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


1

3, 33013333, 2003 Cirrus cloud  

E-Print Network [OSTI]

ACPD 3, 3301­3333, 2003 Cirrus cloud occurrence as function of ambient relative humidity J. Str and Physics Discussions Cirrus cloud occurrence as function of ambient relative humidity: A comparison¨om (johan@itm.su.se) 3301 #12;ACPD 3, 3301­3333, 2003 Cirrus cloud occurrence as function of ambient

Paris-Sud XI, Université de

2

Testing a New Cirrus Cloud Parameterizaton  

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

3

Investigation of Thin Cirrus Cloud Optical and Microphysical Properties on the Basis of Satellite Observations and Fast Radiative Transfer Models  

E-Print Network [OSTI]

function of ?CALIOP. the frequency is scaled by dividing the largest frequency in each ?CALIOP bin. Data are from collocated MODIS and CALIOP measurements made in August 2006. ............... 126 5.7 Daytime frequencies of (a) cloud, (b) ice cloud, (c...) and Stubenrauch et al. (2006) investigated the climatology of thin cirrus properties. 1.2.2 Limb-view-instrument-based observations Limb-view-instruments observe cloud or atmosphere by eliminating the signals from the surface and therefore increase the SNRs...

Wang, Chenxi

2013-07-25T23:59:59.000Z

4

Observed and Simulated Cirrus Cloud Properties at the SGP CART Site  

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

and Simulated Cirrus Cloud Properties and Simulated Cirrus Cloud Properties at the SGP CART Site A. D. Del Genio and A. B. Wolf National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York G. G. Mace University of Utah Salt Lake City, Utah Introduction Despite their potential importance in a long-term climate change, less is known about cirrus clouds than most other cloud types, for a variety of reasons (Del Genio 2001) including: (1) the difficulty of remotely sensing ice water content (IWC), (2) uncertainty in the identities of ice nuclei and the relative importance of different nucleation processes, (3) significant variations in depth and optical thickness caused by formation and sedimentation of large particles, and (4) our relatively poor documentation of

5

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

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

6

Posters Sensitivity of Cirrus Cloud Radiative  

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

7 7 Posters Sensitivity of Cirrus Cloud Radiative Properties to Ice Crystal Size and Shape in General Circulation Model Simulations D. L. Mitchell Desert Research Institute Reno, Nevada J. E. Kristjánsson Department of Geophysics University of Oslo, Norway M. J. Newman Los Alamos National Laboratory Los Alamos, New Mexico Introduction Recent research (e.g., Mitchell and Arnott 1994) has shown that the radiative properties of cirrus clouds (i.e., optical depth, albedo, emissivity) depend on the shapes and sizes of ice crystals. For instance, the cloud albedo may vary by a factor of two, depending on whether hexagonal columns or bullet rosette ice crystals are assumed for a given ice water path (IWP). This variance occurs primarily because, at sizes characteristic of cirrus

7

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

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

channel (0.6 m) to retrieve cloud optical depth. Both channels are common to all weather satellite sensors. Because cirrus clouds are mostly semitransparent at infrared...

8

Laser transmissionbackscattering through inhomogeneous cirrus clouds  

E-Print Network [OSTI]

Laser transmission­backscattering through inhomogeneous cirrus clouds Szu-Cheng Ou, Yoshihide of the transmission and backscattering of high-energy laser beams. The 2D extinction-coefficient and mean effective and backscattering of high-energy laser beams in realistic atmospheres. The results of laser direct transmission

Takano, Yoshihide

9

Cirrus cloud formation and the role of heterogeneous ice nuclei  

E-Print Network [OSTI]

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

Froyd, Karl D.

2013-01-01T23:59:59.000Z

10

Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts  

E-Print Network [OSTI]

of clouds are formed by deep convection and convergence of water vapor. Thus, it is very important to understand the radiative energy balance of the tropics and the effect of clouds on the radiation field. For mixed-phase clouds, error analyses pertaining...

Lee, Joonsuk

2009-06-02T23:59:59.000Z

11

The frequency of tropopause-level thick and thin cirrus clouds as observed by CALIPSO and the relationship to relative humidity and outgoing longwave radiation  

E-Print Network [OSTI]

Thick cloud frequencies, in percent, for SON............................................ 52 15 DJF thin cirrus frequencies in colored contours at a) 121-hPa, b) 100-hPa, and c) 82-hPa with OLR values of 230 W-m-2 in black... contours......................................................................................... 53 16 MAM thin cirrus frequencies in colored contours at a) 121-hPa, b) 100-hPa, and c) 82-hPa with OLR values of 230 W-m-2...

Cardona, Allison Leanne

2008-10-10T23:59:59.000Z

12

Comparison of the CALIPSO satellite and ground-based observations of cirrus clouds at the ARM TWP sites  

SciTech Connect (OSTI)

Statistics of ice cloud macrophysical and optical properties from the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) instrument on board the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite are compared with those from ground-based lidar observations over a 31 month period. Ground-based lidar observations are taken from the micropulse lidars (MPL) at the three Department of Energy Atmospheric Radiation Measurement (ARM) tropical western pacific (TWP) sites: Manus, Nauru and Darwin. CALIPSO observations show a larger cloud fraction at high altitudes while the ground-based MPLs show a larger cloud fraction at low altitudes. The difference in mean ice cloud top and base heights at the Manus and Nauru sites are all within 0.51 km, although differences are statistically significant. Mean ice cloud geometrical thickness agree to within 0.05 km at the Manus and Nauru sites. Larger differences exist at Darwin due to excessive degradation of the MPL output power during our sampling period. Both sets of observations show thicker clouds during the nighttime which may be real but could also be partially an artifact of the decreased signal-to-noise ratio during the daytime. The number of ice cloud layers per profile are also shown to be consistent after accounting for the difference in spatial resolution. For cloud optical depths, four different retrieval methods are compared, two for each set of observations. All products show that the majority of ice cloud optical depths ({approx}60%) fall below an optical depth of 0.2. For most comparisons all four retrievals agree to within the uncertainty intervals. We find that both CALIPSO retrievals agree best to ground-based optical depths when the lidar ratio in the latter is retrieved instead of set to a fixed value. Also thoroughly compared is the cloud properties for the subset of ice clouds which reside in the tropical tropopause layer (TTL).

Thorsen, Tyler J.; Fu, Q.; Comstock, Jennifer M.

2011-11-10T23:59:59.000Z

13

Effectsof ice-crystal structure on halo formation: cirrus cloud  

E-Print Network [OSTI]

Effectsof ice-crystal structure on halo formation: cirrus cloud experimental and ray campaign, four 220halo-producing cirrus clouds were studied jointly from a ground- based polarization lidar of the aircraft, which collecteda total of 84slides byimpaction, preserving the ice crystals for later microscopic

Takano, Yoshihide

14

The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution  

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

The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution Shape d'Entremont, Robert Atmospheric and Environmental Research, Inc. Mitchell, David Desert Research Institute Category: Cloud Properties Our project has focused on using satellite- and ground-based passive thermal infrared radiance observations to retrieve cirrus cloud properties, most importantly ice water path (IWP), effective particle size (Deff), and visible extinction optical thickness (tau). During this past year we began comparing our cirrus retrieval results with aircraft observations at the ARM CART site, and we are participating in a summary intercomparison study with other retrieval algorithms as a member of the high-clouds working group. Our passive-infrared retrieval scheme, based on different wavelength

15

Time Correlations in Backscattering Radar Reflectivity Measurements from Cirrus Clouds  

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

Time Correlations in Backscattering Radar Reflectivity Time Correlations in Backscattering Radar Reflectivity Measurements from Cirrus Clouds K. Ivanova, H. N. Shirer, and E. E. Clothiaux Pennsylvania State University University Park, Pennsylvania T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington Introduction The state variables of the atmosphere exhibit correlations at various spatial and temporal scales. These correlations are crucial for understanding short- and long-term trends in climate. Cirrus clouds are important phenomena in the troposphere affecting climate. To improve future parameterization of cirrus clouds in climate models, we must understand the cloud properties and how they change within the cloud. We consider fluctuations of cloud radar signals obtained at isodepths within cirrus clouds

16

Clarifying the Dominant Sources and Mechanisms of Cirrus Cloud Formation  

E-Print Network [OSTI]

Formation of cirrus clouds depends on the availability of ice nuclei to begin condensation of atmospheric water vapor. Although it is known that only a small fraction of atmospheric aerosols are efficient ice nuclei, the ...

Cziczo, Daniel James

17

Cirrus Classification at Midlatitude from Systematic Lidar Observations  

Science Journals Connector (OSTI)

Systematic cirrus lidar measurements performed in the south of France during 2000 are analyzed statistically to search for cloud classes. The classes are based on cloud characteristics (cloud thickness, light backscattering efficiency, and its ...

P. Keckhut; F. Borchi; S. Bekki; A. Hauchecorne; M. SiLaouina

2006-02-01T23:59:59.000Z

18

Midlatitude Cirrus Clouds and Multiple Tropopauses from a 2002-2006 Climatology over the SIRTA Observatory  

E-Print Network [OSTI]

This study present a comparison of lidar observations of midlatitude cirrus clouds over the SIRTA observatory between 2002 and 2006 with multiple tropopauses (MT) retrieved from radiosounding temperature profiles. The temporal variability of MT properties (frequency, thickness) are discussed. Results show a marked annual cycle, with MT frequency reaching its lowest point in May (~18% occurrence of MT) and slowly rising to more than 40% in DJF. The average thickness of the MT also follows an annual cycle, going from less than 1 km in spring to 1.5 km in late autumn. Comparison with lidar observations show that cirrus clouds show a preference for being located close below the 1st tropopause. When the cloud top is above the 1st tropopause (7% of observations), in 20% of cases the cloud base is above it as well, resulting in a cirrus cloud "sandwiched" between the two tropopauses. Compared to the general distribution of cirrus, cross-tropopause cirrus show a higher frequency of large optical depths, while inter-t...

Noel, Vincent

2007-01-01T23:59:59.000Z

19

Macrophysical Properties of Tropical Cirrus Clouds from the CALIPSO Satellite and from Ground-based Micropulse and Raman Lidars  

SciTech Connect (OSTI)

Lidar observations of cirrus cloud macrophysical properties over the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Darwin, Australia site are compared from the Cloud-Aerosol Lidar and In- frared Pathfinder Satellite Observation (CALIPSO) satellite, the ground-based ARM micropulse lidar (MPL), and the ARM Raman lidar (RL). Comparisons are made using the subset of profiles where the lidar beam is not fully attenuated. Daytime measurements using the RL are shown to be relatively unaffected by the solar background and are therefore suited for checking the validity of diurnal cycles. RL and CALIPSO cloud fraction profiles show good agreement while the MPL detects significantly less cirrus, particularly during the daytime. Both MPL and CALIPSO observations show that cirrus clouds occur less frequently during the day than at night at all altitudes. In contrast, the RL diurnal cy- cle is significantly different than zero only below about 11 km; where it is the opposite sign (i.e. more clouds during the daytime). For cirrus geomet- rical thickness, the MPL and CALIPSO observations agree well and both datasets have signficantly thinner clouds during the daytime than the RL. From the examination of hourly MPL and RL cirrus cloud thickness and through the application of daytime detection limits to all CALIPSO data we find that the decreased MPL and CALIPSO cloud thickness during the daytime is very likely a result of increased daytime noise. This study highlights the vast im- provement the RL provides (compared to the MPL) in the ARM program's ability to observe tropical cirrus clouds as well as a valuable ground-based lidar dataset for the validation of CALIPSO observations and to help im- prove our understanding of tropical cirrus clouds.

Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.; Sivaraman, Chitra; Vaughan, Mark A.; Winker, D.; Turner, David D.

