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they are not comprehensive nor are they the most current set.
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1

Small Cloud Particle Shapes in Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

The shapes of cloud particles with maximum dimensions Dmax between 35 and 60 ?m in mixed-phase clouds were studied using high-resolution particle images collected by a cloud particle imager (CPI) during the Mixed-Phase Arctic Cloud Experiment (M-...

Greg M. McFarquhar; Junshik Um; Robert Jackson

2013-05-01T23:59:59.000Z

2

The Mixed-Phase Arctic Cloud Experiment  

Science Conference Proceedings (OSTI)

The Mixed-Phase Arctic Cloud Experiment (M-PACE) was conducted from 27 September through 22 October 2004 over the Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) on the North Slope of Alaska. The ...

J. Verlinde; J. Y. Harrington; V. T. Yannuzzi; A. Avramov; S. Greenberg; S. J. Richardson; C. P. Bahrmann; G. M. McFarquhar; G. Zhang; N. Johnson; M. R. Poellot; J. H. Mather; D. D. Turner; E. W. Eloranta; D. C. Tobin; R. Holz; B. D. Zak; M. D. Ivey; A. J. Prenni; P. J. DeMott; J. S. Daniel; G. L. Kok; K. Sassen; D. Spangenberg; P. Minnis; T. P. Tooman; M. Shupe; A. J. Heymsfield; R. Schofield

2007-02-01T23:59:59.000Z

3

Microphysical Properties of Single and Mixed-Phase Arctic Clouds...  

NLE Websites -- All DOE Office Websites (Extended Search)

Abstract A novel new approach to retrieve cloud microphysical properties from mixed-phase clouds is presented. This algorithm retrieves cloud optical depth, ice fraction, and...

4

Mixed phase clouds, cloud electrification and remote sensing.  

SciTech Connect

Most of hypothesis trying to explain charge separation in thunderstorm clouds require presence of ice and supercooled water. Thus the existence of ice or at least mixed phase regions near cloud tops should be a necessary (but not a sufficient) condition for development of lightning. We show that multispectral satellite based instruments, like the DOE MTI (Multispectral Thermal Imager) or NASA MODIS (Moderate Resolution Imaging Spectroradiometer), using the near infrared and visible spectral bands are able to distinguish between water, ice and mixed phase cloud regions. An analysis of the MTI images of mixed phase clouds - with spatial resolution of about 20 m - shows regions of pure water, pure ice as well as regions of water/ice mixtures. We suggest that multispectral satellite instruments may be useful for a short time forecast of lightning probabilities.

Chylek, P. (Petr); Borel, C. C. (Christoph C.); Klett, James

2004-01-01T23:59:59.000Z

5

Vertical Motions in Arctic Mixed-Phase Stratiform Clouds  

Science Conference Proceedings (OSTI)

The characteristics of Arctic mixed-phase stratiform clouds and their relation to vertical air motions are examined using ground-based observations during the Mixed-Phase Arctic Cloud Experiment (MPACE) in Barrow, Alaska, during fall 2004. The ...

Matthew D. Shupe; Pavlos Kollias; P. Ola G. Persson; Greg M. McFarquhar

2008-04-01T23:59:59.000Z

6

A Focus On Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

The phase composition and microphysical structure of clouds define the manner in which they modulate atmospheric radiation and contribute to the hydrologic cycle. Issues regarding cloud phase partitioning and transformation come to bear directly ...

Matthew D. Shupe; John S. Daniel; Gijs de Boer; Edwin W. Eloranta; Pavlos Kollias; Edward P. Luke; Charles N. Long; David D. Turner; Johannes Verlinde

2008-10-01T23:59:59.000Z

7

Towards a Characterization of Arctic Mixed-Phase Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

Towards a Characterization of Arctic Mixed-Phase Clouds Towards a Characterization of Arctic Mixed-Phase Clouds Shupe, Matthew CIRES/NOAA/ETL Kollias, Pavlos Brookhaven National Laboratory Category: Cloud Properties Mixed-phase clouds play a unique role in the Arctic, where the delicate balance of phases in these clouds can have a profound impact on the surface radiation balance and various cloud-atmosphere-radiation-surface feedback processes. A better understanding of these clouds is clearly important and has been a recent objective of the ARM program. To this end, multiple sensors including radar, lidar, and temperature soundings, have been utilized in an automated cloud type classification scheme for clouds observed at the North Slope of Alaska site. The performance of this new algorithm at identifying mixed-phase cloud conditions is compared with an

8

Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud  

E-Print Network (OSTI)

simulation that is in the ice-phase. Note that the y-axis isradiative properties of ice and mixed-phase clouds. Quart.include liquid-phase only, ice-phase only, and mixed-phase.

Klein, Stephen A.

2009-01-01T23:59:59.000Z

9

Comparison of Aircraft Observations with Mixed-Phase Cloud Simulations  

Science Conference Proceedings (OSTI)

In order to provide guidance for the further improvement of a mixed-phase cloud scheme being developed for use in an NWP model, comparisons of dynamical, thermodynamical, and microphysical variables between in situ aircraft data and model data ...

Paul A. Vaillancourt; André Tremblay; Stewart G. Cober; George A. Isaac

2003-04-01T23:59:59.000Z

10

Observed Microphysical Structure ofObserved Microphysical Structure of MidMid--Level, MixedLevel, Mixed--Phase CloudsPhase Clouds  

E-Print Network (OSTI)

Level, Mixed--Phase CloudsPhase Clouds DOD Center for Geosciences/ Atmospheric Research Colorado State understood, but they cover ~ 22% of globe. Mixed-Phase Structure of Clouds Unknown. 30% are mixed-phase --- i.e. contain both ice and liquid. We need to know ice structure for weather and climate forecasts, e

11

Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra  

NLE Websites -- All DOE Office Websites (Extended Search)

Mixed-Phase Cloud Retrievals Using Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra M. D. Shupe, S. Y. Matrosov, and T. L. Schneider National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado P. Kollias Rosentiel School of Marine Atmospheric Sciences University of Miami Miami, Florida Introduction The radar Doppler spectrum contains a wealth of information on cloud microphysical properties. Typically, radar-based cloud retrievals use only the zeroth or first moments of the Doppler spectrum - reflectivity and mean Doppler velocity - to derive quantities such as cloud water content and particle characteristic size (e.g., Liou and Sassen 1994; Matrosov et al. 2002). When using only the moments of the Doppler spectrum, important spectral information can be lost, particularly when the spectrum is

12

Limitations of the Wegener–Bergeron–Findeisen Mechanism in the Evolution of Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

Phase transformation and precipitation formation in mixed-phase clouds are usually associated with the Wegener–Bergeron–Findeisen (WBF) process in which ice crystals grow at the expense of liquid droplets. The evolution of mixed-phase clouds, ...

Alexei Korolev

2007-09-01T23:59:59.000Z

13

Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part II: Multi-layered cloud  

SciTech Connect

Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a deep, multi-layered, mixed-phase cloud system observed during the ARM Mixed-Phase Arctic Cloud Experiment. This cloud system was associated with strong surface turbulent sensible and latent heat fluxes as cold air flowed over the open Arctic Ocean, combined with a low pressure system that supplied moisture at mid-level. The simulations, performed by 13 single-column and 4 cloud-resolving models, generally overestimate the liquid water path and strongly underestimate the ice water path, although there is a large spread among the models. This finding is in contrast with results for the single-layer, low-level mixed-phase stratocumulus case in Part I of this study, as well as previous studies of shallow mixed-phase Arctic clouds, that showed an underprediction of liquid water path. The overestimate of liquid water path and underestimate of ice water path occur primarily when deeper mixed-phase clouds extending into the mid-troposphere were observed. These results suggest important differences in the ability of models to simulate Arctic mixed-phase clouds that are deep and multi-layered versus shallow and single-layered. In general, models with a more sophisticated, two-moment treatment of the cloud microphysics produce a somewhat smaller liquid water path that is closer to observations. The cloud-resolving models tend to produce a larger cloud fraction than the single-column models. The liquid water path and especially the cloud fraction have a large impact on the cloud radiative forcing at the surface, which is dominated by the longwave flux for this case.

Morrison, H; McCoy, R B; Klein, S A; Xie, S; Luo, Y; Avramov, A; Chen, M; Cole, J; Falk, M; Foster, M; Genio, A D; Harrington, J; Hoose, C; Khairoutdinov, M; Larson, V; Liu, X; McFarquhar, G; Poellot, M; Shipway, B; Shupe, M; Sud, Y; Turner, D; Veron, D; Walker, G; Wang, Z; Wolf, A; Xu, K; Yang, F; Zhang, G

2008-02-27T23:59:59.000Z

14

Mesoscale Modeling During Mixed-Phase Arctic Cloud Experiment  

SciTech Connect

Mixed-phase arctic stratus clouds are the predominant cloud type in the Arctic (Curry et al. 2000) and through various feedback mechanisms exert a strong influence on the Arctic climate. Perhaps one of the most intriguing of their features is that they tend to have liquid tops that precipitate ice. Despite the fact that this situation is colloidally unstable, these cloud systems are quite long lived - from a few days to over a couple of weeks. It has been hypothesized that mixed-phase clouds are maintained through a balance between liquid water condensation resulting from the cloud-top radiative cooling and ice removal by precipitation (Pinto 1998; Harrington et al. 1999). In their modeling study Harrington et al. (1999) found that the maintenance of this balance depends strongly on the ambient concentration of ice forming nucleus (IFN). In a follow-up study, Jiang et al. (2002), using only 30% of IFN concentration predicted by Meyers et al. (1992) IFN parameterization were able to obtain results similar to the observations reported by Pinto (1998). The IFN concentration measurements collected during the Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004 over the North Slope of Alaska and the Beaufort Sea (Verlinde et al. 2005), also showed much lower values then those predicted (Prenne, pers. comm.) by currently accepted ice nucleation parameterizations (e.g. Meyers et al. 1992). The goal of this study is to use the extensive IFN data taken during M-PACE to examine what effects low IFN concentrations have on mesoscale cloud structure and coastal dynamics.

Avramov, A.; Harringston, J.Y.; Verlinde, J.

2005-03-18T23:59:59.000Z

15

Retrieval of Cloud Phase Using the Moderate Resolution Imaging Spectroradiometer Data during the Mixed-Phase Arctic Cloud Experiment  

SciTech Connect

Improving climate model predictions over Earth's polar regions requires a comprehensive knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface, making it difficult to detect clouds and retrieve their phase from space. Snow and ice cover, temperature inversions, and the predominance of mixed-phase clouds make it even more difficult to determine cloud phase. Also, since determining cloud phase is the first step toward analyzing cloud optical depth, particle size, and water content, it is vital that the phase be correct in order to obtain accurate microphysical and bulk properties. Changes in these cloud properties will, in turn, affect the Arctic climate since clouds are expected to play a critical role in the sea ice albedo feedback. In this paper, the IR trispectral technique (IRTST) is used as a starting point for a WV and 11-{micro}m brightness temperature (T11) parameterization (WVT11P) of cloud phase using MODIS data. In addition to its ability to detect mixed-phase clouds, the WVT11P also has the capability to identify thin cirrus clouds overlying mixed or liquid phase clouds (multiphase ice). Results from the Atmospheric Radiation Measurement (ARM) MODIS phase model (AMPHM) are compared to the surface-based cloud phase retrievals over the ARM North Slope of Alaska (NSA) Barrow site and to in-situ data taken from University of North Dakota Citation (CIT) aircraft which flew during the Mixed-Phase Arctic Cloud Experiment (MPACE). It will be shown that the IRTST and WVT11P combined to form the AMPHM can achieve a relative high accuracy of phase discrimination compared to the surface-based retrievals. Since it only uses MODIS WV and IR channels, the AMPHM is robust in the sense that it can be applied to daytime, twilight, and nighttime scenes with no discontinuities in the output phase.

Spangenberg, D.; Minnis, P.; Shupe, M.; Uttal, T.; Poellot, M.

2005-03-18T23:59:59.000Z

16

TOWARDS A CHARACTERIZATION OF ARCTIC MIXED-PHASE CLOUDS CIRES/NOAA/ETL  

E-Print Network (OSTI)

, radar-based retrieval methods. On average, mixed-phase cloud ice particle mean diameters increase fromTOWARDS A CHARACTERIZATION OF ARCTIC MIXED-PHASE CLOUDS Shupe, M. CIRES/NOAA/ETL Kollias, P Laboratory P.O. Box, Upton, NY www.bnl.gov ABSTRACT Mixed-phase clouds play a unique role in the Arctic

17

Parameterization of Ice Cloud Radiative Properties and Its Application to the Potential Climatic Importance of Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

It is often assumed, in modeling and radiation budget simulation, that clouds below the cirrus level are entirely in the liquid phase. There is substantive evidence from observations that low and middle clouds are often of mixed phase. Using a ...

Zhian Sun; Keith P. Shine

1995-07-01T23:59:59.000Z

18

Influence of parameterized ice habit on simulated mixed phase Arctic clouds  

E-Print Network (OSTI)

Influence of parameterized ice habit on simulated mixed phase Arctic clouds Alexander Avramov1 12 February 2010. [1] The phase partitioning of cloud mass between liquid and ice in mixed phase clouds and its dependence on ambient ice nuclei (IN) concentrations and ice habit parameterizations

19

Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud  

SciTech Connect

Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a cold-air outbreak mixed-phase stratocumulus cloud observed during the Atmospheric Radiation Measurement (ARM) program's Mixed-Phase Arctic Cloud Experiment. The observed cloud occurred in a well-mixed boundary layer with a cloud top temperature of -15 C. The observed liquid water path of around 160 g m{sup -2} was about two-thirds of the adiabatic value and much greater than the mass of ice crystal precipitation which when integrated from the surface to cloud top was around 15 g m{sup -2}. The simulations were performed by seventeen single-column models (SCMs) and nine cloud-resolving models (CRMs). While the simulated ice water path is generally consistent with the observed values, the median SCM and CRM liquid water path is a factor of three smaller than observed. Results from a sensitivity study in which models removed ice microphysics indicate that in many models the interaction between liquid and ice-phase microphysics is responsible for the large model underestimate of liquid water path. Despite this general underestimate, the simulated liquid and ice water paths of several models are consistent with the observed values. Furthermore, there is some evidence that models with more sophisticated microphysics simulate liquid and ice water paths that are in better agreement with the observed values, although considerable scatter is also present. Although no single factor guarantees a good simulation, these results emphasize the need for improvement in the model representation of mixed-phase microphysics. This case study, which has been well observed from both aircraft and ground-based remote sensors, could be a benchmark for model simulations of mixed-phase clouds.

Klein, S A; McCoy, R B; Morrison, H; Ackerman, A; Avramov, A; deBoer, G; Chen, M; Cole, J; DelGenio, A; Golaz, J; Hashino, T; Harrington, J; Hoose, C; Khairoutdinov, M; Larson, V; Liu, X; Luo, Y; McFarquhar, G; Menon, S; Neggers, R; Park, S; Poellot, M; von Salzen, K; Schmidt, J; Sednev, I; Shipway, B; Shupe, M; Spangenberg, D; Sud, Y; Turner, D; Veron, D; Falk, M; Foster, M; Fridlind, A; Walker, G; Wang, Z; Wolf, A; Xie, S; Xu, K; Yang, F; Zhang, G

2008-02-27T23:59:59.000Z

20

Statistical Analysis of Aerosol Effects on Simulated Mixed-Phase Clouds and Precipitation in the Alps  

Science Conference Proceedings (OSTI)

Increasing the aerosol number in warm-phase clouds is thought to decrease the rain formation rate, whereas the physical processes taking place in mixed-phase clouds are more uncertain. Increasing number concentrations of soluble aerosols may ...

Elias M. Zubler; Ulrike Lohmann; Daniel Lüthi; Christoph Schär; Andreas Muhlbauer

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Arctic mixed-phase cloud properties derived from surface-based sensors at SHEBA  

E-Print Network (OSTI)

Mixed-phase clouds are an understudied component of global cloudiness and are thus poorly represented in models at all scales, which typically partition cloud phase as a function of temperature. The proper partitioning of cloud phase is particularly important considering the unique radiative properties of liquid droplets and ice particles, the impact of phase on precipitation processes, and the sensitivity of phase

M. D. Shupe; S. Y. Matrosov; T. Uttal

2006-01-01T23:59:59.000Z

22

LES Simulations of Roll Clouds Observed During Mixed- Phase Arctic Cloud Experiment  

SciTech Connect

Roll clouds, and associated roll convection, are fairly common features of the atmospheric boundary layer. While these organized cumuliform clouds are found over many regions of the planet, they are quite ubiquitous near the edge of the polar ice sheets. In particular, during periods of off-ice flow, when cold polar air flows from the ice pack over the relatively warm ocean water, strong boundary layer convection develops along with frequent rolls. According to Bruemmer and Pohlman (2000), most of the total cloud cover in the Arctic is due to roll clouds. In an effort to examine the influences of mixed-phase microphysics on the boundary layer evolution of roll clouds during off-ice flow, Olsson and Harrington (2000) used a 2D mesoscale model coupled to a bulk microphysical scheme (see Section 2). Their results showed that mixed-phase clouds produced more shallow boundary layers with weaker turbulence than liquid-phase cases. Furthermore, their results showed that because of th e reduced turbulent drag on the atmosphere in the mixed-phase case, regions of mesoscale divergence in the marginal ice-zone were significantly affected. A follow-up 2D study (Harrington and Olsson 2001) showed that the reduced turbulent intensity in mixed-phase cases was due to precipitation. Ice precipitation caused downdraft stabilization which fed back and caused a reduction in the surface heat fluxes. In this work, we extend the work of Olsson and Harrington (2000) and Harrington and Olsson (2001) by examining the impacts of ice microphysics on roll convection. We will present results that illustrate how microphysics alters roll cloud structure and dynamics.

Greenberg, S.D.; Harrington, J.Y.; Prenni, A.; DeMott, P.

2005-03-18T23:59:59.000Z

23

Intercomparison of Bulk Cloud Microphysics Schemes in Mesoscale Simulations of Springtime Arctic Mixed-Phase Stratiform Clouds  

Science Conference Proceedings (OSTI)

A persistent, weakly forced, horizontally extensive mixed-phase boundary layer cloud observed on 4–5 May 1998 during the Surface Heat Budget of the Arctic Ocean (SHEBA)/First International Satellite Cloud Climatology Project (ISCCP) Regional ...

H. Morrison; J. O. Pinto

2006-07-01T23:59:59.000Z

24

Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud  

SciTech Connect

Results are presented from an intercomparison of single-column and cloud-resolving model simulations of a cold-air outbreak mixed-phase stratocumulus cloud observed during the Atmospheric Radiation Measurement (ARM) program's Mixed-Phase Arctic Cloud Experiment. The observed cloud occurred in a well-mixed boundary layer with a cloud top temperature of -15 C. The observed average liquid water path of around 160 g m{sup -2} was about two-thirds of the adiabatic value and much greater than the average mass of ice crystal precipitation which when integrated from the surface to cloud top was around 15 g m{sup -2}. The simulations were performed by seventeen single-column models (SCMs) and nine cloud-resolving models (CRMs). While the simulated ice water path is generally consistent with the observed values, the median SCM and CRM liquid water path is a factor of three smaller than observed. Results from a sensitivity study in which models removed ice microphysics suggest that in many models the interaction between liquid and ice-phase microphysics is responsible for the large model underestimate of liquid water path. Despite this general underestimate, the simulated liquid and ice water paths of several models are consistent with the observed values. Furthermore, there is evidence that models with more sophisticated microphysics simulate liquid and ice water paths that are in better agreement with the observed values, although considerable scatter is also present. Although no single factor guarantees a good simulation, these results emphasize the need for improvement in the model representation of mixed-phase microphysics.

Klein, Stephen A.; McCoy, Renata B.; Morrison, Hugh; Ackerman, Andrew S.; Avramov, Alexander; de Boer, Gijs; Chen, Mingxuan; Cole, Jason N.S.; Del Genio, Anthony D.; Falk, Michael; Foster, Michael J.; Fridlind, Ann; Golaz, Jean-Christophe; Hashino, Tempei; Harrington, Jerry Y.; Hoose, Corinna; Khairoutdinov, Marat F.; Larson, Vincent E.; Liu, Xiaohong; Luo, Yali; McFarquhar, Greg M.; Menon, Surabi; Neggers, Roel A. J.; Park, Sungsu; Poellot, Michael R.; Schmidt, Jerome M.; Sednev, Igor; Shipway, Ben J.; Shupe, Matthew D.; Spangenberg, Douglas A.; Sud, Yogesh C.; Turner, David D.; Veron, Dana E.; von Salzen, Knut; Walker, Gregory K.; Wang, Zhien; Wolf, Audrey B.; Xie, Shaocheng; Xu, Kuan-Man; Yang, Fanglin; Zhang, Gong

2009-02-02T23:59:59.000Z

25

Simulating Arctic mixed-phase clouds: Sensitivity to environmental...  

NLE Websites -- All DOE Office Websites (Extended Search)

as well as aggregates to precipitation fluxes and radar reflectivity. Observations of icewater drop size distributions, cloud phase, etc., allow us to constrain model...

26

Relative Humidity in Liquid, Mixed-Phase, and Ice Clouds  

Science Conference Proceedings (OSTI)

The results of in situ observations of the relative humidity in liquid, mixed, and ice clouds typically stratiform in nature and associated with mesoscale frontal systems at temperatures ?45°C < Ta < ?5°C are presented. The data were collected ...

Alexei Korolev; George A. Isaac

2006-11-01T23:59:59.000Z

27

Studying Mixed-Phased Clouds Using Ground-Based Active and Passive...  

NLE Websites -- All DOE Office Websites (Extended Search)

when >0C and only ice crystals when < -40C, between 0 and -40C, clouds can be of ice, water, or mixed-phase composition (Rauber and Tokay 1991; Cober et al. 2001). Cloud...

28

The Vertical Profile of Liquid and Ice Water Content in Midlatitude Mixed-Phase Altocumulus Clouds  

Science Conference Proceedings (OSTI)

The microphysical properties of mixed-phase altocumulus clouds are investigated using in situ airborne measurements acquired during the ninth Cloud Layer Experiment (CLEX-9) over a midlatitude location. Approximately ? of the sampled profiles are ...

Lawrence D. Carey; Jianguo Niu; Ping Yang; J. Adam Kankiewicz; Vincent E. Larson; Thomas H. Vonder Haar

2008-09-01T23:59:59.000Z

29

A Numerical Sensitivity Study of Aerosol Influence on Immersion Freezing in Mixed-Phase Stratiform Clouds  

E-Print Network (OSTI)

freezing in a mixed-phase stratiform cloud. Immersion freez- ing is represented using a parameterization, and the larger droplets nucleate into ice particles through the immersion freezing process. In mixed-phaseA Numerical Sensitivity Study of Aerosol Influence on Immersion Freezing in Mixed-Phase Stratiform

Eloranta, Edwin W.

30

Improvements of a Mixed-Phase Cloud Scheme Using Aircraft Observations  

Science Conference Proceedings (OSTI)

To improve the quality of forecasts of mixed-phase clouds in winter storms, some aspects of a cloud scheme are examined in detail. Modifications to the basic formalism and specification of selected parameters of the cloud model are studied, and ...

André Tremblay; Paul A. Vaillancourt; Stewart G. Cober; Anna Glazer; George A. Isaac

2003-04-01T23:59:59.000Z

31

An Analytic Scaling Law for the Depositional Growth of Snow in Thin Mixed-Phase Layer Clouds  

Science Conference Proceedings (OSTI)

In various practical problems, such as assessing the threat of aircraft icing or calculating radiative transfer, it is important to know whether mixed-phase clouds contain significant liquid water content. Some mixed-phase clouds remain ...

Vincent E. Larson; Adam J. Smith

2009-09-01T23:59:59.000Z

32

ARM - Measurement - Cloud phase  

NLE Websites -- All DOE Office Websites (Extended Search)

property that captures the state o f the hydrometeors within a cloud (liquid, ice, or mixed-phase). This is distinct from cloud type that involves property descriptors...

33

Radiative Influences on Glaciation Time-Scales of Mixed-Phase Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

Radiative Influences on Glaciation Time-Scales of Mixed-Phase Clouds Radiative Influences on Glaciation Time-Scales of Mixed-Phase Clouds Harrington, Jerry The Pennsylvania State University Category: Modeling Mixed-phase stratus clouds are dominant in the Arctic during much of the year. These clouds typically have liquid tops that precipitate ice. Time scales for the complete glaciation of such clouds (the Bergeron process) are typically computed using the classical mass growth equations for crystals and liquid drops. However, mixed phase arctic stratus have significant infrared cooling and solar heating (during the warm season) rates that can affect the growth of water drops and ice crystals, and therefore the strength of the Bergeron process. To examine the influence of radiative heating and cooling on the Bergeron process, we incorporate a

34

Parameterization of ice cloud radiative properties and its application to the potential climatic importance of mixed-phase clouds  

SciTech Connect

It is often assumed, in modeling and radiation budget simulation, that clouds below the cirrus level are entirely in the liquid phase. There is substantive evidence from observations that low and middle clouds are often of mixed phase. Using a light-scattering program for hexagonal crystals, the authors update a parameterization of the radiative properties of ice clouds from an earlier study and use the new parameterization to investigate the role of mixed-phase clouds in three areas: (i) the interpretation of ISCCP optical depth, (ii) the simulation of the earth radiation budget, and (iii) the sensitivity of a simple radiative-convective model to an increase in CO{sub 2}. In all cases, mixed-phase clouds are shown to have the potential to significantly modify the results obtained using liquid phase clouds. A precise quantification is not yet possible as the dependence of the fraction of ice and liquid water is mixed-phase clouds on atmospheric properties, and the way in which the ice and liquid water are mixed, are not known with sufficient detail. 43 refs., 17 figs., 2 tabs.

Sun, Z.; Shine, K.P. [Univ. of Reading (United Kingdom)] [Univ. of Reading (United Kingdom)

1995-07-01T23:59:59.000Z

35

Using Surface Remote Sensors to Derive Mixed-Phase Cloud Radiative Forcing:  

NLE Websites -- All DOE Office Websites (Extended Search)

Using Surface Remote Sensors to Derive Mixed-Phase Cloud Radiative Forcing: Using Surface Remote Sensors to Derive Mixed-Phase Cloud Radiative Forcing: An Example from M-PACE Title Using Surface Remote Sensors to Derive Mixed-Phase Cloud Radiative Forcing: An Example from M-PACE Publication Type Journal Article Year of Publication 2011 Authors de Boer, Gijs, William D. Collins, Surabi Menon, and Charles N. Long Journal Atmospheric Chemistry and Physics Volume 11 Start Page 11937 Pagination 11937-11949 Abstract Measurements from ground-based cloud radar, high spectral resolution lidar and microwave radiometer are used in conjunction with a column version of the Rapid Radiative Transfer Model (RRTMG) and radiosonde measurements to derive the surface radiative properties under mixed-phase cloud conditions. These clouds were observed during the United States Department of Energy (US DOE) Atmospheric Radiation Measurement (ARM) Mixed-Phase Arctic Clouds Experiment (M-PACE) between September and November of 2004. In total, sixteen half hour time periods are reviewed due to their coincidence with radiosonde launches. Cloud liquid (ice) water paths are found to range between 11.0-366.4 (0.5-114.1) gm-2, and cloud physical thicknesses fall between 286-2075 m. Combined with temperature and hydrometeor size estimates, this information is used to calculate surface radiative flux densities using RRTMG, which are demonstrated to generally agree with measured flux densities from surface-based radiometric instrumentation. Errors in longwave flux density estimates are found to be largest for thin clouds, while shortwave flux density errors are generally largest for thicker clouds. A sensitivity study is performed to understand the impact of retrieval assumptions and uncertainties on derived surface radiation estimates. Cloud radiative forcing is calculated for all profiles, illustrating longwave dominance during this time of year, with net cloud forcing generally between 50 and 90 Wm-2.

36

Effects of Aerosol Solubility and Regeneration on Mixed-Phase Orographic Clouds and Precipitation  

Science Conference Proceedings (OSTI)

A detailed bin aerosol-microphysics scheme has been implemented into the Weather Research and Forecast Model to investigate the effects of aerosol solubility and regeneration on mixed-phase orographic clouds and precipitation. Two-dimensional ...

Lulin Xue; Amit Teller; Roy Rasmussen; Istvan Geresdi; Zaitao Pan; Xiaodong Liu

2012-06-01T23:59:59.000Z

37

Ice properties of single-layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment  

E-Print Network (OSTI)

Ice properties of single-layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment: 2 opportunity to study poorly understood ice formation processes in mixed-phase stratocumulus. Using, were not significant sources of ice based on parameterizations from existing studies. After surveying

38

Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiationmechanisms  

SciTech Connect

The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during October 9th-10th, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-hour simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase initiation due to freezing of supercooled water in both saturated and subsaturated (w.r.t. water) environments is as important as primary ice crystal origination from water vapor. We also find that the BFP is a process mainly responsible for the rates of glaciation of simulated clouds. These glaciation rates cannot be adequately represented by a water-ice saturation adjustment scheme that only depends on temperature and liquid and solid hydrometeors contents as is widely used in bulk microphysics schemes and are better represented by processes that also account for supersaturation changes as the hydrometeors grow.

Sednev, I.; Menon, S.; McFarquhar, G.

2009-04-10T23:59:59.000Z

39

Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms  

SciTech Connect

The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during 9th-10th October, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-h simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase initiation due to freezing of supercooled water in both saturated and undersaturated (w.r.t. water) environments is as important as primary ice crystal origination from water vapor. We also find that the BFP is a process mainly responsible for the rates of glaciation of simulated clouds. These glaciation rates cannot be adequately represented by a water-ice saturation adjustment scheme that only depends on temperature and liquid and solid hydrometeors contents as is widely used in bulk microphysics schemes and are better represented by processes that also account for supersaturation changes as the hydrometeors grow.

Sednev, Igor; Sednev, I.; Menon, S.; McFarquhar, G.

2008-02-18T23:59:59.000Z

40

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

SciTech Connect

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

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

2011-06-16T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Microphysical Properties of Single and Mixed-Phase Arctic Clouds Derived from AERI Observations  

SciTech Connect

A novel new approach to retrieve cloud microphysical properties from mixed-phase clouds is presented. This algorithm retrieves cloud optical depth, ice fraction, and the effective size of the water and ice particles from ground-based, high-resolution infrared radiance observations. The theoretical basis is that the absorption coefficient of ice is stronger than that of liquid water from 10-13 mm, whereas liquid water is more absorbing than ice from 16-25 um. However, due to strong absorption in the rotational water vapor absorption band, the 16-25 um spectral region becomes opaque for significant water vapor burdens (i.e., for precipitable water vapor amounts over approximately 1 cm). The Arctic is characterized by its dry and cold atmosphere, as well as a preponderance of mixed-phase clouds, and thus this approach is applicable to Arctic clouds. Since this approach uses infrared observations, cloud properties are retrieved at night and during the long polar wintertime period. The analysis of the cloud properties retrieved during a 7 month period during the Surface Heat Budget of the Arctic (SHEBA) experiment demonstrates many interesting features. These results show a dependence of the optical depth on cloud phase, differences in the mode radius of the water droplets in liquid-only and mid-phase clouds, a lack of temperature dependence in the ice fraction for temperatures above 240 K, seasonal trends in the optical depth with the clouds being thinner in winter and becoming more optically thick in the late spring, and a seasonal trend in the effective size of the water droplets in liquid-only and mixed-phase clouds that is most likely related to aerosol concentration.

Turner, David D.

2003-06-01T23:59:59.000Z

42

Evaluation of Mixed-Phase Cloud Parameterizations in Short-Range Weather Forecasts with CAM3 and AM2 for Mixed-Phase Arctic Cloud Experiment  

SciTech Connect

By making use of the in-situ data collected from the recent Atmospheric Radiation Measurement Mixed-Phase Arctic Cloud Experiment, we have tested the mixed-phase cloud parameterizations used in the two major U.S. climate models, the National Center for Atmospheric Research Community Atmosphere Model version 3 (CAM3) and the Geophysical Fluid Dynamics Laboratory climate model (AM2), under both the single-column modeling framework and the U.S. Department of Energy Climate Change Prediction Program-Atmospheric Radiation Measurement Parameterization Testbed. An improved and more physically based cloud microphysical scheme for CAM3 has been also tested. The single-column modeling tests were summarized in the second quarter 2007 Atmospheric Radiation Measurement metric report. In the current report, we document the performance of these microphysical schemes in short-range weather forecasts using the Climate Chagne Prediction Program Atmospheric Radiation Measurement Parameterizaiton Testbest strategy, in which we initialize CAM3 and AM2 with realistic atmospheric states from numerical weather prediction analyses for the period when Mixed-Phase Arctic Cloud Experiment was conducted.

Xie, S; Boyle, J; Klein, S; Liu, X; Ghan, S

2007-06-01T23:59:59.000Z

43

Radiative Processes in Upper Tropospheric Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

The diffusional mass evolution of hydrometeors in upper tropospheric clouds for various radiative conditions in the cloud and for varying ambient moisture Supply is simulated using a time dependent microphysical model. Radiation can play an ...

Douglas A. Wesley; Stephen K. Cox

1988-11-01T23:59:59.000Z

44

Effects of ice number concentration on dynamics of a shallow mixed-phase stratiform cloud  

SciTech Connect

Previous modeling studies have shown a high sensitivity of simulated properties of mixed-phase clouds to ice number concentration, Ni, with many models losing their ability to maintain the liquid phase as Ni increases. Although models differ widely at what Ni the mixed-phase cloud becomes unstable, the transition from a mixed-phase to an ice only cloud in many cases occurs over a narrow range of ice concentration. To gain better understanding of this non-linear model behavior, in this study, we analyze simulations of a mixed-phase stratiform Artic cloud observed on 26 April 2008 during recent Indirect and Semi-Direct Aerosol Campaign (ISDAC). The BASE simulation, in which Ni is constrained to match the measured value, produces a long-lived cloud in a quasi steady state similar to that observed. The simulation without the ice (NO_ICE) produces a comparable but slightly thicker cloud because more moisture is kept in the mixed layer due to lack of precipitation. When Ni is quadrupled relative to BASE (HI_ICE), the cloud starts loosing liquid water almost immediately and the liquid water path is reduced by half in less than two hours. The changes in liquid water are accompanied by corresponding reduction in the radiative cooling of the layer and a slow down in the vertical mixing, confirming the important role of interactions among microphysics, radiation and dynamics in this type of clouds. Deviations of BASE and HI_ICE from NO_ICE are used to explore the linearity of the model response to variation in Ni. It is shown that at early stages, changes in liquid and ice water as well as in radiative cooling/heating rates are proportional to the Ni change, while changes in the vertical buoyancy flux are qualitatively different in HI_ICE compared to BASE. Thus, while the positive feedback between the liquid water path and radiative cooling of the cloud layer is essential for glaciation of the cloud at higher Ni, the non-linear (with respect to Ni) reduction in positive buoyancy flux within and below the liquid cloud layer emerges as the process that influences the initial response of the mixed layer dynamics to the appearance of ice and subsequently determines the sustainability of liquid water in the cloud in this case.

Ovchinnikov, Mikhail; Korolev, Alexei; Fan, Jiwen

2011-09-17T23:59:59.000Z

45

Arctic Mixed-Phase Clouds Simulated by a Cloud-Resolving Model: Comparison with ARM Observations and Sensitivity to Microphysics Parameterizations  

Science Conference Proceedings (OSTI)

Single-layer mixed-phase stratiform (MPS) Arctic clouds, which formed under conditions of large surface heat flux combined with general subsidence during a subperiod of the Atmospheric Radiation Measurement (ARM) Program’s Mixed-Phase Arctic ...

Yali Luo; Kuan-Man Xu; Hugh Morrison; Greg McFarquhar

2008-04-01T23:59:59.000Z

46

Estimation of Mixed-Phase Cloud Optical Depth and Position Using In Situ Radiation and Cloud Microphysical Measurements Obtained from a Tethered-Balloon Platform  

Science Conference Proceedings (OSTI)

Microphysical and radiative measurements in boundary layer mixed-phase clouds (MPCs), consisting of ice crystals and liquid droplets, have been analyzed. These cloud measurements were collected during a May–June 2008 tethered-balloon campaign in ...

M. Sikand; J. Koskulics; K. Stamnes; B. Hamre; J. J. Stamnes; R. P. Lawson

2013-01-01T23:59:59.000Z

47

Observed Microphysical Structure of Midlevel, Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

This paper analyzes airborne measurements of six midlevel clouds observed over the Great Plains of the United States in late 1999 and early 2000 during the fifth of the Complex Layered-Cloud Experiments (CLEX-5). Data show that these innocuous-...

Robert P. Fleishauer; Vincent E. Larson; Thomas H. Vonder Haar

2002-06-01T23:59:59.000Z

48

Simulations of Arctic Mixed-Phase Clouds in Forecasts with CAM3 and AM2 for M-PACE  

SciTech Connect

Simulations of mixed-phase clouds in short-range forecasts with the National Center for Atmospheric Research Community Atmosphere Model version 3 (CAM3) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model (AM2) for the Mixed-Phase Arctic Cloud Experiment (M-PACE) are performed under the DOE CCPP-ARM Parameterization Testbed (CAPT), which initializes the climate models with analysis data produced from numerical weather prediction (NWP) centers. It is shown that CAM3 significantly underestimates the observed boundary layer mixed-phase clouds and cannot realistically simulate the variations with temperature and cloud height of liquid water fraction in the total cloud condensate based an oversimplified cloud microphysical scheme. In contrast, AM2 reasonably reproduces the observed boundary layer clouds while its clouds contain much less cloud condensate than CAM3 and the observations. Both models underestimate the observed cloud top and base for the boundary layer clouds. The simulation of the boundary layer mixed-phase clouds and their microphysical properties is considerably improved in CAM3 when a new physically based cloud microphysical scheme is used. The new scheme also leads to an improved simulation of the surface and top of the atmosphere longwave radiative fluxes in CAM3. It is shown that the Bergeron-Findeisen process, i.e., the ice crystal growth by vapor deposition at the expense of coexisting liquid water, is important for the models to correctly simulate the characteristics of the observed microphysical properties in mixed-phase clouds. Sensitivity tests show that these results are not sensitive to the analysis data used for model initializations. Increasing model horizontal resolution helps capture the subgrid-scale features in Arctic frontal clouds but does not help improve the simulation of the single-layer boundary layer clouds. Ice crystal number density has large impact on the model simulated mixed-phase clouds and their microphysical properties and needs to be accurately represented in climate models.

