Sample records for atmospheric boundary layer

  1. THE MARTIAN ATMOSPHERIC BOUNDARY LAYER

    E-Print Network [OSTI]

    Spiga, Aymeric

    THE MARTIAN ATMOSPHERIC BOUNDARY LAYER A. Petrosyan,1 B. Galperin,2 S. E. Larsen,3 S. R. Lewis,4 A [Haberle et al., 1993a; Larsen et al., 2002; Hinson et al., 2008]. At night, convection is inhibited

  2. atmosphere boundary layer: Topics by E-print Network

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

    Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current...

  3. atmospheric boundary layer: Topics by E-print Network

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

    Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current...

  4. atmospheric boundary layers: Topics by E-print Network

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

    Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current...

  5. Interaction between surface and atmosphere in a convective boundary layer /

    E-Print Network [OSTI]

    Garai, Anirban

    2013-01-01T23:59:59.000Z

    of cold fluid constitute most of the heat transport andevent cold air descends to the ground, heat transport fromcold air during sweep events. The convective boundary layer has a great influence on moisture transport,

  6. Wind Energy-Related Atmospheric Boundary Layer Large-Eddy Simulation Using OpenFOAM: Preprint

    SciTech Connect (OSTI)

    Churchfield, M.J.; Vijayakumar, G.; Brasseur, J.G.; Moriarty, P.J.

    2010-08-01T23:59:59.000Z

    This paper develops and evaluates the performance of a large-eddy simulation (LES) solver in computing the atmospheric boundary layer (ABL) over flat terrain under a variety of stability conditions, ranging from shear driven (neutral stratification) to moderately convective (unstable stratification).

  7. Wave-driven wind jets in the marine atmospheric boundary layer

    E-Print Network [OSTI]

    Reading, University of

    Wave-driven wind jets in the marine atmospheric boundary layer Kirsty E. Hanley Stephen E. Belcher;Abstract The interaction between ocean surface waves and the overlying wind leads to a transfer of momentum can also be transferred upwards when long wavelength waves, characteristic of re- motely generated

  8. THE SIMULATION OF FINE SCALE NOCTURNAL BOUNDARY LAYER MOTIONS WITH A MESO-SCALE ATMOSPHERIC MODEL

    SciTech Connect (OSTI)

    Werth, D.; Kurzeja, R.; Parker, M.

    2009-04-02T23:59:59.000Z

    A field project over the Atmospheric Radiation Measurement-Clouds and Radiation Testbed (ARM-CART) site during a period of several nights in September, 2007 was conducted to explore the evolution of the low-level jet (LLJ). Data was collected from a tower and a sodar and analyzed for turbulent behavior. To study the full range of nocturnal boundary layer (NBL) behavior, the Regional Atmospheric Modeling System (RAMS) was used to simulate the ARM-CART NBL field experiment and validated against the data collected from the site. This model was run at high resolution, and is ideal for calculating the interactions among the various motions within the boundary layer and their influence on the surface. The model reproduces adequately the synoptic situation and the formation and dissolution cycles of the low-level jet, although it suffers from insufficient cloud production and excessive nocturnal cooling. The authors suggest that observed heat flux data may further improve the realism of the simulations both in the cloud formation and in the jet characteristics. In a higher resolution simulation, the NBL experiences motion on a range of timescales as revealed by a wavelet analysis, and these are affected by the presence of the LLJ. The model can therefore be used to provide information on activity throughout the depth of the NBL.

  9. Stability and Turbulence in the Atmospheric Boundary Layer: A Comparison of Remote Sensing and Tower Observations

    SciTech Connect (OSTI)

    Friedrich, K.; Lundquist, J. K.; Aitken, M.; Kalina, E. A.; Marshall, R. F.

    2012-01-01T23:59:59.000Z

    When monitoring winds and atmospheric stability for wind energy applications, remote sensing instruments present some advantages to in-situ instrumentation such as larger vertical extent, in some cases easy installation and maintenance, measurements of vertical humidity profiles throughout the boundary layer, and no restrictions on prevailing wind directions. In this study, we compare remote sensing devices, Windcube lidar and microwave radiometer, to meteorological in-situ tower measurements to demonstrate the accuracy of these measurements and to assess the utility of the remote sensing instruments in overcoming tower limitations. We compare temperature and wind observations, as well as calculations of Brunt-Vaisala frequency and Richardson numbers for the instrument deployment period in May-June 2011 at the U.S. Department of Energy National Renewable Energy Laboratory's National Wind Technology Center near Boulder, Colorado. The study reveals that a lidar and radiometer measure wind and temperature with the same accuracy as tower instruments, while also providing advantages for monitoring stability and turbulence. We demonstrate that the atmospheric stability is determined more accurately when the liquid-water mixing ratio derived from the vertical humidity profile is considered under moist-adiabatic conditions.

  10. antarctic boundary layer: Topics by E-print Network

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

    Geosciences Websites Summary: Boundary Layer Meteorology (METR 5103) Spring 2014 Syllabus General information Fundamentals of the atmospheric boundary layer dynamics and...

  11. atmosperic boundary layer: Topics by E-print Network

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

    Geosciences Websites Summary: Boundary Layer Meteorology (METR 5103) Spring 2014 Syllabus General information Fundamentals of the atmospheric boundary layer dynamics and...

  12. Wake Turbulence of Two NREL 5-MW Wind Turbines Immersed in a Neutral Atmospheric Boundary-Layer Flow

    E-Print Network [OSTI]

    Bashioum, Jessica L; Schmitz, Sven; Duque, Earl P N

    2013-01-01T23:59:59.000Z

    The fluid dynamics video considers an array of two NREL 5-MW turbines separated by seven rotor diameters in a neutral atmospheric boundary layer (ABL). The neutral atmospheric boundary-layer flow data were obtained from a precursor ABL simulation using a Large-Eddy Simulation (LES) framework within OpenFOAM. The mean wind speed at hub height is 8m/s, and the surface roughness is 0.2m. The actuator line method (ALM) is used to model the wind turbine blades by means of body forces added to the momentum equation. The fluid dynamics video shows the root and tip vortices emanating from the blades from various viewpoints. The vortices become unstable and break down into large-scale turbulent structures. As the wakes of the wind turbines advect further downstream, smaller-scale turbulence is generated. It is apparent that vortices generated by the blades of the downstream wind turbine break down faster due to increased turbulence levels generated by the wake of the upstream wind turbine.

  13. Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain

    E-Print Network [OSTI]

    Lundquist, Katherine Ann

    2010-01-01T23:59:59.000Z

    large-eddy simulations within mesoscale simulations for windEddy Simulation of a Mesoscale Convective Internal Boundary185, 1957. Pielke, R. , Mesoscale Meteorological Modeling,

  14. 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

    2012-07-23T23:59:59.000Z

    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.

  15. investigating the source, transport, and isotope fractionation of water vapor in the atmospheric boundary layer

    E-Print Network [OSTI]

    Minnesota, University of

    investigating the source, transport, and isotope fractionation of water vapor in the atmospheric-portable mixing ratio generator and Rayleigh distillation device, Agricultural and Forest Meteorology, 150, 1607 ratio generator. Incom- ing dry air passes through a molecular sieve and then a stainless steel frit (a

  16. Boundary Layer The U.S. Department of Energy's Atmospheric Radiation

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced Materials Find FindRewindParticleBorn on anJeffersonBound Boundary

  17. Wind Energy and the Turbulent Nature of the Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Wächter, Matthias; Hölling, Michael; Morales, Allan; Milan, Patrick; Mücke, Tanja; Peinke, Joachim; Reinke, Nico; Rinn, Philip

    2012-01-01T23:59:59.000Z

    The challenge of developing a sustainable and renewable energy supply within the next decades requires collaborative efforts as well as new concepts in the fields of science and engineering. Here we give an overview on the impact of small-scale properties of atmospheric turbulence on the wind energy conversion process. Special emphasis is given to the noisy and intermittent structure of turbulence and its outcome for wind energy conversion and utilization. Experimental, theoretical, analytical, and numerical concepts and methods are presented. In particular we report on new aspects resulting from the combination of basic research, especially in the field of turbulence and complex stochastic systems, with engineering applications.

  18. An investigation of the diabatic wind profile in the atmospheric boundary layer

    E-Print Network [OSTI]

    O'Brien, James Joseph

    1964-01-01T23:59:59.000Z

    in the study; in particular, thanks are extended to Mr. B. Jesse Eckalkamp for his assistance, Mrs. Linda Alexander for typing the final copy, and Mrs. Maxine Pulaski for drafting the figures. The National Space and Aeronautics Administration must...; and the potential temperature at the surface, 8 . After M & 0, the scale 0 length is derived from these quantities by letting Ue be used in place of r /o and H/pc be used in the place of H. since 8 varies little 0 P in the layer concerned, it may be regarded as a...

  19. atmospheric layers: Topics by E-print Network

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

    Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current...

  20. atmospheric superficial layer: Topics by E-print Network

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

    Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current...

  1. METEOROLOGY 130 Boundary Layer Meteorology

    E-Print Network [OSTI]

    Clements, Craig

    4) Turbulence Kinetic Energy · TKE budget and terms · Stability concepts · Richardson number 5) Measuring the Boundary Layer · Balloons · Radars · Sodars · Towers (micrometeorology) · Measuring Turbulence Time Series Analysis 8) Similarity Theory and Turbulence Closure 9) Surface Energy Budgets 10) Special

  2. Isolating Effects of Water Table Dynamics, Terrain, and Soil Moisture Heterogeneity on the Atmospheric Boundary Layer Using Coupled Models

    E-Print Network [OSTI]

    Rihani, Jehan

    2010-01-01T23:59:59.000Z

    boundary conditions of wind, potential temperature, andvariables such as winds, potential temperature, rainfall,variables such as wind speed, potential temperature, and

  3. A case study of boundary layer ventilation by convection and coastal processes

    E-Print Network [OSTI]

    Dacre, Helen

    A case study of boundary layer ventilation by convection and coastal processes H. F. Dacre,1 S. L; published 12 September 2007. [1] It is often assumed that ventilation of the atmospheric boundary layer responsible for ventilation of the atmospheric boundary layer during a nonfrontal day that occurred on 9 May

  4. Large Amplitude Spatial and Temporal Gradients in Atmospheric Boundary Layer CO2 Mole Fractions Detected With a Tower-Based Network in the U.S. Upper Midwest

    SciTech Connect (OSTI)

    Miles, Natasha; Richardson, S. J.; Davis, Kenneth J.; Lauvaux, Thomas; Andrews, A.; West, Tristram O.; Bandaru, Varaprasad; Crosson, Eric R.

    2012-02-21T23:59:59.000Z

    This study presents observations of atmospheric CO{sub 2} mole fraction from a nine-tower, regional network deployed during the North American Carbon Program's Mid-Continent Intensive during 2007-2009. Within this network in a largely agricultural area, mean atmospheric CO{sub 2} gradients were strongly correlated with both ground-based inventory data and estimates from satellite remote sensing. The average seasonal drawdown for corn-dominated sites (35 ppm) is significantly larger than has been observed at other continental boundary layer sites. Observed growing-season median CO{sub 2} gradients are strongly dependent on local flux. The gradients between cross-vegetation site-pairs, for example, average 2.0 ppm/100 km, four times larger than the similar-vegetation site-pair average. Daily-timescale gradients are as large as 5.5 ppm/100 km, but dominated by advection rather than local flux. Flooding in 2008 led to a region-wide 23 week delay in growing-season minima. The observations show that regional-scale CO{sub 2} mole fraction networks yield large, coherent signals governed largely by regional sources and sinks of CO{sub 2}.

  5. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01T23:59:59.000Z

    groundwater, land-surface, and mesoscale atmospheric model-and modification of mesoscale circulations. , Mon. Wea.J. Davis, The effects of mesoscale surface heterogeneity on

  6. Turbulent Fluxes in Stably Stratified Boundary Layers

    E-Print Network [OSTI]

    L'vov, Victor S; Rudenko, Oleksii; 10.1088/0031-8949/2008/T132/014010

    2008-01-01T23:59:59.000Z

    We present an extended version of an invited talk given on the International Conference "Turbulent Mixing and Beyond". The dynamical and statistical description of stably stratified turbulent boundary layers with the important example of the stable atmospheric boundary layer in mind is addressed. Traditional approaches to this problem, based on the profiles of mean quantities, velocity second-order correlations, and dimensional estimates of the turbulent thermal flux run into a well known difficulty, predicting the suppression of turbulence at a small critical value of the Richardson number, in contradiction with observations. Phenomenological attempts to overcome this problem suffer from various theoretical inconsistencies. Here we present an approach taking into full account all the second-order statistics, which allows us to respect the conservation of total mechanical energy. The analysis culminates in an analytic solution of the profiles of all mean quantities and all second-order correlations removing t...

  7. A study of atmosphere-ocean interaction using a one-dimensional numerical air-sea boundary layer model

    E-Print Network [OSTI]

    Hebenstreit, Gerald Thomas

    1974-01-01T23:59:59.000Z

    surface with no allowance for exchange induced by wave action. The model does produce reasonable solutions, in comparison with oceanic data, for the response of the lower atmosphere and the upper ocean to specific. sets of meteorological and oceanic.../2 this function is of the form f(Ri) = (1 + b Ri) , then one obtains ? 3 1/2 2 -1 K (z) = K 62 (gX ) exp(z/W) (z/I + rdI) (1 + b Ri) hw 1 (61) Although KITAIGORODSKII (1961) does not give a specific value of b, it would appear that b = 10/3 would be in line...

  8. Cyclone separator having boundary layer turbulence control

    DOE Patents [OSTI]

    Krishna, Coimbatore R. (Mt. Sinai, NY); Milau, Julius S. (Port Jefferson, NY)

    1985-01-01T23:59:59.000Z

    A cyclone separator including boundary layer turbulence control that is operable to prevent undue build-up of particulate material at selected critical areas on the separator walls, by selectively varying the fluid pressure at those areas to maintain the momentum of the vortex, thereby preventing particulate material from inducing turbulence in the boundary layer of the vortical fluid flow through the separator.

  9. ENTROPY BOUNDARY LAYERS FRANCK SUEUR

    E-Print Network [OSTI]

    Sueur, Franck

    on the boundary. These conditions are used in a reduction of the system. We construct BKW expansions at all order

  10. Energy transport using natural convection boundary layers

    SciTech Connect (OSTI)

    Anderson, R.

    1986-04-01T23:59:59.000Z

    Natural convection is one of the major modes of energy transport in passive solar buildings. There are two primary mechanisms for natural convection heat transport through an aperture between building zones: (1) bulk density differences created by temperature differences between zones; and (2) thermosyphon pumping created by natural convection boundary layers. The primary objective of the present study is to compare the characteristics of bulk density driven and boundary layer driven flow, and discuss some of the advantages associated with the use of natural convection boundary layers to transport energy in solar building applications.

  11. Numerical Simulation of the Wave Bottom Boundary Layer

    E-Print Network [OSTI]

    Slinn, Donald

    boundary layer. Oscillatory boundary layers are examined using a high-resolution time-dependent threeNumerical Simulation of the Wave Bottom Boundary Layer Over a Smooth Surface. Part 1: Three for turbulent boundary layers that occur over a smooth bottom. Results indicate that turbulence levels

  12. Planetary Boundary Layer from AERI and MPL

    SciTech Connect (OSTI)

    Sawyer, Virginia

    2014-02-13T23:59:59.000Z

    The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

  13. Planetary Boundary Layer from AERI and MPL

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

    Sawyer, Virginia

    The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

  14. Coupled wake boundary layer model of wind-farms

    E-Print Network [OSTI]

    Stevens, Richard J A M; Meneveau, Charles

    2014-01-01T23:59:59.000Z

    We present and test a coupled wake boundary layer (CWBL) model that describes the distribution of the power output in a wind-farm. The model couples the traditional, industry-standard wake expansion/superposition approach with a top-down model for the overall wind-farm boundary layer structure. The wake expansion/superposition model captures the effect of turbine positioning, while the top-down portion adds the interaction between the wind-turbine wakes and the atmospheric boundary layer. Each portion of the model requires specification of a parameter that is not known a-priori. For the wake model the wake expansion coefficient is required, while the top-down model requires an effective span-wise turbine spacing within which the model's momentum balance is relevant. The wake expansion coefficient is obtained by matching the predicted mean velocity at the turbine from both approaches, while the effective span-wise turbine spacing depends on turbine positioning and thus can be determined from the wake expansion...

  15. arctic boundary layer: Topics by E-print Network

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

    of many theoretical studies over the last forty years. (A Davies, Christopher 18 Tropical cyclone boundary layer shocks CERN Preprints Summary: This paper presents numerical...

  16. Overcoming the Boundary Layer Turbulence at Dome C: Ground-Layer Adaptive Optics versus Tower

    E-Print Network [OSTI]

    Ashley, Michael C. B.

    Overcoming the Boundary Layer Turbulence at Dome C: Ground-Layer Adaptive Optics versus Tower T the boundary layer: mounting a telescope on a tower that physically puts it above the turbulent layer such a goal, two solutions can be proposed. The most intuitive one is to place a telescope on a tower

  17. Analytic Model of the Universal Structure of Turbulent Boundary Layers

    E-Print Network [OSTI]

    Victor S. L'vov; Itamar Procaccia; Oleksii Rudenko

    2006-06-21T23:59:59.000Z

    Turbulent boundary layers exhibit a universal structure which nevertheless is rather complex, being composed of a viscous sub-layer, a buffer zone, and a turbulent log-law region. In this letter we present a simple analytic model of turbulent boundary layers which culminates in explicit formulae for the profiles of the mean velocity, the kinetic energy and the Reynolds stress as a function of the distance from the wall. The resulting profiles are in close quantitative agreement with measurements over the entire structure of the boundary layer, without any need of re-fitting in the different zones.

  18. Elements of comparison between Martian and terrestrial mesoscale meteorological phenomena: Katabatic winds and boundary layer convection

    E-Print Network [OSTI]

    Spiga, Aymeric

    Elements of comparison between Martian and terrestrial mesoscale meteorological phenomena Keywords: Mesoscale meteorology Katabatic winds Boundary layer convection Comparative planetology a b s t r a c t Terrestrial and Martian atmospheres are both characterised by a large variety of mesoscale

  19. Distributed boundary layer suction utilizing wing tip effects

    E-Print Network [OSTI]

    Edwards, Jay Thomas

    1962-01-01T23:59:59.000Z

    of this system to existing light aircraft would present no mechanical complications, either in the perforation of the wings or in the maintenance of the system. Recommendations for Other A lications 1. An investigation into the possibility of delaying... Means of Effecting Boundary Layer Control by Suction, " Aeronautical En ineerin Review, September, 1953. 17. Cornish, J. , "Practical High Lift Systems Using Distributed Boundary Layer Control, " Research Report $19, Miss. State College, 1958. 18...

  20. Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics

    SciTech Connect (OSTI)

    Manoj, M. G.; Devara, PC S.; Taraphdar, Sourav

    2013-10-01T23:59:59.000Z

    Observational evidence of two-way association between nocturnal boundary layer aerosols and cloud macrophysical properties under different meteorological conditions is reported in this paper. The study has been conducted during 2008-09 employing a high space-time resolution polarimetric micro-pulse lidar over a tropical urban station in India. Firstly, the study highlights the crucial role of boundary layer aerosols and background meteorology on the formation and structure of low-level stratiform clouds in the backdrop of different atmospheric stability conditions. Turbulent mixing induced by the wind shear at the station, which is associated with a complex terrain, is found to play a pivotal role in the formation and structural evolution of nocturnal boundary layer clouds. Secondly, it is shown that the trapping of energy in the form of outgoing terrestrial radiation by the overlying low-level clouds can enhance the aerosol mixing height associated with the nocturnal boundary layer. To substantiate this, the long-wave heating associated with cloud capping has been quantitatively estimated in an indirect way by employing an Advanced Research Weather Research and Forecasting (WRF-ARW) model version 2.2 developed by National Center for Atmospheric Research (NCAR), Colorado, USA, and supplementary data sets; and differentiated against other heating mechanisms. The present investigation as well establishes the potential of lidar remote-sensing technique in exploring some of the intriguing aspects of the cloud-environment relationship.

  1. Changes in the ocean mixed layer following extraordinary atmospheric forcing. Master's thesis

    SciTech Connect (OSTI)

    Mettlach, T.R.

    1985-12-01T23:59:59.000Z

    A one-dimensional ocean planetary boundary-layer model is used to predict the evolution of the thermal structure of the ocean mixed layer at six locations in the ocean following the hypothetical effects on the atmosphere of a major nuclear war. The inputs to the ocean model are the heat and momentum fluxes computed from a 3D climate model designed to simulate nuclear winter effects in the atmosphere. The experiment gives evidence that the summertime mixed layer can cool 5 C within 30 days and that the effect of increased wind along coastal regions due to sudden ocean-land temperture differences will deepen the mixed layer 20 to 30 meters. The scientific literature on the subject of nuclear winter is reviewed and interpreted to trace the evolution of the nuclear winter hypothesis and to assess the quality of the results of the mixed layer experiment.

  2. Sangamon field experiments: observations of the diurnal evolution of the planetary boundary layer over land

    SciTech Connect (OSTI)

    Hicks, B.B.; Hess, G.D.; Wesely, M.L.; Yamada, T.; Frenzen, P.; Hart, R.L.; Sisterson, D.L.; Hess, P.E.; Kulhanek, F.C.; Lipschutz, R.C.; Zerbe, G.A.

    1981-09-01T23:59:59.000Z

    Two complementary experimental studies of the evolving structure of the lower 2 km of the atmosphere, conducted over farmlands in central Illinois during essentially the same mid-summer weeks of two successive years, are described. The first experiment (21 July - 13 August 1975) investigated the early morning break up of the nocturnal stable layer and the rapid growth of the mixed layer before noon; the second (16 to 30 July 1976) examined the decline of the mixed layer through the late afternoon and evening, and the formation and intensification of the ground-based inversion before midnight. Methods of observation and data reduction are summarized in some detail, and the data obtained in the form of hourly wind and temperature profiles, plus sufficient surface flux information to characterize the lower boundary conditions, are tabulated in a series of appendices. These results constitute complete data sets which may be used to test models of the diurnal evolution of the lower atmosphere.

  3. Distributed Roughness Receptivity in a Flat Plate Boundary Layer

    E-Print Network [OSTI]

    Kuester, Matthew Scott

    2014-04-18T23:59:59.000Z

    for the three different unit Reynolds num- ber test conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.4 Spanwise uniformity of boundary layer integral quantities at x = 870 mm for low unit Reynolds number test condition... with the distributed roughness configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 24 3.5 Differential pressure across the flat plate leading edge. . . . . . . . . . 25 3.6 Roughness patch (k = 1 mm), before windowing . . . . . . . . . . . . 27 3...

  4. Carbon transport in the bottom boundary layer. Final report

    SciTech Connect (OSTI)

    Agrawal, Y.C.

    1998-10-05T23:59:59.000Z

    This report summarizes the activities and findings from a field experiment devised to estimate the rates and mechanisms of transport of carbon across the continental shelves. The specific site chosen for the experiment was the mid-Atlantic Bight, a region off the North Carolina coast. The experiment involved a large contingent of scientists from many institutions. The specific component of the program was the transport of carbon in the bottom boundary layer. The postulate mechanisms of transport of carbon in the bottom boundary layer are: resuspension and advection, downward deposition, and accumulation. The high turbulence levels in the bottom boundary layer require the understanding of the coupling between turbulence and bottom sediments. The specific issues addressed in the work reported here were: (a) What is the sediment response to forcing by currents and waves? (b) What is the turbulence climate in the bottom boundary layer at this site? and (c) What is the rate at which settling leads to carbon sequestering in bottom sediments at offshore sites?

  5. Long-term Observations of the Convective Boundary Layer Using Insect Radar Returns at the SGP ARM Climate Research Facility

    SciTech Connect (OSTI)

    Chandra, A S; Kollias, P; Giangrande, S E; Klein, S A

    2009-08-20T23:59:59.000Z

    A long-term study of the turbulent structure of the convective boundary layer (CBL) at the U.S. Department of Energy Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) Climate Research Facility is presented. Doppler velocity measurements from insects occupying the lowest 2 km of the boundary layer during summer months are used to map the vertical velocity component in the CBL. The observations cover four summer periods (2004-08) and are classified into cloudy and clear boundary layer conditions. Profiles of vertical velocity variance, skewness, and mass flux are estimated to study the daytime evolution of the convective boundary layer during these conditions. A conditional sampling method is applied to the original Doppler velocity dataset to extract coherent vertical velocity structures and to examine plume dimension and contribution to the turbulent transport. Overall, the derived turbulent statistics are consistent with previous aircraft and lidar observations. The observations provide unique insight into the daytime evolution of the convective boundary layer and the role of increased cloudiness in the turbulent budget of the subcloud layer. Coherent structures (plumes-thermals) are found to be responsible for more than 80% of the total turbulent transport resolved by the cloud radar system. The extended dataset is suitable for evaluating boundary layer parameterizations and testing large-eddy simulations (LESs) for a variety of surface and cloud conditions.

  6. Polymer Effects on Heat Transport in Laminar Boundary Layer Flow

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching; Vivien W. S. Chu

    2011-04-27T23:59:59.000Z

    We consider a laminar Blasius boundary-layer flow above a slightly heated horizontal plate and study the effect of polymer additives on the heat transport. We show that the action of the polymers can be understood as a space-dependent effective viscosity that first increases from the zero-shear value then decreases exponentially back to the zero-shear value as one moves away from the boundary. We find that with such an effective viscosity, both the horizontal and vertical velocities near the plate are decreased thus leading to an increase in the friction drag and a decrease in the heat transport in the flow.

  7. Wind profile above the surface boundary layer S.-E. Gryning (1), E. Batchvarova (2) and B. Brmmer (3)

    E-Print Network [OSTI]

    Wind profile above the surface boundary layer S.-E. Gryning (1), E. Batchvarova (2) and B. Brümmer in predictions of the wind profile in the lowest hundreds me- ters of the atmosphere, being connected to the general increase in height of structures such as bridges, high houses and wind turbines. The hub height

  8. DOI 10.1007/s10546-005-9005-9 Boundary-Layer Meteorology (2006) 119: 135157 Springer 2006

    E-Print Network [OSTI]

    and to the thermal internal boundary-layer formation. The strong coastal and orographic influences sensing systems such as lidars use aerosols as tracers, with the optical power measured by a lidar proportional to the aerosol content of the atmosphere. The lidar signal shows strong backscattering within

  9. DOI 10.1007/s10546-005-7772-y Boundary-Layer Meteorology (2006) 118: 477501 Springer 2006

    E-Print Network [OSTI]

    Ribes, Aurélien

    2006-01-01T23:59:59.000Z

    radial velocity measurements on a 6-km radius area in the lowest 3 km of the troposphere. Thus the urban effects appear to be negligible. Keywords: Atmospheric boundary layer, Doppler lidar, Numerical the Marseille area are compared to the Doppler lidar data, for which the spatial res- olution is comparable

  10. Boundary-Layer Meteorol (2010) 134:157180 DOI 10.1007/s10546-009-9433-z

    E-Print Network [OSTI]

    Gentine, Pierre

    2010-01-01T23:59:59.000Z

    forcing is dependent on the heat storage and diffusion as well as on the coupling of the soil of surface state variables to the frequency of the forcing is analyzed. Keywords Diurnal cycle · Ground heat cycle of temperature and heat-flux profiles in a coupled land- surface and atmospheric boundary layer

  11. Do stable atmospheric layers exist? S. Lovejoy,1,2

    E-Print Network [OSTI]

    Long, Bernard

    01802, doi:10.1029/2007GL032122. [2] There are two basic theoretical approaches for under- standing atmospheric stratification: the statistical turbulent approach and the deterministic ``dynamical meteorology. [1] The notion of stable atmospheric layers is a classical idealization used for understanding

  12. Examining A Hypersonic Turbulent Boundary Layer at Low Reynolds Number

    E-Print Network [OSTI]

    Semper, Michael Thomas

    2013-05-15T23:59:59.000Z

    z spanwise direction, m Greek Symbols boundary layer thickness, m displacement thickness, m ratio of speci c heats hotwire recovery ratio dynamic viscosity, Pa s density, kg=m3 hotwire overheat ratio, Twire=Tt momentum thickness, m... direct numerical simulation LDV laser doppler velocimetry LES large eddy simulation MTV molecular tagging velocimetry OHR overheat ratio (see ) PIV particle image velocimetry PLIF planar laser induced uorescence RANS Reynolds averaged Navier...

  13. Improving Subtropical Boundary Layer Cloudiness in the 2011 NCEP GFS

    SciTech Connect (OSTI)

    Fletcher, J. K.; Bretherton, Christopher S.; Xiao, Heng; Sun, Ruiyu N.; Han, J.

    2014-09-23T23:59:59.000Z

    The current operational version of National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) shows significant low cloud bias. These biases also appear in the Coupled Forecast System (CFS), which is developed from the GFS. These low cloud biases degrade seasonal and longer climate forecasts, particularly of short-wave cloud radiative forcing, and affect predicted sea surface temperature. Reducing this bias in the GFS will aid the development of future CFS versions and contributes to NCEP's goal of unified weather and climate modelling. Changes are made to the shallow convection and planetary boundary layer parameterisations to make them more consistent with current knowledge of these processes and to reduce the low cloud bias. These changes are tested in a single-column version of GFS and in global simulations with GFS coupled to a dynamical ocean model. In the single-column model, we focus on changing parameters that set the following: the strength of shallow cumulus lateral entrainment, the conversion of updraught liquid water to precipitation and grid-scale condensate, shallow cumulus cloud top, and the effect of shallow convection in stratocumulus environments. Results show that these changes improve the single-column simulations when compared to large eddy simulations, in particular through decreasing the precipitation efficiency of boundary layer clouds. These changes, combined with a few other model improvements, also reduce boundary layer cloud and albedo biases in global coupled simulations.

  14. BOUNDARY LAYER (BL) THERMAL EDDIES OVER A PINE FOREST FROM CARES 2010

    E-Print Network [OSTI]

    BOUNDARY LAYER (BL) THERMAL EDDIES OVER A PINE FOREST FROM CARES 2010 Gunnar Senum and Stephen are three thermal eddies, about 250 meters wide, in the boundary layer. These thermal eddies are formed from the solar heating of the surface and help to form the boundary layer. The eddy updrafts are transporting

  15. Numerical Simulations of the Wave Bottom Boundary Layer over Sand Ripples

    E-Print Network [OSTI]

    Slinn, Donald

    locations. Under conditions of oscillatory potential flow external to the boundary layer causedNumerical Simulations of the Wave Bottom Boundary Layer over Sand Ripples by Thomas Pierro A Thesis boundary layer are believed to play a major role in the re-suspension and transport of sediment, as well

  16. Thermographic analysis of turbulent non-isothermal water boundary layer

    E-Print Network [OSTI]

    Znamenskaya, Irina A

    2015-01-01T23:59:59.000Z

    The paper is devoted to the investigation of the turbulent water boundary layer in the jet mixing flows using high-speed infrared (IR) thermography. Two turbulent mixing processes were studied: a submerged water jet impinging on a flat surface and two intersecting jets in a round disc-shaped vessel. An infrared camera (FLIR Systems SC7700) was focused on the window transparent for IR radiation; it provided high-speed recordings of heat fluxes from a thin water layer close to the window. Temperature versus time curves at different points of water boundary layer near the wall surface were acquired using the IR camera with the recording frequency of 100 Hz. The time of recording varied from 3 till 20 min. The power spectra for the temperature fluctuations at different points on the hot-cold water mixing zone were calculated using the Fast Fourier Transform algorithm. The obtained spectral behavior was compared to the Kolmogorov "-5/3 spectrum" (a direct energy cascade) and the dual-cascade scenario predicted for...

  17. Applications of Fourier analysis in homogenization and boundary layer

    E-Print Network [OSTI]

    Aleksanyan, Hayk; Sjölin, Per

    2012-01-01T23:59:59.000Z

    In this paper we prove convergence results for the boundary layer homogenization problem for solutions of partial differential system with rapidly oscillating Dirichlet data. Our method is based on analysis of oscillatory integrals. In the uniformly convex regime and smooth boundaries we prove pointwise as well as $L^p$ convergence results. Namely, we prove $|u_{\\e}(x)-u_0 (x)| \\leq C_{\\kappa} \\e^{(d-1)/2}\\frac{1}{d(x)^{\\kappa}}$, $\\forall x\\in D$, $ \\forall \\ \\kappa>d-1$, and for $1\\leq pboundary of $D$. In particular for $p=2$ our result relates to the recent result of D. G\\'{e}rarad-Varet and N. Masmoudi \\cite{GM}.

  18. Aerodynamic Models for Hurricanes III. Modeling hurricane boundary layer

    E-Print Network [OSTI]

    Leonov, Arkady I

    2008-01-01T23:59:59.000Z

    The third paper of the series (see previous ones in Refs.[1-2]) discusses basic physicalprocesses in the (quasi-) steady hurricane boundary layer (HBL), develops an approximate airflow model, establishes the HBL structure, and presents integral balance relations for dynamic and thermodynamic variables in HBL. Models of evaporation and condensation are developed, where the condensation is treated similarly to the slow combustion theory. A turbulent approximation for the lower sub-layer of HBL is applied to the sea-air interaction to establish the observed increase in angular momentum in the outer region of HBL.A closed set of balance relations has been obtained. Simple analytical solution of the set yields expressions for the basic dynamic variables - maximal tangential and radial velocities in hurricane, maximal vertical speed in eye wall, the affinity speed of hurricane travel, and the maximal temperature increase after condensation. Estimated values of the variables seem to be realistic. An attempt is also ...

  19. Delaying natural transition of a boundary layer using smooth steps

    E-Print Network [OSTI]

    Xu, Hui; Sherwin, Spencer J

    2015-01-01T23:59:59.000Z

    The boundary layer flow over a smooth forward-facing stepped plate is studied with particular emphasis on the delay of the transition to turbulence. The interaction between the Tollmien-Schlichting (T-S) waves and the base flow over a single/two forward facing smooth steps is conducted by linear analysis indicating the amplitude of the T-S waves are attenuated in the boundary layer over a single smooth plate. Furthermore, we show that two smooth forward facing steps give rise to a further reduction of the amplitude of the T-S waves. A direct numerical simulation (DNS) is performed for the two smooth forward steps correlating favourably with the linear analysis and showing that for the investigated parameters, the K-type transition is inhibited whereas the turbulence onset of the H-type transition is postponed albeit not suppressed. Transition is indeed delayed and drag reduced for both these transition scenarios suggesting smooth forward facing steps could be leveraged as a passive flow control strategy to de...

  20. Laminar-turbulent separatrix in a boundary layer flow

    E-Print Network [OSTI]

    Biau, Damien

    2013-01-01T23:59:59.000Z

    The transitional boundary layer flow over a flat plate is investigated. The boundary layer flow is known to develop unstable Tollmien-Schlichting waves above a critical value of the Reynolds number. However, it is also known that this transition can be observed for sub-critical Reynolds numbers. In that case, the basin of attraction of the laminar state coexists with the sustained turbulence. In this article, the trajectory on the separatrix between these two states is simulated. The state on the separatrix is independent from the initial condition and is dynamically connected to both the laminar flow and the turbulence. Such an edge state provides information regarding the basic features of the transitional flow. The solution takes the form of a low speed streak, flanked by two quasi-streamwise sinuous vortices. The shape of the streaks is close to that simulated with the linear optimal perturbation method. This solution is compared to existing results concerning streak breakdown. The simulations are realize...

  1. Friction of a slider on a granular layer: Nonmonotonic thickness dependence and effect of boundary conditions

    E-Print Network [OSTI]

    Kudrolli, Arshad

    Friction of a slider on a granular layer: Nonmonotonic thickness dependence and effect of boundary the effective friction encountered by a mass sliding on a granular layer as a function of bed thickness and boundary roughness conditions. The observed friction has minima for a small number of layers before

  2. Characterization of Oscillatory Boundary Layer over a Closely Packed Bed of

    E-Print Network [OSTI]

    Apte, Sourabh V.

    Characterization of Oscillatory Boundary Layer over a Closely Packed Bed of Sediment Particles Boundary Layer over a Closely Packed Bed of Sediment Particles Chaitanya D. Ghodke*, Joseph Skitka a detailed knowledge of the small amplitude oscillatory flow over the sediment layer near the sea bed. Fully

  3. Heat transport by laminar boundary layer flow with polymers

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching.; Vivien W. S. Chu

    2011-04-23T23:59:59.000Z

    Motivated by recent experimental observations, we consider a steady-state Prandtl-Blasius boundary layer flow with polymers above a slightly heated horizontal plate and study how the heat transport might be affected by the polymers. We discuss how a set of equations can be derived for the problem and how these equations can be solved numerically by an iterative scheme. By carrying out such a scheme, we find that the effect of the polymers is equivalent to producing a space-dependent effective viscosity that first increases from the zero-shear value at the plate then decreases rapidly back to the zero-shear value far from the plate. We further show that such an effective viscosity leads to an enhancement in the drag, which in turn leads to a reduction in heat transport.

  4. Primary, secondary instabilities and control of the rotating-disk boundary layer

    E-Print Network [OSTI]

    ;Typical 3D boundary layers rotating disk swept wing Common features: · crossflow component near the wall · inflection point · strong inviscid instability · secondary instabilities ; growth and saturation of crossflow

  5. Comparison of reflection boundary conditions for langevin equation modeling of convective boundary layer dispersion

    SciTech Connect (OSTI)

    Nasstrom, J.S.; Ermak, D.L.

    1997-04-01T23:59:59.000Z

    Lagrangian stochastic modeling based on the Langevin equation has been shown to be useful for simulating vertical dispersion of trace material in the convective boundary layer or CBL. This modeling approach can account for the effects of the long velocity correlation time scales, skewed vertical velocity distributions, and vertically inhomogeneous turbulent properties found in the CBL. It has been recognized that Langevin equation models assuming skewed but homogenous velocity statistics can capture the important aspects of diffusion from sources in the CBL, especially elevated sources. We compare three reflection boundary conditions using two different Langevin-equation-based numerical models for vertical dispersion in skewed, homogeneous turbulence. One model, described by Ermak and Nasstrom (1995) is based on a Langevin equation with a skewed random force and a linear deterministic force. The second model, used by Hurley and Physick (1993) is based on a Langevin equation with a Gaussian random force and a non-linear deterministic force. The reflection boundary conditions are all based on the approach described by Thompson and Montgomery (1994).

  6. Turbulent flow over a house in a simulated hurricane boundary layer

    E-Print Network [OSTI]

    Taylor, Zachary; Gurka, Roi; Kopp, Gregory

    2009-01-01T23:59:59.000Z

    Every year hurricanes and other extreme wind storms cause billions of dollars in damage worldwide. For residential construction, such failures are usually associated with roofs, which see the largest aerodynamic loading. However, determining aerodynamic loads on different portions of North American houses is complicated by the lack of clear load paths and non-linear load sharing in wood frame roofs. This problem of fluid-structure interaction requires both wind tunnel testing and full-scale structural testing. A series of wind tunnel tests have been performed on a house in a simulated atmospheric boundary layer (ABL), with the resulting wind-induced pressures applied to the full-scale structure. The ABL was simulated for flow over open country terrain where both velocity and turbulence intensity profiles, as well as spectra, were matched with available full scale measurements for this type of terrain. The first set of measurements was 600 simultaneous surface pressure measurements over the entire house. A key...

  7. Coupled Mesoscale-Large-Eddy Modeling of Realistic Stable Boundary Layer Turbulence

    E-Print Network [OSTI]

    Wang, Yao; Manuel, Lance

    2013-01-01T23:59:59.000Z

    Site-specific flow and turbulence information are needed for various practical applications, ranging from aerodynamic/aeroelastic modeling for wind turbine design to optical diffraction calculations. Even though highly desirable, collecting on-site meteorological measurements can be an expensive, time-consuming, and sometimes a challenging task. In this work, we propose a coupled mesoscale-large-eddy modeling framework to synthetically generate site-specific flow and turbulence data. The workhorses behind our framework are a state-of-the-art, open-source atmospheric model called the Weather Research and Forecasting (WRF) model and a tuning-free large-eddy simulation (LES) model. Using this coupled framework, we simulate a nighttime stable boundary layer (SBL) case from the well-known CASES-99 field campaign. One of the unique aspects of this work is the usage of a diverse range of observations for characterization and validation. The coupled models reproduce certain characteristics of observed low-level jets....

