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Note: This page contains sample records for the topic "liquid water clouds" 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.


1

ARM: Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals  

DOE Data Explorer (OSTI)

Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

Maria Cadeddu

2

Thin Liquid Water Clouds: Their Importance and Our Challenge  

Science Conference Proceedings (OSTI)

Many of the clouds important to the Earth's energy balance, from the Tropics to the Arctic, contain small amounts of liquid water. Longwave and shortwave radiative fluxes are very sensitive to small perturbations of the cloud liquid water path (...

D. D. Turner; A. M. Vogelmann; K. Johnson; M. Miller; R. T. Austin; J. C. Barnard; C. Flynn; C. Long; S. A. McFarlane; K. Cady-Pereira; S. A. Clough; J. C. Chiu; M. M. Khaiyer; J. Liljegren; B. Lin; P. Minnis; A. Marshak; S. Y. Matrosov; Q. Min; W. O'Hirok; Z. Wang; W. Wiscombe

2007-02-01T23:59:59.000Z

3

Cloud Top Liquid Water from Lidar Observations of Marine Stratocumulus  

Science Conference Proceedings (OSTI)

Maine stratus clouds were simultaneously observed by nadir Nd:YAG lidar measurements and in situ cloud physics measurements. A procedure was applied to derive the two-dimensional vertical cross section of the liquid water from within the cloud ...

J. D. Spinhirne; R. Boers; W. D. Hart

1989-02-01T23:59:59.000Z

4

Spectral Density of Cloud Liquid Water Content at High Frequencies  

Science Conference Proceedings (OSTI)

Aircraft measurements of liquid water content (LWC) made at sampling frequencies of 1 and 2 kHz with a particle volume monitor (PVM) probe from horizontal traverses in stratocumulus clouds during the Southern Ocean Cloud Experiment and cumulus ...

H. Gerber; J. B. Jensen; A. B. Davis; A. Marshak; W. J. Wiscombe

2001-03-01T23:59:59.000Z

5

Cloud Liquid Water and Ice Content Retrieval by Multiwavelength Radar  

Science Conference Proceedings (OSTI)

Cloud liquid water and ice content retrieval in precipitating clouds by the differential attenuation method using a dual-wavelength radar, as a function of the wavelength pair, is first discussed. In the presence of non-Rayleigh scatterers, ...

Nicolas Gaussiat; Henri Sauvageot; Anthony J. Illingworth

2003-09-01T23:59:59.000Z

6

Cloud Liquid Water Measurements on the Armored T-28: Intercomparison between Johnson–Williams Cloud Water Meter and CSIRO (King) Liquid Water Probe  

Science Conference Proceedings (OSTI)

Comparisons are made between liquid water concentration (LWC) readings obtained from a Johnson–Williams (J–W) cloud water meter and a King (Commonwealth Scientific and Industrial Research Organisation) liquid water probe, both mounted on the ...

Rand E. Feind; Andrew G. Detwiler; Paul L. Smith

2000-12-01T23:59:59.000Z

7

Entrainment Rate, Cloud Fraction, and Liquid Water Path of PBL Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

The large eddy simulation technique is used to search for key factors in determining the entrainment rate, cloud fraction, and liquid water path in the stratocumulus-topped boundary layer (STBL), with the goal of developing simple schemes of ...

Chin-Hoh Moeng

2000-11-01T23:59:59.000Z

8

Doppler Cloud Radar Derived Drop Size Distributions in Liquid Water Stratus Clouds  

Science Conference Proceedings (OSTI)

A cloud particle size retrieval algorithm that uses radar reflectivity factor and Doppler velocity obtained by a 35-GHz Doppler radar and liquid water path estimated from microwave radiometer radiance measurements is developed to infer the size ...

Seiji Kato; Gerald G. Mace; Eugene E. Clothiaux; James C. Liljegren; Richard T. Austin

2001-10-01T23:59:59.000Z

9

Probability Density Functions of Liquid Water Path and Total Water Content of Marine Boundary Layer Clouds: Implications for Cloud Parameterization  

Science Conference Proceedings (OSTI)

Mathematical forms of probability density functions (PDFs) of liquid water path (LWP) and total water content for marine boundary layer clouds are investigated using the homogeneity, skewness, and kurtosis of PDFs of LWP obtained from observations ...

Hideaki Kawai; João Teixeira

2012-03-01T23:59:59.000Z

10

Impact of the Vertical Variation of Cloud Droplet Size on the Estimation of Cloud Liquid Water Path and Rain Detection  

Science Conference Proceedings (OSTI)

Cloud droplet effective radius (DER) and liquid water path (LWP) are two key parameters for the quantitative assessment of cloud effects on the exchange of energy and water. Chang and Li presented an algorithm using multichannel measurements made ...

Ruiyue Chen; Fu-Lung Chang; Zhanqing Li; Ralph Ferraro; Fuzhong Weng

2007-11-01T23:59:59.000Z

11

Near-Global Survey of Effective Droplet Radii in Liquid Water Clouds Using ISCCP Data  

Science Conference Proceedings (OSTI)

A global survey of cloud particle size variations can provide crucial constraints on how cloud processes determine cloud liquid water contents and their variation with temperature, and further, may indicate the magnitude of aerosol effects on ...

Qingyuan Han; William B. Rossow; Andrew A. Lacis

1994-04-01T23:59:59.000Z

12

Turbulence, Condensation, and Liquid Water Transport in Numerically Simulated Nonprecipitating Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

Condensation and turbulent liquid water transport in stratocumulus clouds involve complicated interactions between turbulence dynamics and cloud microphysical processes, and play essential roles in defining the cloud structure. This work aims at ...

Shouping Wang; Qing Wang; Graham Feingold

2003-01-01T23:59:59.000Z

13

ARM - Evaluation Product - MWR Retrievals of Cloud Liquid Water and Water  

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

ProductsMWR Retrievals of Cloud Liquid Water and ProductsMWR Retrievals of Cloud Liquid Water and Water Vapor Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : MWR Retrievals of Cloud Liquid Water and Water Vapor 2005.02.01 - 2011.04.25 Site(s) FKB GRW HFE NIM PYE SBS General Description A new algorithm is being developed for the ARM Program to derive liquid water path (LWP) and precipitable water vapor (PWV) from the 2-channel (23.8 and 31.4 GHz) microwave radiometers (MWRs) deployed at ARM climate research facilities. This algorithm utilizes the "monoRTM" radiative transfer model (http://rtweb.aer.com), a combination of both an advanced statistical and physical-iterative retrieval, and brightness temperature offsets applied before the retrieval is performed. This allows perhaps the

14

Characteristics of Supercooled Liquid Water in Clouds at Mountaintop Sites in the Colorado Rockies  

Science Conference Proceedings (OSTI)

Observations and measurements were made of supercooled liquid water in clouds which enveloped high elevation sites in the Colorado Rocky Mountains for the winters of 1980/81 through 1983/84. The observations showed that liquid water was more ...

Edward E. Hindman

1986-09-01T23:59:59.000Z

15

An Integrated Approach toward Retrieving Physically Consistent Profiles of Temperature, Humidity, and Cloud Liquid Water  

Science Conference Proceedings (OSTI)

A method is presented for deriving physically consistent profiles of temperature, humidity, and cloud liquid water content. This approach combines a ground-based multichannel microwave radiometer, a cloud radar, a lidar-ceilometer, the nearest ...

Ulrich Löhnert; Susanne Crewell; Clemens Simmer

2004-09-01T23:59:59.000Z

16

Sources of Error in Dual-Wavelength Radar Remote Sensing of Cloud Liquid Water Content  

Science Conference Proceedings (OSTI)

Dual-wavelength ratio (DWR) techniques offer the prospect of producing high-resolution mapping of cloud microphysical properties, including retrievals of cloud liquid water content (LWC) from reflectivity measured by millimeter-wavelength radars. ...

John K. Williams; J. Vivekanandan

2007-08-01T23:59:59.000Z

17

The Temperature Dependence of the Liquid Water Path of Low Clouds in the Southern Great Plains  

Science Conference Proceedings (OSTI)

Satellite observations of low-level clouds have challenged the idea that increasing liquid water content with temperature combined with constant physical thickness will lead to a negative cloud optics feedback in a decadal climate change. The ...

Anthony D. Del Genio; Audrey B. Wolf

2000-10-01T23:59:59.000Z

18

Experimental Verification of the Linear Relationship between IR Extinction and Liquid Water Content of Clouds  

Science Conference Proceedings (OSTI)

The IR extinction of clouds has been measured with a CO2 laster transmissometer (? = 10.6 ?m). Using an established linear relationship (based on the Chýlek approximation to the Mie theory) between extinction and liquid water content, the liquid ...

Alan W. Gertler; Roger L. Steele

1980-11-01T23:59:59.000Z

19

Validation of Cloud Liquid Water Path Retrievals from SEVIRI Using One Year of CloudNET Observations  

Science Conference Proceedings (OSTI)

The accuracy and precision are determined of cloud liquid water path (LWP) retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board Meteosat-8 using 1 yr of LWP retrievals from microwave radiometer (MWR) measurements of ...

R. A. Roebeling; H. M. Deneke; A. J. Feijt

2008-01-01T23:59:59.000Z

20

Modeling the Interactions between Aerosols and Liquid Water Clouds with a Self-Consistent Cloud Scheme in a General Circulation Model  

Science Conference Proceedings (OSTI)

To model aerosol–cloud interactions in general circulation models (GCMs), a prognostic cloud scheme of cloud liquid water and amount is expanded to include droplet number concentration (Nd) in a way that allows them to be calculated using the ...

Yi Ming; V. Ramaswamy; Leo J. Donner; Vaughan T. J. Phillips; Stephen A. Klein; Paul A. Ginoux; Larry W. Horowitz

2007-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

ARM - PI Product - MWR Retrievals of Cloud Liquid Water and Water Vapor  

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

govDataPI Data ProductsMWR Retrievals of Cloud Liquid Water and Water govDataPI Data ProductsMWR Retrievals of Cloud Liquid Water and Water Vapor Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : MWR Retrievals of Cloud Liquid Water and Water Vapor 2005.02.01 - 2011.04.25 Site(s) FKB GRW HFE NIM PYE SBS General Description A new algorithm is being developed for the ARM Program to derive liquid water path (LWP) and precipitable water vapor (PWV) from the 2-channel (23.8 and 31.4 GHz) microwave radiometers (MWRs) deployed at ARM climate research facilities. This algorithm utilizes the "monoRTM" radiative transfer model (http://rtweb.aer.com), a combination of both an advanced statistical and physical-iterative retrieval, and brightness temperature offsets applied before the retrieval is performed. This allows perhaps the

22

A Comparison of Several Radiometric Methods of Deducing Path-Integrated Cloud Liquid Water  

Science Conference Proceedings (OSTI)

Using radiometer data collected during the Canadian Atlantic Storms Program, we have investigated five different methods of estimating the path-integrated, or columnar, cloud liquid water. The methods consist of one- and two-channel physical ...

Chong Wei; H. G. Leighton; R. R. Rogers

1989-12-01T23:59:59.000Z

23

Analysis of Rotating Multicylinder Data in Measuring Cloud-Droplet Size and Liquid Water Content  

Science Conference Proceedings (OSTI)

An objective method is presented for the analysis of rotating multicylinder data in measuring the liquid water content and median volume droplet diameter of icing clouds. The method is based on time-dependent numerical modeling of cylinder icing ...

Lasse Makkonen

1992-06-01T23:59:59.000Z

24

Spatial Variability of Liquid Water Path in Marine Low Cloud: The Importance of Mesoscale Cellular Convection  

Science Conference Proceedings (OSTI)

Liquid water path (LWP) mesoscale spatial variability in marine low cloud over the eastern subtropical oceans is examined using two months of daytime retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Terra ...

Robert Wood; Dennis L. Hartmann

2006-05-01T23:59:59.000Z

25

Liquid Water Cloud Measurements Using the Raman Lidar Technique: Current Understanding and Future Research Needs  

Science Conference Proceedings (OSTI)

This paper describes recent work in the Raman lidar liquid water cloud measurement technique. The range-resolved spectral measurements at the National Aeronautics and Space Administration Goddard Space Flight Center indicate that the Raman ...

Tetsu Sakai; David N. Whiteman; Felicita Russo; David D. Turner; Igor Veselovskii; S. Harvey Melfi; Tomohiro Nagai; Yuzo Mano

2013-07-01T23:59:59.000Z

26

Simulations of the Effects of Water Vapor, Cloud Liquid Water, and Ice on AMSU Moisture Channel Brightness Temperatures  

Science Conference Proceedings (OSTI)

Radiative transfer simulations are performed to determine how water vapor and nonprecipitating cloud liquid water and ice particles within typical midlatitude atmospheres affect brightness temperatures TB's of moisture sounding channels used in ...

Bradley M. Muller; Henry E. Fuelberg; Xuwu Xiang

1994-10-01T23:59:59.000Z

27

Determination of Cloud Liquid Water Distribution by Inversion of Radiometric Data  

Science Conference Proceedings (OSTI)

A method is described whereby the distribution of liquid water through a cross section of a cloud may be determined from radiometric data. It involves the scanning of the cloud by a pair of ground-based centimeter wave radiometers and measuring ...

J. Warner; J. F. Drake; P. R. Krehbiel

1985-09-01T23:59:59.000Z

28

Observations of Liquid Water in Orographic Clouds over Elk Mountain  

Science Conference Proceedings (OSTI)

The relatively simple orographic clouds forming in winter over Elk Mountain, Wyoming provided useful opportunities for field studies of cloud formation and of ice crystal development. In this paper, the observations of cloud droplet populations ...

Marcia K. Politovich; Gabor Vali

1983-05-01T23:59:59.000Z

29

Radiative Importance of ThinŽ Liquid Water Clouds  

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

Program Program Accomplishments of the Cloud Properties Working Group (CPWG) August 2006 Cloud Radiative Forcing at the ARM Climate Research Facility: Using ARM Data to Establish Testable Metrics for GCM Predictions of Cloud Feedback Gerald Mace University of Utah, Salt Lake City, Utah The scientific underpinning of the Atmospheric Radiation Measurement (ARM) Program is largely based on the premise that long term ground-based measurements of certain quantities provide information sufficient to test the skill of general circulation models (GCMs) to predict radiative heating and cloud feedbacks (Stokes and Schwartz, 1994; Ackerman and Stokes, 2003). This hypothesis is based on the assumption that some set of long-term ground-based measurements provide sufficient information to characterize the physical state of the atmospheric

30

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...

31

BALTEX BRIDGE cloud liquid water network project: CLIWA-NET  

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

3/2008 3/2008 ARM-08 Photo courtesy Bjorn Stevens ARM-GEWEX Cloud System Studies (GCSS) Collaborations: Past-Present-Future A. Pier Siebesma siebesma@knmi.nl chair GCCS KNMI, De Bilt, The Netherlands Technical University Delft Multiscale Physics Group Delft, The Netherlands 4/3/2008 ARM-08 Topics Introduction to GCSS activities Examples and Results for parameterization development in the past. (has it made a difference?) Past and Present Collaborations and results between ARM and GCSS The Future: How can we do better? 4/3/2008 ARM-08 Objective of GCSS GCSS is developing improved parameterizations of cloud systems for climate models and numerical weather prediction models by improving our understanding of the physical processes for all the climate relevant cloud types 4/3/2008 ARM-08

32

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

33

Toward a Standard Procedure for Validation of Satellite-Derived Cloud Liquid Water Path: A Study with SEVIRI Data  

Science Conference Proceedings (OSTI)

Differences between satellite-derived and ground-based values of cloud liquid water path (LWPsat and LWPgr, respectively) in validation studies are partly associated with the validation itself, in particular with scale differences and parallax. ...

W. Greuell; R. A. Roebeling

2009-08-01T23:59:59.000Z

34

Importance of Accurate Liquid Water Path for Estimation of Solar Radiation in Warm Boundary Layer Clouds: An Observational Study  

Science Conference Proceedings (OSTI)

A 1-yr observational study of overcast boundary layer stratus at the U.S. Department of Energy Atmospheric Radiation Measurement Program Southern Great Plains site illustrates that surface radiation has a higher sensitivity to cloud liquid water ...

Manajit Sengupta; Eugene E. Clothiaux; Thomas P. Ackerman; Seiji Kato; Qilong Min

2003-09-01T23:59:59.000Z

35

Potential Applications of the SSM/I Cloud Liquid Water Parameter to the Estimation of Marine Aircraft Icing  

Science Conference Proceedings (OSTI)

Images of integrated cloud liquid water derived from the Special Sensor Microwave Imager (SSM/I) aboard the Defense Meteorological Satellite Program polar-orbiting satellite are presented. Examples with infrared and visible images and synoptic ...

Thomas F. Lee; James R. Clark; Steven D. Swadley

1994-06-01T23:59:59.000Z

36

Cloud Liquid Water Path from Satellite-Based Passive Microwave Observations: A New Climatology over the Global Oceans  

Science Conference Proceedings (OSTI)

This work describes a new climatology of cloud liquid water path (LWP), termed the University of Wisconsin (UWisc) climatology, derived from 18 yr of satellite-based passive microwave observations over the global oceans. The climatology is based ...

Christopher W. O’Dell; Frank J. Wentz; Ralf Bennartz

2008-04-01T23:59:59.000Z

37

Equations Governing Space-Time Variability of Liquid Water Path in Stratus Clouds  

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

Equations Governing Space-Time Variability of Equations Governing Space-Time Variability of Liquid Water Path in Stratus Clouds K. Ivanova Pennsylvania State University University Park, Pennsylvania T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington M. Ausloos University of Liège B-4000 Liège, Belgium Abstract We present a method on how to derive an underlying mathematical (statistical or model free) equation for a liquid water path (LWP) signal directly from empirical data. The evolution of the probability density functions (PDFs) from small to large time scales is explicitly derived in the framework of Fokker-Planck equation. A drift and a diffusion term describing the deterministic and stochastic influences on the non-Gaussian fat tails of the liquid water probability distributions are obtained from

38

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

39

Radiative Importance of ThinŽ Liquid Water Clouds  

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

Program Program Accomplishments of the Instantaneous Radiative Flux (IRF) Working Group August 2006 AERI Observations at Southern Great Plains Improve Infrared Radiative Transfer Models Turner et al., JAS, 2004 * AERI observations used to evaluate clear sky IR radiative transfer models * Long-term comparisons have improved - Spectral line database parameters - Water vapor continuum absorption models * Reduced errors in computation of downwelling radiative IR flux by approx 4; current uncertainty is on the order of 1.5 W/m 2 AERI - (Pre-ARM Model) AERI - (Model in 2003) 1 RU = 1 mW / (m 2 sr cm -1 ) Excellent Agreement in Clear Sky Shortwave Radiative Transfer Between Obs and Calcs Shortwave Flux Bias (Solid) Shortwave Flux RMS (Hatched) W m -2 * Comparison of shortwave radiative flux at the surface

40

Integration of Global Positioning System and Scanning Water Vapor Radiometers for Precipitable Water Vapor and Cloud Liquid Path Estimates  

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

Integration of Global Positioning System and Scanning Integration of Global Positioning System and Scanning Water Vapor Radiometers for Precipitable Water Vapor and Cloud Liquid Path Estimates V. Mattioli and P. Basili Department of Electronic and Information Engineering University of Perugia Perugia, Italy E. R. Westwater Cooperative Institute for Research in Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction In recent years the Global Positioning System (GPS) has proved to be a reliable instrument for measuring precipitable water vapor (PWV) (Bevis et al. 1992), offering an independent source of information on water vapor when compared with microwave radiometers (MWRs), and/or radiosonde

Note: This page contains sample records for the topic "liquid water clouds" 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

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

42

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

43

Probability Density Functions of Liquid Water Path and Cloud Amount of Marine Boundary Layer Clouds: Geographical and Seasonal Variations and Controlling Meteorological Factors  

Science Conference Proceedings (OSTI)

The subgrid-scale variability of the liquid water path (LWP) of marine boundary layer clouds in areas that correspond to the typical grid size of large-scale (global climate and weather prediction) atmospheric models (200 km × 200 km) is ...

Hideaki Kawai; João Teixeira

2010-04-01T23:59:59.000Z

44

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

45

Active probing of cloud multiple scattering, optical depth, vertical thickness, and liquid water content using wide-angle imaging LIDAR.  

SciTech Connect

At most optical wavelengths, laser light in a cloud lidar experiment is not absorbed but merely scattered out of the beam, eventually escaping the cloud via multiple scattering. There is much information available in this light scattered far from the input beam, information ignored by traditional 'on-beam' lidar. Monitoring these off-beam returns in a fully space- and time-resolved manner is the essence of our unique instrument, Wide Angle Imaging Lidar (WAIL). In effect, WAIL produces wide-field (60-degree full-angle) 'movies' of the scattering process and records the cloud's radiative Green functions. A direct data product of WAIL is the distribution of photon path lengths resulting from multiple scattering in the cloud. Following insights from diffusion theory, we can use the measured Green functions to infer the physical thickness and optical depth of the cloud layer, and, from there, estimate the volume-averaged liquid water content. WAIL is notable in that it is applicable to optically thick clouds, a regime in which traditional lidar is reduced to ceilometry. Here we present recent WAIL data oti various clouds and discuss the extension of WAIL to full diurnal monitoring by means of an ultra-narrow magneto-optic atomic line filter for daytime measurements.

Love, Steven P.; Davis, A. B. (Anthony B.); Rohde, C. A. (Charles A.); Tellier, L. L. (Larry L.); Ho, Cheng,

2002-01-01T23:59:59.000Z

46

Evaluation of Liquid Water Measuring Instruments in Cold Clouds Sampled during FIRE  

Science Conference Proceedings (OSTI)

Liquid water measurements from the Rosemount icing detector (RICE), Particle Measuring Systems (PMS) forward scattering spectrometer probe (FSSP), and Johnson–williams and King hot-wire probes used on the NCAR King Air aircraft are evaluated for ...

Andrew J. Heymsfield; Larry M. Miloshevich

1989-06-01T23:59:59.000Z

47

Deployment and Evaluation of a System for Ground-Based Measurement of Cloud Liquid Water Turbulent Fluxes  

Science Conference Proceedings (OSTI)

Direct interception of windblown cloud water by forests has been dubbed “occult deposition” because it represents a hydrological input that is hidden from rain gauges. Eddy correlation studies of this phenomenon have estimated cloud water fluxes ...

Andrew S. Kowalski; Peter M. Anthoni; Richard J. Vong; Anthony C. Delany; Gordon D. Maclean

1997-06-01T23:59:59.000Z

48

Design of a Shadowband Spectral Radiometer for the Retrieval of Thin Cloud Optical Depth, Liquid Water Path, and the Effective Radius  

SciTech Connect

The design and operation of a Thin-Cloud Rotating Shadowband Radiometer (TCRSR) described here was used to measure the radiative intensity of the solar aureole and enable the simultaneous retrieval of cloud optical depth, drop effective radius, and liquid water path. The instrument consists of photodiode sensors positioned beneath two narrow metal bands that occult the sun by moving alternately from horizon to horizon. Measurements from the narrowband 415-nm channel were used to demonstrate a retrieval of the cloud properties of interest. With the proven operation of the relatively inexpensive TCRSR instrument, its usefulness for retrieving aerosol properties under cloud-free skies and for ship-based observations is discussed.

Bartholomew M. J.; Reynolds, R. M.; Vogelmann, A. M.; Min, Q.; Edwards, R.; Smith, S.

2011-11-01T23:59:59.000Z

49

Monitoring of Precipitable Water Vapor and Cloud Liquid Path from Scanning Microwave Radiometers During the 2003 Cloudiness Inter-Comparison Experiment  

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

Monitoring of Precipitable Water Vapor and Cloud Liquid Monitoring of Precipitable Water Vapor and Cloud Liquid Path from Scanning Microwave Radiometers During the 2003 Cloudiness Inter-Comparison Experiment V. Mattioli Department of Electronic and Information Engineering University of Perugia Perugia, Italy E. R. Westwater Cooperative Institute for Research in Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado V. Morris Pacific Northwest National Laboratory Richland, Washington Introduction Ground-based microwave radiometers (MWR) are widely used to measure atmospheric precipitable water vapor (PWV) and cloud liquid path (CLP). Comparisons of PWV derived from MWRs with water vapor retrievals from instruments like radiosondes, Global Positioning System (GPS) and Raman

50

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

51

Homogeneous Ice Nucleation and Supercooled Liquid Water in Orographic Wave Clouds  

Science Conference Proceedings (OSTI)

This study investigates ice nucleation mechanisms in cold lenticular wave clouds, a cloud type characterized by quasi-steady-state air motions and microphysical properties. It is concluded that homogeneous ice nucleation is responsible for the ...

Andrew J. Heymsfield; Larry M. Miloshevich

1993-08-01T23:59:59.000Z

52

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

53

Skylab Near-Infrared Observations of Clouds Indicating Supercooled Liquid Water Droplets  

Science Conference Proceedings (OSTI)

Orographically-induced lee-wave clouds were observed over New Mexico by a multichannel scanning radiometer on Skylab during December 1973. Channels centered at 0.83, 1.61 and 2.125 ?m were used to determine the cloud optical thickness, ...

Robert J. Curran; Man-Li C. Wu

1982-03-01T23:59:59.000Z

54

Comparison of Cloud Fraction and Liquid Water Path between ECMWF simulations and ARM long-term Observations at the NSA Site  

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

this poster, seasonal and annual variations of this poster, seasonal and annual variations of cloudiness and liquid water path (LWP) from European Center for Medium-Range Weather Forecasts (ECMWF) model were compared with surface measurement from the ARM Climate Research Facility (ARCF) North Slope of Alaska ( N S A ) s i t e b e t we e n J a n u a r y 1 9 9 9 and December 2004. ● Model simulated large scale features match well with observations. ● There are significant differences in cloud vertical and temporal distributions and in the magnitude. FIG. 1: Time-height display of cloud fraction from model simulations and observations in September 1999. ● Model overestimates high clouds, especially in warm seasons. ● Model makes close estimation for middle clouds. ● Model underestimates low clouds in warm seasons, especially in

55

An Eight-Month Sample of Marine Stratocumulus Cloud Fraction, Albedo, and Integrated Liquid Water  

Science Conference Proceedings (OSTI)

As part of the First International Satellite Cloud Climatology Regional Experiment (FIRE), a surface meteorology and shortwave/longwave irradiance station was operated in a marine stratocumulus regime on the northwest tip of San Nicolas island ...

C. W. Fairall; J. E. Hare; J. B. Snider

1990-08-01T23:59:59.000Z

56

A Simple Method to Retrieve Cloud Properties from Atmospheric Transmittance and Liquid Water Column Measurements  

Science Conference Proceedings (OSTI)

A deeper knowledge of the effects and interactions of clouds in the climatic system requires developing both satellite and ground-based methods to assess their optical properties. A simple method based on a parameterized inversion of a radiative ...

Salvador Matamoros; Josep-Abel González; Josep Calbó

2011-02-01T23:59:59.000Z

57

Influences of Storm-Embedded Orographic Gravity Waves on Cloud Liquid Water and Precipitation  

Science Conference Proceedings (OSTI)

This study illustrates opportunities for much improved orographic quantitative precipitation forecasting, determination of orographic cloud seedability, and flash flood prediction through state-of-the-art remote sensing and numerical modeling of ...

Roger F. Reinking; Jack B. Snider; Janice L. Coen

2000-06-01T23:59:59.000Z

58

Measurement of Condensed Water Content in Liquid and Ice Clouds Using an Airborne Counterflow Virtual Impactor  

Science Conference Proceedings (OSTI)

Condensed water content (CWC) measured using a counterflow virtual impactor (CVI) with a Lyman-? hygrometer downstream is compared with that measured by other airborne instruments (a hot-wire probe, a PMS FSSP, and a PMS 2D-C). Results indicate ...

Cynthia H. Twohy; Allen J. Schanot; William A. Cooper

1997-02-01T23:59:59.000Z

59

Remote sensing of total integrated water vapor, wind speed, and cloud liquid water over the ocean using the Special Sensor Microwave/Imager (SSM/I)  

E-Print Network (OSTI)

A modified D-matrix retrieval method is the basis of the refined total integrated water vapor (TIWV), total integrated cloud liquid water (CLW), and surface wind speed (WS) retrieval methods that are developed. The 85 GHZ polarization difference is used to restrict the application of the geophysical retrieval algorithms which are developed to handle specific atmospheric absorptive situations. An improved semi-empirical sea surface emissivity model is integrated into this refined D-matrix procedure that is being developed for the Advanced Microwave Sounding Radiometer (AMSR). The purpose of this work is to test the refined geophysical parameter retrieval methods using data from the Special Sensor Microwave / Imager (SSM/I). When comparing the statistical performance of the TIWV, WS, and CLW retrieval methods presented to the statistical performance of published retrieval methods for each geophysical parameter, the retrieval methods developed for this study perform only slightly better. However, it is demonstrated that the new retrieval methods are more physically valid than the comparison retrieval methods. The utilization of the polarization difference of the 85 GHZ channels to restrict the application of specifically-derived retrieval algorithms proves to be a valuable and reliable geophysical parameter retrieval tool.