Xie, Shaocheng; Boyle, James; Klein, Stephen A.; Liu, Xiaohong; Ghan, Steven J.

2008-02-29T23:59:59.000Z

49

Aerosol Influence on Mixed-Phase Clouds in CAM-Oslo  

Science Conference Proceedings (OSTI)

A new treatment of mixed-phase cloud microphysics has been implemented in the general circulation model, Community Atmosphere Model (CAM)-Oslo, which combines the NCAR CAM2.0.1 and a detailed aerosol module. The new treatment takes into account ...

Trude Storelvmo; Jón Egill Kristjánsson; Ulrike Lohmann

2008-10-01T23:59:59.000Z

50

Using Doppler spectra to separate hydrometeor populations and analyze ice precipitation in multilayered mixed-phase clouds  

SciTech Connect

Multimodality of cloud radar Doppler spectra is used to partition cloud particle phases and to separate distinct ice populations in the radar sample volume, thereby facilitating analysis of individual ice showers in multilayered mixed-phase clouds. A 35-GHz cloud radar located at Barrow, Alaska, during the Mixed-Phase Arctic Cloud Experiment collected the Doppler spectra. Data from a pair of collocated depolarization lidars confirmed the presence of two liquid cloud layers reported in this study. Surprisingly, both of these cloud layers were embedded in ice precipitation yet maintained their liquid. Our spectral separation of the ice precipitation yielded two distinct ice populations: ice initiated within the two liquid cloud layers and ice precipitation formed in higher cloud layers. Comparisons of ice fall velocity versus radar reflectivity relationships derived for distinct showers reveal that a single relationship might not properly represent the ice showers during this period.

Rambukkange, Mahlon P.; Verlinde, J.; Eloranta, E. W.; Flynn, Connor J.; Clothiaux, Eugene E.

2011-01-31T23:59:59.000Z

51

Ice Formation in Arctic Mixed-Phase Clouds: Insights from a 3-D Cloud-Resolving Model with Size-Resolved Aerosol and Cloud Microphysics  

SciTech Connect

The single-layer mixed-phase clouds observed during the Atmospheric Radiation Measurement (ARM) program’s Mixed-Phase Arctic Cloud Experiment (MPACE) are simulated with a 3-dimensional cloud-resolving model the System for Atmospheric Modeling (SAM) coupled with an explicit bin microphysics scheme and a radar-lidar simulator. Two possible ice enhancement mechanisms – activation of droplet evaporation residues by condensation-followed-by-freezing and droplet freezing by contact freezing inside-out, are scrutinized by extensive comparisons with aircraft and radar and lidar measurements. The locations of ice initiation associated with each mechanism and the role of ice nuclei (IN) in the evolution of mixed-phase clouds are mainly addressed. Simulations with either mechanism agree well with the in-situ and remote sensing measurements on ice microphysical properties but liquid water content is slightly underpredicted. These two mechanisms give very similar cloud microphysical, macrophysical, dynamical, and radiative properties, although the ice nucleation properties (rate, frequency and location) are completely different. Ice nucleation from activation of evaporation nuclei is most efficient near cloud top areas concentrated on the edges of updrafts, while ice initiation from the drop freezing process has no significant location preference (occurs anywhere that droplet evaporation is significant). Both enhanced nucleation mechanisms contribute dramatically to ice formation with ice particle concentration of 10-15 times higher relative to the simulation without either of them. The contribution of ice nuclei (IN) recycling from ice particle evaporation to IN and ice particle concentration is found to be very significant in this case. Cloud can be very sensitive to IN initially and form a nonquilibrium transition condition, but become much less sensitive as cloud evolves to a steady mixed-phase condition. The parameterization of Meyers et al. [1992] with the observed MPACE IN concentration is able to predict the observed mixed-phase clouds reasonably well. This validation may facilitate the application of this parameterization in the cloud and climate models to simulate Arctic clouds.

Fan, Jiwen; Ovtchinnikov, Mikhail; Comstock, Jennifer M.; McFarlane, Sally A.; Khain, Alexander

2009-02-27T23:59:59.000Z

52

DOE/SC-ARM-P-07-006 Evaluation of Mixed-Phase Cloud Microphysics  

NLE Websites -- All DOE Office Websites (Extended Search)

6 6 Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations Second Quarter 2007 ARM Metric Report April 2007 Xiaohong Liu and Steven J. Ghan Pacific Northwest National Laboratory Richland, Washington Shaocheng Xie Lawrence Livermore National Laboratory Livermore, California Work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research X. Lui, S.J. Ghan, and S. Xie, DOE/SC-ARM/P-07-006 Summary Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate models have generally proven unsuccessful at simulating the partitioning of condensed water

53

A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes  

Science Conference Proceedings (OSTI)

Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)–Arctic Cloud Experiment (ACE)/Surface Heat Budget of the Arctic ...

Ann M. Fridlind; Bastiaan van Diedenhoven; Andrew S. Ackerman; Alexander Avramov; Agnieszka Mrowiec; Hugh Morrison; Paquita Zuidema; Matthew D. Shupe

2012-01-01T23:59:59.000Z

54

Representation of Arctic Mixed-Phase clouds and the Wegener-Bergeron-Findeisen Process in Climate Models: Perspectives from a Cloud-Resolving Study  

SciTech Connect

Two types of Arctic mixed-phase clouds observed during the ISDAC and M-PACE field campaigns are simulated using a 3-dimensional cloud-resolving model (CRM) with size-resolved cloud microphysics. The modeled cloud properties agree reasonably well with aircraft measurements and surface-based retrievals. Cloud properties such as the probability density function (PDF) of vertical velocity (w), cloud liquid and ice, the regime of ice growth at the expense of liquid water (i.e., Wegener-Bergeron-Findeisen (WBF) process), and the inherent relationships among cloud properties/processes in the mixed-phase layers are examined to gain insights for improving the representation of the mixed-phase processes in General Circulation Models (GCMs). We find that, the WBF process only occurs in about 50% of the mixed-phase regime with the vast majority occurring in the downdrafts. In updrafts both liquid and ice grow simultaneously. But in GCMs, it is not necessary to treat the WBF process at the subgrid scale. Our CRM results produce a w distribution well represented by a Gaussian normal function, validating, at least for arctic clouds, the subgrid treatment used in GCMs. Our CRM results also support the assumption frequently used in GCMs that mixed phase clouds maintain water vapor very near liquid saturation. A Gamma function with a fixed variance does not accurately represent the subgrid variability of cloud liquid. The PDFs of cloud liquid and cloud ice can be fitted with Gamma functions, and a normal function can be used for total water, but the variance should not be fixed. The relationship between the ice depositional growth rate and cloud ice strongly depends on the capacitance of ice particles. The assumption for the capacitance of ice particles (e.g., 1.0 for spheres) used in GCMs could lead to a large deviation in ice depositional growth. At large sales, the maximum overlap assumption looks appropriate.

Fan, Jiwen; Ghan, Steven J.; Ovchinnikov, Mikhail; Liu, Xiaohong; Rasch, Philip J.; Korolev, Alexei

2011-09-20T23:59:59.000Z

55

Sensitivity Studies of the Importance of Dust Ice Nuclei for the Indirect Aerosol Effect on Stratiform Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

New parameterizations of contact freezing and immersion freezing in stratiform mixed-phase clouds (with temperatures between 0° and ?35°C) for black carbon and mineral dust assumed to be composed of either kaolinite (simulation KAO) or ...

U. Lohmann; K. Diehl

2006-03-01T23:59:59.000Z

56

Mesoscale Modeling of Springtime Arctic Mixed-Phase Stratiform Clouds Using a New Two-Moment Bulk Microphysics Scheme  

Science Conference Proceedings (OSTI)

A new two-moment bulk microphysics scheme is implemented into the polar version of the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) to simulate arctic mixed-phase boundary layer stratiform clouds observed during ...

H. Morrison; J. O. Pinto

2005-10-01T23:59:59.000Z

57

The Sensitivity of Springtime Arctic Mixed-Phase Stratocumulus Clouds to Surface Layer and Cloud-Top Inversion Layer Moisture Sources  

Science Conference Proceedings (OSTI)

In this study a series of idealized large eddy simulations is used to understand the relative impact of cloud top and subcloud layer sources of moisture on the microphysical-radiative-dynamical feedbacks in an Arctic mixed-phase stratocumulus (...

Amy Solomon; Matthew D. Shupe; Ola Persson; Hugh Morrison; Takanobu Yamaguchi; Peter M. Caldwell; Gijs de Boer

58

Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations  

SciTech Connect

Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate models have generally proven unsuccessful at simulating the partitioning of condensed water into liquid droplets and ice crystals in these Arctic clouds, which affect modeled cloud phase, cloud lifetime and radiative properties. An ice nucleation parameterization and a vapor deposition scheme were developed that together provide a physically-consistent treatment of mixed-phase clouds in global climate models. These schemes have been implemented in the National Center for Atmospheric Research (NCAR) Community Atmospheric Model Version 3 (CAM3). This report documents the performance of these schemes against ARM Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the CAM single column model version (SCAM). SCAM with our new schemes has a more realistic simulation of the cloud phase structure and the partitioning of condensed water into liquid droplets against observations during the M-PACE than the standard CAM simulations.

Liu, X; Ghan, SJ; Xie, S

2007-04-01T23:59:59.000Z

59

Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms  

E-Print Network (OSTI)

M. : Role of a parameterized ice-phase mi- crophysics in anof contact nucleation in ice phase initiation in clouds, J.simulated, process of ice phase initiation due to freezing

Sednev, I.

2008-01-01T23:59:59.000Z

60

Evaluation of a New Mixed-Phase Cloud Microphysics Parameterization with CAM3 Single-Column Model and M-PACE Observations  

SciTech Connect

Most global climate models generally prescribe the partitioning of condensed water into liquid droplets and ice crystals in mixed-phase clouds according to a temperature-dependent function, which affects modeled cloud phase, cloud lifetime and radiative properties. This study evaluates a new mixed-phase cloud microphysics parameterization (for ice nucleation and water vapor deposition) against the Atmospheric Radiation Measurement (ARM) Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the NCAR Community Atmospheric Model Version 3 (CAM3) single column model (SCAM). It is shown that SCAM with the new scheme produces a more realistic simulation of the cloud phase structure and the partitioning of condensed waterinto liquid droplets against observations during the M-PACE than the standard CAM. Sensitivity test indicates that ice number concentration could play an important role in the simulated mixed-phase cloud microphysics, and thereby needs to be realistically represented in global climate models.

Liu, Xiaohong; Xie, Shaocheng; Ghan, Steven J.

2007-12-14T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Arctic Mixed-Phase Cloud Properties Derived from Surface-Based Sensors at SHEBA MATTHEW D. SHUPE AND SERGEY Y. MATROSOV  

E-Print Network (OSTI)

, cloud-top liquid layer from which ice particles formed and fell, although deep, multilayered mixed-phase. These values are all larger than those found in single-phase ice clouds at SHEBA. Vertically resolved cloud phases can coexist is in question. A re- view of model parameterizations shows the lower tem- perature

Shupe, Matthew

62

Evaluation of A New Mixed-Phase Cloud Microphysics Parameterization with the NCAR Climate Atmospheric Model (CAM3) and ARM Observations Fourth Quarter 2007 ARM Metric Report  

SciTech Connect

Mixed-phase clouds are composed of a mixture of cloud droplets and ice crystals. The cloud microphysics in mixed-phase clouds can significantly impact cloud optical depth, cloud radiative forcing, and cloud coverage. However, the treatment of mixed-phase clouds in most current climate models is crude and the partitioning of condensed water into liquid droplets and ice crystals is prescribed as temperature dependent functions. In our previous 2007 ARM metric reports a new mixed-phase cloud microphysics parameterization (for ice nucleation and water vapor deposition) was documented and implemented in the NCAR Community Atmospheric Model Version 3 (CAM3). The new scheme was tested against the Atmospheric Radiation Measurement (ARM) Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the single column modeling and short-range weather forecast approaches. In this report this new parameterization is further tested with CAM3 in its climate simulations. It is shown that the predicted ice water content from CAM3 with the new parameterization is in better agreement with the ARM measurements at the Southern Great Plain (SGP) site for the mixed-phase clouds.

X Liu; SJ Ghan; S Xie; J Boyle; SA Klein

2007-09-30T23:59:59.000Z

63

In Situ Aircraft Measurements of the Vertical Distribution of Liquid and Ice Water Content in Midlatitude Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

The vertical distribution of liquid and ice water content and their partitioning is studied using 34 cases of in situ measured microphysical properties in midlatitude mixed-phase clouds, with liquid water path ranging from near zero to ~248 g m?2, ...

Yoo-Jeong Noh; Curtis J. Seaman; Thomas H. Vonder Haar; Guosheng Liu

2013-01-01T23:59:59.000Z

64

A Scheme for Calculation of the Liquid Fraction in Mixed-Phase Stratiform Clouds in Large-Scale Models  

Science Conference Proceedings (OSTI)

A scheme for calculation of the liquid fraction fl in mixed-phase stratiform clouds has been developed for use in large-scale models. An advantage of the scheme, compared to the interpolation in temperature that is typically used, is that it ...

Leon D. Rotstayn; Brian F. Ryan; Jack J. Katzfey

2000-04-01T23:59:59.000Z

65

A Dual-Wavelength Radar Method for Ice-Water Characterization in Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

A dual-wavelength method to differentiate supercooled water from ice and to measure mass content in each phase in cold stratiform clouds is proposed and discussed. The differential attenuation Ad, whose direct measurement is available with dual-...

Marielle Gosset; Henri Sauvageot

1992-10-01T23:59:59.000Z

66

Discrimination of Mixed- versus Ice-Phase Clouds Using Dual-Polarization Radar with Application to Detection of Aircraft Icing Regions  

Science Conference Proceedings (OSTI)

Dual-polarization radar measurements and in situ measurements of supercooled liquid water and ice particles within orographic cloud systems are used to develop probabilistic criteria for identifying mixed-phase versus ice-phase regions of sub-0°C ...

David M. Plummer; Sabine Göke; Robert M. Rauber; Larry Di Girolamo

2010-05-01T23:59:59.000Z

67

Parameterization of the Extinction Coefficient in Ice and Mixed-Phase Arctic Clouds during the ISDAC Field Campaign  

SciTech Connect

This report documents the history of attempts to directly measure cloud extinction, the current measurement device known as the Cloud Extinction Probe (CEP), specific problems with direct measurement of extinction coefficient, and the attempts made here to address these problems. Extinction coefficient is one of the fundamental microphysical parameters characterizing bulk properties of clouds. Knowledge of extinction coefficient is of crucial importance for radiative transfer calculations in weather prediction and climate models given that Earth's radiation budget (ERB) is modulated much by clouds. In order for a large-scale model to properly account for ERB and perturbations to it, it must ultimately be able to simulate cloud extinction coefficient well. In turn this requires adequate and simultaneous simulation of profiles of cloud water content and particle habit and size. Similarly, remote inference of cloud properties requires assumptions to be made about cloud phase and associated single-scattering properties, of which extinction coefficient is crucial. Hence, extinction coefficient plays an important role in both application and validation of methods for remote inference of cloud properties from data obtained from both satellite and surface sensors (e.g., Barker et al. 2008). While estimation of extinction coefficient within large-scale models is relatively straightforward for pure water droplets, thanks to Mie theory, mixed-phase and ice clouds still present problems. This is because of the myriad forms and sizes that crystals can achieve, each having their own unique extinction properties. For the foreseeable future, large-scale models will have to be content with diagnostic parametrization of crystal size and type. However, before they are able to provide satisfactory values needed for calculation of radiative transfer, they require the intermediate step of assigning single-scattering properties to particles. The most basic of these is extinction coefficient, yet it is rarely measured directly, and therefore verification of parametrizations is difficult. The obvious solution is to be able to measure microphysical properties and extinction at the same time and for the same volume. This is best done by in situ sampling by instruments mounted on either balloon or aircraft. The latter is the usual route and the one employed here. Yet the problem of actually measuring extinction coefficient directly for arbitrarily complicated particles still remains unsolved.

Korolev, A; Shashkov, A; Barker, H

2012-03-06T23:59:59.000Z

68

Parameterization of the Extinction Coefficient in Ice and Mixed-Phase Arctic Clouds during the ISDAC Field Campaign  

SciTech Connect

This report documents the history of attempts to directly measure cloud extinction, the current measurement device known as the Cloud Extinction Probe (CEP), specific problems with direct measurement of extinction coefficient, and the attempts made here to address these problems. Extinction coefficient is one of the fundamental microphysical parameters characterizing bulk properties of clouds. Knowledge of extinction coefficient is of crucial importance for radiative transfer calculations in weather prediction and climate models given that Earth's radiation budget (ERB) is modulated much by clouds. In order for a large-scale model to properly account for ERB and perturbations to it, it must ultimately be able to simulate cloud extinction coefficient well. In turn this requires adequate and simultaneous simulation of profiles of cloud water content and particle habit and size. Similarly, remote inference of cloud properties requires assumptions to be made about cloud phase and associated single-scattering properties, of which extinction coefficient is crucial. Hence, extinction coefficient plays an important role in both application and validation of methods for remote inference of cloud properties from data obtained from both satellite and surface sensors (e.g., Barker et al. 2008). While estimation of extinction coefficient within large-scale models is relatively straightforward for pure water droplets, thanks to Mie theory, mixed-phase and ice clouds still present problems. This is because of the myriad forms and sizes that crystals can achieve, each having their own unique extinction properties. For the foreseeable future, large-scale models will have to be content with diagnostic parametrization of crystal size and type. However, before they are able to provide satisfactory values needed for calculation of radiative transfer, they require the intermediate step of assigning single-scattering properties to particles. The most basic of these is extinction coefficient, yet it is rarely measured directly, and therefore verification of parametrizations is difficult. The obvious solution is to be able to measure microphysical properties and extinction at the same time and for the same volume. This is best done by in situ sampling by instruments mounted on either balloon or aircraft. The latter is the usual route and the one employed here. Yet the problem of actually measuring extinction coefficient directly for arbitrarily complicated particles still remains unsolved.

Korolev, A; Shashkov, A; Barker, H

2012-03-06T23:59:59.000Z

69

Sensitivity Studies of Aerosol–Cloud Interactions in Mixed-Phase Orographic Precipitation  

Science Conference Proceedings (OSTI)

Anthropogenic aerosols serve as a source of both cloud condensation nuclei (CCN) and ice nuclei (IN) and affect microphysical properties of clouds. Increasing aerosol number concentration is assumed to retard the cloud droplet coalescence and the ...

Andreas Muhlbauer; Ulrike Lohmann

2009-09-01T23:59:59.000Z

70

The dependence of ice microphysics on aerosol concentration in arctic mixed-phase stratus clouds during ISDAC and M-PACE  

SciTech Connect

Cloud and aerosol data acquired by the National Research Council of Canada (NRC) Convair-580 aircraft in, above, and below single-layer arctic stratocumulus cloud during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 were used to test three aerosol indirect effects hypothesized to act in mixed-phase clouds: the riming indirect effect, the glaciation indirect effect, and the cold second indirect effect. The data showed a correlation of R= 0.75 between liquid drop number concentration, Nliq, inside cloud and ambient aerosol number concentration NPCASP below cloud. This, combined with increasing liquid water content LWC with height above cloud base and the nearly constant profile of Nliq, suggested that liquid drops were nucleated from aerosol at cloud base. No strong evidence of a riming indirect effect was observed, but a strong correlation of R = 0.69 between ice crystal number concentration Ni and NPCASP above cloud was noted. Increases in ice nuclei (IN) concentration with NPCASP above cloud combined with the subadiabatic LWC profiles suggest possible mixing of IN from cloud top consistent with the glaciation indirect effect. The higher Nice and lower effective radius rel for the more polluted ISDAC cases compared to data collected in cleaner single-layer stratocumulus conditions during the Mixed-Phase Arctic Cloud Experiment is consistent with the operation of the cold second indirect effect. However, more data in a wider variety of meteorological and surface conditions, with greater variations in aerosol forcing, are required to identify the dominant aerosol forcing mechanisms in mixed-phase arctic clouds.

Jackson, Robert C.; McFarquhar, Greg; Korolev, Alexei; Earle, Michael; Liu, Peter S.; Lawson, R. P.; Brooks, Sarah D.; Wolde, Mengistu; Laskin, Alexander; Freer, Matthew

2012-08-14T23:59:59.000Z

71

Minimalist Model of Ice Microphysics in Mixed-phase Stratiform Clouds  

SciTech Connect

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

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

2013-07-28T23:59:59.000Z

72

A Modeling Case Study of Mixed-Phase Clouds over the Southern Ocean and Tasmania  

Science Conference Proceedings (OSTI)

The cloud structure associated with two frontal passages over the Southern Ocean and Tasmania is investigated. The first event, during August 2006, is characterized by large quantities of supercooled liquid water and little ice. The second case, ...

Anthony E. Morrison; Steven T. Siems; Michael J. Manton; Alex Nazarov

2010-03-01T23:59:59.000Z

73

AMSU-B Observations of Mixed-Phase Clouds over Land  

Science Conference Proceedings (OSTI)

Measurements from passive microwave satellite instruments such as the Advanced Microwave Sounding Unit B (AMSU-B) are sensitive to both liquid and ice cloud particles. Radiative transfer modeling is exploited to simulate the response of the AMSU-...

M. N. Deeter; J. Vivekanandan

2005-01-01T23:59:59.000Z

74

Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiation mechanisms  

E-Print Network (OSTI)

M. : Role of a parameterized ice-phase micro- physics in anconcentration (N i ) for ice phase in experiments with icei L ?1 Table 8. Composite ice phase effective radius (R ei )

Sednev, I.

2009-01-01T23:59:59.000Z

75

8, 1175511819, 2008 mixed-phase Arctic  

E-Print Network (OSTI)

, process of ice phase initiation due to freezing of25 supercooled water in both saturatedACPD 8, 11755­11819, 2008 Simulating mixed-phase Arctic stratus clouds I. Sednev et al. Title Page.0 License. Atmospheric Chemistry and Physics Discussions Simulating mixed-phase Arctic stratus clouds

Paris-Sud XI, Université de

76

Black carbon enrichment in atmospheric ice particle residuals observed in lower tropospheric mixed phase clouds  

SciTech Connect

The enrichment of black carbon (BC) in residuals of small ice crystals was investigated during intensive experiments in winter 2004 and 2005 at the high alpine research station Jungfraujoch (3580 m asl, Switzerland). Two inlets were used to sample the bulk aerosol (residuals of cloud droplets and ice crystals as well as non-activated aerosol particles) and the residual particles of small ice crystals (diameter 5 - 20 ?m). An enrichment of the BC mass fraction in the ice particle residuals was observed by investigating the measured BC mass concentration as a fraction of the bulk (submicrometer) aerosol mass concentration sampled by the two inlets. On average, the BC mass fraction was 5% for the bulk aerosol and 27% for the ice particle residuals. The observed enrichment of BC in ice particle residuals suggests that BC containing particles preferentially act as ice nuclei, with important implications for the indirect aerosol effect via glaciation of clouds.

Cozic, J.; Mertes, S.; Verheggen, B.; Cziczo, Daniel J.; Gallavardin, S. J.; Walter, S.; Baltensperger, Urs; Weingartner, E.

2008-08-15T23:59:59.000Z

77

Black carbon enrichment in atmospheric ice particle residuals observed in lower trophospheric mixed phase clouds  

SciTech Connect

The enrichment of black carbon (BC) in residuals of small ice particles was investigated during intensive experiments in winter 2004 and 2005 at the high alpine research station Jungfraujoch (3580 m asl, Switzerland). Two inlets were used to sample the bulk aerosol (residuals of cloud droplets and ice crystals as well as non-activated aerosol particles) and the residual particles of small ice crystals (diameter 5 - 20 m). An enrichment of the BC mass fraction in the ice particle residuals was observed by investigating the measured BC mass concentration as a fraction of the bulk (submicrometer) aerosol mass concentration sampled by the two inlets. On average, the BC mass fraction was 5% for the bulk aerosol and 14% for the ice particle residuals. The observed enrichment of BC in ice particle residuals suggests that BC may act as ice nuclei, with important implications for the indirect aerosol effect via glaciation of clouds.

Cozic, J.; Mertes, S.; Verheggen, B.; Cziczo, Dan; Gallavardin, S. J.; Walter, S.; Baltensperger, Urs; Weingartner, E.

2008-08-15T23:59:59.000Z

78

Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiation mechanisms  

E-Print Network (OSTI)

parameterization in BRM scheme accounts for two general mech- anisms distinguishable according to the involvement of liquid phase in the ice

Sednev, I.

2009-01-01T23:59:59.000Z

79

Simulation of Effects of Atmospheric Aerosols on Deep Turbulent Convective Clouds Using a Spectral Microphysics Mixed-Phase Cumulus Cloud Model. Part II: Sensitivity Study  

Science Conference Proceedings (OSTI)

Effects of different size distributions of cloud condensational nuclei (CCN) on the evolution of deep convective clouds under dry unstable continental thermodynamic conditions are investigated using the spectral microphysics Hebrew University ...

A. Khain; A. Pokrovsky

2004-12-01T23:59:59.000Z

80

Simulation of Effects of Atmospheric Aerosols on Deep Turbulent Convective Clouds Using a Spectral Microphysics Mixed-Phase Cumulus Cloud Model. Part I: Model Description and Possible Applications  

Science Conference Proceedings (OSTI)

An updated version of the spectral (bin) microphysics cloud model developed at the Hebrew University of Jerusalem [the Hebrew University Cloud Model (HUCM)] is described. The model microphysics is based on the solution of the equation system for ...

A. Khain; A. Pokrovsky; M. Pinsky; A. Seifert; V. Phillips

2004-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Optical Properties and Phase of Some Midlatitude, Midlevel Clouds in ECLIPS  

Science Conference Proceedings (OSTI)

Several cloud optical quantities were measured for the first time in midlevel, mixed-phase clouds. These included cloud infrared emittance and absorption coefficient (10–12 ?m), effective backscatter-to-extinction ratio, and lidar depolarization ...

S. A. Young; C. M. R. Platt; R. T. Austin; G. R. Patterson

2000-02-01T23:59:59.000Z

82

Final Technical Report for "Ice nuclei relation to aerosol properties: Data analysis and model parameterization for IN in mixed-phase clouds"Ă?Âť (DOE/SC00002354)  

Science Conference Proceedings (OSTI)

Clouds play an important role in weather and climate. In addition to their key role in the hydrologic cycle, clouds scatter incoming solar radiation and trap infrared radiation from the surface and lower atmosphere. Despite their importance, feedbacks involving clouds remain as one of the largest sources of uncertainty in climate models. To better simulate cloud processes requires better characterization of cloud microphysical processes, which can affect the spatial extent, optical depth and lifetime of clouds. To this end, we developed a new parameterization to be used in numerical models that describes the variation of ice nuclei (IN) number concentrations active to form ice crystals in mixed-phase (water droplets and ice crystals co-existing) cloud conditions as these depend on existing aerosol properties and temperature. The parameterization is based on data collected using the Colorado State University continuous flow diffusion chamber in aircraft and ground-based campaigns over a 14-year period, including data from the DOE-supported Mixed-Phase Arctic Cloud Experiment. The resulting relationship is shown to more accurately represent the variability of ice nuclei distributions in the atmosphere compared to currently used parameterizations based on temperature alone. When implemented in one global climate model, the new parameterization predicted more realistic annually averaged cloud water and ice distributions, and cloud radiative properties, especially for sensitive higher latitude mixed-phase cloud regions. As a test of the new global IN scheme, it was compared to independent data collected during the 2008 DOE-sponsored Indirect and Semi-Direct Aerosol Campaign (ISDAC). Good agreement with this new data set suggests the broad applicability of the new scheme for describing general (non-chemically specific) aerosol influences on IN number concentrations feeding mixed-phase Arctic stratus clouds. Finally, the parameterization was implemented into a regional cloud-resolving model to compare predictions of ice crystal concentrations and other cloud properties to those observed in two intensive case studies of Arctic stratus during ISDAC. Our implementation included development of a prognostic scheme of ice activation using the IN parameterization so that the most realistic treatment of ice nuclei, including their budget (gains and losses), was achieved. Many cloud microphysical properties and cloud persistence were faithfully reproduced, despite a tendency to under-predict (by a few to several times) ice crystal number concentrations and cloud ice mass, in agreement with some other studies. This work serves generally as the basis for improving predictive schemes for cloud ice crystal activation in cloud and climate models, and more specifically as the basis for such a scheme to be used in a Multi-scale Modeling Format (MMF) that utilizes a connected system of cloud-resolving models on a global grid in an effort to better resolve cloud processes and their influence on climate.

Paul J. DeMott, Anthony J. Prenni; Sonia M. Kreidenweis

2012-09-28T23:59:59.000Z

83

Observational Constraints on the Cloud Thermodynamic Phase in Midlatitude Storms CATHERINE M. NAUD  

E-Print Network (OSTI)

in the ice versus the liquid phase. Early prognostic cloud water parameterizations for stratiform clouds supercooled liquid water gradually gives way to ice in the mixed-phase regions of clouds are still poorlyObservational Constraints on the Cloud Thermodynamic Phase in Midlatitude Storms CATHERINE M. NAUD

84

Cloud Top Mixing in Small Cumuli  

Science Conference Proceedings (OSTI)

On 28 August 1978 a series of flights was made into small cumuli using the Desert Research Institutes B-26 research aircraft. The low values for the liquid water mixing ratio obtained in cloud indicate considerable entrainment of clear air. A ...

Robert G. LaMontagne; James W. Telford

1983-09-01T23:59:59.000Z

85

Mixing in Shallow Cumulus Clouds Studied by Lagrangian Particle Tracking  

Science Conference Proceedings (OSTI)

Mixing between shallow cumulus clouds and their environment is studied using large-eddy simulations. The origin of in-cloud air is studied by two distinct methods: 1) by analyzing conserved variable mixing diagrams (Paluch diagrams) and 2) by ...

Thijs Heus; Gertjan van Dijk; Harm J. J. Jonker; Harry E. A. Van den Akker

2008-08-01T23:59:59.000Z

86

CALIPSO/CALIOP Cloud Phase Discrimination Algorithm  

Science Conference Proceedings (OSTI)

The current cloud thermodynamic phase discrimination by Cloud-Aerosol Lidar Pathfinder Satellite Observations (CALIPSO) is based on the depolarization of backscattered light measured by its lidar [Cloud-Aerosol Lidar with Orthogonal Polarization (...

Yongxiang Hu; David Winker; Mark Vaughan; Bing Lin; Ali Omar; Charles Trepte; David Flittner; Ping Yang; Shaima L. Nasiri; Bryan Baum; Robert Holz; Wenbo Sun; Zhaoyan Liu; Zhien Wang; Stuart Young; Knut Stamnes; Jianping Huang; Ralph Kuehn

2009-11-01T23:59:59.000Z

87

Cloud Particle Phase Determination with the AVHRR  

Science Conference Proceedings (OSTI)

An accurate determination of cloud particle phase is required for the retrieval of other cloud properties from satellite and for radiative flux calculations in climate models. The physical principles underlying phase determination using the ...

Jeffrey R. Key; Janet M. Intrieri

2000-10-01T23:59:59.000Z

88

Thermodynamic phase profiles of optically thin midlatitude clouds and their relation to temperature  

E-Print Network (OSTI)

parameterizations of cloud phase in general circulation models. However, other aircraft campaigns and different in the Arctic. The relationship between ice phase occurrence and temperature only slightly changes between cloud interest, as they occur in a temperature range where cloud phase can either be liquid, ice, or mixed

89

Evaluation of AIRS cloud thermodynamic phase determination with CALIPSO  

Science Conference Proceedings (OSTI)

The Atmospheric Infrared Sounder (AIRS) infrared-based cloud thermodynamic phase retrievals are evaluated using the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) cloud thermodynamic phase. The AIRS cloud phase is ...

Hongchun Jin; Shaima L. Nasiri

90

A High Resolution Hydrometer Phase Classifier Based on Analysis of Cloud Radar Doppler Spectra.  

SciTech Connect

The lifecycle and radiative properties of clouds are highly sensitive to the phase of their hydrometeors (i.e., liquid or ice). Knowledge of cloud phase is essential for specifying the optical properties of clouds, or else, large errors can be introduced in the calculation of the cloud radiative fluxes. Current parameterizations of cloud water partition in liquid and ice based on temperature are characterized by large uncertainty (Curry et al., 1996; Hobbs and Rangno, 1998; Intriery et al., 2002). This is particularly important in high geographical latitudes and temperature ranges where both liquid droplets and ice crystal phases can exist (mixed-phase cloud). The mixture of phases has a large effect on cloud radiative properties, and the parameterization of mixed-phase clouds has a large impact on climate simulations (e.g., Gregory and Morris, 1996). Furthermore, the presence of both ice and liquid affects the macroscopic properties of clouds, including their propensity to precipitate. Despite their importance, mixed-phase clouds are severely understudied compared to the arguably simpler single-phase clouds. In-situ measurements in mixed-phase clouds are hindered due to aircraft icing, difficulties distinguishing hydrometeor phase, and discrepancies in methods for deriving physical quantities (Wendisch et al. 1996, Lawson et al. 2001). Satellite-based retrievals of cloud phase in high latitudes are often hindered by the highly reflecting ice-covered ground and persistent temperature inversions. From the ground, the retrieval of mixed-phase cloud properties has been the subject of extensive research over the past 20 years using polarization lidars (e.g., Sassen et al. 1990), dual radar wavelengths (e.g., Gosset and Sauvageot 1992; Sekelsky and McIntosh, 1996), and recently radar Doppler spectra (Shupe et al. 2004). Millimeter-wavelength radars have substantially improved our ability to observe non-precipitating clouds (Kollias et al., 2007) due to their excellent sensitivity that enables the detection of thin cloud layers and their ability to penetrate several non-precipitating cloud layers. However, in mixed-phase clouds conditions, the observed Doppler moments are dominated by the highly reflecting ice crystals and thus can not be used to identify the cloud phase. This limits our ability to identify the spatial distribution of cloud phase and our ability to identify the conditions under which mixed-phase clouds form.

Luke,E.; Kollias, P.

2007-08-06T23:59:59.000Z

91

Modeling Entrainment and Finescale Mixing in Cumulus Clouds  

Science Conference Proceedings (OSTI)

A model used to study entrainment and mixing of thermodynamic properties in the stratus-topped boundary layer has been extended to represent these processes in cumulus clouds. The new model, called the “explicit mixing parcel model” (EMPM), ...

Steven K. Krueger; Chwen-Wei Su; Patrick A. McMurtry

1997-12-01T23:59:59.000Z

92

Clouds at Arctic Atmospheric Observatories. Part II: Thermodynamic Phase Characteristics  

Science Conference Proceedings (OSTI)

Cloud phase defines many cloud properties and determines the ways in which clouds interact with other aspects of the climate system. The occurrence fraction and characteristics of clouds distinguished by their phase are examined at three Arctic ...

Matthew D. Shupe

2011-03-01T23:59:59.000Z

93

Does Mixing Promote Cloud Droplet Growth?  

Science Conference Proceedings (OSTI)

A systematic examination of cloud droplet size spectra from the Cooperative Convective Precipitation Experiment (CCOPE) reveals no tendency for an increase in the maximum droplet size with increasing dilution or cloud age.

Ilga R. Paluch; Charles A. Knight

1986-09-01T23:59:59.000Z

94

Vertical Mixing in Clear Air and Clouds  

Science Conference Proceedings (OSTI)

The realization that clouds are diluted by the entrainment of dry air from outside the cloud boundaries began more than 40 years ago. Cloud-top entrainment was first clearly recognized by Squires in 1958. Warner and Squires showed that the ...

James W. Telford; Steven K. Chai

1993-04-01T23:59:59.000Z

95

Numerical Simulation of Cloud–Clear Air Interfacial Mixing  

Science Conference Proceedings (OSTI)

This paper discusses results from a series of direct numerical simulations of the microscale cloud–clear air mixing, set forth in the idealized scenario of decaying moist turbulence. In the moist case, kinetic energy of microscale motions comes ...

Miros?aw Andrejczuk; Wojciech W. Grabowski; Szymon P. Malinowski; Piotr K. Smolarkiewicz

2004-07-01T23:59:59.000Z

96

Deployment of a Tethered-Balloon System for Microphysics and Radiative Measurements in Mixed-Phase Clouds at Ny-Ĺlesund and South Pole  

Science Conference Proceedings (OSTI)

A tethered-balloon system capable of making microphysical and radiative measurements in clouds is described and examples of measurements in boundary layer stratus clouds in the Arctic and at the South Pole are presented. A 43-m3 helium-filled ...

R. Paul Lawson; Knut Stamnes; Jakob Stamnes; Pat Zmarzly; Jeff Koskuliks; Chris Roden; Qixu Mo; Michael Carrithers; Geoffrey L. Bland

2011-05-01T23:59:59.000Z

97

Numerical Simulation of Cloud–Clear Air Interfacial Mixing: Effects on Cloud Microphysics  

Science Conference Proceedings (OSTI)

This paper extends the previously published numerical study of Andrejczuk et al. on microscale cloud–clear air mixing. Herein, the primary interest is on microphysical transformations. First, a convergence study is performed—with well-resolved ...