  8. Intercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed during

    E-Print Network [OSTI]

    Zuidema, Paquita

    /crystal concentration also suggests the need for improved understanding of ice nucleation and its parameterizationIntercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed is presented. This case study is based on observations of a persistent mixed-phase boundary layer cloud

  9. INTERANNUAL AND SEASONAL VARIATIONS IN MARINE BOUNDARY LAYER CLOUD FRACTION AND LOWER

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    : ___________________________________________________________ #12;i Abstract Marine boundary layer (MBL) clouds have a large effect on the global radiation budget cooling effect in the MBL. Thus, simulating MBL clouds in General Circulation Models (GCM) is crucialINTERANNUAL AND SEASONAL VARIATIONS IN MARINE BOUNDARY LAYER CLOUD FRACTION AND LOWER TROPOSPHERIC

  10. Bottom boundary layer measurements in OMP. Final report

    SciTech Connect (OSTI)

    Gross, T.F. [Skidaway Inst. of Oceanography, Savannah, GA (United States); Williams, A.J. [Woods Hole Oceanographic Inst., MA (United States)

    1998-11-01T23:59:59.000Z

    The main role of the Benthic Acoustic Stress Sensor (BASS) tripods within the Ocean Margins Program experiments was to detect and quantify organic carbon rich particle transport off the shelf. This requires measures of the turbulent boundary layer flow and bed stress, the physical forcing of the particle transport, as well as the concentration and type of particles which are being transported. The BASS tripods were deployed at sites 17 and 26. Data from site 26 were recovered spanning three periods: Feb. 2--April 6, May 13--June 27, June 28--Aug. 18. Site 17 was occupied Feb. 12--april 11. The BASS tripods were arrayed with five BASS sensors measuring detailed velocity parameters within four meters of the seabed. Velocity time series indicate a usually weak tidal flow which produces small bed stress by itself. On the occasions when a strong flow, probably the Gulf Stream, crosses the area, the bed shear stress increases dramatically to as much as 10 dyne cm{sup {minus}2}. This is competent to move unconsolidated sediments in the area. Other instruments from the tripods include: two conductivity/temperature sensor pairs, five WetStar fluorometers, thermistors, transmissometer, optical backscatterence sensors and a pressure sensor.

  11. Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems

    E-Print Network [OSTI]

    Putrasahan, Dian Ariyani

    2012-01-01T23:59:59.000Z

    Isolating Mesoscale Coupled Ocean-Atmosphere in the KuroshioSST coupler . . . . Chapter 3 Mesoscale Ocean-Atmosphere4.2 Impact of Mesoscale SST on Precipitation Chapter 4 vi

  12. Interaction between surface and atmosphere in a convective boundary layer /

    E-Print Network [OSTI]

    Garai, Anirban

    2013-01-01T23:59:59.000Z

    resulting in constant wind, and potential temperature andatmospheric wind speed, direction and potential temperatureatmospheric profiles (wind speed, potential temperature),

  13. ARM - Field Campaign - 2013 Lower Atmospheric Boundary Layer 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76)ARM2, 2006 [FacilityMission Under52 NEAQS (New7

  14. ARM - Field Campaign - Lower Atmospheric Boundary Layer 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa

  15. EXPERIMENTAL STUDY OF COMBUSTION IN A TURBULENT BOUNDARY LAYER

    E-Print Network [OSTI]

    Cheng, R.K.

    2011-01-01T23:59:59.000Z

    evaporation, but the thermophoretic migration of particlesboundary layer due to thermophoretic motion and evaporation

  16. DIFFUSION OF A CHEMICAL SPECIES THROUGH A VISCOUS BOUNDARY LAYER

    E-Print Network [OSTI]

    Keller, J.

    2011-01-01T23:59:59.000Z

    2.3 Evaluation of a Coal Gasification Atmosphere. . -iv-a highly cor- rosive coal gasification mixture. It is shown2.3 Evaluation of a Coal Gasification Atmosphere The purpose

  17. F/sub 2/ boundary layer measurement in a chemical laser slit nozzle flow

    SciTech Connect (OSTI)

    Spenser, D.J.; Durran, D.A.; Bixler, H.A.; Varwig, R.L.

    1983-02-01T23:59:59.000Z

    A sensitive F2 absorption diagnostic suitable for slit nozzle scanning was developed and applied to the measurement of an F2 boundary layer in an HF chemical laser flow. The F2 boundary layer profile was determined to be of exponential decay form with peak at the nozzle wall and of width approx. 1/3 the viscous boundary layer. The F2 concentration profile was displaced inwardly and slightly compressed by the H2 slit injection at the nozzle exit plane. The F2 profile apparently remains fairly intact in passing through the lasing zone.

  18. Transforming the representation of the boundary layer and low clouds for high-resolution regional climate modeling: Final report

    SciTech Connect (OSTI)

    Huang, Hsin-Yuan; Hall, Alex

    2013-07-24T23:59:59.000Z

    Stratocumulus and shallow cumulus clouds in subtropical oceanic regions (e.g., Southeast Pacific) cover thousands of square kilometers and play a key role in regulating global climate (e.g., Klein and Hartmann, 1993). Numerical modeling is an essential tool to study these clouds in regional and global systems, but the current generation of climate and weather models has difficulties in representing them in a realistic way (e.g., Siebesma et al., 2004; Stevens et al., 2007; Teixeira et al., 2011). While numerical models resolve the large-scale flow, subgrid-scale parameterizations are needed to estimate small-scale properties (e.g. boundary layer turbulence and convection, clouds, radiation), which have significant influence on the resolved scale due to the complex nonlinear nature of the atmosphere. To represent the contribution of these fine-scale processes to the resolved scale, climate models use various parameterizations, which are the main pieces in the model that contribute to the low clouds dynamics and therefore are the major sources of errors or approximations in their representation. In this project, we aim to 1) improve our understanding of the physical processes in thermal circulation and cloud formation, 2) examine the performance and sensitivity of various parameterizations in the regional weather model (Weather Research and Forecasting model; WRF), and 3) develop, implement, and evaluate the advanced boundary layer parameterization in the regional model to better represent stratocumulus, shallow cumulus, and their transition. Thus, this project includes three major corresponding studies. We find that the mean diurnal cycle is sensitive to model domain in ways that reveal the existence of different contributions originating from the Southeast Pacific land-masses. The experiments suggest that diurnal variations in circulations and thermal structures over this region are influenced by convection over the Peruvian sector of the Andes cordillera, while the mostly dry mountain-breeze circulations force an additional component that results in semi-diurnal variations near the coast. A series of numerical tests, however, reveal sensitivity of the simulations to the choice of vertical grid, limiting the possibility of solid quantitative statements on the amplitudes and phases of the diurnal and semidiurnal components across the domain. According to our experiments, the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer scheme and the WSM6 microphysics scheme is the combination of schemes that performs best. For that combination, mean cloud cover, liquid water path, and cloud depth are fairly wellsimulated, while mean cloud top height remains too low in comparison to observations. Both microphysics and boundary layer schemes contribute to the spread in liquid water path and cloud depth, although the microphysics contribution is slightly more prominent. Boundary layer schemes are the primary contributors to cloud top height, degree of adiabaticity, and cloud cover. Cloud top height is closely related to surface fluxes and boundary layer structure. Thus, our study infers that an appropriate tuning of cloud top height would likely improve the low-cloud representation in the model. Finally, we show that entrainment governs the degree of adiabaticity, while boundary layer decoupling is a control on cloud cover. In the intercomparison study using WRF single-column model experiments, most parameterizations show a poor agreement of the vertical boundary layer structure when compared with large-eddy simulation models. We also implement a new Total-Energy/Mass- Flux boundary layer scheme into the WRF model and evaluate its ability to simulate both stratocumulus and shallow cumulus clouds. Result comparisons against large-eddy simulation show that this advanced parameterization based on the new Eddy-Diffusivity/Mass-Flux approach provides a better performance than other boundary layer parameterizations.

  19. Design of a model propulsor for a boundary layer ingesting aircraft

    E-Print Network [OSTI]

    Grasch, Adam D. (Adam Davis)

    2013-01-01T23:59:59.000Z

    This thesis presents contributions to the analysis and design of propulsion simulators for 1:11 and 1:4 scale model wind tunnel investigations of an advanced civil transport aircraft with boundary layer ingestion (BLI). ...

  20. Boundary-Layer Receptivity to Three-Dimensional Roughness Arrays on a Swept-Wing

    E-Print Network [OSTI]

    Hunt, Lauren Elizabeth

    2012-02-14T23:59:59.000Z

    is required. This study uses detailed hotwire boundary-layer velocity scans to quantify the relationship between roughness height and initial disturbance amplitude. Naphthalene flow visualization provides insight into how transition changes as a result...

  1. Advances in the visualization and analysis of boundary layer flow in swimming fish

    E-Print Network [OSTI]

    Anderson, Erik J

    2005-01-01T23:59:59.000Z

    In biology, the importance of fluid drag, diffusion, and heat transfer both internally and externally, suggest the boundary layer as an important subject of investigation, however, the complexities of biological systems ...

  2. Stability Analysis for a Saline Boundary Layer Formed by Uniform Up ow Using Finite Elements

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    density in the deeper underground and high salt water density at the boundary layer), gravitation plays and Darcy's law. In this report we #12;rst give an overview of semi-analytical methods to analyse

  3. The hydrodynamic stability of crossflow vortices in the Bdewadt boundary layer

    E-Print Network [OSTI]

    The hydrodynamic stability of crossflow vortices in the Bödewadt boundary layer N. A. Culverhouse the critical Reynolds number. extends the laminar flow region. decreasing the magnitude of the crossflow

  4. Analysis and interpretation of tidal currents in the coastal boundary layer

    E-Print Network [OSTI]

    May, Paul Wesley, 1950-

    1979-01-01T23:59:59.000Z

    Concern with the impact of human activities on the coastal region of the world's oceans has elicited interest in the so-called "coastal boundary layer"-that band of water adjacent to the coast where ocean currents adjust ...

  5. The aerodynamic characteristics of an airfoil utilizing boundary layer and circulation control

    E-Print Network [OSTI]

    Boothe, Edward Milton

    1965-01-01T23:59:59.000Z

    THE AERODYNAMIC CHARACTERISTICS OF AN AIRFOIL UTILIZING BOUNDARY LAYER AND CIRCULATION CONTROL A Thesis By EDWARD MILTON BOOTHE Submitted to the Graduate College of the Texas ARM University in partial fulfillment of the requirements... . Wind Tunnel IV Auxiliary Equipment EXPERIMENTAL PROCEDURES . 13 Preliminary Tests 13 Measurement of Boundary Layer And Circulation Control Parameters 16 Wind Tunnel Tests of Airfoil Model. 19 Reduction of Experimental Results 20 V RESULTS...

  6. Shipboard measurements of the cloud-capped marine boundary layer during FIRE/ASTEX

    SciTech Connect (OSTI)

    NONE

    1997-09-01T23:59:59.000Z

    Results are reported on measurements of the cloud-capped marine boundary layer during FIRE/ASTEX. A method was developed from the ASTEX dataset for measuring profiles of liquid water content, droplet size and concentration from cloud radar/microwave radiometer data in marine boundary layer clouds. Profiles were also determined from the first three moments of the Doppler spectrum measured in drizzle with the ETL cloud radar during ASTEX.

  7. Design of an Instrumentation System for a Boundary Layer Transition Wing Glove Experiment 

    E-Print Network [OSTI]

    Williams, Thomas 1987-

    2012-08-23T23:59:59.000Z

    of Air * Complex Conjugate CF Crossflow CFD Computational Fluid Dynamics ! Skin Friction Coefficient cgr,n Group Velocity Measured by Sensor-n CN ASHRAE Clearness Factor for Solar Radiation ! Pressure Coefficient !" Specific Heat of Air... Test Engineer Acceleration due to Gravity G-III Gulfstream G-III Business Jet !" Crossflow Similarity Variable for the Falkner-Scan-Cooke Boundary Layer !"! Value of Crossflow Similarity Variable for the Falkner-Scan-Cooke Boundary Layer...

  8. atmospheric convective boundary: Topics by E-print Network

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

    convective conditions is found to be primarily due to variations in mixed layer wind speed. Low-level winds thus play the major role in regulating the ability of thermals to...

  9. EART 265 Lecture Notes: Boundary Layers We're interested here mainly in boundary layers relevant to planets, i.e. those of planetary atmo-

    E-Print Network [OSTI]

    Nimmo, Francis

    and the surface, thus mediating all interactions between the two. If we look back at the Navier-Stokes equations of a solid (or liquid in the case of gas ows) where diusion is non-negligible. It is characterized by strong then promotes mixing. Outside the boundary layer, uid often mixes only very slowly because turbulence

  10. Technical Tools for Boundary Layers and Applications to Heterogeneous Coefficients

    E-Print Network [OSTI]

    Sarkis, Marcus

    , Poland. This work was supported in part by the Polish Sciences Foundation under grant NN201006933. 2 energy in a thin layer and vice versa, how to control the energy of a discrete harmonic function

  11. Combustion-turbulence interaction in the turbulent boundary layer over a hot surface

    SciTech Connect (OSTI)

    Ng, T.T.; Cheng, R.K.; Robben, F.; Talbot, L.

    1982-01-01T23:59:59.000Z

    The turbulence-combustion interaction in a reacting turbulent boundary layer over a heated flat plate was studied. Ethylene/air mixture with equivalence ratio of 0.35 was used. The free stream velocity was 10.5 m/s and the wall temperature was 1250/sup 0/K. Combustion structures visualization was provided by high-speed schlieren photographs. Fluid density statistics were deduced from Rayleigh scattering intensity measurements. A single-component laser Doppler velocimetry system was used to obtain mean and root-mean-square velocity distributions, the Reynolds stress, the streamwise and the cross-stream turbulent kinetic energy diffusion, and the production of turbulent kinetic energy by Reynolds stress. The combustion process was dominated by large-scale turbulent structures of the boundary layer. Combustion causes expansion of the boundary layer. No overall self-similarity is observed in either the velocity or the density profiles. Velocity fluctuations were increased in part of the boundary layer and the Reynolds stress was reduced. The turbulent kinetic energy diffusion pattern was changed significantly and a modification of the boundary layer assumption will be needed when dealing with this problem analytically. 11 figures, 1 table.

  12. RACORO continental boundary layer cloud investigations. Part I: Case study development and ensemble large-scale forcings

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

    Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; Endo, Satoshi; Lin, Wuyin; Wang, Jian; Feng, Sha; Zhang, Yunyan; Turner, David D.; Liu, Yangang; et al

    2015-05-01T23:59:59.000Z

    Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60-hour case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in-situ measurements from the RACORO field campaign and remote-sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functionsmore »for concise representation in models. Values of the aerosol hygroscopicity parameter, ?, are derived from observations to be ~0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing datasets are derived from the ARM variational analysis, ECMWF forecasts, and a multi-scale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in 'trial' large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds.« less

  13. ARM - Field Campaign - Boundary Layer CO2 Using CW Lidar

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76)ARM2,govCampaignsAircraftCloud ODgovCampaignsBoundary

  14. F/sup 2/ boundary layer measurement in a chemical laser slit nozzle flow. Technical report

    SciTech Connect (OSTI)

    Spencer, D.J.; Durran, D.A.; Bixler, H.A.; Varwig, R.L.

    1983-02-15T23:59:59.000Z

    A sensitive F/sup 2/ absorption diagnostic suitable for slit nozzle scanning was developed and applied to the measurement of an F/sup 2/ boundary layer in an HF chemical laser flow. The F/sup 2/ boundary layer profile was determined to be of exponential decay form with peak at the nozzle wall and of width approx. 1/3 the viscous boundary layer. The F/sup 2/ concentration profile was displaced inwardly and slightly compressed by the H2 slit injection at the nozzle exit plane, which penetration profile followed the relation delta = 0.1(sq. root of x). The F/sup 2/ profile apparently remains fairly intact in passing through the lasing zone.

  15. Mars Exploration Rover (MER) Panoramic Camera (Pancam) Twilight Image Analysis for Determination of Planetary Boundary Layer and Dust Particle Size Parameters

    E-Print Network [OSTI]

    Grounds, Stephanie Beth

    2012-02-14T23:59:59.000Z

    to take surface-based measurements to offer support for dust and boundary layer measurements made from remote sensors (Lemmon et al., 2004a). Mars has different atmospheric characteristics from those on Earth. For example, the solar constant for Mars... is approximately 44% of the value for Earth (varying by approximately 20%), and the temperature ranges on Mars (- 125?C to +25?C) slightly ____________ This thesis follows the style of the Journal of Geophysical Research. 2 overlap those on Earth (- 80?C...

  16. Prospects for Simulating Macromolecular Surfactant Chemistry at the Ocean-Atmosphere Boundary

    SciTech Connect (OSTI)

    Elliott, S.; Burrows, Susannah M.; Deal, C.; Liu, Xiaohong; Long, M.; Ogunro, O.; Russell, Lynn M.; Wingenter, O.

    2014-05-01T23:59:59.000Z

    Biogenic lipids and polymers are surveyed for their ability to adsorb at the water-air interfaces associated with bubbles, marine microlayers and particles in the overlying boundary layer. Representative ocean biogeochemical regimes are defined in order to estimate local concentrations for the major macromolecular classes. Surfactant equilibria and maximum excess are then derived based on a network of model compounds. Relative local coverage and upward mass transport follow directly, and specific chemical structures can be placed into regional rank order. Lipids and denatured protein-like polymers dominate at the selected locations. The assigned monolayer phase states are variable, whether assessed along bubbles or at the atmospheric spray droplet perimeter. Since oceanic film compositions prove to be irregular, effects on gas and organic transfer are expected to exhibit geographic dependence as well. Moreover, the core arguments extend across the sea-air interface into aerosol-cloud systems. Fundamental nascent chemical properties including mass to carbon ratio and density depend strongly on the geochemical state of source waters. High surface pressures may suppress the Kelvin effect, and marine organic hygroscopicities are almost entirely unconstrained. While bubble adsorption provides a well-known means for transporting lipidic or proteinaceous material into sea spray, the same cannot be said of polysaccharides. Carbohydrates tend to be strongly hydrophilic so that their excess carbon mass is low despite stacked polymeric geometries. Since sugars are abundant in the marine aerosol, gel-based mechanisms may be required to achieve uplift. Uncertainties in the surfactant logic distill to a global scale dearth of information regarding two dimensional kinetics and equilibria. Nonetheless simulations are recommended, to initiate the process of systems level quantification.

  17. ESTIMATING BEDROCK AND SURFACE LAYER BOUNDARIES AND CONFIDENCE INTERVALS IN ICE SHEET RADAR IMAGERY USING MCMC

    E-Print Network [OSTI]

    Menczer, Filippo

    ESTIMATING BEDROCK AND SURFACE LAYER BOUNDARIES AND CONFIDENCE INTERVALS IN ICE SHEET RADAR IMAGERY and Computing Indiana University Bloomington, Indiana USA ABSTRACT Climate models that predict polar ice sheet behavior require accurate measurements of the bedrock-ice and ice-air bound- aries in ground

  18. Sensitivity of Swept-Wing, Boundary-Layer Transition to Spanwise-Periodic Discrete Roughness Elements

    E-Print Network [OSTI]

    West, David Edward

    2014-12-12T23:59:59.000Z

    Micron-sized, spanwise-periodic, discrete roughness elements (DREs) were applied to and tested on a 30° swept-wing model in order to study their effects on boundary-layer transition in flight where stationary crossflow waves are the dominant...

  19. Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer

    E-Print Network [OSTI]

    Peltier, Scott Jacob

    2013-08-05T23:59:59.000Z

    field of incompressible boundary layer, taken from Adrian et al. (2000). ............................................................................... 138 Figure 6.15 Schematic of an individual hairpin vortex, describing the sweep and ejection... hairpin vortex, identifying the motions contributing to sweeps and ejections ....................................................................................... 235 Figure 7.46 Illustrations of the possible mechanisms contributing to the reduced...

  20. American Institute of Aeronautics and Astronautics Shock/Boundary Layer Interaction Effects of Transverse

    E-Print Network [OSTI]

    Texas at Arlington, University of

    of Transverse Jets in Crossflow over a Body of Revolution Dean A. Dickmann* Lockheed Martin Missiles and Fire 76019 Shock/boundary layer interaction present in transverse jets in supersonic crossflow alteres suggested a transverse jet in crossflow can be represented by a solid body of given length and shape

  1. Flowfield and wall pressure characteristics downstream of a boundary layer suction device.

    E-Print Network [OSTI]

    Tinney, Charles E.

    Flowfield and wall pressure characteristics downstream of a boundary layer suction device. Meagan A-dimensional slit can significantly reduce the fluctuating wall pressure immediately downstream of the suction slit momentum regions of the flow with the wall at the downstream edge of the suction slit. The third region

  2. Local and Bi-Global Stability Analysis of a Plasma Actuated Boundary Layer

    E-Print Network [OSTI]

    Roy, Subrata

    velocities ¯p Mean pressure ~u, ~v, ~w Disturbance flow velocities ~p Disturbance pressure u , v , w Complex disturbance flow velocities p Complex disturbance pressure u Freestream velocity up Induced velocity Complex spatial frequency in x Complex spatial frequency in z Complex temporal frequency 99% Boundary layer

  3. A novel Whole Air Sample Profiler (WASP) for the quantification of volatile organic compounds in the boundary layer

    SciTech Connect (OSTI)

    Mak, J. E.; Su, L.; Guenther, Alex B.; Karl, Thomas G.

    2013-10-16T23:59:59.000Z

    The emission and fate of reactive VOCs is of inherent interest to those studying chemical biosphere-atmosphere interactions. In-canopy VOC observations are obtainable using tower-based samplers, but the lack of suitable sampling systems for the full boundary 5 layer has limited the data characterizing the vertical structure of such gases above the canopy height and still in the boundary layer. This is the important region where many reactive VOCs are oxidized or otherwise removed. Here we describe an airborne sampling system designed to collect a vertical profile of air into a 3/800 OD tube 150m in length. The inlet ram air pressure is used to flow sampled air through the 10 tube, which results in a varying flow rate based on aircraft speed and altitude. Since aircraft velocity decreases during ascent, it is necessary to account for the variable flow rate into the tube. This is accomplished using a reference gas that is pulsed into the air stream so that the precise altitude of the collected air can be reconstructed post-collection. The pulsed injections are also used to determine any significant effect 15 from diffusion/mixing within the sampling tube, either during collection or subsequent extraction for gas analysis. This system has been successfully deployed, and we show some measured vertical profiles of isoprene and its oxidation products methacrolein and methyl vinyl ketone from a mixed canopy near Columbia, Missouri.

  4. 5A.8 IDENTIFYING NONSTATIONARITY IN THE ATMOSPHERIC SURFACE LAYER Edgar L Andreas*1

    E-Print Network [OSTI]

    Geiger, Cathleen

    1 of 12 5A.8 IDENTIFYING NONSTATIONARITY IN THE ATMOSPHERIC SURFACE LAYER Edgar L Andreas*1 address: Edgar L Andreas, U.S. Army Cold Regions Research and Engineering Laboratory, 72 Lyme Road

  5. Clouds, Precipitation, and Marine Boundary Layer Structure during the MAGIC Field Campaign

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

    Zhou, Xiaoli; Kollias, Pavlos; Lewis, Ernie R.

    2015-03-01T23:59:59.000Z

    The recent ship-based MAGIC (Marine ARM GCSS Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds) field campaign with the marine-capable Second ARM Mobile Facility (AMF2) deployed on the Horizon Lines cargo container M/V Spirit provided nearly 200 days of intraseasonal high-resolution observations of clouds, precipitation, and marine boundary layer (MBL) structure on multiple legs between Los Angeles, California, and Honolulu, Hawaii. During the deployment, MBL clouds exhibited a much higher frequency of occurrence than other cloud types and occurred more often in the warm season than in the cold season. MBL clouds demonstrated a propensity to produce precipitation, which often evaporatedmore »before reaching the ocean surface. The formation of stratocumulus is strongly correlated to a shallow MBL with a strong inversion and a weak transition, while cumulus formation is associated with a much weaker inversion and stronger transition. The estimated inversion strength is shown to depend seasonally on the potential temperature at 700 hPa. The location of the commencement of systematic MBL decoupling always occurred eastward of the locations of cloud breakup, and the systematic decoupling showed a strong moisture stratification. The entrainment of the dry warm air above the inversion appears to be the dominant factor triggering the systematic decoupling, while surface latent heat flux, precipitation, and diurnal circulation did not play major roles. MBL clouds broke up over a short spatial region due to the changes in the synoptic conditions, implying that in real atmospheric conditions the MBL clouds do not have enough time to evolve as in the idealized models. (auth)« less

  6. Clouds, Precipitation, and Marine Boundary Layer Structure during the MAGIC Field Campaign

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

    Zhou, Xiaoli [McGill Univ., Montreal, Quebec (Canada); Dept. of Atmospheric and Oceanic Sciences; Kollias, Pavlos [McGill Univ., Montreal, Quebec (Canada); Dept. of Atmospheric and Oceanic Sciences; Lewis, Ernie R. [Brookhaven National Lab., Upton, NY (United States). Biological, Environmental, and Climate Sciences Dept.

    2015-03-01T23:59:59.000Z

    The recent ship-based MAGIC (Marine ARM GCSS Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds) field campaign with the marine-capable Second ARM Mobile Facility (AMF2) deployed on the Horizon Lines cargo container M/V Spirit provided nearly 200 days of intraseasonal high-resolution observations of clouds, precipitation, and marine boundary layer (MBL) structure on multiple legs between Los Angeles, California, and Honolulu, Hawaii. During the deployment, MBL clouds exhibited a much higher frequency of occurrence than other cloud types and occurred more often in the warm season than in the cold season. MBL clouds demonstrated a propensity to produce precipitation, which often evaporated before reaching the ocean surface. The formation of stratocumulus is strongly correlated to a shallow MBL with a strong inversion and a weak transition, while cumulus formation is associated with a much weaker inversion and stronger transition. The estimated inversion strength is shown to depend seasonally on the potential temperature at 700 hPa. The location of the commencement of systematic MBL decoupling always occurred eastward of the locations of cloud breakup, and the systematic decoupling showed a strong moisture stratification. The entrainment of the dry warm air above the inversion appears to be the dominant factor triggering the systematic decoupling, while surface latent heat flux, precipitation, and diurnal circulation did not play major roles. MBL clouds broke up over a short spatial region due to the changes in the synoptic conditions, implying that in real atmospheric conditions the MBL clouds do not have enough time to evolve as in the idealized models. (auth)

  7. Retrieval of Urban Boundary Layer Structures from Doppler Lidar Data. Part I: Accuracy Assessment

    SciTech Connect (OSTI)

    Xia, Quanxin; Lin, Ching Long; Calhoun, Ron; Newsom, Rob K.

    2008-01-01T23:59:59.000Z

    Two coherent Doppler lidars from the US Army Research Laboratory (ARL) and Arizona State University (ASU) were deployed in the Joint Urban 2003 atmospheric dispersion field experiment (JU2003) held in Oklahoma City. The dual lidar data are used to evaluate the accuracy of the four-dimensional variational data assimilation (4DVAR) method and identify the coherent flow structures in the urban boundary layer. The objectives of the study are three-fold. The first objective is to examine the effect of eddy viscosity models on the quality of retrieved velocity data. The second objective is to determine the fidelity of single-lidar 4DVAR and evaluate the difference between single- and dual-lidar retrievals. The third objective is to correlate the retrieved flow structures with the ground building data. It is found that the approach of treating eddy viscosity as part of control variables yields better results than the approach of prescribing viscosity. The ARL single-lidar 4DVAR is able to retrieve radial velocity fields with an accuracy of 98% in the along-beam direction and 80-90% in the cross-beam direction. For the dual-lidar 4DVAR, the accuracy of retrieved radial velocity in the ARL cross-beam direction improves to 90-94%. By using the dual-lidar retrieved data as a reference, the single-lidar 4DVAR is able to recover fluctuating velocity fields with 70-80% accuracy in the along-beam direction and 60-70% accuracy in the cross-beam direction. Large-scale convective roll structures are found in the vicinity of downtown airpark and parks. Vortical structures are identified near the business district. Strong updrafts and downdrafts are also found above a cluster of restaurants.

  8. Using Mesoscale Weather Model Output as Boundary Conditions for Atmospheric Large-Eddy Simulations and Wind-Plant Aerodynamic Simulations (Presentation)

    SciTech Connect (OSTI)

    Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.

    2013-10-01T23:59:59.000Z

    Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the mesoscale weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. Mesoscale weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture mesoscale-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a mesoscale weather model with a microscale atmospheric large-eddy simulation model. The coupling is one-way beginning with the weather model and ending with a computational fluid dynamics solver using the weather model in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the mesoscale data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.

  9. Evaluating the Performance of Planetary Boundary Layer and Cloud Microphysical Parameterization Schemes in Convection-Permitting Ensemble Forecasts using

    E-Print Network [OSTI]

    Xue, Ming

    uncertainty in how to include various processes (e.g., drop breakup and ice-phase categories 1 Evaluating the Performance of Planetary Boundary Layer and Cloud Microphysical Parameterization In this study, the ability of several cloud microphysical and planetary boundary layer parameterization schemes

  10. Accumulation mode aerosol, pockets of open cells, and particle nucleation in the remote subtropical Pacific marine boundary layer

    E-Print Network [OSTI]

    Russell, Lynn

    Accumulation mode aerosol, pockets of open cells, and particle nucleation in the remote subtropical in the remote subtropical Pacific marine boundary layer, J. Geophys. Res., 111, D02206, doi:10.1029/2004JD005694 the boundary layer via its action on the budgets of heat and water substance. A plausible consequence may

  11. Modeling feedbacks between a boreal forest and the planetary boundary layer

    E-Print Network [OSTI]

    observations at the stand scale (e.g., flux towers) and those at larger scales, e.g., airborne or satellite on the atmospheric surface layer by 21% for latent energy, 64% for air temperature, and 44% for water mixing ratio to the biosphere through the surface energy balance. The response of the terrestrial biosphere to climate

  12. Resuspension of Small Particles from Multilayer Deposits in Turbulent Boundary Layers

    E-Print Network [OSTI]

    F. Zhang; M. Reeks; M. Kissane; R. J. Perkins

    2012-06-09T23:59:59.000Z

    We present a hybrid stochastic model for the resuspension of micron-size particles from multilayer deposits in a fully-developed turbulent boundary layer. The rate of removal of particles from any given layer depends upon the rate of removal of particles from the layer above which acts as a source of uncovering and exposure of particles to the resuspending flow. The primary resuspension rate constant for an individual particle within a layer is based on the Rock'n'Roll (R'n'R) model using non-Gaussian statistics for the aerodynamic forces acting on the particles (Zhang et al., 2012). The coupled layer equations that describe multilayer resuspension of all the particles in each layer are based on the generic lattice model of Friess & Yadigaroglu (2001) which is extended here to include the influence of layer coverage and particle size distribution. We consider the influence of layer thickness on the resuspension along with the spread of adhesion within layers, and the statistics of non-Gaussian versus Gaussian removal forces including their timescale. Unlike its weak influence on long-term resuspension rates for monolayers, this timescale plays a crucial and influential role in multilayer resuspension. Finally we compare model predictions with those of a large-scale and a mesoscale resuspension test, STORM (Castelo et al., 1999) and BISE (Alloul-Marmor, 2002).

  13. Blockage of natural convection boundary layer flow in a multizone enclosure

    SciTech Connect (OSTI)

    Scott, D.; Anderson, R.; Figliola, R.S.

    1986-02-01T23:59:59.000Z

    This paper reports the results of an experimental study that examines the transition between flow regimes, as a function of aperture size, in a two-zone enclosure with heated and cooled end walls. A constant heat flux boundary condition was maintained on one vertical end wall, and an isothermal cold temperature sink was maintained on the opposite vertical end wall. All of the remaining surfaces were highly insulated. The transition between the boundary layer driven regime and the bulk density driven regime was established as a function of the geometry of the aperture in the partition that separated the hot and cold zones. The results demonstrate that transition from the boundary layer driven regime to the bulk density driven regime is caused by blockage of the boundary layer flow, when the area of the flow aperture is reduced below a critical value. A simple flow model has been developed which predicts that the critical aperture area for the onset of flow blockage is directly proportional to the number of active heat transfer surfaces and inversely proportional to the Rayleigh number which characterizes the level of heating and cooling provided to the active heat transfer surfaces.

  14. Quasi-periodic oscillations as global hydrodynamic modes in the boundary layers of viscous accretion disks

    E-Print Network [OSTI]

    M. Hakan Erkut; Dimitrios Psaltis; M. Ali Alpar

    2008-07-28T23:59:59.000Z

    The observational characteristics of quasi-periodic oscillations (QPOs) from accreting neutron stars strongly indicate the oscillatory modes in the innermost regions of accretion disks as a likely source of the QPOs. The inner regions of accretion disks around neutron stars can harbor very high frequency modes related to the radial epicyclic frequency $\\kappa $. The degeneracy of $\\kappa $ with the orbital frequency $\\Omega $ is removed in a non-Keplerian boundary or transition zone near the magnetopause between the disk and the compact object. We show, by analyzing the global hydrodynamic modes of long wavelength in the boundary layers of viscous accretion disks, that the fastest growing mode frequencies are associated with frequency bands around $\\kappa $ and $\\kappa \\pm \\Omega $. The maximum growth rates are achieved near the radius where the orbital frequency $\\Omega $ is maximum. The global hydrodynamic parameters such as the surface density profile and the radial drift velocity determine which modes of free oscillations will grow at a given particular radius in the boundary layer. In accordance with the peak separation between kHz QPOs observed in neutron-star sources, the difference frequency between two consecutive bands of the fastest growing modes is always related to the spin frequency of the neutron star. This is a natural outcome of the boundary condition imposed by the rotating magnetosphere on the boundary region of the inner disk.

  15. Experimental investigation of sound generation by a protuberance in a laminar boundary layer

    SciTech Connect (OSTI)

    Kobayashi, M.; Asai, M.; Inasawa, A. [Department of Aerospace Engineering, Tokyo Metropolitan University, 6-6 Asahigaoka, Hino, Tokyo 191-0065 (Japan)

    2014-08-15T23:59:59.000Z

    Sound radiation from a two-dimensional protuberance glued on the wall in a laminar boundary layer was investigated experimentally at low Mach numbers. When the protuberance was as high as the boundary-layer thickness, a feedback-loop mechanism set in between protuberance-generated sound and Tollmien-Schlichting (T-S) waves generated by the leading-edge receptivity to the upstream-propagating sound. Although occurrence of a separation bubble immediately upstream of the protuberance played important roles in the evolution of instability waves into vortices interacting with the protuberance, the frequency of tonal vortex sound was determined by the selective amplification of T-S waves in the linear instability stage upstream of the separation bubble and was not affected by the instability of the separation bubble.

  16. Viscous boundary layers of radiation-dominated, relativistic jets. II. The free-streaming jet model

    E-Print Network [OSTI]

    Coughlin, Eric R

    2015-01-01T23:59:59.000Z

    We analyze the interaction of a radiation-dominated jet and its surroundings using the equations of radiation hydrodynamics in the viscous limit. In a previous paper we considered the two-stream scenario, which treats the jet and its surroundings as distinct media interacting through radiation viscous forces. Here we present an alternative boundary layer model, known as the free-streaming jet model -- where a narrow stream of fluid is injected into a static medium -- and present solutions where the flow is ultrarelativistic and the boundary layer is dominated by radiation. It is shown that these jets entrain material from their surroundings and that their cores have a lower density of scatterers and a harder spectrum of photons, leading to observational consequences for lines of sight that look "down the barrel of the jet." These jetted outflow models may be applicable to the jets produced during long gamma-ray bursts and super-Eddington phases of tidal disruption events.

  17. Viscous boundary layers of radiation-dominated, relativistic jets. I. The two-stream model

    E-Print Network [OSTI]

    Coughlin, Eric R

    2015-01-01T23:59:59.000Z

    Using the relativistic equations of radiation hydrodynamics in the viscous limit, we analyze the boundary layers that develop between radiation-dominated jets and their environments. In this paper we present the solution for the self-similar, 2-D, plane-parallel two-stream problem, wherein the jet and the ambient medium are considered to be separate, interacting fluids, and we compare our results to those of previous authors. (In a companion paper we investigate an alternative scenario, known as the free-streaming jet model.) Consistent with past findings, we show that the boundary layer that develops between the jet and its surroundings creates a region of low-density material. These models may be applicable to sources such as super-Eddington tidal disruption events and long gamma-ray bursts.

  18. On the relationship between temperature and wind speed in the atmospheric surface layer

    E-Print Network [OSTI]

    Pierrard, John Martin

    1958-01-01T23:59:59.000Z

    LIBRAR& A AN m os??E " "" ON THE RELATIONSHIP BETWEEN T" MP. "RATURE AND WIND SPEED IN THE ATMOSPHERIC SURFACE LAYER A Thesis John Me Pierrard Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... fulfillment of the requirements for the degree of MASTER OF SCI"NCE August 1958 Ma)or Sub)ect: Meteorology ON THE RELATIONSHIP BETWEEN TEMPERATURE AND WIND SP ED IN THE ATMOSPHERIC SUBRACE LAYER A Thesis John M. Pierrard Approved as to style...

  19. Variability of ozone in the marine boundary layer of the equatorial Pacific Ocean1 Xiao-Ming Hu1

    E-Print Network [OSTI]

    Thompson, Anne

    marine boundary layer of the Kwajalein Atoll, Republic of the Marshall Islands (latitude 8o 43'3 N al., 2000; Horowitz et al., 2003; Yang et13 al., 2005; von Glasow, 2008). Due to logistical

  20. An empirical model for the mean-velocity profiles of a turbulent boundary layer under the effects of surface curvature 

    E-Print Network [OSTI]

    Huynh, Long Quang

    1994-01-01T23:59:59.000Z

    An empirical model has been developed to predict the mean-velocity profile of a turbulent boundary layer under the influence of surface curvature. The model proposed is able to determine the profiles for both a convex and concave curvature...

  1. An empirical model for the mean-velocity profiles of a turbulent boundary layer under the effects of surface curvature

    E-Print Network [OSTI]

    Huynh, Long Quang

    1994-01-01T23:59:59.000Z

    An empirical model has been developed to predict the mean-velocity profile of a turbulent boundary layer under the influence of surface curvature. The model proposed is able to determine the profiles for both a convex and concave curvature...

  2. Prediction of continental shelf sediment transport using a theoretical model of the wave-current boundary layer

    E-Print Network [OSTI]

    Goud, Margaret R

    1987-01-01T23:59:59.000Z

    This thesis presents an application of the Grant-Madsen-Glenn bottom boundary layer model (Grant and Madsen, 1979; Glenn and Grant, 1987) to predictions of sediment transport on the continental shelf. The analysis is a ...

  3. Conditionally-Sampled Turbulent and Nonturbulent Measurements of Entropy Generation Rate in the Transition Region of Boundary Layers

    SciTech Connect (OSTI)

    D. M. McEligot; J. R. Wolf; K. P. Nolan; E. J. Walsh; R. J. Volino

    2006-05-01T23:59:59.000Z

    Conditionally-sampled boundary layer data for an accelerating transitional boundary layer have been analyzed to calculate the entropy generation rate in the transition region. By weighing the nondimensional dissipation coefficient for the laminar-conditioned-data and turbulent-conditioned-data with the intermittency factor the average entropy generation rate in the transition region can be determined and hence be compared to the time averaged data and correlations for steady laminar and turbulent flows. It is demonstrated that this method provides, for the first time, an accurate and detailed picture of the entropy generation rate during transition. The data used in this paper have been taken from detailed boundary layer measurements available in the literature. This paper provides, using an intermittency weighted approach, a methodology for predicting entropy generation in a transitional boundary layer.

