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1

Wind Structure in the Atmospheric Boundary Layer  

Science Journals Connector (OSTI)

13 May 1971 research-article Wind Structure in the Atmospheric Boundary Layer...semi-empirical laws for the variation of mean wind speed with height and for the statistical...provide some useful ordering of the mean wind profile characteristics in relation to...

1971-01-01T23:59:59.000Z

2

ARM - Field Campaign - Lower Atmospheric Boundary Layer Experiment  

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

govCampaignsLower Atmospheric Boundary Layer Experiment govCampaignsLower Atmospheric Boundary Layer Experiment Campaign Links LABLE Website Related Campaigns 2013 Lower Atmospheric Boundary Layer Experiment 2013.05.28, Turner, SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Lower Atmospheric Boundary Layer Experiment 2012.09.17 - 2012.11.13 Lead Scientist : David Turner Description Boundary layer turbulence is an important process that is parameterized in most atmospheric numerical models. Turbulence redistributes energy and mass within the boundary layer. Many different characteristics can impact the character of turbulence in the boundary layer, including different surface types, horizontal wind speed and direction, and the vertical temperature structure of the atmosphere. However, there have been few studies that have

3

Modeling the Interaction between the Atmospheric and Oceanic Boundary Layers, Including a Surface Wave Layer  

Science Journals Connector (OSTI)

The interaction between the atmospheric and oceanic boundary layers is simulated by solving a closed system of equations including equations of motion, turbulent kinetic energy (TKE), turbulent exchange coefficient (TEC), expressions for air and ...

Le Ngoc Ly

1986-08-01T23:59:59.000Z

4

High resolution properties of the marine atmospheric boundary layer  

SciTech Connect (OSTI)

Los Alamos National Laboratory (LANL) participated in the Central Equatorial Pacific Experiment (CEPEX) by fielding a water-vapor Raman lidar on board the Research Vessel Vickers. The lidar measured water vapor concentration from the surface to lower tropospheric altitudes in order to support the CEPEX goal of evaluating a hypothesis regarding feedback mechanisms for global circulation models. This report describes some of the features observed within the marine Atmospheric Boundary Layer (ABL) and the lower troposphere. Data was collected continuously 24 hours per day over the equatorial Pacific from March 8th to March 2 1st of 1993 while in route between Guadalcanal and Christmas Island (the transect was at approximately 2{degree} south latitude). The lidar collected vertical transects of water vapor concentration up to 10 km during night operations and 4 km in the day. The vertical lidar profiles of water vapor were produced by summing the data over a period up to 600 seconds. The water-vapor Raman lidar measured the properties of the marine ABL as well as the lower and mid-troposphere. From the lidar water vapor profiles, ``images`` of water vapor concentration versus altitude and date or sea surface temperature will be produced along with other products such as latent heat fluxes. The Raman water vapor lidar data will be used to better understand the role of transport and exchange at the ocean-atmosphere interface and throughout the marine atmosphere.

Cooper, D.; Cottingame, W.; Eichinger, W.; Forman, P.; Lebeda, C.; Poling, D.; Thorton, R.

1994-02-01T23:59:59.000Z

5

Uncertainty in Contaminant Concentration Fields Resulting from Atmospheric Boundary Layer Depth Uncertainty  

Science Journals Connector (OSTI)

The relationship between atmospheric boundary layer (ABL) depth uncertainty and uncertainty in atmospheric transport and dispersion (ATD) simulations is investigated by examining profiles of predicted concentrations of a contaminant. Because ...

Brian P. Reen; Kerrie J. Schmehl; George S. Young; Jared A. Lee; Sue Ellen Haupt; David R. Stauffer

2014-11-01T23:59:59.000Z

6

Wind Direction Dependence of Atmospheric Boundary Layer Turbulence Parameters in the Urban Roughness Sublayer  

Science Journals Connector (OSTI)

A variety of atmospheric boundary layer parameters are examined as a function of wind direction in both urban and suburban settings in Oklahoma City, Oklahoma, derived from measurements during the Joint Urban 2003 field campaign. Heterogeneous ...

Cheryl Klipp

2007-12-01T23:59:59.000Z

7

Large-Eddy Simulation of Marine Atmospheric Boundary Layers above a Spectrum of Moving Waves  

Science Journals Connector (OSTI)

Momentum and scalar transport in the marine atmospheric boundary layer (MABL) is driven by a turbulent mix of winds, buoyancy, and surface gravity waves. To investigate the interaction between these processes, a large-eddy simulation (LES) model ...

Peter P. Sullivan; James C. McWilliams; Edward G. Patton

2014-11-01T23:59:59.000Z

8

Numerical Modeling of the Propagation Environment in the Atmospheric Boundary Layer over the Persian Gulf  

Science Journals Connector (OSTI)

Strong vertical gradients at the top of the atmospheric boundary layer affect the propagation of electromagnetic waves and can produce radar ducts. A three-dimensional, time-dependent, nonhydrostatic numerical model was used to simulate the ...

B. W. Atkinson; J-G. Li; R. S. Plant

2001-03-01T23:59:59.000Z

9

Lidar-Observed Stress Vectors and Veer in the Atmospheric Boundary Layer  

Science Journals Connector (OSTI)

This study demonstrates that a pulsed wind lidar is a reliable instrument for measuring angles between horizontal vectors of significance in the atmospheric boundary layer. Three different angles are considered: the wind turning, the angle between ...

Jacob Berg; Jakob Mann; Edward G. Patton

2013-09-01T23:59:59.000Z

10

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature  

E-Print Network [OSTI]

(WRF) and COAMPS atmospheric models. The SST-induced wind response is assessed from eight simulations of the surface wind relative to the SST gradient. #12;3 1. Introduction Positive correlations of local surfaceModeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Natalie

Kurapov, Alexander

11

Boundary Layer  

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

Sea Spray on the Thermodynamics of the Hurricane Boundary Layer For original submission and image(s), see ARM Research Highlights http:www.arm.govsciencehighlights Research...

12

Modelling the Effect of Ocean Waves on the Atmospheric and Ocean Boundary Layers  

Science Journals Connector (OSTI)

Ocean waves, in addition to generating direct forces on fixed and floating offshore wind generator structures, also have significant indirect effects via their influence on the atmospheric and oceanic boundary layers above and below the water surface. In the atmospheric boundary layer the waves act as roughness elements, influencing the turbulent flow and the vertical wind speed profile, and induce oscillatory motions in the airflow. Spray droplets from breaking wave crests enhance structure corrosion, and may lead to icing under low-temperature conditions. Below the water surface, the air-sea momentum flux and mechanical energy flux, mediated by the waves and wave-generated turbulence, affect the vertical profiles of ocean current, temperature, and salinity. Effects include modifying the structural forces and dynamics, and the movement and dispersion of marine organisms, pollutants, and air bubbles generated by breaking waves, with consequences for fouling, corrosion, and environmental impact. Measurement of relevant airflow and ocean dynamical variables is also challenging, as near the water surface it is often necessary to use instruments mounted on moving measurement platforms. Modelling such boundary-layer effects is a complex task, as a result of feedbacks between the airflow, wave field, current field, and turbulence in the atmosphere and the ocean. We present results from a coupled model study of the North Sea and Norwegian Sea area. We employ a mesoscale atmosphere model (WRF) and a spectral wave model (WAM), running simultaneously and coupled using the open-source coupler MCEL which can interpolate between different model grids and time steps. To investigate the ocean boundary layer, one-dimensional model experiments were performed for an idealized Ekman layer and for locations in the North Sea, Atlantic Ocean, and the northern Pacific, using a version of the GOTM turbulence model, modified to take wave dynamics into account. Results show how the wave field alters the ocean's aerodynamic roughness and the air–sea momentum flux, depending on the relation between the surface wind speed and the propagation speed of the wave crests (the wave age). These effects will feed back into the airflow, wind speed and turbulence profile in the boundary layer. The ocean dynamics experiments showed results which compare favourably with field observations from the LOTUS3 and PROVESS experiments in the north Atlantic and North Sea, and Ocean Weather Station Papa in the Pacific Ocean.

Alastair D. Jenkins; Mostafa Bakhoday Paskyabi; Ilker Fer; Alok Gupta; Muralidhar Adakudlu

2012-01-01T23:59:59.000Z

13

Continuous daily observation of the marine atmospheric boundary layer over the Kuroshio current by a helicopter shuttle service  

Science Journals Connector (OSTI)

We describe a new initiative in which in-situ observations of the marine atmospheric boundary layer (MABL) are made by a helicopter shuttle connecting six islands south of Tokyo. This observation method aims to make frequent measurements of ...

Youichi Tanimoto; Kou Shimoyama; Shoichi Mori

14

Characteristics of wind speed and wind direction in the atmospheric boundary layer on the southern coast of Bulgaria  

Science Journals Connector (OSTI)

The characteristics of wind speed and wind direction in the boundary atmospheric layer measured ... meteorological station. The sodar measurement data on wind parameters at different heights in different months ....

M. A. Novitskii; L. K. Kulizhnikova…

2012-03-01T23:59:59.000Z

15

Separation of climatological imprints of the Kuroshio Extension and Oyashio fronts on the wintertime atmospheric boundary layer: Their sensitivity to SST resolution prescribed for atmospheric reanalysis  

Science Journals Connector (OSTI)

Mesoscale structures of the wintertime marine atmospheric boundary layer (MABL) as climatological imprints of oceanic fronts within the Kuroshio-Oyashio Extension (KOE) region east of Japan are investigated, by taking advantage of high horizontal ...

Ryusuke Masunaga; Hisashi Nakamura; Takafumi Miyasaka; Kazuaki Nishii; Youichi Tanimoto

16

Atmospheric Environment 34 (2000) 2851}2863 Resolution of pollutant concentrations in the boundary layer  

E-Print Network [OSTI]

Atmospheric Environment 34 (2000) 2851}2863 Resolution of pollutant concentrations in the boundary 1999 Abstract This paper investigates the solution of a 3D atmospheric dispersion problem using a time to solve the atmospheric di!usion equation. Preliminary studies of dispersion from a single source

Utah, University of

17

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

SciTech Connect (OSTI)

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.

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

2012-01-01T23:59:59.000Z

18

An experimental study of the airflow over a hill in the atmospheric boundary layer  

Science Journals Connector (OSTI)

Between 1975 and 1977, the Centre Scientifique et Technique du Bâtiment (CSTB) carried out a study of the overspeed effect over a hill in the surface boundary layer. The hill in question was situated in open c...

C. Sacré

1979-11-01T23:59:59.000Z

19

LES of a Spatially Developing Atmospheric Boundary Layer: Application of a Fringe Method for the Stratocumulus to Shallow Cumulus Cloud Transition  

Science Journals Connector (OSTI)

An arrangement of a large-eddy simulation (LES) is described that facilitates a spatially developing thermally stratified atmospheric boundary layer (ABL). When the inflow and outflow boundary conditions are specified, the LES of stably stratified ...

M. Inoue; G. Matheou; J. Teixeira

2014-09-01T23:59:59.000Z

20

Application of acoustic sounding to estimating fusion in an atmospheric boundary layer  

Science Journals Connector (OSTI)

An acoustic sounder system can be configured to provide estimates of the vertical profile of velocity and dissipation rate of kinetic and potential energy. A method based on the concepts of boundary?layer similarity theory is outlined by which the characteristicvelocity in a freely convective boundary layer is deduced from the inversion height and the asymptotic value of the dissipation rate of kinetic energy near the inversion. These values in conjunction with the mean velocity are used to establish the normalized heights downwind and cross?wind distances and cross?wind integrated concentrations. The normalized lateral and vertical standard deviations are then deduced from empirically established laboratory relationships for nonbuoyant particulates. Preliminary analysis indicate a similar methodology may be applicable to the stable boundary layer.

Bryan R. Kerman

1976-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Large-Eddy Simulation of Stratified Turbulence. Part II: Application of the Stretched-Vortex Model to the Atmospheric Boundary Layer  

Science Journals Connector (OSTI)

The buoyancy-adjusted stretched-vortex subgrid-scale (SGS) model is assessed for a number of large-eddy simulations (LESs) corresponding to diverse atmospheric boundary layer conditions. The cases considered are free convection, a moderately ...

Georgios Matheou; Daniel Chung

2014-12-01T23:59:59.000Z

22

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

E-Print Network [OSTI]

, increase in w by removing the dummy -1 bases was 4. 2 cm/sec , and u for these runs was 330 cm/sec -I ?? Using sin [w/u] as a measure of the tilt of the wind field gave an inclination of . 72', in fair agreement with KAIMAL's relation. Therefore.... '?'illlam H. Clayton Direct measurements of the eddy fluxes of mo. . . entum and heat were. made in the atmospheric boundary layer simultaneously with measurements of the profiles of average wind velocity and tempera- ture to evaluate the capability...

Jensen, Paul Alfred

2012-06-07T23:59:59.000Z

23

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

E-Print Network [OSTI]

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.

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

2013-01-01T23:59:59.000Z

24

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

E-Print Network [OSTI]

Atmospheric Sciences Division, Brookhaven National Laboratory, Upton, NY 11973; f Sustainable Energy Systems Group, Environmental Energy Technologies Division, E. O. Lawrence Berkeley National Laboratory, Berkeley agreement with measurements from Mexico City and Atlanta. amines | atmospheric aerosol | climate forcing

25

Boundary Layer Flow Control With a One Atmosphere Uniform Glow Discharge Surface Plasma  

Science Journals Connector (OSTI)

Low speed wind tunnel data have been acquired for planar panels covered by a uniform, glow-discharge surface plasma in atmospheric pressure air known as the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP). Streamwise and spanwise arrays of flush, ...

Roth J. Reece; Sherman Daniel M.; Wilkinson Stephen P.

1998-01-01T23:59:59.000Z

26

Ice at the Interface: Atmosphere-Ice-Ocean Boundary Layer Processes and Their Role in Polar Change---Workshop Report  

SciTech Connect (OSTI)

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.

Hunke, Elizabeth C. [Los Alamos National Laboratory

2012-07-23T23:59:59.000Z

27

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations  

Science Journals Connector (OSTI)

The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current region of the Southern Ocean using the Weather Research and Forecasting (WRF) Model and the U.S. Navy Coupled Ocean–Atmosphere Mesoscale ...

Natalie Perlin; Simon P. de Szoeke; Dudley B. Chelton; Roger M. Samelson; Eric D. Skyllingstad; Larry W. O’Neill

2014-11-01T23:59:59.000Z

28

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

E-Print Network [OSTI]

investigating the source, transport, and isotope fractionation of water vapor in the atmospheric cospectral similarity for temperature and water vapor isotope fluxes. mixing ratio generator Routine field use in water vapor isotope research. The unit generates a stable water vapor mixing ratio by measuring

Minnesota, University of

29

Preliminary Results from Long-Term Measurements of Atmospheric Moisture in the Marine Boundary Layer in the Gulf of Mexico*  

Science Journals Connector (OSTI)

Measurements of boundary layer moisture have been acquired from Rotronic MP-100 sensors deployed on two National Data Buoy Center (NDBC) buoys in the northern Gulf of Mexico from June through November 1993. For one sensor that was retrieved ...

Laurence C. Breaker; David B. Gilhousen; Lawrence D. Burroughs

1998-06-01T23:59:59.000Z

30

ARM - Measurement - Planetary boundary layer height  

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

govMeasurementsPlanetary boundary layer height govMeasurementsPlanetary boundary layer height ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Planetary boundary layer height Top of the planetary boundary layer; also known as depth or height of the mixing layer. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments VCEIL : Vaisala Ceilometer External Instruments NCEPGFS : National Centers for Environment Prediction Global Forecast System Field Campaign Instruments

31

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

E-Print Network [OSTI]

of the pollution in the atmosphere originates from emissions in the atmospheric boundary layer, the region; 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

Dacre, Helen

32

Magnetohydrodynamic boundary layer control system  

SciTech Connect (OSTI)

Accordingly, it is an object of the present invention to provide an active boundary layer control system which is lightweight, operates with low in put power, and occupies little physical space. It is a further object of the invention to provide a boundary layer control system which is robust and can be operated in a damaged condition without creating a hazard to the vehicle. It is yet object of the invention to provide a magnetohydrodynamic (MHD) boundary layer control system for marine vehicles which provides a force directly on the water adjacent to the vehicle hull to provide flow separation control. The invention is a boundary layer control system using magnetic and electric fields interaction to providea driving force to energize boundary layer flow around a marine vehicle. A plurality of magnets are located circumferentially around the hull. Seawater electrodes are placed between each of the magnets and between the poles of each magnet. The resulting interaction of the electric and magnetic fields produces a Lorentz force which reduces the turbulence and may even relaminarize the flow in the boundary layer.

Meng, J.C.

1993-02-11T23:59:59.000Z

33

Transport Processes in the Tropical Warm Pool Boundary Layer. Part II: Vertical Structure and Variability  

Science Journals Connector (OSTI)

The structure of the intertropical convergence zone ITCZ cloud-topped marine atmospheric boundary layer away from the most intense mesoscale convective systems during the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response ...

A. G. Williams; J. M. Hacker; H. Kraus

1997-08-01T23:59:59.000Z

34

A first order geometric auto regressive process for boundary layer wind speed simulation  

Science Journals Connector (OSTI)

Under certain conditions the first order geometric auto regressive (AR) process has statistical properties similar to atmospheric boundary layer wind speed. In this contribution, we investigate ... this stochas...

T. Laubrich; H. Kantz

2009-08-01T23:59:59.000Z

35

About First Order Geometric Auto Regressive Processes for Boundary Layer Wind Speed Simulation  

Science Journals Connector (OSTI)

Under certain conditions the first order geometric auto regressive process has statistical properties similar to atmospheric boundary layer wind speed. In this contribution, we investigate ... this stochastic pro...

Thomas Laubrich; Holger Kantz

2010-01-01T23:59:59.000Z

36

Boundary-Layer Effects in Reverse Osmosis  

Science Journals Connector (OSTI)

Boundary-Layer Effects in Reverse Osmosis ... In FO, water is extracted from a feed solution using the high osmotic pressure of a hypertonic solution that flows on ... ...

Ulrich Merten; H. K. Lonsdale; R. L. Riley

1964-01-01T23:59:59.000Z

37

ARM - Field Campaign - Boundary Layer Cloud IOP  

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

govCampaignsBoundary Layer Cloud IOP govCampaignsBoundary Layer Cloud IOP Campaign Links Campaign Images Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Boundary Layer Cloud IOP 2005.07.11 - 2005.08.07 Lead Scientist : William Shaw For data sets, see below. Description Investigators from Pacific Northwest National Laboratory, in collaboration with scientists from a number of other institutions, carried out a month of intensive measurements at the ARM Climate Research Facility on the North Slope of Alaska in the summer of 2005. The purpose of these measurements was to determine how much the arctic land surface modifies the way low clouds reflect, absorb, and transmit solar and infrared radiation. This is an important problem because arctic clouds play a prominent role in

38

Processes in the Magnetospheric Boundary Layer  

Science Journals Connector (OSTI)

The earth's magnetopause is a boundary that separates two distinctly different plasma regions - the (shocked) solar wind and the hot magnetospheric plasma controlled by the terrestrial magnetic field. Through this boundary a small fraction of the solar wind energy and momentum is transferred. This energy powers all major plasma processes within the magnetosphere. Thus, a proper understanding of boundary layer phenomena is of vital importance for magnetospheric plasma physics. An overview of the two main theories put forward to explain the energy and momentum transfer processes near the earth's magnetospheric boundary - magnetic merging/reconnection and the boundary layer dynamo model - will be given. The theories are compared with recent in situ plasma observations in the vicinity of the magnetopause. It is suggested here that internal processes in the magnetospheric boundary layer are decisive for the transfer of energy and momentum into the inner magnetosphere, which is coupled to the high latitude ionosphere. On the other hand, external conditions at the magnetopause proper determine the coupling to the solar wind. Means of relating transient magnetic field signatures, such as flux transfer events, with plasma dynamo induced currents will also be discussed.

Rickard Lundin

1987-01-01T23:59:59.000Z

39

Development and propagation of a pollution gradient in the marine boundary layer during INDOEX (1999)  

E-Print Network [OSTI]

Development and propagation of a pollution gradient in the marine boundary layer during INDOEX (1999) Matthew Simpson and Sethu Raman Department of Marine, Earth, and Atmospheric Sciences, North and propagation of a pollution gradient in the marine boundary layer over the Arabian Sea during the Intensive

Raman, Sethu

40

TURBULENCE IN SUPERSONIC AND HYPERSONIC BOUNDARY LAYERS  

E-Print Network [OSTI]

TURBULENCE IN SUPERSONIC AND HYPERSONIC BOUNDARY LAYERS Alexander J. Smits and M. Pino Martin in supersonic and hypersonic flow where the effects of compressibility have a direct influence on the turbulence. Experimental and DNS results are presented and compared. Key words: Turbulence, supersonic, hypersonic, shocks

MartĂ­n, Pino

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Viscous drag reduction in boundary layers  

SciTech Connect (OSTI)

The present volume discusses the development status of stability theory for laminar flow control design, applied aspects of laminar-flow technology, transition delays using compliant walls, the application of CFD to skin friction drag-reduction, active-wave control of boundary-layer transitions, and such passive turbulent-drag reduction methods as outer-layer manipulators and complex-curvature concepts. Also treated are such active turbulent drag-reduction technique applications as those pertinent to MHD flow drag reduction, as well as drag reduction in liquid boundary layers by gas injection, drag reduction by means of polymers and surfactants, drag reduction by particle addition, viscous drag reduction via surface mass injection, and interactive wall-turbulence control.

Bushnell, D.M.; Hefner, J.N.

1990-01-01T23:59:59.000Z

42

Laminar boundary layers in convective heat transport  

E-Print Network [OSTI]

We study Rayleigh-Benard convection in the high-Rayleigh-number and high-Prandtl-number regime, i.e., we consider a fluid in a container that is exposed to strong heating of the bottom and cooling of the top plate in the absence of inertia effects. While the dynamics in the bulk are characterized by a chaotic convective heat flow, the boundary layers at the horizontal container plates are essentially conducting and thus the fluid is motionless. Consequently, the average temperature exhibits a linear profile in the boundary layers. In this article, we rigorously investigate the average temperature and oscillations in the boundary layer via local bounds on the temperature field. Moreover, we deduce that the temperature profile is indeed essentially linear close to the horizontal container plates. Our results are uniform in the system parameters (e.g. the Rayleigh number) up to logarithmic correction terms. An important tool in our analysis is a new Hardy-type estimate for the convecting velocity field, which can be used to control the fluid motion in the layer. The bounds on the temperature field are derived with the help of local maximal regularity estimates for convection-diffusion equations.

Christian Seis

2012-12-12T23:59:59.000Z

43

On the Representation of High-Latitude Boundary Layer Mixed-Phase Cloud in the ECMWF Global Model  

Science Journals Connector (OSTI)

Supercooled liquid water (SLW) layers in boundary layer clouds are abundantly observed in the atmosphere at high latitudes, but remain a challenge to represent in numerical weather prediction (NWP) and climate models. Unresolved processes such as ...

Richard M. Forbes; Maike Ahlgrimm

2014-09-01T23:59:59.000Z

44

Atmospheric Boundary SUMMARY: This chapter considers the physics of the lowest portion of the  

E-Print Network [OSTI]

, water the crops and pro- vide a freshwater supply to us on land. Second, turbulent mixing generates and reaches the surface. Land surface, by contrast, is #12;12.1. LOWER ATMOSPHERE 167 opaque, while waterChapter 12 Atmospheric Boundary Layer SUMMARY: This chapter considers the physics of the lowest

Cushman-Roisin, Benoit

45

Characterization of wind noise by the boundary layer meteorology  

Science Journals Connector (OSTI)

The fluctuations in pressure generated by turbulent motions of the atmospheric boundary layer are a principal noise source in outdoor acoustic measurements. The mechanics of wind noise involve not only stagnation pressure fluctuations at the sensor but also shearing and self-interaction of turbulence throughout the flow particularly at low frequencies. The contributions of these mechanisms can be described by the boundary-layer meteorology. An experiment was conducted at the National Wind Institute's 200-meter meteorological tower located outside Lubbock Texas in the Llano Estacado region. For two days a 44-element 400-meter diameter array of unscreened NCPA-UMX infrasound sensors recorded wind noise continuously while the tower and a Doppler SODAR measured vertical profiles of the boundary layer. Analysis of the fluctuating pressure with the meteorological data shows that the statistical structure of wind noise depends on both mean velocity distribution and buoyant stability. The root-mean-square pressure exhibits distinct scalings for stable and unstable stratification. Normalization of the pressure power spectral density depends on the outer scales. In stable conditions the kurtosis of the wind noise increases with Reynolds number. Measures of noise intermittency are explored with respect to the meteorology.

2014-01-01T23:59:59.000Z

46

Boundary layer response to wind gusts  

E-Print Network [OSTI]

of the wind tunnel sir stress caused by tbe addition of the in)actors, the decision was osde to use flew visuslstion ?echniques to detsreine if it wss possible to generate s lsuinar boundary layer on the flat plate. Loup black wss suspended in light..., 8. The data reduction procedure used in this thesis follcwed pxi- maxily the procsduxes of rafax'ence 8. Velocity fluctuations were detected using the constant current technique and computed based on square wave calibration. yor the constant...

Morland, Bruce Thomas

1968-01-01T23:59:59.000Z

47

Numerical Study of Freestream Waves Receptivity and Nonlinear Breakdown in Hypersonic Boundary Layer  

E-Print Network [OSTI]

Numerical Methods for Hypersonic Boundary Layer Stability.of Instability in a Hypersonic Boundary Layer. TheoreticalA. P. , Receptivity of Hypersonic Boundary Layer to Wall

Lei, Jia

2013-01-01T23:59:59.000Z

48

Model of Trace Gas Flux in Boundary Layer  

E-Print Network [OSTI]

Mathematical model of the turbulent flux in the three-layer boundary system is presented. Turbulence is described as a presence of the nonzero vorticity. Generalized advection-diffusion-reaction equation is derived for arbitrary number components in the flux. The fluxes in the layers are objects for matching requirements on the boundaries between the layers.

I. I. Vasenev; I. S. Nurgaliev

2013-03-04T23:59:59.000Z

49

A Climatological Study of Boundary Layer Wind Speed Using a Meso-?-Scale Higher-Order Closure Model  

Science Journals Connector (OSTI)

A mesoscale higher-order closure atmospheric boundary layer model has been used to get more detailed information than is possible from observations regarding horizontal and vertical variations of the wind in an area in southeastern Sweden. To ...

Hans Bergström

1996-08-01T23:59:59.000Z

50

Acoustic sounding of the tropical marine boundary layer during GATE  

Science Journals Connector (OSTI)

A vertically pointed monostatic acoustic sounder was installed on the NOAA ShipOCEANOGRAPHER during the Global Atmospheric Research Program Atlantic Tropical Experiment (GATE). The sounderantenna was mounted on a gyrocontrolled platform to compensate for the ship'spitch and roll motions. Extensive measures such as mounting the antenna assembly on a vibration isolator and installing absorbing cuffs had to be taken to reduce interference by ship?generated noise. Back?scattered acoustic data obtained from up to 850 m height describe the tropical marine boundary layer in unique and hitherto unseen detail. During undisturbed weather conditions the facsimile record showed convective plumes rising from the surface of the water up to 400 m. Storm?generated disturbances resulted in a substantial modification of the boundary layer; low?level multilayered undulating inversions formed from cool outflow currents. The inversions persisted for up to 16 hours. Low?level patchy cumulus clouds produced characteristic hummock?shaped acoustic echoes. Analysis of the Doppler frequency shift of the returns allowed the determination of vertical velocities within these clouds and underlying convective plumes.

P. A. Mandics; J. E. Gaynor; F. F. Hall Jr.

1976-01-01T23:59:59.000Z

51

Turbulence Structure and Wall Signature in Hypersonic Turbulent Boundary Layer  

E-Print Network [OSTI]

Turbulence Structure and Wall Signature in Hypersonic Turbulent Boundary Layer Yin-Chiu Kan , Clara and hypersonic turbulent boundary layer datasets from direct numerical simulation (DNS). Contour plots and Marusic5 and Mathis, Hutchins and Marusic16 ). In contrast to supersonic and hypersonic flow regimes

MartĂ­n, Pino

52

Numerical Simulation of the Wave Bottom Boundary Layer  

E-Print Network [OSTI]

are coupled to the wave cycle; phases of accelerating ow organize the boundary layer structure, decelerating; Zhao and Anastasiou, 1993; Feddersen and Guza, 2000; and Rankin and Hires, 2000]; others have the boundary layer and induce an in ectional instability at ow reversal, while accelerations tend to organize

Slinn, Donald

53

Trans Boundary Transport of Pollutants by Atmospheric Mineral  

E-Print Network [OSTI]

Trans Boundary Transport of Pollutants by Atmospheric Mineral Dust Y I G A L E R E L , * , U R I D, and solid constituents in the atmosphere (3-11). Uptake of pollutants by mineral dust has been shown Jerusalem, Israel The transport of anthropogenic pollution by desert dust in the Eastern Mediterranean

Einat, Aharonov

54

Boundary Layer Dynamics and Cross-Equatorial Hadley Circulation  

Science Journals Connector (OSTI)

The behavior of the Hadley circulation is analyzed in the context of an idealized axisymmetric atmosphere. It is argued that the cross-equatorial Hadley circulation exhibits two different regimes depending on the depth of the planetary boundary ...

Olivier Pauluis

2004-05-01T23:59:59.000Z

55

Performance of an Eddy Diffusivity–Mass Flux Scheme for Shallow Cumulus Boundary Layers  

Science Journals Connector (OSTI)

Comparisons between single-column (SCM) simulations with the total energy–mass flux boundary layer scheme (TEMF) and large-eddy simulations (LES) are shown for four cases from the Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) ...

Wayne M. Angevine; Hongli Jiang; Thorsten Mauritsen

2010-07-01T23:59:59.000Z

56

Performance of a boundary layer ingesting propulsion system  

E-Print Network [OSTI]

This thesis presents an assessment of the aerodynamic performance of an aircraft propulsion system, with embedded engines, in the presence of aircraft fuselage boundary layer ingestion (BLI). The emphasis is on defining ...

Plas, Angélique (Angélique Pascale)

2006-01-01T23:59:59.000Z

57

Examining A Hypersonic Turbulent Boundary Layer at Low Reynolds Number  

E-Print Network [OSTI]

The purpose of the current study was to answer several questions related to hypersonic, low Reynolds number, turbulent boundary layers, of which available data related to turbulence quantities is scarce. To that end, a unique research facility...

Semper, Michael Thomas

2013-05-15T23:59:59.000Z

58

Scaling Laws for the Heterogeneously Heated Free Convective Boundary Layer  

Science Journals Connector (OSTI)

The heterogeneously heated free convective boundary layer (CBL) is investigated by means of dimensional analysis and results from large-eddy simulations (LES) and direct numerical simulations (DNS). The investigated physical model is a CBL that ...

Chiel C. van Heerwaarden; Juan Pedro Mellado; Alberto De Lozar

2014-11-01T23:59:59.000Z

59

Mixing Line Analysis of Clouds and Cloudy Boundary Layers  

Science Journals Connector (OSTI)

The diagnostic study of the thermodynamic structure of nonprecipitating clouds and cloudy boundary layers is formulated using a mixing line and saturation point approach. A parametric model for the mean structure is developed as a tool for ...

Alan K. Betts

1985-12-01T23:59:59.000Z

60

Upstream influence in boundary layers 45 years ago  

Science Journals Connector (OSTI)

...0) = M2 2 ikH(k); (2.19) because M(y) takes the value M2, given by equation (2.15), at the location (here rede ned as y = 0) where the inviscid boundary condition has to be satis ed. Also, at the edge y = of the boundary layer, disturbances...

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Dynamic Balances in a Wavy Boundary Layer  

Science Journals Connector (OSTI)

The authors analyze the influence of waves on the budgets of momentum flux and kinetic energy in the atmospheric flow over sea surface waves and use the findings to reinterpret the results from the earlier empirical studies on the subject. This ...

