 0.99, and the mean normalized errors (MNEs) are less than 1 and 2% for January and August, respectively. It is also demonstrated that the ERSM technique could reproduce fairly well the response of PM??? to continuous changes of precursor emission levels between zero and 150%. Employing this new technique, we identify the major sources contributing to PM??? and its inorganic components in the YRD region. The nonlinearity in the response of PM??? to emission changes is characterized and the underlying chemical processes are illustrated.« less

  3. Assessing the nonlinear response of fine particles to precursor emissions: Development and application of an extended response surface modeling technique v1.0

    SciTech Connect (OSTI)

    Zhao, B. [Tsinghua Univ., Beijing (China); Wang, S. X. [Tsinghua Univ., Beijing (China); State Environmental Protection Key Lab. of Sources and Control of Air Pollution Complex, Beijing (China); Xing, J. [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Fu, K. [Tsinghua Univ., Beijing (China); Fu, J. S. [Univ. of Tennessee, Knoxville, TN (United States); Jang, C. [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Zhu, Y. [South China Univ. of Technology (SCUT), Guangzhou (China); Dong, X. Y. [Univ. of Tennessee, Knoxville, TN (United States); Gao, Y. [Univ. of Tennessee, Knoxville, TN (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wu, W. J. [Tsinghua Univ., Beijing (China); Wang, J. D. [Tsinghua Univ., Beijing (China); Hao, J. M. [Tsinghua Univ., Beijing (China); State Environmental Protection Key Lab. of Sources and Control of Air Pollution Complex, Beijing (China)

    2015-01-01

    An innovative extended response surface modeling technique (ERSM v1.0) is developed to characterize the nonlinear response of fine particles (PM???) to large and simultaneous changes of multiple precursor emissions from multiple regions and sectors. The ERSM technique is developed based on the conventional response surface modeling (RSM) technique; it first quantifies the relationship between PM??? concentrations and the emissions of gaseous precursors from each single region using the conventional RSM technique, and then assesses the effects of inter-regional transport of PM??? and its gaseous precursors on PM??? concentrations in the target region. We apply this novel technique with a widely used regional chemical transport model (CTM) over the Yangtze River delta (YRD) region of China, and evaluate the response of PM??? and its inorganic components to the emissions of 36 pollutant–region–sector combinations. The predicted PM??? concentrations agree well with independent CTM simulations; the correlation coefficients are larger than 0.98 and 0.99, and the mean normalized errors (MNEs) are less than 1 and 2% for January and August, respectively. It is also demonstrated that the ERSM technique could reproduce fairly well the response of PM??? to continuous changes of precursor emission levels between zero and 150%. Employing this new technique, we identify the major sources contributing to PM??? and its inorganic components in the YRD region. The nonlinearity in the response of PM??? to emission changes is characterized and the underlying chemical processes are illustrated.

  4. VOLATILE TRANSPORT INSIDE SUPER-EARTHS BY ENTRAPMENT IN THE WATER-ICE MATRIX

    SciTech Connect (OSTI)

    Levi, A.; Podolak, M.; Sasselov, D.

    2013-05-20

    Whether volatiles can be entrapped in a background matrix composing planetary envelopes and be dragged via convection to the surface is a key question in understanding atmospheric fluxes, cycles, and composition. In this paper, we consider super-Earths with an extensive water mantle (i.e., water planets), and the possibility of entrapment of methane in their extensive water-ice envelopes. We adopt the theory developed by van der Waals and Platteeuw for modeling solid solutions, often used for modeling clathrate hydrates, and modify it in order to estimate the thermodynamic stability field of a new phase called methane filled ice Ih. We find that in comparison to water ice VII the filled ice Ih structure may be stable not only at the high pressures but also at the high temperatures expected at the core-water mantle transition boundary of water planets.

  5. CO2 hydrate dissociation at low temperatures - formation and annealing of ice Ic

    E-Print Network [OSTI]

    Falenty, Andrzej; Kuhs, Werner F

    2015-01-01

    Dissociation of gas hydrates below 240 K leads to the formation of a metastable form of water ice, so called cubic ice (Ic). Through its defective nature and small particle size the surface film composed of such material is incapable of creating any significant diffusion barrier. Above 160 K, cubic ice gradually transforms to the stable hexagonal (Ih) form on laboratory time scales. The annealing, coupled with a parallel decomposition of gas hydrates, accelerates as temperature rises but already above 190 K the first process prevails, transforming cubic stacking sequences in-to ordinary Ih ice within a few minutes. Remaining stacking faults are removed through very slow isothermal annealing or after heating up above 240 K. The role of the proportion of cubic stacking on the decomposition rate is discussed. A better understanding of the dissociation kinetics at low temperatures is particularly im-portant for the critical evaluation of existing hypotheses that consider clathrates as a potential medium that acti...

  6. Weakening of the Stratospheric Polar Vortex by Arctic Sea-Ice Loss

    SciTech Connect (OSTI)

    Kim, Baek-Min; Son, Seok-Woo; Min, Seung-Ki; Jeong, Jee-Hoon; Kim, Seong-Joong; Zhang, Xiangdong; Shim, Taehyoun; Yoon, Jin-Ho

    2014-09-02

    Successive cold winters of severely low temperatures in recent years have had critical social and economic impacts on the mid-latitude continents in the Northern Hemisphere. Although these cold winters are thought to be partly driven by dramatic losses of Arctic sea ice, the mechanism that links sea ice loss to cold winters remains a subject of debate. Here, by conducting observational analyses and model experiments, we show how Arctic sea ice loss and cold winters in extra-polar regions are dynamically connected through the polar stratosphere. We find that decreased sea ice cover during early winter months (November-December), especially over the Barents-Kara seas, enhance the upward propagation of planetary-scale waves with wavenumbers of 1 and 2, subsequently weakening the stratospheric polar vortex in mid-winter (January- February). The weakened polar vortex preferentially induces a negative phase of Arctic Oscillation at the surface, resulting in low temperatures in mid-latitudes.

  7. Electric fields in ice and near water clusters

    SciTech Connect (OSTI)

    Batista, Enrique R. [Department of Physics, P.O. Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States) [Department of Physics, P.O. Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States); Department of Chemistry, P.O. Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Xantheas, Sotiris S. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, P.O. Box 999, MS K8-91, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, P.O. Box 999, MS K8-91, Richland, Washington 99352 (United States); Jonsson, Hannes [Department of Chemistry, P.O. Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)] [Department of Chemistry, P.O. Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

    2000-02-15

    We have studied the electric field near water clusters and in ice Ih using first principles calculations. We employed Moeller-Plesset perturbation theory (MP2) for the calculations of the clusters up to and including the hexamer, and density functional theory (DFT) with a gradient dependent functional [Perdew-Wang (PW91)] for ice Ih as well as the clusters. The electric field obtained from the first principles calculations was used to test the predictions of an induction model based on single center multipole moments and polarizabilities of an isolated water molecule. We found that the fields obtained from the induction model agree well with the first principles results when the multipole expansion is carried out up to and including the hexadecapole moment, and when polarizable dipole and quadrupole moments are included. This implies that accurate empirical water interaction potential functions transferable to various environments such as water clusters and ice surfaces could be based on a single center multipole expansion carried out up to the hexadecapole. Since point charges are not included, the computationally intensive Ewald summations can be avoided. Molecular multipole moments were also extracted from the first principles charge density using zero flux dividing surfaces as proposed by Bader. Although the values of the various molecular multipoles obtained with this method are quite different from the ones resulting from the induction model, the rate of convergence of the electric field is, nevertheless, quite similar. (c) 2000 American Institute of Physics.

  8. Water droplet behavior on superhydrophobic SiO{sub 2} nanocomposite films during icing/deicing cycles

    SciTech Connect (OSTI)

    Lazauskas, A.; Guobien?, A.; Prosy?evas, I.; Baltrušaitis, V.; Grigali?nas, V.; Narmontas, P.; Baltrusaitis, J.

    2013-08-15

    This work investigates water droplet behavior on superhydrophobic (water contact angle value of 162 ± 1°) SiO{sub 2} nanocomposite films subjected to repetitive icing/deicing treatments, changes in SiO{sub 2} nanocomposite film surface morphology and their non-wetting characteristics. During the experiment, water droplets on SiO{sub 2} nanocomposite film surface are subjected to a series of icing and deicing cycles in a humid (? 70% relative humidity) atmosphere and the resulting morphological changes are monitored and characterized using atomic force microscopy (AFM) and contact angle measurements. Our data show that the formation of the frozen or thawed water droplet, with no further shape change, on superhydrophobic SiO{sub 2} nanocomposite film, is obtained faster within each cycle as the number of the icing/deicing cycles increases. After 10 icing and deicing cycles, the superhydrophobic SiO{sub 2} nanocomposite film had a water contact angle value of 146 ± 2° which is effectively non-superhydrophobic. AFM analysis showed that the superhydrophobic SiO{sub 2} nanocomposite film surface area under the water droplet undergoes gradual mechanical damage during the repetitive icing/deicing cycles. We propose a possible mechanism of the morphological changes to the film surface that take place during the consecutive icing/deicing experiments. - Highlights: • Superhydrophobic film is subjected to repetitive icing/deicing treatments. • Water droplet shape transition is recorded and characterized thereafter. • Atomic force microscopy and contact angle measurements are performed. • The surface undergoes gradual mechanical damage during repetitive icing/deicing. • Mechanism for the observed surface morphological changes is suggested.

  9. Understanding cirrus ice crystal number variability for different heterogeneous ice nucleation spectra

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sullivan, S. C.; Morales Betancourt, R.; Barahona, D.; Nenes, A.

    2015-08-11

    Along with minimizing parameter uncertainty, understanding the cause of temporal and spatial variability of nucleated ice crystal number, Ni, is key to improving the representation of cirrus clouds in climate models. To this end, sensitivities of Ni to input variables like aerosol number and diameter provide valuable information about nucleation regime and efficiency for a given model formulation. Here we use the adjoint model of the Barahona and Nenes cirrus formation parameterization to understand Ni variability for various ice-nucleating particle (INP) spectra. Inputs are generated with the Community Atmosphere Model version 5, and simulations are done with a theoretically-derived spectrum,more »a lab-based empirical spectrum, and two field-based empirical spectra that differ in the nucleation threshold for black carbon aerosol and in the active site density for dust. The magnitude and sign of Ni sensitivity to insoluble aerosol number can be directly linked to nucleation regime and efficiency of various INP. The lab-based spectrum calculates much higher INP efficiencies than field-based ones, which reveals a disparity in aerosol surface properties. Ni sensitivity to temperature tends to be low, due to the compensating effects of temperature on INP spectrum parameters; this low temperature sensitivity regime has been experimentally reported before but never unraveled as done here.« less

  10. Hydrogen ICE Vehicle Testing Activities

    SciTech Connect (OSTI)

    J. Francfort; D. Karner

    2006-04-01

    The Advanced Vehicle Testing Activity teamed with Electric Transportation Applications and Arizona Public Service to develop and monitor the operations of the APS Alternative Fuel (Hydrogen) Pilot Plant. The Pilot Plant provides 100% hydrogen, and hydrogen and compressed natural gas (H/CNG)-blended fuels for the evaluation of hydrogen and H/CNG internal combustion engine (ICE) vehicles in controlled and fleet testing environments. Since June 2002, twenty hydrogen and H/CNG vehicles have accumulated 300,000 test miles and 5,700 fueling events. The AVTA is part of the Department of Energy’s FreedomCAR and Vehicle Technologies Program. These testing activities are managed by the Idaho National Laboratory. This paper discusses the Pilot Plant design and monitoring, and hydrogen ICE vehicle testing methods and results.

  11. FAFCO Ice Storage test report

    SciTech Connect (OSTI)

    Stovall, T.K.

    1993-11-01

    The Ice Storage Test Facility (ISTF) is designed to test commercial ice storage systems. FAFCO provided a storage tank equipped with coils designed for use with a secondary fluid system. The FAFCO ice storage system was tested over a wide range of operating conditions. Measured system performance during charging showed the ability to freeze the tank fully, storing from 150 to 200 ton-h. However, the charging rate showed significant variations during the latter portion of the charge cycle. During discharge cycles, the storage tank outlet temperature was strongly affected by the discharge rate and tank state of charge. The discharge capacity was dependent upon both the selected discharge rate and maximum allowable tank outlet temperature. Based on these tests, storage tank selection must depend on both charge and discharge conditions. This report describes FAFCO system performance fully under both charging and discharging conditions. While the test results reported here are accurate for the prototype 1990 FAFCO Model 200, currently available FAFCO models incorporate significant design enhancements beyond the Model 200. At least one major modification was instituted as a direct result of the ISTF tests. Such design improvements were one of EPRI`s primary goals in founding the ISTF.

  12. Early Mars climate near the NoachianHesperian boundary: Independent evidence for cold conditions from basal melting of the south polar ice sheet (Dorsa

    E-Print Network [OSTI]

    Marchant, David R.

    from basal melting of the south polar ice sheet (Dorsa Argentea Formation) and implications for valley of the Amazonian, the mean annual surface temperatures of Mars are so cold that basal melting does not occur in ice-developed eskers (sediment-filled former sub-glacial meltwater chan- nels) in the south circumpolar Dorsa Argentea

  13. Modeling the summertime evolution of sea-ice melt ponds rsted-DTU, Electromagnetic Systems, Technical University of Denmark, Lyngby, Denmark

    E-Print Network [OSTI]

    Feltham, Daniel

    Modeling the summertime evolution of sea-ice melt ponds M. LuØthje Ųrsted-DTU, Electromagnetic of sea ice. We simulate the evolution of melt ponds and determine area coverage and total surface rate beneath the melt ponds, vertical seepage, and horizontal permeability. The model is initialized

  14. JOURNAL OF GEOPHYSICAL RESEARCH, VOL 104, NO C7, PAGES 15,66915,677, JULY 15, 1999 An energyconserving thermodynamic model of sea ice

    E-Print Network [OSTI]

    Bitz, Cecilia

    of internal brine­pocket melting on surface ablation. Sea ice models that parameterize latent heat storage season. Compared with our energy­conserving model, a nonconserving model underestimates top to brine pockets, which change size in order to remain in thermal equilibrium with the ice [Schwerdtfeger

  15. Further observations of a decreasing atmospheric CO2 uptake capacity in the Canada Basin (Arctic Ocean) due to sea ice loss

    E-Print Network [OSTI]

    Boyer, Edmond

    decayed ice cover, we found surprisingly high pCO2sw (~290­320 matm), considering that surface waterFurther observations of a decreasing atmospheric CO2 uptake capacity in the Canada Basin (Arctic as an atmospheric CO2 sink under the summertime ice-free conditions expected in the near future. Beneath a heavily

  16. Benchmarking the x-ray phase contrast imaging for ICF DT ice characterization using roughened surrogates

    SciTech Connect (OSTI)

    Dewald, E; Kozioziemski, B; Moody, J; Koch, J; Mapoles, E; Montesanti, R; Youngblood, K; Letts, S; Nikroo, A; Sater, J; Atherton, J

    2008-06-26

    We use x-ray phase contrast imaging to characterize the inner surface roughness of DT ice layers in capsules planned for future ignition experiments. It is therefore important to quantify how well the x-ray data correlates with the actual ice roughness. We benchmarked the accuracy of our system using surrogates with fabricated roughness characterized with high precision standard techniques. Cylindrical artifacts with azimuthally uniform sinusoidal perturbations with 100 um period and 1 um amplitude demonstrated 0.02 um accuracy limited by the resolution of the imager and the source size of our phase contrast system. Spherical surrogates with random roughness close to that required for the DT ice for a successful ignition experiment were used to correlate the actual surface roughness to that obtained from the x-ray measurements. When comparing average power spectra of individual measurements, the accuracy mode number limits of the x-ray phase contrast system benchmarked against surface characterization performed by Atomic Force Microscopy are 60 and 90 for surrogates smoother and rougher than the required roughness for the ice. These agreement mode number limits are >100 when comparing matching individual measurements. We will discuss the implications for interpreting DT ice roughness data derived from phase-contrast x-ray imaging.

  17. Geol 795 Paleoceanography Ice Sheet Dynamics and Climate Change

    E-Print Network [OSTI]

    Barranco, Joseph

    Geol 795 ­ Paleoceanography Ice Sheet Dynamics and Climate Change Class Meetings: Tuesday 9 of articles related ice sheet dynamics and the role of ice sheets in past, present, and future climate change ice sheet dynamics and the role of ice sheets in climate change. We will discuss effective ways

  18. IceT users' guide and reference.

    SciTech Connect (OSTI)

    Moreland, Kenneth D.

    2011-01-01

    The Image Composition Engine for Tiles (IceT) is a high-performance sort-last parallel rendering library. In addition to providing accelerated rendering for a standard display, IceT provides the unique ability to generate images for tiled displays. The overall resolution of the display may be several times larger than any viewport that may be rendered by a single machine. This document is an overview of the user interface to IceT.

  19. In situ cosmogenic radiocarbon production and 2-D ice flow line modeling for an Antarctic blue ice area

    E-Print Network [OSTI]

    Severinghaus, Jeffrey P.

    In situ cosmogenic radiocarbon production and 2-D ice flow line modeling for an Antarctic blue ice; accepted 12 April 2012; published 24 May 2012. [1] Radiocarbon measurements at ice margin sites and blue and 2-D ice flow line modeling for an Antarctic blue ice area, J. Geophys. Res., 117, F02029, doi:10

  20. Predicting Land-Ice Retreat and Sea-Level Rise with the Community Earth System Model

    SciTech Connect (OSTI)

    Lipscomb, William

    2012-06-19

    Coastal stakeholders need defensible predictions of 21st century sea-level rise (SLR). IPCC assessments suggest 21st century SLR of {approx}0.5 m under aggressive emission scenarios. Semi-empirical models project SLR of {approx}1 m or more by 2100. Although some sea-level contributions are fairly well constrained by models, others are highly uncertain. Recent studies suggest a potential large contribution ({approx}0.5 m/century) from the marine-based West Antarctic Ice Sheet, linked to changes in Southern Ocean wind stress. To assess the likelihood of fast retreat of marine ice sheets, we need coupled ice-sheet/ocean models that do not yet exist (but are well under way). CESM is uniquely positioned to provide integrated, physics based sea-level predictions.

  1. BISICLES Captures Details of Retreating Antarctic Ice

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    software framework, and linked them to the existing Community Ice Sheet Model code (CISM). With AMR, researchers can now model dynamic points of interest at extremely high...

  2. The Next ICE Age | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    More Documents & Publications The Next ICE Age Fuel Modification t Facilitate Future Combustion Regimes? Optimization of Advanced Diesel Engine Combustion Strategies...

  3. The Stability of the Greenland Ice Sheet

    E-Print Network [OSTI]

    Biasutti, Michela

    , distribution and seasonality · Solid Earth: · Geothermal heatflux Abrupt Climate Change Studies Symposium 21 Rebound (GIA) GPS stations measure vertical deformation of solid Earth as ice

  4. Relationships between Water Wettability and Ice Adhesion

    E-Print Network [OSTI]

    Meuler, Adam J.

    Ice formation and accretion may hinder the operation of many systems critical to national infrastructure, including airplanes, power lines, windmills, ships, and telecommunications equipment. Yet despite the pervasiveness ...

  5. Mathematics Of Ice To Aid Global Warming Forecasts Mathematics Of Ice To Aid Global Warming Forecasts

    E-Print Network [OSTI]

    Golden, Kenneth M.

    Mathematics Of Ice To Aid Global Warming Forecasts Mathematics Of Ice To Aid Global Warming forecasts of how global warming will affect polar icepacks. See also: Earth & Climate q Global Warming q the effects of climate warming, and its presence greatly reduces solar heating of the polar oceans." "Sea ice

  6. Relationship between ice water content and equivalent radar reflectivity for clouds consisting of nonspherical ice particles

    E-Print Network [OSTI]

    Baum, Bryan A.

    Relationship between ice water content and equivalent radar reflectivity for clouds consisting investigates the relationship between ice water content (IWC) and equivalent radar reflectivity (Ze) at 94 GHz. Baum, and A. J. Heymsfield (2008), Relationship between ice water content and equivalent radar

  7. A New Approach for Exploring Ice Sheets and Sub-Ice Geology

    E-Print Network [OSTI]

    Kristoffersen, Yngve

    A New Approach for Exploring Ice Sheets and Sub-Ice Geology Active seismic measurements were geology driven by ice flow [Smith et al., 2007] and the long record of seismic exploration of subglacial sur- veys because of the considerable logistical effort necessary for seismic data acquisition

  8. Water, O2 and Ice in Molecular Clouds

    E-Print Network [OSTI]

    David Hollenbach; Michael J. Kaufman; Edwin A. Bergin; Gary J. Melnick

    2009-03-02

    We model the temperature and chemical structure of molecular clouds as a function of depth into the cloud, assuming a cloud of constant density n illuminated by an external FUV (6 eV < E < 13.6 eV) flux G_0 (scaling factor in multiples of the local interstellar field). Extending previous photodissociation region models, we include the freezing of species, simple grain surface chemistry, and desorption (including FUV photodesorption) of ices. We also treat the opaque cloud interior with time-dependent chemistry. Here, under certain conditions, gas phase elemental oxygen freezes out as water ice and the elemental C/O abundance ratio can exceed unity, leading to complex carbon chemistry. Gas phase H2O and O2 peak in abundance at intermediate depth into the cloud, roughly A_V~3-8 from the surface, the depth proportional to ln(G_0/n). Closer to the surface, molecules are photodissociated. Deeper into the cloud, molecules freeze to grain surfaces. At intermediate depths photodissociation rates are attenuated by dust extinction, but photodesorption prevents total freezeout. For G_0 < 500, abundances of H2O and O2 peak at values ~10^(-7), producing columns ~10^(15) per cm^2, independent of G_0 and n. The peak abundances depend primarily on the product of the photodesorption yield of water ice and the grain surface area per H nucleus. At higher values of G_0, thermal desorption of O atoms from grains enhances the gas phase H2O peak abundance and column slightly, whereas the gas phase O2 peak abundance rises to ~10^(-5) and the column to ~2x10^(16) per cm^2. We present simple analytic equations for the abundances as a function of depth which clarify the dependence on parameters. The models are applied to observations of H2O, O2, and water ice in a number of sources, including B68, NGC 2024, and Rho Oph.

  9. Ice Nucleation of Bare and Sulfuric Acid-coated Mineral Dust Particles and Implication for Cloud Properties

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Sanders, Cassandra N.; Zhang, Kai; Liu, Xiaohong; Zhao, Chun

    2014-08-27

    Ice nucleation properties of different dust species coated with soluble material are not well understood. We determined the ice nucleation ability of bare and sulfuric acid coated mineral dust particles as a function of temperature (-25 to -35 deg C) and relative humidity with respect to water (RHw). Five different mineral dust species: Arizona test dust (ATD), illite, montmorillonite, quartz and kaolinite were dry dispersed and size-selected at 150 nm and exposed to sulfuric acid vapors in the coating apparatus. The condensed sulfuric acid soluble mass fraction per particle was estimated from the cloud condensation nuclei activated fraction measurements. The fraction of dust particles nucleating ice at various temperatures and RHw was determined using a compact ice chamber. In water-subsaturated conditions, compared to bare dust particles, we found that only coated ATD particles showed suppression of ice nucleation ability while other four dust species did not showed the effect of coating on the fraction of particles nucleating ice. The results suggest that interactions between the dust surface and sulfuric acid vapor are important, such that interactions may or may not modify the surface via chemical reactions with sulfuric acid. At water-supersaturated conditions we did not observed the effect of coating, i.e. the bare and coated dust particles had similar ice nucleation behavior.

  10. Outgassing of icy bodies in the solar system - I. The sublimation of hexagonal water ice through dust layers

    E-Print Network [OSTI]

    Gundlach, Bastian; Blum, Jürgen

    2011-01-01

    Our knowledge about the physical processes determining the activity of comets were mainly influenced by several extremely successful space missions, the predictions of theoretical models and the results of laboratory experiments. However, novel computer models should not be treated in isolation but should be based on experimental results. Therefore, a new experimental setup was constructed to investigate the temperature dependent sublimation properties of hexagonal water ice and the gas diffusion through a dry dust layer covering the ice surface. We show that this experimental setup is capable to reproduce known gas production rates of pure hexagonal water ice. The reduction of the gas production rate due to an additional dust layer on top of the ice surface was measured and compared with the results of another experimental setup in which the gas diffusion through dust layers at room temperature was investigated. We found that the relative permeability of the dust layer is inversely proportional to its thickn...

  11. ARKTOS: An intelligent system for SAR sea ice image classification

    E-Print Network [OSTI]

    Soh, L. K.; Tsatsoulis, Costas; Gineris, D.; Bertoia, C.

    2004-01-01

    We present an intelligent system for satellite sea ice image analysis named Advanced Reasoning using Knowledge for T ping Of Sea ice (ARKTOS). ARKTOS performs fully automated analysis of synthetic aperture radar (SAR) sea ice images by mimicking...

  12. The measured compositions of Uranus and Neptune from their formation on the CO ice line

    SciTech Connect (OSTI)

    Ali-Dib, Mohamad; Mousis, Olivier; Petit, Jean-Marc

    2014-09-20

    The formation mechanisms of the ice giants Uranus and Neptune, and the origin of their elemental and isotopic compositions, have long been debated. The density of solids in the outer protosolar nebula is too low to explain their formation, and spectroscopic observations show that both planets are highly enriched in carbon, very poor in nitrogen, and the ices from which they originally formed might have had deuterium-to-hydrogen ratios lower than the predicted cometary value, unexplained properties that were observed in no other planets. Here, we show that all these properties can be explained naturally if Uranus and Neptune both formed at the carbon monoxide ice line. Due to the diffusive redistribution of vapors, this outer region of the protosolar nebula intrinsically has enough surface density to form both planets from carbon-rich solids but nitrogen-depleted gas, in abundances consistent with their observed values. Water-rich interiors originating mostly from transformed CO ices reconcile the D/H value of Uranus's and Neptune's building blocks with the cometary value. Finally, our scenario generalizes a well known hypothesis that Jupiter formed on an ice line (water snow line) for the two ice giants, and might be a first step toward generalizing this mechanism for other giant planets.

  13. ARM - TWP-ICE Maps

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, AlaskaManus Site-Inactive TWP Related Links Facilities andTWP-ICE Maps

  14. IceCube at NERSC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.FoodHydropower,Principal InvestigatorsIceCube at

  15. Results from IceCube/IceTop Ooty, 17/12/12 Tom Gaisser for the IceCube Collab. 1

    E-Print Network [OSTI]

    Gaisser, Thomas K.

    , 17/12/12 Tom Gaisser for the IceCube Collab. 3 #12;Mumbai, 11/12/12 Tom;Mumbai, 11/12/12 Tom Gaisser for the IceCube Collab. 5 DetecMng neutrinos in H of interac,ons IceTop #12;Mumbai, 11/12/12 Tom Gaisser for the IceCube Collab. 6

  16. What Determines the Sticking Probability of Water Molecules on Ice?

    SciTech Connect (OSTI)

    Batista, Enrique; Ayotte, Patrick; Bilic , Ante; Kay, Bruce D.; Jonsson, Hannes

    2005-11-22

    We present both experimental and theoretical studies of the sticking of water molecules on ice. The sticking probability is unity over a wide range in energy (0.5 eV–1.5 eV) when the molecules are incident along the surface normal, but drops as the angle increases at high incident energy. This is explained in terms of the strong orientational dependence of the interaction of the molecule with the surface and the time required for the reorientation of the molecule. The sticking probability is found to scale with the component of the incident velocity in the plane of the surface, unlike the commonly assumed normal or total energy scaling.

  17. Radar attenuation and temperature within the Greenland Ice Sheet

    E-Print Network [OSTI]

    2015-01-01

    on obliquely propagating radio waves, IEEE Trans. Geosci.dielectric attenuation of radio waves through ice is alsoattenuation of radio waves through ice is also temperature

  18. ICR-ICE Standard Operating Procedures (Update Sept 2013) | Department...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ICR-ICE Standard Operating Procedures (Update Sept 2013) ICR-ICE Standard Operating Procedures (Update Sept 2013) ICRICE SOPSep 2013Final.pdf More Documents & Publications...