  4. Accretion Disk Boundary Layers Around Neutron Stars: X-ray Production in Low-Mass X-ray Binaries

    E-Print Network [OSTI]

    Robert Popham; Rashid Sunyaev

    2000-04-03T23:59:59.000Z

    We present solutions for the structure of the boundary layer where the accretion disk meets the neutron star, which is expected to be the dominant source of high-energy radiation in low-mass X-ray binaries which contain weakly magnetized accreting neutron stars. We find that the main portion of the boundary layer gas is hot (> ~10^8 K), low in density, radially and vertically extended, and optically thick to scattering but optically thin to absorption. It will produce large X-ray luminosity by Comptonization. Energy is transported inward by viscosity, concentrating the energy dissipation in the dense, optically thick zone close to the stellar surface. We explore the dependence of the boundary layer structure on the mass accretion rate, the rotation rate of the star, the alpha viscosity parameter and the viscosity prescription. Radiation pressure is the dominant source of pressure in the boundary layer; the flux is close to the Eddington limiting flux even for luminosities well below (~0.01 times) L(Edd). At luminosities near L(Edd), the boundary layer expands radially, and has a radial extent larger than one stellar radius. Based on the temperatures and optical depths which characterize the boundary layer, we expect that Comptonization will produce a power-law spectrum at low source luminosities. At high luminosities, a Planckian spectrum will be produced in the dense region where most of the energy is released, and modified by Comptonization as the radiation propagates outward.

  5. An enriched finite element model with q-refinement for radiative boundary layers in glass cooling

    SciTech Connect (OSTI)

    Mohamed, M. Shadi [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Seaid, Mohammed; Trevelyan, Jon [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom)] [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Laghrouche, Omar [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2014-02-01T23:59:59.000Z

    Radiative cooling in glass manufacturing is simulated using the partition of unity finite element method. The governing equations consist of a semi-linear transient heat equation for the temperature field and a stationary simplified P{sub 1} approximation for the radiation in non-grey semitransparent media. To integrate the coupled equations in time we consider a linearly implicit scheme in the finite element framework. A class of hyperbolic enrichment functions is proposed to resolve boundary layers near the enclosure walls. Using an industrial electromagnetic spectrum, the proposed method shows an immense reduction in the number of degrees of freedom required to achieve a certain accuracy compared to the conventional h-version finite element method. Furthermore the method shows a stable behaviour in treating the boundary layers which is shown by studying the solution close to the domain boundaries. The time integration choice is essential to implement a q-refinement procedure introduced in the current study. The enrichment is refined with respect to the steepness of the solution gradient near the domain boundary in the first few time steps and is shown to lead to a further significant reduction on top of what is already achieved with the enrichment. The performance of the proposed method is analysed for glass annealing in two enclosures where the simplified P{sub 1} approximation solution with the partition of unity method, the conventional finite element method and the finite difference method are compared to each other and to the full radiative heat transfer as well as the canonical Rosseland model.

  6. Numerical modeling of boundary layer flow under shoaling and breaking waves

    E-Print Network [OSTI]

    Pattipawaej, Olga Catherina

    1998-01-01T23:59:59.000Z

    is governed by the mass conservation equation 0U 0W ? + =0 0x 0" (2. 1) and the boundary layer approximation to the horizontal momentum equation DU 0U?0U 0 I 0U +U ?+ ? iv ? ?&utc& (2. 2) where D 0 0 0 ? = ? + U ? + W ?. Dt 0t 0z 0 (2. 3) In 2. 1 and 2... stresses. Following Kanetkar (1985), the governing equations 2. 11 and 2. 12 can be written to the first order of approximation as (3. 1) = cqql ? + ? cscsql ? ? ? ci? (3. 2) where the value of ci is found to be 0. 054 by setting production equal...

  7. The effect of tangential mass addition on the boundary layer velocity distribution of a flat plate at zero angle of attack

    E-Print Network [OSTI]

    Miller, Edward Peter

    1965-01-01T23:59:59.000Z

    . V . RESULTS AND DISCUSSION 16 18 20 21 24 Boundary Layer Conditions Downstream of Blowing Slot . Boundary Layer Conditions Upstream of Slot Accuracy of Data 24 40 47 VI. CONCLUSIONS AND RECOMMENDATIONS ~ 51 LITERATURE CITED 54 APPENDIX... of u with Distance Downstream of Slot max Velocity Profile of a Boundary Layer in the Presence of a Blowing Jet 32 7 ~ Comparison of Boundaries A, 8, C, in, Present Experiment with that of Carriere and Eichelbrenner's Results 37 Comparison...

  8. icBIE: A Boundary Integral Equation Program for an Ion Channel in Layered Membrane/Electrolyte Media

    E-Print Network [OSTI]

    Cai, Wei

    in this paper. The program uses a layered media Green's function of the P-B equation in order to accurately and Electromagnetics. External routines/libraries: OpenMP (http://openmp.org/wp/) Nature of problem: Electrostatic method: Boundary integral equation method and the layered media Green's function of the Poisson

  9. X-ray and EUV Spectroscopy of the Boundary Layer Emission of Nonmagnetic Cataclysmic Variables

    E-Print Network [OSTI]

    Christopher W. Mauche

    1997-09-11T23:59:59.000Z

    EUVE, ROSAT, and ASCA observations of the boundary layer emission of nonmagnetic cataclysmic variables (CVs) are reviewed. EUVE spectra reveal that the effective temperature of the soft component of high-Mdot nonmagnetic CVs is kT ~ 10-20 eV and that its luminosity is ~ 0.1-0.5 times the accretion disk luminosity. Although the EUV spectra are very complex and belie simple interpretation, the physical conditions of the boundary layer gas are constrained by emission lines of highly ionized Ne, Mg, Si, and Fe. ROSAT and ASCA spectra of the hard component of nonmagnetic CVs are satisfactorily but only phenomenologically described by multi-temperature thermal plasmas, and the constraints imposed on the physical conditions of this gas are limited by the relatively weak and blended lines. It is argued that significant progress in our understanding of the X-ray spectra of nonmagnetic CVs will come with future observations with XMM, AXAF, and Astro-E.

  10. Turbulence structure of the surface layer Boun 2247-03D TURBULENCE STRUCTURE OF THE UNSTABLE ATMOSPHERIC

    E-Print Network [OSTI]

    Moncrieff, John B.

    to the creation of emerging TEAL structures to the power passing down the Richardson cascade in the outer layer-Obukhov similarity, self-organizing systems 1. Introduction In convective boundary layers the structureTurbulence structure of the surface layer Boun 2247-03D TURBULENCE STRUCTURE OF THE UNSTABLE

  11. Horizontal-Velocity and Variance Measurements in the Stable Boundary Layer Using Doppler Lidar: Sensitivity to Averaging Procedures

    SciTech Connect (OSTI)

    Pichugina, Yelena L.; Banta, Robert M.; Kelley, Neil D.; Jonkman, Bonnie J.; Tucker, Sara C.; Newsom, Rob K.; Brewer, W. A.

    2008-08-01T23:59:59.000Z

    Quantitative data on turbulence variables aloft--above the region of the atmosphere conveniently measured from towers--has been an important but difficult measurement need for advancing understanding and modeling of the stable boundary layer (SBL). Vertical profiles of streamwise velocity variances obtained from NOAA’s High Resolution Doppler Lidar (HRDL), which have been shown to be numerically equivalent to turbulence kinetic energy (TKE) for stable conditions, are a measure of the turbulence in the SBL. In the present study, the mean horizontal wind component U and variance ?u2 were computed from HRDL measurements of the line-of-sight (LOS) velocity using a technique described in Banta, et al. (2002). The technique was tested on datasets obtained during the Lamar Low-Level Jet Project (LLLJP) carried out in early September 2003, near the town of Lamar in southeastern Colorado. This paper compares U with mean wind speed obtained from sodar and sonic anemometer measurements. It then describes several series of averaging tests that produced the best correlation between TKE calculated from sonic anemometer data at several tower levels and lidar measurements of horizontal velocity variance ?u2. The results show high correlation (0.71-0.97) of the mean U and average wind speed measured by sodar and in-situ instruments, independent of sampling strategies and averaging procedures. Comparison of estimates of variance, on the other hand, proved sensitive to both the spatial and temporal averaging techniques.

  12. Transitions of cloud-topped marine boundary layers characterized by AIRS, MODIS, and a large eddy simulation model

    SciTech Connect (OSTI)

    Yue, Qing; Kahn, Brian; Xiao, Heng; Schreier, Mathias; Fetzer, E. J.; Teixeira, J.; Suselj, Kay

    2013-08-16T23:59:59.000Z

    Cloud top entrainment instability (CTEI) is a hypothesized positive feedback between entrainment mixing and evaporative cooling near the cloud top. Previous theoretical and numerical modeling studies have shown that the persistence or breakup of marine boundary layer (MBL) clouds may be sensitive to the CTEI parameter. Collocated thermodynamic profile and cloud observations obtained from the Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments are used to quantify the relationship between the CTEI parameter and the cloud-topped MBL transition from stratocumulus to trade cumulus in the northeastern Pacific Ocean. Results derived from AIRS and MODIS are compared with numerical results from the UCLA large eddy simulation (LES) model for both well-mixed and decoupled MBLs. The satellite and model results both demonstrate a clear correlation between the CTEI parameter and MBL cloud fraction. Despite fundamental differences between LES steady state results and the instantaneous snapshot type of observations from satellites, significant correlations for both the instantaneous pixel-scale observations and the long-term averaged spatial patterns between the CTEI parameter and MBL cloud fraction are found from the satellite observations and are consistent with LES results. This suggests the potential of using AIRS and MODIS to quantify global and temporal characteristics of the cloud-topped MBL transition.

  13. Photophoretic contribution to the transport of absorbing particles across combustion gas boundary layers

    SciTech Connect (OSTI)

    Castillo, J.L. (U.N.E.D., Madrid (Spain)); Mackowski, D.W.; Rosner, D.E. (Yale Univ., New Haven, CT (USA))

    1989-01-01T23:59:59.000Z

    Since radiation energy fluxes can be comparable to convective (Fourier) fluxes in large fossil-fuel-fired power stations and furnaces, the authors have examined particle drift (phoresis) induced by nonuniform photon-particle heating in a host gas. The authors analysis of the photophoretic velocity includes the important slipflow regime, and the numerical results show that photophoresis is a significant transport mechanism for micron-sized absorbing particles in high radiative transfer combustion environments, with equivalent photophoretic diffusivities (dimensionless photophoretic velocities) being as large as 10% of the better-known thermophoretic diffusivity (Rosner, 1980, 1985). Since previous experimental results (Rosner and Kim, 1984) demonstrated that thermophoresis causes over a 3-decade increase in particle deposition rates by convective diffusion, clearly, for small, absorbing particles, photophoresis will also be an important contributor to observed deposition rates. Accordingly, they present mass transfer coefficients for particle transport across laminar gaseous boundary layers, including both particle thermophoresis and photophoresis.

  14. Electron distributions observed with Langmuir waves in the plasma sheet boundary layer

    SciTech Connect (OSTI)

    Hwang, Junga [Solar and Space Weather Research Group, Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Department of Astronomy and Space Science, University of Science and Technology, Daejeon (Korea, Republic of); Rha, Kicheol [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Seough, Jungjoon [Solar and Space Weather Research Group, Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Yoon, Peter H. [School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States)

    2014-09-15T23:59:59.000Z

    The present paper investigates the Langmuir turbulence driven by counter-streaming electron beams and its plausible association with observed features in the Earth's plasma sheet boundary layer region. A one-dimensional electrostatic particle-in-cell simulation code is employed in order to simulate broadband electrostatic waves with characteristic frequency in the vicinity of the electron plasma frequency ?/?{sub pe}?1.0. The present simulation confirms that the broadband electrostatic waves may indeed be generated by the counter-streaming electron beams. It is also found that the observed feature associated with low energy electrons, namely quasi-symmetric velocity space plateaus, are replicated according to the present simulation. However, the present investigation only partially succeeds in generating the suprathermal tails such that the origin of observed quasi power-law energetic population formation remains outstanding.

  15. Pulsed Plasma with Synchronous Boundary Voltage for Rapid Atomic Layer Etching

    SciTech Connect (OSTI)

    Economou, Demetre J.; Donnelly, Vincent M.

    2014-05-13T23:59:59.000Z

    Atomic Layer ETching (ALET) of a solid with monolayer precision is a critical requirement for advancing nanoscience and nanotechnology. Current plasma etching techniques do not have the level of control or damage-free nature that is needed for patterning delicate sub-20 nm structures. In addition, conventional ALET, based on pulsed gases with long reactant adsorption and purging steps, is very slow. In this work, novel pulsed plasma methods with synchronous substrate and/or “boundary electrode” bias were developed for highly selective, rapid ALET. Pulsed plasma and tailored bias voltage waveforms provided controlled ion energy and narrow energy spread, which are critical for highly selective and damage-free etching. The broad goal of the project was to investigate the plasma science and engineering that will lead to rapid ALET with monolayer precision. A combined experimental-simulation study was employed to achieve this goal.

  16. 'Maximum' entropy production in self-organized plasma boundary layer: A thermodynamic discussion about turbulent heat transport

    SciTech Connect (OSTI)

    Yoshida, Z. [Graduate School of Frontier Sciences, University of Tokyo, Chiba 277-8561 (Japan); Mahajan, S. M. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

    2008-03-15T23:59:59.000Z

    A thermodynamic model of a plasma boundary layer, characterized by enhanced temperature contrasts and ''maximum entropy production,'' is proposed. The system shows bifurcation if the heat flux entering through the inner boundary exceeds a critical value. The state with a larger temperature contrast (larger entropy production) sustains a self-organized flow. An inverse cascade of energy is proposed as the underlying physical mechanism for the realization of such a heat engine.

  17. A study of low-level wind and temperature profiles as a function of stability in the surface boundary layer

    E-Print Network [OSTI]

    Williams, Morgan Glenn

    1970-01-01T23:59:59.000Z

    A STUDY OF LOW-LEVEL WIND AND TEMPERATURE PROFILES AS A FUNCTION OF STABILITY IN THE SURFACE BOUNDARY LAYER A Thesis By Morgan Glenn Williams Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... and content by: . . jy ~( (Chairman of Committee) (lread of Dep. ent) ', ea'ocr) ~!A|I)~ Decemb. r 19 70 ABSTRACT A Study of I. ow-Level Wind and Temperature Profiles as a Function of Stability in the Surface Boundary Layer (December 1970) Morgan...

  18. Numerical calculation of reflected and transmitted radiance in a plane parallel atmosphere by doubling very thin layers

    E-Print Network [OSTI]

    Entrekin, Robert David

    1976-01-01T23:59:59.000Z

    NUMERICAL CALCULATION OF REFLECTED AND TRANSMITTED RADIANCE IN A PLANE PARALLEL ATMOSPHERE BY DOUBLING VERY THIN LAYERS A Thesis by ROBERT DAVID ENTREKIN Submitted to the Graduate College of Texas ASM University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE December 1976 Major Subject: Physics NUMERICAL CALCULATION OF REFLECTED AND TRANSMITTED RADIANCE IN A PLANE PARALLEL ATMOSPHERE BY DOUBLING VERY THIN LAYERS A Thesis by ROBERT DAVID ENTREKIN Approved...

  19. Evolution and lifetimes of flow topology in a turbulent boundary layer G. E. Elsinga and I. Marusic

    E-Print Network [OSTI]

    Marusic, Ivan

    -similar forms of fluid flow and heat-mass transfer in turbulent boundary layer flow of a nanofluid Phys. Fluids that are coherent in time and space, commonly referred to as eddies or coherent structures.1 They are fundamental remain regarding the dynamics and time scales of these coherent motions. In this study we provide a first

  20. Boundary-Layer Meteorol (2009) 132:129149 DOI 10.1007/s10546-009-9380-8

    E-Print Network [OSTI]

    Porté-Agel, Fernando

    2009-01-01T23:59:59.000Z

    deficit and the turbulence intensity, which are important factors affecting turbine power generation by Vermeer et al. (2003). Detailed understanding of the turbulent properties of turbine wakes under different-Tunnel Investigation of Wind-Turbine Wakes: Boundary-Layer Turbulence Effects Leonardo P. Chamorro · Fernando Porté

  1. Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002 during the IHOP_2002 Campaign

    E-Print Network [OSTI]

    Guichard, Francoise

    Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002, Boulder, Colorado (Manuscript received 4 September 2007, in final form 23 June 2008) ABSTRACT Mesoscale at the mesoscale, with the spatial pattern and the magnitude of the variability changing from day to day. On 14

  2. Two-equation model computations of high-speed (ma=2.25, 7.2), turbulent boundary layers

    E-Print Network [OSTI]

    Arasanipalai, Sriram Sharan

    2009-05-15T23:59:59.000Z

    of the Boussinesq coefficient (Cu) and turbulenttransport coefficients (sigmak; sigmaE; sigma; sigma*) on the boundary layer ow is examined. Further,the performance of a new model with realizability-based correction to Cu and corresponding modifications to sigma...

  3. Boundary Layer Convergence Induced by Strong Winds across a Midlatitude THOMAS KILPATRICK, NIKLAS SCHNEIDER, AND BO QIU

    E-Print Network [OSTI]

    Qiu, Bo

    Boundary Layer Convergence Induced by Strong Winds across a Midlatitude SST Front* THOMAS in an idealized, dry, two- dimensional configuration, for winds crossing from cold to warm SST and from warm to cold SST. For strong cross-front winds, O(10 m s21 ), changes in the turbulent mixing and MABL depth

  4. A one-dimensional sectional model to simulate multicomponent aerosol dynamics in the marine boundary layer 1. Model description

    SciTech Connect (OSTI)

    Fitzgerald, J.W.; Hoppel, W.A. [Remote Sensing Division, Naval Research Laboratory, Washington, District of Columbia (United States)] [Remote Sensing Division, Naval Research Laboratory, Washington, District of Columbia (United States); Gelbard, F. [Modeling and Analysis Department, Sandia National Laboratories, Albuquerque, New Mexico (United States)] [Modeling and Analysis Department, Sandia National Laboratories, Albuquerque, New Mexico (United States)

    1998-07-01T23:59:59.000Z

    A one-dimensional, multicomponent sectional model has been developed to simulate the temporal and vertical variations of the aerosol size distribution and composition in the marine boundary layer (MBL). An important aspect of the model is its ability to handle the transport of aerosols in an atmosphere with humidity gradients with no numerical diffusion caused by the swelling and shrinking of the particles as they move through the humidity gradients. This is achieved by rewriting the aerosol general dynamical equation (GDE) in terms of dry radius thus transferring all variations in radius caused by temporal and spatial humidity variations to the rate coefficients appearing in the equations. The model then solves the new GDE in fixed dry size sections, with the humidity dependence of the processes now included in variable coefficients. This procedure also results in correct gradient transport. A limiting assumption is that the particles equilibrate instantaneously with the ambient water vapor. This assumption limits the maximum particle size which can be treated in the model to ambient (wet) radii less than about 30 {mu}m. All processes currently believed to be important in shaping the MBL size distribution are included in the current version of the model. These include generation of sea-salt aerosol at the ocean surface, nucleation of new particles, coagulation, growth due to condensation of gas-phase reaction products, growth due to sulfate formation during cloud processing, precipitation scavenging, surface deposition, turbulent mixing, gravitational settling, and exchange with the free troposphere. Simple gas-phase chemistry which includes the oxidation of dimethylsulfide and SO{sub 2} to sulfate is incorporated in the current version of the model. {copyright} 1998 American Geophysical Union

  5. On the Interaction between Marine Boundary Layer Cellular Cloudiness and Surface Heat Fluxes

    SciTech Connect (OSTI)

    Kazil, J.; Feingold, G.; Wang, Hailong; Yamaguchi, T.

    2014-01-02T23:59:59.000Z

    The interaction between marine boundary layer cellular cloudiness and surface uxes of sensible and latent heat is investigated. The investigation focuses on the non-precipitating closed-cell state and the precipitating open-cell state at low geostrophic wind speed. The Advanced Research WRF model is used to conduct cloud-system-resolving simulations with interactive surface fluxes of sensible heat, latent heat, and of sea salt aerosol, and with a detailed representation of the interaction between aerosol particles and clouds. The mechanisms responsible for the temporal evolution and spatial distribution of the surface heat fluxes in the closed- and open-cell state are investigated and explained. It is found that the horizontal spatial structure of the closed-cell state determines, by entrainment of dry free tropospheric air, the spatial distribution of surface air temperature and water vapor, and, to a lesser degree, of the surface sensible and latent heat flux. The synchronized dynamics of the the open-cell state drives oscillations in surface air temperature, water vapor, and in the surface fluxes of sensible and latent heat, and of sea salt aerosol. Open-cell cloud formation, cloud optical depth and liquid water path, and cloud and rain water path are identified as good predictors of the spatial distribution of surface air temperature and sensible heat flux, but not of surface water vapor and latent heat flux. It is shown that by enhancing the surface sensible heat flux, the open-cell state creates conditions by which it is maintained. While the open-cell state under consideration is not depleted in aerosol, and is insensitive to variations in sea-salt fluxes, it also enhances the sea-salt flux relative to the closed-cell state. In aerosol-depleted conditions, this enhancement may replenish the aerosol needed for cloud formation, and hence contribute to the perpetuation of the open-cell state as well. Spatial homogenization of the surface fluxes is found to have only a small effect on cloud properties in the investigated cases. This indicates that sub-grid scale spatial variability in the surface flux of sensible and latent heat and of sea salt aerosol may not be required in large scale and global models to describe marine boundary layer cellular cloudiness.

  6. Atmospheric pressure spatial atomic layer deposition web coating with in situ monitoring of film thickness

    SciTech Connect (OSTI)

    Yersak, Alexander S.; Lee, Yung C. [Department of Mechanical Engineering, University of Colorado at Boulder, 1045 Regent Drive, 422 UCB, Boulder, Colorado 80309-0422 (United States); Spencer, Joseph A.; Groner, Markus D., E-mail: mgroner@aldnanosolutions.com [ALD NanoSolutions, Inc., 580 Burbank Street, Unit 100, Broomfield, Colorado 80020 (United States)

    2014-01-15T23:59:59.000Z

    Spectral reflectometry was implemented as a method for in situ thickness monitoring in a spatial atomic layer deposition (ALD) system. Al{sub 2}O{sub 3} films were grown on a moving polymer web substrate at 100?°C using an atmospheric pressure ALD web coating system, with film growth of 0.11–0.13?nm/cycle. The modular coating head design and the in situ monitoring allowed for the characterization and optimization of the trimethylaluminum and water precursor exposures, purge flows, and web speed. A thickness uniformity of ±2% was achieved across the web. ALD cycle times as low as 76?ms were demonstrated with a web speed of 1?m/s and a vertical gap height of 0.5?mm. This atmospheric pressure ALD system with in situ process control demonstrates the feasibility of low-cost, high throughput roll-to-roll ALD.

  7. Application of Atmospheric Plasma-Sprayed Ferrite Layers for Particle Accelerators

    E-Print Network [OSTI]

    Caspers, F; Federmann, S; Taborelli, M; Schulz, C; Bobzin, K; Wu, J

    2013-01-01T23:59:59.000Z

    A common problem in all kinds of cavity-like structures in particle accelerators is the occurrence of RF-resonances. Typically, ferrite plates attached to the walls of such structures as diagnostic devices, kickers or collimators, are used to dampen those undesired modes. However, the heat transfer rate from these plates to the walls is rather limited. Brazing ferrite plates to the walls is not possible in most cases due to the different thermal expansion coefficients. To overcome those limitations, atmospheric plasma spraying techniques have been investigated. Ferrite layers with a thickness from 50 ?m to about 300 ?m can be deposited on metallic surfaces like stainless steel exhibiting good thermal contact and still reasonable absorption properties. In this paper the technological aspects of plasma deposition are discussed and results of specifically developed RF loss measurement procedures for such thin magnetically lossy layers on metal are presented.

  8. ANGULAR MOMENTUM TRANSPORT BY ACOUSTIC MODES GENERATED IN THE BOUNDARY LAYER. II. MAGNETOHYDRODYNAMIC SIMULATIONS

    SciTech Connect (OSTI)

    Belyaev, Mikhail A.; Rafikov, Roman R.; Stone, James M., E-mail: rrr@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08540 (United States)

    2013-06-10T23:59:59.000Z

    We perform global unstratified three-dimensional magnetohydrodynamic simulations of an astrophysical boundary layer (BL)-an interface region between an accretion disk and a weakly magnetized accreting object such as a white dwarf-with the goal of understanding the effects of magnetic field on the BL. We use cylindrical coordinates with an isothermal equation of state and investigate a number of initial field geometries including toroidal, vertical, and vertical with zero net flux. Our initial setup consists of a Keplerian disk attached to a non-rotating star. In a previous work, we found that in hydrodynamical simulations, sound waves excited by shear in the BL were able to efficiently transport angular momentum and drive mass accretion onto the star. Here we confirm that in MHD simulations, waves serve as an efficient means of angular momentum transport in the vicinity of the BL, despite the magnetorotational instability (MRI) operating in the disk. In particular, the angular momentum current due to waves is at times larger than the angular momentum current due to MRI. Our results suggest that angular momentum transport in the BL and its vicinity is a global phenomenon occurring through dissipation of waves and shocks. This point of view is quite different from the standard picture of transport by a local anomalous turbulent viscosity. In addition to angular momentum transport, we also study magnetic field amplification within the BL. We find that the field is indeed amplified in the BL, but only by a factor of a few, and remains subthermal.

  9. Harmonic propagation of variability in surface energy balance within a coupled soil-vegetation-atmosphere system

    E-Print Network [OSTI]

    Gentine, P.

    [1] The response of a soil-vegetation-atmosphere continuum model to incoming radiation forcing is investigated in order to gain insights into the coupling of soil and atmospheric boundary layer (ABL) states and fluxes. The ...

  10. Forecast of surface layer meteorological parameters at Cerro Paranal with a mesoscale atmospherical model

    E-Print Network [OSTI]

    Lascaux, Franck; Fini, Luca

    2015-01-01T23:59:59.000Z

    This article aims at proving the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed and direction, temperature) above the ESO ground-base site of Cerro Paranal with a mesoscale atmospherical model called Meso-Nh. In a precedent paper we have preliminarily treated the model performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30~m studying the bias and the RMSE on a statistical sample of 20 nights. Results were very encouraging and it appeared therefore mandatory to confirm such a good result on a much richer statistical sample. In this paper, the study was extended to a total sample of 129 nights between 2007 and 2011 distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the model performances and permitted us to confirm the excellent performances of the model. Besides, we present an independent analysis of the model p...

  11. Nitrogen Oxides in the Nocturnal Boundary Layer: Chemistry of Nitrous Acid (HONO) and the Nitrate Radical (N03)

    SciTech Connect (OSTI)

    Jochen Stutz

    2005-05-24T23:59:59.000Z

    Summary Chemical processes occurring at night in the lowest part of the urban atmosphere, the so called nocturnal boundary layer (NBL), can influence the composition of the atmosphere during the night as well as the following day. They may impact the budgets of some of the most important pollutants, such as ozone and nitrogen oxides, as well as influence size and composition of particular matter. Few studies have thus far concentrated on the nocturnal chemistry of the urban NBL, most likely due to the strong influence of vertical transport and mixing, which requires the measurement of trace gas profiles instead of simple point observations. Motivated by our lack of observations and understanding of nocturnal chemistry, the focus of this project was the study of the vertical distribution of trace gases and the altitude dependence of nocturnal chemistry under polluted conditions through field observations and modeling studies. The analysis of three field experiments (TEXAQS, Houston, 2000; Phoenix Sunrise Ozone Experiment, 2001; NAPOX, Boston, 2002), two of which were performed in this project, showed that ozone concentrations typically increase with height in the lowest 150m, while NO2 typically decreases. NO3, the dominant nocturnal radical species, showed much higher concentrations in the upper part of the NBL, and was often not present at the ground. With the help of a one-dimensional chemical transport model, developed in this project, we found that the interaction of ground emissions of NOx and hydrocarbons, together with their vertical transport, is responsible for the vertical profiles. The dominant chemical reactions influencing ozone, NO2 and NO3 are the reaction of ozone and NO3 with freshly emitted NO. Sensitivity studies with our model showed that the magnitude of the trace gas gradients depend both on the emission rates and the vertical stability of the NBL. Observations and model analysis clearly show that nocturnal chemistry in urban areas is altitude dependent. Measurements at one altitude, for example at the ground, where most air quality monitoring stations are located, are not representative for the rest of the NBL. Our model also revealed that radical chemistry is, in general, altitude dependent at night. We distinguish three regions: an unreactive, NO rich, ground layer; an upper, O3 and NO3 dominated layer, and a reactive mixing layer, where RO2 radicals are mixed from aloft with NO from the ground. In this reactive layer an active radical chemistry and elevated OH radical levels can be found. The downward transport of N2O5 and HO2NO2, followed by their thermal decay, was also identified as a radical source in this layer. Our observations also gave insight into the formation of HONO in the NBL. Based on our field experiments we were able to show that the NO2 to HONO conversion was relative humidity dependent. While this fact was well known, we found that it is most likely the uptake of HONO onto surfaces which is R.H. dependent, rather than the NO2 to HONO conversion. This finding led to the proposal of a new NO2 to HONO conversion mechanism, which is based on solid physical chemical principles. Noteworthy is also the observation of enhanced NO2 to HONO conversion during a dust storm event in Phoenix. The final activity in our project investigated the influence of the urban canopy, i.e. building walls and surfaces, on nocturnal chemistry. For the first time the surface area of a city was determined based on a Geographical Information System database of the city of Santa Monica. The surface to volume areas found in this study showed that, in the 2 lower part of the NBL, buildings provide a much larger surface area than the aerosol. In addition, buildings take up a considerable amount of the volume near the ground. The expansion of our model and sensitivity studies based on the Santa Monica data revealed that the surface area of buildings considerably influences HONO levels in urban areas. The volume reduction leads to a decrease of O3 and an increase of NO2 near the ground due to the stronger impact o

  12. PLASMOID RELEASES IN THE HELIOSPHERIC CURRENT SHEET AND ASSOCIATED CORONAL HOLE BOUNDARY LAYER EVOLUTION

    SciTech Connect (OSTI)

    Foullon, C. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Lavraud, B.; Opitz, A.; Sauvaud, J.-A. [Institut de Recherche en Astrophysique et Planetologie (IRAP), Universite de Toulouse (UPS) and Centre National de la Recherche Scientifique, UMR 5277, Toulouse (France); Luhmann, J. G. [Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720 (United States); Farrugia, C. J.; Simunac, K. D. C.; Galvin, A. B.; Kucharek, H.; Popecki, M. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Retino, A. [Laboratoire de Physique des Plasmas-CNRS, Observatoire de Saint-Maur, 4 avenue de Neptune, Saint-Maur-Des-Fosses, 94107 (France); Wardle, N. C.; Owen, C. J., E-mail: claire.foullon@warwick.ac.uk [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom)

    2011-08-10T23:59:59.000Z

    As the heliospheric current sheet (HCS) is corotating past STEREO-B, near-Earth spacecraft ACE, Wind and Cluster, and STEREO-A over more than three days between 2008 January 10 and 14, we observe various sections of (near-pressure-balanced) flux-rope- and magnetic-island-type plasmoids in the associated heliospheric plasma sheet (HPS). The plasmoids can qualify as slow interplanetary coronal mass ejections and are relatively low proton beta (<0.5) structures, with small length scales (an order of magnitude lower than typical magnetic cloud values) and low magnetic field strengths (2-8 nT). One of them, in particular, detected at STEREO-B, corresponds to the first reported evidence of a detached plasmoid in the HPS. The in situ signatures near Earth are associated with a long-decay X-ray flare and a slow small-scale streamer ejecta, observed remotely with white-light coronagraphs aboard STEREO-B and SOHO and tracked by triangulation. Before the arrival of the HPS, a coronal hole boundary layer (CHBL) is detected in situ. The multi-spacecraft observations indicate a CHBL stream corotating with the HCS but with a decreasing speed distribution suggestive of a localized or transient nature. While we may reasonably assume that an interaction between ejecta and CHBL provides the source of momentum for the slow ejecta's acceleration, the outstanding composition properties of the CHBL near Earth provide here circumstantial evidence that this interaction or possibly an earlier one, taking place during streamer swelling when the ejecta rises slowly, results in additional mixing processes.

  13. Collaborative Research: ARM observations for the development and evaluation of models and parameterizations of cloudy boundary layers

    SciTech Connect (OSTI)

    Albrecht, Bruce,

    2013-07-12T23:59:59.000Z

    This is a collaborative project with Dr. Ping Zhu at Florida International University. It was designed to address key issues regarding the treatment of boundary layer cloud processes in climate models with UM’s research focusing on the analyses of ARM cloud radar observations from MMCR and WACR and FIU’s research focusing on numerical simulations of boundary layer clouds. This project capitalized on recent advancements in the ARM Millimeter Cloud Radar (MMCR) processing and the development of the WACR (at the SGP) to provide high temporal and spatial resolution Doppler cloud radar measurements for characterizing in-cloud turbulence, large-eddy circulations, and high resolution cloud structures of direct relevance to high resolution numerical modeling studies. The principal focus of the observational component of this collaborative study during this funding period was on stratocumulus clouds over the SGP site and fair-weather cumuli over the Nauru site. The statistical descriptions of the vertical velocity structures in continental stratocumulus clouds and in the Nauru shallow cumuli that are part of this study represents the most comprehensive observations of the vertical velocities in boundary layer clouds to date and were done in collaboration with Drs. Virendra Ghate and Pavlos Kollias.

  14. Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

    DOE Patents [OSTI]

    Farrington, Robert B. (Golden, CO); Anderson, Ren (Broomfield, CO)

    2001-01-01T23:59:59.000Z

    The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

  15. MOMENTUM AND THERMAL BOUNDARY-LAYER THICKNESS IN A STAGNATION FLOW CHEMICAL VAPOR DEPOSITION REACTOR

    E-Print Network [OSTI]

    Dandy, David

    REACTOR DAVID S. DANDY AND JUNGHEUM YUN Department of Chemical Engineering Colorado State University Fort deposition pedestal reactors. Expressions for the velocity and temperature profiles within the boundary

  16. Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain

    E-Print Network [OSTI]

    Lundquist, Katherine Ann

    2010-01-01T23:59:59.000Z

    laminar flow over a ribbed channel. v ? U n F = + U · ?U + ?dimensional channel flow with smooth and ribbed surfaces. In

  17. Horizontal Velocity and Variance Measurements in the Stable Boundary Layer Using Doppler Lidar: Sensitivity to Averaging Procedures

    SciTech Connect (OSTI)

    Pichugina, Y. L.; Banta, R. M.; Kelley, N. D.; Jonkman, B. J.; Tucker, S. C.; Newsom, R. K.; Brewer, W. A.

    2008-08-01T23:59:59.000Z

    Quantitative data on turbulence variables aloft--above the region of the atmosphere conveniently measured from towers--have been an important but difficult measurement need for advancing understanding and modeling of the stable boundary layer (SBL). Vertical profiles of streamwise velocity variances obtained from NOAA's high-resolution Doppler lidar (HRDL), which have been shown to be approximately equal to turbulence kinetic energy (TKE) for stable conditions, are a measure of the turbulence in the SBL. In the present study, the mean horizontal wind component U and variance {sigma}2u were computed from HRDL measurements of the line-of-sight (LOS) velocity using a method described by Banta et al., which uses an elevation (vertical slice) scanning technique. The method was tested on datasets obtained during the Lamar Low-Level Jet Project (LLLJP) carried out in early September 2003, near the town of Lamar in southeastern Colorado. This paper compares U with mean wind speed obtained from sodar and sonic anemometer measurements. The results for the mean U and mean wind speed measured by sodar and in situ instruments for all nights of LLLJP show high correlation (0.71-0.97), independent of sampling strategies and averaging procedures, and correlation coefficients consistently >0.9 for four high-wind nights, when the low-level jet speeds exceeded 15 m s{sup -1} at some time during the night. Comparison of estimates of variance, on the other hand, proved sensitive to both the spatial and temporal averaging parameters. Several series of averaging tests are described, to find the best correlation between TKE calculated from sonic anemometer data at several tower levels and lidar measurements of horizontal-velocity variance {sigma}{sup 2}{sub u}. Because of the nonstationarity of the SBL data, the best results were obtained when the velocity data were first averaged over intervals of 1 min, and then further averaged over 3-15 consecutive 1-min intervals, with best results for the 10- and 15-min averaging periods. For these cases, correlation coefficients exceeded 0.9. As a part of the analysis, Eulerian integral time scales ({tau}) were estimated for the four high-wind nights. Time series of {tau} through each night indicated erratic behavior consistent with the nonstationarity. Histograms of {tau} showed a mode at 4-5 s, but frequent occurrences of larger {tau} values, mostly between 10 and 100 s.

  18. MEMS Pressure Sensor Array for Aeroacoustic Analysis of the Turbulent Boundary Layer

    E-Print Network [OSTI]

    White, Robert D.

    holes Density of air c Speed of sound µ Viscosity of air 1 Density of diaphragm (Polysilicon) E1 Modulus of elasticity of diaphragm 1 Poisson's ratio of diaphragm t2 Thickness of Parylene-C layer 2 Density of Parylene-C layer E2 Modulus of elasticity of Parylene-C layer Research Assistant, Department

  19. Atmospheric Boundary Layer Studies with Unified RANS-LES and Dynamic LES Methods

    E-Print Network [OSTI]

    Heinz, Stefan

    computational cost. Details about the characteristic features of these methods and applications to channel flow and the numerical method applied. The results obtained by unified and dynamic LES models are discussed in section IV of Mechanical Engineering, 1000 E. University Avenue, Laramie WY 82071. PhD student, Department of Mathematics

  20. Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Zhou, Bowen

    2012-01-01T23:59:59.000Z

    eddy Simulation of Wind-turbine Wakes: Evaluation of Turbineperformed LES of wind-turbine wakes in neutrally stratified

  1. THE THERMODYNAMIC EFFECTS OF SUBLIMATING, BLOWING SNOW IN THE ATMOSPHERIC BOUNDARY LAYER

    E-Print Network [OSTI]

    Dery, Stephen

    . Apart from the transport of snow, the thermodynamic impact of sublimat- ing blowing snow in air near process is self- limiting despite ongoing transport of snow by wind, yielding significantly lower values their lengthy winters (Stewart et al., 1995). These storms are often associated with sub-freezing temper- atures

  2. Buoyancy Effects on the Scaling Characteristics of Atmospheric Boundary Layer Wind Fields in the Mesoscale Range

    E-Print Network [OSTI]

    Kiliyanpilakkil, V P; Ruiz-Columbié, A; Araya, G; Castillo, L; Hirth, B; Burgett, W

    2015-01-01T23:59:59.000Z

    We have analyzed long-term wind speed time-series from five field sites up to a height of 300 m from the ground. Structure function-based scaling analysis has revealed that the scaling exponents in the mesoscale regime systematically depend on height. This anomalous behavior is shown to be caused by the buoyancy effects. In the framework of the extended self-similarity, the relative scaling exponents portray quasi-universal behavior.