2013-08-27T23:59:59.000Z

20

Perturbed Physics Ensemble Simulations of Cirrus on the Cloud System-resolving Scale  

SciTech Connect (OSTI)

In this study, the effect of uncertainties in the parameterization of ice microphysical processes and initial conditions on the variability of cirrus microphysical and radiative properties are investigated in a series of cloud system-resolving perturbed physics ensemble (PPE) and initial condition ensemble (ICE) simulations. Three cirrus cases representative of mid-latitude, subtropical and tropical cirrus are examined. It is found that the variability in cirrus properties induced by perturbing uncertain parameters in ice microphysics parameterizations outweighs the variability induced by perturbing the initial conditions in midlatitude and subtropical cirrus. However, in tropical anvil cirrus the variability in the PPE and ICE simulations is about the same order of magnitude. The cirrus properties showing the largest sensitivity are ice water content (IWC) and cloud thickness whereas the averaged high cloud cover is only marginally affected. Changes in cirrus ice water path and outgoing longwave radiation are controlled primarily by changes in IWC and cloud thickness but not by changes is the averaged high cloud cover. The change in the vertical distribution of cloud fraction and cloud thickness is caused by changes in cirrus cloud base whereas cloud top is not sensitive to either perturbed physics or perturbed initial conditions. In all cirrus cases, the top three parameters controlling the microphysical variability and radiative impact of cirrus clouds are ice fall speeds, ice autoconversion size thresholds and heterogeneous ice nucleation. Changes in the ice deposition coefficient do not affect the ice water path and outgoing longwave radiation. Similarly, changes in the number concentration of aerosols available for homogeneous freezing have virtually no effect on the microphysical and radiative properties of midlatitude and subtropical cirrus but only little impact on tropical anvil cirrus. Overall, the sensitivity of cirrus microphysical and radiative properties to uncertainties in ice microphysics is largest for midlatitude cirrus and smallest for tropical anvil cirrus.

Muhlbauer, Andreas; Berry, Elizabeth; Comstock, Jennifer M.; Mace, Gerald G.

2014-04-16T23:59:59.000Z

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


21

The study of cirrus clouds using airborne and satellite data  

E-Print Network [OSTI]

Cirrus clouds are known to play a key role in the earth's radiation budget, yet are one of the most uncertain components of the earth-atmosphere system. With the development of instruments such as the Airborne Visible/Infrared Imaging Spectrometer...

Meyer, Kerry Glynne

2004-09-30T23:59:59.000Z

22

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

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

23

Remote Sensing of Cirrus Cloud Particle Size and Optical Depth Using Polarimetric Sensor Measurements  

Science Journals Connector (OSTI)

This paper presents a conceptual approach toward the remote sensing of cirrus cloud particle size and optical depth using the degree of polarization and polarized reflectance associated with the first three Stokes parameters, I, Q, and U, for the ...

S. C. Ou; K. N. Liou; Y. Takano; R. L. Slonaker

2005-12-01T23:59:59.000Z

24

A Comparison of Cirrus Cloud Visible Optical Depth Derived from Lidar  

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

Comparison of Cirrus Cloud Visible Optical Depth Derived from Lidar Comparison of Cirrus Cloud Visible Optical Depth Derived from Lidar Lo, Chaomei Pacific Northwest National Laboratory Comstock, Jennifer Pacific Northwest National Laboratory Flynn, Connor Pacific Northwest National Laboratory Category: Cloud Properties Optically thin clouds (e.g. optical depth < 3) can have a significant impact on radiative heating in the atmosphere, particularly in the cold upper troposphere. Currently, there is no value-added product (VAP) in the Atmospheric Radiation Measurement (ARM) program archive that produces thin cloud optical depth, particularly at the Tropical Western Pacific and North Slope of Alaska sites. A VAP is under development to obtain the cirrus cloud visible optical depth from the MPLNOR (Micro Pulse Lidar Normalized

25

Laser transmission through thin cirrus clouds K. N. Liou, Y. Takano, S. C. Ou, and M. W. Johnson  

E-Print Network [OSTI]

Laser transmission through thin cirrus clouds K. N. Liou, Y. Takano, S. C. Ou, and M. W. Johnson A near-infrared airborne-laser transmission model for thin cirrus clouds has been developed on the basis optical depth, and ice crystal size on laser transmission for tactical applications. We show

Takano, Yoshihide

26

Remote Sensing and In-Situ Observations of Arctic Mixed-Phase and Cirrus Clouds Acquired During Mixed-Phase Arctic Cloud Experiment: Atmospheric Radiation Measurement Uninhabited Aerospace Vehicle Participation  

SciTech Connect (OSTI)

The Atmospheric Radiation Monitor (ARM) uninhabited aerospace vehicle (UAV) program aims to develop measurement techniques and instruments suitable for a new class of high altitude, long endurance UAVs while supporting the climate community with valuable data sets. Using the Scaled Composites Proteus aircraft, ARM UAV participated in Mixed-Phase Arctic Cloud Experiment (M-PACE), obtaining unique data to help understand the interaction of clouds with solar and infrared radiation. Many measurements obtained using the Proteus were coincident with in-situ observations made by the UND Citation. Data from M-PACE are needed to understand interactions between clouds, the atmosphere and ocean in the Arctic, critical interactions given large-scale models suggest enhanced warming compared to lower latitudes is occurring.

McFarquhar, G.M.; Freer, M.; Um, J.; McCoy, R.; Bolton, W.

2005-03-18T23:59:59.000Z

27

Modeling, Simulation and Comparison Study of Cirrus Clouds' Ice Jorge M. Villa*a  

E-Print Network [OSTI]

Modeling, Simulation and Comparison Study of Cirrus Clouds' Ice Crystals Jorge M. Villa*a , Sandra of the bullets. This software allows us to create irregular models of particles using the Discrete Dipole of earth's energy dynamics, therefore affecting climate systems1 . In addition, they indirectly affect

Cruz-Pol, Sandra L.

28

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

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

29

Development and Comparison of Ground and Satellite-based Retrievals of Cirrus Cloud Physical Properties  

SciTech Connect (OSTI)

This report is the final update on ARM research conducted at DRI through May of 2006. A relatively minor amount of work was done after May, and last month (November), two journal papers partially funded by this project were published. The other investigator on this project, Dr. Bob d'Entremont, will be submitting his report in February 2007 when his no-cost extension expires. The main developments for this period, which concludes most of the DRI research on this project, are as follows: (1) Further development of a retrieval method for cirrus cloud ice particle effective diameter (De) and ice water path (IWP) using terrestrial radiances measured from satellites; (2) Revision and publication of the journal article 'Testing and Comparing the Modified Anomalous Diffraction Approximation'; and (3) Revision and publication of our radar retrieval method for IWC and snowfall rate.

Mitchell, David L

2009-10-14T23:59:59.000Z

30

Small Particles in Cirrus  

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

Particles in Cirrus Particles in Cirrus Because the reflective properties of ice crystals in cirrus clouds can greatly influence the amount of solar energy that reaches the Earth, scientists use information about the shape and size of ice crystals as input to climate models. These data are obtained by satellite instruments, ground-based sensors, and research aircraft equipped with probes. However, notable discrepancies among these measurements have led to considerable uncertainty in how to represent these properties in climate models. From December 2009 through April 2010, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will sponsor the use of an instrumented aircraft to obtain the most comprehensive set of measurements of ice crystals in cirrus clouds yet obtained. In conjunction with

31

A Composite and Microphysical Study of Jet Stream Cirrus Over the ARM Site  

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

Composite and Microphysical Study of Composite and Microphysical Study of Jet Stream Cirrus Over the ARM Site J. M. Haynes and G. L. Stephens Department of Atmospheric Science Colorado State University Fort Collins, Colorado Introduction Cirrus are known to play an important role in the radiative budget of the earth-atmosphere system. Previous studies have shown that cirrus within strong jet streams account for about 40% to 60% of all cirrus observed in the continental United States during the winter (Menzel et al. 1992). However, the connection between the properties of mid-latitude cirrus clouds and the large-scale flow that supports them is still, to a large degree, unknown. This study seeks to better quantify and understand this relationship through two interrelated investigations.

32

Radiative Effects of Dust Aerosols, Natural Cirrus Clouds and Contrails: Broadband Optical Properties and Sensitivity Studies  

E-Print Network [OSTI]

This dissertation aims to study the broadband optical properties and radiative effects of dust aerosols and ice clouds. It covers three main topics: the uncertainty of dust optical properties and radiative effects from the dust particle shape...

Yi, Bingqi

2013-07-09T23:59:59.000Z

33

Simultaneous detection/separation of mineral dust and cirrus clouds using MODIS thermal infrared window data  

E-Print Network [OSTI]

and cloud coverage for the Persian Gulf case compares reasonably well to those from the ``Deep Blue-laden scenes, including a daytime dust case over the Persian Gulf and two nighttime dust events over the Cape

Liou, K. N.

34

A GCM Parameterization of Ice Particle Mean Effective Sizes for High Latitude Cirrus Clouds and It's Comparison with Mid-Latitude Parmaterization  

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

GCM Parameterization of Ice Particle Mean Effective GCM Parameterization of Ice Particle Mean Effective Sizes for High Latitude Cirrus Clouds and It's Comparison with Mid-Latitude Parameterization F. S. Boudala Department of Oceanography Dalhousie University Halifax, Nova Scotia, Canada Q. Fu Department of Atmospheric Sciences University of Washington Seattle, Washington G. A. Issac Meteorological Service of Canada Toronto, Ontario, Canada Introduction Single-scattering properties of ice clouds depend on both ice water content (IWC) and effective size of cloud particles (Fu 1996; Fu et al. 1998). However, only the IWC information is provided in numerical models. Stephens et al. (1990) showed that the ice cloud feedback on a CO 2 warming simulation could be either positive or negative depending on the value of the ice particle size assumed. Parameterizations

35

Molecular Hydrogen in Infrared Cirrus  

E-Print Network [OSTI]

We combine data from our recent FUSE survey of interstellar molecular hydrogen absorption toward 50 high-latitude AGN with COBE-corrected IRAS 100 micron emission maps to study the correlation of infrared cirrus with H2. A plot of the H2 column density vs. IR cirrus intensity shows the same transition in molecular fraction, f_H2, as seen with total hydrogen column density, N_H. This transition is usually attributed to H2 self-shielding, and it suggests that many diffuse cirrus clouds contain H2 in significant fractions, f_H2 = 1-30%. These clouds cover approximately 50% of the northern sky at latitudes b > 30 degrees, at temperature-corrected 100 micron intensities D_100 > 1.5 MJy/sr. The sheetlike cirrus clouds, with hydrogen densities n_H > 30 cm^-3, may be compressed by dynamical processes at the disk-halo interface, and they are conducive to H2 formation on grain surfaces. Exploiting the correlation between N(H2) and 100 micron intensity, we estimate that cirrus clouds at b > 30 contain approximately 3000 M_sun in H2. Extrapolated over the inner Milky Way, the cirrus may contain 10^7 M_sun of H2 and 10^8 M_sun in total gas mass. If elevated to 100 pc, their gravitational potential energy is ~10^53 erg.

Kristen Gillmon; J. Michael Shull

2005-07-25T23:59:59.000Z

36

Electron cloud observations : a retrospective.  

SciTech Connect (OSTI)

A growing number of observations of electron cloud effects (ECEs) have been reported in positron and proton rings. Low-energy, background electrons ubiquitous in high-intensity particle accelerators. Amplification of electron cloud (EC) can occur under certain operating conditions, potentially giving rise to numerous effects that can seriously degrade accelerator performance. EC observations and diagnostics have contributed to a better understanding of ECEs, in particular, details of beam-induced multipacting and cloud saturation effects. Such experimental results can be used to provide realistic limits on key input parameters for modeling efforts and analytical calculations to improve prediction capability. Electron cloud effects are increasingly important phenomena in high luminosity, high brightness, or high intensity machines - Colliders, Storage rings, Damping rings, Heavy ion beams. EC generation and instability modeling increasingly complex and benchmarked against in situ data: {delta}, {delta}{sub 0}, photon reflectivity, and SE energy distributions important. Surface conditioning and use of solenoidal windings in field-free regions are successful cures: will they be enough? What are new observations and how do they contribute to body of work and understanding physics of EC?

Harkay, K.; Accelerator Systems Division (APS)

2004-01-01T23:59:59.000Z

37

Observing Warm Clouds in 3D Using ARM Scanning Cloud  

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

Observing Warm Clouds in 3D Using ARM Scanning Cloud Radars and a Novel Ensemble Method For original submission and image(s), see ARM Research Highlights http:www.arm.gov...