Miroslaw Andrejczuk; Wojciech W. Grabowski; Szymon P. Malinowski; Piotr K. Smolarkiewicz

2006-12-01T23:59:59.000Z

98

Numerical Simulation of Cloud–Clear Air Interfacial Mixing: Homogeneous versus Inhomogeneous Mixing  

Science Conference Proceedings (OSTI)

This note presents an analysis of several dozens of direct numerical simulations of the cloud–clear air mixing in a setup of decaying moist turbulence with bin microphysics. The goal is to assess the instantaneous relationship between the ...

Miroslaw Andrejczuk; Wojciech W. Grabowski; Szymon P. Malinowski; Piotr K. Smolarkiewicz

2009-08-01T23:59:59.000Z

99

An Arctic Springtime Mixed-Phase Cloudy Boundary Layer Observed during SHEBA  

Science Conference Proceedings (OSTI)

The microphysical characteristics, radiative impact, and life cycle of a long-lived, surface-based mixed-layer, mixed-phase cloud with an average temperature of approximately ?20°C are presented and discussed. The cloud was observed during the ...

P. Zuidema; B. Baker; Y. Han; J. Intrieri; J. Key; P. Lawson; S. Matrosov; M. Shupe; R. Stone; T. Uttal

2005-01-01T23:59:59.000Z

100

Homogeneous and Inhomogeneous Mixing in Cumulus Clouds: Dependence on Local Turbulence Structure  

Science Conference Proceedings (OSTI)

The helicopter-borne instrument payload known as the Airborne Cloud Turbulence Observation System (ACTOS) was used to study the entrainment and mixing processes in shallow warm cumulus clouds. The characteristics of the mixing process are ...

Katrin Lehmann; Holger Siebert; Raymond A. Shaw

2009-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Observational Study of the Entrainment-Mixing Process in Warm Convective Clouds  

Science Conference Proceedings (OSTI)

Thermodynamical and microphysical measurements collected in convective clouds are examined within the frame of the homogeneous/inhomogeneous mixing concept, to determine how entrainment-mixing processes affect cloud droplets, their number ...

Frédéric Burnet; Jean-Louis Brenguier

2007-06-01T23:59:59.000Z

102

A THREE-DIMENSIONAL MODELING STUDY OF THE EFFECTS OF SOLID-PHASE HYDROMETEOR-CHEMICAL INTERACTIONS IN CUMULONIMBUS CLOUDS ON TROPOSPHERIC CHEMICAL DISTRIBUTIONS  

E-Print Network (OSTI)

- and mixed-phase hydrometeors (cloud ice, snow, graupel, and hail) are often excluded or limited due of interactions of ice-phase cloud hydrometeors with volatile chemicals have found that they may significantly. 2. ICE- AND MIXED-PHASE CHEMISTRY 2.1 Gas-Solid Transfer Gas-phase chemical species can diffuse

Stuart, Amy L.

103

Cirrus clouds in a global climate model with a statistical cirrus cloud scheme  

E-Print Network (OSTI)

supersaturation in mixed-phase clouds is the saturation vapor pressure weighted by the proportions of ice to be in the liquid phase for clouds warmer than -35ÂşC, and is assumed to be in the ice phase for cirrus clouds. The conversion of this detrained condensate from liquid phase into the ice phase in the mixed-phase clouds

Meskhidze, Nicholas

104

A Fair-Weather Cumulus Cloud Classification Scheme for Mixed-Layer Studies  

Science Conference Proceedings (OSTI)

Not all cumulus clouds can vent mixed-layer air into the free atmosphere. Therefore, three subtypes of fair-weather cumulus clouds are identified based on the nature of their interaction with the mixed layer: forced, active and passive clouds. ...

Roland B. Stull

1985-01-01T23:59:59.000Z

105

A Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus  

NLE Websites -- All DOE Office Websites (Extended Search)

Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Gijs de Boer, Edwin W. Eloranta, Tempei Hashino, and Gregory J. Tripoli The University of Wisconsin - Madison (1) Introduction Ice formation appears to a dominant factor controlling the lifecycle of Arctic mixed-phase clouds. To date, our understanding of ice formation in these long-lasting cloud structures does not explain the formation of observed ice amounts. Particularly puzzling are observa-

106

Mixed-Phase Microphysics and Cloud Electrification  

Science Conference Proceedings (OSTI)

A number of experimental studies have shown that sublimating ice acquires negative charge and ice undergoing vapor deposition acquires positive charge. Microphysical calculations are performed to determine the diffusional state (i.e., sublimation ...

E. R. Williams; R. Zhang; J. Rydock

1991-10-01T23:59:59.000Z

107

Direct Numerical Simulations of a Smoke Cloud–Top Mixing Layer as a Model for Stratocumuli  

Science Conference Proceedings (OSTI)

A radiatively driven cloud-top mixing layer is investigated using direct numerical simulations. This configuration mimics the mixing process across the inversion that bounds the stratocumulus-topped boundary layer. The main focus of this paper is ...

Alberto de Lozar; Juan Pedro Mellado

2013-08-01T23:59:59.000Z

108

The Effects of Radiative Cooling in a Cloud-Topped Mixed Layer  

Science Conference Proceedings (OSTI)

The sensitivity of models of cloud-topped mixed layers to various specifications of the radiative cooling rate near the cloud top is investigated. It is found that for the “dry cloud” case an assumed distributed cooling rate leads to a shallower ...

Douglas K. Lilly; Wayne H. Schubert

1980-02-01T23:59:59.000Z

109

MIXING OF CLUMPY SUPERNOVA EJECTA INTO MOLECULAR CLOUDS  

SciTech Connect

Several lines of evidence, from isotopic analyses of meteorites to studies of the Sun's elemental and isotopic composition, indicate that the solar system was contaminated early in its evolution by ejecta from a nearby supernova. Previous models have invoked supernova material being injected into an extant protoplanetary disk, or isotropically expanding ejecta sweeping over a distant (>10 pc) cloud core, simultaneously enriching it and triggering its collapse. Here, we consider a new astrophysical setting: the injection of clumpy supernova ejecta, as observed in the Cassiopeia A supernova remnant, into the molecular gas at the periphery of an H II region created by the supernova's progenitor star. To track these interactions, we have conducted a suite of high-resolution (1500{sup 3} effective) three-dimensional numerical hydrodynamic simulations that follow the evolution of individual clumps as they move into molecular gas. Even at these high resolutions, our simulations do not quite achieve numerical convergence, due to the challenge of properly resolving the small-scale mixing of ejecta and molecular gas, although they do allow some robust conclusions to be drawn. Isotropically exploding ejecta do not penetrate into the molecular cloud or mix with it, but, if cooling is properly accounted for, clumpy ejecta penetrate to distances {approx}10{sup 18} cm and mix effectively with large regions of star-forming molecular gas. In fact, the {approx}2 M{sub Sun} of high-metallicity ejecta from a single core-collapse supernova is likely to mix with {approx}2 Multiplication-Sign 10{sup 4} M{sub Sun} of molecular gas material as it is collapsing. Thus, all stars forming late ( Almost-Equal-To 5 Myr) in the evolution of an H II region may be contaminated by supernova ejecta at the level {approx}10{sup -4}. This level of contamination is consistent with the abundances of short-lived radionuclides and possibly some stable isotopic shifts in the early solar system and is potentially consistent with the observed variability in stellar elemental abundances. Supernova contamination of forming planetary systems may be a common, universal process.

Pan Liubin; Desch, Steven J.; Scannapieco, Evan; Timmes, F. X. [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287-1404 (United States)

2012-09-01T23:59:59.000Z

110

Q. J. R. Meteorol. Soc. (2006), 132, pp. 16931715 doi: 10.1256/qj.05.145 Evaluation of a large-eddy model simulation of a mixed-phase altocumulus  

E-Print Network (OSTI)

of mixed-phase clouds, the case shows the importance of using: (i) separate prognostic ice and liquid water-eddy model simulation of a mixed-phase altocumulus cloud using microwave radiometer, lidar and Doppler radar February 2006) SUMMARY Using the Met Office large-eddy model (LEM) we simulate a mixed-phase altocumulus

Hogan, Robin

111

Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences  

NLE Websites -- All DOE Office Websites (Extended Search)

Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences and Relationship to Adiabacity Kim, Byung-Gon Kangnung National University Schwartz, Stephen Brookhaven National Laboratory Miller, Mark Brookhaven National Laboratory Min, Qilong State University of New York at Albany Category: Cloud Properties The microphysical properties of continental stratus clouds observed over SGP appear to be substantially influenced by micrometeorological conditions, such as static stability and updraft velocity. These influences may contribute to the observed weak correlation of aerosol light scattering coefficient with cloud-drop effective radius [Kim et al., JGR, 2003], although aerosol light scattering coefficient is not necessarily the most suitable surrogate aerosol property for number concentration of cloud

112

Limitations of Bispectral Infrared Cloud Phase Determination and Potential for Improvement  

Science Conference Proceedings (OSTI)

Determining cloud thermodynamic phase using infrared satellite observations typically requires a priori assumptions about relationships between cloud phase and cloud temperature. In this study, limitations of an approach using two infrared ...

Shaima L. Nasiri; Brian H. Kahn

2008-11-01T23:59:59.000Z

113

ARM - Field Campaign - Fall 1997 Cloud IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

and with surface instruments. Cloud types of interest included single-layer liquid phase, ice-phase, and mixed-phase clouds, as well as multi-layered conditions. To some degree,...

114

The Influence of Entrainment and Mixing Assumption on Aerosol–Cloud Interactions in Marine Stratocumulus  

Science Conference Proceedings (OSTI)

This study uses large-eddy simulation with bin microphysics to investigate the influence of entrainment and mixing on aerosol–cloud interactions in the context of idealized, nocturnal, nondrizzling marine stratocumulus (Sc). Of particular ...

Adrian A. Hill; Graham Feingold; Hongli Jiang

2009-05-01T23:59:59.000Z

115

The Effects of Subgrid Model Mixing and Numerical Filtering in Simulations of Mesoscale Cloud Systems  

Science Conference Proceedings (OSTI)

Using the newly developed Weather Research and Forecasting (WRF) model, this study investigates the effects of subgrid mixing and numerical filtering in mesoscale cloud simulations by examining the sensitivities to the parameters in turbulence-...

Tetsuya Takemi; Richard Rotunno

2003-09-01T23:59:59.000Z

116

Dry powder mixes comprising phase change materials  

DOE Green Energy (OSTI)

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft. 3 figs.

Salyer, I.O.

1995-12-26T23:59:59.000Z

117

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft. 3 figures.

Salyer, I.O.

1994-12-06T23:59:59.000Z

118

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft.

Salyer, Ival O. (Dayton, OH)

1994-01-01T23:59:59.000Z

119

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft.

Salyer, Ival O. (Dayton, OH)

1995-01-01T23:59:59.000Z

120

Heterogeneous chemistry of atmospheric mineral dust particles and their resulting cloud-nucleation properties  

E-Print Network (OSTI)

ice nucleation in ice and mixed- phase clouds are: 1. WhatWhat is the phase, hygroscopicity, and warm and ice cloudmixed phase clouds, while cirrus clouds are composed of ice

Sullivan, Ryan Christopher

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

A free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7 [times] 10[sup [minus]3] to about 7 [times] 10[sup [minus]2] microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 9 figs.

Salyer, I.O.

1992-04-21T23:59:59.000Z

122

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7[times]10[sup [minus]3] to about 7[times]10[sup [minus]2] microns and the p.c.m. must be added to the silica in an amount of 80 wt. % or less p.c.m. per combined weight of silica and p.c.m. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a p.c.m. material. The silica-p.c.m. mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, I.O.

1993-05-18T23:59:59.000Z

123

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1993-01-01T23:59:59.000Z

124

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1992-01-01T23:59:59.000Z

125

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garmets, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1993-01-01T23:59:59.000Z

126

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

Free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a PCM material. The silica-PCM mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1994-01-01T23:59:59.000Z

127

Dry powder mixes comprising phase change materials  

DOE Patents (OSTI)

Free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a PCM material. The silica-PCM mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 2 figures.

Salyer, I.O.

1994-02-01T23:59:59.000Z

128

A Stochastic Mixing Model for Nonprecipitating Cumulus Clouds  

Science Conference Proceedings (OSTI)

Recent work suggests that nonprecipitating cumulus clouds must be considered as aggregates of many parcels always moving toward buoyancy equilibrium, but otherwise subject to a multiplicity of fates. For example, some parcels originating at low ...

David J. Raymond; Alan M. Blyth

1986-11-01T23:59:59.000Z

129

A Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Gijs de Boer,Edwin W.Eloranta,Tempei Hashino,and Gregory J.Tripoli  

E-Print Network (OSTI)

to a dominant factor controlling the lifecycle of Arctic mixed-phase clouds. To date, our understanding of ice Stratus from M-PACE Mixed-Phase Layer Ice Precipitation "Bursts" Time (UT) Altitude(km) Lidar backscatter. - Additionally, Shupe illustrated that ice water content and liquid water content seem to vary in phase with each

Eloranta, Edwin W.

130

Synoptic sensitivities of subtropical clouds separating aerosol effects from meteorology  

E-Print Network (OSTI)

identi?ed as liquid, ice, mixed phase, or uncertain. Here wePhase Infrared Day Histogram Counts Cloud Fraction Liquid Cloud Fraction Iceice as well as the di?erent temperatures at which each phase

Mauger, Guillaume S.

2008-01-01T23:59:59.000Z

131

A Mixed Scheme for Subgrid-Scale Fluxes in Cloud-Resolving Models  

Science Conference Proceedings (OSTI)

A large-domain large-eddy simulation of a tropical deep convection system is used as a benchmark to derive and test a mixed subgrid-scale (SGS) scheme for scalar and momentum fluxes in cloud-resolving models (CRMs). The benchmark simulation ...

C.-H. Moeng; P. P. Sullivan; M. F. Khairoutdinov; D. A. Randall

2010-11-01T23:59:59.000Z

132

On the Calibration and Performance of an Instrument for Measuring Total Water Mixing Ratio in Cloud  

Science Conference Proceedings (OSTI)

An instrument which measures the total water mixing ratio in cloud has been calibrated to an accuracy of ±0.1 g kg?1 in the presence of liquid water contents ranging up to 7 g kg?1. Evaporation occurs in a labyrinth of heated plates and the ...

C. E. Coulman; M. A. Parker

1982-05-01T23:59:59.000Z

133

A Calorimetric Jet Engine Technique for Estimating the Condensed Water Mixing Ratio in Cumulus Clouds for Cloud Physical and Weather Modification Research  

Science Conference Proceedings (OSTI)

A technique has been developed for deriving estimates of condensed water mixing ratio in cumulus clouds from measurements of potential temperature in the air in the compressor of a jet engine. Condensate that enters the engine at low temperatures ...

Griffith Morgan; Mark Schormann; Erika Botha; Graeme K. Mather

2000-11-01T23:59:59.000Z

134

New insights into single-particle mixing state using aircraft aerosol time-of-flight mass spectrometry  

E-Print Network (OSTI)

of contact nucleation in ice phase initiation in clouds, J.of cloud sampling. The ice phase CVI sample was collectedthe liquid, mixed, and ice phase sampling, externally mixed

Pratt, Kerri Anne

2009-01-01T23:59:59.000Z

135

Aerosol–Cloud Interactions in a Mesoscale Model. Part II: Sensitivity to Aqueous-Phase Chemistry  

Science Conference Proceedings (OSTI)

The feedbacks between aerosols, cloud microphysics, and cloud chemistry are investigated in a mesoscale model. A simple bulk aqueous-phase sulfur chemistry scheme was fully coupled to the existing aerosol and microphysics schemes. The ...

Irena T. Ivanova; Henry G. Leighton

2008-02-01T23:59:59.000Z

136

Application of CALIOP Measurements to the Evaluation of Cloud Phase Derived from MODIS Infrared Channels  

Science Conference Proceedings (OSTI)

In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) infrared-based cloud thermodynamic phase retrievals are evaluated using Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) retrievals for the 6 months from January to ...

Hyoun-Myoung Cho; Shaima L. Nasiri; Ping Yang

2009-10-01T23:59:59.000Z

137

Cloud Properties Working Group Break Out Session  

NLE Websites -- All DOE Office Websites (Extended Search)

(Kollias; Albecht) Q2: Growth of ice crystals in different environments: Ice initiation, ice growth regimes, precipitation formation, mixed-phase cloud lifecycle. (Korolev) Q3:...

138

CALIPSO/CALIOP Cloud Phase Discrimination Algorithm YONGXIANG HU,* DAVID WINKER,* MARK VAUGHAN,* BING LIN,* ALI OMAR,* CHARLES TREPTE,*  

E-Print Network (OSTI)

In passive remote sensing, cloud thermodynamic phase (water or ice) information typically comes from the specCALIPSO/CALIOP Cloud Phase Discrimination Algorithm YONGXIANG HU,* DAVID WINKER,* MARK VAUGHAN The current cloud thermodynamic phase discrimination by Cloud-Aerosol Lidar Pathfinder Satellite Ob

Baum, Bryan A.

139

Mixing Layer Formation near the Tropopause Due to Gravity Wave–Critical Level Interactions in a Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

A plausible mechanism for the formation of mixing layers in the lower stratosphere above regions of tropical convection is demonstrated numerically using high-resolution, two-dimensional (2D), anelastic, nonlinear, cloud-resolving simulations. ...

Mohamed Moustaoui; Binson Joseph; Hector Teitelbaum

2004-12-01T23:59:59.000Z

140

Effects of turbulent mixing on the structure and macroscopic properties of stratocumulus clouds demonstrated by a Lagrangian trajectory model  

Science Conference Proceedings (OSTI)

The role of turbulent mixing in formation of the structure of stratocumulus clouds is investigated using a Lagrangian-Eulerian parcel cloud model containing ~2000-5000 adjacent parcels with the linear size of 25-40 m, moving with a turbulent-like ...

L. Magaritz-Ronen; M. Pinsky; A. Khain

Note: This page contains sample records for the topic "mixed phase cloud" 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

CMIP3 Subtropical Stratocumulus Cloud Feedback Interpreted through a Mixed-Layer Model  

Science Conference Proceedings (OSTI)

Large-scale conditions over subtropical marine stratocumulus areas are extracted from global climate models (GCMs) participating in phase 3 of the Coupled Model Intercomparison Project (CMIP3) and used to drive an atmospheric mixed-layer model (...

Peter M. Caldwell; Yunyan Zhang; Stephen A. Klein

2013-03-01T23:59:59.000Z

142

Autumnal Mixed-Phase Cloudy Boundary Layers in the Arctic  

Science Conference Proceedings (OSTI)

Two mixed-phase cloudy boundary layer events observed over the Arctic ice pack in autumn are extensively analyzed. The local dynamic and thermodynamic structure of the boundary layers is determined from aircraft measurements including analysis of ...

James O. Pinto

1998-06-01T23:59:59.000Z

143

Non-stoichiometric mixed-phase titania photocatalyst  

SciTech Connect

A mixed anatase-rutile phase, non-stoichiometric titania photocatalyst material is a highly reactive and is a UV and visible light responsive photocastalyst in the as-deposited condition (i.e. without the need for a subsequent thermal treatment). The mixed phase, non-stoichiometric titania thin film material is non-stoichiometric in terms of its oxygen content such that the thin film material shows a marked red-shift in photoresponse.

Chen, Le (Lakewood, CO); Gray, Kimberly A. (Evanston, IL); Graham, Michael E. (Evanston, IL)

2012-06-19T23:59:59.000Z

144

Modeling clouds observed at SHEBA using a bulk microphysics parameterization implemented into a single-column model  

E-Print Network (OSTI)

cloud fraction, that is, underpredicting the frequency of liquid- or mixed-phase clouds. The mean ice associated with leads, ``clear-sky'' ice crystal precipitation, and persis- tent mixed-phase clouds. BiasesModeling clouds observed at SHEBA using a bulk microphysics parameterization implemented

Shupe, Matthew

145

Impact of cloud microphysics on squall line organization  

NLE Websites -- All DOE Office Websites (Extended Search)

of turbulent- microphysical interactions and impact on optical properties. * Mixed-phase and ice clouds. We will use microphysical retrievals and aircraft observations from...

146

A New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part II: Single-Column Modeling of Arctic Clouds  

E-Print Network (OSTI)

of the arctic bound- ary layer, the presence of leads (cracks) in the sea ice surface, the persistence of mixed-phaseA New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part- dicted cloud boundaries and total cloud fraction compare reasonably well with observations. Cloud phase

Zuidema, Paquita

147

EVALUATING CLOUD RETRIEVAL ALGORITHMS WITH THE ARM BBHRP FRAMEWORK  

E-Print Network (OSTI)

of liquid, ice, and mixed-phase clouds have been processed in BBHRP for the ACRF Southern Great Plains (SGP, and phase of clouds above each ACRF site. Various approaches to retrieve the microphysical properties, including those from Microbase, the current `reference' retrieval approach in BBHRP. At the NSA, mixed-phase

148

Numerical Simulation of Ice-Phase Convective Cloud Seeding  

Science Conference Proceedings (OSTI)

A two-dimensional time-dependent cloud model which covers a region 19.2 km × 19.2 km in the x and z directions with 200 m grid intervals, has been used to simulate silver iodide (AgI) seeding effects on strong convective clouds. The model is a ...

Eirh-Yu Hsie; Richard D. Farley; Harold D. Orville

1980-08-01T23:59:59.000Z

149

Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations  

E-Print Network (OSTI)

ice nucleation parameterization slightly improves the model performance for low-level mixed-phase ice loss by enhancing ice-albedo feedbacks [Kay et al., 2008]. Arctic clouds are often mixed-phase (i-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its

150

Cloud Phase Determination Using Ground-Based AERI Observations at SHEBA  

Science Conference Proceedings (OSTI)

A new technique for ascertaining the thermodynamic cloud phase from high-spectral-resolution ground-based infrared measurements made by the Atmospheric Emitted Radiance Interferometer (AERI) is presented. This technique takes advantage of the ...

D. D. Turner; S. A. Ackerman; B. A. Baum; H. E. Revercomb; P. Yang

2003-06-01T23:59:59.000Z

151

The Impact of Ice Phase Cloud Parameterizations on Tropical Cyclone Prediction  

Science Conference Proceedings (OSTI)

The impact of ice phase cloud microphysical processes on prediction of tropical cyclone environment is examined for two microphysical parameterizations using the Coupled Ocean / Atmosphere Mesoscale Prediction System –Tropical Cyclone model. An ...

Yi Jin; Shouping Wang; Jason Nachamkin; James D. Doyle; Gregory Thompson; Louis Grasso; Teddy Holt; Jon Moskaitis; Hao Jin; Richard M. Hodur; Qingyun Zhao; Ming Liu; Mark DeMaria

152

Retrieval of Vertical Profiles of Liquid Water and Ice Content in Mixed Clouds from Doppler Radar and Microwave Radiometer Measurements  

Science Conference Proceedings (OSTI)

A new method to retrieve vertical profiles of liquid water content Mw(z), ice water content Mi(z), and ice particle size distribution Ni(D, z), (where D is the ice particle size and z the vertical coordinate) in mixed nonprecipitating clouds ...

Henri Sauvageot

1996-01-01T23:59:59.000Z

153

Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

heated by the sun, produces rising columns of air in which the moisture condenses into tall fleecy white clouds At night, when the sky is clear, the earth cools to give those...

154

A Study of Cloud Mixing and Evolution Using PDF Methods. Part I: Cloud Front Propagation and Evaporation  

Science Conference Proceedings (OSTI)

The evolution of mean relative humidity (RH) is studied in an isobaric system of clear and cloudy air mixed by an incompressible velocity field. A constant droplet radius assumption is employed that implies a simple dependence of the mixing time ...

Christopher A. Jeffery; Jon M. Reisner

2006-11-01T23:59:59.000Z

155

Mixing and the Evolution of Cloud Droplet Size Spectra in a Vigorous Continental Cumulus  

Science Conference Proceedings (OSTI)

Aircraft measurements in a vigorous, highly turbulent continental cumulus show predominantly bimodal and multiple peaked cloud droplet spectral shapes. The data are 100 m (1 s) averages. Three factors involved in the development of the cloud ...

Ilga R. Paluch; Charles A. Knight

1984-06-01T23:59:59.000Z

156

Large-Eddy Simulation of Evaporatively Driven Entrainment in Cloud-Topped Mixed Layers  

Science Conference Proceedings (OSTI)

Cloud-top entrainment instability (CTEI) is a hypothesized positive feedback between cloud-top entrainment and enhanced turbulence associated with buoyancy reversal. A sufficiently strong positive feedback is hypothesized to lead to the ...

Takanobu Yamaguchi; David A. Randall

2008-05-01T23:59:59.000Z

157

Sensitivity of Cloud Liquid Water Content Estimates to the Temperature-Dependent Thermodynamic Phase: A Global Study Using CloudSat Data  

Science Conference Proceedings (OSTI)

The main purpose of this study is to underline the sensitivity of cloud liquid water content (LWC) estimates purely to 1) the shape of computationally simplified temperature-dependent thermodynamic phase and 2) the range of subzero temperatures ...

Abhay Devasthale; Manu Anna Thomas

2012-10-01T23:59:59.000Z

158

Evaluation of Cloud-Phase Retrieval Methods for SEVIRI on Meteosat-8 Using Ground-Based Lidar and Cloud Radar Data  

Science Conference Proceedings (OSTI)

Three cloud-phase determination algorithms from passive satellite imagers are explored to assess their suitability for climate monitoring purposes in midlatitude coastal climate zones. The algorithms are the Moderate Resolution Imaging ...

Erwin L. A. Wolters; Robert A. Roebeling; Arnout J. Feijt

2008-06-01T23:59:59.000Z

159

DRAFT, Revised June 2012 Aerosol cloud-mediated radiative forcing: highly uncertain and  

E-Print Network (OSTI)

clouds is even lower than for the shallow clouds, as mixed phase and ice processes play an important role state of cloud and aerosol parameterizations, but intense research efforts aimed at improving. Respectively, the parameterization of these processes for GCMs is further away than for the low clouds

Daniel, Rosenfeld

160

Life Cycle of Numerically Simulated Shallow Cumulus Clouds. Part II: Mixing Dynamics  

Science Conference Proceedings (OSTI)

This paper is the second in a two-part series in which life cycles of six numerically simulated shallow cumulus clouds are systematically examined. The six clouds, selected from a single realization of a large-eddy simulation, grow as a series of ...

Ming Zhao; Philip H. Austin

2005-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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.


161

DRAFT, last update 5 January 2012 Aerosol cloud-mediated radiative forcing: highly uncertain and  

E-Print Network (OSTI)

phase and ice processes. Respectively, the parameterization of these processes for GCMs is further away and aerosol parameterizations, but intense research efforts aimed at improving the realism of cloud lower than for the shallow clouds, as the deep clouds are much more complicated, because mixed phase

Wood, Robert

162

Entrainment-Mixing and Radiative Transfer Simulation in Boundary Layer Clouds  

Science Conference Proceedings (OSTI)

In general circulation models, clouds are parameterized and radiative transfer calculations are performed using the plane-parallel approximation over the cloudy fraction of each model grid. The albedo bias resulting from the plane-parallel ...

Frédérick Chosson; Jean-Louis Brenguier; Lothar Schüller

2007-07-01T23:59:59.000Z

163

Investigation of the Turbulent Structure of a Cloud-Capped Mixed Layer Using Doppler Radar  

Science Conference Proceedings (OSTI)

A new method for retrieving air velocity fluctuations in the cloud-capped boundary layer (BL) using radar reflectivity and the Doppler velocity fields is proposed. The method was developed on the basis of data obtained by the Transportable ...

M. Pinsky; O. Krasnov; H. W. J. Russchenberg; A. Khain

2010-06-01T23:59:59.000Z

164

Evolution of the Vertical Mass Flux and Diagnosed Net Lateral Mixing in Isolated Convective Clouds  

Science Conference Proceedings (OSTI)

The evolution of the vertical mass flux in isolated cumulus and cumulus congestus clouds is documented using two King Airs during the Convection and Precipitation/Electrification Experiment (CaPE,), conducted in east-central Florida during the ...

Gary M. Barnes; James C. Fankhauser; Wesley D. Browning

1996-12-01T23:59:59.000Z

165

Application of AVHRR/3 Imagery for the Improved Detection of Thin Cirrus Clouds and Specification of Cloud-Top Phase  

Science Conference Proceedings (OSTI)

A multisensor, data fusion technique has been developed that merges the spectral signatures of ice and water clouds in Advanced Very High Resolution Radiometer (AVHRR) imagery with cloud-top pressure analyses derived from the High-Resolution ...

Keith D. Hutchison

1999-12-01T23:59:59.000Z

166

Cloud-Resolving Modeling of Tropical Cloud Systems during Phase III of GATE. Part I: Two-Dimensional Experiments  

Science Conference Proceedings (OSTI)

A formal framework is established for the way in which cloud-resolving numerical models are used to investigate the role of precipitating cloud systems in climate and weather forecasting models. Emphasis is on models with periodic lateral ...

Wojciech W. Grabowski; Xiaoqing Wu; Mitchell W. Moncrieff

1996-12-01T23:59:59.000Z

167

Cloud-Top Entrainment Instability through Small-Scale Mixing and Its Parameterization in Numerical Models  

Science Conference Proceedings (OSTI)

In a recent paper, Kuo and Schubert demonstrated the lack of observational support for the relevance of the criterion for cloud-top entrainment instability proposed by Randall and by Deardorff. Here we derive a new criterion, based on a model of ...

M. K. MacVean; P. J. Mason

1990-04-01T23:59:59.000Z

168

Effects of Aerosol Solubility and Regeneration on Warm-Phase Orographic Clouds and Precipitation Simulated by a Detailed Bin Microphysical Scheme  

Science Conference Proceedings (OSTI)

This study evaluates the possible impact of aerosol solubility and regeneration on warm-phase orographic clouds and precipitation. The sensitivity evaluation is performed by simulating cloud formation over two identical 2D idealized mountains ...

Lulin Xue; Amit Teller; Roy Rasmussen; Istvan Geresdi; Zaitao Pan

2010-10-01T23:59:59.000Z

169

Buoyant Production and Consumption of Turbulence Kinetic Energy in Cloud-Topped Mixed Layers  

Science Conference Proceedings (OSTI)

Entrainment closure theories for mixed-layer models entail assumptions about how the net rate of buoyant production of turbulence kinetic energy is partitioned into gross production and consumption. Three alternative partitioning theories are ...

David A. Randall

1984-02-01T23:59:59.000Z

170

Homogeneous Nucleation Rate for Highly Supercooled Cirrus Cloud Droplets  

Science Conference Proceedings (OSTI)

A mixed-phase hydrometer growth model has been applied to determining the nucleation mode and rate responsible for the glaciation of a highly supercooled liquid cloud studied jointly by ground-based polarization lidar and aircraft in situ probes. ...

Kenneth Sassen; Gregory C. Dodd

1988-04-01T23:59:59.000Z

171

Investigation of Microphysical Parameterizations of Snow and Ice in Arctic Clouds during M-PACE through ModelObservation Comparisons  

E-Print Network (OSTI)

Investigation of Microphysical Parameterizations of Snow and Ice in Arctic Clouds during M the microphysical properties of Arctic mixed-phase stratocumulus. Intensive measurements taken during the Department of Energy Atmospheric Radiation Measurement Program Mixed-Phase Arctic Cloud Experiment (M

Solomon, Amy

172

Centrifugal contactor with liquid mixing and flow control vanes and method of mixing liquids of different phases  

DOE Patents (OSTI)

The invention is directed to a centrifugal contactor for solvent extraction systems. The centrifugal contactor is provided with an annular vertically oriented mixing chamber between the rotor housing and the rotor for mixing process liquids such as the aqueous and organic phases of the solvent extraction process used for nuclear fuel reprocessing. A set of stationary helically disposed vanes carried by the housing is in the lower region of the mixing chamber at a location below the process-liquid inlets for the purpose of urging the liquids in an upward direction toward the inlets and enhancing the mixing of the liquids and mass transfer between the liquids. The upper region of the mixing vessel above the inlets for the process liquids is also provided with a set helically disposed vanes carried by the housing for urging the process liquids in a downward direction when the liquid flow rates through the inlets are relatively high and the liquids contact the vane set in the upper region. The use of these opposing vane sets in the mixing zone maintains the liquid in the mixing zone at suitable levels.

Jubin, Robert T. (Powell, TN); Randolph, John D. (Maryville, TN)

1991-01-01T23:59:59.000Z

173

HIGH SPECTRAL RESOLUTION LIDAR EMULATION VIA DOPPLER CLOUD RADAR SPECTRUM PROCESSING AND ITS IMPLICATIONS FOR  

E-Print Network (OSTI)

targeting the liquid, and radar, the ice. Depolarization measurements can assist in resolving phase to identify liquid, ice, and mixed-phase clouds. __________ NOTICE: This manuscript has been authored IMPLICATIONS FOR CLOUD PHASE IDENTIFICATION E. Luke, P. Kollias, and M. Shupe Presented at the American

174

Polarization Lidar at Summit, Greenland for the Detection of Cloud Phase and Particle Orientation  

Science Conference Proceedings (OSTI)

Accurate measurements of cloud properties are necessary to document the full range of cloud conditions and characteristics. The Cloud, Aerosol Polarization and Backscatter Lidar (CAPABL) has been developed to address this need by measuring ...

Ryan R. Neely III; Matthew Hayman; Robert Stillwell; Jeffrey P. Thayer; R. Michael Hardesty; Michael O’Neill; Matthew D. Shupe; Catherine Alvarez

175

Polarization Lidar at Summit, Greenland, for the Detection of Cloud Phase and Particle Orientation  

Science Conference Proceedings (OSTI)

Accurate measurements of cloud properties are necessary to document the full range of cloud conditions and characteristics. The Cloud, Aerosol Polarization and Backscatter Lidar (CAPABL) has been developed to address this need by measuring ...

Ryan R. Neely III; Matthew Hayman; Robert Stillwell; Jeffrey P. Thayer; R. Michael Hardesty; Michael O'Neill; Matthew D. Shupe; Catherine Alvarez

2013-08-01T23:59:59.000Z

176

Liquid-gas mixed phase in nuclear matter at finite temperature  

E-Print Network (OSTI)

We explore the geometrical structure of Liquid-gas (LG) mixed phase which is relevant to nuclear matter in the crust region of compact stars or supernovae. To get the equation of state (EOS) of the system, the Maxwell construction is found to be applicable to symmetric nuclear matter, where protons and neutrons behave simultaneously. For asymmetric nuclear matter, on the other hand, the phase equilibrium can be obtained by fully solving the Gibbs conditions since the components in the L and G phases are completely different. We also discuss the effects of surface and the Coulomb interaction on the mixed phase.

Toshiki Maruyama; Toshitaka Tatsumi

2010-09-07T23:59:59.000Z

177

A Coordinated Effort to Improve Parameterization of High-Latitude Cloud and Radiation Processes  

SciTech Connect

The goal of this project is the development and evaluation of improved parameterization of arctic cloud and radiation processes and implementation of the parameterizations into a climate model. Our research focuses specifically on the following issues: (1) continued development and evaluation of cloud microphysical parameterizations, focusing on issues of particular relevance for mixed phase clouds; and (2) evaluation of the mesoscale simulation of arctic cloud system life cycles.

J. O. Pinto, A.H. Lynch

2005-12-14T23:59:59.000Z

178

Mixed quark-nucleon phase in neutron stars and nuclear symmetry energy  

E-Print Network (OSTI)

The influence of the nuclear symmetry energy on the formation of a mixed quark-nucleon phase in neutron star cores is studied. We use simple parametrizations of the nuclear matter equation of state, and the bag model for the quark phase. The behavior of nucleon matter isobars, which is responsible for the existence of the mixed phase, is investigated. The role of the nuclear symmetry energy changes with the value of the bag constant B. For lower values of B the properties of the mixed phase do not depend strongly on the symmetry energy. For larger B we find that a critical pressure for the first quark droplets to form is strongly dependent on the nuclear symmetry energy, but the pressure at which last nucleons disappear is independent of it.

M. Kutschera; J. Niemiec

2000-06-30T23:59:59.000Z

179

Structure and Evolution of North Australian Cloud Lines Observed during AMEX Phase I  

Science Conference Proceedings (OSTI)

North Australian Clouds Lines are distinctive, squall-line phenomena that occur in easterly flow across northern Australia. Three basic types have been identified, ranging from a long, narrow line of convective clouds (Type 1) to a severe squall ...

Wasyl Drosdowsky; Greg J. Holland; Roger K. Smith

1989-06-01T23:59:59.000Z

180

ARM - PI Product - Cloud-Scale Vertical Velocity and Turbulent Dissipation  

NLE Websites -- All DOE Office Websites (Extended Search)

ProductsCloud-Scale Vertical Velocity and Turbulent ProductsCloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Site(s) NSA General Description Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May

Note: This page contains sample records for the topic "mixed phase cloud" 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

Unraveling the origins of electromechanical response in mixed-phase Bismuth Ferrite  

SciTech Connect

The origin of giant electromechanical response in a mixed-phase rhombohedral-tetragonal BiFeO3 thin film is probed using sub-coercive scanning probe microscopy based multiple-harmonic measurements. Significant contributions to the strain arise from a second-order harmonic response localized at the phase boundaries. Strain and dissipation data, backed by thermodynamic calculations suggest that the source of the enhanced electromechanical response is the motion of phase boundaries. These findings elucidate the key role of labile phase boundaries, both natural and artificial, in achieving thin films with giant electromechanical properties.