  3. Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Zhou, Bowen

    2012-01-01T23:59:59.000Z

    coordinate and (b) wind and potential temperature at the up-coordinate and (b) wind and potential temperature at the up-Mean profiles of wind and potential temperature, turbulent

  4. Acidbase chemical reaction model for nucleation rates in the polluted atmospheric boundary layer

    E-Print Network [OSTI]

    June 18, 2012) Climate models show that particles formed by nucleation can affect cloud cover and, therefore, the earth's radiation budget. Measurements worldwide show that nucleation rates in the atmo be a significant source of condensation nuclei (2) and cloud condensation nuclei (CCN) (3). The cloud albedo effect

  5. DOE/SC-ARM-14-034 Lower Atmospheric Boundary Layer 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContract Management Fermi SitePARTOffice ofHale Plan24,7,INL is62 The35414

  6. Friction of a slider on a granular layer: Non-monotonic thickness dependence and effect of boundary conditions

    E-Print Network [OSTI]

    Saloome Siavoshi; Ashish V. Orpe; Arshad Kudrolli

    2005-12-22T23:59:59.000Z

    We investigate the effective friction encountered by a mass sliding on a granular layer as a function of bed thickness and boundary roughness conditions. The observed friction has minima for a small number of layers before it increases and saturates to a value which depends on the roughness of the sliding surface. We use an index-matched interstitial liquid to probe the internal motion of the grains with fluorescence imaging in a regime where the liquid has no significant effect on the measured friction. The shear profiles obtained as a function of depth show decrease in slip near the sliding surface as the layer thickness is increased. We propose that the friction depends on the degree of grain confinement relative to the sliding surfaces.

  7. Cumulant expansions for atmospheric flows

    E-Print Network [OSTI]

    Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B

    2015-01-01T23:59:59.000Z

    The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...

  8. Seismic and gravitational studies of melting in the mantle's thermal boundary layers

    E-Print Network [OSTI]

    Van Ark, Emily M

    2007-01-01T23:59:59.000Z

    This thesis presents three studies which apply geophysical tools to the task of better understanding mantle melting phenomena at the upper and lower boundaries of the mantle. The first study uses seafloor bathymetry and ...

  9. The Effects of Step Excrescences on Swept-Wing Boundary-Layer Transition

    E-Print Network [OSTI]

    Duncan, Jr., Glen T.

    2014-08-12T23:59:59.000Z

    flutter and handling-quality clearance flight proved the new test article is safe for the flight-testing experiments. Pressure measurements are compared with computational results, infrared thermography is used to globally detect boundary...

  10. Establishment of a research facility for investigating the effects of unsteady inlet flow, pressure gradient and curvature on boundary layer development, wake development and heat transfer

    E-Print Network [OSTI]

    Pardivala, Darayus Noshir

    1991-01-01T23:59:59.000Z

    ESTABLISHMENT OF A RESEARCH FACILITY FOR INVESTIGATING THE EFFECTS OF UNSTEADY INLET FLOW) PRESSURE GRADIENT AND CURVATURE ON BOUNDARY LAYER DEVELOPMENT) %'AKE DEVELOPMENT AND HEAT TRANSFER A Thesis by DARAYUS NOSHIR PARDIVALA Submitted... THE EFFECTS OF UNSTEADY INLET FLOW, PRESSURE GRADIENT AND CURVATURE ON BOUNDARY LAYER DEVELOPMENT, WAKE DEVELOPMENT AND HEAT TRANSFER A Thesis by DARAYUS NOSHIR PARDIVALA Approved as to style and content by: Taher Schobeiri (Chair of Committee) Gerald...

  11. On the use of a nascent delta function in radiative-transfer calculations for multi-layer media subject to Fresnel boundary

    E-Print Network [OSTI]

    Siewert, Charles E.

    subject to Fresnel boundary and interface conditions R.D.M. Garcia a,Ã, C.E. Siewert b a Instituto de: Radiative transfer Nascent delta function Fresnel conditions Discrete-ordinates method a b s t r a c in a plane-parallel, multi-layer medium subject to Fresnel boundary and interface conditions. As a result

  12. Cloud climatology at the Southern Great Plains and the layer structure, drizzle, and atmospheric modes of continental stratus

    E-Print Network [OSTI]

    of cloud layers, an issue that is important in calculating both the radiative and the hydro- logic effects.5 years) cloud observations from the Atmospheric Radiation Measurements (ARM) program Southern Great in Global Climate Models (GCMs) remains a source of uncertainty in climate simulations. Cloud climatologies

  13. MEMS Pressure Sensor Array for Aeroacoustic Analysis of the Turbulent Boundary Layer

    E-Print Network [OSTI]

    White, Robert D.

    vent holes Cc Center­to­center spacing of vent holes Density of air c Speed of sound µ Viscosity of air 1 Density of diaphragm (Polysilicon) E1 Modulus of elasticity of diaphragm 1 Poisson's ratio Density of Parylene-C layer E2 Modulus of elasticity of Parylene-C layer 2 Poisson's ratio of Parylene

  14. Turbulent boundary layers interacting with groups of obstacles Project Staff Principal investigator: Dr Costantino Manes

    E-Print Network [OSTI]

    Sóbester, András

    (wind or marine) can generate, estimating carbon dioxide exchange between forests and the atmosphere-Dimensional (2-D) flow, where mean turbulent properties are uniform (or almost uniform) along one direction

  15. Behavior of buoyant moist plumes in turbulent atmospheres

    E-Print Network [OSTI]

    Hamza, Redouane

    1981-01-01T23:59:59.000Z

    A widely applicable computational model of buoyant moist plumes in turbulent atmospheres has been constructed. To achieve this a one dimensional Planetary Boundary Layer (P.B.L.) model has been developed to account for ...

  16. atmospheric pollution episodes: Topics by E-print Network

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

    to capture atmospheric boundary layer (ABL) characteristics in Interior Alaska during low solar irradiation (11-01-2005 to 02-28-2006). Biases determined based on all 9...

  17. On the thermodynamic boundary conditions of a solidifying mushy layer with outflow

    E-Print Network [OSTI]

    Rees Jones, David W.; Worster, M. Grae

    2014-11-27T23:59:59.000Z

    –207. Thermodynamic boundary conditions with outflow 11 Beckermann, C. & Wang, C.Y. 1995 Multiphase/-scale modeling of alloy solidification. In Annual Reviews of Heat Transfer (ed. C. L. Tien), vol. 6, pp. 115–198. Begell House. Conroy, D. & Worster, M. G. 2006 Mush...

  18. Use of shear-stress-sensitive, temperature-insensitive liquid crystals for hypersonic boundary-layer transition detection

    SciTech Connect (OSTI)

    Aeschliman, D.P.; Croll, R.H.; Kuntz, D.W.

    1997-04-01T23:59:59.000Z

    The use of shear-stress-sensitive, temperature-insensitive (SSS/TI) liquid crystals (LCs) has been evaluated as a boundary-layer transition detection technique for hypersonic flows. Experiments were conducted at Mach 8 in the Sandia National Laboratories Hypersonic Wind Tunnel using a flat plate model at near zero-degree angle of attack over the freestream unit Reynolds number range 1.2-5.8x10{sup 6}/ft. Standard 35mm color photography and Super VHS color video were used to record LC color changes due to varying surface shear stress during the transition process for a range of commercial SSS liquid crystals. Visual transition data were compared to an established method using calorimetric surface heat-transfer measurements to evaluate the LC technique. It is concluded that the use of SSS/TI LCs can be an inexpensive, safe, and easy to use boundary-layer transition detection method for hypersonic flows. However, a valid interpretation of the visual records requires careful attention to illumination intensity levels and uniformity, lighting and viewing angles, some prior understanding of the general character of the flow, and the selection of the appropriate liquid crystal for the particular flow conditions.

  19. Hygroscopic growth of submicron and supermicron aerosols in the marine boundary layer

    E-Print Network [OSTI]

    balance and climate directly through absorption and scattering of the incoming solar radiation and indirectly through modification of cloud properties [Intergovernmental Panel on Climate Change, 2007 behaviors of the dynamic and complex atmospheric aerosol consisting of particles with a wide range of sizes

  20. The Effects of Step Excrescences on Swept-Wing Boundary-Layer Transition 

    E-Print Network [OSTI]

    Duncan, Jr., Glen T.

    2014-08-12T23:59:59.000Z

    of an unswept model of similar 2-D pressure gradient. The crossflow instability is believed to dominate the transition process up to the critical step height, while the shear-layer instability dominates after the critical step height. The critical step height...

  1. Confinement of the Sun's interior magnetic field: some exact boundary-layer solutions

    E-Print Network [OSTI]

    T. S. Wood; M. E. McIntyre

    2007-09-10T23:59:59.000Z

    High-latitude laminar confinement of the Sun's interior magnetic field is shown to be possible, as originally proposed by Gough and McIntyre (1998) but contrary to a recent claim by Brun and Zahn (A&A 2006). Mean downwelling as weak as 2x10^-6cm/s -- gyroscopically pumped by turbulent stresses in the overlying convection zone and/or tachocline -- can hold the field in advective-diffusive balance within a confinement layer of thickness scale ~ 1.5Mm ~ 0.002 x (solar radius) while transmitting a retrograde torque to the Ferraro-constrained interior. The confinement layer sits at the base of the high-latitude tachocline, near the top of the radiative envelope and just above the `tachopause' marking the top of the helium settling layer. A family of exact, laminar, frictionless, axisymmetric confinement-layer solutions is obtained for uniform downwelling in the limit of strong rotation and stratification. A scale analysis shows that the flow is dynamically stable and the assumption of laminar flow realistic. The solution remains valid for downwelling values of the order of 10^-5cm/s but not much larger. This suggests that the confinement layer may be unable to accept a much larger mass throughput. Such a restriction would imply an upper limit on possible internal field strengths, perhaps of the order of hundreds of gauss, and would have implications also for ventilation and lithium burning. The solutions have interesting chirality properties not mentioned in the paper owing to space restrictions, but described at http://www.atmos-dynamics.damtp.cam.ac.uk/people/mem/papers/SQBO/solarfigure.html

  2. Squeezout phenomena and boundary layer formation of a model ionic liquid under confinement and charging

    E-Print Network [OSTI]

    R. Capozza; A. Vanossi; A. Benassi; E. Tosatti

    2014-12-22T23:59:59.000Z

    Electrical charging of parallel plates confining a model ionic liquid down to nanoscale distances yields a variety of charge-induced changes in the structural features of the confined film. That includes even-odd switching of the structural layering and charging-induced solidification and melting, with important changes of local ordering between and within layers, and of squeezout behavior. By means of molecular dynamics simulations, we explore this variety of phenomena in the simplest charged Lennard-Jones coarse-grained model including or excluding the effect a neutral tail giving an anisotropic shape to one of the model ions. Using these models and open conditions permitting the flow of ions in and out of the interplate gap, we simulate the liquid squeezout to obtain the distance dependent structure and forces between the plates during their adiabatic appraoch under load. Simulations at fixed applied force illustrate an effective electrical pumping of the ionic liquid, from a thick nearly solid film that withstands the interplate pressure for high plate charge to complete squeezout following melting near zero charge. Effective enthalpy curves obtained by integration of interplate forces versus distance show the local minima that correspond to layering, and predict the switching between one minimum and another under squeezing and charging.

  3. Friction and Diapycnal Mixing at a Slope: Boundary Control of Potential Vorticity

    E-Print Network [OSTI]

    Benthuysen, Jessica

    Although atmospheric forcing by wind stress or buoyancy flux is known to change the ocean’s potential vorticity (PV) at the surface, less is understood about PV modification in the bottom boundary layer. The adjustment of ...

  4. Stress concentration near stiff inclusions: validation of rigid inclusion model and boundary layers by means of photoelasticity

    E-Print Network [OSTI]

    Diego Misseroni; Francesco Dal Corso; Summer Shahzad; Davide Bigoni

    2014-04-03T23:59:59.000Z

    Photoelasticity is employed to investigate the stress state near stiff rectangular and rhombohedral inclusions embedded in a 'soft' elastic plate. Results show that the singular stress field predicted by the linear elastic solution for the rigid inclusion model can be generated in reality, with great accuracy, within a material. In particular, experiments: (i.) agree with the fact that the singularity is lower for obtuse than for acute inclusion angles; (ii.) show that the singularity is stronger in Mode II than in Mode I (differently from a notch); (iii.) validate the model of rigid quadrilateral inclusion; (iv.) for thin inclusions, show the presence of boundary layers deeply influencing the stress field, so that the limit case of rigid line inclusion is obtained in strong dependence on the inclusion's shape. The introduced experimental methodology opens the possibility of enhancing the design of thin reinforcements and of analyzing complex situations involving interaction between inclusions and defects.

  5. Influence of surface heating on the boundary layer stability of flows with favorable pressure gradients

    E-Print Network [OSTI]

    Landrum, David Brian

    1986-01-01T23:59:59.000Z

    $ of its chord heated to about 1. 5 times the adiabatic temperature. Compared to the adiabatic case, the nose heating slightly delayed the initial amplification of disturbances and significantly incr eased the transition length. A vertical traverse... . . . . 10 Fig. 3 Neutral stability cur ve f' or a typical boundar y layer velocity profile 13 Fig. 4a Falkner-Skan velocity profiles with wall heating, 8 0. 0 18 Fig. 4b Falkner-Skan temperature profiles, B=O. O 19 Fig. 5a Falkner-Skan velocity prof...

  6. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer: Analysis of Results from the ARM Mobile Facility Deployment to the Azores (2009/2010)

    SciTech Connect (OSTI)

    Wood, Robert [University of Washington, Dept of Atmos Sci

    2013-05-31T23:59:59.000Z

    The project focuses upon dataset analysis and synthesis of datasets from the AMF deployment entitled “Clouds, Aerosols, and Precipitation in the Marine Boundary Layer (CAP?MBL)” at Graciosa Island in the Azores. Wood is serving a PI for this AMF deployment.

  7. Boundary layer (shear-band) in frustrated viscoplastic flows T. CHEVALIER, S. RODTS, X. CHATEAU, J. BOUJLEL, M. MAILLARD, P. COUSSOT

    E-Print Network [OSTI]

    Boyer, Edmond

    (paints, mortars, concrete, drilling fluids) in food industry and cooking (purees, sauces, dough stress fluids give rise to a boundary layer, which takes the form of a liquid region of uniform stress fluids such as concentrated colloids, emul- sions, foams, are jammed systems which behave as liq

  8. TRANSPORT OF HEAT, WATER VAPOR AND CARBON DOXIDE BY LONG PERIOD EDDIES IN THE STABLE BOUNDARY LAYER

    SciTech Connect (OSTI)

    Kurzeja, R.

    2010-07-26T23:59:59.000Z

    The vertical transport of heat and trace chemicals for a night in April has been studied with a wavelet analysis and conventional one-hour averages. It was found that for the night of April 20, 2009, turbulent kinetic energy, heat and trace chemicals were transported directed downward from the jet core. The most significant periods for this transport were less than 5 minutes and greater than one hour with intermittent transport taking place in the 5 min to 1 hour time frame. The nocturnal boundary layer is characterized by turbulent intermittency, long period oscillations, and a slow approach to equilibrium, (Mahrt, 1999). Although turbulence is usually maintained by surface friction, downward transport from low-level jets can also play an important role in turbulence maintenance and in the transport of scalars, Mahrt (1999), Banta et al. (2006). The eddy covariance flux measurement technique assumes continuous turbulence which is unusual in the stable boundary because significant flux transport occurs via turbulent eddies whose periods are long compared with the averaging time (Goulden et al., 1996). Systematic error in eddy flux measurements is attributed mainly to the neglect of long period eddies. Banta et al. (2006) noted that observations of turbulence below the low level jet suggested that while upward transport of turbulence kinetic energy (TKE) is common, downward transport from the jet can also occur. They found that in the CASES 99 experiments that turbulence scaled well with the strength of the low-level jet, and that surface cooling was more important than surface roughness. Because nocturnal turbulence is intermittent and non-stationary, the appropriate averaging time for calculation of TKE and EC fluxes is not obvious. Wavelet analysis is, thus, a more suitable analysis tool than conventional Fourier analysis.

  9. Soil moisture regulates the biological response of elevated atmospheric CO2 concentrations in a coupled

    E-Print Network [OSTI]

    Niyogi, Dev

    and Atmospheric Sciences, Purdue University, United States b Departments of Geography and Atmospheric and Oceanic Sciences, University of California at Los Angeles, United States Received 16 March 2005; received surface model, dynamically coupled to an atmospheric boundary layer and surface energy balance scheme

  10. Coupled Vadose Zone and Atmospheric Surface-Layer Transport of CO2 from Geologic Carbon Sequestration Sites

    SciTech Connect (OSTI)

    Oldenburg, Curtis M.; Unger, Andre J.A.

    2004-03-29T23:59:59.000Z

    Geologic carbon dioxide (CO{sub 2}) sequestration is being considered as a way to offset fossil-fuel-related CO{sub 2} emissions to reduce the rate of increase of atmospheric CO{sub 2} concentrations. The accumulation of vast quantities of injected carbon dioxide (CO{sub 2}) in geologic sequestration sites may entail health and environmental risks from potential leakage and seepage of CO{sub 2} into the near-surface environment. We are developing and applying a coupled subsurface and atmospheric surface-layer modeling capability built within the framework of the integral finite difference reservoir simulator TOUGH2. The overall purpose of modeling studies is to predict CO{sub 2} concentration distributions under a variety of seepage scenarios and geologic, hydrologic, and atmospheric conditions. These concentration distributions will provide the basis for determining above-ground and near-surface instrumentation needs for carbon sequestration monitoring and verification, as well as for assessing health, safety, and environmental risks. A key feature of CO{sub 2} is its large density ({rho} = 1.8 kg m{sup -3}) relative to air ({rho} = 1.2 kg m{sup -3}), a property that may allow small leaks to cause concentrations in air above the occupational exposure limit of 4 percent in low-lying and enclosed areas such as valleys and basements where dilution rates are low. The approach we take to coupled modeling involves development of T2CA, a TOUGH2 module for modeling the multicomponent transport of water, brine, CO{sub 2}, gas tracer, and air in the subsurface. For the atmospheric surface-layer advection and dispersion, we use a logarithmic vertical velocity profile to specify constant time-averaged ambient winds, and atmospheric dispersion approaches to model mixing due to eddies and turbulence. Initial simulations with the coupled model suggest that atmospheric dispersion quickly dilutes diffuse CO{sub 2} seepage fluxes to negligible concentrations, and that rainfall infiltration causes CO{sub 2} to return to the subsurface as a dissolved component in infiltrating rainwater.

  11. Low-Frequency Variability in the Midlatitude Baroclinic Atmosphere Induced by an Oceanic Thermal Front

    E-Print Network [OSTI]

    Ghil, Michael

    oscillatory modes dominate. As the two layers become nearly equal, antisymmetric oscillatory modes become of the atmospheric marine boundary layer (AMBL) to oceanic fronts has been studied in observations, as well's dynamics depends on the layer-depth ratio. When the model is nearly equivalent-barotropic, symmetric

  12. Boundary Layer Lubrication

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

    refinement of scuffing model to include all classes of materials, especially ceramics and thin-film coatings. Redesign and refine the x-ray accessible tribometer for in-situ study...

  13. Intercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed during SHEBA/FIRE-ACE

    SciTech Connect (OSTI)

    Morrison, H.; Zuidema, Paquita; Ackerman, Andrew; Avramov, Alexander; de Boer, Gijs; Fan, Jiwen; Fridlind, Ann; Hashino, Tempei; Harrington, Jerry Y.; Luo, Yali; Ovchinnikov, Mikhail; Shipway, Ben

    2011-06-16T23:59:59.000Z

    An intercomparison of six cloud-resolving and large-eddy simulation models is presented. This case study is based on observations of a persistent mixed-phase boundary layer cloud gathered on 7 May, 1998 from the Surface Heat Budget of Arctic Ocean (SHEBA) and First ISCCP Regional Experiment - Arctic Cloud Experiment (FIRE-ACE). Ice nucleation is constrained in the simulations in a way that holds the ice crystal concentration approximately fixed, with two sets of sensitivity runs in addition to the baseline simulations utilizing different specified ice nucleus (IN) concentrations. All of the baseline and sensitivity simulations group into two distinct quasi-steady states associated with either persistent mixed-phase clouds or all-ice clouds after the first few hours of integration, implying the existence of multiple equilibria. These two states are associated with distinctly different microphysical, thermodynamic, and radiative characteristics. Most but not all of the models produce a persistent mixed-phase cloud qualitatively similar to observations using the baseline IN/crystal concentration, while small increases in the IN/crystal concentration generally lead to rapid glaciation and conversion to the all-ice state. Budget analysis indicates that larger ice deposition rates associated with increased IN/crystal concentrations have a limited direct impact on dissipation of liquid in these simulations. However, the impact of increased ice deposition is greatly enhanced by several interaction pathways that lead to an increased surface precipitation flux, weaker cloud top radiative cooling and cloud dynamics, and reduced vertical mixing, promoting rapid glaciation of the mixed-phase cloud for deposition rates in the cloud layer greater than about 1-2x10-5 g kg-1 s-1. These results indicate the critical importance of precipitation-radiative-dynamical interactions in simulating cloud phase, which have been neglected in previous fixed-dynamical parcel studies of the cloud phase parameter space. Large sensitivity to the IN/crystal concentration also suggests the need for improved understanding of ice nucleation and its parameterization in models.

  14. Adding Complex Terrain and Stable Atmospheric Condition Capability to the Simulator for On/Offshore Wind Farm Applications (SOWFA) (Presentation)

    SciTech Connect (OSTI)

    Churchfield, M. J.

    2013-06-01T23:59:59.000Z

    This presentation describes changes made to NREL's OpenFOAM-based wind plant aerodynamics solver so that it can compute the stably stratified atmospheric boundary layer and flow over terrain. Background about the flow solver, the Simulator for Off/Onshore Wind Farm Applications (SOWFA) is given, followed by details of the stable stratification/complex terrain modifications to SOWFA, along with some preliminary results calculations of a stable atmospheric boundary layer and flow over a simple set of hills.

  15. A Comparison of Atmospheric Reanalysis Surface Products over the Ocean and Implications for Uncertainties in Air–Sea Boundary Forcing

    E-Print Network [OSTI]

    Chaudhuri, Ayan H.

    This paper investigates the uncertainties related to atmospheric fields from reanalysis products used in forcing ocean models. Four reanalysis products, namely from 1) the interim ECMWF Re-Analysis (ERA-Interim), 2) version ...

  16. The chemistry of OH and HO2 radicals in the boundary layer over the tropical Atlantic Ocean

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    fore passing near to the Canary Islands on its way to Capepassing close to the Canary Islands before approaching CapePolarstern north of the Canary Islands. Significant boundary

  17. Contributions of the wall boundary layer to the formation of the counter-rotating vortex pair in transverse jets

    E-Print Network [OSTI]

    Schlegel, Fabrice

    Using high-resolution 3-D vortex simulations, this study seeks a mechanistic understanding of vorticity dynamics in transverse jets at a finite Reynolds number. A full no-slip boundary condition, rigorously formulated in ...

  18. Experimental development of the predictive relations for the eddy exchange coefficients for momentum and heat in the atmospheric boundary layer

    E-Print Network [OSTI]

    Jensen, Paul Alfred

    1972-01-01T23:59:59.000Z

    . 3 &ii. t' i' 1i~:. . ;at of: t'ai. , : -. . '. ; r. ;. ;. r, ': i r:;. - ~ leer-. . - . :. . . , , . ;: o i r ". pc i' FC:"1;', );, 1')7p EXPERIYENT'L Dj. 'VELOPkjENT OF THE PRFDICTZFF. RETATIONS 1'OR T13E Fl)DY E1CH'NGF CO1'FFZCZENTS I'OR 3j...ONENTDF! 1'ND kicAT 13, Tl!E ATk!OSPkjERIC EcjUNDj!PY Ll TER A Thesi. s by PAUL ALFRED JENSEN APProved as to sty]e encl content by; (Cbairman of Cocami tree. ) ll!ead o= Departs nnl. , 'I' (t; /jc jJ. '~' (Member) l'jec em. bor ID; p c& rra Ai...

  19. A Large-Eddy Simulation Study of the Influence of Subsidence on the Stably Stratified Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Mirocha, Jeffrey D.; Kosovi?, Branko

    2010-01-01T23:59:59.000Z

    to the surface of the snow/ice pack is often prevented byheat ?ux from the snow/ice pack interior, which constrainsover the Arctic Ocean snow/ice pack during clear-sky, winter

  20. Atmospheric Boundary Layer Research Rocket Ulises Espinoza, Braeden Moore, Scott Schoen, Trevor Seguin, Jordan Van Dyke, Greg Woolston

    E-Print Network [OSTI]

    Provancher, William

    micro SD card for analysis. - Compact chassis designed to increases overall rocket stability. Flight launch. Project Description Develop an efficient, cost effective alternative to gathering data of low to validate FEA material model. Testing Wind Tunnel - 1:6 scale rocket tested in wind tunnel to determine

  1. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01T23:59:59.000Z

    When the convection heat transfer model is well validated,models, convection heat transfer model is often over-and a convection heat transfer model with local accuracy is

  2. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01T23:59:59.000Z

    losses of a flat-plate collector, Solar Energy 35, 15–19.from outer cover of solar collectors, Renew. Energ. 10 (4)

  3. A Large-Eddy Simulation Study of the Influence of Subsidence on the Stably Stratified Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Mirocha, Jeffrey D.; Kosovi?, Branko

    2010-01-01T23:59:59.000Z

    Mean pro?les of potential temperature, wind speed, verticalsection. 4.1 Potential Temperature and Wind Speed Pro?lesequilibrium LES potential temperature and wind speed pro?les

  4. Measurement of Boundary-Layer Temperature Profiles by a Scanning 5-MM Radiometer During the 1999 Winter NSA/AAO Radiometer Exp

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from a NewCuneo Matthew1, 20121 H( 7 Be,Boundary-Layer

  5. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01T23:59:59.000Z

    74 ii Soil Moisture Sensors: Decagon ECH2O Capacitance133 A.10 Soil types corresponding to each75 Soil Moisture and Temperature Probe

  6. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01T23:59:59.000Z

    red indicates “water towers” generated by kinematic wavethe kinematic wave equation will begin to collect water onred indicates “water towers” generated by kinematic wave

  7. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01T23:59:59.000Z

    direction, (b) wind speed, (c) potential temperature, and (Airport of potential temperature, wind speed, winderrors (bias) for potential temperature, wind speed, wind

  8. Effect of unsteady wake passing frequency on boundary layer transition on the concave surface of a curved plate

    E-Print Network [OSTI]

    Read, Robert Kevin

    1997-01-01T23:59:59.000Z

    frequencies. The periodic unsteady flow is generated utilizing an unsteady flow research facility with a rotating cascade of rods positioned upstream of the curved plate. The inlet velocity is measured using a X-wire hot-film probe while the unsteady boundary...

  9. DOI 10.1007/s10546-006-9050-z Boundary-Layer Meteorology (2006) 120: 315351 Springer 2006

    E-Print Network [OSTI]

    Ribes, Aurélien

    2006-01-01T23:59:59.000Z

    parametrization for the urban surface energy balance. A three-day period was modelled and evaluated against data THERMODYNAMIC ISLAND IN A COASTAL CITY ANALYSED FROM AN OPTIMIZED SURFACE NETWORK GR ´EGOIRE PIGEON,1, AUDE on the study of the urban atmosphere over the coastal city of Marseille. A methodology developed to optimize

  10. Boundary-Layer Meteorol (2010) 134:223242 DOI 10.1007/s10546-009-9440-0

    E-Print Network [OSTI]

    Katul, Gabriel

    2010-01-01T23:59:59.000Z

    ). However, even though longwave radiation effects on an evolving NBL have been the subject of a number-sky conditions, which is the subject here. Atmospheric emissivity varies with cloud cover and concentration emissivity in modelling the radiative properties of the NBL especially for clear-sky conditions. Keywords

  11. ATMOSPHERIC TURBULENCE MODELING AND IMPLICATIONS FOR WIND ENERGY

    E-Print Network [OSTI]

    Chow, Fotini Katopodes

    turbines off too early in high winds, or may risk severe damage to the rotors and blades by operating under Introduction Wind turbines sit at the very bottom of the at- mospheric boundary layer, where winds are highly turbulent, shear events are intermittent, and land- atmosphere interactions may be strong. Turbine hub

  12. Detailed study of the influence of surface misorientation on the density of Anti-Phase Boundaries in 3C-SiC layers grown on (001) silicon

    SciTech Connect (OSTI)

    Jiao, S. [Universite Francois Rabelais, Tours, Laboratoire de Microelectronique de Puissance, 16 rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Centre de Recherche sur l'Hetero-Epitaxie et ses Applications CNRS-UPR10, rue Bernard Gregory, 06560 Valbonne (France); Zielinski, M.; Chassagne, T. [NOVASiC, Savoie Technolac, Arche Bat 4, BP 267, 73375 Le Bourget du Lac Cedex (France); Roy, S. [Saint Gobain recherche, 39 Quai Lucien Lefranc 93300 Aubervilliers cedex (France); Michaud, J. F.; Alquier, D. [Universite Francois Rabelais, Tours, Laboratoire de Microelectronique de Puissance, 16 rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Portail, M. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications CNRS-UPR10, rue Bernard Gregory, 06560 Valbonne (France)

    2010-11-01T23:59:59.000Z

    In this work we investigated the influence of the Si substrate misorientation and 3C-SiC film thickness on the density of Anti-Phase Boundaries, in order to better understand the mechanism of antiphase domain annihilation. The two highlights in our work are the utilization of [001] orientated Si on-axis wafer with spherical dimples, which gave us access to a continuum of off-cut angles (0 deg. to {approx}11 deg.) and directions, and the deposition of elongated silicon islands on the surface of 3C-SiC epilayers, which improved the detection of APDs by analysis of Scanning Electron Microscopy images. We found that for a given layer thickness the relative surface occupation of one domain increases with the off-cut angle value, leading to single domain film up to a certain angle. This critical value is reduced as the film is thickened.

  13. Interface boundary conditions for dynamic magnetization and spin wave dynamics in a ferromagnetic layer with the interface Dzyaloshinskii-Moriya interaction

    SciTech Connect (OSTI)

    Kostylev, M. [School of Physics, M013, University of Western Australia, Crawley, Perth 6009, Western Australia (Australia)

    2014-06-21T23:59:59.000Z

    In this work, we derive the interface exchange boundary conditions for the classical linear dynamics of magnetization in ferromagnetic layers with the interface Dzyaloshinskii-Moriya interaction (IDMI). We show that IDMI leads to pinning of dynamic magnetization at the interface. An unusual peculiarity of the IDMI-based pinning is that its scales as the spin-wave wave number. We incorporate these boundary conditions into an existing numerical model for the dynamics of the Damon-Eshbach spin wave in ferromagnetic films. IDMI affects the dispersion and the frequency non-reciprocity of the travelling Damon-Eshbach spin wave. For a broad range of film thicknesses L and wave numbers, the results of the numerical simulations of the spin wave dispersion are in a good agreement with a simple analytical expression, which shows that the contribution of IDMI to the dispersion scales as 1/L, similarly to the effect of other types of interfacial anisotropy. Suggestions to experimentalists how to detect the presence of IDMI in a spin wave experiment are given.

  14. Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint

    SciTech Connect (OSTI)

    Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

    2011-12-01T23:59:59.000Z

    Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

  15. Scientific uncertainties in atmospheric mercury models III: Boundary and initial conditions, model grid resolution, and Hg(II) reduction mechanism

    SciTech Connect (OSTI)

    Lin, Che-Jen [ORNL; Pongprueksa, Pruek [Lamar University; Lindberg, Steven Eric [ORNL; Jang, Carey [U.S. Environmental Protection Agency, Raleigh, North Carolina; Braverman, Thomas [U.S. Environmental Protection Agency, Raleigh, North Carolina; Bullock, Russell O [NOAA; Ho, Thomas [ORNL; Chu, Hsing-Wei [Lamar University

    2008-03-01T23:59:59.000Z

    In this study, the model response in terms of simulated mercury concentration and deposition to boundary condition (BC), initial condition (IC), model grid resolution (12 km versus 36 km), and two alternative Hg(II) reduction mechanisms, was investigated. The model response to the change of gaseous elemental mercury (GEM) concentration from 0 to 2 ngm3 in IC/BC is found to be very linear (r240.99) based on the results of sensitivity simulations in July 2001. An increase of 1 ngm3 of GEM in BC resulted in an increase of 0.81 ngm3 in the monthly average of total mercury concentration, and 1270 ngm2 in the monthly total deposition. IC has similar but weaker effects compared to those of BC. An increase of 1 ngm3 of GEM in IC resulted in an increase of 0.14 ngm3 in the monthly average of total mercury concentration, and 250 ngm2 in the monthly total deposition. Varying reactive gaseous mercury (RGM) or particulate mercury (PHg) in BC/IC has much less significant impact. Simulation results at different grid resolutions show good agreement (slope 0.950 1.026, r 0.816 0.973) in mercury concentration, dry deposition, and total deposition. The agreement in wet deposition is somewhat weaker (slope 0.770 0.794, r 0.685 0.892) due to the difference in emission dilution and simulated precipitation that subsequently change reaction rates in the aqueous phase. Replacing the aqueous Hg(II)-HO2 reduction by either RGM reduction by CO (51018cm3 molecule1 s1) or photoreduction of RGM (1105 s1) gives significantly better model agreement with the wet deposition measured by Mercury Deposition Network (MDN). Possible ranges of the reduction rates are estimated based on model sensitivity results. The kinetic estimate requires further verification by laboratory studies.

  16. Oval BA (and the Great Red Spot) extend down to a supersolar water cloud layer in Jupiter's atmosphere

    E-Print Network [OSTI]

    Marcus, Philip S.

    Oval BA (and the Great Red Spot) extend down to a supersolar water cloud layer in Jupiter in Jupiter's troposphere, with stable layers near cloud bases [4,6,7]. We use these two results to determine horizontal band in Fig. 2 shows that vortex- model derived static stability (white bars) is consistent

  17. Global warming and its implications for conservation. 3. How does it work? Part two: atmospheric science and the layer model

    E-Print Network [OSTI]

    Creel, Scott

    that energy comes in from the sun and shines back out to space as IR. The main points are: 1. The outflow of IR energy from a planet must balance heating from the sun. 2. The planet accomplishes this balance warms the surface of the planet as it moves toward an equilibrium of energy fluxes in and out. The layer

  18. Boundary Layer Cloud Turbulence Characteristics

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced Materials Find FindRewindParticleBorn on anJeffersonBound

  19. The atmospheric circulation over the North Atlantic as induced by the SST field

    E-Print Network [OSTI]

    Robertson, Andrew W.

    over the North Atlantic. A model of the atmospheric marine boundary layer coupled to a baroclinic quasi. In particular, significant oscillatory modes with periods of 8.5, 4.2 and 2.8 years are found in both series. These oscillatory modes in the simulations are shown to be suppressed when either (a) the Gulf

  20. Heat transport and weakening of atmospheric stability induced by mesoscale flows

    E-Print Network [OSTI]

    Pielke, Roger A.

    Heat transport and weakening of atmospheric stability induced by mesoscale flows G. A. Dalu boundary layer (CBL) is transported upward into the midtroposphere by mesoscale flows, and how the air, and diffusion, associated with the mesoscale flow, is more clearly shown when the forcing is periodic in time

  1. Investigating the local atmospheric response to a5 realistic shift in the Oyashio sea surface6

    E-Print Network [OSTI]

    Newman, Matthew

    , where extratropical SST forcing produces31 shallow anomalous heating balanced by strong equatorward cold the atmosphere, beyond basic thermodynamic air-sea coupling via59 turbulent boundary layer heat flux exchange, most of the SST anomaly induced diabatic heating ( ) is balanced by29 poleward transient eddy heat

  2. Effect of annealing atmosphere on the structure and luminescence of Sn-implanted SiO{sub 2} layers

    SciTech Connect (OSTI)

    Lopes, J.M.J.; Zawislak, F.C.; Fichtner, P.F.P.; Lovey, F.C.; Condo, A.M. [Instituto de Fisica - UFRGS, Cx. Postal 15051, 91501-970 Porto Alegre (Brazil); Departamento de Metalurgia, Escola de Engenharia - UFRGS, Porto Alegre (Brazil); Centro Atomico Bariloche, 8400 S.C. Bariloche (Argentina)

    2005-01-10T23:59:59.000Z

    Sn nanoclusters are synthesized in 180 nm SiO{sub 2} layers after ion implantation and heat treatment. Annealings in N{sub 2} ambient at high temperatures (T{>=}700 deg. C) lead to the formation of Sn nanoclusters of different sizes in metallic and in oxidized phases. High-resolution transmission electron microscopy (TEM) analyses revealed that the formed larger nanoparticles are composed by a Sn metallic core and a SnO{sub x} shell. The corresponding blue-violet photoluminescence (PL) presents low intensity. However, for heat treatments in vacuum, the PL intensity is increased by a factor of 5 and the TEM data show a homogeneous size distribution of Sn nanoclusters. The low intensity of PL for the N{sub 2} annealed samples is associated with Sn oxidation.

  3. Boundary streaming with Navier boundary condition Jin-Han Xiea)

    E-Print Network [OSTI]

    Vanneste, Jacques

    is the fluid's kinematic shear viscosity and is the wave's angular frequency. In water, and for frequencies applications involving high-frequency acoustic waves over a solid boundary, the Stokes boundary-layer thickness to travelling and standing waves shows that the boundary slip respectively increases and decreases the streaming

  4. Atmospheric science and power production

    SciTech Connect (OSTI)

    Randerson, D. (ed.)

    1984-07-01T23:59:59.000Z

    This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.

  5. 8, 88178846, 2008 Observed boundary-

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 8, 8817­8846, 2008 Observed boundary- layer/mesoscale impacts on Saharan dust J. H. Marsham et and Enviroment, University of Leeds, Leeds, UK 2 Institut f¨ur Meteorologie und Klimaforschung, Universit@env.leeds.ac.uk) 8817 #12;ACPD 8, 8817­8846, 2008 Observed boundary- layer/mesoscale impacts on Saharan dust J. H

  6. Pacific Northwest Laboratory annual report for 1984 to the DOE Office of Energy Research. Part 3. Atmospheric sciences

    SciTech Connect (OSTI)

    Elderkin, C.E.

    1985-02-01T23:59:59.000Z

    The goals of atmospheric research at Pacific Northwest Laboratory (PNL) are to assess, describe, and predict the nature and fate of atmospheric contaminants and to study the impacts of contaminants on local, regional, and global climates. The contaminants being investigated are those resulting from the development and use of conventional resources (coal, gas, oil, and nuclear power) as well as alternative energy sources. The description of the research is organized into 3 sections: (1) Atmospheric Studies in Complex Terrain (ASCOT); (2) Boundary Layer Meteorology; and (3) Dispersion, Deposition, and Resuspension of Atmospheric Contaminants. Separate analytics have been done for each of the sections and are indexed and contained in the EDB. (MDF)

  7. Diamond and Related Materials, 2 (1993) 661 666 661 Degenerate four-wave mixing diagnostics of atmospheric pressure

    E-Print Network [OSTI]

    Zare, Richard N.

    -3]. An r.f. inductively coupled plasma offers the benefits of an "electrodeless" discharge for minimum film application of this new spectroscopic technique to an atmospheric pressure plasma synthesis reactor. DFWM measurements of the CH radicals in the boundary layer of an r.f. inductively coupled plasma deposition reactor

  8. The Atmospheric Circulation over the North Atlantic as Induced by the SST Field YIZHAK FELIKS* AND MICHAEL GHIL1

    E-Print Network [OSTI]

    Ghil, Michael

    over the North Atlantic. A model of the atmospheric marine boundary layer coupled to a baroclinic oscillatory modes with periods of 8.5, 4.2, and 2.8 yr are found in both ob- served and simulated indices and are shown to be highly synchronized and of similar energy in both time series. These oscillatory modes

  9. Climatic effects of nuclear war: The role of atmospheric stability and ground heat fluxes

    SciTech Connect (OSTI)

    Mitchell, J.F.B.; Slingo, A.