  19. Rapid development of an ice sheet climate application using the...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Rapid development of an ice sheet climate application using the components-based approach Citation Details In-Document Search Title: Rapid development of an ice...

  20. Complex systems influence melting of Greenland ice sheet

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Complex systems influence melting of Greenland ice sheet Complex systems influence melting of Greenland ice sheet International research team's field work shows that, well, things...

  1. Cosmic-ray results from IceCube/ Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 1

    E-Print Network [OSTI]

    Gaisser, Thomas K.

    Cosmic-ray results from IceCube/ IceTop Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 1 #12;Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 2 events ­ IceTop/deep IceCube Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab

  2. Understanding subsidence in the Mississippi Delta region due to sediment, ice, and ocean loading

    E-Print Network [OSTI]

    Törnqvist, Torbjörn E.

    Understanding subsidence in the Mississippi Delta region due to sediment, ice, and ocean loading The processes responsible for land surface subsidence in the Mississippi Delta (MD) have been vigorously debated. Numerous studies have postulated a dominant role for isostatic subsidence associated with sediment loading

  3. Modeling production and climate-related impacts on Be concentration in ice cores

    E-Print Network [OSTI]

    strength and the solar activity modulation parameter (f), CO2, sea surface temperatures, and volcanic for studying changes in solar output. However, interpreting 10 Be ice core records on centennial timescales. By using the Goddard Institute for Space Studies ModelE general circulation model to selectively vary

  4. Some Thoughts on the Freezing and Melting of Sea Ice and Their Effects on the Ocean

    E-Print Network [OSTI]

    Washington at Seattle, University of

    Some Thoughts on the Freezing and Melting of Sea Ice and Their Effects on the Ocean K. Aagaard. The high-latitude freezing and melting cycle can variously result in haline con- vection, freshwater of this process is that water distilled at the surface of the Arctic Ocean by freezing ends up at mid

  5. Compositions of subsurface ices at the Mars Phoenix landing site Selby Cull,1

    E-Print Network [OSTI]

    Skemer, Philip

    Compositions of subsurface ices at the Mars Phoenix landing site Selby Cull,1 Raymond E. Arvidson,1 25 October 2010; accepted 2 November 2010; published 22 December 2010. [1] NASA's Phoenix Lander that broke during Robotic Arm operations; and a darker icy deposit. Spectra from the Phoenix Surface Stereo

  6. Estimating a Volumetric Backscatter Coefficient from Measurements on the Greenland Ice Sheet

    E-Print Network [OSTI]

    Kansas, University of

    Estimating a Volumetric Backscatter Coefficient from Measurements on the Greenland Ice Sheet J (> 25°) the measured backscatter is dominated by volumetric scattering, as opposed to surface and specu the volumetric backscatter coefficient as a function of depth in flrn. Re- sults show trends consistent with both

  7. Passive ice freezing-releasing heat pipe

    DOE Patents [OSTI]

    Gorski, Anthony J. (Lemont, IL); Schertz, William W. (Batavia, IL)

    1982-01-01

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  8. Ice Cover on the Great Lakes NATIONALOCEANIC

    E-Print Network [OSTI]

    : In the shallow waters where whitefish spawn, ice cover protects their eggs from destructive wind and wave action://coastwatch.glerl.noaa.gov/glsea/cur/glsea_cur.png #12;GLERL Research Forecast capability The capability to forecast and predict ice cover is important for recreational safety and rescue efforts as well as for navigation, weather forecasting, adapting to lake level

  9. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

    PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 µm) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 µm), known as the “small mode”. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 µm wavelength relative to 11 µm wavelength due to the process of wave resonance or photon tunneling more active at 12 µm. This makes the 12/11 µm absorption optical depth ratio (or equivalently the 12/11 µm Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

  10. Nanotextured Anti-Icing Surfaces | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    researchers are developing super water-repellent coatings to improve moisture control in steam turbines to enable higher efficiency. They also are exploring these coatings for...

  11. Novel two-step laser ablation and ionization mass spectrometry (2S-LAIMS) of actor-spectator ice layers: Probing chemical composition of D{sub 2}O ice beneath a H{sub 2}O ice layer

    SciTech Connect (OSTI)

    Yang, Rui Gudipati, Murthy S.

    2014-03-14

    In this work, we report for the first time successful analysis of organic aromatic analytes imbedded in D{sub 2}O ices by novel infrared (IR) laser ablation of a layered non-absorbing D{sub 2}O ice (spectator) containing the analytes and an ablation-active IR-absorbing H{sub 2}O ice layer (actor) without the analyte. With these studies we have opened up a new method for the in situ analysis of solids containing analytes when covered with an IR laser-absorbing layer that can be resonantly ablated. This soft ejection method takes advantage of the tenability of two-step infrared laser ablation and ultraviolet laser ionization mass spectrometry, previously demonstrated in this lab to study chemical reactions of polycyclic aromatic hydrocarbons (PAHs) in cryogenic ices. The IR laser pulse tuned to resonantly excite only the upper H{sub 2}O ice layer (actor) generates a shockwave upon impact. This shockwave penetrates the lower analyte-containing D{sub 2}O ice layer (spectator, a non-absorbing ice that cannot be ablated directly with the wavelength of the IR laser employed) and is reflected back, ejecting the contents of the D{sub 2}O layer into the vacuum where they are intersected by a UV laser for ionization and detection by a time-of-flight mass spectrometer. Thus, energy is transmitted from the laser-absorbing actor layer into the non-absorbing spectator layer resulting its ablation. We found that isotope cross-contamination between layers was negligible. We also did not see any evidence for thermal or collisional chemistry of PAH molecules with H{sub 2}O molecules in the shockwave. We call this “shockwave mediated surface resonance enhanced subsurface ablation” technique as “two-step laser ablation and ionization mass spectrometry of actor-spectator ice layers.” This method has its roots in the well-established MALDI (matrix assisted laser desorption and ionization) method. Our method offers more flexibility to optimize both the processes—ablation and ionization. This new technique can thus be potentially employed to undertake in situ analysis of materials imbedded in diverse media, such as cryogenic ices, biological samples, tissues, minerals, etc., by covered with an IR-absorbing laser ablation medium and study the chemical composition and reaction pathways of the analyte in its natural surroundings.

  12. Laboratory investigations of irradiated acetonitrile-containing ices on an interstellar dust analog

    SciTech Connect (OSTI)

    Abdulgalil, Ali G. M.; Marchione, Demian; Rosu-Finsen, Alexander; Collings, Mark P.; McCoustra, Martin R. S.

    2012-07-15

    Reflection-absorption infrared spectroscopy is used to study the impact of low-energy electron irradiation of acetonitrile-containing ices, under conditions close to those in the dense star-forming regions in the interstellar medium. Both the incident electron energy and the surface coverage were varied. The experiments reveal that solid acetonitrile is desorbed from its ultrathin solid films with a cross section of the order of 10{sup -17} cm{sup 2}. Evidence is presented for a significantly larger desorption cross section for acetonitrile molecules at the water-ice interface, similar to that previously observed for the benzene-water system.

  13. Effects of exchange bias on magnetotransport in permalloy kagome artificial spin ice

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Le, B. L.; Rench, D. W.; Misra, R.; O’Brien, L.; Leighton, C.; Samarth, N.; Schiffer, P.

    2015-02-01

    We investigate the magnetotransport properties of connected kagome artificial spin ice networks composed of permalloy nanowires. Our data show clear evidence of magnetic switching among the wires, both in the longitudinal and transverse magnetoresistance. An unusual asymmetry with field sweep direction appears at temperatures below about 20 K that appears to be associated with exchange bias resulting from surface oxidation of permalloy, and which disappears in alumina-capped samples. These results demonstrate that exchange bias is a phenomenon that must be considered in understanding the physics of such artificial spin ice systems, and that opens up new possibilities for their control.

  14. Radiostratigraphy and age structure of the Greenland Ice Sheet

    E-Print Network [OSTI]

    2015-01-01

    is 3.15, equivalent to a radio-wave velocity in ice of 168.9to be vertical) that a radio wave travels through ice during?t is where v ice is the radio-wave velocity in ice, ?z ¼ v

  15. Crystalline water ice on the Kuiper belt object (50000) Quaoar

    E-Print Network [OSTI]

    Jewitt, David C.

    .............................................................. Crystalline water ice on the Kuiper the presence of crystalline water ice and ammonia hydrate. Crystallinity indicates that the ice has been heated to at least 110 K. Both ammonia hydrate and crystalline water ice should be destroyed by energetic particle

  16. In Situ Airborne Instrumentation: Addressing and Solving Measurement Problems in Ice Clouds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Baumgardner, Darrel; Kok, Greg; Avallone, L.; Bansemer, A.; Borrmann, S.; Brown, P.; Bundke, U.; Chuang, P. Y.; Cziczo, D.; Field, P.; et al

    2012-02-01

    A meeting of 31 international experts on in situ measurements from aircraft was held to identify unresolved questions concerning ice formation and evolution in ice clouds, assess the current state of instrumentation that can address these problems, introduce emerging technology that may overcome current measurement issues and recommend future courses of action that can improve our understanding of ice cloud microphysical processes and their impact on the environment. The meeting proceedings and outcome has been described in detail in a manuscript submitted to the Bulletin of the American Meteorological Society (BAMS) on March 24, 2011. This paper is currently undermore »review. The remainder of this summary, in the following pages, is the text of the BAMS article. A technical note that will be published by the National Center for Atmospheric Research is currently underway and is expected to be published before the end of the year.« less

  17. In Situ Airborne Instrumentation: Addressing and Solving Measurement Problems in Ice Clouds

    SciTech Connect (OSTI)

    Baumgardner, Darrel; Kok, Greg; Avallone, L.; Bansemer, A.; Borrmann, S.; Brown, P.; Bundke, U.; Chuang, P. Y.; Cziczo, D.; Field, P.; Gallagher, M.; Gayet, J. -F.; Korolev, A.; Kraemer, M.; McFarquhar, G.; Mertes, S.; Moehler, O.; Lance, S.; Lawson, P.; Petters, M. D.; Pratt, K.; Roberts, G.; Rogers, D.; Stetzer, O.; Stith, J.; Strapp, W.; Twohy, C.; Wendisch, M.

    2012-02-01

    A meeting of 31 international experts on in situ measurements from aircraft was held to identify unresolved questions concerning ice formation and evolution in ice clouds, assess the current state of instrumentation that can address these problems, introduce emerging technology that may overcome current measurement issues and recommend future courses of action that can improve our understanding of ice cloud microphysical processes and their impact on the environment. The meeting proceedings and outcome has been described in detail in a manuscript submitted to the Bulletin of the American Meteorological Society (BAMS) on March 24, 2011. This paper is currently under review. The remainder of this summary, in the following pages, is the text of the BAMS article. A technical note that will be published by the National Center for Atmospheric Research is currently underway and is expected to be published before the end of the year.

  18. Nitrate ions spikes in ice cores are not suitable proxies for solar proton events

    E-Print Network [OSTI]

    Duderstadt, Katharine A; Jackman, Charles H; Randall, Cora E; Schwadron, Nathan A; Solomon, Stanley C; Spence, Harlan E; Yudin, Valery A

    2015-01-01

    Nitrate ion spikes in polar ice cores are contentiously used to estimate the intensity, frequency, and probability of historical solar proton events, quantities that are needed to prepare for potentially society-crippling space weather events. We use the Whole Atmosphere Community Climate Model to calculate how large an event would have to be to produce enough odd nitrogen throughout the atmosphere to be discernible as nitrate peaks at the Earth's surface. These hypothetically large events are compared with probability of occurrence estimates derived from measured events, sunspot records, and cosmogenic radionuclides archives. We conclude that the fluence and spectrum of solar proton events necessary to produce odd nitrogen enhancements equivalent to the spikes of nitrate ions in Greenland ice cores are unlikely to have occurred throughout the Holocene, confirming that nitrate ions in ice cores are not suitable proxies for historical individual solar proton events.

  19. Do blue-ice moraines in the Heritage Range show the West Antarctic ice sheet survived the last interglacial?

    E-Print Network [OSTI]

    Do blue-ice moraines in the Heritage Range show the West Antarctic ice sheet survived the last in revised form 10 January 2011 Accepted 28 January 2011 Available online xxxx Keywords: Blue-ice moraine cosmogenic isotope data on blue-ice moraines in the Heritage Range, West Antarctica. The age of the moraines

  20. Inter-annual sea-ice dynamics and micro-algal biomass in winter pack ice of Marguerite Bay, Antarctica

    E-Print Network [OSTI]

    Stewart, Frank

    in this region (Stammerjohn et al., 2003; Stammerjohn and Smith, 1996). Changes in mesoscale ice dynamics

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

    E-Print Network [OSTI]

    Eisenman, Ian

    the southern ice edge, especially on the western side. The sea ice force balance analysis shows that sea ice air from northerly winds and ice motion away from the coast. South of St Lawrence Island, winds drive is important both climatically and economically. Understanding the processes that control the temporal

  2. Communication: On the stability of ice 0, ice i, and I{sub h}

    SciTech Connect (OSTI)

    Quigley, D.; Alfč, D.; Slater, B.

    2014-10-28

    Using ab initio methods, we examine the stability of ice 0, a recently proposed tetragonal form of ice implicated in the homogeneous freezing of water [J. Russo, F. Romano, and H. Tanaka, Nat. Mater. 13, 670 (2014)]. Vibrational frequencies are computed across the complete Brillouin Zone using Density Functional Theory (DFT), to confirm mechanical stability and quantify the free energy of ice 0 relative to ice I{sub h}. The robustness of this result is tested via dispersion corrected semi-local and hybrid DFT, and Quantum Monte-Carlo calculation of lattice energies. Results indicate that popular molecular models only slightly overestimate the stability of ice zero. In addition, we study all possible realisations of proton disorder within the ice zero unit cell, and identify the ground state as ferroelectric. Comparisons are made to other low density metastable forms of ice, suggesting that the ice i structure [C. J. Fennel and J. D. Gezelter, J. Chem. Theory Comput. 1, 662 (2005)] may be equally relevant to ice formation.

  3. Water ice deuteration: a tracer of the chemical history of protostars

    E-Print Network [OSTI]

    Taquet, Vianney; Kahane, Claudine; Ceccarelli, Cecilia; Lņpez-Sepulcre, Ana; Toubin, Céline; Duflot, Denis; Wiesenfeld, Laurent

    2012-01-01

    Context. Millimetric observations have measured large degrees of molecular deuteration in several species seen around low-mass protostars. The Herschel Space Telescope, launched in 2009, is now providing new measures of the deuterium fractionation of water, the main constituent of interstellar ices. Aims. We aim at theoretically studying the formation and the deuteration of water which is believed to be formed on interstellar grain surfaces in molecular clouds. Methods. We used our gas-grain astrochemical model GRAINOBLE which considers the multilayer formation of interstellar ices. We varied several input parameters to study their impact on water deuteration. We included the treatment of ortho and para states of key species, including H2, that affects the deuterium fractionation of all molecules. The model also includes relevant laboratory and theoretical works on water formation and deuteration on grain surfaces. In particular, we computed the transmission probabilities of surface reactions using the Eckart...

  4. Multipole moments of water molecules in clusters and ice Ih from first principles calculations

    SciTech Connect (OSTI)

    Batista, E.R. [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States)] [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States); [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Xantheas, S.S. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K8-91, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K8-91, Richland, Washington 99352 (United States); Jonsson, H. [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)] [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

    1999-10-01

    We have calculated {ital molecular} multipole moments for water molecules in clusters and in ice Ih by partitioning the charge density obtained from first principles calculations. Various schemes for dividing the electronic charge density among the water molecules were used. They include Bader{close_quote}s zero flux surfaces and Voronoi partitioning schemes. A comparison was also made with an induction model including dipole, dipole-quadrupole, quadrupole-quadrupole polarizability and first hyperpolarizability as well as fixed octopole and hexadecapole moments. We have found that the different density partitioning schemes lead to widely different values for the molecular multipoles, illustrating how poorly defined molecular multipoles are in clusters and condensed environments. For instance, the magnitude of the molecular dipole moment in ice Ih ranges between 2.3 D and 3.1 D depending on the partitioning scheme used. Within each scheme, though, the value for the molecular dipole moment in ice is larger than in the hexamer. The magnitude of the molecular dipole moment in the clusters shows a monotonic increase from the gas phase value to the one in ice Ih, with the molecular dipole moment in the water ring hexamer being smaller than the one in ice Ih for all the partitioning schemes used. {copyright} {ital 1999 American Institute of Physics.}

  5. Weakening of ice by magnesium perchlorate hydrate

    E-Print Network [OSTI]

    Lenferink, Hendrik J., 1985-

    2012-01-01

    I show that perchlorate hydrates, which have been indirectly detected at high Martian circumpolar latitudes by the Phoenix Mars Lander, have a dramatic effect upon the rheological behavior of polycrystalline water ice under ...

  6. Largest Ice-Bank Promotes Load Management 

    E-Print Network [OSTI]

    Brarmann, G. L.

    1983-01-01

    conservation measures were incorporated in the design of the new research facility, the ice-bank system has been the most cost-effective of the load management projects at Union Oil....

  7. Widespread Excess Ice in Arcadia Planitia, Mars

    E-Print Network [OSTI]

    Bramson, Ali M; Putzig, Nathaniel E; Sutton, Sarah; Plaut, Jeffrey J; Brothers, T Charles; Holt, John W

    2015-01-01

    The distribution of subsurface water ice on Mars is a key constraint on past climate, while the volumetric concentration of buried ice (pore-filling versus excess) provides information about the process that led to its deposition. We investigate the subsurface of Arcadia Planitia by measuring the depth of terraces in simple impact craters and mapping a widespread subsurface reflection in radar sounding data. Assuming that the contrast in material strengths responsible for the terracing is the same dielectric interface that causes the radar reflection, we can combine these data to estimate the dielectric constant of the overlying material. We compare these results to a three-component dielectric mixing model to constrain composition. Our results indicate a widespread, decameters-thick layer that is excess water ice ~10^4 km^3 in volume. The accumulation and long-term preservation of this ice is a challenge for current Martian climate models.

  8. Recent vs from IceCube

    E-Print Network [OSTI]

    Klein, Spencer R.; IceCube Collaboration

    2008-01-01

    in the Sun and the Earth, look for low-energy (10 MeV)Sun. IceTop has made a preliminary measurement of the cosmic-ray energy

  9. Development of a Mobile Ice Nucleus Counter

    SciTech Connect (OSTI)

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70 deg C, and a single stage system can operate the warm wall at -45 deg C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  10. Liquid Water Oceans in Ice Giants

    E-Print Network [OSTI]

    Sloane J. Wiktorowicz; Andrew P. Ingersoll

    2006-09-26

    Aptly named, ice giants such as Uranus and Neptune contain significant amounts of water. While this water cannot be present near the cloud tops, it must be abundant in the deep interior. We investigate the likelihood of a liquid water ocean existing in the hydrogen-rich region between the cloud tops and deep interior. Starting from an assumed temperature at a given upper tropospheric pressure (the photosphere), we follow a moist adiabat downward. The mixing ratio of water to hydrogen in the gas phase is small in the photosphere and increases with depth. The mixing ratio in the condensed phase is near unity in the photosphere and decreases with depth; this gives two possible outcomes. If at some pressure level the mixing ratio of water in the gas phase is equal to that in the deep interior, then that level is the cloud base. Alternately, if the mixing ratio of water in the condensed phase reaches that in the deep interior, then the surface of a liquid ocean will occur. We find that Neptune is both too warm (photospheric temperature too high) and too dry (mixing ratio of water in the deep interior too low) for liquid oceans to exist at present. To have a liquid ocean, Neptune's deep interior water to gas ratio would have to be higher than current models allow, and the density at 19 kbar would have to be ~ 0.8 g/cm^3. Such a high density is inconsistent with gravitational data obtained during the Voyager flyby. As Neptune cools, the probability of a liquid ocean increases. Extrasolar "hot Neptunes," which presumably migrate inward toward their parent stars, cannot harbor liquid water oceans unless they have lost almost all of the hydrogen and helium from their deep interiors.

  11. On the correlation between ice water content and ice crystal size and its application to radiative transfer and general circulation models

    E-Print Network [OSTI]

    Liou, K. N.

    On the correlation between ice water content and ice crystal size and its application to radiative analysis involving ice water content (IWC) and mean effective ice crystal size (De) intended, K. N., Y. Gu, Q. Yue, and G. McFarguhar (2008), On the correlation between ice water content and ice

  12. Application of an online-coupled regional climate model, WRF-CAM5, over East Asia for examination of ice nucleation schemes. Part II. Sensitivity to heterogeneous ice nucleation parameterizations and dust emissions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Yang; Chen, Ying; Fan, Jiwen; Leung, Lai -Yung

    2015-09-14

    Aerosol particles can affect cloud microphysical properties by serving as ice nuclei (IN). Large uncertainties exist in the ice nucleation parameterizations (INPs) used in current climate models. In this Part II paper, to examine the sensitivity of the model predictions to different heterogeneous INPs, WRF-CAM5 simulation using the INP of Niemand et al. (N12) [1] is conducted over East Asia for two full years, 2006 and 2011, and compared with simulation using the INP of Meyers et al. (M92) [2], which is the original INP used in CAM5. M92 calculates the nucleated ice particle concentration as a function of icemore »supersaturation, while N12 represents the nucleated ice particle concentration as a function of temperature and the number concentrations and surface areas of dust particles. Compared to M92, the WRF-CAM5 simulation with N12 produces significantly higher nucleated ice crystal number concentrations (ICNCs) in the northern domain where dust sources are located, leading to significantly higher cloud ice number and mass concentrations and ice water path, but the opposite is true in the southern domain where temperatures and moistures play a more important role in ice formation. Overall, the simulation with N12 gives lower downward shortwave radiation but higher downward longwave radiation, cloud liquid water path, cloud droplet number concentrations, and cloud optical depth. The increase in cloud optical depth and the decrease in downward solar flux result in a stronger shortwave and longwave cloud forcing, and decreases temperature at 2-m and precipitation. Changes in temperature and radiation lower surface concentrations of OH, O?, SO?²?, and PM2.5, but increase surface concentrations of CO, NO?, and SO? over most of the domain. By acting as cloud condensation nuclei (CCN) and IN, dust particles have different impacts on cloud water and ice number concentrations, radiation, and temperature at 2-m and precipitation depending on whether the dominant role of dust is CCN or IN. These results indicate the importance of the heterogeneous ice nucleation treatments and dust emissions in accurately simulating regional climate and air quality.« less

  13. Assimilation of Ice Concentration in an IceOcean Model R. W. LINDSAY AND J. ZHANG

    E-Print Network [OSTI]

    Zhang, Jinlun

    of the actual fields. The simulated ice thickness can then be used to determine the major modes of variability of the ice thickness and the physical processes that are important in their formation. The simulations from concentration measured by satellites is subject to errors (Kwok 2002), particularly during the summer when

  14. ICED'09/148 INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN, ICED'09

    E-Print Network [OSTI]

    Papalambros, Panos

    , marketing, and psychology. Quantitative models from these disciplines can be integrated into a design for teaching product design and for designing products taking into account market and policy environments alongICED'09/148 INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN, ICED'09 24 - 27 AUGUST 2009, STANFORD

  15. A Comprehensive Parameterization of Heterogeneous Ice Nucleation of Dust Surrogate: Laboratory Study with Hematite Particles and Its Application to Atmospheric Models

    SciTech Connect (OSTI)

    Hiranuma, Naruki; Paukert, Marco; Steinke, Isabelle; Zhang, Kai; Kulkarni, Gourihar R.; Hoose, Corinna; Schnaiter, Martin; Saathoff, Harald; Mohler, Ottmar

    2014-12-10

    A new heterogeneous ice nucleation parameterization that covers a wide temperature range (-36 ?C to -78 ?C) is presented. Developing and testing such an ice nucleation parameterization, which is constrained through identical experimental conditions, is critical in order to accurately simulate the ice nucleation processes in cirrus clouds. The surface-scaled ice nucleation efficiencies of hematite particles, inferred by ns, were derived from AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud chamber measurements under water subsaturated conditions that were realized by continuously changing temperature (T) and relative humidity with respect to ice (RHice) in the chamber. Our measurements showed several different pathways to nucleate ice depending on T and RHice conditions. For instance, almost independent freezing was observed at -60 ?C < T < -50 ?C, where RHice explicitly controlled ice nucleation efficiency, while both T and RHice played roles in other two T regimes: -78 ?C < T < -60 ?C and -50 ?C < T < -36 ?C. More specifically, observations at T colder than -60 ?C revealed that higher RHice was necessary to maintain constant ns, whereas T may have played a significant role in ice nucleation at T warmer than -50 ?C. We implemented new ns parameterizations into two cloud models to investigate its sensitivity and compare with the existing ice nucleation schemes towards simulating cirrus cloud properties. Our results show that the new AIDA-based parameterizations lead to an order of magnitude higher ice crystal concentrations and inhibition of homogeneous nucleation in colder temperature regions. Our cloud simulation results suggest that atmospheric dust particles that form ice nuclei at lower temperatures, below -36 ?C, can potentially have stronger influence on cloud properties such as cloud longevity and initiation when compared to previous parameterizations.

  16. Critical Mechanisms for the Formation of Extreme Arctic Sea-Ice Extent in the Summers of 2007 and 1996

    SciTech Connect (OSTI)

    Dong, Xiquan; Zib, Benjamin J.; Xi, Baike; Stanfield, Ryan; Deng, Yi; Zhang, Xiangdong; Lin, B.; Long, Charles N.

    2014-07-29

    A warming Arctic climate is undergoing significant e 21 nvironmental change, most evidenced by the reduction of Arctic sea-ice extent during the summer. In this study, we examine two extreme anomalies of September sea-ice extent in 2007 and 1996, and investigate the impacts of cloud fraction (CF), atmospheric precipitable water vapor (PWV), downwelling longwave flux (DLF), surface air temperature (SAT), pressure and winds on the sea-ice variation in 2007 and 1996 using both satellite-derived sea-ice products and MERRA reanalysis. The area of the Laptev, East Siberian and West Chukchi seas (70-90oN, 90-180oE) has experienced the largest variation in sea-ice extent from year-to-year and defined here as the Area Of Focus (AOF). The record low September sea-ice extent in 2007 was associated with positive anomalies 30 of CF, PWV, DLF, and SAT over the AOF. Persistent anti-cyclone positioned over the Beaufort Sea coupled with low pressure over Eurasia induced easterly zonal and southerly meridional winds. In contrast, negative CF, PWV, DLF and SAT anomalies, as well as opposite wind patterns to those in 2007, characterized the 1996 high September sea-ice extent. Through this study, we hypothesize the following positive feedbacks of clouds, water vapor, radiation and atmospheric variables on the sea-ice retreat during the summer 2007. The record low sea-ice extent during the summer 2007 is initially triggered by the atmospheric circulation anomaly. The southerly winds across the Chukchi and East Siberian seas transport warm, moist air from the north Pacific, which is not only enhancing sea-ice melt across the AOF, but also increasing clouds. The positive cloud feedback results in higher SAT and more sea-ice melt. Therefore, 40 more water vapor could be evaporated from open seas and higher SAT to form more clouds, which will enhance positive cloud feedback. This enhanced positive cloud feedback will then further increase SAT and accelerate the sea-ice retreat during the summer 2007.

  17. Heat transfer in ice hockey halls: measurements, energy analysis and analytical ice pad temperature profile

    E-Print Network [OSTI]

    Ferrantelli, Andrea

    2015-01-01

    We consider heat transfer processes in an ice hockey hall, during operating conditions, with a bottom-up approach based upon on-site measurements. Detailed temperature data of both the ice pad and the air above the ice rink are used for a heat balance calculation in the steady-state regime, which quantifies the impact of each single heat source. We solve the heat equation in the ice slab in transient regime, and obtain a general analytical formula for the temperature profile. This solution is then applied to the resurfacing process by using our measurements as (time-dependent) boundary conditions (b.c.), and compared to an analogous numerical computation with good agreement. Our analytical formula is given with implicit initial condition and b.c., therefore it can be used not only in ice halls, but in a large variety of engineering applications.