Vasudevan, Rama K [ORNL; Okatan, M. B. [University of New South Wales; Liu, Y. Y. [University of Washington, Seattle; Jesse, Stephen [ORNL; Yang, J.-C. [University of California, Berkeley; Liang, W. -I. [National Chiao Tung University, Hsinchu, Taiwan; Chu, Ying-Hao [National Chiao Tung University, Hsinchu, Taiwan; Li, J. Y. [University of Washington, Seattle; Kalinin, Sergei V [ORNL; Valanoor, Nagarajan V [ORNL

2013-01-01T23:59:59.000Z

182

Testing Cloud Microphysics Parameterizations in NCAR CAM5 with ISDAC and M-PACE Observations  

SciTech Connect

Arctic clouds simulated by the NCAR Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic Spring and Fall seasons performed under the Cloud- Associated Parameterizations Testbed (CAPT) framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary layer mixed-phase stratocumulus, and multilayer or deep frontal clouds. However, for low-level clouds, the model significantly underestimates the observed cloud liquid water content in both seasons and cloud fraction in the Spring season. As a result, CAM5 significantly underestimates the surface downward longwave (LW) radiative fluxes by 20-40 W m-2. The model with a new ice nucleation parameterization moderately improves the model simulations by increasing cloud liquid water content in mixed-phase clouds through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron- Findeisen (WBF) process. The CAM5 single column model testing shows that change in the homogeneous freezing temperature of rain to form snow from -5 C to -40 C has a substantial impact on the modeled liquid water content through the slowing-down of liquid and rain-related processes. In contrast, collections of cloud ice by snow and cloud liquid by rain are of minor importance for single-layer boundary layer mixed-phase clouds in the Arctic.

Liu, Xiaohong; Xie, Shaocheng; Boyle, James; Klein, Stephen A.; Shi, Xiangjun; Wang, Zhien; Lin, Wuyin; Ghan, Steven J.; Earle, Michael; Liu, Peter; Zelenyuk, Alla

2011-12-24T23:59:59.000Z

183

Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations  

SciTech Connect

Arctic clouds simulated by the National Center for Atmospheric Research (NCAR) Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic spring and fall seasons performed under the Cloud-Associated Parameterizations Testbed framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary-layer mixed-phase stratocumulus and multilayer or deep frontal clouds. However, for low-level stratocumulus, the model significantly underestimates the observed cloud liquid water content in both seasons. As a result, CAM5 significantly underestimates the surface downward longwave radiative fluxes by 20-40 W m{sup -2}. Introducing a new ice nucleation parameterization slightly improves the model performance for low-level mixed-phase clouds by increasing cloud liquid water content through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron-Findeisen process. The CAM5 single-column model testing shows that changing the instantaneous freezing temperature of rain to form snow from -5 C to -40 C causes a large increase in modeled cloud liquid water content through the slowing down of cloud liquid and rain-related processes (e.g., autoconversion of cloud liquid to rain). The underestimation of aerosol concentrations in CAM5 in the Arctic also plays an important role in the low bias of cloud liquid water in the single-layer mixed-phase clouds. In addition, numerical issues related to the coupling of model physics and time stepping in CAM5 are responsible for the model biases and will be explored in future studies.

Liu X.; Lin W.; Xie, S.; Boyle, J.; Klein, S. A.; Shi, X.; Wang, Z.; Ghan, S. J.; Earle, M.; Liu, P. S. K.; Zelenyuk, A.

2011-12-24T23:59:59.000Z

184

A New Two-Moment Bulk Stratiform Cloud Microphysics Scheme in the Community Atmosphere Model, Version 3 (CAM3). Part II: Single-Column and Global Results  

E-Print Network (OSTI)

the importance of these interactions and the dif- ficulty in parameterizing clouds due to the wide range prognostic variables for cloud liquid and ice mass, specification of the effective cloud particle size for treating radiative interactions, and limited treatment of mixed-phase processes. There are several

Gettelman, Andrew

185

Molecular Tagging Diagnostics for the Study of Kinematics and Mixing in Liquid-Phase Flows  

E-Print Network (OSTI)

Molecular Tagging Diagnostics for the Study of Kinematics and Mixing in Liquid-Phase Flows M. M based on molecular tagging approaches. These developments take advantage of a class of newly engineered and caged fluorescein are briefly discussed and compared. The application of molecular tagging velocimetry

Koochesfahani, Manoochehr M.

186

Application of Stochastic Radiative Transfer Theory to the ARM Cloud-Radiative Parameterization Problem  

Science Conference Proceedings (OSTI)

This project had two primary goals: (1) development of stochastic radiative transfer as a parameterization that could be employed in an AGCM environment, and (2) exploration of the stochastic approach as a means for representing shortwave radiative transfer through mixed-phase layer clouds. To achieve these goals, climatology of cloud properties was developed at the ARM CART sites, an analysis of the performance of the stochastic approach was performed, a simple stochastic cloud-radiation parameterization for an AGCM was developed and tested, a statistical description of Arctic mixed phase clouds was developed and the appropriateness of stochastic approach for representing radiative transfer through mixed-phase clouds was assessed. Significant progress has been made in all of these areas and is detailed in the final report.

Dana E. Veron

2012-04-09T23:59:59.000Z

187

Mixed-Phase Arctic Cloud Experiment (M-PACE): the Field Campaign  

DOE Data Explorer (OSTI)

This case study presents data from 27 Sep 2004 to 22 Oct 2004 and covers a region from 65N to 75N latitude and from 160W to 145W longitude.

188

A Simplified Model of the Walker Circulation with an Interactive Ocean Mixed Layer and Cloud-Radiative Feedbacks  

Science Conference Proceedings (OSTI)

Cloud–climate feedbacks between precipitation, radiation, circulation strength, atmospheric temperature and moisture, and ocean temperature are studied with an idealized model of the Walker circulation in a nonrotating atmosphere coupled to an ...

Matthew E. Peters; Christopher S. Bretherton

2005-10-01T23:59:59.000Z

189

Investigations of cloud altering effects of atmospheric aerosols using a new mixed Eulerian-Lagrangian aerosol model  

E-Print Network (OSTI)

Industry, urban development, and other anthropogenic influences have substantially altered the composition and size-distribution of atmospheric aerosol particles over the last century. This, in turn, has altered cloud ...

Steele, Henry Donnan, 1974-

2004-01-01T23:59:59.000Z

190

Mixed Waste Focus Area integrated technical baseline report, Phase 1: Volume 1  

SciTech Connect

The Department of Energy (DOE) established the Mixed Waste Characterization, Treatment, and Disposal Focus Area (MWFA) to develop and facilitate implementation of technologies required to meet the Department`s commitments for treatment of mixed low-level and transuranic wastes. The mission of the MWFA is to provide acceptable treatment systems, developed in partnership with users and with participation of stakeholders, tribal governments, and regulators, that are capable of treating DOE`s mixed waste. These treatment systems include all necessary steps such as characterization, pretreatment, and disposal. To accomplish this mission, a technical baseline is being established that forms the basis for determining which technology development activities will be supported by the MWFA. The technical baseline is the prioritized list of deficiencies, and the resulting technology development activities needed to overcome these deficiencies. This document presents Phase I of the technical baseline development process, which resulted in the prioritized list of deficiencies that the MWFA will address. A summary of the data and the assumptions upon which this work was based is included, as well as information concerning the DOE Office of Environmental Management (EM) mixed waste technology development needs. The next phase in the technical baseline development process, Phase II, will result in the identification of technology development activities that will be conducted through the MWFA to resolve the identified deficiencies.

1996-01-16T23:59:59.000Z

191

Neutrino Mixings and Leptonic CP Violation from CKM Matrix and Majorana Phases  

E-Print Network (OSTI)

The high scale mixing unification hypothesis recently proposed by three of us (R. N. M., M. K. P. and G. R.) states that if at the seesaw scale, the quark and lepton mixing matrices are equal then for quasi-degenerate neutrinos, radiative corrections can lead to large solar and atmospheric mixings and small reactor angle at the weak scale in agreement with data. Evidence for quasi-degenerate neutrinos could, within this framework, be interpreted as a sign of quark-lepton unification at high scale. In the current work, we extend this model to show that the hypothesis works quite successfully in the presence of CP violating phases (which were set to zero in the first paper). In the case where the PMNS matrix is identical to the CKM matrix at the seesaw scale, with a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to be ($\\simeq 0.3^{\\circ}$) and leptonic CP-violation parameter $J_{CP} \\simeq (4 - 8)\\times 10^{-5}$ and $\\theta_{13} = 3.5^{\\circ}$. If on the other hand, the PMNS matrix is assumed to also have Majorana phases initially, the resulting theory damps radiative magnification phenomenon for a large range of parameters but nevertheless has enough parameter space to give the two necessary large neutrino mixing angles. In this case, one has $\\theta_{13} = 3.5^{\\circ} - 10^{\\circ}$ and $|J_{CP}|$ as large as $0.02-0.04$ which are accessible to long baseline neutrino oscillation experiments.

S. K. Agarwalla; M. K. Parida; R. N. Mohapatra; G. Rajasekaran

2006-11-16T23:59:59.000Z

192

Symmetry energy effects on the mixed hadron-quark phase at high baryon density  

Science Conference Proceedings (OSTI)

The phase transition of hadronic to quark matter at high baryon and isospin density is analyzed. Relativistic mean-field models are used to describe hadronic matter, and the MIT bag model is adopted for quark matter. The boundaries of the mixed phase and the related critical points for symmetric and asymmetric matter are obtained. Due to the different symmetry term in the two phases, isospin effects appear to be rather significant. With increasing isospin asymmetry the binodal transition line of the (T,{rho}{sub B}) diagram is lowered to a region accessible through heavy-ion collisions in the energy range of the new planned facilities (e.g., the FAIR/NICA projects). Some observable effects are suggested, in particular an isospin distillation mechanism with a more isospin asymmetric quark phase, to be seen in charged meson yield ratios, and an onset of quark number scaling of the meson-baryon elliptic flows. The presented isospin effects on the mixed phase appear to be robust with respect to even large variations of the poorly known symmetry term at high baryon density in the hadron phase. The dependence of the results on a suitable treatment of isospin contributions in effective QCD Lagrangian approaches, at the level of explicit isovector parts and/or quark condensates, is discussed.

Di Toro, M.; Greco, V.; Plumari, S. [Laboratori Nazionali del Sud INFN, I-95123 Catania (Italy); Pysics and Astronomy Department, University of Catania (Italy); Liu, B. [IHEP, Chinese Academy of Sciences, Beijing (China); Theoretical Physics Center for Scientific Facilities, Chinese Academy of Sciences, 100049 Beijing (China); Baran, V. [Pysics Faculty, University of Bucharest and NIPNE-HH (Romania); Colonna, M. [Laboratori Nazionali del Sud INFN, I-95123 Catania (Italy)

2011-01-15T23:59:59.000Z

193

A Modeling Study of the Influence of Ice Scavenging on the Chemical Composition of Liquid-Phase Precipitation of a Cumulonimbus Cloud  

Science Conference Proceedings (OSTI)

Evidence of the efficient removal of chemicals by ice particles has been deduced from past field experiments and laboratory studies. However, the ice phase has been poorly represented in prior cloud chemistry modeling. This paper uses a two-...

Nicole Audiffren; Sylvie Cautenet; Nadine Chaumerliac

1999-08-01T23:59:59.000Z

194

Parameterizing Size Distribution in Ice Clouds  

SciTech Connect

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

DeSlover, Daniel; Mitchell, David L.

2009-09-25T23:59:59.000Z

195

From Single-Phase To Compositional Flow: Applicability Of Mixed Finite Elements  

E-Print Network (OSTI)

. In this paper we discuss the formulation of the governing equations that describe flow of fluids in porous media. Various types of fluid flow, ranging from single-phase flow to compositional flow, are considered. It is shown that all the differential equations governing these types of flow can be effectively rewritten in a fractional flow formulation; i.e., in terms of a global pressure and saturation (or saturations), and that mixed finite element methods can be accurately exploited to solve the pressure equation. Extensive numerical results are presented to see the performance of the mixed methods for the flow equations using different mixed finite elements. 1. Introduction Multiphase flow of fluids in porous media is physically and chemically complex. It involves heterogeneities in the porous media at many different length scales and complicated processes such as diffusion and dispersion. Numerical simulation of these phenomena is a critical step in understanding multicom...

Zhangxin Chen; Richard E. Ewing

1997-01-01T23:59:59.000Z

196

Broken and inhomogeneous cloud impact on satellite cloud particle effective radius and cloudphase retrievals  

E-Print Network (OSTI)

on the particle size distribution, height, and thermo- dynamic phase of clouds. Water and ice clouds have parameterizations is the global dis- tribution of cloud thermodynamic phase, i.e., whether a cloud is composed on satellitederived cloud particle effective radius (re) and cloud phase (CPH) for broken and overcast inhomogeneous

Stoffelen, Ad

197

Improved Airborne Hot-Wire Measurements of Ice Water Content in Clouds  

Science Conference Proceedings (OSTI)

Airborne measurements of ice water content (IWC) in both ice and mixed phase clouds remain one of the long standing problems in experimental cloud physics. For nearly three decades, IWC has been measured with the help of the Nevzorov hot-wire ...

A. Korolev; J. W. Strapp; G. A. Isaac; E. Emery

198

Global simulations of ice nucleation and ice supersaturation with an improved cloud scheme in the Community  

E-Print Network (OSTI)

and supersaturation in CAM. The new model is able to reproduce field observations of ice mass and mixed phase cloudGlobal simulations of ice nucleation and ice supersaturation with an improved cloud scheme; accepted 3 June 2010; published 28 September 2010. [1] A processbased treatment of ice supersaturation

Gettelman, Andrew

199

Range–Height Scans of Lidar Depolarization for Characterizing Properties and Phase of Clouds and Precipitation  

Science Conference Proceedings (OSTI)

Backscatter and depolarization lidar measurements from clouds and precipitation are reported as functions of the elevation angle of the pointing lidar direction. The data were recorded by scanning the lidar beam (Nd:YAG) at a constant angular ...

Luc R. Bissonnette; Gilles Roy; Frédéric Fabry

2001-09-01T23:59:59.000Z

200

In situ study of the formation of silicide phases in amorphous Co-Si mixed layers  

Science Conference Proceedings (OSTI)

We investigate Co silicide phase formation when extra Si is added within an as deposited 50nm Co film. The addition of Si is investigated for both the Co/SiO"2 and Co/Si(100) system. A series of 10 Co-Si mixed films with a Si content varying from 21 ... Keywords: Cobalt silicides, EBSD, Grain size, In situ XRD, Nucleation

C. Van Bockstael; K. De Keyser; J. Demeulemeester; A. Vantomme; R. L. Van Meirhaeghe; C. Detavernier; J. L. Jordan-Sweet; C. Lavoie

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Hydration characteristics of tricalcium aluminate phase in mixes containing {beta}-hemihydate and phosphogypsum  

SciTech Connect

The tricalcium aluminte phase was prepared from pure chemicals on a laboratory scale. Five mixes were formulated from the prepared C{sub 3}A phase, {beta}-hemihydate, phosphogypsum, calcium hydroxide and quartz. Different mixes were hydrated at various time intervals, namely, 6, 24, 72 and 168 h. The kinetics of hydration was measured from chemically combined water and combined lime contents. The phase compositions and microstructures of the hydrated products were studied by X-ray diffraction (XRD), differential thermal analysis (DTA)/TG, scanning electron microscopy (SEM) techniques and FT-IR spectroscopy. This work aimed to study the effect of partial to full substitution of phosphogypsum by {beta}-hemihydate on the hydration characteristics and microstructures of tricalcium aluminte phase. The results showed that the combined lime slightly increases with the increase of amounts of phosphogypsum. The XRD patterns showed the increase in the intensities of monosulphate and different forms of calcium aluminate (C{sub 4}AH{sub 13} and C{sub 4}AH{sub 19}) with phosphogypsum content. Ettringite is less stable than monosulphoaluminate, so it transformed into monosulpho-aluminate after 24 h, which persisted up to 168 h. The mechanism of the hydration process of C{sub 3}A phase in the presence of phosphogypsum proceeds in a similar path as with {beta}-hemihydate. Phosphogypsum reacts with C{sub 3}A in the presence of Ca(OH){sub 2} forming sulphoaluminate hydrates, which are responsible for setting regulation in cementitious system.

Radwan, M.M. [National Research Center, Dokki, Cairo (Egypt); Heikal, M. [Chemistry Department, Faculty of Science, Zagazig University, Benha Branch, Benha (Egypt)]. E-mail: ayaheikal@hotmail.com

2005-08-01T23:59:59.000Z

202

Mitigation of Tank 241-SY-101 by pump mixing: Results of testing phases A and B  

Science Conference Proceedings (OSTI)

A spare mixing pump from the Hanford Grout Program was installed in Hanford double-shell waste Tank 241-SY-101 on July 3, 1993, after being modified to take advantage of waste stratification. It was anticipated that pump mixing would prevent large episodic flammable gas releases that had been occurring about every 100-150 days. A cautious initial test plan, called Phase A, was run to find how the pump and tank would behave in response to very brief and gentle pump operation. No large gas releases were triggered, and the pump performed well except for two incidents of nozzle plugging. On October 21, 1993, the next test series, Phase B, began, and the pump was applied more aggressively to mix the tank contents and mitigate uncontrolled gas releases. Orienting the pump in new directions released large volumes of gas and reduced the waste level to a near-record low. Results of the entire period from pump installation to the end of Phase B on December 17, 1993, are presented in detail in this document. Though long-term effects require further evaluation, we conclude from these data that the jet mixer pump is an effective means of controlling flammable gas release and that it has met the success criteria for mitigation in this tank.

Allemann, R.T.; Antoniak, Z.I.; Chvala, W.D.; Friley, J.R.; Gregory, W.B.; Hudson, J.D.; Michener, T.E.; Panisko, F.E.; Stewart, C.W.; Wise, B.M. [Pacific Northwest Lab., Richland, WA (United States); Efferding, L.E.; Fadeff, J.G.; Irwin, J.J.; Kirch, N.W. [Westinghouse Hanford Co., Richland, WA (United States)

1994-03-01T23:59:59.000Z

203

Mass-transport considerations pertinent to aqueous-phase reactions of gases in liquid-water clouds  

SciTech Connect

Reactions of gases in liquid-water clouds are potentially important in the transformation of atmospheric pollutants affecting their transport in the atmosphere and subsequent removal and deposition to the surface. Such processes consist of the following sequence of steps. Mass-transport of the reagent gas or gases to the air-water interface; transfer across the interface and establishment of solubility equilibria locally at the interface; mass-transport of the dissolved gas or gases within the aqeuous phase; aqueous-phase chemical reactions(s); mass-transport of reaction product(s) and possible subsequent evolution into the gas-phase. Description of the rate of the overall process requires identification of the rate-limiting step (or steps) and evaluation of the rate of such step(s). Identification of the rate-limiting step may be achieved by evaluation and comparison of the characteristic times pertinent to the several processes and may be readily carried out by methods outlined herein, for known or assumed reagent concentrations, drop size, and fundamental constants as follows: gas- and aqueous-phase diffusion coefficients; Henry's law coefficient and other pertinent equilibrium constants; interfacial mass-transfer accommodation coefficient; aqueous-phase reaction rate constant(s). A graphical method is described whereby it may be ascertained whether a given reaction is controlled solely by reagent solubility and intrinsic chemical kinetics or is mass-transport limited by one or another of the above processes. In the absence of mass-transport limitation, reaction rates may be evaluated uniformly for the entire liquid-water content of the cloud using equilibrium reagent concentrations. In contrast, where appreciable mass-transport limitation is indicated, evaluation of the overall rate requires knowledge of and integration over the drop-size distribution characterizing the cloud. 68 references, 16 figures.

Schwartz, S.E.

1983-01-01T23:59:59.000Z

204

The Influence of Entrainment and Mixing on the Initial Formation of Rain in a Warm Cumulus Cloud  

Science Conference Proceedings (OSTI)

The objective of this study is to address the problem of the production of rain in warm cumulus clouds that has been observed to occur within about 20 min. A hybrid model approach is used where a microphysical parcel model is run along ...

William A. Cooper; Sonia G. Lasher-Trapp; Alan M. Blyth

2013-06-01T23:59:59.000Z

205

Microwave radiative transfer in the mixed-phase regions of tropical rainfall  

E-Print Network (OSTI)

Current physically-based Radiative Transfer Model (RTM) algorithms for estimating oceanic rain use a very simplified hydrometeor profile that ignores the mixed-phase regions (Wilheit et al., 1977). However, to estimate hydrometeor profiles more reasonably in the tropical precipitation regions, understanding of the brightness temperature (Tb) variations in the mixed-phase regions is essential. Further, establishing physical assumptions for microwave radiative transfer in the mixed-phase regions is necessary for quantifying and minimizing the uncertainties in the rainfall retrieval. Consequently, the objective of this study was to quantify uncertainties and to achieve a solid basis for improvement of the current rainfall retrieval, which is based on an RTM. To accomplish this, we examined data taken by the Convair-580 aircraft during the KWAJEX (Kwajalein Experiment). In order to calculate radiative transfer, the AMMR (Airborne Multi-channel Microwave Radiometer) data were combined with radiosonde data and aircraft microphysics data. Analyses were performed for the stratiform and convective rainfall regions respectively. In stratiform precipitation with a bright band, the main concern was to examine the needed physical assumptions for describing the abrupt change of Tb just below the freezing level. In the case of convective precipitation, the focus was to investigate the effective additional rain layer thickness corresponding to the super-cooled water layer above the freezing level. From the results, it was required to assume the bright-band (around 1/2 km below the FL) as having 2 times the absorption as the rain below to explain the Tb variation due to the phase change of hydrometeors. On the other hand, in the case of convective rainfall, it was suggested that approximately from 1/4km to 3km of super-cooled layer thickness should be considered to describe the additional hydrometeor layer due to the strong updrafts in the convective regions.

Jin, Kyoung-Wook

2001-01-01T23:59:59.000Z

206

Nonaqueous seeded growth of flower-like mixed-phase titania nanostructures for photocatalytic applications  

SciTech Connect

A nonaqueous seeded-grown synthesis of three-dimensional TiO{sub 2} nanostructures in the benzyl alcohol reaction system was reported. The synthesis was simple, high-yield, and requires no structural directing or capping agents. It could be largely accelerated by applying microwave heating. The TiO{sub 2} nanostructures had a unique flower-like morphology and high surface area. Furthermore, the structural analyses suggested that the nanostructures had a non-uniform distribution of crystalline phases, with the inner part rich in anatase and the outer part rich in rutile. After heat treatments, the mixed-phase TiO{sub 2} nanostructures exhibited high photocatalytic activities for the photodegradation of methylene blue as compared to Degussa P25. The high photoactivities may be associated with the high surface area and the synergistic effect resulting from the anisotropic mixed-phase nanostructures. The results demonstrate the uniqueness of the nonaqueous seeded growth and the potential of the TiO{sub 2} nanostructures for practical applications. - Graphical abstract: Flower-like TiO{sub 2} nanostructures synthesized by a nonaqueous seeded growth without using any structural directing or capping agents.

Hsu, Y.-C.; Lin, H.-C.; Chen, C.-H.; Liao, Y.-T. [Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Yang, C.-M., E-mail: cmyang@mx.nthu.edu.t [Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

2010-09-15T23:59:59.000Z

207

Mixing-Demixing Phase Diagram for Simple Liquids in Non-Uniform Electric Fields  

E-Print Network (OSTI)

We deduce the mixing-demixing phase diagram for binary liquid mixtures in an electric field for various electrode geometries and arbitrary constitutive relation for the dielectric constant. By focusing on the behavior of the liquid-liquid interface, we produce simple analytic expressions for the dependence of the interface location on experimental parameters. We also show that the phase diagram contains regions where liquid separation cannot occur under any applied field. The analytic expression for the boundary "electrostatic binodal" line reveals that the regions' size and shape depend strongly on the dielectric relation between the liquids. Moreover, we predict the existence of an "electrostatic spinodal" line that identifies conditions where the liquids are in a metastable state. We finally construct the phase diagram for closed systems by mapping solutions onto those of an open system via an effective liquid composition. For closed systems at a fixed temperature and mixture composition, liquid separation occurs in a finite "window" of surface potential (or charge density). Larger potentials or charge densities counterintuitively destroy the interface, leading to liquid mixing. These results give valuable guides for experiments by providing easily testable predictions for how liquids behave in non-uniform electric fields.

Jennifer Galanis; Yoav Tsori

2013-07-17T23:59:59.000Z

208

Final measurement of $B^0_s$ mixing phase in the full CDF Run II data set  

E-Print Network (OSTI)

We report the final CDF measurement of the $B^0_s$ mixing phase, mean lifetime, and decay-width difference through the fit of the time evolution of flavor-tagged $B^0_s \\rightarrow J/\\psi \\phi$ decays. The measurement is based on the full data set of 1.96 TeV $p\\bar{p}$ collisions collected between February 2002 and September 2011 by the CDF experiment. The results are consistent with the standard model and other experimental determinations and are amongst the most precise to date.

Sabato Leo

2012-07-28T23:59:59.000Z

209

Storm Peak Lab Cloud Property Validation  

NLE Websites -- All DOE Office Websites (Extended Search)

Storm Peak Lab Cloud Storm Peak Lab Cloud Property Validation Experiment (STORMVEX) Operated by the Atmospheric Radiation Measurement (ARM) Climate Research Facility for the U.S. Department of Energy, the second ARM Mobile Facility (AMF2) begins its inaugural deployment November 2010 in Steamboat Springs, Colorado, for the Storm Peak Lab Cloud Property Validation Experiment, or STORMVEX. For six months, the comprehensive suite of AMF2 instruments will obtain measurements of cloud and aerosol properties at various sites below the heavily instrumented Storm Peak Lab, located on Mount Werner at an elevation of 3220 meters. The correlative data sets that will be created from AMF2 and Storm Peak Lab will equate to between 200 and 300 in situ aircraft flight hours in liquid, mixed phase, and precipitating

210

Particle-resolved simulation of aerosol size, composition, mixing state, and the associated optical and cloud condensation nuclei activation properties in an evolving urban plume  

SciTech Connect

The recently developed particle-resolved aerosol box model PartMC-MOSAIC was used to simulate the evolution of aerosol mixing state and the associated optical and cloud condensation nuclei (CCN) activation properties in an idealized urban plume. The model explicitly resolved the size and composition of individual particles from a number of sources and tracked their evolution due to condensation/evaporation, coagulation, emission, and dilution. The ensemble black carbon (BC) specific absorption cross section increased by 40% over the course of two days as a result of BC aging by condensation and coagulation. Three- and four-fold enhancements in CCN/CN ratios were predicted to occur within 6 hours for 0.2% and 0.5% supersaturations (S), respectively. The particle-resolved results were used to evaluate the errors in the optical and CCN activation properties that would be predicted by a conventional sectional framework that assumes monodisperse, internally-mixed particles within each bin. This assumption artificially increased the ensemble BC specific absorption by 14-30% and decreased the single scattering albedo by 0.03-0.07 while the bin resolution had a negligible effect. In contrast, the errors in CCN/CN ratios were sensitive to the bin resolution, and they depended on the chosen supersaturation. For S = 0.2%, the CCN/CN ratio predicted using 100 internally-mixed bins was up to 25% higher than the particle-resolved results, while it was up to 125% higher using 10 internally-mixed bins. Errors introduced in the predicted optical and CCN properties by neglecting coagulation were also quantified.

Zaveri, Rahul A.; Barnard, James C.; Easter, Richard C.; Riemer, Nicole; West, Matthew

2010-09-11T23:59:59.000Z

211

Saturation Point Representation of Cloud-Top Entrainment Instability  

Science Conference Proceedings (OSTI)

Cloud-top entrainment instability was investigated using a mixing line analysis. Mixing time scales are closely related to the actual size of the parcel, so that local instabilities are largely dependent on the scales of mixing near the cloud ...

Reinout Boers

1991-11-01T23:59:59.000Z

212

Long-term impacts of aerosols on vertical development of cloud and precipitation  

Science Conference Proceedings (OSTI)

Aerosols alter cloud density and the radiative balance of the atmosphere. This leads to changes in cloud microphysics and atmospheric stability, which can either suppress or foster the development of clouds and precipitation. The net effect is largely unknown, but depends on meteorological conditions and aerosol properties. Here, we examine the long-term impact of aerosols on the vertical development of clouds and rainfall frequencies, using a 10-year dataset of aerosol, cloud and meteorological variables collected in the Southern Great Plains in the United States. We show that cloud-top height and thickness increase with aerosol concentration measured near the ground in mixed-phase clouds-which contain both liquid water and ice-that have a warm, low base. We attribute the effect, which is most significant in summer, to an aerosol-induced invigoration of upward winds. In contrast, we find no change in cloud-top height and precipitation with aerosol concentration in clouds with no ice or cool bases. We further show that precipitation frequency and rain rate are altered by aerosols. Rain increases with aerosol concentration in deep clouds that have a high liquid-water content, but declines in clouds that have a low liquid-water content. Simulations using a cloud-resolving model confirm these observations. Our findings provide unprecedented insights of the long-term net impacts of aerosols on clouds and precipitation.

Li Z.; Liu Y.; Niu, F.; Fan, J.; Rosenfeld, D.; Ding, Y.

2011-11-13T23:59:59.000Z

213

Cloud Properties Simulated by a Single-Column Model. Part II: Evaluation of Cumulus Detrainment and Ice-Phase Microphysics Using a Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

This paper is the second in a series in which kilometer-scale-resolving observations from the Atmospheric Radiation Measurement Program and output from the University of California, Los Angeles/Colorado State University cloud-resolving model (CRM)...

Yali Luo; Steven K. Krueger; Kuan-Man Xu

2006-11-01T23:59:59.000Z

214

Two-moment Bulk Stratiform Cloud Microphysics in the Grid-point Atmospheric Model of IAP LASG (GAMIL)  

SciTech Connect

A two-moment bulk stratiform microphysics scheme, including recently developed physically-based droplet activation/ice nucleation parameterizations has been implemented into the Grid-point Atmospheric Model of IAP LASG (GAMIL) as an effort to enhance the model capability for studying aerosol indirect effects. Unlike the previous one-moment cloud microphysics scheme, the new scheme produces reasonable representation of cloud particle size and number concentration. This scheme captures the observed spatial variations in cloud droplet number concentrations. Simulated ice crystal number concentrations in cirrus clouds qualitatively agree with in-situ observations. The longwave and shortwave cloud forcing are in better agreement with observations. Sensitivity tests show that the column cloud droplet number concentrations calculated from two different droplet activation parameterizations are similar. However, ice crystal number concentration in mixed-phased clouds is sensitive to different heterogeneous freezing formulations. The simulation with high ice crystal number concentration in mixed-phase clouds has less liquid water path and weaker cloud forcing. Furthermore, ice crystal number concentration in cirrus clouds is sensitive to different ice nucleation parameterizations. Sensitivity tests also suggest that impact of pre-existing ice crystals on homogeneous freezing in old clouds should be taken into account.

Shi, Xiangjun; Wang, Bin; Liu, Xiaohong; Wang, Minghuai

2013-05-01T23:59:59.000Z

215

Particle Size Estimation in Ice-Phase Clouds Using Multifrequency Radar Reflectivity Measurements at 95, 33, and 2.8 GHz  

Science Conference Proceedings (OSTI)

Multifrequency radar measurements collected at 2.8 (S band), 33.12 (Ka band), and 94.92 GHz (W band) are processed using a neural network to estimate median particle size and peak number concentration in ice-phase clouds composed of dry crystals ...

Stephen M. Sekelsky; Warner L. Ecklund; John M. Firda; Kenneth S. Gage; Robert E. McIntosh

1999-01-01T23:59:59.000Z

216

Influence of Micro-mixing on the Size of Liposomes Self-Assembled from Miscible Liquid Phases  

E-Print Network (OSTI)

Ethanol injection and variations of it are a class of methods where two miscible phases---one of which contains dissolved lipids---are mixed together leading to the self-assembly of lipid molecules to form liposomes. This method has been suggested, among other applications, for in-situ synthesis of liposomes as drug delivery capsules. However, the mechanism that leads to a specific size selection of the liposomes in solution based self-assembly in general, and in flow-focussing microfluidic devices in particular, has so far not been established. Here we report two aspects of this problem. A simple and easily fabricated device for synthesis of monodisperse unilamellar liposomes in a co-axial flow-focussing microfluidic geometry is presented. We also show that the size of liposomes is dependent on the extent of micro-convective mixing of the two miscible phases. Here, a viscosity stratification induced hydrodynamic instability leads to a gentle micro-mixing which results in larger liposome size than when the streams are mixed turbulently. The results are in sharp contrast to a purely diffusive mixing in macroscopic laminar flow that was believed to occur under these conditions. Further precise quantification of the mixing characteristics should provide the insights to develop a general theory for size selection for the class of ethanol injection methods. This will also lay grounds for obtaining empirical evidence that will enable better control of liposome sizes and for designing drug encapsulation and delivery devices.

Sopan Phapal; P Sunthar

2013-01-12T23:59:59.000Z

217

Phase stability of the mixed-conducting Sr-Fe-Co-O system.  

DOE Green Energy (OSTI)

Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} (with x = 0, 0.6, 1.0, and 1.4) were prepared by solid-state reaction method in atmospheres with various oxygen partial pressures (pO{sub 2}) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity testing. Phase components of the sample are dependent on cobalt concentration and pO{sub 2}. Electrical conductivity increases with increasing temperature and cobalt content in the material.

Ma, B.; Balachandran, U.; Hodges, J. P.; Jorgensen, J. D.; Miller, D. J.; Richardson, J. W., Jr.

1997-12-12T23:59:59.000Z

218

Observations of the Interaction between Cumulus Clouds and Warm Stratocumulus Clouds in the Marine Boundary Layer during ASTEX  

Science Conference Proceedings (OSTI)

Decoupling of the marine boundary layer beneath stratocumulus clouds and the formation of cumulus clouds at the top of a surface-based mixed layer (SML) have frequently been observed and modeled. When such cumulus clouds penetrate the overlying ...

G. M. Martin; D. W. Johnson; D. P. Rogers; P. R. Jonas; P. Minnis; D. A. Hegg

1995-08-01T23:59:59.000Z

219

Improvements in Representations of Cloud Microphysics for BBHRP and Models using Data Collected during M-PACE and TWP-ICE  

SciTech Connect

In our research we proposed to use data collected during the 2004 Mixed-Phase Arctic Cloud Experiment (MPACE) and the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) to improve retrievals of ice and mixed-phase clouds, to improve our understanding of how cloud and radiative processes affect cloud life cycles, and to develop and test methods for using ARM data more effectively in model. In particular, we proposed to: 1) use MPACE in-situ data to determine how liquid water fraction and cloud ice and liquid effective radius (r{sub ei} and r{sub ew}) vary with temperature, normalized cloud altitude and other variables for Arctic mixed-phase clouds, and to use these data to evaluate the performance of model parameterization schemes and remote sensing retrieval algorithms; 2) calculate rei and size/shape distributions using TWP-ICE in-situ data, investigate their dependence on cirrus type (oceanic or continental anvils or cirrus not directly traced to convection), and develop and test representations for MICROBASE; 3) conduct fundamental research enhancing our understanding of cloud/radiative interactions, concentrating on effects of small crystals and particle shapes and sizes on radiation; and 4) improve representations of microphysical processes for models (fall-out, effective density, mean scattering properties, rei and rew) and provide them to ARM PIs. In the course of our research, we made substantial progress on all four goals.

Greg M. McFarquhar

2010-02-22T23:59:59.000Z

220

The radiative influence of aerosol effects on liquid-phase cumulus clouds based on sensitivity studies with two climate models  

E-Print Network (OSTI)

A global black carbon aerosol model. J Geophys Res 101:of interactions between aerosols and cloud microphysics overby anthropogenic sulfate aerosol. J Geophys Res 106: 5279-

Menon, Surabi; Rotstayn, Leon

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

IC cloud: Enabling compositional cloud  

Science Conference Proceedings (OSTI)

Cloud computing has attracted great interest from both academic and industrial communities. Different paradigms, architectures and applications based on the concept of cloud have emerged. Although many of them have been quite successful, efforts are ... Keywords: Cloud computing, cloud elasticity, cloud service, compositional cloud, infrastructure as a service (IaaS)

Yi-Ke Guo; Li Guo

2011-08-01T23:59:59.000Z

222

The Experimental Cloud Lidar Pilot Study (ECLIPS) for Cloud—Radiation Research  

Science Conference Proceedings (OSTI)

The Experimental Cloud Lidar Pilot Study (ECLIPS) was initiated to obtain statistics on cloud-base height, extinction, optical depth, cloud brokenness, and surface fluxes. Two observational phases have taken place, in October-December 1989 and ...

C. M. Platt; S. A. Young; A. I. Carswell; S. R. Pal; M. P. McCormick; D. M. Winker; M. DelGuasta; L. Stefanutti; W. L. Eberhard; M. Hardesty; P. H. Flamant; R. Valentin; B. Forgan; G. G. Gimmestad; H. Jäger; S. S. Khmelevtsov; I. Kolev; B. Kaprieolev; Da-ren Lu; K. Sassen; V. S. Shamanaev; O. Uchino; Y. Mizuno; U. Wandinger; C. Weitkamp; A. Ansmann; C. Wooldridge

1994-09-01T23:59:59.000Z

223

Evaluating cloud retrieval algorithms with the ARM BBHRP framework  

SciTech Connect

Climate and weather prediction models require accurate calculations of vertical profiles of radiative heating. Although heating rate calculations cannot be directly validated due to the lack of corresponding observations, surface and top-of-atmosphere measurements can indirectly establish the quality of computed heating rates through validation of the calculated irradiances at the atmospheric boundaries. The ARM Broadband Heating Rate Profile (BBHRP) project, a collaboration of all the working groups in the program, was designed with these heating rate validations as a key objective. Given the large dependence of radiative heating rates on cloud properties, a critical component of BBHRP radiative closure analyses has been the evaluation of cloud microphysical retrieval algorithms. This evaluation is an important step in establishing the necessary confidence in the continuous profiles of computed radiative heating rates produced by BBHRP at the ARM Climate Research Facility (ACRF) sites that are needed for modeling studies. This poster details the continued effort to evaluate cloud property retrieval algorithms within the BBHRP framework, a key focus of the project this year. A requirement for the computation of accurate heating rate profiles is a robust cloud microphysical product that captures the occurrence, height, and phase of clouds above each ACRF site. Various approaches to retrieve the microphysical properties of liquid, ice, and mixed-phase clouds have been processed in BBHRP for the ACRF Southern Great Plains (SGP) and the North Slope of Alaska (NSA) sites. These retrieval methods span a range of assumptions concerning the parameterization of cloud location, particle density, size, shape, and involve different measurement sources. We will present the radiative closure results from several different retrieval approaches for the SGP site, including those from Microbase, the current 'reference' retrieval approach in BBHRP. At the NSA, mixed-phase clouds and cloud with a low optical depth are prevalent; the radiative closure studies using Microbase demonstrated significant residuals. As an alternative to Microbase at NSA, the Shupe-Turner cloud property retrieval algorithm, aimed at improving the partitioning of cloud phase and incorporating more constrained, conditional microphysics retrievals, also has been evaluated using the BBHRP data set.