    1988-06-20T23:59:59.000Z

    Most studies of the climatic effects of nuclear war have used atmospheric models with simple representations of important physical processes. In this work, a model is used which treats the diurnal cycle of insolation, and includes surface and boundary layer parameterizations which take into account static stability and a four-layer soil model. Three idealized experiments are described in which a band of smoke is prescribed over northern mid-latitudes in In the experiment, the standard model is used, in the second the effect of deep soil layers is ignored and in the third the stability dependence in the surface and boundary layer processes is removed. It is found that the inclusion of deep soil layers decreases the surface cooling by about 20%, whereas the inclusion of stability effects increases the cooling by about the same amount, though conclusions will depend to some extent on the model used. copyright American Geophysical Union 1988

  10. Improved heterojunction quality in Cu2O-based solar cells through the optimization of atmospheric pressure spatial atomic layer deposited Zn1-xMgxO

    E-Print Network [OSTI]

    Ievskaya, Yulia; Hoye, Robert L. Z.; Sadhanala, Aditya; Musselman, Kevin P.; MacManus-Driscoll, Judith L.

    2015-01-01T23:59:59.000Z

    films.12 Herein, we still refer to the reactor as an AP-SALD reactor because it has the same fundamental design principles as other AP-SALD reactors.11 We used our reactor to deposit the n-type layer for our solar cells, in particular zinc oxide... in Figure 2. This allows the metal oxide film to grow layer by layer. A detailed description of AP-SALD reactor design and operation can be found elsewhere.11,12 This approach allows the deposition to occur one to two orders of magnitude faster than...

  11. Atmospheric heat redistribution and collapse on tidally locked rocky planets

    E-Print Network [OSTI]

    Wordsworth, Robin

    2014-01-01T23:59:59.000Z

    Atmospheric collapse is likely to be of fundamental importance to tidally locked rocky exoplanets but remains understudied. Here, general results on the heat transport and stability of tidally locked terrestrial-type atmospheres are reported. First, the problem is modeled with an idealized 3D general circulation model (GCM) with gray gas radiative transfer. It is shown that over a wide range of parameters the atmospheric boundary layer, rather than the large-scale circulation, is the key to understanding the planetary energy balance. Through a scaling analysis of the interhemispheric energy transfer, theoretical expressions for the day-night temperature difference and surface wind speed are created that reproduce the GCM results without tuning. Next, the GCM is used with correlated-k radiative transfer to study heat transport for two real gases (CO2 and CO). For CO2, empirical formulae for the collapse pressure as a function of planetary mass and stellar flux are produced, and critical pressures for atmospher...

  12. ChEAS Data: The Chequamegon Ecosystem Atmosphere Study

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

    Davis, Kenneth J. [Penn State

    The Chequamegon Ecosystem-Atmosphere Study (ChEAS) is a multi-organizational research effort studying biosphere/atmosphere interactions within a northern mixed forest in Northern Wisconsin. A primary goal is to understand the processes controlling forest-atmosphere exchange of carbon dioxide and the response of these processes to climate change. Another primary goal is to bridge the gap between canopy-scale flux measurements and the global CO2 flask sampling network. The ChEAS flux towers participate in AmeriFlux, and the region is an EOS-validation site. The WLEF tower is a NOAA-CMDL CO2 sampling site. ChEAS sites are primarily located within or near the Chequamegon-Nicolet National Forest in northern Wisconsin, with one site in the Ottawa National Forest in the upper peninsula of Michigan. Current studies observe forest/atmosphere exchange of carbon dioxide at canopy and regional scales, forest floor respiration, photosynthesis and transpiration at the leaf level and use models to scale to canopy and regional levels. EOS-validation studies quantitatively assess the land cover of the area using remote sensing and conduct extensive ground truthing of new remote sensing data (i.e. ASTER and MODIS). Atmospheric remote sensing work is aimed at understanding atmospheric boundary layer dynamics, the role of entrainment in regulating the carbon dioxide mixing ratio profiles through the lower troposphere, and feedback between boundary layer dynamics and vegetation (especially via the hydrologic cycle). Airborne studies have included include balloon, kite and aircraft observations of the CO2 profile in the troposphere.

  13. Atmospheric dispersion in mountain valleys and basins

    SciTech Connect (OSTI)

    Allwine, K.J.

    1992-01-01T23:59:59.000Z

    The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ventilation rate'' of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.

  14. Atmospheric dispersion in mountain valleys and basins

    SciTech Connect (OSTI)

    Allwine, K.J.

    1992-01-01T23:59:59.000Z

    The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ``ventilation rate`` of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.

  15. Oscillatory flow across an irregular boundary Geno Pawlak

    E-Print Network [OSTI]

    Pawlak, Geno

    ; KEYWORDS: eddies, tidal mixing, rough boundary, oscillatory flow, residual currents, wave boundary layers 1Oscillatory flow across an irregular boundary Geno Pawlak Department of Ocean and Resources. Introduction [2] Oscillatory flow past a rough boundary is a prevalent feature in a number of oceanographic

  16. The sensitivity of a coupled atmospheric-oceanic model to variations in the albedo and absorptivity of a stratospheric aerosol layer

    SciTech Connect (OSTI)

    Walsh, K.; Pittock, A.B. (Commonwealth Scientific and Industrial Research Organization, Victoria (Australia))

    1990-06-20T23:59:59.000Z

    Considerable uncertainty exists regarding the precise physical parameters of a smoke or aerosol cloud that would be injected into the lower stratosphere by a catastrophic event such as a nuclear war, a major volcanic eruption, or an asteroid impact. In this paper, the sensitivity of the sea surface temperature of a one-dimensional coupled atmospheric-oceanic model to variations in the albedo and absorptivity of an aerosol cloud introduced into the lower stratosphere is examined. Zonally averaged results are produced for two latitudes in the southern hemisphere. The temperature response of the oceans to forcings by a cloud with realistic aerosol properties is examined, with particular emphasis on the impact on the surface climate on time scales of 6 months to 2 years.

  17. Boundary layer response to wind gusts

    E-Print Network [OSTI]

    Morland, Bruce Thomas

    1968-01-01T23:59:59.000Z

    . and Mrs. Sruce T'. garland. Ths author took his gachslcr cf Science degree frns Arlington Stats College in lp66. He worked briefly fcr X, lug&secs~ought dircraft in ths airlcads group ior the p g Crusader. While working ca his Meeter ef Science degree...

  18. Convective Instability of a Boundary Layer with

    E-Print Network [OSTI]

    Conrad, Clint

    proportional to the integral over the depth of the lithosphere of the 19 #12;ratio of thermal buoyancy. Such instabilities are driven by the negative thermal buoyancy of the cold lithosphere and retarded largely for driving convective downwelling. For non-Newtonian viscosity with power law exponent n and temperature

  19. Stability of Small Viscosity Noncharacteristic Boundary Layers

    E-Print Network [OSTI]

    Métivier, Guy

    . . . . . . . . . . . . . . . . . . . 17 1.3.2 The mixed Cauchy-problem . . . . . . . . . . . . . . . 17 1.4 BKW expansions

  20. Stability of Small Viscosity Noncharacteristic Boundary Layers

    E-Print Network [OSTI]

    Métivier, Guy

    . . . . . . . . . . . . . . . . . . . 17 1.3.2 The mixed Cauchy­problem . . . . . . . . . . . . . . . 17 1.4 BKW expansions

  1. Thunderstorm influence on boundary layer winds

    E-Print Network [OSTI]

    Schmidt, Jill Marie

    1986-01-01T23:59:59.000Z

    of this research was to develop a conceptual model of selected pre-storm ambient conditions as a function of the strength of a thunderstorm's outflow. The time of maximum rainfall during the thunderstorm in relation to the time of maximum outflow was a... selected for study from well-defined Code 3 cells (thunderstorms). The results indicated that two conceptual models were necessary to describe the pre-storm ambient conditions that led to thunderstorm development and outflow. One model contained...

  2. Boundary Layer Lubrication Mechanisms | Department of Energy

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

    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 Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergyandapproximatelyBoostingand Capacity Concerns inStudy1

  3. Boundary Layer Lubrication Mechanisms | Department of Energy

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

    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 Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergyandapproximatelyBoostingand Capacity Concerns

  4. Boundary Layer Lubrication | Department of Energy

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

    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 Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergyandapproximatelyBoostingand Capacity

  5. Boundary Layer Lubrication | Department of Energy

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

    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 Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergyandapproximatelyBoostingand Capacity2009 DOE Hydrogen

  6. ARM - Field Campaign - Boundary Layer Cloud IOP

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76)ARM2,govCampaignsAircraftCloud

  7. ARM - Measurement - Planetary boundary layer height

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwelling irradiancenumber concentration

  8. Is Magnetic Topology Important for Heating the Solar Atmosphere?

    E-Print Network [OSTI]

    Parnell, C E; Threlfall, J; Edwards, S J

    2015-01-01T23:59:59.000Z

    Magnetic fields permeate the entire solar atmosphere weaving an extremely complex pattern on both local and global scales. In order to understand the nature of this tangled web of magnetic fields, its magnetic skeleton, which forms the boundaries between topologically distinct flux domains, may be determined. The magnetic skeleton consists of null points, separatrix surfaces, spines and separators. The skeleton is often used to clearly visualize key elements of the magnetic configuration, but parts of the skeleton are also locations where currents and waves may collect and dissipate. In this review, the nature of the magnetic skeleton on both global and local scales, over solar cycle time scales, is explained. The behaviour of wave pulses in the vicinity of both nulls and separators is discussed and so too is the formation of current layers and reconnection at the same features. Each of these processes leads to heating of the solar atmosphere, but collectively do they provide enough heat, spread over a wide e...

  9. MAE Seminar Series Boundary Closures for

    E-Print Network [OSTI]

    Krovi, Venkat

    ) boundary layer stability and transition. 206 Furnas Hall Thursday, April 8th, 2010 11:00 am ­ 12:00 pmMAE Seminar Series Boundary Closures for ESWENO Schemes Mark H. Carpenter, Ph.D. Computational AeroSciences Branch NASA Langley Research Center Abstract Energy Stable Weighted Essentially Non--Oscillatory (ESWENO

  10. The Daytime Mixed Layer Observed by Radiosonde, Profiler, and LIDAR during MILAGRO

    SciTech Connect (OSTI)

    Shaw, William J.; Pekour, Mikhail S.; Coulter, Richard L.; Martin, Tim J.; Walters, Justin

    2007-10-19T23:59:59.000Z

    During the MILAGRO campaign centered in the Mexico City area, Pacific Northwest National Laboratory (PNNL) and Argonne National Laboratory (ANL) operated several atmospheric profiling systems at Veracruz and at two locations on the Central Mexican Plateau in the region around Mexico City. These systems included radiosondes, wind profilers, a sodar, and an aerosol backscatter lidar. An additional wind profiler was operated by the University of Alabama in Huntsville (UAH) at the Mexican Petroleum Institue (IMP) near the center of Mexico City. Because of the opportunity afforded by collocation of profilers, radiosondes, and a lidar, and because of the importance of boundary layer depth on aerosol properties, we have carried out a comparison of mixed layer depth as determined independently from these three types of measurement systems during the campaign. We have then used results of this comparison and additional measurements to develop a detailed description of the daily structure and evolution of the boundary layer on the Central Mexican Plateau during MILAGRO. Our analysis indicates that the profilers were more consistently successful in establishing the mixing layer depth during the daytime. The boundary layer growth was similar at the three locations, although the mixing layer tended to be slightly deeper in the afternoon in central Mexico City. The sodar showed that convection began about an hour after sunrise. Maximum daily mixed layer depths always reached 2000 m AGL and frequently extended to 4000 m. The rate and variability of mixing layer growth was essentially the same as that observed during the IMADA-AVER campaign in the same season in 1997. This growth did not seem to be related to whether deep convection was reported on a given day. Wind speeds within the boundary layer exhibited a daily low-altitude maximum in the late afternoon with lighter winds aloft, consistent with previous reports of diurnal regional circulations. Norte events, which produced high winds at Veracruz, did not appreciably modulate the winds on the plateau. Finally, despite the typically dry conditions at the surface, radiosonde profiles showed that relative humidity often exceeded 50% in the early morning and in the upper part of the boundary layer.

  11. HYPERsensarium : an archive of atmospheric conditions

    E-Print Network [OSTI]

    Shaw, Kelly E. (Kelly Evelyn)

    2013-01-01T23:59:59.000Z

    HYPERsensarium proposes a tangible interface of atmospheres for public experience through an archive of historical and projected weathers. While architecture's purpose has long been to act as the technical boundary between ...

  12. Response of the upper ocean to a large summertime injection of smoke in the atmosphere. Final report

    SciTech Connect (OSTI)

    Mettlach, T.R.; Haney, R.L.; Garwood, R.W.; Ghan, S.J.

    1987-02-15T23:59:59.000Z

    A one-dimensional oceanic planetary boundary-layer model is used to investigate the response of the upper ocean to the atmospheric conditions predicted to develop following a hypothetical nuclear exchange. The ocean model is driven by the surface heat and momentum fluxes predicted by an atmospheric general circulation model following a summertime injection of 1.5 X 10/sup 14/ g of smoke from postwar fires over Europe, Asia, and North America. Although the specific response of the upper ocean is highly dependent on the geographic location, the mid-latitude summertime mixed layer typically cools 3 to 5/degree/C and deepens 25 m during the first 30 days following the smoke injection. Moreover, a large fraction of this response is found to take place during a short 2- to 3-day period of very intense winds and falling air temperatures, which occurs during the first week or two after the smoke injection.

  13. Convection induced by radiative cooling of a layer of participating medium

    SciTech Connect (OSTI)

    Prasanna, Swaminathan, E-mail: prasannaswam@gmail.com [Laboratoire EM2C, CNRS UPR 288 92295, Chatenay-Malabry, France and Ecole Centrale Paris, Grande Voie des Vignes 92295, Chatenay-Malabry (France)] [Laboratoire EM2C, CNRS UPR 288 92295, Chatenay-Malabry, France and Ecole Centrale Paris, Grande Voie des Vignes 92295, Chatenay-Malabry (France); Venkateshan, S. P., E-mail: spv@iitm.ac.in [HTTP Laboratory, Department of Mechanical Engineering IIT Madras, Chennai (India)

    2014-05-15T23:59:59.000Z

    Simulations and experiments have been conducted to study the effect of radiative cooling on natural convection in a horizontal layer of a participating medium enclosed between isothermal opaque wall and radiatively transparent wall and exposed to a cold background. The study is of relevance to a nocturnal boundary layer under clear and calm conditions. The focus of the study is to capture the onset of convection caused by radiative cooling. The experiments have been designed to mimic the atmospheric radiative boundary conditions, and hence decoupling convection and radiation boundary conditions. Planck number Pl and optical thickness of the layer ?{sub H} are the two important parameters that govern the interaction between radiation and convection. The radiation-convection coupling is a strong function of length scale. Convection sets up within first few seconds for all the experiments. Strong plume like convection is observed for the experimental conditions used in the present study. Both simulations and experiments confirm that radiative cooling increases substantially with decrease in emissivity of the bottom wall. Radiative cooling is strongly influenced by the nongray nature of the participating medium, especially when strong emission from the medium escapes to space, in the window region of the atmosphere. Accurate representation of radiative properties is critical. Linear stability analysis of onset of convection indicates that radiation stabilizes convection as Pl decreases. The observations are similar to the case of Rayleigh Bénard convection in a radiating gas. However, for both experimental and numerical conditions, the observed Rayleigh numbers are much greater than the critical Rayleigh number. To conclude, the role of radiation is to drive and sustain convection in the unstable layer.

  14. Atmospheric Neutrinos

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2006-12-11T23:59:59.000Z

    This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.

  15. Study Of The Fundamental Physical Principles in Atmospheric Modeling Based On Identification Of Atmosphere - Climate Control Factors: Bromine Explosion At The Polar Arctic Sunrise

    E-Print Network [OSTI]

    M. Iudin

    2010-07-09T23:59:59.000Z

    We attempt is to provide accumulated evidence and qualitative understanding of the associated atmospheric phenomena of the Arctic bromine explosion and their role in the functioning of the biotic Earth. We rationalize the empirical expression of the bromine influx into atmospheric boundary layer and calculate total amounts of the tropospheric BrO and Bry of the Arctic origin. Based on the quantities and partitioning of the reactive bromine species, we estimate the biogeochemical parametric constraint on the surface ozone field of the springtime NH. The constraint expresses strong relationship between atmosphere-climate control factors of the Earth's life and of external energy source. Physical atmosphere can be seen as a complex network of maximum complexity. Henceforth, we analyze the network context of the Arctic bromine pollution. We suggest that demonstrated attitudinal approach to the distributed surface flux would be successfully used in the innovative atmospheric modeling. The analysis is illustrated by GEM model results which stay in a good agreement with the observational data and support the original idea of the global NH effect of bromine chemistry.

  16. Finite element analysis of shells with layers

    E-Print Network [OSTI]

    Hiller, Jean-François, 1974-

    2002-01-01T23:59:59.000Z

    It is well established that thin shell structures frequently feature narrow bands of strain concentration and localized displacement irregularities referred to as boundary and internal layers. It is crucial to capture these ...

  17. Star-planet magnetic interaction and evaporation of planetary atmospheres

    E-Print Network [OSTI]

    Lanza, A F

    2013-01-01T23:59:59.000Z

    Stars interact with their close-in planets through radiation, gravitation, and magnetic fields. We investigate the energy input to a planetary atmosphere by reconnection between stellar and planetary magnetic fields and compare it to the energy input of the extreme ultraviolet (EUV) radiation field of the star. We quantify the power released by magnetic reconnection at the boundary of the planetary magnetosphere that is conveyed to the atmosphere by accelerated electrons. We introduce simple models to evaluate the energy spectrum of the accelerated electrons and the energy dissipated in the atmospheric layers in the polar regions of the planet upon which they impinge. A simple transonic isothermal wind flow along field lines is considered to estimate the increase in mass loss rate in comparison with a planet irradiated only by the EUV flux of its host star. We find that energetic electrons can reach levels down to column densities of 10^{23}-10^{25} m^{-2}, comparable with or deeper than EUV photons, and incr...

  18. PROBING NEAR-SURFACE ATMOSPHERIC TURBULENCE WITH LIDAR MEASUREMENTS AND HIGH-RESOLUTION HYDRODYNAMIC MODELS

    SciTech Connect (OSTI)

    J. KAO; D. COOPER; ET AL

    2000-11-01T23:59:59.000Z

    As lidar technology is able to provide fast data collection at a resolution of meters in an atmospheric volume, it is imperative to promote a modeling counterpart of the lidar capability. This paper describes an integrated capability based on data from a scanning water vapor lidar and a high-resolution hydrodynamic model (HIGRAD) equipped with a visualization routine (VIEWER) that simulates the lidar scanning. The purpose is to better understand the spatial and temporal representativeness of the lidar measurements and, in turn, to extend their utility in studying turbulence fields in the atmospheric boundary layer. Raman lidar water vapor data collected over the Pacific warm pool and the simulations with the HIGRAD code are used for identifying the underlying physics and potential aliasing effects of spatially resolved lidar measurements. This capability also helps improve the trade-off between spatial-temporal resolution and coverage of the lidar measurements.

  19. Pacific Northwest Laboratory annual report for 1993 to the DOE Office of Energy Research. Part 3: Atmospheric and climate research

    SciTech Connect (OSTI)

    Not Available

    1994-05-01T23:59:59.000Z

    The US Department of Energy`s (DOE`s) Office of Health and Environmental Research (OHER) atmospheric sciences and carbon dioxide research programs provide the DOE with scientifically defensible information on the local, regional, and global distributions of energy-related pollutants and their effects on climate. PNL has had a long history of technical leadership in the atmospheric sciences research programs within OHER. Within the Environmental Sciences Division of OHER, the Atmospheric Chemistry Program continues DOE`s long-term commitment to understanding the local, regional, and global effects of energy-related air pollutants. Research through direct measurement, numerical modeling, and analytical studies in the Atmospheric Chemistry Program emphasizes the long-range transport, chemical transformation, and removal of emitted pollutants, photochemically produced oxidant species, nitrogen-reservoir species, and aerosols. The atmospheric studies in Complex Terrain Program applies basic research on atmospheric boundary layer structure and evolution over inhomogeneous terrain to DOE`s site-specific and generic mission needs in site safety, air quality, and climate change. Research at PNL provides basic scientific underpinnings to DOE`s program of global climate research. Research projects within the core carbon dioxide and ocean research programs are now integrated with those in the Atmospheric Radiation Measurements, the Computer Hardware, Advanced Mathematics and Model Physics, and Quantitative Links program to form DOE`s contribution to the US Global Change Research Program. The description of ongoing atmospheric and climate research at PNL is organized in two broad research areas: atmospheric research; and climate research. This report describes the progress in fiscal year 1993 in each of these areas. Individual papers have been processed separately for inclusion in the appropriate data bases.

  20. PROPAGATION OF ALFVN WAVES AT THE PLASMA SHEET BOUNDARY Robert L. Lysak and Yan Song

    E-Print Network [OSTI]

    Lysak, Bob

    PROPAGATION OF ALFVÃ?N WAVES AT THE PLASMA SHEET BOUNDARY LAYER Robert L. Lysak and Yan Song School conversion or by localized plasma flows in the tail. The generation and propagation of these waves is studied nonlinear MHD simulations of wave propagation at the boundary layer. INTRODUCTION Recent observations from

  1. Momentum and heat fluxes in a turbulent air flow over a wet, smooth boundary

    E-Print Network [OSTI]

    Rice, Warren

    1958-01-01T23:59:59.000Z

    Idealized sketch, of boundary layer flow regions................ .............45 Figure 2 Schematic diagram of wind tunnel. . . . 46 Figure 3 Photograph of wind tunnel............ .. 47 Figure 4 Photograph of wind tunnel............ .. 47 Figure 5... mechanism and probe.................. .. 49 Figure 9 Distances of interest in the momentum and thermal boundary layers ............ 50 Figure 10 A typical velocity and temperature profile comparison .................. .. 51 Figure 1 1 Variation...

  2. Atmospheric Aerosols Workshop | EMSL

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

    Atmospheric Aerosols Workshop Atmospheric Aerosols Workshop EMSL Science Theme Advisory Panel Workshop - Atmospheric Aerosol Chemistry, Climate Change, and Air Quality. Baer DR, BJ...

  3. Atmospheric Aerosol Systems | EMSL

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

    Science Themes Atmospheric Aerosol Systems Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems...

  4. Running Boundary Condition

    E-Print Network [OSTI]

    Satoshi Ohya; Makoto Sakamoto; Motoi Tachibana

    2013-01-28T23:59:59.000Z

    In this paper we argue that boundary condition may run with energy scale. As an illustrative example, we consider one-dimensional quantum mechanics for a spinless particle that freely propagates in the bulk yet interacts only at the origin. In this setting we find the renormalization group flow of U(2) family of boundary conditions exactly. We show that the well-known scale-independent subfamily of boundary conditions are realized as fixed points. We also discuss the duality between two distinct boundary conditions from the renormalization group point of view. Generalizations to conformal mechanics and quantum graph are also discussed.

  5. Field measurement of the fate of atmospheric H? in a forest environment : from canopy to soil

    E-Print Network [OSTI]

    Meredith, Laura Kelsey, 1982-

    2013-01-01T23:59:59.000Z

    Atmospheric hydrogen (H? ), an indirect greenhouse gas, plays a notable role in the chemistry of the atmosphere and ozone layer. Current anthropogenic emissions of H? are substantial and may increase with its widespread ...

  6. Trace analysis of atmospheric organic bases

    E-Print Network [OSTI]

    Clark, Dwayne C.

    1984-01-01T23:59:59.000Z

    chromatographic fractions for NS analyses ( 121) and its use as a thin layer chromatography (TLC) adsorbent ( 122). The National Institute of Occupational Safety and Health (NIOSH) recommends its use in the analysis of many industrial vapors ( 113 - 120... analysis of atmospheric organic bases were investigated; the study included (1) the analysis of submarine charcoal filter bed samples for nitrogen bases and (2) the use of metallic tetraphenylporphines (TPP) as specific adsorbents for atmospheric...

  7. 3D convection simulations of the outer layers of the Sun using realistic physics

    E-Print Network [OSTI]

    F. J. Robinson; P. Demarque; L. H. Li; S. Sofia; Y. -C. Kim; K. L. Chan; D. B. Guenther

    2002-12-12T23:59:59.000Z

    This paper describes a series of 3D simulations of shallow inefficient convection in the outer layers of the Sun. The computational domain is a closed box containing the convection-radiation transition layer, located at the top of the solar convection zone. The most salient features of the simulations are that: i)The position of the lower boundary can have a major effect on the characteristics of solar surface convection (thermal structure, kinetic energy and turbulent pressure). ii)The width of the box has only a minor effect on the thermal structure, but a more significant effect on the dynamics (rms velocities). iii)Between the surface and a depth of 1 Mm, even though the density and pressure increase by an order of magnitude, the vertical correlation length of vertical velocity is always close to 600 km. iv) In this region the vertical velocity cannot be scaled by the pressure or the density scale height. This casts doubt on the applicability of the mixing length theory, not only in the superadiabatic layer, but also in the adjacent underlying layers. v) The final statistically steady state is not strictly dependent on the initial atmospheric stratification.

  8. Jupiter's Great Red Spot and zonal winds as a self-consistent, one-layer, quasigeostrophic flow

    E-Print Network [OSTI]

    Marcus, Philip S.

    -value calculations in which the weather layer starts at rest produce oscillatory east-west winds. Like the Jovian stratified with respect to thermal convection. The layer's top boundary is the tropo- pause which acts boundary is the top of an underlying convective zone. Because the layer's stratification (Brunt

  9. Response of the upper ocean to a large summertime injection of smoke in the atmosphere

    SciTech Connect (OSTI)

    Mettlach, T.R.; Haney, R.L.; Garwood R.W. Jr.; Ghan, S.J.

    1987-02-15T23:59:59.000Z

    A one-dimensional oceanic planetary boundary layer model is used to investigate the response of the upper ocean to the atmospheric conditions which are predicted to develop following a hypothetical nuclear exchange. The ocean model is driven by the surface heat and momentum fluxes predicted by an atmospheric general circulation model following a summertime injection of 1.5 x 10/sup 14/ g of smoke from postwar fires over Europe, Asia, and North America. Although the specific response of the upper ocean is highly dependent on the geographic location, the mid-latitude summertime mixed layer typically cools 3/sup 0/ to 5/sup 0/C and deepens 25 m during the first 30 days following the smoke injection. Moreover, a large fraction of this response is found to take place during a short 2- to 3-day period of very intense winds and falling air temperatures, which occurs during the first week or two after the smoke injection. copyrightAmerican Geophysical Union 1987

  10. Mars atmosphere modelling and observations workshop

    E-Print Network [OSTI]

    Forget, François

    /TES (W. C. Maguire et al.): 10' · Mars surface boundary layer meteorology (S. E. Larsen, H. E. Jørgensen. Lewis et al.) 10' · Assimilation of TES data from the Mars Global Surveyor scientific mapping phase. (L : Breeding vectors and predictability in the Oxford Mars GCM (C. E. Newman, P. L. Read and S. R. Lewis) 3

  11. INTRODUCTIONTOTHE SOLAR ATMOSPHERE

    E-Print Network [OSTI]

    ? #12;WHAT ISTHE SOLAR ATMOSPHERE? #12;#12;1-D MODEL ATMOSPHERE · Averaged over space and time · GoodINTRODUCTIONTOTHE SOLAR ATMOSPHERE D. Shaun Bloomfield Trinity College Dublin #12;OUTLINE · What is the solar atmosphere? · How is the solar atmosphere observed? · What structures exist and how do they evolve

  12. Energy transport, overshoot, and mixing in the atmospheres of very cool stars

    E-Print Network [OSTI]

    H. -G. Ludwig

    2002-08-30T23:59:59.000Z

    We constructed hydrodynamical model atmospheres for mid M-type main-, as well as pre-main-sequence objects. Despite the complex chemistry encountered in such cool atmospheres a reasonably accurate representation of the radiative transfer is possible. The detailed treatment of the interplay between radiation and convection in the hydrodynamical models allows to study processes usually not accessible within the framework conventional model atmospheres. In particular, we determined the efficiency of the convective energy transport, and the efficiency of mixing by convective overshoot. The convective transport efficiency expressed in terms of an equivalent mixing-length parameter amounts to values around ~2 in the optically thick, and ~2.8 in the optically thin regime. The thermal structure of the formally convectively stable layers is little affected by convective overshoot and wave heating, i.e. stays close to radiative equilibrium. Mixing by convective overshoot shows an exponential decline with geometrical distance from the Schwarzschild stability boundary. The scale height of the decline varies with gravitational acceleration roughly as g^(-1/2), with 0.5 pressure scale heights at log(g)=5.0.

  13. Boundaries and Topological Algorithms

    E-Print Network [OSTI]

    Fleck, Margaret Morrison

    1988-09-01T23:59:59.000Z

    This thesis develops a model for the topological structure of situations. In this model, the topological structure of space is altered by the presence or absence of boundaries, such as those at the edges of objects. ...

  14. Intrusive gravity currents in two-layer

    E-Print Network [OSTI]

    Flynn, Morris R.

    Intrusive gravity currents in two-layer stratified media Morris R. Flynn & Paul F. Linden Dept.avalanche.org/pictures #12;· `Microbursts' pose a non-trivial threat to airplane safety Introduction Impacts on human health;· Whereas gravity currents travel along a solid boundary, intrusive gravity currents or intrusions propagate

  15. DOE Workshop; Pan-Gass Conference on the Representation of Atmospheric Processes in Weather and Climate Models

    SciTech Connect (OSTI)

    Morrison, PI Hugh

    2012-09-21T23:59:59.000Z

    This is the first meeting of the whole new GEWEX (Global Energy and Water Cycle Experiment) Atmospheric System Study (GASS) project that has been formed from the merger of the GEWEX Cloud System Study (GCSS) Project and the GEWEX Atmospheric Boundary Layer Studies (GABLS). As such, this meeting will play a major role in energizing GEWEX work in the area of atmospheric parameterizations of clouds, convection, stable boundary layers, and aerosol-cloud interactions for the numerical models used for weather and climate projections at both global and regional scales. The representation of these processes in models is crucial to GEWEX goals of improved prediction of the energy and water cycles at both weather and climate timescales. This proposal seeks funds to be used to cover incidental and travel expenses for U.S.-based graduate students and early career scientists (i.e., within 5 years of receiving their highest degree). We anticipate using DOE funding to support 5-10 people. We will advertise the availability of these funds by providing a box to check for interested participants on the online workshop registration form. We will also send a note to our participants' mailing lists reminding them that the funds are available and asking senior scientists to encourage their more junior colleagues to participate. All meeting participants are encouraged to submit abstracts for oral or poster presentations. The science organizing committee (see below) will base funding decisions on the relevance and quality of these abstracts, with preference given to under-represented populations (especially women and minorities) and to early career scientists being actively mentored at the meeting (e.g. students or postdocs attending the meeting with their advisor).

  16. Water Vapor Turbulence Profiles in Stationary Continental Convective Mixed Layers

    SciTech Connect (OSTI)

    Turner, D. D.; Wulfmeyer, Volker; Berg, Larry K.; Schween, Jan

    2014-10-08T23:59:59.000Z

    The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program’s Raman lidar at the ARM Southern Great Plains (SGP) site in north-central Oklahoma has collected water vapor mixing ratio (q) profile data more than 90% of the time since October 2004. Three hundred (300) cases were identified where the convective boundary layer was quasi-stationary and well-mixed for a 2-hour period, and q mean, variance, third order moment, and skewness profiles were derived from the 10-s, 75-m resolution data. These cases span the entire calendar year, and demonstrate that the q variance profiles at the mixed layer (ML) top changes seasonally, but is more related to the gradient of q across the interfacial layer. The q variance at the top of the ML shows only weak correlations (r < 0.3) with sensible heat flux, Deardorff convective velocity scale, and turbulence kinetic energy measured at the surface. The median q skewness profile is most negative at 0.85 zi, zero at approximately zi, and positive above zi, where zi is the depth of the convective ML. The spread in the q skewness profiles is smallest between 0.95 zi and zi. The q skewness at altitudes between 0.6 zi and 1.2 zi is correlated with the magnitude of the q variance at zi, with increasingly negative values of skewness observed lower down in the ML as the variance at zi increases, suggesting that in cases with larger variance at zi there is deeper penetration of the warm, dry free tropospheric air into the ML.

  17. Turn-key Raman lidar for profiling atmospheric water vapor, clouds, and aerosols at the US Southern Great Plains Climate Study Site

    SciTech Connect (OSTI)

    Goldsmith, J.E.M.; Blair, F.H.; Bisson, S.E.

    1997-12-31T23:59:59.000Z

    There are clearly identified scientific requirements for continuous profiling of atmospheric water vapor at the Department of Energy, Atmospheric Radiation Measurement program, Southern Great Plains CART (Cloud and Radiation Testbed) site in northern Oklahoma. Research conducted at several laboratories has demonstrated the suitability of Raman lidar for providing measurements that are an excellent match to those requirements. We have developed and installed a ruggedized Raman lidar system that resides permanently at the CART site, and that is computer automated to eliminate the requirements for operator interaction. In addition to the design goal of profiling water vapor through most of the troposphere during nighttime and through the boundary layer during daytime, the lidar provides quantitative characterizations of aerosols and clouds, including depolarization measurements for particle phase studies.

  18. Numerical simulations of the stratified oceanic bottom boundary layer

    E-Print Network [OSTI]

    Taylor, John R.

    2008-01-01T23:59:59.000Z

    approximation that the mean wave energy and the backgroundfound that only 6% of the wave energy was re?ected back fromfound that the internal wave energy spec- trum in the outer

  19. Supersonic turbulent boundary layers with periodic mechanical non-equilibrium 

    E-Print Network [OSTI]

    Ekoto, Isaac Wesley

    2007-04-25T23:59:59.000Z

    questions have been raised. The fundamental questions this dissertation addressed are: (1) What are the effects of wall topology with sharp versus blunt leading edges? and (2) Is it possible that a further reduction of turbulent scales can occur if surface...

  20. EXPERIMENTAL STUDY OF COMBUSTION IN A TURBULENT BOUNDARY LAYER

    E-Print Network [OSTI]

    Cheng, R.K.

    2011-01-01T23:59:59.000Z

    States Section of the Combustion Institute, Stanford, CA,Cheng, R. K. , "Catalyzed Combustion of H2/ Air Mixtures inWorkshop on Catalytic Combustion, Asheville, North Carolina,

  1. A Note on the Intermediate Region in Turbulent Boundary Layers

    E-Print Network [OSTI]

    G. I. Barenblatt; A. J. Chorin; V. M. Prostokishin

    2000-02-16T23:59:59.000Z

    We demonstrate that the processing of the experimental data for the average velocity profiles obtained by J. M. \\"Osterlund (www.mesh.kth.se/$\\sim$jens/zpg/) presented in [1] was incorrect. Properly processed these data lead to the opposite conclusion: they confirm the Reynolds-number-dependent scaling law and disprove the conclusion that the flow in the intermediate (`overlap') region is Reynolds-number-independent.

  2. DIRECT SIMULATION OF SPATIALLY EVOLVING COMPRESSIBLE TURBULENT BOUNDARY LAYERS

    E-Print Network [OSTI]

    Erlebacher, Gordon

    of the cold wall condition used in Ref. 6, and, other differences. The computational method used in this study compressible flows because of the interest in designing high speed vehicles and the associated propulsion on temperature. Under the adiabatic conditions of the experiment, the temperature increases as the wall

  3. Control of the Transitional Boundary Layer Brandt A. Belson

    E-Print Network [OSTI]

    Rowley, Clarence W.

    in the presence of unmodeled disturbances. Next, we focus on a specific type of actuator, the single dielectric barrier discharge (SDBD) plasma actuator. An array of these plasma actuators is oriented to produce stream such that the controllers perform well when applied to the experiment. Lastly, we also simulate the plasma actuators

  4. THERMOPHORESIS OF PARTICLES IN A HEATED BOUNDARY LAYER

    E-Print Network [OSTI]

    Talbot, L.

    2012-01-01T23:59:59.000Z

    I (f) X Fig. 6 Reduced thermophoretic force as a function offrom the plate surface by thermophoretic forces. causing aseveral theories for the thermophoretic force. It was found

  5. absorbing boundary layers: Topics by E-print Network

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

    limits: (a) Pr>1, Pr1 and (b) Pr>>1. These two theoretical predictions are in excellent agreement with the results of our direct numerical simulations for Pr4.38 (water) and...

  6. IMPACT OF BOUNDARY-LAYER CUTTING ON FREE-SURFACE

    E-Print Network [OSTI]

    California at San Diego, University of

    height ~ 1 m · Overall height ~ 5.5 m E Flow conditionerE Flow conditioner F NozzleF Nozzle G Liquid

  7. ORIGINAL PAPER Mechanical filtering by the boundary layer and fluidstructure

    E-Print Network [OSTI]

    McHenry, Matt

    force coefficient for fluid c speed of sound in water C integration constant Em Young's modulus of cupular matrix F stimulus frequency Fb buoyant force Fe elastic force Fm inertial force Fa acceleration

  8. The effect of tangential blowing on boundary-layer profiles

    E-Print Network [OSTI]

    Olson, Milford Eugene

    1967-01-01T23:59:59.000Z

    downstream of the slot. The width of the slot was set at 0. 013, 0. 033, and 0. 0415 inches. The blowing rates were varied to give a jet velocity of approximately 0, 163, 246, and 2 /5 feet per s cond. Results of the data are presented in graphical...; Blowing Rate Symbols B) B2 B 3 Cl C 2 C 3 D V (fps) J 163 246 2 75 163 246 275 163 Bjowing Rale (ft /sec) . 3 0. 0418 0. 0630 0. 0705 0. 1061 0. 1600 0. 1790 0. 1333 D D 3 246 275 0. 2013 0. 2250 A theory which expressed a...

  9. Experimental and theoretical study of turbulent oscillatory boundary layers

    E-Print Network [OSTI]

    Yuan, Jing, Ph. D. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    Sediment transport is of crucial importance to engineering projects in coastal regions, so it is of primary interest in coastal engineering. The driving forces for sediment transport are mostly determined by the hydrodynamics ...

  10. Supersonic turbulent boundary layers with periodic mechanical non-equilibrium

    E-Print Network [OSTI]

    Ekoto, Isaac Wesley

    2007-04-25T23:59:59.000Z

    questions have been raised. The fundamental questions this dissertation addressed are: (1) What are the effects of wall topology with sharp versus blunt leading edges? and (2) Is it possible that a further reduction of turbulent scales can occur if surface...

  11. Thermal boundary layer development in dispersed flow film boiling

    E-Print Network [OSTI]

    Hull, Lawrence M.

    1982-01-01T23:59:59.000Z

    Dispersed flow film boiling consists of a dispersion of droplets which are carried over a very hot surface by their vapor. This process occurs in cryogenic equipment and wet steam turbines. It is also of interest in the ...

  12. Linear Stability Analysis of a Boundary Layer with Plasma Actuators

    E-Print Network [OSTI]

    Roy, Subrata

    in the ith direction p Pressure ¯ui Mean flow velocity in the ith direction ¯p Mean pressure ~ui Disturbance flow velocity in the ith direction ~p Disturbance pressure ui Complex 1D disturbance flow velocity Complex spatial frequency in x1 Complex spatial frequency in x3 Complex temporal frequency cp Complex

  13. Boundary layer ingesting inlet design for a silent aircraft

    E-Print Network [OSTI]

    Freuler, Patrick N., 1980-

    2005-01-01T23:59:59.000Z

    (cont.) common nacelle, L/D ratios between 2.5 and 3.0, fan face to throat area ratios above 1.06, and offsets lower than 11%. Curvature ahead of the inlet should be avoided as well as bifurcations inside the duct. Inlet ...

  14. Large-Scale Streamwise Turbulent Structures in Hypersonic Boundary Layers

    E-Print Network [OSTI]

    English, Benjamin L.

    2013-04-22T23:59:59.000Z

    13 Before and after example of pre-processed images........................... 27 14 Average velocity and TKE comparison ............................................ 37 15 Reynolds shear stress comparison... 19 Instantaneous velocity field comparison at ? ..................... 42 20 Instantaneous velocity field comparison at ? ..................... 44 21 Instantaneous velocity field comparison at ? ..................... 45...