Manning, Norman Willis William

1997-01-01T23:59:59.000Z

60

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

Note: This page contains sample records for the topic "liquid water clouds" 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

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

62

Observations of Quasi-Stationary and Shallow Orographic Snow Clouds: Spatial Distributions of Supercooled Liquid Water and Snow Particles  

Science Conference Proceedings (OSTI)

On 25 February 1999, due to a winter monsoon after a cyclonic storm, orographic snow clouds formed under conditions of weak cold advection on the western side of the central mountain range of Japan. In this study, the Ka-band Doppler radar and ...

Kenichi Kusunoki; Masataka Murakami; Narihiro Orikasa; Mizuho Hoshimoto; Yoshinobu Tanaka; Yoshinori Yamada; Hakaru Mizuno; Kyosuke Hamazu; Hideyuki Watanabe

2005-04-01T23:59:59.000Z

63

Response of ice and liquid water paths of tropical cyclones to global warming simulated by a global nonhydrostatic model with explicit cloud microphysics  

Science Conference Proceedings (OSTI)

Cloud feedback plays a key role in the future climate projection. Using global non-hydrostatic model (GNHM) simulation data for a present-day (CTL) and a warmer (GW) experiment, we estimate the contribution of tropical cyclones (TC) to ice/liquid ...

Yohei Yamada; Masaki Satoh

64

An Analytic Longwave Radiation Formula for Liquid Layer Clouds  

Science Conference Proceedings (OSTI)

Many Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study (GCSS) intercomparisons of boundary layer clouds have used a convenient but idealized longwave radiation formula for clouds in their large-eddy simulations (LESs). Under ...

Vincent E. Larson; Kurt E. Kotenberg; Norman B. Wood

2007-02-01T23:59:59.000Z

65

Estimation of Liquid Cloud Properties that Conserve Total-Scene Reflectance Using Satellite Measurements  

Science Conference Proceedings (OSTI)

A new method of deriving statistical moments related to the distribution of liquid water path over partially cloudy scenes is tested using a satellite cloud climatology. The method improves the ability to reconstruct total-scene visible ...

Michael J. Foster; Ralf Bennartz; Andrew Heidinger

2011-01-01T23:59:59.000Z

66

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

67

A Theoretical Study of the Accuracy of Tomographic Retrieval of Cloud Liquid with an Airborne Radiometer  

Science Conference Proceedings (OSTI)

Prior studies of the technique of inferring the Liquid water distribution in a cloud with microwave cloud tomography have concentrated on the use of ground-based instruments. An extension of the technique to the analysis of measurements at 31.65 ...

J. F. Drake; J. Warner

1988-12-01T23:59:59.000Z

68

Relationships between Total Water, Condensed Water, and Cloud Fraction in Stratiform Clouds Examined Using Aircraft Data  

Science Conference Proceedings (OSTI)

Relationships among total water, condensed water, and cloud fraction in boundary layer and cold tropospheric stratiform clouds are investigated using a large observational dataset collected by the U.K. Met. Office C-130 aircraft. Values of the ...

Robert Wood; Paul R. Field

2000-06-01T23:59:59.000Z

69

Lidar-Based Characterization of the Geometry and Structure of Water Clouds  

Science Conference Proceedings (OSTI)

Lidar remote sensing measurements of low-level water clouds in the form of vertical soundings and instantaneous (1 min) azimuth-over-elevation scans are reported. Retrievals are made of the liquid water content and effective droplet diameter at ...

Luc R. Bissonnette; Gilles Roy; Grégoire Tremblay

2007-08-01T23:59:59.000Z

70

Diabatic Forcing and Initialization with Assimilation of Cloud Water and Rainwater in a Forecast Model  

Science Conference Proceedings (OSTI)

In this study, diabatic initialization, diabatic forcing, and liquid water assimilation techniques are tested in a semi-implicit hydrostatic regional forecast model containing explicit representations of grid-scale cloud water and rainwater. ...

William H. Raymond; William S. Olson; Geary Callan

1995-02-01T23:59:59.000Z

71

Liquid Water Oceans in Ice Giants  

E-Print Network (OSTI)

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

Sloane J. Wiktorowicz; Andrew P. Ingersoll

2006-09-26T23:59:59.000Z

72

Determination of Supercooled Liquid Water Content by Measuring Rime Rate  

Science Conference Proceedings (OSTI)

A ground-based technique is described for determining the liquid water content of supercooled clouds orfog by measuring the mass rate of rime accumulation on a small rotating wire. Development of the techniqueis described, examples of the data ...

David C. Rogers; Darrel Baumgardner; Gabor Vali

1983-01-01T23:59:59.000Z

73

Determination of Liquid Water Altitudes Using Combined Remote Sensors  

Science Conference Proceedings (OSTI)

Methods by which attitude ranges of supercooled cloud liquid water in the atmosphere may be estimated are explored using measurements from a combination of ground-based remote sensors. The tests were conducted as part of the Winter Icing and ...

Marcia K. Politovich; B. Boba Stankov; Brooks E. Martner

1995-09-01T23:59:59.000Z

74

Comparison of Cloud Liquid Content Measured by Two Independent Ground-Based Systems  

Science Conference Proceedings (OSTI)

We report on observations of liquid water in clouds made by two independent ground-based microwave instruments. One system is a dual-frequency (20.6, 31.65 GHz) microwave radiometer designed to measure emission from the precipitable water vapor ...

J. B. Snider; F. O. Guiraud; D. C. Hogg

1980-05-01T23:59:59.000Z

75

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

76

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

77

Design of a Shadowband Spectral Radiometer for the Retrieval of Thin Cloud Optical Depth, Liquid Water Path, and the Effective Radius  

Science Conference Proceedings (OSTI)

The design and operation of a Thin-Cloud Rotating Shadowband Radiometer (TCRSR) described here was used to measure the radiative intensity of the solar aureole and enable the simultaneous retrieval of cloud optical depth, drop effective radius, ...

M. J. Bartholomew; R. M. Reynolds; A. M. Vogelmann; Q. Min; R. Edwards; S. Smith

2011-11-01T23:59:59.000Z

78

A Prognostic Cloud Water Parameterization for Global Climate Models  

Science Conference Proceedings (OSTI)

An efficient new prognostic cloud water parameterization designed for use in global climate models is described. The scheme allows for life cycle effects in stratiform clouds and permits cloud optical properties to be determined interactively. ...

Anthony D. Del Genio; Mao-Sung Yao; William Kovari; Kenneth K-W. Lo

1996-02-01T23:59:59.000Z

79

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

80

Cirrus Cloud Ice Water Content Radar Algorithm Evaluation Using an Explicit Cloud Microphysical Model  

Science Conference Proceedings (OSTI)

A series of cirrus cloud simulations performed using a model with explicit cloud microphysics is applied to testing ice water content retrieval algorithms based on millimeter-wave radar reflectivity measurements. The simulated ice particle size ...

Kenneth Sassen; Zhien Wang; Vitaly I. Khvorostyanov; Graeme L. Stephens; Angela Bennedetti

2002-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Measurement of Vertical Liquid Water Path by Means of an Airborne Radiometer and the Shortwave Albedo of Marine Low-Level Clouds during WENPEX in Japan  

Science Conference Proceedings (OSTI)

Special observations were made over the southwest island area of the East China Sea from 12 to 27 January 1991 as part of the World Climate Research Program in Japan (WENPEX?Western North Pacific Cloud?Radiation Experiment). Two aircraft were ...

Y. Fujiyoshi; Y. Ishizaka; T. Takeda; T. Hayasaka; M. Tanaka

1995-02-01T23:59:59.000Z

82

Factors influencing the microphysics and radiative properties of liquid-dominated Arctic clouds: insight from observations of aerosol and clouds during ISDAC  

SciTech Connect

Aircraft measurements during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 are used to investigate aerosol indirect effects in Arctic clouds. Two aerosol-cloud regimes are considered in this analysis: single-layer stratocumulus cloud with below-cloud aerosol concentrations (N{sub a}) below 300 cm{sup -3} on April 8 and April 26-27 (clean cases); and inhomogeneous layered cloud with N{sub a} > 500 cm{sup -3} below cloud base on April 19-20, concurrent with a biomass burning episode (polluted cases). Vertical profiles through cloud in each regime are used to determine average cloud microphysical and optical properties. Positive correlations between the cloud droplet effective radius (Re) and cloud optical depth ({tau}) are observed for both clean and polluted cases, which are characteristic of optically-thin, non-precipitating clouds. Average Re values for each case are {approx} 6.2 {mu}m, despite significantly higher droplet number concentrations (Nd) in the polluted cases. The apparent independence of Re and Nd simplifies the description of indirect effects, such that {tau} and the cloud albedo (A) can be described by relatively simple functions of the cloud liquid water path. Adiabatic cloud parcel model simulations show that the marked differences in Na between the regimes account largely for differences in droplet activation, but that the properties of precursor aerosol also play a role, particularly for polluted cases where competition for vapour amongst the more numerous particles limits activation to larger and/or more hygroscopic particles. The similarity of Re for clean and polluted cases is attributed to compensating droplet growth processes for different initial droplet size distributions.

Earle, Michael; Liu, Peter S.; Strapp, J. Walter; Zelenyuk, Alla; Imre, D.; McFarquhar, Greg; Shantz, Nicole C.; Leaitch, W. R.

2011-11-04T23:59:59.000Z

83

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

84

Distance-Scaled Water Concentrations versus Mass-Median Drop Size, Temperature, and Altitude in Supercooled Clouds  

Science Conference Proceedings (OSTI)

About 28 000 nautical miles (n mi) of select in-flight measurements of liquid water content (LWC), droplet sizes, temperature, and other variables in supercooled clouds from a variety of research projects over portions of North America, Europe, ...

Richard K. Jeck

2008-07-01T23:59:59.000Z

85

Further Performance Tests on the CSIRO Liquid Water Probe  

Science Conference Proceedings (OSTI)

A further 400 h of flying experience with the CSIRO hot-wire probe has shown that it can accurately measure liquid water content in clouds. Computations and experiments suggest that when an epoxy coating is used for protection, it should be less ...

W. D. King; C. T. Maher; G. A. Hepburn

1981-02-01T23:59:59.000Z

86

Information Content and Uncertainties in Thermodynamic Profiles and Liquid Cloud Properties Retrieved from the Ground-Based Atmospheric Emitted Radiance Interferometer (AERI)  

Science Conference Proceedings (OSTI)

The Atmospheric Emitted Radiance Interferometer (AERI) observes spectrally resolved downwelling radiance emitted by the atmosphere in the infrared portion of the electromagnetic spectrum. Profiles of temperature and water vapor, and cloud liquid ...

D.D. Turner; U. Löhnert

87

Determining Cloud Ice Water Path from High-Frequency Microwave...  

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

Determining Cloud Ice Water Path from High-Frequency Microwave Measurements G. Liu Department of Meteorology Florida State University Tallahassee, Florida Introduction A better...

88

The Plane-Parallel Albedo Bias of Liquid Clouds from MODIS Observations  

Science Conference Proceedings (OSTI)

The authors present the global plane-parallel shortwave albedo bias of liquid clouds for two months, July 2003 and January 2004. The cloud optical properties necessary to perform the bias calculations come from the operational Moderate Resolution ...

Lazaros Oreopoulos; Robert F. Cahalan; Steven Platnick

2007-10-01T23:59:59.000Z

89

Multiple Remote Sensor Observations of Supercooled Liquid Water in a Winter Storm at Beaver, Utah  

Science Conference Proceedings (OSTI)

The temporal and spatial distribution of cloud liquid water in a winter storm from the 1983 Utah/NOAA Cooperative Weather Modification Program is characterized using remote sensing observations. The remote sensors, located at a mountain-base site ...

Kenneth Sassen; Robert M. Rauber; J. B. Snider

1986-06-01T23:59:59.000Z

90

Calibrations of Johnson-Williams Liquid Water Content Meters in a High-Speed Icing Tunnel  

Science Conference Proceedings (OSTI)

Wind tunnel tests have provided calibrations and intercomparisons of 14 Johnson-Williams (J–W) cloud liquid water content (LWC) measuring devices with 23 sensor heads from 10 research organizations. The absolute tunnel LWC was deduced using a ...

J. Walter Strapp; Robert S. Schemenauer

1982-01-01T23:59:59.000Z

91

Analysis of Supercooled Liquid Water Measurements Using Microwave Radiometer and Vibrating Wire Devices  

Science Conference Proceedings (OSTI)

A review is made of the theoretical basis for using a vibrating wire to measure supercooled liquid water in clouds. The device consists of a vibrating wire and associated electronics added to radiosondes. The sensing wire that collects ...

Geoffrey E. Hill

1994-10-01T23:59:59.000Z

92

On water ice formation in interstellar clouds  

E-Print Network (OSTI)

A model is proposed for the formation of water ice mantles on grains in interstellar clouds. This occurs by direct accretion of monomers from the gas, be they formed by gas or surface reactions. The model predicts the existence of a threshold in interstellar light extinction, A(v), which is mainly determined by the adsorption energy of water molecules on the grain material; for hydrocarbon material, chemical simulation places this energy between 0.5 and 2 kcal/mole, which sets the visible exctinction threshold at a few magnitudes, as observed. Once the threshold is crossed, all available water molecules in the gas are quickly adsorbed, forming an ice mantle, because the grain cools down and the adsorption energy on ice is higher than on bare grain. The model also predicts that the thickness of the mantle, and, hence, the optical thickness at 3 mu, grow linearly with A(v), as observed, with a slope which depends upon the total amount of water in the gas. Chemical simulation was also used to determine the adsorption sites and energies of O and OH on hydrocarbons, and study the dynamics of formation of water molecules by surface reactions with gaseous H atoms, as well as their chances of sticking in situ.

Renaud Papoular

2005-07-06T23:59:59.000Z

93

Extinction and Liquid Water Content Measurements at CO2 Laser wavelengths  

Science Conference Proceedings (OSTI)

Measurements have been made of both extinction coefficients in an evaporating laboratory cloud at wavelength ? = 10.591 ?m using a CO2 laser, and of liquid water content (LWC) at the center of the cloud using a continuous filtration LWC device. ...

P. F. Nolan; S. G. Jennings

1987-09-01T23:59:59.000Z

94

Measurements of Cloud Nuclei in the Effluents from Launches of Liquid- and Solid-Fueled Rockets  

Science Conference Proceedings (OSTI)

Airborne measurements of cloud nuclei [cloud condensation nuclei (CCN) and ice nuclei (IN)] were made in the stabilized ground clouds resulting from the launches of a liquid-fueled ATLAS/Centaur rocket and a solid-fueled TITAN III rocket. ...

Edward E. Hindman; Lawrence F. Radke; Mark W. Eltgroth

1982-09-01T23:59:59.000Z

95

Water Vapor, Condensed Water, and Crystal Concentration in Orographically Influenced Cirrus Clouds  

Science Conference Proceedings (OSTI)

Results are presented from measurements made with a counterflow virtual impactor (CVI) in cirriform clouds containing crystals with dimensions typically less than 30 ?m. Independent measurements of crystal number concentration and cloud water ...

Johan Ström; Jost Heintzenberg

1994-08-01T23:59:59.000Z

96

A Prognostic Parameterization for the Subgrid-Scale Variability of Water Vapor and Clouds in Large-Scale Models and Its Use to Diagnose Cloud Cover  

Science Conference Proceedings (OSTI)

A parameterization for the horizontal subgrid-scale variability of water vapor and cloud condensate is introduced, which is used to diagnose cloud fraction in the spirit of statistically based cloud cover parameterizations. High-resolution cloud-...

Adrian M. Tompkins

2002-06-01T23:59:59.000Z

97

Aerosol First Indirect Effects on Non-Precipitating Low-Level Liquid Cloud Properties as Simulated by CAM5 at ARM Sites  

SciTech Connect

We quantitatively examine the aerosol first indirect effects (FIE) for non-precipitating low-level single-layer liquid phase clouds simulated by the Community Atmospheric Model version 5 (CAM5) running in the weather forecast mode at three DOE Atmospheric Radiation Measurement (ARM) sites. The FIE is quantified in terms of a relative change in cloud droplet effective radius for a relative change in aerosol accumulation mode number concentration under conditions of fixed liquid water content (LWC). CAM5 simulates aerosol-cloud interactions reasonably well for this specific cloud type, and the simulated FIE is consistent with the long-term observations at the examined locations. The FIE in CAM5 generally decreases with LWC at coastal ARM sites, and is larger by using cloud condensation nuclei rather than aerosol accumulation mode number concentration as the choice of aerosol amount. However, it has no significant variations with location and has no systematic strong seasonal variations at examined ARM sites.

Zhao, Chuanfeng; Klein, Stephen A.; Xie, Shaocheng; Liu, Xiaohong; Boyle, James; Zhang, Yuying

2012-04-28T23:59:59.000Z

98

The Use of Routine Weather Observations to Calculate Liquid Water Content in Summertime High-Elevation Fog  

Science Conference Proceedings (OSTI)

This paper represents a stage within a larger project to estimate acid ion deposition from cloud impacting on high-elevation forests. Acid ion deposition depends principally on three factors: the liquid water content (LWC), the ion concentration(...

John L. Walmsley; William R. Burrows; Robert S. Schemenauer

1999-04-01T23:59:59.000Z

99

Defining Marine Boundary Layer Clouds with a Prognostic Scheme  

Science Conference Proceedings (OSTI)

A prognostic cloud scheme is described based on Tiedtke's cloud parameterization for large-scale meteorological models, which uses prognostic equations for both mean liquid water content and cloud fraction. The present work parameterizes the ...

Shouping Wang

1996-08-01T23:59:59.000Z

100

Electrokinetic Power Generation from Liquid Water Microjets  

E-Print Network (OSTI)

Electrokinetic power generation using liquid water microjetscalculations of power generation and conversion efficiency.for electrokinetic power generation. By creating a jet of

Duffin, Andrew M.

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Artificial Cloud Seeding Using Liquid Carbon Dioxide: Comparisons of Experimental Data and Numerical Analyses  

Science Conference Proceedings (OSTI)

An artificial seeding experiment was carried out over the Genkai Sea, Japan, using liquid carbon dioxide. The seeded cloud was followed by an aircraft and radar at Kyushu University. A radar-echo intensity of 19 dBZ was formed in the seeded cloud ...

Jinichiro Seto; Kikuro Tomine; Kenji Wakimizu; Koji Nishiyama

2011-07-01T23:59:59.000Z

102

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

103

Tropical Water Vapor and Cloud Feedbacks in Climate Models: A Further Assessment Using Coupled Simulations  

Science Conference Proceedings (OSTI)

By comparing the response of clouds and water vapor to ENSO forcing in nature with that in Atmospheric Model Intercomparison Project (AMIP) simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor ...

De-Zheng Sun; Yongqiang Yu; Tao Zhang

2009-03-01T23:59:59.000Z

104

Electrokinetic Power Generation from Liquid Water Microjets  

DOE Green Energy (OSTI)

Although electrokinetic effects are not new, only recently have they been investigated for possible use in energy conversion devices. We have recently reported the electrokinetic generation of molecular hydrogen from rapidly flowing liquid water microjets [Duffin et al. JPCC 2007, 111, 12031]. Here, we describe the use of liquid water microjets for direct conversion of electrokinetic energy to electrical power. Previous studies of electrokinetic power production have reported low efficiencies ({approx}3%), limited by back conduction of ions at the surface and in the bulk liquid. Liquid microjets eliminate energy dissipation due to back conduction and, measuring only at the jet target, yield conversion efficiencies exceeding 10%.

Duffin, Andrew M.; Saykally, Richard J.

2008-02-15T23:59:59.000Z

105

Droplet Growth in Warm Water Clouds Observed by the A-Train. Part II: A Multisensor View  

Science Conference Proceedings (OSTI)

Hydrometeor droplet growth processes are inferred from a combination of Aqua/Moderate Resolution Imaging Spectroradiometer (MODIS) cloud particle size observations and CloudSat/Cloud Profiling Radar (CPR) observations of warm water clouds. This ...

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

2010-06-01T23:59:59.000Z

106

Mobile Microwave Radiometer Observations: Spatial Characteristics of Supercooled Cloud Water and Cloud Seeding Implications  

Science Conference Proceedings (OSTI)

Previous studies of the spatial distribution of supercooled liquid water in winter storms over mountainous terrain were performed primarily with instrumented aircraft and to a lesser extent with scans from a stationary microwave radiometer. The ...

Arlen W. Huggins

1995-02-01T23:59:59.000Z

107

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

108

Simulation of Lidar Return Signals Associated with Water Clouds  

E-Print Network (OSTI)

We revisited an empirical relationship between the integrated volume depolar- ization ratio, oacc, and the effective multiple scattering factor, -n, on the basis of Monte Carlo simulations of spaceborne lidar backscatter associated with homogeneous wa- ter clouds. The relationship is found to be sensitive to the extinction coefficient and to the particle size. The layer integrated attenuated backscatter is also obtained. Comparisons made between the simulations and statistics derived relationships of the layer integrated depolarization ratio, oacc, and the layer integrated attenuated backscatter, -n, based on the measurement by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite show that a cloud with a large effective size or a large extinction coefficient has a relatively large integrated backscatter and a cloud with a small effective size or a large extinction coefficient has a large integrated volume depolarization ratio. The present results also show that optically thin water clouds may not obey the empirical relationship derived by Y. X. Hu. and co-authors.

Lu, Jianxu

2009-08-01T23:59:59.000Z

109

A Balloonborne Instrument for the Measurement of Vertical Profiles of Supercooled Liquid Water Concentration  

Science Conference Proceedings (OSTI)

A vibrating wire placed in the humidity duct of a standard U.S. rawinsonde is used to measure vertical profiles of the concentration of supercooled liquid water in clouds. The natural frequency of vibration varies according to the mass of ice ...

Geoffrey E. Hill; Duard S. Woffinden

1980-11-01T23:59:59.000Z

110

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

111

Implementation of the Cloud Prediction Scheme in the Eta Model at NCEP  

Science Conference Proceedings (OSTI)

An explicit cloud prediction scheme has been developed and incorporated into the Eta Model at the National Centers for Environmental Prediction (NCEP) to improve the cloud and precipitation forecasts. In this scheme, the cloud liquid water and ...

Qingyun Zhao; Thomas L. Black; Michael E. Baldwin

1997-09-01T23:59:59.000Z

112

Drizzle in Stratiform Boundary Layer Clouds. Part I: Vertical and Horizontal Structure  

Science Conference Proceedings (OSTI)

Detailed observations of stratiform boundary layer clouds on 12 days are examined with specific reference to drizzle formation processes. The clouds differ considerably in mean thickness, liquid water path (LWP), and droplet concentration. Cloud-...

R. Wood

2005-09-01T23:59:59.000Z

113

An Axial-Flow Cyclone for Aircraft-Based Cloud Water Sampling  

Science Conference Proceedings (OSTI)

A new aircraft-based cloud water collection system has been developed to provide samples of cloud water for chemical analysis. The collection system makes use of centrifugal separation in an axial-flow cyclone to remove cloud drops from the ...

Derek J. Straub; Jeffrey L. Collett Jr.

2004-12-01T23:59:59.000Z

114

Fluid Metrology Calibration Services - Gas, Water, or Liquid ...  

Science Conference Proceedings (OSTI)

Fluid Metrology Calibration Services - Gas, Water, Natural Gas, or Liquid Hydrocarbon Flows Special Tests. Fluid Metrology ...

2013-01-25T23:59:59.000Z

115

Liquid chromatographic determination of water  

DOE Green Energy (OSTI)

A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present.

Fortier, Nancy E. (Fairfield, OH); Fritz, James S. (Ames, IA)

1990-11-13T23:59:59.000Z

116

A Scheme for Parameterizing Ice-Cloud Water Content in General Circulation Models  

Science Conference Proceedings (OSTI)

The optical properties of ice clouds are a primary issue for climate and climate change. Evaluating these optical properties in three-dimensional models for studying climate will require a method to calculate the ice water content of such clouds. ...

Andrew J. Heymsfield; Leo J. Donner

1990-08-01T23:59:59.000Z

117

Detecting and Evaluating the Effect of Overlaying Thin Cirrus Cloud on MODIS Retrieved Water-Cloud Droplet Effective Radius  

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

Detecting and Evaluating the Effect Detecting and Evaluating the Effect of Overlaying Thin Cirrus Cloud on MODIS Retrieved Water-Cloud Droplet Effective Radius F.-L Chang and Z. Li Earth System Science Interdisciplinary Center University of Maryland College Park, Maryland Z. Li Department of Meteorology University of Maryland College Park, Maryland Introduction Cirrus clouds can largely modify the solar reflected and terrestrial emitted radiances. The ubiquitous presence of cirrus clouds has a global coverage of about 20% to30% and more than 70% in the tropics (Wylie et al. 1994). The probability of cirrus clouds overlaying a low-level boundary layer cloud system is greater than 50% (Hahn et al. 1982, 1984; Tian and Curry 1989; Mace et al. 1997). They are often optically thin and semitransparent and frequently reside in high altitude overlapping with a low-level

118

Soot microphysical effects on liquid clouds, a multi-model investigation  

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

Soot microphysical effects on liquid clouds, a multi-model investigation Soot microphysical effects on liquid clouds, a multi-model investigation Title Soot microphysical effects on liquid clouds, a multi-model investigation Publication Type Journal Article Year of Publication 2011 Authors Koch, Dorothy M., Yves Balkanski, Susanne E. Bauer, Richard C. Easter, Sylvaine Ferrachat, Steven J. Ghan, Corinna Hoose, Trond Iversen, Alf Kirkevåg, Jon E. Kristjánsson, Xiaohong Liu, Ulrike Lohmann, Surabi Menon, Johannes Quaas, Michael Schulz, Øyvind Seland, Toshihiko Takemura, and N. Yan Journal Atmospheric Chemistry and Physics Volume 11 Pagination 1051-1064 Abstract We use global models to explore the microphysical effects of carbonaceous aerosols on liquid clouds. Although absorption of solar radiation by soot warms the atmosphere, soot may cause climate cooling due to its contribution to cloud condensation nuclei (CCN) and therefore cloud brightness. Six global models conducted three soot experiments; four of the models had detailed aerosol microphysical schemes. The average cloud radiative response to biofuel soot (black and organic carbon), including both indirect and semi-direct effects, is -0.11 Wm-2, comparable in size but opposite in sign to the respective direct effect. In a more idealized fossil fuel black carbon experiment, some models calculated a positive cloud response because soot provides a deposition sink for sulfuric and nitric acids and secondary organics, decreasing nucleation and evolution of viable CCN. Biofuel soot particles were also typically assumed to be larger and more hygroscopic than for fossil fuel soot and therefore caused more negative forcing, as also found in previous studies. Diesel soot (black and organic carbon) experiments had relatively smaller cloud impacts with five of the models <±0.06 Wm-2 from clouds. The results are subject to the caveats that variability among models, and regional and interrannual variability for each model, are large. This comparison together with previously published results stresses the need to further constrain aerosol microphysical schemes. The non-linearities resulting from the competition of opposing effects on the CCN population make it difficult to extrapolate from idealized experiments to likely impacts of realistic potential emission changes.

119

Supersaturation and diffusional drop growth in liquid clouds  

Science Conference Proceedings (OSTI)

The process of collective diffusional growth of droplets in an adiabatic parcel ascending or descending with the constant vertical velocity is analyzed in the frame of the regular condensation approach. Closed equations for the evolution of liquid ...

M. Pinsky; I. P. Mazin; A. Korolev; A. Khain

120

Satellite Determination of Stratus Cloud Microphysical Properties  

Science Conference Proceedings (OSTI)

Satellite measurements of liquid water path from SSM/I, broadband albedo from ERBE, and cloud characteristics from ISCCP are used to study stratus regions. An average cloud liquid water path of 0.120 ± 0.032 kg m?2 is derived by dividing the ...

Paquita Zuidema; Dennis L. Hartmann

1995-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Determination of 3-D Cloud Ice Water Contents by Combining Multiple...  