Mlawer,E.; Dunn,M.; Mlawer, E.; Shippert, T.; Troyan, D.; Johnson, K. L.; Miller, M. A.; Delamere, J.; Turner, D. D.; Jensen, M. P.; Flynn, C.; Shupe, M.; Comstock, J.; Long, C. N.; Clough, S. T.; Sivaraman, C.; Khaiyer, M.; Xie, S.; Rutan, D.; Minnis, P.

2008-03-10T23:59:59.000Z

224

Statistical Analysis of Forecasting Models across the North Slope of Alaska during the Mixed-Phase Arctic Clouds Experiment  

Science Conference Proceedings (OSTI)

The National Centers for Environmental Prediction’s (NCEP) Eta Model, the models of the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Aeronautics and Space Administration’s (NASA) Global Modeling and Assimilation ...

Victor T. Yannuzzi; Eugene E. Clothiaux; Jerry Y. Harrington; Johannes Verlinde

2009-12-01T23:59:59.000Z

225

Theory for Dual-Wavelength C02 Lidar Method to Distinguish Ice, Mixed-Phase, and Water Clouds  

Science Conference Proceedings (OSTI)

An analytical study shows that the ratio of backscatter from ice particles at two CO2 lidar wavelengths is substantially different from the ratio from water drops. This forms the basis for a new method to discriminate between ice, water, and ...

Wynn L. Eberhard

1995-02-01T23:59:59.000Z

226

ISCCP Cloud Data Products  

Science Conference Proceedings (OSTI)

The operational data collection phase of the International Satellite Cloud Climatology Project (ISCCP) began in July 1983. Since then, visible and infrared images from an international network of weather satellites have been routinely processed ...

William B. Rossow; Robert A. Schiffer

1991-01-01T23:59:59.000Z

227

ARM - Measurement - Hydrometeor phase  

NLE Websites -- All DOE Office Websites (Extended Search)

phase phase 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 : Hydrometeor phase Hydrometeor phase such as liquid ice or mixed phase Categories Cloud 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. Value-Added Products VISST : Minnis Cloud Products Using Visst Algorithm (Process) VISSTPX04G08V2MINNIS : VISST-derived pixel-level products from satellite GOES8, version 2 VISSTPX04G08V3MINNIS : VISST-derived pixel-level products from satellite GOES8, version 3

228

Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships  

E-Print Network (OSTI)

This dissertation consists of three parts, each devoted to a particular issue of significant importance for CALIPSO lidar observation of depolarization ratio (delta) and backscatter (gamma?) to improve current understanding of the microphysical properties of clouds and aerosols. The relationships between depolarization ratio and backscatter allow us to retrieve particle thermodynamic phase and shape and/or orientation of aerosols and clouds. The first part is devoted to the investigation of the relationships between lidar backscatter and the corresponding depolarization ratio for different cloud classifications and aerosol types. For each cloud and aerosol types, layer-averaged backscatter and backscattering depolarization ratio from the CALIPSO measurements are discussed. The present results demonstrate the unique capabilities of the CALIPSO lidar instrument for determining cloud phase and aerosols subtypes. In the second part, we evaluate the MODIS IR cloud phase with the CALIPSO cloud products. The three possible misclassifications of MODIS IR cloud phasealgorithm, which are studied by Nasiri and Kahn (2008) with radiative transfer modeling, are tested by comparing between MODIS IR phase and CALIOP observations. The current results support their hypotheses, which is that the MODIS phase algorithm may tend to classify thin cirrus clouds as water clouds or mixed phase clouds or unknown, and classify midlevel and/or mid-temperature clouds as mixed or unknown phase. In the third part, we present a comparison of mineral dust aerosol retrievals from two instruments, MODIS and CALIPSO lidar. And, we implement and evaluate a new mineral dust detection algorithm based on the analysis of thin dust radiative signature. In comparison, three commonly used visible and IR mineral dust detection algorithms, including BTD procedure, D parameter method, and multi-channel image algorithm, are evaluated with CALIPSO aerosol classification. The comparison reveals that those dust detection algorithms are not effective for optically thin dust layers, but for thick dust storm. The new algorithm using discriminant analysis with CALIPSO observation is much better in detecting thin dust layer of optical thickness between 0.1 and 2.

Cho, Hyoun-Myoung

2011-12-01T23:59:59.000Z

229

Pore-scale imaging and lattice Boltzmann modeling of single- and multi-phase flow in fractured and mixed-wet permeable media.  

E-Print Network (OSTI)

??Three investigations of pore-scale single-phase and multiphase flow in fractured porous media and mixed-wet porous media are presented here. With an emphasis on validating and… (more)

Landry, Christopher

2013-01-01T23:59:59.000Z

230

Controlling the fluid-fluid mixing-demixing phase transition with electric fields  

E-Print Network (OSTI)

We review recent theoretical advances on controlling the fluid-fluid phase transition with electric fields. Using a mean-field approach, we compare the effects of uniform versus non-uniform electric fields, and show how non-uniform fields are better at altering the phase diagram. Focusing on non-uniform fields, we then discuss the behavior of the fluid concentration profile and the parameters (temperature, fluid concentration, etc.) that control the location of the fluid-fluid interface from both equilibrium and dynamic perspectives.

Jennifer Galanis; Sela Samin; Yoav Tsori

2012-12-06T23:59:59.000Z

231

Cumulus Entrainment and Cloud Droplet Spectra: A Numerical Model within a Two-Dimensional Dynamical Framework  

Science Conference Proceedings (OSTI)

A simple numerical model designed to predict the evolution of cloud droplet spectra with special emphasis on the role of entrainment is developed for a case of nonprecipitating cloud. The model assumes that the cloud water mixing ratio at any ...

Jean-Louis Brenguier; Wojciech W. Grabowski

1993-01-01T23:59:59.000Z

232

Cancellation of Aerosol Indirect Effects in Marine Stratocumulus through Cloud Thinning  

Science Conference Proceedings (OSTI)

Applying perturbation theory within a mixed layer framework, the response of the marine boundary layer (MBL) cloud thickness h to imposed increases of the cloud droplet concentration Nd as a surrogate for increases in cloud condensation nuclei (...

Robert Wood

2007-07-01T23:59:59.000Z

233

Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

This paper reviews the current knowledge of the climatological, structural, and organizational aspects of stratocumulus clouds and the physical processes controlling them. More of Earth’s surface is covered by stratocumulus clouds than by any ...

Robert Wood

2012-08-01T23:59:59.000Z

234

The Effects of Clouds on Aerosol and Chemical Species Production and Distribution. Part III: Aerosol Model Description and Sensitivity Analysis  

Science Conference Proceedings (OSTI)

A modeling study of the effects of clouds on the evolution and redistribution of aerosol particles in the troposphere is presented. A two-mode, two-moment aerosol evolution model is coupled with a two-dimensional, mixed-phase, two-moment ...

Yiping Zhang; Sonia Kreidenweis; Gregory R. Taylor

1998-03-01T23:59:59.000Z

235

Shock hugoniot behavior of mixed phases with widely varying shock imepdances  

Science Conference Proceedings (OSTI)

The shock velocity dependence on shock pressure in composite explosive materials containing polymeric binders is known to exhibit marked non-linear behavior in the U{sub s} - u{sub p} plane at low pressures. This is in addition to the non-linear behavior noted in pure polymeric materials. The precise description of this behavior is important in analyzing the response of energetic materials to impact shocks. We will show that the mismatch of the shock impedances in materials such as rocket propellants composed of polymer binder, aluminum, and ammonium Perchlorate can be expected to exhibit a very large initial slope of the shock velocity, U{sub s}, dependence on the particle velocity, u{sub p}. This slope is simply a result of the equilibration of Hugoniot pressure amongst the phases. With accurate descriptions for the equations of state of the individual components, we successfully predict the extreme slope at low compression. The effect is primarily due to the very large change in compressibility of the polymeric phase at relatively low volumetric compression of the whole mixture. Examples are shown and compared with available experimental results.

Reaugh, J.E.; Lee, E.L.

1997-07-01T23:59:59.000Z

236

ARM - Measurement - Total cloud water  

NLE Websites -- All DOE Office Websites (Extended Search)

cloud water cloud water 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 : Total cloud water The total concentration (mass/vol) of ice and liquid water particles in a cloud; this includes condensed water content (CWC). Categories Cloud 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. External Instruments NCEPGFS : National Centers for Environment Prediction Global Forecast System Field Campaign Instruments CSI : Cloud Spectrometer and Impactor PDI : Phase Doppler Interferometer

237

ARM - Measurement - Cloud droplet size  

NLE Websites -- All DOE Office Websites (Extended Search)

droplet size droplet size 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 : Cloud droplet size Linear size (e.g. radius or diameter) of a cloud particle Categories Cloud 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. Field Campaign Instruments CPI : Cloud Particle Imager CVI-AIR : Counterflow Virtual Impactor MIRAI : JAMSTEC Research Vessel Mirai PDI : Phase Doppler Interferometer UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments SPEC-CPI : Stratton Park Engineering Company - Cloud particle imager

238

Cloud Chmabers  

NLE Websites -- All DOE Office Websites (Extended Search)

Video - (Requires Windows Media Player) Build your own cloud chamber - Instructions Project Contact: Tom Jordan Web Maintainer: qnet-webmaster@fnal.gov Last Update: May 31, 2011...

239

ARM - Evaluation Product - Cloud Classification VAP  

NLE Websites -- All DOE Office Websites (Extended Search)

properties includes cloud boundaries, thickness, phase, type, and precipitation information, and hence provides a useful tool for evaluation of model simulations and...

240

Quantifying the Impact of Dust on Heterogeneous Ice Generation in Midlevel Supercooled Stratiform Clouds  

Science Conference Proceedings (OSTI)

Dust aerosols have been regarded as effective ice nuclei (IN), but large uncertainties regarding their efficiencies remain. Here, four years of collocated CALIPSO and CloudSat measurements are used to quantify the impact of dust on heterogeneous ice generation in midlevel supercooled stratiform clouds (MSSCs) over the ‘dust belt’. The results show that the dusty MSSCs have an up to 20% higher mixed-phase cloud occurrence, up to 8 dBZ higher mean maximum Ze (Ze_max), and up to 11.5 g/m2 higher ice water path (IWP) than similar MSSCs under background aerosol conditions. Assuming similar ice growth and fallout history in similar MSSCs, the significant differences in Ze_max between dusty and non-dusty MSSCs reflect ice particle number concentration differences. Therefore, observed Ze_max differences indicate that dust could enhance ice particle concentration in MSSCs by a factor of 2 to 6 at temperatures colder than ?12°C. The enhancements are strongly dependent on the cloud top temperature, large dust particle concentration and chemical compositions. These results imply an important role of dust particles in modifying mixed-phase cloud properties globally.

Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Liu, Dong; Zhao, Ming

2012-09-26T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Cellular clouds  

Science Conference Proceedings (OSTI)

This paper progresses an analysis of what it means to be a cellular network operator and what form the ownership and control of future cellular networks may take. Alternative modes of ownership may allow for the creation of more flexible cellular networking ... Keywords: Cellular Cloud, Cellular network, Cloud Computing, Cognitive radio, DSA, LTE, MVNO, Services, Utility Cellular Network

Tim Forde; Linda Doyle

2013-03-01T23:59:59.000Z

242

Distribution of Local Open-Circuit Voltage on Amorphous and Nanocrystalline Mixed-Phase Si:H and SiGe:H Solar Cells: Preprint  

DOE Green Energy (OSTI)

Local open-circuit voltage (Voc) distributions on amorphous and nanocrystalline mixed-phase silicon solar cells were measured using a scanning Kelvin probe microscope (SKPM) on the p layer of an n-i-p structure without the top ITO contact. During the measurement, the sample was illuminated with a laser beam that was used for the atomic force microscopy (AFM). Therefore, the surface potential measured by SKPM is the sum of the local Voc and the difference in workfunction between the p layer and the AFM tip. Comparing the SKPM and AFM images, we find that nanocrystallites aggregate in the amorphous matrix with an aggregation size of {approx}0.5 ..mu..m in diameter, where many nanometer-size grains are clustered. The Voc distribution shows valleys in the nanocrystalline aggregation area. The transition from low to high Voc regions is a gradual change within a distance of about 1 ..mu..m. The minimum Voc value in the nanocrystalline clusters in the mixed-phase region is larger than the Voc of a nc-Si:H single-phase solar cell. These results could be due to lateral photo-charge redistribution between the two phases. We have also carried out local Voc measurements on mixed-phase SiGe:H alloy solar cells. The magnitudes of Voc in the amorphous and nanocrystalline regions are consistent with the J-V measurements.

Jiang, C.-S.; Moutinho, H. R.; Al-Jassim, M. M.; Kazmerski, L. L.; Yan, B.; Owens, J. M.; Yang, J.; Guha, S.

2006-05-01T23:59:59.000Z

243

Droplet Growth in Warm Water Clouds Observed by the A-Train. Part I: Sensitivity Analysis of the MODIS-Derived Cloud Droplet Sizes  

Science Conference Proceedings (OSTI)

This study examines the sensitivity of the retrieved cloud droplet radii (CDR) to the vertical inhomogeneity of droplet radii, including the existence of a drizzle mode in clouds. The focus of this study is warm water-phase clouds. Radiative ...

Takashi Y. Nakajima; Kentaroh Suzuki; Graeme L. Stephens

2010-06-01T23:59:59.000Z

244

Cloud Thermodynamic Models in Saturation Point Coordinates  

Science Conference Proceedings (OSTI)

One-dimensional thermodynamic models for cloud-environment mixing, evaporation into downdrafts and precipitation from updrafts are presented in a parallel treatment using convective pressure scales and saturation point coordinates. This common ...

Alan K. Betts

1982-10-01T23:59:59.000Z

245

Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model  

Science Conference Proceedings (OSTI)

A process-based treatment of ice supersaturation and ice-nucleation is implemented in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). The new scheme is designed to allow (1) supersaturation with respect to ice, (2) ice nucleation by aerosol particles and (3) ice cloud cover consistent with ice microphysics. The scheme is implemented with a 4-class 2 moment microphysics code and is used to evaluate ice cloud nucleation mechanisms and supersaturation in CAM. The new model is able to reproduce field observations of ice mass and mixed phase cloud occurrence better than previous versions of the model. Simulations indicate heterogeneous freezing and contact nucleation on dust are both potentially important over remote areas of the Arctic. Cloud forcing and hence climate is sensitive to different formulations of the ice microphysics. Arctic radiative fluxes are sensitive to the parameterization of ice clouds. These results indicate that ice clouds are potentially an important part of understanding cloud forcing and potential cloud feedbacks, particularly in the Arctic.

Gettelman, A.; Liu, Xiaohong; Ghan, Steven J.; Morrison, H.; Park, Sungsu; Conley, Andrew; Klein, Stephen A.; Boyle, James; Mitchell, David; Li, J-L F.

2010-09-28T23:59:59.000Z

246

Exploration of the MODIS Cloud-Top Property Products for the Investigation of Equatorial Wave Systems  

Science Conference Proceedings (OSTI)

The Moderate Resolution Imaging Spectroradiometer (MODIS) observations provide an unprecedented opportunity for studying cloud macrophysical (cloud-top pressure, temperature, height, and phase), microphysical (effective particle size), and ...

Yue Li; Gerald R. North; Ping Yang; Bryan A. Baum

2010-09-01T23:59:59.000Z

247

Drop Growth Due to High Supersaturation Caused by Isobaric Mixing  

Science Conference Proceedings (OSTI)

A new conceptual model is proposed for enhanced cloud droplet growth during condensation. Rapid droplet growth may occur in zones of high supersaturation resulting from isobaric mixing of saturated volumes with different temperatures. Cloud ...

Alexei V. Korolev; George A. Isaac

2000-05-01T23:59:59.000Z

248

Distribution of Local Open-Circuit Voltage on Amorphous and Nanocrystalline Mixed-Phase Si:H and SiGe:H Solar Cells (Poster)  

DOE Green Energy (OSTI)

By combining SKPM and AFM, they have developed a method to measure the local V{sub oc} distribution in mixed-phase solar cells. The results clearly show the nanocrystalline aggregation. The V{sub oc} is smaller in the nanocrystalline aggregates than in the surrounding amorphous matrix, and the transition from the low to high V{sub oc} is a gradual change. Although there are some lateral charge redistributions, a clear distinction between the amorphous and nanocrystalline regions has been observed. The current SKPM results and previous C-AFM results provide extra support for the two-diode model for explaining the carrier transport in the mixed-phase solar cells.

Jiang, C.-S.; Moutinho, H. R.; Al-Jassim, M. M.; Kazmerski, L. L.; Yan, B.; Yang, J.; Guha, S.

2006-05-01T23:59:59.000Z

249

Cloud computing beyond objects: seeding the cloud  

Science Conference Proceedings (OSTI)

Cloud computing is an emerging computing milieu which dynamically enables scalable and virtually unlimited resources. This panel will discuss emerging tools, skills and technologies that will ""seed the cloud"" - enabling improved interoperability, security, ... Keywords: cloud computing, skills, technologies, tools

Steven Fraser; Robert Biddle; Scott Jordan; Kate Keahey; Bob Marcus; E. Michael Maximilien; Dave Thomas

2009-10-01T23:59:59.000Z

250

HI Narrow Self-Absorption in Dark Clouds: Correlations with Molecular Gas and Implications for Cloud Evolution and Star Formation  

E-Print Network (OSTI)

We present the results of a comparative study of HI narrow self-absorption (HINSA), OH, 13CO, and C18O in five dark clouds. The HINSA follows the distribution of the emission of the carbon monoxide isotopologues, and has a characteristic size close to that of 13CO. This confirms that the HINSA is produced by cold HI which is well mixed with molecular gas in well-shielded regions. The ratio of the atomic hydrogen density to total proton density for these sources is 5 to 27 x 10^{-4}. Using cloud temperatures and the density of HI, we set an upper limit to the cosmic ray ionization rate of 10^{-16} s^{-1}. Comparison of observed and modeled fractional HI abundances indicates ages for these clouds to be 10^{6.5} to 10^{7} yr. The low values of the HI density we have determined make it certain that the time scale for evolution from an atomic to an almost entirely molecular phase, must be a minimum of several million years. This clearly sets a lower limit to the overall time scale for star formation and the lifetime of molecular clouds.

P. F. Goldsmith; D. Li

2004-12-16T23:59:59.000Z

251

Coupling Aerosol-Cloud-Radiative Processes in the WRF-Chem Model: Investigating the Radiative Impact of Elevated Point Sources  

Science Conference Proceedings (OSTI)

The local and regional influence of elevated point sources on summertime aerosol forcing and cloud-aerosol interactions in northeastern North America was investigated using the WRF-Chem community model. The direct effects of aerosols on incoming solar radiation were simulated using existing modules to relate aerosol sizes and chemical composition to aerosol optical properties. Indirect effects were simulated by adding a prognostic treatment of cloud droplet number and adding modules that activate aerosol particles to form cloud droplets, simulate aqueous phase chemistry, and tie a two-moment treatment of cloud water (cloud water mass and cloud droplet number) to an existing radiation scheme. Fully interactive feedbacks thus were created within the modified model, with aerosols affecting cloud droplet number and cloud radiative properties, and clouds altering aerosol size and composition via aqueous processes, wet scavenging, and gas-phase-related photolytic processes. Comparisons of a baseline simulation with observations show that the model captured the general temporal cycle of aerosol optical depths (AODs) and produced clouds of comparable thickness to observations at approximately the proper times and places. The model slightly overpredicted SO2 mixing ratios and PM2.5 mass, but reproduced the range of observed SO2 to sulfate aerosol ratios, suggesting that atmospheric oxidation processes leading to aerosol sulfate formation are captured in the model. The baseline simulation was compared to a sensitivity simulation in which all emissions at model levels above the surface layer were set to zero, thus removing stack emissions. Instantaneous, site-specific differences for aerosol and cloud related properties between the two simulations could be quite large, as removing above-surface emission sources influenced when and where clouds formed within the modeling domain. When summed spatially over the finest resolution model domain (the extent of which corresponds to the typical size of a single GCM grid cell) and temporally over a three day analysis period, total rainfall in the sensitivity simulation increased by 31% over that in the baseline simulation. Fewer optically thin clouds, arbitrarily defined as a cloud exhibiting an optical depth less than 1, formed in the sensitivity simulation. Domain-averaged AODs dropped from 0.46 in the baseline simulation to 0.38 in the sensitivity simulation. The overall net effect of additional aerosols attributable to primary particulates and aerosol precursors from point source emissions above the surface was a domain-averaged reduction of 5 W m-2 in mean daytime downwelling shortwave radiation.

Chapman, Elaine G.; Gustafson, William I.; Easter, Richard C.; Barnard, James C.; Ghan, Steven J.; Pekour, Mikhail S.; Fast, Jerome D.

2009-02-01T23:59:59.000Z

252

Simulation of Cloud Microphysical and Chemical Processes Using a Multicomponent Framework. Part II: Microphysical Evolution of a Wintertime Orographic Cloud  

Science Conference Proceedings (OSTI)

A detailed microphysical model is used to simulate the formation of wintertime orographic clouds in a two-dimensional domain under steady-state conditions. Mass contents and number concentrations of both liquid- and ice-phase cloud particles are ...

Jen-Ping Chen; Dennis Lamb

1999-07-01T23:59:59.000Z

253

Testing ice microphysics parameterizations in the NCAR Community Atmospheric Model Version 3 using Tropical Warm Pool–International Cloud Experiment data  

SciTech Connect

Cloud properties have been simulated with a new double-moment microphysics scheme under the framework of the single column version of NCAR CAM3. For comparisons, the same simulation was made with the standard single-moment microphysics scheme of CAM3. Results from both simulations were compared favorably with observations during the Tropical Warm Pool- International Cloud Experiment by US Department of Energy Atmospheric Radiation Program in terms of the temporal variation and vertical distribution of cloud fraction and cloud condensate. Major differences between the two simulations are in the magnitude and distribution of ice water content within the mixed-phase cloud during the monsoon period, though the total frozen water (snow plus ice) content is similar. The ice mass content in the mixed-phase cloud from the new scheme is larger than that from the standard scheme, and extends 2 km further downward, which are closer to observations. The dependence of the frozen water mass fraction in total condensate on temperature from the new scheme is also closer to available observations. Outgoing longwave radiation (OLR) at the top of the atmosphere (TOA) from the simulation with the new scheme is in general larger than that with the standard scheme, while the surface downward longwave radiation is similar. Sensitivity tests suggest that different treatments of the ice effective radius contribute significantly to the difference in the TOA OLR in addition to cloud water path. The deep convection process affects both TOA OLR and surface downward longwave radiation. The over-frequently-triggered deep convention process in the model is not the only mechanism for the excess middle and high level clouds. Further evaluation especially for ice cloud properties based on in-situ data is needed.

Wang, Weiguo; Liu, Xiaohong; Xie, Shaocheng; Boyle, James; McFarlane, Sally A.

2009-07-23T23:59:59.000Z

254

Evaluation of Hydrometeor Phase and Ice Properties in Cloud-Resolving Model Simulations of Tropical Deep Convection Using Radiance and Polarization Measurements  

Science Conference Proceedings (OSTI)

Satellite measurements are used to evaluate the glaciation, particle shape, and effective radius in cloud-resolving model simulations of tropical deep convection. Multidirectional polarized reflectances constrain the ice crystal geometry and the ...

Bastiaan van Diedenhoven; Ann M. Fridlind; Andrew S. Ackerman; Brian Cairns

2012-11-01T23:59:59.000Z

255

The Chemistry of a Dry Cloud: The Effects of Radiation and Turbulence  

Science Conference Proceedings (OSTI)

The combined effect of ultraviolet radiation and turbulent mixing on chemistry in a cloud-topped boundary layer is investigated. The authors study a flow driven by longwave radiative cooling at cloud top. They consider a chemical cycle that is ...

Jordi Vilŕ-Guerau de Arellano; Joannes W. M. Cuijpers

2000-05-01T23:59:59.000Z

256

Determination of Mean Cumulus Cloud vorticity from GATE A/B-Scale Potential Vorticity Budget  

Science Conference Proceedings (OSTI)

The effects of cumulus clouds on the large-scale potential vorticity field are investigated using GATE data. Clouds are found to modify the mean potential vorticity field not only through vertical mixing but also through the generation of ...

Lawrence Cheng; Tsoi-Ching Yip; Han-Ru Cho

1980-04-01T23:59:59.000Z

257

Applications of Fast Response Continuous SF6 Analyzers to In Situ Cloud Studies  

Science Conference Proceedings (OSTI)

The airborne applications of two recently developed analyzers for sulfur hexafluoride (SF6) to investigations of cloud top mixing and cloud seeding are described. The analyzers were developed by AeroVironment (AV) and by Washington State ...

Jeffrey L. Stith; Richard L. Benner

1987-12-01T23:59:59.000Z

258

Interpretation of Multiwavelength-Retrieved Droplet Effective Radii for Warm Water Clouds in Terms of In-Cloud Vertical Inhomogeneity by Using a Spectral Bin Microphysics Cloud Model  

Science Conference Proceedings (OSTI)

This study examines the impact of in-cloud vertical inhomogeneity on cloud droplet effective radii (CDERs) of water-phase cloud retrieved from 1.6-, 2.1-, and 3.7-?m-band measurements (denoted by r1.6, r2.1, and r3.7, respectively). Discrepancies ...

Takashi M. Nagao; Kentaroh Suzuki; Takashi Y. Nakajima

2013-08-01T23:59:59.000Z

259

A Simple Model of Droplet Spectral Evolution during Turbulent Mixing  

Science Conference Proceedings (OSTI)

The mixing of cloudy, saturated air with cloud-free, subsaturated air is examined with a simple one-dimensional model of the mixing process. The model incorporates (i) a one-dimensional parameterization of turbulent deformation, (ii) molecular ...

Jřrgen B. Jensen; Marcia B. Baker

1989-09-01T23:59:59.000Z

260

Assessing Cloud-Phase Conditions  

Science Conference Proceedings (OSTI)

In situ microphysics measurements made during the First and Third Canadian Freezing Drizzle Experiments (CFDE I and III, respectively) have been used to assess the relative responses to ice and liquid hydrometeors for several common instruments. ...

Stewart G. Cober; George A. Isaac; Alexei V. Korolev; J. Walter Strapp

2001-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Precipitating clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

or virga An multiple sensor based approach to provide water phase as well as ice phase properties Measurements - MWR - MPL or Raman lidar - MMCR The approach Water...

262

A Three-Dimensional Cloud Chemistry Model  

Science Conference Proceedings (OSTI)

A cloud chemistry model is formulated in term of continuity equations for chemical species in the aqueous and aqueous phases within the cloud. The model includes scavenging of SO2, HNO3, HN3, H2O3, and sulphate aerosol particles. Calculations ...

Andre Tremblay; Henry Leighton

1986-05-01T23:59:59.000Z

263

Simulations of Arctic mixed-phase clouds using a new aerosol-linked ice nuclei parameterization in a prognostic ice prediction scheme.  

E-Print Network (OSTI)

??Despite the nearly universally-accepted notion that the Arctic is one of the most important areas to fully understand in the face of a changing global… (more)

Carpenter, James Michael

2013-01-01T23:59:59.000Z

264

Cloud Computing Operations Research  

Science Conference Proceedings (OSTI)

This paper argues that the cloud computing industry faces many decision problems where operations research OR could add tremendous value. To this end, we provide an OR perspective on cloud computing in three ways. First, we compare the cloud computing ... Keywords: cloud IT, cloud computing, green IT, operations research, supply chain

Ilyas Iyoob, Emrah Zarifoglu, A. B. Dieker

2013-06-01T23:59:59.000Z

265

Modification of Precipitation from Warm Clouds—A Review  

Science Conference Proceedings (OSTI)

This review is begun with a brief summary of the current status of our understanding of the physics of precipitation in warm clouds. The impact of warm-cloud precipitation processes on the evolution of the ice phase in supercooled clouds also is ...

William R. Cotton

1982-02-01T23:59:59.000Z

266

Observations of the Madden Julian Oscillation for Cloud Modeling...  

NLE Websites -- All DOE Office Websites (Extended Search)

Manus MJO IOP * Scientific Focus - What are the primary cloud, precipitation, and thermodynamic property differences between the active and suppressed phases of the MJO,...

267

Cloud Condensation Nuclei  

Science Conference Proceedings (OSTI)

The state of knowledge of the particles upon which liquid droplets condense to form atmospheric water clouds is presented. The realization of cloud condensation nuclei (CCN) as a distinct aerosol subset originated with the cloud microphysical ...

James G. Hudson

1993-04-01T23:59:59.000Z

268

Forecasting of Supercooled Clouds  

Science Conference Proceedings (OSTI)

Using parameterizations of cloud microphysics, a technique to forecast supercooled cloud events is suggested. This technique can be coupled on the mesoscale with a prognostic equation for cloud water to improve aircraft icing forecasts. The ...

André Tremblay; Anna Glazer; Wanda Szyrmer; George Isaac; Isztar Zawadzki

1995-07-01T23:59:59.000Z

269

Stratocumulus Cloud Field Reflected Fluxes: The Effect of Cloud Shape  

Science Conference Proceedings (OSTI)

Reflected fluxes are calculated for stratocumulus cloud fields as a function of sky cover, cloud aspect ratio, and cloud shape. Cloud liquid water volume is held invariant as cloud shape is varied so that the results can be utilized more ...

R. M. Welch; B. A. Wielicki

1984-11-01T23:59:59.000Z

270

Glossary Term - Cloud Chamber  

NLE Websites -- All DOE Office Websites (Extended Search)

Ceres Previous Term (Ceres) Glossary Main Index Next Term (Composition of the Earth's Atmosphere) Composition of the
Earth's Atmosphere Cloud Chamber A cloud chamber showing the...

271

Improved Hydrogen Gas Getters for TRU Waste Transuranic and Mixed Waste Focus Area - Phase 2 Final Report  

DOE Green Energy (OSTI)

Alpha radiolysis of hydrogenous waste and packaging materials generates hydrogen gas in radioactive storage containers. For that reason, the Nuclear Regulatory Commission (NRC) limits the flammable gas (hydrogen) concentration in the Transuranic Package Transporter-II (TRUPACT-II) containers to 5 vol% of hydrogen in air, which is the lower explosion limit. Consequently, a method is needed to prevent the build up of hydrogen to 5 vol% during the storage and transport of the TRUPACT-II containers (up to 60 days). One promising option is the use of hydrogen getters. These materials scavenge hydrogen from the gas phase and irreversibly bind it in the solid phase. One proven getter is a material called 1,4-bis (phenylethynyl) benzene, or DEB. It has the needed binding rate and capacity, but some of the chemical species that might be present in the containers could interfere with its ability to remove hydrogen. This project is focused upon developing a protective polymeric membrane coating for the DEB getter material, which comes in the form of small, irregularly shaped particles. This report summarizes the experimental results of the second phase of the development of the materials.

Stone, Mark Lee

2002-04-01T23:59:59.000Z

272

Exploring parameterization for turbulent entrainmentmixing processes in clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

Exploring Exploring parameterization for turbulent entrainment-mixing processes in clouds Chunsong Lu, 1,2 Yangang Liu, 2 Shengjie Niu, 1 Steven Krueger, 3 and Timothy Wagner 4 Received 11 July 2012; revised 29 November 2012; accepted 5 December 2012; published 16 January 2013. [1] Different turbulent entrainment-mixing processes (e.g., homogeneous and inhomogeneous) occur in clouds; accurate representation of these processes is critical for improving cloud-related parameterizations in large-scale models, but poorly understood and quantified. Using in situ aircraft observations over the U. S. Department of Energy's Atmospheric Radiation Measurement Southern Great Plains site during the March 2000 Cloud Intensive Observation Period and numerical simulations with the Explicit Mixing Parcel Model (EMPM), here we explore the potential of using degree of homogeneous mixing

273

Observations of Cloud Microstructure at the Centimeter Scale  

Science Conference Proceedings (OSTI)

Current conceptual models of the processes that modify the droplet spectrum in convective clouds starts with entrainment of environmental air followed by turbulent mixing of these parcels into progressively finer filaments. Thus, one would expect,...

Jean-Louis Brenguier

1993-04-01T23:59:59.000Z

274

Tracer Study of Vertical Exchange by Cumulus Clouds  

Science Conference Proceedings (OSTI)

This paper examines the exchange of material by convective cloud processes between the mixed layer and the overlying free troposphere. It describes results of a field experiment that was conducted in Lexington, Kentucky, during the period from 20 ...

J. K. S. Ching; A. J. Alkezweeny

1986-11-01T23:59:59.000Z

275

Boundary Layer Clouds and Vegetation–Atmosphere Feedbacks  

Science Conference Proceedings (OSTI)

An analysis of boundary layer cumulus clouds and their impact on land surface–atmosphere exchange is presented. Seasonal trends indicate that in response to increasing insolation and sensible heat flux, both the mixed-layer height (zi) and the ...

Jeffrey M. Freedman; David R. Fitzjarrald; Kathleen E. Moore; Ricardo K. Sakai

2001-01-01T23:59:59.000Z

276

Remote Spectroscopic Sounding of Liquid Water Path in Thick Clouds...  

NLE Websites -- All DOE Office Websites (Extended Search)

restored for this particular case. For sounding of the mixed clouds, three intervals in a spectrum of solar radiation are analyzed: 0.97-1.03 m; 1.60-1.70 m; and 2.15-2.35 m...

277

Numerical Simulation of Dry Ice Cloud Seeding Experiments  

Science Conference Proceedings (OSTI)

The application of a two-dimensional, time-dependent cloud model to describe the effects of dry ice cloud seeding is demonstrated. A conservation equation and associated auxiliary equations for the mixing ratio of dry ice (CO2) are presented. The ...

Fred J. Kopp; Harold D. Orville; Richard D. Farley; John H. Hirsch

1983-09-01T23:59:59.000Z

278

Adsorption of propane, isopropyl, and hydrogen on cluster models of the M1 phase of Mo-V-Te-Nb-O mixed metal oxide catalyst  

Science Conference Proceedings (OSTI)

The Mo-V-Te-Nb-O mixed metal oxide catalyst possessing the M1 phase structure is uniquely capable of directly converting propane into acrylonitrile. However, the mechanism of this complex eight-electron transformation, which includes a series of oxidative H-abstraction and N-insertion steps, remains poorly understood. We have conducted a density functional theory study of cluster models of the proposed active and selective site for propane ammoxidation, including the adsorption of propane, isopropyl (CH{sub 3}CHCH{sub 3}), and H which are involved in the first step of this transformation, that is, the methylene C-H bond scission in propane, on these active site models. Among the surface oxygen species, the telluryl oxo (Te=O) is found to be the most nucleophilic. Whereas the adsorption of propane is weak regardless of the MO{sub x} species involved, isopropyl and H adsorption exhibits strong preference in the order of Te=O > V=O > bridging oxygens > empty Mo apical site, suggesting the importance of TeO{sub x} species for H abstraction. The adsorption energies of isopropyl and H and consequently the reaction energy of the initial dehydrogenation of propane are strongly dependent on the number of ab planes included in the cluster, which points to the need to employ multilayer cluster models to correctly capture the energetics of surface chemistry on this mixed metal oxide catalyst.

Govindasamy, Agalya [University of Cincinnati; Muthukumar, Kaliappan [University of Cincinnati; Yu, Junjun [University of Cincinnati; Xu, Ye [ORNL; Guliants, Vadim V. [University of Cincinnati

2010-01-01T23:59:59.000Z

279

Sensitivity of Simulated Global Climate to Perturbations in Low Cloud Microphysical Properties. Part II: Spatially Localized Perturbations  

Science Conference Proceedings (OSTI)

The sensitivity of the global climate to spatially localized (20°–70°N) perturbations in the microphysical properties of low clouds is investigated using a general circulation model coupled to a mixed layer ocean with fixed cloud distributions. ...

C-T. Chen; V. Ramaswamy

1996-11-01T23:59:59.000Z

280

The convective structures associated with cloud-to-ground lightning in TOGA COARE Mesoscale Convective Systems  

E-Print Network (OSTI)

The TOGA COARE experiment was carried out in the western Pacific warm pool region from November 1992 through February 1993. Data from TOGA COARE provide the opportunity for comprehensive studies of tropical oceanic convection. This study seeks to understand more about the structures of tropical mesoscale convective systems in relation to their lightning activity and cold cloud area. The properties of convective cores within the MCSs, as well as their infrared (IR) cloud top temperatures are related to cloud-to-ground lightning. IR and lightning time histories for each case are compared, and the cases ranked by mean flashes per 10000 km2. For selected cases, radar/lightning overlays and vertical profiles of maximum radar reflectivities (VPRRs) are shown in order to describe the convective structures of cells that produced lightning, and also cells that did not produce lightning. IR cloud-top temperature and lightning histories indicate the highly variable nature of the TOGA COARE MCSs. Some MCSs which have very cold cloud-top temperatures have little or no lightning. When a system did produce lightning, more flashes generally occurred during its growth phase. Overall, IR measurements seem to be a poor indicator of lightning due to the lack of a clear relationship between the size of cold cloud-top area and cloud-to-ground flashes. The overall flash rates of the TOGA COARE MCSs support previous work which showed that tropical oceanic convection has an order of magnitude less cloud-to-ground lightning than continental convection. In fact, the highest flash rate for the 13 cases was less than the weakest continental case in a Texas MCS study (Toracinta et al. 1995). Examination of individual VPRR and of all convective VPRR from the 13 cases indicate a pronounced difference between lightning producing and non-lightning producing cells. Lightning producing convective cells have higher radar reflectivity in the 5.0- 8.0 km layer, and a slower decrease with height, both observations indicating larger ice particles in the mixed phase region between 00 C and-200 C.