  15. OFFSHORE BOUNDARY-LAYER MODELLING H. Bergstrm1

    E-Print Network [OSTI]

    currently be incorporated into a wind farm design tool. The offshore thermal stratification climate is also investigated. 1 INTRODUCTION Mapping the offshore wind climate, it is important to take into account both land contribute to a complex wind field, and affect the wind also at large offshore distances. Spatial variations

  16. Vertical Velocities in Continental Boundary Layer Stratocumulus Clouds

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1 - USAFof EnergyVendorwinsVenue andVertical

  17. ARM - PI Product - Planetary Boundary Layer from AERI and MPL

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowbandheatProductsISDAC

  18. A dual mass flux framework for boundary layer convection

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032) -Less isNFebruaryOctober 2,generation high-performanceA dual mass

  19. Spectrum of local boundary operators from boundary form factor bootstrap

    E-Print Network [OSTI]

    M. Szots; G. Takacs

    2007-03-26T23:59:59.000Z

    Using the recently introduced boundary form factor bootstrap equations, we map the complete space of their solutions for the boundary version of the scaling Lee-Yang model and sinh-Gordon theory. We show that the complete space of solutions, graded by the ultraviolet behaviour of the form factors can be brought into correspondence with the spectrum of local boundary operators expected from boundary conformal field theory, which is a major evidence for the correctness of the boundary form factor bootstrap framework.

  20. Transgressing the Boundaries: An Afterword

    E-Print Network [OSTI]

    Sokal, Alan

    the Boundaries: Toward a Transformative Hermeneutics of Quantum Gravity'', which appeared in Social Text #46

  1. ECMWF workshop on Ocean-Atmosphere Interactions, 10-12 Nov 2008 A revised ocean-atmosphere

    E-Print Network [OSTI]

    interface #12;1*- Sensible heat flux 6*- Evaporation + int. energy [+ Qlat] ECMWF workshop on Ocean layer) 5- Surface ocean current 7- Surface height 7 1- Continental runoff + internal Energy 8 1*- SurfECMWF workshop on Ocean-Atmosphere Interactions, 10-12 Nov 2008 A revised ocean-atmosphere physical

  2. Improved detection of atmospheric turbulence with SLODAR

    E-Print Network [OSTI]

    Michael Goodwin; Charles Jenkins; Andrew Lambert

    2007-06-19T23:59:59.000Z

    We discuss several improvements in the detection of atmospheric turbulence using SLOpe Detection And Ranging (SLODAR). Frequently, SLODAR observations have shown strong ground-layer turbulence, which is beneficial to adaptive optics. We show that current methods which neglect atmospheric propagation effects can underestimate the strength of high altitude turbulence by up to ~ 30%. We show that mirror and dome seeing turbulence can be a significant fraction of measured ground-layer turbulence, some cases up to ~ 50%. We also demonstrate a novel technique to improve the nominal height resolution, by a factor of 3, called Generalized SLODAR. This can be applied when sampling high-altitude turbulence, where the nominal height resolution is the poorest, or for resolving details in the important ground-layer.

  3. Combined influence of atmospheric physics and soil hydrology on the simulated meteorology at the SIRTA atmospheric

    E-Print Network [OSTI]

    Hourdin, Chez Frédéric

    for This paper is a contribution to the special issue on the IPSL and CNRM global climate and Earth System Models it to evaluate the standard and new parametrizations of boundary layer/convection/clouds in the Earth System Model (ESM) of Institut Pierre Simon Laplace (IPSL), which differentiate the IPSL-CM5A and IPSL- CM5B

  4. Wavelet analysis study of microbubble drag reduction in a boundary channel flow 

    E-Print Network [OSTI]

    Zhen, Ling

    2006-04-12T23:59:59.000Z

    Particle Image Velocimetry (PIV) and pressure measurement techniques were performed to investigate the drag reduction due to microbubble injection in the boundary layer of a fully developed turbulent channel flow. ...

  5. Preprint of the paper "A General Formulation based on the Boundary Element Method for the Analysis

    E-Print Network [OSTI]

    Colominas, Ignasi

    cost) to the analysis of large grounding systems in electrical substations. In this paper we present a new Boundary Element formulation for substation grounding systems embedded in layered soils of the substation site. Obviously, from a technical (and

  6. Interface dynamics for layered structures

    E-Print Network [OSTI]

    Takao Ohta; David Jasnow

    1997-07-17T23:59:59.000Z

    We investigate dynamics of large scale and slow deformations of layered structures. Starting from the respective model equations for a non-conserved system, a conserved system and a binary fluid, we derive the interface equations which are a coupled set of equations for deformations of the boundaries of each domain. A further reduction of the degrees of freedom is possible for a non-conserved system such that internal motion of each domain is adiabatically eliminated. The resulting equation of motion contains only the displacement of the center of gravity of domains, which is equivalent to the phase variable of a periodic structure. Thus our formulation automatically includes the phase dynamics of layered structures. In a conserved system and a binary fluid, however, the internal motion of domains turns out to be a slow variable in the long wavelength limit because of concentration conservation. Therefore a reduced description only involving the phase variable is not generally justified.

  7. Boundary Plasma Turbulence Simulations for Tokamaks

    SciTech Connect (OSTI)

    Xu, X; Umansky, M; Dudson, B; Snyder, P

    2008-05-15T23:59:59.000Z

    The boundary plasma turbulence code BOUT models tokamak boundary-plasma turbulence in a realistic divertor geometry using modified Braginskii equations for plasma vorticity, density (ni), electron and ion temperature (T{sub e}; T{sub i}) and parallel momenta. The BOUT code solves for the plasma fluid equations in a three dimensional (3D) toroidal segment (or a toroidal wedge), including the region somewhat inside the separatrix and extending into the scrape-off layer; the private flux region is also included. In this paper, a description is given of the sophisticated physical models, innovative numerical algorithms, and modern software design used to simulate edge-plasmas in magnetic fusion energy devices. The BOUT code's unique capabilities and functionality are exemplified via simulations of the impact of plasma density on tokamak edge turbulence and blob dynamics.

  8. Condition Number Estimates for Combined Potential Boundary Integral

    E-Print Network [OSTI]

    Langdon, Stephen

    Condition Number Estimates for Combined Potential Boundary Integral Operators in Acoustic parameter. Of independent interest we also obtain upper and lower bounds on the norms of two oscillatory integral operators, namely the classical acoustic single- and double-layer potential operators. 1

  9. Condition Number Estimates for Combined Potential Boundary Integral

    E-Print Network [OSTI]

    Langdon, Stephen

    Condition Number Estimates for Combined Potential Boundary Integral Operators in Acoustic parameter. Of independent interest we first obtain upper and lower bounds on the norms of two oscillatory integral operators, namely the classical acoustic single- and double-layer potential operators. 1

  10. Gas-surface interaction and boundary conditions for the Boltzmann equation

    E-Print Network [OSTI]

    Mieussens, Luc

    Gas-surface interaction and boundary conditions for the Boltzmann equation St´ephane Brull, Pierre Equation. The interaction between the wall atoms and the gas molecules within a thin surface layer of the gas in the bulk flow. Boundary conditions are formally derived from this model by using classical

  11. Boundary transfer matrices and boundary quantum KZ equations

    E-Print Network [OSTI]

    Bart Vlaar

    2014-10-31T23:59:59.000Z

    A simple relation between inhomogeneous transfer matrices and boundary quantum KZ equations is exhibited for quantum integrable systems with reflecting boundary conditions, analogous to an observation by Gaudin for periodic systems. Thus the boundary quantum KZ equations receive a new motivation. We also derive the commutativity of Sklyanin's boundary transfer matrices by merely imposing appropriate reflection equations, i.e. without using the conditions of crossing symmetry and unitarity of the R-matrix.

  12. A new twist on Stokes' second problem: Partial penetration of nonlinearity in sheared viscoelastic layers

    E-Print Network [OSTI]

    Forest, M. Gregory

    viscoelastic layer to an oscillating boundary, greater than the gap-loading limit of typical shear rheometers oscillatory shear driving con- ditions on the mucus layer. Very little evidence is available on the details extend our previous studies [3­5] of viscoelas- tic layers under oscillatory driving conditions

  13. Atmospheric Transport of Radionuclides

    SciTech Connect (OSTI)

    Crawford, T.V.

    2003-03-03T23:59:59.000Z

    The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

  14. Sensitivity of Tropical Cyclone Intensity to Ventilation in an Axisymmetric Model National Center for Atmospheric Research,* Boulder, Colorado

    E-Print Network [OSTI]

    Tang, Brian

    into the boundary layer. The sensitivity of tropical cyclone intensity to ventilation can be viewed in the context mixing above the boundary layer. In the latter, ventilation weakens the eyewall entropy front, resulting, an oscillatory intensity regime materializes and is tied to transient convective bursts and strong downdrafts

  15. asaia stably associate: Topics by E-print Network

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

    boundary layers with the important example of the stable atmospheric boundary layer in mind is addressed. Traditional approaches to this problem, based on the profiles of mean...

  16. How atmospheric ice forms | EMSL

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

    atmospheric ice forms How atmospheric ice forms Released: September 08, 2014 New insights into atmospheric ice formation could improve climate models This study advances our...

  17. Atmospheric Pressure Reactor System | EMSL

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

    Atmospheric Pressure Reactor System Atmospheric Pressure Reactor System The atmospheric pressure reactor system is designed for testing the efficiency of various catalysts for the...

  18. Climate Sciences: Atmospheric Thermodynamics

    E-Print Network [OSTI]

    Russell, Lynn

    1 Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http://aerosol.ucsd.edu/courses.html Text: Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http

  19. VALDRIFT 1.0: A valley atmospheric dispersion model with deposition

    SciTech Connect (OSTI)

    Allwine, K.J.; Bian, X.; Whiteman, C.D.

    1995-05-01T23:59:59.000Z

    VALDRIFT version 1.0 is an atmospheric transport and diffusion model for use in well-defined mountain valleys. It is designed to determine the extent of ddft from aedal pesticide spraying activities, but can also be applied to estimate the transport and diffusion of various air pollutants in valleys. The model is phenomenological -- that is, the dominant meteorological processes goveming the behavior of the valley atmosphere are formulated explicitly in the model, albeit in a highly parameterized fashion. The key meteorological processes treated are: (1) nonsteady and nonhomogeneous along-valley winds and turbulent diffusivities, (2) convective boundary layer growth, (3) inversion descent, (4) noctumal temperature inversion breakup, and (5) subsidence. The model is applicable under relatively cloud-free, undisturbed synoptic conditions and is configured to operate through one diumal cycle for a single valley. The inputs required are the valley topographical characteristics, pesticide release rate as a function of time and space, along-valley wind speed as a function of time and space, temperature inversion characteristics at sunrise, and sensible heat flux as a function of time following sunrise. Default values are provided for certain inputs in the absence of detailed observations. The outputs are three-dimensional air concentration and ground-level deposition fields as a function of time.

  20. Terrestrial Planet Atmospheres. The Moon's Sodium Atmosphere

    E-Print Network [OSTI]

    Walter, Frederick M.

    ;Origins of Atmospheres · Outgassing ­ Volcanoes expel water, CO2, N2, H2S, SO2 removed by the Fme convecFon reaches deserts #12;Water and Ice Clouds #12;H2SO4

  1. A New Ensemble of Perturbed-Input-Parameter Simulations by the Community Atmosphere Model

    SciTech Connect (OSTI)

    Covey, C; Brandon, S; Bremer, P T; Domyancis, D; Garaizar, X; Johannesson, G; Klein, R; Klein, S A; Lucas, D D; Tannahill, J; Zhang, Y

    2011-10-27T23:59:59.000Z

    Uncertainty quantification (UQ) is a fundamental challenge in the numerical simulation of Earth's weather and climate, and other complex systems. It entails much more than attaching defensible error bars to predictions: in particular it includes assessing low-probability but high-consequence events. To achieve these goals with models containing a large number of uncertain input parameters, structural uncertainties, etc., raw computational power is needed. An automated, self-adapting search of the possible model configurations is also useful. Our UQ initiative at the Lawrence Livermore National Laboratory has produced the most extensive set to date of simulations from the US Community Atmosphere Model. We are examining output from about 3,000 twelve-year climate simulations generated with a specialized UQ software framework, and assessing the model's accuracy as a function of 21 to 28 uncertain input parameter values. Most of the input parameters we vary are related to the boundary layer, clouds, and other sub-grid scale processes. Our simulations prescribe surface boundary conditions (sea surface temperatures and sea ice amounts) to match recent observations. Fully searching this 21+ dimensional space is impossible, but sensitivity and ranking algorithms can identify input parameters having relatively little effect on a variety of output fields, either individually or in nonlinear combination. Bayesian statistical constraints, employing a variety of climate observations as metrics, also seem promising. Observational constraints will be important in the next step of our project, which will compute sea surface temperatures and sea ice interactively, and will study climate change due to increasing atmospheric carbon dioxide.

  2. CORIOLIS EFFECTS IN MESOSCALE SHALLOW LAYER FLOWS J. C. R. Hunt

    E-Print Network [OSTI]

    Hunt, Julian

    CORIOLIS EFFECTS IN MESOSCALE SHALLOW LAYER FLOWS J. C. R. Hunt ¢¡ £ ,A. Orr , D. Cresswell layer or inversion layer, is developed for idealised and steady, but typical, mesoscale atmospheric estimates for a wide range of perturbed mesoscale flows, especially where the surface conditions change

  3. Overturning and wind driven circulation in a low-order ocean-atmosphere model

    E-Print Network [OSTI]

    van Veen, Lennaert

    july 2002 Abstract A low-order ocean-atmosphere model is presented which combines coupling through heat exchange at the interface and wind stress forcing. The coupling terms are derived from the boundary conditions and the forcing terms of the constituents. Both the ocean and the atmosphere model are based

  4. A fast multipole boundary element method for 3D multi-domain acoustic scattering problems based on the BurtonMiller formulation

    E-Print Network [OSTI]

    Liu, Yijun

    A fast multipole boundary element method for 3D multi-domain acoustic scattering problems based: Received 9 August 2011 Accepted 30 November 2011 Keywords: Boundary element method Fast multipole method Acoustics Multi-domain Multi-layered Effective moment computations a b s t r a c t A fast multipole boundary

  5. Spherical Hamiltonian Isentropic Two-Layer Model for Atmospheric Dynamics

    E-Print Network [OSTI]

    Al Hanbali, Ahmad

    : · structure-preserving numerical schemes; Hamiltonian Particle Mesh method (HPM) (Frank, Gottwald and Reich. Conclusion and discussion: Relevance HPM to forced-dissipative climate simulations? 5 #12;' & $ % Other

  6. atmospheric surface layer: Topics by E-print Network

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

    greenhouse gas, contributing to approximately two-thirds of the Earth's greenhouse effect Mitchell, 1989; IntergovernmentalA meta-analysis of water vapor...

  7. Photovoltaic devices comprising zinc stannate buffer layer and method for making

    DOE Patents [OSTI]

    Wu, Xuanzhi (Golden, CO); Sheldon, Peter (Lakewood, CO); Coutts, Timothy J. (Lakewood, CO)

    2001-01-01T23:59:59.000Z

    A photovoltaic device has a buffer layer zinc stannate Zn.sub.2 SnO.sub.4 disposed between the semiconductor junction structure and the transparent conducting oxide (TCO) layer to prevent formation of localized junctions with the TCO through a thin window semiconductor layer, to prevent shunting through etched grain boundaries of semiconductors, and to relieve stresses and improve adhesion between these layers.

  8. Comparison of atmospheric hydrology over convective continental regions using water vapor isotope measurements from space

    E-Print Network [OSTI]

    . Correlation analysis shows that mixing with boundary layer air, enhanced isotopic fractionation during precipitation, and subsiding air parcels contribute to intraseasonal isotopic variability. These local controls distillation in a Lagrangrian framework underestimates the observed isotopic depletion during the monsoons

  9. Synergistic Effects of Turbine Wakes and Atmospheric Stability on Power Production at an Onshore Wind Farm

    SciTech Connect (OSTI)

    Wharton, S; Lundquist, J K; Marjanovic, N

    2012-01-25T23:59:59.000Z

    This report examines the complex interactions between atmospheric stability and turbine-induced wakes on downwind turbine wind speed and power production at a West Coast North American multi-MW wind farm. Wakes are generated when the upwind flow field is distorted by the mechanical movement of the wind turbine blades. This has two consequences for downwind turbines: (1) the downwind turbine encounters wind flows with reduced velocity and (2) the downwind turbine encounters increased turbulence across multiple length scales via mechanical turbulence production by the upwind turbine. This increase in turbulence on top of ambient levels may increase aerodynamic fatigue loads on the blades and reduce the lifetime of turbine component parts. Furthermore, ambient atmospheric conditions, including atmospheric stability, i.e., thermal stratification in the lower boundary layer, play an important role in wake dissipation. Higher levels of ambient turbulence (i.e., a convective or unstable boundary layer) lead to higher turbulent mixing in the wake and a faster recovery in the velocity flow field downwind of a turbine. Lower levels of ambient turbulence, as in a stable boundary layer, will lead to more persistent wakes. The wake of a wind turbine can be divided into two regions: the near wake and far wake, as illustrated in Figure 1. The near wake is formed when the turbine structure alters the shape of the flow field and usually persists one rotor diameter (D) downstream. The difference between the air inside and outside of the near wake results in a shear layer. This shear layer thickens as it moves downstream and forms turbulent eddies of multiple length scales. As the wake travels downstream, it expands depending on the level of ambient turbulence and meanders (i.e., travels in non-uniform path). Schepers estimates that the wake is fully expanded at a distance of 2.25 D and the far wake region begins at 2-5 D downstream. The actual distance traveled before the wake recovers to its inflow velocity is dependent on the amount ambient turbulence, the amount of wind shear, and topographical and structural effects. The maximum velocity deficit is estimated to occur at 1-2 D but can be longer under low levels of ambient turbulence. Our understanding of turbine wakes comes from wind tunnel experiments, field experiments, numerical simulations, and from studies utilizing both experimental and modeling methods. It is well documented that downwind turbines in multi-Megawatt wind farms often produce less power than upwind turbine rows. These wake-induced power losses have been estimated from 5% to up to 40% depending on the turbine operating settings (e.g., thrust coefficient), number of turbine rows, turbine size (e.g., rotor diameter and hub-height), wind farm terrain, and atmospheric flow conditions (e.g., ambient wind speed, turbulence, and atmospheric stability). Early work by Elliott and Cadogan suggested that power data for different turbulent conditions be segregated to distinguish the effects of turbulence on wind farm power production. This may be especially important for downwind turbines within wind farms, as chaotic and turbulent wake flows increase stress on downstream turbines. Impacts of stability on turbine wakes and power production have been examined for a flat terrain, moderate size (43 turbines) wind farm in Minnesota and for an offshore, 80 turbine wind farm off the coast of Denmark. Conzemius found it difficult to distinguish wakes (i.e., downwind velocity deficits) when the atmosphere was convective as large amounts of scatter were present in the turbine nacelle wind speed data. This suggested that high levels of turbulence broke-up the wake via large buoyancy effects, which are generally on the order of 1 km in size. On the other hand, they found pronounced wake effects when the atmosphere was very stable and turbulence was either suppressed or the length scale was reduced as turbulence in this case was mechanically produced (i.e., friction forces). This led to larger reductions at downwind turbines and maximum ve

  10. EMSL - Atmospheric Aerosol Systems

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

    scienceatmospheric The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model...

  11. Atmospheric Neutrino Fluxes

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2005-02-18T23:59:59.000Z

    Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.

  12. Geometry of Weak Stability Boundaries

    E-Print Network [OSTI]

    Edward Belbruno; Marian Gidea; Francesco Topputo

    2012-04-06T23:59:59.000Z

    The notion of a weak stability boundary has been successfully used to design low energy trajectories from the Earth to the Moon. The structure of this boundary has been investigated in a number of studies, where partial results have been obtained. We propose a generalization of the weak stability boundary. We prove analytically that, in the context of the planar circular restricted three-body problem, under certain conditions on the mass ratio of the primaries and on the energy, the weak stability boundary about the heavier primary coincides with a branch of the global stable manifold of the Lyapunov orbit about one of the Lagrange points.

  13. A simplex model for layered niche networks

    E-Print Network [OSTI]

    P. Fraundorf

    2007-03-06T23:59:59.000Z

    The standing crop of correlations in metazoan communities may be assessed by an inventory of niche structures focused inward and outward from the physical boundaries of skin (self), gene-pool (family), and meme-pool (culture). We consider tracking the progression from three and four correlation layers in many animal communities, to five of six layers for the shared adaptation of most humans, with an attention-slice model that maps the niche-layer focus of individuals onto the 6-variable space of a 5-simplex. The measure puts questions about the effect, on culture and species, of policy and natural events into a common context, and may help explore the impact of electronically-mediated codes on community health.

  14. Furnace atmosphere effects on casting of eutectic superalloys

    SciTech Connect (OSTI)

    Gigliotti, M.F.X.; Greskovich, C.

    1980-02-01T23:59:59.000Z

    Control of furnace atmosphere is a key factor in the use of silica-bonded alumina shell molds for the directional solidification of eutectic superalloys reinforced with tantalum monocarbide whiskers. The use of a furnace atmosphere which is simultaneously oxidizing to aluminum in the eutectic alloy and reducing to silica phases in the mold results in the formation of an alumina barrier layer in situ at the metal/mold interface and an absence of silica phases in the mold region adjacent to this barrier layer. The presence of this microstructure permits castings of eutectics at metal temperatures up to 1750/sup 0/C.

  15. Atmospheric Dynamics II Instructor

    E-Print Network [OSTI]

    AT602 Atmospheric Dynamics II 2 credits Instructor: David W. J. Thompson davet: An Introduction to Dynamic Meteorology, 5th Edition, Academic Press (recommended) · Marshall, J., and Plumb, R. A., 2008: Atmosphere, Ocean, and Climate Dynamics: An Introductory Text, Academic Press. · Vallis, G. K

  16. Atmospheric Thermodynamics Composition

    E-Print Network [OSTI]

    Russell, Lynn

    1 Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 EnergyBalance Ch4 Water Ch Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http #12;2 Review from Ch. 1 · Thermodynamic quantities · Composition · Pressure · Density · Temperature

  17. Cell boundary fault detection system

    DOE Patents [OSTI]

    Archer, Charles Jens (Rochester, MN); Pinnow, Kurt Walter (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian Edward (Rochester, MN)

    2011-04-19T23:59:59.000Z

    An apparatus and program product determine a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

  18. Recursion Relation for Boundary Contribution

    E-Print Network [OSTI]

    Qingjun Jin; Bo Feng

    2015-05-01T23:59:59.000Z

    It is well known that under a BCFW-deformation, there is a boundary contribution when the amplitude scales as O(1) or worse. We show that boundary contributions have a similar recursion relation as scattering amplitude. Just like the BCFW recursion relation, where scattering amplitudes are expressed as the products of two on-shell sub-amplitudes (plus possible boundary contributions), our new recursion relation expresses boundary contributions as products of sub-amplitudes and boundary contributions with less legs, plus yet another possible boundary contribution. In other words, the complete scattering amplitude, including boundary contributions, can be obtained by multiple steps of recursions, unless the boundary contributions are still non-zero when all possible deformations are exploited. We demonstrate this algorithm by several examples. Especially, we show that for standard model like renormalizable theory in 4D, i.e., the theory including only gauge boson, fermions and scalars, the complete amplitude can always be computed by at most four recursive steps using our algorithm.

  19. Photonic layered media

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A new class of structured dielectric media which exhibit significant photonic bandstructure has been invented. The new structures, called photonic layered media, are easy to fabricate using existing layer-by-layer growth techniques, and offer the ability to significantly extend our practical ability to tailor the properties of such optical materials.

  20. Formation of a sandy near-bed transport layer from a fine-grained bed under oscillatory flow

    E-Print Network [OSTI]

    Formation of a sandy near-bed transport layer from a fine-grained bed under oscillatory flow to be an important effect for the formation of ripples and the dynamics of the boundary layer above a predominantly), Formation of a sandy near-bed transport layer from a fine-grained bed under oscillatory flow, J. Geophys

  1. Vacuum Structure and Boundary Renormalization Group

    E-Print Network [OSTI]

    M. Asorey; J. M. Munoz-Castaneda

    2007-12-28T23:59:59.000Z

    The vacuum structure is probed by boundary conditions. The behaviour of thermodynamical quantities like free energy, boundary entropy and entanglement entropy under the boundary renormalization group flow are analysed in 2D conformal field theories. The results show that whereas vacuum energy and boundary entropy turn out to be very sensitive to boundary conditions, the vacuum entanglement entropy is independent of boundary properties when the boundary of the entanglement domain does not overlap the boundary of the physical space. In all cases the second law of thermodynamics holds along the boundary renormalization group flow.

  2. Fiscal year 1998 summary report of the NOAA Atmospheric Sciences Modeling Division to the U.S. Environmental Protection Agency. Technical memo

    SciTech Connect (OSTI)

    Poole-Kober, E.M.; Viebrock, H.J.

    1999-06-01T23:59:59.000Z

    During Fiscal Year 1998, the Atmospheric Sciences Modeling Division provided meteorological and modeling assistance to the US Environmental Protection Agency. Among the significant research studies and results were the following: publication and distribution of Models-3/Community Mutliscale Air Quality system; estimation of the nitrogen deposition to Chesapeake Bay, continued evaluation and application of air quality models for mercury, dioxin, and heavy metals, continued conduct of deposition velocity field studies over various major categories of land-use; conduct of the Ozark Isoprene Experiment to investigate biogenic isoprene emissions; analysis and modeling of dust resuspension data; continued study of buoyant puff dispersion in the convective boundary layer; and development of a standard practice for an objective statistical procedure for comparing air quality model outputs with field data.

  3. ON THE ACOUSTIC SINGLE LAYER POTENTIAL: STABILIZATION AND FOURIER ANALYSIS

    E-Print Network [OSTI]

    Buffa, Annalisa

    ON THE ACOUSTIC SINGLE LAYER POTENTIAL: STABILIZATION AND FOURIER ANALYSIS A. BUFFA AND S. SAUTER in the stability and convergence estimates attains its minumum. Key words. Acoustic scattering, Galerkin boundary discretizations for the Helmholtz problem suffer from the pollution effect, i.e., the constants in the Galerkin

  4. Electric Field in a Double Layer and the Imparted Momentum

    SciTech Connect (OSTI)

    Fruchtman, A. [Holon Academic Institute of Technology, 52 Golomb Street, Holon 58102 (Israel)

    2006-02-17T23:59:59.000Z

    It is shown that the net momentum delivered by the large electric field inside a one-dimensional double layer is zero. This is demonstrated through an analysis of the momentum balance in the double layer at the boundary between the ionosphere and the aurora cavity. For the recently observed double layer in a current-free plasma expanding along a divergent magnetic field, an analysis of the evolution of the radially averaged variables shows that the increase of plasma thrust results from the magnetic-field pressure balancing the plasma pressure in the direction of acceleration, rather than from electrostatic pressure.

  5. Energy transport, overshoot, and mixing in the atmospheres of M-type main- and pre-main-sequence objects

    E-Print Network [OSTI]

    H. -G. Ludwig; F. Allard; P. H. Hauschildt

    2006-08-12T23:59:59.000Z

    We constructed hydrodynamical model atmospheres for mid M-type main-, as well as pre-main-sequence (PMS) objects. Despite the complex chemistry encountered in these cool atmospheres a reasonably accurate representation of the radiative transfer is possible, even in the context of time-dependent and three-dimensional models. The models provide detailed information about the morphology of M-type granulation and statistical properties of the convective surface flows. In particular, we determined the efficiency of the convective energy transport, and the efficiency of mixing by convective overshoot. The convective transport efficiency was expressed in terms of an equivalent mixing-length parameter alpha in the formulation of mixing-length theory (MLT) given by Mihalas (1978). Alpha amounts to values around 2 for matching the entropy of the deep, adiabatically stratified regions of the convective envelope, and lies between 2.5 and 3.0 for matching the thermal structure of the deep photosphere. For current spectral analysis of PMS objects this implies that MLT models based on alpha=2.0 overestimate the effective temperature by 100 K and surface gravities by 0.25 dex. The average thermal structure of the formally convectively stable layers is little affected by convective overshoot and wave heating, i.e., stays close to radiative equilibrium conditions. Our models suggest that the rate of mixing by convective overshoot declines exponentially with geometrical distance to the Schwarzschild stability boundary. It increases at given effective temperature with decreasing gravitational acceleration.

  6. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

    1988-01-01T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

  7. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, R.L.; Cannon, T.W.

    1988-10-25T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

  8. Layered plasma polymer composite membranes

    DOE Patents [OSTI]

    Babcock, W.C.

    1994-10-11T23:59:59.000Z

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is [>=]2 and is the number of selective layers. 2 figs.

  9. Photochemistry of OIO: Laboratory study and atmospheric implications

    E-Print Network [OSTI]

    Ashworth, Stephen H.

    Photochemistry of OIO: Laboratory study and atmospheric implications Juan C. Go´mez Marti´n,1 layer ozone budget. Citation: Go´mez Marti´n, J. C., S. H. Ashworth, A. S. Mahajan, and J. M. C. Plane% and 60%, respec- tively [Go´mez Marti´n et al., 2007]. Theoretical calculations indicate that IOIO

  10. TRANSONIC HYDRODYNAMIC ESCAPE OF HYDROGEN FROM EXTRASOLAR PLANETARY ATMOSPHERES

    E-Print Network [OSTI]

    De Sterck, Hans

    . The model uses a two-dimensional energy depo- sition calculation instead of the single-layer heating planets is investigated using the model. The importance of hydrogen hydrodynamic escape for the longTRANSONIC HYDRODYNAMIC ESCAPE OF HYDROGEN FROM EXTRASOLAR PLANETARY ATMOSPHERES Feng Tian,1, 2 Owen

  11. Boundary Waters Canoe Area (Minnesota)

    Broader source: Energy.gov [DOE]

    The Boundary Waters Canoe Area occupies a large section of northern Minnesota, and is preserved as a primitive wilderness area. Construction and new development is prohibited. A map of the...

  12. NOTES AND CORRESPONDENCE An Analytic Longwave Radiation Formula for Liquid Layer Clouds

    E-Print Network [OSTI]

    NOTES AND CORRESPONDENCE An Analytic Longwave Radiation Formula for Liquid Layer Clouds VINCENT E of boundary layer clouds have used a convenient but idealized longwave radiation formula for clouds in their large-eddy simulations (LESs). Under what conditions is this formula justified? Can it be extended

  13. Cross-Layer Attack and Defense in Cognitive Radio Networks Wenkai Wang and Yan (Lindsay) Sun

    E-Print Network [OSTI]

    Sun, Yan Lindsay

    Cross-Layer Attack and Defense in Cognitive Radio Networks Wenkai Wang and Yan (Lindsay) Sun ECE research on security issues in cognitive radio networks mainly focuses on attack and defense in individual network layers. However, the attackers do not necessarily restrict themselves within the boundaries

  14. The viscosity structure of the D00 layer of the Earth's mantle inferred

    E-Print Network [OSTI]

    The viscosity structure of the D00 layer of the Earth's mantle inferred from the analysis layer Core­mantle boundary Viscosity Maxwell body a b s t r a c t The viscosity structure of the D00-diurnal to 18.6 years tidal deformations combined with model viscosity­depth profiles corresponding to a range

  15. Atmospheric Science: An introductory survey 1. Introduction to the atmosphere

    E-Print Network [OSTI]

    Folkins, Ian

    Sound Convergence Zone #12;Terrain effects #12;Von Karman vortex streets #12;Atmosphere in Earth system

  16. Changing the Structure Boundary Geometry

    SciTech Connect (OSTI)

    Karasev, Viktor; Dzlieva, Elena; Ivanov, Artyom [St.-Petersburg State University, Physics Faculty, Ulianovskaya 1, Peterhof, St. Petersburg, 198504 (Russian Federation)

    2008-09-07T23:59:59.000Z

    Analysis of previously obtained results shows that hexagonal crystal lattice is the dominant type of ordering, in particular, in striated glow discharges. We explore the possibility for changing the dust distribution in horizontal cross sections of relatively highly ordered structures in a glow-discharge. Presuming that boundary geometry can affect dust distribution, we used cylindrical coolers held at 0 deg. C and placed against a striation containing a structure, to change the geometry of its outer boundary. By varying the number of coolers, their positions, and their separations from the tube wall, azimuthally asymmetric thermophoretic forces can be used to form polygonal boundaries and vary the angles between their segments (in a horizontal cross section). The corner in the structure's boundary of 60 deg. stimulates formation of hexagonal cells. The structure between the supported parallel boundaries is also characterized by stable hexagonal ordering. We found that a single linear boundary segment does not give rise to any sizable domain, but generates a lattice extending from the boundary (without edge defects). A square lattice can be formed by setting the angle equal to 90 deg. . However, angles of 45 deg. and 135 deg. turned out easier to form. Square lattice was created by forming a near-135 deg. corner with four coolers. It was noted that no grain ordering is observed in the region adjacent to corners of angles smaller than 30 deg. , which do not promote ordering into cells of any shape. Thus, manipulation of a structure boundary can be used to change dust distribution, create structures free of the ubiquitous edge defects that destroy orientation order, and probably change the crystal lattice type.

  17. Strain tensors in layer systems by precision ion channeling measurements

    SciTech Connect (OSTI)

    Trinkaus, H.; Buca, D.; Hollaender, B.; Minamisawa, R. A.; Mantl, S. [Institute of Bio- and Nanosystems (IBN 1) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Juelich, D-52425 Juelich (Germany); Hartmann, J. M. [CEA-LETI, MINATEC, 17 Rue des Martyrs, F-38054 Grenoble, Cedex 9 (France)

    2010-06-15T23:59:59.000Z

    A powerful method for analyzing general strain states in layer systems is the measurement of changes in the ion channeling directions. We present a systematic derivation and compilation of the required relations between the strain induced angle changes and the components of the strain tensor for general crystalline layer systems of reduced symmetry compared to the basic (cubic) crystal. It is shown that, for the evaluation of channeling measurements, virtually all layers of interest may be described as being 'pseudo-orthorhombic'. The commonly assumed boundary conditions and the effects of surface misorientations on them are discussed. Asymmetric strain relaxation in layers of reduced symmetry is attributed to a restriction in the slip system of the dislocations inducing it. The results are applied to {l_brace}110{r_brace}SiGe/Si layer systems.

  18. A MOVING-BOUNDARY PROBLEM FOR CONCRETE CARBONATION: GLOBAL EXISTENCE AND UNIQUENESS OF

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    in a porous solid ­ concrete ­ which incorporates slow diffusive transport, interfacial exchange between wet of gaseous CO2 from the atmosphere penetrate the concrete via the unsaturated porous matrix. After enteringA MOVING-BOUNDARY PROBLEM FOR CONCRETE CARBONATION: GLOBAL EXISTENCE AND UNIQUENESS OF WEAK

  19. Layered Cathode Materials

    Broader source: Energy.gov (indexed) [DOE]

    Layered Cathode Materials presented by Michael Thackeray Chemical Sciences and Engineering Division, Argonne Annual Merit Review DOE Vehicle Technologies Program Washington, D.C....

  20. Limits to the lunar atmosphere

    SciTech Connect (OSTI)

    Morgan, T.H. (National Aeronautics and Space Administration, Washington, D.C. (USA)); Shemansky, D.E. (Univ. of Arizona, Tucson (USA))

    1991-02-01T23:59:59.000Z

    The presence of sodium and potassium on the Moon implies that other more abundant species should be present. Volatile molecules like H{sub 2}O are significantly more abundant than sodium in any of the proposed external atmospheric sources. Source mechanisms which derive atoms from the surface should favor abundant elements in the regolith. It is therefore puzzling that the Apollo ultraviolet spectrometer experiment set limits on the density of oxygen of N{sub O} < 5 {times} 10{sup 2} cm{sup {minus}3}, and that the Apollo Lunar Atmospheric Composition Experiment data imply N{sub O} < 50 cm{sup {minus}3} above the subsolar point. These limits are surprisingly small relative to the measured value for sodium. A simple consideration of sources and sinks predicts significantly greater densities of oxygen. It is possible but doubtful that the Apollo measurements occur ed during an epoch in which source rates were small. A preferential loss process for oxygen on the darkside of the Moon is considered in which ionization by electron capture in surface collisions leads to escape through acceleration in the local electric field. Cold trapping in permanently shadowed regions as a net sink is considered and discounted, but the episodic nature of cometary insertion may allow formation of ice layers which act as a stablized source of OH. On the basis of an assumed meteoroid impact source, the authors predict a possible emission brightness of {approximately} 50 R in the OH(A {minus} X)(0,0) band above the lunar bright limb. A very uncertain small comet source of H{sub 2}O could raise this value by more than two orders of magnitude.

  1. A bridging technique to analyze the influence of boundary conditions on instability patterns

    SciTech Connect (OSTI)

    Hu Heng, E-mail: huheng@whu.edu.c [School of Civil Engineering, Wuhan University, 8 South Road of East Lake, 430072 Wuhan (China); Damil, Noureddine, E-mail: noureddine.damil@gmail.co [Laboratoire de Calcul Scientifique en Mecanique, Faculte des Sciences Ben M'Sik, Universite Hassan II Mohammedia-Casablanca, Sidi Othman, Casablanca (Morocco); Potier-Ferry, Michel, E-mail: michel.potierferry@univ-metz.f [Laboratoire d'Etude des Microstructures et de Mecanique des Materiaux, LEM3, UMR CNRS 7239, Universite Paul Verlaine-Metz, Ile du Saulcy, 57045 Metz Cedex 01 (France)

    2011-05-10T23:59:59.000Z

    In this paper, we present a new numerical technique that permits to analyse the effect of boundary conditions on the appearance of instability patterns. Envelope equations of Landau-Ginzburg type are classically used to predict pattern formation, but it is not easy to associate boundary conditions for these macroscopic models. Indeed, envelope equations ignore boundary layers that can be important, for instance in cases where the instability starts first near the boundary. In this work, the full model is considered close to the boundary, an envelope equation in the core and they are bridged by the Arlequin method . Simulation results are presented for the problem of buckling of long beams lying on a non-linear elastic foundation.

  2. Layering as Optimization Decomposition 3-1 Layering as OptimizationLayering as Optimization

    E-Print Network [OSTI]

    Fan, Xingzhe

    1 Layering as Optimization Decomposition 3-1 Layering as OptimizationLayering as Optimization DecompositionDecomposition Layering as Optimization Decomposition 3-2 CONTENTSCONTENTS Introduction (Marta;2 Layering as Optimization Decomposition 3-3 Layering as Optimization Decomposition Introduction By Marta

  3. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, Terry W. (Tracy, CA)

    1994-01-01T23:59:59.000Z

    A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

  4. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, T.W.

    1994-09-06T23:59:59.000Z

    A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

  5. Alternative barrier layers for surface covers in dry climates

    SciTech Connect (OSTI)

    Stormont, J.C.

    1994-09-01T23:59:59.000Z

    Surface covers are one of the most widespread remediation and waste management options in all climates. Barrier layers to limit percolation through cover systems are principal features of engineered, multi-component cover designs. Conventional barrier layer components developed for humid climates have limitations in dry climates. One alternative barrier layer is a capillary barrier, which consists of a fine-over-coarse soil arrangement. The capacity of capillary barrier to laterally divert downward moving water is the key to their success. Another alternative is a dry barrier, in which atmospheric air is circulated through a coarse layer within the cover to remove water vapor. Incorporating a coarse layer which stores water for subsequent removal by air flow reduces the requirements for the air flow velocity and increases the applicability of the dry barrier.