Tihomir Hristov; Jesus Ruiz-Plancarte

2014-12-01T23:59:59.000Z

62

Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics  

SciTech Connect (OSTI)

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.

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

2013-10-01T23:59:59.000Z

63

A dual mass flux framework for boundary layer convection  

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

A dual mass flux framework for boundary layer convection A dual mass flux framework for boundary layer convection Neggers, Roel European Centre for Medium-range Weather Forecasts (ECMWF) Category: Modeling A new convective boundary layer scheme is presented that is currently being developed for the Integrated Forecasting System (IFS) of the European Centre for Medium-range Weather Forecasts (ECMWF). Part of the total turbulent flux is modeled through advective mass flux by multiple updrafts, initialized at the surface. Two groups of updrafts are explicitly represented; i) updrafts that never reach their lifting condensation level, and ii) updrafts that condensate and become cloudy. Key new ingredient is the flexibility of the associated updraft area fractions, as a function of model state. As a result, an extra degree of freedom is introduced in the

64

ARM - Field Campaign - Boundary Layer CO2 Using CW Lidar  

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

govCampaignsBoundary Layer CO2 Using CW Lidar govCampaignsBoundary Layer CO2 Using CW Lidar Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Boundary Layer CO2 Using CW Lidar 2005.05.21 - 2005.05.24 Lead Scientist : Michael Dobbs Description Overflights Underway at ACRF Southern Great Plains Site (M.Dobbs/J.Liljegren) Science collaborators at ITT Industries and the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) conducted flights over the Central Facility at ACRF's Southern Great Plains (SGP) site as part of the Climate Sources and Sink (CO2) Intensive Operational Period (IOP), using a CW lidar. The objective of the flights was to validate, by demonstration and comparison with SGP ground observations, the performance of the ITT system when used in conjunction with retrieval

65

Distributed boundary layer suction utilizing wing tip effects  

E-Print Network [OSTI]

that this is not the case. The rotational force at the tip accounts for the suction power. Since this power is utilized to suck air from the boundary, energy is dissipated, thereby weakening the vortex strength. Providing this assumption is valid, the effect would... was done. TABLE OF CONTENTS Chapter Page INTRODUCTION OBJECTIVES AND SCOPE EXPERIMENTAL FACILITY AND PROCEDURES Wing Model . Wake Rake Boundary Layer Probe . . Multiple Tube Manometers Wind Tunnel and Related Equipment Procedures Computation...

Edwards, Jay Thomas

2012-06-07T23:59:59.000Z

66

Posters Triggering of Boundary Layer Cumulus Clouds Over a Heterogeneous Surface  

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

5 5 Posters Triggering of Boundary Layer Cumulus Clouds Over a Heterogeneous Surface K. Schrieber, R. Stull, and Q. Zhang Boundary Layer Research Team Department of Atmospheric and Oceanic Science University of Wisconsin Madison, Wisconsin Complex multimodal joint frequency distributions of LCL height versus θ v in surface-layer air over a large heteroge- neous surface area are modeled as the superposition of simpler mono-modal distributions. These simpler distri- butions, which apply to quasi-homogeneous subdomains, are approximated with bivariate distribution models. The shape of each of these modeled distributions depends on variations of the Bowen ratio and heat input forcings. These forcings are a function of the landscape, insolation, surface albedo, cloud-shading, soil moisture, and other

67

Carbon transport in the bottom boundary layer. Final report  

SciTech Connect (OSTI)

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?

Agrawal, Y.C.

1998-10-05T23:59:59.000Z

68

Turbulence Structure and Wall Signature in Hypersonic Boundary Layer  

E-Print Network [OSTI]

Turbulence Structure and Wall Signature in Hypersonic Boundary Layer Yin-Chiu Kan , Beekman Izaak and low- speed features, found in subsonic experiments, are present in our supersonic and hypersonic and hypersonic regimes due to the lack of detailed flow field data, and the studies have been mostly restricted

MartĂ­n, Pino

69

OFFSHORE BOUNDARY-LAYER MODELLING H. Bergstrm1  

E-Print Network [OSTI]

OFFSHORE BOUNDARY-LAYER MODELLING H. Bergström1 and R. Barthelmie2 1) Uppsala Univ., Dept. of Earth) of the ENDOW (EfficieNt Development of Offshore Windfarms) project, where the objectives are to provide currently be incorporated into a wind farm design tool. The offshore thermal stratification climate is also

70

Boundary layer transition as a source of noise and vibration  

Science Journals Connector (OSTI)

When laminar flow over a rigid or flexible surface becomes unstable an intermittent flow state occurs. This intermittent flow regime called the transition region is where turbulent spots are created and then grow as they convect downstream at a velocity typically equal to 0.7 times the free?stream velocity. The spots eventually coalesce to form the beginning of the fully developed turbulent boundary layer. The statistics of the velocity or pressure fluctuations in the transition region are essentially stationary in time but nonhomogeneous in the streamwise direction. Fundamentally it has been argued that this region is capable of creating monopole sound radiation e.g. Lauchle [J. Acoust. Soc. Am. 69 665–671 (1981)] and Sornette and Lagier [Acustica 55 255–267 (1984)]. Also it has been suspected that a transitional boundary layer can induce wall vibrations. These issues have been under study for some time. We have completed a set of measurements on the. space?time statistics of turbulent spots in a naturally occurring transition zone and from them developed an analytical model for the wavenumber?frequency spectrum of the pressure fluctuations. Based on this model it appears that the transition zone wall pressure is less intense than that of a fully developed turbulent layer by a factor equal approximately to the intermittency factor. This presentation will review the current research findings on wall pressure fluctuations and radiated sound caused by boundary layer transition. [Work supported by Applied Research Laboratory under NAVSEA contract.

Gerald C. Lauchle; M. A. Josserand

1986-01-01T23:59:59.000Z

71

Unexpected vertical wind speed profiles in the boundary layer over the southern North Sea  

Science Journals Connector (OSTI)

Abstract Shallow atmospheric internal boundary layers over the southern part of the North Sea are common. Analysis of one year of meteorological data from the FINO1 research platform in the German Bight reveals that vertical wind speed profiles frequently do not conform to the expected modified logarithmic profile of Monin–Obukhov similarity theory. The wind profiles are mostly characterized by local maxima or kinks within the first 100 m over the sea surface. The data reveals the most frequent occurrence of a single maximum, but multiple maxima are often present, and there are sometimes even reversed profiles with the wind speed decreasing with height. The expected modified logarithmic profile occurs for a minority of cases. The evidence suggests the frequent presence of internal boundary layers that propagate from coastal land masses that surround the North Sea. A census of vertical wind speed profiles is presented that shows how different inflection states are linked with wind speed and atmospheric stability. The kinks are most prevalent in the upper part of the measurement range near the 100 m hub height of modern offshore the wind turbines, so that internal boundary layers represent a possible concern for the offshore wind energy industry in the North Sea region.

Anthony J. Kettle

2014-01-01T23:59:59.000Z

72

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. BrĂĽmmer 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

73

Four-Dimensional Data Assimilation Boundary-Layer Observations Over the Southern  

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

Boundary-Layer Observations Over the Southern Boundary-Layer Observations Over the Southern Great Plains Cloud and Radiation Testbed Site During the November Flux-Profiler Test s. P. Oncley and J. Van Baelen National Center for Atmospheric Research(8) Boulder, CO 80307-3000 Introduction Resu Its Figure 1 shows the raw data from two of the ten profile patterns flown during this experiment. Each aircraft profile consisted of a descent to the profiler site followed by 3-5 legs at increasing heights. Note that because of this flightpattern, the downward and upward profiles may differ due to temporal changes during the time of the pattern (about 50 minutes) and due to horizontal gradients. The profiler was operated in DBS mode alternating between two sets of three beams. Thus, two sets of consensus- averaged winds were available. Finally, several

74

Multi-dimensional Longwave Forcing of Boundary Layer Cloud Systems  

SciTech Connect (OSTI)

The importance of multi-dimensional (MD) longwave radiative effects on cloud dynamics is evaluated in a large eddy simulation (LES) framework employing multi-dimensional radiative transfer (Spherical Harmonics Discrete Ordinate Method —SHDOM). Simulations are performed for a case of unbroken, marine boundary layer stratocumulus and a broken field of trade cumulus. “Snapshot” calculations of MD and IPA (independent pixel approximation —1D) radiative transfer applied to LES cloud fields show that the total radiative forcing changes only slightly, although the MD effects significantly modify the spatial structure of the radiative forcing. Simulations of each cloud type employing MD and IPA radiative transfer, however, differ little. For the solid cloud case, relative to using IPA, the MD simulation exhibits a slight reduction in entrainment rate and boundary layer TKE relative to the IPA simulation. This reduction is consistent with both the slight decrease in net radiative forcing and a negative correlation between local vertical velocity and radiative forcing, which implies a damping of boundary layer eddies. Snapshot calculations of the broken cloud case suggest a slight increase in radiative cooling, though few systematic differences are noted in the interactive simulations. We attribute this result to the fact that radiative cooling is a relatively minor contribution to the total energetics. For the cloud systems in this study, the use of IPA longwave radiative transfer is sufficiently accurate to capture the dynamical behavior of BL clouds. Further investigations are required in order to generalize this conclusion for other cloud types and longer time integrations. 1

Mechem, David B.; Kogan, Y. L.; Ovtchinnikov, Mikhail; Davis, Anthony B; Evans, K. F.; Ellingson, Robert G.

2008-12-20T23:59:59.000Z

75

Improving Subtropical Boundary Layer Cloudiness in the 2011 NCEP GFS  

SciTech Connect (OSTI)

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.

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

2014-09-23T23:59:59.000Z

76

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

77

Simulation of bubble migration in a turbulent boundary layer M. Mattson and K. Mahesha  

E-Print Network [OSTI]

Simulation of bubble migration in a turbulent boundary layer M. Mattson and K. Mahesha Aerospace of bubbles injected into a turbulent boundary layer. The Reynolds number of the turbulent boundary layer varies from 420 Re 1800, and the bubble Reynolds number Reb 1. Simulation parameters were chosen to match

Mahesh, Krishnan

78

Transition in Hypersonic Boundary Layers: Role of Dilatational Waves  

E-Print Network [OSTI]

Transition and turbulence production in a hypersonic boundary layer is investigated in a Mach 6 quiet wind tunnel using Rayleigh-scattering visualization, fast-response pressure measurements, and particle image velocimetry. It is found that the second instability acoustic mode is the key modulator of the transition process. The second mode experiences a rapid growth and a very fast annihilation due to the effect of bulk viscosity. The second mode interacts strongly with the first vorticity mode to directly promote a fast growth of the latter and leads to immediate transition to turbulence.

Zhu, Yiding; Yuan, Huijing; Wu, Jiezhi; Chen, Shiyi; Lee, Cunbiao; Gad-el-Hak, Mohamed

2015-01-01T23:59:59.000Z

79

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]

of the bounding surface. Note that the vertical shear caused by the surface generates turbulence, whichEART 265 Lecture Notes: Boundary Layers We're interested here mainly in boundary layers relevant and the surface, thus mediating all interactions between the two. If we look back at the Navier-Stokes equations

Nimmo, Francis

80

Predictive Inner-Outer Model for Turbulent Boundary Layers Applied to Hypersonic DNS Data  

E-Print Network [OSTI]

Predictive Inner-Outer Model for Turbulent Boundary Layers Applied to Hypersonic DNS Data Clara numerical simulation (DNS) data of supersonic and hypersonic turbulent boundaries with Mach 3 and Mach 7, and Martin12­14 on DNS of hypersonic turbulent boundary layers demonstrates the existence of large scale

MartĂ­n, Pino

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Heat transport by laminar boundary layer flow with polymers  

E-Print Network [OSTI]

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.

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

2011-04-23T23:59:59.000Z

82

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

E-Print Network [OSTI]

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

Kudrolli, Arshad

83

Estimation of boundary layer transition noise from velocity measurements  

Science Journals Connector (OSTI)

Velocity measurements of artificially generatedflow structures in the transition region of an incompressible boundary layer with zero pressure gradient are described. These measurements made in a laminar flow water channel allow calculation of the velocity normal to the wall in a turbulent spot. This velocity specifies the linearized boundary condition for the acoustic equation at the wall. The approach relates the radiated noise to fluctuations in the normal velocity at the plate through fluctuations in the displacement thickness. Although this approach has been previously proposed [H. W. Liepmann unpublished (1954) J. Laufer J. E. Ffowcs?Williams and S. Childress AGARDograph 90 39–42 (1964) G. C. Lauchle J. Acoust. Soc. Am. 69 665–671 (1981) G. C. Lauchle ASME NCA 5 31–38 (1989)] it has never been applied. The results of these experiments will be compared to concurrent experiments run in an anechoic wind tunnel. Ultimately this work will be extended to naturally occurring structures in the transition region. [Work supported by ONR under Grant ?N00014?90?J?1365.

Michael H. Krane; Wayne R. Pauley

1991-01-01T23:59:59.000Z

84

Planetary boundary layer depth in Global climate models induced biases in surface climatology  

E-Print Network [OSTI]

The Earth has warmed in the last century with the most rapid warming occurring near the surface in the arctic. This enhanced surface warming in the Arctic is partly because the extra heat is trapped in a thin layer of air near the surface due to the persistent stable-stratification found in this region. The warming of the surface air due to the extra heat depends upon the amount of turbulent mixing in the atmosphere, which is described by the depth of the atmospheric boundary layer (ABL). In this way the depth of the ABL determines the effective response of the surface air temperature to perturbations in the climate forcing. The ABL depth can vary from tens of meters to a few kilometers which presents a challenge for global climate models which cannot resolve the shallower layers. Here we show that the uncertainties in the depth of the ABL can explain up to 60 percent of the difference between the simulated and observed surface air temperature trends and 50 percent of the difference in temperature variability...

Davy, Richard

2014-01-01T23:59:59.000Z

85

Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Stable Boundary Layer. Part 1: The Boundary-Layer Simulation  

Science Journals Connector (OSTI)

Measurements have been made in both a neutral and a stable boundary layer as part of an investigation of the wakes of wind turbines in an offshore environment, in the EnFlo stratified flow wind tunnel. The wor...

Philip E. Hancock; Frauke Pascheke

2014-04-01T23:59:59.000Z

86

Similarity Equations for Wind and Temperature Profiles in the Radix Layer, at the Bottom of the Convective Boundary Layer  

Science Journals Connector (OSTI)

In the middle of the convective boundary layer, also known as the mixed layer, is a relatively thick region where wind speed and potential temperature are nearly uniform with height. Below this uniform layer (UL), wind speed decreases to zero at ...

Edi Santoso; Roland Stull

2001-06-01T23:59:59.000Z

87

E-Print Network 3.0 - atmospheric layers Sample Search Results  

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

layer model Summary: an atmosphere, using the layer model, which incorporates the greenhouse effect of the atmosphere. For now... ,atm + Idown,atm Iup, ground If radiation up and...

88

Interaction between surface and atmosphere in a convective boundary layer /  

E-Print Network [OSTI]

II.4) to measure vertical profiles of wind speed, direction,a larger vertical gradient of horizontal wind-speed in theintense vertical mixing, resulting in constant wind speed,

Garai, Anirban

2013-01-01T23:59:59.000Z

89

Turbulent flux events in a nearly neutral atmospheric boundary layer  

Science Journals Connector (OSTI)

...Abstract Algorithm Technologies Pvt. LtdHebbal...not suited to handling questions of...event detection procedure; a classification...anemometer (Applied Technologies, Inc., USA...figure 3). This procedure results in a...

2007-01-01T23:59:59.000Z

90

Interaction between surface and atmosphere in a convective boundary layer /  

E-Print Network [OSTI]

heat, and thermal conductivity of the ground and grid sizegrid was stretched uniformly to 0.1 m resolution. The heatheat flux) are friction velocity and convective velocity respectively. The grid

Garai, Anirban

2013-01-01T23:59:59.000Z

91

Simulation of Hypersonic Shock Wave/Boundary Layer Interaction Using High Order WENO Scheme  

E-Print Network [OSTI]

Simulation of Hypersonic Shock Wave/Boundary Layer Interaction Using High Order WENO Scheme Yiqing for predicting hypersonic shock wave/boundary layer interaction. The implicit time marching method number of 1.09 Ă? 105 /ft. 1 Introduction Hypersonic aerothermodynamics is one of the most challenging

Zha, Gecheng

92

Study of Emission TurbulenceRadiation Interaction in Hypersonic Boundary Layers  

E-Print Network [OSTI]

Study of Emission Turbulence­Radiation Interaction in Hypersonic Boundary Layers L. Duan and M. P of emission turbulence­radiation interaction in hypersonic turbulent boundary layers, representative interaction between turbulence and emission at the hypersonic environment under investigation. An explanation

MartĂ­n, Pino

93

Assessment of TurbulenceChemistry Interaction in Hypersonic Turbulent Boundary Layers  

E-Print Network [OSTI]

Assessment of Turbulence­Chemistry Interaction in Hypersonic Turbulent Boundary Layers L. Duan of the turbulence­chemistry interaction are performed in hypersonic turbulent boundary layers using direct numerical simulation flowfields under typical hypersonic conditions representative of blunt-body and slender- body

MartĂ­n, Pino

94

Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers  

E-Print Network [OSTI]

Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers Lian Duan and M of the turbulence-chemistry interaction (TCI) are performed in hypersonic tur- bulent boundary layers using direct numerical simulation (DNS) flow fields under typical hypersonic conditions representative of blunt

MartĂ­n, Pino

95

Direct injection of ionospheric O sup + into the dayside low latitude boundary layer  

SciTech Connect (OSTI)

Observations from the AMPTE/Charge Composition Explorer (AMPTE/CCE) indicate the presence of two distinct O{sup +} populations in the dayside subsolar low latitude boundary layer during some periods of northward Interplanetary Magnetic Field (IMF). The first population is O{sup +} convected into the boundary layer from the outer magnetosphere and has been reported previously. It is suggested here that the new, second, O{sup +} population is injected into the dayside boundary layer directly from the high latitude ionosphere. This second population can have a significant density and distinct characteristics such as field-aligned flow relative to boundary layer H{sup +} that modify both the plasma composition and dynamics in the low latitude boundary layer. {copyright} American Geophysical Union 1989

Fuselier, S.A.; Klumpar, D.M.; Peterson, W.K.; Shelley, E.G. (Lockheed Palo Alto Research Laboratory, Palo Alto, California (US))

1989-10-01T23:59:59.000Z

96

DIFFUSION OF A CHEMICAL SPECIES THROUGH A VISCOUS BOUNDARY LAYER  

E-Print Network [OSTI]

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

Keller, J.

2011-01-01T23:59:59.000Z

97

Interface modes and their instabilities in accretion disc boundary layers  

Science Journals Connector (OSTI)

......magnetosphere with and low plasma density, while the...terminated at the stellar atmosphere with high density and...systems and 300 Hz for kHz QPOs in the NS systems...uniformly rotating stellar atmosphere. This simplified model...compressible stellar atmosphere truncating the accretion......

David Tsang; Dong Lai

2009-06-11T23:59:59.000Z

98

Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Stable Boundary Layer: Part 2, the Wake Flow  

Science Journals Connector (OSTI)

Measurements have been made in the wake of a model wind turbine in both a neutral and a stable atmospheric boundary layer, in the EnFlo stratified-flow wind tunnel, between 0.5 and 10 rotor diameters from the ...

Philip E. Hancock; Frauke Pascheke

2014-04-01T23:59:59.000Z

99

The Boulder Atmospheric Observatory  

Science Journals Connector (OSTI)

The Boulder Atmospheric Observatory (BAO) is a unique research facility for studying the planetary boundary layer and for testing and calibrating atmospheric sensors. The facility includes a 300 m tower instrumented with fast- and slow-response ...

J. C. Kaimal; J. E. Gaynor

1983-05-01T23:59:59.000Z

100

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

SciTech Connect (OSTI)

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.

Huang, Hsin-Yuan; Hall, Alex

2013-07-24T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Turbulent boundary-layer control with plasma actuators  

Science Journals Connector (OSTI)

...oscillation. When the non-dimensional...discharge (DBD) plasma actuators in air at atmospheric conditions. 2...corrected for any thermal influence of the plasma based on temperature...2007Airflow control by non-thermal plasma actuatorsJ. Phys...

2011-01-01T23:59:59.000Z

102

Observations of turbulent fluxes and turbulence dynamics in the ocean surface boundary layer  

E-Print Network [OSTI]

This study presents observations of turbulence dynamics made during the low winds portion of the Coupled Boundary Layers and Air-Sea Transfer experiment (CBLAST-Low). Observations were made of turbulent fluxes, turbulent ...

Gerbi, Gregory Peter

2008-01-01T23:59:59.000Z

103

Observational Boundary Layer Energy and Water Budgets of the Stratocumulus-to-Cumulus Transition  

Science Journals Connector (OSTI)

The authors estimate summer mean boundary layer water and energy budgets along a northeast Pacific transect from 35° to 15°N, which includes the transition from marine stratocumulus to trade cumulus clouds. Observational data is used from three A-...

Peter Kalmus; Matthew Lebsock; Joăo Teixeira

2014-12-01T23:59:59.000Z

104

Properties of a Simulated Convective Boundary Layer in an Idealized Supercell Thunderstorm Environment  

Science Journals Connector (OSTI)

Nearly all previous numerical simulations of supercell thunderstorms have neglected surface fluxes of heat, moisture, and momentum. This choice precludes horizontal inhomogeneities associated with dry boundary layer convection in the near-storm ...

Christopher J. Nowotarski; Paul M. Markowski; Yvette P. Richardson; George H. Bryan

2014-11-01T23:59:59.000Z

105

Observations of Turbulence in the Ocean Surface Boundary Layer: Energetics and Transport  

E-Print Network [OSTI]

Observations of turbulent kinetic energy (TKE) dynamics in the ocean surface boundary layer are presented here and compared with results from previous observational, numerical, and analytic studies. As in previous studies, ...

Gerbi, Gregory P.

106

Airship Measurements of Ship’s Exhaust Plumes and Their Effect on Marine Boundary Layer Clouds  

Science Journals Connector (OSTI)

High-resolution aerosol, trace gas, and cloud microphysical measurements were made from an airship during transects across ships exhaust plumes advecting downwind of ships in the marine boundary layer (MBL). This study was part of the Office of ...

G. M. Frick; W. A. Hoppel

2000-08-01T23:59:59.000Z

107

The surface roughness effects in computation of the turbulent boundary layer on slender ship-hull  

Science Journals Connector (OSTI)

An improved version of an integral method for computing turbulent boundary layers on a slender ship-hull with auxiliary shape parameter and lag- ... modifying an approximate technique of scaling model-to-ship rou...

Si-Young Kim; A. K. Lewkowicz

1991-09-01T23:59:59.000Z

108

Quantifying the Hygroscopic Growth of Marine Boundary Layer Aerosols by Satellite-base and Buoy Observations  

Science Journals Connector (OSTI)

In this study, collocated satellite and buoy observations as well as satellite observations over an extended region during 2006-2010 were used to quantify the humidity effects on marine boundary layer (MBL) aerosols. Although the near-surface ...

Tao Luo; Renmin Yuan; Zhien Wang; Damao Zhang

109

Magnetic reconnection structures in the boundary layer of an interplanetary magnetic cloud  

Science Journals Connector (OSTI)

An interplanetary magnetic diffusion region was detected by WIND during 0735-0850 UT on May 15, 1997 when the front boundary layer of a magnetic cloud passed through the spacecraft about 190 earth radii upstre...

Fengsi Wei; Rui Liu; Xueshang Feng…

2004-01-01T23:59:59.000Z

110

Near-surface wind estimates using statistics from a planetary boundary-layer model  

Science Journals Connector (OSTI)

This paper shows the possibilities of a procedure for estimating near-surface wind statistics, by means of the numerical integration of a simple boundary-layer model with a second-order turbulent closure. Stan...

J. C. Labraga

1988-04-01T23:59:59.000Z

111

Nonlinear equilibration of baroclinic eddies : the role of boundary layer processes and seasonal forcing  

E-Print Network [OSTI]

In this thesis, the influence of boundary layer processes and seasonal forcing on baroclinic eddy equilibration is studied to understand how the baroclinic adjustment is modified when taking into account these two factors. ...

Zhang, Yang, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

112

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

E-Print Network [OSTI]

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

Eindhoven, Technische Universiteit

113

A Case Study of Mid-Atlantic Nocturnal Boundary Layer Events during WAVES 2006  

Science Journals Connector (OSTI)

The Water Vapor Variability-Satellite/Sondes (WAVES) 2006 field campaign provided a contiguous 5-day period of concentrated high-resolution measurements to examine finescale boundary layer phenomena under the influence of a summertime subtropical ...

S. Rabenhorst; D. N. Whiteman; D.-L. Zhang; B. Demoz

2014-11-01T23:59:59.000Z

114

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

E-Print Network [OSTI]

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 ...

Anderson, Erik J

2005-01-01T23:59:59.000Z

115

On the magnetospheric boundary layer and solar wind energy transfer into the magnetosphere  

Science Journals Connector (OSTI)

The magnetopause and the magnetospheric boundary layer constitute the interface between the shocked solar wind plasma and the terrestrial magnetic cavity populated by a predominantly hot plasma in the outer po...

Rickard Lundin

1988-01-01T23:59:59.000Z

116

Investigation of the Diurnal Variation of Marine Boundary Layer Cloud Microphysical Properties at the Azores  

Science Journals Connector (OSTI)

A new method has been developed to retrieve the nighttime marine boundary layer (MBL) cloud microphysical properties, which provides a complete 19-month dataset to investigate the diurnal variation of MBL cloud microphysical properties at the ...

Xiquan Dong; Baike Xi; Peng Wu

2014-12-01T23:59:59.000Z

117

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

E-Print Network [OSTI]

INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABI E PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1986 Major Subject: Aerospace Engineering INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABLE PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Approved as to style and content...

Landrum, David Brian

2012-06-07T23:59:59.000Z

118

Effect of a surface boundary layer on an intensifying, downward-propagating vortex  

E-Print Network [OSTI]

EFFECT OF A SURFACE BOUNDARY LAYER ON AN INTENSIFYING, DOWNWARD-PROPAGATING VORTEX A Thesis by VINCENT TUNSTALL WOOD Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1977 Major Subject: Meteorology EFFECT OF A SURFACE BOUNDARY LAYER ON AN INTENSIFYING, DOWNWARD-PROPAGATING VORTEX A Thesis by VINCENT TUNSTALL WOOD Approved as to style and content by: (Chairman of Committee) (Head of Department...

Wood, Vincent Tunstall

2012-06-07T23:59:59.000Z

119

The development of a low velocity wind tunnel with instrumentation for boundary layer investigations  

E-Print Network [OSTI]

THE DEVELOPMENT OF A LOW VELOCITY WIND TUNNEL WITH INSTRUMENTATION FOR BOUNDARY LAYER INVESTIGATIONS A Dissertation B y John Robert Massey Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 1958 Major Subject: Mechanical Engineering THE DEVELOPMENT OF A LOW VELOCITY WIND TUNNEL WITH INSTRUMENTATION FOR BOUNDARY LAYER INVESTIGATIONS A Dissertation By John Robert...

Massey, John Robert

2013-10-04T23:59:59.000Z

120

IMPACT OF BOUNDARY-LAYER CUTTING ON FREE-SURFACE  

E-Print Network [OSTI]

issue into air at atmospheric pressure Working fluids: water and ethanol #12;11 Surface Breakup Efficiency Factor · Radial droplet velocity relative to jet surface · Surface breakup efficiency factor Gives area of liquid surface · Efficiency factor correlation (valid for Wed = 235­270,000) L mass flux

California at San Diego, University of

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Tide-Induced Sediment Resuspension and the Bottom Boundary Layer in an Idealized Estuary with a Muddy Bed  

Science Journals Connector (OSTI)

Sediment transport and bottom boundary layer (BBL) in an idealized estuary with a muddy bed were studied by numerical simulations. The focus was placed on description and prediction of the dynamics of nepheloid layer (a fluid–mud layer) developed ...

X. H. Wang

2002-11-01T23:59:59.000Z

122

THE HORIZONTAL BOUNDARY-LAYER STRUCTURE FOR THE CONVECTIVE REGIME IN A LATERALLY HEATED VERTICAL SLOT  

Science Journals Connector (OSTI)

......for the case when the horizontal walls of the slot are...and a main two-tier horizontal boundary layer is identified...closed form for the outer horizontal layer which is dominated...reactor cooling systems, solar collectors and cavity insulation......

P. G. DANIELS

1987-05-01T23:59:59.000Z

123

Role of Amorphous Boundary Layer in Enhancing Ionic Conductivity of Lithium–lanthanum–titanate Electrolyte  

SciTech Connect (OSTI)

The low ionic conductivity is a bottleneck of the inorganic solid state electrolyte used for lithium ion battery. In ceramic electrolytes, grain boundary usually dominates the total conductivity. In order to improve the grain boundary effect, an amorphous silica layer is introduced into grain boundary of ceramic electrolytes based on lithium-lanthanum-titanate, as evidenced by electron microscopy. The results showed that the total ionic conductivity could be to be enhanced over 1 x 10{sup -4} S/cm at room temperature. The reasons can be attributed to removing the anisotropy of outer-shell of grains, supplement of lithium ions in various sites in grain boundary and close bindings among grains by the amorphous boundary layer among grains.

Mei, A.; Wang, X.; Lana, J.-L.; Fenga, Y.-C.; Genga, H.-X.; Lina, Y.-H.; Nana, C.-W.

2010-03-01T23:59:59.000Z

124

Attenuation of Electromagnetic Waves by a Plasma Layer at Atmospheric Pressure  

Science Journals Connector (OSTI)

Plasma layers at atmospheric pressure, are good broad band absorbers of ... have to be optimized. These are the plasma number density, and the thickness of the plasma layer. It is found that in order ... an effec...

Mounir Laroussi; William T. Anderson

1998-03-01T23:59:59.000Z

125

Thermal boundary layer effects in an annular acoustic Stirling engine  

Science Journals Connector (OSTI)

A stability and transport analysis is performed for a simplified model of a strongly coupled thermoacoustic prime mover stack in an annular resonator. The result demonstrates that even in the limit that other flow impedances of the resonator and stack can be ignored there is a thermal impedance mismatch created in the boundary region at the ends of the stack. This can cause the gain predicted for the wave traversing the interior of the stack to differ significantly from the gain that drives sound in the resonator. The analysis is used to derive scaling relations between the heat and mass transport around the annulus and to show how different scaling regimes relate to the maximum sound intensity that the stack can induce in the absence of other losses.

Eric Smith

1996-01-01T23:59:59.000Z

126

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)

Boundary-Layer Temperature Profiles by Boundary-Layer Temperature Profiles by a Scanning 5-MM Radiometer During the 1999 Winter NSA/AAO Radiometer Experiment and WVIOP 2000 V. Y. Leuski and E. R. Westwater Cooperative Institute for Research in the Environmental Sciences National Oceanic and Atmospheric Administration Environmental Technology Laboratory University of Colorado Boulder, Colorado Introduction A scanning 5-mm-wavelength radiometer was deployed during two Intensive Operational Periods (IOPs) at the Atmospheric Radiation Measurement (ARM) Program's Cloud and Radiation Testbed (CART) facilities. The first was conducted at the North Slope of Alaska (NSA) and Adjacent arctic Ocean (AAO) site near Barrow, Alaska, during March 1999. One goal was to evaluate the ability of an

127

Atmospheric Flow Development and Associated Changes in Turbulent Sensible Heat Flux over a Patchy Mountain Snow Cover  

Science Journals Connector (OSTI)

In this study we numerically investigated the small-scale boundary layer dynamics and the energy balance over a fractional snow-cover. The atmospheric boundary layer flows over a patchy snow-cover were calculated with an atmospheric model (...