  18. Heat transfer in ice hockey halls: measurements, energy analysis and analytical ice pad temperature profile

    E-Print Network [OSTI]

    Andrea Ferrantelli; Klaus Viljanen

    2015-06-30

    We consider heat transfer processes in an ice hockey hall, during operating conditions, with a bottom-up approach based upon on-site measurements. Detailed temperature data of both the ice pad and the air above the ice rink are used for a heat balance calculation in the steady-state regime, which quantifies the impact of each single heat source. We solve the heat equation in the ice slab in transient regime, and obtain a general analytical formula for the temperature profile. This solution is then applied to the resurfacing process by using our measurements as (time-dependent) boundary conditions (b.c.), and compared to an analogous numerical computation with good agreement. Our analytical formula is given with implicit initial condition and b.c., therefore it can be used not only in ice halls, but in a large variety of engineering applications.

  19. Spreading of crude petroleum in brash ice; Effects of oil`s physical properties and water current

    SciTech Connect (OSTI)

    Sayed, M.; Kotlyar, L.S.; Sparks, B.D.

    1994-12-31

    Experiments were conducted in a refrigerated, circulating current flume to examine crude oil spreading in brash ice. Amauligak, Hibernia and Norman Wells crudes were tested. Measurements of the physical properties of the oils were also conducted, including: surface and interfacial tensions as well as viscosities. Spreading coefficients were calculated from measured surface and interfacial tensions. Results were obtained for original and weathered oils. For the spreading tests, spill volumes up to 3 liters and water currents up to 0.55 m/s were used. Tests were done using both fresh water ice and saline ice. Slick dimensions were measured, and modes of oil spreading were observed. Slick dimensions depended on oil type, but were not influenced by water current. Oils of high spreading coefficient and low viscosity spread over larger areas than those with low spreading coefficient and high viscosity.

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

    SciTech Connect (OSTI)

    Barry, Roger G.

    2007-12-19

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

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

    ScienceCinema (OSTI)

    Barry, Roger G.

    2009-09-01

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

  2. Energy conservation potential of surface modification technologies

    SciTech Connect (OSTI)

    Le, H.K.; Horne, D.M.; Silberglitt, R.S.

    1985-09-01

    This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

  3. Structural transformation in supercooled water controls the crystallization rate of ice

    E-Print Network [OSTI]

    Emily B. Moore; Valeria Molinero

    2011-09-27

    One of water's unsolved puzzles is the question of what determines the lowest temperature to which it can be cooled before freezing to ice. The supercooled liquid has been probed experimentally to near the homogeneous nucleation temperature TH{\\approx}232 K, yet the mechanism of ice crystallization - including the size and structure of critical nuclei - has not yet been resolved. The heat capacity and compressibility of liquid water anomalously increase upon moving into the supercooled region according to a power law that would diverge at Ts{\\approx}225 K,(1,2) so there may be a link between water's thermodynamic anomalies and the crystallization rate of ice. But probing this link is challenging because fast crystallization prevents experimental studies of the liquid below TH. And while atomistic studies have captured water crystallization(3), the computational costs involved have so far prevented an assessment of the rates and mechanism involved. Here we report coarse-grained molecular simulations with the mW water model(4) in the supercooled regime around TH, which reveal that a sharp increase in the fraction of four-coordinated molecules in supercooled liquid water explains its anomalous thermodynamics and also controls the rate and mechanism of ice formation. The simulations reveal that the crystallization rate of water reaches a maximum around 225 K, below which ice nuclei form faster than liquid water can equilibrate. This implies a lower limit of metastability of liquid water just below TH and well above its glass transition temperature Tg{\\approx}136 K. By providing a relationship between the structural transformation in liquid water, its anomalous thermodynamics and its crystallization rate, this work provides a microscopic foundation to the experimental finding that the thermodynamics of water determines the rates of homogeneous nucleation of ice.(5)

  4. Fast Numerical Method for Growth and Retreat of Subsurface Ice on Mars Norbert Schorghofer

    E-Print Network [OSTI]

    Schörghofer, Norbert

    ice, retreat of pore ice, retreat of an ice sheet, and retreat of pore ice due to geothermal heating is the vertical spatial resolution and D the diffusion coefficient. The vertical grid spacing needs to be finer

  5. Optimization of Ice Thermal Storage Systems Design for HVAC Systems 

    E-Print Network [OSTI]

    Nassif, N.; Hall, C.; Freelnad, D.

    2013-01-01

    energy cost. A tool for optimal ice storage design is developed, considering the charging and discharge times and optimal sizing of ice thermal storage system. Detailed simulation studies using real office building located near Orlando, FL including...

  6. Searching for Cosmic Accelerators via IceCube

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Searching for Cosmic Accelerators via IceCube Searching for Cosmic Accelerators via IceCube Berkeley Lab Researchers Part of an International Hunt November 21, 2013 Lynn Yarris,...

  7. Cirrus cloud formation and the role of heterogeneous ice nuclei

    E-Print Network [OSTI]

    Froyd, Karl D.

    2013-01-01

    Composition, size, and phase are key properties that define the ability of an aerosol particle to initiate ice in cirrus clouds. Properties of cirrus ice nuclei (IN) have not been well constrained due to a lack of systematic ...

  8. Did changes in the Subpolar North Atlantic trigger the recent mass loss from the Greenland Ice Sheet?

    E-Print Network [OSTI]

    Straneo, Fiamma

    . The loss was not so much a result of increased surface melt but, rather, of ice loss due to the widespread; Holland et al. 2008]. Specifically, increased melting due, for example, to warming ocean waters can speed that STW penetrate inside Greenland's glacial fjords is limited to a handful of summer profiles from

  9. Energy conservation in ice skating rinks

    SciTech Connect (OSTI)

    Dietrich, B.K.; McAvoy, T.J.

    1980-01-01

    An economic and energy analysis of ice rinks was made to examine the areas in which energy could be profitably conserved. The areas where new equipment could make a major reduction in energy use are: the use of waste heat for space heating, the installation of a low emissivity false ceiling to reduce radiant heat, the use of a load cycling controller to reduce refrigeration costs, and the installation of more efficient lighting systems. Changes in rink operating procedure that could cut energy use are: higher refrigerant temperatures, thinner ice, the use of colder resurfacing water, turning the compressors and pumps off at night, and reducing ventilation.

  10. Covered Product Category: Water-Cooled Ice Machines

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Federal Energy Management Program (FEMP) provides acquisition guidance and federal efficiency requirements for water-cooled ice machines.

  11. Assessment of surface air temperature over the Arctic Ocean in reanalysis and IPCC AR4 model simulations with IABP/POLES

    E-Print Network [OSTI]

    Hu, Yongyun

    simulations with IABP/POLES observations Jiping Liu,1 Zhanhai Zhang,2 Yongyun Hu,3 Liqi Chen,4 Yongjiu Dai,5 Surface (IABP/POLES) observations for the period 1979­ 1999. The reanalyses, including the National Forecast 40-year Reanalysis (ERA40), show encouraging agreement with the IABP/POLES observations, although

  12. Operation and Control of Full Ice-storage System 

    E-Print Network [OSTI]

    Liu, Q.; Liu, Y.

    2006-01-01

    In a dividing time ice-storage system, the refrigerator does not operate during power's on-peak period, and all the cooling is supplied by the ice stored in off-peak period, so that the use of electricity can be maintained. When the ice is thawing...

  13. Ice Simulation Using GPGPU Shadi Alawneh and Dennis Peters

    E-Print Network [OSTI]

    Peters, Dennis

    is to increase the understanding of interactions between ice and steel structures such as ships and oil rigsIce Simulation Using GPGPU Shadi Alawneh and Dennis Peters Electrical and Computer Engineering.alawneh, dpeters}@mun.ca Abstract-- Simulation of the behaviour of a ship operating in pack ice

  14. Hyper-Real-Time Ice Simulation and Modeling Using GPGPU

    E-Print Network [OSTI]

    Peters, Dennis

    Hyper-Real-Time Ice Simulation and Modeling Using GPGPU By c Shadi Alawneh, B. Eng., M. Eng's, Newfoundland Title: Hyper-Real-Time Ice Simulation and Modeling Using GPGPU Author: Shadi Alawneh, B. Eng operating in pack ice is a computationally in- tensive process to which General Purpose Computing

  15. Introduction Microorganisms in sea ice function ecologically in the

    E-Print Network [OSTI]

    Stewart, Frank

    where pelagic and sea ice habitats are intrinsically coupled (Laws 1985, Garrison 1991, Eicken 1992, Knox 1994, Garrison & Mathot 1996, Arrigo et al. 1997, Brierley & Thomas 2002). For instance, sea ice algae - primarily diatoms and phototrophic flagellates (e.g. Garrison 1991) - are inocula for ice

  16. 29April2011JohnLearnedatIceCubeDedication1 IceCube Dedication Symposium, Madison, Wisconsin

    E-Print Network [OSTI]

    Learned, John

    29April2011JohnLearnedatIceCubeDedication1 IceCube Dedication Symposium, Madison, Wisconsin 29 of Neutrino Studies #12;"Talking to the neighbors" 29April2011JohnLearnedatIceCubeDedication2 "A modest://www.economist.com/PrinterFriendly.cfm?story_id=18526871 Not what this talk is about.... SETI with Neutrinos #12;29April2011JohnLearnedatIceCubeDedication3

  17. Role of surface oxygen-to-metal ratio on the wettability of rare-earth oxides

    E-Print Network [OSTI]

    Khan, Sami

    Hydrophobic surfaces that are robust can have widespread applications in drop-wise condensation, anti-corrosion, and anti-icing. Recently, it was shown that the class of ceramics comprising the lanthanide series rare-earth ...

  18. Decadal scale variations in ice flow along Whillans Ice Stream and its tributaries, West Antarctica

    E-Print Network [OSTI]

    Stearns, Leigh; Jezek, Kenneth C.; van der Veen, Cornelis J.

    2005-01-05

    We investigate velocity changes occurring along Whillans Ice Stream (WIS) by comparing velocities derived from repeat aerial photographs acquired in 1985–89 (average date of 1987) to interferometric satellite radar (InSAR) ...

  19. Decadal-scale variations in ice flow along Whillans Ice Stream and its tributaries, West Antarctica

    E-Print Network [OSTI]

    Stearns, Leigh; Jezek, K.A.; van der Veen, Cornelis J.

    2005-01-01

    We investigate velocity changes occurring along Whillans Ice Stream (WIS) by comparing velocities derived from repeat aerial photographs acquired in 1985–89 (average date of 1987) to interferometric satellite radar (InSAR) ...

  20. Focused synthetic aperture radar processing of ice-sounder data collected over the Greenland ice sheet

    E-Print Network [OSTI]

    Legarsky, J.; Gogineni, Sivaprasad; Akins, T. L.

    2001-10-01

    We developed a synthetic aperture radar (SAR) processing algorithm for airborne/spaceborne ice-sounding radar systems and applied it to data collected in Greenland. By using focused SAR (phase-corrected coherent averaging), we improved along...

  1. Ice-volcano interactions Eyjafjallajkull volcano, Iceland

    E-Print Network [OSTI]

    Berthier, Etienne

    Ice-volcano interactions in Eyjafjallajökull volcano, Iceland Eyjólfur Magnśsson1, Magnśs Tumi Sciences, University of Iceland, Reykjavķk, Iceland 2. Institute of Earth Sciences, University of Iceland, Reykjavķk, Iceland 3. Icelandic Coast Guard SPIRIT workshop 29&30 April 2010, Toulouse Picture by Eyjólfur

  2. Break-up of the Larsen B Ice Shelf Triggered by Chain-Reaction Drainage of Supraglacial Lakes

    E-Print Network [OSTI]

    Banwell, Alison F.; MacAyeal, Douglas R.; Sergienko, Olga V.

    2014-12-12

    ) that are less than the critical value (~0.6) 26 necessary for capsize (and thus ice-shelf disintegration through capsize-liberated energy) 27 [MacAyeal et al., 2003; 2011; Burton et al., 2012]. Second, although multiple studies 28 have documented both... addition to the ring-type surface fracture, a fracture produced by tensile stress at the ice 52 shelf base, immediately below the lake, would propagate upward in a radial, linear 53 pattern [Beltaos, 2002] (Figure 1a). 54 The hydrostatic rebound of a...

  3. Neutrino Data from IceCube and its Predecessor at the South Pole, the Antarctic Muon and Neutrino Detector Array (AMANDA)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Abbasi, R.

    IceCube is a neutrino observatory for astrophysics with parts buried below the surface of the ice at the South Pole and an air-shower detector array exposed above. The international group of sponsors, led by the National Science Foundation (NSF), that designed and implemented the experiment intends for IceCube to operate and provide data for 20 years. IceCube records the interactions produced by astrophysical neutrinos with energies above 100 GeV, observing the Cherenkov radiation from charged particles produced in neutrino interactions. Its goal is to discover the sources of high-energy cosmic rays. These sources may be active galactic nuclei (AGNs) or massive, collapsed stars where black holes have formed.[Taken from http://www.icecube.wisc.edu/] The data from IceCube's predecessor experiment and detector, AMANDA, IceCube’s predecessor detector and experiment is also available at this website. AMANDA pioneered neutrino detection in ice. Over a period of years in the 1990s, detecting “strings” were buried and activated and by 2000, AMANDA was successfully recording an average of 1,000 neutrino events per year. This site also makes available many images and video from the two experiments.

  4. Modeling the Fracture of Ice Sheets on Parallel Computers

    SciTech Connect (OSTI)

    Waisman, Haim; Tuminaro, Ray

    2013-10-10

    The objective of this project was to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. This objective was achieved by developing novel physics based models for ice, novel numerical tools to enable the modeling of the physics and by collaboration with the ice community experts. At the present time, ice fracture is not explicitly considered within ice sheet models due in part to large computational costs associated with the accurate modeling of this complex phenomena. However, fracture not only plays an extremely important role in regional behavior but also influences ice dynamics over much larger zones in ways that are currently not well understood. To this end, our research findings through this project offers significant advancement to the field and closes a large gap of knowledge in understanding and modeling the fracture of ice sheets in the polar regions. Thus, we believe that our objective has been achieved and our research accomplishments are significant. This is corroborated through a set of published papers, posters and presentations at technical conferences in the field. In particular significant progress has been made in the mechanics of ice, fracture of ice sheets and ice shelves in polar regions and sophisticated numerical methods that enable the solution of the physics in an efficient way.

  5. Distributed road assessment system

    DOE Patents [OSTI]

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

    A system that detects damage on or below the surface of a paved structure or pavement is provided. A distributed road assessment system includes road assessment pods and a road assessment server. Each road assessment pod includes a ground-penetrating radar antenna array and a detection system that detects road damage from the return signals as the vehicle on which the pod is mounted travels down a road. Each road assessment pod transmits to the road assessment server occurrence information describing each occurrence of road damage that is newly detected on a current scan of a road. The road assessment server maintains a road damage database of occurrence information describing the previously detected occurrences of road damage. After the road assessment server receives occurrence information for newly detected occurrences of road damage for a portion of a road, the road assessment server determines which newly detected occurrences correspond to which previously detected occurrences of road damage.

  6. Interactive Evolution of Multiple Water-Ice Reservoirs on Mars: Insights from Hydrogen Isotope Compositions

    E-Print Network [OSTI]

    Kurokawa, Hiroyuki; Sato, Masahiko

    2015-01-01

    Remote sensing data from orbiter missions have proposed that ground ice may currently exist on Mars, although the volume is still uncertain. Recent analyses of Martian meteorites have suggested that the water reservoirs have at least three distinct hydrogen isotope compositions (D/H ratios): primordial and high D/H ratios, which are approximately the same and six times that of ocean water on Earth, respectively, and a newly identified intermediate D/H ratio, which is approximately two to three times higher than that in ocean water on Earth. We calculate the evolution of the D/H ratios and the volumes of the water reservoirs on Mars by modeling the exchange of hydrogen isotopes between multiple water reservoirs and the atmospheric escape. The D/H ratio is slightly higher in the topmost thin surface-ice layer than that in the atmosphere because of isotopic fractionation by sublimation, whereas the water-ice reservoir just below the exchangeable topmost surface layer retains the intermediate D/H signature found ...

  7. A SEMI-AUTOMATIC APPROACH FOR ESTIMATING NEAR SURFACE INTERNAL LAYERS FROM SNOW RADAR IMAGERY

    E-Print Network [OSTI]

    A SEMI-AUTOMATIC APPROACH FOR ESTIMATING NEAR SURFACE INTERNAL LAYERS FROM SNOW RADAR IMAGERY changing polar ice sheets. Identifying and tracing near surface internal layers in snow radar echograms can developed an approach for semi-automatically esti- mating near surface internal layers in snow radar

  8. Atom addition reactions in interstellar ice analogues

    E-Print Network [OSTI]

    Linnartz, Harold; Fedoseev, Gleb

    2015-01-01

    This review paper summarizes the state-of-the-art in laboratory based interstellar ice chemistry. The focus is on atom addition reactions, illustrating how water, carbon dioxide and methanol can form in the solid state at astronomically relevant temperatures, and also the formation of more complex species such as hydroxylamine, an important prebiotic molecule, and glycolaldehyde, the smallest sugar, is discussed. These reactions are particularly relevant during the dark ages of star and planet formation, i.e., when the role of UV light is restricted. A quantitative characterization of such processes is only possible through dedicated laboratory studies, i.e., under full control of a large set of parameters such as temperature, atom-flux, and ice morphology. The resulting numbers, physical and chemical constants, e.g., barrier heights, reaction rates and branching ratios, provide information on the molecular processes at work and are needed as input for astrochemical models, in order to bridge the timescales t...

  9. Should we geoengineer larger ice caps?

    E-Print Network [OSTI]

    Haqq-Misra, Jacob

    2015-01-01

    The climate of Earth is susceptible to catastrophes that could threaten the longevity of human civilization. Geoengineering to reduce incoming solar radiation has been suggested as a way to mediate the warming effects of contemporary climate change, but a geoengineering program for thousands of years could also be used to enlarge the size of the polar ice caps and create a permanently cooler climate. Such a large ice cap state would make Earth less susceptible to climate threats and could allow human civilization to survive further into the future than otherwise possible. Intentionally extending Earth's glacial coverage will require uninterrupted commitment to this program for millenia but would ultimately reach a cooler equilibrium state where geoengineering is no longer needed. Whether or not this program is ever attempted, this concept illustrates the need to identify preference among potential climate states to ensure the long-term success of civilization.

  10. Surface Soil

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Surface Soil Surface Soil We compare local soil samples with samples collected from northern New Mexico locations that are beyond the range of potential influence from normal...

  11. Drilling deep in South Pole Ice

    E-Print Network [OSTI]

    Karg, Timo

    2014-01-01

    To detect the tiny flux of ultra-high energy neutrinos from active galactic nuclei or from interactions of highest energy cosmic rays with the microwave background photons needs target masses of the order of several hundred cubic kilometers. Clear Antarctic ice has been discussed as a favorable material for hybrid detection of optical, radio and acoustic signals from ultra-high energy neutrino interactions. To apply these technologies at the adequate scale hundreds of holes have to be drilled in the ice down to depths of about 2500 m to deploy the corresponding sensors. To do this on a reasonable time scale is impossible with presently available tools. Remote drilling and deployment schemes have to be developed to make such a detector design reality. After a short discussion of the status of modern hot water drilling we present here a design of an autonomous melting probe, tested 50 years ago to reach a depth of about 1000 m in Greenland ice. A scenario how to build such a probe today with modern technologies...

  12. Resonant vibrational energy transfer in ice Ih

    SciTech Connect (OSTI)

    Shi, L.; Li, F.; Skinner, J. L.

    2014-06-28

    Fascinating anisotropy decay experiments have recently been performed on H{sub 2}O ice Ih by Timmer and Bakker [R. L. A. Timmer, and H. J. Bakker, J. Phys. Chem. A 114, 4148 (2010)]. The very fast decay (on the order of 100 fs) is indicative of resonant energy transfer between OH stretches on different molecules. Isotope dilution experiments with deuterium show a dramatic dependence on the hydrogen mole fraction, which confirms the energy transfer picture. Timmer and Bakker have interpreted the experiments with a Förster incoherent hopping model, finding that energy transfer within the first solvation shell dominates the relaxation process. We have developed a microscopic theory of vibrational spectroscopy of water and ice, and herein we use this theory to calculate the anisotropy decay in ice as a function of hydrogen mole fraction. We obtain very good agreement with experiment. Interpretation of our results shows that four nearest-neighbor acceptors dominate the energy transfer, and that while the incoherent hopping picture is qualitatively correct, vibrational energy transport is partially coherent on the relevant timescale.

  13. ORIGINAL PAPER Sedimentary pellets as an ice-cover proxy in a High Arctic

    E-Print Network [OSTI]

    Vincent, Warwick F.

    ORIGINAL PAPER Sedimentary pellets as an ice-cover proxy in a High Arctic ice-covered lake Jessica-cover extent and dynamics on this perennially ice-covered, High Arctic lake. These pellets are interpreted growth. The pellets remain frozen in the ice until a summer or series of summers with reduced ice cover

  14. Glacial conditions that contribute to the regeneration of Fountain Glacier proglacial icing, Bylot Island, Canada

    E-Print Network [OSTI]

    Moorman, Brian

    Glacial conditions that contribute to the regeneration of Fountain Glacier proglacial icing, Bylot icings are one of the most common forms of extrusive ice found in the Canadian Arctic. However, the icing. Its regeneration depends on the availability of subglacial water and on the balance between ice

  15. Meltwater effects on flow of Greenland's ice sheet less severe...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Side effects of increasing meltwater less severe than feared Meltwater effects on flow of Greenland's ice sheet less severe for sea level rise than earlier feared, scientists...

  16. Sandia Energy - NASA Award for Marginal Ice Zone Observations...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NASA Award for Marginal Ice Zone Observations and Process Experiment (MIZOPEX) Home Climate Office of Science News News & Events Research & Capabilities Monitoring Analysis...

  17. optimal initial conditions for coupling ice sheet models to earth...

    Office of Scientific and Technical Information (OSTI)

    optimal initial conditions for coupling ice sheet models to earth system models Perego, Mauro Sandia National Laboratories Sandia National Laboratories; Price, Stephen F. Dr...

  18. Basal melt rates beneath Whillans Ice Stream, West Antarctica

    E-Print Network [OSTI]

    Beem, Lucas H.; Jezek, Ken C.; van der Veen, Cornelis J.

    2010-08-05

    and J.E. Mitchell. 1994. The role of the margins in the dynamics of an active ice stream. J. Glaciol., 40(136), 527–538. Engelhardt, H. 2004a. Ice temperature and high geothermal flux at Siple Dome, West Antarctica, from borehole measurements. J. Glaciol... ratio which varies laterally across the shear margin. Basal drag, ?b, basal velocity, U(b), basal temperature gradient, @T/@z(b), esti- mates of geothermal flux, G, plus knowledge of basal ice properties, density, ?, latent heat of fusion of ice, Li...

  19. IceCube: An Instrument for Neutrino Astronomy

    E-Print Network [OSTI]

    Halzen, F.

    2010-01-01

    detectors: searching for radio waves or for acoustic pulsespredictions 93 . In cold ice, radio-wave attenuation lengthperfect reflector for radio waves. With this reflection,

  20. Covered Product Category: Air-Cooled Ice Machines

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance for air-cooled ice machines, which are covered by the ENERGY STAR program.

  1. Acceleration of Greenland ice mass loss in spring 2004

    E-Print Network [OSTI]

    Velicogna, I; Velicogna, I; Wahr, J

    2006-01-01

    10.1029/ 2005GL025550 (2006). Peltier, W. R. Global glacial2004). Tushingham, A. M. & Peltier, W. R. ICE-3G: A new

  2. IceCube: A Cubic Kilometer Radiation Detector

    E-Print Network [OSTI]

    Klein, S.; IceCube Collaboration

    2008-01-01

    Cubic Kilometer Radiation Detector The IceCube CollaborationA Cubic Kilometer Radiation Detector Spencer R. Klein, forlarge detector is to search for optical Cherenkov radiation

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

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston

    2013-07-01

    Arctic sea ice is an important component of the global climate system, reflecting a significant amount of solar radiation, insulating the ocean from the atmosphere and influencing ocean circulation by modifying the salinity of the upper ocean. The thickness and extent of Arctic sea ice have shown a significant decline in recent decades with implications for global climate as well as regional geopolitics. Increasing interest in exploration as well as climate feedback effects make predictive mathematical modeling of sea ice a task of tremendous practical import. Satellite data obtained over the last few decades have provided a wealth of information on sea ice motion and deformation. The data clearly show that ice deformation is focused along narrow linear features and this type of deformation is not well-represented in existing models. To improve sea ice dynamics we have incorporated an anisotropic rheology into the Los Alamos National Laboratory global sea ice model, CICE. Sensitivity analyses were performed using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) to determine the impact of material parameters on sea ice response functions. Two material strength parameters that exhibited the most significant impact on responses were further analyzed to evaluate their influence on quantitative comparisons between model output and data. The sensitivity analysis along with ten year model runs indicate that while the anisotropic rheology provides some benefit in velocity predictions, additional improvements are required to make this material model a viable alternative for global sea ice simulations.

  4. optimal initial conditions for coupling ice sheet models to earth...

    Office of Scientific and Technical Information (OSTI)

    for coupling ice sheet models to earth system models Authors: Perego, Mauro 1 ; Price, Stephen F. Dr 2 ; Stadler, Georg 3 + Show Author Affiliations Sandia National...

  5. A METHOD FOR AIRCRAFT ICING DIAGNOSIS IN PRECIPITATION

    E-Print Network [OSTI]

    Fabry, Frederic

    A METHOD FOR AIRCRAFT ICING DIAGNOSIS IN PRECIPITATION Franēois A. Turcotte Department precipitation event and its microphysics was simulated using a high resolution three-dimensional kinematic cloud

  6. Radiokrypton Dating Identifies Ancient Antarctic Ice | U.S. DOE...

    Office of Science (SC) Website

    Radiokrypton Dating Identifies Ancient Antarctic Ice Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science...

  7. The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Solomon, A.; Feingold, G.; Shupe, M. D.

    2015-09-25

    This study investigates the maintenance of cloud ice production in Arctic mixed-phase stratocumulus in large eddy simulations that include a prognostic ice nuclei (IN) formulation and a diurnal cycle. Balances derived from a mixed-layer model and phase analyses are used to provide insight into buffering mechanisms that maintain ice in these cloud systems. We find that, for the case under investigation, IN recycling through subcloud sublimation considerably prolongs ice production over a multi-day integration. This effective source of IN to the cloud dominates over mixing sources from above or below the cloud-driven mixed layer. Competing feedbacks between dynamical mixing andmore »recycling are found to slow the rate of ice lost from the mixed layer when a diurnal cycle is simulated. The results of this study have important implications for maintaining phase partitioning of cloud ice and liquid that determine the radiative forcing of Arctic mixed-phase clouds.« less

  8. The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Solomon, A.; Feingold, G.; Shupe, M. D.

    2015-04-21

    This study investigates the maintenance of cloud ice production in Arctic mixed phase stratocumulus in large-eddy simulations that include a prognostic ice nuclei (IN) formulation and a diurnal cycle. Balances derived from a mixed-layer model and phase analyses are used to provide insight into buffering mechanisms that maintain ice in these cloud systems. We find that for the case under investigation, IN recycling through subcloud sublimation considerably prolongs ice production over a multi-day integration. This effective source of IN to the cloud dominates over mixing sources from above or below the cloud-driven mixed layer. Competing feedbacks between dynamical mixing andmore »recycling are found to slow the rate of ice lost from the mixed layer when a diurnal cycle is simulated. The results of this study have important implications for maintaining phase partitioning of cloud ice and liquid that determine the radiative forcing of Arctic mixed-phase clouds.« less

  9. Effective stress profiles and seepage flows beneath glaciers and ice sheets

    E-Print Network [OSTI]

    Rempel, Alan W.

    stress for ice infiltration Qb Heat flux into glacier base Qf Heat produced by dissipation Qg Geothermal Vertical coordinate Exponent in permeability relation #12; Exponent in ice-saturation relation il Ice

  10. Analytical determination of performance degradation on a helicopter main rotor due to ice accretion 

    E-Print Network [OSTI]

    Camba, Javier

    1986-01-01

    artificial icing tests Canada's National Research Council (NRC) Icing Tunnel and simulated ice tests the OSU Transonic Airfoil Facility using a irfo'1 1 s inbicitave of current rotorcraft technol ogy. The final correlations are: Lift Increment Prediction...