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

Determination of 3-D Cloud Ice Water Contents by Combining Multiple Data Sources from Satellite, Ground Radar, and a Numerical Model Liu, Guosheng Florida State University Seo,...

122

The Effect of Stochastic Cloud Structure on the Icing Process  

Science Conference Proceedings (OSTI)

Current understanding of the icing process through collisions between a surface and supercooled cloud droplets is based upon two factors. First, for a given temperature, when the cloud liquid water content, W, exceeds a critical value, wc (the ...

A. R. Jameson; A. B. Kostinski

2000-09-01T23:59:59.000Z

123

Mass-Flux Budgets of Shallow Cumulus Clouds  

Science Conference Proceedings (OSTI)

The vertical transport by shallow nonprecipitating cumulus clouds of conserved variables, such as the total specific humidity or the liquid water potential temperature, can be well modeled by the mass-flux approach, in which the cloud field is ...

Stephan R. de Roode; Christopher S. Bretherton

2003-01-01T23:59:59.000Z

124

Molecular mean field theory for liquid water  

E-Print Network (OSTI)

Attractive bonding interactions between molecules typically have inherent conservation laws which influence the statistical properties of such systems in terms of corresponding sum rules. We considered lattice water as an example and enunciated the consequences of the sum rule through a general computational procedure called "Molecular mean field" theory. Fluctuations about mean field are computed and many of the liquid properties have been deduced and compared with Monte Carlo simulation, molecular dynamics and experimental results. Large correlation lengths are seen to be a consequence of the sum rule in liquid phase. Long range Coulomb interactions are shown to have minor effects on our results.

Jampa Maruthi Pradeep Kanth; Ramesh Anishetty

2010-04-09T23:59:59.000Z

125

Cold Water Model Simulation of Aluminum Liquid Fluctuations ...  

Science Conference Proceedings (OSTI)

Symposium, Electrode Technology for Aluminium Production ... Cold Water Model Simulation of Aluminum Liquid Fluctuations Induced by Anodic Gas in New ...

126

Validation of Satellite-Derived Liquid Water Paths Using ARM SGP Microwave Radiometers  

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

Satellite-Derived Liquid Water Paths Using Satellite-Derived Liquid Water Paths Using ARM SGP Microwave Radiometers M. M. Khaiyer and J. Huang Analytical Services & Materials, Inc. Hampton, Virginia P. Minnis, B. Lin, and W. L. Smith, Jr. National Aeronautics and Space Administration Langley Research Center Hampton, Virginia A. Fan Science Applications International Corporation Hampton, Virginia A. Rapp Colorado State University Fort Collins, Colorado Introduction Satellites are useful for monitoring climatological parameters over large domains. They are especially useful for measuring various cloud microphysical and radiative parameters where ground-based instruments are not available. The geostationary operational environmental satellite (GOES) has been used to retrieve cloud and radiative properties over an extended domain centered on the Atmospheric

127

Retrieval of Cloud Water and Water Vapor Contents from Doppler Radar Data in a Tropical Squall Line  

Science Conference Proceedings (OSTI)

This paper describes the retrieval of cloud water and water vapor contents from Doppler radar data. The convective part of a tropical squall line (22 June 1981) observed during the COPT 81 (Convection Profonde Tropicale 1981) West African ...

Danièle Hauser; Paul Amayenc

1986-04-01T23:59:59.000Z

128

Wind Tunnel Measurements of the Response of Hot-Wire Liquid Water Content Instruments to Large Droplets  

Science Conference Proceedings (OSTI)

Wet wind tunnel tests were performed on more than 23 cloud liquid water content (LWC) probes and drop spectrometers at the NASA Icing Research Tunnel, with a main objective to characterize their response to large-droplet conditions. As a part of ...

J. W. Strapp; J. Oldenburg; R. Ide; L. Lilie; S. Bacic; Z. Vukovic; M. Oleskiw; D. Miller; E. Emery; G. Leone

2003-06-01T23:59:59.000Z

129

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...

130

Accurate Liquid Water Path Retrieval from Low-Cost Microwave Radiometers Using Additional Information from a Lidar Ceilometer and Operational Forecast Models  

Science Conference Proceedings (OSTI)

Water clouds have an important impact on the radiative balance of the earth. The use of ground-based dual-frequency microwave radiometers to derive both liquid water path (LWP) and water vapor path (WVP) is well established, but uncertainties ...

Nicolas Gaussiat; Robin J. Hogan; Anthony J. Illingworth

2007-09-01T23:59:59.000Z

131

The Structure of Low-Altitude Clouds over the Southern Ocean as Seen by CloudSat  

Science Conference Proceedings (OSTI)

A climatology of the structure of the low-altitude cloud field (tops below 4 km) over the Southern Ocean (40°–65°S) in the vicinity of Australia (100°–160°E) has been constructed with CloudSat products for liquid water and ice water clouds. ...

Yi Huang; Steven T. Siems; Michael J. Manton; Luke B. Hande; John M. Haynes

2012-04-01T23:59:59.000Z

132

Detecting Cirrus-Overlapping-Water Clouds and Retrieving their...  

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

Different methods have been proposed to detect multilayer clouds using passive remote sensing data. Baum et al. (1995) used the CO 2 -slicing technique applied to the...

133

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

134

An Explanation for the Existence of Supercooled Water at the Top of Cold Clouds  

Science Conference Proceedings (OSTI)

Aircraft measurements in many cold cloud systems have found a narrow layer of supercooled water to exist at the cloud top, even at temperatures colder than ?30°C. We show in this paper that the imbalance between the condensate supply rate and the ...

Robert M. Rauber; Ali Tokay

1991-04-01T23:59:59.000Z

135

Airborne Measurement of Liquid and Total Water Content  

Science Conference Proceedings (OSTI)

Two identical liquid water content (LWC) King probes—one total water content/liquid water content (TWC/LWC) Nevzorov probe and two constant-temperature T probes that are different in size to distinguish particles of different densities and ...

German Vidaurre; John Hallett; David C. Rogers

2011-09-01T23:59:59.000Z

136

Ab Initio Quantum Liquid Water and Aqueous Ionic Solutions |...  

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

250 Million Year: 2013 Research Domain: Physics A highly accurate and detailed understanding of the microscopic structure of liquid water is of great importance to a number of...

137

Liquid Fuels from CO2, Water, and Solar Energy  

Science Conference Proceedings (OSTI)

Symposium, Energy Technologies and Carbon Dioxide Management. Presentation Title, Liquid Fuels from CO2, Water, and Solar Energy. Author(s), Aldo ...

138

Numerical Weather Simulations with Different Formulations for the Advection of Humidity and Cloud Water  

Science Conference Proceedings (OSTI)

This study investigates the effect on short-range weather prediction of using different numerical advection schemes for humidity and cloud water. Comparisons are made between predictions using the basic centered and upstream schemes and the more ...

Erik Berge; Jón Egill Kristjánsson

1992-08-01T23:59:59.000Z

139

Absorption of Visible Radiation by Atmospheric Aerosol Particles Fog and Cloud Water Residues  

Science Conference Proceedings (OSTI)

Light absorption by samples of atmospheric aerosol particles as a function of size was studied using the integrating sphere method. In addition, the optical properties of fog and cloud-water residues were determined. The samples were taken at two ...

Karl Andre; Ralph Dlugi; Gottfried Schnatz

1981-01-01T23:59:59.000Z

140

A GCM Parameterization for the Shortwave Radiative Properties of Water Clouds  

Science Conference Proceedings (OSTI)

A new parameterization is presented for the shortwave radiative properties of water clouds, which is fast enough to be included in general circulation models (GCMs). It employs the simple relationships found by Slingo and Schrecker for the ...

A. Slingo

1989-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

LASE Measurements of Water Vapor, Aerosol, and Cloud Distributions in Saharan Air Layers and Tropical Disturbances  

Science Conference Proceedings (OSTI)

The Lidar Atmospheric Sensing Experiment (LASE) on board the NASA DC-8 measured high-resolution profiles of water vapor and aerosols, and cloud distributions in 14 flights over the eastern North Atlantic during the NASA African Monsoon ...

Syed Ismail; Richard A. Ferrare; Edward V. Browell; Gao Chen; Bruce Anderson; Susan A. Kooi; Anthony Notari; Carolyn F. Butler; Sharon Burton; Marta Fenn; Jason P. Dunion; Gerry Heymsfield; T. N. Krishnamurti; Mrinal K. Biswas

2010-04-01T23:59:59.000Z

142

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

143

Condensation Coefficient Measurement for Water in the UMR Cloud Simulation Chamber  

Science Conference Proceedings (OSTI)

A systematic series of condensation coefficient measurements of water have been made using the University of Missouri—Rolla cooled-wall expansion chamber which simulates the thermodynamics of cloud. This coefficient is seen to decrease from a ...

D. E. Hagen; J. Schmitt; M. Trueblood; J. Carstens; D. R. White; D. J. Alofs

1989-03-01T23:59:59.000Z

144

A Simple Parameterization of Cloud Water Related Variables for Use in Boundary Layer Models  

Science Conference Proceedings (OSTI)

A simple parameterization of cloud water related variables has been developed which can be used in meteorological models that use a prognostic equation for the turbulent kinetic energy. Based on the results of large-eddy simulations (LES), ...

J. W. M. Cuijpers; P. Bechtold

1995-07-01T23:59:59.000Z

145

A Parameterization of the Visible Extinction Coefficient of Ice Clouds in Terms of the Ice/Water Content  

Science Conference Proceedings (OSTI)

This article describes a parameterization of the visible extinction coefficient of cirrus and frontal ice cloud in terms of the ice/water content. The parameterization is based on the discovery that the ice cloud particle size spectra from a ...

C. Martin R. Platt

1997-08-01T23:59:59.000Z

146

Field Intercomparison of Ground-Based Cloud Physics Instruments at Whitetop Mountain, Virginia  

Science Conference Proceedings (OSTI)

In May 1987 a two-week field intercomparison study of ground-based cloud liquid water content (LWC) and cloud detector instruments was performed at the Tennessee Valley Authority research station at the summit of Whitetop Mountain, Virginia. The ...

R. J. Valente; R. K. A. M. Mallant; S. E. McLaren; R. S. Schemenauer; R. E. Stogner

1989-06-01T23:59:59.000Z

147

Performance of a Triclass Parameterization for the Collision–Coalescence Process in Shallow Clouds  

Science Conference Proceedings (OSTI)

Focusing on the formation of precipitation in marine stratiform clouds, a two-moment bulk parameterization for three liquid water classes (cloud, drizzle, and rain) is proposed to describe the process of collision–coalescence. Based on the ...

Vivek Sant; Ulrike Lohmann; Axel Seifert

2013-06-01T23:59:59.000Z

148

The Structures of Summer Convective Clouds in Eastern Montana. II: Effects of Artificial Seeding  

Science Conference Proceedings (OSTI)

The seeding of clouds in Miles City, Montana with AgI pyrotechnics at cloud tops generally produced large increases in ice particle concentrations, decreases in liquid water contents, and increases in precipitation particles lower down in the ...

Peter V. Hobbs; Marcia K. Politovich

1980-06-01T23:59:59.000Z

149

Liquid and Ice Cloud Microphysics in the CSU General Circulation Model. Part 1: Model Description and Simulated Microphysical Processes  

Science Conference Proceedings (OSTI)

Microphysical processes responsible for the formation and dissipation of water and ice clouds have been incorporated into the Colorado State University General Circulation Model in order to 1) yield a more physically based representation of the ...

Laura D. Fowler; David A. Randall; Steven A. Rutledge

1996-03-01T23:59:59.000Z

150

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

151

Energetics of Hydrogen Bond Network Rearrangements in Liquid Water  

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

Energetics of Hydrogen Bond Network Rearrangements in Liquid Water Print Energetics of Hydrogen Bond Network Rearrangements in Liquid Water Print The unique chemical and physical properties of liquid water are thought to result from the highly directional hydrogen bonding (H-bonding) network structure and its associated dynamics. However, despite intense experimental and theoretical scrutiny, a complete description of this structure has been elusive. Recently, with the help of their novel liquid microjet apparatus, a University of California, Berkeley, group derived a new energy criterion for H-bonds based on experimental data. With this new criterion based on analysis of the temperature dependence of the x-ray absorption spectra of normal and supercooled liquid water, they concluded that the traditional structural model of water is valid.

152

Energetics of Hydrogen Bond Network Rearrangements in Liquid Water  

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

Energetics of Hydrogen Bond Network Rearrangements in Liquid Water Print Energetics of Hydrogen Bond Network Rearrangements in Liquid Water Print The unique chemical and physical properties of liquid water are thought to result from the highly directional hydrogen bonding (H-bonding) network structure and its associated dynamics. However, despite intense experimental and theoretical scrutiny, a complete description of this structure has been elusive. Recently, with the help of their novel liquid microjet apparatus, a University of California, Berkeley, group derived a new energy criterion for H-bonds based on experimental data. With this new criterion based on analysis of the temperature dependence of the x-ray absorption spectra of normal and supercooled liquid water, they concluded that the traditional structural model of water is valid.

153

Energetics of Hydrogen Bond Network Rearrangements in Liquid Water  

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

Energetics of Hydrogen Bond Network Rearrangements in Liquid Water Print Energetics of Hydrogen Bond Network Rearrangements in Liquid Water Print The unique chemical and physical properties of liquid water are thought to result from the highly directional hydrogen bonding (H-bonding) network structure and its associated dynamics. However, despite intense experimental and theoretical scrutiny, a complete description of this structure has been elusive. Recently, with the help of their novel liquid microjet apparatus, a University of California, Berkeley, group derived a new energy criterion for H-bonds based on experimental data. With this new criterion based on analysis of the temperature dependence of the x-ray absorption spectra of normal and supercooled liquid water, they concluded that the traditional structural model of water is valid.

154

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

155

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...

156

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

157

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

158

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

159

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

160

Water an Unusual Liquid; LCLS Provides New Insights | Stanford Synchrotron  

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

Water an Unusual Liquid; LCLS Provides New Insights Water an Unusual Liquid; LCLS Provides New Insights Wednesday, November 13, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Anders Nilsson, SUNCAT The anomalous physical properties of water are responsible for sustaining much of life on earth; for example, water displays a higher heat capacity than common liquids and expands upon freezing. Some of these anomalous physical properties become dramatically enhanced upon supercooling below the freezing point. In particular, extrapolations of the thermal expansion coefficient, isothermal compressibility, heat capacity and correlation length can all be fitted with a power law divergence with the same apparent singularity temperature of about 228 K. Experiments on pure bulk water below about ~240 K have so far been difficult: water crystallization occurs

Note: This page contains sample records for the topic "liquid water clouds" 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

Stratocumulus Liquid Water Content from Dual-Wavelength Radar  

Science Conference Proceedings (OSTI)

A technique is described to retrieve stratocumulus liquid water content (LWC) using the differential attenuation measured by vertically pointing radars at 35 and 94 GHz. Millimeter-wave attenuation is proportional to LWC and increases with ...

Robin J. Hogan; Nicolas Gaussiat; Anthony J. Illingworth

2005-08-01T23:59:59.000Z

162

Assessment of Vertically Integrated Liquid (VIL) Water Content Radar Measurement  

Science Conference Proceedings (OSTI)

Vertically integrated liquid (VIL) water content is a parameter obtained from a radar performing voluminal scanning. This parameter has proven useful in the detection of severe storms and may be a worthwhile indicator for very short-term rainfall ...

Brice Boudevillain; Hervé Andrieu

2003-06-01T23:59:59.000Z

163

Icing Wind Tunnel Tests on the CSIRO Liquid Water Probe  

Science Conference Proceedings (OSTI)

Wet wind tunnel tests have been Performed on several versions of the CSIRO probe designed for the airborne measurement of liquid water content. Four different controller units and 17 different Probe sensors (including half-size and shielded ...

W. D. King; J. E. Dye; D. Baumgardner; J. W. Strapp; D. Huffman

1985-09-01T23:59:59.000Z

164

Forced Dispersion of Liquefied Natural Gas Vapor Clouds with Water Spray Curtain Application  

E-Print Network (OSTI)

There has been, and will continue to be, tremendous growth in the use and distribution of liquefied natural gas (LNG). As LNG poses the hazard of flammable vapor cloud formation from a release, which may result in a massive fire, increased public concerns have been expressed regarding the safety of this fuel. In addition, regulatory authorities in the U.S. as well as all over the world expect the implementation of consequence mitigation measures for LNG spills. For the effective and safer use any safety measure to prevent and mitigate an accidental release of LNG, it is critical to understand thoroughly the action mechanisms. Water spray curtains are generally used by petro-chemical industries to prevent and mitigate heavier-than-air toxic or flammable vapors. It is also used to cool and protect equipment from heat radiation of fuel fires. Currently, water spray curtains are recognized as one of the economic and promising techniques to enhance the dispersion of the LNG vapor cloud formed from a spill. Usually, water curtains are considered to absorb, dilute, disperse and warm a heavier-than-air vapor cloud. Dispersion of cryogenic LNG vapor behaves differently from other dense gases because of low molecular weight and extremely low temperature. So the interaction between water curtain and LNG vapor is different than other heavier vapor clouds. Only two major experimental investigations with water curtains in dispersing LNG vapor clouds were undertaken during the 1970s and 1980s. Studies showed that water spray curtains enhanced LNG vapor dispersion from small spills. However, the dominant phenomena to apply the water curtain most effectively in controlling LNG vapor were not clearly demonstrated. The main objective of this research is to investigate the effectiveness of water spray curtains in controlling the LNG vapor clouds from outdoor experiments. A research methodology has been developed to study the dispersion phenomena of LNG vapor by the action of different water curtains experimentally. This dissertation details the research and experiment development. Small scale outdoor LNG spill experiments have been performed at the Brayton Fire Training Field at Texas A&M University. Field test results regarding important phenomena are presented and discussed. Results have determined that the water curtains are able to reduce the concentration of the LNG vapor cloud, push the vapor cloud upward and transfer heat to the cloud. These are being identified due to the water curtain mechanisms of entrainment of air, dilution of vapor with entrained air, transfer of momentum and heat to the gas cloud. Some of the dominant actions required to control and disperse LNG vapor cloud are also identified from the experimental tests. The gaps are presented as the future work and recommendation on how to improve the experiments in the future. This will benefit LNG industries to enhance its safety system and to make LNG facilities safer.

Rana, Morshed A.

2009-12-01T23:59:59.000Z

165

Process for blending coal with water immiscible liquid  

DOE Patents (OSTI)

A continuous process for blending coal with a water immiscible liquid produces a uniform, pumpable slurry. Pulverized raw feed coal and preferably a coal derived, water immiscible liquid are continuously fed to a blending zone (12 and 18) in which coal particles and liquid are intimately admixed and advanced in substantially plug flow to form a first slurry. The first slurry is withdrawn from the blending zone (12 and 18) and fed to a mixing zone (24) where it is mixed with a hot slurry to form the pumpable slurry. A portion of the pumpable slurry is continuously recycled to the blending zone (12 and 18) for mixing with the feed coal.

Heavin, Leonard J. (Olympia, WA); King, Edward E. (Gig Harbor, WA); Milliron, Dennis L. (Lacey, WA)

1982-10-26T23:59:59.000Z

166

Effects of Radiation and Turbulence on the Diabatic Heating and Water Budget of the Stratiform Region of a Tropical Cloud Cluster  

Science Conference Proceedings (OSTI)

A two-dimensional, kinematic model, incorporating ice- and water-cloud microphysics, visible and infrared radiation, and convective adjustment, is used to diagnose the thermodynamic, water vapor, and hydrometeor fields of the stratiform clouds ...

Dean D. Churchill; Robert A. Houze Jr.

1991-04-01T23:59:59.000Z

167

A Thermal Device for Aircraft Measurement of the Solid Water Content of Clouds  

Science Conference Proceedings (OSTI)

A constant temperature probe for the measurement of solid water content of clouds is described. The probe is operated at a temperature of approximately 25°C, and is designed to collect and melt ice particles that impact in an open half-cylinder, ...

W. D. King; D. E. Turvey

1986-09-01T23:59:59.000Z

168

An Airborne Millimeter-Wave Imaging Radiometer for Cloud, Precipitation, and Atmospheric Water Vapor Studies  

Science Conference Proceedings (OSTI)

A six-channel airborne total-power Millimeter-wave Imaging Radiometer (MIR) was recently built to provide measurements of atmospheric water vapor, clouds, and precipitation. The instrument is a cross-track scanner that has a 3-dB beamwidth of 3.5°...

P. Racette; R. F. Adler; J. R. Wang; A. J. Gasiewski; D. M. Jakson; D. S. Zacharias

1996-06-01T23:59:59.000Z

169

The cloud condensation nuclei and ice nuclei effects on tropical anvil characteristics and water vapor of the tropical tropopause layer  

SciTech Connect

Cloud anvils from deep convective clouds are of great importance to the radiative energy budget and the aerosol impact on them is the least understood. Few studies examined the effects of both cloud condensation nuclei (CCN) and ice nuclei (IN) on anvil properties and water vapor content (WVC) in the Tropical Tropopause Layer (TTL). Using a 3-dimensional cloud-resolving model with size-resolved cloud microphysics, we focus on the CCN and IN effects on cloud anvil properties and WVC in the TTL. We find that cloud microphysical changes induced by CCN/IN play a very important role in determining cloud anvil area and WVC in the TTL, whether convection is enhanced or suppressed. Also, CCN effects on anvil microphysical properties, anvil size and lifetime are much more evident relative to IN. IN has little effect on convection, but can increase ice number and mass concentrations significantly under humid conditions. CCN in the PBL is found to have greater effects on convective strength and mid-tropospheric CCN has negligible effects on convection and cloud properties. Convective transport may only moisten the main convective outflow region but the cloud anvil size determines the WVC in the TTL domain. This study shows an important role of CCN in the lower-troposphere in modifying convection, the upper-level cloud properties. It also shows the effects of IN and the PBL CCN on the upper-level clouds depends on the humidity, resolving some contradictory results in past studies. 2

Fan, Jiwen; Comstock, Jennifer M.; Ovchinnikov, Mikhail

2010-11-10T23:59:59.000Z

170

Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds  

Science Conference Proceedings (OSTI)

Project goals: (1) Use the routine surface and airborne measurements at the ARM SGP site, and the routine surface measurements at the NSA site, to continue our evaluations of model aerosol simulations; (2) Determine the degree to which the Raman lidar measurements of water vapor and aerosol scattering and extinction can be used to remotely characterize the aerosol humidification factor; (3) Use the high temporal resolution CARL data to examine how aerosol properties vary near clouds; and (4) Use the high temporal resolution CARL and Atmospheric Emitted Radiance Interferometer (AERI) data to quantify entrainment in optically thin continental cumulus clouds.

Richard A. Ferrare; David D. Turner

2011-09-01T23:59:59.000Z

171

The Putative Liquid-Liquid Transition is a Liquid-Solid Transition in Atomistic Models of Water, Part II  

E-Print Network (OSTI)

This paper extends our earlier studies of free energy functions of density and crystalline order parameters for models of supercooled water, which allows us to examine the possibility of two distinct metastable liquid phases [J. Chem. Phys. 135, 134503 (2011) and arXiv:1107.0337v2]. Low-temperature reversible free energy surfaces of several different atomistic models are computed: mW water, TIP4P/2005 water, SW silicon and ST2 water, the last of these comparing three different treatments of long-ranged forces. In each case, we show that there is one stable or metastable liquid phase, and there is an ice-like crystal phase. The time scales for crystallization in these systems far exceed those of structural relaxation in the supercooled metastable liquid. We show how this wide separation in time scales produces an illusion of a low-temperature liquid-liquid transition. The phenomenon suggesting metastability of two distinct liquid phases is actually coarsening of the ordered ice-like phase, which we elucidate u...

Limmer, David T

2013-01-01T23:59:59.000Z

172

The Putative Liquid-Liquid Transition is a Liquid-Solid Transition in Atomistic Models of Water, Part II  

E-Print Network (OSTI)

This paper extends our earlier studies of free energy functions of density and crystalline order parameters for models of supercooled water, which allows us to examine the possibility of two distinct metastable liquid phases [J. Chem. Phys. 135, 134503 (2011) and arXiv:1107.0337v2]. Low-temperature reversible free energy surfaces of several different atomistic models are computed: mW water, TIP4P/2005 water, SW silicon and ST2 water, the last of these comparing three different treatments of long-ranged forces. In each case, we show that there is one stable or metastable liquid phase, and there is an ice-like crystal phase. The time scales for crystallization in these systems far exceed those of structural relaxation in the supercooled metastable liquid. We show how this wide separation in time scales produces an illusion of a low-temperature liquid-liquid transition. The phenomenon suggesting metastability of two distinct liquid phases is actually coarsening of the ordered ice-like phase, which we elucidate using both analytical theory and computer simulation. For the latter, we describe robust methods for computing reversible free energy surfaces, and we consider effects of electrostatic boundary conditions. We show that sensible alterations of models and boundary conditions produce no qualitative changes in low-temperature phase behaviors of these systems, only marginal changes in equations of state. On the other hand, we show that altering sampling time scales can produce large and qualitative nonequilibrium effects. Recent reports of evidence of a liquid-liquid critical point in computer simulations of supercooled water are considered in this light.

David T. Limmer; David Chandler

2013-03-13T23:59:59.000Z

173

Structure and Depletion at Fluoro- and Hydro-carbon/Water Liquid/Liquid Interfaces  

E-Print Network (OSTI)

The results of x-ray reflectivity studies of two oil/water (liquid/liquid) interfaces are inconsistent with recent predictions of the presence of a vapor-like depletion region at hydrophobic/aqueous interfaces. One of the oils, perfluorohexane, is a fluorocarbon whose super-hydrophobic interface with water provides a stringent test for the presence of a depletion layer. The other oil, heptane, is a hydrocarbon and, therefore, is more relevant to the study of biomolecular hydrophobicity. These results are consistent with the sub-angstrom proximity of water to soft hydrophobic materials.

Kaoru Kashimoto; Jaesung Yoon; Binyang Hou; Chiu-hao Chen; Binhua Lin; Makoto Aratono; Takanori Takiue; Mark L. Schlossman

2008-07-18T23:59:59.000Z

174

Impacts of Ice Clouds on GPS Radio Occultation Measurements  

Science Conference Proceedings (OSTI)

Mathematical solutions accounting for the effects of liquid and ice clouds on the propagation of the GPS radio signals are first derived. The percentage contribution of ice water content (IWC) to the total refractivity increases linearly with the ...

X. Zou; S. Yang; P. S. Ray

2012-12-01T23:59:59.000Z

175

Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds  

Science Conference Proceedings (OSTI)

The 'Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds' project focused extensively on the analysis and utilization of water vapor and aerosol profiles derived from the ARM Raman lidar at the Southern Great Plains ARM site. A wide range of different tasks were performed during this project, all of which improved quality of the data products derived from the lidar or advanced the understanding of atmospheric processes over the site. These activities included: upgrading the Raman lidar to improve its sensitivity; participating in field experiments to validate the lidar aerosol and water vapor retrievals; using the lidar aerosol profiles to evaluate the accuracy of the vertical distribution of aerosols in global aerosol model simulations; examining the correlation between relative humidity and aerosol extinction, and how these change, due to horizontal distance away from cumulus clouds; inferring boundary layer turbulence structure in convective boundary layers from the high-time-resolution lidar water vapor measurements; retrieving cumulus entrainment rates in boundary layer cumulus clouds; and participating in a field experiment that provided data to help validate both the entrainment rate retrievals and the turbulent profiles derived from lidar observations.

Turner, David, D.; Ferrare, Richard, A.

2011-07-06T23:59:59.000Z

176

Equation of State for Supercooled Water Near the Liquid-Liquid Critical Point  

E-Print Network (OSTI)

We have developed a scaled parametric equation of state to describe and predict thermodynamic properties of supercooled water. The equation of state, built on the growing evidence that the critical point of supercooled liquid-liquid water separation exists, is universal in terms of theoretical scaling fields and is shown to belong to the Ising-model class of universality. The theoretical scaling fields are postulated to be analytical combinations of the physical fields, pressure and temperature. The equation of state enables us to accurately locate the "Widom line" (the locus of stability minima) and determine that the critical pressure is considerably lower than predicted by computer simulations.