Rebecca Mott; Michael Lehning; Megan Daniels; Michael Lehning

128

Comparison of two-equation turbulence models for boundary layers with pressure gradient  

SciTech Connect (OSTI)

This paper compares the performance of eight low Reynolds number k-epsilon and k-omega models for high Reynolds number, incompressible turbulent boundary layers with favorable, zero, and adverse pressure gradients. Results obtained underscore the k-epsilon model's unsuitability for such flows. Even more seriously, the k-epsilon model is demonstrated to be inconsistent with the well-established physical structure of the turbulent boundary layer, and low Reynolds number corrections cannot remove the inconsistency. By contrast, the k-omega model, with and without low Reynolds number modifications, proves to be very accurate for all of the tests conducted. 16 refs.

Wilcox, D.C. (DCW Industries, Inc., La Canada, CA (United States))

1993-08-01T23:59:59.000Z

129

The effect of periodic unsteady wakes on boundary layer transition and heat transfer on a curved plate.  

E-Print Network [OSTI]

??The effect of unsteady periodic wakes on heat transfer and boundary layer transition was investigated on a constant curvature heat transfer curved plate in a… (more)

Wright, Lance Cole

2012-01-01T23:59:59.000Z

130

Effects of passive porous walls on the first Mack mode instability of hypersonic boundary layers over a sharp cone.  

E-Print Network [OSTI]

??Passive porous coatings have been proposed in literature as a means of delaying transition to turbulence in hypersonic boundary layers. The nonlinear stability of hypersonic… (more)

Michael, Vipin George

2013-01-01T23:59:59.000Z

131

BOUNDARY LAYER ASSOCIATED WITH THE DARCY-BRINKMAN-BOUSSINESQ MODEL FOR  

E-Print Network [OSTI]

BOUNDARY LAYER ASSOCIATED WITH THE DARCY-BRINKMAN-BOUSSINESQ MODEL FOR CONVECTION IN POROUS MEDIA of the infinite Darcy- Prandtl number Darcy-Brinkman-Boussinesq system for convection in porous media at small number Darcy-Brinkman-Boussinesq system, infinite Darcy-Prandtl number Darcy-Boussinesq sys- tem

Wang, Xiaoming

132

Acoustic boundary layer and acoustic radiation from a ribbed flat plate  

Science Journals Connector (OSTI)

The acoustic boundary?layer theory(patterned after the viscous boundary?layer theory) is derived by noting that for low frequencies where the structural wavelength is much less than the fluid acoustic wavelength there is a region about the vibrating structure which behaves as if the fluid was incompressible. The dimension of this region depends upon the particular conditions of the problem. In a paper presented by the author [J. Acoust. Soc. Am. 62 S32(A) (1977)] the theory behind the acoustic boundary layer was developed and applied to simple unit problems. In this paper the near and the far field of a force driven plate is obtained by the use of the acoustic boundary?layer theory. Two different problems are addressed. In the first instance the structure is assumed to be homogeneous while in the second problem presented a rib is attached to the flat plate. In both instances the fully coupled fluid structure problem is solved and comparisons between the exact classical approach and the proposed theory are discussed.

Mauro Pierucci

1978-01-01T23:59:59.000Z

133

Transport and Resuspension of Fine Particles in a Tidal Boundary Layer near a Small Peninsula  

Science Journals Connector (OSTI)

The authors present a theory on the transport and resuspension of fine particles in a tidal boundary layer when the ambient tidal flow is nonuniform due to a peninsula along the coastline. As a first step toward better physical understanding the ...

Chiang C. Mei; Chimin Chian; Feng Ye

1998-11-01T23:59:59.000Z

134

Device for measuring the boundary layer parameters in a high-temperature gas stream  

SciTech Connect (OSTI)

The authors describe a device enabling one to simultaneously measure the distributions of electrical conductivity and electron density of the working substance of an MHD generator. The structure and a block diagram of the device are shown. The measured results give information on the thermal boundary layer thickness, and temperature profiles are calculated.

Kosov, V.F.; Molotkov, V.I.; Nefedov, A.P.

1985-05-01T23:59:59.000Z

135

The Impact of Horizontal Model Grid Resolution on the Boundary Layer Structure over an Idealized Valley  

Science Journals Connector (OSTI)

The role of horizontal model grid resolution on the development of the daytime boundary layer over mountainous terrain is studied. A simple idealized valley topography with a cross-valley width of 20 km, a valley depth of 1.5 km, and a constant ...

Johannes S. Wagner; Alexander Gohm; Mathias W. Rotach

2014-09-01T23:59:59.000Z

136

Acoustic Properties of Porous Coatings for Hypersonic Boundary-Layer Control  

E-Print Network [OSTI]

Acoustic Properties of Porous Coatings for Hypersonic Boundary-Layer Control Guillaume A. Brès for hypersonic laminar flow control. The reflection coefficient, characterizing the ratio of the reflected wave of incidence, for coatings of different porosities, at various acoustic Reynolds numbers relevant to hypersonic

Dabiri, John O.

137

Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers  

E-Print Network [OSTI]

Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers Lian on future air-breathing hypersonic cruise vehicles will be turbulent and chemically reacting. To aid the design of such vehicles, a greater understanding of turbulent hypersonic flows is needed. Although

MartĂ­n, Pino

138

Direct Numerical Simulation of a Hypersonic Turbulent Boundary Layer on a Large Domain  

E-Print Network [OSTI]

Direct Numerical Simulation of a Hypersonic Turbulent Boundary Layer on a Large Domain Stephan Priebe , M. Pino Mart´in The direct numerical simulation (DNS) of a spatially-developing hypersonic There are few studies of hypersonic flows at Mach number greater than 5 and few involve the measurement of mean

MartĂ­n, Pino

139

EUROPEAN CONFERENCE FOR AEROSPACE SCIENCES Shock Wave / Boundary Layer Interactions in Hypersonic  

E-Print Network [OSTI]

and a combina- tion of laminar and turbulent (transitional) computations as well as preliminary 3D simulations the impact on the shock / boundary layer interaction and on the size of the shock induced separation. Laminar have been conducted and show the experimental shock-tunnel results to be influenced by transition and 3

140

The Minimum Wind Speed for Sustainable Turbulence in the Nocturnal Boundary Layer  

Science Journals Connector (OSTI)

The collapse of turbulence in the nocturnal boundary layer is studied by means of a simple bulk model that describes the basic physical interactions in the surface energy balance. It is shown that for a given mechanical forcing, the amount of ...

B. J. H. Van de Wiel; A. F. Moene; H. J. J. Jonker; P. Baas; S. Basu; J. M. M. Donda; J. Sun; A. A. M. Holtslag

2012-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Shock-like structures in the tropical cyclone boundary layer Gabriel J. Williams,1  

E-Print Network [OSTI]

the horizontal and vertical velocity data shown by the blue curves in Figure 1. The extreme horizontal wind m in the northeast sector. Since these extreme structures in the boundary layer wind field occur produces a shock-like structure in the radial wind, i.e., near the radius of maximum tangential wind

Schubert, Wayne H.

142

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

SciTech Connect (OSTI)

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.

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

2013-10-16T23:59:59.000Z

143

E-Print Network 3.0 - atmosphere-surface exchange processes Sample...  

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

atmospheric surface layer during CBLAST, in 16th Symposium on Boundary Layers... on heat, gas, and momentum transport, infrared remote sensing, upper-ocean processes,...

144

Computation of hypersonic shock boundary layer interaction on a double wedge using a differential Reynolds Stress Model  

E-Print Network [OSTI]

Computation of hypersonic shock boundary layer interaction on a double wedge using a differential The simulation of hypersonic flows presents some difficulties due to the interaction between boundary layers on the standard test case of a subsonic flat plate and on a hypersonic configuration. The results show a good

145

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

E-Print Network [OSTI]

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

Russell, Lynn

146

Resuspension of Small Particles from Multilayer Deposits in Turbulent Boundary Layers  

E-Print Network [OSTI]

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).

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

2012-06-09T23:59:59.000Z

147

Resuspension of small particles from multilayer deposits in turbulent boundary layers  

Science Journals Connector (OSTI)

Abstract This paper describes a hybrid kinetic 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 removal forces acting on the particles (Zhang et al., 2013). 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. The model is used to investigate a range of effects, including the influence of layer thickness on resuspension, the spread of inter-particle adhesive forces within layers, Gaussian and non-Gaussian pdfs for the removal forces and the associated timescales. Finally model predictions are compared with data from two resuspension experiments – STORM (Castelo et al., 1999) and BISE (Alloul-Marmor, 2002).

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

2013-01-01T23:59:59.000Z

148

Atmospheric Science The Earth's atmosphere, a layered sphere of gas extending  

E-Print Network [OSTI]

division study the composition, structure, chemical, and physical processes of the Earth's atmosphere. The division's four interrelated groups focus on satellite, airborne, and ground-based observations processes such as atmospheric dynamics, chemistry, and radiation on Earth and other planets. Our atmospheric

Mojzsis, Stephen J.

149

Aircraft Observations of the Marine Boundary Layer Adjustment near Point Arguello, California  

E-Print Network [OSTI]

.g., Parish 2000). Several authors (e.g., Dorman 1985; Samelson 1992; Burk et al. 1999; Haack et al. 2001) represent the fluid system near the coast in terms of a two-layer shallow water model with the coastal terrain serving as a lateral boundary. The Froude... of the layer. Discontinuities such as hy- draulic jumps can result as the flow transitions from supercritical (Fr. 1) to subcritical (Fr, 1). As the flow in the MBL impinges on coastal points, significant modulation of the MBL height and wind field occurs...

Parish, Thomas R.; Rahn, David A.; Leon, David

2014-04-01T23:59:59.000Z

150

The effects of sound on the boundary layer of an airfoil at high angles of attack  

E-Print Network [OSTI]

* Numbers in parentheses refer to the References. introducing sound waves into the airstream by means of a variable-frequency oscillator and a loudspeaker mounted near the leading edge of a flat plate. Eventually, another method of producing... these disturbances was settled upon, but several interesting results caused by the use of sound were noted. Laminar boundary layer oscillations could be induced, depending upon the proper combination of sound frequency, speaker position, and free stream velocity...

Hutchinson, Thomas Ira

1963-01-01T23:59:59.000Z

151

Observations of the Evolution of the Nocturnal and Convective Boundary Layers and the Structure of Open-Celled Convection on 14 June 2002  

Science Journals Connector (OSTI)

The Boundary Layer Evolution (BLE) missions of the International H2O Project (IHOP_2002) were designed to provide comprehensive observations of the distribution of water vapor in the quiescent boundary layer and its evolution during the early ...

Lindsay J. Bennett; Tammy M. Weckwerth; Alan M. Blyth; Bart Geerts; Qun Miao; Yvette P. Richardson

2010-07-01T23:59:59.000Z

152

34th AIAA Fluid Dynamics Conference and Exhibit, June 28July 1, 2004/Portland, OR DNS of Hypersonic Turbulent Boundary Layers  

E-Print Network [OSTI]

of Hypersonic Turbulent Boundary Layers M. Pino Martin Department of Mechanical and Aerospace Engineering and hypersonic turbu- lent boundary layers. The systematic procedure for initializing the turbulent flow fields layers is important in advancing supersonic and hypersonic flight technology. In a high-speed boundary

MartĂ­n, Pino

153

The Effect of Heavy Oil Viscosity Reduction by Solvent Dissolution on Natural Convection in the Boundary Layer of VAPEX  

Science Journals Connector (OSTI)

We have studied the effect of viscosity on natural convection in the boundary layer of the vapor extraction (VAPEX) process. VAPEX is a heavy oil recovery method that uses solvents to reduce oil viscosity, and...

Mohammad Javaheri; Jalal Abedi

2013-09-01T23:59:59.000Z

154

Mean Structure and diurnal cycle of Southeast Atlantic boundary layer clouds: Insights from satellite observations and multiscale modeling framework simulations  

Science Journals Connector (OSTI)

The mean structure and diurnal cycle of Southeast (SE) Atlantic boundary layer clouds are described with satellite observations and multi-scale modeling framework (MMF) simulations during austral spring (September-November). Hourly resolution ...

David Painemal; Kuan-Man Xu; Anning Cheng; Patrick Minnis; Rabindra Palikonda

155

Effect of Finite Spatial Resolution on the Turbulent Energy Spectrum Measured in the Coastal Ocean Bottom Boundary Layer  

Science Journals Connector (OSTI)

The effect of finite spatial resolution on the measured energy spectrum is examined via a parametric study using in situ particle image velocimetry (PIV) measurements performed in the bottom boundary layer on the Atlantic continental shelf. Two-...

Erin E. Hackett; Luksa Luznik; Joseph Katz; Thomas R. Osborn

2009-12-01T23:59:59.000Z

156

Doppler Lidar–Based Wind-Profile Measurement System for Offshore Wind-Energy and Other Marine Boundary Layer Applications  

Science Journals Connector (OSTI)

Accurate measurement of wind speed profiles aloft in the marine boundary layer is a difficult challenge. The development of offshore wind energy requires accurate information on wind speeds above the surface at least at the levels occupied by ...

Yelena L. Pichugina; Robert M. Banta; W. Alan Brewer; Scott P. Sandberg; R. Michael Hardesty

2012-02-01T23:59:59.000Z

157

Glacial Cooling in the Tropics: Exploring the Roles of Tropospheric Water Vapor, Surface Wind Speed, and Boundary Layer Processes  

Science Journals Connector (OSTI)

This paper is a modeling study of possible roles for tropospheric water vapor, surface wind speed, and boundary layer processes in glacial cooling in the Tropics. The authors divide the Tropics into a region of persistent deep convection and a ...

Richard Seager; Amy C. Clement; Mark A. Cane

2000-07-01T23:59:59.000Z

158

A Comparison Between Boundary Layer Measurements in a Laminar Separation Bubble Flow and Linear Stability Theory Calculations  

Science Journals Connector (OSTI)

This research examines the details of the boundary layer flowfield from wind tunnel measurements of a two-dimensional Liebeck LA2573A airfoil over a range of Reynolds numbers from 235000 to 500000. In this range,...

P. LeBlanc; R. Blackwelder; R. Liebeck

1989-01-01T23:59:59.000Z

159

Data/model integration for vertical mixing in the stable Arctic boundary layer  

SciTech Connect (OSTI)

This is the final report of a short Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Data on atmospheric trace constituents and the vertical structure of stratus clouds from a 1996 expedition to the central Arctic reveal mechanisms of vertical mixing that have not been observed in mid-latitudes. Time series of the altitude and thickness of summer arctic stratus have been observed using an elastic backscatter lidar aboard an icebreaker. With the ship moored to the pack ice during 14 data collection stations and the lidar staring vertically, the time series represent advected cloud fields. The lidar data reveal a significant amount of vertical undulation in the clouds, strongly suggestive of traveling waves in the buoyantly damped atmosphere that predominates in the high Arctic. Concurrent observations of trace gases associated with the natural sulfur cycle (dimethyl sulfide, SO{sub 2}, NH{sub 3}, H{sub 2}O{sub 2}) and aerosols show evidence of vertical mixing events that coincide with a characteristic signature in the cloud field that may be called dropout or lift out. A segment of a cloud deck appears to be relocated from the otherwise quasicontinuous layer to another altitude a few hundred meters lower or higher. Atmospheric models have been applied to identify the mechanism that cause the dropout phenomenon and connect it dynamically to the surface layer mixing.

Barr, S.; ReVelle, D.O.; Kao, C.Y.J.; Bigg, E.K.

1998-12-31T23:59:59.000Z

160

Highly Accurate Solutions of the Blasius and Falkner-Skan Boundary Layer Equations via Convergence Acceleration  

E-Print Network [OSTI]

A new highly accurate algorithm for the solution of the Falkner-Skan equation of boundary layer theory is presented. The algorithm, based on a Maclaurin series representation, finds its coefficients from recurrence. In addition, Wynn-epsilon convergence acceleration and continuous analytical continuation enable an accurate evaluation. The most accurate skin friction coefficients (shooting angle) to date are presented along with comparisons to past and present values found in the literature. The algorithm, coded in FORTRAN, uses neither enhanced precision arithmetic beyond quadruple precision nor computer algebra to achieve results in a timely fashion. Key Words: Falkner-Skan flow; Blasius flow; Wynn-epsilon acceleration; Romberg acceleration; Continuous analytical continuation

B. D. Ganapol

2010-06-19T23:59:59.000Z

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161

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

SciTech Connect (OSTI)

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.

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

2013-08-16T23:59:59.000Z

162

Model of the boundary layer of a vacuum-arc magnetic filter  

SciTech Connect (OSTI)

A model is developed to describe the electrostatic boundary layer in a positively biased magnetic filter in filtered arcs with low collisionality. The set of equations used includes the electron momentum equation, with an anomalous collision term due to micro-instabilities leading to Bohm diffusion, electron mass conservation, and Poisson equation. Analytical solutions are obtained, valid for the regimes of interest, leading to an explicit expression to determine the electron density current to the filter wall as a function of the potential of the filter and the ratio of electron density at the plasma to that at the filter wall. Using a set of planar and cylindrical probes it is verified experimentally that the mentioned ratio of electron densities remains reasonably constant for different magnetic field values and probe bias, which allows to obtain a closed expression for the current. Comparisons are made with the experimentally determined current collected at different sections of a positively biased straight filter.

Minotti, F.; Giuliani, L.; Grondona, D.; Della Torre, H.; Kelly, H. [Departamento de Fisica, FCEyN, Universidad de Buenos Aires, Instituto de Fisica del Plasma, CONICET-UBA, Cdad. Universitaria, Pab.I, 1428 Buenos Aires (Argentina)

2013-03-21T23:59:59.000Z

163

Pulsed Plasma with Synchronous Boundary Voltage for Rapid Atomic Layer Etching  

SciTech Connect (OSTI)

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.

Economou, Demetre J.; Donnelly, Vincent M.

2014-05-13T23:59:59.000Z

164

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

SciTech Connect (OSTI)

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.

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

165

Boundary layer flow and heat transfer analysis of a second-grade fluid  

SciTech Connect (OSTI)

Boundary layer flow and heat transfer analysis of a homogeneous, incompressible, non-Newtonian fluid of grade two at a stagnation point is presented. The flow is assumed to be steady and laminar. A power-law representation is assumed for the velocity distribution and wall temperature variation. The governing equations are solved using an iterative central difference approximation method in a non-uniform grid domain. This analysis show the effect of non-Newtonian nature of the fluid and the effect of suction/injection on the velocity profile. The effect of non-Newtonian nature of the fluid on the heat transfer coefficient at the wall for different values of Prandtl number and wall-temperature variation is also presented. (VC)

Massoudi, M. [USDOE Pittsburgh Energy Technology Center, PA (United States); Ramezan, M. [Burns and Roe Services Corp., Pittsburgh, PA (United States)

1992-04-01T23:59:59.000Z

166

Atmospheric Sciences Program Department of Marine, Earth and Atmospheric Sciences (MEAS)  

E-Print Network [OSTI]

atmospheric chemistry/air quality, boundary layer and air pollution meteorology, regional/global climatology MODELING OF MULTIPLE AIR POLLUTANTS AT URBAN AND REGIONAL SCALES Our atmosphere is a complex systemAtmospheric Sciences Program Department of Marine, Earth and Atmospheric Sciences (MEAS) (http

Parker, Matthew D. Brown

167

Boundary-Layer Meteorol (2008) 127:7395 DOI 10.1007/s10546-007-9255-9  

E-Print Network [OSTI]

-scale (SFS) models to reproduce the statistical proper- ties of SFS stresses and energy transfers over boundary layer. In this study, several SFS models are evaluated a priori using experimental data acquired down- wind of a rough-to-smooth transition in a wind tunnel. The SFS models studied include the eddy

Porté-Agel, Fernando

168

IMPACT OF BOUNDARY-LAYER CUTTING AND FLOW CONDITIONING ON FREE-SURFACE BEHAVIOR IN TURBULENT LIQUID SHEETS  

E-Print Network [OSTI]

IMPACT OF BOUNDARY-LAYER CUTTING AND FLOW CONDITIONING ON FREE-SURFACE BEHAVIOR IN TURBULENT LIQUID dimension) = 1 cm into ambient air are compared with empirical correlations at a nearly prototypical term, for a well- conditioned jet but is not a substitute for well-designed flow conditioning. I

California at San Diego, University of

169

Measurement of Vertical Kinetic Energy and Vertical Velocity Skewness in Oceanic Boundary Layers by Imperfectly Lagrangian Floats  

Science Journals Connector (OSTI)

The effects of upward buoyancy on the accuracy with which Lagrangian floats can measure the Eulerian mean variance ?ww?E and skewness SwE of vertical fluid velocity w in the wind-driven upper-ocean boundary layer is investigated using both ...

Ramsey R. Harcourt; Eric A. D’Asaro

2010-11-01T23:59:59.000Z

170

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

SciTech Connect (OSTI)

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.

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

2014-01-02T23:59:59.000Z

171

Open-loop control of noise amplification in a separated boundary layer flow  

SciTech Connect (OSTI)

Linear optimal gains are computed for the subcritical two-dimensional separated boundary-layer flow past a bump. Very large optimal gain values are found, making it possible for small-amplitude noise to be strongly amplified and to destabilize the flow. The optimal forcing is located close to the summit of the bump, while the optimal response is the largest in the shear layer. The largest amplification occurs at frequencies corresponding to eigenvalues which first become unstable at higher Reynolds number. Nonlinear direct numerical simulations show that a low level of noise is indeed sufficient to trigger random flow unsteadiness, characterized here by large-scale vortex shedding. Next, a variational technique is used to compute efficiently the sensitivity of optimal gains to steady control (through source of momentum in the flow, or blowing/suction at the wall). A systematic analysis at several frequencies identifies the bump summit as the most sensitive region for control with wall actuation. Based on these results, a simple open-loop control strategy is designed, with steady wall suction at the bump summit. Linear calculations on controlled base flows confirm that optimal gains can be drastically reduced at all frequencies. Nonlinear direct numerical simulations also show that this control allows the flow to withstand a higher level of stochastic noise without becoming nonlinearly unstable, thereby postponing bypass transition. In the supercritical regime, sensitivity analysis of eigenvalues supports the choice of this control design. Full restabilization of the flow is obtained, as evidenced by direct numerical simulations and linear stability analysis.

Boujo, E., E-mail: edouard.boujo@epfl.ch; Gallaire, F., E-mail: francois.gallaire@epfl.ch [Laboratory of Fluid Mechanics and Instabilities, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Ehrenstein, U., E-mail: ehrenstein@irphe.univ-mrs.fr [Aix Marseille Université, CNRS, Centrale Marseille, IRPHE UMR 7342, F-13384 Marseille (France)

2013-12-15T23:59:59.000Z

172

Particle resuspension in turbulent boundary layers and the influence of non-Gaussian removal forces  

Science Journals Connector (OSTI)

The work described is concerned with the way micron-size particles attached to a surface are resuspended when exposed to a turbulent flow. An improved version of the Rock’n’Roll model (Reeks & Hall, 2001) is developed where this model employs a stochastic approach to 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 improved by using values of both the streamwise fluid velocity and acceleration close to the wall obtained from Direct Numerical Simulation (DNS) of turbulent channel flow. Using analysis and numerical calculations of the drag force on a sphere near a wall in shear flow (O’Neill, 1968; Lee & Balachandar, 2010) these values are used to obtain the joint distribution of the moments of the fluctuating drag force f(t) and its derivative f ? ( t ) acting on a particle attached to a surface. In so doing the influence of highly non-Gaussian forces (associated with the sweeping and ejection events in a turbulent boundary layer) on short and long term resuspension rates is examined for a sparse monolayer coverage of particles, along with the dependence of the resuspension upon the timescale of the particle motion attached to the surface, the ratio of the rms/mean of the removal force and the distribution of adhesive forces. Model predictions of the fraction resuspended are compared with experimental results.

F. Zhang; M. Reeks; M. Kissane

2013-01-01T23:59:59.000Z

173

Experimental study of acoustic radiation from a boundary layer transition region  

Science Journals Connector (OSTI)

Wall pressurefluctuations were measured on a rigid axisymmetric body in the CEPRA 19 low?noise anechoic wind tunnel using flush?mounted microphones placed from the laminar region to the fully turbulent boundary layer. Microphones placed in the laminar flow region are used to detect noise radiated from the transition region which occurs naturally without separation under a slightly positive pressure gradient. Cross?spectral analyses show upstream acoustic propagation in a very wide frequency band 4–30 kHz detected in the laminar region. A method of conditional analysis is then used to establish the sequence of events from the onset of near?harmonic instability wave packets to the generation about 10 ms later of turbulent spots leading to the acoustic emission. This intermittent acoustic radiation is detected in the nearfield for wind velocities ranging from 20–70 ms. Farfield detection was not achieved probably because of instrument limitations and propagation effects. [Work supported by DRET Direction des Recherches et Etudes Techniques.

J. C. Perraud; A. Julienne

1986-01-01T23:59:59.000Z

174

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

SciTech Connect (OSTI)

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.

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

175

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

E-Print Network [OSTI]

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... logarithmically with height+ Also, the choice of a method of determination of the roughness length must be governed by an awareness of possible errors in the wind speed meas- urementso The system used to collect the data employed in this study is susceptible...

Pierrard, John Martin

2012-06-07T23:59:59.000Z

176

Atmospheric Plasma Effect on Cotton Nonwovens  

Science Journals Connector (OSTI)

Atmospheric Plasma Effect on Cotton Nonwovens ... (22) Plasma II is more effective than Plasma I with the ability to develop homogeneous plasmas and eliminate boundary-layer air effects. ...

Sudheer Jinka; Uday Turaga; Vinitkumar Singh; Rachel L. Behrens; Cenk Gumeci; Carol Korzeniewski; Todd Anderson; Rory Wolf; Seshadri Ramkumar

2014-07-22T23:59:59.000Z

177

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

E-Print Network [OSTI]

Wind Energy Association Windpower 2008 Conference, AmericanWind Energy Association Windpower 2006 Conference, American

Lundquist, Katherine Ann

2010-01-01T23:59:59.000Z

178

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

E-Print Network [OSTI]

in today’s numerical weather prediction models is stillability of a numerical weather prediction model to predictthe context of numerical weather prediction models. The two-

Lundquist, Katherine Ann

2010-01-01T23:59:59.000Z

179

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

SciTech Connect (OSTI)

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

Jochen Stutz

2005-05-24T23:59:59.000Z

180

Boundary-Layer Stability and Transition on a Flared Cone in a Mach 6 Quiet Wind Tunnel  

E-Print Network [OSTI]

quality features. .................................. 31? 2?4 Upstream settling chamber flow conditioning components. .............................. 31? 2?5 Cross-section of contraction?nozzle assembly, with bleed lip and plenum. ...... 33? 3?1 Cross... by maximizing the laminar extent of the nozzle-wall boundary layer. After much research, success was achieved with a design as depicted by Figure 1?5(b). A bleed slot is employed upstream of the nozzle throat for the extraction of the contraction...

Hofferth, Jerrod William

2013-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Nitric oxide emissions from the high-temperature viscous boundary layers of hypersonic aircraft within the stratosphere  

SciTech Connect (OSTI)

The authors study the nitric oxide emission characteristics of supersonic aircraft resulting from heating of viscous boundary layers along the skin of the aircraft. Previous study has concentrated on nitric oxide emissions coming from combustion products from the scramjet engines. This work shows that above mach 8, emissions from viscous heating become a significant factor in total emission of nitric oxide. Above mach 16 it becomes the dominant source of emission.

Brooks, S.B.; Lewis, M.J.; Dickerson, R.R. [Univ. of Maryland, College Park, MD (United States)

1993-09-20T23:59:59.000Z

182

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

SciTech Connect (OSTI)

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.

Albrecht, Bruce,

2013-07-12T23:59:59.000Z

183

Time-dependent laser ignition of a combustible stagnant boundary layer  

Science Journals Connector (OSTI)

......research-article Articles Time-dependent laser ignition of a combustible stagnant boundary...55,257-268 Time-dependent laser ignition of a combustible stagnant boundary...examines the conditions for laser ignition of a number of industrial gases......

J. ADLER

1995-12-01T23:59:59.000Z

184

Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer  

E-Print Network [OSTI]

by providing accurate vertical wind speed profiles. TurbineC-1 Schematic of vertical wind speed and density profiles in50,000 s) vertical profiles of wind speed for the moderately

Zhou, Bowen

2012-01-01T23:59:59.000Z

185

An investigation of the air flow structure over a rooftop in the turbulent atmospheric boundary layer  

E-Print Network [OSTI]

wind speed, the mean vertical wind speed, and the verticalA variation in the mean vertical wind speed was observed forpredominantly positive vertical wind speed, whereas the

Hayes, William Joseph

2010-01-01T23:59:59.000Z

186

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature  

E-Print Network [OSTI]

to local SST perturbations decreases rapidly with height to near-zero at 150-300m. The simulated wind speed of local SST perturbations, and the orientation of the surface wind to the SST gradient. #12;3 1. Introduction Positive correlations of local surface wind anomalies with sea surface temperature (SST) anomalies

187

Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer  

E-Print Network [OSTI]

Emissions from Landfills". Submitted to Environmentalflow rate on top of the landfill from 1400 LST onwards. Toplume dispersion over a landfill and good results are

Zhou, Bowen

2012-01-01T23:59:59.000Z

188

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

E-Print Network [OSTI]

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.

Saloome Siavoshi; Ashish V. Orpe; Arshad Kudrolli

2005-12-22T23:59:59.000Z

189

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

E-Print Network [OSTI]

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 ...

Van Ark, Emily M

2007-01-01T23:59:59.000Z

190

On the role of monoterpene chemistry in the remote continental boundary layer  

E-Print Network [OSTI]

The formation of organic nitrates (RONO[subscript 2]) represents an important NO[subscript x] (NO[subscript x] = NO + NO[subscript 2]) sink in the remote and rural continental atmosphere, thus impacting ozone production ...

Wooldridge, P. J.

191

A Numerical Study of the Evolving Convective Boundary Layer and Orographic Circulation around the Santa Catalina Mountains in Arizona. Part I: Circulation without Deep Convection  

Science Journals Connector (OSTI)

The daytime evolution of the thermally forced boundary layer (BL) circulation over an isolated mountain, about 30 km in diameter and 2 km high, is examined by means of numerical simulations validated with data collected in the Cumulus ...

J. Cory Demko; Bart Geerts

2010-05-01T23:59:59.000Z

192

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]

. 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... 55 Estimation of Error Caused by Leaks in the Pressure Measuring System 56 LIST OF FIGURES Figure Page 3" x 48" Smoke Tunnel 2. Flat Plate Model 3. Schematic of Pressure System 4. Volume Flow Rates of Working Pipe Tap Orifice 14 Variation...

Miller, Edward Peter

2012-06-07T23:59:59.000Z

193

Pacific Northwest Laboratory annual report for 1982 to the DOE Office of Energy Research. Part 3. Atmospheric sciences  

SciTech Connect (OSTI)

This report is organized in terms of generic studies: theoretical studies of atmospheric processes; pollutant characterizations and transformation; boundary layer meteorology; and dispersion, deposition and resuspension of atmospheric pollutants.

Elderkin, C.E.

1983-02-01T23:59:59.000Z

194

Characterization of particle cloud droplet activity and composition in the free troposphere and the boundary layer during INTEX-B  

SciTech Connect (OSTI)

Measurements of cloud condensation nuclei (CCN), aerosol size distributions, and submicron aerosol composition were made as part of the Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign during spring 2006. Measurements were conducted from an aircraft platform over the northeastern Pacific and western North America with a focus on how the transport and evolution of Asian pollution across the Pacific Ocean affected CCN properties. A broad range of air masses were sampled and here we focus on three distinct air mass types defined geographically: the Pacific free troposphere (FT), the marine boundary layer (MBL), and the polluted continental boundary layer in the California Central Valley (CCV). These observations add to the few observations of CCN in the FT. CCN concentrations showed a large range of concentrations between air masses, however CCN activity was similar for the MBL and CCV ({kappa} {approx} 0.2-0.25). FT air masses showed evidence of long-range transport from Asia and CCN activity was consistently higher than for the boundary layer air masses. Bulk chemical measurements predicted CCN activity reasonably well for the CCV and FT air masses. Decreasing trends in {kappa} with organic mass fraction were observed for the combination of the FT and CCV air masses and can be explained by the measured soluble inorganic chemical components. Changes in hygroscopicity associated with differences in the non-refractory organic composition were too small to be distinguished from the simultaneous changes in inorganic ion composition in the FT and MBL, although measurements for the large organic fractions (0.6-0.8) found in the CCV showed values of the organic fraction hygroscopicity consistent with other polluted regions ({kappa}{sub org} {approx} 0.1-0.2). A comparison of CCN-derived {kappa} (for particles at the critical diameter) to H-TDMA-derived {kappa} (for particles at 100 nm diameter) showed similar trends, however the CCN-derived {kappa} values were significantly higher.