  11. Modeling the evolution of polar ice sheets: Ice sheet system model workshop; Bergen, Norway, 2-4 June 2014

    E-Print Network [OSTI]

    Larour, E; Schlegel, N; Morlighem, M

    2014-01-01

    Model Workshop; Bergen, Norway, 2?4 June 2014 The Ice SheetUniversity of Bergen in Norway, in June 2014. This is the

  12. Distributions of H2O and CO2 ices on Ariel, Umbriel, Titania, and Oberon from IRTF/SpeX observations

    E-Print Network [OSTI]

    W. M. Grundy; L. A. Young; J. R. Spencer; R. E. Johnson; E. F. Young; M. W. Buie

    2007-04-12

    We present 0.8 to 2.4 micron spectral observations of uranian satellites, obtained at IRTF/SpeX on 17 nights during 2001-2005. The spectra reveal for the first time the presence of CO2 ice on the surfaces of Umbriel and Titania, by means of 3 narrow absorption bands near 2 microns. Several additional, weaker CO2 ice absorptions have also been detected. No CO2 absorption is seen in Oberon spectra, and the strengths of the CO2 ice bands decline with planetocentric distance from Ariel through Titania. We use the CO2 absorptions to map the longitudinal distribution of CO2 ice on Ariel, Umbriel, and Titania, showing that it is most abundant on their trailing hemispheres. We also examine H2O ice absorptions in the spectra, finding deeper H2O bands on the leading hemispheres of Ariel, Umbriel, and Titania, but the opposite pattern on Oberon. Potential mechanisms to produce the observed longitudinal and planetocentric distributions of the two ices are considered.

  13. Final scientific report for DOE award title: Improving the Representation of Ice Sedimentation Rates in Global Climate Models

    SciTech Connect (OSTI)

    Mitchell, David L.

    2013-09-05

    It is well known that cirrus clouds play a major role in regulating the earth’s climate, but the details of how this works are just beginning to be understood. This project targeted the main property of cirrus clouds that influence climate processes; the ice fall speed. That is, this project improves the representation of the mass-weighted ice particle fall velocity, Vm, in climate models, used to predict future climate on global and regional scales. Prior to 2007, the dominant sizes of ice particles in cirrus clouds were poorly understood, making it virtually impossible to predict how cirrus clouds interact with sunlight and thermal radiation. Due to several studies investigating the performance of optical probes used to measure the ice particle size distribution (PSD), as well as the remote sensing results from our last ARM project, it is now well established that the anomalously high concentrations of small ice crystals often reported prior to 2007 were measurement artifacts. Advances in the design and data processing of optical probes have greatly reduced these ice artifacts that resulted from the shattering of ice particles on the probe tips and/or inlet tube, and PSD measurements from one of these improved probes (the 2-dimensional Stereo or 2D-S probe) are utilized in this project to parameterize Vm for climate models. Our original plan in the proposal was to parameterize the ice PSD (in terms of temperature and ice water content) and ice particle mass and projected area (in terms of mass- and area-dimensional power laws or m-D/A-D expressions) since these are the microphysical properties that determine Vm, and then proceed to calculate Vm from these parameterized properties. But the 2D-S probe directly measures ice particle projected area and indirectly estimates ice particle mass for each size bin. It soon became apparent that the original plan would introduce more uncertainty in the Vm calculations than simply using the 2D-S measurements to directly calculate Vm. By calculating Vm directly from the measured PSD, ice particle projected area and estimated mass, more accurate estimates of Vm are obtained. These Vm values were then parameterized for climate models by relating them to (1) sampling temperature and ice water content (IWC) and (2) the effective diameter (De) of the ice PSD. Parameterization (1) is appropriate for climate models having single-moment microphysical schemes whereas (2) is appropriate for double-moment microphysical schemes and yields more accurate Vm estimates. These parameterizations were developed for tropical cirrus clouds, Arctic cirrus, mid-latitude synoptic cirrus and mid-latitude anvil cirrus clouds based on field campaigns in these regions. An important but unexpected result of this research was the discovery of microphysical evidence indicating the mechanisms by which ice crystals are produced in cirrus clouds. This evidence, derived from PSD measurements, indicates that homogeneous freezing ice nucleation dominates in mid-latitude synoptic cirrus clouds, whereas heterogeneous ice nucleation processes dominate in mid-latitude anvil cirrus. Based on these findings, De was parameterized in terms of temperature (T) for conditions dominated by (1) homo- and (2) heterogeneous ice nucleation. From this, an experiment was designed for global climate models (GCMs). The net radiative forcing from cirrus clouds may be affected by the means ice is produced (homo- or heterogeneously), and this net forcing contributes to climate sensitivity (i.e. the change in mean global surface temperature resulting from a doubling of CO2). The objective of this GCM experiment was to determine how a change in ice nucleation mode affects the predicted global radiation balance. In the first simulation (Run 1), the

  14. SIZE AND TEMPERATURE DEPENDENCE IN THE FAR-IR SPECTRA OF WATER ICE PARTICLES

    SciTech Connect (OSTI)

    Medcraft, Chris; McNaughton, Don; Thompson, Chris D. [School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800 (Australia); Appadoo, Dominique [Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168 (Australia); Bauerecker, Sigurd [Institut fuer Physikalische und Theoretische Chemie, Technische Universitaet Braunschweig, Hans-Sommer-Strasse 10, D-38106 Braunschweig (Germany); Robertson, Evan G., E-mail: E.Robertson@latrobe.edu.au [Department of Chemistry and La Trobe Institute of Molecular Sciences, La Trobe University, Bundoora, Victoria 3086 (Australia)

    2012-10-10

    Spectra of water-ice aerosol particles have been measured in the far-IR region using synchrotron radiation. The particles in the nanoscale size regime of 1-100 nm were formed by rapid collisional cooling at temperatures ranging from 4 to 190 K. The spectra show the characteristic bands centered near 44 {mu}m (230 cm{sup -1}) and 62 {mu}m (160 cm{sup -1}) associated with the intermolecular lattice modes of crystalline ice at all temperatures, in contrast to previous studies of thin films formed by vapor deposition where amorphous ice is generated below 140 K. The bands shift to higher wavenumber values as the temperature is reduced, consistent with the trend seen in earlier studies, but in our experiments the actual peak positions in the aerosol particle spectra are consistently higher by ca. 4 cm{sup -1}. This finding has implications for the potential use of these spectral features as a temperature probe. The particle sizes are small enough for their spectra to be free of scattering effects, and therefore provide a means to assess imaginary refractive index values obtained through Kramers-Kronig analyses of thin film spectra.

  15. Technology Assessment TECHNOLOGY ASSESSMENT

    E-Print Network [OSTI]

    Rock, Chris

    Technology Assessment 10/14/2004 1 TECHNOLOGY ASSESSMENT STRATEGIC PLAN MISSION STATEMENT Support the Mission of Texas Tech University and the TTU Information Technology Division by providing timely and relevant information and assistance in current and emerging technologies and their practical applications

  16. H2 ICE Combustion | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Lowļ‚— WeUpdate JonGuided 8/12/15GuyH2 ICE Combustion

  17. Ice in Arctic Mixed-phase Stratocumulus

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHighHussein KhalilResearch88 Sign In AboutWorkshop:Ice Nuclei

  18. Southern Great Plains Ice Nuclei Characterization Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation ofAlbuquerque|Sensitive Species3performedValleySouthern Great Plains Ice Nuclei

  19. The Hierarchic Theory of Liquids and Solids. Computerized applications for ice, water, and Biosystems

    E-Print Network [OSTI]

    Alex Kaivarainen

    2008-06-05

    This is a new book of quantum Hierarchic theory of condensed matter, general for liquids and solids, developed by this author during 20 years and its numerous applications. Computer program, based on new theory, was used for simulations of big number of physical properties of water and ice. Condensed matter is considered as a superposition of 3D standing waves (collective excitations) of different nature: thermal de Broglie waves, IR photons and thermal phonons. New theories of total internal energy, heat capacity, surface tension, vapor pressure, thermal conductivity, viscosity and self-diffusion are described. Hierarchic theory of osmotic pressure, based on new state equation, new theories of light refraction, Brillouin light scattering and Mossbauer effect are presented also and compared with available experimental data for water and ice. The agreement between theoretical and available experimental results for water and ice is very good. New approach to the turbulence, superfluidity and superconductivity is developed. A lot of applications of new theory to biophysics, including model of Quantum of Mind are described. New optoacoustic device: Comprehensive Analyzer of Matter Properties (CAMP) is proposed.

  20. Total reflection infrared spectroscopy of water-ice and frozen aqueous NaCl solutions

    SciTech Connect (OSTI)

    Walker, Rachel L.; Searles, Keith; Willard, Jesse A.; Michelsen, Rebecca R. H., E-mail: RMichelsen@rmc.edu [Department of Chemistry, Randolph-Macon College, P.O. Box 5005, Ashland, Virginia 23005 (United States)] [Department of Chemistry, Randolph-Macon College, P.O. Box 5005, Ashland, Virginia 23005 (United States)

    2013-12-28

    Liquid-like and liquid water at and near the surface of water-ice and frozen aqueous sodium chloride films were observed using attenuated total reflection infrared spectroscopy (ATR-IR). The concentration of NaCl ranged from 0.0001 to 0.01 M and the temperature varied from the melting point of water down to 256 K. The amount of liquid brine at the interface of the frozen films with the germanium ATR crystal increased with salt concentration and temperature. Experimental spectra are compared to reflection spectra calculated for a simplified morphology of a uniform liquid layer between the germanium crystal and the frozen film. This morphology allows for the amount of liquid observed in an experimental spectrum to be converted to the thickness of a homogenous layer with an equivalent amount of liquid. These equivalent thickness ranges from a nanometer for water-ice at 260 K to 170 nm for 0.01 M NaCl close to the melting point. The amounts of brine observed are over an order of magnitude less than the total liquid predicted by equilibrium thermodynamic models, implying that the vast majority of the liquid fraction of frozen solutions may be found in internal inclusions, grain boundaries, and the like. Thus, the amount of liquid and the solutes dissolved in them that are available to react with atmospheric gases on the surfaces of snow and ice are not well described by thermodynamic equilibrium models which assume the liquid phase is located entirely at the surface.

  1. The effect of ice crystal surface roughness on the retrieval of ice cloud microphysical and optical properties 

    E-Print Network [OSTI]

    Xie, Yu

    2007-09-17

    ?Āµm). The discrete ordinates radiative transfer (DISORT) model is used to compute the radiances for a set of optical thicknesses, particle effective sizes, viewing and illumination angles, and cloud temperatures. A parameterization of cloud bi...

  2. THE CONTRIBUTION OF GREENLAND ICE SHEET MELTING TO

    E-Print Network [OSTI]

    THE CONTRIBUTION OF GREENLAND ICE SHEET MELTING TO GLOBAL SEA-LEVEL CHANGE Conor Mc, orbital cycles, glacial isostatic adjustment and tectonics. Each of these elements contribute different it to be directly observed. This project examined the contribution to sea-level change due to melting of ice from

  3. IceCube Project Monthly Report November 2007

    E-Print Network [OSTI]

    Saffman, Mark

    the current budgets or the budgets modified by the cost performance index. Change Log - IceCube Total Project IceCube array with a detector uptime of 97%, above the internal monthly goal of 95%. #12;Cost design, development, procured materials, and the construction of the infrastructure that supports

  4. Integrated navigation for AUV operations under ice shelves

    E-Print Network [OSTI]

    Griffiths, Gwyn

    2000 Heat Wipes Out Giant Antarctic Ice Shelf The Independent, 31 January 2000 Catastrophic Melting VI Pine Island Bay #12;The (virtual) mission ... #12;The first mission- March 2003: Pine Island Bay NASA 30 km Sea Ice Pine Island Glacier Open Water 9 February 2003 #12;The Pine Island Bay Glacier

  5. ENERGY BASED ICE COLLISION FORCES Claude Daley1

    E-Print Network [OSTI]

    Daley, Claude

    1 ENERGY BASED ICE COLLISION FORCES Claude Daley1 1 Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 3X5 ABSTRACT Ice collision forces can be determined by energy considerations. A variety of interaction geometry cases are considered. The indentation energy functions for eight different

  6. ENERGY BASED ICE COLLISION FORCES Claude Daley1

    E-Print Network [OSTI]

    Daley, Claude

    ENERGY BASED ICE COLLISION FORCES Claude Daley1 1 Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 3X5 ABSTRACT Ice collision forces can be determined by energy considerations. A variety of interaction geometry cases are considered. The indentation energy functions for eight different

  7. ORIGINAL ARTICLE Diatom assemblages promote ice formation in large

    E-Print Network [OSTI]

    Lee Jr., Richard E.

    (Oyserman et al., 2012; Twiss et al., 2012). Conducted during times of expansive ice cover, these surveys (Saxton et al., 2012; Twiss et al., 2012). The physical processes involved in the develop- ment of diatom demonstrated the presence of viable diatoms in meltwater from lake ice (Twiss et al., 2012), consistent

  8. Passive ice freezing-releasing heat pipe. [Patent application

    DOE Patents [OSTI]

    Gorski, A.J.; Schertz, W.W.

    1980-09-29

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  9. Ice Storm Damage Greater Along the Terrestrial-Aquatic Interface

    E-Print Network [OSTI]

    Kraft, Clifford E.

    Ice Storm Damage Greater Along the Terrestrial-Aquatic Interface in Forested Landscapes Andrew A- tems. In 1998, a severe ice storm damaged over ten million hectares of forest across northern New York investigated the spatial arrangement of forest damage at the terrestrial-aquatic interface, an ecological edge

  10. Fluid Migration During Ice/Rock Planetesimal Differentiation 

    E-Print Network [OSTI]

    Raney, Robert 1987-

    2012-12-12

    fast melt water can segregate from the core of an ice-rich planetesimal. To answer this question we treat the core as two phase flow problem: a compacting viscous “solid” (ice/rock mixture) and a segregating liquid (melt water). The model developed...

  11. Third international workshop on ice storage for cooling applications

    SciTech Connect (OSTI)

    Gorski, A.J.

    1986-04-01

    The third international workshop on ice storage for cooling applications which was informal and interactive in nature, was open to persons interested in all ice-growing technologies and in ice storage, both seasonal and diurnal. Presentations were made on some 20 topics, ranging from freezers in Alaska to ice cooling of commercial jet aircraft. Workshop tours included visits to ice-storage systems at Commonwealth Edison's facilities in Bolingbrook and Des Plaines Valley, the A.C. Neilsen builing in Northbrook, and the new State of Illinois Center in Chicago. The first workshop in the present series considered the future of ice storage and predicted applications in the agricultural sector, desalinization, and commercial ice production. Progress has been rapid in the intervening two years, and an important topic at the third workshop was the possible use of ''warm ices'' (clathrate hydrates) for energy storage. This report consists primarily of abstracts of presentations made at the workshop. Persons wishing to obtain further information about particular papers should contact the speakers directly; speakers' addresses and telephone numbers are listed in this report.

  12. Has the ice man arrived? Tact on the Internet

    E-Print Network [OSTI]

    Hearst, Marti

    Has the ice man arrived? Tact on the Internet Jonathan Grudin, UC Irvine and Microsoft Research resides in this extremely efficient spread of information. It is efficient, but it is not dis- crete. Eugene O'Neill's play The Ice Man Cometh outlines a series of calamities that occur when his characters

  13. UV Irradiation of Polycyclic Aromatic Hydrocarbons in Ices

    E-Print Network [OSTI]

    UV Irradiation of Polycyclic Aromatic Hydrocarbons in Ices: Production of Alcohols, Quinones. Clemett,3 Richard N. Zare3 Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultra, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account

  14. Molecular multipole moments of water molecules in ice Ih

    SciTech Connect (OSTI)

    Batista, E.R. [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States)] [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States); [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Xantheas, S.S. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K1-96, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K1-96, Richland, Washington 99352 (United States); Jonsson, H. [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)] [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

    1998-09-01

    We have used an induction model including dipole, dipole{endash}quadrupole, quadrupole{endash}quadrupole polarizability and first hyperpolarizability as well as fixed octopole and hexadecapole moments to study the electric field in ice. The self-consistent induction calculations gave an average total dipole moment of 3.09 D, a 67{percent} increase over the dipole moment of an isolated water molecule. A previous, more approximate induction model study by Coulson and Eisenberg [Proc. R. Soc. Lond. A {bold 291}, 445 (1966)] suggested a significantly smaller average value of 2.6 D. This value has been used extensively in recent years as a reference point in the development of various polarizable interaction potentials for water as well as for assessment of the convergence of water cluster properties to those of bulk. The reason for this difference is not due to approximations made in the computational scheme of Coulson and Eisenberg but rather due to the use of less accurate values for the molecular multipoles in these earlier calculations. {copyright} {ital 1998 American Institute of Physics.}

  15. Spatial mapping of ices in the Oph-F core: A direct measurement of CO depletion and the formation of CO2

    E-Print Network [OSTI]

    K. M. Pontoppidan

    2006-05-22

    Aims: Ices in dense star-forming cores contain the bulk of volatile molecules apart from H2 and thus represent a large fraction of dark cloud chemistry budget.To directly constrain the freeze-out profile of CO, the formation route of CO2 and the carrier of the 6.8 micron band, the spatial distribution of the CO/CO2 ice system and the 6.8 micron band carrier are measured in a nearby dense core. Methods: VLT-ISAAC, ISOCAM-CVF and Spitzer-IRS archival mid-infrared (3-20 micron) spectroscopy of young stellar objects is used to construct a map of the abundances of CO and CO2 ices in the Oph-F star-forming core, probing core radii from 2 10^3 to 14 10^3 AU or densities from 5 10^4 to 5 10^5 cm^-3 with a resolution of ~ 3000 AU. Results: The line-of-sight averaged abundances relative to water ice of both CO and CO2 ices increase monotonously with decreasing distance to the core center. The map traces the shape of the CO abundance profile between freeze-out ratios of 5-60% and shows that the CO2 ice abundance increases by a factor of 2 as the CO freezes out. It is suggested that this indicates a formation route of CO2 on a CO ice surface to produce a CO2 component dilute in CO ice, in addition to a fraction of the CO2 formed at lower densities along with the water ice mantle. It is predicted that the CO2 bending mode band profile should reflect a high CO:CO2 number ratio in the densest parts of dark clouds. In contrast to CO and CO2, the abundance of the carrier of the 6.8 micron band remains relatively constant throughout the core. A simple freeze-out model of the CO abundance profile is used to estimate the binding energy of CO on a CO ice surface to 814+/-30 K.

  16. 2009 Community Sequencing Program: Life Under Ice

    ScienceCinema (OSTI)

    Victo Kunin, PhD (Project co-PI); Microbial Ecology Group, DOE JGI; Phil Hugenholtz, PhD (CSP Project PI); Microbial Ecology Program Head, DOE JGI

    2010-09-01

    A JGI Multimedia Presentation: Buried deep beneath the surface of Antarctica is a fresh water lake, Lake Vostok.

  17. Methods and apparatus for rotor blade ice detection

    DOE Patents [OSTI]

    LeMieux, David Lawrence

    2006-08-08

    A method for detecting ice on a wind turbine having a rotor and one or more rotor blades each having blade roots includes monitoring meteorological conditions relating to icing conditions and monitoring one or more physical characteristics of the wind turbine in operation that vary in accordance with at least one of the mass of the one or more rotor blades or a mass imbalance between the rotor blades. The method also includes using the one or more monitored physical characteristics to determine whether a blade mass anomaly exists, determining whether the monitored meteorological conditions are consistent with blade icing; and signaling an icing-related blade mass anomaly when a blade mass anomaly is determined to exist and the monitored meteorological conditions are determined to be consistent with icing.

  18. The future of water, ice, snow underThe future of water, ice, snow under global warmingglobal warming

    E-Print Network [OSTI]

    Hurricane Katrina, the Kerry--Gingrich debate over globalGingrich debate over global warming, the local and regional warming.effects of global warming. Climate extends beyond temperature and rainfall, toClimate extendsThe future of water, ice, snow underThe future of water, ice, snow under global warmingglobal

  19. Observations of ice thickness and frazil ice in the St. Lawrence Island polynya from satellite imagery, upward looking sonar, and

    E-Print Network [OSTI]

    Washington at Seattle, University of

    with meteorological observations and a heat flux model. South of the island, we compare the ULS and thermalObservations of ice thickness and frazil ice in the St. Lawrence Island polynya from satellite, this paper examines the behavior of the Bering Sea St. Lawrence Island polynya using a combination

  20. Results from IceCube Mumbai, 11/12/12 Tom Gaisser for the IceCube Collab. 1

    E-Print Network [OSTI]

    Gaisser, Thomas K.

    Results from IceCube Mumbai, 11/12/12 Tom Gaisser for the IceCube Collab. 1 #12;2 39 Ins>tu>ons ~220 collaborators Mumbai, 11/12/12 Tom Gaisser-10 20 79 2010-11 7 86 Mumbai, 11/12/12 Tom Gaisser

  1. CO2 diffusion in polar ice: observations from naturally formed CO2 spikes in the Siple Dome (Antarctica) ice core

    E-Print Network [OSTI]

    Raggio Parkway, Reno, Nevada 89512-1095, USA ABSTRACT. One common assumption in interpreting ice-core CO2 records is that diffusion in the ice does not affect the concentration profile. However, this assumption/Ar and Kr/Ar), electrical conductivity and Ca2+ ion concentrations to show that substantial CO2 diffusion

  2. Sea ice in the paleoclimate system: the challenge of reconstructing sea ice from proxies e an introduction

    E-Print Network [OSTI]

    University, Denmark e Department of Earth Sciences, University of Cambridge, UK f British Antarctic Survey. In the climate system, sea ice cover generally acts as an amplifier: it in- fluences the energy budget). Under perennial sea ice there is generally little primary production apart from under special conditions

  3. Integrating laboratory and field data to quantify the immersion freezing ice nucleation activity of mineral dust particles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    DeMott, P. J.; Prenni, A. J.; McMeeking, G. R.; Sullivan, R. C.; Petters, M. D.; Tobo, Y.; Niemand, M.; Möhler, O.; Snider, J. R.; Wang, Z.; et al

    2014-06-27

    Data from both laboratory studies and atmospheric measurements are used to develop a simple parametric description for the immersion freezing activity of natural mineral dust particles. Measurements made with the Colorado State University (CSU) continuous flow diffusion chamber (CFDC) when processing mineral dust aerosols at a nominal 105% relative humidity with respect to water (RHw) are taken to approximate the immersion freezing nucleation activity of particles. Ice active frozen fractions vs. temperature for dusts representative of Saharan and Asian desert sources were consistent with similar measurements in atmospheric dust plumes for a limited set of comparisons available. The parameterization developedmore »follows the form of one suggested previously for atmospheric particles of non-specific composition in quantifying ice nucleating particle concentrations as functions of temperature and the total number concentration of particles larger than 0.5 ?m diameter. Such an approach does not explicitly account for surface area and time dependencies for ice nucleation, but sufficiently encapsulates the activation properties for potential use in regional and global modeling simulations, and possible application in developing remote sensing retrievals for ice nucleating particles. A correction factor is introduced to account for the apparent underestimate (by approximately 3, on average) of the immersion freezing fraction of mineral dust particles for CSU CFDC data processed at an RHw of 105% vs. maximum fractions active at higher RHw. Instrumental factors that affect activation behavior vs. RHw in CFDC instruments remain to be fully explored in future studies. Nevertheless, the use of this correction factor is supported by comparison to ice activation data obtained for the same aerosols from Aerosol Interactions and Dynamics of the Atmosphere (AIDA) expansion chamber cloud parcel experiments. Further comparison of the new parameterization to the immersion freezing surface active site density parameterization for mineral dust particles, developed separately from AIDA experimental data alone, shows excellent agreement for data collected in a descent through a Saharan aerosol layer. These studies support the utility of laboratory measurements to obtain atmospherically-relevant data on the ice nucleation properties of dust and other particle types, and suggest the suitability of considering all mineral dust as a single type of ice nucleating particle as a useful first order approximation in numerical modeling investigations.« less

  4. Integrating laboratory and field data to quantify the immersion freezing ice nucleation activity of mineral dust particles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    DeMott, P. J.; Prenni, A. J.; McMeeking, G. R.; Sullivan, R. C.; Petters, M. D.; Tobo, Y.; Niemand, M.; Möhler, O.; Snider, J. R.; Wang, Z.; et al

    2015-01-13

    Data from both laboratory studies and atmospheric measurements are used to develop an empirical parameterization for the immersion freezing activity of natural mineral dust particles. Measurements made with the Colorado State University (CSU) continuous flow diffusion chamber (CFDC) when processing mineral dust aerosols at a nominal 105% relative humidity with respect to water (RHw) are taken as a measure of the immersion freezing nucleation activity of particles. Ice active frozen fractions vs. temperature for dusts representative of Saharan and Asian desert sources were consistent with similar measurements in atmospheric dust plumes for a limited set of comparisons available. The parameterizationmore »developed follows the form of one suggested previously for atmospheric particles of non-specific composition in quantifying ice nucleating particle concentrations as functions of temperature and the total number concentration of particles larger than 0.5 ?m diameter. Such an approach does not explicitly account for surface area and time dependencies for ice nucleation, but sufficiently encapsulates the activation properties for potential use in regional and global modeling simulations, and possible application in developing remote sensing retrievals for ice nucleating particles. A calibration factor is introduced to account for the apparent underestimate (by approximately 3, on average) of the immersion freezing fraction of mineral dust particles for CSU CFDC data processed at an RHw of 105% vs. maximum fractions active at higher RHw. Instrumental factors that affect activation behavior vs. RHw in CFDC instruments remain to be fully explored in future studies. Nevertheless, the use of this calibration factor is supported by comparison to ice activation data obtained for the same aerosols from Aerosol Interactions and Dynamics of the Atmosphere (AIDA) expansion chamber cloud parcel experiments. Further comparison of the new parameterization, including calibration correction, to predictions of the immersion freezing surface active site density parameterization for mineral dust particles, developed separately from AIDA experimental data alone, shows excellent agreement for data collected in a descent through a Saharan aerosol layer. These studies support the utility of laboratory measurements to obtain atmospherically relevant data on the ice nucleation properties of dust and other particle types, and suggest the suitability of considering all mineral dust as a single type of ice nucleating particle as a useful first-order approximation in numerical modeling investigations.« less

  5. Quantitative estimates of velocity sensitivity to surface melt variations at a large Greenland outlet glacier

    E-Print Network [OSTI]

    Anderson, M. L.; Nettles, M.; Larsen, T. B.; Hamilton, Gordon S.; Stearns, Leigh

    2011-09-01

    , marine-terminating outlet glaciers that drain the ice sheet. We use a validated model of meltwater input and GPS-derived surface velocities to quantify the sensitivity of glacier flow speed to changes in surface melt at Helheim Glacier during two summer...

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

    DOE Patents [OSTI]

    Weng, Kuo-Lianq (Taichung, TW); Weng, Kuo-Liang (Taichung, TW)

    1998-01-01

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

  7. Gas ageice age differences and the chronology of the Vostok ice core, M. L. Bender,1

    E-Print Network [OSTI]

    Chappellaz, Jérōme

    Gas age­ice age differences and the chronology of the Vostok ice core, 0­100 ka M. L. Bender,1 G. [1] Gas is trapped in polar ice at depths of $50­120 m and is therefore significantly younger than cores (Vostok, Dome Fuji, and Dome C). We recorrelate the gas records of Vostok and Greenland Ice Sheet

  8. Fast numerical method for growth and retreat of subsurface ice on Mars Norbert Schorghofer

    E-Print Network [OSTI]

    Schörghofer, Norbert

    ice, retreat of pore ice, retreat of an ice sheet, and retreat of pore ice due to geothermal heating) Dtexpl: vertical spatial resolution and D the diffusion coef- ficient. The vertical grid spacing needs to be finer than the diurnal skin depth of the temperature cycle. The diurnal

  9. Modelling the reorientation of sea-ice faults as the wind changes direction

    E-Print Network [OSTI]

    Feltham, Daniel

    Modelling the reorientation of sea-ice faults as the wind changes direction Alexander V. WILCHINSKY-1290, USA ABSTRACT. A discrete-element model of sea ice is used to study how a 908 change in wind direction alters the pattern of faults generated through mechanical failure of the ice. The sea-ice domain is 400

  10. Development, sensitivity analysis, and uncertainty quantification of high-fidelity arctic sea ice models.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana S.