M. A. Anisimov; D. A. Fuentevilla

2006-09-19T23:59:59.000Z

177

An Evaluation of MWR Retrievals of Liquid Water Path  

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

Evaluation of MWR Retrievals Evaluation of MWR Retrievals of Liquid Water Path and Precipitable Water Vapor R. T. Marchand and T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington Introduction This paper offers some observations on the quality of Microwave Radiometer (MWR) retrievals of precipitable water vapor (PWV) and liquid water path (LWP). The paper shows case study comparisons between the standard "statistical" approach and those obtained using an iterative solution of the microwave radiative transfer equations. These examples show how improvements in the retrieval of LWP can be obtained by using an iterative approach, but that possible improvements are limited by the accuracy of the forward model absorption coefficients and errors in the brightness temperature measurements. Each of these effects limits the

178

Core-softened Fluids, Water-like Anomalies and the Liquid-Liquid Critical Points  

E-Print Network (OSTI)

Molecular dynamics simulations are used to examine the relationship between water-like anomalies and the liquid-liquid critical point in a family of model fluids with multi-Gaussian, core-softened pair interactions. The core-softened pair interactions have two length scales, such that the longer length scale associated with a shallow, attractive well is kept constant while the shorter length scale associated with the repulsive shoulder is varied from an inflexion point to a minimum of progressively increasing depth. As the shoulder well depth increases, the pressure required to form the high density liquid decreases and the temperature up to which the high-density liquid is stable increases, resulting in the shift of the liquid-liquid critical point to much lower pressures and higher temperatures. The pair correlation entropy is computed to show that the excess entropy anomaly diminishes when the shoulder well depth increases. Excess entropy scaling of diffusivity in this class of fluids is demonstrated, showing that decreasing strength of the excess entropy anomaly with increasing shoulder depth results in the progressive loss of water-like thermodynamic, structural and transport anomalies. Instantaneous normal mode analysis was used to index the overall curvature distribution of the fluid and the fraction of imaginary frequency modes was shown to correlate well with the anomalous behaviour of the diffusivity and the pair correlation entropy. The results suggest in the case of core-softened potentials, in addition to the presence of two length scales, energetic and entropic effects associated with local minima and curvatures of the pair interaction play an important role in determining the presence of water-like anomalies and the liquid-liquid phase transition.

Evy Salcedo; Alan B. de Oliveira; Ney M. Barraz Jr; Charusita Chakravarty; Marcia C. Barbosa

2011-03-21T23:59:59.000Z

179

Liquid-liquid interfaces of semifluorinated alkane diblock copolymers with water, alkanes, and perfluorinated alkanes.  

DOE Green Energy (OSTI)

The liquid-liquid interface between semifluorinated alkane diblock copolymers of the form F3C(CF2)n-1-(CH2)m-1CH3 and water, protonated alkanes, and perfluorinated alkanes are studied by fully atomistic molecular dynamics simulations. A modified version of the OPLS-AA (Optimized Parameter for Liquid Simulation All-Atom) force field of Jorgensen et al. has been used to study the interfacial behavior of semifluorinated diblocks. Aqueous interfaces are found to be sharp, with correspondingly large values of the interfacial tension. Due to the reduced hydrophobicity of the protonated block compared to the fluorinated block, hydrogen enhancement is observed at the interface. Water dipoles in the interfacial region are found to be oriented nearly parallel to the liquid-liquid interface. A number of protonated alkanes and perfluorinated alkanes are found to be mutually miscible with the semifluorinated diblocks. For these liquids, interdiffusion follows the expected Fickian behavior, and concentration-dependent diffusivities are determined.

Perahia, Dvora, Dr. (Clemson University, Clemson, SC); Pierce, Flint (Clemson University, Clemson, SC); Tsige, Mesfin (Southern Illinois University, Carbondale, IL); Grest, Gary Stephen, Dr.

2008-08-01T23:59:59.000Z

180

Hurricane Debby—An Illustration of the Complementary Nature of VAS Soundings and Cloud and Water Vapor Motion Winds  

Science Conference Proceedings (OSTI)

The utility of VISSR Atmospheric Sounder (VAS) temperature and moisture soundings and cloud and water vapor motion winds in defining a storm and its surroundings at subsynoptic scales has been examined using a numerical analysis and prognosis ...

John F. Le Marshall; William L. Smith; Geary M. Callan

1985-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Retrieval of cloud properties using CALIPSO Imaging Infrared Radiometer. Part II: effective diameter and ice water path  

Science Conference Proceedings (OSTI)

The paper describes the version 3 Level 2 operational analysis of the Imaging Infrared Radiometer (IIR) data collected in the framework of the CALIPSO mission to retrieve cirrus cloud effective diameter and ice water path in synergy with the ...

Anne Garnier; Jacques Pelon; Philippe Dubuisson; Ping Yang; Michaël Faivre; Olivier Chomette; Nicolas Pascal; Pat Lucker; Tim Murray

182

Demonstration Measurements of Water Vapor, Cirrus Clouds, and Carbon Dioxide Using a High-Performance Raman Lidar  

Science Conference Proceedings (OSTI)

Profile measurements of atmospheric water vapor, cirrus clouds, and carbon dioxide using the Raman Airborne Spectroscopic lidar (RASL) during ground-based, upward-looking tests are presented here. These measurements improve upon any previously ...

David N. Whiteman; Kurt Rush; Igor Veselovskii; Martin Cadirola; Joseph Comer; John R. Potter; Rebecca Tola

2007-08-01T23:59:59.000Z

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

Evaluation of the Daylight Cycle of Model-Predicted Cloud Amount and Condensed Water Path over Europe with Observations from MSG SEVIRI  

Science Conference Proceedings (OSTI)

The evaluation of the diurnal cycle of cloud amount (CA) and cloud condensed water path (CWP) as predicted by climate models receives relatively little attention, mostly because of the lack of observational data capturing the diurnal cycle of ...

R. A. Roebeling; E. van Meijgaard

2009-04-01T23:59:59.000Z

185

The Characteristics and Distribution of Cloud Water over the Mountains of Northern Colorado during Wintertime Storms. Part II: Spatial Distribution and Microphysical Characteristics  

Science Conference Proceedings (OSTI)

The Physical and microphysical structure of the supercooled water fields in wintertime storms over the Park Range of the northern Colorado Rocky Mountains is examined using aircraft and ground-based measurements. Cloud top, cloud base, and zones ...

Robert M. Rauber; Lewis O. Grant

1986-04-01T23:59:59.000Z

186

Performance Evaluation of Advanced LLW Liquid Processing Technology: Boiling Water Reactor Liquid Processing  

Science Conference Proceedings (OSTI)

This report provides condensed information on boiling water reactor (BWR) membrane based liquid radwaste processing systems. The report presents specific details of the technology, including design, configuration, and performance. This information provides nuclear plant personnel with data useful in evaluating the merits of applying advanced processes at their plant.

2001-11-26T23:59:59.000Z

187

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

188

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

189

Comparisons of SSM/I Liquid Water Paths with Aircraft Measurements  

Science Conference Proceedings (OSTI)

Comparisons have been made between in situ aircraft measurements of integrated liquid water and retrievals of integrated liquid water path (LWP) from algorithms using SSM/I brightness temperatures. The aircraft measurements were made over the ...

Stewart G. Cober; Andre Tremblay; George A. Isaac

1996-03-01T23:59:59.000Z

190

Assessing the Radiative Impact of Clouds of Low Optical Depth  

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

the Radiative Impact of Clouds of the Radiative Impact of Clouds of Low Optical Depth W. O'Hirok and P. Ricchiazzi Institute for Computational Earth System Science University of California Santa Barbara, California C. Gautier Department of Geography and Institute for Computational Earth System Science University of California Santa Barbara, California Introduction Analysis from the International Satellite Cloud Climatology Project (ISCCP) reveals that the global mean cloud optical depth is surprisingly low (i.e., τ = 3.8). While this value is probably dominated by extensive fields of cirrus, the average for liquid water clouds is also likely smaller than expected. It is in this regime (τ <10) where remote measurements of cloud optical thickness or liquid water path (LWP)

191

Liquid-Water-Droplet Adhesion-Force Measurements on Fresh and...  

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

tilted plate, wettability Abstract Optimal water management in proton-exchange-membrane fuel cells at lower temperatures requires the efficient removal of liquid water from the...

192

Liquid water transport in fuel cell gas diffusion layers Aimy Ming Jii Bazylak  

E-Print Network (OSTI)

Liquid water transport in fuel cell gas diffusion layers by Aimy Ming Jii Bazylak Bachelor means, without the permission of the author. #12;ii Liquid water transport in fuel cell gas diffusion State University) Abstract Liquid water management has a major impact on the performance and durability

Victoria, University of

193

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

194

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

195

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

196

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

197

Gas-Liquid Coexistence in the Primitive Model for Water  

E-Print Network (OSTI)

We evaluate the location of the gas-liquid coexistence line and of the associated critical point for the primitive model for water (PMW), introduced by Kolafa and Nezbeda [J. Kolafa and I. Nezbeda, Mol. Phys. 61, 161 (1987)]. Besides being a simple model for a molecular network forming liquid, the PMW is representative of patchy proteins and novel colloidal particles interacting with localized directional short-range attractions. We show that the gas-liquid phase separation is metastable, i.e. it takes place in the region of the phase diagram where the crystal phase is thermodynamically favored, as in the case of articles interacting via short-range attractive spherical potentials. Differently from spherical potentials, we do not observe crystallization close to the critical point. The region of gas-liquid instability of this patchy model is significantly reduced as compared to equivalent models of spherically interacting particles, confirming the possibility of observing kinetic arrest in an homogeneous sample driven by bonding as opposed to packing.

F. Romano; P. Tartaglia; F. Sciortino

2007-03-14T23:59:59.000Z

198

Spin states of para-water and ortho-water molecule in gas and liquid phases  

E-Print Network (OSTI)

Spin degrees of freedom of water molecule in gas and liquid state were investigated in order to provide a reasonable answer about the unsolved problem of a long-term behavior of water spin isomers. The approach used involves an assumption that molecules change their spin state from a pure state to a mixed one when they interact with some sorts of adsorbent surface. Some models and conceptions of the quantum information processing were used.

V. K. Konyukhov

2009-09-23T23:59:59.000Z

199

Electronic structure effects in liquid water studied by photoelectron spectroscopy and density functional theory  

E-Print Network (OSTI)

in comparison with gas-phase water, ice close to the meltingcrystalline ice at two different temperatures, and gas-phaseof gas-phase water, liquid water and crystalline ice using

Nordlund, Dennis

2008-01-01T23:59:59.000Z

200

Frostbite Theater - Liquid Nitrogen Experiments - Dry Ice vs. Liquid  

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

Egg + Liquid Nitrogen + Time-lapse! Egg + Liquid Nitrogen + Time-lapse! Previous Video (Egg + Liquid Nitrogen + Time-lapse!) Frostbite Theater Main Index Next Video (Liquid Nitrogen Cooled Dry Ice in Water!) Liquid Nitrogen Cooled Dry Ice in Water! Dry Ice vs. Liquid Nitrogen! Dry ice is cold. Liquid nitrogen is cold, too. What happens when the two are mixed together? [ Show Transcript ] Announcer: Frostbite Theater presents... Cold Cuts! No baloney! Joanna and Steve: Just science! Joanna: Hi! I'm Joanna! Steve: And I'm Steve! Joanna: Have you ever wondered what happens when you mix dry ice and liquid nitrogen? Steve: Well, we just happen to have a chunk of dry ice left over from when we filmed 'How to Make a Cloud Chamber,' and here at Jefferson Lab, liquid nitrogen flows like water, so we're going to find out!

Note: This page contains sample records for the topic "liquid water clouds" 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

Combined Observational and Model Investigations of the Z–LWC Relationship in Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

In situ measurements indicate the complexity and nonunique character of radar reflectivity–liquid water content (Z–LWC) relationships in stratocumulus and cumulus clouds. Parameters of empirical (statistical) Z–LWC dependences vary within a wide ...

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

2008-02-01T23:59:59.000Z

202

Retrieval of Cloud Microphysical Properties from Thermal Infrared Observations by a Fast Iterative Radiance Fitting Method  

Science Conference Proceedings (OSTI)

An algorithm is presented for inferring the IR optical depth, effective radius, and liquid water path of clouds from multispectral observations of emitted thermal radiation, which takes advantage of the larger number of spectral channels of ...

C. Rathke; J. Fischer

2000-11-01T23:59:59.000Z

203

A Missing Solution to the Transport Equation and Its Effect on Estimation of Cloud Absorptive Properties  

Science Conference Proceedings (OSTI)

Most of the existing cloud radiation models treat liquid water drops of a variety of sizes as an ensemble of particles. The ensemble approach assumes that all drop sizes are well represented in an elementary volume, and its scattering and ...

Y. Knyazikhin; A. Marshak; W. J. Wiscombe; J. V. Martonchik; R. B. Myneni

2002-12-01T23:59:59.000Z

204

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

205

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

206

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

207

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

208

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

209

Bond orientational ordering in liquids: Towards a unified description of water-like anomalies, liquid-liquid transition, glass transition, and crystallization  

E-Print Network (OSTI)

There are at least three fundamental states of matter, depending upon temperature and pressure: gas, liquid, and solid (crystal). These states are separated by first-order phase transitions between them. In both gas and liquid phases the complete translational and rotational symmetry exist, whereas in a solid phase both symmetries are broken. In intermediate phases between liquid and solid, which include liquid crystal and plastic crystal phases, only one of the two symmetries is preserved. Among the fundamental states of matter, the liquid state is most poorly understood. We argue that it is crucial for a better understanding of liquid to recognize that a liquid generally has a tendency to have local structural order and its presence is intrinsic and universal to any liquid. Such structural ordering is a consequence of many body correlations, more specifically, bond angle correlations, which we believe are crucial for the description of the liquid state. We show that this physical picture may naturally explain difficult unsolved problems associated with the liquid state, such as anomalies of water-type liquids (water, Si, Ge, ...), liquid-liquid transition, liquid-glass transition, crystallization and quasicrystal formation, in a unified manner. In other words, we need a new order parameter representing low local free-energy configuration, which is bond orientational order parameter in many cases, in addition to density order parameter for the physical description of these phenomena. Here we review our two-order-parameter model of liquid and consider how transient local structural ordering is linked to all of the above-mentioned phenomena. The relationship between these phenomena are also discussed.

Hajime Tanaka

2013-07-02T23:59:59.000Z

210

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

211

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

212

A Study of Homogeneous Condensation-Freezing Nucleation of Small Water Droplets in an Expansion Cloud Chamber  

Science Conference Proceedings (OSTI)

Observations of the homogeneous nucleation of water vapor in an expansion cloud chamber have been carried out for the temperature range ?50 to +17°C in the carrier gases argon and helium. We have found that the onset of the ice phase in freshly ...

Rodney J. Anderson; Ronald C. Miller; James L. Kassner Jr.; Donald E. Hagen

1980-11-01T23:59:59.000Z

213

Relationship between Ice Water Path and Downward Longwave Radiation for Clouds Optically Thin in the Infrared: Observations and Model Calculations  

Science Conference Proceedings (OSTI)

A vertically pointing 3.2-cm radar is used to observe altostratus and cirrus clouds as they pass overhead. Radar reflectivities are used in combination with an empirical Zi-IWC (ice water content) relationship developed by Sassen (1987) to ...

Taneil Uttal; Sergey Y. Matrosov; Jack B. Snider; Robert A. Kropfli

1994-03-01T23:59:59.000Z

214

Detachment of Liquid-Water Droplets from Gas-Diffusion Layers  

SciTech Connect

A critical issue for optimal water management in proton-exchange-membrane fuel cells at lower temperatures is the removal of liquid water from the cell. This pathway is intimately linked with the phenomena of liquid-water droplet removal from surface of the gas-diffusion layer and into the flow channel. Thus, a good understanding of liquid-water transport and droplet growth and detachment from the gas-diffusion layer is critical. In this study, liquid-water droplet growth and detachment on the gas-diffusion layer surfaces are investigated experimentally to improve the understating of water transport through and removal from gas-diffusion layers. An experiment using a sliding-angle measurement is designed and used to quantify and directly measure the adhesion force for liquid-water droplets, and to understand the droplets? growth and detachment from the gas-diffusion layers.

Das, Prodip K.; Grippin, Adam; Weber, Adam Z.

2011-07-01T23:59:59.000Z

215

Liquid and Ice Cloud Microphysics in the CSU General Circulation Model. Part III: Sensitivity to Modeling Assumptions  

Science Conference Proceedings (OSTI)

The inclusion of cloud microphysical processes in general circulation models makes it possible to study the multiple interactions among clouds, the hydrological cycle, and radiation. The gaps between the temporal and spatial scales at which such ...

Laura D. Fowler; David A. Randall

1996-03-01T23:59:59.000Z

216

Objective Assessment of the Information Content of Visible and Infrared Radiance Measurements for Cloud Microphysical Property Retrievals over the Global Oceans. Part I: Liquid Clouds  

Science Conference Proceedings (OSTI)

The importance of accurately representing the role of clouds in climate change studies has become increasingly apparent in recent years, leading to a substantial increase in the number of satellite sensors and associated algorithms that are ...

Tristan S. L’Ecuyer; Philip Gabriel; Kyle Leesman; Steven J. Cooper; Graeme L. Stephens

2006-01-01T23:59:59.000Z

217

Electrokinetic Hydrogen Generation from Liquid WaterMicrojets  

SciTech Connect

We describe a method for generating molecular hydrogen directly from the charge separation effected via rapid flow of liquid water through a metal orifice, wherein the input energy is the hydrostatic pressure times the volume flow rate. Both electrokinetic currents and hydrogen production rates are shown to follow simple equations derived from the overlap of the fluid velocity gradient and the anisotropic charge distribution resulting from selective adsorption of hydroxide ions to the nozzle surface. Pressure-driven fluid flow shears away the charge balancing hydronium ions from the diffuse double layer and carries them out of the aperture. Downstream neutralization of the excess protons at a grounded target electrode produces gaseous hydrogen molecules. The hydrogen production efficiency is currently very low (ca. 10-6) for a single cylindrical jet, but can be improved with design changes.

Duffin, Andrew M.; Saykally, Richard J.

2007-05-31T23:59:59.000Z

218

Influence of gravity on the collective molecular dynamics of liquid water: the case of the floating water bridge  

E-Print Network (OSTI)

Quantum electrodynamics (QED) produces a picture of liquid water as a mixture of a low density coherent phase and an high density non-coherent phase. Consequently, the Archimedes principle prescribes that, within a gravitational field, liquid water should be made up, at surface, mainly of the coherent fraction, which becomes a cage where the gas-like non-coherent fraction is trapped, acquiring a non-vanishing pressure (vapor tension). Therefore, it is possible to probe the QED picture by observing the behavior of liquid water under reduced gravity conditions. The floating water bridge could be a useful test model.

Emilio Del Giudice; Giuseppe Vitiello

2010-09-29T23:59:59.000Z

219

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

220

Physical Response of Convective Clouds over the Sierra Nevada to Seeding with Dry Ice  

Science Conference Proceedings (OSTI)

The effect of seeding convective clouds with dry ice was studied using simultaneous aircraft and radar observations. Clouds that were initially ice-free with supercooled liquid water contents of 0.5 g m?3 when the tops reached the ?10°C level had ...

Arlen W. Huggins; Alfred R. Rodi

1985-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Thermal signature reduction through liquid nitrogen and water injection  

E-Print Network (OSTI)

The protection of aircraft against shoulder fired heat seeking missiles is of growing concern in the aviation community. This thesis presents a simple method for shielding the infrared signature of a jet engine from heat seeking missiles. The research efforts investigated two approaches to shield the thermal signature of the Noel Penny Type 401 turbojet at the Texas A&M University Propulsion Lab Test Cell. First, liquid nitrogen was injected through a manifold at a flow rate equivalent to the flow rate of exhaust gases, producing a small temperature reduction in the exhaust but no infrared shielding. Second, water was injected at a flow rate of 13% of the flow of exhaust gases, producing a greater temperature reduction and some shielding. Water was then injected through a manifold at a ?ow rate of 118% of the flow rate of exhaust gases, producing a substantial reduction in temperature and complete shielding of the infrared signature. Additionally, numerical simulations were performed using FLUENT to support these experiments. Results are presented in the form of thermocouple data and thermal images from the experiments, and in the form of temperature contours and streamtraces from the simulations.

Guarnieri, Jason Antonio

2004-12-01T23:59:59.000Z

222

Radiative effects of supercooled water Summary. Supercooled liquid water layers are visible in lidar imagery as a strongly enhanced return followed by  

E-Print Network (OSTI)

parameters. Hence cloud phase parameterizations in numerical forecast and climate models have tended parameterizations use other model variables (such as vertical velocity) to aid the diagnosis of liquid/ice fraction, suggesting that they are radiatively important. In this chapter, three profiles of liquid and ice extinction

Hogan, Robin

223

Understanding the Importance of Microphysics and Macrophysics for Warm Rain in Marine Low Clouds. Part I: Satellite Observations  

Science Conference Proceedings (OSTI)

The importance of macrophysical variables [cloud thickness, liquid water path (LWP)] and microphysical variables (effective radius re, effective droplet concentration Neff) on warm drizzle intensity and frequency across the tropics and subtropics ...

Terence L. Kubar; Dennis L. Hartmann; Robert Wood

2009-10-01T23:59:59.000Z

224

USE OF IONIC LIQUIDS IN PRODUCED WATER CLEAN UP J. McFarlane  

E-Print Network (OSTI)

USE OF IONIC LIQUIDS IN PRODUCED WATER CLEAN UP J. McFarlane Oak Ridge National Laboratory P.O. Box amounts of contaminated water along with the hydrocarbon phase, termed "produced water" by the industry 1 Agency (EPA) limit on oil and grease content in produced water discharged in the ocean is a daily maximum

225

Elucidating through-plane liquid water profile in a polymer electrolyte membrane fuel cell.  

DOE Green Energy (OSTI)

In this paper, a numerical model incorporating micro-porous layers (MPLs) is presented for simulating water transport within the gas diffusion layers (GDLs) and MPLs as well as across their interfaces in a polymer electrolyte membrane (PEM) fuel cell. One-dimensional analysis is conducted to investigate the impacts of MPL and GDL properties on the liquid-water profile across the anode GDL-MPL and cathode MPL-GDL regions. Furthermore, two-dimensional numerical simulations that take MPLs into account are also carried out to elucidate liquid water transport, particularly through-plane liquid-water profile in a PEM fuel cell. Results from case studies are presented.

Wang, Yun (University of California, Irvine, CA); Chen, Ken Shuang

2010-10-01T23:59:59.000Z

226

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

227

On the Fluctuations that Order and Frustrate Liquid Water  

E-Print Network (OSTI)

Quantitative water model . . . . . . . . . . . . . . . .5.3 Determining T g for water . . . . . . . . . . . . . . .iv Contents 6 Frustrating water at ordered surfaces 6.1

Limmer, David

2013-01-01T23:59:59.000Z

228

The Use of lce-Liquid Water Potential Temperature as a Thermodynamic Variable In Deep Atmospheric Models  

Science Conference Proceedings (OSTI)

Previous studies have shown liquid water potential temperature to be an inappropriate choice for a thermodynamic variable in a deep cumulus convection model. In this study, an alternate form of this variable called ice-liquid water potential ...

Gregory J. Tripoli; William R. Cotton

1981-05-01T23:59:59.000Z

229

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

230

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

231

Sound speed in liquid–gas mixtures: Water–air and water  

E-Print Network (OSTI)

The sound speed of a two-phase fluid, such as a magma-gas, water-air, or water-steam mixture, is dramatically different from the sound speed of either pure component. In numerous geologic situations the sound speed of such two-phase systems may be of interest: in the search for magma reservoirs, in seismic exploration of geothermal areas, in prediction of P wave velocity decreases prior to earthquakes, and in inversion of crustal and upper mantle seismic records. Probably most dramatically, fluid flow characteristics during eruptions of volcanoes and geysers are strongly dependent on the sound speed of erupting two-phase (or multiphase) fluids. In this paper the sound speeds of water, air, steam, water-air mixtures, and water-steam mixtures are calculated. It is demonstrated that sound speeds calculated from classical acoustic and fluid dynamics analyses agree with results obtained from finite amplitude 'vaporization wave ' theory. To the extent that air and steam are represented as perfect gases with an adiabatic exponent •, independent of temperature, their sound speeds vary in a simple manner directly with the square root of the absolute temperature. The sound speed of pure liquid water is a complex function of pressure and temperature and is given here to 8 kbar, 900øC. In pure water at all pressures the sound speed attains a maximum value near 100øC and decreases at higher temperatures; at high pressures the decrease is continuous, but at pressures below 1 kbar the sound speed reaches a minimum value in the

Susan Werner Kieffer

1977-01-01T23:59:59.000Z

232

Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt laser system  

E-Print Network (OSTI)

Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced of liquid water using electron pulses produced by a table-top terawatt laser system (T3 ). The results

Umstadter, Donald

233

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print The geometric structure of liquid water has been investigated in detail by many techniques, but many details are still under debate, such as the actual number of hydrogen bonds (at a given time) between the various water molecules. Even less is known about the electronic structure. Since it is the intermittent bonding between water molecules that gives liquid water its peculiar characteristics, the electronic structure plays a crucial role in understanding the properties of the liquid state. Consequently, information essential for insight into chemical and biological processes in aqueous environments is lacking. To address this need, researchers from Germany and the U.S. have used soft x-ray spectroscopy at the ALS to gain detailed insight into the electronic structure of liquid water. Their spectra show a strong isotope and a weak temperature effect, and, for the first time, a splitting of the primary emission line in x-ray emission spectra. By making use of the internal "femtosecond clock" of the core-hole lifetime, a detailed picture of the electronic structure can be painted that involves fast dissociation processes of the probed water molecules.

234

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print The geometric structure of liquid water has been investigated in detail by many techniques, but many details are still under debate, such as the actual number of hydrogen bonds (at a given time) between the various water molecules. Even less is known about the electronic structure. Since it is the intermittent bonding between water molecules that gives liquid water its peculiar characteristics, the electronic structure plays a crucial role in understanding the properties of the liquid state. Consequently, information essential for insight into chemical and biological processes in aqueous environments is lacking. To address this need, researchers from Germany and the U.S. have used soft x-ray spectroscopy at the ALS to gain detailed insight into the electronic structure of liquid water. Their spectra show a strong isotope and a weak temperature effect, and, for the first time, a splitting of the primary emission line in x-ray emission spectra. By making use of the internal "femtosecond clock" of the core-hole lifetime, a detailed picture of the electronic structure can be painted that involves fast dissociation processes of the probed water molecules.

235

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print The geometric structure of liquid water has been investigated in detail by many techniques, but many details are still under debate, such as the actual number of hydrogen bonds (at a given time) between the various water molecules. Even less is known about the electronic structure. Since it is the intermittent bonding between water molecules that gives liquid water its peculiar characteristics, the electronic structure plays a crucial role in understanding the properties of the liquid state. Consequently, information essential for insight into chemical and biological processes in aqueous environments is lacking. To address this need, researchers from Germany and the U.S. have used soft x-ray spectroscopy at the ALS to gain detailed insight into the electronic structure of liquid water. Their spectra show a strong isotope and a weak temperature effect, and, for the first time, a splitting of the primary emission line in x-ray emission spectra. By making use of the internal "femtosecond clock" of the core-hole lifetime, a detailed picture of the electronic structure can be painted that involves fast dissociation processes of the probed water molecules.

236

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print The geometric structure of liquid water has been investigated in detail by many techniques, but many details are still under debate, such as the actual number of hydrogen bonds (at a given time) between the various water molecules. Even less is known about the electronic structure. Since it is the intermittent bonding between water molecules that gives liquid water its peculiar characteristics, the electronic structure plays a crucial role in understanding the properties of the liquid state. Consequently, information essential for insight into chemical and biological processes in aqueous environments is lacking. To address this need, researchers from Germany and the U.S. have used soft x-ray spectroscopy at the ALS to gain detailed insight into the electronic structure of liquid water. Their spectra show a strong isotope and a weak temperature effect, and, for the first time, a splitting of the primary emission line in x-ray emission spectra. By making use of the internal "femtosecond clock" of the core-hole lifetime, a detailed picture of the electronic structure can be painted that involves fast dissociation processes of the probed water molecules.