Roberts, G. C.; Day, D. A.; Russell, Lynn M.; Dunlea, E. J.; Jimenez, J. L.; Tomlinson, Jason M.; Collins, Donald R.; Shinozuka, Y.; Clarke, A. D.

2010-07-20T23:59:59.000Z

195

A Lagrangian stochastic model for estimating the high order statistics of a fluctuating plume in the neutral boundary layer  

Science Journals Connector (OSTI)

We use a Lagrangian stochastic micromixing model to predict the concentration fluctuations of a continuous release in a neutral boundary layer. We present the computational algorithm that implements the interaction by exchange with the conditional mean model and we compare the numerical solutions with the experimental values in order to evaluate the reliability of the model. The influence of the source size on the concentration probability density function in the near and far-field is discussed and some shortcomings of the model are pointed out.

Massimo Marro; Chiara Nironi; Pietro Salizzoni; Lionel Soulhac

2014-01-01T23:59:59.000Z

196

Microstructure of Josephson junctions: Effect on supercurrent transport in YBCO grain boundary and barrier layer junctions  

SciTech Connect (OSTI)

The electric transport of high-temperature superconductors, such as YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (YBCO), can be strongly restricted by the presence of high-angle grain boundaries (GB). This weak-link behavior is governed by the macroscopic GB geometry and the microscopic grain boundary structure and composition at the atomic level. Whereas grain boundaries present a considerable impediment to high current applications of high T{sub c} materials, there is considerable commercial interest in exploiting the weak-link-nature of grain boundaries for the design of microelectronic devices, such as superconducting quantum interference devices (SQUIDs). The Josephson junctions which form the basis of this technology can also be formed by introducing artificial barriers into the superconductor. The authors have examined both types of Josephson junctions by EM techniques in an effort to understand the connection between microstructure/chemistry and electrical transport properties. This knowledge is a valuable resource for the design and production of improved devices.

Merkle, K.L.; Huang, Y.

1998-01-01T23:59:59.000Z

197

Alternate Designs of Ultrasonic Absorptive Coatings for Hypersonic Boundary Layer Control  

E-Print Network [OSTI]

-wall boundary condition. A particular case with a relatively shallow cavities and very high porosity showed number, wawb/µw Re Reynolds number, eUe/µe s Cavity spacing T Temperature t Time U Freestream streamwise of thermal protection systems (TPS).2,3 State-of- the-art active and reactive lam- inar flow control (LFC

Dabiri, John O.

198

An Examination of Configurations for Using Infrared to Measure Boundary Layer Transition  

E-Print Network [OSTI]

reflections are the driving issues in designing an IR system for detecting transition. Aluminum has a high thermal diffusivity so is a poor choice for this method. However, its performance can be improved using an insulating layer. Internal fluid circulation...

Freels, Justin Reed

2012-10-19T23:59:59.000Z

199

Estimates of North American summertime planetary boundary layer depths derived from space-borne lidar  

E-Print Network [OSTI]

), are sensitive to empirical parameters in addition to the diagnostic method chosen and verification by direct determines the PBL depth using the TKE (turbulent kinetic energy) method. This method identifies the PBL exchanges of energy, moisture, momentum, carbon, and pollutants between the surface and the atmosphere

Collett Jr., Jeffrey L.

200

Evaluation of Three Planetary Boundary Layer Schemes in the WRF Model XIAO-MING HU  

E-Print Network [OSTI]

. Introduction Southeast Texas, especially the Houston­Galveston area, frequently exceeds the National Ambient of Atmospheric Sciences, Texas A&M University, College Station, Texas, and Department of Meteorology Sciences, Texas A&M University, College Station, Texas FUQING ZHANG Department of Meteorology

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Modeling scatterers embedded in plane?layered media by a hybrid Haskell?Thompson and boundary integral equation method  

Science Journals Connector (OSTI)

A hybrid Haskell?Thompson and Boundary IntegralEquation (BIE) method is formulated which can model the acoustic and elastic response of scatterers embedded in plane?layered media. The scatterers can have an arbitrary smooth shape but must not intersect layer interfaces. The Green's function of the scatterer is computed by BIEs in the (x z w) domain and the Green's functions of the layers is computed by a Haskell?Thompson method in the (kx z w) domain. Their fields are coupled by the appropriate combination of FFTs and extrapolation operators and are finally summed up in a Born series. For notational convenience this hybrid method will be called a Generalized Born Series (GBS) method. Two advantages of the GBS method are (1) it is more efficient than finite elements or finite differences for small scatterers embedded in thickly layered media; and (2) no artificial side reflections are generated from the infinitely extended plane interfaces. The disadvantages are (1) the convergence rate of the GBS depends on the model and is unknown a priori; and (2) the computation time increases with the size of the scatterer. [Work supported by MIDAS a consortium of oil and geophysical companies.

Gerard T. Schuster; Lance Smith

1984-01-01T23:59:59.000Z

202

Modeling scatterers embedded in plane?layered media by a hybrid Haskell–Thomson and boundary integral equation method  

Science Journals Connector (OSTI)

A hybrid Haskell–Thomson and boundary integralequation (BIE) method is formulated which can model the acoustic or elastic response of scatterers embedded in plane?layered media. The scatterers can have an arbitrary smooth shape but must not intersect layer interfaces. The Green’s function of the scatterer is computed by BIEs in the (x z ?) domain and the Green’s function of the layers is computed by a Haskell–Thomson method in the (k x z ?) domain. Their fields are coupled by the appropriate combination of FFTs and extrapolation operators and are finally summed up in a Born series. For notational convenience this hybrid method will be called a generalized Born series (GBS) method. Two advantages of the GBS method are (1) it is more efficient than finite elements or finite differences for small scatterers embedded in thickly layered media and (2) no artificial side reflections are generated from the infinitely extended plane interfaces. The disadvantages are (1) the convergence rate of the GBS depends on the model and is unknown a p r i o r i and (2) the computation time increases with the size of the scatterer.

Gerard T. Schuster; Lance C. Smith

1985-01-01T23:59:59.000Z

203

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

SciTech Connect (OSTI)

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.

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

1997-04-01T23:59:59.000Z

204

Mean and Turbulent Flow Downstream of a Low-Intensity Fire: Influence of Canopy and Background Atmospheric Conditions  

Science Journals Connector (OSTI)

This study examines the sensitivity of mean and turbulent flow in the planetary boundary layer (PBL) and roughness sub-layer to a low-intensity fire and evaluates whether the sensitivity is dependent on canopy and background atmospheric ...

Michael T. Kiefer; Warren E. Heilman; Shiyuan Zhong; Joseph J. Charney; Xindi Bian

205

Behavior of buoyant moist plumes in turbulent atmospheres  

E-Print Network [OSTI]

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 ...

Hamza, Redouane

1981-01-01T23:59:59.000Z

206

Simulated Climatology of Atmospheric Ducts Over the Persian Gulf  

Science Journals Connector (OSTI)

A simulated climatology of ducts in the Persian Gulf area was produced with the MM3 atmospheric ... boundary layer prevented duct formation. Over the Gulf in the season, duct coverage was complete ... from north-...

M. Zhu; B. W. Atkinson

2005-06-01T23:59:59.000Z

207

A physical model of the turbulent boundary layer consonant with mean momentum balance structure  

Science Journals Connector (OSTI)

...compared with the prevalent, well-established, model. Some...O(U ) ((u tau /kappa)log(delta/C)) D (wake layer...Engineering, University of Alabama. Wark, C.E , and H.M Nagib1991Experimental...comparison, the prevalent, well-established, physical model...

2007-01-01T23:59:59.000Z

208

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

E-Print Network [OSTI]

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.

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

2014-12-22T23:59:59.000Z

209

Simplified turbulent spiral boundary layer and thermal wind simulator for acid rain modeling  

SciTech Connect (OSTI)

To determine the possible future impact of acid rain on the ecosystem requires the ability to numerically simulate the transport of various acids and their precursors from various sources to the locations of interest. Such a simulation is very complex and includes the evolution of the materials of interest as an aerosol within the ever changing local atmospheric motion. Wind patterns, however, are complex and difficult to model. They depend not only on local surface conditions and topology but on the global meteorological conditions. This paper presents an algebraic model to be used to simulate the vertical variation of the wind velocity and direction. The proposed model requires a minimum of input yet it qualitatively captures the mechanistic behavior of the wind with altitude. Results of the model are compared with both finite difference calculations and field data.

Lemmon, E.C.; Wiersma, G.B.; Bruns, D.A.

1986-04-01T23:59:59.000Z

210

E-Print Network 3.0 - atmospheric surface layer Sample Search...  

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

determining albedo and opacity Clouds Snow and ice Aerosols Time... Horizontal transport in the atmosphere Dry and moist static energy Eddy ... Source: Sherwood, Steven -...

211

Measurements of diurnal variations and Eddy Covariance (EC) fluxes of glyoxal in the1 tropical marine boundary layer: description of the Fast LED-CE-DOAS instrument2  

E-Print Network [OSTI]

marine boundary layer: description of the Fast LED-CE-DOAS instrument2 3 4 S. Coburn1,2 , I. Ortega1 Emitting Diode Cavity Enhanced Differential Optical Absorption24 Spectroscopy (Fast LED-CE-DOAS) instrument Halogens28 and OVOC (TORERO) field experiment (January to March 2012). The Fast LED-CE-DOAS is a29

212

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)

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.

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

2013-05-31T23:59:59.000Z

213

Boundary Layer Lubrication  

Broader source: Energy.gov [DOE]

2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C.

214

Boundary Layer Lubrication  

Broader source: Energy.gov [DOE]

Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February 25, 2008 in Bethesda, Maryland.

215

Boundary Layer Lubrication Mechanisms  

Broader source: Energy.gov [DOE]

2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

216

Boundary Layer Lubrication Mechanisms  

Broader source: Energy.gov [DOE]

2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation

217

Solar wind energy transfer regions inside the dayside magnetopause: Accelerated heavy ions as tracers for MHD-processes in the dayside boundary layer  

Science Journals Connector (OSTI)

Plasma and magnetic field data from PROGNOZ-7 have revealed that solar wind (magnetosheath) plasma elements may penetrate the dayside magnetopause surface and form high density regions with enhanced cross-field flow in the boundary layer. The injected magnetosheath plasma is observed to have an excess drift velocity as compared to the local boundary layer plasma, comprising both “cold” plasma of terrestrial origin and a hot ring current component. A differential drift between two plasma components can be understood in terms of a momentum transfer process driven by an injected magnetosheath plasma population. The braking action of the injected plasma may be described as a dynamo process where particle kinetic energy is transferred into electromagnetic energy (electric field). The generated electric field will force the local plasma to ?×B-drift, and the dynamo region therefore also constitutes an accelerator region for the local plasma. Whenever energy is dissipated from the energy transfer process (a net current is flowing through a load), there will also be a difference between the induced electric field and the v×B term of the generator plasma. Thus, the local plasma will drift more slowly than the injected generator plasma. We will present observations showing that a relation between the momentum transferred, the injected plasma and the momentum taken up by the local plasma exists. For instance, if the local plasma density is sufficiently high, the differential drift velocity of the injected and local plasma will be small. A large fraction of the excess momentum is then transferred to the local plasma. Conversely, a low local plasma density results in a high velocity difference and a low fraction of local momentum transfer. In our study cases the “cold” plasma component was frequently found to dominate the local magnetospheric plasma density in the boundary layer. Accordingly, this component may have the largest influence on the local momentum transfer process. We will demonstrate that this also seems to be the case. Moreover we show that the accelerated “cold” plasma component may be used as a tracer element reflecting both the momentum and energy transfer and the penetration process in the dayside boundary layer. The high He+ percentage of the accelerated “cold” plasma indicates a plasmaspheric origin. Considering the quite high densities of energetic He+ found in the boundary layer, the overall low abundance of He+ (as compared to e.g. O+) found in the plasma sheet and outer ring current evidently reduces the importance of the dayside boundary layer as a plasma source in the large scale magnetospheric circulation system.

R. Lundin; E.M. Dubinin

1985-01-01T23:59:59.000Z

218

ARM - Publications: Science Team Meeting Documents: Atmospheric...  

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

layer is sensitive to the boundary layer scheme. Furthermore, little is known on the climatology of drizzling or precipitating boundary layer clouds, their seasonal variability and...

219

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

E-Print Network [OSTI]

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 ...

Chaudhuri, Ayan H.

220

The Local Structure of Atmospheric Turbulence and Its Effect on the Smagorinsky Model for Large Eddy Simulation  

Science Journals Connector (OSTI)

Phenomena such as large-scale shear, buoyancy, and the proximity to the ground surface significantly affect interactions among scales in atmospheric boundary layer turbulent flows. Hence, these phenomena impact parameters that enter subgrid-scale ...

Marcelo Chamecki; Charles Meneveau; Marc B. Parlange

2007-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

E-Print Network [OSTI]

temperature, wind speed, vertical heat and momentum ?uxes,ABL is vertical wind shear, with the wind speed at the

Mirocha, Jeffrey D.; Kosovi?, Branko

2010-01-01T23:59:59.000Z

222

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

E-Print Network [OSTI]

depth (PBLD), (b) vertical wind speed (w), (c) latent heatdepth (PBLD), (b) vertical wind speed (w), (c) latent heatdepth (PBLD) and (b) vertical wind speed (w) versus water

Rihani, Jehan

2010-01-01T23:59:59.000Z

223

PIV Measurements in the Atmospheric Boundary Layer within and above a Mature Corn Canopy. Part I: Statistics and Energy Flux  

Science Journals Connector (OSTI)

Particle image velocimetry (PIV) measurements just within and above a mature corn canopy have been performed to clarify the small-scale spatial structure of the turbulence. The smallest resolved scales are about 15 times the Kolmogorov length ...

R. van Hout; W. Zhu; L. Luznik; J. Katz; J. Kleissl; M. B. Parlange

2007-08-01T23:59:59.000Z

224

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

E-Print Network [OSTI]

snow/ice pack interior, which constrains surface cooling.snow/ice pack. They suggest that the strong cooling of theice pack. During clear-sky conditions, strong radiative cooling

Mirocha, Jeffrey D.; Kosovi?, Branko

2010-01-01T23:59:59.000Z

225

High-Resolution Large-Eddy Simulations of Scalar Transport in Atmospheric Boundary Layer Flow over Complex Terrain  

E-Print Network [OSTI]

of Electric Power Industry, Chiba, Japan FOTINI KATOPODES CHOW Department of Civil and Environmental to the choice of numerical simulation parameters than is typically needed for mean wind field predictions. Large-eddy simulation is used in a mesoscale setting, providing modeling advantages through the use of robust turbulence

Chow, Fotini Katopodes

226

Testing a Detailed Biophysical Parameterization for Land–Air Exchange in a High-Resolution Boundary-Layer Model  

Science Journals Connector (OSTI)

In order to properly model the influence of land surface properties on mesoscale atmospheric phenomena, it is important to include physically realistic parameterizations of major biophysical processes involved. The primary influence of the ...

S. Argentini; P. J. Wetzel; V. M. Karyampudi

1992-02-01T23:59:59.000Z

227

Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loadings  

SciTech Connect (OSTI)

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.

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

2012-01-01T23:59:59.000Z

228

A New Method to Produce Sea Surface Temperature Using Satellite Data Assimilation into an AtmosphereOcean Mixed Layer Coupled Model  

E-Print Network [OSTI]

A New Method to Produce Sea Surface Temperature Using Satellite Data Assimilation method of producing sea surface temperature (SST) data for numerical weather prediction is sug- gested, which is obtained from the assimilation of satellite-derived SST into an atmosphere­ocean mixed layer

Noh, Yign

229

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]

compressible numerical weather prediction model incompressible numerical weather prediction model withcompressible numerical weather prediction model in

Daniels, Megan Hanako

2010-01-01T23:59:59.000Z

230

Heat transfer in a horizontal fluid layer heated from below upon rotation of one of the boundaries  

Science Journals Connector (OSTI)

The mixed convection in a horizontal fluid layer which is generated by uniform heating from below and by rotation of one ... studied experimentally. The region occupied by the fluid is a cylinder of radius320 mm ...

V. S. Berdnikov; V. A. Markov

231

Boundary-Layer Meteorol (2010) 134:327351 DOI 10.1007/s10546-009-9442-y  

E-Print Network [OSTI]

of tracer transport in an idealised, east-west aligned valley are performed with the Regional Atmospheric simulations of tracer dispersion using a two-dimensional (2D) north-west to south-east oriented valley Simulations of Daytime Pollution Transport in a Steep Valley and its Sensitivity to Thermal Stratification

Gohm, Alexander

232

Water Structure at Aqueous Solution Surfaces of Atmospherically Relevant Dimethyl Sulfoxide and Methanesulfonic Acid Revealed by Phase-Sensitive Sum Frequency  

E-Print Network [OSTI]

layer (MBL), the sulfur cycle dominates in the gas-to-particle conversion process and in the growth-containing aerosols play an important role in atmospheric chemistry and climate.1-3 Especially in the marine boundary

233

On Techniques to Characterize and Correlate Grain Size, Grain Boundary Orientation and the Strength of the SiC Layer of TRISO Coated Particles: A Preliminary Study  

SciTech Connect (OSTI)

The mechanical properties of the silicon carbide (SiC) layer of the TRi-ISOtropic (TRISO) coated particle (CP) for high temperature gas reactors (HTGR) are performance parameters that have not yet been standardized by the international HTR community. Presented in this paper are the results of characterizing coated particles to reveal the effect of annealing temperature (1000 to 2100°C) on the strength and grain size of unirradiated coated particles. This work was further expanded to include possible relationships between the grain size and strength values. The comparative results of two strength measurement techniques and grain size measured by the Lineal intercept method are included. Preliminary grain boundary characterization results determined by electron backscatter diffraction (EBSD) are included. These results are also important for future fission product transport studies, as grain boundary diffusion is identified as a possible mechanism by which 110mAg, one of the fission activation products, might be released through intact SiC layers. Temperature is a parameter known to influence the grain size of SiC and therefore it is important to investigate the effect of high temperature annealing on the SiC grain size. Recommendations and future work will also be briefly discussed.

I.J.van Rooyen; J.L. Dunzik Gougar; T. Trowbridge; Philip M van Rooyen

2012-10-01T23:59:59.000Z

234

Johnson et al.: Europa's Sputter-induced Atmosphere 507 Composition and Detection of Europa's  

E-Print Network [OSTI]

Johnson et al.: Europa's Sputter-induced Atmosphere 507 507 Composition and Detection of Europa's Sputter-induced Atmosphere R. E. Johnson University of Virginia M. H. Burger University of Maryland, it is also called a surface boundary-layer atmos- phere (Johnson, 2002), i.e., as at Mercury, the Moon

Johnson, Robert E.

235

Low-temperature formation of Si O 2 layers using a two-step atmospheric pressure plasma-enhanced deposition-oxidation process  

Science Journals Connector (OSTI)

Silicon oxide ( Si O 2 ) layers were fabricated at low temperatures ( ? 400 ° C ) by combining the deposition of hydrogenated amorphous Si ( a - Si : H ) with its oxidation using atmospheric pressure plasmas excited by a 150 MHz very high-frequency (VHF) power. The surface excitation by the atmospheric pressure VHF plasma was capable of reducing the temperature for the hydrogen effusion from a - Si : H . As a result a porous a - Si : H film containing a large amount of hydrogen could be transformed into a stoichiometric Si O 2 with an approximately 24% increase in oxidation rate compared with the oxidation of Si(001) at a temperature of 400 ° C .

Hiroaki Kakiuchi; Hiromasa Ohmi; Makoto Harada; Heiji Watanabe; Kiyoshi Yasutake

2007-01-01T23:59:59.000Z

236

Large eddy simulation of wind turbine wake dynamics in the stable boundary layer using the Weather Research and Forecasting Model  

Science Journals Connector (OSTI)

Recently an actuator disk parameterization was implemented in the Weather Research and Forecasting (WRF) Model for large eddy simulation (LES) of wind turbine wakes. To thoroughly verify this model simulations of various types of turbines and atmospheric conditions must be evaluated against corresponding experimental data. In this work numerical simulations are compared to nacelle-based scanning lidar measurements taken in stable atmospheric conditions during a field campaign conducted at a wind farm in the western United States. Using several wake characteristics—such as the velocity deficit centerline location and wake width—as metrics for model verification the simulations show good agreement with the observations. Notable results include a high average velocity deficit decreasing from 73% at a downwind distance x of 1.2 rotor diameters (D) to 25% at x?=?6.6D resulting from a low average wind speed and therefore high average turbine thrust coefficient. Moreover the wake width expands from 1.4D at x?=?1.2D to 2.3D at x?=?6.6D. Finally new features—namely rotor tilt and drag from the nacelle and tower—are added to the existing actuator disk model in WRF-LES. Compared to the rotor the effect of the tower and nacelle on the flow is relatively small but nevertheless important for an accurate representation of the entire turbine. Adding rotor tilt to the model causes the vertical location of the wake center to shift upward. Continued advancement of the actuator disk model in WRF-LES will help lead to optimized turbine siting and controls at wind farms.

Matthew L. Aitken; Branko Kosovi?; Jeffrey D. Mirocha; Julie K. Lundquist

2014-01-01T23:59:59.000Z

237

Clouds, Aerosols and Precipitation in the Marine Boundary Layer (CAP-MBL) AMF Deployment Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010  

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

the Marine Boundary Layer (CAP-MBL) Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010 Rob Wood, University of Washington CAP-MBL Proposal Team AMF Deployment Team Thanks to Mark Miller: AMF Site Scientist Kim Nitschke: AMF Site Manager Importance of Low-Clouds for Climate Imperative that we understand the processes controlling the formation, maintenance and dissipation of low clouds in order to improve their representation in climate models. Which clouds matter for climate sensitivity? Climate Feedbacks Model Intercomparison Project (CFMIP) 12 slab ocean models 2xCO 2 - control Correlation of global mean CRF with local values Mark Webb, Hadley Center 90 N 45 N 0 45 S 90S 0 90 E 180 90 W 0

238

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

SciTech Connect (OSTI)

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.

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

2014-06-21T23:59:59.000Z

239

Finescale Structure and Dynamics of an Atmospheric Temperature Interface  

Science Journals Connector (OSTI)

Near-ground observations of an atmospheric temperature interface in the stable nocturnal boundary layer are reported. The thermal effect of the interface passage was a 5-K decrease in temperature during a 5-min period in which changes in wind ...

Vincent Hohreiter

2008-05-01T23:59:59.000Z

240

Generation of Teflon-like layers on cellophane surfaces under atmospheric pressure non-equilibrium SF6-plasma environments  

Science Journals Connector (OSTI)

In this contribution a novel atmospheric pressure SF6–cold–plasma method is suggested for the conversion of... x , (x< 6 ) species generated in the discharge for oxygen extractio...

L. E. Cruz-Barba; S. Manolache; F. Denes

2003-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

SciTech Connect (OSTI)

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.

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

2011-12-01T23:59:59.000Z

242

Low-temperature formation of SiO{sub 2} layers using a two-step atmospheric pressure plasma-enhanced deposition-oxidation process  

SciTech Connect (OSTI)

Silicon oxide (SiO{sub 2}) layers were fabricated at low temperatures ({<=}400 deg. C) by combining the deposition of hydrogenated amorphous Si (a-Si:H) with its oxidation using atmospheric pressure plasmas excited by a 150 MHz very high-frequency (VHF) power. The surface excitation by the atmospheric pressure VHF plasma was capable of reducing the temperature for the hydrogen effusion from a-Si:H. As a result, a porous a-Si:H film containing a large amount of hydrogen could be transformed into a stoichiometric SiO{sub 2} with an approximately 24% increase in oxidation rate compared with the oxidation of Si(001) at a temperature of 400 deg. C.

Kakiuchi, Hiroaki; Ohmi, Hiromasa; Harada, Makoto; Watanabe, Heiji; Yasutake, Kiyoshi [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

2007-10-15T23:59:59.000Z

243

Carbon project-atmosphere "BL meteorology along route  

E-Print Network [OSTI]

2 CO2 CO2 CO2 CO2 Mixing heightEddie/coherent structure mixing Atmospheric CO2 gas CO2 gas layer and why is it important in a CO2 context · What are we doing onboard · What are we looking for and why · Interesting messurements from Coast of Namibia #12;What is a boundary layer ? CO2 CO2 CO2 CO2 CO

244

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

E-Print Network [OSTI]

with other data sets, climate-scale relation- ships between cloud properties and dynamical or micro- physical of cloud layers, an issue that is important in calculating both the radiative and the hydro- logic effects

245

Dissipation of Marine Stratiform Clouds and Collapse of the Marine Boundary Layer Due to the Depletion of Cloud Condensation Nuclei by Clouds  

Science Journals Connector (OSTI)

...JOURNAL OF THE ATMOSPHERIC SCIENCES...of cloud condensation nuclei by...and 2533 water molecules...Department of Atmospheric Sciences...of cloud condensation nuclei...of cloud water. Albrecht...liquid-water content...depending on the atmospheric conditions...the-6-hour recovery from the...

Andrew S. Ackerman; Owen B. Toon; Peter V. Hobbs

1993-10-08T23:59:59.000Z

246

Complex-plasma boundaries  

Science Journals Connector (OSTI)

This study deals with the boundary between a normal plasma of ions and electrons, and an adjacent complex plasma of ions, electrons, and microparticles, as found in innumerable examples in nature. Here we show that the matching between the two plasmas involve electrostatic double layers. These double layers explain the sharp boundaries observed in the laboratory and in astrophysics. A modified theory is derived for the double layers that form at the discontinuity between two different complex plasmas and at the point of contact of three complex plasmas. The theory is applied to the first measurements from the Plasma Kristall Experiment (PKE) Nefedov Laboratory in the International Space Station.

B. M. Annaratone; S. A. Khrapak; P. Bryant; G. E. Morfill; H. Rothermel; H. M. Thomas; M. Zuzic; V. E. Fortov; V. I. Molotkov; A. P. Nefedov; S. Krikalev; Yu. P. Semenov

2002-11-26T23:59:59.000Z

247

Atmospheric Environment 36 (2002) 51855196 FTIR measurements of functional groups and organic mass in  

E-Print Network [OSTI]

the National Center for Atmospheric Research C-130 aircraft during the passing efficiency of a low, with higher Al/Ca ratios in the boundary layer. Organic compounds were present in high and low dust conditions or may condense onto pre- existing particles. Partly as a result of this vapor-to- particle conversion

Russell, Lynn

248

Correlation Between Grain and Grain-Boundary Critical Current Densities in ex situ Coated Conductors with Variable YBa2Cu3O7- ? Layer Thickness  

SciTech Connect (OSTI)

The dependence of the percolative critical current density at low magnetic fields on YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) layer thickness is studied by comparing grain, J{sub c}{sup G}, and grain-boundary, J{sub c}{sup GB}, critical current densities for a series of ex situ processed YBCO films on a RABiTS template. Both critical current densities decrease as a function of thickness and the values of J{sub c}{sup G} and J{sub c}{sup GB} show a clear correlation which suggests the existence of an interaction between Abrikosov-Josephson vortices on the grain boundaries and Abrikosov vortices in the bulk of the grains. This opens the possibility to improve J{sub c}{sup GB} by optimizing the pinning capabilities of the grains.

Palau, A. [ICMAB, Barcelona, Spain; Puig, T. [ICMAB, Barcelona, Spain; Obradors, X. [ICMAB, Barcelona, Spain; Feenstra, Roeland [ORNL; Gapud, Albert Agcaoili [ORNL

2006-01-01T23:59:59.000Z

249

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

SciTech Connect (OSTI)

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)

Elderkin, C.E.

1985-02-01T23:59:59.000Z

250

Large-Eddy Simulation of a Residual Layer: Low-Level Jet, Convective Rolls, and Kelvin–Helmholtz Instability  

Science Journals Connector (OSTI)

Diurnal variations of an atmospheric boundary layer from 0900 LST on day 33 to 0600 LST on day 34 of the Wangara experiment are studied using a large-eddy simulation (LES) model that includes longwave radiation and baroclinicity. The present study ...

Mikio Nakanishi; Ryosuke Shibuya; Junshi Ito; Hiroshi Niino

2014-12-01T23:59:59.000Z

251

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]

used in models for dust storm decay, and an influence on radiative heating due to a non- static dust distribution following a storm can be expected to affect the atmospheric structure (Taylor et al., 2007; Davy et al., 2009). According to temperature... to function at varying temperatures on the Martian surface (-55?C to +5?C) while also allowing for sun-finding to aid rover navigation, digital modeling of Martian surface terrain, high-resolution imaging for sampling in an in-situ environment, and general...

Grounds, Stephanie Beth

2012-02-14T23:59:59.000Z

252

Grain boundary defects initiation at the outer surface of dissimilar welds: Corrosion mechanism studies  

SciTech Connect (OSTI)

Dissimilar welds located on the primary coolant system of the French PWR plants exhibit grain boundary defects in the true austenitic zones of the first buttering layer. If grain boundaries reach the interface, they can extend to the martensitic band. Those defects are filled with compact oxides. In addition, the ferritic base metal presents some pits along the interface. Nowadays, three mechanisms are proposed to explain the initiation of those defects: stress corrosion cracking, intergranular corrosion and high temperature intergranular oxidation. This paper is dealing with the study of the mechanisms involved in the corrosion phenomenon. Intergranular corrosion tests performed on different materials show that only the first buttering layer, even with some {delta} ferrite, is sensitized. The results of stress corrosion cracking tests in water solutions show that intergranular cracking is possible on a bulk material representative of the first buttering layer. It is unlikely on actual dissimilar welds where the ferritic base metal protects the first austenitic layer by galvanic coupling. Therefore, the stress corrosion cracking assumption cannot explain the initiation of the defects in aqueous environment. The results of the investigations and of the corrosion studies led to the conclusion that the atmosphere could be the only possible aggressive environment. This conclusion is based on natural atmospheric exposure and accelerated corrosion tests carried out with SO{sub 2} additions in controlled atmosphere. They both induce a severe intergranular corrosion on true sensitized austenitic materials.

Bouvier, O. De; Yrieix, B. [Electricite De France, Moret Sur Loing (France). Research and Development Division

1995-12-31T23:59:59.000Z

253

Atmospheric heat redistribution and collapse on tidally locked rocky planets  

E-Print Network [OSTI]

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...

Wordsworth, Robin

2014-01-01T23:59:59.000Z

254

Atmospheric Chemistry  

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

competencies Atmospheric Chemistry Atmospheric Chemistry is the study of the composition of the atmosphere, the sources and fates of gases and particles in air, and changes induced...

255

Atmospheres of Brown Dwarfs  

E-Print Network [OSTI]

Brown Dwarfs are the coolest class of stellar objects known to date. Our present perception is that Brown Dwarfs follow the principles of star formation, and that Brown Dwarfs share many characteristics with planets. Being the darkest and lowest mass stars known makes Brown Dwarfs also the coolest stars known. This has profound implication for their spectral fingerprints. Brown Dwarfs cover a range of effective temperatures which cause brown dwarfs atmospheres to be a sequence that gradually changes from a M-dwarf-like spectrum into a planet-like spectrum. This further implies that below an effective temperature of atmospheres of objects marking the boundary between M-Dwarfs and brown dwarfs. Recent developments have sparked the interest in plasma processes in such very cool atmospheres: sporadic and quiescent radio emission has been observed in combination with decaying Xray-activity indicators across the fully convective boundary.

Helling, Christiane

2014-01-01T23:59:59.000Z

256

Entropy Production in Relativistic Jet Boundary Layers  

E-Print Network [OSTI]

Hot relativistic jets, passing through a background medium with a pressure gradient p \\propto r^{-\\eta} where 2 gamma-ray bursts from ...