    2010-09-01

    Arctic sea ice is an important component of the global climate system and due to feedback effects the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice to model physical parameters. A new sea ice model that has the potential to improve sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of the Los Alamos National Laboratory CICE code and the MPM sea ice code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness, and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  11. A Model of Viscoelastic Ice-Shelf Flexure

    E-Print Network [OSTI]

    MacAyeal, Douglas R.; Sergienko, Olga V.; Banwell, Alison F.

    2015-07-15

    -shelf and ice-stream motion and stress fields. Examples of these phenomena27 include tide-driven grounding-line flexure and migration [e.g., Sayag and Worster, 2013, Tsai and28 Gudmundsson, 2015], tidally pulsed grounding line ice velocity variations [e... -shelf flexure that is applicable to circumstances where the114 ratio of vertical to horizontal length scales, H and L, respectively, is small (H/L ? 1), and where115 the vertical displacement (assumed constant through the depth of the ice shelf) due to flexure...

  12. Microscopic simulation of methanol and formaldehyde ice formation in cold dense cores

    E-Print Network [OSTI]

    Cuppen, H M; Herbst, E; Tielens, A G G M

    2009-01-01

    Methanol and its precursor formaldehyde are among the most studied organic molecules in the interstellar medium and are abundant in the gaseous and solid phases. We recently developed a model to simulate CO hydrogenation via H atoms on interstellar ice surfaces, the most important interstellar route to H2CO and CH3OH, under laboratory conditions. We extend this model to simulate the formation of both organic species under interstellar conditions, including freeze-out from the gas and hydrogenation on surfaces. Our aim is to compare calculated abundance ratios with observed values and with the results of prior models. Simulations under different conditions, including density and temperature, have been performed. We find that H2CO and CH3OH form efficiently in cold dense cores or the cold outer envelopes of young stellar objects. The grain mantle is found to have a layered structure with CH3OH on top. The species CO and H2CO are found to exist predominantly in the lower layers of ice mantles where they are not ...

  13. On the detection of crevasses in glacial ice with synthetic-aperture radar.

    SciTech Connect (OSTI)

    Brock, Billy C.

    2010-02-01

    The intent of this study is to provide an analysis of the scattering from a crevasse in Antarctic ice, utilizing a physics-based model for the scattering process. Of primary interest is a crevasse covered with a snow bridge, which makes the crevasse undetectable in visible-light images. It is demonstrated that a crevasse covered with a snow bridge can be visible in synthetic-aperture-radar (SAR) images. The model of the crevasse and snow bridge incorporates a complex dielectric permittivity model for dry snow and ice that takes into account the density profile of the glacier. The surface structure is based on a fractal model that can produce sastrugi-like features found on the surface of Antarctic glaciers. Simulated phase histories, computed with the Shooting and Bouncing Ray (SBR) method, are processed into SAR images. The viability of the SBR method for predicting scattering from a crevasse covered with a snow bridge is demonstrated. Some suggestions for improving the model are given.

  14. Ice Nucleation of Fungal Spores from the Classes Agaricomycetes, Ustilaginomycetes, and Eurotiomycetes, and the effect on the Atmospheric Transport of these Spores

    SciTech Connect (OSTI)

    Haga, D. I.; Burrows, Susannah M.; Iannone, R.; Wheeler, M. J.; Mason, R.; Chen, J.; Polishchuk, E. A.; Poschl, U.; Bertram, Allan K.

    2014-08-26

    Ice nucleation on fungal spores may affect the frequency and properties of ice and mixed-phase clouds. We studied the ice nucleation properties of 12 different species of fungal spores chosen from three classes: Agaricomycetes, Ustilagomycetes, and Eurotiomycetes. Agaricomycetes include many types of mushroom species and are cosmopolitan all over the globe. Ustilagomycetes are agricultural pathogens and have caused widespread damage to crops. Eurotiomycetes are found on all types of decaying material and include important human allergens. We focused on these classes since they are thought to be abundant in the atmosphere and because there is very little information on the ice nucleation ability of these classes of spores in the literature. All of the fungal spores investigated were found to cause freezing of water droplets at temperatures warmer than homogeneous freezing. The cumulative number of ice nuclei per spore was 0.001 at temperatures between -19 °C and -29 °C, 0.01 between -25.5 °C and -31 °C, and 0.1 between -26 °C and -36 °C. On average, the order of ice nucleating ability for these spores is Ustilagomycetes > Agaricomycetes ? Eurotiomycetes. We show that at temperatures below -20 °C, all of the fungal spores studied here are less efficient ice nuclei compared to Asian mineral dust on a per surface area basis. We used our new freezing results together with data in the literature to compare the freezing temperatures of spores from the phyla Basidiomycota and Ascomycota, which together make up 98 % of known fungal species found on Earth. The data show that within both phyla (Ascomycota and Basidiomycota) there is a wide range of freezing properties, and also that the variation within a phylum is greater than the variation between the average freezing properties of the phyla. Using a global chemistry-climate transport model, we investigated whether ice nucleation on the studied spores, followed by precipitation, can influence the atmospheric transport and global distributions of these spores in the atmosphere. Simulations show that inclusion of ice nucleation scavenging of fungal spores in mixed-phase clouds can decrease the surface annual mean mixing ratios of fungal spores over the oceans and polar regions and decrease annual mean mixing ratios in the upper troposphere.

  15. Surface Sensitivity in Cluster-Ion-Induced Sputtering

    SciTech Connect (OSTI)

    Szakal, Christopher; Kozole, Joseph; Russo, Michael F. Jr.; Garrison, Barbara J.; Winograd, Nicholas

    2006-06-02

    The ion beam-induced removal of thin water ice films condensed onto Ag and bombarded by energetic Au, Au{sub 2}, Au{sub 3}, and C{sub 60} projectiles is examined both experimentally and with molecular dynamics computer simulations. For water overlayers of thicknesses greater than 10 A, the yields of sputtered Ag{sup +} secondary ions decay exponentially with increasing ice thickness, revealing characteristic decay lengths of 24, 20, 18, and 7.0 A ring , respectively. It is shown that these values manifest the characteristic depths of projectile energy loss, rather than escape depths of the sputtered Ag atoms through the water ice overlayer. Computer simulations show that the mechanism of ejection involves the sweeping away of overlayer water molecules, allowing for an unimpeded escape of ejected Ag atoms. The relevance of these data with respect to surface sensitivity in secondary ion mass spectrometry is discussed.

  16. Microphysical Consequences of the Spatial Distribution of Ice Nucleation in Mixed-Phase Stratiform Clouds

    SciTech Connect (OSTI)

    Yang, Fan; Ovchinnikov, Mikhail; Shaw, Raymond A.

    2014-07-28

    Mixed-phase stratiform clouds can persist even with steady ice precipitation fluxes, and the origin and microphysical properties of the ice crystals are of interest. Vapor deposition growth and sedimentation of ice particles along with a uniform volume source of ice nucleation, leads to a power law relation between ice water content wi and ice number concentration ni with exponent 2.5. The result is independent of assumptions about the vertical velocity structure of the cloud and is therefore more general than the related expression of Yang et al. [2013]. The sensitivity of the wi-ni relationship to the spatial distribution of ice nucleation is confirmed by Lagrangian tracking and ice growth with cloud-volume, cloud-top, and cloud-base sources of ice particles through a time-dependent cloud field. Based on observed wi and ni from ISDAC, a lower bound of 0.006 m^3/s is obtained for the ice crystal formation rate.

  17. Minimalist Model of Ice Microphysics in Mixed-phase Stratiform Clouds

    SciTech Connect (OSTI)

    Yang, F.; Ovchinnikov, Mikhail; Shaw, Raymond A.

    2013-07-28

    The question of whether persistent ice crystal precipitation from super cooled layer clouds can be explained by time-dependent, stochastic ice nucleation is explored using an approximate, analytical model, and a large-eddy simulation (LES) cloud model. The updraft velocity in the cloud defines an accumulation zone, where small ice particles cannot fall out until they are large enough, which will increase the residence time of ice particles in the cloud. Ice particles reach a quasi-steady state between growth by vapor deposition and fall speed at cloud base. The analytical model predicts that ice water content (wi) has a 2.5 power law relationship with ice number concentration ni. wi and ni from a LES cloud model with stochastic ice nucleation also confirm the 2.5 power law relationship. The prefactor of the power law is proportional to the ice nucleation rate, and therefore provides a quantitative link to observations of ice microphysical properties.

  18. Ice Concentration Retrieval in Stratiform Mixed-phase Clouds Using Cloud Radar Reflectivity Measurements and 1D Ice Growth Model Simulations

    SciTech Connect (OSTI)

    Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Luo, Tao

    2014-10-01

    Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculated from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.

  19. Micro-Spectroscopic Imaging and Characterization of Individually Identified Ice Nucleating Particles from a Case Field Study

    SciTech Connect (OSTI)

    Knopf, Daniel A.; Alpert, Peter A.; Wang, Bingbing; O'Brien, Rachel E.; Kelly, Stephen T.; Laskin, Alexander; Gilles, Mary K.; Moffet, Ryan C.

    2014-09-03

    The effect of anthropogenic and biogenic organic particles on atmospheric glaciation processes is poorly understood. We use an optical microscopy (OM) setup to identify the location of ice nuclei (IN) active in immersion freezing and deposition ice nucleation for temperatures of 200-273 K within a large population of particles sampled from an ambient environment. Applying multi-modal micro-spectroscopy methods we characterize the physicochemical properties of individual IN in particle populations collected in central California. Chemical composition and mixing state analysis of particle populations are performed to identify characteristic particle-type classes. All particle-types contained organic material. Particles in these samples take up water at subsaturated conditions, induce immersion freezing at subsaturated and saturated conditions above 226 K, and act as deposition IN below 226 K. The identified IN belong to the most common particle-type classes observed in the field samples: organic coated sea salt, Na-rich, and secondary and refractory carbonaceous particles. Based on these observations, we suggest that the IN are not always particles with unique chemical composition and exceptional ice nucleation propensity; rather, they are common particles in the ambient particle population. Thus, particle composition and morphology alone are insufficient to assess their potential to act as IN. The results suggest that particle-type abundance is also a crucial factor in determining the ice nucleation efficiency of specific IN types. These findings emphasize that ubiquitous organic particles can induce ice nucleation under atmospherically relevant conditions and that they may play an important role in atmospheric glaciation processes.

  20. 1 | De-icing salt damage to trees | November 2011 Pathology Advisory Note

    E-Print Network [OSTI]

    1 | De-icing salt damage to trees | November 2011 Pathology Advisory Note (No. 11) De-icing salt damage to trees De-icing Salt Damage to Trees Joan F Webber, David R Rose, Martin C Dobson #12;2 | De-icing salt damage to trees | November 2011 S a l t D a m a g e De-icing Salt Damage Introduction Rock salt

  1. Autosub missions beneath Polar Ice: Preparation and Experience

    E-Print Network [OSTI]

    Griffiths, Gwyn

    events implemented (up from 1); ordered sequences of events to trigger next mission element added. J and shelf ice. 4 - 12 kHz chirp sub-bottom profiler to obtain the stratigraphy within sediments Water

  2. Hydrological and biogeochemical cycling along the Greenland ice sheet margin

    E-Print Network [OSTI]

    Bhatia, Maya Pilar, 1979-

    2012-01-01

    Global warming has led to a significant increase in Greenland ice sheet (GrIS) melt and runoff since 1990, resulting in escalated export of fresh water and associated sediment to the surrounding North Atlantic and Arctic ...

  3. Intelligent Matchmaking for Polar Ice Sheet Data Collection and Delivery

    E-Print Network [OSTI]

    Kansas, University of

    for the dynamic configuration of sensors and the motion of the rovers that carry them. The PRISM intelligent intelligent sensor and roveIntelligent Matchmaking for Polar Ice Sheet Data Collection and Delivery Costas Tsatsoulis, Sudha

  4. Neutrino Physics with the IceCube Detector

    E-Print Network [OSTI]

    Kiryluk, Joanna; IceCube Collaboration

    2008-01-01

    Science, O?ce of Nu- clear Physics, of the U.S. Departmentjkiryluk?lake?louise?lbl NEUTRINO PHYSICS WITH THE ICECUBESNRs). Other IceCube physics topics include searches for

  5. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Saha, Raj

    2015-01-01

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...

  6. Immersion freezing of clay minerals and bacterial ice nuclei

    E-Print Network [OSTI]

    Hiranuma, Naruki

    2013-01-01

    The immersion mode ice nucleation efficiency of clay minerals and biological aerosols has been investigated using the AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud chamber. Both monodisperse and polydisperse ...

  7. Psychology General Of1ice P217 Biological Sciences Building

    E-Print Network [OSTI]

    Machel, Hans

    Psychology General Of1ice P217 Biological Sciences Building Edmonton, Alberta. Robert Cook ----------------------------------------------- Professor of Psychology Dean in 1986, when he joined the Department of Psychology as an assistant

  8. Thermal desorption of CH4 retained in CO2 ice

    E-Print Network [OSTI]

    Luna, R; Domingo, M; Satorre, M A

    2008-01-01

    CO2 ices are known to exist in different astrophysical environments. In spite of this, its physical properties (structure, density, refractive index) have not been as widely studied as those of water ice. It would be of great value to study the adsorption properties of this ice in conditions related to astrophysical environments. In this paper, we explore the possibility that CO2 traps relevant molecules in astrophysical environments at temperatures higher than expected from their characteristic sublimation point. To fulfil this aim we have carried out desorption experiments under High Vacuum conditions based on a Quartz Crystal Microbalance and additionally monitored with a Quadrupole Mass Spectrometer. From our results, the presence of CH4 in the solid phase above the sublimation temperature in some astrophysical scenarios could be explained by the presence of several retaining mechanisms related to the structure of CO2 ice.

  9. Magnetization plateaus of dipolar spin ice on kagome lattice

    SciTech Connect (OSTI)

    Xie, Y. L.; Wang, Y. L.; Yan, Z. B.; Liu, J.-M.

    2014-05-07

    Unlike spin ice on pyrochlore lattice, the spin ice structure on kagome lattice retains net magnetic charge, indicating non-negligible dipolar interaction in modulating the spin ice states. While it is predicted that the dipolar spin ice on kagome lattice exhibits a ground state with magnetic charge order and ?3?×??3 spin order, our work focuses on the magnetization plateau of this system. By employing the Wang-Landau algorithm, it is revealed that the lattice exhibits the fantastic three-step magnetization in response to magnetic field h along the [10] and [01] directions, respectively. For the h//[1 0] case, an additional ?3/6M{sub s} step, where M{sub s} is the saturated magnetization, is observed in a specific temperature range, corresponding to a new state with charge order and short-range spin order.

  10. Thermal desorption of CH4 retained in CO2 ice

    E-Print Network [OSTI]

    R. Luna; C. Millan; M. Domingo; M. A. Satorre

    2008-01-21

    CO2 ices are known to exist in different astrophysical environments. In spite of this, its physical properties (structure, density, refractive index) have not been as widely studied as those of water ice. It would be of great value to study the adsorption properties of this ice in conditions related to astrophysical environments. In this paper, we explore the possibility that CO2 traps relevant molecules in astrophysical environments at temperatures higher than expected from their characteristic sublimation point. To fulfil this aim we have carried out desorption experiments under High Vacuum conditions based on a Quartz Crystal Microbalance and additionally monitored with a Quadrupole Mass Spectrometer. From our results, the presence of CH4 in the solid phase above the sublimation temperature in some astrophysical scenarios could be explained by the presence of several retaining mechanisms related to the structure of CO2 ice.

  11. Radio-frequency probes of Antarctic ice at South Pole

    E-Print Network [OSTI]

    Besson, David Zeke; Kravchenko, I.

    2013-05-16

    consistent with measurements in East Antarctica. Combined with other radio echo sounding data, we conclude that observed birefringent asymmetries at South Pole are generated entirely in the lower half of the ice sheet. By contrast, birefringent asymmetries...

  12. Improving snow albedo processes in WRF/SSiB regional climate model to assess impact of dust and black carbon in snow on surface energy balance and hydrology over western U.S.

    E-Print Network [OSTI]

    2015-01-01

    in snow, and surface water and energy balances in of?inesnow and surface/soil water and energy balances (Figure 1).albedo can affect the water and energy balance, snowcover

  13. SIZE AND SURFACE AREA OF ICY DUST AGGREGATES AFTER A HEATING EVENT AT A PROTOPLANETARY NEBULA

    SciTech Connect (OSTI)

    Sirono, Sin-iti

    2013-03-01

    The activity of a young star rises abruptly during an FU Orionis outburst. This event causes a temporary temperature increase in the protoplanetary nebula. H{sub 2}O icy grains are sublimated by this event, and silicate cores embedded inside the ice are ejected. During the high-temperature phase, the silicate grains coagulate to form silicate core aggregates. After the heating event, the temperature drops, and the ice recondenses onto the aggregates. I determined numerically the size distribution of the ice-covered aggregates. The size of the aggregates exceeds 10 {mu}m around the snow line. Because of the migration of the ice to large aggregates, only a small fraction of the silicate core aggregate is covered with H{sub 2}O ice. After the heating event, the surface of an ice-covered aggregate is totally covered by silicate core aggregates. This might reduce the fragmentation velocity of aggregates when they collide. It is possible that the covering silicate cores shield the UV radiation field which induces photodissociation of H{sub 2}O ice. This effect may cause the shortage of cold H{sub 2}O vapor observed by Herschel.

  14. Determining Greenland Ice Sheet sensitivity to regional climate change: one-way coupling of a 3-D thermo-mechanical ice sheet model with a mesoscale climate model

    E-Print Network [OSTI]

    Schlegel, Nicole-Jeanne

    2011-01-01

    ice sheet model with a mesoscale climate model By Nicole-ice sheet model with a mesoscale climate model Copyrightice sheet model with a mesoscale climate model by Nicole-

  15. Structure order, local potentials, and physical anomalies of water ice

    E-Print Network [OSTI]

    Chang Q Sun

    2014-07-11

    Hydrogen-bond forms a pair of asymmetric, coupled, H-bridged oscillators with ultra-short-range interactions and memory. hydrogen bond cooperative relaxation and the associated binding electron entrapment and nonbonding electron polarization discriminate water and ice from other usual materials in the physical anomalies. As a strongly correlated fluctuating system, water prefers the statistically mean of tetrahedrally-coordinated structure with a supersolid skin that is elastic, polarized, ice like, hydrophobic, with 3/4 density.

  16. CO and N$_2$ desorption energies from water ice

    E-Print Network [OSTI]

    Fayolle, Edith C; Loomis, Ryan; Bergner, Jennifer; Graninger, Dawn M; Rajappan, Mahesh; Öberg, Karin I

    2015-01-01

    The relative desorption energies of CO and N$_2$ are key to interpretations of observed interstellar CO and N$_2$ abundance patterns, including the well-documented CO and N$_2$H$^+$ anti-correlations in disks, protostars and molecular cloud cores. Based on laboratory experiments on pure CO and N$_2$ ice desorption, the difference between CO and N$_2$ desorption energies is small; the N$_2$-to-CO desorption energy ratio is 0.93$\\pm$0.03. Interstellar ices are not pure, however, and in this study we explore the effect of water ice on the desorption energy ratio of the two molecules. We present temperature programmed desorption experiments of different coverages of $^{13}$CO and $^{15}$N$_2$ on porous and compact amorphous water ices and, for reference, of pure ices. In all experiments, $^{15}$N$_2$ desorption begins a few degrees before the onset of $^{13}$CO desorption. The $^{15}$N$_2$ and $^{13}$CO energy barriers are 770 and 866 K for the pure ices, 1034-1143 K and 1155-1298 K for different sub-monolayer co...

  17. IceCube: An Instrument for Neutrino Astronomy

    SciTech Connect (OSTI)

    IceCube Collaboration; Halzen, F.; Klein, S.

    2010-06-04

    Neutrino astronomy beyond the Sun was first imagined in the late 1950s; by the 1970s, it was realized that kilometer-scale neutrino detectors were required. The first such instrument, IceCube, is near completion and taking data. The IceCube project transforms a cubic kilometer of deep and ultra-transparent Antarctic ice into a particle detector. A total of 5,160 optical sensors are embedded into a gigaton of Antarctic ice to detect the Cherenkov light emitted by secondary particles produced when neutrinos interact with nuclei in the ice. Each optical sensor is a complete data acquisition system, including a phototube, digitization electronics, control and trigger systems and LEDs for calibration. The light patterns reveal the type (flavor) of neutrino interaction and the energy and direction of the neutrino, making neutrino astronomy possible. The scientific missions of IceCube include such varied tasks as the search for sources of cosmic rays, the observation of Galactic supernova explosions, the search for dark matter, and the study of the neutrinos themselves. These reach energies well beyond those produced with accelerator beams.

  18. INDICATOR: LAKE ERIE ICE COVER Winter ice cover on Lake Erie affects the amount of heat and moisture transferred

    E-Print Network [OSTI]

    by impeding or stopping navigation, interfering with power plants and cooling water intakes, and damaging was virtually free of any significant ice cover in 1998 and, with the exception of portions of January, the same

  19. Programmable surfaces

    E-Print Network [OSTI]

    Sun, Amy (Amy Teh-Yu)

    2012-01-01

    Robotic vehicles walk on legs, roll on wheels, are pulled by tracks, pushed by propellers, lifted by wings, and steered by rudders. All of these systems share the common character of momentum transport across their surfaces. ...

  20. 115 year ice-core data from Akademii Nauk ice cap, Severnaya Zemlya: high-resolution record of Eurasian Arctic climate change

    E-Print Network [OSTI]

    Fischer, Hubertus

    ice core has been drilled within the framework of the European Project for Ice Coring in Antarctica of Antarctica. Drilling reached bedrock during the last field season 2005/06 providing ice over a time span. Since Ca2+ is derived from terrestrial dust and marine sources, the non-sea-salt calcium concentrations

  1. Antarctic ice sheet fertilises the Southern Ocean

    E-Print Network [OSTI]

    Death, R.

    Southern Ocean (SO) marine primary productivity (PP) is strongly influenced by the availability of iron in surface waters, which is thought to exert a significant control upon atmospheric CO2 concentrations on glacial/interglacial ...

  2. 6, 1105111066, 2006 Sea ice, frost flowers

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ozone to deposition of mercury to alteration of the fate and lifetime of organic pollutants (Barrie et to provide the surface from which bromine is released (Rankin et al., 2002). Kaleschke et al. (2004) and co

  3. FULLY SAMPLED MAPS OF ICES AND SILICATES IN FRONT OF CEPHEUS A EAST WITH THE SPITZER SPACE TELESCOPE1

    E-Print Network [OSTI]

    Gerakines, Perry

    are relatively constant over the mapped region exhibiting both ice absorptions. The fraction of CO2 ice are invoked. The routine detection of solid CO2, with a fraction relative to water ice between 9% and 37 report the first fully sampled maps of the distribution of interstellar CO2 ices, H2O ices, and total

  4. On the radiolysis of ethylene ices by energetic electrons and implications to the extraterrestrial hydrocarbon chemistry

    SciTech Connect (OSTI)

    Zhou, Li; Maity, Surajit; Abplanalp, Matt; Turner, Andrew; Kaiser, Ralf I.

    2014-07-20

    The chemical processing of ethylene ices (C{sub 2}H{sub 4}) by energetic electrons was investigated at 11 K to simulate the energy transfer processes and synthesis of new molecules induced by secondary electrons generated in the track of galactic cosmic ray particles. A combination of Fourier transform infrared spectrometry (solid state) and quadrupole mass spectrometry (gas phase) resulted in the identification of six hydrocarbon molecules: methane (CH{sub 4}), the C2 species acetylene (C{sub 2}H{sub 2}), ethane (C{sub 2}H{sub 6}), the ethyl radical (C{sub 2}H{sub 5}), and—for the very first time in ethylene irradiation experiments—the C4 hydrocarbons 1-butene (C{sub 4}H{sub 8}) and n-butane (C{sub 4}H{sub 10}). By tracing the temporal evolution of the newly formed molecules spectroscopically online and in situ, we were also able to fit the kinetic profiles with a system of coupled differential equations, eventually providing mechanistic information, reaction pathways, and rate constants on the radiolysis of ethylene ices and the inherent formation of smaller (C1) and more complex (C2, C4) hydrocarbons involving carbon-hydrogen bond ruptures, atomic hydrogen addition processes, and radical-radical recombination pathways. We also discuss the implications of these results on the hydrocarbon chemistry on Titan's surface and on ice-coated, methane-bearing interstellar grains as present in cold molecular clouds such as TMC-1.

  5. A Comparison of TWP-ICE Observational Data with Cloud-Resolving Model Results

    SciTech Connect (OSTI)

    Fridlind, A. M.; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Grabowski, Wojciech W.; Hill, A.; Jones, T. R.; Khaiyer, M. M.; Liu, G.; Minnis, Patrick; Morrison, H.; Nguyen, L.; Park, S.; Petch, Jon C.; Pinty, Jean-Pierre; Schumacher, Courtney; Shipway, Ben; Varble, A. C.; Wu, Xiaoqing; Xie, Shaocheng; Zhang, Minghua

    2012-03-13

    Observations made during the TWP-ICE campaign are used to drive and evaluate thirteen cloud-resolving model simulations with periodic lateral boundary conditions. The simulations employ 2D and 3D dynamics, one- and two-moment microphysics, several variations on large-scale forcing, and the use of observationally derived aerosol properties to prognose droplet numbers. When domain means are averaged over a 6-day active monsoon period, all simulations reproduce observed surface precipitation rate but not its structural distribution. Simulated fractional areas covered by convective and stratiform rain are uncorrelated with one another, and are both variably overpredicted by up to a factor of {approx}2. Stratiform area fractions are strongly anticorrelated with outgoing longwave radiation (OLR) but are negligibly correlated with ice water path (IWP), indicating that ice spatial distribution controls OLR more than mean IWP. Overpredictions of OLR tend to be accompanied by underpredictions of reflected shortwave radiation (RSR). When there are two simulations differing only in microphysics scheme or large-scale forcing, the one with smaller stratiform area tends to exhibit greater OLR and lesser RSR by similar amounts. After {approx}10 days, simulations reach a suppressed monsoon period with a wide range of mean precipitable water vapor, attributable in part to varying overprediction of cloud-modulated radiative flux divergence compared with observationally derived values. Differences across the simulation ensemble arise from multiple sources, including dynamics, microphysics, and radiation treatments. Close agreement of spatial and temporal averages with observations may not be expected, but the wide spreads of predicted stratiform fraction and anticorrelated OLR indicate a need for more rigorous observation-based evaluation of the underlying micro- and macrophysical properties of convective and stratiform structures.

  6. Attenuation of acoustic waves in glacial ice and salt domes

    E-Print Network [OSTI]

    P. B. Price

    2005-06-27

    Two classes of natural solid media (glacial ice and salt domes) are under consideration as media in which to deploy instruments for detection of neutrinos with energy >1e18 eV. Though insensitive to 1e11 to 1e16 eV neutrinos for which observatories (e.g., AMANDA and IceCube) that utilize optical Cherenkov radiation detectors are designed, radio and acoustic methods are suited for searches for the very low fluxes of neutrinos with energies >1017 eV. This is because, due to the very long attenuation lengths of radio and acoustic waves in ice and salt, detection modules can be spaced very far apart. In this paper, I calculate the absorption and scattering coefficients as a function of frequency and grain size for acoustic waves in glacial ice and salt domes and show that experimental measurements on laboratory samples and in glacial ice and salt domes are consistent with theory. For South Pole ice with grain size 0.2 cm at -51 degrees C, scattering lengths are calculated to be 2000 km and 25 km at 10 kHz and 30 kHz, respectively, and the absorption length is calculated to be 9 km at frequencies above 100 Hz. For NaCl (rock salt) with grain size 0.75 cm, scattering lengths are calculated to be 120 km and 1.4 km at 10 kHz and 30 kHz, and absorption lengths are calculated to be 30,000 km and 3300 km at 10 kHz and 30 kHz. Existing measurements are consistent with theory. For ice, absorption is the limiting factor; for salt, scattering is the limiting factor.