237

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays Print The geometric structure of liquid water has been investigated in detail by many techniques, but many details are still under debate, such as the actual number of hydrogen bonds (at a given time) between the various water molecules. Even less is known about the electronic structure. Since it is the intermittent bonding between water molecules that gives liquid water its peculiar characteristics, the electronic structure plays a crucial role in understanding the properties of the liquid state. Consequently, information essential for insight into chemical and biological processes in aqueous environments is lacking. To address this need, researchers from Germany and the U.S. have used soft x-ray spectroscopy at the ALS to gain detailed insight into the electronic structure of liquid water. Their spectra show a strong isotope and a weak temperature effect, and, for the first time, a splitting of the primary emission line in x-ray emission spectra. By making use of the internal "femtosecond clock" of the core-hole lifetime, a detailed picture of the electronic structure can be painted that involves fast dissociation processes of the probed water molecules.

238

Supercooled Liquid Water Clouds in Utah Winter Mountain Storms: Cloud-seeding Implications of a Remote-Sensing Dataset  

Science Conference Proceedings (OSTI)

A polarization lidar, dual-wavelength microwave radiometer, and radiosonde dataset from 19 winter storms studied over the Tushar Mountains in the 1985 and 1987 Utah?NOAA cooperative weather modification field campaigns are used to characterize ...

Kenneth Sassen; Hongjie Zhao

1993-09-01T23:59:59.000Z

239

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

240

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

Note: This page contains sample records for the topic "liquid water clouds" 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

A comparison of cloud microphysical quantities with forecasts from cloud prediction models  

SciTech Connect

Numerical weather prediction models (ECMWF, NCEP) are evaluated using ARM observational data collected at the Southern Great Plains (SGP) site. Cloud forecasts generated by the models are compared with cloud microphysical quantities, retrieved using a variety of parameterizations. Information gained from this comparison will be utilized during the FASTER project, as models are evaluated for their ability to reproduce fast physical processes detected in the observations. Here the model performance is quantified against the observations through a statistical analysis. Observations from remote sensing instruments (radar, lidar, radiometer and radiosonde) are used to derive the cloud microphysical quantities: ice water content, liquid water content, ice effective radius and liquid effective radius. Unfortunately, discrepancies in the derived quantities arise when different retrieval schemes are applied to the observations. The uncertainty inherent in retrieving the microphysical quantities using various retrievals is estimated from the range of output microphysical values. ARM microphysical retrieval schemes (Microbase, Mace) are examined along with the CloudNet retrieval processing of data from the ARM sites for this purpose. Through the interfacing of CloudNet and “ARM” processing schemes an ARMNET product is produced and employed as accepted observations in the assessment of cloud model predictions.

Dunn, M.; Jensen, M.; Hogan, R.; O’Connor, E.; Huang, D.

2010-03-15T23:59:59.000Z

242

Cloud and Water Vapor Feedbacks in a Vertical Energy-Balance Model with Maximum Entropy Production  

Science Conference Proceedings (OSTI)

A vertically one-dimensional model is developed with cloud fraction constrained by the maximum entropy production (MEP) principle. The model reasonably reproduces the global mean climate with its surface temperature, radiation and heat fluxes, ...

Biao Wang; Teruyuki Nakajima; Guangyu Shi

2008-12-01T23:59:59.000Z

243

A Comparison of the Water Budgets between Clouds from AMMA and TWP-ICE  

Science Conference Proceedings (OSTI)

Two field campaigns, the African Monsoon Multidisciplinary Analysis (AMMA) and the Tropical Warm Pool–International Cloud Experiment (TWP-ICE), took place in 2006 near Niamey, Niger, and Darwin, Northern Territory, Australia, providing extensive ...

Xiping Zeng; Wei-Kuo Tao; Scott W. Powell; Robert A. Houze Jr.; Paul Ciesielski; Nick Guy; Harold Pierce; Toshihisa Matsui

2013-02-01T23:59:59.000Z

244

Hierarchical Tropical Cloud Systems in an Analog Shallow-Water Model  

Science Conference Proceedings (OSTI)

Recent observations have revealed an hierarchy of cloud clusters and superclusters within the Madden-Julian oscillation of the equatorial troposphere. The authors here report on the results of simulations with a model based on a simple nonlinear ...

Jun-Ichi Yano; James C. McWilliams; Mitchell W. Moncrieff; Kerry A. Emanuel

1995-05-01T23:59:59.000Z

245

Multilayer Cloud Detection with the MODIS Near-Infrared Water Vapor Absorption Band  

Science Conference Proceedings (OSTI)

Data Collection 5 processing for the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the NASA Earth Observing System (EOS) Terra and Aqua spacecraft includes an algorithm for detecting multilayered clouds in daytime. The main ...

Galina Wind; Steven Platnick; Michael D. King; Paul A. Hubanks; Michael J. Pavolonis; Andrew K. Heidinger; Ping Yang; Bryan A. Baum

2010-11-01T23:59:59.000Z

246

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

247

Results of Year-Round Remotely Sensed Integrated Water Vapor by Ground-Based Microwave Radiometry  

Science Conference Proceedings (OSTI)

Based on two years of measurements with a time resolution of 1 min, some climatological findings on precipitable water vapor (PWV) and cloud liquid water (CLW) in central Europe are given. A weak diurnal cycle is apparent. The mean overall ...

J. Güldner; D. Spänkuch

1999-07-01T23:59:59.000Z

248

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

249

Molecular mode-coupling theory for supercooled liquids: Application to water L. Fabbian,1  

E-Print Network (OSTI)

Molecular mode-coupling theory for supercooled liquids: Application to water L. Fabbian,1 A. Latz,2 observed in supercooled molecular liquids close to the glass transition. The mode-coupling theory MCT, rigid molecules. We compare the predictions of the theory for the q-vector dependence of the molecular

Sciortino, Francesco

250

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 -35ºC, 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

251

The Role of Eddy Diffusivity Profiles on Stratocumulus Liquid Water Path Biases  

Science Conference Proceedings (OSTI)

Results from simulations of the stratocumulus-topped boundary layer with one-dimensional versions of general simulation models typically exhibit a wide range of spread in the modeled liquid water path (LWP). These discrepancies are often ...

Stephan R. de Roode

2007-07-01T23:59:59.000Z

252

Radiometric Observations of Supercooled Liquid Water within a Split Front over the Sierra Nevada  

Science Conference Proceedings (OSTI)

A storm bearing close structural resemblance to a katafront was observed from the ground with microwave radiometry and a vertically pointing Ka-band radar over the Sierra Nevada of California. The onset and duration of supercooled liquid water ...

Mark F. Heggli; David W. Reynolds

1985-11-01T23:59:59.000Z

253

Comparison of Nimbus-7 SMMR and GOES-1 VISSR Atmospheric Liquid Water Content  

Science Conference Proceedings (OSTI)

Vertically integrated atmospheric liquid water content derived from Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) brightness temperatures and from GOES-1 Visible and Infrared Spin-Scan Radiometer (VISSR) radiances in the visible are ...

Jean-Yves Lojou; Robert Frouin; René Bernard

1991-02-01T23:59:59.000Z

254

Comparison of Simultaneous Airborne and Radiometric Measurements of Supercooled Liquid Water  

Science Conference Proceedings (OSTI)

Simultaneous measurements of supercooled liquid water by an instrumented aircraft and a dual-frequency microwave radiometer were made at Lake Ontario, New York, during wintertime. The geographic location and typical meteorological conditions for ...

Geoffrey E. Hill

1991-07-01T23:59:59.000Z

255

Further Comparisons of Simultaneous Airborne and Radiometric Measurements of Supercooled Liquid Water  

Science Conference Proceedings (OSTI)

Simultaneous measurements of supercooled liquid water were made by an instrumented aircraft and a microwave radiometer at Muskegon, Michigan during wintertime. The purpose was to confirm recent findings that there is good agreement between the ...

Geoffrey E. Hill

1992-04-01T23:59:59.000Z

256

Ground-Based FSSP and PVM Measurements of Liquid Water Content  

Science Conference Proceedings (OSTI)

Recently published ground-based measurements of liquid water content (LWC) measured in fogs by two microphysical instruments, the FSSP-100 and PVM-100, are evaluated. These publications had suggested that the PVM-100 underestimated LWC ...

H. Gerber; Glendon Frick; Alfred R. Rodi

1999-08-01T23:59:59.000Z

257

Process for hydrogen isotope concentration between liquid water and hydrogen gas  

DOE Patents (OSTI)

A process for hydrogen isotope exchange and concentration between liquid water and hydrogen gas, wherein liquid water and hydrogen gas are contacted, in an exchange section, with one another and with at least one catalyst body comprising at least one metal selected from Group VIII of the Periodic Table and preferably a support therefor, the catalyst body has a liquid-water-repellent, gas permeable polymer or organic resin coating, preferably a fluorinated olefin polymer or silicone coating, so that the isotope concentration takes place by two simultaneously occurring steps, namely, ##EQU1## WHILE THE HYDROGEN GAS FED TO THE EXCHANGE SECTION IS DERIVED IN A REACTOR VESSEL FROM LIQUID WATER THAT HAS PASSED THROUGH THE EXCHANGE SECTION.

Stevens, William H. (Deep River, CA)

1976-09-21T23:59:59.000Z

258

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

259

Nuclear tanker producing liquid fuels from air and water  

E-Print Network (OSTI)

Emerging technologies in CO? air capture, high temperature electrolysis, microchannel catalytic conversion, and Generation IV reactor plant systems have the potential to create a shipboard liquid fuel production system ...

Galle-Bishop, John Michael

2011-01-01T23:59:59.000Z

260

Polymer formulation for removing hydrogen and liquid water from an enclosed space  

DOE Patents (OSTI)

This invention describes a solution to the particular problem of liquid water formation in hydrogen getters exposed to quantities of oxygen. Water formation is usually desired because the recombination reaction removes hydrogen without affecting gettering capacity and the oxygen removal reduces the chances for a hydrogen explosion once free oxygen is essentially removed. The present invention describes a getter incorporating a polyacrylate compound that can absorb up to 500% of its own weight in liquid water without significantly affecting its hydrogen gettering/recombination properties, but that also is insensitive to water vapor.

Shepodd, Timothy J. (Livermore, CA)

2006-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Climatology and Formation of Tropical Midlevel Clouds at the Darwin ARM Site  

SciTech Connect

A 4-yr climatology of midlevel clouds is presented from vertically pointing cloud lidar and radar measurements at the Atmospheric Radiation Measurement Program (ARM) site at Darwin, Australia. Few studies exist of tropical midlevel clouds using a dataset of this length. Seventy percent of clouds with top heights between 4 and 8 km are less than 2 km thick. These thin layer clouds have a peak in cloud-top temperature around the melting level (0°C) and also a second peak around -12.5°C. The diurnal frequency of thin clouds is highest during the night and reaches a minimum around noon, consistent with variation caused by solar heating. Using a 1.5-yr subset of the observations, the authors found that thin clouds have a high probability of containing supercooled liquid water at low temperatures: ~20% of clouds at -30°C, ~50% of clouds at -20°C, and ~65% of clouds at -10°C contain supercooled liquid water. The authors hypothesize that thin midlevel clouds formed at the melting level are formed differently during active and break monsoon periods and test this over three monsoon seasons. A greater frequency of thin midlevel clouds are likely formed by increased condensation following the latent cooling of melting during active monsoon periods when stratiform precipitation is most frequent. This is supported by the high percentage (65%) of midlevel clouds with preceding stratiform precipitation and the high frequency of stable layers slightly warmer than 0°C. In the break monsoon, a distinct peak in the frequency of stable layers at 0°C matches the peak in thin midlevel cloudiness, consistent with detrainment from convection.

Riihimaki, Laura D.; McFarlane, Sally A.; Comstock, Jennifer M.

2012-10-01T23:59:59.000Z

262

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

263

Evaluate the Effect of Upper-Level Cirrus Clouds on Satellite Retrievals of Low-Level Cloud Droplet Effective Radius  

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

the Effect of Upper-Level Cirrus Clouds the Effect of Upper-Level Cirrus Clouds on Satellite Retrievals of Low-Level Cloud Droplet Effective Radius F.-L. Chang and Z. Li Earth System Science Interdisciplinary Center University of Maryland College Park, Maryland Z. Li Department of Meteorology University of Maryland College Park, Maryland Introduction The earth's radiation budget is sensitive to changes in the microphysical properties of low-level stratiform clouds. Their extensive coverage can significantly reduce the solar energy absorbed by the earth system. An estimate of reducing the global-mean droplet effective radius (r e ) of these low-level clouds by ~2 µm, while keeping the column liquid water constant would balance the warming due to CO 2 doubling in the atmosphere (Slingo 1990). Accurate determination of the droplet r

264

Water clusters: Untangling the mysteries of the liquid, one molecule at a time  

E-Print Network (OSTI)

and solid phases of water, including an accurate universal force field. The quest to achieve an accurate of the surfaces of either ice or liquid water (3), nor do we understand the origin of the intriguing anomalies difficult to accurately parameterize these interactions from ab initio calcu- lations. Moreover, the ab

Cohen, Ronald C.

265

The Drop-Size Response of the CSIRO Liquid Water Probe  

Science Conference Proceedings (OSTI)

The response of the CSIRO liquid water content (LWC) device to water drops of different sizes has been investigated in a wind tunnel. Two series of experiments were conducted. The first compared the probe-measured LWC of sprays with different ...

C. J. Biter; J. E. Dye; D. Huffman; W. D. King

1987-09-01T23:59:59.000Z

266

A Steerable Dual-Channel Microwave Radiometer for Measurement of Water Vapor and Liquid in the Troposphere  

Science Conference Proceedings (OSTI)

An instrument that remotely senses the integrated amounts of water vapor and liquid on a path through the atmosphere is discussed. The vapor and liquid are measured simultaneously but independently by microwave radiometers. Comparison of the ...

D. C. Hogg; F. O. Guiraud; J. B. Snider; M. T. Decker; E. R. Westwater

1983-05-01T23:59:59.000Z

267

Validating the validation: the influence of liquid water distribution in clouds on the intercomparison  

E-Print Network (OSTI)

of stellite radiance wavenumber spectra. Rem. Sens. Environ., 42, 51 ­ 64. Brenguier, J.-L., H. Pawlowska, L

Stoffelen, Ad

268

Stable Isotopes in Hailstones. Part I: The Isotopic Cloud Model  

Science Conference Proceedings (OSTI)

Equations describing the isotopic balance between five water species (vapor, cloud water, rainwater, cloud ice and graupel)have been incorporated into a one-dimensional steady-state cloud model. The isotope contents of the various water ...

B. Federer; N. Brichet; J. Jouzel

1982-06-01T23:59:59.000Z

269

Prepulse effect on laser-induced water-window radiation from a liquid nitrogen jet  

E-Print Network (OSTI)

is schematically shown in Fig. 1. A high-purity nitrogen gas was cooled and liquefied through the cooling stagesPrepulse effect on laser-induced water-window radiation from a liquid nitrogen jet J. Son,a M. Cho.3­4.4 nm x ray from a liquid nitrogen jet. It is observed that a prepulse of only 2 mJ enhances

Kim, Jae-Hoon

270

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

271

Coupling atomistic and continuum hydrodynamics through a mesoscopic model: application to liquid water  

E-Print Network (OSTI)

We have conducted a triple-scale simulation of liquid water by concurrently coupling atomistic, mesoscopic, and continuum models of the liquid. The presented triple-scale hydrodynamic solver for molecular liquids enables the insertion of large molecules into the atomistic domain through a mesoscopic region. We show that the triple-scale scheme is robust against the details of the mesoscopic model owing to the conservation of linear momentum by the adaptive resolution forces. Our multiscale approach is designed for molecular simulations of open domains with relatively large molecules, either in the grand canonical ensemble or under non-equilibrium conditions.

Rafael Delgado-Buscalioni; Kurt Kremer; Matej Praprotnik

2009-08-04T23:59:59.000Z

272

Revisiting the total ion yield x-ray absorption spectra of liquid water microjets  

SciTech Connect

Measurements of the total ion yield (TIY) x-ray absorption spectrum (XAS) of liquid water by Wilson et al. (2002 J. Phys.: Condens. Matter 14 L221 and 2001 J. Phys. Chem. B 105 3346) have been revisited in light of new experimental and theoretical efforts by our group. Previously, the TIY spectrum was interpreted as a distinct measure of the electronic structure of the liquid water surface. However, our new results indicate that the previously obtained spectrum may have suffered from as yet unidentified experimental artifacts. Although computational results indicate that the liquid water surface should exhibit a TIY-XAS that is fundamentally distinguishable from the bulk liquid XAS, the new experimental results suggest that the observable TIY-XAS is actually nearly identical in appearance to the total electron yield (TEY-)XAS, which is a bulk probe. This surprising similarity between the observed TIY-XAS and TEY-XAS likely results from large contributions from x-ray induced electron stimulated desorption of ions, and does not necessarily indicate that the electronic structure of the bulk liquid and liquid surface are identical.

Saykally, Richard J; Cappa, Chris D.; Smith, Jared D.; Wilson, Kevin R.; Saykally, Richard J.

2008-02-16T23:59:59.000Z

273

Homogeneous Condensation—Freezing Nucleation Rate Measurements for Small Water Droplets in an Expansion Cloud Chamber  

Science Conference Proceedings (OSTI)

Experimental data on ice nucleation, presented in an earlier paper, are analyzed to yield information about the homogeneous nucleation rate of ice from supercooled liquid and the heights of energy barriers to that nucleation. The experiment ...

Donald E. Hagen; Rodney J. Anderson; James L. Kassner Jr.

1981-06-01T23:59:59.000Z

274

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

275

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,...

276

Cloud/Aerosol Parameterizations: Application and Improvement of General Circulation Models  

Science Conference Proceedings (OSTI)

One of the biggest uncertainties associated with climate models and climate forcing is the treatment of aerosols and their effects on clouds. The effect of aerosols on clouds can be divided into two components: The first indirect effect is the forcing associated with increases in droplet concentrations; the second indirect effect is the forcing associated with changes in liquid water path, cloud morphology, and cloud lifetime. Both are highly uncertain. This project applied a cloud-resolving model to understand the response of clouds under a variety of conditions to changes in aerosols. These responses are categorized according to the large-scale meteorological conditions that lead to the response. Meteorological conditions were sampled from various fields, which, together with a global aerosol model determination of the change in aerosols from present day to pre-industrial conditions, was used to determine a first order estimate of the response of global cloud fields to changes in aerosols. The response of the clouds in the NCAR CAM3 GCM coupled to our global aerosol model were tested by examining whether the response is similar to that of the cloud resolving model and methods for improving the representation of clouds and cloud/aerosol interactions were examined.

Penner, Joyce

2012-06-30T23:59:59.000Z

277

The Microbase Value-Added Product: A Baseline Retrieval of Cloud Microphysical Properties  

SciTech Connect

This report describes the Atmospheric Radiation Measurement (ARM) Climate Research Facility baseline cloud microphysical properties (MICROBASE) value-added product (VAP). MICROBASE uses a combination of millimeter-wavelength cloud radar, microwave radiometer, and radiosonde observations to estimate the vertical profiles of the primary microphysical parameters of clouds including the liquid/ice water content and liquid/ice cloud particle effective radius. MICROBASE is a baseline algorithm designed to apply to most conditions and locations using a single set of parameterizations and a simple determination of water phase based on temperature. This document provides the user of this product with guidelines to assist in determining the accuracy of the product under certain conditions. Quality control flags are designed to identify outliers and indicate instances where the retrieval assumptions may not be met. The overall methodology is described in this report through a detailed description of the input variables, algorithms, and output products.

Dunn, M; Johnson, K; Jensen, M

2011-05-31T23:59:59.000Z

278

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

279

Application of Feature Calibration and Alignment to High-resolution Analysis: Examples Using Observations Sensitive to Cloud and Water Vapor  

Science Conference Proceedings (OSTI)

Alignment errors, i.e. cases where coherent structures (“features”) of clouds or precipitation in the background have position errors, can lead to large and non-Gaussian background errors. Assimilation of cloud-affected radiances using additive ...

Thomas Nehrkorn; Bryan Woods; Thomas Auligné; Ross N. Hoffman

280

Improved Detection of Optically Thin Cirrus Clouds in Nighttime Multispectral Meteorological Satellite Imagery Using Total Integrated Water Vapor Information  

Science Conference Proceedings (OSTI)

The accurate identification of optically thin cirrus clouds in global meteorological satellite imagery by automated cloud analysis algorithms is critical to environmental remote sensing studies, such as those related to climate change. While ...

Keith D. Hutchison; Kenneth R. Hardy; Bo-Cai Gao

1995-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

The Effects of Evaporation, Water Load and Wind Shear on Cloud Development in a Three-Dimensional Numerical Model  

Science Conference Proceedings (OSTI)

Steiner's (1973) three-dimensional cloud model has been updated to incorporate the deep anelastic system of equations and the microphysical parameterization scheme of Kessler (1969) for precipitation growth. The interactions between cloud ...

Man Kong Yau

1980-02-01T23:59:59.000Z

282

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

283

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

284

Distributed Reforming of Renewable Liquids via Water Splitting using Oxygen Transport Membrane (OTM) (Presentation)  

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

Reforming of Renewable Reforming of Renewable Liquids via Water Splitting using Oxygen Transport Membrane (OTM) * U. (Balu) Balachandran, T. H. Lee, C. Y. Park, and S. E. Dorris Energy Systems Division E-mail: balu@anl.gov * Work supported by the Hydrogen, Fuel Cells, and Infrastructure Technologies Program of DOE's Office of Energy Efficiency and Renewable Energy Presented at the Bio-derived Liquids Working Group (BILIWG) Meeting, Nov. 6, 2007. BILIWG Meeting, Nov. 6, 2007 2 Objective & Rationale Objective: Develop compact dense ceramic membrane reactors that enable the efficient and cost-effective production of hydrogen by reforming renewable liquid fuels using pure oxygen produced by water splitting and transported by an OTM. Rationale: Membrane technology provides the means to attack barriers to the

285

Summary of Zero Liquid Discharge (ZLD) Water Management Installations at U.S. Power Plants  

Science Conference Proceedings (OSTI)

This report presents an inventory of zero liquid discharge (ZLD) water management systems currently operating at U.S. power generating stations. A total of 146 ZLD operations were identified and described. The report discusses the numerous treatment methods used at these ZLD facilities along with their merits and detractions of each method.

2008-12-12T23:59:59.000Z

286

Liquid Water Content of Fogs and Hazes from Visible Light Scattering  

Science Conference Proceedings (OSTI)

A new method is proposed for measuring the liquid water content of fogs and hazes. It consists of a planar circular light sensor placed perpendicular to and coaxial with a narrow collimated light beam of a visible wavelength. The direct light ...

H. Gerber

1984-08-01T23:59:59.000Z

287

Laboratory Calibration of a Vibrating Wire Device for Measuring Concentrations of Supercooled Liquid Water  

Science Conference Proceedings (OSTI)

Laboratory measurements of supercooled liquid water are made by a vibrating-wire sensor whose frequency of vibration varies according to the mass of ice collected on it. The vibrating-wire system is designed to be placed in the humidity duct of ...

Geoffrey E. Hill

1989-12-01T23:59:59.000Z

288

Influence of Water on Diffusion in Imidazolium-Based Ionic Liquids by NMR  

E-Print Network (OSTI)

Influence of Water on Diffusion in Imidazolium-Based Ionic Liquids by NMR Sergey Vasenkov AMRIS - Chemical Engineering, University of Florida In this work we applied a novel pulsed field gradient (PFG) NMR) NMR and high magnetic field gradients (up to 30 T/m). Application of high field allows for an easy

Weston, Ken

289

Study of Mechanisms of Aerosol Indirect Effects on Glaciated Clouds: Progress during the Project Final Technical Report  

SciTech Connect

This 3-year project has studied how aerosol pollution influences glaciated clouds. The tool applied has been an 'aerosol-cloud model'. It is a type of Cloud-System Resolving Model (CSRM) modified to include 2-moment bulk microphysics and 7 aerosol species, as described by Phillips et al. (2009, 2013). The study has been done by, first, improving the model and then performing sensitivity studies with validated simulations of a couple of observed cases from ARM. These are namely the Tropical Warm Pool International Cloud Experiment (TWP-ICE) over the tropical west Pacific and the Cloud and Land Surface Interaction Campaign (CLASIC) over Oklahoma. During the project, sensitivity tests with the model showed that in continental clouds, extra liquid aerosols (soluble aerosol material) from pollution inhibited warm rain processes for precipitation production. This promoted homogeneous freezing of cloud droplets and aerosols. Mass and number concentrations of cloud-ice particles were boosted. The mean sizes of cloud-ice particles were reduced by the pollution. Hence, the lifetime of glaciated clouds, especially ice-only clouds, was augmented due to inhibition of sedimentation and ice-ice aggregation. Latent heat released from extra homogeneous freezing invigorated convective updrafts, and raised their maximum cloud-tops, when aerosol pollution was included. In the particular cases simulated in the project, the aerosol indirect effect of glaciated clouds was twice than of (warm) water clouds. This was because glaciated clouds are higher in the troposphere than water clouds and have the first interaction with incoming solar radiation. Ice-only clouds caused solar cooling by becoming more extensive as a result of aerosol pollution. This 'lifetime indirect effect' of ice-only clouds was due to higher numbers of homogeneously nucleated ice crystals causing a reduction in their mean size, slowing the ice-crystal process of snow production and slowing sedimentation. In addition to the known indirect effects (glaciation, riming and thermodynamic), new indirect effects were discovered and quantified due to responses of sedimentation, aggregation and coalescence in glaciated clouds to changing aerosol conditions. In summary, the change in horizontal extent of the glaciated clouds ('lifetime indirect effects'), especially of ice-only clouds, was seen to be of higher importance in regulating aerosol indirect effects than changes in cloud properties ('cloud albedo indirect effects').

Phillips, Vaughan T. J.

2013-10-18T23:59:59.000Z

290

Ultrafast conversions between hydrogen bonded structures in liquid water observed by femtosecond x-ray spectroscopy  

DOE Green Energy (OSTI)

We present the first femtosecond soft x-ray spectroscopy in liquids, enabling the observation of changes in hydrogen bond structures in water via core-hole excitation. The oxygen K-edge of vibrationally excited water is probed with femtosecond soft x-ray pulses, exploiting the relation between different water structures and distinct x-ray spectral features. After excitation of the intramolecular OH stretching vibration, characteristic x-ray absorption changes monitor the conversion of strongly hydrogen-bonded water structures to more disordered structures with weaker hydrogen-bonding described by a single subpicosecond time constant. The latter describes the thermalization time of vibrational excitations and defines the characteristic maximum rate with which nonequilibrium populations of more strongly hydrogen-bonded water structures convert to less-bonded ones. On short time scales, the relaxation of vibrational excitations leads to a transient high-pressure state and a transient absorption spectrum different from that of statically heated water.

Wen, Haidan; Huse, Nils; Schoenlein, Robert W.; Lindenberg, Aaron M.

2010-05-01T23:59:59.000Z

291

Observed Increase of TTL Temperature and Water Vapor in Polluted Clouds over Asia  

Science Conference Proceedings (OSTI)

Satellite observations are analyzed to examine the correlations between aerosols and the tropical tropopause layer (TTL) temperature and water vapor. This study focuses on two regions, both of which are important pathways for the mass transport ...

Hui Su; Jonathan H. Jiang; Xiaohong Liu; Joyce E. Penner; William G. Read; Steven Massie; Mark R. Schoeberl; Peter Colarco; Nathaniel J. Livesey; Michelle L. Santee

2011-06-01T23:59:59.000Z

292

Scale dependency of total water variance, and its implication for cloud parameterizations  

Science Conference Proceedings (OSTI)

The scale dependency of variance of total water mixing ratio is explored by analyzing data from a General Circulation Model (GCM), a Numerical Weather Prediction Model (NWP) and Large Eddy Simulations (LES). For clarification Direct Numerical ...

Vera Schemann; Bjorn Stevens; Verena Grützun; Johannes Quaas

293

How Total Precipitable Water Vapor Anomalies Relate to Cloud Vertical Structure  

Science Conference Proceedings (OSTI)

The NOAA operational total precipitable water (TPW) anomaly product is available to forecasters to display percentage of normal TPW in real time for applications like heavy precipitation forecasts. In this work, the TPW anomaly is compared to ...

John M. Forsythe; Jason B. Dodson; Philip T. Partain; Stanley Q. Kidder; Thomas H. Vonder Haar

2012-04-01T23:59:59.000Z

294

Dynamics of particle clouds in ambient currents with application to open-water sediment disposal  

E-Print Network (OSTI)

Open-water sediment disposal is used in many applications around the world, including land reclamation, dredging, and contaminated sediment isolation. Timely examples include the land reclamation campaign currently underway ...