Kohler, Susanna

2014-01-01T23:59:59.000Z

257

Boundary layer induced by a conical vortex  

Science Journals Connector (OSTI)

......for later convenience. On the other hand, in order to improve the accuracy of the computations as the axis is approached, we rede fi ne the radial coordinate as l =? ln ?, (29) so that the interval 1 ? ? ? 0 is mapped onto 0 ? l < ?. Substituting (26......

R. Fernandez-Feria; J. C. Arrese

2000-11-01T23:59:59.000Z

258

Numerical Experiments in Supersonic Boundary Layer Stability  

E-Print Network [OSTI]

advances in supersonic and hypersonic aerospace technology have led to a renewed interest in the stability Methods Branch M. Y. Hussaini Institute for Computer Applications in Science and Engineering NASA Langley­dimensional quantity superscripts T : transpose â?? : Fourier component 0 : perturbation variable 2 Introduction Recent

Erlebacher, Gordon

259

Thunderstorm influence on boundary layer winds  

E-Print Network [OSTI]

moisture convergence The ambient condition, horizontal moisture convergence, through the vertical, was determined using the vector identity v . qv2 = v2 v q + q v ' V2 p p p (2) where q is specific humidity. Term 1 was computed by the centered finite... the relationship rpo J (v qv) dp ? 7 ('v. . qv) 1 p=900 1 =1 14 where N is the number of 50 mb pressure levels beginning with the 900 mb level to the level of zero divergence, p , the integral of horizontal 0' moisture convergence was determined by summing...

Schmidt, Jill Marie

2012-06-07T23:59:59.000Z

260

Journal of Atmospheric and Solar-Terrestrial Physics 69 (2007) 191211 The magnetosphereionosphere system from the perspective of  

E-Print Network [OSTI]

and plasmasheet boundary layer and in downward-current ``pressure cookers.'' Observational evidence indicating

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Coastal Atmospheric Circulation around an Idealized Cape during Wind-Driven Upwelling Studied from a Coupled Ocean–Atmosphere Model  

Science Journals Connector (OSTI)

The study analyzes atmospheric circulation around an idealized coastal cape during summertime upwelling-favorable wind conditions simulated by a mesoscale coupled ocean–atmosphere model. The domain resembles an eastern ocean boundary with a ...

Natalie Perlin; Eric D. Skyllingstad; Roger M. Samelson

2011-03-01T23:59:59.000Z

262

HYPERsensarium : an archive of atmospheric conditions  

E-Print Network [OSTI]

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 ...

Shaw, Kelly E. (Kelly Evelyn)

2013-01-01T23:59:59.000Z

263

In situ Carbon 13 and Oxygen 18 Ratios of Atmospheric CO2 from Cape Grim,  

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

Oxygen Isotopes and Ratios » 13C and 18O Oxygen Isotopes and Ratios » 13C and 18O Ratios, Atmospheric CO2, Cape Grim In situ Carbon 13 and Oxygen 18 Ratios of Atmospheric CO2 from Cape Grim, Tasmania, Australia: 1982-1993 DOI: 10.3334/CDIAC/atg.db1014 data Data Investigators Francey R. J. and C. E. Allison Description Since 1982, a continuous program of sampling atmospheric CO2 to determine stable isotope ratios has been maintained at the Australian Baseline Air Pollution Station, Cape Grim, Tasmania (40°, 40'56"S, 144°, 41'18"E). The process of in situ extraction of CO2 from air, the preponderance of samples collected in conditions of strong wind from the marine boundary layer of the Southern Ocean, and the determination of all isotope ratios relative to a common high purity CO2 reference gas with isotopic δ13C close to

264

Musical Atmospherics  

Science Journals Connector (OSTI)

... THE characteristics of audio musical atmospherics which are obtained when an ... musical atmospherics which are obtained when an audio amplifier is placed in a long line or aerial have been discussed from time to ...

T. L. ECKERSLEY

1935-01-19T23:59:59.000Z

265

Southeast Pacific atmospheric composition and variability sampled along 20?S during VOCALS-REx  

SciTech Connect (OSTI)

The VAMOS Ocean-Climate-Atmosphere-Land Regional Experiment (VOCALS-REx) was conducted from 15 October to 15 November 2008 in the South East Pacific region to investigate interactions between land, sea and atmosphere in this unique tropical eastern ocean environment and to improve the skill of global and regional models in representing the region. This study synthesises selected aircraft, ship and surface site observations from VOCALS-REx to statistically summarise and characterise the atmospheric composition and variability of the Marine Boundary Layer (MBL) and Free Troposphere (FT) along the 20{sup o} S parallel between 70{sup o} W and 85{sup o} W. Significant zonal gradients in mean MBL sub-micron aerosol particle size and composition, carbon monoxide, ozone and sulphur dioxide were seen over the campaign, with a generally more variable and polluted coastal environment and a less variable, more pristine remote maritime regime. Gradients are observed to be associated with strong gradients in cloud droplet number. The FT is often more polluted in terms of trace gases than the MBL in the mean; however increased variability in the FT composition suggests an episodic nature to elevated concentrations. This is consistent with a complex vertical interleaving of airmasses with diverse sources and hence pollutant concentrations as seen by generalised back trajectory analysis, which suggests contributions from both local and long-range sources. Furthermore, back trajectory analysis demonstrates that the observed zonal gradients both in the boundary layer and the free troposphere are characteristic of marked changes in airmass history with distance offshore - coastal boundary layer airmasses having been in recent contact with the local land surface and remote maritime airmasses having resided over ocean for in excess of ten days. Boundary layer composition to the east of 75{sup o} W was observed to be dominated by coastal emissions from sources to the west of the Andes, with evidence for diurnal pumping of the Andean boundary layer above the height of the marine capping inversion. The climatology presented here aims to provide a valuable dataset to inform model simulation and future process studies, particularly in the context of aerosol-cloud interaction and further evaluation of dynamical processes in the SEP region for conditions analogous to those during VOCALS-REx.

Allen, G.; Kleinman, L.; Coe, H.; Clarke, A.; Bretherton, C.; Wood, R.; Abel, S. J.; Barrett, P.; Brown, P.; George, R.; Freitag, S.; McNaughton, C.; Howell, S.; Shank, L.; Kapustin, V.; Brekhovskikh, V.; Lee, Y.-N.; Springston, S.; Toniazzo, T.; Krejci, R.; Fochesatto, J.; Shaw, G.; Krecl, P.; Brooks, B.; McKeeking, G.; Bower, K. N.; Williams, P. I.; Crosier, J.; Crawford, I.; Connolly, P.; Covert, D.; Bandy, A. R.

2011-01-10T23:59:59.000Z

266

Humidity variations in the atmospheric surface layer  

E-Print Network [OSTI]

anemometer system used in this study, computed for five different wind speeds. 15 View from micrometeorologi cal tower towards the direction from which the wind was blowing for most of the runs select- ed. The left hand side is roughly 230' and the right... ASM Department of Meteorology by the Climatro- nics Corporation. The system consists of three sets of fast response wind, temperature, and relative humidity sensors, as well as a data acquisition system and a tape drive to store the data on magnetic...

Humphrey, Scott Richard

2012-06-07T23:59:59.000Z

267

Layering Technologies  

Science Journals Connector (OSTI)

Planar technology requires that thin layers of materials be formed and patterned sequentially, commencing with a flat rigid substrate. The key aspects of each layer are its Thi...

Ivor Brodie; Julius J. Muray

1992-01-01T23:59:59.000Z

268

Atmospheric Neutrinos  

E-Print Network [OSTI]

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.

Thomas K. Gaisser

2006-12-11T23:59:59.000Z

269

Interactions Between the Daytime Mixed Layer and the Surface: Oklahoma Mesonet and EBBR Heat Fluxes  

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

Interactions Between the Daytime Mixed Layer Interactions Between the Daytime Mixed Layer and the Surface: Oklahoma Mesonet and EBBR Heat Fluxes R. L. Coulter Argonne National Laboratory Argonne, Illinois Introduction Surface layer estimates of surface sensible heat flux have been made at 10 - 14 locations within the Central Facility (CF) of the Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) Program site by using energy balance Bowen ratio (EBBR) stations located mostly in uncultivated areas. The advent of the Oklahoma Mesonet (OKM) with approximately 50 stations within the boundaries of the Cloud and Radiation Testbed (CART) site that measure a variety of meteorological parameters leads to the possibility of using the OKM to provide additional estimates of surface energy budget to augment

270

Hierardlicsl Diagnosis V. V. Zuev Institute of Atmospheric Optics  

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

of Atmospheric Optics Siberian Branch of the Russian Academy of Sciences Tomsk, Russia Systematic observations of the earth's ozone layer over the last ten years indicate a...

271

Finite element analysis of shells with layers  

E-Print Network [OSTI]

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 ...

Hiller, Jean-François, 1974-

2002-01-01T23:59:59.000Z

272

Atmospheric tritium  

SciTech Connect (OSTI)

Research progress for the year 1979 to 1980 are reported. Concentrations of tritiated water vapor, tritium gas and tritiated hydrocarbons in the atmosphere at selected sampling points are presented. (ACR)

Oestlund, H.G.; Mason, A.S.

1980-01-01T23:59:59.000Z

273

Compressed absorbing boundary conditions for the Helmholtz equation  

E-Print Network [OSTI]

Absorbing layers are sometimes required to be impractically thick in order to offer an accurate approximation of an absorbing boundary condition for the Helmholtz equation in a heterogeneous medium. It is always possible ...

Bélanger-Rioux, Rosalie

2014-01-01T23:59:59.000Z

274

Energy Loss of Solar p Modes due to the Excitation of Magnetic Sausage Tube Waves: Importance of Coupling the Upper Atmosphere  

Science Journals Connector (OSTI)

We consider damping and absorption of solar p modes due to their energy loss to magnetic tube waves that can freely carry energy out of the acoustic cavity. The coupling of p modes and sausage tube waves is studied in a model atmosphere composed of a polytropic interior above which lies an isothermal upper atmosphere. The sausage tube waves, excited by p modes, propagate along a magnetic fibril which is assumed to be a vertically aligned, stratified, thin magnetic flux tube. The deficit of p-mode energy is quantified through the damping rate, ?, and absorption coefficient, ?. The variation of ? and ? as a function of frequency and the tube's plasma properties is studied in detail. Previous similar studies have considered only a subphotospheric layer, modeled as a polytrope that has been truncated at the photosphere. Such studies have found that the resulting energy loss by the p modes is very sensitive to the upper boundary condition, which, due to the lack of an upper atmosphere, have been imposed in a somewhat ad hoc manner. The model presented here avoids such problems by using an isothermal layer to model the overlying atmosphere (chromosphere, and, consequently, allows us to analyze the propagation of p-mode-driven sausage waves above the photosphere. In this paper, we restrict our attention to frequencies below the acoustic cut off frequency. We demonstrate the importance of coupling all waves (acoustic, magnetic) in the subsurface solar atmosphere with the overlying atmosphere in order to accurately model the interaction of solar f and p modes with sausage tube waves. In calculating the absorption and damping of p modes, we find that for low frequencies, below ?3.5 mHz, the isothermal atmosphere, for the two-region model, behaves like a stress-free boundary condition applied at the interface (z = –z 0).

A. Gascoyne; R. Jain; B. W. Hindman

2014-01-01T23:59:59.000Z

275

Degenerate Metric Phase Boundaries  

E-Print Network [OSTI]

The structure of boundaries between degenerate and nondegenerate solutions of Ashtekar's canonical reformulation of Einstein's equations is studied. Several examples are given of such "phase boundaries" in which the metric is degenerate on one side of a null hypersurface and non-degenerate on the other side. These include portions of flat space, Schwarzschild, and plane wave solutions joined to degenerate regions. In the last case, the wave collides with a planar phase boundary and continues on with the same curvature but degenerate triad, while the phase boundary continues in the opposite direction. We conjecture that degenerate phase boundaries are always null.

Ingemar Bengtsson; Ted Jacobson

1999-01-23T23:59:59.000Z

276

A comparison of fine particle and aerosol strong acidity at the interface zone (1540 m) and within (452 m) the planetary boundary layer of the Great Gulf and Presidential-Dry River Class I Wildernesses on the Presidential Range, New Hampshire USA  

Science Journals Connector (OSTI)

Mount Washington, NH in the White Mountain National Forest, is flanked to the north-northeast and south by two Class I Wilderness areas, the Great Gulf and Presidential Range-Dry River Wildernesses, respectively. The Clean Air Act protects Class I Area natural resource values from air pollution. Aerosol sulfate, a fine particulate component that is often transported long distances, is a known contributor to visibility degradation and acidic deposition. We examined summertime fine particulate aerosol mass and sulfate, strong acidity and ammonium concentrations from 1988 to 2007 on Mount Washington at two elevations, 452 and 1540 m (msl). The former site is often within, and the latter at the interface of, the planetary boundary layer. Comparisons of sampling interval durations (10 and 24 h) and site vs. site are made. We also examine the extent to which aerosol sulfate is neutralized. Ten hour (daytime) compared to 24 h samples have higher mass and aerosol sulfate concentrations, however paired samples are well correlated. Fine mass concentrations compared between the 452 m and 1540 m sites (standard temperature and pressure corrected) show a weak positive linear relationship with the later being approximately 32% lower. We attribute the lack of a strong correlation to the facts that the 1540 m site is commonly at the interface of and even above the regional planetary boundary layer in summer and that it can intercept different air masses relative to the 452 m site. Sulfate is ?18% lower at the higher elevation site, but comprises a greater percentage of total fine mass; 42% compared to 37% for the high and low elevation site, respectively. Aerosol strong acidity was found to increase with increasing sulfate concentrations at both sites. Further the ratio of hydrogen to sulfate ion was greater in 24 h than 10 h samples at the higher elevation site likely due to overnight transport of fresh acidic aerosols.

Georgia L.D. Murray; Kenneth Kimball; L. Bruce Hill; George A. Allen; Jack M. Wolfson; Alex Pszenny; Thomas Seidel; Bruce G. Doddridge; Alexandra Boris

2009-01-01T23:59:59.000Z

277

atmospheric pressure | OpenEI  

Open Energy Info (EERE)

pressure pressure Dataset Summary Description (Abstract):Atmospheric Pressure (kPa)NASA Surface meteorology and Solar Energy (SSE) Release 6.0 Data Set (Nov 2007)22-year Monthly & Annual Average (July 1983 - June 2005)Parameter: Atmospheric Pressure (kPa)Internet: http://eosweb.larc.nasa.gov/sse/Note 1: SSE Methodology & Accuracy sections onlineNote 2: Lat/Lon values indicate the lower left corner of a 1x1 degree region. Negative values are south and west; positive values are north and east. Boundaries of the -90/-180 region Source U.S. National Aeronautics and Space Administration (NASA), Surface meteorology and Solar Energy (SSE) Date Released March 31st, 2009 (5 years ago) Date Updated Unknown Keywords atmospheric pressure climate NASA SWERA UNEP Data text/csv icon Download Data (csv, 46 MiB)

278

Spectral behavior of the coupled land-atmosphere system  

E-Print Network [OSTI]

The main objective of this thesis is to understand the daily cycle of the energy coupling between the land and the atmosphere in response to a forcing of incoming radiation at their common boundary, the land surface. This ...

Gentine, Pierre

2010-01-01T23:59:59.000Z

279

Testing outer boundary treatments for the Einstein equations  

E-Print Network [OSTI]

Various methods of treating outer boundaries in numerical relativity are compared using a simple test problem: a Schwarzschild black hole with an outgoing gravitational wave perturbation. Numerical solutions computed using different boundary treatments are compared to a `reference' numerical solution obtained by placing the outer boundary at a very large radius. For each boundary treatment, the full solutions including constraint violations and extracted gravitational waves are compared to those of the reference solution, thereby assessing the reflections caused by the artificial boundary. These tests use a first-order generalized harmonic formulation of the Einstein equations. Constraint-preserving boundary conditions for this system are reviewed, and an improved boundary condition on the gauge degrees of freedom is presented. Alternate boundary conditions evaluated here include freezing the incoming characteristic fields, Sommerfeld boundary conditions, and the constraint-preserving boundary conditions of Kreiss and Winicour. Rather different approaches to boundary treatments, such as sponge layers and spatial compactification, are also tested. Overall the best treatment found here combines boundary conditions that preserve the constraints, freeze the Newman-Penrose scalar Psi_0, and control gauge reflections.

Oliver Rinne; Lee Lindblom; Mark A. Scheel

2007-04-05T23:59:59.000Z

280

Running Boundary Condition  

E-Print Network [OSTI]

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.

Ohya, Satoshi; Tachibana, Motoi

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Running Boundary Condition  

E-Print Network [OSTI]

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.

Satoshi Ohya; Makoto Sakamoto; Motoi Tachibana

2010-05-25T23:59:59.000Z

282

Fiscal year 1997 summary report of the NOAA Atmospheric Sciences Modeling Division to the U.S. Environmental Protection Agency. Technical memo  

SciTech Connect (OSTI)

During Fiscal Year 1997, the Atmospheric Sciences Modeling Division provided meteorological and modeling support to the US Environmental Protection Agency. Research efforts emphasized the development and evaluation of air quality models using numerical and physical techniques supported by field studies. Among the significant research studies were the continued development and evaluation of Models-3; development of a community multiscale air quality modeling system; continued development and application of air quality models for mercury, dioxin, and heavy metals; evaluation of enhanced human exposure models; analysis and modeling of dust resuspension data; study of buoyant puff dispersion in the convective boundary layer; and development of methodologies to estimate the drift of airborne agricultural pesticides.

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

1998-06-01T23:59:59.000Z

283

Boundaries and Topological Algorithms  

E-Print Network [OSTI]

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. ...

Fleck, Margaret Morrison

1988-09-01T23:59:59.000Z

284

Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems  

E-Print Network [OSTI]

response of the ocean eddies . The power spectrum of thethe ocean. As such, the larger energy in the power spectrumocean eddies. On the other hand, Smoothed ROMS has higher power

Putrasahan, Dian Ariyani

2012-01-01T23:59:59.000Z

285

Terrestrial magma ocean solidification and formation of a candidate D" layer  

E-Print Network [OSTI]

In this thesis we investigate the solidification of early magma oceans on the Earth and the formation of a deep dense layer at the core-mantle boundary. We also study the concentrations and densities of the last layers of ...

Springmann, Alessondra

2011-01-01T23:59:59.000Z

286

Experimental and theoretical study of turbulent oscillatory boundary layers  

E-Print Network [OSTI]

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 ...

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

2013-01-01T23:59:59.000Z

287

BOUNDARY LAYER CONTROL IN PIPES THROUGH STRONG INJECTION  

E-Print Network [OSTI]

normal-injection model. y Coal gasification gas mixture ,ZUSAMMENFASSUNG) In coal gasification, oxidation andthan that in the coal gasification mixture. Outside the

Yeung, William Chor Chun

2014-01-01T23:59:59.000Z

288

Distributed Roughness Receptivity in a Flat Plate Boundary Layer  

E-Print Network [OSTI]

- Distributed Receptivity . . . . . 6 2. FACILITY DESCRIPTION - THE KLEBANOFF–SARIC WIND TUNNEL 11 2.1 Test Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Fan and Motor... of this dissertation describes the Klebanoff–Saric Wind Tunnel facility, which was used for this experiment. Section 3 describes the experimental setup (roughness design and the flat plate model) and defines the metrics by which the flow field is decomposed...

Kuester, Matthew Scott

2014-04-18T23:59:59.000Z

289

Thermal boundary layer development in dispersed flow film boiling  

E-Print Network [OSTI]

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 ...

Hull, Lawrence M.

1982-01-01T23:59:59.000Z

290

Boundary layer ingesting inlet design for a silent aircraft  

E-Print Network [OSTI]

(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 ...

Freuler, Patrick N., 1980-

2005-01-01T23:59:59.000Z

291

Computation of Hypersonic Double Wedge Shock / Boundary Layer Interaction  

E-Print Network [OSTI]

of a Scramjet Demonstrator for Future Space Transportation Systems" a combined numerical as well as experimental

292

DIFFUSION OF A CHEMICAL SPECIES THROUGH A VISCOUS BOUNDARY LAYER  

E-Print Network [OSTI]

use an operating coal gasifier will be discussed. ofof the products of the gasifier with H S removed, then theconditions existing in coal gasifiers the con- centration

Keller, J.

2011-01-01T23:59:59.000Z

293

BOUNDARY LAYER CONTROL IN PIPES THROUGH STRONG INJECTION  

E-Print Network [OSTI]

the environment in a gasifier contains hydrogen, water,compo- nents of the gasifier must be corrosion resistant atis used in existing coal gasifiers. Since hydrogen sulfide

Yeung, William Chor Chun

2014-01-01T23:59:59.000Z

294

Large-Scale Streamwise Turbulent Structures in Hypersonic Boundary Layers  

E-Print Network [OSTI]

Marine Corps for allowing me the time off during my career and necessary financial support to complete this endeavor. The help and guidance provided by Scott Peltier and Dr. Ray Humble have been indispensable in the completion of this work. Scott... helped greatly in the initial setup and design of this experiment. He has also been completely open in sharing his data and findings to help complete and emphasize my own. Dr. Humble was a source of inspiration and both conceptual and technical...

English, Benjamin L.

2013-04-22T23:59:59.000Z

295

Control of cavity-driven separated boundary layer  

E-Print Network [OSTI]

and D. S. Henningson1 1 KTH Mechanics, S-100 44 Stockholm, Sweden 2 Laboratoire J.A. Dieudonn´e, Parc, like for instances the Tollmien-Schlichting waves on an aeroplane wing (see e.g. H¨ogberg & Henningson, thanks to increasing computational power and the use of Arnoldi method (see Edwards et al. (1994

Hoepffner, JĂ©rĂ´me

296

ccsd00002450, Boundary layers and emitted excitations in  

E-Print Network [OSTI]

and Bose-Einstein condensates of ultra-cold atomic vapor. In the case of super uid 4 He, the NLSE can to be negligible. This is clearly the case in recent experiments [5] that are performed at temperatures below 130 mK

297

Supersonic turbulent boundary layers with periodic mechanical non-equilibrium  

E-Print Network [OSTI]

. It was documented that proper roughness selection coupled with a sufficiently strong favorable pressure gradient produced regions of �negative� production in the transport of turbulent stress. This led to localized areas of significant turbulence stress...

Ekoto, Isaac Wesley

2007-04-25T23:59:59.000Z

298

Boundary-Layer Meteorology An International Journal of Physical,  

E-Print Network [OSTI]

simulations agree well with observed soundings in temperature, wind speed, and wind direc- tion and their interactions with local-scale processes are analyzed to understand the factors that influence the onset-valley · Numerical simulation · Salt Lake City · Weather Research and Forecasting (WRF) model 1 Introduction

Pu, Zhaoxia

299

Z(N) model of grain-boundary wetting  

Science Journals Connector (OSTI)

Even though van der Waals forces should prevent the wetting of a grain boundary by a liquid at the melting temperature, experiment and simulations indicate an instability in grain-boundary structure in the vicinity of this temperature. We study the structure of analogous boundaries in a Z(N) model in which a region of solid with a given orientation is replaced by a spin in that orientation. Different interfacial behaviors are found for different regions of a model parameter which is related to N. For the value appropriate to grain boundaries, our model suggests that boundaries of a sufficiently large angle should be unstable, not to the intrusion of a layer of liquid, however, but to the intrusion of solid of intermediate orientation. Such an intrusion can occur below the melting temperature.

M. Schick and Wei-Heng Shih

1987-04-01T23:59:59.000Z

300

Turbulent Vertical Kinetic Energy in the Ocean Mixed Layer  

Science Journals Connector (OSTI)

Vertical velocities in the ocean boundary layer were measured for two weeks at an open ocean, wintertime site using neutrally buoyant floats. Simultaneous measurements of the surface meteorology and surface waves showed a large variability in ...

Eric A. D'Asaro

2001-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Superconducting nano-layer coating without insulator  

E-Print Network [OSTI]

The superconducting nano-layer coating without insulator layer is studied. The magnetic-field distribution and the forces acting on a vortex are derived. Using the derived forces, the vortex-penetration field and the lower critical magnetic field can be discussed. The vortex-penetration field is identical with the multilayer coating, but the lower critical magnetic field is not. Forces acting on a vortex from the boundary of two superconductors play an important role in evaluations of the free energy.

Kubo, Takayuki

2014-01-01T23:59:59.000Z

302

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

E-Print Network [OSTI]

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.

H. -G. Ludwig

2002-08-30T23:59:59.000Z

303

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

SciTech Connect (OSTI)

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).

Morrison, PI Hugh

2012-09-21T23:59:59.000Z

304

Our Dusty Atmosphere | Department of Energy  

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

Dusty Atmosphere Dusty Atmosphere Our Dusty Atmosphere September 6, 2011 - 4:26pm Addthis A heavy layer of air pollution, a mix of aerosol particles and vapors, obscures the view over Mexico City. Two studies by the Pacific Northwest National Laboratory show the importance of including the small-scale effects of aerosols in climate modeling. | Image courtesy of PNNL A heavy layer of air pollution, a mix of aerosol particles and vapors, obscures the view over Mexico City. Two studies by the Pacific Northwest National Laboratory show the importance of including the small-scale effects of aerosols in climate modeling. | Image courtesy of PNNL Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science What are the key facts? Researchers are developing a better understanding of the effects of

305

Our Dusty Atmosphere | Department of Energy  

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

Our Dusty Atmosphere Our Dusty Atmosphere Our Dusty Atmosphere September 6, 2011 - 4:26pm Addthis A heavy layer of air pollution, a mix of aerosol particles and vapors, obscures the view over Mexico City. Two studies by the Pacific Northwest National Laboratory show the importance of including the small-scale effects of aerosols in climate modeling. | Image courtesy of PNNL A heavy layer of air pollution, a mix of aerosol particles and vapors, obscures the view over Mexico City. Two studies by the Pacific Northwest National Laboratory show the importance of including the small-scale effects of aerosols in climate modeling. | Image courtesy of PNNL Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science What are the key facts? Researchers are developing a better understanding of the effects of

306

Boundaries on Spacetimes: An Outline  

E-Print Network [OSTI]

The causal boundary construction of Geroch, Kronheimer, and Penrose has some universal properties of importance for general studies of spacetimes, particularly when equipped with a topology derived from the causal structure. Properties of the causal boundary are detailed for spacetimes with spacelike boundaries, for multi-warped spacetimes, for static spacetimes, and for spacetimes with group actions.

Steven G. Harris

2003-10-15T23:59:59.000Z

307

Topology of the Future Chronological Boundary: Universality for Spacelike Boundaries  

E-Print Network [OSTI]

A method is presented for imputing a topology for any chronological set, i.e., a set with a chronology relation, such as a spacetime or a spacetime with some sort of boundary. This topology is shown to have several good properties, such as replicating the manifold topology for a spacetime and replicating the expected topology for some simple examples of spacetime-with-boundary; it also allows for a complete categorical characterization, in topological categories, of the Future Causal Boundary construction of Geroch, Kronheimer, and Penrose, showing that construction to have a universal property for future-completing chronological sets with spacelike boundaries. Rigidity results are given for any reasonable future completion of a spacetime, in terms of the GKP boundary: In the imputed topology, any such boundary must be homeomorphic to the GKP boundary (if all points have indecomposable pasts) or to a topological quotient of a closely related boundary (if boundaries are spacelike). A large class of warped-product-type spacetimes with spacelike boundaries is examined, calculating the GKP and other possible boundaries, and showing that the imputed topology gives expected results; included among these are the Schwarzschild singularity and those Robertson-Walker singularities which are spacelike.

Steven G. Harris

1999-07-19T23:59:59.000Z

308

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

E-Print Network [OSTI]

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

Hourdin, Chez Frédéric

309

Preprint of the paper "A Boundary Element Numerical Approach for Substation Grounding in a Two  

E-Print Network [OSTI]

Preprint of the paper "A Boundary Element Numerical Approach for Substation Grounding in a Two://caminos.udc.es/gmni #12;A BOUNDARY ELEMENT NUMERICAL APPROACH FOR SUBSTATION GROUNDING IN A TWO LAYER EARTH STRUCTURE3~na, SPAIN SUMMARY Analysis and design of substation grounding requires computing the distribution

Colominas, Ignasi

310

Gas-surface interaction and boundary conditions for the Boltzmann equation  

E-Print Network [OSTI]

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

Mieussens, Luc

311

Dependence of offshore wind turbine fatigue loads on atmospheric stratification  

Science Journals Connector (OSTI)

The stratification of the atmospheric boundary layer (ABL) is classified in terms of the M-O length and subsequently used to determine the relationship between ABL stability and the fatigue loads of a wind turbine located inside an offshore wind farm. Recorded equivalent fatigue loads, representing blade-bending and tower bottom bending, are combined with the operational statistics from the instrumented wind turbine as well as with meteorological statistics defining the inflow conditions. Only a part of all possible inflow conditions are covered through the approximately 8200 hours of combined measurements. The fatigue polar has been determined for an (almost) complete 360° inflow sector for both load sensors, representing mean wind speeds below and above rated wind speed, respectively, with the inflow conditions classified into three different stratification regimes: unstable, neutral and stable conditions. In general, impact of ABL stratification is clearly seen on wake affected inflow cases for both blade and tower fatigue loads. However, the character of this dependence varies significantly with the type of inflow conditions – e.g. single wake inflow or multiple wake inflow.

K S Hansen; G C Larsen; S Ott

2014-01-01T23:59:59.000Z

312

Stratigraphic Boundaries | Open Energy Information  

Open Energy Info (EERE)

Stratigraphic Boundaries Stratigraphic Boundaries Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Stratigraphic Boundaries Dictionary.png Stratigraphic Boundaries: No definition has been provided for this term. Add a Definition Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault Fault Intersection Accommodation Zone Displacement Transfer Zone Pull-Apart in Strike-Slip Fault Zone Intrusion Margins and Associated Fractures Stratigraphic Boundaries Fissure Swarms Caldera Rim Margins Lithologically Controlled Hydrothermal circulation may occur at the contacts between different lithologies. Examples

313

Atmospheric Transport of Radionuclides  

SciTech Connect (OSTI)

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.

Crawford, T.V.

2003-03-03T23:59:59.000Z

314

Surface Temperature and Surface-Layer Turbulence in a Convective Boundary Layer  

E-Print Network [OSTI]

The vertical gradient of horizontal wind-speed was estimateda larger vertical gradient of horizontal wind-speed in thewind speed, direction, temperature, humidity up to 20 km with a vertical

Garai, Anirban; Pardyjak, Eric; Steeneveld, Gert-Jan; Kleissl, Jan

2013-01-01T23:59:59.000Z

315

Surface Temperature and Surface-Layer Turbulence in a Convective Boundary Layer  

E-Print Network [OSTI]

are density, specific heat of the soil, and grid size in theThe ground heat-flux G then computed from T g as grid was

Garai, Anirban; Pardyjak, Eric; Steeneveld, Gert-Jan; Kleissl, Jan

2013-01-01T23:59:59.000Z

316

8, 10691088, 2008 Atmospheric  

E-Print Network [OSTI]

into the atmosphere (Molina et al., 1974; Farman et al., 1985) has led to an interna- tional effort to replace

Boyer, Edmond

317

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...with *the plasma frethe progress...explorcreated an even larger number of...the upper atmosphere and ionosphere...the upper atmosphere. For this...ionospheric plasma motion simul-taneously...field is large, the horizontal...resolved. The atmospheric gravity waves...simul-taneously at a large number of...two regions plasma drifts separated...

J. V. Evans

1972-05-05T23:59:59.000Z

318

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...DATA, JOURNAL OF ATMOSPHERIC AND TERRESTRIAL...IN NEAR-EARTH PLASMA, SPACE SCIENCE...INVESTIGATION OF WHISTLING ATMOSPHERICS, PHILOSOPHICAL...TRANSPOLAR EXOSPHERIC PLASMA .1. PLASMASPHERE...dynamics of the upper atmosphere. For this purpose...the ionospheric plasma motion simul-taneously...