38

ARM - Publications: Science Team Meeting Documents: Cirrus properties and  

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

Cirrus properties and air mean vertical motion retrieval using Cirrus properties and air mean vertical motion retrieval using mm-wavelength Doppler radar moments Deng, Min University of Utah Mace, Gerald University of Utah Vertically pointing millimeter wavelength Doppler radar provides valuable information on upper tropospheric cloud properties and dynamics. We are developing an innovative algorithm to simultaneously retrieve cirrus microphysical parameters and air mean vertical motion by using the three moments of the Doppler spectrum. The technique utilizes a statement that the observed Doppler spectrum is the convolution of a quiet air reflectivity spectrum with the turbulence PDF (probability density function). The set of equations describing the Doppler spectrum moments are inverted using optimal estimation theory to derive estimates of the

39

Evaluation of cirrus statistics produced by general circulation...  

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

models for producing climatological cloud statistics by comparing them to the cirrus climatology compiled over the Southern Great Plains (SGP) ARM site. This evaluation includes...

40

First Observations of Tracking Clouds Using Scanning ARM Cloud Radars  

Science Journals Connector (OSTI)

Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large-drop formation (weather radar first echo). These measurements also complement cloud and precipitation tracking using ...

Paloma Borque; Pavlos Kollias; Scott Giangrande

2014-12-01T23:59:59.000Z

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


41

CLOUD, DRIZZLE, AND TURBULENCE OBSERVATIONS IN MARINE STRATOCUMULUS CLOUDS IN THE AZORES  

E-Print Network [OSTI]

CLOUD, DRIZZLE, AND TURBULENCE OBSERVATIONS IN MARINE STRATOCUMULUS CLOUDS IN THE AZORES Jasmine at the Azores provided a unique, long-term record (May 2009 to December 2010) of cloud observations in a regime dominated by low-level stratiform clouds. First, a comprehensive cloud classification scheme that utilizes

42

Electron Cloud observation in the LHC  

E-Print Network [OSTI]

Operation of LHC with bunch trains at different spacings has revealed the formation of an electron cloud inside the machine. The main observations of electron cloud build up are the pressure rise measured at the vacuum gauges in the warm regions, as well as the increase of the beam screen temperature in the cold regions due to an additional heat load. The effects of the electron cloud were also visible as instability and emittance growth affecting the last bunches of longer trains, which could be improved running with higher chromaticity or larger transverse emittances. A summary of the 2010 and 2011 observations and measurements and a comparison with models will be presented. The efficiency of scrubbing to improve the machine running performance will be briefly discussed.

Rumolo, G; Baglin, V; Bartosik, H; Biancacci, N; Baudrenghien, P; Bregliozzi, G; Chiggiato, P; Claudet, S; De Maria, R; Esteban-Muller, J; Favier, M; Hansen, C; Hfle, W; Jimenez, J M; Kain, V; Lanza, G; Li, K S B; Maury Cuna, G H I; Mtral, E; Papotti, G; Pieloni, T; Roncarolo, F; Salvant, B; Shaposhnikova, E N; Steinhagen, R J; Tavian, L J; Valuch, D; Venturini Delsolaro, W; Zimmermann, F; Iriso, U; Dominguez, O; Koukovini-Platia, E; Mounet, N; Zannini, C; Bhat, C M

2011-01-01T23:59:59.000Z

43

Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical modeling of drizzle evolution  

E-Print Network [OSTI]

Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical I, the influence of cloud microphysics and dynamics on the shape of cloud radar Doppler spectra in warm stratiform clouds was discussed. The traditional analysis of radar Doppler moments was extended

44

arm_stm_2008_borg_cirrus_poster.ppt  

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

Cirrus Cloud Characterization Cirrus Cloud Characterization with Raman Lidar Measurements at Southern Great Plains Lori Borg, David Turner, Robert Holz, David Tobin, Bob Knuteson, Leslie Moy, Daniel DeSlover, Ed Eloranta, Hank Revercomb (PI) Altitude [km] Radar + Lidar Heating Rate [deg/day] Altitude [km] Radar Heating Rate [deg/day] Altitude [km] MMCR Radar Reflectivity [dBZ] (color) with Lidar Boundaries (black) SGP Cirrus Case Study: 11/08/2005 18:00UTC - 11/11/2005 12:00 UTC Lori Borg, lori.borg@ssec.wisc.edu Introduction: Cirrus clouds play a significant role in the energy budget of the atmosphere and represent a major source of uncertainly in understanding climate and climate change. A large part of this uncertainty lies in the modeling of the cloud, which requires assumptions and

45

ELECTRON CLOUD OBSERVATIONS AND CURES IN RHIC.  

SciTech Connect (OSTI)

Since 2081 MIC has experienced electron cloud effects, which have limited the beam intensity. These include dynamic pressure rises - including pressure instabilities, tune shifts: electrons, a reduction of the stability threshold for bunches crossing the transition energy, and possibly slow emittance growth. We summarize the main observations in operation and dedicated experiments, as well as countermeasures including baking, NEG coated warm beam pipes, solenoids, bunch patterns, anti-grazing rings, pre-pumped cold beam pipes, and scrubbing.

FISCHER,W.; BLASKIEWICZ, M.; HUAN, H.; HSEUH, H.C.; PTITSYN, V.; ROSER, T.; THIEBERGER, P.; TRBOJEVIC, D.; WEI, J.; ZHANG, S.Y.; IRISO, U.

2007-03-01T23:59:59.000Z

46

ELECTRON CLOUD OBSERVATIONS AND CURES IN RHIC  

SciTech Connect (OSTI)

Since 2001 RHIC has experienced electron cloud effects, which have limited the beam intensity. These include dynamic pressure rises - including pressure instabilities, tune shifts, a reduction of the stability threshold for bunches crossing the transition energy, and possibly incoherent emittance growth. We summarize the main observations in operation and dedicated experiments, as well as countermeasures including baking, NEG coated warm beam pipes, solenoids, bunch patterns, anti-grazing rings, pre-pumped cold beam pipes, scrubbing, and operation with long bunches.

FISCHER,W.; BLASKIEWICZ, M.; HUANG, H.; HSEUH, H.C.; ET AL.

2007-06-25T23:59:59.000Z

47

Cloud Properties and Precipitation Formation Processes Observed  

E-Print Network [OSTI]

of spring time precipitation that develops in the Riyadh, Saudi Arabia region. · What are the cloud properties for developing cloud in the Riyadh, Saudi Arabia region. Research Objective #12;#12;Quality is based on calibration conducted by Kelly bosch and Dennis Afseth at Weather Modification Inc. (WMI) on 22

Delene, David J.

48

Impact of Ice Crystal Roughness on Satellite Retrieved Cloud Properties  

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

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

49

GIANT MOLECULAR CLOUD FORMATION IN DISK GALAXIES: CHARACTERIZING SIMULATED VERSUS OBSERVED CLOUD CATALOGS  

SciTech Connect (OSTI)

We present the results of a study of simulated giant molecular clouds (GMCs) formed in a Milky Way-type galactic disk with a flat rotation curve. This simulation, which does not include star formation or feedback, produces clouds with masses ranging between 10{sup 4} M{sub ?} and 10{sup 7} M{sub ?}. We compare our simulated cloud population to two observational surveys: the Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey and the BIMA All-Disk Survey of M33. An analysis of the global cloud properties as well as a comparison of Larson's scaling relations is carried out. We find that simulated cloud properties agree well with the observed cloud properties, with the closest agreement occurring between the clouds at comparable resolution in M33. Our clouds are highly filamentarya property that derives both from their formation due to gravitational instability in the sheared galactic environment, as well as to cloud-cloud gravitational encounters. We also find that the rate at which potentially star-forming gas accumulates within dense regionswherein n{sub thresh} ? 10{sup 4} cm{sup 3}is 3% per 10 Myr, in clouds of roughly 10{sup 6} M{sub ?}. This suggests that star formation rates in observed clouds are related to the rates at which gas can be accumulated into dense subregions within GMCs via filamentary flows. The most internally well-resolved clouds are chosen for listing in a catalog of simulated GMCsthe first of its kind. The cataloged clouds are available as an extracted data set from the global simulation.

Benincasa, Samantha M.; Pudritz, Ralph E.; Wadsley, James [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Tasker, Elizabeth J. [Department of Physics, Faculty of Science, Hokkaido University, Kita-ku, Sapporo 060-0810 (Japan)

2013-10-10T23:59:59.000Z

50

Radiosonde observations at Pt. Reyes and cloud properties retrieved from  

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

Radiosonde observations at Pt. Reyes and cloud properties retrieved from Radiosonde observations at Pt. Reyes and cloud properties retrieved from GOES-WEST Inoue, Toshiro MRI/JMA Category: Field Campaigns Low-level cloud formed off the west coast of continents plays an important role in general circulation and climate. Marine Stratus Radiation Aerosol and Drizzle (MASRAD) was conducted at the ARM mobile site deployed at Pt Reyes, California during April to September. Here, we studied the relationship between meteorological parameters observed by GPS sonde and cloud properties observed from GOES-WEST during the MASRAD intensive operational period. Cloud properties are retrieved from VISST (Visible Infrared Solar-infrared Split window Technique). The vertical profile of stability, relative humidity (RH) and wind speed observed by GPS sonde are

51

Climatological Data for Clouds Over the Globe from Surface Observations  

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

for Clouds Over the Globe from Surface Observations for Clouds Over the Globe from Surface Observations (1988) (NDP-026) DOI: 10.3334/CDIAC/cli.ndp026 data Data Investigators C. J. Hahn, S. G. Warren, J. London, R. L. Jenne, and R. M. Chervin With some data from as early as 1930, global long-term monthly and/or seasonal total cloud cover, cloud type amounts and frequencies of occurrence, low cloud base heights, harmonic analyses of annual and diurnal cycles, interannual variations and trends, and cloud type co-occurrences have been compiled and presented in two atlases (Warren et al. 1988, 1990). These data were derived from land and ship synoptic weather reports from the "SPOT" archive of the Fleet Numerical Oceanography Center (FNOC) and from Release 1 of the Comprehensive Ocean-Atmosphere Data Set (COADS) for

52

Topographically Generated Cloud Plumes  

Science Journals Connector (OSTI)

Two topographically generated cirrus plume events have been examined through satellite observations and real-data simulations. On 30 October 2002, an approximately 70-km-wide cirrus plume, revealed by a high-resolution Moderate Resolution Imaging ...

Qingfang Jiang; James D. Doyle

2006-08-01T23:59:59.000Z

53

1. ABSTRACT Clouds substantially affect the observed infrared  

E-Print Network [OSTI]

initial guess Clouds vary over orders from BT difference between observed of magnitude and Jacobians of clouds 4. TESTING ASSUMPTIONS: FORWARD MODEL ERRORS * Comparing model that includes scattering (CHARTS heights and optical depths can be adequately modeled by our approach 3. ASSUMPTIONS / APPROACH In order

54

Discrimination between thin cirrus and and tropospheric aerosol using  

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

Discrimination between thin cirrus and and tropospheric aerosol using Discrimination between thin cirrus and and tropospheric aerosol using multiple measurements from Darwin ARCS Mitchell, Ross CSIRO Category: Aerosols Thin cirrus cloud occurs frequently in the tropics, and is often difficult to distinguish from tropospheric aerosol on the basis of temporal variations in ground based measurements, since both can be rather spatially uniform. In this study we investigate their discrimination by combining data from three instruments at the Darwin Atmospheric Radiation and Cloud Station (ARCS): the Cimel sun photometer (CSP), the micropulse lidar (MPL), and the total sky imager (TSI). The study was carried out over the dry season of 2005, with the usual widespread burning of tropical savanna leading to extensive smoke plumes. It is shown that the locus of data in

55

Observed Southern Ocean Cloud Properties and Shortwave Reflection. Part I: Calculation of SW Flux from Observed Cloud Properties  

Science Journals Connector (OSTI)

The sensitivity of the reflection of shortwave radiation over the Southern Ocean to the cloud properties there is estimated using observations from a suite of passive and active satellite instruments in combination with radiative transfer ...