Gensheimer, Robert James, III

2010-01-01T23:59:59.000Z

295

Radiometric Determination of Uranium in Natural Waters after Enrichment and Separation by Cation-Exchange and Liquid-Liquid Extraction  

E-Print Network (OSTI)

The alpha-radiometric determination of uranium after its pre-concentration from natural water samples using the cation-exchange resin Chelex-100, its selective extraction by tributylphosphate and electrodeposition on stainless steel discs is reported. The validity of the separation procedure and the chemical recoveries were checked by addition of uranium standard solution as well as by tracing with U-232. The average uranium yield was determined to be (97 +- 2) % for the cation-exchange, (95 +- 2) % for the liquid-liquid extraction, and more than 99% for the electrodeposition. Employing high-resolution alpha-spectroscopy, the measured activity of the U-238 and U-234 radioisotopes was found to be of similar magnitude; i.e. ~7 mBq/L and ~35 mBq/L for ground- and seawater samples, respectively. The energy resolution (FWHM) of the alpha-peaks was 22 keV, while the Minimum Detectable Activity (MDA) was estimated to be 1 mBq/L (at the 95% confidence limit).

I. Pashalidis; H. Tsertos

2003-04-28T23:59:59.000Z

296

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

297

In situ separation of root hydraulic redistribution of soil water from liquid and vapor transport  

SciTech Connect

Nocturnal increases in water potential ( ) and water content (WC) in the upper soil profile are often attributed to root water efflux into the soil, a process termed hydraulic lift or hydraulic redistribution (HR). We have previously reported HR values up to ~0.29 mm day-1 in the upper soil for a seasonally dry old-growth ponderosa pine site. However, unsaturated liquid or vapor flux of water between soil layers independent of roots also contributes to the diurnal patterns in WC, confounding efforts to determine the actual magnitude of HR. In this study, we estimated liquid (Jl) and vapor (Jv) soil water fluxes and their impacts on quantifying HR in situ by applying existing data sets of , WC, temperature (T) and soil physical properties to soil water transport equations. Under moist conditions, Jl between layers was estimated to be larger than necessary to account for measured nocturnal increases in WC of upper soil layers. However, as soil drying progressed unsaturated hydraulic conductivity declined rapidly such that Jl was irrelevant (< 2E-06 cm hr-1 at 0-60 cm depths) to total water flux by early August. In surface soil at depths above 15 cm, large T fluctuations can impact Jv leading to uncertainty concerning the role, if any, of HR in nocturnal WC dynamics. Vapor flux was estimated to be the highest at the shallowest depths measured (20 - 30 cm) where it could contribute up to 40% of hourly increases in nocturnal soil moisture depending on thermal conditions. While both HR and net soil water flux between adjacent layers contribute to WC in the 15-65 cm soil layer, HR was the dominant process and accounted for at least 80% of the diurnal increases in WC. While the absolute magnitude of HR is not easily quantified, total diurnal fluctuations in upper soil water content can be quantified and modeled, and remain highly applicable for establishing the magnitude and temporal dynamics of total ecosystem water flux.

Warren, Jeffrey [ORNL; Brooks, J Renee [U.S. Environmental Protection Agency, Corvallis, OR; Dragila, Maria [Oregon State University, Corvallis; Meinzer, Rick [USDA Forest Service

2011-01-01T23:59:59.000Z

298

Liquid and Ice Cloud Microphysics in the CSU General Circulation Model. Part II: Impact on Cloudiness, the Earth's Radiation Budget, and the General Circulation of the Atmosphere  

Science Conference Proceedings (OSTI)

A prognostic equation for the mass of condensate associated with large-scale cloudiness introduces a direct coupling between the atmospheric moisture budget and the radiation budget through interactive cloud amounts and cloud optical properties. ...

Laura D. Fowler; David A. Randall

1996-03-01T23:59:59.000Z

299

Liquid-Water Uptake and Removal in PEM Fuel-Cell Components  

Science Conference Proceedings (OSTI)

Management of liquid water is critical for optimal fuel-cell operation, especially at low temperatures. It is therefore important to understand the wetting properties and water holdup of the various fuel-cell layers. While the gas-diffusion layer is relatively hydrophobic and exhibits a strong intermediate wettability, the catalyst layer is predominantly hydrophilic. In addition, the water content of the ionomer in the catalyst layer is lower than that of the bulk membrane, and is affected by platinum surfaces. Liquid-water removal occurs through droplets on the surface of the gas-diffusion layer. In order to predict droplet instability and detachment, a force balance is used. While the pressure or drag force on the droplet can be derived, the adhesion or surface-tension force requires measurement using a sliding-angle approach. It is shown that droplets produced by forcing water through the gas-diffusion layer rather than placing them on top of it show much stronger adhesion forces owing to the contact to the subsurface water.

Das, Prodip K.; Gunterman, Haluna P.; Kwong, Anthony; Weber, Adam Z.

2011-09-23T23:59:59.000Z

300

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

Note: This page contains sample records for the topic "liquid water clouds" 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

Empirical relationship between entrainment rate and microphysics in cumulus clouds  

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

Empirical Empirical relationship between entrainment rate and microphysics in cumulus clouds Chunsong Lu, 1,2 Shengjie Niu, 1 Yangang Liu, 2 and Andrew M. Vogelmann 2 Received 16 March 2013; accepted 3 April 2013; published 22 May 2013. [1] The relationships between fractional entrainment rate and key microphysical quantities (e.g., liquid water content, droplet number concentration, volume mean radius, and standard deviation of cloud droplet size distributions) in shallow cumuli are empirically examined using in situ aircraft observations from the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign over the Atmospheric Radiation Measurement Southern Great Plains site. The results show that the microphysical quantities examined generally exhibit strong relationships with

302

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

303

Constraining cloud lifetime effects of aerosols using A-Train satellite observations  

Science Conference Proceedings (OSTI)

Aerosol indirect effects have remained the largest uncertainty in estimates of the radiative forcing of past and future climate change. Observational constraints on cloud lifetime effects are particularly challenging since it is difficult to separate aerosol effects from meteorological influences. Here we use three global climate models, including a multi-scale aerosol-climate model PNNL-MMF, to show that the dependence of the probability of precipitation on aerosol loading, termed the precipitation frequency susceptibility (S{sub pop}), is a good measure of the liquid water path response to aerosol perturbation ({lambda}), as both Spop and {lambda} strongly depend on the magnitude of autoconversion, a model representation of precipitation formation via collisions among cloud droplets. This provides a method to use satellite observations to constrain cloud lifetime effects in global climate models. S{sub pop} in marine clouds estimated from CloudSat, MODIS and AMSR-E observations is substantially lower than that from global climate models and suggests a liquid water path increase of less than 5% from doubled cloud condensation nuclei concentrations. This implies a substantially smaller impact on shortwave cloud radiative forcing (SWCF) over ocean due to aerosol indirect effects than simulated by current global climate models (a reduction by one-third for one of the conventional aerosol-climate models). Further work is needed to quantify the uncertainties in satellite-derived estimates of S{sub pop} and to examine S{sub pop} in high-resolution models.

Wang, Minghuai; Ghan, Steven J.; Liu, Xiaohong; Ecuyer, Tristan L.; Zhang, Kai; Morrison, H.; Ovchinnikov, Mikhail; Easter, Richard C.; Marchand, Roger; Chand, Duli; Qian, Yun; Penner, Joyce E.

2012-08-15T23:59:59.000Z

304

Ultrafast dynamics of liquid water: Frequency fluctuations of the OH stretch and the HOH bend  

SciTech Connect

Frequency fluctuations of the OH stretch and the HOH bend in liquid water are reported from the third-order response function evaluated using the TTM3-F potential for water. The simulated two-dimensional infrared (IR) spectra of the OH stretch are similar to previously reported theoretical results. The present study suggests that the frequency fluctuation of the HOH bend is faster than that of the OH stretch. The ultrafast loss of the frequency correlation of the HOH bend is due to the strong couplings with the OH stretch as well as the intermolecular hydrogen bond bend.

Imoto, Sho; Xantheas, Sotiris S.; Saito, Shinji

2013-07-28T23:59:59.000Z

305

Electronic structure effects in liquid water studied by photoelectron spectroscopy and density functional theory  

DOE Green Energy (OSTI)

We present valence photoelectron emission spectra of liquid water in comparison with gas-phase water, ice close to the melting point, low temperature amorphous and crystalline ice. All aggregation states have major electronic structure changes relative to the free molecule, with rehybridization and development of bonding and anti-bonding states accompanying the hydrogen bond formation. Sensitivity to the local structural order, most prominent in the shape and splitting of the occupied 3a{sub 1} orbital, is understood from the electronic structure averaging over various geometrical structures, and reflects the local nature of the orbital interaction.

Nordlund, Dennis; Odelius, Michael; Bluhm, Hendrik; Ogasawara, Hirohito; Pettersson, Lars G.M.; Nilsson, Anders

2008-04-29T23:59:59.000Z

306

Zero Liquid Discharge (ZLD) System for Flue-Gas Derived Water From Oxy-Combustion Process  

Science Conference Proceedings (OSTI)

Researchers at the National Energy Technology Laboratory (NETL) located in Albany, Oregon, have patented a process - Integrated Pollutant Removal (IPR) that uses off-the-shelf technology to produce a sequestration ready CO{sub 2} stream from an oxy-combustion power plant. Capturing CO{sub 2} from fossil-fuel combustion generates a significant water product which can be tapped for use in the power plant and its peripherals. Water condensed in the IPR{reg_sign} process may contain fly ash particles, sodium (from pH control), and sulfur species, as well as heavy metals, cations and anions. NETL is developing a treatment approach for zero liquid discharge while maximizing available heat from IPR. Current treatment-process steps being studied are flocculation/coagulation, for removal of cations and fine particles, and reverse osmosis, for anion removal as well as for scavenging the remaining cations. After reverse osmosis process steps, thermal evaporation and crystallization steps will be carried out in order to build the whole zero liquid discharge (ZLD) system for flue-gas condensed wastewater. Gypsum is the major product from crystallization process. Fast, in-line treatment of water for re-use in IPR seems to be one practical step for minimizing water treatment requirements for CO{sub 2} capture. The results obtained from above experiments are being used to build water treatment models.

Sivaram Harendra; Danylo Oryshchyn; Thomas Ochs; Stephen J. Gerdemann; John Clark

2011-10-16T23:59:59.000Z

307

Crystalline, liquid crystalline, and isotropic phases of sodium deoxycholate in water  

SciTech Connect

Sodium deoxycholate (NaDC) is an important example of bile salts, representing systems with complex phase behavior involving both crystalline and mesophase structures. In this study, properties of NaDC-water mixtures were evaluated as a function of composition and temperature via X-ray diffraction with synchrotron (sXRD) and laboratory radiation sources, water sorption, polarized light, hot-stage microscopy, and freezing-point osmometry. Several phases were detected depending on the composition and temperature, including isotropic solution phase, liquid crystalline (LC) phase, crystalline hydrate, and ice. The LC phase was identified as hexagonal structure by sXRD, with up to 14 high-order reflections detected. The crystalline phase was found to be nonstoichiometric hydrate, based on XRD and water sorption data. The phase diagram of NaDC-water system has been refined based on both results of this study and other reports in literature.

Su, Ziyang; Luthra, Suman; Krzyzaniak, Joseph F.; Agra-Kooijman, Dena M.; Kumar, Satyendra; Byrn, Stephen R.; Shalaev, Evgenyi Y. (Pfizer); (Purdue); (Kent)

2012-09-06T23:59:59.000Z

308

The Use of Microwave Radiometry to Determine a Cloud Seeding Opportunity  

Science Conference Proceedings (OSTI)

A ground-based combination microwave radiometer-satellite receiver operating at 28.5 GHz (wavelength = 1.05 cm) was employed to measure liquid water in clouds during the 1979-80 field season of the Sierra Cooperative Pilot Project (SCPP) in ...

J. B. Snider; D. Rottner

1982-09-01T23:59:59.000Z

309

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

SciTech Connect

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

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

1997-12-31T23:59:59.000Z

310

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.

311

Nationwide Comparisons of Hail Size with WSR-88D Vertically Integrated Liquid Water and Derived Thermodynamic Sounding Data  

Science Conference Proceedings (OSTI)

This study tests hypothetical correspondences between size of severe hail, WSR-88D derived vertically integrated liquid water (VIL), and an array of thermodynamic variables derived from computationally modified sounding analyses. In addition, ...

Roger Edwards; Richard L. Thompson

1998-06-01T23:59:59.000Z

312

ON THE FORMATION OF INTERSTELLAR WATER ICE: CONSTRAINTS FROM A SEARCH FOR HYDROGEN PEROXIDE ICE IN MOLECULAR CLOUDS  

SciTech Connect

Recent surface chemistry experiments have shown that the hydrogenation of molecular oxygen on interstellar dust grains is a plausible formation mechanism, via hydrogen peroxide (H{sub 2}O{sub 2}), for the production of water (H{sub 2}O) ice mantles in the dense interstellar medium. Theoretical chemistry models also predict the formation of a significant abundance of H{sub 2}O{sub 2} ice in grain mantles by this route. At their upper limits, the predicted and experimental abundances are sufficiently high that H{sub 2}O{sub 2} should be detectable in molecular cloud ice spectra. To investigate this further, laboratory spectra have been obtained for H{sub 2}O{sub 2}/H{sub 2}O ice films between 2.5 and 200 {mu}m, from 10 to 180 K, containing 3%, 30%, and 97% H{sub 2}O{sub 2} ice. Integrated absorbances for all the absorption features in low-temperature H{sub 2}O{sub 2} ice have been derived from these spectra. For identifying H{sub 2}O{sub 2} ice, the key results are the presence of unique features near 3.5, 7.0, and 11.3 {mu}m. Comparing the laboratory spectra with the spectra of a group of 24 protostars and field stars, all of which have strong H{sub 2}O ice absorption bands, no absorption features are found that can definitely be identified with H{sub 2}O{sub 2} ice. In the absence of definite H{sub 2}O{sub 2} features, the H{sub 2}O{sub 2} abundance is constrained by its possible contribution to the weak absorption feature near 3.47 {mu}m found on the long-wavelength wing of the 3 {mu}m H{sub 2}O ice band. This gives an average upper limit for H{sub 2}O{sub 2}, as a percentage of H{sub 2}O, of 9% {+-} 4%. This is a strong constraint on parameters for surface chemistry experiments and dense cloud chemistry models.

Smith, R. G.; Wright, C. M.; Robinson, G. [School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2600 (Australia); Charnley, S. B. [Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Pendleton, Y. J. [NASA Lunar Science Institute, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Maldoni, M. M., E-mail: r.smith@adfa.edu.au, E-mail: c.wright@adfa.edu.au, E-mail: g.robinson@adfa.edu.au, E-mail: Steven.B.Charnley@nasa.gov, E-mail: yvonne.pendleton@nasa.gov [Geoscience Australia, Canberra, ACT 2601 (Australia)

2011-12-20T23:59:59.000Z

313

Polymer Electrolyte Fuel Cells Membrane Hydration by Direct Liquid Water Contact  

DOE Green Energy (OSTI)

An effective means of providing direct liquid hydration of the membrane tends to improve performance particularly of cells with thicker membranes or at elevated temperatures. Supplying the water to the membrane from the anode flow-field through the anode backing via wicks would appear to have advantages over delivering the water through the thickness of the membrane with regards to the uniformity and stability of the supply and the use of off-the-shelf membranes or MEAs. In addition to improving cell performance, an important contribution of direct liquid hydration approaches may be that the overall fuel cell system becomes simpler and more effective. The next steps in the evolution of this approach are a demonstration of the effectiveness of this technique with larger active area cells as well as the implementation of an internal flow-field water reservoir (to eliminate the injection method). Scale-up to larger cell sizes and the use of separate water channels within the anode flow-field is described.

Wilson, M.S.; Zawodzinski, C.; Gottesfeld, S.

1998-11-01T23:59:59.000Z

314

Atmospheric Water Content over the Tropical Pacific Derived from the Nimbus-6 Scanning Microwave Spectrometer  

Science Conference Proceedings (OSTI)

The scanning microwave spectrometer (SCAMS) aboard Nimbus-6 contains a 22.23 GHz water vapor channel and 31.65 GHz window channel for deriving integrated water vapor (precipitable water) and cloud liquid water through a column over the oceans. ...

N. C. Grody; A. Gruber; W. C. Shen

1980-08-01T23:59:59.000Z

315

Molecular origin of the difference in the HOH bend of the IR spectra between liquid water and ice  

SciTech Connect

The intensity of the HOH bend in the IR spectrum of ice is significantly smaller than the corresponding one in liquid water. This difference in the IR intensities of the HOH bend in the two systems is investigated using MD simulations with the flexible, polarizable, ab-initio based TTM3-F model for water, a potential that correctly reproduces the experimentally observed increase of the HOH bend in liquid water and ice from the water monomer value. We have identified two factors that are responsible for the difference in the intensity of the HOH bend in liquid water and ice: (i) the decrease of the intensity of the HOH bend in ice caused by the strong anti-correlation between the permanent dipole moment of a molecule and the induced dipole moment of a neighboring hydrogen bond acceptor molecule and (ii) the weakening of this anti-correlation by the disordered hydrogen bond network in liquid water. The presence of the anti-correlation in ice is further confirmed by ab initio electronic structure calculations of water pentamer clusters extracted from the trajectories of the MD simulations for ice and liquid water.

Imoto, Sho; Xantheas, Sotiris S.; Saito, Shinji

2013-02-07T23:59:59.000Z

316

Nighttime Multilayered Cloud Detection Using MODIS and ARM Data  

Science Conference Proceedings (OSTI)

This study reports on recent progress toward the discrimination between pixels containing multilayered clouds, specifically optically thin cirrus overlying lower-level water clouds, and those containing single-layered clouds in nighttime Moderate ...

Bryan A. Baum; Richard A. Frey; Gerald G. Mace; Monica K. Harkey; Ping Yang

2003-07-01T23:59:59.000Z

317

On the Global Variation of Precipitating Layer Clouds  

Science Conference Proceedings (OSTI)

The aim of the Global Energy and Water Cycle Experiment Cloud System Study (GCSS) is to promote the description and understanding of key cloud system processes, with the aim of developing and improving the representation of cloud processes in ...

B. F. Ryan

1996-01-01T23:59:59.000Z

318

Cloud Type and Macrophysical Property Retrieval Using Multiple Remote Sensors  

Science Conference Proceedings (OSTI)

A cloud detection algorithm based on ground-based remote sensors has been developed that can differentiate among various atmospheric targets such as ice and water clouds, virga, precipitation, and aerosol layers. Standard cloud type and ...

Zhien Wang; Kenneth Sassen

2001-10-01T23:59:59.000Z

319

On the Relationship between Sulfate and Cloud Droplet Number Concentrations  

Science Conference Proceedings (OSTI)

Comparisons are drawn between the aerosol cloud microphysical theory implicit in the modeling of Kaufman et al. and the cloud droplet and cloud water sulfate concentrations of Leaitch et al. for the purpose of helping to understand the effect of ...

W. R. Leaitch; G. A. Isaac

1994-01-01T23:59:59.000Z

320

Stabilizing Cloud Feedback Dramatically Expands the Habitable Zone of Tidally Locked Planets  

E-Print Network (OSTI)

The habitable zone (HZ) is the circumstellar region where a planet can sustain surface liquid water. Searching for terrestrial planets in the HZ of nearby stars is the stated goal of ongoing and planned extrasolar planet surveys. Previous estimates of the inner edge of the HZ were based on one-dimensional radiative-convective models. The most serious limitation of these models is the inability to predict cloud behavior. Here we use global climate models with sophisticated cloud schemes to show that due to a stabilizing cloud feedback, tidally locked planets can be habitable at twice the stellar flux found by previous studies. This dramatically expands the HZ and roughly doubles the frequency of habitable planets orbiting red dwarf stars. At high stellar flux, strong convection produces thick water clouds near the substellar location that greatly increase the planetary albedo and reduce surface temperatures. Higher insolation produces stronger substellar convection and therefore higher albedo, making this phen...

Yang, Jun; Abbot, Dorian S

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Method and apparatus for electrokinetic co-generation of hydrogen and electric power from liquid water microjets  

SciTech Connect

A method and apparatus for producing both a gas and electrical power from a flowing liquid, the method comprising: a) providing a source liquid containing ions that when neutralized form a gas; b) providing a velocity to the source liquid relative to a solid material to form a charged liquid microjet, which subsequently breaks up into a droplet spay, the solid material forming a liquid-solid interface; and c) supplying electrons to the charged liquid by contacting a spray stream of the charged liquid with an electron source. In one embodiment, where the liquid is water, hydrogen gas is formed and a streaming current is generated. The apparatus comprises a source of pressurized liquid, a microjet nozzle, a conduit for delivering said liquid to said microjet nozzle, and a conductive metal target sufficiently spaced from said nozzle such that the jet stream produced by said microjet is discontinuous at said target. In one arrangement, with the metal nozzle and target electrically connected to ground, both hydrogen gas and a streaming current are generated at the target as it is impinged by the streaming, liquid spray microjet.

Saykally, Richard J; Duffin, Andrew M; Wilson, Kevin R; Rude, Bruce S

2013-02-12T23:59:59.000Z

322

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

323

Interrelationships between Cloud Properties and Sea Surface Temperatures on Seasonal and Interannual Time Scales  

Science Conference Proceedings (OSTI)

Monthly means of selected variables of the 2.5° International Satellite Cloud Climatology Project (ISCCP) C2 total cloud cover (CC), cloud-top pressure (CTP), and cloud water (CW) are statistically related to sea surface temperature (SST). The ...

Bryan C. Weare

1994-02-01T23:59:59.000Z

324

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

325

Nanoparticle enhanced evaporation of liquids: A case study of silicone oil and water  

E-Print Network (OSTI)

Evaporation is a fundamental physical phenomenon, of which many challenging questions remain unanswered. Enhanced evaporation of liquids in some occasions is of enormous practical significance. Here we report the enhanced evaporation of the nearly permanently stable silicone oil by dispersing with nanopariticles including CaTiO3, anatase and rutile TiO2. The results can inspire the research of atomistic mechanism for nanoparticle enhanced evaporation and exploration of evaporation control techniques for treatment of oil pollution and restoration of dirty water.

Wenbin Zhang; Rong Shen; Kunquan Lu; Ailing Ji; Zexian Cao

2012-10-23T23:59:59.000Z

326

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

327

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

328

On Deriving Vertical Air Motions from Cloud Radar Doppler Spectra  

Science Conference Proceedings (OSTI)

A method for deriving vertical air motions from cloud radar Doppler spectrum measurements is introduced. The method is applicable to cloud volumes containing small particles, in this case liquid droplets, which are assumed to trace vertical air ...

Matthew D. Shupe; Pavlos Kollias; Michael Poellot; Edwin Eloranta

2008-04-01T23:59:59.000Z

329

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

330

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

331

Alpha and gamma radiation effects on air-water systems at high gas/liquid ratios  

SciTech Connect

Radiolysis tests were conducted on air-water systems to examine the effects of radiation on liquid phase chemistry under high gas/liquid volume (G/L) ratios that are characteristic of an unsaturated nuclear waste repository setting. Test parameters included temperatures of 25, 90, and 200{degrees}C; gamma vs. alpha radiation; dose rates of {approximately}3500 and 50,000 rad/h; and G/L ratios of 10 and 100. Formate, oxalate, and total organic carbon contents increased during irradiation of the air-water systems in gamma and alpha tests at low-dose rate ({approximately}3500 rad/h). Increases in organic components were not observed for tests run at 200{degrees}C or high-dose rates (50,000 rad/h). In the tests where increases in organics occurred, the formate and oxalate were preferentially enriched in solutions that were rinsed from the test vessel walls. Nitrate (NO{sub 3}{sup {minus}}) is the dominant anion produced during the radiolysis reactions. Significant nitrite (NO{sub 2}{sup {minus}}) also occurs in some high-dose rate tests, with the reduced form of nitrogen possibly resulting from reactions with the test vessels. These results indicate that nitrogen acids are being produced and concentrated in the limited quantities of solution present in the tests. Nitrate + nitrite production varied inversely with temperature, with the lowest quantities being detected for the higher temperature tests. The G(NO{sub 3}{sup {minus}} + NO{sub 2}{sup {minus}}) values for the 25, 90, and 200{degrees}C experiments with gamma radiation are 3.2 {+-} 0.7, 1.3 {+-} 1.0, and 0.4 {+-} 0.3, respectively. Thus, the elevated temperatures expected early in the life of a repository may counteract pH decreases resulting from nitrogen acid production. Little variation was observed in G values as a function of dose rate or gas/liquid ratio.

Wronkiewicz, D.J.; Bates, J.K.

1993-08-01T23:59:59.000Z

332

Possible Aerosol Effects on Ice Clouds via Contact Nucleation  

Science Conference Proceedings (OSTI)

The indirect effect of aerosols on water clouds, whereby aerosol particles change cloud optical properties, is caused by aerosol-induced changes of the size and number of cloud droplets. This affects the lifetime of the water clouds as well as ...

Ulrike Lohmann

2002-02-01T23:59:59.000Z

333

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

334

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

335

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

336

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

337

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

338

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

339

Liquid CO2 Displacement of Water in a Dual-Permeability Pore Network Micromodel  

Science Conference Proceedings (OSTI)

Permeability contrasts exist in multilayer geological formations under consideration for carbon sequestration. To improve our understanding of heterogeneous pore-scale displacements, liquid CO2 (LCO2) - water displacement was evaluated in a pore network micromodel with two distinct permeability zones. Due to the low viscosity ratio (logM = -1.1), unstable displacement occurred at all injection rates over two orders of magnitude. LCO2 displaced water only in the high permeability zone at low injection rates with the mechanism shifting from capillary fingering to viscous fingering with increasing flow rate. At high injection rates, LCO2 displaced water in the low permeability zone with capillary fingering as the dominant mechanism. LCO2 saturation (SLCO2) as a function of injection rate was quantified using fluorescent microscopy. In all experiments, more than 50% of LCO2 resided in the active flowpaths, and this fraction increased as displacement transitioned from capillary to viscous fingering. A continuum-scale two-phase flow model with independently determined fluid and hydraulic parameters was used to predict SLCO2 in the dual-permeability field. Agreement with the micromodel experiments was obtained for low injection rates. However, the numerical model does not account for the unstable viscous fingering processes observed experimentally at higher rates and hence overestimated SLCO2.

Zhang, Changyong; Oostrom, Martinus; Grate, Jay W.; Wietsma, Thomas W.; Warner, Marvin G.

2011-09-01T23:59:59.000Z

340

Water Detritiation: Better SCK-CEN Catalysts for Liquid Phase Catalytic Exchange  

SciTech Connect

A technically and economically sound technology for water detritiation is mandatory for the future of fusion. This technology is expected to be based on water electrolysis and Liquid Phase Catalytic Exchange (LPCE). LPCE requires an efficient hydrophobic catalyst. SCK-CEN invented and developed such a catalyst in the past, which is prepared by depositing platinum on an activated charcoal carrier and mixing it with polytetrafluorethylene as a hydrophobic material. In combination with an appropriate wettable packing, different batches of this catalyst performed very well during years of extensive testing, allowing us to develop the ELEX process for water detritiation at inland reprocessing plants. Recently we succeeded in reproducing this catalyst and preparing a slightly different but clearly ameliorated type. By extrapolation these new results would allow us to obtain, at 40 deg. C and under typical but conservative operating conditions, a decontamination factor of 10000 with a column of less than 3 meters long. Such performances would make this catalyst an excellent candidate for application at JET or ITER. To confirm the performances of our improved catalyst for a longer period of time and in a longer column, we are now starting experiments in a newly built installation and we are collaborating with ICSI, Romania.

Bruggeman, Aime; Braet, Johan; Vanderbiesen, Sven [SCK-CEN (Belgium)

2005-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

Method of extracting iodine from liquid mixtures of iodine, water and hydrogen iodide  

DOE Green Energy (OSTI)

The components of a liquid mixture consisting essentially of HI, water and at least about 50 w/o iodine are separated in a countercurrent extraction zone by treating with phosphoric acid containing at least about 90 w/o H.sub.3 PO.sub.4. The bottom stream from the extraction zone is substantially completely molten iodine, and the overhead stream contains water, HI, H.sub.3 PO.sub.4 and a small fraction of the amount of original iodine. When the water and HI are present in near-azeotropic proportions, there is particular advantage in feeding the overhead stream to an extractive distillation zone wherein it is treated with additional concentrated phosphoric acid to create an anhydrous HI vapor stream and bottoms which contain at least about 85 w/o H.sub.3 PO.sub.4. Concentration of these bottoms provides phosphoric acid infeed for both the countercurrent extraction zone and for the extractive distillation zone.