  7. Evidence of NAO control on subsurface ice accumulation in a 1200 yr old cave-ice sequence, St. Livres ice cave, Switzerland

    E-Print Network [OSTI]

    Butler, David R. - Department of Geography, Texas State University

    . Livres ice cave, Switzerland Markus Stoffel a,b,c, , Marc Luetscher d,e , Michelle Bollschweiler b Sciences, University of Geneva, Site de Batelle, chemin de Drize 7, CH-1227 Carouge-Geneva, Switzerland b, Baltzerstrasse 1+3, CH-3012 Berne, Switzerland c Department of Geosciences, Geography, University of Fribourg

  8. Surface Soil

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar Fuel Production 1: TotalofSupplySurface Soil Surface Soil We

  9. Adsorption of 2-propanol on ice probed by ambient pressure X-ray photoelectron spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Newberg, John T.; Bluhm, Hendrik

    2015-08-18

    The interaction of 2-propanol with ice was examined via ambient pressure X-ray photoelectron spectroscopy (APXPS), a surface sensitive technique that probes the adsorbed 2-propanol directly with submonolayer resolution. Isothermal uptake experiments were performed on vapor deposited ice at 227 K in the presence of the equilibrium water vapor pressure of 0.05 Torr and 2-propanol partial pressures ranging from 5 × 10-5 to 2 × 10-3 Torr. The C 1s APXPS spectra of adsorbed 2-propanol showed two characteristic peaks associated with the COH alcohol group and CMe methyl groups in a 1 : 2 ratio, respectively. Coverage increased with 2-propanol partialmore »pressure and followed first order Langmuir kinetics with a Langmuir constant of K = 6.3 × 103 Torr-1. The 1 : 2 ratio of COH : CMe remained constant with increasing coverage, indicating there is no chemical reaction upon adsorption. The observed Langmuir kinetics using APXPS is consistent with previous observations of other small chain alcohols via indirect adsorption methods using, e.g., Knudsen cell and coated wall flow tube reactors.« less

  10. On Surface Approximation using Developable Surfaces

    E-Print Network [OSTI]

    Lee, In-Kwon

    manufacturing, e.g. in shipbuilding. Keywords: computer aided design, computer aided manufacturing, surface ap- proximation, reverse engineering, surface of revolution, developable surface, shipbuilding. 2 #12

  11. Microbial Diversity Studies in Sediments of Perennially Ice-covered Lakes, McMurdo Dry Valleys, Antarctica

    E-Print Network [OSTI]

    Tang, Chao

    2009-01-01

    perennial ice cover. Sedimentology 38: 363-379. Takacs,perennial ice cover. Sedimentology 38: 363-379. Suzuki, M. ,perennial ice cover. Sedimentology 38: 363-379. Tamaki, H. ,

  12. Sensor development and calibration for acoustic neutrino detection in ice

    E-Print Network [OSTI]

    Karg, Timo; Laihem, Karim; Semburg, Benjamin; Tosi, Delia

    2009-01-01

    A promising approach to measure the expected low flux of cosmic neutrinos at the highest energies (E > 1 EeV) is acoustic detection. There are different in-situ test installations worldwide in water and ice to measure the acoustic properties of the medium with regard to the feasibility of acoustic neutrino detection. The parameters of interest include attenuation length, sound speed profile, background noise level and transient backgrounds. The South Pole Acoustic Test Setup (SPATS) has been deployed in the upper 500 m of drill holes for the IceCube neutrino observatory at the geographic South Pole. In-situ calibration of sensors under the combined influence of low temperature, high ambient pressure, and ice-sensor acoustic coupling is difficult. We discuss laboratory calibrations in water and ice. Two new laboratory facilities, the Aachen Acoustic Laboratory (AAL) and the Wuppertal Water Tank Test Facility, have been set up. They offer large volumes of bubble free ice (3 m^3) and water (11 m^3) for the devel...

  13. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Raj Saha

    2015-02-21

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural periodicity and produces burst patterns very similar to what is observed in temperature proxy data. Numerical experiments with the model also suggests that the characteristic period of 1,500 years is due to the geometry, or the effective heat capacity, of the ocean that comes under sea ice cover.

  14. pMSSM Dark Matter Searches on Ice

    SciTech Connect (OSTI)

    Cotta, R.C.; /SLAC; Howe, K.T.K.; /SLAC /Stanford U., Phys. Dept.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2011-08-12

    We explore the capability of the IceCube/Deepcore array to discover signal neutrinos resulting from the annihilations of Supersymmetric WIMPS that may be captured in the solar core. In this analysis, we use a previously generated set of {approx} 70k model points in the 19-dimensional parameter space of the pMSSM which satisfy existing experimental and theoretical constraints. Our calculations employ a realistic estimate of the IceCube/DeepCore effective area that has been modeled by the IceCube collaboration. We find that a large fraction of the pMSSM models are shown to have significant signal rates in the anticipated IceCube/DeepCore 1825 day dataset, including some prospects for an early discovery. Many models where the LSP only constitutes a small fraction of the total dark matter relic density are found to have observable rates. We investigate in detail the dependence of the signal neutrino fluxes on the LSP mass, weak eigenstate composition, annihilation products and thermal relic density, as well as on the spin-independent and spin-dependent scattering cross sections. Lastly, We compare the model coverage of IceCube/DeepCore to that obtainable in near-future direct detection experiments and to pMSSM searches at the 7 TeV LHC.

  15. Effects of Pre-Existing Ice Crystals on Cirrus Clouds and Comparison between Different Ice Nucleation Parameterizations with the Community Atmosphere Model (CAM5)

    SciTech Connect (OSTI)

    Shi, Xiangjun; Liu, Xiaohong; Zhang, Kai

    2015-01-01

    In order to improve the treatment of ice nucleation in a more realistic manner in the Community Atmospheric Model version 5.3 (CAM5.3), the effects of preexisting ice crystals on ice nucleation in cirrus clouds are considered. In addition, by considering the in-cloud variability in ice saturation ratio, homogeneous nucleation takes place spatially only in a portion of cirrus cloud rather than in the whole area of cirrus cloud. With these improvements, the two unphysical limiters used in the representation of ice nucleation are removed. Compared to observations, the ice number concentrations and the probability distributions of ice number concentration are both improved with the updated treatment. The preexisting ice crystals significantly reduce ice number concentrations in cirrus clouds, especially at mid- to high latitudes in the upper troposphere (by a factor of ~10). Furthermore, the contribution of heterogeneous ice nucleation to cirrus ice crystal number increases considerably.Besides the default ice nucleation parameterization of Liu and Penner (2005, hereafter LP) in CAM5.3, two other ice nucleation parameterizations of Barahona and Nenes (2009, hereafter BN) and Kärcher et al. (2006, hereafter KL) are implemented in CAM5.3 for the comparison. In-cloud ice crystal number concentration, percentage contribution from heterogeneous ice nucleation to total ice crystal number, and preexisting ice effects simulated by the three ice nucleation parameterizations have similar patterns in the simulations with present-day aerosol emissions. However, the change (present-day minus pre-industrial times) in global annual mean column ice number concentration from the KL parameterization (3.24×106 m-2) is obviously less than that from the LP (8.46×106 m-2) and BN (5.62×106 m-2) parameterizations. As a result, experiment using the KL parameterization predicts a much smaller anthropogenic aerosol longwave indirect forcing (0.24 W m-2) than that using the LP (0.46 W m-2) and BN (0.39 W m-2) parameterizations.

  16. Are both BL Lacs and pulsar wind nebulae the astrophysical counterparts of IceCube neutrino events?

    E-Print Network [OSTI]

    P. Padovani; E. Resconi

    2014-06-10

    IceCube has recently reported the discovery of high-energy neutrinos of astrophysical origin, opening up the PeV (10^15 eV) sky. Because of their large positional uncertainties, these events have not yet been associated to any astrophysical source. We have found plausible astronomical counterparts in the GeV -- TeV bands by looking for sources in the available large area high-energy gamma-ray catalogues within the error circles of the IceCube events. We then built the spectral energy distribution of these sources and compared it with the energy and flux of the corresponding neutrino. Likely counterparts include mostly BL Lacs and two Galactic pulsar wind nebulae. On the one hand many objects, including the starburst galaxy NGC 253 and Centaurus A, despite being spatially coincident with neutrino events, are too weak to be reconciled with the neutrino flux. On the other hand, various GeV powerful objects cannot be assessed as possible counterparts due to their lack of TeV data. The definitive association between high-energy astrophysical neutrinos and our candidates will be significantly helped by new TeV observations but will be confirmed or disproved only by further IceCube data. Either way, this will have momentous implications for blazar jets, high-energy astrophysics, and cosmic-ray and neutrino astronomy.

  17. Fast particle-driven ion cyclotron emission (ICE) in tokamak plasmas and the case for an ICE diagnostic in ITER

    E-Print Network [OSTI]

    McClements, K G; Dendy, R O; Carbajal, L; Chapman, S C; Cook, J W S; Harvey, R W; Heidbrink, W W; Pinches, S D

    2014-01-01

    Fast particle-driven waves in the ion cyclotron frequency range (ion cyclotron emission or ICE) have provided a valuable diagnostic of confined and escaping fast ions in many tokamaks. This is a passive, non-invasive diagnostic that would be compatible with the high radiation environment of deuterium-tritium plasmas in ITER, and could provide important information on fusion {\\alpha}-particles and beam ions in that device. In JET, ICE from confined fusion products scaled linearly with fusion reaction rate over six orders of magnitude and provided evidence that {\\alpha}-particle confinement was close to classical. In TFTR, ICE was observed from super-Alfv\\'enic {\\alpha}-particles in the plasma edge. The intensity of beam-driven ICE in DIII-D is more strongly correlated with drops in neutron rate during fishbone excitation than signals from more direct beam ion loss diagnostics. In ASDEX Upgrade ICE is produced by both super-Alfv\\'enic DD fusion products and sub-Alfv\\'enic deuterium beam ions.

  18. A study of carbon-14 of paleoatmospheric methane for the last glacial termination from ancient glacial ice

    E-Print Network [OSTI]

    Petrenko, Vasilii Victorovich

    2008-01-01

    for the last glacial termination." xii VITA Education Ph.D.the Last Glacial Termination: a horizontal ice core.the Last Glacial Termination: a horizontal ice core.

  19. Spatial patterns of ice storm disturbance in the forested landscape of Ouachita Mountains, Arkansas and Oklahoma 

    E-Print Network [OSTI]

    Isaacs, Rachel E.

    2009-05-15

    Large-extent ice storms have received relatively little attention from researchers. This research investigates the effects of abiotic and biotic factors on the spatial patterns of ice storm disturbance on a forested landscape. This investigation...

  20. The Development of Measurement Techniques to Identify and Characterize Dusts and Ice Nuclei in the Atmosphere 

    E-Print Network [OSTI]

    Glen, Andrew

    2014-01-15

    Mineral dusts and ice crystals directly influence the Earth's radiative budget through radiative scattering and absorption. The interaction of spherical particles on the radiative budget are well known, however mineral dusts and ice crystals...

  1. VoICE: A semi-automated pipeline for standardizing vocal analysis across models

    E-Print Network [OSTI]

    Burkett, ZD; Day, NF; Peńagarikano, O; Geschwind, DH; White, SA

    2015-01-01

    al. VoICE: A semi-automated pipeline for standardizing vocalVoICE: A semi-automated pipeline for standardizing vocalwe designed an analysis pipeline into which any type of

  2. Thesis proposal CSF Brazil 2014 Innovant de-icing system for more electric aircraft

    E-Print Network [OSTI]

    Bordenave, Charles

    . Mechanical de-icing systems are low energy solution that are focused on breaking down and shedding the ice-mechanical systems give a durable, light-weight, power-saver solution which justifies the recent efforts

  3. Ice nucleation and droplet formation by bare and coated soot particles

    E-Print Network [OSTI]

    Friedman, Beth

    We have studied ice formation at temperatures relevant to homogeneous and heterogeneous ice nucleation, as well as droplet activation and hygroscopicity, of soot particles of variable size and composition. Coatings of ...

  4. Glacial geology and glaciology of the Younger Dryas ice cap in Scotland 

    E-Print Network [OSTI]

    Golledge, Nicholas Robert

    2009-01-01

    This thesis uses geological field data and numerical ice sheet modelling to study the Younger Dryas ice cap in Scotland. The Younger Dryas stadial is important because it represents the most recent period of high-magnitude ...

  5. The Role of Oceans and Sea Ice in Abrupt Transitions between Multiple Climate States

    E-Print Network [OSTI]

    Rose, Brian E. J.

    The coupled climate dynamics underlying large, rapid, and potentially irreversible changes in ice cover are studied. A global atmosphere–ocean–sea ice general circulation model with idealized aquaplanet geometry is forced ...

  6. Fast proton hopping detection in ice I{sub h} by quasi-elastic...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Fast proton hopping detection in ice Isub h by quasi-elastic neutron scattering. Citation Details In-Document Search Title: Fast proton hopping detection in ice...

  7. Analysis of Antarctic Sea Ice Thickness: A Newly Created Database for 2000-2009 

    E-Print Network [OSTI]

    Morgan, Benjamin Patrick

    2012-10-19

    Observations of Antarctic sea ice thickness are sporadic in space and time, hindering knowledge of its variability. A proxy based on stage of development data from the National Ice Center (NIC) weekly operational charts is used to create a high...

  8. Modeling the impact of atmospheric moisture transport on global ice volume

    E-Print Network [OSTI]

    Nisancioglu, Kerim Hestnes, 1975-

    2004-01-01

    Following Milankovitch's original hypothesis most model studies of changes in global ice volume on orbital time scales have focused on the impact of ablation on ice sheet mass balance. In most cases, poleward moisture flux ...

  9. NOAA Data Report ERL GLERL-24 A COMPUTERIZED ICE CONCENTRATION DATA BASE FOR THE GREAT LAKES

    E-Print Network [OSTI]

    1 NOAA Data Report ERL GLERL-24 A COMPUTERIZED ICE CONCENTRATION DATA BASE FOR THE GREAT LAKES ......................................................................................................... 5 2. Computerized ice concentration data base .............................................................................................................................................. 5 2. BASIC DATAAND DATA REDUCTION

  10. Using Temporal Information in an Automated Classification of Summer, Marginal Ice Zone Imagery*

    E-Print Network [OSTI]

    Kansas, University of

    * Donna Haverkamp and Costas Tsatsoulis Department of Electrical Engineering and Computer Science- analyzed temperature records and regional statistics in order to achieve an automated ice's ice/water concentrations and melt state with temperature and wind data, a current interpretation

  11. A Computational Study of Icing Effects on the Performance of an S-Duct Inlet

    E-Print Network [OSTI]

    Jin, Wonjin

    2009-01-01

    The performance of a diffusing S-duct inlet (M2129) is computationally studied for the effects of inlet icing. Different ice accretion shapes, predicted by numerical analysis in the literature reviewed, are simulated on the inlet lip. Two commercial...

  12. Incorporation of particulates into accreted ice above subglacial Vostok lake, Antarctica

    E-Print Network [OSTI]

    Christner, Brent C.

    polycarbonate membranes, and secondary electron images were collected at Ā500 magnification using a scanning conductivity suggest that the ice comprises lake water which has refrozen to the underside of the ice sheet

  13. Global ice cloud observations: radiative properties and statistics from moderate-resolution imaging spectroradiometer measurements 

    E-Print Network [OSTI]

    Meyer, Kerry Glynne

    2009-05-15

    Ice clouds occur quite frequently, yet so much about these clouds is unknown. In recent years, numerous investigations and field campaigns have been focused on the study of ice clouds, all with the ultimate goal of gaining a better understanding...

  14. 2,000-year record of atmospheric methyl bromide from a South Pole ice core

    E-Print Network [OSTI]

    Saltzman, Eric S; Aydin, Murat; Tatum, Cheryl; Williams, Margaret B

    2008-01-01

    air from firn at the South Pole, Nature, 383, 231 – 235. 5METHYL BROMIDE FROM SOUTH POLE ICE CORE Butler, J. H. , M.of methyl chloride from a South Pole ice core: Evidence for

  15. A descriptive study of the zonation of the Antarctic Circumpolar Current and its relation to wind stress and ice cover 

    E-Print Network [OSTI]

    Clifford, Melody Ann

    1983-01-01

    is examined. The Subtropical Front is located in the region of Ekman downwelling south of the transition between west and east winds, while the Subantarctic Front occurs at the position of maximum westerlies. These relationships hold true for the Han... with the transition from east to west winds, the northern edge of the summer ice, or the Antarctic continent-probably the latter. From the monthly Han and Lee wind distributions, the Ekman transports in the surface layers were calculated across the three northern...

  16. Stable levitation and dynamics of ice particles at low pressures

    E-Print Network [OSTI]

    Nicholas Kowalski; Bernard Xie; Colin V. Parker; Cheng Chin

    2015-04-13

    We demonstrate stable levitation and trapping of ice particles of 30~200 micon at low background gas pressures in the presence of a temperature gradient. The thermophoretic force levitates the particles, which have long lifetimes of over an hour. The equilibrium position depends on the background pressure and temperature gradient, which is consistent with theoretical expectations. Furthermore, we investigate interesting launching and merging dynamics of the levitated particles, as well as the development of instability at high background pressures. Our system provides a robust platform to investigate the aggregation of floating ice particles in air, and potentially chemical and biological processes in a microgravity environment.

  17. Ice plug employed on subsea pipeline bend during repair

    SciTech Connect (OSTI)

    1997-12-22

    The first controlled-temperature ice plug in the bend of an offshore gas trunkline has been carried out for Phillips Petroleum Co. Norway on its Norpipe A.S. platform in the German sector of the North Sea. The procedure was part of a subsea valve repair operation. The ice plug was successfully formed offshore and tested to a differential pressure of 1,450 psi. Repair of two valves required only 5 days during which time gas production was operating at close to 50--60% via the platform bypass, says the service company. The paper discusses the procedure.

  18. Deep and Surface Circulation in the Northwest Indian Ocean from Argo, Surface Drifter, Satellite, and In Situ Profiling Current Observations 

    E-Print Network [OSTI]

    Stryker, Sarah

    2012-10-19

    , but little is understood about the Sea of Oman. This thesis incorporated observations from Argo floats, surface drifters and satellite imagery to study the deep and surface circulation in the northwest Indian Ocean. An assessment of four independent moorings...

  19. Fluid Flow and Thermodynamic Analysis of a Wing Anti-Icing System

    E-Print Network [OSTI]

    is controlled through regulating the hot flow passing a wing anti-icing valve by an automatic control system

  20. Ice formation on nitric acid coated dust particles: Laboratory and modeling studies

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Zhang, Kai; Zhao, Chun; Nandasiri, Manjula I.; Shutthanandan, V.; Liu, Xiaohong; Fast, Jerome D.; Berg, Larry K.

    2015-08-16

    Changes in the ice nucleation characteristics of atmospherically relevant mineral dust particles due to nitric acid coating are not well understood. Further, the atmospheric implications of dust coating on ice-cloud properties under different assumptions of primary ice nucleation mechanisms are unknown. We investigated ice nucleation ability of Arizona test dust, illite, K-feldspar and quartz as a function of temperature (-25 to -30°C) and relative humidity with respect to water (75 to 110%). Particles were size selected at 250 nm and transported (bare or coated) to the ice nucleation chamber to determine the fraction of particles nucleating ice at various temperature and water saturation conditions. All dust nucleated ice at water-subsaturated conditions, but the coated particles showed a reduction in their ice nucleation ability compared to bare particles. However, at water-supersaturated conditions, we observed that bare and coated particles had nearly similar ice nucleation characteristics. X-ray diffraction patterns indicated that structural properties of bare dust particles modified after acid treatment. We found that lattice parameters were slightly different, but crystallite sizes of the coated particles were reduced compared to bare particles. Next, single-column model results show that simulated ice crystal number concentrations mostly depends upon fraction of particles that are coated, primary ice nucleation mechanisms, and the competition between ice nucleation mechanisms to nucleate ice. In general, we observed that coating modify the ice-cloud properties and the picture of ice and mixed-phase cloud evolution is complex when different primary ice nucleation mechanisms are competing for fixed water vapor mass.

  1. Ice at the Interface: Atmosphere-Ice-Ocean Boundary Layer Processes and Their Role in Polar Change---Workshop Report

    SciTech Connect (OSTI)

    Hunke, Elizabeth C. [Los Alamos National Laboratory

    2012-07-23

    The atmosphere-ocean boundary layer in which sea ice resides includes many complex processes that require a more realistic treatment in GCMs, particularly as models move toward full earth system descriptions. The primary purpose of the workshop was to define and discuss such coupled processes from observational and modeling points of view, including insight from both the Arctic and Antarctic systems. The workshop met each of its overarching goals, including fostering collaboration among experimentalists, theorists and modelers, proposing modeling strategies, and ascertaining data availability and needs. Several scientific themes emerged from the workshop, such as the importance of episodic or extreme events, precipitation, stratification above and below the ice, and the marginal ice zone, whose seasonal Arctic migrations now traverse more territory than in the past.

  2. TransCom N[subscript 2]O model inter-comparison – Part 1: Assessing the influence of transport and surface fluxes on tropospheric N[subscript 2]O variability

    E-Print Network [OSTI]

    Thompson, R. L.

    We present a comparison of chemistry-transport models (TransCom-N2O) to examine the importance of atmospheric transport and surface fluxes on the variability of N2O mixing ratios in the troposphere. Six different models ...

  3. Improving snow albedo processes in WRF/SSiB regional climate model to assess impact of dust and black carbon in snow on surface energy balance and hydrology over western U.S.

    E-Print Network [OSTI]

    2015-01-01

    Basin: 1. A 6 year record of energy balance, radiation, andorganic carbon aerosol from energy-related combustion, 1850–carbon in snow on surface energy balance and hydrology over

  4. THE EXTENT OF PLEISTOCENE ICE CAP, GLACIAL DEPOSITS AND GLACIOKARST IN THE ALADAGLAR

    E-Print Network [OSTI]

    Zreda, Marek

    holes, ice caves, glacial melt-water streams, stone circles and girlands represent glacialTHE EXTENT OF PLEISTOCENE ICE CAP, GLACIAL DEPOSITS AND GLACIOKARST IN THE ALADAGLAR MASSIF between 1100 m and 3756 m of altitudes. Many of the glacial landforms, such as moraines and ice

  5. TRMM observations of the global relationship between ice water content and lightning

    E-Print Network [OSTI]

    Rutledge, Steven

    TRMM observations of the global relationship between ice water content and lightning Walter A to retrieve ice water content. Citation: Petersen, W. A., H. J. Christian, and S. A. Rutledge (2005), TRMM observations of the global relationship between ice water content and lightning, Geophys. Res. Lett., 32, L

  6. Nonlinear Thermal Transport and Brine Convection in First Year Sea Ice

    E-Print Network [OSTI]

    temperature gradients and at greater depths in the ice. Preliminary modelling of the impact of brine migration of thermistors frozen into first­year Antarctic sea ice provides temperature against depth data, which is fitted on heat transport through first­year sea ice is presented. Diffusion­driven brine pocket migration

  7. Sensitivity of Cenozoic Antarctic ice sheet variations to geothermal heat flux

    E-Print Network [OSTI]

    Sensitivity of Cenozoic Antarctic ice sheet variations to geothermal heat flux David Pollard a sheet to geothermal heat flux is investigated, using a coupled climate­ice sheet model with various prescribed values and patterns of geothermal heat flux. The sudden growth of major ice across the Eocene

  8. A Computational Study of the Spreading of Oil Underneath a Sheet of Ice Mark Sussman

    E-Print Network [OSTI]

    Sussman, Mark

    A Computational Study of the Spreading of Oil Underneath a Sheet of Ice Mark Sussman Department) The spreading of oil underneath a sheet of ice is computed using an adaptive level set method for incompressible of a body of oil under ice in water. The computational models are used to make further observations

  9. A Computational Study of the Spreading of Oil Underneath a Sheet of Ice

    E-Print Network [OSTI]

    Ferguson, Thomas S.

    A Computational Study of the Spreading of Oil Underneath a Sheet of Ice Mark Sussman Department) Abstract The spreading of oil underneath a sheet of ice is computed using an adaptive level set method the final steady profile of a body of oil under ice in water. The computational models are used to make

  10. Cloud Detection over Snow and Ice Using MISR Data , Eugene E. Clothiaux

    E-Print Network [OSTI]

    Yu, Bin

    Cloud Detection over Snow and Ice Using MISR Data Tao Shi , Bin Yu , Eugene E. Clothiaux detection is particularly difficult in the snow- and ice-covered po- lar regions and availability WORDS: Cloud detection; Feature selection; Ice and snow; Multi-angle Imaging Spectro- Radiometer (MISR

  11. Wind speed influence on phytoplankton bloom dynamics in the Southern Ocean Marginal Ice Zone

    E-Print Network [OSTI]

    Moore, Keith

    Wind speed influence on phytoplankton bloom dynamics in the Southern Ocean Marginal Ice Zone Dillon; published 7 August 2007. [1] Analysis of satellite ocean color and wind speed data within the seasonal ice. Moore (2007), Wind speed influence on phytoplankton bloom dynamics in the Southern Ocean Marginal Ice

  12. Elastic uplift in southeast Greenland due to rapid ice mass loss

    E-Print Network [OSTI]

    Khan, Shfaqat A.; Wahr, John; Stearns, Leigh; Hamilton, Gordon; van Dam, Tonie; Larson, Kristine M.; Francis, Olivier

    2007-11-01

    [1] The rapid unloading of ice from the southeastern sector of the Greenland ice sheet between 2001 and 2006 caused an elastic uplift of ?35 mm at a GPS site in Kulusuk. Most of the uplift results from ice dynamic-induced volume losses on two nearby...

  13. Dynamics of stickslip motion, Whillans Ice Stream, Antarctica J. Paul Winberry a,

    E-Print Network [OSTI]

    an additional asperity in the northern part of the ice stream, producing another pulse of seismic energy 6Dynamics of stick­slip motion, Whillans Ice Stream, Antarctica J. Paul Winberry a, , Sridhar 6 April 2011 Editor: P. Shearer Keywords: glacial geophysics ice stream seismology The stick

  14. Ice iron/sodium film as cause for high noctilucent cloud radar reflectivity

    E-Print Network [OSTI]

    Bellan, Paul M.

    Ice iron/sodium film as cause for high noctilucent cloud radar reflectivity P. M. Bellan1 Received by assuming the ice grains are coated by a thin metal film; substantial evidence exists indicating that such a film exists and is caused by the deposition of iron and sodium atoms on the ice grain from iron

  15. Interannual Variability in Pollen Dispersal and Deposition on the Tropical Quelccaya Ice Cap*

    E-Print Network [OSTI]

    Liu, Kam-biu

    should also be considered Key Words: biogeography, ice-core palynology, Peru, pollen dispersal, Quelccaya is represented in the modern pollen rain on the ice caps. A modern analog is our most powerful calibration tool from the Quelccaya Ice Cap (Reese and Liu 2002) in southern Peru and Mt. Parinacota (Reese, Liu

  16. Impact of sudden Arctic sea-ice loss on stratospheric polar ozone recovery

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Impact of sudden Arctic sea-ice loss on stratospheric polar ozone recovery Article Published.G. and Ravishankara, A.R. (2009) Impact of sudden Arctic sea-ice loss on stratospheric polar ozone recovery's research outputs online #12;Impact of sudden Arctic sea-ice loss on stratospheric polar ozone recovery J. F

  17. Polar Sea Ice Mapping Using SeaWinds Data Hyrum S. Anderson and David G. Long

    E-Print Network [OSTI]

    Long, David G.

    of Bayes detection to produce sea ice extent maps. Statistical models for sea ice and ocean are represented of their independence of solar illumination, their ability to penetrate to ever-present canopy of clouds in the polar of these same measure- ments. The A imagery exhibits good statistical contrast between sea ice and ocean

  18. Abrupt climate changes for Iceland during the last millennium: evidence from high resolution sea ice reconstructions

    E-Print Network [OSTI]

    Paris-Sud XI, UniversitƩ de

    Abrupt climate changes for Iceland during the last millennium: evidence from high resolution sea, Norway Abstract A high resolution account of Icelandic sea ice over the last millennium has been ice and/or climate conditions around Iceland during the Little Ice Age. Author for correspondence

  19. Experimental Investigation of Direct Expansion Dynamic Ice-on-coil Storage System Used in Residential Buildings 

    E-Print Network [OSTI]

    Zheng, M.; Kong, F.; Han, Z.; Liu, W.