Daniel T. McCoy; Dennis L. Hartmann; Daniel P. Grosvenor

56

Climatological Data For Clouds Over the Globe From Surface Observations,  

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

For Clouds Over the Globe From Surface Observations, For Clouds Over the Globe From Surface Observations, 1982-1991: The Total Cloud Edition (1994) (NDP-026a) data Data Investigators C. J. Hahn, S. G. Warren, and J. London Routine, synoptic surface weather reports from ships and land stations over the entire globe, for the10-year period December 1981 through November 1991, were processed for total cloud cover and the frequencies of occurrence of clear sky, sky-obscured due to precipitation, and sky-obscured due to fog. Archived data, consisting of various annual, seasonal and monthly averages, are provided in grid boxes that are typically 2.5° × 2.5° for land and 5° × 5° for ocean. Day and nighttime averages are also given separately for each season. Several derived quantities, such as interannual variations and annual and diurnal

57

Global Hydrometeor Occurrence as Observed by CloudSAT: Initial Observations from Summer 2006  

SciTech Connect (OSTI)

Measurements of global hydrometeor coverage and occurrence frequencies as observed by the cloud radar on CloudSat are summarized using data collected during Summer 2006. CloudSat was launched on 28 April 2006 and began collecting data routinely on 7 June 2006. In this article we document the distribution of cloudiness from the ITCZ to the Polar regions as observed by CloudSat during the first summer of operations. The overall global hydrometeor coverage as observed by CloudSat is found to be 0.506. The vertical distribution of zonally averaged hydrometeor occurrence shows the relationship of clouds with components of the atmospheric general circulation such as the Hadley Cell, the ubiquitous storms over the Southern Ocean, and the subtropical stratocumulus regimes.

Mace, Gerald G.; Marchand, Roger T.; Zhang, Qiuqing; Stephens, Graeme L.

2007-05-08T23:59:59.000Z

58

Evaluation of Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Sa...  

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

Cloud Type Occurrences Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Satellite and Cloud Radar Y. Luo and S. K. Krueger University of Utah Salt Lake City, Utah Introduction Because of both the various effects clouds exert on the earth-atmospheric system and the cloud feedback, correct representations of clouds in numerical models are critical for accurate climate modeling and weather forecast. Unfortunately, determination of clouds and their radiative feedback processes is still the weakest component of current general circulation models (e.g., Senior and Mitchell 1993, Cess et al. 1996). Using radiative fluxes at the top of atmosphere (TOA) available from satellite observations made by the Earth Radiation Budget Experiment (ERBE; Barkstrom 1984), one could assess cloud radiative effects

59

Phase Transformations of the Ternary System (NH4)2SO4-H2SO4-H2O and the Implications for Cirrus Cloud Formation  

E-Print Network [OSTI]

the presence of NH4 + ions in the aerosol of the upper troposphere. Low-temperature ternary phase diagrams distribution alters the cloud's radiative properties, persistence, and surface area available for heterogeneous radiation, which insulates or warms Earth, and scattering the sun's visible radiation upward, thus cooling

60

Combining the Perspective of Satellite- and Ground-Based Observations to Analyze Cloud Frontal Systems  

Science Journals Connector (OSTI)

A method is presented to analyze the cloud life cycle of frontal systems passing over European supersites. It combines information on the vertical profiles of cloud properties derived from ground-based observations with cloud products obtained ...

Anja Hnerbein; Hartwig Deneke; Andreas Macke; Kerstin Ebell; Ulrich Grsdorf

2014-11-01T23:59:59.000Z

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


61

Preliminary Studies on the Variational Assimilation of Cloud-Radiation Observations Using ARM Observations  

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

Studies on the Variational Assimilation Studies on the Variational Assimilation of Cloud-Radiation Observations Using ARM Observations M. Janisková, J.-F. Mahfouf, and J.-J. Morcrette European Centre for Medium-Range Weather Forecasts Shinfield Park, Reading Berskshire, United Kingdom Abstract A linearized cloud scheme and a radiation scheme including cloud effects have been developed at European Centre for Medium-Range Weather Forecasts (ECMWF) to assimilate cloud properties in the framework of the four-dimensional variational (4D-Var) assimilation system. To investigate the potential of those schemes to modify the model temperature, humidity and cloud profiles and produce a better match to the observed radiation fluxes, one-dimensional variational (1D-Var) assimilation experiments have been carried out using data from the Atmospheric Radiation Measurement (ARM)

62

Cirrus 1 | Open Energy Information  

Open Energy Info (EERE)

Cirrus 1 Cirrus 1 Jump to: navigation, search Name Cirrus 1 Facility Cirrus 1 Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Cirrus Wind Energy Developer Wind Tex Energy Energy Purchaser Merchant Location Tahoka TX Coordinates 33.027294°, -101.696782° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.027294,"lon":-101.696782,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

63

Scanning Cloud Radar Observations at Azores: Preliminary 3D Cloud Products  

SciTech Connect (OSTI)

The deployment of the Scanning W-Band ARM Cloud Radar (SWACR) during the AMF campaign at Azores signals the first deployment of an ARM Facility-owned scanning cloud radar and offers a prelude for the type of 3D cloud observations that ARM will have the capability to provide at all the ARM Climate Research Facility sites by the end of 2010. The primary objective of the deployment of Scanning ARM Cloud Radars (SACRs) at the ARM Facility sites is to map continuously (operationally) the 3D structure of clouds and shallow precipitation and to provide 3D microphysical and dynamical retrievals for cloud life cycle and cloud-scale process studies. This is a challenging task, never attempted before, and requires significant research and development efforts in order to understand the radar's capabilities and limitations. At the same time, we need to look beyond the radar meteorology aspects of the challenge and ensure that the hardware and software capabilities of the new systems are utilized for the development of 3D data products that address the scientific needs of the new Atmospheric System Research (ASR) program. The SWACR observations at Azores provide a first look at such observations and the challenges associated with their analysis and interpretation. The set of scan strategies applied during the SWACR deployment and their merit is discussed. The scan strategies were adjusted for the detection of marine stratocumulus and shallow cumulus that were frequently observed at the Azores deployment. Quality control procedures for the radar reflectivity and Doppler products are presented. Finally, preliminary 3D-Active Remote Sensing of Cloud Locations (3D-ARSCL) products on a regular grid will be presented, and the challenges associated with their development discussed. In addition to data from the Azores deployment, limited data from the follow-up deployment of the SWACR at the ARM SGP site will be presented. This effort provides a blueprint for the effort required for the development of 3D cloud products from all new SACRs that the program will deploy at all fixed and mobile sites by the end of 2010.

Kollias, P.; Johnson, K.; Jo, I.; Tatarevic, A.; Giangrande, S.; Widener, K.; Bharadwaj, N.; Mead, J.

2010-03-15T23:59:59.000Z

64

Multiwavelength observations of cirrus clouds in the North Celestial Loop: the transition from atomic to molecular gas  

Science Journals Connector (OSTI)

......2500 University Drive NW, Calgary, AB...discovered in diffuse gas at high Galactic latitude...smaller in the molecular gas, the ratios would...produced. In these news maps, the extent...in the H i and H2 gas. The velocity difference...was supported by the Natural Sciences and Engineering......

L. Barriault; G. Joncas; E. Falgarone; D. J. Marshall; M. Heyer; F. Boulanger; T. Foster; C. Brunt; M.-A. Miville-Deschnes; K. Blagrave; R. Kothes; T. L. Landecker; P. G. Martin; D. Scott; J. M. Stil; A. R. Taylor

2010-08-21T23:59:59.000Z

65

Cloud condensation nuclei in Western Colorado : observations and model predictions.  

E-Print Network [OSTI]

??Variations in the warm cloud?active portion of atmospheric aerosols, or cloud condensation nuclei (CCN), have been shown to impact cloud droplet number concentration and subsequently (more)

Ward, Daniel Stewart

2010-01-01T23:59:59.000Z

66

Cloud system resolving model simulations of tropical cloud systems observed during the Tropical  

E-Print Network [OSTI]

the Weather Research and Forecasting (WRF) model. The WRF model is configured with a highest-resolving domain convection. The second regime is a monsoon break, which contains intense localized systems that are rep-based observational systems including a polarimetric weather radar, cloud radar, wind profilers, radi- ation

Jakob, Christian

67

Electron cloud observations at the ISIS Proton Synchrotron  

E-Print Network [OSTI]

The build up of electron clouds inside a particle accelerator vacuum chamber can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the behaviour of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which allows energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. This paper presents the first electron cloud observations at the ISIS Proton Synchrotron. These results are compared against signals from a beam position monitor and a fast beam loss monitor installed at the same location.

Pertica, A

2013-01-01T23:59:59.000Z

68

Physical Properties of High-Level Cloud over Land and Ocean from CloudSatCALIPSO Data  

Science Journals Connector (OSTI)

Unlike other cloud types, high-level clouds play an important role, often imposing a warming effect, in the earthatmosphere radiative energy budget. In this paper, macro- and microphysical characteristics of cirrus clouds, such as their ...

Juan Huo; Daren Lu

2014-12-01T23:59:59.000Z

69

Electron Cloud Observations and Predictions at KEKB, PEP-II and SuperB Factories  

E-Print Network [OSTI]

Electron cloud observations at B factories, i.e. KEKB and PEP-II, are reviewed. Predictions of electron cloud effects at Super B factories, i.e. SuperB and Super KEKB, are also reviewed.

Fukuma, H

2013-01-01T23:59:59.000Z

70

ARM - Publications: Science Team Meeting Documents: Nighttime cirrus  

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

Nighttime cirrus detection using AIRS radiances and total column Nighttime cirrus detection using AIRS radiances and total column precipitable water Kahn, Brian Jet Propulsion Laboratory Liou, Kuo-Nan UCLA A method of cirrus detection at nighttime is presented that utilizes 3.8 and 10.4 m infrared (IR) window brightness temperature differences (dBT) and total column precipitable water (PW) measurements. This technique is applied to the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit A (AMSU-A) instrument suite onboard EOS-Aqua, where dBT is determined from sets of carefully selected AIRS window channels, while PW is derived from the synergistic AIRS and AMSU-A water vapor retrievals. Simulated and observed dBT for a particular value of PW is not constant; several physical factors impact dBT, including the variability in

71

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

SciTech Connect (OSTI)

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

72

A new model of cloud drop distribution that simulates the observed drop  

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

A new model of cloud drop distribution that simulates the observed drop A new model of cloud drop distribution that simulates the observed drop clustering: effect of clustering on extinction coefficient estimates Knyazikhin, Yuri Boston University Marshak, Alexander NASA Goddard Space Flight Center Larsen, Michael Michigan Technological University Wiscombe, Warren BNL/NASA Goddard Space Flight Center Category: Modeling Cloud droplet size distribution is one of the most fundamental subjects in cloud physics. Understanding of spatial distribution and small-scale fluctuations of cloud droplets is essential for both cloud physics and atmospheric radiation. For cloud physics, it relates to the coalescence growth of raindrops while for radiation, it has a strong impact on a cloud's radiative properties. We have developed new size dependent models

73

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

E-Print Network [OSTI]

Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations October 2011; accepted 26 October 2011; published 24 December 2011. [1] Arctic clouds simulated-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its

74

ARM - Small Particles In Cirrus (SPARTICUS)  

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

(the albedo effect) and reducing radiative heat loss through the atmosphere (the greenhouse effect). Quantifying cirrus albedo and greenhouse effects is an important factor in...

75

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

SciTech Connect (OSTI)

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

76

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

SciTech Connect (OSTI)

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

77

An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a  

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

An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a Decade of Observations at a Mid-Continental Site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Category: Aerosols Continuing observations of aerosol and cloud optical property have been made using MFRSR and MWR at the ARM SGP site since 1993. Diurnal, monthly, seasonal and interannual variability of aerosol (optical depth and Angstrom coefficient) and cloud (optical depth and effective radius) have been analyzed. We have correlated an "aerosol index" computed from clear-sky observations of MFRSR with cloud droplet mean effective radius to study the

78

Influence of Microscale Turbulent Droplet Clustering on Radar Cloud Observations  

Science Journals Connector (OSTI)

This study investigates the influence of microscale turbulent clustering of cloud droplets on the radar reflectivity factor and proposes a new parameterization to account for it. A three-dimensional direct numerical simulation of particle-laden ...