  6. Multiple layer insulation cover

    DOE Patents [OSTI]

    Farrell, James J. (Livingston Manor, NY); Donohoe, Anthony J. (Ovid, NY)

    1981-11-03T23:59:59.000Z

    A multiple layer insulation cover for preventing heat loss in, for example, a greenhouse, is disclosed. The cover is comprised of spaced layers of thin foil covered fabric separated from each other by air spaces. The spacing is accomplished by the inflation of spaced air bladders which are integrally formed in the cover and to which the layers of the cover are secured. The bladders are inflated after the cover has been deployed in its intended use to separate the layers of the foil material. The sizes of the material layers are selected to compensate for sagging across the width of the cover so that the desired spacing is uniformly maintained when the cover has been deployed. The bladders are deflated as the cover is stored thereby expediting the storage process and reducing the amount of storage space required.

  7. Title: Ontario Greenbelt Boundary File Data Creator /

    E-Print Network [OSTI]

    Greenbelt Act 2005. Data contains three shapefiles: Greenbelt Designated Areas, Outer Boundary and River

  8. Computer Modeling of Transport of Oxidizing Species in Grain Boundaries during Zirconium Corrosion

    SciTech Connect (OSTI)

    Xian-Ming Bai; Yongfeng Zhang; Michael R. Tonks

    2014-06-01T23:59:59.000Z

    Zirconium (Zr) based alloys are widely used as the cladding materials in light-water reactors. The water-side corrosion of these alloys degrades their structural integrity and poses serious safety concerns. During the Zr corrosion process, a thin Zr oxide (ZrO2) layer forms on the alloy surface and serves as a barrier layer for further corrosion. The majority of the oxide has the monoclinic phase. At the transition region between the oxide and the metal, the oxide contains a thin layer of stabilized tetragonal phase. It is found that the texture of the tetragonal layer determines the protectiveness of the oxide for corrosion. The transport of oxidizing species, such as anion defects, cation defects, and electron through the tetragonal oxide layer could be the rate limiting step of the corrosion. The defect diffusion can be affected by the growing stresses and microstructures such as grain boundaries and dislocations. In this work molecular dynamics simulations are used to investigate the anion and cation diffusion in bulk and at grain boundaries in tetragonal ZrO2. The results show that defect diffusion at grain boundaries is complex and the behavior strongly depends on the grain boundary type. For most of the grain boundaries studied the defect diffusion are much slower than in the bulk, implying that grain boundaries may not be fast defect transport paths during corrosion. The connection between the modeling results and published experimental work will also be discussed. This work is funded by the Laboratory Directed Research and Development (LDRD) program at Idaho National Laboratory.

  9. Where do fossil fuel carbon dioxide emissions from California go? An analysis based on radiocarbon observations and an atmospheric transport model

    SciTech Connect (OSTI)

    Riley, W.J.; Hsueh, D.Y.; Randerson, J.T.; Fischer, M.L.; Hatch, J.G.; Pataki, D.E.; Wang, W.; Goulden, M.L.

    2008-05-01T23:59:59.000Z

    Characterizing flow patterns and mixing of fossil fuel-derived CO{sub 2} is important for effectively using atmospheric measurements to constrain emissions inventories. Here we used measurements and a model of atmospheric radiocarbon ({sup 14}C) to investigate the distribution and fluxes of atmospheric fossil fuel CO{sub 2} across the state of California. We sampled {sup 14}C in annual C{sub 3} grasses at 128 sites and used these measurements to test a regional model that simulated anthropogenic and ecosystem CO{sub 2} fluxes, transport in the atmosphere, and the resulting {sup 14}C of annual grasses ({Delta}{sub g}). Average measured {Delta}{sub g} in Los Angeles, San Francisco, the Central Valley, and the North Coast were 27.7 {+-} 20.0, 44.0 {+-} 10.9, 48.7 {+-} 1.9, and 59.9 {+-} 2.5{per_thousand}, respectively, during the 2004-2005 growing season. Model predictions reproduced regional patterns reasonably well, with estimates of 27.6 {+-} 2.4, 39.4 {+-} 3.9, 46.8 {+-} 3.0, and 59.3 {+-} 0.2{per_thousand} for these same regions and corresponding to fossil fuel CO{sub 2} mixing ratios (Cf) of 13.7, 6.1, 4.8, and 0.3 ppm. {Delta}{sub g} spatial heterogeneity in Los Angeles and San Francisco was higher in the measurements than in the predictions, probably from insufficient spatial resolution in the fossil fuel inventories (e.g., freeways are not explicitly included) and transport (e.g., within valleys). We used the model to predict monthly and annual transport patterns of fossil fuel-derived CO{sub 2} within and out of California. Fossil fuel CO{sub 2} emitted in Los Angeles and San Francisco was predicted to move into the Central Valley, raising Cf above that expected from local emissions alone. Annually, about 21, 39, 35, and 5% of fossil fuel emissions leave the California airspace to the north, east, south, and west, respectively, with large seasonal variations in the proportions. Positive correlations between westward fluxes and Santa Ana wind conditions were observed. The southward fluxes over the Pacific Ocean were maintained in a relatively coherent flow within the marine boundary layer, while the eastward fluxes were more vertically dispersed. Our results indicate that state and continental scale atmospheric inversions need to consider areas where concentration measurements are sparse (e.g., over the ocean to the south and west of California), transport within and across the marine boundary layer, and terrestrial boundary layer dynamics. Measurements of {Delta}{sub g} can be very useful in constraining these estimates.

  10. Effect of O3 on the atmospheric temperature structure of early Mars

    E-Print Network [OSTI]

    von Paris, P; Godolt, M; Grenfell, J L; Stracke, B; Rauer, H

    2015-01-01T23:59:59.000Z

    Ozone is an important radiative trace gas in the Earth's atmosphere. The presence of ozone can significantly influence the thermal structure of an atmosphere, and by this e.g. cloud formation. Photochemical studies suggest that ozone can form in carbon dioxide-rich atmospheres. We investigate the effect of ozone on the temperature structure of simulated early Martian atmospheres. With a 1D radiative-convective model, we calculate temperature-pressure profiles for a 1 bar carbon dioxide atmosphere. Ozone profiles are fixed, parameterized profiles. We vary the location of the ozone layer maximum and the concentration at this maximum. The maximum is placed at different pressure levels in the upper and middle atmosphere (1-10 mbar). Results suggest that the impact of ozone on surface temperatures is relatively small. However, the planetary albedo significantly decreases at large ozone concentrations. Throughout the middle and upper atmospheres, temperatures increase upon introducing ozone due to strong UV absorpt...

  11. Measurements of grain boundary properties in nanocrystalline ceramics

    SciTech Connect (OSTI)

    Chiang, Y.M.; Smyth, I.P.; Terwilliger, C.D. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Materials Science and Engineering); Petuskey, W.T. (Arizona State Univ., Tempe, AZ (USA). Dept. of Chemistry); Eastman, J.A. (Argonne National Lab., IL (USA))

    1990-11-01T23:59:59.000Z

    The advent of nanocrystalline ceramics prepared by a variety of solution-chemical and vapor deposition methods offers a unique opportunity for the determination grain boundary properties by bulk'' thermodynamic methods. In this paper we discuss results from two types of measurements on model nanocrystalline ceramics. The first is a solution thermodynamic measurement of the activity of nanocrystalline SiC in polycarbosilane-derived silicon carbide fibers (Nicalon). Structural studies have shown that Nicalon consists of well-ordered cubic ({beta} or 3C polytype) SiC grains separated by a very thin grain boundary layer (<1 nm thick) containing the oxygen. The physical properties and chemical reactivity of these fibers are distinctly different from that of bulk silicon carbide. Direct measurement of the alloy composition and analysis of the microstructure has allowed the dissolution reaction to be identified and a lower limit for the SiC activity in the nanocrystalline form to be determined. A second method of measuring grain boundary properties we have investigated for nanocrystalline Si and TiO{sub 2} is high temperature calorimetry. In appropriate samples the grain boundary enthalpy can be measured through the heat evolved during grain growth. Preliminary results on nanocrystalline Si prepared by the recrystallization of amorphous evaporated films and on TiO{sub 2} condensed from the vapor phase are discussed. 29 refs., 3 figs., 1 tab.

  12. Are nanophase grain boundaries anomalous?

    SciTech Connect (OSTI)

    Stern, E.A.; Siegel, R.W.; Newville, M.; Sanders, P.G.; Haskel, D. [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States); [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); [Materials Science and Engineering Department, Northwestern University, Evanston, Illinois 60208 (United States)

    1995-11-20T23:59:59.000Z

    The grain boundary regions of nanophase Cu metal are investigated using the x-ray absorption fine structure (XAFS) technique. Typical samples made by standard techniques need to be greatly thinned if measured in transmission in order to eliminate experimental artifacts which erroneously lower the apparent coordination number. To avoid this problem the samples were measured by the total electron yield technique. The results indicate a grain boundary structure which, on the average, is similar to that in conventional polycrystalline Cu, contrary to previous XAFS measurements made in transmission which indicated a lower coordination number. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.

  13. Compliant layer chucking surface

    DOE Patents [OSTI]

    Blaedel, Kenneth L. (Dublin, CA); Spence, Paul A. (Pleasanton, CA); Thompson, Samuel L. (Pleasanton, CA)

    2004-12-28T23:59:59.000Z

    A method and apparatus are described wherein a thin layer of complaint material is deposited on the surface of a chuck to mitigate the deformation that an entrapped particle might cause in the part, such as a mask or a wafer, that is clamped to the chuck. The harder particle will embed into the softer layer as the clamping pressure is applied. The material composing the thin layer could be a metal or a polymer for vacuum or electrostatic chucks. It may be deposited in various patterns to affect an interrupted surface, such as that of a "pin" chuck, thereby reducing the probability of entrapping a particle.

  14. Dynamics of Atmospheres

    E-Print Network [OSTI]

    Read, Peter L.

    transfer ­ Solar heating of surface, and atmosphere via dust absorption ­ Infrared CO2 band cooling (especially around 667 cm-1) ­ nonLTE near-infrared heating of CO2 and nonLTE cooling effects above ~60-80 km. Baroclinic waves, scales, heat and momentum transport, seasonal occurrence. Qualitative treatment

  15. Laboratory for Atmospheric and

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    . Along with this growth came a new building on campus and a new name: the Laboratory for Atmospheric of the Sun to the outermost fringes of the solar system. With LASP's continuing operations role in the planet traditional and stable approach based on federal agency funding of research grant

  16. A Vertical Grid Module for Baroclinic Models of the Atmosphere

    SciTech Connect (OSTI)

    Drake, John B [ORNL

    2008-04-01T23:59:59.000Z

    The vertical grid of an atmospheric model assigns dynamic and thermo- dynamic variables to grid locations. The vertical coordinate is typically not height but one of a class of meteorological variables that vary with atmo- spheric conditions. The grid system is chosen to further numerical approx- imations of the boundary conditions so that the system is terrain following at the surface. Lagrangian vertical coordinates are useful in reducing the numerical errors from advection processes. That the choices will effect the numercial properties and accuracy is explored in this report. A MATLAB class for Lorentz vertical grids is described and applied to the vertical struc- ture equation and baroclinic atmospheric circulation. A generalized meteo- rolgoical coordinate system is developed which can support ?, isentropic ? vertical coordinate, or Lagrangian vertical coordinates. The vertical atmo- spheric column is a MATLAB class that includes the kinematic and ther- modynamic variables along with methods for computing geopoentials and terms relevant to a 3D baroclinc atmospheric model.

  17. Thermal convection in a spherical shell with melting/freezing at either or both of its boundaries

    E-Print Network [OSTI]

    Deguen, Renaud

    2013-01-01T23:59:59.000Z

    In a number of geophysical or planetological settings (Earth's inner core, a silicate mantle crystallizing from a magma ocean, or an ice shell surrounding a deep water ocean) a convecting crystalline layer is in contact with a layer of its melt. Allowing for melting/freezing at one or both of the boundaries of the solid layer is likely to affect the pattern of convection in the layer. We study here the onset of thermal convection in a viscous spherical shell with dynamically induced melting/freezing at either or both of its boundaries. It is shown that the behavior of each interface depends on the value of a dimensional number P, which is the ratio of a melting/freezing timescale over a viscous relaxation timescale. A small value of P corresponds to permeable boundary conditions, while a large value of P corresponds to impermeable boundary conditions. The linear stability analysis predicts a significant effect of semi-permeable boundaries when the number P characterizing either of the boundary is small enough...

  18. Boundary Behavior of the GinzburgLandau Order Parameter in the Surface Superconductivity Regime

    E-Print Network [OSTI]

    Recanati, Catherine

    Boundary Behavior of the Ginzburg­Landau Order Parameter in the Surface Superconductivity Regime M­Landau theory for a type­II superconductor in an applied magnetic field varying between the second and third of this energy expansion, which allows us to prove the desired uniformity of the surface superconductivity layer

  19. Layered Spinach Salad Ingredients

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    cucumbers 2 tomatoes 1/2 cup low-fat mayonnaise 1/2 cup parmesan cheese, grated 1/4 cup milk 1 1/2 teaspoons size pieces, layer on bottom of a large bowl. 2. Rinse mushrooms off under cool water and use a soft half. Layer on top of vegetables. 6. To make salad dressing, add mayonnaise, cheese, milk, dill weed

  20. Structured luminescence conversion layer

    DOE Patents [OSTI]

    Berben, Dirk; Antoniadis, Homer; Jermann, Frank; Krummacher, Benjamin Claus; Von Malm, Norwin; Zachau, Martin

    2012-12-11T23:59:59.000Z

    An apparatus device such as a light source is disclosed which has an OLED device and a structured luminescence conversion layer deposited on the substrate or transparent electrode of said OLED device and on the exterior of said OLED device. The structured luminescence conversion layer contains regions such as color-changing and non-color-changing regions with particular shapes arranged in a particular pattern.

  1. 2. System boundaries; Balance equations

    E-Print Network [OSTI]

    Zevenhoven, Ron

    Example: an electric hot water heater in a house ­ The electric heater is a closed system ­ The water with the surroundings for example: combustion engines, pumps, distillation columns, living organisms Picture: SEHB06 #12;5/28 Systems and boundaries /3 An isolated system is a special kind of closed system Pictures: KJ05 Q = heat W

  2. Lagrangian Variational Framework for Boundary Value Problems

    E-Print Network [OSTI]

    Alexander Figotin; Guillermo Reyes

    2014-07-29T23:59:59.000Z

    A boundary value problem is commonly associated with constraints imposed on a system at its boundary. We advance here an alternative point of view treating the system as interacting "boundary" and "interior" subsystems. This view is implemented through a Lagrangian framework that allows to account for (i) a variety of forces including dissipative acting at the boundary; (ii) a multitude of features of interactions between the boundary and the interior fields when the boundary fields may differ from the boundary limit of the interior fields; (iii) detailed pictures of the energy distribution and its flow; (iv) linear and nonlinear effects. We provide a number of elucidating examples of the structured boundary and its interactions with the system interior. We also show that the proposed approach covers the well known boundary value problems.

  3. SIO 217a Atmospheric and Climate Sciences I: Atmospheric Thermodynamics

    E-Print Network [OSTI]

    Russell, Lynn

    SIO 217a Atmospheric and Climate Sciences I: Atmospheric Thermodynamics Course Syllabus and Lecture Schedule Instructor: Lynn Russell, 343 NH, 534-4852, lmrussell@ucsd.edu Text: Thermodynamics of Atmospheres of Thermodynamics (Work, Heat, First Law, Second Law, Heat Capacity, Adiabatic Processes) 5-Oct F Hurricane Example

  4. Pluto's Atmosphere Does Not Collapse

    E-Print Network [OSTI]

    Olkin, C B; Borncamp, D; Pickles, A; Sicardy, B; Assafin, M; Bianco, F B; Buie, M W; de Oliveira, A Dias; Gillon, M; French, R G; Gomes, A Ramos; Jehin, E; Morales, N; Opitom, C; Ortiz, J L; Maury, A; Norbury, M; Ribas, F B; Smith, R; Wasserman, L H; Young, E F; Zacharias, M; Zacharias, N

    2013-01-01T23:59:59.000Z

    Combining stellar occultation observations probing Pluto's atmosphere from 1988 to 2013 and models of energy balance between Pluto's surface and atmosphere, we conclude that Pluto's atmosphere does not collapse at any point in its 248-year orbit. The occultation results show an increasing atmospheric pressure with time in the current epoch, a trend present only in models with a high thermal inertia and a permanent N2 ice cap at Pluto's north rotational pole.

  5. Irradiation Assisted Grain Boundary Segregation in Steels

    SciTech Connect (OSTI)

    Lu, Zheng; Faulkner, Roy G. [IPTME, Loughborough University, Loughborough, Leics (United Kingdom)

    2008-07-01T23:59:59.000Z

    The understanding of radiation-induced grain boundary segregation (RIS) has considerably improved over the past decade. New models have been introduced and much effort has been devoted to obtaining comprehensive information on segregation from the literature. Analytical techniques have also improved so that chemical analysis of layers 1 nm thick is almost routine. This invited paper will review the major methods used currently for RIS prediction: namely, Rate Theory, Inverse Kirkendall, and Solute Drag approaches. A summary is made of the available data on phosphorus RIS in reactor pressure vessel (RPV) steels. This will be discussed in the light of the predictions of the various models in an effort to show which models are the most reliable and easy to use for forecasting P segregation behaviour in steels. A consequence of RIS in RPV steels is a radiation induced shift in the ductile to brittle transition temperature (DBTT). It will be shown how it is possible to relate radiation-induced P segregation levels to DBTT shift. Examples of this exercise will be given for RPV steels and for ferritic steels being considered for first wall fusion applications. Cr RIS in high alloy stainless steels and associated irradiation-assisted stress corrosion cracking (IASCC) will be briefly discussed. (authors)

  6. Boundary Integral Equations and the Method of Boundary Elements

    E-Print Network [OSTI]

    Tsynkov, Semyon V.

    to consider the interior and exterior Dirichlet and Neumann boundary value problems for the Laplace equation: u 2u x2 1 + 2u x2 2 + 2u x2 3 = 0. Let be a bounded domain of the three-dimensional space R3 and exterior Dirichlet problems, respectively, and problems (13.1b) and (13.1d) are the interior and exterior

  7. Differential atmospheric tritium sampler

    DOE Patents [OSTI]

    Griesbach, O.A.; Stencel, J.R.

    1987-10-02T23:59:59.000Z

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The moisture then passes through a combustion chamber where hydrogen gas in the form of H/sub 2/ or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  8. Differential atmospheric tritium sampler

    DOE Patents [OSTI]

    Griesbach, Otto A. (Langhorne, PA); Stencel, Joseph R. (Skillman, NJ)

    1990-01-01T23:59:59.000Z

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The mixture then passes through a combustion chamber where hydrogen gas in the form of H.sub.2 or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  9. Growth of Large-Area Single- and Bi-Layer Graphene by Controlled Carbon Precipitation on Polycrystalline Ni Surfaces

    E-Print Network [OSTI]

    Reina, Alfonso

    2009-01-01T23:59:59.000Z

    We report graphene films composed mostly of one or two layers of graphene grown by controlled carbon precipitation on the surface of polycrystalline Ni thin films during atmospheric chemical vapor deposition (CVD). Controlling ...

  10. Beyond the no-slip boundary condition

    E-Print Network [OSTI]

    Brenner, Howard

    This paper offers a simple macroscopic approach to the question of the slip boundary condition to be imposed upon the tangential component of the fluid velocity at a solid boundary. Plausible reasons are advanced for ...

  11. Revised Knudsen-layer reduction of fusion reactivity

    SciTech Connect (OSTI)

    Albright, B. J.; Molvig, Kim; Huang, C.-K.; Simakov, A. N.; Dodd, E. S.; Hoffman, N. M.; Kagan, G. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Schmit, P. F. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1186 (United States)] [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1186 (United States)

    2013-12-15T23:59:59.000Z

    Recent work by Molvig et al. [Phys. Rev. Lett. 109, 095001 (2012)] examined how fusion reactivity may be reduced from losses of fast ions in finite assemblies of fuel. In this paper, this problem is revisited with the addition of an asymptotic boundary-layer treatment of ion kinetic losses. This boundary solution, reminiscent of the classical Milne problem from linear transport theory, obtains a free-streaming limit of fast ion losses near the boundary, where the diffusion approximation is invalid. Thermonuclear reaction rates have been obtained for the ion distribution functions predicted by this improved model. It is found that while Molvig's “Knudsen distribution function” bounds from above the magnitude of the reactivity reduction, this more accurate treatment leads to less dramatic losses of tail ions and associated reduction of thermonuclear reaction rates for finite fuel volumes.

  12. SLE($?,?$)and Boundary Coulomb Gas

    E-Print Network [OSTI]

    S. Moghimi-Araghi; M. A. Rajabpour; S. Rouhani

    2005-08-07T23:59:59.000Z

    We consider the coulomb gas model on the upper half plane with different boundary conditions, namely Drichlet, Neuman and mixed. We related this model to SLE($\\kappa,\\rho$) theories. We derive a set of conditions connecting the total charge of the coulomb gas, the boundary charges, the parameters $\\kappa$ and $\\rho$. Also we study a free fermion theory in presence of a boundary and show with the same methods that it would lead to logarithmic boundary changing operators.

  13. Layered semiconductor neutron detectors

    DOE Patents [OSTI]

    Mao, Samuel S; Perry, Dale L

    2013-12-10T23:59:59.000Z

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  14. Title: Boundary File: GTA (Greater Toronto Area) Data Creator /

    E-Print Network [OSTI]

    Municipal Boundary shapefiles: Municipal Boundary ­ Upper Tier and District, and Municipal Boundary ­ Lower Municipality of Durham, Regional Municipality of York Data Type: Digital Vector Data Format: Shapefile Datum

  15. ARM - Atmospheric Heat Budget

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OFMaterialsAnnual Reports27,ListAtmospheric Heat

  16. ARM - Atmospheric Pressure

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OFMaterialsAnnual Reports27,ListAtmospheric

  17. Atmospheric PSF Interpolation

    Office of Scientific and Technical Information (OSTI)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Found The itemAIR SEPARATION BYAbrasion andArticle)Atmospheric

  18. Impact of boundaries on velocity profiles in bubble rafts

    E-Print Network [OSTI]

    Yuhong Wang; Kapilanjan Krishan; Michael Dennin

    2006-01-31T23:59:59.000Z

    Under conditions of sufficiently slow flow, foams, colloids, granular matter, and various pastes have been observed to exhibit shear localization, i.e. regions of flow coexisting with regions of solid-like behavior. The details of such shear localization can vary depending on the system being studied. A number of the systems of interest are confined so as to be quasi-two dimensional, and an important issue in these systems is the role of the confining boundaries. For foams, three basic systems have been studied with very different boundary conditions: Hele-Shaw cells (bubbles confined between two solid plates); bubble rafts (a single layer of bubbles freely floating on a surface of water); and confined bubble rafts (bubbles confined between the surface of water below and a glass plate on top). Often, it is assumed that the impact of the boundaries is not significant in the ``quasi-static limit'', i.e. when externally imposed rates of strain are sufficiently smaller than internal kinematic relaxation times. In this paper, we directly test this assumption for rates of strain ranging from $10^{-3}$ to $10^{-2} {\\rm s^{-1}}$. This corresponds to the quoted quasi-static limit in a number of previous experiments. It is found that the top plate dramatically alters both the velocity profile and the distribution of nonlinear rearrangements, even at these slow rates of strain.

  19. Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification

    SciTech Connect (OSTI)

    Balaguru, Karthik; Chang, P.; Saravanan, R.; Leung, Lai-Yung R.; Xu, Zhao; Li, M.; Hsieh, J.

    2012-09-04T23:59:59.000Z

    Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are 'quasi-permanent' features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

  20. atmospheres thin atmospheres: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  1. Observation of thermally etched grain boundaries with the FIB/TEM technique

    SciTech Connect (OSTI)

    Palizdar, Y., E-mail: y.palizdar@merc.ac.ir [Nanotechnology and advanced materials department, Materials and energy research centre (MERC), Karaj (Iran, Islamic Republic of); San Martin, D. [MATERALIA group, Department of Physical Metallurgy, (CENIM-CSIC), Centro Nacional de Investigaciones Metalúrgicas Av. Gregorio del Amo 8, 28040 Madrid (Spain); Ward, M.; Cochrane, R.C.; Brydson, R.; Scott, A.J. [Institute for Materials Research, SPEME, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2013-10-15T23:59:59.000Z

    Thermal etching is a method which is able to reveal and characterize grain boundaries, twins or dislocation structures and determine parameters such as grain boundary energies, surface diffusivities or study phase transformations in steels, intermetallics or ceramic materials. This method relies on the preferential transfer of matter away from grain boundaries on a polished sample during heating at high temperatures in an inert/vacuum atmosphere. The evaporation/diffusion of atoms at high temperatures results in the formation of grooves at the intersections of the planes of grain/twin boundaries with the polished surface. This work describes how the combined use of Focussed Ion Beam and Transmission Electron Microscopy can be used to characterize not only the grooves and their profile with the surface, but also the grain boundary line below the groove, this method being complementary to the commonly used scanning probe techniques. - Highlights: • Thermally etched low-carbon steel samples have been characterized by FIB/TEM • Grain boundary (GB) lines below the groove have been characterized in this way • Absence of ghost traces and large ? angle suggests that GB are not stationary but mobile • Observations correlate well with previous works and Mullins' investigations [22].

  2. Layer-by-layer assembly in confined geometries

    E-Print Network [OSTI]

    DeRocher, Jonathan P

    2011-01-01T23:59:59.000Z

    The fundamental nature of layer-by-layer (LbL) assembly in confined geometries was investigated for a number of different chemical systems. The first part of this thesis concerns the modification of microfluidic and ...

  3. Ion transport and structure of layer-by-layer assemblies

    E-Print Network [OSTI]

    Lutkenhaus, Jodie Lee

    2007-01-01T23:59:59.000Z

    Layer-by-layer (LbL) films of various architectures were examined as potential solid state electrolytes for electrochemical systems (e.g. batteries and fuel cells). The relationship between materials properties and ion ...

  4. Thermal Transitions in Layer-By-Layer Assemblies

    E-Print Network [OSTI]

    Sung, Choonghyun

    2014-10-13T23:59:59.000Z

    Thermal transitions in layer-by-layer (LbL) assemblies were investigated under dry and hydrated conditions. In the dry state, the effects of film thickness and the film deposition method on the glass transition temperature (Tg) were studied...

  5. Engineering electroresponsive layer-by-layer thin films

    E-Print Network [OSTI]

    Schmidt, Daniel J., Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Electroresponsive layer-by-layer (LbL) polymer films and polymer nanocomposite films were investigated as model systems for electrically triggered drug delivery applications and "mechanomutable" surface coating applications. ...

  6. Gradient zone-boundary control in salt-gradient solar ponds

    DOE Patents [OSTI]

    Hull, J.R.

    1982-09-29T23:59:59.000Z

    A method and apparatus for suppressing zone boundary migration in a salt gradient solar pond includes extending perforated membranes across the pond at the boundaries, between the convective and non-convective zones, the perforations being small enough in size to prevent individual turbulence disturbances from penetrating the hole, but being large enough to allow easy molecular diffusion of salt thereby preventing the formation of convective zones in the gradient layer. The total area of the perforations is a sizeable fraction of the membrane area to allow sufficient salt diffusion while preventing turbulent entrainment into the gradient zone.

  7. Shaping Environmental Justice: Applying Science, Technology, and Society Boundary Work

    E-Print Network [OSTI]

    Huang, Chih-Tung

    2012-01-01T23:59:59.000Z

    Applying Science, Technology and Society Boundary Work Chih-the STS (Science, Technology and Society) study as boundary-

  8. Sandia National Laboratories: atmospheric chemistry

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

    and atmospheric chemistry that is expected to benefit auto and engine manufacturers, oil and gas utilities, and other industries that employ combustion models. A paper...

  9. A dominant role of oxygen additive on cold atmospheric-pressure He + O{sub 2} plasmas

    SciTech Connect (OSTI)

    Yang, Aijun; Liu, Dingxin, E-mail: liudingxin@gmail.com, E-mail: xhw@mail.xjtu.edu.cn; Rong, Mingzhe; Wang, Xiaohua, E-mail: liudingxin@gmail.com, E-mail: xhw@mail.xjtu.edu.cn [Centre for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); Kong, Michael G. [Centre for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States)

    2014-08-15T23:59:59.000Z

    We present in this paper how oxygen additive impacts on the cold atmospheric-pressure helium plasmas by means of a one-dimensional fluid model. For the oxygen concentration [O{sub 2}]?>??0.1%, the influence of oxygen on the electron characteristics and the power dissipation becomes important, e.g., the electron density, the electron temperature in sheath, the electron-coupling power, and the sheath width decreasing by 1.6 to 16 folds with a two-log increase in [O{sub 2}] from 0.1% to 10%. Also the discharge mode evolves from the ? mode to the ? mode. The reactive oxygen species are found to peak in the narrow range of [O{sub 2}]?=?0.4%–0.9% in the plasmas, similar to their power-coupling values. This applies to their wall fluxes except for those of O* and O{sub 2}{sup ?}. These two species have very short lifetimes, thus only when generated in boundary layers within several micrometers next to the electrode can contribute to the fluxes. The dominant reactive oxygen species and the corresponding main reactions are schematically presented, and their relations are quantified for selected applications.

  10. Winter mixed-layer development in the central Irminger Sea : the effect of strong, intermittent wind events

    E-Print Network [OSTI]

    Våge, Kjetil

    2006-01-01T23:59:59.000Z

    The impact of the Greenland tip jet on the wintertime mixed-layer of the southwest Irminger Sea is investigated using in-situ moored profiler data and a variety of atmospheric data sets. The mixed-layer was observed to ...

  11. Experimental investigation of mixing in a stratified fluid due to diffusion-driven flows in a loosely-packed particle layer

    E-Print Network [OSTI]

    Etheridge, William B. (William Bruce)

    2007-01-01T23:59:59.000Z

    An experimental study was undertaken to investigate if a loosely-packed particle layer can induce mixing due to diffusion-driven Phillips-Wunsch boundary flows in a quiescent stratified fluid. Diffusion-driven flows can ...

  12. A mathematical model of corrosion of a conducting porous layer on a rotating disk electrode

    E-Print Network [OSTI]

    Ryan, William Edward

    1986-01-01T23:59:59.000Z

    . This approach, however, fails to account, for many of the complexities involved in actual corrosion such as pH effects upon passivation and reverse kinetics of oxygen reduction reaction. In a later study, Alkire and Siitari (21) characterized an ideal pitting.... Description of Porous Electrode B. Governing Equations? Solution Diffusion Layer C. Governing Equations? Porous Electrode Layer D. Butler-Volmer Kinetic Rate Equation E. Boundary Conditions F. Solution Technique 12 14 17 IV RESULTS AND DISCUSSION A...

  13. Analysis of leakage current in buried heterostructure lasers with semiinsulating blocking layers

    SciTech Connect (OSTI)

    Asada, S.; Sugou, S.; Kasahara, K.; Kumashiro, S.

    1989-06-01T23:59:59.000Z

    An effective device structure for reducing leakage current in buried heterostructure laser diodes with semiinsulating InP blocking layers has been analyzed with the use of a semiconductor device simulator in which deep trap levels are taken into account. Adding a thin wide-bandgap InGaP layer in the semiinsulating region at the mesa boundaries as a barrier to prevent double injection into the semiinsulating region is predicted to be markedly effective in reducing leakage current.

  14. ELSEVIER AtmosphericResearch 38 (1995) 207-235 ATMOSPHERIC

    E-Print Network [OSTI]

    Moelders, Nicole

    ELSEVIER AtmosphericResearch 38 (1995) 207-235 ATMOSPHERIC RESEARCH On the parameterization of ice and water substance mixing ratio fields were only strongly altered by turning off the ice phase of these schemes includes ice processes. But in mid- latitudes and also in tropics the ice phase is an important

  15. ATMOSPHERIC ELSEVIER AtmosphericResearch 44 (1997) 231-241

    E-Print Network [OSTI]

    Reading, University of

    ATMOSPHERIC RESEARCH ELSEVIER AtmosphericResearch 44 (1997) 231-241 Error analysis of backscatter;accepted 14 February 1997 Abstract Ice sphere backscatter has been calculated using both Mie theory as a reasonable approximation for rv 1997 Elsevier Science B.V. 1. Introduction Cirrus clouds play

  16. Space Science : Atmosphere Greenhouse Effect

    E-Print Network [OSTI]

    Johnson, Robert E.

    Space Science : Atmosphere Greenhouse Effect Part-5a Solar + Earth Spectrum IR Absorbers Grey Atmosphere Greenhouse Effect #12;Radiation: Solar and Earth Surface B"(T) Planck Ideal Emission Integrate at the carbon cycle #12;However, #12;Greenhouse Effect is Complex #12;PLANETARY ENERGY BALANCE G+W fig 3-5

  17. Spatially Resolved Mapping of Electrical Conductivity around Individual Domain (Grain) Boundaries in Graphene

    SciTech Connect (OSTI)

    Li, An-Ping [ORNL; Clark, Kendal W [ORNL; Zhang, Xiaoguang [ORNL; Vlassiouk, Ivan V [ORNL; He, Guowei [Carnegie Mellon University (CMU); Feenstra, Randall [Carnegie Mellon University (CMU)

    2013-01-01T23:59:59.000Z

    Graphene films can now be produced on the scale of up to meters. However, all large-scale graphene films contain topological defects that can significantly affect the characteristic transport behaviors of graphene. Here, we spatially map the structures and electronic transport near specific domain and grain boundaries in graphene, and evaluate effects of different types of defect on the electronic conductivity in epitaxial graphene grown on SiC and CVD graphene on Cu subsequently transferred to a SiO2 substrate. We use a combined approach with a multi-probe scanning tunneling potentiometry to investigate both structures and transport at individual grain boundaries and domain boundaries that are defined by coalesced grains, surface steps, and changes in layer thickness. It is found that the substrate step on SiC presents a significant potential barrier for electron transport of epitaxial graphene due to the reduced charge transport from the substrate at the step edges, monolayer-bilayer boundaries exhibit a high resistivity that can change depending on directions of the current across the boundary, and the resistivity of grain boundaries changes with the transition width of the disordered region between two adjacent grains in graphene. The detailed understanding of graphene defects will provide the feedback for controlled engineering of defects in large-scale graphene films.

  18. Atmospheric Dispersion at Spatial Resolutions Below Mesoscale for university of Tennessee SimCenter at Chattanooga: Final Report

    SciTech Connect (OSTI)

    Dr. David Whitfield; Dr. Daniel Hyams

    2009-09-14T23:59:59.000Z

    In Year 1 of this project, items 1.1 and 1.2 were addressed, as well as item 2.2. The baseline parallel computational simulation tool has been refined significantly over the timeline of this project for the purpose of atmospheric dispersion and transport problems; some of these refinements are documented in Chapter 3. The addition of a concentration transport capability (item 1.2) was completed, along with validation and usage in a highly complex urban environment. Multigrid capability (item 2.2) was a primary focus of Year 1 as well, regardless of the fact that it was scheduled for Year 2. It was determined by the authors that due to the very large nature of the meshes required for atmospheric simulations at mesoscale, multigrid was a key enabling technology for the rest of the project to be successful. Therefore, it was addressed early according to the schedule laid out in the original proposal. The technology behind the multigrid capability is discussed in detail in Chapter 5. Also in Year 1, the issue of ground topography specification is addressed. For simulations of pollutant transport in a given region, a key prerequisite is the specification of the detailed ground topography. The local topography must be placed into a form suitable for generating an unstructured grid both on the topography itself and the atmospheric volume above it; this effort is documented in Chapter 6. In Year 2 of this project, items 1.3 and 2.1 were addressed. Weather data in the form of wind speeds, relative humidity, and baseline pollution levels may be input into the code in order to improve the real-world fidelity of the solutions. Of course, the computational atmospheric boundary layer (ABL) boundary condition developed in Year 1 may still be used when necessary. Cloud cover may be simulated via the levels of actinic flux allowed in photochemical reactions in the atmospheric chemistry model. The primary focus of Year 2 was the formulation of a multispecies capability with included chemical reactions (item 2.1). This proved to be a very arduous task, taking the vast majority of the time and personnel allocation for Year Two. The addition of this capability and related verification is documented in Chapter 7. A discussion of available tropospheric chemistry models is located in Chapter 8; and, a technology demonstrator for the full multispecies capability is detailed in Chapter 9. Item 2.3 has been partially addressed, in that the computation of sensitivity derivatives have been incorporated in the Tenasi code [7]. However, it has not been utilized in this project in order to compute probability distribution functions for pollutant deposition. In order to completely address the integration of weather and sensor data into the code (item 1.3) and integrate with existing sensor networks (item 3.1), a customizable interface was established. Weather data is most commonly available via a real database, and as such, support for accessing these databases is present in the solver source code. For integration functionality, a method of dynamic code customization was developed in Year 3, which is documented in Chapter 11.

  19. A Continuous ` \\Gamma oe Vertical Coordinate for a Baroclinic Model of the Atmospheric Circulation

    E-Print Network [OSTI]

    Drake, John B.

    meteorolgoical coordinate system is developed which can support a continuous isentropic­ oe vertical coordinate and boundary layer approximations were addressed by the introduction of a hybrid (patched) model [15]. By use analysis [14, 8]. The effects of heating on the circulation are most clearly seen with the isentropic

  20. Ch4. Atmosphere and Surface Energy Balances

    E-Print Network [OSTI]

    Pan, Feifei

    ;Energy Pathways #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Atmosphere or performing any work. #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Transmission or water. #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Transmission Atmosphere

  1. Moment problems and boundaries of number triangles

    E-Print Network [OSTI]

    Gnedin, Alexander

    2008-01-01T23:59:59.000Z

    The boundary problem for graphs like Pascal's but with general multiplicities of edges is related to a `backward' problem of moments of the Hausdorff type.

  2. Performance Boundaries in Nb3Sn Superconductors

    E-Print Network [OSTI]

    Godeke, Arno

    2006-01-01T23:59:59.000Z

    Boundaries in Nb 3 Sn Superconductors – Berkeley, CABoundaries in Nb 3 Sn Superconductors – Berkeley, CABoundaries in Nb 3 Sn Superconductors Arno Godeke Berkeley,

  3. Might Carbon-Atmosphere White Dwarfs Harbour a New Type of Pulsating Star?

    E-Print Network [OSTI]

    G. Fontaine; P. Brassard; P. Dufour

    2008-03-14T23:59:59.000Z

    In the light of the recent and unexpected discovery of a brand new type of white dwarfs, those with carbon-dominated atmospheres, we examine the asteroseismological potential of such stars. The motivation behind this is based on the observation that past models of carbon-atmosphere white dwarfs have partially ionized outer layers that bear strong resemblance with those responsible for mode excitation in models of pulsating DB (helium-atmosphere) and pulsating DA (hydrogen-atmosphere) white dwarfs. Our exciting main result is that, given the right location in parameter space, some carbon-atmosphere white dwarfs are predicted to show pulsational instability against gravity modes. We are eagerly waiting the results of observational searches for luminosity variations in these stars.

  4. Climatological simulations of ozone and atmospheric aerosols in the Greater Cairo region

    SciTech Connect (OSTI)

    Steiner, A. L.; Tawfik, A. B.; Shalaby, A.; Zakey, A. S.; Abdel Wahab, M. M.; Salah, Z.; Solmon, F.; Sillman, S.; Zaveri, Rahul A.

    2014-04-16T23:59:59.000Z

    An integrated chemistry-climate model (RegCM4-CHEM) simulates present-day climate, ozone and tropospheric aerosols over Egypt with a focus on Greater Cairo (GC) region. The densley populated GC region is known for its severe air quality issues driven by high levels of anthropogenic pollution in conjuction with natural sources such as dust and agricultural burning events. We find that current global emission inventories underestimate key pollutants such as nitrogen oxides and anthropogenic aerosol species. In the GC region, average-ground-based NO2 observations of 40-60 ppb are substantially higher than modeled estimates (5-10 ppb), likely due to model grid resolution, improper boundary layer representation, and poor emissions inventories. Observed ozone concentrations range from 35 ppb (winter) to 80 ppb (summer). The model reproduces the seasonal cycle fairly well, but modeled summer ozone is understimated by approximately 15 ppb and exhibits little interannual variability. For aerosols, springtime dust events dominate the seasonal aerosol cycle. The chemistry-climate model captures the springtime peak aerosol optical depth (AOD) of 0.7-1 but is slightly greater than satellite-derived AOD. Observed AOD decreases in the summer and increases again in the fall due to agricultural burning events in the Nile Delta, yet the model underestimates this fall observed AOD peak, as standard emissions inventories underestimate this burning and the resulting aerosol emissions. Our comparison of modeled gas and particulate phase atmospheric chemistry in the GC region indicates that improved emissions inventories of mobile sources and other anthropogenic activities are needed to improve air quality simulations in this region.