Restivo, Michael Edward

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Global Circuit Model with Clouds  

Science Conference Proceedings (OSTI)

Cloud data from the International Satellite Cloud Climatology Project (ISCCP) database have been introduced into the global circuit model developed by Tinsley and Zhou. Using the cloud-top pressure data and cloud type information, the authors ...

Limin Zhou; Brian A. Tinsley

2010-04-01T23:59:59.000Z

282

One-Particle Spectral Function and Local Density of States in a Phenomenological Mixed-Phase Model for High-Temperature Superconductors  

SciTech Connect

The dynamical properties of a recently introduced phenomenological model for high-temperature superconductors are investigated. In the clean limit, it was observed that none of the homogeneous or striped states that are induced by the model at low temperatures can reproduce the recent angle-resolved photoemission results for La{sub 2-x}Sr{sub x}CuO{sub 4} [Yoshida et al., Phys. Rev. Lett. 91, 027001 (2003)], which show a signal with two branches in the underdoped regime. On the other hand, upon including quenched disorder in the model and breaking the homogeneous state into 'patches' that are locally either superconducting or antiferromagnetic, the two-branch spectra can be reproduced. In this picture, the nodal regions are caused by d-wave superconducting clusters. Studying the density of states (DOS), a pseudogap is observed, caused by the mixture of the gapped antiferromagnetic state and a d-wave superconductor. The local DOS can be interpreted using a mixed-phase picture, similar to what is observed in tunneling experiments. It is concluded that a simple phenomenological model for cuprates can capture several of the one-particle features observed in the underdoped regime of these materials.

Mayr, Matthias [Max-Planck-Institut fur Feskorperforschung, Stuttgart, Germany; Alvarez, Gonzalo [ORNL; Moreo, Adriana [ORNL; Dagotto, Elbio R [ORNL

2006-01-01T23:59:59.000Z

283

Cloud Computing Forum & Workshop II  

Science Conference Proceedings (OSTI)

Cloud Computing Forum & Workshop II. Purpose: On May 20, 2010, NIST hosted the first Cloud Computing Forum & Workshop. ...

2013-08-07T23:59:59.000Z

284

ISCCP Cloud Algorithm Intercomparison  

Science Conference Proceedings (OSTI)

The International Satellite Cloud Climatology Project (ISCCP) will provide a uniform global climatology of satellite-measured radiances and derive an experimental climatology of cloud radiative properties from these radiances. A pilot study to ...

W. B. Rossow; F. Mosher; E. Kinsella; A. Arking; M. Desbois; E. Harrison; P. Minnis; E. Ruprecht; G. Seze; C. Simmer; E. Smith

1985-09-01T23:59:59.000Z

285

Automated cloud resource orchestration  

Science Conference Proceedings (OSTI)

Realizing Infrastructure-as-a-Service (IaaS) cloud requires a control platform for orchestrating the provisioning, configuration, management and decommissioning of a distributed set of diverse cloud resources (i.e., compute, storage, network) serving ...

Changbin Liu / Boon Thau Loo

2012-01-01T23:59:59.000Z

286

ARM - Measurement - Cloud type  

NLE Websites -- All DOE Office Websites (Extended Search)

type 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 : Cloud type Cloud type such as...

287

Entrainment in Cumulus Clouds  

Science Conference Proceedings (OSTI)

Entrainment of dry air into cumulus clouds influences the development of the clouds in a major way. The many aspects of the entrainment process are examined in this paper by critically reviewing the literature from the time when investigations ...

Alan M. Blyth

1993-04-01T23:59:59.000Z

288

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Clouds within the inner regions of tropical cyclones are unlike those anywhere else in the atmosphere. Convective clouds contributing to cyclogenesis have rotational and deep intense updrafts but tend to have relatively weak downdrafts. Within ...

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

289

North Australian Cloud Lines  

Science Conference Proceedings (OSTI)

A satellite classification and climatology of propagating mesoscale cloud fines in northern Australia is presented. These cloud fines range from long, narrow lines of shallow convection to extensive deep convective squall lines with mesoscale ...

W. Drosdowsky; G. J. Holland

1987-11-01T23:59:59.000Z

290

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Clouds within the inner regions of tropical cyclones are unlike those anywhere else in the atmosphere. Convective clouds contributing to cyclogenesis have rotational and deep intense updrafts but tend to have relatively weak downdrafts. Within the ...

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

291

Phenomenological Description of Tropical Clouds Using CloudSat Cloud Classification  

Science Conference Proceedings (OSTI)

Two years of tropical oceanic cloud observations are analyzed using the operational CloudSat cloud classification product and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar. Relationships are examined between ...

Ali Behrangi; Terry Kubar; Bjorn Lambrigtsen

2012-10-01T23:59:59.000Z

292

Computing and Partitioning Cloud Feedbacks Using Cloud Property Histograms. Part I: Cloud Radiative Kernels  

Science Conference Proceedings (OSTI)

This study proposes a novel technique for computing cloud feedbacks using histograms of cloud fraction as a joint function of cloud-top pressure (CTP) and optical depth (?). These histograms were generated by the International Satellite Cloud ...

Mark D. Zelinka; Stephen A. Klein; Dennis L. Hartmann

2012-06-01T23:59:59.000Z

293

Cloud Computing at NERSC  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud Computing Energy Efficient Computing Exascale Computing Performance & Monitoring Tools Petascale Initiative Science Gateway Development Storage and IO Technologies Testbeds...

294

Rope Cloud over Land  

Science Conference Proceedings (OSTI)

Satellite imagery is used to document several rope clouds over the southeastern Unites States. Surface and upper-air data are examined for one of the rope clouds and possible reasons for the development and maintenance of this type cloud line are ...

Von S. Woods

1983-03-01T23:59:59.000Z

295

User Centric Community Clouds  

Science Conference Proceedings (OSTI)

With the evolution in cloud technologies, users are becoming acquainted with seamless service provision. Nevertheless, clouds are not a user centric technology, and users become completely dependent on service providers. We propose a novel concept for ... Keywords: Cloud infrastructure, Identity management, User-centric systems

Joăo Paulo Barraca; Alfredo Matos; Rui L. Aguiar

2011-05-01T23:59:59.000Z

296

Sensitivity Study of Cloud-Resolving Convective Simulations with WRF Using Two Bulk Microphysical Parameterizations: Ice-Phase Microphysics versus Sedimentation Effects  

Science Conference Proceedings (OSTI)

This study examines the relative importance of ice-phase microphysics and sedimentation velocity for hydrometeors in bulk microphysics schemes. The two bulk microphysics schemes having the same number of prognostic water substances, the Weather ...

Song-You Hong; Kyo-Sun Sunny Lim; Ju-Hye Kim; Jeong-Ock Jade Lim; Jimy Dudhia

2009-01-01T23:59:59.000Z

297

Turbulent molecular clouds  

E-Print Network (OSTI)

Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds trying to confront the two approaches wherever possible. After a broad presentation of the cold interstellar medium and molecular clouds, we emphasize the dynamical processes with special focus to turbulence and its impact on cloud evolution. We then review our knowledge of the velocity, density and magnetic fields. We end by openings towards new chemistry models and the links between molecular cloud structure and star--formation rates.

Hennebelle, Patrick

2012-01-01T23:59:59.000Z

298

Cloud displays for mobile users in a display cloud  

Science Conference Proceedings (OSTI)

The display cloud model allows users to select local and remote programmable displays, and add them to a user specific cloud display where the user can arrange them freely. On a cloud display, the abstraction representing remote graphical content is ... Keywords: cloud displays, display clouds, ubiquitous displays

Lars Tiede; John Markus Bjřrndalen; Otto J. Anshus

2013-02-01T23:59:59.000Z

299

Cloud Properties Working Group Low Clouds Update  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud Properties Working Group Cloud Properties Working Group Low Clouds Update Low Clouds Update Jennifer Comstock Jennifer Comstock Dave Turner Dave Turner Andy Andy Vogelmann Vogelmann Instruments Instruments 90/150 GHz microwave radiometer 90/150 GHz microwave radiometer Deployed during COPS AMF Deployed during COPS AMF Exploring calibration w/ DPR ( Exploring calibration w/ DPR ( Crewell Crewell & & L L ö ö hnert hnert ) ) See COPS Breakout, Wednesday evening See COPS Breakout, Wednesday evening 183 GHz (GVR) deployed at the NSA 183 GHz (GVR) deployed at the NSA Neural network algorithm to retrieve PWV & LWP (Maria Neural network algorithm to retrieve PWV & LWP (Maria Cadeddu Cadeddu ) ) Potential VAP candidate (RPWG) Potential VAP candidate (RPWG)

300

BNL | Cloud Lifecycle Infrastructure  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud Life Cycle Infrastructure Cloud Life Cycle Infrastructure An important component of any long-term atmospheric measurement program is the quality control and maintenance of the datastreams from instrument systems. Further, the raw measurements from atmospheric remote sensing instrumentation are not directly useable by the majority of the scientific community. These raw measurements must be interpreted and converted to geophysical quantities that can be more readily used by a greater number of scientists to address important questions regarding the Earth's climate system. The cloud life cycle infrastructure group at BNL is led by Dr. Michael Jensen and is responsible for the development and production of cloud-related value-added products (VAPs). The cloud life cycle infrastructure group also provides mentorships for the millimeter cloud

Note: This page contains sample records for the topic "mixed phase cloud" 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

BNL | Cloud Lifecycle Research  

NLE Websites -- All DOE Office Websites (Extended Search)

to be one of the major sources of uncertainty in numerical simulations of climate and weather. Improvement of the representation of clouds in numerical models requires fundamental...

302

Dispersion of Cloud Droplet Size Distributions, Cloud Parameterization...  

NLE Websites -- All DOE Office Websites (Extended Search)

National Laboratory Upton, New York Introduction Most studies of the effect of aerosols on cloud radiative properties have considered only changes in the cloud droplet...

303

A 94-GHz Doppler Radar for Cloud Observations  

Science Conference Proceedings (OSTI)

A Doppler radar operating at 3.2 mm wavelength was designed and assembled primarily for observation of clouds and precipitation. Phase detection of the radar signals which is required for Doppler operation is implemented through the use of a ...

Roger Lhermitte

1987-03-01T23:59:59.000Z

304

Chaff Seeding Effects in a Dynamical-Electrical Cloud Model  

Science Conference Proceedings (OSTI)

A two-dimensional, slab-symmetric, time-dependent cloud model has been devised to simulate deep convection in the atmosphere. The dynamics and thermodynamics of deep convection are prescribed and the microphysics of the liquid phase is ...

John H. Helsdon Jr.

1980-09-01T23:59:59.000Z

305

Cloud Classification Before Luke Howard  

Science Conference Proceedings (OSTI)

A brief outline of the history of cloud painting prior to the first cloud classification schemes of Luke Howard and Lamarck is presented. It is shown that European painters had accurately represented most of the different cloud forms between ...

Stanely David Gedzelman

1989-04-01T23:59:59.000Z

306

Radar Reflectivity of Cumulus Clouds  

Science Conference Proceedings (OSTI)

The relationships between the radar reflectivity factor Z and significant physical cloud parameters are studied from a dataset collected with an instrumented aircraft in non- or very weakly precipitating warm clouds. The cloud droplet populations ...

Henri Sauvageot; Jilani Omar

1987-06-01T23:59:59.000Z

307

Cloud microphysical properties retrieved from downwelling infrared radiance measurements made at Eureka, Nunavut, Canada (2006-2009)  

Science Conference Proceedings (OSTI)

The radiative properties of clouds are related to cloud microphysical and optical properties, including water path, optical depth, particle size, and thermodynamic phase. Ground-based observations provide high quality, long-term, continuous ...

Christopher J. Cox; David D. Turner; Penny M. Rowe; Matthew D. Shupe; Von P. Walden

308

Molecular cloud regulated star formation in galaxies  

E-Print Network (OSTI)

We describe a numerical implementation of star formation in disk galaxies, in which the conversion of cooling gas to stars in the multiphase interstellar medium is governed by the rate at which molecular clouds are formed and destroyed. In the model, clouds form from thermally unstable ambient gas and get destroyed by feedback from massive stars and thermal conduction. Feedback in the ambient phase cycles gas into a hot galactic fountain or wind. We model the ambient gas hydrodynamically using smoothed particle hydrodynamics (SPH). However, we cannot resolve the Jeans mass in the cold and dense molecular gas and, therefore, represent the cloud phase with ballistic particles that coagulate when colliding. We show that this naturally produces a multiphase medium with cold clouds, a warm disk, hot supernova bubbles and a hot, tenuous halo. Our implementation of this model is based on the Gadget N-Body code. We illustrate the model by evolving an isolated Milky Way-like galaxy and study the properties of a disk formed in a rotating spherical collapse. Many observed properties of disk galaxies are reproduced well, including the molecular cloud mass spectrum, the molecular fraction as a function of radius, the Schmidt law, the stellar density profile and the appearance of a galactic fountain.

C. M. Booth; T. Theuns; T. Okamoto

2007-01-30T23:59:59.000Z

309

Cloud Computing Forum & Workshop IV  

Science Conference Proceedings (OSTI)

Cloud Computing Forum & Workshop IV. ... NIST announces the Cloud Computing Forum & Workshop IV to be held on November 2, 3 and 4, 2011. ...

2013-08-07T23:59:59.000Z

310

BNL | Aerosol, Cloud, Precipitation Interactions  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud-Aerosol-Precipitation Interactions Cloud-Aerosol-Precipitation Interactions Atmospheric aerosols exert important "indirect effects" on clouds and climate by serving as cloud condensation nuclei (CCN) and ice nuclei that affect cloud radiative and microphysical properties. For example, an increase in CCN increases the number concentration of droplets enhances cloud albedo, and suppresses precipitation that alters cloud coverage and lifetime. However, in the case of moist and strong convective clouds, increasing aerosols may increase precipitation and enhance storm development. Although aerosol-induced indirect effects on climate are believed to have a significant impact on global climate change, estimating their impact continues to be one of the most uncertain climate forcings.

311

Cirrus Cloud Properties from a Cloud-Resolving Model Simulation Compared to Cloud Radar Observations  

Science Conference Proceedings (OSTI)

Cloud radar data collected at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains site were used to evaluate the properties of cirrus clouds that occurred in a cloud-resolving model (CRM) simulation of the 29-day summer ...

Yali Luo; Steven K. Krueger; Gerald G. Mace; Kuan-Man Xu

2003-02-01T23:59:59.000Z

312

CONTRIBUTED Green Cloud Computing  

E-Print Network (OSTI)

widely dis- cussed, the shift in energy usage in a cloud computing model has received little attention cloud computing services typically operate. We consider energy consumption models of the transport of energy per bit also allows the results to be easily scaled to any usage level. We consider both public

Tucker, Rod

313

Cryptographic cloud storage  

Science Conference Proceedings (OSTI)

We consider the problem of building a secure cloud storage service on top of a public cloud infrastructure where the service provider is not completely trusted by the customer. We describe, at a high level, several architectures that combine recent and ...

Seny Kamara; Kristin Lauter

2010-01-01T23:59:59.000Z

314

ARM - Measurement - Cloud extinction  

NLE Websites -- All DOE Office Websites (Extended Search)

extinction extinction 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 : Cloud extinction The removal of radiant energy from an incident beam by the process of cloud absorption and/or scattering. Categories Cloud 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 NEPHELOMETER : Nephelometer Field Campaign Instruments CEP : Cloud Extinction Probe CLDAEROSMICRO : Cloud and Aerosol Microphysical Properties EC-CONVAIR580-BULK : Environment Canada Convair 580 Bulk Parameters

315

Thermodynamics of Icing Cylinder for Measurements of Liquid Water Content in Supercooled Clouds  

Science Conference Proceedings (OSTI)

The Rosemount Icing Detector (RICE) has been used extensively over the last three decades for aircraft measurements of the rate of ice riming in supercooled liquid and mixed clouds. Because of difficulties related to calibration and ...

I. P. Mazin; A. V. Korolev; A. Heymsfield; G. A. Isaac; S. G. Cober

2001-04-01T23:59:59.000Z

316

Moisture Transport, Lower-Tropospheric Stability, and Decoupling of Cloud-Topped Boundary Layers  

Science Conference Proceedings (OSTI)

Decoupling during the “Lagrangian” evolution of a cloud-topped boundary layer advected equatorward by the trade winds in an idealized eastern subtropical ocean is studied using a mixed-layer model (MLM). The sea surface temperature is gradually ...

Christopher S. Bretherton; Matthew C. Wyant

1997-01-01T23:59:59.000Z

317

Daytime Cycle of Low-Level Clouds and the Tropical Convective Boundary Layer in Southwestern Amazonia  

Science Conference Proceedings (OSTI)

During the wet season in the southwestern Amazon region, daytime water transport out of the atmospheric mixed layer into the deeper atmosphere is shown to depend upon cloud amounts and types and synoptic-scale velocity fields. Interactions among ...

C. Strong; J. D. Fuentes; M. Garstang; A. K. Betts

2005-10-01T23:59:59.000Z

318

Effect of Marine Stratocumulus Clouds on the Ocean-Surface Heat Budget  

Science Conference Proceedings (OSTI)

The mixed-layer stratocumulus model first developed by Lilly is extended to include liquid-water-dependent solar optical properties and infrared radiative fluxes. The ocean-surface heat budget under these clouds is discussed as a function of ...

Howard P. Hanson; Patricia L. Gruber

1982-04-01T23:59:59.000Z

319

CO2 Retrieval over Clouds from the OCO Mission: Model Simulations and Error Analysis  

Science Conference Proceedings (OSTI)

Spectral characteristics of the future Orbiting Carbon Observatory (OCO) sensor, which will be launched in January 2009, were used to infer the carbon dioxide column-averaged mixing ratio over liquid water clouds over ocean by means of radiative ...

Jérôme Vidot; Ralf Bennartz; Christopher W. O’Dell; René Preusker; Rasmus Lindstrot; Andrew K. Heidinger

2009-06-01T23:59:59.000Z

320

ADVANCED MIXING MODELS  

Science Conference Proceedings (OSTI)

The process of recovering and processing High Level Waste (HLW) the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four mixers (pumps) located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are typically set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The focus of the present work is to establish mixing criteria applicable to miscible fluids, with an ultimate goal of addressing waste processing in HLW tanks at SRS and quantifying the mixing time required to suspend sludge particles with the submersible jet pump. A single-phase computational fluid dynamics (CFD) approach was taken for the analysis of jet flow patterns with an emphasis on the velocity decay and the turbulent flow evolution for the farfield region from the pump. Literature results for a turbulent jet flow are reviewed, since the decay of the axial jet velocity and the evolution of the jet flow patterns are important phenomena affecting sludge suspension and mixing operations. The work described in this report suggests a basis for further development of the theory leading to the identified mixing indicators, with benchmark analyses demonstrating their consistency with widely accepted correlations. Although the indicators are somewhat generic in nature, they are applied to Savannah River Site (SRS) waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. One of the main objectives in the waste processing is to provide feed of a uniform slurry composition at a certain weight percentage (e.g. typically {approx}13 wt% at SRS) over an extended period of time. In preparation of the sludge for slurrying, several important questions have been raised with regard to sludge suspension and mixing of the solid suspension in the bulk of the tank: (1) How much time is required to prepare a slurry with a uniform solid composition? (2) How long will it take to suspend and mix the sludge for uniform composition in any particular waste tank? (3) What are good mixing indicators to answer the questions concerning sludge mixing stated above in a general fashion applicable to any waste tank/slurry pump geometry and fluid/sludge combination?

Lee, S.; Dimenna, R.; Tamburello, D.

2011-02-14T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Cloud Computing Forensic Science Workshop  

Science Conference Proceedings (OSTI)

Cloud Computing Forensic Science Workshop. Purpose: The New Frontiers in IT and Measurement Science Rapid advances ...

2013-09-05T23:59:59.000Z

322

A marketplace for cloud resources  

Science Conference Proceedings (OSTI)

Cloud computing is an emerging paradigm aimed to offer users pay-per-use computing resources, while leaving the burden of managing the computing infrastructure to the cloud provider. We present a new programming and pricing model that gives the cloud ... Keywords: cloud computing, iaas, large-scale scheduling, pricing models, worst-case execution time

Thomas A. Henzinger; Anmol V. Singh; Vasu Singh; Thomas Wies; Damien Zufferey

2010-10-01T23:59:59.000Z

323

The lattice QCD simulation of the quark-gluon mixed condensate g at finite temperature and the phase transition of QCD  

E-Print Network (OSTI)

The thermal effects on the quark-gluon mixed condensate g, which is another chiral order parameter, are studied using the SU(3)c lattice QCD with the Kogut-Susskind fermion at the quenched level. We perform the accurate measurement of the mixed condensate as well as the quark condensate for 0MeVcondensates around T_c \\simeq 280MeV, while the thermal effects below T_c are found to be weak. We also find that the ratio m_0^2 = g/ is almost independent of the temperature even in the very vicinity of T_c, which indicates that the two condensates have nontrivial similarity in the chiral behaviors. We also present the correlation between the condensates and the Polyakov loop to understand the vacuum structure of QCD.

Takumi Doi; Noriyoshi Ishii; Makoto Oka; Hideo Suganuma

2004-09-14T23:59:59.000Z

324

CDIAC Cloud Data Sets  

NLE Websites -- All DOE Office Websites (Extended Search)

Period of Record A Gridded Climatology of Clouds over Land (1971-1996) and Ocean (1954-2008) from Surface Observations Worldwide (CDIAC NDP-026E) C.J. Hahn and S.G. Warren...

325

3. New Cloud Climatology  

NLE Websites -- All DOE Office Websites (Extended Search)

New Cloud Climatology New Cloud Climatology Computed for the summers (May-Au- gust) 2000 through 2004 (Berg and Kassianov 2008). Uses ARSCL VAP, Total Sky Imager, and radar wind profiler. * * Initial Evaluation of the Cumulus Potential Scheme at the ACRF SGP Site Larry Berg, William Gustafson, and Evgueni Kassianov Pacific Northwest National Laboratory 1. Motivation Shallow clouds are poorly predicted by current global and regional scale models. A new parameterization has been devel- oped that links the boundary-layer turbu- lence and the shallow clouds. 2. The CuP Parameterization The Cumulus Potential (CuP) param- eterization uses Probability Density Functions (PDFs) of temperature and moisture to represent the subgrid scale

326

Cloud Transmissivities for Canada  

Science Conference Proceedings (OSTI)

Transmissivities are determined for different cloud types using nine years of hourly irradiance measurements under overcast skies at six Canadian stations. Values for individual stations and for pooled data using irradiances uncorrected for ...

J. A. Davies; M. Abdel-Wahab; J. E. Howard

1985-03-01T23:59:59.000Z

327

A New Approach for Estimating Entrainment Rate in Cumulus Clouds  

SciTech Connect

A new approach is presented to estimate entrainment rate in cumulus clouds. The new approach is directly derived from the definition of fractional entrainment rate and relates it to mixing fraction and the height above cloud base. The results derived from the new approach compare favorably with those obtained with a commonly used approach, and have smaller uncertainty. This new approach has several advantages: it eliminates the need for in-cloud measurements of temperature and water vapor content, which are often problematic in current aircraft observations; it has the potential for straightforwardly connecting the estimation of entrainment rate and the microphysical effects of entrainment-mixing processes; it also has the potential for developing a remote sensing technique to infer entrainment rate.

Lu C.; Liu, Y.; Yum, S. S.; Niu, S.; Endo, S.

2012-02-16T23:59:59.000Z

328

Detection of supercooled liquid in mixedphase clouds using radar Doppler spectra  

E-Print Network (OSTI)

in the temperature range from 0 to -40°C, where both liquid and ice hydrometeor phases are sustainable of their hydrometeors (i.e., liquid or ice). Current cloud parameterizations that parti- tion water into liquid and ice 2010; published 1 October 2010. [1] Cloud phase identification from active remote sensors

Shupe, Matthew

329

Marine Cloud Brightening  

Science Conference Proceedings (OSTI)

The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could - subject to satisfactory resolution of technical and scientific problems identified herein - have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seedparticle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

Latham, John; Bower, Keith; Choularton, Tom; Coe, H.; Connolly, P.; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Philip J.; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Robert

2012-09-07T23:59:59.000Z

330

FORMATION OF MASSIVE MOLECULAR CLOUD CORES BY CLOUD-CLOUD COLLISION  

SciTech Connect

Recent observations of molecular clouds around rich massive star clusters including NGC 3603, Westerlund 2, and M20 revealed that the formation of massive stars could be triggered by a cloud-cloud collision. By using three-dimensional, isothermal, magnetohydrodynamics simulations with the effect of self-gravity, we demonstrate that massive, gravitationally unstable, molecular cloud cores are formed behind the strong shock waves induced by cloud-cloud collision. We find that the massive molecular cloud cores have large effective Jeans mass owing to the enhancement of the magnetic field strength by shock compression and turbulence in the compressed layer. Our results predict that massive molecular cloud cores formed by the cloud-cloud collision are filamentary and threaded by magnetic fields perpendicular to the filament.

Inoue, Tsuyoshi [Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258 (Japan); Fukui, Yasuo, E-mail: inouety@phys.aoyama.ac.jp [Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

2013-09-10T23:59:59.000Z

331

X-ray Absorption and Diffraction Studies of the Mixed-phase State of (CrxV1-x)2O3  

Science Conference Proceedings (OSTI)

X-ray diffraction and vanadium x-ray absorption near-edge structure (XANES) data have been obtained for (V{sub 1-x}Cr{sub x}){sub 2}O{sub 3} samples containing several concentrations of Cr, crossing the metal-insulator transition boundary. For single-phase single-crystal samples our theoretical results are generally in good qualitative agreement with our experimental single-crystal XANES, for both crystal orientations relative to the incident-beam electric vector. However, an anomalous peak occurs for both orientations in the K pre-edge of the single-crystal sample containing 1.2% Cr, a paramagnetic insulator sample that is in the concentration regime corresponding to the room-temperature two-phase (coexistence) region of the phase diagram. Upon increasing the temperature of the 0.4% Cr powdered material to 400 K so that one enters the two-phase region of the phase diagram, a similar peak appears and then diminishes at 600 K. These results, as well as experiments done by others involving room-temperature and low-temperature XANES of a 1.1% Cr sample, suggest that this feature in the V pre-edge structure is associated with the appearance under some circumstances of a small amount of highly distorted VO{sub 6} octahedra in the interface region between coexisting metal and insulating phases. Finally, we find that, for the two-phase regime, the concentration ratio of the metal-to-insulating phase varies between different regions from a sample batch of uniform composition made by the skull melting method.

D Pease; A Frenkel; V Krayzman; T Huang; P Shanthakumar; J Budnick; P Metcalf; F Chudnovsky; E Stern

2011-12-31T23:59:59.000Z

332

Remote Sounding of High Clouds. III: Monte Carlo Calculations of Multiple-Scattered Lidar Returns  

Science Conference Proceedings (OSTI)

Monte Carlo calculations of multiple-scattered contributions to the total energy received in a lidar beam have been made for a representative cirrus ice-cloud scattering phase function. The phase function is varied arbitrarily near the back ...

C. M. R. Platt

1981-01-01T23:59:59.000Z

333

Analysis of In situ Observations of Cloud Microphysics from M-PACE Final Report, DOE Grant Agreement No. DE-FG02-06ER64168  

SciTech Connect

This report summarizes the findings and accomplishments of work performed under DOE Grant Agreement No. DE-FG02-06ER64168. The focus of the work was the analysis of in situ observations collected by the University of North Dakota Citation research aircraft during the Mixed-Phase Arctic Cloud Experiment (M-PACE). This project was conducted in 2004 along the North Slope of Alaska. The objectives of the research were: to characterize certain microphysical properties of clouds sampled during M-PACE, including spatial variability, precipitation formation, ice multiplication; to examine instrument performance and certain data processing algorithms; and to collaborate with other M-PACE investigators on case study analyses. A summary of the findings of the first two objectives is given here in parts 1 and 2; full results are contained in reports listed in part 3 of this report. The collaborative efforts are described in the publications listed in part 3.

Michael R. Poellot

2009-01-09T23:59:59.000Z

334

The evolution of interstellar clouds in a streaming hot plasma including heat conduction  

E-Print Network (OSTI)

To examine the evolution of giant molecular clouds in the stream of a hot plasma we performed two-dimensional hydrodynamical simulations that take full account of self-gravity, heating and cooling effects and heat conduction by electrons. We use the thermal conductivity of a fully ionized hydrogen plasma proposed by Spitzer and a saturated heat flux according to Cowie & McKee in regions where the mean free path of the electrons is large compared to the temperature scaleheight. Significant structural and evolutionary differences occur between simulations with and without heat conduction. Dense clouds in pure dynamical models experience dynamical destruction by Kelvin-Helmholtz (KH) instability. In static models heat conduction leads to evaporation of such clouds. Heat conduction acting on clouds in a gas stream smooths out steep temperature and density gradients at the edge of the cloud because the conduction timescale is shorter than the cooling timescale. This diminishes the velocity gradient between the streaming plasma and the cloud, so that the timescale for the onset of KH instabilities increases, and the surface of the cloud becomes less susceptible to KH instabilities. The stabilisation effect of heat conduction against KH instability is more pronounced for smaller and less massive clouds. As in the static case more realistic cloud conditions allow heat conduction to transfer hot material onto the cloud's surface and to mix the accreted gas deeper into the cloud.

W. Vieser; G. Hensler

2007-04-26T23:59:59.000Z

335

ARM - Field Campaign - Cloud LAnd Surface Interaction Campaign (CLASIC)  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsCloud LAnd Surface Interaction Campaign (CLASIC) govCampaignsCloud LAnd Surface Interaction Campaign (CLASIC) Campaign Links CLASIC Website Related Campaigns CLASIC - SAM Support 2007.06.09, DeVore, SGP CLASIC - 9.4 GHz Phase Array Radar 2007.06.08, Kollias, SGP CLASIC - Southern Great Plains Aerosol Evolution Study (SGPAES) 2007.06.08, Collins, SGP CLASIC - Land Surface 2007.06.01, Jackson, SGP CLASIC - Radiosonde Campaign 2007.06.01, Orr, SGP CLASIC - SGP Particle Phase Experiment 2007.06.01, Martin, SGP CLASIC - Land-Cloud Coupled Data Assimilation System 2007.06.01, Jackson, SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Cloud LAnd Surface Interaction Campaign (CLASIC) 2007.06.01 - 2007.06.30 Website : http://acrf-campaign.arm.gov/clasic/ Lead Scientist : Mark Miller

336

Cirrus Clouds. Part I: A Cirrus Cloud Model  

Science Conference Proceedings (OSTI)

A two-dimensional (x, z), time-dependent, numerical cloud model is developed for the purpose of investigating the role of various physical processes involved in the maintenance of cirriform clouds. In addition to accounting for dynamic and ...

David O'C. Starr; Stephen K. Cox

1985-12-01T23:59:59.000Z

337

On the Use of Cloud Forcing to Estimate Cloud Feedback  

Science Conference Proceedings (OSTI)

Uncertainty in cloud feedback is the leading cause of discrepancy in model predictions of climate change. The use of observed or model-simulated radiative fluxes to diagnose the effect of clouds on climate sensitivity requires an accurate ...

Brian J. Soden; Anthony J. Broccoli; Richard S. Hemler

2004-10-01T23:59:59.000Z

338

Heat, Moisture, and Momentum Budgets of Isolated Deep Midlatitude and Tropical Convective Clouds as Diagnosed from Three-Dimensional Model Output. Part I: Control Experiments  

Science Conference Proceedings (OSTI)

This project uses a three-dimensional anelastic cloud model with a simple ice phase parameterization to evaluate the feedback between isolated deep convective clouds and their near surroundings. The horizontal Reynolds averaging approach of ...

Robert E. Schlesinger

1994-12-01T23:59:59.000Z

339

Comparisons of CCN with Supercooled Clouds  

Science Conference Proceedings (OSTI)

More than 140 supercooled clouds were compared with corresponding out-of-cloud cloud condensation nuclei (CCN) measurements. In spite of significant differences in altitude, temperature, distances from cloud base, updraft velocity (W), ...

James G. Hudson; Stephen Noble; Vandana Jha

2010-09-01T23:59:59.000Z

340

Effects of CCN Concentrations on Stratus Clouds  

Science Conference Proceedings (OSTI)

Comparisons between cloud-base CCN concentrations and cloud droplet concentrations in stratus clouds over San Diego and 100 km out to sea showed a positive correlation. The supersaturation in these clouds, as derived from the matching of the CCN ...

James G. Hudson

1983-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 3, NO. 3, JULY 2006 287 The Influence of Thermodynamic Phase on the  

E-Print Network (OSTI)

with respect to the assumption of a cloud containing solely liquid or ice phase particles. The analyses suggest liquid phase (or pure ice phase) is assumed for the cloud, whereas the corresponding cloud optical, optical thickness, remote sensing. I. INTRODUCTION BOTH ice and water phase particles may coexist

Baum, Bryan A.

342

ETSI CLOUD - initial standardization requirements for cloud services  

Science Conference Proceedings (OSTI)

While the technological basis for cloud services is relatively mature, the development of the market is still at an early stage. There is considerable potential, but also a number of widely held concerns which are inhibiting mainstream adoption of cloud ... Keywords: ETSI, cloud services, standardization

Karsten Oberle; Mike Fisher

2010-08-01T23:59:59.000Z

343

More Observations of Small Funnel Clouds and Other Tubular Clouds  

Science Conference Proceedings (OSTI)

In this brief contribution, photographic documentation is provided of a variety of small, tubular-shaped clouds and of a small funnel cloud pendant from a convective cloud that appears to have been modified by flow over high-altitude mountains in ...

Howard B. Bluestein

2005-12-01T23:59:59.000Z

344

Observations of Cloud-Top Entrainment in Marine Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

Measurements of the thermodynamic and dynamic properties of entrainment events in marine stratocumulus are used to explain why cloud-top entrainment instability may not lead to the breakup of the clouds and to define the role of cloud-top ...

Qing Wang; Bruce A. Albrecht

1994-06-01T23:59:59.000Z

345

The Magellan Final Report on Cloud Computing  

E-Print Network (OSTI)

resources. 1. Finding Tropical Cyclones on a Cloud Computing2010 2. Finding Tropical Cyclones on Clouds, D. Hasenkamp

Coghlan, Susan

2013-01-01T23:59:59.000Z

346

Formation and Development of Nocturnal Boundary Layer Clouds over the Southern Great Plains  

Science Conference Proceedings (OSTI)

The formation and evolution of nocturnal boundary layer clouds over land are studied using a simple well-mixed boundary layer theory. By analyzing the deepening rate of the mixed layer depth based on the turbulent kinetic energy budget of the ...

Ping Zhu; Bruce Albrecht; Jon Gottschalck

2001-06-01T23:59:59.000Z

347

Internet ware cloud computing :Challenges  

E-Print Network (OSTI)

After decades of engineering development and infrastructural investment, Internet connections have become commodity product in many countries, and Internet scale "cloud computing" has started to compete with traditional software business through its technological advantages and economy of scale. Cloud computing is a promising enabling technology of Internet ware Cloud Computing is termed as the next big thing in the modern corporate world. Apart from the present day software and technologies, cloud computing will have a growing impact on enterprise IT and business activities in many large organizations. This paper provides an insight to cloud computing, its impacts and discusses various issues that business organizations face while implementing cloud computing. Further, it recommends various strategies that organizations need to adopt while migrating to cloud computing. The purpose of this paper is to develop an understanding of cloud computing in the modern world and its impact on organizations and businesse...

Qamar, S; Singh, Mrityunjay

2010-01-01T23:59:59.000Z

348

Mechanisms of Banner Cloud Formation  

Science Conference Proceedings (OSTI)

Banner clouds are clouds in the lee of steep mountains or sharp ridges. Their formation has previously been hypothesized as due to three different mechanisms: (i) vertical uplift in a lee vortex (which has a horizontal axis), (ii) adiabatic ...

Matthias Voigt; Volkmar Wirth

2013-11-01T23:59:59.000Z

349

Remote Sensing of Cloud Parameters  

Science Conference Proceedings (OSTI)

Day and night mapping of the global distributions of the horizontal cloud covers and the corresponding cloud-top pressure levels are derived from the same set of infrared radiance data used to retrieve clear-column temperature profiles. General ...

Moustafa T. Chahine

1982-01-01T23:59:59.000Z

350

A Computer for the Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

Computer for the Clouds A Computer for the Clouds August 1, 2008 By PHILIP E. ROSS Columnist IEEE Spectrum: Inside Technology In May an IBM-built supercomputer called Roadrunner...

351

Supersaturation Intermittency in Turbulent Clouds  

Science Conference Proceedings (OSTI)

It is hypothesized that bursts of high supersaturation are produced in turbulent, convective clouds through interactions between cloud droplets and the small-scale structure of atmospheric turbulence. This hypothesis is based on the observation ...

Raymond A. Shaw

2000-10-01T23:59:59.000Z

352

Ash cloud aviation advisories  

SciTech Connect

During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast Asia, India and beyond. The low-level eruptions (< 7 km) and quasi-steady-state venting produced a plume which generally dispersed to the north and east throughout the support period. Modeling the sequence of eruptions presented a unique challenge. Although the initial approach proved viable, further refinement is necessary and possible. A distinct need exists to quantify eruptions consistently such that ``relative`` ash concentrations relate to specific aviation hazard categories.