    2006-01-01

    expansion dynamic ice-on-coil storage system that overcame the disadvantages of static and dynamic ice-storage system. It is concluded that periodic ice moving avoids the increased heat resistance that creates a decreased evaporating temperature. Due to a...

  20. 9 The Dynamics of Snow and Ice Masses J.S. Wettlaufer

    E-Print Network [OSTI]

    Wettlaufer, John S.

    of Physics, University of Washington, Seattle, WA 98105-5640, USA 9.1 Ice: Land, Sea and Air On Earth today the storage of relatively slow inland (upstream) ice [2]. These contemporary observations give strength transport through the connected network of air pockets that separate individual ice grains. Eventually

  1. NOAA Technical Memorandum ERL GLERL-18 PHOTOSYNTHETICALLY ACTIVE RADIATION TRANSMITTANCE THROUGH ICE

    E-Print Network [OSTI]

    to obtain the ratios shown in Figure 9. 9. Ratio of under-ice to above-ice radiation (T) versus true solar. 12. Ratio of below- to above-ice radiation (T) as a function of true solar time (TST) during a period of melting snow for 7 March 1977. 13. Radiation transmittance (T) as a function of true solar time (TST

  2. The effect of snow: How to better model ground surface temperatures E.E. Jafarov a,

    E-Print Network [OSTI]

    The effect of snow: How to better model ground surface temperatures E.E. Jafarov a, , D.J. Nicolsky b , V.E. Romanovsky b,d , J.E. Walsh c , S.K. Panda b , M.C. Serreze a a National Snow and Ice Data 2013 Accepted 25 February 2014 Available online 11 March 2014 Keywords: Snow Thermal properties Snow

  3. Black carbon in Arctic snow and its effect on surface albedo

    E-Print Network [OSTI]

    1 Black carbon in Arctic snow and its effect on surface albedo Stephen Warren, University wavelengths: ice is nearly transparent. Absorptive impurities: Black carbon (soot) Brown carbon (organics broadband albedo: 83% 71% (2) by addition of black carbon (BC) (20 ppb): 0.5% for r = 100 µm 1.6% for r

  4. Purchasing Energy-Efficient Air-Cooled Ice Machines

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Federal Energy Management Program (FEMP) provides acquisition guidance for air-cooled ice machines, a product category covered by ENERGY STAR efficiency requirements. Federal laws and requirements mandate that agencies purchase ENERGY STAR-qualified products or FEMP-designated products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.

  5. IceCube Project Monthly Report -April 2010 Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    Water Drill equipment (http://www.icecube.wisc.edu/disposition/index.php) and the site was circulated to solicit interest in the equipment following the end of IceCube construction. · The training at shorter distances. #12; 2 Cost and Schedule Performance ­ The project is 94.7% complete

  6. Development and Applications of the Community Ice Sheet Model

    SciTech Connect (OSTI)

    Hoffman, Matthew J.; Lipscomb, William H.; Price, Stephen F.; Johnson, Jesse; Sacks, William

    2012-07-23

    The initial goals of the project are: (1) create a model for land ice that includes relevant and necessary dynamics, physical processes, and couplings; and (2) apply that model to say something more substantial about SLR in Lme for IPCC AR5 (AR6?).

  7. Ultrafast Electron Dynamics at Alkali/Ice Structures

    E-Print Network [OSTI]

    Wolf, Martin

    trapping sites, i.e. at local potential minima, are formed. Photoinjection of excess electrons into these alkali-ion covered amorphous ice layers, results in the trapping of a solvated electron at an alkali, i.e. pump-probe time delay, the electron transfer is mediated by tunneling through a potential

  8. Visible and near infrared reflectances measured from laboratory ice clouds

    E-Print Network [OSTI]

    Liou, K. N.

    ,aswellasuncertaintiesin data, validation by means of the independent in situ airborne and ground-based measurements that are co. Liou Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles the measured ice particle morphology. We demonstrate that laboratory scat- tering and reflectance data for thin

  9. FLOOD-PLAIN DELINEATION IN ICE JAM PRONE REGIONS

    E-Print Network [OSTI]

    Vogel, Richard M.

    methodology is introduced for incorporating the risk of icejams into flood-plain delineations in northern in the computation of annual maximum flood elevation distributions and flood risk in icejam prone regionsFLOOD-PLAIN DELINEATION IN ICE JAM PRONE REGIONS By Richard M. Vogel,1 S. M. ASCE and Jery R

  10. Water and Ice Dielectric Spectra Scaling at 0 °C

    E-Print Network [OSTI]

    V. G. Artemov; A. A. Volkov

    2013-08-06

    Dielectric spectra (10^4-10^11 Hz) of water and ice at 0 {\\deg}C are considered in terms of proton conductivity and compared to each other. In this picture, the Debye relaxations, centered at 1/{\\tau}_W ~ 20 GHz (in water) and 1/{\\tau}_I ~ 5 kHz (in ice), are seen as manifestations of diffusion of separated charges in the form of H3O+ and OH- ions. The charge separation results from the self-dissociation of H2O molecules, and is accompanied by recombination in order to maintain the equilibrium concentration, N. The charge recombination is a diffusion-controlled process with characteristic lifetimes of {\\tau}_W and {\\tau}_I, for water and ice respectively. The static permittivity, {\\epsilon}(0), is solely determined by N. Both, N and {\\epsilon}(0), are roughly constant at the water-ice phase transition, and both increase, due to a slowing down of the diffusion rate, as the temperature is lowered. The transformation of the broadband dielectric spectra at 0 {\\deg}C with the drastic change from {\\tau}_W to {\\tau}_I is mainly due to an abrupt (by 0.4 eV) change of the activation energy of the charge diffusion.

  11. Ice method for production of hydrogen clathrate hydrates

    DOE Patents [OSTI]

    Lokshin, Konstantin (Santa Fe, NM); Zhao, Yusheng (Los Alamos, NM)

    2008-05-13

    The present invention includes a method for hydrogen clathrate hydrate synthesis. First, ice and hydrogen gas are supplied to a containment volume at a first temperature and a first pressure. Next, the containment volume is pressurized with hydrogen gas to a second higher pressure, where hydrogen clathrate hydrates are formed in the process.

  12. The Method of Generated Solutions for Numerical Verification of ICE

    E-Print Network [OSTI]

    for verifying numerical code. The exact solution to the set of equations is derived using mathematical methodsThe Method of Generated Solutions for Numerical Verification of ICE Code Amjidanutpan Ramanujam, Christopher Sikorski, Todd Harman* UUCS­07­006 School of Computing University of Utah Salt Lake City, UT 84112

  13. The Method of Generated Solutions for Numerical Verification of ICE

    E-Print Network [OSTI]

    for verifying numerical code. The exact solution to the set of equations is derived using mathematical methodsThe Method of Generated Solutions for Numerical Verification of ICE Code Amjidanutpan Ramanujam, Christopher Sikorski, Todd Harman* UUCS-07-006 School of Computing University of Utah Salt Lake City, UT 84112

  14. http://www.ices.cmu.edu/ballista Prof. Philip Koopman

    E-Print Network [OSTI]

    Koopman, Philip

    http://www.ices.cmu.edu/ballista Prof. Philip Koopman koopman@cmu.edu - (412) 268-5225 - http robustness #12;3 Overview: Automated Robustness Testing u System Robustness · Motivation · Ballista automatic · Technology Transfer · Application to Non OS APIs u Conclusions A Ballista is an ancient siege weapon

  15. Optical constants of carbon dioxide ice Stephen G. Warren

    E-Print Network [OSTI]

    Warren, Stephen

    Optical constants of carbon dioxide ice Stephen G. Warren Laboratory measurements of the absorption. At pressures belowthe triple point (5.2atm), carbon dioxide exists only as a gas or solid. The sublimation in the ultraviolet (50-130-nm wavelength) due to elec- tronic transitions. It is relatively transparent

  16. GREAT LAKES ICE COVER RaymondA. Asset'

    E-Print Network [OSTI]

    to the early fifteenth centllry. in central Japan. southern Germany,and Switzerland." I National Oceanographic hydropower production and cooling water intakes, and damaging shore structures. Ice cover also impacts, and spring energy exchanges between the lake and the planetary boundary layer. Although observations of shore

  17. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-11-06

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice numbermore »is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.« less

  18. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    SciTech Connect (OSTI)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-12-01

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice number is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.

  19. Dimensions and aspect ratios of natural ice crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Um, J.; McFarquhar, G. M.; Hong, Y. P.; Lee, S. -S.; Jung, C. H.; Lawson, R. P.; Mo, Q.

    2014-12-10

    During the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) in the Tropics, the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) in the Arctic, and the 2010 Small PARTicles In CirrUS (SPARTICUS) campaign in mid-latitudes, high-resolution images of ice crystals were recorded by a Cloud Particle Imager at temperatures (T) between -87 and 0 °C. The projected maximum dimension (D'), length (L'), and width (W') of pristine columns, plates, and component bullets of bullet rosettes were measured using newly developed software, the Ice Crystal Ruler. The number of bullets in each bullet rosette was also measured. Column crystals were furthermore »distinguished as either horizontally oriented columns or columns with other orientations to eliminate any orientation effect on the measured dimensions. Dimensions and aspect ratios (AR, dimension of major axis divided by dimension of minor axis) of crystals were determined as functions of temperature, geophysical location, and type of cirrus. Dimensions of crystals generally increased as temperature increased. Columns and bullets had larger dimensions (i.e., W') of the minor axis (i.e., a axis) for a given dimension (i.e., D' or L') of the major axis (i.e., c axis), and thus smaller AR, as T increased, whereas this trend did not occur for plate crystals. The average number of branches in bullet rosettes was 5.50±1.35 during three campaigns and 6.32±1.34 (5.46±1.34; 4.95±1.01) during TWP-ICE (SPARTICUS; ISDAC). The AR of bullets increased with the number of branches in bullet rosettes. Most dimensions of crystals and ARs of columnar crystals measured during SPARTICUS were larger than those measured during TWP-ICE and ISDAC at ?67 T T L–W relationships of columns derived using current data exhibited a strong dependence on temperature; similar relationship determined in previous studies were within the range of the current data.« less

  20. Determination of Ice Water Path Over the ARM SGP Using Combined Surface and Satellite Datasets

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeeting |Design CompetitionsFuelofSources fromDetermination

  1. Tuesday, March 13, 2007 POSTER SESSION I: MARS: POLAR, GLACIAL, AND NEAR-SURFACE ICE

    E-Print Network [OSTI]

    Rathbun, Julie A.

    .m. Fitness Center Milkovich S. M. Plaut J. J. Martian South Polar Layered Deposit Stratigraphy and Implications for Accumulation History [#1929] Several correlatable layer sequences are observed in the south polar layered deposits. The distribution of these sequences provide insight into the nature

  2. Surface roughness over the northern half of the Greenland Ice Sheet from airborne laser altimetry

    E-Print Network [OSTI]

    van der Veen, Cornelis J.; Ahn, Y.; Csatho, B. M.; Mosley-Thompson, E.; Krabill, William B.

    2009-06-05

    radioactivity from atmospheric thermonuclear testing. The five cores contain a 66-year period of overlap from 1928 to 1994 (the most recent complete year of accumula- tion). Annual accumulation rates for each of the cores are shown in Figure 2. 2.3. Validation...

  3. Surface Science Letters P) reactions with small alkenes adsorbed on Rh, Au, and ice

    E-Print Network [OSTI]

    Sibener, Steven

    of the excess energy. For low gas pressures, the products of vapor phase reactions are associated or diluted in propane, or as a solution with liquid nitrogen using sev- eral Torr of ambient oxygen atoms [7

  4. Sediment plume response to surface melting and supraglacial lake drainages on the Greenland ice sheet

    E-Print Network [OSTI]

    Space Center, Technical University of Denmark, Ųrsteds Plads Building 348, DK-2800 Kgs. Lyngby, Denmark-sheet melt extent from Special Sensor Microwave/Imager (SSM/I) passive microwave data; and (3) supraglacial extent and timing with passive microwave, thermal and scatterometer satellite data and show melt

  5. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    E-Print Network [OSTI]

    2013-01-01

    In most parts of Antarc- tica the subglacial landscape istopography for Antarc- tica were presented by the BEDMAP

  6. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    E-Print Network [OSTI]

    2013-01-01

    Geography, Swansea University, Swansea, UK 11 Federal Institute for Geosciences and Natural Resources,

  7. A Nano Surface Icephobic Coating Delays Ice Formation | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries Print Lithium-ionAAEngine Applications |Nano

  8. ELECTRON IRRADIATION OF CARBON DISULFIDE-OXYGEN ICES: TOWARD THE FORMATION OF SULFUR-BEARING MOLECULES IN INTERSTELLAR ICES

    SciTech Connect (OSTI)

    Maity, Surajit; Kaiser, Ralf I. [Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822 (United States)

    2013-08-20

    The formation of sulfur-bearing molecules in interstellar ices was investigated during the irradiation of carbon disulfide (CS{sub 2})-oxygen (O{sub 2}) ices with energetic electrons at 12 K. The irradiation-induced chemical processing of these ices was monitored online and in situ via Fourier transform infrared spectroscopy to probe the newly formed products quantitatively. The sulfur-bearing molecules produced during the irradiation were sulfur dioxide (SO{sub 2}), sulfur trioxide (SO{sub 3}), and carbonyl sulfide (OCS). Formations of carbon dioxide (CO{sub 2}), carbon monoxide (CO), and ozone (O{sub 3}) were observed as well. To fit the temporal evolution of the newly formed products and to elucidate the underlying reaction pathways, kinetic reaction schemes were developed and numerical sets of rate constants were derived. Our studies suggest that carbon disulfide (CS{sub 2}) can be easily transformed to carbonyl sulfide (OCS) via reactions with suprathermal atomic oxygen (O), which can be released from oxygen-containing precursors such as water (H{sub 2}O), carbon dioxide (CO{sub 2}), and/or methanol (CH{sub 3}OH) upon interaction with ionizing radiation. This investigation corroborates that carbonyl sulfide (OCS) and sulfur dioxide (SO{sub 2}) are the dominant sulfur-bearing molecules in interstellar ices.

  9. Space geodesy constrains ice age terminal deglaciation: The global ICE-6G_C (VM5a) model

    E-Print Network [OSTI]

    Peltier, W. Richard

    . Peltier1 , D. F. Argus2 , and R. Drummond1 1 Department of Physics, University of Toronto, Toronto] or a combination of such influences [Vettoretti and Peltier, 2003]. Simple ice sheet coupled climate models have been successful in explaining the origins of this 100 kyr cyclic behavior [Tarasov and Peltier, 1997

  10. Consequence Assessment

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1997-08-21

    This volume focuses on the process of performing timely initial assessments necessary to support critical first decisions and the continuous process of refining those initial assessments as more information and resources become available. Canceled by DOE G 151.1-4.

  11. Eos, Vol. 91, No. 29, 20 July 2010 Water and wet sediments under ice sheets

    E-Print Network [OSTI]

    Priscu, John C.

    Research Drilling (WISSARD) project (http://www .wissard.org). Begun in 2009, WISSARD will assess how water diversity within glacial environments. Exact selection of drill sites will be based on safety considerations and accessibility as determined through radar, seismic, and satellite data. Surface geophysical surveys will also

  12. Far-infrared surface emissivity and climate

    SciTech Connect (OSTI)

    Feldman, Daniel R.; Collins, William D.; Pincus, Robert; Huang, Xianglei; Chen, Xiuhong

    2014-11-03

    Presently, there are no global measurement constraints on the surface emissivity at wavelengths longer than 15 ?m, even though this surface property in this far-IR region has a direct impact on the outgoing longwave radiation (OLR) and infrared cooling rates where the column precipitable water vapor (PWV) is less than 1 mm. Such dry conditions are common for high-altitude and high-latitude locations, with the potential for modeled climate to be impacted by uncertain surface characteristics. This paper explores the sensitivity of instantaneous OLR and cooling rates to changes in far-IR surface emissivity and how this unconstrained property impacts climate model projections. At high latitudes and altitudes, a 0.05 change in emissivity due to mineralogy and snow grain size can cause a 1.8–2.0 W m?² difference in the instantaneous clear-sky OLR. A variety of radiative transfer techniques have been used to model the far-IR spectral emissivities of surface types defined by the International Geosphere-Biosphere Program. Incorporating these far-IR surface emissivities into the Representative Concentration Pathway (RCP) 8.5 scenario of the Community Earth System Model leads to discernible changes in the spatial patterns of surface temperature, OLR, and frozen surface extent. The model results differ at high latitudes by as much as 2°K, 10 W m?², and 15%, respectively, after only 25 y of integration. The calculated difference in far-IR emissivity between ocean and sea ice of between 0.1 and 0.2, suggests the potential for a far-IR positive feedback for polar climate change.

  13. Far-infrared surface emissivity and climate

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Feldman, Daniel R.; Collins, William D.; Pincus, Robert; Huang, Xianglei; Chen, Xiuhong

    2014-11-03

    Presently, there are no global measurement constraints on the surface emissivity at wavelengths longer than 15 ?m, even though this surface property in this far-IR region has a direct impact on the outgoing longwave radiation (OLR) and infrared cooling rates where the column precipitable water vapor (PWV) is less than 1 mm. Such dry conditions are common for high-altitude and high-latitude locations, with the potential for modeled climate to be impacted by uncertain surface characteristics. This paper explores the sensitivity of instantaneous OLR and cooling rates to changes in far-IR surface emissivity and how this unconstrained property impacts climate modelmore »projections. At high latitudes and altitudes, a 0.05 change in emissivity due to mineralogy and snow grain size can cause a 1.8–2.0 W m?² difference in the instantaneous clear-sky OLR. A variety of radiative transfer techniques have been used to model the far-IR spectral emissivities of surface types defined by the International Geosphere-Biosphere Program. Incorporating these far-IR surface emissivities into the Representative Concentration Pathway (RCP) 8.5 scenario of the Community Earth System Model leads to discernible changes in the spatial patterns of surface temperature, OLR, and frozen surface extent. The model results differ at high latitudes by as much as 2°K, 10 W m?², and 15%, respectively, after only 25 y of integration. The calculated difference in far-IR emissivity between ocean and sea ice of between 0.1 and 0.2, suggests the potential for a far-IR positive feedback for polar climate change.« less

  14. LABORATORY STUDIES ON THE IRRADIATION OF SOLID ETHANE ANALOG ICES AND IMPLICATIONS TO TITAN'S CHEMISTRY

    SciTech Connect (OSTI)

    Kim, Y. S.; Bennett, C. J.; Chen, L-H; Kaiser, R. I.; O'Brien, K.

    2010-03-10

    Pure ethane ices (C{sub 2}H{sub 6}) were irradiated at 10, 30, and 50 K under contamination-free, ultrahigh vacuum conditions with energetic electrons generated in the track of galactic cosmic-ray (GCR) particles to simulate the interaction of GCRs with ethane ices in the outer solar system. The chemical processing of the samples was monitored by a Fourier transform infrared spectrometer and a quadrupole mass spectrometer during the irradiation phase and subsequent warm-up phases on line and in situ in order to extract qualitative (products) and quantitative (rate constants and yields) information on the newly synthesized molecules. Six hydrocarbons, methane (CH{sub 4}), acetylene (C{sub 2}H{sub 2}), ethylene (C{sub 2}H{sub 4}), and the ethyl radical (C{sub 2}H{sub 5}), together with n-butane (C{sub 4}H{sub 10}) and butene (C{sub 4}H{sub 8}), were found to form at the radiation dose reaching 1.4 eV per molecule. The column densities of these species were quantified in the irradiated ices at each temperature, permitting us to elucidate the temperature and phase-dependent production rates of individual molecules. A kinetic reaction scheme was developed to fit column densities of those species produced during irradiation of amorphous/crystalline ethane held at 10, 30, or 50 K. In general, the yield of the newly formed molecules dropped consistently for all species as the temperature was raised from 10 K to 50 K. Second, the yield in the amorphous samples was found to be systematically higher than in the crystalline samples at constant temperature. A closer look at the branching ratios indicates that ethane decomposes predominantly to ethylene and molecular hydrogen, which may compete with the formation of n-butane inside the ethane matrix. Among the higher molecular products, n-butane dominates. Of particular relevance to the atmosphere of Saturn's moon Titan is the radiation-induced methane production from ethane-an alternative source of replenishing methane into the atmosphere. Finally, we discuss to what extent the n-butane could be the source of ''higher organics'' on Titan's surface thus resembling a crucial sink of condensed ethane molecules.

  15. Annual satellite imaging of the world's glaciers Assessment of glacier extent and change

    E-Print Network [OSTI]

    GLIMS HIGH ICE Annual satellite imaging of the world's glaciers Assessment of glacier extent is an international consortium of 23 regional centers ·Coordinated by U.S. Geological Survey - Flagstaff #12.S. National Research Applications: · Energy Forecasting: Energy for U.S. Northwest derived partly from

  16. Hydrogen Fuel Pilot Plant and Hydrogen ICE Vehicle Testing

    SciTech Connect (OSTI)

    J. Francfort (INEEL)

    2005-03-01

    The U.S. Department Energy's Advanced Vehicle Testing Activity (AVTA) teamed with Electric Transportation Applications (ETA) and Arizona Public Service (APS) to develop the APS Alternative Fuel (Hydrogen) Pilot Plant that produces and compresses hydrogen on site through an electrolysis process by operating a PEM fuel cell in reverse; natural gas is also compressed onsite. The Pilot Plant dispenses 100% hydrogen, 15 to 50% blends of hydrogen and compressed natural gas (H/CNG), and 100% CNG via a credit card billing system at pressures up to 5,000 psi. Thirty internal combustion engine (ICE) vehicles (including Daimler Chrysler, Ford and General Motors vehicles) are operating on 100% hydrogen and 15 to 50% H/CNG blends. Since the Pilot Plant started operating in June 2002, they hydrogen and H/CNG ICE vehicels have accumulated 250,000 test miles.

  17. Risk Assessment

    Broader source: Energy.gov [DOE]

    A set of issues that state and local governments should carefully consider, with the goal of helping them assess and anticipate solutions for some worst case or unfortunate case scenarios as they...

  18. Environmental Assessment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for the SAR. 2.2 Description of Alternatives. Alternative B - No Action The BLM NEPA Handbook (H-1790-1) states that for Environmental Assessments (EAs) on externally initiated...

  19. Significant groundwater contribution to Antarctic ice streams hydrologic budget

    E-Print Network [OSTI]

    Christoffersen, Poul; Bougamont, Marion; Carter, Sasha P.; Fricker, Helen A.; Tulaczyk, Slawek

    2014-03-26

    et al., 1986; Rooney et al., 1987; Smith, 1997], so far this has only been directly observed at the Siple Coast, where samples collected in boreholes confirmed it to be till [Engelhardt et al., 1990], a glacially produced material with highly non... ] and (B) 2009 [Rignot et al., 2011]. With constant model geometry [Fretwell et al., 2013], climate [Arthern et al., 2006; Comiso, 2000], and geothermal heat flux [Maule et al., 2005; Shapiro and Ritzwoller, 2004], we converge ice temperature, effective...

  20. American Indian Complex to Cool Off Using Ice Storage System

    Broader source: Energy.gov [DOE]

    In Oklahoma City, summer temperatures can get above 100 degrees, making cooling more of a necessity than a luxury. But the designers of the American Indian Cultural Center and Museum (AICCM) wanted to make cooling choices that reflect American Indian cultures' respect for the land. So, rather than using conventional air-conditioning, the museum's main complex will use an ice storage system estimated to save 644,000 kilowatt hours of electricity a year.

  1. Localization of water monomers inside ice-like clusters

    E-Print Network [OSTI]

    V. L. Golo; S. M. Pershin

    2012-04-04

    On the basis of the experimental data we suggest that water monomers could be trapped in channels running through ice-like clusters in water. Our argument relies on a simple model that describes the motion of a dipole particle inside a channel in the presence of an electric field with linear gradient. The model admits of both finite and infinite regimes of motion so that the finite one could correspond to the particle being confined to a channel.

  2. Wideband measurements of ice sheet attenuation and basal scattering

    E-Print Network [OSTI]

    Allen, Christopher Thomas; Gogineni, Sivaprasad; Paden, J. D.; Jezek, K. C.; Dahl-Jensen, D.; Larsen, L. B.

    2005-04-01

    SENSING LETTERS, VOL. 2, NO. 2, APRIL 2005 Wideband Measurements of Ice Sheet Attenuation and Basal Scattering John D. Paden, Student Member, IEEE, Christopher T. Allen, Senior Member, IEEE, Sivaprasad Gogineni, Fellow, IEEE, Kenneth C. Jezek, Dorthe Dahl... the real part of the permittivity by [11] (4) and the imaginary part of the permittivity by [11] (5) To determine the total loss as the radio wave propagates to and from the bedrock, we discretize the temperature, density, and conductivity profiles shown...

  3. Multifunctional Graphene/Platinum/Nafion Hybrids via Ice Templating

    SciTech Connect (OSTI)

    Estevez, Luis; Kelarakis, Antonios; Gong, Qianming; Da’as, Eman Husni; Giannelis, Emmanuel P.

    2011-01-01

    We report the synthesis of multifunctional hybrids in both films and bulk form, combining electrical and ionic conductivity with porosity and catalytic activity. The hybrids are synthesized by a two-step process: (a) ice templation of an aqueous suspension comprised of Nafion, graphite oxide, and chloroplatinic acid to form a microcellular porous network and (b) mild reduction in hydrazine or monosodium citrate which leads to graphene-supported Pt nanoparticles on a Nafion scaffold

  4. Probability distributions of land surface wind speeds over North America

    E-Print Network [OSTI]

    Dai, Aiguo

    Probability distributions of land surface wind speeds over North America Yanping He,1 Adam Hugh of the probability distributions of surface wind speeds (SWS) is essential for surface flux estimation, wind power estimation, and wind risk assessments. The two-parameter Weibull distribution is the most widely used

  5. A detailed assessment of snow accumulation in katabatic wind areas on the Ross Ice Shelf, Antarctica

    E-Print Network [OSTI]

    Braaten, David A.

    1997-12-27

    to activate the aerosol generators and disperse the microspheres. The MDSs at both sites were programmed to activate every 14 days for 10 s, dispersing -75 mL of the inert, colored microspheres from a height of-1.2 m. The microspheres have a terminal... planned for Willie Field and Ferrell, BRAATEN: SNOW ACCUMULATION IN KATABATIC WIND AREAS 30,051 First Field Survey- January 1995 Willie Field MDS site o o o ųų o ųo 0 o ß AWS 70m Ferrell MDS site ß o ß ų e ß e  õ o co ß ß ß ee ee O ß 0...

  6. Assessment of Future ICE and Fuel-Cell Powered Vehicles and Their Potential Impacts

    Broader source: Energy.gov [DOE]

    2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: Massachusetts Institute of Technology

  7. Dimensions and aspect ratios of natural ice crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Um, J.; McFarquhar, G. M.; Hong, Y. P.; Lee, S. -S.; Jung, C. H.; Lawson, R. P.; Mo, Q.