Keigo Matsuda; Ryo Onishi; Masaaki Hirahara; Ryoichi Kurose; Keiko Takahashi; Satoru Komori

2014-10-01T23:59:59.000Z

79

Cloud Effects on Radiative Heating Rate Profiles over Darwin using ARM and A-train Radar/Lidar Observations  

SciTech Connect (OSTI)

Observations of clouds from the ground-based U.S. Department of Energy Atmospheric Radiation Measurement program (ARM) and satellite-based A-train are used to compute cloud radiative forcing profiles over the ARM Darwin, Australia site. Cloud properties are obtained from both radar (the ARM Millimeter Cloud Radar (MMCR) and the CloudSat satellite in the A-train) and lidar (the ARM Micropulse lidar (MPL) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite in the A-train) observations. Cloud microphysical properties are taken from combined radar and lidar retrievals for ice clouds and radar only or lidar only retrievals for liquid clouds. Large, statistically significant differences of up to 1.43 K/day exist between the mean ARM and A-train net cloud radiative forcing profiles. The majority of the difference in cloud radiative forcing profiles is shown to be due to a large difference in the cloud fraction above 12 km. Above this altitude the A-train cloud fraction is significantly larger because more clouds are detected by CALIPSO than by the ground-based MPL. It is shown that the MPL is unable to observe as many high clouds as CALIPSO due to being more frequently attenuated and a poorer sensitivity even in otherwise clear-sky conditions. After accounting for cloud fraction differences and instrument sampling differences due to viewing platform we determined that differences in cloud radiative forcing due to the retrieved ice cloud properties is relatively small. This study demonstrates that A-train observations are better suited for the calculation cloud radiative forcing profiles. In addition, we find that it is necessary to supplement CloudSat with CALIPSO observations to obtain accurate cloud radiative forcing profiles since a large portion of clouds at Darwin are detected by CALIPSO only.

Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.

2013-06-11T23:59:59.000Z

80

Observed Southern Ocean Cloud Properties and Shortwave Reflection. Part II: Phase Changes and Low Cloud Feedback  

Science Journals Connector (OSTI)

Climate models produce an increase in cloud optical depth in midlatitudes associated with climate warming, but the magnitude of this increase and its impact on reflected solar radiation vary from model to model. Transition from ice to liquid in ...

Daniel T. McCoy; Dennis L. Hartmann; Daniel P. Grosvenor

2014-12-01T23:59:59.000Z

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


81

Understanding and Improving CRM and GCM Simulations of Cloud Systems with ARM Observations  

SciTech Connect (OSTI)

The works supported by this ASR project lay the solid foundation for improving the parameterization of convection and clouds in the NCAR CCSM and the climate simulations. We have made a significant use of CRM simulations and ARM observations to produce thermodynamically and dynamically consistent multi-year cloud and radiative properties; improve the GCM simulations of convection, clouds and radiative heating rate and fluxes using the ARM observations and CRM simulations; and understand the seasonal and annual variation of cloud systems and their impacts on climate mean state and variability. We conducted multi-year simulations over the ARM SGP site using the CRM with multi-year ARM forcing data. The statistics of cloud and radiative properties from the long-term CRM simulations were compared and validated with the ARM measurements and value added products (VAP). We evaluated the multi-year climate simulations produced by the GCM with the modified convection scheme. We used multi-year ARM observations and CRM simulations to validate and further improve the trigger condition and revised closure assumption in NCAR GCM simulations that demonstrate the improvement of climate mean state and variability. We combined the improved convection scheme with the mosaic treatment of subgrid cloud distributions in the radiation scheme of the GCM. The mosaic treatment of cloud distributions has been implemented in the GCM with the original convection scheme and enables the use of more realistic cloud amounts as well as cloud water contents in producing net radiative fluxes closer to observations. A physics-based latent heat (LH) retrieval algorithm was developed by parameterizing the physical linkages of observed hydrometeor profiles of cloud and precipitation to the major processes related to the phase change of atmospheric water.

Wu, Xiaoqing

2014-02-25T23:59:59.000Z

82

A Comparison of Simulated Cloud Radar Output from the Multiscale Modeling Framework Global Climate Model with CloudSat Cloud Radar Observations  

SciTech Connect (OSTI)

Over the last few years a new type of global climate model (GCM) has emerged in which a cloud-resolving model is embedded into each grid cell of a GCM. This new approach is frequently called a multiscale modeling framework (MMF) or superparameterization. In this article we present a comparison of MMF output with radar observations from the NASA CloudSat mission, which uses a near-nadir-pointing millimeter-wavelength radar to probe the vertical structure of clouds and precipitation. We account for radar detection limits by simulating the 94 GHz radar reflectivity that CloudSat would observe from the high-resolution cloud-resolving model output produced by the MMF. Overall, the MMF does a good job of reproducing the broad pattern of tropical convergence zones, subtropical belts, and midlatitude storm tracks, as well as their changes in position with the annual solar cycle. Nonetheless, the comparison also reveals a number of model shortfalls including (1) excessive hydrometeor coverage at all altitudes over many convectively active regions, (2) a lack of low-level hydrometeors over all subtropical oceanic basins, (3) excessive low-level hydrometeor coverage (principally precipitating hydrometeors) in the midlatitude storm tracks of both hemispheres during the summer season (in each hemisphere), and (4) a thin band of low-level hydrometeors in the Southern Hemisphere of the central (and at times eastern and western) Pacific in the MMF, which is not observed by CloudSat. This band resembles a second much weaker ITCZ but is restricted to low levels.

Marchand, Roger T.; Haynes, J. M.; Mace, Gerald G.; Ackerman, Thomas P.; Stephens, Graeme L.

2009-01-13T23:59:59.000Z

83

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

SciTech Connect (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

84

A cloud detection algorithm for AATSR data, optimized for daytime observations in Canada  

Science Journals Connector (OSTI)

To extract information about the Earth's surface from Earth Observation data, a key processing step is the separation of pixels representing clear-sky observations of land or water surfaces from observations substantially influenced by clouds. This paper presents an algorithm used for this purpose specifically for data from the AATSR sensor on ENVISAT. The algorithm is based on the structure of the SPARC cloud detection scheme developed at CCRS for AVHRR data, then modified, calibrated and validated for AATSR data. It uses a series of weighted tests to calculate per-pixel cloud presence probability, and also produces an estimate of cloud top height and a cloud shadow flag. Algorithm parameters have been optimized for daytime use in Canada, and evaluation shows good performance with a mean daytime kappa coefficient of 0.76 for the cloud/clear classification when compared to independent validation data. Performance is independent of season, and is a dramatic improvement over the existing AATSR L1B cloud flag for Canada. The algorithm will be used at CCRS for processing AATSR data, and will form the basis of similar processing for data from the SLSTR sensors on Sentinel-3.

Anders Knudby; Rasim Latifovic; Darren Pouliot

2011-01-01T23:59:59.000Z

85

Evaluating Clouds, Aerosols, and their Interactions in Three Global Climate Models using COSP and Satellite Observations  

SciTech Connect (OSTI)

Accurately representing aerosol-cloud interactions in global climate models is challenging. As parameterizations evolve, it is important to evaluate their performance with appropriate use of observations. In this work we compare aerosols, clouds, and their interactions in three climate models (AM3, CAM5, ModelE) to MODIS satellite observations. Modeled cloud properties were diagnosed using the CFMIP Observations Simulator Package (COSP). Cloud droplet number concentrations (N) were derived using the same algorithm for both satellite-simulated model values and observations. We find that aerosol optical depth tau simulated by models is similar to observations. For N, AM3 and CAM5 capture the observed spatial pattern of higher values in near-coast versus remote ocean regions, though modeled values in general are higher than observed. In contrast, ModelE simulates lower N in most near-coast versus remote regions. Aerosol- cloud interactions were computed as the sensitivity of N to tau for marine liquid clouds off the coasts of South Africa and Eastern Asia where aerosol pollution varies in time. AM3 and CAM5 are in most cases more sensitive than observations, while the sensitivity for ModelE is statistically insignificant. This widely used sensitivity could be subject to misinterpretation due to the confounding influence of meteorology on both aerosols and clouds. A simple framework for assessing the N tau sensitivity at constant meteorology illustrates that observed sensitivity can change from positive to statistically insignificant when including the confounding influence of relative humidity. Satellite simulated values of N were compared to standard model output and found to be higher with a bias of 83 cm-3.

Ban-Weiss, George; Jin, Ling; Bauer, S.; Bennartz, Ralph; Liu, Xiaohong; Zhang, Kai; Ming, Yi; Guo, Huan; Jiang, Jonathan

2014-09-23T23:59:59.000Z

86

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Climate Impacts of Cirrus Ice Nucleation1  

E-Print Network [OSTI]

in the climate system. Ice clouds reflect solar radiation23 back to space, cooling the planet. However, cold ice finely balanced between warming and cooling, with warming thought to be slightly larger.27 Changes to iceJOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Climate Impacts of Cirrus Ice

Gettelman, Andrew

87

Shortwave Spectral Radiative Forcing of Cumulus Clouds from Surface Observations  

SciTech Connect (OSTI)

The spectral changes of the total cloud radiative forcing (CRF) and its diffuse and direct components are examined by using spectrally resolved (visible spectral range) all-sky surface irradiances measured by Multi-Filter Rotating Shadowband Radiometer. We demonstrate: (i) the substantial contribution of the diffuse component to the total CRF, (ii) the well-defined spectral variations of total CRF in the visible spectral region, and (iii) the strong statistical relationship between spectral (500 nm) and shortwave broadband values of total CRF. Our results suggest that the framework based on the visible narrowband fluxes can provide important radiative quantities for rigorous evaluation of radiative transfer parameterizations and can be applied for estimation of the shortwave total CRF.

Kassianov, Evgueni I.; Barnard, James C.; Berg, Larry K.; Long, Charles N.; Flynn, Connor J.

2011-04-02T23:59:59.000Z

88

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

SciTech Connect (OSTI)

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

89

Coordinated observations of sprites and in-cloud lightning flash structure  

E-Print Network [OSTI]

Coordinated observations of sprites and in-cloud lightning flash structure Gaopeng Lu,1,2 Steven A June 2013. [1] The temporal and spatial development of sprite-producing lightning flashes is examined the Oklahoma Lightning Mapping Array (LMA). Sprites produced by a total of 26 lightning flashes were observed

Cummer, Steven A.

90

Radiative Heating of the ISCCP Upper Level Cloud Regimes and its Impact on the Large-scale Tropical Circulation  

SciTech Connect (OSTI)

Radiative heating profiles of the International Satellite Cloud Climatology Project (ISCCP) cloud regimes (or weather states) were estimated by matching ISCCP observations with radiative properties derived from cloud radar and lidar measurements from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) sites at Manus, Papua New Guinea, and Darwin, Australia. Focus was placed on the ISCCP cloud regimes containing the majority of upper level clouds in the tropics, i.e., mesoscale convective systems (MCSs), deep cumulonimbus with cirrus, mixed shallow and deep convection, and thin cirrus. At upper levels, these regimes have average maximum cloud occurrences ranging from 30% to 55% near 12 km with variations depending on the location and cloud regime. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating contributions from the longwave and shortwave components. Upper level minima occur near 15 km, with the MCS regime showing the strongest cooling of 0.2 K/day and the thin cirrus showing no cooling. The gradient of upper level heating ranges from 0.2 to 0.4 K/(day?km), with the most convectively active regimes (i.e., MCSs and deep cumulonimbus with cirrus) having the largest gradient. When the above heating profiles were applied to the 25-year ISCCP data set, the tropics-wide average profile has a radiative heating maximum of 0.45Kday-1 near 250 hPa. Column-integrated radiative heating of upper level cloud accounts for about 20% of the latent heating estimated by the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The ISCCP radiative heating of tropical upper level cloud only slightly modifies the response of an idealized primitive equation model forced with the tropics-wide TRMM PR latent heating, which suggests that the impact of upper level cloud is more important to large-scale tropical circulation variations because of convective feedbacks rather than direct forcing by the cloud radiative heating profiles. However, the height of the radiative heating maxima and gradient of the heating profiles are important to determine the sign and patterns of the horizontal circulation anomaly driven by radiative heating at upper levels.

Li, Wei; Schumacher, Courtney; McFarlane, Sally A.