Sullivan, T.J.; Ellis, J.S. [Lawrence Livermore National Lab., CA (United States); Schalk, W.W.; Nasstrom, J.S. [EG and G, Inc., Pleasanton, CA (United States)

1992-06-25T23:59:59.000Z

353

NIST Cloud Computing Related Publications  

Science Conference Proceedings (OSTI)

... Challenging Security Requirements for US Government Cloud Computing Adoption", December 2012 C. Dabrowski and K. Mills, "VM Leakage and ...

2013-07-31T23:59:59.000Z

354

Single-Column Modeling A Stratiform Cloud Parameterization for General Circulation Models  

NLE Websites -- All DOE Office Websites (Extended Search)

A Stratiform Cloud Parameterization A Stratiform Cloud Parameterization for General Circulation Models S. J. Ghan and L. R. Leung Pacific Northwest Laboratory Richland, WA 99352 C. C. Chuang and J. E. Penner Lawrence Livermore National Laboratory : Livermore. CA 94550 J. McCaa University of Washington Seattle, Washington The crude treatment of clouds in general circulation models (GCMs) is widely recognized as a major limitation in applying these models to predictions of global climate change. The purpose of this project is to develop in GCMs a stratiform cloud parameterization that expresses clouds in terms of bulk microphysical properties and their subgrid variability. Figure 1 summarizes the various cloud variables and their interactions. Precipitating cloud species are distinguished from non-precipitating species, and the liquid phase is

355

Episodic Mixing and Buoyancy-Sorting Representations of Shallow Convection: A Diagnostic Study  

Science Conference Proceedings (OSTI)

Episodic mixing and buoyancy-sorting (EMBS) models have been proposed as a physically more realistic alternative to entraining plume models of cumulus convection. Applying these models to shallow nonprecipitating clouds requires assumptions about ...

Ming Zhao; Philip H. Austin

2003-04-01T23:59:59.000Z

356

Response of a Subtropical Stratocumulus-Capped Mixed Layer to Climate and Aerosol Changes  

Science Conference Proceedings (OSTI)

In this paper, an idealized framework based on a cloud-topped mixed layer model is developed for investigating feedbacks between subtropical stratocumulus (Sc) and global warming. The two principal control parameters are Sc-region sea surface ...

Peter Caldwell; Christopher S. Bretherton

2009-01-01T23:59:59.000Z

357

Contract RBAC in cloud computing  

Science Conference Proceedings (OSTI)

Cloud computing is a fast growing field, which is arguably a new computing paradigm. In cloud computing, computing resources are provided as services over the Internet and users can access resources based on their payments. The issue of access control ... Keywords: Cloud computing, Contract, Contract RBAC, Datacenter, RBAC

Hsing-Chung (Jack) Chen, Marsha Anjanette Violetta, Cheng-Ying Yang

2013-11-01T23:59:59.000Z

358

Improving Utilization of Infrastructure Clouds  

Science Conference Proceedings (OSTI)

A key advantage of infrastructure-as-a-service (IaaS) clouds is providing users on-demand access to resources. To provide on-demand access, however, cloud providers must either significantly overprovision their infrastructure (and pay a high price for ... Keywords: Cloud Computing, Infrastructure-as-a-Service, High Throughput Computing

Paul Marshall; Kate Keahey; Tim Freeman

2011-05-01T23:59:59.000Z

359

Parameterizing Vertically Coherent Cloud Distributions  

Science Conference Proceedings (OSTI)

A parameterization for specifying subgrid-scale cloud distributions in atmospheric models is developed. The fractional area of a grid-scale column in which clouds from two levels overlap (i.e., the cloud overlap probability) is described in terms ...

John W. Bergman; Philip J. Rasch

2002-07-01T23:59:59.000Z

360

Numerical Experiments on the Dynamics of the Cloud–Environment Interface: Small Cumulus in a Shear-Free Environment  

Science Conference Proceedings (OSTI)

We report herein high resolution two-dimensional numerical experiments on the dynamics of the mixing between the environment and a small cumulus cloud in the absence of shear. The current paper extends the work of Klaassen and Clark. Serious ...

Wojciech W. Grabowski

1989-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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.


361

A New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part I: Description  

Science Conference Proceedings (OSTI)

A new double-moment bulk microphysics scheme predicting the number concentrations and mixing ratios of four hydrometeor species (droplets, cloud ice, rain, snow) is described. New physically based parameterizations are developed for simulating ...

H. Morrison; J. A. Curry; V. I. Khvorostyanov

2005-06-01T23:59:59.000Z

362

A Smooth Cloud Model  

Science Conference Proceedings (OSTI)

In this paper a large-eddy “smooth” cloud (SC) model will be presented with smooth implying that the entire model converges under a Newton-based solution procedure or that time scales within the SC model are being resolved. Besides ensuring that ...

J. M. Reisner; C. A. Jeffery

2009-06-01T23:59:59.000Z

363

Cumulus Cloud Properties Derived Using Landsat Satellite Data  

Science Conference Proceedings (OSTI)

Landsat Multispectral Scanner (MSS) digital data are used to remotely sense cumulus cloud properties such as cloud fraction and cloud reflectance, along with the distribution of cloud number and cloud fraction as a function of cloud size. The ...

Bruce A. Wielicki; Ronald M. Welch

1986-03-01T23:59:59.000Z

364

Environmental control of cloud-to-ground lightning polarity in severe storms  

E-Print Network (OSTI)

In this study, it is hypothesized that the mesoscale environment can indirectly control the cloud-to-ground (CG) lightning polarity of severe storms by directly affecting their structural, dynamical, and microphysical properties, which in turn directly control cloud electrification and CG flash polarity. A more specific hypothesis, which has been supported by past observational and laboratory charging studies, suggests that broad, strong updrafts and associated large liquid water contents in severe storms lead to enhanced positive charging of graupel and hail via the noninductive charging mechanism, the generation of an inverted charge structure, and increased positive CG lightning production. The corollary is that environmental conditions favoring these kinematic and microphysical characteristics should support severe storms generating an anomalously high (> 25%) percentage of positive CG lightning (i.e., positive storms), while environmental conditions relatively less favorable should sustain storms characterized by a typical (? 25%) percentage of positive CG lightning (i.e., negative storms). Forty-eight inflow proximity soundings were analyzed to characterize the environments of nine distinct mesoscale regions of severe storms (four positive and five negative) on six days during May – June 2002 over the central United States. This analysis clearly demonstrated significant and systematic differences in the mesoscale environments of positive and negative storms, which were consistent with the stated hypothesis. When compared to negative storms, positive storms occurred in environments associated with a drier low to midtroposphere, higher cloud base height, smaller warm cloud depth, stronger conditional instability, larger 0-3 km AGL wind shear, stronger 0-2 km AGL storm-relative wind speed, and larger buoyancy in the mixed-phase zone, at a statistically significant level. Differences in the warm cloud depth of positive and negative storms were by far the most dramatic, suggesting an important role for this parameter in controlling CG lightning polarity. Subjective visual inspection of radar imagery revealed no strong relationship between convective mode and CG lightning polarity, and also illustrated that positive and negative severe storms can be equally intense.

Buffalo, Kurt Matthew

2007-12-01T23:59:59.000Z

365

Environmental control of cloud-to-ground lightning polarity in severe storms  

E-Print Network (OSTI)

In this study, it is hypothesized that the mesoscale environment can indirectly control the cloud-to-ground (CG) lightning polarity of severe storms by directly affecting their structural, dynamical, and microphysical properties, which in turn directly control cloud electrification and CG flash polarity. A more specific hypothesis, which has been supported by past observational and laboratory charging studies, suggests that broad, strong updrafts and associated large liquid water contents in severe storms lead to enhanced positive charging of graupel and hail via the noninductive charging mechanism, the generation of an inverted charge structure, and increased positive CG lightning production. The corollary is that environmental conditions favoring these kinematic and microphysical characteristics should support severe storms generating an anomalously high (> 25%) percentage of positive CG lightning (i.e., positive storms), while environmental conditions relatively less favorable should sustain storms characterized by a typical (? 25%) percentage of positive CG lightning (i.e., negative storms). Forty-eight inflow proximity soundings were analyzed to characterize the environments of nine distinct mesoscale regions of severe storms (four positive and five negative) on six days during May - June 2002 over the central United States. This analysis clearly demonstrated significant and systematic differences in the mesoscale environments of positive and negative storms, which were consistent with the stated hypothesis. When compared to negative storms, positive storms occurred in environments associated with a drier low to midtroposphere, higher cloud base height, smaller warm cloud depth, stronger conditional instability, larger 0-3 km AGL wind shear, stronger 0-2 km AGL storm-relative wind speed, and larger buoyancy in the mixed-phase zone, at a statistically significant level. Differences in the warm cloud depth of positive and negative storms were by far the most dramatic, suggesting an important role for this parameter in controlling CG lightning polarity. Subjective visual inspection of radar imagery revealed no strong relationship between convective mode and CG lightning polarity, and also illustrated that positive and negative severe storms can be equally intense.

Buffalo, Kurt Matthew

2007-12-01T23:59:59.000Z

366

An Investigation of Ice Production Mechanisms in Small Cumuliform Clouds Using a 3D Model with Explicit Microphysics. Part II: Case Study of New Mexico Cumulus Clouds  

Science Conference Proceedings (OSTI)

A new 3D model with explicit liquid- and ice-phase microphysics and a detailed treatment of ice nucleation and multiplication processes is applied to study ice formation and evolution in cumulus clouds. Simulation results are compared with in ...

Mikhail Ovtchinnikov; Yefim L. Kogan; Alan M. Blyth

2000-09-01T23:59:59.000Z

367

Diurnal effects in the composition of cirrus clouds Kenneth Sassen,1  

E-Print Network (OSTI)

measurements discriminate cloud phase and yield indications of ice particle shape and orientation [Sassen 2003; published 30 May 2003. [1] Extended (7-y) polarization lidar data, which are sensitive to ice parameterizations that treat the diurnal frequen- cies of some obvious cloud candidates such as cumulo- nimbus

Liou, K. N.

368

Statistical cloud coverage as a function of cloud optical thickness  

Science Conference Proceedings (OSTI)

The time-averaged, daylight fractional statistical cloud coverages as a function of cloud optical thickness and selected values of cloud transmission were determined for various geographic areas using D1 data from the International Satellite Cloud Climatology Project (ISCCP). The regions of interest chosen for this report are: global earth, global sea, global land, global coast, and the six 30{degree}-latitude bands over sea, over land, and over coast with longitude 0{degree}--360{degree}. This statistical information is deduced from data determined from satellite measurements of terrestrial, atmospheric and cloud properties by the International Satellite Cloud Climatology Project. In particular the results are based on the ISCCP D1 data base.

Brower, K.L.

1998-07-01T23:59:59.000Z

369

Hupmobile cloud chamber parameters  

SciTech Connect

The accompanying table lists the presently selected parameters for the twelve cloud chambers. The chambers are numbered consecutively from 4 through 15 as they are lined up in the bunker. The lowest number is closest to the source. All except the first chamber have some thin metal filters to attenuate the flux and harden the spectrum. Cloud chambers 10, 12, and 14 are shielded by a collimator with about 200 pinholes in it. The flux in these chambers is attenuated by the ratio of the pinhole area to total beam area which is a factor of 50. Various gases and gas pressures are used to obtain suitable track lengths and interaction cross sections. Neon, argon, and krypton are used to obtain photo electrons. Hydrogen is used to obtain Compton electrons.

Hansen, N. E.

1967-09-28T23:59:59.000Z

370

FORMATION OF TURBULENT AND MAGNETIZED MOLECULAR CLOUDS VIA ACCRETION FLOWS OF H I CLOUDS  

Science Conference Proceedings (OSTI)

Using three-dimensional magnetohydrodynamic simulations, including the effects of radiative cooling/heating, chemical reactions, and thermal conduction, we investigate the formation of molecular clouds in the multi-phase interstellar medium. As suggested by recent observations, we consider the formation of molecular clouds due to accretion of H I clouds. Our simulations show that the initial H I medium is piled up behind the shock waves induced by accretion flows. Since the initial medium is highly inhomogeneous as a consequence of thermal instability, a newly formed molecular cloud becomes very turbulent owing to the development of the Richtmyer-Meshkov instability. The kinetic energy of the turbulence dominates the thermal, magnetic, and gravitational energies throughout the entire 10 Myr evolution. However, the kinetic energy measured using CO-fraction-weighted densities is comparable to the other energies, once the CO molecules are sufficiently formed as a result of UV shielding. This suggests that the true kinetic energy of turbulence in molecular clouds as a whole can be much larger than the kinetic energy of turbulence estimated using line widths of molecular emission. We find that clumps in a molecular cloud show the following statistically homogeneous evolution: the typical plasma {beta} of the clumps is roughly constant ({beta}) {approx_equal} 0.4; the size-velocity dispersion relation is {Delta}v {approx_equal} 1.5 km s{sup -1} (l/1 pc){sup 0.5}, irrespective of the density; the clumps evolve toward magnetically supercritical, gravitationally unstable cores; and the clumps seem to evolve into cores that satisfy the condition for fragmentation into binaries. These statistical properties may represent the initial conditions of star formation.

Inoue, Tsuyoshi [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Chuou-ku, Sagamihara 252-5258 (Japan); Inutsuka, Shu-ichiro, E-mail: inouety@phys.aoyama.ac.jp [Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

2012-11-01T23:59:59.000Z

371

An Automated Cirrus Cloud Detection Method for a Ground-Based Cloud Image  

Science Conference Proceedings (OSTI)

Cloud detection is a basic research for achieving cloud-cover state and other cloud characteristics. Because of the influence of sunlight, the brightness of sky background on the ground-based cloud image is usually nonuniform, which increases the ...

Jun Yang; Weitao Lu; Ying Ma; Wen Yao

2012-04-01T23:59:59.000Z

372

A Cloud-Resolving Model with an Adaptive Vertical Grid for Boundary Layer Clouds  

Science Conference Proceedings (OSTI)

Accurate cloud-resolving model simulations of cloud cover and cloud water content for boundary layer clouds are difficult to achieve without vertical grid spacing well below 100 m, especially for inversion-topped stratocumulus. The need for fine ...

Roger Marchand; Thomas Ackerman

2011-05-01T23:59:59.000Z

373

Preliminary definition of Barstow standard cloud model  

DOE Green Energy (OSTI)

The motion of cloud shadows across a collector field for a central receiver solar power plant can affect the design of such a facility. Cloud models were developed to be used for basis of design in technology areas. The first effect, that of the temperature gradient, is simulated by postulating the worst case cloud situation. The cyclic effects require realistic cloud shadow time histories for simulation. Cloud shadow models were developed to determine probable cloud type, the cloud area and shape, cloud velocity and cloud-to-cloud spacing. The probability of cloud occurrence is estimated. A collector field computer program is run to determine the effect of cloud variables on collector field power delivery capability. Recommendation of cloud models to be used for basis of design are then made.

None

1978-04-05T23:59:59.000Z

374

CloudCast: Cloud Computing for Short-Term Weather Forecasts  

Science Conference Proceedings (OSTI)

CloudCast provides clients with personalized short-term weather forecasts based on their current location using cloud services

Dilip Kumar Krishnappa; David Irwin; Eric Lyons; Michael Zink

2013-01-01T23:59:59.000Z

375

Cumulus Clouds and Reflected Sunlight  

NLE Websites -- All DOE Office Websites (Extended Search)

Cumulus Clouds and Reflected Sunlight Cumulus Clouds and Reflected Sunlight from Landsat ETM+ G. Wen and L. Oreopoulos National Aeronautics and Space Administration Goddard Space Flight Center University of Maryland Baltimore County Joint Center of Earth System Technology Greenbelt, Maryland R. F. Cahalan and S. C. Tsay National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland Introduction Cumulus clouds attenuate solar radiation casting shows on the ground. Cumulus clouds can also enhance solar radiation in the clear region nearby. The enhancement of down-welling solar radiation has been observed at the ground level in the clear region near cumulus clouds (Mims and Frederick 1994). The additional diffuse radiation source from cumulus clouds makes the clear gaps appear to be

376

Size of Cloud from Shadow  

NLE Websites -- All DOE Office Websites (Extended Search)

Size of Cloud from Shadow Size of Cloud from Shadow Name: mike Status: other Grade: other Location: N/A Country: USA Date: Summer 2011 Question: I see a cloud and I see its shadow in a field - knowing high sun angles - is there a way of telling how far away the cloud is or how big? - I am thinking if the shadow is 30' wide and the sun is at 2:00 pm- ? Replies: Hi Mike, Try this, draw a small circle representing the Sun. Somewhere below this circle and maybe to the right, draw an oblong, make this oblong bigger than the circle. Now connect the leftmost edge of the circle with the leftmost edge of the oblong with a straight line. Do the same for the rightmost edges. The oblong now represent the shadow of a cloud on the ground, and the lines represent the rays of the sun passing along the edges of the cloud.

377

Impact of Ice Crystal Roughness on Satellite Retrieved Cloud Properties  

NLE Websites -- All DOE Office Websites (Extended Search)

Ice Crystal Roughness on Satellite Retrieved Cloud Properties Ice Crystal Roughness on Satellite Retrieved Cloud Properties P. Minnis 1 , P. W. Heck 2 , R. F. Arduini 3 , R. Palikonda 3 , J. K. Ayers 3 , M. M. Khaiyer 3 , P. Yang 4 , Y. Xie 4 3 Science Systems & Applications, Inc. Hampton, VA 1 NASA Langley Research Center Hampton, VA Current Cirrus Models Inadequate Cirrus cloud optical depths Ď„ (heights z e ) are often over (under) estimated when derived from solar reflectances. In situ data suggest smaller asymmetry factors, g, than used in most retrieval models. Multi-angle measurements point to smoother phase functions than for solid, smooth xtals. Calculations show that solid crystals with roughened facets or embedded bubbles --both observed in real cirrus particles-- yield smoother phase functions & smaller g

378

The Physics of the Marine Stratocumulus-Capped Mixed Layer  

Science Conference Proceedings (OSTI)

In order to simulate the stratocumulus-capped mixed layer, a one-dimensional stratocumulus model is developed. This model consists of five major points: 1) a one-dimensional (1D) option of the CSU Cloud/Mesoscale Model, 2) a partially diagnostic ...

Chaing Chen; William R. Cotton

1987-10-01T23:59:59.000Z

379

TC_CLOUD_REGIME.cdr  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical cloud properties as a function of regime Regimes? Monsoon versus Break * Different synoptic vertical velocity profiles - Changes convective inhibition, corresponding...

380

Service Availability in Cloud Computing.  

E-Print Network (OSTI)

?? Cloud computing provides access to on-demand computing resources and storage space, whereby applications and data are hosted with data centers managed by third parties,… (more)

Adegoke, Adekunle

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

China Total Cloud Amount Trends  

NLE Websites -- All DOE Office Websites (Extended Search)

Trends in Total Cloud Amount Over China DOI: 10.3334CDIACcli.008 data Data image Graphics Investigator Dale P. Kaiser Carbon Dioxide Information Analysis Center, Environmental...

382

Cloud, Surface Temperature, and Outgoing Longwave Radiation for the Period from 1979 to 1990  

Science Conference Proceedings (OSTI)

Quasi-biennial global, midlatitude, and tropical oscillations were observed using top-of-the-atmosphere outgoing longwave radiation (OLR), surface air temperature (SAT), and cloud amount for the period from 1979 to 1989. The in-phase quasi-...

H. Lee Kyle; Mitchell Weiss; Philip Ardanuy

1995-11-01T23:59:59.000Z

383

Characteristics of Precipitation, Cloud, and Latent Heating Associated with the Madden–Julian Oscillation  

Science Conference Proceedings (OSTI)

This study investigates the evolution of cloud and rainfall structures associated with Madden–Julian oscillation (MJO) using Tropical Rainfall Measuring Mission (TRMM) data. Two complementary indices are used to define MJO phases. Joint ...

K-M. Lau; H-T. Wu

2010-02-01T23:59:59.000Z

384

Reproducibility by Climate Models of Cloud Radiative Forcing Associated with Tropical Convection  

Science Conference Proceedings (OSTI)

In this study, cloud radiative forcing (CRF) associated with convective activity over tropical oceans is analyzed for monthly mean data from twentieth-century simulations of 18 climate models participating in phase 3 of the Coupled Model ...

Hiroki Ichikawa; Hirohiko Masunaga; Yoko Tsushima; Hiroshi Kanzawa

2012-02-01T23:59:59.000Z

385

Wavelet Analysis of Simulated Tropical Convective Cloud Systems. Part I: Basic Analysis  

Science Conference Proceedings (OSTI)

A wavelet analysis of a three-dimensional 7-day explicit simulation of the tropical cloud systems in the Global Atmosphere Research Programme (GARP) Atlantic Tropical Experiment Phase III is performed. Three physically distinct regimes (squall ...

Jun-Ichi Yano; Mitchell W. Moncrieff; Xiaoqing Wu; Michio Yamada

2001-04-01T23:59:59.000Z

386

Distributions of Liquid, Vapor, and Ice in an Orographic Cloud from Field Observations  

Science Conference Proceedings (OSTI)

The phase distribution of the water mass of a cold orographic cloud into vapor, liquid, and ice is calculated from measurements made from an instrumented aircraft. The vapor values are calculated from thermodynamic measurements, and the liquid is ...

Taneil Uttal; Robert M. Rauber; Lewis O. Grant

1988-04-01T23:59:59.000Z

387

Erroneous Use of the Modified Kohler Equation in Cloud and Aerosol Physics Applications  

Science Conference Proceedings (OSTI)

The phase equilibrium equation between water vapor and a liquid droplet is an important tool of cloud physics. Although several different forms of the modified Kohler equation were derived in the past, the authors show that a thermodynamically ...

Petr Chýlek; J. G. D. Wong

1998-04-01T23:59:59.000Z

388

Sensitivity of Computed Incoming Solar Radiation at the Surface to Cloud Analyses  

Science Conference Proceedings (OSTI)

A radiation model was used to simulate daily incoming solar radiation at four ships during Phase III of GATE. The accuracy of the simulations from several different cloud analyses based on ship or satellite data was estimated by comparison with ...

John T. Ball; Marshall A. Atwater; Stephen J. Thoren

1981-04-01T23:59:59.000Z

389

Cloud Microphysical Relationships in California Marine Stratus  

Science Conference Proceedings (OSTI)

Cloud microphysical measurements off the southern California coast are presented and compared with in situ airborne measurements of cloud condensation nuclei (CCN) spectra. Large-scale variations in cloud droplet concentrations were due to CCN ...

James G. Hudson; Gunilla Svensson

1995-12-01T23:59:59.000Z

390

Statistical Description of Radiation Transfer in Clouds  

Science Conference Proceedings (OSTI)

The statistical characteristics of simulated cloud fields constructed based on Poisson point fluxes are studied. The input parameters of mathematical models of cloudiness include the cloud fraction and the mean horizontal size of clouds ...

Georgi A. Titov

1990-01-01T23:59:59.000Z

391

Radiative Effects of Cloud-Type Variations  

Science Conference Proceedings (OSTI)

Radiative flux changes induced by the occurrence of different cloud types are investigated using International Satellite Cloud Climatology Project cloud data and a refined radiative transfer model from National Aeronautics and Space ...

Ting Chen; William B. Rossow; Yuanchong Zhang

2000-01-01T23:59:59.000Z

392

The Visualization of Cloud Droplet Spectra  

Science Conference Proceedings (OSTI)

This paper draws attention to the use of readily available, wire cage graphics for inspecting cloud droplet spectra measured using a Forward Light-Scattering Spectrometer Probe. The high resolution cloud droplet spectra from two different clouds ...

Robert R. Czys

1989-02-01T23:59:59.000Z

393

A Survey on Cloud Provider Security  

E-Print Network (OSTI)

A Survey on Cloud Provider Security Measures Alex Pucher, Stratos Dimopoulos Abstract Cloud take advantage of this model already, but security and privacy concerns limit the further adoption agencies and start offering security certifications and separate tightly controlled "government" cloud

394

Pulse Jet Mixing Tests With Noncohesive Solids  

SciTech Connect

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid. The tests were conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants, and the test data were used to develop models predicting two measures of mixing performance for full-scale WTP vessels. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure all solids are suspended off the floor, though not fully mixed). From the cloud height, the concentration of solids at the pump inlet can be estimated. The predicted critical suspension velocity for lifting all solids is not precisely the same as the mixing requirement for 'disturbing' a sufficient volume of solids, but the values will be similar and closely related. These predictive models were successfully benchmarked against larger scale tests and compared well with results from computational fluid dynamics simulations. The application of the models to assess mixing in WTP vessels is illustrated in examples for 13 distinct designs and selected operational conditions. The values selected for these examples are not final; thus, the estimates of performance should not be interpreted as final conclusions of design adequacy or inadequacy. However, this work does reveal that several vessels may require adjustments to design, operating features, or waste feed properties to ensure confidence in operation. The models described in this report will prove to be valuable engineering tools to evaluate options as designs are finalized for the WTP. Revision 1 refines data sets used for model development and summarizes models developed since the completion of Revision 0.

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael K.; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro

2012-02-17T23:59:59.000Z

395

Diagnosis of the Net Cloud Mass Flux in Gate  

Science Conference Proceedings (OSTI)

A diagnostic analysis of the net cloud mass flux for the mean state of Phase III is presented. In the upper troposphere, the environmental mass flux is shown to be slightly larger than the adiabatic sinking motion required by radiative cooling. ...

Yi-Leng Chen

1985-08-01T23:59:59.000Z

396

The Impact of the Ice Phase and Radiation on a Midlatitude Squall Line System  

Science Conference Proceedings (OSTI)

A two-dimensional cloud model is used to study the interrelationships among cloud microphysics, radiation, and dynamics in a midlatitude broken-line squall system. The impact of the ice phase, longwave and shortwave radiation on the dynamic and ...

Hung-Neng S. Chin

1994-11-01T23:59:59.000Z

397

Advanced Mixing Models  

Propose mixing indicators. Turbulence kinetic energy ... (Turbulence intensity observed at Point 8 in Tank B & C) Advanced Mixing Models. Computational Sciences. 13.

398

NIST Joint Cloud and Big Data Workshop  

Science Conference Proceedings (OSTI)

NIST Joint Cloud and Big Data Workshop. Purpose: ... The second and third days of the workshop focused on the intersection of Cloud and Big Data. ...

2013-01-31T23:59:59.000Z

399

6.1 Cloud Management Broker  

Science Conference Proceedings (OSTI)

... the cloud-management-broker programming or human interface, and ... broker notifies cloud-user with error specifics or ... Transient errors can be retried ...

2010-11-02T23:59:59.000Z

400

Radiative Effects of Cloud Inhomogeneity and  

NLE Websites -- All DOE Office Websites (Extended Search)

cloud-overlap assumptions and optical property approximations (Del Genio et al. 1996; Fowler and Randall 1996; Liang and Wang 1997). While GCMs require convection and cloud...

Note: This page contains sample records for the topic "mixed phase cloud" 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

Cloud Computing Towards Technological Convergence  

Science Conference Proceedings (OSTI)

With the popularization and improvement of social and industrial IT development, information appears to explosively increase, and people put much higher expectations on the services of computing, communication and network. Today's public communication ... Keywords: Architectural Strategies, Cloud Computing, Cloud Environments, Communication Network, Computing, Convergence

P. Sasikala

2011-10-01T23:59:59.000Z

402

Enabling cloud interoperability with COMPSs  

Science Conference Proceedings (OSTI)

The advent of Cloud computing has given to researchers the ability to access resources that satisfy their growing needs, which could not be satisfied by traditional computing resources such as PCs and locally managed clusters. On the other side, such ... Keywords: PaaS, cloud computing, data mining, parallel programming models

Fabrizio Marozzo; Francesc Lordan; Roger Rafanell; Daniele Lezzi; Domenico Talia; Rosa M. Badia

2012-08-01T23:59:59.000Z

403

ARM - Measurement - Cloud base height  

NLE Websites -- All DOE Office Websites (Extended Search)

base height base 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 : Cloud base height For a given cloud or cloud layer, the lowest level of the atmosphere where cloud properties are detectable. Categories Cloud 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 BLC : Belfort Laser Ceilometer MPL : Micropulse Lidar MWRP : Microwave Radiometer Profiler RL : Raman Lidar VCEIL : Vaisala Ceilometer External Instruments NOAASURF : NOAA Surface Meteorology Data, collected by NWS and NCDC

404

ARM - Measurement - Cloud ice particle  

NLE Websites -- All DOE Office Websites (Extended Search)

ice particle ice particle 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 : Cloud ice particle Particles made of ice found in clouds. Categories Cloud 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 MET : Surface Meteorological Instrumentation Field Campaign Instruments REPLICATOR : Balloon-borne Ice Crystal Replicator CPI : Cloud Particle Imager CVI-AIR : Counterflow Virtual Impactor LEARJET : Lear Jet PARTIMG : Particle imager UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments

405

TWP Island Cloud Trail Studies  

NLE Websites -- All DOE Office Websites (Extended Search)

Pacific Island Cloud Trail Studies Pacific Island Cloud Trail Studies W. M. Porch Los Alamos National Laboratory Los Alamos, New Mexico S. Winiecki University of Chicago Chicago, Illinois Introduction Images and surface temperature measurements from the U.S. Department of Energy (DOE) Multi- spectral Thermal Imaging (MTI) satellite are combined with geostationary meteorological satellite (GMS) images during 2000 and 2001 to better understand cloud trail formation characteristics from the Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) site. Figure 1 shows a comparison on two consecutive days in December 2000. The day for which a cloud trail developed was more moist and cooler at the altitude the cloud developed (about 600 m) and there was very little

406

ARM - Measurement - Cloud condensation nuclei  

NLE Websites -- All DOE Office Websites (Extended Search)

condensation nuclei condensation nuclei 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 : Cloud condensation nuclei Small particles (typically 0.0002 mm, or 1/100 th the size of a cloud droplet) about which cloud droplets coalesce. Categories Aerosols, Cloud 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 AOS : Aerosol Observing System CCN : Cloud Condensation Nuclei Particle Counter Field Campaign Instruments AOS : Aerosol Observing System

407

Cloud Computing: Exploring the scope  

E-Print Network (OSTI)

Cloud computing refers a paradigm shift to overall IT solutions while raising the accessibility, scalability and effectiveness through its enabling technologies. However, migrated cloud platforms and services cost benefits as well as performances are neither clear nor summarized. Globalization and the recessionary economic times have not only raised the bar of a better IT delivery models but also have given access to technology enabled services via internet. Cloud computing has vast potential in terms of lean Retail methodologies that can minimize the operational cost by using the third party based IT capabilities, as a service. It will not only increase the ROI but will also help in lowering the total cost of ownership. In this paper we have tried to compare the cloud computing cost benefits with the actual premise cost which an organization incurs normally. However, in spite of the cost benefits, many IT professional believe that the latest model i.e. "cloud computing" has risks and security concerns. This ...

Pandey, Abhinav; Tandon, Ankit; Maurya, Brajesh Kr; Kushwaha, Upendra

2010-01-01T23:59:59.000Z

408

Zenith Radiance Retrieval of Cloud Properties  

NLE Websites -- All DOE Office Websites (Extended Search)

retrievals of cloud properties retrievals of cloud properties from the AMF/COPS campaign Preliminary retrievals of cloud properties from the AMF/COPS campaign Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC The cloud optical properties of interest are: The cloud optical properties of interest are: * Cloud optical depth Ď„ - the great unknown * Radiative cloud fraction * Cloud effective drop size, r eff * Cloud optical depth Ď„ - the great unknown * Radiative cloud fraction * Cloud effective drop size, r eff Ď„ = 3 2 LWP r eff r eff in ÎĽm, LWP in g/m 2 The 2-ch narrow-field-of-view radiometer (2NFOV) The 2-ch narrow-field-of-view radiometer

409

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system  

SciTech Connect

We have initiated studies that include radiation model validation, improved treatment of the three-dimensional structure of cloud-radiation interactions, and sensitivity runs that will unravel the role of cloud-convection-radiation interactions in the Pacific Sear Surface Temperatures and the overlying Walker and Hadley circulation. The research program is divided into three phases: (1) radiation, (2) cloud parameterization issues; (3) feedback and ocean-atmosphere interactions.

Ramanathan, V.; Barnett, T.P.

1992-03-05T23:59:59.000Z

410

Mission to planet Earth: Role of clouds and radiation in climate  

SciTech Connect

The role of clouds in modifying the earth`s radiation balance is well recognized as a key uncertainty in predicting any potential future climate change. This statement is true whether the climate change of interest is caused by changing emissions of greenhouse gases and sulfates, deforestation, ozone depletion, volcanic eruptions, or changes in the solar constant. This paper presents and overview of the role of the National Aeronautics and Space Administration`s Earth Observing System (EOR) satellite data in understanding the role of clouds in the global climate system. The paper gives a brief summary of the cloud/radiation problem, and discusses the critical observations needed to support further investigation. The planned EOS data products are summarized, including the critical advances over current satellite cloud and radiation budget data. Key advances include simultaneous observation on cloud particle size and phase, improved detection of thin clouds and multilayer cloud systems, greatly reduced ambiguity in partially cloud-filled satellite fields of view, improved calibration and stability of satellite-observed radiances, and improved estimates of radiative fluxes at the top of the atmosphere, at the surface, and at levels within the atmosphere. outstanding sampling and remote sensing issues that effect data quality are also discussed. Finally, the EOS data are placed in the context of other satellite observations as well as the critical surface, field experiment and laboratory data needed to address the role in clouds on the climate system. I is concluded that the EOS data are a necessary but insufficient condition for solution of the scientific cloud/radiation issues. A balanced approach of satellite, field, and laboratory data will be required. These combined data can span the necessary spatial scales of global, regional, cloud cell and cloud particle physics. 137 refs., 12 fig., 4 tab.

Wielicki, B.A.; Harrison, E.F. [NASA Langley Research Center, Hampton, VA (United States)] [and others

1995-11-01T23:59:59.000Z

411

Discussion of Intelligent Cloud Computing System  

Science Conference Proceedings (OSTI)

Cloud Computing System (CCS) aims to power the next generation data centers and enables application service providers to lease data center capabilities for deploying applications depending on user Quality of Service (QoS) requirements. Huge investments ... Keywords: cloud computing system, intelligent cloud computing system, data warehouse, cloud computing management information system

Yu Hua Zhang; Jian Zhang; Wei Hua Zhang

2010-10-01T23:59:59.000Z

412

ARM - Field Campaign - Colorado: The Storm Peak Lab Cloud Property  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsColorado: The Storm Peak Lab Cloud Property Validation govCampaignsColorado: The Storm Peak Lab Cloud Property Validation Experiment (STORMVEX) Campaign Links STORMVEX Website Related Campaigns Colorado: CFH/CMH Deployment to StormVEx 2011.02.01, Mace, AMF Colorado: SP2 Deployment at StormVEx 2010.11.15, Sedlacek, AMF Colorado : Cavity Attenuated Phase Shift 2010.11.15, Massoli, AMF Colorado: Infrared Thermometer (IRT) 2010.11.15, Mace, AMF Colorado: StormVEX Aerosol Size Distribution 2010.11.15, Hallar, AMF Colorado: Direct Measurements of Snowfall 2010.11.15, McCubbin, AMF Colorado: Thunderhead Radiative Flux Analysis Campaign 2010.11.15, Long, AMF Colorado: Ice Nuclei and Cloud Condensation Nuclei Characterization 2010.11.15, Cziczo, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA.

413

Cloud Droplet Size Distributions in Low-Level Stratiform Clouds  

Science Conference Proceedings (OSTI)

A database of stratus cloud droplet (diameter <50 ?m) size distribution parameters, derived from in situ data reported in the existing literature, was created, facilitating intercomparison among datasets and quantifying typical values and their ...

Natasha L. Miles; Johannes Verlinde; Eugene E. Clothiaux

2000-01-01T23:59:59.000Z

414

AIRS Subpixel Cloud Characterization Using MODIS Cloud Products  

Science Conference Proceedings (OSTI)

The Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS) measurements from the Earth Observing System's (EOS's) Aqua satellite enable improved global monitoring of the distribution of clouds. MODIS is ...

Jun Li; W. Paul Menzel; Fengying Sun; Timothy J. Schmit; James Gurka

2004-08-01T23:59:59.000Z

415

Icebergs in the clouds: the other risks of cloud computing  

Science Conference Proceedings (OSTI)

Cloud computing is appealing from management and efficiency perspectives, but brings risks both known and unknown. Well-known and hotly-debated information security risks, due to software vulnerabilities, insider attacks, and side-channels for example, ...

Bryan Ford

2012-06-01T23:59:59.000Z

416

The Role of Cloud Top Entrainment in Cumulus Clouds  

Science Conference Proceedings (OSTI)

The entrainment process and its resultant effects on the microphysics and dynamics within cumuli are not yet clearly understood. This research was undertaken to discover the role which cloud top plays in the entrainment process and to determine ...

Joey F. Boatman; August H. Auer Jr.

1983-06-01T23:59:59.000Z

417

Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics  

SciTech Connect

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

418

Total aerosol effect: forcing or radiative flux perturbation?  

E-Print Network (OSTI)

heterogeneous ice nucleation in mixed-phase clouds, Environ.interactions with mixed-phase and ice clouds can be comparedice nuclei for the indirect aerosol effect on stratiform mixed-phase

Lohmann, Ulrike

2010-01-01T23:59:59.000Z

419

Millimeter Wave Cloud Radar (MMCR) Handbook  

SciTech Connect

The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

KB Widener; K Johnson

2005-01-30T23:59:59.000Z

420

ARM - Field Campaign - Cloud IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsCloud IOP govCampaignsCloud IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Cloud IOP 1998.04.27 - 1998.05.17 Lead Scientist : Gerald Mace For data sets, see below. Summary Monday, April 27, 1998 IOP Opening Activities: Heavy rain (nearly 2.5" since 12Z 4/26/98) at the central facility (CF) dominated the first day of the Cloud Physics/Single Column Model IOP and limited the daily activities. A 1430 GMT sonde launch commenced the 3-hour sonde launch schedule at the CF and 4 boundary facilities (BFs). Scientists/Instrumentation on Site: Citation: Has arrived and is located at the Ponca City Airport. No flights are currently planned. Flights are tentatively planned for stratus sampling when precipitation ends.