J. V. Evans

1972-05-05T23:59:59.000Z

319

5, 60416076, 2005 Atmospheric  

E-Print Network [OSTI]

opportunity to examine atmospheric oxidation in a megacity that has more pollution than typical USACPD 5, 6041­6076, 2005 Atmospheric oxidation in the Mexico City Metropolitan Area T. R. Shirley et.atmos-chem-phys.org/acpd/5/6041/ SRef-ID: 1680-7375/acpd/2005-5-6041 European Geosciences Union Atmospheric Chemistry

Boyer, Edmond

320

Building biomedical materials layer-by-layer  

E-Print Network [OSTI]

In this materials perspective, the promise of water based layer-by-layer (LbL) assembly as a means of generating drug-releasing surfaces for biomedical applications, from small molecule therapeutics to biologic drugs and ...

Hammond, Paula T.

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Sensitivities of zonal mean atmospheric circulation to SST warming in an aquaplanet model  

E-Print Network [OSTI]

warming, the Hadley cell is intensified in the deep tropics, yet the Hadley cell boundary contracts, storm tracks, or the boundaries of Hadley cell circulations under global warming [e.g., Yin, 2005]. In the troposphere, however, the atmosphere displays nearly opposite changes in the Hadley cell width

Chen, Gang

322

Modeling inductively coupled plasmas: The coil current boundary condition  

Science Journals Connector (OSTI)

In modeling inductively coupled plasmas the boundary condition for the electromagnetic field equations can be treated by specifying either the current in the induction coil or the total power dissipated in the plasma. This paper presents a method for using the coil current boundary condition. An advantage of using the coil current boundary condition is that coil current unlike plasma power dissipation is easily measured; in this approach the plasma power dissipation is an outcome of the calculation. The results of sample calculations are presented covering a range of coil currents from 59 to 110 A. The conditions of the calculations correspond to experimental argon plasmas at atmospheric pressure and at 3.0 MHz frequency. The calculated isotherms are in good qualitative agreement with photographs of the laboratory plasmas.

Benjamin W. Yu; Steven L. Girshick

1991-01-01T23:59:59.000Z

323

A new mechanism for ocean-atmosphere coupling in midlatitudes  

E-Print Network [OSTI]

to the tropopause are met frequently over all major western boundary currents and their extension in the oceanicA new mechanism for ocean-atmosphere coupling in midlatitudes A. Czaja, and N. Blunt Department The role of moist convection in "transferring" upward surface ocean condi- tions throughout the troposphere

324

Intermittent Turbulence in the Very Stable Ekman Layer  

SciTech Connect (OSTI)

INTERMITTENT TURBULENCE IN THE VERY STABLE EKMAN LAYER This study describes a Direct Numerical Simulation (DNS) of a very stable Ekman layer in which a constant downward heat flux is applied at the lower boundary, thus cooling the fluid above. Numerical experiments were performed in which the strength of the imposed heat flux was varied. For downward heat fluxes above a certain critical value the turbulence becomes intermittent and, as the heat flux increases beyond this value, the flow tends to relaminarize because of the very strong ambient stratification. We adopt Mahrt?s (1999) definition of the very stable boundary layer as a boundary layer in which intermittent, rather than continuous turbulence, is observed. Numerical experiments were used to test various hypothesis of where in ?stability parameter space? the very stable boundary layer is found. These experiments support the findings of Howell and Sun (1999) that the boundary layer will exhibit intermittency and therefore be categorized as ?very stable?, when the stability parameter, z/L, exceeds unity. Another marker for the very stable boundary layer, Derbyshire?s (1990) maximum heat flux criterion, was also examined. Using a case study drawn from the simulations where turbulence intermittency was observed, the mechanism that causes the intermittence was investigated. It was found that patchy turbulence originates from a vigorous inflectional, Ekman-like instability -- a roll cell -- that lifts colder air over warmer air. The resulting convective instability causes an intense burst of turbulence. This turbulence is short-lived because the lifting motion of the roll cell, as well as the roll cell itself, is partially destroyed after the patchy turbulence is generated. Examples of intermittent turbulence obtained from the simulations appear to be consistent with observations of intermittency even though the Reynolds number of the DNS is relatively low (400).

Barnard, James C.

2001-01-05T23:59:59.000Z

325

Improvement of Moist and Radiative Processes in Highly Parallel Atmospheric General Circulation Models: Validation and Development  

SciTech Connect (OSTI)

Research on designing an integrated moist process parameterization package was carried. This work began with a study that coupled an ensemble of cloud models to a boundary layer model to examine the feasibility of such a methodology for linking boundary layer and cumulus parameterization schemes. The approach proved feasible, prompting research to design and evaluate a coupled parameterization package for GCMS. This research contributed to the development of an Integrated Cumulus Ensemble-Turbulence (ICET) parameterization package. This package incorporates a higher-order turbulence boundary layer that feeds information concerning updraft properties and the variances of temperature and water vapor to the cloud parameterizations. The cumulus ensemble model has been developed, and initial sensitivity tests have been performed in the single column model (SCM) version of CCM2. It is currently being coupled to a convective wake/gust front model. The major function of the convective wake/gust front model is to simulate the partitioning of the boundary layer into disturbed and undisturbed regions. A second function of this model is to predict the nonlinear enhancement of surface to air sensible heat and moisture fluxes that occur in convective regimes due to correlations between winds and anomalously cold, dry air from downdrafts in the gust front region. The third function of the convective wake/gust front model is to predict the amount of undisturbed boundary layer air lifted by the leading edge of the wake and the height to which this air is lifted. The development of the wake/gust front model has been completed, and it has done well in initial testing as a stand-alone component. The current task, to be completed by the end of the funding period, is to tie the wake model to a cumulus ensemble model and to install both components into the single column model version of CCM3 for evaluation. Another area of parametrization research has been focused on the representation of cloud radiative properties. An examination of the CCM2 simulation characteristics indicated that many surface temperature and warm land precipitation problems were linked to deficiencies in the specification of cloud optical properties, which allowed too much shortwave radiation to reach the surface. In-cloud liquid water path was statically specified in the CCM2 using a "prescribed, meridionally and height varying, but time independent, cloud liquid water density profile, which was analytically determined from a meridionally specified liquid water scale height. Single-column model integrations were conducted to explore alternative formulations for the cloud liquid water path diagnostic, converging on an approach that employs a similar, but state-dependent technique for determining in-cloud liquid water concentration. The new formulation, results in significant improvements to both the top-of- atmosphere and surface energy budgets. In particular, when this scheme is incorporated in the three-dimensional GCM, simulated July surface temperature biases are substantially reduced, where summer precipitation over the northern hemisphere continents, as well as precipitation rates over most all warm land areas, is more consistent with observations". This improved parameterization has been incorporated in the CCM3.

Frank, William M.; Hack, James J.; Kiehl, Jeffrey T.

1997-02-24T23:59:59.000Z

326

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

SciTech Connect (OSTI)

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.

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

327

Atmospheres and radiating surfaces of neutron stars  

E-Print Network [OSTI]

The beginning of the 21st century was marked by a breakthrough in the studies of thermal radiation of neutron stars. Observations with modern space telescopes have provided a wealth of valuable information. Being correctly interpreted, this information can elucidate physics of superdense matter in the interiors of these stars. The theory of formation of thermal spectra of neutron stars is based on the physics of plasmas and radiative processes in stellar photospheres. It provides the framework for interpretation of observational data and for extracting neutron-star parameters from these data. This paper presents a review of the current state of the theory of surface layers of neutron stars and radiative processes in these layers, with the main focus on the neutron stars that possess strong magnetic fields. In addition to the conventional deep (semi-infinite) atmospheres, radiative condensed surfaces of neutron stars and "thin" (finite) atmospheres are also considered.

Potekhin, A Y

2014-01-01T23:59:59.000Z

328

AtmosphericAtmospheric Composition Introduction The division investigates the atmospheric  

E-Print Network [OSTI]

development on observation side was the installation of an ozone observation station in Surinam in close co-operation with the Surinam Meteorological Service. Processes in the tropical regions are important for the global climate and the global atmospheric composition. The participation in Indoex (Indian Ocean Experiment) and this Surinam

Haak, Hein

329

2. System boundaries; Balance equations  

E-Print Network [OSTI]

;5/28 Systems and boundaries /3 An isolated system is a special kind of closed system Pictures: KJ05 Q = heat W Example: an electric hot water heater in a house ­ The electric heater is a closed system ­ The water1/28 2. System boundaries; Balance equations Ron Zevenhoven �bo Akademi University Thermal and flow

Zevenhoven, Ron

330

Sensitivity Analysis for Decision Boundaries  

Science Journals Connector (OSTI)

A novel approach is presented to visualize and analyze decision boundaries for feedforward neural networks. First order sensitivity analysis of the neural network output function with respect to input perturbations is used to visualize the position ... Keywords: decision boundary, feature extraction, feedforward neural network, irrelevant parameters, pruning, sensitivity analysis

A. P. Engelbrecht

1999-12-01T23:59:59.000Z

331

Atmospheric Radiation Measurement Program  

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

3 3 ARM 2003 Tom Ackerman Chief Scientist Tom Ackerman Chief Scientist ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement WARNING! WARNING! Today is April 1 But that has NO bearing on this message Today is April 1 But that has NO bearing on this message ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement Two Topics Two Topics * Status of ARM (quick overview) * Science plan - ARM in the next 5 years * Status of ARM (quick overview) * Science plan - ARM in the next 5 years ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement ARM Status - Science ARM Status - Science * Steadily increasing productivity - Poster session - over 220 posters (may need to do something about submissions next year) - Peer-reviewed articles: 2.5 to 3 per year per

332

Atmospheric Neutrino Fluxes  

E-Print Network [OSTI]

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

Thomas K. Gaisser

2005-02-18T23:59:59.000Z

333

ARM - Atmospheric Heat Budget  

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

ListAtmospheric Heat Budget Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About...

334

A general boundary integral approach to elliptical boundary value problems  

Science Journals Connector (OSTI)

Based upon basic principles of continuum theory a unified direct boundary integral representation of three-dimensional elliptical boundary value problems is presented. Within this framework many interesting engineering problems, e.g. elastostatics, manetostatic and heat conduction may be considered. The special analysis of the problem under consideration appears in the fundamental solutions. A general procedure for derivation of fundamental solutions with regard to an effecient numerical realisation of the boundary element method is discussed. In the appendix a FORTRAN IV code concerning the calculation of fundamental solutions in anisotropic elastostatics is presented.

H. Gründemann

1987-01-01T23:59:59.000Z

335

Intermediate layers in the a-Si:H growth processes  

SciTech Connect (OSTI)

The intermediate layers (IL) exist at the boundary between liquid (plasma, gas) and solid phases during production processes of a-Si:H. The IL properties differ from the properties of the boundary regions anomaly. The substance in IL is in a strong nonequilibrium state of the bifurcation or the cascade of bifurcations. The processes in the IL determine the properties and the structure of the material being produced.

Aivazov, A.A.; Bodyagin, N.V. [Moscow Inst. of Electronic Technology (Russian Federation); Vikhrov, S.P. [Radiotechnical Academy, Ryazan (Russian Federation). CR Faculty

1996-12-31T23:59:59.000Z

336

Flow boundary conditions for chain-end adsorbing polymer blends  

E-Print Network [OSTI]

Using the phenol-terminated polycarbonate blend as an example, we demonstrate that the hydrodynamic boundary conditions for a flow of an adsorbing polymer melt are extremely sensitive to the structure of the epitaxial layer. Under shear, the adsorbed parts (chain ends) of the polymer melt move along the equipotential lines of the surface potential whereas the adsorbed additives serve as the surface defects. In response to the increase of the number of the adsorbed additives the surface layer becomes thinner and solidifies. This results in a gradual transition from the slip to the no-slip boundary condition for the melt flow, with a non-monotonic dependence of the slip length on the surface concentration of the adsorbed ends.

X. Zhou; D. Andrienko; L. Delle Site; K. Kremer

2005-07-18T23:59:59.000Z

337

Toward a Diurnal Climatology of Cold-Season Turbulence Statistics in Continental Stratocumulus as Observed by the Atmospheric Radiation Millimeter- Wavelength Cloud Radars  

SciTech Connect (OSTI)

Numerous observational studies of marine stratocumulus have demonstrated a pronounced diurnal cycle. At night, longwave flux divergence at the top of the cloud drives negatively buoyant eddies that tend to keep the boundary layer well mixed. During the day, solar absorption by the cloud tends to reduce the turbulent intensity and often decouples the planetary boundary layer (PBL) into cloud- and sub-cloud circulations. The delicate balance between turbulent intensity, entrainment, and fluxes dictates cloud geometry and persistence, which can significantly impact the shortwave radiation budget. Millimeter-wavelength cloud radars (MMCRs) have been used to study the turbulent structure of boundary layer stratocumulus (e.g. Frisch et al. 1995; Kollias and Albrecht 2000). Analysis is confined to nondrizzling or lightly drizzling cloud systems for which precipitation contamination is negligible. Under such assumptions the Doppler velocity field becomes a proxy for vertical velocity. Prior research has mainly consisted of a few case studies of specific cloud systems using radar scan strategies optimized for this particular cloud type. The MMCR operating at the Southern Great Plains Atmospheric Radiation Measurement Climate Research Facility is broadly configured to be able to detect many different cloud types over a broad range of reflectivities and altitudes, so it is not specifically optimized for PBL clouds. Being in more-or-less continuous operation since the end of 1996, it does, however, have the advantage of long data coverage, which suggests that statistically significant measures of the diurnal cycle of turbulence should be attainable. This abstract summarizes the first few steps toward this goal, using 7 months of cold season MMCR data.

Mechem, D.B.; Kogan, Y.L.; Childers, M.E.; Donner, K.M.

2005-03-18T23:59:59.000Z

338

The impact of traffic emissions on atmospheric ozone and OH: results from QUANTIFY  

E-Print Network [OSTI]

on the boundary layer. The effect of ship emissions does notfor road. Globally the effect of ship emissions on ozone insouthern hemisphere the effect of ship emissions is among

2009-01-01T23:59:59.000Z

339

Theory of Grain Boundary Diffusion  

Science Journals Connector (OSTI)

The previously proposed dependence of the structure of grain boundaries upon the angle of disorientation of the two grains is used as a basis of a quantitative consideration of diffusion along grain boundaries and in particular of the apparent activation energies. At small angles in the dislocation range the diffusion is controlled by volume diffusion mechanism. At high angles near 45° the model of a uniform grain boundary is applicable. In the intermediate range an array of rod-like areas of distorted lattice leads to low or even negative apparent activation energies. The theory is in good agreement with experiment.

R. Smoluchowski

1952-08-01T23:59:59.000Z

340

Conference on Atmospheric Pollution  

Science Journals Connector (OSTI)

... THE half-yearly Conference of representatives of local authorities and other organisations co-operating with the Department of Scientific ... of atmospheric pollution was held in the offices of the Department on May 25. The Conference received from Dr. G. M. B. Dobson, chairman of the Atmospheric Pollution ...

1936-05-30T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

A Model-Based Decomposition of the Sea Ice–Atmosphere Feedback over the Barents Sea during Winter  

Science Journals Connector (OSTI)

The feedback between Barents Sea ice and the winter atmosphere was studied in a modeling framework by decomposing it into two sequential boundary forcing experiments. The Community Ice Code (CICE) model was initialized with anomalously high sea ...

Jessica Liptak; Courtenay Strong

2014-04-01T23:59:59.000Z

342

Atmospheric Pollution Research 1 (2010) 220228 Atmospheric Pollution Research  

E-Print Network [OSTI]

Atmospheric Pollution Research 1 (2010) 220228 Atmospheric Pollution Research www in modeling of the associated multiphase processes. Iron redox species are important pollutants. The oxidative capacity of the atmospheric cloud water decreases when dissolution is included

Boyer, Edmond

343

Earth's Core Hottest Layer  

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

Earth's Core Hottest Layer Earth's Core Hottest Layer Name: Alfred Status: Grade: 6-8 Location: FL Country: USA Date: Spring 2011 Question: Why is the inner core the hottest layer? How is that possible? Replies: There are two factors causing the center of the Earth hotter than various layers of the Earth's. First, the more dense is the layer. The denser layer, the hotter it will be. In addition, the source of the heating is due to heat produced by nuclear decay. These substances tend to be more dense than lower dense substances. So the source of heat (temperature) is higher, the greater will be the temperature. Having said all that, the reasons are rather more complicated in the "real" Earth. If the inner layers were less dense they would rise (bubble) to the "surface" leaving the inner layers more dense and thus hotter layers.

344

The Method of Boundary Perturbation,  

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

Method of Boundary Perturbation, Method of Boundary Perturbation, and Its Application to Wakefield Calculationst Weiren Chou+ Advanced Photon Source Argonne National Laboratory 9700 S. Cass Ave. Argonne, IL 60439 USA Spring Meeting of The American Physical Society Division of Physics of Beams Washington, D.C. April 16-19, 1990 tWork supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract W-31-109-ENG-38. tPresent address: SSC Laboratory, Accelerator Division, MS-I046, 2550 Beckleymeade Ave., Dallas, TX 75237, USA. LS-/~ Boundary Perturbation, and Its Application to Wakefield Calculations ABSTRACT The boundary perturbation method, suggested by Zhang and, independently, by Chatard-Moulin, Cooper, and their colleagues, is employed to the wakefield cal-

345

South Campus Boundary/Landscape  

E-Print Network [OSTI]

South Campus Boundary/Landscape April 18, 2012 #12;#12;7:00 - 7:05 Introductions and Review of the Agenda 7:05 - 7:20 Principles of the South Campus Boundary/Landscape from the Feb 21 Design Charette 7:20 - 7:30 Landscape Examples 7:30 - 7:45 Concepts and Ideas for LeMarchant St. 7:45 - 7:50 Break

Brownstone, Rob

346

Charge Transport Anisotropy Due to Grain Boundaries in Directionally  

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

Charge Transport Anisotropy Due to Grain Charge Transport Anisotropy Due to Grain Boundaries in Directionally Crystallized Thin Films of Regio-Regular Poly(3-hexylthiophene) Semicrystalline polymers, such as polythiophenes, hold much promise as active layers in printable electronic devices such as photovoltaic cells, sensors, and thin film transistors. As organic semiconductors approach commercialization, there is a need to better understand the relationship between charge transport and microstructure, in particular, to identify the inherent bottlenecks to charge transport. In semicrystalline and polycrystalline materials, charge transport is most likely dominated by grain-boundary effects, although the exact mechanism is not well understood. Unfortunately, grain boundaries in semicrystalline thin films are difficult to characterize: the grains are too small to allow for measurements across individual grain boundaries (as is often done for polycrystalline films of small molecules) and bulk measurements are complicated by the unknown orientation of polymer chains within the grain. To better understand the effect of chain orientation on grain boundaries, we use anisotropic thin films of poly(3-hexylthiophene) (P3HT) - one of the most well-studied polymeric semiconductors, as a tool to study charge transport.

347

Atmospheric Physics and Earth Observations  

Science Journals Connector (OSTI)

...has been used by atmospheric modelers as a vertical...Ackerman, in Atmospheric Physics from Spacelab...shut-tle allows recovery of the film, we...dry nitrogen at atmospheric pressure. To avoid water condensation on the optical...

M. HERSÉ

1984-07-13T23:59:59.000Z

348

Convective heat transfer in a locally heated plane incompressible fluid layer  

Science Journals Connector (OSTI)

The problem of convection in a plane horizontal layer of incompressible fluid with rigid boundaries when the temperature is ... . Together with the wellknown solutions which describe heat transfer for the linear ...

S. N. Aristov; K. G. Shvarts

2013-05-01T23:59:59.000Z

349

A Perfectly Matched Layer Method for the Navier-Stokes equations  

E-Print Network [OSTI]

The Perfectly Matched Layer Method (PML) has found widespread application as a high-accuracy, non-reflecting boundary treatment in many wave propagation simulations. However, in the area of computational fluid dynamics, ...

Whitney, John Peter, 1982-

2006-01-01T23:59:59.000Z

350

Nature: Earth's Atmosphere and Beyond  

Science Journals Connector (OSTI)

Nature: Earth's Atmosphere and Beyond ... The column summarizes research articles from Nature that report on anthropogenic activities and natural phenomena that influence the chemical composition of Earth's atmosphere. ...

Sabine Heinhorst; Gordon Cannon

2003-10-01T23:59:59.000Z

351

Strategic Environmental Research and Development Program: Atmospheric Remote Sensing and Assessment Program -- Final Report. Part 1: The lower atmosphere  

SciTech Connect (OSTI)

This report documents work done between FY91 and FY95 for the lower atmospheric portion of the joint Department of Defense (DoD) and Department of Energy (DOE) Atmospheric Remote Sensing and Assessment Program (ARSAP) within the Strategic Environmental Research and Development Program (SERDP). The work focused on (1) developing new measurement capabilities and (2) measuring atmospheric heating in a well-defined layer and then relating it to cloud properties an water vapor content. Seven new instruments were develop3ed for use with Unmanned Aerospace Vehicles (UAVs) as the host platform for flux, radiance, cloud, and water vapor measurements. Four major field campaigns were undertaken to use these new as well as existing instruments to make critically needed atmospheric measurements. Scientific results include the profiling of clear sky fluxes from near surface to 14 km and the strong indication of cloudy atmosphere absorption of solar radiation considerably greater than predicted by extant models.

Tooman, T.P. [ed.] [Sandia National Labs., Livermore, CA (United States). Exploratory Systems Technology Dept.

1997-01-01T23:59:59.000Z

352

A perfectly matched layer formulation for the nonlinear shallow water equations models: The split  

E-Print Network [OSTI]

In a limited-area numerical weather prediction model, the lateral boundaries are not physical boundaries interest since the early days of numerical weather prediction. Several good reviews are availableA perfectly matched layer formulation for the nonlinear shallow water equations models: The split

Navon, Michael

353

The atmosphere of Venus  

Science Journals Connector (OSTI)

The investigations of Venus take a special position in planetary researches. It was just the atmosphere of Venus where first measurements in situ were carried out by means of the equipment delivered by a space pr...

V. I. Moroz

1981-01-01T23:59:59.000Z

354

Atmospheric Dynamics of Exoplanets  

E-Print Network [OSTI]

The characterization of exoplanetary atmospheres has come of age in the last decade, as astronomical techniques now allow for albedos, chemical abundances, temperature profiles and maps, rotation periods and even wind speeds to be measured. Atmospheric dynamics sets the background state of density, temperature and velocity that determines or influences the spectral and temporal appearance of an exoplanetary atmosphere. Hot exoplanets are most amenable to these characterization techniques; in the present review, we focus on highly-irradiated, large exoplanets (the "hot Jupiters"), as astronomical data begin to confront theoretical questions. We summarize the basic atmospheric quantities inferred from the astronomical observations. We review the state of the art by addressing a series of current questions and look towards the future by considering a separate set of exploratory questions. Attaining the next level of understanding will require a concerted effort of constructing multi-faceted, multi-wavelength dat...

Heng, Kevin

2014-01-01T23:59:59.000Z

355

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

SciTech Connect (OSTI)

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.

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

1999-06-01T23:59:59.000Z

356

Simulating atmosphere flow for wind energy applications with WRF-LES  

SciTech Connect (OSTI)

Forecasts of available wind energy resources at high spatial resolution enable users to site wind turbines in optimal locations, to forecast available resources for integration into power grids, to schedule maintenance on wind energy facilities, and to define design criteria for next-generation turbines. This array of research needs implies that an appropriate forecasting tool must be able to account for mesoscale processes like frontal passages, surface-atmosphere interactions inducing local-scale circulations, and the microscale effects of atmospheric stability such as breaking Kelvin-Helmholtz billows. This range of scales and processes demands a mesoscale model with large-eddy simulation (LES) capabilities which can also account for varying atmospheric stability. Numerical weather prediction models, such as the Weather and Research Forecasting model (WRF), excel at predicting synoptic and mesoscale phenomena. With grid spacings of less than 1 km (as is often required for wind energy applications), however, the limits of WRF's subfilter scale (SFS) turbulence parameterizations are exposed, and fundamental problems arise, associated with modeling the scales of motion between those which LES can represent and those for which large-scale PBL parameterizations apply. To address these issues, we have implemented significant modifications to the ARW core of the Weather Research and Forecasting model, including the Nonlinear Backscatter model with Anisotropy (NBA) SFS model following Kosovic (1997) and an explicit filtering and reconstruction technique to compute the Resolvable Subfilter-Scale (RSFS) stresses (following Chow et al, 2005).We are also modifying WRF's terrain-following coordinate system by implementing an immersed boundary method (IBM) approach to account for the effects of complex terrain. Companion papers presenting idealized simulations with NBA-RSFS-WRF (Mirocha et al.) and IBM-WRF (K. A. Lundquist et al.) are also presented. Observations of flow through the Altamont Pass (Northern California) wind farm are available for validation of the WRF modeling tool for wind energy applications. In this presentation, we use these data to evaluate simulations using the NBA-RSFS-WRF tool in multiple configurations. We vary nesting capabilities, multiple levels of RSFS reconstruction, SFS turbulence models (the new NBA turbulence model versus existing WRF SFS turbulence models) to illustrate the capabilities of the modeling tool and to prioritize recommendations for operational uses. Nested simulations which capture both significant mesoscale processes as well as local-scale stable boundary layer effects are required to effectively predict available wind resources at turbine height.

Lundquist, J K; Mirocha, J D; Chow, F K; Kosovic, B; Lundquist, K A

2008-01-14T23:59:59.000Z

357

Rusting Evolution of MnCuP Weathering Steel Submitted to Simulated Industrial Atmospheric Corrosion  

Science Journals Connector (OSTI)

The rusting evolution of MnCuP weathering steel in a simulated industrial atmosphere as a...?-FeOOH. During the second corrosion stage, a compact and protective inner rust layer forms with a higher relative abund...

Long Hao; Sixun Zhang; Junhua Dong; Wei Ke

2012-05-01T23:59:59.000Z

358

Density Perturbations in the Upper Atmosphere Caused by the Dissipation of Solar Wind Energy  

Science Journals Connector (OSTI)

The upper atmosphere constitutes the outer region of the terrestrial gas envelope above about 100 km altitude. The energy budget of this outer gas layer is partly controlled by the dissipation of solar wind energy

Gerd W. Prölss

2011-03-01T23:59:59.000Z

359

Modeling open boundaries in dissipative MHD simulation  

Science Journals Connector (OSTI)

The truncation of large physical domains to concentrate computational resources is necessary or desirable in simulating many natural and man-made plasma phenomena. Three open boundary condition (BC) methods for such domain truncation of dissipative magnetohydrodynamics ... Keywords: Approximate Riemann, Artificial boundary, Calderon method, Dissipative, Lacuna, Lacunae, MHD, Magnetohydrodynamics, Non-reflecting boundary, Nonlinear, Open boundary, hyperbolic-parabolic

E. T. Meier; A. H. Glasser; V. S. Lukin; U. Shumlak

2012-04-01T23:59:59.000Z

360

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

E-Print Network [OSTI]

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.

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

2006-08-12T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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361

Identifying Chemicals That Are Planetary Boundary Threats  

Science Journals Connector (OSTI)

Identifying Chemicals That Are Planetary Boundary Threats ... Our point of departure to develop profiles for chemicals that are potential planetary boundary threats is to identify scenarios in which a chemical could fulfill each of the three conditions for being a planetary boundary threat. ... Note that chemicals named as examples do not necessarily represent planetary boundary threats since at least one scenario from each of the three conditions must be fulfilled for a chemical to pose a planetary boundary threat. ...

Matthew MacLeod; Magnus Breitholtz; Ian T. Cousins; Cynthia A. de Wit; Linn M. Persson; Christina Rudén; Michael S. McLachlan

2014-09-02T23:59:59.000Z

362

The Magnetic Field in the Solar Atmosphere  

E-Print Network [OSTI]

This publication provides an overview of magnetic fields in the solar atmosphere with the focus lying on the corona. The solar magnetic field couples the solar interior with the visible surface of the Sun and with its atmosphere. It is also responsible for all solar activity in its numerous manifestations. Thus, dynamic phenomena such as coronal mass ejections and flares are magnetically driven. In addition, the field also plays a crucial role in heating the solar chromosphere and corona as well as in accelerating the solar wind. Our main emphasis is the magnetic field in the upper solar atmosphere so that photospheric and chromospheric magnetic structures are mainly discussed where relevant for higher solar layers. Also, the discussion of the solar atmosphere and activity is limited to those topics of direct relevance to the magnetic field. After giving a brief overview about the solar magnetic field in general and its global structure, we discuss in more detail the magnetic field in active regions, the quie...

Wiegelmann, Thomas; Solanki, Sami K

2014-01-01T23:59:59.000Z

363

Lecture(s) 9 Slides from atmosphere-ocean lectures  

E-Print Network [OSTI]

albedo and ice can insulate the ocean from the atmosphere above. When the ocean surface freezes and ocean, meshed together and yet also forced by buoyant density differences. Ice and snow..the cryosphere it melts in summer this ice makes a layer of quite fresh water at the surface. ­ beside the density

364

QUANTIFYING ORGANIZATION OF ATMOSPHERIC TURBULENT EDDY MOTION USING NONLINEAR TIME SERIES ANALYSIS  

E-Print Network [OSTI]

the exchange rates of mass and energy between the terrestrial biosphere and atmosphere. Around the world measurements of carbon and energy exchange between the vegetation and the atmosphere (Kaiser, 1998). It has layer (ASL). Within the ASL, the flow statistics are typically one-dimensional and well described

Katul, Gabriel

365

The Atmospheric Response to Realistic Reduced Summer Arctic Sea Ice Anomalies  

E-Print Network [OSTI]

for the continued ice melt [Polyakov et al., 2005], and recent work shows that heat from the Atlantic layer can91 The Atmospheric Response to Realistic Reduced Summer Arctic Sea Ice Anomalies Uma S. Bhatt,1 and Robert A. Tomas3 The impact of reduced Arctic summer sea ice on the atmosphere is investigated by forcing

Bhatt, Uma

366

Hydrodynamics of Embedded Planets' First Atmospheres. II. A Rapid Recycling of Atmospheric Gas  

E-Print Network [OSTI]

Following Paper I we investigate the properties of atmospheres that form around small protoplanets embedded in a protoplanetary disc by conducting hydrodynamical simulations. These are now extended to three dimensions, employing a spherical grid centred on the planet. Compression of gas is shown to reduce rotational motions. Contrasting the 2D case, no clear boundary demarcates bound atmospheric gas from disc material; instead, we find an open system where gas enters the Bondi sphere at high latitudes and leaves through the midplane regions, or, vice versa, when the disc gas rotates sub-Keplerian. The simulations do not converge to a time-independent solution; instead, the atmosphere is characterized by a time-varying velocity field. Of particular interest is the timescale to replenish the atmosphere by nebular gas, $t_\\mathrm{replenish}$. It is shown that the replenishment rate, $M_\\mathrm{atm}/t_\\mathrm{replenish}$, can be understood in terms of a modified Bondi accretion rate, $\\sim$$R_\\mathrm{Bondi}^2\\rho...

Ormel, Chris W; Kuiper, Rolf

2014-01-01T23:59:59.000Z

367

Analysis of mid-tropospheric carbon monoxide data using a three- dimensional Global atmospheric Chemistry numerical Model  

SciTech Connect (OSTI)

The GChM atmospheric chemistry and transport model has been used to analyze the mid-tropospheric CO dataset obtained from NASA`s Measurement of Air Pollution by Satellites (MAPS) program. Fourteen simulations with a 3.75 horizontal resolution have been performed, including a base case and 13 sensitivity runs. The model reproduces many, but not all, of the major features of the MAPS dataset. Locations of peak CO mixing ratios associated with biomass burning as observed in the MAPS experiment are slightly farther south than the model result, indicating either greater horizontal transport than present in the model representation or a spatial difference between the location of modeled biomass fires and actual fires. The current version of GChM was shown to be relatively insensitive to the magnitude of the prescribed NO{sub x} and O{sub 3} global distributions and very insensitive to the depth of the mixed layer as parameterized in the model. Cloud convective transport was shown to play an important role in venting boundary layer CO to the free troposphere. This result agrees with prior meteorological analyses of the MAPS dataset that have-indirectly inferred the presence of convective activity through satellite-based information. Work is continuing to analyze the results of these simulations further and to perform more detailed comparisons between model results and MAPS data.