2013-01-31T23:59:59.000Z

91

Use of In Situ Observations to Characterize Cloud Microphysical and Radiative Properties: Application to Climate Studies  

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

Use of In Situ Observations to Characterize Use of In Situ Observations to Characterize Cloud Microphysical and Radiative Properties: Application to Climate Studies G. M. McFarquhar and T. Nousiainen Department of Atmospheric Sciences University of Illinois Urbana, Illinois M. S. Timlin, S. F. Iacobellis, and R. C. J. Somerville Scripps Institution of Oceanography La Jolla, California Introduction Cloud radiative feedback is the most important effect determining climate response to human activity. Ice clouds reflect solar radiation and absorb thermal emission from the ground and the lower atmosphere and emit infrared radiation to space. The representation of these processes in models affects future climate predictions and there is much uncertainty in the representation of these processes. The size and

92

The gravitational redshift of photons traversing a collapsing dust cloud and observable consequences  

E-Print Network [OSTI]

We analyze the frequency shift of photons propagating on an asymptotically flat spacetime describing a collapsing, spherical dust cloud. We focus on the case where the interaction of the photons with the matter can be neglected. Under fairly general assumptions on the initial data characterizing the collapse, we show that photons with zero angular momentum which travel from past to future null infinity, crossing the collapsing cloud through its center, are always redshifted with respect to stationary observers. We compute this redshift as a function of proper time of a distant stationary observer and discuss its dependency on the mass distribution of the cloud. Possible implications of this redshift effect for weak cosmic censorship and light propagation in cosmological spacetimes are also briefly discussed.

Nstor Ortiz; Olivier Sarbach

2014-11-24T23:59:59.000Z

93

Observed Scaling in Clouds and Precipitation and Scale Incognizance in Regional to Global Atmospheric Models  

SciTech Connect (OSTI)

We use observations of robust scaling behavior in clouds and precipitation to derive constraints on how partitioning of precipitation should change with model resolution. Our analysis indicates that 90-99% of stratiform precipitation should occur in clouds that are resolvable by contemporary climate models (e.g., with 200 km or finer grid spacing). Furthermore, this resolved fraction of stratiform precipitation should increase sharply with resolution, such that effectively all stratiform precipitation should be resolvable above scales of ~50 km. We show that the Community Atmosphere Model (CAM) and the Weather Research and Forecasting (WRF) model also exhibit the robust cloud and precipitation scaling behavior that is present in observations, yet the resolved fraction of stratiform precipitation actually decreases with increasing model resolution. A suite of experiments with multiple dynamical cores provides strong evidence that this `scale-incognizant' behavior originates in one of the CAM4 parameterizations. An additional set of sensitivity experiments rules out both convection parameterizations, and by a process of elimination these results implicate the stratiform cloud and precipitation parameterization. Tests with the CAM5 physics package show improvements in the resolution-dependence of resolved cloud fraction and resolved stratiform precipitation fraction.

O'Brien, Travis A.; Li, Fuyu; Collins, William D.; Rauscher, Sara; Ringler, Todd; Taylor, Mark; Hagos, Samson M.; Leung, Lai-Yung R.

2013-12-01T23:59:59.000Z

94

Cloud features and zonal wind measurements of Saturn's atmosphere as observed by Cassini/VIMS  

E-Print Network [OSTI]

Cloud features and zonal wind measurements of Saturn's atmosphere as observed by Cassini/VIMS D. S Cassini's Visual and Infrared Mapping Spectrometer (VIMS), focusing on the meteorology of the features seen in the 5 mm spectral window. We present VIMS mosaics and discuss the morphology and general

Choi, David S.

95

STATUS, EVALUATION AND NEW DEVELOPMENTS IN THE AUTOMATED CLOUD OBSERVATIONS IN THE NETHERLANDS  

E-Print Network [OSTI]

STATUS, EVALUATION AND NEW DEVELOPMENTS IN THE AUTOMATED CLOUD OBSERVATIONS IN THE NETHERLANDS Wiel Netherlands Meteorological Institute (KNMI), Instrumental Department, (1) wauben@knmi.nl, P.O. Box 201, 3730 AE De Bilt, The Netherlands (2) KNMI, Climate Research Department, baltink@knmi.nl (3) KNMI

Wauben, Wiel

96

Observation of cloud-to-ground lightning channels with high-speed video camera  

E-Print Network [OSTI]

Between May and October 2013 (period of sustained thunderstorm activity in France), several cloud-to-ground lightning flashes have been observed in Paris area with a high-speed video camera (14000 frames per second). The localization and the polarity of the recorded cloud-to-ground flashes have been obtained from the French lightning detection network M{\\'e}t{\\'e}orage which is equipped with the same low frequency sensors used by the US NLDN. In this paper we focused on 7 events (3 positive cloud-to-ground lightning flashes and 4 negative cloud-to-ground lightning flashes). The propagation velocity of the leaders and its temporal evolution have been estimated; the evolution of branching of the negative leaders have been observed during the propagation of the channel which get connected to ground and initiate the first return stroke. One aim of this preliminary study is to emphasize the differences between the characteristics of the positive and of the negative leaders.

Buguet, M; Blanchet, P; Pdeboy, S; Barnoud, P; Laroche, P

2014-01-01T23:59:59.000Z

97

MAGNETIZATION OF CLOUD CORES AND ENVELOPES AND OTHER OBSERVATIONAL CONSEQUENCES OF RECONNECTION DIFFUSION  

SciTech Connect (OSTI)

Recent observational results for magnetic fields in molecular clouds reviewed by Crutcher seem to be inconsistent with the predictions of the ambipolar diffusion theory of star formation. These include the measured decrease in mass to flux ratio between envelopes and cores, the failure to detect any self-gravitating magnetically subcritical clouds, the determination of the flat probability distribution function (PDF) of the total magnetic field strengths implying that there are many clouds with very weak magnetic fields, and the observed scaling B{proportional_to}{rho}{sup 2/3} that implies gravitational contraction with weak magnetic fields. We consider the problem of magnetic field evolution in turbulent molecular clouds and discuss the process of magnetic field diffusion mediated by magnetic reconnection. For this process that we termed 'reconnection diffusion', we provide a simple physical model and explain that this process is inevitable in view of the present-day understanding of MHD turbulence. We address the issue of the expected magnetization of cores and envelopes in the process of star formation and show that reconnection diffusion provides an efficient removal of magnetic flux that depends only on the properties of MHD turbulence in the core and the envelope. We show that as the amplitude of turbulence as well as the scale of turbulent motions decrease from the envelope to the core of the cloud, the diffusion of the magnetic field is faster in the envelope. As a result, the magnetic flux trapped during the collapse in the envelope is being released faster than the flux trapped in the core, resulting in much weaker fields in envelopes than in cores, as observed. We provide simple semi-analytical model calculations which support this conclusion and qualitatively agree with the observational results. Magnetic reconnection is also consistent with the lack of subcritical self-gravitating clouds, with the observed flat PDF of field strengths, and with the scaling of field strength with density. In addition, we demonstrate that the reconnection diffusion process can account for the empirical Larson relations and list a few other implications of the reconnection diffusion concept. We argue that magnetic reconnection provides a solution to the magnetic flux problem of star formation that agrees better with observations than the long-standing ambipolar diffusion paradigm. Due to the illustrative nature of our simplified model we do not seek quantitative agreement, but discuss the complementary nature of our approach to the three-dimensional MHD numerical simulations.

Lazarian, A. [Astronomy Department, University of Wisconsin, Madison, WI 53706 (United States); Esquivel, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Crutcher, R. [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States)

2012-10-01T23:59:59.000Z

98

Irregular Magnetic Fields in Interstellar Clouds and Variations in the Observed Circular Polarization of Spectral Lines  

E-Print Network [OSTI]

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps other causes, and may play an essential role in the structure and evolution of the gas clouds. To infer information about these irregularities from the observational data, we develop statistical relationships between the rms values of the irregular component of the magnetic field and spatial variations in the circular polarization of the spectral line radiation. The irregularities are characterized in analogy with descriptions of turbulence---by a sum of Fourier waves having a power spectrum with a slope similar to that of Kolmogorov turbulence. For comparison, we also perform computations in which turbulent magnetic and velocity fields from representative MHD simulations by others are utilized. Although the effects of the variations about the mean value of the magnetic field along the path of a ray tend to cancel, a significant residual effect in the polarization of the emergent radiation remains for typical values of the relevant parameters. A map of observed spectra of the 21 cm line toward Orion A is analyzed and the results are compared with our calculations in order to infer the strength of the irregular component of the magnetic field. The rms of the irregular component is found to be comparable in magnitude to the mean magnetic field within the cloud. Hence, the turbulent and Alfven velocities should also be comparable.

W. D. Watson; D. S. Wiebe; R. M. Crutcher

2000-10-13T23:59:59.000Z

99

Remote Sensing of Cirrus Particle Size Vertical Profile Using...  

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

inhomogeneity in terms of ice crystal sizes and shapes. The vertical variation of ice crystal size can alter the radiative heatingcooling profiles in cirrus cloudy...

100

Global ice cloud observations: radiative properties and statistics from moderate-resolution imaging spectroradiometer measurements  

E-Print Network [OSTI]

Ice clouds occur quite frequently, yet so much about these clouds is unknown. In recent years, numerous investigations and field campaigns have been focused on the study of ice clouds, all with the ultimate goal of gaining a better understanding...

Meyer, Kerry Glynne

2009-05-15T23:59:59.000Z

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


101

An Artificial Neural Network Model to Reduce False Alarms in Satellite Precipitation Products Using MODIS and CloudSat Observations  

Science Journals Connector (OSTI)

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the NASA Earth Observing System (EOS) Aqua and Terra platform with 36 spectral bands provides valuable information about cloud microphysical characteristics and therefore ...

Nasrin Nasrollahi; Kuolin Hsu; Soroosh Sorooshian

2013-12-01T23:59:59.000Z

102

Observations of Stratocumulus Clouds and Their Effect on the Eastern Pacific Surface Heat Budget along 20S  

E-Print Network [OSTI]

Widespread stratocumulus clouds were observed on nine transects from seven research cruises to the southeastern tropical Pacific Ocean along 20S, 7585W in OctoberNovember of 200108. The nine transects sample a unique ...

de Szoeke, Simon P.; Yuter, Sandra; Mechem, David B.; Fairall, Chris W.; Burleyson, Casey D.; Zuidema, Paquita

2012-12-01T23:59:59.000Z

103

Investigation of the Dynamical, Macrophysical and Radiative Properties of High Clouds Combining Satellite Observations and Climate Model Simulations  

E-Print Network [OSTI]

of the physical mechanism governing the fixed anvil temperature (FAT) hypothesis and test of FAT hypothesis with CTT measurements; and 3) the intercomparison of cloud fraction and radiative effects between satellite-based observations and reanalysis product...

Li, Yue

2012-02-14T23:59:59.000Z

104

Ocean Frontal Effects on the Vertical Development of Clouds over the Western North Pacific: In Situ and Satellite Observations  

Science Journals Connector (OSTI)

A suite of shipboard and satellite observations are analyzed and synthesized to investigate the three-dimensional structure of clouds and influences from sea surface temperature fronts over the western North Pacific. Sharp transitions are ...

Hiroki Tokinaga; Youichi Tanimoto; Shang-Ping Xie; Takeaki Sampe; Hiroyuki Tomita; Hiroshi Ichikawa

2009-08-01T23:59:59.000Z

105

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

Science Journals Connector (OSTI)

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

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

106

Assimilation of Satellite Cloud and Precipitation Observations in Numerical Weather Prediction Models: Introduction to the JAS Special Collection  

Science Journals Connector (OSTI)

To date, the assimilation of satellite measurements in numerical weather prediction (NWP) models has focused on the clear atmosphere. But satellite observations in the visible, infrared, and microwave provide a great deal of information on clouds ...