Note: This page contains sample records for the topic "mixed phase cloud" 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

Clouds, Aerosols and Precipitation in  

NLE Websites -- All DOE Office Websites (Extended Search)

the Marine Boundary Layer (CAP-MBL) Graciosa Island, Azores, NE Atlantic Ocean Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010 May 2009-December 2010 Rob Wood, University of Washington Rob Wood, University of Washington AMF Deployment Team Thanks to Mark Miller: AMF Site Scientist Mark Miller: AMF Site Scientist Kim Nitschke: AMF Site Manager CAP-MBL Proposal Team Importance of Low-Clouds for Climate Imperative that we understand the processes controlling the formation, maintenance and dissipation of low clouds in order to formation, maintenance and dissipation of low clouds in order to improve their representation in climate models. Which clouds matter for climate sensitivity? Cli t F db k

422

NIST Cloud Computing Standards Roadmap  

Science Conference Proceedings (OSTI)

... in this clause is a natural extension to the ... which take advantage of the homogeneity and power of cloud ... such as WS-I) and grid standards (such as ...

2013-08-07T23:59:59.000Z

423

Fractal Statistics of Cloud Fields  

Science Conference Proceedings (OSTI)

Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM) data, with 80 and 30 m spatial resolution, respectively, have been employed to study the spatial structure of boundary-layer and intertropical convergence zone (ITCZ) clouds. The ...

Robert F. Cahalan; Joachim H. Joseph

1989-02-01T23:59:59.000Z

424

Cloud Cover and Climate Sensitivity  

Science Conference Proceedings (OSTI)

This study discusses how the sensitivity of climate may be affected by the variation of cloud cover based on the results from numerical experiments with a highly simplified, three-dimensional model of the atmospheric general circulation. The ...

Richard T. Wetherald; Syukuro Manabe

1980-07-01T23:59:59.000Z

425

Cloud computing for dynamic systems  

Science Conference Proceedings (OSTI)

Cloud computing is a fast emerging model for enabling dynamic on-demand computing and IT-based services. It promotes dynamic properties and characteristics such as scalability, agility, flexibility, virtualised and distributed on-demand computing. However, ...

Khaled Sabry

2011-11-01T23:59:59.000Z

426

Breaking the Cloud Parameterization Deadlock  

Science Conference Proceedings (OSTI)

A key factor limiting the reliability of simulations of anthropogenic climate change is the inability to accurately represent the various effects of clouds on climate. Despite the best efforts of the community, the problem has resisted solution ...

David Randall; Marat Khairoutdinov; Akio Arakawa; Wojciech Grabowski

2003-11-01T23:59:59.000Z

427

The Hercules-Aquila Cloud  

E-Print Network (OSTI)

We present evidence for a substantial overdensity of stars in the direction of the constellations of Hercules and Aquila. The Cloud is centered at a Galactic longitude of about 40 degrees and extends above and below the Galactic plane by at least 50 degrees. Given its off-centeredness and height, it is unlikely that the Hercules-Aquila Cloud is related to the bulge or thick disk. More likely, this is a new structural component of the Galaxy that passes through the disk. The Cloud stretches about 80 degrees in longitude. Its heliocentric distance lies between 10 and 20 kpc so that the extent of the Cloud in projection is roughly 20 kpc by 15 kpc. It has an absolute magnitude of -13 and its stellar population appears to be comparable to, but somewhat more metal-rich than, M92.

Belokurov, V; Bell, E F; Irwin, M J; Hewett, P C; Koposov, S; Rockosi, C M; Gilmore, G; Zucker, D B; Fellhauer, M; Wilkinson, M I; Bramich, D M; Vidrih, S; Rix, H W; Beers, T C; Schneider, D P; Barentine, J C; Brewington, H; Brinkmann, J; Harvanek, M; Krzesínski, J; Long, D; Pan, K; Snedden, S A; Malanushenko, O; Malanushenko, V

2007-01-01T23:59:59.000Z

428

The Hercules-Aquila Cloud  

E-Print Network (OSTI)

We present evidence for a substantial overdensity of stars in the direction of the constellations of Hercules and Aquila. The Cloud is centered at a Galactic longitude of about 40 degrees and extends above and below the Galactic plane by at least 50 degrees. Given its off-centeredness and height, it is unlikely that the Hercules-Aquila Cloud is related to the bulge or thick disk. More likely, this is a new structural component of the Galaxy that passes through the disk. The Cloud stretches about 80 degrees in longitude. Its heliocentric distance lies between 10 and 20 kpc so that the extent of the Cloud in projection is roughly 20 kpc by 15 kpc. It has an absolute magnitude of -13 and its stellar population appears to be comparable to, but somewhat more metal-rich than, M92.

V. Belokurov; N. W. Evans; E. F. Bell; M. J. Irwin; P. C. Hewett; S. Koposov; C. M. Rockosi; G. Gilmore; D. B. Zucker; M. Fellhauer; M. I. Wilkinson; D. M. Bramich; S. Vidrih; H. -W. Rix; T. C. Beers; D. P. Schneider; J. C. Barentine; H. Brewington; J. Brinkmann; M. Harvanek; J. Krzesinski; D. Long; K. Pan; S. A. Snedden; O. Malanushenko; V. Malanushenko

2007-01-27T23:59:59.000Z

429

Research Highlight  

NLE Websites -- All DOE Office Websites (Extended Search)

super-cooled liquid in them. If these clouds also contain ice, they are called mixed-phase clouds. Because mixed-phase clouds are particularly common in the Arctic and because...

430

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

E-Print Network (OSTI)

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

Xue, Ming

431

Marine low cloud sensitivity to an idealized climate change: The CGILS LES intercomparison  

NLE Websites -- All DOE Office Websites (Extended Search)

low low cloud sensitivity to an idealized climate change: The CGILS LES intercomparison Peter N. Blossey, 1 Christopher S. Bretherton, 1 Minghua Zhang, 2 Anning Cheng, 3 Satoshi Endo, 4 Thijs Heus, 5 Yangang Liu, 4 Adrian P. Lock, 6 Stephan R. de Roode, 7 and Kuan-Man Xu 8 Received 31 July 2012; revised 4 February 2013; accepted 20 February 2013. [1] Subtropical marine low cloud sensitivity to an idealized climate change is com- pared in six large-eddy simulation (LES) models as part of CGILS. July cloud cover is simulated at three locations over the subtropical northeast Pacific Ocean, which are typified by cold sea surface temperatures (SSTs) under well-mixed stratocumulus, cool SSTs under decoupled stratocumulus, and shallow cumulus clouds overlying warmer SSTs. The idealized climate change includes a uniform 2 K SST increase with corre- sponding moist-adiabatic warming aloft and

432

Comparison of an Experimental NOAA AVHRR Cloud Dataset with Other Observed and Forecast Cloud Datasets  

Science Conference Proceedings (OSTI)

CLAVR [cloud from AVHRR (Advanced Very High Resolution Radiometer)] is a global cloud dataset under development at NOAA/NESDIS (National Environmental Satellite, Data, and Information Service). Total cloud amount from two experimental cases, 9 ...

Yu-Tai Hou; Kenneth A. Campana; Kenneth E. Mitchell; Shi-Keng Yang; Larry L. Stowe

1993-12-01T23:59:59.000Z

433

ISCCP Cloud Properties Associated with Standard Cloud Types Identified in Individual Surface Observations  

Science Conference Proceedings (OSTI)

Individual surface weather observations from land stations and ships are compared with individual cloud retrievals of the International Satellite Cloud Climatology Project (ISCCP), stage C1, for an 8-yr period (1983–91) to relate cloud optical ...

Carole J. Hahn; William B. Rossow; Stephen G. Warren

2001-01-01T23:59:59.000Z

434

Biogeography of Tropical Montane Cloud Forests. Part II: Mapping of Orographic Cloud Immersion  

Science Conference Proceedings (OSTI)

This study details two unique methods to quantify cloud-immersion statistics for tropical montane cloud forests (TMCFs). The first technique uses a new algorithm for determining cloud-base height using Moderate Resolution Imaging ...

Udaysankar S. Nair; Salvi Asefi; Ronald M. Welch; D. K. Ray; Robert O. Lawton; Vani Starry Manoharan; Mark Mulligan; Tom L. Sever; Daniel Irwin; J. Alan Pounds

2008-08-01T23:59:59.000Z

435

Cloud-Resolving Simulation of Low-Cloud Feedback to an Increase in Sea Surface Temperature  

Science Conference Proceedings (OSTI)

This study investigates the physical mechanisms of the low cloud feedback through cloud-resolving simulations of cloud-radiative equilibrium response to an increase in sea surface temperature (SST). Six pairs of perturbed and control simulations ...

Kuan-Man Xu; Anning Cheng; Minghua Zhang

2010-03-01T23:59:59.000Z

436

Aircraft Microphysical Documentation from Cloud Base to Anvils of Hailstorm Feeder Clouds in Argentina  

Science Conference Proceedings (OSTI)

Documentation during January and February 2000 of the structure of severe convective storms in Mendoza, Argentina, with a cloud-physics jet aircraft penetrating the major feeder clouds from cloud base to the ?45°C isotherm level is reported. ...

Daniel Rosenfeld; William L. Woodley; Terrence W. Krauss; Viktor Makitov

2006-09-01T23:59:59.000Z

437

Biogeography of Tropical Montane Cloud Forests. Part I: Remote Sensing of Cloud-Base Heights  

Science Conference Proceedings (OSTI)

Cloud-base heights over tropical montane cloud forests are determined using Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products and National Centers for Environmental Prediction global tropospheric final analysis (FNL) fields. ...

Ronald M. Welch; Salvi Asefi; Jian Zeng; Udaysankar S. Nair; Qingyuan Han; Robert O. Lawton; Deepak K. Ray; Vani Starry Manoharan

2008-04-01T23:59:59.000Z

438

Estimation of Cloud Physical Parameters from Airborne Solar Spectral Reflectance Measurements for Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

A new method is proposed to retrieve various cloud physical parameters of water clouds from the solar-flux reflectances at four wavelengths measured by using the airborne Multi-channel Cloud Pyranometer (MCP) system. The MCP system was designed ...

Shoji Asano; Masataka Shiobara; Akihiro Uchiyama

1995-10-01T23:59:59.000Z

439

Arctic Cloud Characteristics as Derived from MODIS, CALIPSO, and CloudSat  

Science Conference Proceedings (OSTI)

The Moderate Resolution Imaging Spectroradiometer (MODIS), Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP), and CloudSat Cloud Profiling Radar (CPR) set of sensors, all in the Afternoon Constellation (A-Train), has been regarded as among ...

Mark Aaron Chan; Josefino C. Comiso

2013-05-01T23:59:59.000Z

440

Kinetics of Cloud Drop Formation and Its Parameterization for Cloud and Climate Models  

Science Conference Proceedings (OSTI)

To study the kinetics of drop nucleation in clouds, the integro–differential equation for integral water supersaturation in cloud is derived and analyzed. Solving the supersaturation equation with an algebraic form of the cloud condensation ...

Vitaly I. Khvorostyanov; Judith A. Curry

2008-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Observed Relationships between Arctic Longwave Cloud Forcing and Cloud Parameters Using a Neural Network  

Science Conference Proceedings (OSTI)

A neural network technique is used to quantify relationships involved in cloud–radiation feedbacks based on observations from the Surface Heat Budget of the Arctic (SHEBA) project. Sensitivities of longwave cloud forcing (CFL) to cloud parameters ...

Yonghua Chen; Filipe Aires; Jennifer A. Francis; James R. Miller

2006-08-01T23:59:59.000Z

442

An Improved Cloud Classification Algorithm Based on the SGP CART...  

NLE Websites -- All DOE Office Websites (Extended Search)

studies which need to group clouds according to cloud types, but also provides necessary information to implement different retrieval algorithms to generate integrated cloud...

443

Cloud-state-dependent Sampling in AIRS Observations based on CloudSat Cloud Classification  

Science Conference Proceedings (OSTI)

The precision, accuracy, and potential sampling biases of temperature (T) and water vapor (q) vertical profiles obtained by satellite infrared sounding instruments are highly cloud-state dependent and poorly quantified. We describe progress ...

Qing Yue; Eric J. Fetzer; Brian H. Kahn; Sun Wong; Gerald Manipon; Alexandre Guillaume; Brian Wilson

444

Mixed Waste Treatment Study  

Science Conference Proceedings (OSTI)

As part of an ongoing integrated mixed waste program, EPRI has documented nuclear utility industry experience in the on-site treatment of mixed waste. This report reviews all available exclusions/exceptions to EPA permitting requirements for environmentally responsible on-site management of mixed waste. Included is a description of emerging mixed waste treatment technologies along with a detailed evaluation of off-site treatment/disposal facilities.

1996-01-31T23:59:59.000Z

445

Argonne CNM Highlight: Mixing up surface properties  

NLE Websites -- All DOE Office Websites (Extended Search)

Mixing up surface properties Mixing up surface properties Mixed self-assembled monolayers This image was selected for the "Back Scatter" back cover feature of Physics Today, Vol. 62, No. 2 (Feb. 2009) Mixed self-assembled monolayers (SAMs) offer the intriguing possibility of tailoring wetting properties, surface energy, and other interfacial characteristics by combining suitable molecular constituents. This atomic force micrograph, 800 nm tall, shows the onset of nanoscopic phase separation in an ideally mixed two-component SAM. The small domains of each material can be distinguished with topographic contrast because of their 2-Ă… length difference. The larger domains are due to atomic terracing of the underlying gold surface. Seth Darling (CNM) and Steven Sibener (University of Chicago) are working

446

Modeling aerosol growth by aqueous chemistry in nonprecipitating stratiform cloud  

SciTech Connect

A new microphysics module based on a two-dimensional (2D) joint size distribution function representing both interstitial and cloud particles is developed and applied to studying aerosol processing in non-precipitating stratocumulus clouds. The module is implemented in a three-dimensional dynamical framework of a large-eddy simulation (LES) model and in a trajectory ensemble model (TEM). Both models are used to study the modification of sulfate aerosol by the activation - aqueous chemistry - resuspension cycle in shallow marine stratocumulus clouds. The effect of particle mixing and different size-distribution representations on modeled aerosol processing are studied in a comparison of the LES and TEM simulations with the identical microphysics treatment exposes and a comparison of TEM simulations with a 2D fixed and moving bin microphysics. Particle mixing which is represented in LES and neglected in the TEM leads to the mean relative per particle dry mass change in the TEM simulations being about 30% lower than in analogous subsample of LES domain. Particles in the final LES spectrum are mixed in from different “parcels”, some of which have experienced longer in-cloud residence times than the TEM parcels, all of which originated in the subcloud layer, have. The mean relative per particle dry mass change differs by 14% between TEM simulations with fixed and moving bin microphysics. Finally, the TEM model with the moving bin microphysics is used to evaluate assumptions about liquid water mass partitioning among activated cloud condensation nuclei (CCN) of different dry sizes. These assumptions are used in large-scale models to map the bulk aqueous chemistry sulfate production, which is largely proportional to the liquid water mass, to the changes in aerosol size distribution. It is shown that the commonly used assumptions that the droplet mass is independent of CCN size or that the droplet mass is proportional to the CCN size to the third power do not perform well in the considered case. The explicitly predicted water partitioning indicates that the mean mass of droplets participating in the models aqueous chemistry calculations is proportional to the dry CCN size.

Ovchinnikov, Mikhail; Easter, Richard C.

2010-07-29T23:59:59.000Z

447

Tropical Warm Pool International Cloud Experiment (TWP-ICE): Cloud and Rain Characteristics in the Australian Monsoon  

SciTech Connect

The impact of oceanic convection on its environment and the relationship between the characteristics of the convection and the resulting cirrus characteristics is still not understood. An intense airborne measurement campaign combined with an extensive network of ground-based observations is being planned for the region near Darwin, Northern Australia, during January-February, 2006, to address these questions. The Tropical Warm Pool – International Cloud Experiment (TWP-ICE) will be the first field program in the tropics that attempts to describe the evolution of tropical convection, including the large scale heat, moisture, and momentum budgets, while at the same time obtaining detailed observations of cloud properties and the impact of the clouds on the environment. The emphasis will be on cirrus for the cloud properties component of the experiment. Cirrus clouds are ubiquitous in the tropics and have a large impact on their environment but the properties of these clouds are poorly understood. A crucial product from this experiment will be a dataset suitable to provide the forcing and testing required by cloud-resolving models and parameterizations in global climate models. This dataset will provide the necessary link between cloud properties and the models that are attempting to simulate them. The experiment is a collaboration between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program, the Bureau of Meteorology (BoM), the National Aeronautics and Space Administration (NASA), the European Commission DG RTD-1.2, and several United States, Australian, Canadian, and European Universities. This experiment will be undertaken over a 4-week period in early 2006. January and February corresponds to the wet phase of the Australia monsoon. This season has been selected because, despite Darwin’s coastal location, the convection that occurs over and near Darwin at this time is largely of maritime origin with a large fetch over water. Based on previous experiments, the convection appears typical of maritime convection with widespread convection that has complex organization, but is not as deep or as intense as continental or coastal convection. Therefore, it is expected that the convection and cloud characteristics will be representative of conditions typical for wide areas of the tropics.

PT May; C Jakob; JH Mather

2004-05-30T23:59:59.000Z

448

Cirrus Cloud Properties Derived from POLDER-1/ADEOS Polarized Radiances: First Validation Using a Ground-Based Lidar Network  

Science Conference Proceedings (OSTI)

Bidirectional polarized reflectances measured with the POLDER-1 instrument on board Advanced Earth Observing Satellite-1 have been used to infer cloud altitude and thermodynamical phase (ice/liquid) at a global scale. This paper presents a ...

Hélčne Chepfer; Philippe Goloub; James Spinhirne; Pierre H. Flamant; Mario Lavorato; Laurent Sauvage; Gérard Brogniez; Jacques Pelon

2000-02-01T23:59:59.000Z

449

Measurements of the Total Water Content of Cirrus Clouds. Part II: Instrument Performance and Validation  

Science Conference Proceedings (OSTI)

This paper describes the performance and in-flight validation of an instrument mounted in a pallet on the NASA WB-57 research aircraft that measures the sum of gas phase and solid phase water, or total water, in cirrus clouds. Using a heated ...

E. M. Weinstock; J. B. Smith; D. Sayres; J. V. Pittman; N. Allen; J. G. Anderson

2006-11-01T23:59:59.000Z

450

Measurements of the Total Water Content of Cirrus Clouds. Part I: Instrument Details and Calibration  

Science Conference Proceedings (OSTI)

This paper describes an instrument designed to measure the sum of gas phase and solid phase water, or total water, in cirrus clouds, and to be mounted in a pallet in the underbelly of the NASA WB-57 research aircraft. The ice water content of ...

E. M. Weinstock; J. B. Smith; D. Sayres; J. R. Spackman; J. V. Pittman; N. Allen; J. Demusz; M. Greenberg; M. Rivero; L. Solomon; J. G. Anderson

2006-11-01T23:59:59.000Z

451

Carbon Dioxide and Climate: Mechanisms of Changes in Cloud  

Science Conference Proceedings (OSTI)

Changes in cloud distribution may provide a major feedback on climate change. General circulation model simulations show an upward shift of high cloud and a general reduction of free-tropospheric cloud when climate warms. The shift of high cloud ...

J. F. B. Mitchell; W. J. Ingram

1992-01-01T23:59:59.000Z

452

A Critical Review of the Australian Experience in Cloud Seeding  

Science Conference Proceedings (OSTI)

From 1947 to 1994 a number of cloud-seeding experiments were done in Australia based on the static cloud-seeding hypothesis. A critical analysis of these successive cloud-seeding experiments, coupled with microphysical observations of the clouds, ...

Brian F. Ryan; Warren D. King

1997-02-01T23:59:59.000Z

453

Influence of Cloud Condensation Nuclei on Orographic Snowfall  

Science Conference Proceedings (OSTI)

Pollution aerosols acting as cloud condensation nuclei (CCN) have the potential to alter warm rain clouds via the aerosol first and second indirect effects in which they modify the cloud droplet population, cloud lifetime and size, rainfall ...

Stephen M. Saleeby; William R. Cotton; Douglas Lowenthal; Randolph D. Borys; Melanie A. Wetzel

2009-05-01T23:59:59.000Z

454

Electron Cloud Simulations with PyECLOUD  

E-Print Network (OSTI)

PyECLOUD is a newly developed code for the simulation of the electron cloud (EC) build-up in particle accelerators. Almost entirely written in Python, it is mostly based on the physical models already used in the ECLOUD code but, thanks to the implementation of new optimized algorithms, it exhibits a significantly improved performance in accuracy, speed, reliability and flexibility. PyECLOUD simulations have been already broadly employed for benchmarking the EC observations in the Large Hadron Collider (LHC). Thanks to the new feature of running EC simulations with bunch-by-bunch length and intensity data from machine measurements, the scrubbing process of the LHC beam pipes could be reconstructed from heat load measurements in the cryogenic dipoles. In addition, PyECLOUD simulations also provide the estimation of the bunch-by-bunch energy loss, which can be compared with the measurements of the stable phase shift.

Iadarola, G

2012-01-01T23:59:59.000Z

455

ARM - Measurement - Cloud optical depth  

NLE Websites -- All DOE Office Websites (Extended Search)

optical depth optical depth 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 : Cloud optical depth Amount of light cloud droplets or ice particles prevent from passing through a column of atmosphere. Categories Cloud 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. External Instruments GOES : Geostationary Operational Environmental Satellites Field Campaign Instruments EC-CONVAIR580-BULK : Environment Canada Convair 580 Bulk Parameters GOES : Geostationary Operational Environmental Satellites

456

Ice in Clouds Experiment–Layer Clouds. Part II: Testing Characteristics of Heterogeneous Ice Formation in Lee Wave Clouds  

Science Conference Proceedings (OSTI)

Heterogeneous ice nucleation is a source of uncertainty in models that represent ice clouds. The primary goal of the Ice in Clouds Experiment–Layer Clouds (ICE-L) field campaign was to determine if a link can be demonstrated between ice ...

P. R. Field; A. J. Heymsfield; B. J. Shipway; P. J. DeMott; K. A. Pratt; D. C. Rogers; J. Stith; K. A. Prather

2012-03-01T23:59:59.000Z

457

SCALED EXPERIMENTS EVALUATING PULSE JET MIXING OF SLURRIES  

Science Conference Proceedings (OSTI)

Pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid were conducted at three geometric scales to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant. The test data will be used to develop mixing models. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate, the concentration of solids near the vessel floor and the minimum velocity predicted to lift solids can be calculated. The test objective was to observe the influence of vertically downward-directed jets on noncohesive solids in a series of scaled tanks with several bottom shapes. The test tanks and bottom shapes included small-and large-scale tanks with elliptical bottoms, a mid-scale tank with a spherical bottom, and a large-scale tank with an F&D bottom. During testing, the downward-directed jets were operated in either a steady flow condition or a pulsed (periodic) flow condition. The mobilization of the solids resulting from the jets was evaluated based on: the motion/agitation of the particulate on the tank floor and the elevation the solids reach within the tank; the height the solids material reaches in the tank is referred to as the cloud height (HC).

Bamberger, Judith A.; Meyer, Perry A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Minette, Michael J.; Burns, Carolyn A.; Baer, Ellen BK; Eakin, David E.; Elmore, Monte R.; Snyder, Sandra F.

2009-11-13T23:59:59.000Z

458

Cloud Detection with MODIS. Part II: Validation  

Science Conference Proceedings (OSTI)

An assessment of the performance of the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask algorithm for Terra and Aqua satellites is presented. The MODIS cloud mask algorithm output is compared with lidar observations from ground [...

S. A. Ackerman; R. E. Holz; R. Frey; E. W. Eloranta; B. C. Maddux; M. McGill

2008-07-01T23:59:59.000Z

459

Cloud Color and Ocean Radiant Heating  

Science Conference Proceedings (OSTI)

It is well recognized that clouds regulate the flux of solar radiation reaching the sea surface. Clouds also affect the spectral distribution of incident irradiance. Observations of spectral and total incident solar irradiance made from the ...

David A. Siegel; Toby K. Westberry; J. Carter Ohlmann

1999-04-01T23:59:59.000Z

460

Near-Global Observations of Low Clouds  

Science Conference Proceedings (OSTI)

This paper analyzes several near-global datasets of low cloud cover, including the the International Satellite Cloud Climatology Project (ISCCP) satellite observations, C. J. Hahn et al. surface-derived observations, and the National Centers for ...

Bryan C. Weare

2000-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" 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

Analytical Solutions for Cloud-Drop Concentration  

Science Conference Proceedings (OSTI)

This note compares and evaluates the analytical solutions of Squires and Twomey for cloud droplet concentration. Either solution is likely to be fairly accurate (±30%) when the slope parameter (?) of the cloud condensation nuclei distribution is ...

David B. Johnson

1981-01-01T23:59:59.000Z

462

Comparison of ISCCP and Other Cloud Amounts  

Science Conference Proceedings (OSTI)

A new 8-year global cloud climatology has been produced by the International Satellite Cloud Climatology Project (ISCCP) that provides information every 3 h at 280-km spatial resolution covering the period from July 1983 through June 1991. If ...

William B. Rossow; Alison W. Walker; Leonid C. Garder

1993-12-01T23:59:59.000Z

463

ARM - Field Campaign - Spring Cloud IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsSpring Cloud IOP govCampaignsSpring Cloud IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Spring Cloud IOP 2000.03.01 - 2000.03.26 Lead Scientist : Gerald Mace For data sets, see below. Summary The Atmospheric Radiation Measurement (ARM) Program conducted a Cloud Intensive Operational Period (IOP) in March 2000 that was the first-ever effort to document the 3-dimensional cloud field from observational data. Prior numerical studies of solar radiation propagation through the atmosphere in the presence of clouds have been limited by the necessity to use theoretical representations of clouds. Three-dimensional representations of actual clouds and their microphysical properties, such as the distribution of ice and water, had previously not been possible

464

Ground-based Microwave Cloud Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwave Cloud Tomography Microwave Cloud Tomography Experiment, SGP, May 15-June 15, 2009 Lead Scientist Dong Huang, BNL Co-Investigators Al Gasiewski, UC Boulder Maria Cadeddu, ANL Warren Wiscombe, BNL Radiation Processes Working Group March 30, 2009 multiple radiometers All good cloud radiation modelers should close their airplane window shades so as not to be corrupted by the spectacle of real 3D clouds. - Roger Davies In case you forget to do this, you see 3/30/2009 ARM RPWG 2 Effects of cloud structure on radiation 3/30/2009 ARM RPWG 3 Typical climate model - Cloud fraction & mean water content - Horizontally uniform clouds, no side radiation - Assumption on overlap Courtesy of Bernhard Mayer Cloud structure important to radiation - Cumulus (Benner & Evans 2001, Pincus et al. 2005), deep convection (DiGiuseppe &

465

Entrainment and Detrainment in Cumulus Clouds  

Science Conference Proceedings (OSTI)

Vertical redistribution of air and its properties inside convective clouds can be studied by standard thermodynamic analyses (Paluch and saturation point diagrams) if the clouds are nonprecipitating and ice free. It is shown from such analysis ...

Gregory R. Taylor; Marcia B. Baker

1991-01-01T23:59:59.000Z

466

Tropical Thermostats and Low Cloud Cover  

Science Conference Proceedings (OSTI)

The ability of subtropical stratus low cloud cover to moderate or amplify the tropical response to climate forcing such as increased CO2 is considered. Cloud radiative forcing over the subtropics is parameterized using an empirical relation ...

R. L. Miller

1997-03-01T23:59:59.000Z

467

Cloud Condensation Nuclei and Ship Tracks  

Science Conference Proceedings (OSTI)

Enhancements of droplet concentrations in clouds affected by four ships were fairly accurately predicted from ship emission factors and plume and background cloud condensation nucleus (CCN) spectra. Ship exhausts thus accounted for the increased ...

James G. Hudson; Timothy J. Garrett; Peter V. Hobbs; Scott R. Strader; Yonghong Xie; Seong Soo Yum

2000-08-01T23:59:59.000Z

468

Global Cloud Climatologies: A Historical Review  

Science Conference Proceedings (OSTI)

Accurate global cloud information is required for many climate studies, particularly for validation of climate model simulations. This paper reviews the cloud climatologies currently available, identifying and attempting to explain the ...

N. A. Hughes

1984-05-01T23:59:59.000Z

469

The Tropical Warm Pool International Cloud Experiment  

Science Conference Proceedings (OSTI)

A comprehensive dataset describing tropical cloud systems and their environmental setting and impacts has been collected during the Tropical Warm Pool International Cloud Experiment (TWP-ICE) and Aerosol and Chemical Transport in Tropical ...

Peter T. May; James H. Mather; Geraint Vaughan; Keith N. Bower; Christian Jakob; Greg M. McFarquhar; Gerald G. Mace

2008-05-01T23:59:59.000Z

470

Simultaneous Occurrence of Different Cloud Types  

Science Conference Proceedings (OSTI)

Cloud observations from land stations and from ships in the ocean are used to investigate the frequency of observation and the co-occurrence of different cloud types, and the geographical and seasonal variations of these co-occurrences. Ground-...

Stephen G. Warren; Carole J. Hahn; Julius London

1985-07-01T23:59:59.000Z

471

Radar and Radiation Properties of Ice Clouds  

Science Conference Proceedings (OSTI)

The authors derive relations of the equivalent radar reflectivity Ze and extinction coefficient ? of ice clouds and confirm the theory by in situ aircraft observations during the First International Satellite Cloud Climatology Project Regional ...

David Atlas; Sergey Y. Matrosov; Andrew J. Heymsfield; Ming-Dah Chou; David B. Wolff

1995-11-01T23:59:59.000Z

472

Scale Localization of Cloud Particle Clustering Statistics  

Science Conference Proceedings (OSTI)

Recent work has examined the spatial distribution of droplets within a cloud. Experimentally, most studies analyze interevent times from static probes flown linearly through a cloud, allowing the spatial information to be conveyed through a time ...

Michael L. Larsen

2012-11-01T23:59:59.000Z

473

Aquaplanets, Climate Sensitivity, and Low Clouds  

Science Conference Proceedings (OSTI)

Cloud effects have repeatedly been pointed out as the leading source of uncertainty in projections of future climate, yet clouds remain poorly understood and simulated in climate models. Aquaplanets provide a simplified framework for comparing ...

Brian Medeiros; Bjorn Stevens; Isaac M. Held; Ming Zhao; David L. Williamson; Jerry G. Olson; Christopher S. Bretherton

2008-10-01T23:59:59.000Z

474

Satellite Remote Sensing of Multiple Cloud Layers  

Science Conference Proceedings (OSTI)

The goals of the current study are threefold: 1) to present a multispectral, multiresolution (MSMR) methodology for analysis of scenes containing multiple cloud layers; 2) to apply the MSMR method to two multilevel cloud scenes recorded by the ...

B.A. Baum; T. Uttal; M. Poellot; T.P. Ackerman; J.M. Alvarez; J. Intrieri; D.O'C. Starr; J. Titlow; V. Tovinkere; E. Clothiaux

1995-12-01T23:59:59.000Z

475

Precipitation and Cloud Structure in Midlatitude Cyclones  

Science Conference Proceedings (OSTI)

Composite mean fields and probability distribution functions (PDFs) of rain rate, cloud type and cover, cloud-top temperature, surface wind velocity, and water vapor path (WVP) are constructed using satellite observations of midlatitude cyclones ...

Paul R. Field; Robert Wood

2007-01-01T23:59:59.000Z

476

Cloud Optical Thickness Estimation from Irradiance Measurements  

Science Conference Proceedings (OSTI)

Radiative transfer algorithms are developed to estimate the optical thickness of clouds using an irradiance detector located above, deep within, and beneath a cloud. Both monodirectional and diffuse illumination cases are considered. For each ...

H. C. Yi; N. J. McCormick; R. Sanchez

1990-11-01T23:59:59.000Z

477

Thin Cloud Length Scales Using CALIPSO and CloudSat Data  

E-Print Network (OSTI)

Thin clouds are the most difficult cloud type to observe. The recent availability of joint cloud products from the active remote sensing instruments aboard CloudSat and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) facilitates the study of these clouds. Using one of these joint cloud products, 2B-GEOPROF-Lidar, and a post-processing algorithm designed to find horizontally continuous thin clouds within the cloud product, the locations, length scales, and vertical distributions by length of thin clouds are determined. It is found that thin clouds vary in length from a few km to over 2900 km and tend to be longer in the tropical upper troposphere than lower in the atmosphere and at higher latitudes. In the upper troposphere between 0° and 40°N, over 20% of all thin cloud measurements in the 2B-GEOPROF-Lidar product are contributed by thin clouds that are longer than 500 km. In fact, in this latitude range, over 65% of all thin cloud measurements are contributed by clouds longer than 100 km. Also, thin cloud length and frequency differ between the four seasons in the year of data used here.

Solbrig, Jeremy E.

2009-08-01T23:59:59.000Z

478

SPACE4CLOUD: a tool for system performance and costevaluation of cloud systems  

Science Conference Proceedings (OSTI)

Cloud Computing is assuming a relevant role in the world of web applications and web services. Cloud technologies allow to build dynamic systems which are able to adapt their performance to workload fluctuations delegating to the Cloud Provider the intensive ... Keywords: cloud computing, model-driven software development, performance prediction

Davide Franceschelli; Danilo Ardagna; Michele Ciavotta; Elisabetta Di Nitto

2013-04-01T23:59:59.000Z

479

Standards Acceleration to Jumpstart Adoption of Cloud ...  

Science Conference Proceedings (OSTI)

... Standards Acceleration to Jumpstart Adoption of Cloud Computing (SAJACC). The goal of the SAJACC initiative is to drive ...

2013-07-02T23:59:59.000Z

480

Cloud Application Architectures: Building Applications and Infrastructure in the Cloud  

Science Conference Proceedings (OSTI)

Much is said about the advantages and risks of cloud computing, but how do you actually create a web application for this environment or migrate existing applications to it? With this book, you'll learn the programming and system administration skills ...

George Reese

2009-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "mixed phase cloud" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


481

When Clouds become Green: the Green Open Cloud Architecture  

E-Print Network (OSTI)

. They differ from Grids as explained in [2] and can be part of the next-generation data centers with ensl to the requirements of distributed applications. Cloud systems provide on-demand computing power and storage, so of the electric cost of a virtual machine in Section 2. Section 3 outlines the architecture and the components

Paris-Sud XI, Université de

482

Cloud service selection based on variability modeling  

Science Conference Proceedings (OSTI)

The selection among Cloud services is a recent problem in research and practice. The diversity of decision-relevant criteria, configurability of Cloud services and the need to involve human decision-makers require holistic support through models, methodologies ... Keywords: cloud service selection, decision-making, feature modeling, variability modeling

Erik Wittern; Jörn Kuhlenkamp; Michael Menzel

2012-11-01T23:59:59.000Z

483

The CloudBrowser web application framework  

Science Conference Proceedings (OSTI)

CloudBrowser is a web application framework that supports the development of rich Internet applications whose entire user interface and application logic resides on the server, while all client/server communication is provided by the framework. CloudBrowser ... Keywords: ajax, cloud applications, paas, remote display, server-centric, web application framework

Brian McDaniel; Godmar Back

2012-10-01T23:59:59.000Z

484

Efficient Mushroom Cloud Simulation on GPU  

Science Conference Proceedings (OSTI)

In this paper, we present a method to simulate the Mushroom Cloud efficient on GPU using advanced particle system, and our particle system is a state-preserving simulation system. We provide the visual-only model of Mushroom Cloud and we divide the Mushroom ... Keywords: Floating Point Textures, GPU (Graphics Processing Unit), Mushroom Cloud simulation, particle system, state-preserving simulation

Xingquan Cai; Jinhong Li; Zhitong Su

2008-06-01T23:59:59.000Z

485

Cloud-Cover Distributions and Correlations  

Science Conference Proceedings (OSTI)

Observations of cloud cover (in oktas or tenths) by ground-based observers have been studied to investigate the distribution of cloud-cover amounts and the correlation of cloud cover in time and space. The correlation between observations at the ...

P. A. Jones

1992-07-01T23:59:59.000Z

486

Large scale data analytics on clouds  

Science Conference Proceedings (OSTI)

We summarize important overall issues affecting use of clouds to support Data Science. We describe the mapping of different applications to HPCC and Cloud systems and the architecture that support data analytics that is interoperable between these architectures. Keywords: clouds, data science, exascale, hpcc, iterative mapreduce, mapreduce, mpi, programming paradigms

Geoffrey C. Fox

2012-10-01T23:59:59.000Z

487

Adaptive resource configuration for Cloud infrastructure management  

Science Conference Proceedings (OSTI)

To guarantee the vision of Cloud Computing QoS goals between the Cloud provider and the customer have to be dynamically met. This so-called Service Level Agreement (SLA) enactment should involve little human-based interaction in order to guarantee the ... Keywords: Autonomic Computing, Case-Based Reasoning, Cloud Computing, Knowledge management, Resource management, Rule-based system

Michael Maurer; Ivona Brandic; Rizos Sakellariou

2013-02-01T23:59:59.000Z

488

Positive perspectives on cloud security  

Science Conference Proceedings (OSTI)

The adoption of cloud computing has faced challenges and there are concerns about the risks, the loss of control of data and the assurance of security and access control. This paper aims to show that these should be viewed as requirements which need ...

Piers Wilson

2011-08-01T23:59:59.000Z

489

Autonomous Participation in Cloud Services  

Science Conference Proceedings (OSTI)

A Cyber-Physical System (CPS) is a combination of multiple physical devices connected and organised by a central controlling infrastructure using a feedback-loop mechanism. In order to increase the autonomy of CPS they must be connected to rich cloud ... Keywords: autonomic computing, service science, cyber-physical systems

Josef Spillner; Christian Piechnick; Claas Wilke; Uwe Abmann; Alexander Schill

2012-11-01T23:59:59.000Z

490