  5. Metal deposition using seed layers

    DOE Patents [OSTI]

    Feng, Hsein-Ping; Chen, Gang; Bo, Yu; Ren, Zhifeng; Chen, Shuo; Poudel, Bed

    2013-11-12T23:59:59.000Z

    Methods of forming a conductive metal layers on substrates are disclosed which employ a seed layer to enhance bonding, especially to smooth, low-roughness or hydrophobic substrates. In one aspect of the invention, the seed layer can be formed by applying nanoparticles onto a surface of the substrate; and the metallization is achieved by electroplating an electrically conducting metal onto the seed layer, whereby the nanoparticles serve as nucleation sites for metal deposition. In another approach, the seed layer can be formed by a self-assembling linker material, such as a sulfur-containing silane material.

  6. Buried oxide layer in silicon

    DOE Patents [OSTI]

    Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir, TN)

    2001-01-01T23:59:59.000Z

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  7. The Influence of Grain Boundary Type upon Damage Evolution at Grain Boundary Interfaces

    SciTech Connect (OSTI)

    Perez-Bergquist, Alejandro G [Los Alamos National Laboratory; Brandl, Christian [Los Alamos National Laboratory; Escobedo, Juan P [Los Alamos National Laboratory; Trujillo, Carl P [Los Alamos National Laboratory; Cerreta, Ellen K [Los Alamos National Laboratory; Gray III, George T [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory

    2012-07-09T23:59:59.000Z

    In a prior work, it was found that grain boundary structure strongly influences damage evolution at grain boundaries in copper samples subjected to either shock compression or incipient spall. Here, several grain boundaries with different grain boundary structures, including a {Sigma}3 (10-1) boundary, are interrogated via conventional transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) to investigate the effects of atomic-scale structural differences on grain boundary strength and mobility. Boundaries are studied both before and after shock compression at a peak shock stress of 10 GPa. Results of the TEM and HRTEM work are used in conjunction with MD modeling to propose a model for shock-induced damage evolution at grain boundary interfaces that is dependent upon coincidence.

  8. Analysis of the Younger Dryas Impact Layer

    SciTech Connect (OSTI)

    Firestone, Richard B.; West, Allen; Revay, Zsolt; Hagstrum, Jonathon T,; Belgya, Thomas; Hee, Shane S. Que; Smith, Alan R.

    2010-02-27T23:59:59.000Z

    We have uncovered a thin layer of magnetic grains and microspherules, carbon spherules, and glass-like carbon at nine sites across North America, a site in Belgium, and throughout the rims of 16 Carolina Bays. It is consistent with the ejecta layer from an impact event and has been dated to 12.9 ka BP coinciding with the onset of Younger Dryas (YD) cooling and widespread megafaunal extinctions in North America. At many locations the impact layer is directly below a black mat marking the sudden disappearance of the megafauna and Clovis people. The distribution pattern of the Younger Dryas boundary (YDB) ejecta layer is consistent with an impact near the Great Lakes that deposited terrestrial-like ejecta near the impact site and unusual, titanium-rich projectile-like ejecta further away. High water content associated with the ejecta, up to 28 at. percent hydrogen (H), suggests the impact occurred over the Laurentide Ice Sheet. YDB microspherules and magnetic grains are highly enriched in TiO{sub 2}. Magnetic grains from several sites are enriched in iridium (Ir), up to 117 ppb. The TiO{sub 2}/FeO, K/Th, TiO{sub 2}/Zr, Al{sub 2}O{sub 3}/FeO+MgO, CaO/Al{sub 2}O{sub 3}, REE/ chondrite, FeO/MnO ratios and SiO{sub 2}, Na{sub 2}O, K{sub 2}O, Cr{sub 2}O{sub 3}, Ni, Co, U, Th and other trace element abundances are inconsistent with all terrestrial and extraterrestrial (ET) sources except for KREEP, a lunar igneous rock rich in potassium (K), rare-earth elements (REE), phosphorus (P), and other incompatible elements including U and Th. Normal Fe, Ti, and {sup 238}U/{sup 235}U isotopic abundances were found in the magnetic grains, but {sup 234}U was enriched over equilibrium values by 50 percent in Murray Springs and by 130 percent in Belgium. 40K abundance is enriched by up to 100 percent in YDB sediments and Clovis chert artifacts. Highly vesicular carbon spherules containing nanodiamonds, glass-like carbon, charcoal and soot found in large quantities in the YDB layer are consistent with an impact followed by intense burning. Four holes in the Great Lakes, some deeper than Death Valley, are proposed as possible craters produced by the airburst breakup of a loosely aggregated projectile.

  9. 12th AIAA/CEAS Aeroacoustics Conference, May 8---10, 2006, Cambridge, Massachusetts PML absorbing boundary condition for nonlinear

    E-Print Network [OSTI]

    Hu, Fang Q.

    . R. China Perfectly Matched Layer (PML) absorbing boundary condition for the compressible non­ linear shedding from a viscous flow over a circular cylinder are presented. Satisfactory results demonstrated that the absorbing zone is theoretically reflectionless for multi­dimensional linear waves of any angle and frequency

  10. ASYMPTOTIC MODELLING OF CRYSTALLISATION IN TWO-LAYER SYSTEMS. APPLICATION TO METHANE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ,b; Skovborg and Rasmussen, 1994 ; Herri et al.,1999). Models generally assume a two-layer configuration which'(z, t) in dissolved gas. Boundary conditions are: c'(0, t) = Cext and c'(, t) = cb(t); Cext is the gas solubility; cb(t) is the bulk concentration. - bulk zone : due to the effect of stirring, concentration

  11. Transverse oscillations in a single-layer dusty plasma under microgravity V. E. Fortov,2

    E-Print Network [OSTI]

    Goree, John

    and A. V. Ivlev3 1 Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242 microgravity conditions. This single layer is confined at a void boundary by a balance of ion drag and electric a source of energy for microparticles. Under microgravity conditions, micropar- ticles are suspended

  12. Interaction of Ekman Layers and Islands MICHAEL A. SPALL AND JOSEPH PEDLOSKY

    E-Print Network [OSTI]

    to that found for the interaction of Ekman layers and an infinite boundary, namely downwelling (upwelling around the island so that the regions of upwelling and downwelling are dynamically connected, for positive wind stress, exhibits an anticyclonic phase rotation with depth (direction of Kelvin wave

  13. SHEAR LAYER INSTABILITY AND MIXING IN MICRO HEAT SPREADERS C. Sert and A. Beskok

    E-Print Network [OSTI]

    Beskok, Ali

    SHEAR LAYER INSTABILITY AND MIXING IN MICRO HEAT SPREADERS C. Sert and A. Beskok Texas A the chip surface temperature by oscillatory flow forced convection and mixing. Numerical simulations are performed for an MHS device with channel to reservoir expansion ratio H/h 25. The boundary conditions

  14. Hybrid asymptotic-finite element method for stiff two-point boundary value problems

    SciTech Connect (OSTI)

    Chin, R.C.Y.; Krasny, R.

    1983-06-01T23:59:59.000Z

    An accurate and efficient numerical method has been developed for a nonlinear stiff second order two-point boundary value problem. The scheme combines asymptotic methods with the usual solution techniques for two-point boundary value problems. A new modification of Newton's method or quasilinearization is used to reduce the nonlinear problem to a sequence of linear problems. The resultant linear problem is solved by patching local solutions at the knots or equivalently by projecting onto an affine subset constructed from asymptotic expansions. In this way, boundary layers are naturally incorporated into the approximation. An adaptive mesh is employed to achieve an error of O(1/N/sup 2/) + O(..sqrt..e). Here, N is the number of intervals and epsilon << 1 is the singular perturbation parameter. Numerical computations are presented.

  15. Boundary Behavior of the Ginzburg-Landau Order Parameter in the Surface Superconductivity Regime

    E-Print Network [OSTI]

    M. Correggi; N. Rougerie

    2015-01-27T23:59:59.000Z

    We study the 2D Ginzburg-Landau theory for a type-II superconductor in an applied magnetic field varying between the second and third critical value. In this regime the order parameter minimizing the GL energy is concentrated along the boundary of the sample and is well approximated to leading order by a simplified 1D profile in the direction perpendicular to the boundary. Motivated by a conjecture of Xing-Bin Pan, we address the question of whether this approximation can hold uniformly in the boundary region. We prove that this is indeed the case as a corollary of a refined, second order energy expansion including contributions due to the curvature of the sample. Local variations of the GL order parameter are controlled by the second order term of this energy expansion, which allows us to prove the desired uniformity of the surface superconductivity layer.

  16. Modeling Atmospheric Aerosols V. Rao Kotamarthi

    E-Print Network [OSTI]

    Modeling Atmospheric Aerosols V. Rao Kotamarthi and Yan Feng Climate Research Section Environmental Science Division Argonne National Laboratory #12;Outline Atmospheric Aerosols and gas phase heterogeneous reactions Regional Scales and Atmospheric Aerosols Regional Scale Aerosols: Ganges Valley Aerosol

  17. Prediction Error and Event Boundaries 1 Running Head: PREDICTION ERROR AND EVENT BOUNDARIES

    E-Print Network [OSTI]

    Zacks, Jeffrey M.

    Prediction Error and Event Boundaries 1 Running Head: PREDICTION ERROR AND EVENT BOUNDARIES A computational model of event segmentation from perceptual prediction. Jeremy R. Reynolds, Jeffrey M. Zacks, and Todd S. Braver Washington University Manuscript #12;Prediction Error and Event Boundaries 2 People tend

  18. The Deep Layers of Sunspot Umbrae

    E-Print Network [OSTI]

    Stellmacher, Goetz

    2012-01-01T23:59:59.000Z

    We model the deepest observable layers of dark sunspot umbral atmospheres in terms of an empirical model which equally describes observed near infrared continuum intensities and line profiles. We use the umbral continuum intensity at 1.67 nm and the three C I lines at 1,6888, 1,7449 and 1,7456 nm to model the deep layers near the minimum of H- absorption. We find that a radiative equilibrium stratification yields the best compromise between continuum and C I line observations. We determine the effective temperature from the umbral and photospheric flux ratio by down-scaling the monochromatic photospheric flux with the umbral contrast for each frequency. The thus obtained monochromatic umbral flux and the photospheric one are integratied over the whole frequency range, yielding the ratio of total umbral and photospheric flux, which gives 3560 K < T_eff < 3780 K. We assume for our model M3 T_eff=3750 K and fit M3 to the theoretical model by Meyer et al. (1974). Comparison of the model's 'nabla' gradient w...

  19. 2001 TRAFFIC ZONE BOUNDARIES Zone Numbers

    E-Print Network [OSTI]

    Toronto, University of

    2001 TRAFFIC ZONE BOUNDARIES Zone Numbers & Detailed Definitions #12;2001 TRAFFIC ZONE BOUNDARIES of Toronto Joint Program in Transportation January 2003 #12;PREFACE This report presents the 2001 traffic zone numbers by local municipalities in the 2001 TTS survey area. The second part presents detailed

  20. Green's functions for Neumann boundary conditions

    E-Print Network [OSTI]

    Jerrold Franklin

    2012-08-27T23:59:59.000Z

    Green's functions for Neumann boundary conditions have been considered in Math Physics and Electromagnetism textbooks, but special constraints and other properties required for Neumann boundary conditions have generally not been noticed or treated correctly. In this paper, we derive an appropriate Neumann Green's function with these constraints and properties incorporated.

  1. Boundary integral formulation for interfacial cracks in thermodiffusive bimaterials

    E-Print Network [OSTI]

    L. Morini; A. Piccolroaz

    2015-04-29T23:59:59.000Z

    An original boundary integral formulation is proposed for the problem of a semi-infinite crack at the interface between two dissimilar elastic materials in the presence of heat flows and mass diffusion. Symmetric and skew-symmetric weight function matrices are used together with a generalized Betti's reciprocity theorem in order to derive a system of integral equations that relate the applied loading, the temperature and mass concentration fields, the heat and mass fluxes on the fracture surfaces and the resulting crack opening. The obtained integral identities can have many relevant applications, such as for the modelling of crack and damage processes at the interface between different components in electrochemical energy devices characterized by multi-layered structures (solid oxide fuel cells and lithium ions batteries).

  2. Fragmentation Energetics of Clusters Relevant to Atmospheric...

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

    of Clusters Relevant to Atmospheric New Particle Formation. Fragmentation Energetics of Clusters Relevant to Atmospheric New Particle Formation. Abstract: The exact mechanisms by...

  3. Al{sub 2}O{sub 3} multi-density layer structure as a moisture permeation barrier deposited by radio frequency remote plasma atomic layer deposition

    SciTech Connect (OSTI)

    Jung, Hyunsoo [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Samsung Display Co. Ltd., Tangjeong, Chungcheongnam-Do 336-741 (Korea, Republic of); Jeon, Heeyoung [Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Choi, Hagyoung; Ham, Giyul; Shin, Seokyoon [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jeon, Hyeongtag, E-mail: hjeon@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2014-02-21T23:59:59.000Z

    Al{sub 2}O{sub 3} films deposited by remote plasma atomic layer deposition have been used for thin film encapsulation of organic light emitting diode. In this study, a multi-density layer structure consisting of two Al{sub 2}O{sub 3} layers with different densities are deposited with different deposition conditions of O{sub 2} plasma reactant time. This structure improves moisture permeation barrier characteristics, as confirmed by a water vapor transmission rate (WVTR) test. The lowest WVTR of the multi-density layer structure was 4.7 × 10{sup ?5} gm{sup ?2} day{sup ?1}, which is one order of magnitude less than WVTR for the reference single-density Al{sub 2}O{sub 3} layer. This improvement is attributed to the location mismatch of paths for atmospheric gases, such as O{sub 2} and H{sub 2}O, in the film due to different densities in the layers. This mechanism is analyzed by high resolution transmission electron microscopy, elastic recoil detection, and angle resolved X-ray photoelectron spectroscopy. These results confirmed that the multi-density layer structure exhibits very good characteristics as an encapsulation layer via location mismatch of paths for H{sub 2}O and O{sub 2} between the two layers.

  4. Environmental boundaries to energy development

    SciTech Connect (OSTI)

    Trivelpiece, A.W.

    1989-01-01T23:59:59.000Z

    Public concern about the environment, health and safety consequences of energy technology has been growing steadily for more than two decades in the United States. This concern forms an important boundary condition as the United States seeks to develop a new National Energy Strategy. Furthermore, the international aspects of the energy/environment interface such as acid rain global climate change and stratospheric ozone depletion are very prominent in US thinking. In fact, the energy systems of the world are becoming more closely coupled environmentally and otherwise. Now where is this coupling more important than that between the industrialized and developing world; the choices made by each will have profound effects on the other. The development of energy technologies compatible with both economic growth and improving and sustaining environmental quality represents a major R D challenge to the US and USSR. Decision about adoption of new technology and R D priorities can be improved by better measurements of how energy sources and uses are changing throughout the world and better methods to project the potential consequences of these decisions. Such projection require understanding relative risks of alternating existing and evolving technologies. All of these R D areas, technology improvement energy system monitoring and projection and comparative risk assessment are the topics of this seminar. Progress in each may be enhanced by collaboration and cooperation between our two countries. 7 refs., 27 figs., 5 tabs.

  5. Environmental Chemistry II (Atmospheric Chemistry)

    E-Print Network [OSTI]

    Dibble, Theodore

    SYLLABUS FOR Environmental Chemistry II (Atmospheric Chemistry) FCH 511 Fall 2013 Theodore S/explaining the trends in J as a function of altitude and solar zenith angle. The second involves analyzing real

  6. Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization Artificial Neural Networks

    E-Print Network [OSTI]

    Kjellström, Hedvig

    Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization Artificial Neural Networks Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization 1 Artificial Neural Networks Properties Applications Classical Examples Biological Background 2 Single Layer

  7. Laser Atmospheric Studies with VERITAS

    E-Print Network [OSTI]

    C. M. Hui; for the VERITAS collaboration

    2007-09-25T23:59:59.000Z

    As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of ultra-high-energy cosmic-ray fluorescence telescopes but is also applicable to imaging atmospheric Cherenkov telescopes (IACTs). In this paper, we present two nights of laser data taken with the laser at various distances away from the VERITAS telescopes and compare it to Rayleigh scattering simulations.

  8. Method of deforming a biaxially textured buffer layer on a textured metallic substrate and articles therefrom

    DOE Patents [OSTI]

    Lee, Dominic F. (Knoxville, TN); Kroeger, Donald M. (Knoxville, TN); Goyal, Amit (Knoxville, TN)

    2000-01-01T23:59:59.000Z

    The present invention provides methods and biaxially textured articles having a deformed epitaxial layer formed therefrom for use with high temperature superconductors, photovoltaic, ferroelectric, or optical devices. A buffer layer is epitaxially deposited onto biaxially-textured substrates and then mechanically deformed. The deformation process minimizes or eliminates grooves, or other irregularities, formed on the buffer layer while maintaining the biaxial texture of the buffer layer. Advantageously, the biaxial texture of the buffer layer is not altered during subsequent heat treatments of the deformed buffer. The present invention provides mechanical densification procedures which can be incorporated into the processing of superconducting films through the powder deposit or precursor approaches without incurring unfavorable high-angle grain boundaries.

  9. Oxygen-reducing catalyst layer

    DOE Patents [OSTI]

    O'Brien, Dennis P. (Maplewood, MN); Schmoeckel, Alison K. (Stillwater, MN); Vernstrom, George D. (Cottage Grove, MN); Atanasoski, Radoslav (Edina, MN); Wood, Thomas E. (Stillwater, MN); Yang, Ruizhi (Halifax, CA); Easton, E. Bradley (Halifax, CA); Dahn, Jeffrey R. (Hubley, CA); O'Neill, David G. (Lake Elmo, MN)

    2011-03-22T23:59:59.000Z

    An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

  10. Air Resources Laboratory The Air Resources Laboratory (ARL) is a research laboratory within the National Oceanic and Atmospheric Administration

    E-Print Network [OSTI]

    in West Texas. The data collected and analyzed by ARL will improve forecasts of winds at heights more research and development in the fields of atmospheric dispersion, air quality, climate change, and boundary of hazardous chemicals and materials; developing, evaluating, and applying air quality models; conducting

  11. Boundary definition of a multiverse measure

    E-Print Network [OSTI]

    Raphael Bousso; Ben Freivogel; Stefan Leichenauer; Vladimir Rosenhaus

    2010-09-18T23:59:59.000Z

    We propose to regulate the infinities of eternal inflation by relating a late time cut-off in the bulk to a short distance cut-off on the future boundary. The light-cone time of an event is defined in terms of the volume of its future light-cone on the boundary. We seek an intrinsic definition of boundary volumes that makes no reference to bulk structures. This requires taming the fractal geometry of the future boundary, and lifting the ambiguity of the conformal factor. We propose to work in the conformal frame in which the boundary Ricci scalar is constant. We explore this proposal in the FRW approximation for bubble universes. Remarkably, we find that the future boundary becomes a round three-sphere, with smooth metric on all scales. Our cut-off yields the same relative probabilities as a previous proposal that defined boundary volumes by projection into the bulk along timelike geodesics. Moreover, it is equivalent to an ensemble of causal patches defined without reference to bulk geodesics. It thus yields a holographically motivated and phenomenologically successful measure for eternal inflation.

  12. LARGE ABUNDANCES OF POLYCYCLIC AROMATIC HYDROCARBONS IN TITAN'S UPPER ATMOSPHERE

    SciTech Connect (OSTI)

    Lopez-Puertas, M.; Funke, B.; Garcia-Comas, M. [Instituto de Astrofisica de Andalucia (CSIC), E-18080 Granada (Spain); Dinelli, B. M. [ISAC-CNR, I-40129 Bologna (Italy); Adriani, A.; D'Aversa, E. [IAPS-INAF, I-00133 Rome (Italy); Moriconi, M. L. [ISAC-CNR, I-00133 Rome (Italy); Boersma, C.; Allamandola, L. J., E-mail: puertas@iaa.es [NASA Ames Research Center, Moffett Field, CA 94035-1000 (United States)

    2013-06-20T23:59:59.000Z

    In this paper, we analyze the strong unidentified emission near 3.28 {mu}m in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 {mu}m. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) Multiplication-Sign 10{sup 4} particles cm{sup -3}. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is {approx}430 u; the mean area is about 0.53 nm{sup 2}; they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.

  13. CATALYZED COMBUSTION IN A FLAT PLATE BOUNDARY LAYER II. NUMERICAL CALCULATIONS

    E-Print Network [OSTI]

    Schefer, R.

    2010-01-01T23:59:59.000Z

    at Simulated Gas Turbine Combustor Operating Conditions",on the use of catalytic combustors for aircraft gas turbineof prototype catalytic combustor configurations. studies are

  14. The effects of sound on the boundary layer of an airfoil at high angles of attack

    E-Print Network [OSTI]

    Hutchinson, Thomas Ira

    1963-01-01T23:59:59.000Z

    were run to determine the lift coefficients for the NACA 4415 airfoil model used. At this time, irreparable internal leaks in the static pressure system of the airfoil were discovered, apparently caused by aging since the airfoil had last been used.... This report also contains an early mention of the use of sound as a means of controlling airflow. This came about while seeking a means of producing artificial disturbances in the airflow of known frequency and amplitude. One of these methods involved...

  15. CATALYZED COMBUSTION IN A FLAT PLATE BOUNDARY LAYER II. NUMERICAL CALCULATIONS

    E-Print Network [OSTI]

    Schefer, R.

    2010-01-01T23:59:59.000Z

    D.G. , Fourteenth Sympo- sium (International) on Combustion,The Combustion Institute, Pittsburgh, 107 (1973). Wilson,Program for Calculation of Combustion Reaction Equilibrium

  16. CATALYZED COMBUSTION IN A FLAT PLATE BOUNDARY LAYER I. EXPERIMENTAL MEASUREMENTS AND COMPARISON WITH NUMERICAL CALCULATIONS

    E-Print Network [OSTI]

    Robben, R.

    2010-01-01T23:59:59.000Z

    l~ Roberts, "Catathermal Combustion: A New Process for Lm'l-significant gas phase combustion is induced by the presenceInternational) on Combustion (to be published), The

  17. Eos,Vol. 85, No. 23, 8 June 2004 enhanced convergence,boundary layer desta-

    E-Print Network [OSTI]

    Segall, Paul

    -dynamics and aerosol-micro- physics arguments. Human-related activities associated with transportation,energy of the week in NewYork City.This cycle was hypothesized to be related to increased trans- portation activity,the impact of urbanization on net primary productivity (NPP) and its consequences for carbon balance and food

  18. UBL/CLU-ESCOMPTE : THE URBAN BOUNDARY LAYER FIELD EXPERIMENT OVER MARSEILLE AND THE DATA BASE

    E-Print Network [OSTI]

    Boyer, Edmond

    ) thé comparison of thé Town Energy Balance model with thé data obtained over thé city center, (d) thé-comparison of energy flux instrumentations, (b) thé quality évaluation of thé measurements at thé urban stations, (c, among which two on ships, and two in trucks. Thé surface energy budget was measured at 9 sites. Thé

  19. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K

    2010-01-01T23:59:59.000Z

    three California wind farms: San Gorgonio Pass and Tehachapibuoy Ontario San Gorgonio Pass Wind Farm Palm Springs Blytherecords from the San Gorgonio Pass wind farm are not avail-

  20. On the role of monoterpene chemistry in the remote continental boundary layer E. C. Browne1

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    MGLY methyl glyoxal PROPNN propanone nitrate MO2 methyl peroxy radical PYAC pyruvic acid MOBA organic methacrolein nitrate OP2 > C-1 organic peroxides MACRO2 peroxy radicals from MACR ORA1 formic acid MAHP methyl acrylic acid ORA2 acetic and higher acids MCTO alkoxy radicals from methyl catechol oxidation PER1 peroxy

  1. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    B. , Hebestreit, K. , and Platt, U. : Short-lived alkylR. , Lawrence, M. G. , Platt, U. , ,and Crutzen, P. J. :Peleg, M. , Luria, M. , and Platt, U. : DOAS measurements of

  2. Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer

    E-Print Network [OSTI]

    Hawkins, Lelia Nahid

    2010-01-01T23:59:59.000Z

    consistent with diesel and oil combustion were also observedwith diesel and residual oil combustion, and has a strongto identify OM from oil combustion, woodsmoke, processed

  3. An efficient approximation for the vibro-acoustic response of a turbulent boundary layer excited panel

    E-Print Network [OSTI]

    Boyer, Edmond

    hal-01004463,version1-11Jun2014 Author manuscript, published in "Journal of Sound and Vibration 264, 4 and the acoustic pressure radiated when a thin elastic plate is immersed in a low Mach number flow of fluid. The mechanical properties of this panel are a Young's modulus E, a Pois- son coefficient and a mass per unit

  4. A BOUNDARY LAYER PROBLEM FOR AN ASYMPTOTIC PRESERVING SCHEME IN THE QUASI-NEUTRAL LIMIT FOR

    E-Print Network [OSTI]

    Vignal, Marie-Hélène

    , see [31]. The second application is related to electric arc phenomena on satellite solar panels, see as the asymptotic pre- serving scheme developed in [9] are unstable for general Roe type solvers when the mesh does, the quasi-neutral model is not valid in non quasi-neutral zones and, we have to use different models

  5. RACORO LONG-TERM, SYSTEMATIC AIRCRAFT OBSERVATIONS OF BOUNDARY LAYER CLOUDS

    E-Print Network [OSTI]

    ). This type of cloud is common globally, and the Earth's radiative energy balance is particularly sensitive the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid to do so, for United States Government purposes. BNL-91362-2010-CP #12;

  6. Design of an Instrumentation System for a Boundary Layer Transition Wing Glove Experiment

    E-Print Network [OSTI]

    Williams, Thomas 1987-

    2012-08-23T23:59:59.000Z

    side of the glove. Infrared (IR) thermography has been selected as the primary transition detection tool. A heat transfer analysis has shown that solar radiation will warm the surface of the glove above the adiabatic wall temperature and therefore...

  7. American Institute of Aeronautics and Astronautics The Influence of Stable Boundary Layer Flows

    E-Print Network [OSTI]

    Manuel, Lance

    generated by shear and destroyed by negative buoyancy. Wind shear (both magnitude and direction) under and forecasting of LLJs is needed for robust wind turbine design and for more reliable power generation prediction on Wind Turbine Fatigue Loads Chungwook Sim1 Dept. of Civil, Architectural, and Environmental Engineering

  8. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    close to or East of the Canary Islands, before arriving atpassing near to the Canary Islands on its way to Cape Verde.passing close to the Canary islands before approaching Cape

  9. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K.

    2010-01-01T23:59:59.000Z

    maps showing locations of wind power conversion facilities,of US winds and wind power at 80 m derived fromEvaluation of global wind power. Journal of Geo- physical

  10. Study of active control of instability in a boundary layer over a flat plate flow 

    E-Print Network [OSTI]

    Oryu, Hiroshi

    2000-01-01T23:59:59.000Z

    -Sommerfeld equation. The development of a sensor-actuator control system unit using synthetic jet actuators for flow transition control was studied. The implementation of the disturbance generator using a DC motor for the generation of a desired frequency...

  11. LES of the adverse-pressure gradient turbulent boundary layer M. Inoue a,

    E-Print Network [OSTI]

    Marusic, Ivan

    at the University of Melbourne wind tunnel where a plate section with zero pressure gradient is followed by section accurate simulations, for example, of separated flow on the wings of airplanes or for flow through turbine such as the amplified wake of the mean velocity profile and the increasing turbulence intensity in the outer region

  12. Study of active control of instability in a boundary layer over a flat plate flow

    E-Print Network [OSTI]

    Oryu, Hiroshi

    2000-01-01T23:59:59.000Z

    ). . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 9 34 Power spectrum and time record at a freestream of 136. 8 mm/s, 2. 5 mm off the bottom wall and 25. 4 mm upstream of the actuator. . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 35 Power specnum and time record at a Ireestream... of 201. 3 mm/s, 2. 5 mm off the bottom wall and 25. 4 mm upstream of the actuator. . . . . . . . . . . . . . . . . . . . . . . . . . . 41 FIGURE Page 36 Power spectrum and time record at a &eestream of 263. 8 mm/s, 2. 5 mm off the bottom wall and 25...

  13. Numerical prediction of the boundary layers in the flow around a cylinder using a fixed

    E-Print Network [OSTI]

    Wapperom, Peter

    .1. (Webster [We2]): A generic real ellipsoid in Cn with n 3 does not admit any umbilical point. Umbilical]. A natural question arising from [We2] is then to ask whether a generic real ellipsoid in C2 shares the same

  14. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K.

    2010-01-01T23:59:59.000Z

    3.4.2 Wind roses . . . . . . . .Figure 5.5: Downscaled wind speed changes and componentin?uences on California’s wind energy resource. Part 1:

  15. Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer

    E-Print Network [OSTI]

    Hawkins, Lelia Nahid

    2010-01-01T23:59:59.000Z

    carbon (OC) and for specific components like bacteria and viruses. The production of sea spray from bubble

  16. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K

    2010-01-01T23:59:59.000Z

    power conversion facilities, nearby METARs stations, and other ob- servation and buoypower con- version facilities, nearby METARs stations, and other observation and buoy

  17. Pollution-enhanced reactive chlorine chemistry in the eastern tropical Atlantic boundary layer

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    doi:10.1029/2008GL036666, 2009 Pollution-enhanced reactiveE. S. Saltzman (2009), Pollution-enhanced reactive chlorine5 L08810 LAWLER ET AL. : POLLUTION-ENHANCED CLX IN THE MBL

  18. Initial-Boundary Layer Associated with the Nonlinear Darcy-Brinkman System

    E-Print Network [OSTI]

    Aluffi, Paolo

    dependent. We also assume the zeroth order compatibility condition v0|z=0,1 = 0. The Darcy-Brinkman equation), the Darcy-Brinkman equation reduces to the classical Darcy equation u = - () 0 [pl]l + lg0 V ez . (1 in system (1.1), we arrive at the following Darcy equation v0 + p0 = F, div v0 = 0, v0 · n|z=0,1 = 0, v0

  19. Motion of a sphere in an oscillatory boundary layer: an optical tweezer based study

    E-Print Network [OSTI]

    Prerna Sharma; Shankar Ghosh; S. Bhattacharya

    2006-08-11T23:59:59.000Z

    The drag forces acting on a single polystyrene sphere in the vicinity of an oscillating glass plate have been measured using an optical tweezer. The phase of the sphere is found to be a sensitive probe of the dynamics of the sphere. The evolution of the phase from an inertially-coupled regime to a purely velocity-coupled regime is explored. Moreover, the frequency dependent response is found to be characteristic of a damped oscillator with an effective inertia which is several orders of magnitude greater than that of the particle.

  20. The effect of periodic-unsteady wakes, curvature, and pressure gradient on boundary-layer transition

    E-Print Network [OSTI]

    Radke, Robert Edward

    1994-01-01T23:59:59.000Z

    generator cross section looking upstream . . Test section with the curved plate located at the mid-height of the channel Page 10 12 Figure 4. Figure 5. 14 Curved plate detail drawing with side and top views Cross-sections A-A (showing the internal... for the next generation of research in this area will be accomplished. 10 4. TEST FACILITY AND MEASUREMENT TECHNIQUE 4. 1 Wind Tunnel The test facility in Figure 1 is described in Schobeiri and Pardivala (1992) in detaiL The air is supplied with a...

  1. Observations of gas phase hydrochloric acid in the polluted marine boundary layer

    E-Print Network [OSTI]

    , California, USA, 2 Chemical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA Ship-based measurements of gas phase hydrochloric acid (HCl), particulate chloride (p the lifetime of methane [Finlayson-Pitts, 1993; Pszenny et al., 2007; Singh and Kasting, 1988; von Glasow

  2. A deterministic model for the sublayer streaks in turbulent boundary layers for application

    E-Print Network [OSTI]

    Davies, Christopher

    control BY PETER W. CARPENTER 1,*, KAREN L. KUDAR 1 , REZA ALI 1 , PRADEEP K. SEN 2 AND CHRISTOPHER DAVIES

  3. Surface heterogeneity impacts on boundary layer dynamics via energy balance partitioning

    E-Print Network [OSTI]

    Brunsell, Nathaniel A.; Mechem, David B.; Anderson, M. C.

    2011-04-11T23:59:59.000Z

    .23 0.0002 1600 309.19 2.04 0.21 0.0012 12800 308.06 3.15 0.23 0.0017 u3 100 307.07 4.97 0.22 0.0030 200 306.31 0.54 0.22 0.0003 1600 307.34 2.17 0.21 0.0019 12800 306.13 3.15 0.22 0.0019 u6 100 305.38 5.65 0.21 0.0043 200 304.87 0.50 0.22 0.0004 1600...

  4. Measurement of three-dimensional coherent fluid structure in high Reynolds number turbulent boundary layers

    E-Print Network [OSTI]

    Clark, Thomas Henry

    2012-07-03T23:59:59.000Z

    of difference between original and filled-in vectors . . 158 6.22 Restoration of field with 20% missing data . . . . . . . . . . . . . 160 6.23 Restoration of field with 50% missing data . . . . . . . . . . . . . 161 6.24 Median error in restoration of a field... Binary mask used to relate pixel indices in matrix Wij to the reduced pixel indices in Wrs. ?js Binary mask used to relate voxel indices in matrix Wij to the reduced voxel indices in Wrs. ei Error in the ith velocity component. u?iu ? j u? Turbulent...

  5. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K.

    2010-01-01T23:59:59.000Z

    of observed summertime mesoscale pressure gradient and ??observed wind speeds and mesoscale SLP di?erences at pointsand modi?cation of mesoscale circulations. Monthly Weather

  6. An Examination of Configurations for Using Infrared to Measure Boundary Layer Transition

    E-Print Network [OSTI]

    Freels, Justin Reed

    2012-10-19T23:59:59.000Z

    as an external source and circulating fluid inside of the airfoil. Furthermore, ABS plastic and aluminum airfoils are tested with and without coatings such as black paint and surface wraps. The results show that thermal conduction within the model and surface...

  7. Advances in Differential Equations Volume xx, Number xxx, , Pages xxxx BOUNDARY LAYER FOR A PENALIZATION METHOD

    E-Print Network [OSTI]

    Carbou, Gilles

    experiments. To obtain these results we perform an asymptotic expansion of the solution in the spirit of BKW the BKW method is that one has to obtain very regular solutions on the limit problem. 1.1. Main results

  8. Viscous boundary layers for the NavierStokes equations with the Navier slip conditions

    E-Print Network [OSTI]

    Iftimie, Dragoº

    , such as in aerodynamics (space shuttles covered by tiles), in weather forecast (where trees, buildings, water waves have that the Navier slip­with­friction condition was derived in the kinematic theory of gases by Maxwell. In this case

  9. Viscous boundary layers for the Navier-Stokes equations with the Navier slip conditions

    E-Print Network [OSTI]

    Sueur, Franck

    , such as in aerodynamics (space shuttles covered by tiles), in weather forecast (where trees, buildings, water waves have that the Navier slip-with-friction condition was derived in the kinematic theory of gases by Maxwell. In this case

  10. Solute dispersion in the coastal boundary layer of southern Lake Michigan

    E-Print Network [OSTI]

    of southern Lake Michigan, J. Geophys. Res. Oceans, 118, 1606­1617, doi:10.1002/jgrc.20136. 1. Introduction [2) with turbid waters contributing to increased survival by limiting sunlight penetration, removal of bacteria

  11. Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer

    E-Print Network [OSTI]

    Hawkins, Lelia Nahid

    2010-01-01T23:59:59.000Z

    2.2.2 FTIR and XRF analyses . . . . . . . . . . . . . .Ray Fluorescence (XRF) . . . . . . . . . . 4.2.3 Quadrupoleof OM (by mass), sum of XRF elements K, Ni, Ca, Fe, Sn, V,

  12. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    105, 24191–24204, 2000. Allan, B. J. , Plane J. M. C. , andlayer, Geophys. Res. Lett. , Allan, J. D. , Topping, D. O. ,1,2 , G. McFiggans 3 , J. D. Allan 3,4 , A. R. Baker 5 , S.

  13. Primary crossflow vortices, secondary absolute instabilities and their control in the rotating-disk boundary layer

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Primary crossflow vortices, secondary absolute instabilities and their control in the rotating patterns of crossflow vortices are derived by employing asymptotic techniques. This approach accounts three-dimensional velocity profiles, are subject to inviscid crossflow in- stabilities and rapidly

  14. Field boundary layer characteristics as modified by clams in habitats of varying survival rates

    E-Print Network [OSTI]

    Profile u (m s-1) y(m) Q (m3 s-1) Vertical Jet + = Q UU -Vertical jets in crossflow have been shown as those in the jets-in-crossflow literature. Hypothesis and Objective · Hypothesis: Clam presence

  15. High-Speed Boundary-Layer Transition : : Study of Stationary Crossflow Using Spectral Analysis

    E-Print Network [OSTI]

    McGuire, Patrick Joseph

    2014-01-01T23:59:59.000Z

    Secondary Instability of Crossflow Vortices. J. Fluid Mech.R. & S ARIC , W. S. 1999 Crossflow Stability and TransitionSaturation of Stationary Crossflow Vortices in a Swept-Wing

  16. American Institute of Aeronautics and Astronautics Shock/Boundary Layer Interaction Effects on Transverse

    E-Print Network [OSTI]

    Texas at Arlington, University of

    on Transverse Jets in Crossflow Over a Flat Plate Dean A. Dickmann* Lockheed Martin Missiles and Fire Control crossflow by bifurcating the phase portrait of the separation topology through the addition of saddle points

  17. Particle Resuspension in Turbulent Boundary Layers and the Influence of Non-Gaussian Removal Forces

    E-Print Network [OSTI]

    Zhang, F; Kissane, M

    2012-01-01T23:59:59.000Z

    The work presented is concerned with the way very small micron-size particles attached to a surface are resuspended when exposed to a turbulent flow. Of particular concern is the remobilization of radioactive particles as a consequence of potential nuclear accidents. In this particular case the focus is on small particles, resuspension involving the rocking and rolling of a particle about surface asperities arising from the moments of the fluctuating drag forces acting on the particle close to the surface. In this work the model is significantly improved by using values of both the stream-wise fluid velocity and acceleration close to the wall obtained from Direct Numerical Simulation (DNS) of turbulent channelflow. Using an...

  18. Improving tropical and subtropical boundary layer cloudiness in the NCEP GFS

    E-Print Network [OSTI]

    Bretherton, Chris

    , as well as in the Community Earth System Model (CESM, http://www.cesm.ucar.edu/), using the relative

  19. Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer

    E-Print Network [OSTI]

    Hawkins, Lelia Nahid

    2010-01-01T23:59:59.000Z

    show: aluminum (solid red bowtie), silicon (solid bluesolid turquoise vertical bowtie), calcium (solid orangeshow: aluminum (solid red bowtie), silicon (solid blue

  20. Numerical Study of Freestream Waves Receptivity and Nonlinear Breakdown in Hypersonic Boundary Layer

    E-Print Network [OSTI]

    Lei, Jia

    2013-01-01T23:59:59.000Z

    each fixed-frequency disturbance can be represented by eq. (and LST with the disturbance frequency of 744.5 kHz for theDNS and LST at the disturbance frequency of 744.5 kHz for