    2015-04-15

    During the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) in the tropics, the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) in the Arctic, and the 2010 Small PARTicles In CirrUS (SPARTICUS) campaign at mid-latitudes, high-resolution images of ice crystals were recorded by a Cloud Particle Imager at temperatures (T) between -87 and 0 °C. The projected maximum dimension (D'), length (L'), and width (W') of pristine columns, plates, and component bullets of bullet rosettes were measured using newly developed software, the Ice Crystal Ruler. The number of bullets in each bullet rosette was also measured. Column crystals were furthermore »distinguished as either horizontally oriented columns or columns with other orientations to eliminate any orientation effect on the measured dimensions. The dimensions and aspect ratios (AR, the dimension of the major axis divided by the dimension of the minor axis) of crystals were determined as functions of temperature, geophysical location, and type of cirrus. Dimensions of crystals generally increased with temperature. Columns and bullets had larger dimensions (i.e., W') of the minor axis (i.e., a axis) for a given dimension (i.e., D' orL') of the major axis (i.e., c axis), and thus smaller AR, as T increased, whereas this trend did not occur for plate crystals. The average number of branches in bullet rosettes was 5.50 ± 1.35 during three campaigns and 6.32 ± 1.34 (5.46 ± 1.34; 4.95 ± 1.01) during TWP-ICE (SPARTICUS; ISDAC). The AR of bullets increased with the number of branches in bullet rosettes. Most dimensions of crystals and ARs of columnar crystals measured during SPARTICUS were larger than those measured during TWP-ICE and ISDAC at ?67 L–W relationships of columns derived using current data exhibited a strong dependence on temperature; similar relationships determined in previous studies were within the range of the current data.« less

  8. Observational Possibility of the "Snow Line" on the Surface of Circumstellar Disks with the Scattered Light

    E-Print Network [OSTI]

    Akio K. Inoue; Mitsuhiko Honda; Taishi Nakamoto; Akinori Oka

    2008-02-07

    We discuss how we obtain the spatial distribution of ice on the surface of the circumstellar disk around young stars. Ice in the disks plays a very important role in various issues, for instance, on the disk structure, on the planet formation, on the isotopic anomaly in meteorites, and on the origin of the sea on the Earth. Therefore, the spatially resolved observation of the condensation/sublimation front of ice, so-called ``snow line'' is strongly required. Here, we propose a new method for obtaining the spatially resolved ``snow line'' on the circumstellar disks by observing 3 \\micron H$_2$O ice feature in the scattered light. Based on radiative transfer considerations, we show that the feature is clearly imprinted in the spectrum of the scattered light from both optically thick and thin circumstellar disks. We also show that the scattered light and the H$_2$O ice feature from protoplanetary disks are detectable and spatially resolvable with the current instruments through a $H_2O$ narrowband filter around 3 \\micron. Finally, we present a diagnostics of disk dust properties on the $K-H_2O$ and $K-L'$ two color diagram.

  9. Reflection and transmission of ocean wave spectra by a band of randomly distributed ice floes

    E-Print Network [OSTI]

    Montiel, Fabien; Bennetts, Luke

    2014-01-01

    A new ocean wave/sea-ice interaction model is proposed that simulates how a directional wave spectrum evolves as it travels through an arbitrary finite array of circular ice floes, where wave/ice dynamics are entirely governed by wave scattering effects. The model is applied to characterise the wave reflection and transmission properties of a strip of ice floes, such as an ice edge band. A method is devised to extract the reflected and transmitted directional wave spectra produced by the array. The method builds upon an integral mapping from polar to Cartesian coordinates of the scattered wave components. Sensitivity tests are conducted for a row of floes randomly perturbed from a regular arrangement. Results for random arrays are generated using ensemble averaging. A realistic ice edge band is then reconstructed from field experiments data. Simulations show a good qualitative agreement with the data in terms of transmitted wave energy and directional spreading. In particular, it is observed that short waves ...

  10. Realizing three-dimensional artificial spin ice by stacking planar nano-arrays

    SciTech Connect (OSTI)

    Chern, Gia-Wei; Reichhardt, Charles; Nisoli, Cristiano

    2014-01-06

    Artificial spin ice is a frustrated magnetic two-dimensional nano-material, recently employed to study variety of tailor-designed unusual collective behaviours. Recently proposed extensions to three dimensions are based on self-assembly techniques and allow little control over geometry and disorder. We present a viable design for the realization of a three-dimensional artificial spin ice with the same level of precision and control allowed by lithographic nano-fabrication of the popular two-dimensional case. Our geometry is based on layering already available two-dimensional artificial spin ice and leads to an arrangement of ice-rule-frustrated units, which is topologically equivalent to that of the tetrahedra in a pyrochlore lattice. Consequently, we show, it exhibits a genuine ice phase and its excitations are, as in natural spin ice materials, magnetic monopoles interacting via Coulomb law.

  11. Discrete-element model for the interaction between ocean waves and sea ice

    SciTech Connect (OSTI)

    Xu, Zhijie; Tartakovsky, Alexandre M.; Pan, Wenxiao

    2012-01-05

    We present a discrete element method (DEM) model to simulate the mechanical behavior of sea ice in response to ocean waves. The wave/ice interaction can potentially lead to the fracture and fragmentation of sea ice depending on the wave amplitude and period. The fracture behavior of sea ice is explicitly modeled by a DEM method, where sea ice is modeled by densely packed spherical particles with finite size. These particles are bonded together at their contact points through mechanical bonds that can sustain both tensile & compressive forces and moments. Fracturing can be naturally represented by the sequential breaking of mechanical bonds. For a given amplitude and period of incident ocean wave, the model provides information for the spatial distribution and time evolution of stress and micro-fractures and the fragment size distribution. We demonstrate that the fraction of broken bonds,, increases with increasing wave amplitude. In contrast, the ice fragment size decreases with increasing amplitude.

  12. An investigation of ice shape prediction methodologies and comparison with experimental data 

    E-Print Network [OSTI]

    Britton, Randall Keith

    1989-01-01

    water content has allowed rime, mixed, and glaze ice shapes on the leading edge of an airfoil to be investigated. To my beloved parents, their 6rst grandson, and his mother ACKNOWLEDGEMENTS I would like to thank the members of my committee, Dr... water droplets. The free air temperature heavily inSuences what type and the extent which ice will accrete. Higher temperatures are usually associated with higher liquid water contents and thus lend themselves to the formation of glaze ice. Conversely...

  13. Heterogeneous ice nucleation and water uptake by field-collected atmospheric particles below 273 K

    SciTech Connect (OSTI)

    Wang, Bingbing; Laskin, Alexander; Roedel, Tobias R.; Gilles, Marry K.; Moffet, Ryan C.; Tivanski, Alexei V.; Knopf, Daniel A.

    2012-09-25

    Atmospheric ice formation induced by particles with complex chemical and physical properties through heterogeneous nucleation is not well understood. Heterogeneous ice nucleation and water uptake by ambient particles collected from urban environments in Los Angeles and Mexico City are presented. Using a vapour controlled cooling system equipped with an optical microscopy, the range of onset conditions for ice nucleation and water uptake by the collected particles was determined as a function of temperature (200{273 K) and relative humidity with respect to ice (RHice) up to water saturation. Three distinctly different types of authentic atmospheric particles were investigated including soot particles associated with organics/inorganics, inorganic particles of marine origin coated with organic material, and Pb/Zn containing inorganic particles apportioned to anthropogenic emissions relevant to waste incineration. Single particle characterization was provided by micro-spectroscopic analyses using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption ne structure spectroscopy (STXM/NEXAFS). Above 230 K, signicant differences in water uptake and immersion freezing effciencies of the different particle types were observed. Below 230 K, the particles exhibited high deposition ice nucleation effciencies and formed ice at RHice values well below homogeneous ice nucleation limits. The data show that the chemical composition of these eld{collected particles plays an important role in determining water uptake and immersion freezing. Heterogeneous ice nucleation rate coeffcients, cumulative ice nuclei (IN) spectrum, and IN activated fraction for deposition ice nucleation are derived. The presented ice nucleation data demonstrate that anthropogenic and marine particles comprising of various chemical and physical properties exhibit distinctly different ice nucleation effciencies and can serve as effcient IN at atmospheric conditions typical for cirrus and mixed phase clouds. This indicates a potential link between human activities and cloud formation, and thus climate.

  14. Risk assessment of climate systems for national security.

    SciTech Connect (OSTI)

    Backus, George A.; Boslough, Mark Bruce Elrick; Brown, Theresa Jean; Cai, Ximing; Conrad, Stephen Hamilton; Constantine, Paul; Dalbey, Keith R.; Debusschere, Bert J.; Fields, Richard; Hart, David Blaine; Kalinina, Elena Arkadievna; Kerstein, Alan R.; Levy, Michael; Lowry, Thomas Stephen; Malczynski, Leonard A.; Najm, Habib N.; Overfelt, James Robert; Parks, Mancel Jordan; Peplinski, William J.; Safta, Cosmin; Sargsyan, Khachik; Stubblefield, William Anthony; Taylor, Mark A.; Tidwell, Vincent Carroll; Trucano, Timothy Guy; Villa, Daniel L.

    2012-10-01

    Climate change, through drought, flooding, storms, heat waves, and melting Arctic ice, affects the production and flow of resource within and among geographical regions. The interactions among governments, populations, and sectors of the economy require integrated assessment based on risk, through uncertainty quantification (UQ). This project evaluated the capabilities with Sandia National Laboratories to perform such integrated analyses, as they relate to (inter)national security. The combining of the UQ results from climate models with hydrological and economic/infrastructure impact modeling appears to offer the best capability for national security risk assessments.

  15. VUV spectroscopy and photo-processing of astrochemical ices: an experimental study

    E-Print Network [OSTI]

    Kaiser, Ralf I.

    VUV spectroscopy and photo-processing of astrochemical ices: an experimental study Nigel J. Mason environments within our universe has relied critically upon the continuing technological advances

  16. Using Satellite Radar Data to Map and Monitor Variations in Great Lakes Ice Cover

    E-Print Network [OSTI]

    . Many practical applications such as winter navigation, shore structure protection, hydropower generation, lake ecology, and potential flooding caused by ice jams necessitate mapping and monitoring

  17. Methyl chloride variability in the Taylor Dome ice core during the Holocene

    E-Print Network [OSTI]

    Verhulst, Kristal R; Aydin, Murat; Saltzman, Eric S

    2013-01-01

    in the Taylor Dome ice core during the Holocene Kristal R.2005GB002680. Lee-Taylor, J. , and K. R. Redeker (2005),

  18. Direct Calculation of Ice Homogeneous Nucleation Rate for a Molecular Model of Water

    E-Print Network [OSTI]

    Amir Haji-Akbari; Pablo G. Debenedetti

    2015-07-08

    Ice formation is ubiquitous in nature, with important consequences in a variety of environments, including biological cells, soil, aircraft, transportation infrastructure and atmospheric clouds. However, its intrinsic kinetics and microscopic mechanism are difficult to discern with current experiments. Molecular simulations of ice nucleation are also challenging, and direct rate calculations have only been performed for coarse-grained models of wate. For molecular models, only indirect estimates have been obtained, e.g. by assuming the validity of classical nucleation theory. We use a path sampling approach to perform the first direct rate calculation of homogeneous nucleation of ice in a molecular model of water. We use TIP4P/Ice, the most accurate among existing molecular models for studying ice polymorphs. By using a novel topological approach to distinguish different polymorphs, we are able to identify a freezing mechanism that involves a competition between cubic and hexagonal ice in the early stages of nucleation. In this competition, the cubic polymorph takes over since the addition of new topological structural motifs consistent with cubic ice leads to the formation of more compact crystallites. This is not true for topological hexagonal motifs, which give rise to elongated crystallites that are not able to grow. This leads to transition states that are rich in cubic ice, and not the thermodynamically stable hexagonal polymorph. This mechanism provides a molecular explanation to the earlier experimental and computational observations of the preference for cubic ice in the literature.

  19. Wintertime high-altitude surface energy balance of a Bolivian glacier, Illimani, 6340 m above sea level

    E-Print Network [OSTI]

    Berthier, Etienne

    glacier, Illimani (16°390 S; 67°470 W, 6340 m above sea level (asl)), where a 137 m ice core was drilled snow surfaces of the intermediate slopes of Antarctica. INDEX TERMS: 0342 Atmospheric Composition experiments were conducted on the drilling site of Illimani (6340 m asl, 16°390 S; 67°470 W) during 6 days

  20. Decontamination of surfaces by blasting with crystals of H{sub 2}O and CO{sub 2}

    SciTech Connect (OSTI)

    Benson, C.E.; Parfitt, J.E.; Patton, B.D.

    1995-02-01

    A major mission of the US Department of Energy during the 1990s is site and environmental cleanup. In pursuit of this mission, numerous remediation projects are under way and many others are being planned at Oak Ridge National Laboratory (ORNL). In this report, tests using two proposed methods for decontaminating surfaces one using water ice crystals [Crystalline Ice Blast (CIB)], the other using dry ice crystals (CO{sub 2} Cleanblast{trademark}) -- are described. Both methods are adaptations of the commonly used sand blasting technology. The two methods tested differ from sand blasting in that the particles are not particularly abrasive and do not accumulate as particles in the wastes. They differ from each other in that the CO{sub 2} particles sublime during and after impact and the ice particles melt. Thus, the two demonstrations provide important information about two strong candidate decontamination methodologies. Each process was tested at ORNL using contaminated lead bricks and contaminated tools and equipment. Demonstrations with the prototype Crystalline Ice Blast and the CO{sub 2} Cleanblast systems showed that paint, grease, and oil can be removed from metal, plastic, asphalt, and concrete surfaces. Furthermore, removal of contamination from lead bricks was highly effective. Both processes were found to be less effective, under the conditions tested, with contaminated tools and equipment that had chemically bonded contamination or contamination located in crevices since neither technology abrades the substrates or penetrates deeply into crevices to remove particulates. Some process improvements are recommended.

  1. Ice shelf-ocean interactions in a general circulation model : melt-rate modulation due to mean flow and tidal currents

    E-Print Network [OSTI]

    Dansereau, Véronique

    2012-01-01

    Interactions between the ocean circulation in sub-ice shelf cavities and the overlying ice shelf have received considerable attention in the context of observed changes in flow speeds of marine ice sheets around Antarctica. ...

  2. Evolution of the surface area of a snow layer

    SciTech Connect (OSTI)

    Hanot, L.; Domine, F.

    1999-12-01

    Atmospheric trace gases can partition between the atmosphere and the snow surface. Because snow has a large surface-to-volume ratio, an important interaction potential between ice and atmospheric trace gases exists. Quantifying this partitioning requires the knowledge of the surface area (SA) of snow. Eleven samples were taken from a 50 cm thick snow fall at Col de Porte, near Grenoble (French Alps) between January 20 and February 4, 1998. Fresh snow and 3, 8, and 15-day-old snow were sampled at three different depths. Surface hoar, formed after the fall, was also sampled. Air and surface snow temperature, snow density, and snow fall rate were measured. Snow temperature always remained below freezing. Snow SA was measured using methane adsorption at 77.15 K. Values ranged from 2.25 m{sup 2}/g for fresh snow to 0.25 m{sup 2}/g for surface hoar and surface snow after 15 days. These values are much too high to be explained by the macroscopic aspect of snow crystals, and microstructures such as small rime droplets must have been present. Large decrease in SA with time were observed. The first meter of snowpack had a total surface area of about 50,000 m{sup 2} per m{sup 2} of ground. Reduction in SA will lead to the emission of adsorbed species by the snowpack, with possible considerable increase in atmospheric concentrations.

  3. ICE CHEMISTRY IN EMBEDDED YOUNG STELLAR OBJECTS IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect (OSTI)

    Oliveira, J. M.; Van Loon, J. Th. [School of Physical and Geographical Sciences, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Chen, C.-H. R.; Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Tielens, A. G. G. M. [Leiden Observatory, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Sloan, G. C. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Woods, P. M.; Kemper, F. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Gordon, K. D.; Boyer, M. L.; Shiao, B.; Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Madden, S. [Service d'Astrophysique, Commissariat a L'Energie Atomique de Saclay, 91191 Gif-sur-Yvette (France); Speck, A. K. [Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Marengo, M. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50010 (United States)

    2009-12-20

    We present spectroscopic observations of a sample of 15 embedded young stellar objects (YSOs) in the Large Magellanic Cloud (LMC). These observations were obtained with the Spitzer Infrared Spectrograph (IRS) as part of the SAGE-Spec Legacy program. We analyze the two prominent ice bands in the IRS spectral range: the bending mode of CO{sub 2} ice at 15.2 mum and the ice band between 5 and 7 mum that includes contributions from the bending mode of water ice at 6 mum among other ice species. The 5-7 mum band is difficult to identify in our LMC sample due to the conspicuous presence of polycyclic aromatic hydrocarbon emission superimposed onto the ice spectra. We identify water ice in the spectra of two sources; the spectrum of one of those sources also exhibits the 6.8 mum ice feature attributed in the literature to ammonium and methanol. We model the CO{sub 2} band in detail, using the combination of laboratory ice profiles available in the literature. We find that a significant fraction (approx>50%) of CO{sub 2} ice is locked in a water-rich component, consistent with what is observed for Galactic sources. The majority of the sources in the LMC also require a pure-CO{sub 2} contribution to the ice profile, evidence of thermal processing. There is a suggestion that CO{sub 2} production might be enhanced in the LMC, but the size of the available sample precludes firmer conclusions. We place our results in the context of the star formation environment in the LMC.

  4. Observed hemispheric asymmetry in global sea ice changes

    SciTech Connect (OSTI)

    Cavalieri, D.J.; Gloersen, P.; Parkinson, C.L.; Comiso, J.C.; Zwally, H.J.

    1997-11-07

    From November 1978 through December 1996, the areal extent of sea ice decreased by 2.9 {+-} 0.4 percent decade in the Arctic and increased by 1.3 {+-} 0.2 percent per decade in the Antarctic. The observed hemispheric asymmetry in these trends is consistent with a modeled response to a carbon dioxide-induced climate warming. The interannual variations, which are 2.3 percent of the annual mean in the Arctic, with a predominant period of about 5 years, and 3.4 percent of the annual mean in the Antarctic, with a predominant period of about 3 years, are uncorrelated. 29 refs., 2 figs., 1 tab.

  5. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    SciTech Connect (OSTI)

    Kalesse, Heike

    2013-06-27

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  6. Rigid pile response to ice plate and current loads 

    E-Print Network [OSTI]

    Nolte, John George

    1986-01-01

    Using Light Ice-Breaking Recording Vessel, " Proceedinxls, Qffsbore Technolo Confer~ace, OTC Paper No. 2225, lloOl~J~ PP. McLeod, W. R. , Adamo, L. C. , and Hamilton, R. C. , "A Unique Strategy for Obtaining Wave and Wind Data in the Gulf of Alaska... stream_source_info 1986 Thesis N798.pdf.txt stream_content_type text/plain stream_size 88765 Content-Encoding ISO-8859-1 stream_name 1986 Thesis N798.pdf.txt Content-Type text/plain; charset=ISO-8859-1 RIGID PILE...

  7. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kalesse, Heike

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  8. Impact of Ice Crystal Roughness on Satellite Retrieved Cloud Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATION PLAN FOR THE SITE- SPECIFIC SAVINGS PORTFOLIOImpactIce

  9. A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of 17 ice nucleation measurement techniques

    SciTech Connect (OSTI)

    Hiranuma, Naruki; Augustin-Bauditz, Stefanie; Bingemer, Heinz; Budke, Carsten; Curtius, J.; Danielczok, Anja; Diehl, K.; Dreischmeier, Katharina; Ebert, Martin; Frank, F.; Hoffmann, Nadine; Kandler, Kondrad; Kiselev, Alexei; Koop, Thomas; Leisner, Thomas; Mohler, Ottmar; Nillius, Bjorn; Peckhaus, Andreas; Rose, Diana; Weinbruch, Stephan; Wex, Heike; Boose, Yvonne; DeMott, Paul J.; Hader, John D.; Hill, Thomas; Kanji, Zamin; Kulkarni, Gourihar R.; Levin, Ezra; McCluskey, Christina; Murakami, Masataka; Murray, Benjamin J.; Niedermeier, Dennis; Petters, Markus D.; O'Sullivan, Daniel; Saito, Atsushi; Schill, Gregory; Tajiri, Takuya; Tolbert, Margaret A.; Welti, Andre; Whale, Thomas; Wright, Timothy; Yamashita, Katsuya

    2015-01-01

    Immersion freezing is the most relevant heterogeneous ice nucleation mechanism 3 through which ice crystals are formed in mixed-phase clouds. In recent years, an increasing 4 number of laboratory experiments utilizing a variety of instruments have examined immersion 5 freezing activity of atmospherically relevant ice nucleating particles (INPs). However, an 6 inter-comparison of these laboratory results is a difficult task because investigators have used 7 different ice nucleation (IN) measurement methods to produce these results. A remaining 8 challenge is to explore the sensitivity and accuracy of these techniques and to understand how 9 the IN results are potentially influenced or biased by experimental parameters associated with 10 these techniques. 11 Within the framework of INUIT (Ice Nucleation research UnIT), we distributed an 12 illite rich sample (illite NX) as a representative surrogate for atmospheric mineral dust 13 particles to investigators to perform immersion freezing experiments using different IN 14 measurement methods and to obtain IN data as a function of particle concentration, 15 temperature (T), cooling rate and nucleation time. Seventeen measurement methods were 16 involved in the data inter-comparison. Experiments with seven instruments started with the 17 test sample pre-suspended in water before cooling, while ten other instruments employed 18 water vapor condensation onto dry-dispersed particles followed by immersion freezing. The 19 resulting comprehensive immersion freezing dataset was evaluated using the ice nucleation 20 active surface-site density (ns) to develop a representative ns(T) spectrum that spans a wide 21 temperature range (-37 °C < T < -11 °C) and covers nine orders of magnitude in ns. 22 Our inter-comparison results revealed a discrepancy between suspension and dry-23 dispersed particle measurements for this mineral dust. While the agreement was good below ~-24 26 °C, the ice nucleation activity, expressed in ns, was smaller for the wet suspended samples 25 and higher for the dry-dispersed aerosol samples between about -26 and -18 °C. Only 26 instruments making measurement techniques with wet suspended samples were able to 27 measure ice nucleation above -18 °C. A possible explanation for the deviation between -26 28 and -18 °C is discussed. In general, the seventeen immersion freezing measurement 29 techniques deviate, within the range of about 7 °C in terms of temperature, by three orders of 30 magnitude with respect to ns. In addition, we show evidence that the immersion freezing 31 efficiency (i.e., ns) of illite NX particles is relatively independent on droplet size, particle 32 mass in suspension, particle size and cooling rate during freezing. A strong temperature-33 2 dependence and weak time- and size-dependence of immersion freezing efficiency of illite-34 rich clay mineral particles enabled the ns parameterization solely as a function of temperature. 35 We also characterized the ns(T) spectra, and identified a section with a steep slope between -36 20 °C and -27 °C, where a large fraction of active sites of our test dust may trigger immersion 37 freezing. This slope was followed by a region with a gentler slope at temperatures below -27 38 °C. A multiple exponential distribution fit is expressed as ns(T) = exp(23.82 × exp(-exp(0.16 × 39 (T + 17.49))) + 1.39) based on the specific surface area and ns(T) = exp(25.75 × exp(-exp(0.13 40 × (T + 17.17))) + 3.34) based on the geometric area (ns and T in m-2 and °C, respectively). 41 These new fits, constrained by using an identical reference samples, will help to compare IN 42 measurement methods that are not included in the present study and, thereby, IN data from 43 future IN instruments.

  10. Chapter 1 x Introduction 63 C1.2 When a person ice-skates, the ice surface actually melts beneath the blades, so

    E-Print Network [OSTI]

    Bahrami, Majid

    100 kg, L 30 cm, W 5 mm, and h 0.1 mm. Do you think our assumption of negligible air resistance! It appears that our assumption of negligible air drag was grossly incorrect. C1.3 Two thin flat plates)] Ans. (b) C1.4 Oil of viscosity P and density U drains steadily down the side of a tall, wide vertical

  11. Limits on a muon flux from neutralino annihilations in the Sun with the IceCube 22-string detector

    E-Print Network [OSTI]

    Klein, Spencer; IceCube Collaboration

    2009-01-01

    neutralino annihilations in the Sun with the IceCube 22-neutralino annihilations in the Sun with the IceCube 22-neutralino annihilations in the Sun has been performed with

  12. Reconstruction of the Past and Forecast of the Future European and British Ice Sheets and Associated Sea–Level Change 

    E-Print Network [OSTI]

    Hagdorn, Magnus K M

    The aim of this project is to improve our understanding of the past European and British ice sheets as a basis for forecasting their future. The behaviour of these ice sheets is investigated by simulating them using a ...

  13. Time-variable gravity observations of ice sheet mass balance: Precision and limitations of the GRACE satellite data

    E-Print Network [OSTI]

    Velicogna, I.; Wahr, J.

    2013-01-01

    observations, Science, 314, Peltier, W. R. (2004), Globalice history models (ICE5G [Peltier, 2004] and Fleming andfor Greenland; ICE5G [Peltier, 2004] and IJ05 [Ivins and

  14. Investigation of Glacial Dynamics in the Lambert Glacier-Amery Ice Shelf System (LAS) Using Remote Sensing 

    E-Print Network [OSTI]

    Chi, Zhaohui 1982-

    2012-12-10

    Numerous recent studies have documented dynamic changes in the behaviors of large marine-terminating outlet glaciers and ice streams in Greenland, the Antarctic Peninsula, and West Antarctica. However, fewer observations of outlet glaciers and ice...

  15. The Development and Use of the Berkeley Fluorescence Spectrometer to Characterize Microbial Content and Detect Volcanic Ash in Glacial Ice

    E-Print Network [OSTI]

    Rohde, Robert Andrew

    2010-01-01

    optical log of dust, ash, and stratigraphy in South PoleContent and Detect Volcanic Ash in Glacial Ice by RobertContent and Detect Volcanic Ash in Glacial Ice by Robert

  16. A deep high-resolution optical log of dust, ash, and stratigraphy in South Pole glacial ice

    E-Print Network [OSTI]

    Woschnagg, Kurt

    A deep high-resolution optical log of dust, ash, and stratigraphy in South Pole glacial ice N. E (2005), A deep high-resolution optical log of dust, ash, and stratigraphy in South Pole glacial ice

  17. Cryoconite Hole Ecosystems in Antarctic Glacier Ice Brent C. Christner, Montana State University, Department of Land

    E-Print Network [OSTI]

    Christner, Brent C.

    released from the melted glacial ice and attached to deposited airborne particulates provide the biological glacial melting. Cryoconite hole ecosystems exist and thrive under the harsh conditions associated, are warmed by the sun, and melt into the ice producing a cylindrical basin of liquid water. Organisms

  18. Ocean Challenge, Vol.19, Autumn 2012 Early Online The shrinking Greenland ice Sheet

    E-Print Network [OSTI]

    Johnson, Helen

    , the circulation within Greenland's fjords is not well known, and the interaction between glacial ice and the ocean's melting demands that oceanographers get involved! Unlike Antarctica, Greenland is not surrounded speeding up of the glacial ice flux over land. This in turn has caused concern over the vulnerability

  19. INTO DEEP ICEWhat does the future hold for Earth's ice? A group of British researchers seeks

    E-Print Network [OSTI]

    Lu, Chenyang

    INTO DEEP ICEWhat does the future hold for Earth's ice? A group of British researchers seeks.spectrum.ieee.org INTO DEEP ICEWhat does the future hold for Earth's ice? A group of British researchers seeks answers 2005 | IEEE Spectrum | NA 29 A COOL MISSION: A team of engineers and glaciologists [center] from

  20. Use of CAD Tools in the Integrated Computer Engineering Design (ICED) Curriculum

    E-Print Network [OSTI]

    Uht, Augustus K.

    Use of CAD Tools in the Integrated Computer Engineering Design (ICED) Curriculum Augustus K. Uht undergraduate computer engineering curriculum, ICED, is being introduced at the University of Rhode Island. The main feature of the curriculum is a design project span­ ning the last three years of the major