Easter, R.C.; Saylor, R.D.; Chapman, E.G.

1993-12-01T23:59:59.000Z

368

Article Atmospheric Science  

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

© The Author(s) 2012. This article is published with open access at Springerlink.com csb.scichina.com www.springer.com/scp © The Author(s) 2012. This article is published with open access at Springerlink.com csb.scichina.com www.springer.com/scp *Corresponding author (email: luchunsong110@gmail.com) Article Atmospheric Science February 2013 Vol.58 No.4-5: 545  551 doi: 10.1007/s11434-012-5556-6 A method for distinguishing and linking turbulent entrainment mixing and collision-coalescence in stratocumulus clouds LU ChunSong 1,2* , LIU YanGang 2 & NIU ShengJie 1 1 Key Laboratory for Atmospheric Physics and Environment of China Meteorological Administration, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China; 2 Atmospheric Sciences Division, Brookhaven National Laboratory, New York 11973, USA

369

ARM - Measurement - Atmospheric moisture  

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

moisture moisture ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Atmospheric moisture The moisture content of the air as indicated by several measurements including relative humidity, specific humidity, dewpoint, vapor pressure, water vapor mixing ratio, and water vapor density; note that precipitable water is a separate type. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AERI : Atmospheric Emitted Radiance Interferometer

370

BNL | Atmospheric Systems Research  

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

Atmospheric System Research is a DOE observation-based research program Atmospheric System Research is a DOE observation-based research program created to advance process-level understanding of the key interactions among aerosols, clouds, precipitation, radiation, dynamics, and thermodynamics, with the ultimate goal of reducing the uncertainty in global and regional climate simulations and projections. General areas of research at BNL under this program include studies of aerosol and cloud lifecycles, and cloud-aerosol-precipitation interactions. Contact Robert McGraw, 631.344.3086 aerosols Aerosol Life Cycle The strategic focus of the Aerosol Life Cycle research is observation-based process science-examining the properties and evolution of atmospheric aerosols. Observations come from both long-term studies conducted by the

371

ARM - Measurement - Atmospheric pressure  

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

pressure pressure ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Atmospheric pressure The pressure exerted by the atmosphere as a consequence of gravitational attraction exerted upon the "column" of air lying directly above the point in question. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments SONDE : Balloon-Borne Sounding System CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System

372

ARM - Measurement - Atmospheric temperature  

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

temperature temperature ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Atmospheric temperature The temperature indicated by a thermometer exposed to the air in a place sheltered from direct solar radiation. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AERI : Atmospheric Emitted Radiance Interferometer SONDE : Balloon-Borne Sounding System CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System

373

Layered plasma polymer composite membranes  

DOE Patents [OSTI]

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.

Babcock, W.C.

1994-10-11T23:59:59.000Z

374

Lagrangian Variational Framework for Boundary Value Problems  

E-Print Network [OSTI]

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.

Alexander Figotin; Guillermo Reyes

2014-07-29T23:59:59.000Z

375

Managing across boundaries: identity, differentiation and interaction  

Science Journals Connector (OSTI)

The impact of organisational restructuring on organisational boundaries has become increasingly important, especially because modernisation of work practices within large organisations generates increasing boundary complexity. Psychoanalytic theory offers a means of exploring boundaries and emphasises the importance of boundary in the emergence of an integrated sense of identity. In the UK, restructuring of health services has resulted in changes to organisational, professional and work group boundaries, seemingly, without attention being given to what may constitute a healthy set of boundary relationships. Four interrelated case studies illustrate a variety of organisational relationships and cross-boundary processes in mental health services, and how threats to particular boundaries can lead organisational members to engage in defensive activity. Whilst defences may be healthy for the individual or the organisation, they may generate more problems than they solve. Although the examples given here are highly specific, they may illuminate boundary systems more generally within organisations.

Paula Hyde

2006-01-01T23:59:59.000Z

376

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

SciTech Connect (OSTI)

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.

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

2014-06-01T23:59:59.000Z

377

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 Core�mantle 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 viscosity�depth profiles corresponding to a range

378

Boundary County, Idaho: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Boundary County, Idaho: Energy Resources Boundary County, Idaho: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 48.7987617°, -116.5627065° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":48.7987617,"lon":-116.5627065,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

379

Kinetic Alfven double layer formed by electron viscosity  

SciTech Connect (OSTI)

The effect of the electron viscosity on the kinetic Alfven solitary wave is investigated. It is found that small electron viscosity changes the electron motion along the magnetic field producing a boundary layer, and thus that in a low beta electron-ion plasma({beta} Much-Less-Than m{sub e}/m{sub i}), an obliquely propagating kinetic solitary Alfven wave can become a double layer. This double layer can exist in the sub-Alfvenic and super-Alfvenic regimes. The length scale of density drop for this double layer is on the order of that of the conventional kinetic solitary Alfven wave, and thus this double layer can accelerate electrons on a very short length scale.

Woo, M. H.; Ryu, C.-M. [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Choi, C. R. [Department of Physics, Korea Advanced Institute of Science and Technology, Taejon 305-701 (Korea, Republic of)

2012-07-15T23:59:59.000Z

380

Annual and Seasonal Global Variation in Total Ozone and Layer-Mean Ozone,  

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

Atmospheric Trace Gases » Ozone » Total Ozone and Layer-Mean Ozone Atmospheric Trace Gases » Ozone » Total Ozone and Layer-Mean Ozone Annual and Seasonal Global Variation in Total Ozone and Layer-Mean Ozone, 1958-1987 (1991) DOI: 10.3334/CDIAC/atg.ndp023 data Data Investigators J. K. Angell, J. Korshover, and W. G. Planet Description For 1958 through 1987, this data base presents total ozone variations and layer mean ozone variations expressed as percent deviations from the 1958 to 1977 mean. The total ozone variations were derived from mean monthly ozone values published in Ozone Data for the World by the Atmospheric Environment Service in cooperation with the World Meteorological Organization. The layer mean ozone variations are derived from ozonesonde and Umkehr observations. The data records include year, seasonal and annual

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

An Instrumentation Complex for Atmospheric Radiation Measurements in Siberia  

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

Instrumentation Complex for Atmospheric Radiation Instrumentation Complex for Atmospheric Radiation Measurements in Siberia S. M. Sakerin, F. V. Dorofeev, D. M. Kabanov, V. S. Kozlov, M. V. Panchenko, Yu. A. Pkhalagov, V. V. Polkin, V. P. Shmargunov, S. A. Terpugova, S. A. Turchinovich, and V. N. Uzhegov Institute of Atmospheric Optics Tomsk, Russia Introduction The instrumentation complex is described, which has been prepared for radiative experiments in the region of Tomsk (West Siberia). The complex consists of three groups of devices to measure (a) the characteristics of the total downward radiation; (b) the most variable components of the atmospheric transparency directly affecting the income of radiation (aerosol optical depth [AOD], total content of water vapor, ozone, etc.); and (c) aerosol and meteorological parameters of the near-ground layer of the

382

Dynamics of Planetary Atmospheres  

E-Print Network [OSTI]

pressure (bars) N2 82%; Ar 12%; CH4 6%CO2 96.5%; N2 3.5%Atmospheric composition 26177Orbital inclination (1992) orbiter ­ Winds from cloud-tracking and probe drifts ­ IR temperatures, solar-fixed tides, polar-Huygens mission (from 2005) ­ Doppler wind descent profile ­ IR temperature and composition maps ­ Visible, IR

Read, Peter L.

383

Multiple density layered insulator  

DOE Patents [OSTI]

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.

Alger, Terry W. (Tracy, CA)

1994-01-01T23:59:59.000Z

384

ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement  

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

An Integrated Column Description An Integrated Column Description of the Atmosphere An Integrated Column Description of the Atmosphere Tom Ackerman Chief Scientist Tom Ackerman Chief Scientist ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement Pacific Northwest National Laboratory Pacific Northwest National Laboratory The "other" Washington ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement Credits to Credits to * Ric Cederwall * Xiquan Dong * Chuck Long * Jay Mace * Mark Miller * Robin Perez * Dave Turner and the rest of the ARM science team * Ric Cederwall * Xiquan Dong * Chuck Long * Jay Mace * Mark Miller * Robin Perez * Dave Turner and the rest of the ARM science team ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement Outline Outline * A little philosophy

385

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

E-Print Network [OSTI]

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

Fan, Xingzhe

386

2797Bulletin of the American Meteorological Society 1. Introduction  

E-Print Network [OSTI]

and associated length scales, boundary layer formulation, runoff generation, and groundwa- Modeling Root Water2797Bulletin of the American Meteorological Society 1. Introduction Within atmospheric modeling properties may directly affect the atmospheric boundary layer. Deforestation experi- ments showed

Jackson, Robert B.

387

Multiple layer insulation cover  

DOE Patents [OSTI]

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.

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

1981-11-03T23:59:59.000Z

388

Grain boundary loops in graphene  

Science Journals Connector (OSTI)

Topological defects can affect the physical properties of graphene in unexpected ways. Harnessing their influence may lead to enhanced control of both material strength and electrical properties. Here we present a class of topological defects in graphene composed of a rotating sequence of dislocations that close on themselves, forming grain boundary loops that either conserve the number of atoms in the hexagonal lattice or accommodate vacancy or interstitial reconstruction, while leaving no unsatisfied bonds. One grain boundary loop is observed as a “flower” pattern in scanning tunneling microscopy studies of epitaxial graphene grown on SiC(0001). We show that the flower defect has the lowest energy per dislocation core of any known topological defect in graphene, providing a natural explanation for its growth via the coalescence of mobile dislocations.

Eric Cockayne; Gregory M. Rutter; Nathan P. Guisinger; Jason N. Crain; Phillip N. First; Joseph A. Stroscio

2011-05-12T23:59:59.000Z

389

Irradiation Assisted Grain Boundary Segregation in Steels  

SciTech Connect (OSTI)

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)

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

2008-07-01T23:59:59.000Z

390

Market boundaries for coking-coal concentrates  

Science Journals Connector (OSTI)

The construction of geographic and commodity boundaries is considered in relation to the Russian market for coking-coal concentrates. In this market, uniform commodities ... construction of the market boundaries....

V. A. Brodskii

2011-05-01T23:59:59.000Z

391

Solitons induced by boundary conditions  

SciTech Connect (OSTI)

Although soliton phenomena have attracted wide attention since 1965, there are still not enough efforts paid to mixed-boundary - initial-value problems that are important in real physical cases. The main purpose of this thesis is to study carefully the various boundary-induced soliton under different initial conditions. The author states with three sets of nonlinear equations: KdV equations and Boussinesq equations (for water); two-fluid equations for cold-ion plasma. He was interested in four types of problems involved with water solitons: excitation by different time-dependent boundary conditions under different initial conditions; head-on and over-taking collisions; reflection at a wall and the excitation by pure initial conditions. For KdV equations, only cases one and four are conducted. The results from two fully nonlinear KdV and Boussinesq equations are compared, and agree extremely well. The Boussinesq equations permit solition head-on collisions and reflections, studied the first time. The results from take-over collision agree with KdV results. For the ion-acoustic plasma, a set of Boussinesq-type equations was derived from the standard two-fluid equations for the ion-acoustic plasma. It theoretically proves the essential nature of the solitary wave solutions of the cold-ion plasma. The ion acoustic solitons are also obtained by prescribing a potential phi/sub 0/ at one grid point.

Zhou, R.L.

1987-01-01T23:59:59.000Z

392

Multiple Equilibria and Hysteresis of Two Unequal-Transport Western Boundary Currents Colliding at a Gap  

Science Journals Connector (OSTI)

The nonlinear collision of two western boundary currents (WBCs) of Munk thickness LM colliding near a gap of width 2a is studied using a 1.5-layer, reduced-gravity, quasigeostrophic ocean model. The work is a continuation of our recent study on ...

Zheng Wang; Dongliang Yuan

2014-07-01T23:59:59.000Z

393

ATMOSPHERIC ELSEVIER AtmosphericResearch40 (1996) 223-259  

E-Print Network [OSTI]

of atmospheric aerosol particles and cloud hydrometeors (water drops, ice particles, and, particularlyATMOSPHERIC RESEARCH ELSEVIER AtmosphericResearch40 (1996) 223-259 Simulations of drop fall turbulence. The model permits us to generate different realizations of the random velocity field component

Mark, Pinsky

394

SLE($?,?$)and Boundary Coulomb Gas  

E-Print Network [OSTI]

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.

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

2005-08-07T23:59:59.000Z

395

The Influence of Chemi-ionization and Recombination Processes on Spectral Line Shapes in Stellar Atmospheres  

E-Print Network [OSTI]

In this work, the chemi-ionization processes in atom- Rydberg atom collisions, as well as the corresponding chemi-recombination processes are considered as factors of influence on the atom exited-state populations in weakly ionized layers of stellar atmospheres. The presented results are related to the photospheres of the Sun and some M red dwarfs as well as weakly ionized layers of DB white dwarfs atmospheres. It has been found that the mentioned chemi ionization/recombination processes dominate over the relevant concurrent electron-atom and electron-ion ionization and recombination process in all parts of considered stellar atmospheres. The obtained results demonstrate the fact that the considered chemi ionization/recombination processes must have a very significant influence on the optical properties of the stellar atmospheres. Thus, it is shown that these processes and their importance for non-local thermodynamic equilibrium (non-LTE) modeling of the solar atmospheres should be investigated further.

Mihajlov, Anatolij A; Sreckovic, Vladimir A; Dimitrijevic, Milan S

2011-01-01T23:59:59.000Z

396

ARM - Measurement - Atmospheric turbulence  

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

turbulence turbulence ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Atmospheric turbulence High frequency velocity fluctuations that lead to turbulent transport of momentum, heat, mositure, and passive scalars, and often expressed in terms of variances and covariances. Categories Atmospheric State, Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System

397

Differential atmospheric tritium sampler  

DOE Patents [OSTI]

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.

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

1987-10-02T23:59:59.000Z

398

Differential atmospheric tritium sampler  

DOE Patents [OSTI]

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.

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

1990-01-01T23:59:59.000Z

399

IONIZATION OF EXTRASOLAR GIANT PLANET ATMOSPHERES  

SciTech Connect (OSTI)

Many extrasolar planets orbit close in and are subject to intense ionizing radiation from their host stars. Therefore, we expect them to have strong, and extended, ionospheres. Ionospheres are important because they modulate escape in the upper atmosphere and can modify circulation, as well as leave their signatures, in the lower atmosphere. In this paper, we evaluate the vertical location Z{sub I} and extent D{sub I} of the EUV ionization peak layer. We find that Z{sub I{approx}}1-10 nbar-for a wide range of orbital distances (a = 0.047-1 AU) from the host star-and D{sub I}/H{sub p{approx}}>15, where H{sub p} is the pressure scale height. At Z{sub I}, the plasma frequency is {approx}80-450 MHz, depending on a. We also study global ion transport, and its dependence on a, using a three-dimensional thermosphere-ionosphere model. On tidally synchronized planets with weak intrinsic magnetic fields, our model shows only a small, but discernible, difference in electron density from the dayside to the nightside ({approx}9 x 10{sup 13} m{sup -3} to {approx}2 x 10{sup 12} m{sup -3}, respectively) at Z{sub I}. On asynchronous planets, the distribution is essentially uniform. These results have consequences for hydrodynamic modeling of the atmospheres of close-in extrasolar giant planets.

Koskinen, Tommi T. [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ (United States); Cho, James Y-K. [Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Achilleos, Nicholas; Aylward, Alan D., E-mail: tommi@lpl.arizona.ed [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2010-10-10T23:59:59.000Z

400

The changing atmosphere  

SciTech Connect (OSTI)

The chemistry of the atmosphere is changing, in large measure because of gases emitted by such human activities as farming, manufacturing, and the combustion of fossil fuels. The deleterious effects are increasingly evident; they may well become worse in the years ahead. This paper discusses the pollutants and the environmental perturbations with which they are associated. The authors believe the solution to the earth's environmental problems lies in a truly global effort.

Graedel, T.E.; Crutzen, P.J.

1989-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Structured luminescence conversion layer  

DOE Patents [OSTI]

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.

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

2012-12-11T23:59:59.000Z

402

Modeling of atmospheric corrosion behavior of weathering steel in sulfur dioxide-polluted atmospheres  

SciTech Connect (OSTI)

Atmospheric corrosion resistance of carbon steel (CS) and high-phosphorus weathering steel (WS, Acr-Ten A) was compared after exposure for up to 6 years in Taiwan. In an industrial atmosphere, corrosion kinetics of WS after 3 years of exposure deviated from behavior predicted by the well-known bilogarithmic law. This deviation was simulated using a laboratory accelerated test under cyclic wet/dry conditions with addition of 1 ppm sulfur dioxide (SO{sub 2}). In-situ electrochemical impedance measurements also were carried out in a modified three-electrode cell covered by a thin electrolyte layer to investigate corrosion behavior of WS in SO{sub 2}-polluted environments. Three impedance models were proposed to explain the characteristic corrosion behavior of WS in various stages of exposure.

Wang, J.H.; Shih, H.C. [National Tsing Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Materials Science and Engineering; Wei, F.I. [China Steel Corp., Kaoshiung (Taiwan, Province of China)

1996-12-01T23:59:59.000Z

403

Universality of the Future Chronological Boundary  

E-Print Network [OSTI]

The purpose of this note is to establish, in a categorical manner, the universality of the Geroch-Kronheimer-Penrose causal boundary when considering the types of causal structures that may profitably be put on any sort of boundary for a spacetime. Actually, this can only be done for the future causal boundary (or the past causal boundary) separately; furthermore, only the chronology relation, not the causality relation, is considered, and the GKP topology is eschewed. The final result is that there is a unique map, with the proper causal properties, from the future causal boundary of a spacetime onto any ``reasonable" boundary which supports some sort of chronological structure and which purports to consist of a future completion of the spacetime. Furthermore, the future causal boundary construction is categorically unique in this regard.

Steven G. Harris

1997-04-04T23:59:59.000Z

404

Geometric Boundary Data for the Gravitational Field  

E-Print Network [OSTI]

An outstanding issue in the treatment of boundaries in general relativity is the lack of a local geometric interpretation of the necessary boundary data. For the Cauchy problem, the initial data is supplied by the 3-metric and extrinsic curvature of the initial Cauchy hypersurface.. This Cauchy data determines a solution to Einstein's equations which is unique up to a diffeomorphism. Here, we show how three pieces of boundary data, which are associated locally with the geometry of the boundary, likewise determine a solution of the initial-boundary value problem which is unique up to a diffeomorphism. One piece of this data, constructed from the extrinsic curvature of the boundary, determines the dynamical evolution of the boundary. The other two pieces constitute a conformal class of rank-2, positive definite metrics, which represent the two gravitational degrees of freedom.

H-O. Kreiss; J. Winicour

2014-02-25T23:59:59.000Z

405

ORISE: Climate and Atmospheric Research  

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

Climate and Atmospheric Research Climate and Atmospheric Research Capabilities Overview U.S. Climate Reference Network U.S. Historical Climate Network Contact Us Oak Ridge Institute for Science Education Climate and Atmospheric Research The Oak Ridge Institute for Science and Education (ORISE) partners with the National Oceanic and Atmospheric Administration's Atmospheric Turbulence and Diffusion Division (ATDD) to conduct climate research focused on issues of national and global importance. Research is performed with personnel support from ORISE's Independent Environmental Assessment and Verification (IEAV) programs, as well as in collaboration with scientists and engineers from Oak Ridge National Laboratory (ORNL), and numerous other organizations, government agencies, universities and private research institutions.

406

New P2 Compound with Brucite-Like Layers: Potassium Lithiostannate  

Science Journals Connector (OSTI)

New P2 Compound with Brucite-Like Layers: Potassium Lithiostannate ... A new compound with brucite-like layers (K0.72Li0.24Sn0.76O2) ... A new compound with brucite-like layers, K0.72Li0.24Sn0.76O2, has been obtained two ways, via solid-state reactions: with a big excess of KOH and in a controllable atmosphere without water and carbon dioxide. ...

Igor L. Shukaev; Vera V. Butova

2012-04-11T23:59:59.000Z

407

Atmospheric model intercomparison project: Monsoon simulations  

SciTech Connect (OSTI)

The simulation of monsoons, in particular the Indian summer monsoon, has proven to be a critical test of a general circulation model`s ability to simulate tropical climate and variability. The Monsoon Numerical Experimentation Group has begun to address questions regarding the predictability of monsoon extremes, in particular conditions associated with El Nino and La Nina conditions that tend to be associated with drought and flood conditions over the Indian subcontinent, through a series of seasonal integrations using analyzed initial conditions from successive days in 1987 and 1988. In this paper the authors present an analysis of simulations associated with the Atmospheric Model Intercomparison Project (AMIP), a coordinated effort to simulate the 1979--1988 decade using standardized boundary conditions with approximately 30 atmospheric general circulation models. The 13 models analyzed to date are listed. Using monthly mean data from these simulations they have calculated indices of precipitation and wind shear in an effort to access the performance of the models over the course of the AMIP decade.

Sperber, K.R. [Lawrence Livermore National Lab., CA (United States). Program for Climate Model Diagnosis and Intercomparison; Palmer, T.N. [European Centre for Medium-Range Weather Forecasts, Reading (United Kingdom)

1994-06-01T23:59:59.000Z

408

Atmospheric Pressure Deposition for Electrochromic Windows |...  

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

Atmospheric Pressure Deposition for Electrochromic Windows Atmospheric Pressure Deposition for Electrochromic Windows Emerging Technologies Project for the 2013 Building...

409

A simple, quantitative method to infer the minimum atmospheric height of small exoplanets  

Science Journals Connector (OSTI)

......straddle the boundary between rocky, terrestrial worlds (super-Earths...helium-dominated atmospheres. Assuming a rocky/icy core, the- transition...exoplanet is a mini-Neptune or a rocky super-Earth is not possible...when the spectrum is relatively flat as in the case of GJ 1214b for......

David M. Kipping; David S. Spiegel; Dimitar D. Sasselov

2013-01-01T23:59:59.000Z

410

Layered electrode for electrochemical cells  

DOE Patents [OSTI]

There is provided an electrode structure comprising a current collector sheet and first and second layers of electrode material. Together, the layers improve catalyst utilization and water management.

Swathirajan, Swathy (West Bloomfield, MI); Mikhail, Youssef M. (Sterling Heights, MI)

2001-01-01T23:59:59.000Z

411

GFD-2 Spring 2004 Syllabus Text: a nearly complete set of text handouts, plus A.E.Gill, Atmosphere-Ocean Dynamics  

E-Print Network [OSTI]

geography of potential vorticity -lateral circulation: wind-driven ocean gyres and boundary currents -circumpolar ocean currents and the atmospheric westerly winds: stationary Rossby waves with mountains; waveGFD-2 Spring 2004 Syllabus Text: a nearly complete set of text handouts, plus A.E.Gill, Atmosphere-Ocean

412

Observation of thermally etched grain boundaries with the FIB/TEM technique  

SciTech Connect (OSTI)

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].

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

413

Atmospheric Chemistry of Dichlorvos  

Science Journals Connector (OSTI)

Atmospheric Chemistry of Dichlorvos ... In the positive ion mode, protonated water hydrates (H3O+(H2O)n) generated by the corona discharge in the chamber diluent air were responsible for the protonation of analytes, and the ions that were mass analyzed were mainly protonated molecules ([M + H]+) and their protonated homo- and heterodimers. ... Methyl nitrite, 2-propyl nitrite and N2O5 were prepared and stored as described previously,(8, 10) and O3 in O2 diluent was generated using a Welsbach T-408 ozone generator. ...

Sara M. Aschmann; Ernesto C. Tuazon; William D. Long; Roger Atkinson

2011-03-15T23:59:59.000Z

414

On the effects of atmospheric refraction on radar ground patterns  

E-Print Network [OSTI]

of superrefraction. A radial pattern of AP echoes occurred in a number of cases when there was a strong gradient of N in an elevated refractive layer, but this pattern was not nearly as common as others. Investigations [10, 13, 14, 15, 16] of the atmosphere... when the antenna elevation angle is less than 2 deg and when there is an elevated refracting layer between 1500 ft and 3000 ft above the radar in which the gradient of refractivity is greater than 48N/1000 ft. ACKNONLEDGMENT The author wishes...

Cobb, Lalovee Glendale

1963-01-01T23:59:59.000Z

415

Dissipative expansion chambers with two concentric layers of fibrous material  

Science Journals Connector (OSTI)

The acoustic performance of a dissipative expansion chamber lined with two concentric, annular layers of fibrous material with different resistances is investigated. A two-dimensional analytical approach is used to determine the transmission loss of this dissipative silencer. From the boundary conditions at the rigid wall, and the interfaces between the fibre layers and the central airway, the characteristic function and thus eigenvalues and eigenfunctions for sound propagation in the dissipative chamber are obtained, leading to transmission loss through application of pressure and velocity matching. The effects of geometry and fibre properties on the acoustic attenuation are also discussed.

A. Selamet; M.B. Xu; I.J. Lee; N.T. Huff

2005-01-01T23:59:59.000Z

416

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

E-Print Network [OSTI]

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 ...

Reina, Alfonso

2009-01-01T23:59:59.000Z

417

P8.13 CONTRAIL STUDIES AND FORECASTS IN THE SUBARCTIC ATMOSPHERE ABOVE FAIRBANKS, Martin Stuefer* and Gerd Wendler  

E-Print Network [OSTI]

, the radiative characteristics of contrails are similar to those of thin layers of naturally occurring cirrus are of interest for scientists investigating atmospheric radiation transfer processes, the chemical state of temperatures in the lower atmosphere by reducing the net radiation to the surface during the day and reducing

Stuefer, Martin

418

Inertial theory of the mean Hadley circulation under the condition of nonstatic equilibrium  

Science Journals Connector (OSTI)

Tropical atmosphere is divided into two layers, the layer near the ground is the planet boundary layer, where the motion is linear, if the radiation equilibrium temperature is given at the top of the boundary lay...

Jiping Chao; Liu Fei

2006-05-01T23:59:59.000Z

419

Plasma transport near material boundaries  

SciTech Connect (OSTI)

The fluid theory of two-dimensional (2-d) plasma transport in axisymmetric devices is reviewed. The forces which produce flow across the magnetic field in a collisional plasma are described. These flows may lead to up-down asymmetries in the poloidal rotation and radial fluxes. Emphasis is placed on understanding the conditions under which the known 2-d plasma fluid equations provide a valid description of these processes. Attempts to extend the fluid treatment to less collisional, turbulent plasmas are discussed. A reduction to the 1-d fluid equations used in many computer simulations is possible when sources or boundary conditions provide a large enough radial scale length. The complete 1-d fluid equations are given in the text, and 2-d fluid equations are given in the Appendix.

Singer, C.E.

1985-06-01T23:59:59.000Z

420

SWERA/Climate Layers Information | Open Energy Information  

Open Energy Info (EERE)

Climate Layers Information Climate Layers Information < SWERA Jump to: navigation, search SWERA logo.png Solar and Wind Energy Resource Assessment (SWERA) Interactive Web PortalPowered by OpenEI Getting Started Data Sets Analysis Tools About SWERA Climate Layers The climate layers are derived from data provided by NASA's Prediction of Worldwide Energy Resource (POWER) project derived from NASA's climate research to support renewable energy industries. The Surface meteorology and Solar Energy (SSE) data set contains solar parameters principally derived from satellite observations and meteorology parameters from an atmospheric model constrained to satellite and sounding observations. It is a 22-year climatology (July 1983- June 2005) on a one-degree latitude by one-degree longitude grid. The global coverage of the SSE data set fills

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Atmospheric propagation of THz radiation.  

SciTech Connect (OSTI)

In this investigation, we conduct a literature study of the best experimental and theoretical data available for thin and thick atmospheres on THz radiation propagation from 0.1 to 10 THz. We determined that for thick atmospheres no data exists beyond 450 GHz. For thin atmospheres data exists from 0.35 to 1.2 THz. We were successful in using FASE code with the HITRAN database to simulate the THz transmission spectrum for Mauna Kea from 0.1 to 2 THz. Lastly, we successfully measured the THz transmission spectra of laboratory atmospheres at relative humidities of 18 and 27%. In general, we found that an increase in the water content of the atmosphere led to a decrease in the THz transmission. We identified two potential windows in an Albuquerque atmosphere for THz propagation which were the regions from 1.2 to 1.4 THz and 1.4 to 1.6 THz.

Wanke, Michael Clement; Mangan, Michael A.; Foltynowicz, Robert J.

2005-11-01T23:59:59.000Z

422

The Lithium Depletion Boundary as a Clock and Thermometer  

E-Print Network [OSTI]

We take a critical look at the lithium depletion boundary (LDB) technique that has recently been used to derive the ages of open clusters. We identify the sources of experimental and systematic error and show that the probable errors are larger by approximately a factor two than presently claimed in the literature. We then use the Pleiades LDB age and photometry in combination with evolutionary models to define empirical colour-T_eff relations that can be applied to younger clusters. We find that these relationships DO NOT produce model isochrones that match the younger cluster data. We propose that this is due either to systematic problems in the evolutionary models or an age (gravity) sensitivity in the colour-T_eff relation which is not present in published atmospheric models.

R. D. Jeffries; T. Naylor

2000-09-12T23:59:59.000Z

423

Disembodied boundary data for Einstein's equations  

SciTech Connect (OSTI)

A strongly well-posed initial boundary value problem based upon constraint-preserving boundary conditions of the Sommerfeld type has been established for the harmonic formulation of the vacuum Einstein's equations. These Sommerfeld conditions have been previously presented in a four-dimensional geometric form. Here we recast the associated boundary data as three-dimensional tensor fields intrinsic to the boundary. This provides a geometric presentation of the boundary data analogous to the three-dimensional presentation of Cauchy data in terms of three-metric and extrinsic curvature. In particular, diffeomorphisms of the boundary data lead to vacuum spacetimes with isometric geometries. The proof of well-posedness is valid for the harmonic formulation and its generalizations. The Sommerfeld conditions can be directly applied to existing harmonic codes which have been used in simulating binary black holes, thus ensuring boundary stability of the underlying analytic system. The geometric form of the boundary conditions also allows them to be formally applied to any metric formulation of Einstein's equations, although well-posedness of the boundary problem is no longer ensured. We discuss to what extent such a formal application might be implemented in a constraint-preserving manner to 3+1 formulations, such as the Baumgarte-Shapiro-Shibata-Nakamura system which has been highly successful in binary black hole simulation.

Winicour, Jeffrey [Department of Physics and Astronomy University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany)

2009-12-15T23:59:59.000Z

424

Casimir pistons with hybrid boundary conditions  

E-Print Network [OSTI]

The Casimir effect giving rise to an attractive or repulsive force between the configuration boundaries that confine the massless scalar field is reexamined for one to three-dimensional pistons in this paper. Especially, we consider Casimir pistons with hybrid boundary conditions, where the boundary condition on the piston is Neumann and those on other surfaces are Dirichlet. We show that the Casimir force on the piston is always repulsive, in contrast with the same problem where the boundary conditions are Dirichlet on all surfaces.

Xiang-hua Zhai; Xin-zhou Li

2007-04-30T23:59:59.000Z

425

PIA - Savannah River Remediation Accreditation Boundary (SRR...  

Office of Environmental Management (EM)

PIA - Savannah River Nuclear Solution IBARS Srs Site Apps. Accreditation Boundary PIA - WEB Physical Security Major Application Occupational Medical Surveillance System (OMSS)...

426

Gradient zone-boundary control in salt-gradient solar ponds  

DOE Patents [OSTI]

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.

Hull, J.R.