Ronald M. Errico; George Ohring; Fuzhong Weng; Peter Bauer; Brad Ferrier; Jean-Franois Mahfouf; Joe Turk

2007-11-01T23:59:59.000Z

107

CLOUD AND HAZE IN THE WINTER POLAR REGION OF TITAN OBSERVED WITH VISUAL AND INFRARED MAPPING SPECTROMETER ON BOARD CASSINI  

SciTech Connect (OSTI)

A large cloud in the north polar region of Titan was first observed by the Visual and Infrared Mapping Spectrometer (VIMS) in 2005 and then in 2006. This cloud, confined beyond the latitude 62 Degree-Sign N, is surrounded by a mixture of aerosol and mist probably lying in the low stratosphere and troposphere. Subsequent images of this region of Titan show a gradual vanishing of this cloud which was reported previously. In this paper, we characterize the physical properties of this cloud, haze, and mist as well as their time evolutions. We note several details on the images such as a secondary cloud above the main cloud and latitudes beyond 70 Degree-Sign N. We also show that the cloud disappearance leaves the polar region poorly loaded in aerosols, yielding an annular zone of aerosols between 50 Degree-Sign N and 65 Degree-Sign N. Our analysis suggests that this structure observed by VIMS in the near-IR is an annular structure observed by ISS on board Voyager one Titan year ago in 1980.

Rannou, P. [GSMA, UMR CNRS 7331, Universite de Reims Champagne-Ardenne (France); Le Mouelic, S. [LPGN, UMR CNRS 6112, Universite de Nantes (France); Sotin, C. [JPL, California Institute of Technology, PA (United States); Brown, R. H., E-mail: pascal.rannou@univ-reims.fr [LPL, University of Arizona, Tucson, AZ (United States)

2012-03-20T23:59:59.000Z

108

Electron cloud observations and cures in the Relativistic Heavy Ion Collider  

Science Journals Connector (OSTI)

Since 2001, the Relativistic Heavy Ion Collider has experienced electron cloud effects, some of which have limited the beam intensity. These include dynamic pressure rises (including pressure instabilities), tune shifts, a reduction of the instability threshold for bunches crossing the transition energy, and possibly incoherent emittance growth. We summarize the main observations in operation and dedicated experiments as well as countermeasures including baking, nonevaporable getter coated warm beam pipes, solenoids, bunch patterns, antigrazing rings, prepumped cold beam pipes, scrubbing, and operation with long bunches.

W. Fischer, M. Blaskiewicz, J. M. Brennan, H. Huang, H.-C. Hseuh, V. Ptitsyn, T. Roser, P. Thieberger, D. Trbojevic, J. Wei, S. Y. Zhang, and U. Iriso

2008-04-18T23:59:59.000Z

109

Constructing a Merged Cloud-Precipitation Radar Dataset for Tropical Convective Clouds during the DYNAMO/AMIE Experiment at Addu Atoll  

SciTech Connect (OSTI)

To improve understanding of the convective processes key to the Madden-Julian-Oscillation (MJO) initiation, the Dynamics of the MJO (DYNAMO) and Atmospheric Radiation Measurement MJO Investigation Experiment (AMIE) collected four months of observations from three radars, the S-band Polarization Radar (S-Pol), the C-band Shared Mobile Atmospheric Research & Teaching Radar (SMART-R), and Ka-band Zenith Radar (KAZR) on Addu Atoll in the tropical Indian Ocean. This study compares the measurements from the S-Pol and SMART-R to those from the more sensitive KAZR in order to characterize the hydrometeor detection capabilities of the two scanning precipitation radars. Frequency comparisons for precipitating convective clouds and non-precipitating high clouds agree much better than non-precipitating low clouds for both scanning radars due to issues in ground clutter. On average, SMART-R underestimates convective and high cloud tops by 0.3 to 1.1 km, while S-Pol underestimates cloud tops by less than 0.4 km for these cloud types. S-Pol shows excellent dynamic range in detecting various types of clouds and therefore its data are well suited for characterizing the evolution of the 3D cloud structures, complementing the profiling KAZR measurements. For detecting non-precipitating low clouds and thin cirrus clouds, KAZR remains the most reliable instrument. However, KAZR is attenuated in heavy precipitation and underestimates cloud top height due to rainfall attenuation 4.3% of the time during DYNAMO/AMIE. An empirical method to correct the KAZR cloud top heights is described, and a merged radar dataset is produced to provide improved cloud boundary estimates, microphysics and radiative heating retrievals.

Feng, Zhe; McFarlane, Sally A.; Schumacher, Courtney; Ellis, Scott; Comstock, Jennifer M.; Bharadwaj, Nitin

2014-05-16T23:59:59.000Z

110

Tracking tropical cloud systems - Observations for the diagnosis of simulations by the Weather Research and Forecasting (WRF) Model  

SciTech Connect (OSTI)

To aid in improving model parameterizations of clouds and convection, we examine the capability of models, using explicit convection, to simulate the life cycle of tropical cloud systems in the vicinity of the ARM Tropical Western Pacific sites. The cloud life cycle is determined using a satellite cloud tracking algorithm (Boer and Ramanathan, 1997), and the statistics are compared to those of simulations using the Weather Research and Forecasting (WRF) Model. Using New York Blue, a Blue Gene/L supercomputer that is co-operated by Brookhaven and Stony Brook, simulations are run at a resolution comparable to the observations. Initial results suggest a computational paradox where, even though the size of the simulated systems are about half of that observed, their longevities are still similar. The explanation for this seeming incongruity will be explored.

Vogelmann, A.M.; Lin, W.; Cialella, A.; Luke, E.; Jensen, M.; Zhang, M.

2010-03-15T23:59:59.000Z

111

Clarifying the Dominant Sources and Mechanisms of Cirrus Cloud Formation  

Science Journals Connector (OSTI)

...Institute for Research in Environmental Science, University of Colorado, Boulder, CO 80309, USA.4Institute for Meteorology and...studied. Our 2002 and 2011 measurements are noteworthy: wildfires injected EC- and biomass-burning particles into the upper...

Daniel J. Cziczo; Karl D. Froyd; Corinna Hoose; Eric J. Jensen; Minghui Diao; Mark A. Zondlo; Jessica B. Smith; Cynthia H. Twohy; Daniel M. Murphy

2013-06-14T23:59:59.000Z

112

Observations and Modeling of Shallow Convective Clouds: Implications for the Indirect Aerosol Effects  

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

Observations Observations and Modeling of Shallow Convective Clouds: Implications for the Indirect Aerosol Effects Sylwester Arabas 1 , Joanna Slawinska 1 , Wojciech Grabowski 2 , Hugh Morrison 2 , Hanna Pawlowska 1 1 : Institute of Geophysics, University of Warsaw, Poland 2 : National Center for Atmospheric Research, Boulder, Colorado, USA 348 constants for reference state and lateral boundary conditions 349 ibcx=icyx 350 ibcy=icyy*j3 351 ibcz=icyz 352 irlx=irelx 353 irly=irely*j3 354 irdbc=0 355 fcr0=fcr0*icorio 356 itdl=0 357 tdt=40.*3600. 358 u0tdl=u00 359 360 361 constants for thermodynamics 362 c bv=sqrt(st*g) 363 bv=st 364 st=bv**2/g 365 cp=3.5*rg 366 cap=rg/cp 367 pr00=rg*rh00*tt00

113

3D Atmospheric Radiative Transfer for Cloud System-Resolving Models: Forward Modelling and Observations  

SciTech Connect (OSTI)

Utilization of cloud-resolving models and multi-dimensional radiative transfer models to investigate the importance of 3D radiation effects on the numerical simulation of cloud fields and their properties.

Howard Barker; Jason Cole

2012-05-17T23:59:59.000Z

114

Cloud Features and Zonal Wind Measurements of Saturn's Atmosphere as Observed by Cassini/VIMS  

E-Print Network [OSTI]

We present an analysis of data about Saturn's atmosphere from Cassini's Visual and Infrared Mapping Spectrometer (VIMS), focusing on the meteorology of the features seen in the 5-micron spectral window. We present VIMS mosaics and discuss the morphology and general characteristics of the features backlit by Saturn's thermal emission. We have also constructed a zonal wind profile from VIMS feature tracking observation sequences using an automated cloud feature tracker. Comparison with previously constructed profiles from Voyager and Cassini imaging data reveals broad similarities, suggesting minimal vertical shear of the zonal wind. However, areas of apparent wind shear are present in the VIMS zonal wind profile at jet stream cores. In particular, our analysis shows that the equatorial jet reaches speeds exceeding 450 m/s, similar to speeds obtained during the Voyager era. This suggests that recent inferences of relatively slower jet speeds of ~275-375 m/s are confined to the upper troposphere and that the dee...

Choi, David S; Brown, Robert H; 10.1029/2008JE003254

2013-01-01T23:59:59.000Z

115

Final Report on the Development of an Improved Cloud Microphysical Product for Model and Remote Sensing Evaluation using RACORO Observations  

SciTech Connect (OSTI)

We proposed to analyze data collected during the Routine Aerial Facilities (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) in order to develop an integrated product of cloud microphysical properties (number concentration of drops in different size bins, total liquid drop concentration integrated over all bin sizes, liquid water content LWC, extinction of liquid clouds bw, effective radius of water drops re, and radar reflectivity factor) that could be used to evaluate large-eddy simulations (LES), general circulation models (GCMs) and ground-based remote sensing retrievals, and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. We have completed the development of this microphysical database and have submitted it to ARM for consideration of its inclusion on the ARM database as a PI product. This report describes the development of this database, and also describes research that has been conducted on cloud-aerosol interactions using the data obtained during RACORO. A list of conference proceedings and publications is also included.

McFarquhar, Greg

2012-09-19T23:59:59.000Z

116

Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations  

SciTech Connect (OSTI)

Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulations in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity, for both inter-model deviation and model-measurement discrepancy. Our intercomparisons of three CF or sky-cover related dataset reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and the inter-model deviations have a similar magnitude for the total CF (TCF) and the normalized cloud effect, and they are twice as large as the surface downward solar radiation and cloud transmissivity. This implies that the other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that a better agreement among the GCMs in solar radiative fluxes could be the result of compensating errors in either cloud vertical structure, cloud optical depth or cloud fraction. Similar deviation pattern between inter-model and model-measurement suggests that the climate models tend to generate larger bias against observations for those variables with larger inter-model deviation. The simulated TCF from IPCC AR4 GCMs are very scattered through all seasons over three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at Manus and NSA in simulating the seasonal variation and probability distribution of TCF; however, the TCF in these models is remarkably underpredicted and cloud transmissivity is less susceptible to the change of TCF than the observed at SGP. Much larger inter-model deviation and model bias are found over NSA than the other sites in estimating the TCF, cloud transmissivity and cloud-radiation interaction, suggesting that the Arctic region continues to challenge cloud simulations in climate models. Most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels in the tropics. The high altitude CF is much larger in the GCMs than the observation and the inter-model variability of CF also reaches maximum at high levels in the tropics. Most of the GCMs tend to underpredict CF by 50-150% relative to the measurement average at low and middle levels over SGP. While the GCMs generally capture the maximum CF in the boundary layer and vertical variability, the inter-model deviation is largest near surface over the Arctic. The internal variability of CF simulated in ensemble runs with the same model is very minimal.

Qian, Yun; Long, Charles N.; Wang, Hailong; Comstock, Jennifer M.; McFarlane, Sally A.; Xie, Shaocheng

2012-02-17T23:59:59.000Z

117

Recent changes in the coverage of high cloud  

E-Print Network [OSTI]

Midland 1022 1114 1087 1115 1058 1134 1170 1120 (54-61) 1074 (5I-56) 25 Corrections For Cloud Overlap Van Allen (1962a) calculated the correction factor for the overlap of different cloud layers by using data from the Baltimore, Maryland... individual probability of occurrence. Cirrus and cirrostratus each accounted for "about 6 per cent annual sky coverage" for the Baltimore sta- tion; the correction factor for "total overlap" for cirrus was 2). 2 per cent and for cirrostratus was 49. 2...

Harriman, Roy Edward

2012-06-07T23:59:59.000Z

118

ARM Cloud Aerosol Precipitation Experiment  

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

Satellite Observation CAS Cloud Aerosol Spectrometer CCN Cloud Condensation Nuclei CIP Cloud Imaging Probe CPC Condensation Particle Counter CSPHOT Cimel sunphotometer CVI...