Mysels, Karol J. (La Jolla, CA)

1979-01-01T23:59:59.000Z

342

Resonant x-ray emission spectroscopy of liquid water: novel instrumentation, high resolution, and the"map" approach  

DOE Green Energy (OSTI)

Techniques to study the electronic structure of liquids are rare. Most recently, resonant x-ray emission spectroscopy (XES) has been shown to be an extremely versatile spectroscopy to study both occupied and unoccupied electronic states for liquids in thermodynamic equilibrium. However, XES requires high-brilliance soft x-ray synchrotron radiation and poses significant technical challenges to maintain a liquid sample in an ultra-high vacuum environment. Our group has therefore developed and constructed a novel experimental setup for the study of liquids, with the long-term goal of investigating the electronic structure of biological systems in aqueous environments. We have developed a flow-through liquid cell in which the liquid is separated from vacuum by a thin Si3N4 or SiC window and which allows a precise control of temperature. This approach has significant advantages compared to static liquids cells used in the past. Furthermore, we have designed a dedicated high-transmission, high-resolution soft x-ray spectrometer. The high transmission makes it possible to measure complete resonant XES"maps" in less than an hour, giving unprecedented detailed insight into the electronic structure of the investigated sample. Using this new equipment we have investigated the electronic structure of liquid water. Furthermore, our XES spectra and maps give information about ultra-fast dissociation on the timescale of the O 1s core hole lifetime, which is strongly affected by the initial state hydrogen bonding configuration.

Weinhardt, L.; Fuchs, O.; Blum, M.; Bär, M.; Weigand, M.; Denlinger, J.D.; Zubavichus, Y.; Zharnikov, M.; Grunze, M.; Heske, C.; Umbach, E.

2008-06-17T23:59:59.000Z

343

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...

344

The Influence of Chain Dynamics on the Far Infrared Spectrum of Liquid Methanol-Water Mixtures  

DOE Green Energy (OSTI)

Far-infrared absorption spectroscopy has been used to study the low frequency ({center_dot} 100 cm{sup -1}) intermolecular modes of methanol in mixtures with water. With the aid of a first principles molecular dynamics simulation on an equivalent system, a detailed understanding about the origin of the low frequency IR modes has been established. The total dipole spectrum from the simulation suggests that the bands appearing in the experimental spectra at approximately 55 cm{sup -1} and 70 cm{sup -1} in methanol and methanol-rich mixtures arise from both fluctuations and torsional motions occurring within the methanol hydrogen-bonded chains. The influence of these modes on both the solvation dynamics and the relaxation mechanisms in the liquid are discussed within the context of recent experimental and theoretical results that have emerged from studies focusing on the short time dynamics in the methanol hydrogen bond network.

Woods, K.N.; /Stanford U., Phys. Dept.; Wiedemann, H.; /SLAC, SSRL

2005-07-12T23:59:59.000Z

345

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

346

Freezing Nucleation Rates of Dilute Solution Droplets Measured between ?30° and ?40°C in Laboratory Simulations of Natural Clouds  

Science Conference Proceedings (OSTI)

A 1.2 m3 continuous slow-expansion cloud chamber was used to simulate natural, liquid cloud formation on soluble cloud condensation nuclei (CCN). Droplet freezing was observed during continued simulated adiabatic ascent and cooling to ?40°C. ...

Paul J. DeMott; David C. Rogers

1990-05-01T23:59:59.000Z

347

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

348

Validating the Validation: The Influence of Liquid Water Distribution in Clouds on the Intercomparison of Satellite and Surface Observations  

Science Conference Proceedings (OSTI)

The intercomparison of LWP retrievals from observations by a geostationary satellite imager [Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board Meteosat Second Generation (MSG)] and a ground-based microwave (MW) radiometer is ...

N. A. J. Schutgens; R. A. Roebeling

2009-08-01T23:59:59.000Z

349

Bulk Parameterization of the Snow Field in a Cloud Model  

Science Conference Proceedings (OSTI)

A two-dimensional, time-dependent cloud model has been used to simulate a moderate intensity thunderstorm for the High Plains region. Six forms of water substance (water vapor, cloud water, cloud ice, rain, snow and hail, i.e., graupel) are ...

Yuh-Lang Lin; Richard D. Farley; Harold D. Orville

1983-06-01T23:59:59.000Z

350

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

351

Model analysis of the anthropogenic aerosol effect on clouds over East Asia  

Science Conference Proceedings (OSTI)

A coupled meteorology and aerosol/chemistry model WRF-Chem (Weather Research and Forecast model coupled with Chemistry) was used to conduct a pair of simulations with present-day (PD) and preindustrial (PI) emissions over East Asia to examine the aerosol indirect effect on clouds. As a result of an increase in aerosols in January, the cloud droplet number increased by 650 cm{sup -3} over the ocean and East China, 400 cm{sup -3} over Central and Southwest China, and less than 200 cm{sup -3} over North China. The cloud liquid water path (LWP) increased by 40-60 g m{sup -2} over the ocean and Southeast China and 30 g m{sup -2} over Central China; the LWP increased less than 5 g m{sup -2} or decreased by 5 g m{sup -2} over North China. The effective radius (Re) decreased by more than 4 {mu}m over Southwest, Central, and Southeast China and 2 {mu}m over North China. In July, variations in cloud properties were more uniform; the cloud droplet number increased by approximately 250-400 cm{sup -3}, the LWP increased by approximately 30-50 g m{sup -2}, and Re decreased by approximately 3 {mu}m over most regions of China. In response to cloud property changes from PI to PD, shortwave (SW) cloud radiative forcing strengthened by 30 W m{sup -2} over the ocean and 10 W m{sup -2} over Southeast China, and it weakened slightly by approximately 2-10 W m{sup -2} over Central and Southwest China in January. In July, SW cloud radiative forcing strengthened by 15 W m{sup -2} over Southeast and North China and weakened by 10 W m{sup -2} over Central China. The different responses of SW cloud radiative forcing in different regions was related to cloud feedbacks and natural variability.

Gao, Yi; Zhang, Meigen; Liu, Xiaohong; Zhao, Chun

2012-01-16T23:59:59.000Z

352

Search for the First-Order Liquid-to-Liquid Phase Transition in Low-Temperature Confined Water by Neutron Scattering  

SciTech Connect

It has been conjectured that a 1st order liquid-to-liquid (L-L) phase transition (LLPT) between high density liquid (HDL) and low density liquid (LDL) in supercooled water may exist, as a thermodynamic extension to the liquid phase of the 1st order transition established between the two bulk solid phases of amorphous ice, the high density amorphous ice (HDA) and the low density amorphous ice (LDA). In this paper, we first recall our previous attempts to establish the existence of the 1st order L-L phase transition through the use of two neutron scattering techniques: a constant Q elastic diffraction study of isobaric temperature scan of the D2O density, namely, the equation of state (EOS) measurements. A pronounced density hysteresis phenomenon in the temperature scan of the density above P = 1500 bar is observed which gives a plausible evidence of crossing the 1st order L-L phase transition line above this pressure; an incoherent quasi-elastic scattering measurements of temperature-dependence of the alpha-relaxation time of H2O at a series of pressures, namely, the study of the Fragile-to-Strong dynamic crossover (FSC) phenomenon as a function of pressure which we interpreted as the results of crossing the Widom line in the one-phase region. In this new experiment, we used incoherent inelastic neutron scattering (INS) to measure the density of states (DOS) of H atoms in H2O molecules in confined water as function of temperature and pressure, through which we may be able to follow the emergence of the LDL and HDL phases at supercooled temperature and high pressures. We here report for the first time the differences of librational and translational DOSs between the hypothetical HDL and LDL phases, which are similar to the corresponding differences between the well-established HDA and LDA ices. This is plausible evidence that the HDL and LDL phases are the thermodynamic extensions of the corresponding amorphous solid water HDA and LDA ices.

Chen, Sow-Hsin [Massachusetts Institute of Technology (MIT); Wang, Zhe [Massachusetts Institute of Technology (MIT); Kolesnikov, Alexander I [ORNL; Zhang, Yang [ORNL; Liu, Kao-Hsiang [National Taiwan University

2013-01-01T23:59:59.000Z

353

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

354

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 &

355

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

356

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

357

MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Data Sets (Revision 2)  

SciTech Connect

This report provides a short description of the Atmospheric Radiation Measurement (ARM) Climate Research Facility microwave radiometer (MWR) Retrieval (MWRRET) value-added product (VAP) algorithm. This algorithm utilizes a complementary physical retrieval method and applies brightness temperature offsets to reduce spurious liquid water path (LWP) bias in clear skies resulting in significantly improved precipitable water vapor (PWV) and LWP retrievals. We present a general overview of the technique, input parameters, output products, and describe data quality checks. A more complete discussion of the theory and results is given in Turner et al. (2007b).

Gaustad, KL; Turner, DD; McFarlane, SA

2011-07-25T23:59:59.000Z

358

Final Scientific/Technical Report Grant title: Use of ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction This is a collaborative project with the NASA GSFC project of Dr. A. Marshak and W. Wiscombe (PIs). This report covers BU activities from February 2011 to June 2011 and BU "Â?no-cost extension" activities from June 2011 to June 2012. This report summarizes results that complement a final technical report submitted by the PIs in 2011.  

SciTech Connect

Main results are summarized for work in these areas: spectrally-invariant approximation within atmospheric radiative transfer; spectral invariance of single scattering albedo for water droplets and ice crystals at weakly absorbing wavelengths; seasonal changes in leaf area of Amazon forests from leaf flushing and abscission; and Cloud droplet size and liquid water path retrievals from zenith radiance measurements.

Knyazikhin, Y

2012-09-10T23:59:59.000Z

359

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

360

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

Note: This page contains sample records for the topic "liquid water clouds" 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

Gas processing/The boiling behavior of LPG and liquid ethane, ethylene, propane, and n-butane spilled on water  

SciTech Connect

Boiling-rate calorimeter studies showed that unlike liquid nitrogen, methane, and LNG, LPG (84.7% propane, 6.0% ethane, and 9.3% n-butane; 442/sup 0/C bp), or pure propane, when rapidly spilled on water, reacted violently, ejecting water and ice into the vapor space; but in 1-2 sec, a coherent ice layer was formed and further boiloff was quiet and well predicted by a simple one-dimensional, moving-boundary-value, heat transfer model with a growing ice shield. Increasing the content of ethane and butane in LPG to 20% and 10%, respectively, had almost no effect on the LPG boiling, indicating that boiling may be modeled by using pure propane. Ethane, ethylene, and n-butane behaved quite differently from LPG. In spills of pure liquid propane on solid ice, the boiloff rate was almost identical to that predicted by the moving-boundary model.

Reid, R.C.; Smith, K.A.

1978-04-01T23:59:59.000Z

362

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

363

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

364

ARM - Measurement - Cloud particle size distribution  

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

size distribution size distribution 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 particle size distribution The number of cloud particles present in any given volume of air within a specified size range, including liquid and ice. 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 WSACR : Scanning ARM Cloud Radar, tuned to W-Band (95GHz) Field Campaign Instruments CPI : Cloud Particle Imager CLDAEROSMICRO : Cloud and Aerosol Microphysical Properties

365

Cloud Properties inferred from 8?12-µm Data  

Science Conference Proceedings (OSTI)

A trispectral combination of observations at 8-, 11-, and 12-µm bands is suggested for detecting cloud and cloud properties in the infrared. Atmospheric ice and water vapor absorption peak in opposite halves of the window region so that positive ...

Kathleen I. Strabala; Steven A. Ackerman; W. Paul Menzel

1994-02-01T23:59:59.000Z

366

Confronting Models with Data: The GEWEX Cloud Systems Study  

Science Conference Proceedings (OSTI)

The Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study (GCSS) was organized to promote the development of improved parameterizations of cloud systems for use in climate and numerical weather prediction models, with an emphasis on ...

David Randall; Steven Krueger; Christopher Bretherton; Judith Curry; Peter Duynkerke; Mitchell Moncrieff; Brian Ryan; David Starr; Martin Miller; William Rossow; George Tselioudis; Bruce Wielicki

2003-04-01T23:59:59.000Z

367

Retrieval of Ice Cloud Parameters Using a Microwave Imaging Radiometer  

Science Conference Proceedings (OSTI)

Based on the radiative transfer theory, the microwave radiance emanating from ice clouds at arbitrary viewing angles is expressed as an analytic function of the cloud ice water path (IWP), the particle effective diameter (De), and the particle ...

Fuzhong Weng; Norman C. Grody

2000-04-01T23:59:59.000Z

368

Water Vapor Structure Displacements from Cloud-Free Meteosat Scenes and Their Interpretation for the Wind Field  

Science Conference Proceedings (OSTI)

The evaluation of water vapor (WV) images taken by satellite-borne radiometers has become an essential source of data in modern meteorology. The analysis of structure displacements within sections of WV images is an effective way to get ...

G. Büche; H. Karbstein; A. Kummer; H. Fischer

2006-04-01T23:59:59.000Z

369

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

370

Ice Cloud Retrievals and Analysis with the Compact Scanning Submillimeter Imaging Radiometer and the Cloud Radar System during CRYSTAL FACE  

Science Conference Proceedings (OSTI)

Submillimeter-wave radiometry is a new technique for determining ice water path (IWP) and particle size in upper-tropospheric ice clouds. The first brightness temperatures images of ice clouds above 340 GHz were measured by the Compact Scanning ...

K. Franklin Evans; James R. Wang; Paul E. Racette; Gerald Heymsfield; Lihua Li

2005-06-01T23:59:59.000Z

371

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system. Progress report, September 1, 1991--August 31, 1992  

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

372

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

373

Apparatus and method for pumping hot, erosive slurry of coal solids in coal derived, water immiscible liquid  

SciTech Connect

An apparatus for and method of pumping hot, erosive slurry of coal solids in a coal derived, water immiscible liquid to higher pressure involves the use of a motive fluid which is miscible with the liquid of the slurry. The apparatus includes a pump 12, a remote check valve 14 and a chamber 16 between and in fluid communication with the pump 12 and check valve 14 through conduits 18,20. Pump 12 exerts pressure on the motive fluid and thereby on the slurry through a concentration gradient of coal solids within chamber 16 to alternately discharge slurry under pressure from the outlet port of check valve 14 and draw slurry in through the inlet port of check valve 14.

Ackerman, Carl D. (Olympia, WA)

1983-03-29T23:59:59.000Z

374

Nucleation and Characteristics of Liquid Nitrogen  

Science Conference Proceedings (OSTI)

This paper describes experiments on a refrigerating catalyst?liquid nitrogen (LN)?in different cloud chambers and their results. The nucleation threshold temperature of liquid nitrogen is 0°C, and when the temperature less than ?2°C, the ice ...

Cao Xuecheng; Wang Weimin

1996-09-01T23:59:59.000Z

375

Calculation of releases of radioactive materials in gaseous and liquid effluents from pressurized water reactors (PWR-GALE Code). Revision 1  

SciTech Connect

This report revises the original issuance of NUREG-0017, ''Calculation of Releases of Radioactive Materials in Gaseous and Liquid Effluents from Pressurized Water Reactors (PWR-GALE-Code)'' (April 1976), to incorporate more recent operating data now available as well as the results of a number of in-plant measurement programs at operating pressurized water reactors. The PWR-GALE Code is a computerized mathematical model for calculating the releases of radioactive material in gaseous and liquid effluents (i.e., the gaseous and liquid source terms). The US Nuclear Regulatory Commission uses the PWR-GALE Code to determine conformance with the requirements of Appendix I to 10 CFR Part 50.

Chandrasekaran, T.; Lee, J.Y.; Willis, C.A.

1985-04-01T23:59:59.000Z

376

Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds  

SciTech Connect

A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic boundary layer in the vicinity of Barrow, Alaska was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) sponsored by the Department of Energy Atmospheric Radiation Measurement (ARM) and Atmospheric Science Programs. The primary aim of ISDAC was to examine indirect effects of aerosols on clouds that contain both liquid and ice water. The experiment utilized the ARM permanent observational facilities at the North Slope of Alaska (NSA) in Barrow. These include a cloud radar, a polarized micropulse lidar, and an atmospheric emitted radiance interferometer as well as instruments specially deployed for ISDAC measuring aerosol, ice fog, precipitation and spectral shortwave radiation. The National Research Council of Canada Convair-580 flew 27 sorties during ISDAC, collecting data using an unprecedented 42 cloud and aerosol instruments for more than 100 hours on 12 different days. Data were obtained above, below and within single-layer stratus on 8 April and 26 April 2008. These data enable a process-oriented understanding of how aerosols affect the microphysical and radiative properties of arctic clouds influenced by different surface conditions. Observations acquired on a heavily polluted day, 19 April 2008, are enhancing this understanding. Data acquired in cirrus on transit flights between Fairbanks and Barrow are improving our understanding of the performance of cloud probes in ice. Ultimately the ISDAC data will be used to improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and to determine the extent to which long-term surface-based measurements can provide retrievals of aerosols, clouds, precipitation and radiative heating in the Arctic.

McFarquhar, Greg; Ghan, Steven J.; Verlinde, J.; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Mengistu; Brooks, Sarah D.; Cziczo, Daniel J.; Dubey, Manvendra K.; Fan, Jiwen; Flynn, Connor J.; Gultepe, Ismail; Hubbe, John M.; Gilles, Mary K.; Laskin, Alexander; Lawson, Paul; Leaitch, W. R.; Liu, Peter S.; Liu, Xiaohong; Lubin, Dan; Mazzoleni, Claudio; Macdonald, A. M.; Moffet, Ryan C.; Morrison, H.; Ovchinnikov, Mikhail; Shupe, Matthew D.; Turner, David D.; Xie, Shaocheng; Zelenyuk, Alla; Bae, Kenny; Freer, Matthew; Glen, Andrew

2011-02-01T23:59:59.000Z

377

Low-Dimensional Water on Ru(0001); Model System for X-ray Absorption Spectroscopy Studies of Liquid Water  

E-Print Network (OSTI)

geometries other than ice and gas-phase. This approach has1-4 . In its condensed ice Ih phase each water molecule is150 K. Spectra of gas phase and ice 5, 15, 16 are shown as

Nordlund, D.

2009-01-01T23:59:59.000Z

378

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...

379

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

380

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

Note: This page contains sample records for the topic "liquid water clouds" 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

Single Aircraft Integration of Remote Sensing and In Situ Sampling for the Study of Cloud Microphysics and Dynamics  

Science Conference Proceedings (OSTI)

Clouds are a critical component of the Earth's coupled water and energy cycles. Poor understanding of cloud–radiation–dynamics feedbacks results in large uncertainties in forecasting human-induced climate changes. Better understanding of cloud ...

Zhien Wang; Jeffrey French; Gabor Vali; Perry Wechsler; Samuel Haimov; Alfred Rodi; Min Deng; Dave Leon; Jeff Snider; Liran Peng; Andrew L. Pazmany

2012-05-01T23:59:59.000Z

382

Recovery of Non-Aqueous Phase Liquids from Contaminated Soil by CO2-Supersaturated Water Injection.  

E-Print Network (OSTI)

??Supersaturated water injection (SWI) is a novel remediation technology which is able to remove entrapped residual NAPLs from saturated porous media by both volatilization (partitioning… (more)

Li, Meichun

2009-01-01T23:59:59.000Z

383

Cloud-Resolving Model Simulation and Mosaic Treatment of Subgrid Cloud-Radiation Interaction  

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

Cloud-Resolving Model Simulation and Mosaic Treatment Cloud-Resolving Model Simulation and Mosaic Treatment of Subgrid Cloud-Radiation Interaction X. Wu Department of Geological and Atmospheric Sciences Iowa State University Ames, Iowa X.-Z. Liang Illinois State Water Survey University of Illinois at Urbana-Champaign Champaign, Illinois Introduction Improving the representation of cloud-radiation interaction is a major challenge for the global climate simulation. The development of cloud-resolving models (CRMs) and the extensive Atmospheric Radiation Measurements (ARMs) provide a unique opportunity for shading some lights on this problem. Current general circulation models (GCMs) predict cloud cover fractions and hydrometeor concentra- tions only in individual model layers, where clouds are assumed to be horizontally homogeneous in a

384

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

385

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

386

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

387

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...

388

7-88 A geothermal power plant uses geothermal liquid water at 160C at a specified rate as the heat source. The actual and maximum possible thermal efficiencies and the rate of heat rejected from this power plant  

E-Print Network (OSTI)

7-31 7-88 A geothermal power plant uses geothermal liquid water at 160ºC at a specified rate and potential energy changes are zero. 3 Steam properties are used for geothermal water. Properties Using saturated liquid properties, the source and the sink state enthalpies of geothermal water are (Table A-4) k

Bahrami, Majid

389

High-Resolution Electrospray Ionization Mass Spectrometry Analysis of Water- Soluble Organic Aerosols Collected with a Particle into Liquid Sampler  

DOE Green Energy (OSTI)

This work demonstrates the utility of a particle-into-liquid sampler (PILS) a technique traditionally used for identification of inorganic ions present in ambient or laboratory aerosols for the analysis of water soluble organic aerosol (OA) using high resolution electrospray ionization mass spectrometry (HR ESI-MS). Secondary organic aerosol (SOA) was produced from 0.5 ppm mixing ratios of limonene and ozone in a 5 m3 Teflon chamber. SOA was collected simultaneously using a traditional filter sampler and a PILS. The filter samples were later extracted with either water or acetonitrile, while the aqueous PILS samples were analyzed directly. In terms of peak intensities, types of detectable compounds, average O:C ratios, and organic mass to organic carbon ratios, the resulting high resolution mass spectra were essentially identical for the PILS and filter based samples. SOA compounds extracted from both filter/acetonitrile extraction and PILS/water extraction accounted for >95% of the total ion current in ESI mass spectra. This similarity was attributed to high solubility of limonene SOA in water. In contrast, significant differences in detected ions and peak abundances were observed for pine needle biomass burning organic aerosol (BBOA) collected with PILS and filter sampling. The water soluble fraction of BBOA is considerably smaller than for SOA, and a number of unique peaks were detectable only by the filter/acetonitrile method. The combination of PILS collection with HR-ESI-MS analysis offers a new approach for molecular analysis of the water-soluble organic fraction in biogenic SOA, aged photochemical smog, and BBOA.

Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

2010-10-01T23:59:59.000Z

390

A Lagrangian Interpretation of 3D Tropical Cloud Structure: ...  

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

the distributions requires further investigation, the implications are that TWP-Microbase retrieval would provide information about the tropical cloud water content for 2...

391

The Queensland Cloud Seeding Research Program  

Science Conference Proceedings (OSTI)

As a response to extreme water shortages in southeast Queensland, Australia, brought about by reduced rainfall and increasing population, the Queensland government decided to explore the potential for cloud seeding to enhance rainfall. The Queensland ...

Sarah A. Tessendorf; Roelof T. Bruintjes; Courtney Weeks; James W. Wilson; Charles A. Knight; Rita D. Roberts; Justin R. Peter; Scott Collis; Peter R. Buseck; Evelyn Freney; Michael Dixon; Matthew Pocernich; Kyoko Ikeda; Duncan Axisa; Eric Nelson; Peter T. May; Harald Richter; Stuart Piketh; Roelof P. Burger; Louise Wilson; Steven T. Siems; Michael Manton; Roger C. Stone; Acacia Pepler; Don R. Collins; V. N. Bringi; M. Thurai; Lynne Turner; David McRae

2012-01-01T23:59:59.000Z

392

On the Use of Pyrgeometers in Cloud  

Science Conference Proceedings (OSTI)

Laboratory and airborne observations show that the protective hemispheres of aircraft pyrgeometers are partly covered by water when used in cloud. This cover can reduce the incident longwave flux by as much as 60%. Improved agreement between ...

S. G. Bradley; R. G. Gibson

1982-08-01T23:59:59.000Z

393

Liquid-phase and vapor-phase dehydration of organic/water solutions  

DOE Patents (OSTI)

Processes for dehydrating an organic/water solution by pervaporation or vapor separation using fluorinated membranes. The processes are particularly useful for treating mixtures containing light organic components, such as ethanol, isopropanol or acetic acid.

Huang, Yu (Palo Alto, CA); Ly, Jennifer (San Jose, CA); Aldajani, Tiem (San Jose, CA); Baker, Richard W. (Palo Alto, CA)

2011-08-23T23:59:59.000Z

394

Structure and Dynamics of N, N-diethyl-N-methylammonium Triflate Ionic Liquid, Neat and with Water, from Molecular Dynamics Simulations  

DOE Green Energy (OSTI)

We investigated by means of molecular dynamics simulations the properties (structure, thermodynamics, ion transport, and dynamics) of the protic ionic liquid N,N-diethyl-N-methyl-ammonium triflate (dema:Tfl) and of selected aqueous mixtures of dema:Tfl. This ionic liquid, a good candidate for a water-free proton exchange membrane, is shown to exhibit high ion mobility and conductivity. For bulk melts in the temperature range of 303-453K, both liquid densities and enthalpies of vaporization are found to decrease roughly linearly with increasing temperature. The radial distribution functions reveal a significant long-range structural correlation. The ammonium cations [dema]+ are found to diffuse slightly faster than the triflate anions [Tfl]-, and both types of ions exhibit enhanced mobility at higher temperatures, leading to higher ionic conductivity of these ionic liquids. Analysis of the dynamics of ion pairing clearly points to the existence of long-lived contact ion pairs in this ionic liquid. We also examined the effects of water on the ionic properties of dema:Tfl-water mixtures. From the structural analysis it was found that water molecules tend to replace counter ions in the coordination shell and hydrogen bond to both ions, thus weakening their mutual association. As water concentration increases, water molecules start to connect with each other and eventually form a large network that percolates through the system. It is also found that water has a strong influence on the ion dynamics in the mixtures. As the concentration of water increases, both translational and rotational motion of [dema]+ and [Tfl]- are significantly enhanced. As a result, higher ionic conductivity is observed with increased hydration level. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Chang, Tsun-Mei; Dang, Liem X.; Devanathan, Ramaswami; Dupuis, Michel

2010-12-09T23:59:59.000Z

395

Radiation Parameterization for Three-Dimensional Inhomogeneous Cirrus Clouds Applied to ARM Data and Climate Models  

DOE Green Energy (OSTI)

OAK-B135 (a) We developed a 3D radiative transfer model to simulate the transfer of solar and thermal infrared radiation in inhomogeneous cirrus clouds. The model utilized a diffusion approximation approach (four-term expansion in the intensity) employing Cartesian coordinates. The required single-scattering parameters, including the extinction coefficient, single-scattering albedo, and asymmetry factor, for input to the model, were parameterized in terms of the ice water content and mean effective ice crystal size. The incorporation of gaseous absorption in multiple scattering atmospheres was accomplished by means of the correlated k-distribution approach. In addition, the strong forward diffraction nature in the phase function was accounted for in each predivided spatial grid based on a delta-function adjustment. The radiation parameterization developed herein is applied to potential cloud configurations generated from GCMs to investigate broken clouds and cloud-overlapping effects on the domain-averaged heating rate. Cloud inhomogeneity plays an important role in the determination of flux and heating rate distributions. Clouds with maximum overlap tend to produce less heating than those with random overlap. Broken clouds show more solar heating as well as more IR cooling as compared to a continuous cloud field (Gu and Liou, 2001). (b) We incorporated a contemporary radiation parameterization scheme in the UCLA atmospheric GCM in collaboration with the UCLA GCM group. In conjunction with the cloud/radiation process studies, we developed a physically-based cloud cover formation scheme in association with radiation calculations. The model clouds were first vertically grouped in terms of low, middle, and high types. Maximum overlap was then used for each cloud type, followed by random overlap among the three cloud types. Fu and Liou's 1D radiation code with modification was subsequently employed for pixel-by-pixel radiation calculations in the UCLA GCM. We showed that the simulated cloud cover and OLR fields without special tuning are comparable to those of ISCCP dataset and the results derived from radiation budget experiments. Use of the new radiation and cloud schemes enhances the radiative warming in the middle to upper tropical troposphere and alleviates the cold bias in the UCLA atmospheric GCM. We also illustrated that ice crystal size and cloud inhomogeneous are significant factors affecting the radiation budgets at the top of the atmosphere and the surface (Gu et al. 2003). (c) An innovative approach has been developed to construct a 3D field of inhomogeneous clouds in general and cirrus in particular in terms of liquid/ice water content and particle size on the basis of a unification of satellite and ground-based cloud radar data. Satellite remote sensing employing the current narrow-band spectro-radiometers has limitation and only the vertically integrated cloud parameters (optical depth and mean particle size) can be determined. However, by combining the horizontal cloud mapping inferred from satellites with the vertical structure derived from the profiling Doppler cloud radar, a 3D cloud field can be constructed. This represents a new conceptual approach to 3D remote sensing and imaging and offers a new perspective in observing the cloud structure. We applied this novel technique to AVHRR/NOAA satellite and mm-wave cloud radar data obtained from the ARM achieve and assessed the 3D cirrus cloud field with the ice crystal size distributions independently derived from optical probe measurements aboard the University of North Dakota Citation. The retrieved 3D ice water content and mean effective ice crystal size involving an impressive cirrus cloud occurring on April 18, 1997, are shown to be comparable to those derived from the analysis of collocated and coincident in situ aircraft measurements (Liou et al. 2002). (d) Detection of thin cirrus with optical depths less than 0.5, particularly those occurring i n the tropics remains a fundamental problem in remote sensing. We developed a new detection scheme for the

Kuo-Nan Liou

2003-12-29T23:59:59.000Z

396

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

397

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

398

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

399

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

400

A Ten-Winter Record of Cloud-Droplet Physical and Chemical Properties at a Mountaintop Site in Colorado  

Science Conference Proceedings (OSTI)

Cloud-droplet spectra and coincident cloud water pH measurements have been made for a portion of ten consecutive winters (1983/84?1992/93) from clouds that enveloped Storm Peak Laboratory in northwestern Colorado; cloud water ion measurements ...