1982-09-29T23:59:59.000Z

427

Reflection of Waterborne acoustic waves from a viscoelastic layer on a rigid hacking with perforations  

Science Journals Connector (OSTI)

The reflection coefficient is calculated for a plane acoustic wave normally incident on a viscoelasticrubber cover layer submerged in water. The rubber layer is mounted on a rigid backing with air?filled cylindrical perforations. Acoustical losses are attributed to motion of the layer over the perforations. This motion is calculated by treating the layer above each perforation as a vibrating circular viscoelastic plate. Different boundary conditions are assumed and in each case the soundreflection coefficient is calculated. The results are compared with the experimental data of R. Lane [Ultrason. 19 28–30 (1981)].

J. Jarzynski

1982-01-01T23:59:59.000Z

428

EMSL: Science: Atmospheric Aerosol Systems  

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

Atmospheric Aerosol Systems Atmospheric Aerosol Systems atmospheric logo Nighttime enhancement of nitrogen-containing organic compounds, or NOC Observed nighttime enhancement of nitrogen-containing organic compounds, or NOC, showed evidence of being formed by reactions that transform carbonyls into imines. The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model parameterization to improve the accuracy of climate model simulations and develop a predictive understanding of climate. By elucidating the role of natural and anthropogenic regional and global climate forcing mechanisms, EMSL can provide DOE and others with the ability to develop cost-effective strategies to monitor, control and mitigate them.

429

ARM - Evolution of the Atmosphere  

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

provides clues as to the composition of the early atmosphere. Volcanic emissions include nitrogen, sulfur dioxide, carbon dioxide, and trace gases such as argon. Although oxygen,...

430

Modeling and inversion of PS-wave moveout asymmetry for tilted TI media: Part 2 --Dipping TTI layer  

E-Print Network [OSTI]

for anisotropic imaging beneath TTI formations and characterization of dipping fracture systems. Mode-converted PS to the anisotropic parameters. In Part 1 Dewangan and Tsvankin, 2006a , we proposed a modi- fication of the PP + PS to the layer boundaries. Dipping shale layers of this type are commonly ob- Manuscript received by the Editor

Tsvankin, Ilya

431

Control System For Cryogenic THD Layering At The National Ignition Facility  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) is the world largest and most energetic laser system for Inertial Confinement Fusion (ICF). In 2010, NIF began ignition experiments using cryogenically cooled targets containing layers of the tritium-hydrogen-deuterium (THD) fuel. The 75 {micro}m thick layer is formed inside of the 2 mm target capsule at temperatures of approximately 18 K. The ICF target designs require sub-micron smoothness of the THD ice layers. Formation of such layers is still an active research area, requiring a flexible control system capable of executing the evolving layering protocols. This task is performed by the Cryogenic Target Subsystem (CTS) of the NIF Integrated Computer Control System (ICCS). The CTS provides cryogenic temperature control with the 1 mK resolution required for beta-layering and for the thermal gradient fill of the capsule. The CTS also includes a 3-axis x-ray radiography engine for phase contrast imaging of the ice layers inside of the plastic and beryllium capsules. In addition to automatic control engines, CTS is integrated with the Matlab interactive programming environment to allow flexibility in experimental layering protocols. The CTS Layering Matlab Toolbox provides the tools for layer image analysis, system characterization and cryogenic control. The CTS Layering Report tool generates qualification metrics of the layers, such as concentricity of the layer and roughness of the growth boundary grooves. The CTS activities are automatically coordinated with other NIF controls in the carefully orchestrated NIF Shot Sequence.

Fedorov, M; Blubaugh, J; Edwards, O; Mauvais, M; Sanchez, R; Wilson, B

2011-03-18T23:59:59.000Z

432

Layered permeable systems  

SciTech Connect (OSTI)

Permeability is a second rank tensor relating flow rate to pressure gradient in a porous medium. If the permeability is a constant times the identity tensor the permeable medium is isotropic; otherwise it is anisotropic. A formalism is presented for the simple calculation of the permeability tensor of a heterogeneous layered system composed of interleaved thin layers of several permeable constituent porous media in the static limit. Corresponding to any cumulative thickness {ital H} of a constituent is an element consisting of scalar {ital H} and a matrix which is {ital H} times a hybrid matrix function of permeability. The calculation of the properties of a medium equivalent to the combination of permeable constituents may then be accomplished by simple addition of the corresponding scalar/matrix elements. Subtraction of an element removes a permeable constituent, providing the means to decompose a permeable medium into many possible sets of permeable constituents, all of which have the same flow properties. A set of layers of a constituent medium in the heterogeneous layered system with permeability of the order of 1{ital h} as {ital h} {r arrow} 0, where {ital h} is that constituent's concentration, acts as a set of infinitely thin channels and is a model for a set of parallel cracks or fractures. Conversely, a set of layers of a given constituent with permeability of the order of {ital h} as {ital h} {r arrow} 0 acts as a set of parallel flow barriers and models a set of parallel, relatively impermeable, interfaces, such as shale stringers or some faults.

Schoenberg, M. (Schlumberger-Doll Research, Ridgefield, CT (US))

1991-02-01T23:59:59.000Z

433

Regional forecasting with global atmospheric models; Final report  

SciTech Connect (OSTI)

The purpose of the project was to conduct model simulations for past and future climate change with respect to the proposed Yucca Mtn. repository. The authors report on three main topics, one of which is boundary conditions for paleo-hindcast studies. These conditions are necessary for the conduction of three to four model simulations. The boundary conditions have been prepared for future runs. The second topic is (a) comparing the atmospheric general circulation model (GCM) with observations and other GCMs; and (b) development of a better precipitation data base for the Yucca Mtn. region for comparisons with models. These tasks have been completed. The third topic is preliminary assessments of future climate change. Energy balance model (EBM) simulations suggest that the greenhouse effect will likely dominate climate change at Yucca Mtn. for the next 10,000 years. The EBM study should improve rational choice of GCM CO{sub 2} scenarios for future climate change.

Crowley, T.J.; Smith, N.R. [Applied Research Corp., College Station, TX (United States)

1994-05-01T23:59:59.000Z

434

Direct Simulation of Shock Layer Plasmas  

SciTech Connect (OSTI)

Approximate models of the electric field used with the DSMC method all impose quasi-neutrality everywhere in the shock layer plasma. The shortcomings of these models are examined in this study by simulating a weak shock layer plasma with a coupled DSMC-Particle-In-Cell (PIC) method. The stagnation streamline of an axisymmetric shock layer is simulated for entry velocities in air that correspond to both lunar and Mars return trajectories. The atmospheric densities, particle diameters and chemical reaction rates are varied from the actual values to make the computations tractable while retaining the mean free path of air at 85 km altitude. In contrast to DSMC flow field predictions, regions of non-neutrality are predicted by the DSMC-PIC method, and the electrons are predicted to be isothermal. Perhaps the most important result of this study is that the DSMC-PIC results at both reentry energies yield a 14% increase in heat flux to the vehicle surface relative to the DSMC results. Rather unintuitively, this is mostly due to an increase in ion flux to the surface, rather than the potential energy gained by each ion as it traverses the plasma sheath. In this study, an approximate electric field model is presented, with the goal of accounting for this heat flux augmentation without the need for a computationally expensive DSMC-PIC calculation of the entire flow-field. Convective heat flux results obtained with new electric field model are compared to results from the rigorous DSMC-PIC calculations.

Farbar, E. D.; Boyd, I. D. [Dept. of Aerospace Engineering, University of Michigan, 1320 Beal Ave., Ann Arbor MI, 48109 (United States)

2011-05-20T23:59:59.000Z

435

Spatially Resolved Mapping of Electrical Conductivity around Individual Domain (Grain) Boundaries in Graphene  

SciTech Connect (OSTI)

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.

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

436

A dominant role of oxygen additive on cold atmospheric-pressure He + O{sub 2} plasmas  

SciTech Connect (OSTI)

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.

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

437

Cherokee Clitics: The Word Boundary Problem  

E-Print Network [OSTI]

The problem of identifying Cherokee clitics is complicated by the fact that the prosodic word, marked by the presence of a tonal boundary, may not match the morphological word. Clitics may or may not respect the the word boundary as marked by tone...

Haag, Marcia

1999-01-01T23:59:59.000Z

438

Green's functions for Neumann boundary conditions  

E-Print Network [OSTI]

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.

Jerrold Franklin

2012-01-29T23:59:59.000Z

439

DOE research on atmospheric aerosols  

SciTech Connect (OSTI)

Atmospheric aerosols are the subject of a significant component of research within DOE`s environmental research activities, mainly under two programs within the Department`s Environmental Sciences Division, the Atmospheric Radiation Measurement (ARM) Program and the Atmospheric Chemistry Program (ACP). Research activities conducted under these programs include laboratory experiments, field measurements, and theoretical and modeling studies. The objectives and scope of these programs are briefly summarized. The ARM Program is the Department`s major research activity focusing on atmospheric processes pertinent to understanding global climate and developing the capability of predicting global climate change in response to energy related activities. The ARM approach consists mainly of testing and improving models using long-term measurements of atmospheric radiation and controlling variables at highly instrumented sites in north central Oklahoma, in the Tropical Western Pacific, and on the North Slope of Alaska. Atmospheric chemistry research within DOE addresses primarily the issue of atmospheric response to emissions from energy-generation sources. As such this program deals with the broad topic known commonly as the atmospheric source-receptor sequence. This sequence consists of all aspects of energy-related pollutants from the time they are emitted from their sources to the time they are redeposited at the Earth`s surface.

Schwartz, S.E.

1995-11-01T23:59:59.000Z

440

Space Science : Atmosphere Greenhouse Effect  

E-Print Network [OSTI]

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

Johnson, Robert E.

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification  

SciTech Connect (OSTI)

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.

Balaguru, Karthik; Chang, P.; Saravanan, R.; Leung, Lai-Yung R.; Xu, Zhao; Li, M.; Hsieh, J.

2012-09-04T23:59:59.000Z

442

Climate: monthly and annual average atmospheric pressure GIS data at  

Open Energy Info (EERE)

atmospheric pressure GIS data at atmospheric pressure GIS data at one-degree resolution of the World from NASA/SSE Dataset Summary Description (Abstract):Atmospheric Pressure (kPa)NASA Surface meteorology and Solar Energy (SSE) Release 6.0 Data Set (Nov 2007)22-year Monthly & Annual Average (July 1983 - June 2005)Parameter: Atmospheric Pressure (kPa)Internet: http://eosweb.larc.nasa.gov/sse/Note 1: SSE Methodology & Accuracy sections onlineNote 2: Lat/Lon values indicate the lower left corner of a 1x1 degree region. Negative values are south and west; positive values are north and east. Boundaries of the -90/-180 region are -90 to -89 (south) and -180 to -179 (west). The last region, 89/180, is bounded by 89 to 90 (north) and 179 to 180 (east). The mid-point of the region is +0.5 added to the the Lat/Lon value. These data are

443

Corrosion behavior of weathering steel in marine atmosphere  

Science Journals Connector (OSTI)

The corrosion behavior of weathering steel and carbon steel exposed in marine atmosphere for 4 years were studied by means of regression analysis, rust structure observation, X-ray diffraction, Raman spectrum and electrochemical impedance spectra techniques. The results show that the corrosion procedure of weathering steel is divided into two steps. In the first step, the corrosion rate is higher, while in the second step the corrosion rate is remarkably reduced due to a compact rust layer formed gradually during exposure. The compact rust layer on weathering steel, darkened observed using polarized light, is composed of Cr substitute iron oxyhydroxide. Furthermore, an equivalent circuit is set up to represent the interfaces between rusted steels and 3% NaCl solution, and the rust layer resistances of the steels were deduced from an extrapolation of the electrochemistry impedance spectra to estimate the protective properties.

Q.C Zhang; J.S Wu; J.J Wang; W.L Zheng; J.G Chen; A.B Li

2003-01-01T23:59:59.000Z

444

Ion transport and structure of layer-by-layer assemblies  

E-Print Network [OSTI]

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 ...

Lutkenhaus, Jodie Lee

2007-01-01T23:59:59.000Z

445

Atmospheric Radiation Measurement (ARM) Climate Research Facility and Atmospheric  

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

Atmospheric Radiation Measurement (ARM) Atmospheric Radiation Measurement (ARM) Climate Research Facility and Atmospheric System Research (ASR) Science and Infrastructure Steering Committee CHARTER June 2012 DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not

446

Theory of Leakage Preventing Layer  

Science Journals Connector (OSTI)

It is a brand new concept for leakage prevention layer. The practice to place HEPA filter at the terminal is improved when the theory of leakage prevention layer applies, which becomes the core of novel air distr...

Zhonglin Xu

2014-01-01T23:59:59.000Z

447

Atmospheric controls on northeast Pacific temperature variability and change, 1900–2012  

Science Journals Connector (OSTI)

...of daily surface map analyses from various...10-m height) winds, boundary-layer...with 20CR surface winds, include near-surface...temperatures and vertical velocities. Linear regression was...Stoelinga MT Albright MD Mass CF ( 2010 ) A new look...observed heat-flux and wind stress anomalies . Clim Dyn 9...

James A. Johnstone; Nathan J. Mantua

2014-01-01T23:59:59.000Z

448

Observing chemistry of atmospheric particles | EMSL  

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

Observing chemistry of atmospheric particles Observing chemistry of atmospheric particles Review article reached the International Reviews in Physical Chemistry most read list NULL...

449

Lattice Boltzmann boundary conditions via singular forces: irregular expansion analysis  

E-Print Network [OSTI]

Lattice Boltzmann boundary conditions via singular forces: irregular expansion analysis. We benchmark the method on lattice Boltzmann flows past a rigid disk, comparing its numerical performances with standard boundary condition approaches. Key words: lattice Boltzmann method, boundary

450

Radon Content of the Atmosphere  

Science Journals Connector (OSTI)

... preliminary work. The absence of levels of a higher order suggests that the contribution of radon from this source does not represent a significant addition to the total atmospheric level. ... Domestic 0.70

W. ANDERSON; R. C. TURNER

1956-07-28T23:59:59.000Z

451

Property:Building/Boundaries | Open Energy Information  

Open Energy Info (EERE)

Boundaries Boundaries Jump to: navigation, search This is a property of type String. Boundaries Pages using the property "Building/Boundaries" Showing 25 pages using this property. (previous 25) (next 25) S Sweden Building 05K0001 + Several buildings + Sweden Building 05K0002 + Part of a building + Sweden Building 05K0003 + One building + Sweden Building 05K0004 + One building + Sweden Building 05K0005 + One building + Sweden Building 05K0006 + Several buildings + Sweden Building 05K0007 + One building + Sweden Building 05K0008 + One building + Sweden Building 05K0009 + One building + Sweden Building 05K0010 + One building + Sweden Building 05K0011 + One building + Sweden Building 05K0012 + One building + Sweden Building 05K0013 + One building + Sweden Building 05K0014 + One building +

452

Boundary conditions for the lattice Boltzmann method.  

E-Print Network [OSTI]

?? Based on the no-slip boundary condition for walls at rest for the lattice Boltzmann Bathnagar-Gross-Krook method by J.C.G. Verschaeve [Phys. Rev. 80,036703 (2009)], a… (more)

le coupanec, erwan

2010-01-01T23:59:59.000Z

453

Nonlinear boundary value problem of magnetic insulation  

E-Print Network [OSTI]

On the basis of generalization of upper and lower solution method to the singular two point boundary value problems, the existence theorem of solutions for the system, which models a process of magnetic insulation in plasma is proved.

A. V. Sinitsyn

2000-09-09T23:59:59.000Z

454

Brownian walkers within subdiffusing territorial boundaries  

E-Print Network [OSTI]

Inspired by the collective phenomenon of territorial emergence, whereby animals move and interact through the scent marks they deposit, we study the dynamics of a 1D Brownian walker in a random environment consisting of confining boundaries that are themselves diffusing anomalously. We show how to reduce, in certain parameter regimes, the non-Markovian, many-body problem of territoriality to the analytically tractable one-body problem studied here. The mean square displacement (MSD) of the 1D Brownian walker within subdiffusing boundaries is calculated exactly and generalizes well known results when the boundaries are immobile. Furthermore, under certain conditions, if the boundary dynamics are strongly subdiffusive, we show the appearance of an interesting non-monotonicity in the time dependence of the MSD, giving rise to transient negative diffusion.

Luca Giuggioli; Jonathan R. Potts; Stephen Harris

2011-02-04T23:59:59.000Z

455

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

E-Print Network [OSTI]

AND DISCUSSION 22 Effects on Lift Effects on Drag 33 Effects on Pitching Moment 36 Accuracy of Data 37 Flow Interference 38 111 Chapte r VI CONCLUSIONS BIB LIO GRAPHY APPENDIX . Page 41 43 44 Table l. Aerodynamic Characteristics for Varying... control. The suction slot was 0. 065 inches wide and 2. 50 inches long in the spanwise direction. In order to measure the pressure distribution on the model, static pressure orifices were installed in the model surface at the spanwise centerline...

Boothe, Edward Milton

2012-06-07T23:59:59.000Z

456

Eddy-resolving Lidar Measurements and Numerical Simulations of the Convective Internal Boundary Layer  

E-Print Network [OSTI]

in speed. The vertical gradient of wind-speed decreases offshore because of strong vertical mixing caused correlation functions and winds derived from horizontal (PPI) and vertical (RHI) scans of the VIL during Lake.4 0.5 0.6 0.7 DOWNSTREAM WIND SPEEDS FROM RHI SCANS ON 13 JANUARY 1998 SPATIALLY RESOLVED 5-m WINDS

Eloranta, Edwin W.

457

Synoptic and local influences on boundary layer processes, with an application to California wind power  

E-Print Network [OSTI]

th percentiles of daily wind speeds (vertical axis) largelyand warm SST. Mean vertical pro?les of wind speed from EPICspeed at the wind farm sites, since inversion strength is largely controlled by the vertical

Mansbach, David K.

2010-01-01T23:59:59.000Z

458

Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer  

E-Print Network [OSTI]

than 600 m). Vertical velocity and wind speed profiles are? v ), vertical velocity (w ) and horizontal wind speed (WS)? v ), vertical velocity (w ), horizontal wind speed (WS),

Hawkins, Lelia Nahid

2010-01-01T23:59:59.000Z

459

New similarity solutions of the unsteady incompressible boundary-layer equations  

Science Journals Connector (OSTI)

......resulting reduction can be put into generic form by noting that on rede fi ning ? 6 (x, t) appropriately so that ? 6 (x, t...p-independent terms can be freely set to zero). After suitable rede fi nitions according to the transformations (2.6), this......

DK Ludlow; PA Clarkson; AP Bassom

2000-05-01T23:59:59.000Z

460

Synoptic and local influences on boundary layer processes, with an application to California wind power  

E-Print Network [OSTI]

means fall in greater windpower classes than does Palmcontrast, would only fall in windpower classes 1, 3, 2, and

Mansbach, David K

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric boundary layer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Dynamical Model Simulation of the Morning Boundary Layer Development in Deep Mountain Valleys  

Science Journals Connector (OSTI)

A dry, two-dimensional version of the Colorado State University Multi-dimensional Cloud/Mesoscale Model was used to study the cross-valley evolution of the wind and temperature structures in an idealized east-west oriented mountain valley. Two ...

David C. Bader; Thomas B. Mckee

1983-03-01T23:59:59.000Z

462

Synoptic and local influences on boundary layer processes, with an application to California wind power  

E-Print Network [OSTI]

Makarov, Y. , 2007: Wind Integration Issues and So- lutionsexpectations, and integration strategy for any wind powerwind climate and variability. Site design and operation, as well as market integration

Mansbach, David K.

2010-01-01T23:59:59.000Z

463

DOE/SC-ARM/TR-132 Planetary Boundary Layer (PBL) Height Value  

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

determination of the PBL height in models can significantly impact the formation and maintenance of low-level clouds (Zeng et al. 2004). Routine estimates of PBL height are useful...

464

Particle Resuspension in Turbulent Boundary Layers and the Influence of Non-Gaussian Removal Forces  

E-Print Network [OSTI]

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...

Zhang, F; Kissane, M

2012-01-01T23:59:59.000Z

465

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

E-Print Network [OSTI]

Will Seward for his machining expertise and general advice. I would like to thank Dr. Isaac Ekoto, who was responsible for the design and construction of the facilities used during my Ph.D. program, and whose research inspired much of the work... in this dissertation. I also appreciate the assistance of all the students at the National Aerothermochemistry Laboratory. Keeping the lab running is definitely a team effort, and I couldn?t have completed my research without their assistance. Finally, I would like...

Peltier, Scott Jacob

2013-08-05T23:59:59.000Z

466

Catalysis Today 59 (2000) 4760 A critical evaluation of NavierStokes, boundary-layer,  

E-Print Network [OSTI]

for conditions that are typical of the catalytic combustion of natural gas. In developing simulation capabilities ultra-low emission of NOx in applications like gas turbines for electric-power gen- eration [1]. The combustor designs typically call for monolith systems that offer high catalyst area yet low pressure drop

Raja, Laxminarayan L.

467

Synoptic and local influences on boundary layer processes, with an application to California wind power  

E-Print Network [OSTI]

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

Mansbach, David K.

2010-01-01T23:59:59.000Z

468

Investigation of a pulsed-plasma jet for shock / boundary layer control  

E-Print Network [OSTI]

by rapidly heating the air inside a chamber with an electrical discharge. The heated pressurized gas issues actuation mechanisms. Several types of discharges like glow discharge (e.g. [1,2,3]), arc discharge [4. Recently pulsed arc discharges were employed by Caraballo et al. (2009) [9] for controlling an impinging

Clemens, Noel T.

469

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

E-Print Network [OSTI]

The immense fuel savings and environmental benefits of reducing aircraft skin-friction drag through laminar flow is well known. However, obtaining substantial laminar flow on an aircraft in an operational environment has proven to be a difficult...

Duncan, Jr., Glen T.

2014-08-12T23:59:59.000Z

470

Dynamics of flow control in an emulated boundary layer-ingesting offset diffuser  

Science Journals Connector (OSTI)

Dynamics of flow control comprised of arrays of active (synthetic jets) and passive (vanes) control elements , and its effectiveness for suppression of total-pressure distortion is investigated experimentally ...

A. N. Gissen; B. Vukasinovic; A. Glezer

2014-08-01T23:59:59.000Z

471

Direct Numerical Simulation of Supersonic Turbulent Boundary Layer over a Compression Ramp  

E-Print Network [OSTI]

they impinge on a surface. Yet, STBLI problems are of great importance for the efficient design of scramjet

MartĂ­n, Pino

472

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

E-Print Network [OSTI]

or regarded as incompressible, or scramjet engine applications where mixing is the primary concern. Reaction

Texas at Arlington, University of

473

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

E-Print Network [OSTI]

applications, where the freestream is either quiescent or regarded as incompressible, or scramjet engine

Texas at Arlington, University of

474

Preliminary Surface Pressure Measurements of Transitional, Hypersonic Shock Boundary Layer Interactions  

E-Print Network [OSTI]

96-4541 M P Re rms X (T Preliminary Surface Pressure Measurements of Transitional, Hypersonic Shock moves into the hypersonic realm. A critical aspect in designing an airbreathing hy- personic vehicle a number of recent investigations in un- derstanding hypersonic, laminar and turbulent, shock wave

Texas at Arlington, University of

475

Non Linear Evolution of a Second Mode Wave in Supersonic Boundary Layers  

E-Print Network [OSTI]

theory as generalized by Herbert. 1 Introduction Recent advances in supersonic and hypersonic aerospace Langley Research Center M. Y. Hussaini Institute for Computer Applications in Science and Engineering

Erlebacher, Gordon

476

Synoptic and local influences on boundary layer processes, with an application to California wind power  

E-Print Network [OSTI]

700 hPa speed Sfc speed Bight-Great Basin Temp Edwards MAMMeridional SLP CA Bight-Great Basin temp Palm Springs SONCalifornia Bight and the Great Basin (Fig. 5.6). This

Mansbach, David K.

2010-01-01T23:59:59.000Z

477

Active Control of Instabilities in Laminar BoundaryLayer Flow--Part I: An Overview  

E-Print Network [OSTI]

of the downstream wave which counter (cancel) the evolution of the upstream generated wave. Milling (1981) to generate traveling waves 180 o out of phase, Milling (1981) showed that a wave with a 0.6­percent amplitude resembled a wave shape. By using hot strips to generate and control traveling waves, Liep­ mann

Erlebacher, Gordon

478

Analysis and identification of vortices within a turbulent channel boundary layer flow  

E-Print Network [OSTI]

understanding of the drag reduction mechanism is still lacking. Vortices play an important role in turbulence structure. Nevertheless, the identification of vortices is still unclear, not even a universal definition of a vortex is accepted. In the present study...

Maroni Veiga, Adrian Gaston

2006-08-16T23:59:59.000Z

479

Spectral particulate attenuation and particle size distribution in the bottom boundary layer of a continental shelf  

E-Print Network [OSTI]

are consistent with particle resuspension and settling in the BBL, two processes that are dependent on particle size and density. For particles of similar density, resuspension and settling would result

Boss, Emmanuel S.

480

Boundary Layer Forcing of a Semidiurnal, Cross-Channel Seiche WAYNE MARTIN AND PARKER MACCREADY  

E-Print Network [OSTI]

School of Oceanography, University of Washington, Seattle, Washington RICHARD DEWEY School of Earth actual vertical advection of the water mass they are significant because of the potential impact on bio waves (Rhines 1970; Eriksen 1998), nonlinear waves and solitons (Farmer and Armi 1999; Bourgault

MacCready, Parker

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481

AN INVESTIGATION INTO THE VIABILITY OF MEMS TECHNOLOGY FOR BOUNDARY LAYER  

E-Print Network [OSTI]

/compressor blades and ducts within gas turbine engines. Further research is required to develop some of the concepts sensing, actuating and control strategies. Significant advances have been made in the understanding and the preliminary design, development, fabrication and testing of appropriate prototype sensors, actuators

Davies, Christopher

482

Aerosol-Cloud-Precipitation Interactions in the Trade Wind Boundary Layer.  

E-Print Network [OSTI]

??This dissertation includes an overview of aerosol, cloud, and precipitation properties associated with shallow marine cumulus clouds observed during the Barbados Aerosol Cloud Experiment (BACEX,… (more)

Jung, Eunsil

2012-01-01T23:59:59.000Z

483

Boundary-layer transition on broad cones rotating in an imposed axial flow  

E-Print Network [OSTI]

for the fuel efficiency through increased noise and energy dissipation, and for projectile applications films of optical and electrical materials on substrates in the electrochemical industry. Such reactors

484

E-Print Network 3.0 - arctic boundary layer Sample Search Results  

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

12;NOAA Arctic Tiger Team Laura K. Furgione Deputy Assistant Administrator National Weather ... Source: Kuligowski, Bob - Satellite Meteorology and Climatology Division,...

485

Ruga-formation instabilities of a graded stiffness boundary layer in a neo-Hookean solid  

Science Journals Connector (OSTI)

...Brau et al. [12], Sun et al. [13] and Hutchinson...exponentially or following a distribution of an error function...modelled using the linearly temperature-dependent elastic...represented by the stiffness distribution exponentially decaying...1038/nphys1806 ) 13 Sun, J-Y , S Xia, M-W...

2014-01-01T23:59:59.000Z

486

Physica D 210 (2005) 203226 Boundary layers and emitted excitations in nonlinear  

E-Print Network [OSTI]

two quite different physical systems: superfluid 4He and Bose­Einstein condensates of ultra. This is clearly the case in recent experiments [5] that are performed at temperatures below 130 mK. Note

Nore, Caroline

487

ccsd-00002450,version1-4Aug2004 Boundary layers and emitted excitations in  

E-Print Network [OSTI]

and Bose-Einstein condensates of ultra-cold atomic vapor. In the case of superfluid 4 He, the NLSE can to be negligible. This is clearly the case in recent experiments [5] that are performed at temperatures below 130 mK

488

Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer  

E-Print Network [OSTI]

Absorbance Polluted Marine Fossil Fuel Combustion BiomassBiomass Fossil Fuel Polluted Marine Burning Combustion FTIRof both coastal fossil fuel combustion and marine sources of

Hawkins, Lelia Nahid

2010-01-01T23:59:59.000Z

489

Study of active control of instability in a boundary layer over a flat plate flow  

E-Print Network [OSTI]

A feasibility study of utilizing synthetic jet actuators as a mean to mitigate disturbances that can cause instability and turbulent flow is described. Prediction of flow transition via linear stability theory was performed by solving the Orr...

Oryu, Hiroshi

2012-06-07T23:59:59.000Z

490

E-Print Network 3.0 - absorbing boundary layers Sample Search...  

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

C7, supplementau Journal de Physique 111, Volume 4,juillet 1994 Summary: beam across the pump beam cross section yields the acoustic power transmitted to the absorber......

491

Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer  

E-Print Network [OSTI]

whereas fossil fuel combustion and biomass burning emissionsof fossil fuel combustion and biomass burning emissionsMarine Fossil Fuel Combustion Biomass Burning Frequency (

Hawkins, Lelia Nahid

2010-01-01T23:59:59.000Z

492

A study of wind speed modification and internal boundary-layer heights in a coastal region  

Science Journals Connector (OSTI)

Wind profile data within the first two kilometres of a coast have been used to study the wind field modification downstream of this surface discontinuity. The land area is generally very flat, having an overal...

Hans Bergström; Per-Erik Johansson; Ann-Sofi Smedman

1988-03-01T23:59:59.000Z

493

Boundary-Layer Meteorol DOI 10.1007/s10546-013-9875-1  

E-Print Network [OSTI]

is a complex phenomenon involving local physical and microphysical processes that take place when particular meteorological variables driving this process: 2-m temperature tendency, 10-m wind speed, 2-m relative humidity, Bartok et al. (2012) used the WRF model, coupled with the PAFOG model (presented in Bott and Trautmann

Menut, Laurent

494

Improving tropical and subtropical boundary layer cloudiness in the NCEP GFS  

E-Print Network [OSTI]

, as well as in the Community Earth System Model (CESM, http://www.cesm.ucar.edu/), using the relative

Bretherton, Chris

495

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

E-Print Network [OSTI]

. .................................................................................................. 108 xix Figure 70 Uncertainty in measurements as a function of element spacing for (a) phase and ..................... (b) velocity...

Williams, Thomas 1987-

2012-08-23T23:59:59.000Z

496

American Institute of Aeronautics and Astronautics The Influence of Stable Boundary Layer Flows  

E-Print Network [OSTI]

on Wind Turbine Fatigue Loads Chungwook Sim1 Dept. of Civil, Architectural, and Environmental Engineering for wind turbine design. This is surprising since such near-neutral conditions occur in so generated by shear and destroyed by negative buoyancy. Wind shear (both magnitude and direction) under

Manuel, Lance

497

Conjugate observations of the day-side reconnection electric eld: A GEM boundary layer campaign  

E-Print Network [OSTI]

Introduction Magnetic reconnection on the day-side magnetopause is the dominant mechanism by which solar wind energy is transferred to the Earth's magnetosphere, at least when the interplanetary magnetic ®eld (IMF

Paris-Sud XI, Université de

498

Surface and bottom boundary layer dynamics on a shallow submarine bank : southern flank of Georges Bank  

E-Print Network [OSTI]

The thesis investigates the circulation at a 76-m deep study site on the southern flank of Georges Bank, a shallow submarine bank located between the deeper Gulf of Maine and the continental slope. Emphasis is placed on ...

Werner, Sandra R. (Sandra Regina)

1999-01-01T23:59:59.000Z

499

Synoptic and local influences on boundary layer processes, with an application to California wind power  

E-Print Network [OSTI]

corresponding to extreme winds for di?erent stations andin turn would lead to extreme downscaled wind speed changeextreme quintiles or more exacting classi?cations of wind

Mansbach, David K.

2010-01-01T23:59:59.000Z

500

Boundary-Layer Meteorol DOI 10.1007/s10546-011-9682-5  

E-Print Network [OSTI]

, Momentum, and Energy Exchange Rates of a Uniform Crop Situated in an Extensive Screenhouse Mario B Science+Business Media B.V. 2011 Abstract The area of crops cultivated in extensive screenhouses heat released or taken up by crops within such protected environments can substantially alter

Katul, Gabriel