Edward E. Hindman; Mechel A. Campbell; Randolph D. Borys

1994-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "liquid water clouds" 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

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

402

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

403

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

404

ISLAND AND SHIP TRAIL CLOUDS: THE ROSETTA STONE OF CLOUDS, POLLUTION, AND CLIMATE?  

SciTech Connect

Cloud/Climate Feedback is a combination of words known to be important but extremely difficult to quantify or even assign a direction. A 4 % increase in boundary layer clouds would cool the earth as much as a doubling of CO{sub 2} would warm it (Randall et al, 1984). Studies have shown that warmer sea surface temperatures are associated with fewer clouds (Oreopoulos and Davies, 1992). We do not know how much of this effect is due to direct solar warming of surface water in the absence of clouds. We also know there are more eastern ocean marine boundary layer clouds in summer than winter. Do warmer sea surface temperatures or more summer-like conditions best represent global warming? Twomey, 1974 has proposed that increasing aerosol pollution would lead to brighter clouds (indirect aerosol effect). This relationship does have determined sign (i.e. cooling) but is very difficult to quantify. Cloud trails from ships and islands hold the potential of addressing Cloud/Climate Feedback by observing atmospheric response to large perturbations in turbulence and aerosol. However, before cloud trails can be used as a Rosetta Stone connecting pollution and climate, much more needs to be understood about the micro- and macrophysics of cloud trails.

W. PORCH; S. WINIECKI; L. O' STEEN

2001-06-01T23:59:59.000Z

405

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

406

Month-Long 2D Cloud-Resolving Model Simulation and Resultant Statistics of Cloud Systems Over the ARM SGP  

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

Month-Long 2D Cloud-Resolving Model Simulation Month-Long 2D Cloud-Resolving Model Simulation and Resultant Statistics of Cloud Systems Over the ARM SGP X. Wu Department of Geological and Atmospheric Sciences Iowa State University Ames, Iowa X.-Z. Liang Illinois State Water Survey University of Illinois Urbana-Champaign, Illinois Introduction The cloud-resolving model (CRM) has recently emerged as a useful tool to develop improved representations of convections, clouds, and cloud-radiation interactions in general circulation models (GCMs). In particular, the fine spatial resolution allows the CRM to more realistically represent the detailed structure of cloud systems, including cloud geometric and radiative properties. The CRM simulations thus provide unique and comprehensive datasets, based on which more realistic GCM

407

Tropical and subtropical cloud transitions in weather and climate prediction models: the GCSS/WGNE Pacific Cross-Section Intercomparison (GPCI)  

SciTech Connect

A model evaluation approach is proposed where weather and climate prediction models are analyzed along a Pacific Ocean cross-section, from the stratocumulus regions off the coast of California, across the shallow convection dominated trade-winds, to the deep convection regions of the ITCZ: the GCSS/WGNE Pacific Cross-section Intercomparison (GPCI). The main goal of GPCI is to evaluate, and help understand and improve the representation of tropical and sub-tropical cloud processes in weather and climate prediction models. In this paper, a detailed analysis of cloud regime transitions along the cross-section from the sub-tropics to the tropics for the season JJA of 1998 is presented. This GPCI study confirms many of the typical weather and climate prediction model problems in the representation of clouds: underestimation of clouds in the stratocumulus regime by most models with the corresponding consequences in terms of shortwave radiation biases; overestimation of clouds by the ECMWF Re-Analysis (ERA40) in the deep tropics (in particular) with the corresponding impact in the outgoing longwave radiation; large spread between the different models in terms of cloud cover, liquid water path and shortwave radiation; significant differences between the models in terms of vertical crosssections of cloud properties (in particular), vertical velocity and relative humidity. An alternative analysis of cloud cover mean statistics is proposed where sharp gradients in cloud cover along the GPCI transect are taken into account. This analysis shows that the negative cloud bias of some models and ERA40 in the stratocumulus regions (as compared to ISCCP) is associated not only with lower values of cloud cover in these regimes, but also with a stratocumulus-to-cumulus transition that occurs too early along the trade-wind Lagrangian trajectory. Histograms of cloud cover along the cross-section differ significantly between models. Some models exhibit a quasi-bimodal structure with cloud cover being either very large (close to 100%) or very small, while other models show a more continuous transition. The ISCCP observations suggest that reality is in-between these two extreme examples. These different patterns reflect the diverse nature of the cloud, boundary layer, and convection parameterizations in the participating weather and climate prediction models.

Teixeira, J.; Cardoso, S.; Bonazzola, M.; Cole, Jason N.; DelGenio, Anthony D.; DeMott, C.; Franklin, A.; Hannay, Cecile; Jakob, Christian; Jiao, Y.; Karlsson, J.; Kitagawa, H.; Koehler, M.; Kuwano-Yoshida, A.; LeDrian, C.; Lock, Adrian; Miller, M.; Marquet, P.; Martins, J.; Mechoso, C. R.; Meijgaard, E. V.; Meinke, I.; Miranda, P.; Mironov, D.; Neggers, Roel; Pan, H. L.; Randall, David A.; Rasch, Philip J.; Rockel, B.; Rossow, William B.; Ritter, B.; Siebesma, A. P.; Soares, P.; Turk, F. J.; Vaillancourt, P.; Von Engeln, A.; Zhao, M.

2011-11-01T23:59:59.000Z

408

Infrared Spectroscopy and Hydrogen-Bond Dynamics of Liquid Water from Centroid Molecular Dynamics with an Ab Initio-Based Force Field  

DOE Green Energy (OSTI)

A molecular-level description of the unique properties of hydrogen-bond networks is critical for understanding many fundamental physico-chemical processes in aqueous environments. In this article a novel simulation approach, combining an ab-initio based force field for water with a quantum treatment of the nuclear motion, is applied to investigate hydrogen-bond dynamics in liquid water with a specific focus on the relationship of these dynamics to vibrational spectroscopy. Linear and nonlinear infrared (IR) spectra are calculated for liquid water, HOD in D2O and HOD in H2O and discussed in the context of the results obtained using other approaches that have been employed in studies of water dynamics. A comparison between the calculated spectra and the available experimental data yields an overall good agreement, indicating the accuracy of the present simulation approach in describing the properties of liquid water at ambient conditions. Possible improvements on the representation of the underlying water interactions as well as the treatment of the molecular motion at the quantum-mechanical level are also discussed. This research was supported by the Division of Chemical Sciences, Biosciences and Geosciences, US Department of Energy. Battelle operates the Pacific Northwest National Laboratory for the US Department of Energy.

Paesani, Francesco; Xantheas, Sotiris S.; Voth, Gregory A.

2009-10-01T23:59:59.000Z

409

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

410

A Parameterization of the Particle Size Spectrum of Ice Clouds in Terms of the Ambient Temperature and the Ice Water Content  

Science Conference Proceedings (OSTI)

A data set obtained in cirrus clouds has been examined to deduce any dependencies of the particle size spectral form or the crystal habit on the temperature. It was found that both form of the spectra and crystal habit changed systematically with ...

Andrew J. Heymsfield; C. M. R. Platt

1984-03-01T23:59:59.000Z

411

The Partitioning of Acetic, Formic, and Phosphoric Acids Between Liquid Water and Steam  

Science Conference Proceedings (OSTI)

The chemical carryover of impurities and treatment chemicals from the boiler to the steam phase, and ultimately to the low-pressure turbine and condenser, can be quantified based on laboratory experiments preformed over ranges of temperature, pH, and composition. The two major assumptions are that thermodynamic equilibrium is maintained and no deposition, adsorption or decomposition occurs. The most recent results on acetic, formic and phosphoric acids are presented with consideration of the effects of hydrolysis and dimerization reactions. Complications arising from thermal decomposition of the organic acids are discussed. The partitioning constants for these acids and other solutes measured in this program have been incorporated into a simple thermodynamic computer code that calculates the effect of chemical and mechanical carryover on the composition of the condensate formed to varying extents in the water/steam cycle.

Gruszkiewicz, M.S.; Marshall, S.L.; Palmer, D.A.; Simonson, J.M.

1999-06-22T23:59:59.000Z

412

Initialization of a Cloud-Resolving Model with Airborne Doppler Radar Observations of an Oceanic Tropical Convective System  

Science Conference Proceedings (OSTI)

Doppler radar–derived fields of wind and reflectivity, retrieved temperature perturbations, estimated water vapor, and cloud water contents are used to initialize a nonhydrostatic cloud-resolving model. Airborne Doppler data collected in a ...

Soline Bielli; Frank Roux

1999-06-01T23:59:59.000Z

413

Testing a New Cirrus Cloud Parameterizaton  

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

Testing a New Cirrus Cloud Parameterization Testing a New Cirrus Cloud Parameterization in NCAR CCM3 D. Zurovac-Jevtic, G. J. Zhang, and V. Ramanathan Center for Atmospheric Sciences Scripps Institute of Oceanography La Jolla, California Introduction Cirrus cloud cover and ice water content (IWC) are the two most important properties of cirrus clouds. However, in general circulation models (GCMs), their treatment is very crude. For example, in the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM3), IWC is prescribed as a function of column-integrated water vapor and height (Hack 1998). The in situ observations in the tropics indicate that the cirrus IWC is an order of magnitude larger than what is prescribed in the model (McFarquhar and Heymsfield 1996). The comparison with the International

414

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

415

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

416

A system to test the effects of materials on the electron drift lifetime in liquid argon and observations on the effect of water  

SciTech Connect

A materials test system (MTS) has been developed at FNAL to assess the suitability of materials for use in a large liquid argon time projection chamber. During development of the MTS, it was noted that controlling the cryostat pressure with a 'raining' condenser reduced the electron drift lifetime in the liquid argon. The effect of condensing has been investigated using a series of passive materials to filter the condensate. We report the results of these studies and of tests on different candidate materials for detector construction. The inferred reduction of electron drift lifetime by water concentrations in the parts per trillion is of particular interest.

Andrews, R.; Jaskierny, W.; Jostlein, H.; Kendziora, C.; Pordes, S.; Tope, T.; /Fermilab

2009-07-01T23:59:59.000Z

417

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

418

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

419

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...

420

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

Note: This page contains sample records for the topic "liquid water clouds" 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 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

422

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

423

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

424

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

425

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

426

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...

427

Correlated k-Distribution Treatment of Cloud Optical Properties and Related Radiative Impact  

Science Conference Proceedings (OSTI)

A new scheme of water cloud optical properties is proposed for correlated k-distribution (CKD) models, in which the correlation in spectral distributions between the gaseous absorption coefficient and cloud optical properties is maintained. This ...

Peng Lu; Hua Zhang; Jiangnan Li

2011-11-01T23:59:59.000Z

428

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...

429

Fluctuations of Cloud, Humidity, and Thermal Structure near the Tropical Tropopause  

Science Conference Proceedings (OSTI)

Thermal and humidity structures near the tropical tropopause are studied using microwave satellite retrievals of water vapor, along with contemporaneous dynamical structure in ECMWF analyses and cold clouds in high-resolution global cloud ...

Murry Salby; Fabrizio Sassi; Patrick Callaghan; William Read; Hugh Pumphrey

2003-11-01T23:59:59.000Z

430

Interactions between Cloud Microphysics and Cumulus Convection in a General Circulation Model  

Science Conference Proceedings (OSTI)

In the Colorado State University general circulation model, cumulus detrainment of cloud water and cloud ice has been, up to now, the only direct coupling between convective and large-scale condensation processes. This one-way interaction from ...

Laura D. Fowler; David A. Randall

2002-11-01T23:59:59.000Z

431

Indian Summer Monsoon Drought 2009: Role of Aerosol and Cloud Microphysics  

SciTech Connect

Cloud dynamics played a fundamental role in defining Indian summer monsoon (ISM) rainfall during drought in 2009. The anomalously negative precipitation was consistent with cloud properties. Although, aerosols inhibited the growth of cloud effective radius in the background of sparse water vapor, their role is secondary. The primary role, however, is played by the interactive feedback between cloud microphysics and dynamics owing to reduced efficient cloud droplet growth, lesser latent heating release and shortage of water content. Cloud microphysical processes were instrumental for the occurrence of ISM drought 2009.

Hazra, Anupam; Taraphdar, Sourav; Halder, Madhuparna; Pokhrel, S.; Chaudhari, H. S.; Salunke, K.; Mukhopadhyay, P.; Rao, S. A.

2013-07-01T23:59:59.000Z

432

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

433

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

João Paulo Barraca; Alfredo Matos; Rui L. Aguiar

2011-05-01T23:59:59.000Z

434

Limiting Factors for Convective Cloud Top Height in the Tropics  

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

Limiting Factors for Convective Cloud Top Limiting Factors for Convective Cloud Top Height in the Tropics M. P. Jensen and A. D. Del Genio National Aeronautics and Space Administration Goddard Institute for Space Studies Columbia University New York, New York Introduction Populations of tropical convective clouds are mainly comprised of three types: shallow trade cumulus, mid-level cumulus congestus and deep convective clouds (Johnson et al. 1999). Each of these cloud types has different impacts on the local radiation and water budgets. For climate model applications it is therefore important to understand the factors which determine the type of convective cloud that will occur. In this study, we concentrate on describing the factors that limit the cloud-top heights of mid-

435

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

436

Systematic Flights Obtain Long-Term Data Set of Cloud Properties  

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

Systematic Flights Obtain Long-Term Data Set of Cloud Properties Systematic Flights Obtain Long-Term Data Set of Cloud Properties Beginning in January 2009, the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility is sponsoring the first-of-its-kind long-term airborne research campaign to obtain data from low-level clouds above its Southern Great Plains (SGP) site. The five-month campaign is centered near Lamont, Oklahoma, a mid-latitude region that experiences a wide range of cloud types, including the "thin" clouds that are the focus of the campaign. Thin clouds contain so little water that the sun can be seen through them. Scientists refer to such clouds as "clouds with low-optical water depth," or CLOWD. Because these clouds are often tenuous and scattered, even some of the best

437

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.

438

Simulations of cirrus clouds using an explicit cloud model: integrating ARM  

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

Simulations of cirrus clouds using an explicit cloud model: integrating ARM Simulations of cirrus clouds using an explicit cloud model: integrating ARM water vapor and forcing data for analysis of cirrus formation and evolution Comstock, Jennifer Pacific Northwest National Laboratory Lin, Ruei-Fong NASA/Goddard Space Flight Center Starr, David NASA/Goddard Space Flight Center Yang, Ping Texas A&M Category: Modeling Understanding the atmospheric conditions required to initiate cirrus formation and produce observed microphysical properties is crucial to improving the representation of cirrus clouds in climate models. Ice formation in cirrus generally occurs at cold temperatures (below -30 C) and can take the form of either homogeneous or heterogeneous nucleation. The ice supersaturation required for ice formation is smaller for

439

FINAL REPORT FOR THE DOE/ARM PROJECT TITLED Representation of the Microphysical and Radiative Properties of Ice Clouds in SCMs and GCMs  

SciTech Connect

The broad goal of this research is to improve climate prediction through better representation of cirrus cloud microphysical and radiative properties in global climate models (GCMs). Clouds still represent the greatest source of uncertainty in climate prediction, and the representation of ice clouds is considerably more challenging than liquid water clouds. While about 40% of cloud condensate may be in the form of ice by some estimates, there have been no credible means of representing the ice particle size distribution and mass removal rates from ice clouds in GCMs. Both factors introduce large uncertainties regarding the global net flux, the latter factor alone producing a change of 10 W/m2 in the global net flux due to plausible changes in effective ice particle fallspeed. In addition, the radiative properties of ice crystals themselves are in question. This research provides GCMs with a credible means of representing the full (bimodal) ice particle size distribution (PSD) in ice clouds, including estimates of the small crystal (D < 65 microns) mode of the PSD. It also provides realistic estimates of mass sedimentation rates from ice clouds, which have a strong impact on their ice contents and radiative properties. This can be done through proper analysis of ice cloud microphysical data from ARM and other field campaigns. In addition, this research tests the ice cloud radiation treatment developed under two previous ARM projects by comparing it against laboratory measurements of ice cloud extinction efficiency and by comparing it with explicit theoretical calculations of ice crystal optical properties. The outcome of this project includes two PSD schemes for ice clouds; one appropriate for mid-latitude cirrus clouds and another for tropical anvil cirrus. Cloud temperature and ice water content (IWC) are the inputs for these PSD schemes, which are based on numerous PSD observations. The temperature dependence of the small crystal mode of the PSD for tropical anvils is opposite to that of mid-latitude cirrus, and this results in very different radiative properties for these two types of cirrus at temperatures less than about 50 C for a given ice water path. In addition, the representative PSD fall velocity is strongly influenced by the small crystal mode, and for temperatures less than 52 C, this fall velocity for mid-latitude cirrus is 2-8 times greater than for tropical anvil cirrus. Finally, the treatment of ice cloud optical properties was found to agree with laboratory measurements and exact theory within 15% for any given wavelength, PSD and ice particle shape. This treatment is analytical, formulated in terms of the PSD and ice particle shape properties. It thus provides the means for explicitly coupling the ice cloud microphysical and radiative properties, and can treat any combination of ice particle shape. It is very inexpensive regarding computer time. When these three deliverables were incorporated into the GCM at the National Center for Atmospheric Research (NCAR) under another project, it was found that the sunlight reflected and the amount of upwelling heat absorbed by cirrus clouds depended strongly on the PSD scheme used (i.e. mid-latitude or tropical anvil). This was largely due to the fall velocities associated with the two PSD schemes, although the PSD shape was also important.

Mitchell, David L.

2005-08-08T23:59:59.000Z

440

Reading Comprehension - The Water Cycle  

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

The Water Cycle The Water Cycle Evaporation, Condensation and Precipitation The _________ moon sun water clouds evaporates _________ fish oceans rain water from lakes and oceans. As the air rises, it cools. The water vapor condenses into tiny droplets of _________ evaporation clouds water sunshine . The droplets crowd together and form a _________ cloud lake storm precipitation . Wind blows the _________ rain sun droplet cloud towards the land. The tiny droplets join together and fall as precipitation to the _________ river lake ground cloud . The water soaks into the ground and collects in _________ rivers and lakes oceans and clouds jars and cups plants and animals . The _________ storm cycle river house that never ends has started again! A water cycle diagram. Use the diagram to identify the different parts of the water cycle:

Note: This page contains sample records for the topic "liquid water clouds" 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

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 Bjørndalen; Otto J. Anshus

2013-02-01T23:59:59.000Z

442

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)

443

Numerical simulation of cloud droplet formation in a tank  

Science Conference Proceedings (OSTI)

Using the computational fluid dynamics (CFD) code FLUENT 6 together with the fine particle model (FPM), numerical simulations of droplet dynamics in a 12.4m^3 cloud tank were conducted. The coupled fields of water vapor, temperature, flow velocity, particle ... Keywords: Cloud droplet formation, Particle-dynamics modeling, Stirred tank, Turbulence

Matthias Schütze; Frank Stratmann

2008-09-01T23:59:59.000Z

444

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

445

Posters A Stratiform Cloud Parameterization for General Circulation Models  

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

Posters A Stratiform Cloud Parameterization for General Circulation Models S. J. Ghan and L. R. Leung Pacific Northwest Laboratory Richland, Washington C. C. Chuang and J. E. Penner Lawrence Livermore National Laboratory Livermore, California 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 a parameterization for stratiform clouds in GCMs that expresses stratiform clouds in terms of bulk microphysical properties and their subgrid variability. In this parameterization, precipitating cloud species are distinguished from non-precipitating species, and the liquid

446

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

447

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...

448

Characterization of water-based liquid scintillator response to gammas and neutrons at varying scintillator-surfactant concentrations  

E-Print Network (OSTI)

Large scale solar neutron and neutrino flux experiments require many tons of bulk liquid organic scintillator to take spectroscopic data of these energetic particles. However, material and chemical concerns make such ...

Chilton, Lauren (Lauren M.)

2012-01-01T23:59:59.000Z

449

Water  

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

Laws Envirosearch Institutional Controls NEPA Activities RCRA RQ*Calculator Water HSS Logo Water Laws Overview of water-related legislation affecting DOE sites Clean...

450

Testing the Role of Radiation in Determining Tropical Cloud-Top Temperature  

Science Conference Proceedings (OSTI)

A cloud-resolving model is used to test the hypothesis that radiative cooling by water vapor emission is the primary control on the temperature of tropical anvil clouds. The temperature of ice clouds in the simulation can be increased or decreased ...

Bryce E. Harrop; Dennis L. Hartmann

2012-09-01T23:59:59.000Z

451

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...

452

Toward Understanding of Differences in Current Cloud Retrievals of ARM Ground-based Measurements  

SciTech Connect

Accurate observations of cloud microphysical properties are needed for evaluating and improving the representation of cloud processes in climate models. However, large differences are found in current cloud products retrieved from ground-based remote sensing measurements using various retrieval algorithms. Understanding the differences is an important step to address uncertainties in the cloud retrievals. In this study, an in-depth analysis of nine existing ground-based cloud retrievals using ARM remote sensing measurements is carried out. We place emphasize on boundary layer overcast clouds and high level ice clouds, which are the focus of many current retrieval development efforts due to their radiative importance and relatively simple structure. Large systematic discrepancies in cloud microphysical properties are found in these two types of clouds among the nine cloud retrieval products, particularly for the cloud liquid and ice effective radius. It is shown that most of these large differences have their roots in the retrieval algorithms used by these cloud products, including the retrieval theoretical bases, assumptions, as well as input and constraint parameters. This study suggests the need to further validate current retrieval theories and assumptions and even the development of new retrieval algorithms with more observations under different cloud regimes.

Zhao, Chuanfeng; Xie, Shaocheng; Klein, Stephen A.; Protat, Alain; Shupe, Matthew D.; McFarlane, Sally A.; Comstock, Jennifer M.; Delanoe, Julien; Deng, Min; Dunn, Maureen; Hogan, Robin; Huang, Dong; Jensen, Michael; Mace, Gerald G.; McCoy, Renata; O'Conner, Ewan J.; Turner, Dave; Wang, Zhien

2012-05-30T23:59:59.000Z

453

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

454

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

455

Ice in Clouds Experiment—Layer Clouds. Part I: Ice Growth Rates Derived from Lenticular Wave Cloud Penetrations  

Science Conference Proceedings (OSTI)

Lenticular wave clouds are used as a natural laboratory to estimate the linear and mass growth rates of ice particles at temperatures from ?20° to ?32°C and to characterize the apparent rate of ice nucleation at water saturation at a nearly ...

Andrew J. Heymsfield; Paul R. Field; Matt Bailey; Dave Rogers; Jeffrey Stith; Cynthia Twohy; Zhien Wang; Samuel Haimov

2011-11-01T23:59:59.000Z

456

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

457

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.

458

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

459

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

460

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

Note: This page contains sample records for the topic "liquid water clouds" 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

Fragmentation of Freezing Drops in Shallow Maritime Frontal Clouds  

Science Conference Proceedings (OSTI)

Images of frozen drops with pieces missing were collected on two days of airborne sampling in shallow supercooled stratiform frontal clouds in the coastal waters of Washington State. In those limited regions where ice appeared to be newly formed, ...

Arthur L. Rangno

2008-04-01T23:59:59.000Z

462

Emissions from Ships with respect to Their Effects on Clouds  

Science Conference Proceedings (OSTI)

Emissions of particles, gases, heat, and water vapor from ships are discussed with respect to their potential for changing the microstructure of marine stratiform clouds and producing the phenomenon known as “ship tracks.” Airborne measurements ...

Peter V. Hobbs; Timothy J. Garrett; Ronald J. Ferek; Scott R. Strader; Dean A. Hegg; Glendon M. Frick; William A. Hoppel; Richard F. Gasparovic; Lynn M. Russell; Douglas W. Johnson; Colin O’Dowd; Philip A. Durkee; Kurt E. Nielsen; George Innis

2000-08-01T23:59:59.000Z

463

Degradation of Radar Reflectivity by Cloud Attenuation at Microwave Frequency  

Science Conference Proceedings (OSTI)

The main object of this paper is to emphasize that clouds—the nonprecipitating component of condensed atmospheric water—can produce a strong attenuation at operational microwave frequencies, although they present a low reflectivity preventing ...

Olivier Pujol; Jean-François Georgis; Laurent Féral; Henri Sauvageot

2007-04-01T23:59:59.000Z

464

Cloud Droplet Growth by Condensation in Homogeneous Isotropic Turbulence  

Science Conference Proceedings (OSTI)

The growth of cloud droplets by diffusion of water vapor in a three-dimensional homogeneous isotropic turbulent flow is considered. Within a simple model of advection and condensation, the dynamics and growth of millions of droplets are ...

Alessandra S. Lanotte; Agnese Seminara; Federico Toschi

2009-06-01T23:59:59.000Z

465

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

466

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

467

The Influence of Solar Zenith Angle and Cloud Type on Cloud Radiative Forcing at the Surface in the Arctic  

Science Conference Proceedings (OSTI)

Measurements of the long- and shortwave incident radiation taken from the USCGC Polar Sea during a research cruise to the Northeast Water Polynya during the summer of 1993 are analyzed together with observations of cloud type and amount to ...

Peter J. Minnett

1999-01-01T23:59:59.000Z

468

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

469

Energy Basics: Solar Liquid Heating  

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

EERE: Energy Basics Solar Liquid Heating Solar liquid heating systems use a collector with a heat transfer or "working" fluid such as water, antifreeze (usually non-toxic propylene...

470

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

471

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

472

Toward understanding of differences in current cloud retrievals of ARM ground-based measurements  

SciTech Connect

Accurate observations of cloud microphysical properties are needed for evaluating and improving the representation of cloud processes in climate models and better estimate of the Earth radiative budget. However, large differences are found in current cloud products retrieved from ground-based remote sensing measurements using various retrieval algorithms. Understanding the differences is an important step to address uncertainties in the cloud retrievals. In this study, an in-depth analysis of nine existing ground-based cloud retrievals using ARM remote sensing measurements is carried out. We place emphasis on boundary layer overcast clouds and high level ice clouds, which are the focus of many current retrieval development efforts due to their radiative importance and relatively simple structure. Large systematic discrepancies in cloud microphysical properties are found in these two types of clouds among the nine cloud retrieval products, particularly for the cloud liquid and ice particle effective radius. Note that the differences among some retrieval products are even larger than the prescribed uncertainties reported by the retrieval algorithm developers. It is shown that most of these large differences have their roots in the retrieval theoretical bases, assumptions, as well as input and constraint parameters. This study suggests the need to further validate current retrieval theories and assumptions and even the development of new retrieval algorithms with more observations under different cloud regimes.

Zhao C.; Dunn M.; Xie, S.; Klein, S. A.; Protat, A.; Shupe, M. D.; McFarlane, S. A.; Comstock, J. M.; Delanoë, J.; Deng, M.; Hogan, R. J.; Huang, D.; Jensen, M. P.; Mace, G. G.; McCoy, R.; O’Connor, E. J.; Turner, D. D.; Wang, Z.

2012-05-30T23:59:59.000Z

473

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

474

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

475

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

476

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

477