119

Polarimetric Radar Observation Operator for a Cloud Model with Spectral Microphysics  

E-Print Network [OSTI]

-proven advantages such as hydro- meteor classification and improvement in radar data quality and rainfall modeling via improvement of micro- physical parameterization and direct assimilation of polarimetric radar the output of numerical cloud models was pioneered using the models with bulk parameterization of cloud micro

Mark, Pinsky

120

High-accuracy diagnostic tool for electron cloud observation in the LHC based on synchronous phase measurements  

E-Print Network [OSTI]

Electron cloud effects such as heat load in the cryogenic system, pressure rise and beam instabilities are among the main limitations for the LHC operation with 25 ns spaced bunches. A new observation tool was developed to monitor the e-cloud activity and has been successfully used in the LHC during Run 1 (2010-2012). The power loss of each bunch due to the e-cloud can be estimated using very precise bunch-by-bunch measurement of the synchronous phase shift. In order to achieve the required accuracy, corrections for reflection in the cables and some systematic errors need to be applied followed by a post-processing of the measurements. Results clearly show the e-cloud build-up along the bunch trains and its evolution during each LHC fill as well as from fill to fill. Measurements during the 2012 LHC scrubbing run reveal a progressive reduction in the e-cloud activity and therefore a decrease in the secondary electron yield (SEY). The total beam power loss can be computed as a sum of the contributions from all...

Esteban Mller, J F; Shaposhnikova, E; Valuch, D; Mastoridis, T

2014-01-01T23:59:59.000Z

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


121

Cloud Services Cloud Services  

E-Print Network [OSTI]

Cloud Services Cloud Services In 2012 UCD IT Services launched an exciting new set of cloud solutions called CloudEdu, which includes cloud servers, cloud storage, cloud hosting and cloud network. The CloudEdu package includes a consultancy service in design, deployment, management and utilisation

122

Analysis of the electron cloud observations with 25 ns bunch spacing at LHC  

E-Print Network [OSTI]

Electron Cloud (EC) effects have been identified as a major performance limitation for the Large Hadron Collider (LHC) when operating with the nominal bunch spacing of 25 ns. During the LHC Run 1 (2010 - 2013) the luminosity production mainly used beams with 50 ns spacing, while 25 ns beams were only employed for short periods in 2011 and 2012 for test purposes. On these occasions, observables such as pressure rise, heat load in the cold sections as well as clear signatures on bunch-by-bunch emittance blow up, particle loss and energy loss indicated the presence of an EC in a large portion of the LHC. The analysis of the recorded data, together with EC build up simulations, has led to a significant improvement of our understanding of the EC effect in the different components of the LHC. Studies were carried out both at injection energy (450 GeV) and at top energy (4 TeV) aiming at determining the energy dependence of the EC formation and its impact on the quality of the proton beam.

Iadarola, G; Rumolo, G; Arduini, G; Baglin, V; Banfi, D; Claudet, S; Dominguez, O; Esteban Mller, J; Pieloni, T; Shaposhnikova, E; Tavian, L; Zannini, C; Zimmermann, F

2014-01-01T23:59:59.000Z

123

Using A-Train Arctic cloud observations to constrain and improve...  

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

than predicted by climate models... * * 2007 Stroeve et al., 2007 OUTLINE: 1. New A-train satellite data 2. Summer 2007 anomalies 3. Beyond Summer 2007 New cloud and radiation...

124

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 (OSTI)

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

125

Multiangle Observations of Arctic Clouds from FIRE ACE: June 3, 1998 Case Study  

SciTech Connect (OSTI)

In May and June 1998 the Airborne Multiangle Imaging Spectroradiometer (AirMISR) participated in the FIRE Arctic Cloud Experiment (ACE). AirMISR is an airborne instrument for obtaining multiangle imagery similar to that of the satellite-borne MISR instrument. This paper presents a detailed analysis of the data collected on June 3, 1998. In particular, AirMISR radiance measurements are compared with measurements made by two other instruments, the Cloud Absorption Radiometer (CAR) and the MODIS airborne simulator (MAS), as well as to plane-parallel radiative transfer simulations. It is found that the AirMISR radiance measurements and albedo estimates compare favorably both with the other instruments and with the radiative transfer simulations. In addition to radiance and albedo, the multiangle AirMISR data can be used to obtain estimates of cloud top height using stereoimaging techniques. Comparison of AirMISR retrieved cloud top height (using the complete MISR-based stereoimaging approach) shows excellent agreement with the measurements from the airborne Cloud Lidar System (CLS) and ground-based millimeter-wave cloud radar.

Marchand, Roger T.; Ackerman, Thomas P.; King, M. D.; Moroney, C.; Davies, R.; Muller, J.-P. A. L.; Gerber, H.

2001-07-27T23:59:59.000Z

126

Final Technical Report for "Radiative Heating Associated with Tropical Convective Cloud Systems: Its Importance at Meso and Global Scales"  

SciTech Connect (OSTI)

Heating associated with tropical cloud systems drive the global circulation. The overall research objectives of this project were to i) further quantify and understand the importance of heating in tropical convective cloud systems with innovative observational techniques, and ii) use global models to determine the large-scale circulation response to variability in tropical heating profiles, including anvil and cirrus cloud radiative forcing. The innovative observational techniques used a diversity of radar systems to create a climatology of vertical velocities associated with the full tropical convective cloud spectrum along with a dissection of the of the total heating profile of tropical cloud systems into separate components (i.e., the latent, radiative, and eddy sensible heating). These properties were used to validate storm-scale and global climate models (GCMs) and were further used to force two different types of GCMs (one with and one without interactive physics). While radiative heating was shown to account for about 20% of the total heating and did not have a strong direct response on the global circulation, the indirect response was important via its impact on convection, esp. in how radiative heating impacts the tilt of heating associated with the Madden-Julian Oscillation (MJO), a phenomenon that accounts for most tropical intraseasonal variability. This work shows strong promise in determining the sensitivity of climate models and climate processes to heating variations associated with cloud systems.

Schumacher, Courtney

2012-12-13T23:59:59.000Z

127

Operational Forecasts of Cloud Cover and Water Vapour  

E-Print Network [OSTI]

of the forecast programme, which involved the additional use of 10.7 µm GOES-8 satellite data and surface weather cirrus cloud cover 15 5. A satellite-derived extinction parameter 17 5.1 Background 17 5.2 Previous work 20 5.3 Continued development of a satellite-derived 22 extinction parameter 6. Suggestions

128

TRACKING TROPICAL CLOUD SYSTEMS -OBSERVATIONS FOR THE DIAGNOSIS OF SIMULATIONS BY THE WEATHER RESEARCH  

E-Print Network [OSTI]

using a satellite cloud tracking algorithm (Boer and Ramanathan, 1997), and the statistics are compared with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish

129

Study of Multi-Scale Cloud Processes Over the Tropical Western Pacific Using Cloud-Resolving Models Constrained by Satellite Data  

SciTech Connect (OSTI)

Clouds in the tropical western Pacific are an integral part of the large scale environment. An improved understanding of the multi-scale structure of clouds and their interactions with the environment is critical to the ARM (Atmospheric Radiation Measurement) program for developing and evaluating cloud parameterizations, understanding the consequences of model biases, and providing a context for interpreting the observational data collected over the ARM Tropical Western Pacific (TWP) sites. Three-dimensional cloud resolving models (CRMs) are powerful tools for developing and evaluating cloud parameterizations. However, a significant challenge in using CRMs in the TWP is that the region lacks conventional data, so large uncertainty exists in defining the large-scale environment for clouds. This project links several aspects of the ARM program, from measurements to providing improved analyses, and from cloud-resolving modeling to climate-scale modeling and parameterization development, with the overall objective to improve the representations of clouds in climate models and to simulate and quantify resolved cloud effects on the large-scale environment. Our objectives will be achieved through a series of tasks focusing on the use of the Weather Research and Forecasting (WRF) model and ARM data. Our approach includes: -- Perform assimilation of COSMIC GPS radio occultation and other satellites products using the WRF Ensemble Kalman Filter assimilation system to represent the tropical large-scale environment at 36 km grid resolution. This high-resolution analysis can be used by the community to derive forcing products for single-column models or cloud-resolving models. -- Perform cloud-resolving simulations using WRF and its nesting capabilities, driven by the improved regional analysis and evaluate the simulations against ARM datasets such as from TWP-ICE to optimize the microphysics parameters for this region. A cirrus study (Mace and co-authors) already exists for TWP-ICE using satellite and ground-based observations. -- Perform numerical experiments using WRF to investigate how convection over tropical islands in the Maritime Continent interacts with large-scale circulation and affects convection in nearby regions. -- Evaluate and apply WRF as a testbed for GCM cloud parameterizations, utilizing the ability of WRF to run on multiple scales (from cloud resolving to global) to isolate resolution and physics issues from dynamical and model framework issues. Key products will be disseminated to the ARM and larger community through distribution of data archives, including model outputs from the data assimilation products and cloud resolving simulations, and publications.

Dudhia, Jimy

2013-03-12T23:59:59.000Z

130

HIGH-RESOLUTION OBSERVATIONS AND THE PHYSICS OF HIGH-VELOCITY CLOUD A0  

SciTech Connect (OSTI)

The neutral hydrogen structure of high-velocity cloud A0 (at about -180 km s{sup -1}) has been mapped with a 9.'1 resolution. Gaussian decomposition of the profiles is used to separately map families of components defined by similarities in center velocities and line widths. About 70% of the H I gas is in the form of a narrow, twisted filament whose typical line widths are of the order of 24 km s{sup -1}. Many bright features with narrow line widths of the order of 6 km s{sup -1}, clouds, are located in and near the filament. A third category with properties between those of the filament and clouds appears in the data. The clouds are not always co-located with the broader line width filament emission as seen projected on the sky. Under the assumption that magnetic fields underlie the presence of the filament, a theorem is developed for its stability in terms of a toroidal magnetic field generated by the flow of gas along field lines. It is suggested that the axial magnetic field strength may be derived from the excess line width of the H I emission over and above that due to kinetic temperature by invoking the role of Alfven waves that create what is in essence a form of magnetic turbulence. At a distance of 200 pc the axial and the derived toroidal magnetic field strengths in the filament are then about 6 {mu}G while for the clouds they are about 4 {mu}G. The dependence of the derived field strength on distance is discussed.

Verschuur, Gerrit L., E-mail: verschuur@aol.com [Physics Department, University of Memphis, Memphis, TN 38152 (United States)

2013-04-01T23:59:59.000Z

131

Probing the Climatological Impact of a Cosmic Ray-Cloud Connection through Low-Frequency Radio Observations  

E-Print Network [OSTI]

It has been proposed that cosmic ray events could have a causal relationship with cloud formation rates. Given the weak constraints on the role that cloud formation plays in climate forcing it is essential to understand the role such a relationship could have in shaping the Earth's climate. This issue has been previously investigated in the context of the long-term effect of cosmic ray events on climate. However, in order to establish whether or not such a relationship exists, measurements of short-timescale solar events, individual cosmic ray events, and spatially correlated cloud parameters could be of great significance. Here we propose such a comparison using observations from a pair of radio telescopes arrays, the Long Wavelength Array (LWA) and the Eight-meter-wavelength Transient Array (ETA). These low-frequency radio arrays have a unique ability to simultaneously conduct solar, ionospheric and cosmic rays observations and are thus ideal for such a comparison. We will outline plans for a comparison usi...

Magee, Nathan

2011-01-01T23:59:59.000Z

132

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

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

133

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

SciTech Connect (OSTI)

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

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

2005-03-18T23:59:59.000Z

134

Thin Cloud Length Scales Using CALIPSO and CloudSat Data  

E-Print Network [OSTI]

Thin clouds are the most difficult cloud type to observe. The recent availability of joint cloud products from the active remote sensing instruments aboard CloudSat and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) facilitates...

Solbrig, Jeremy E.

2010-10-12T23:59:59.000Z

135

Final Report fir DE-SC0005507 (A1618): The Development of an Improved Cloud Microphysical Product for Model and Remote Sensing Evaluation using RACORO Observations  

SciTech Connect (OSTI)

We proposed to analyze data collected during the Routine Aerial Facilities (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) in order to develop an integrated product of cloud microphysical properties (number concentration of drops in different size bins, total liquid drop concentration integrated over all bin sizes, liquid water content LWC, extinction of liquid clouds, effective radius of water drops, and radar reflectivity factor) that could be used to evaluate large-eddy simulations (LES), general circulation models (GCMs) and ground-based remote sensing retrievals, and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. We have completed the development of this microphysical database. we investigated the differences in the size distributions measured by the Cloud and Aerosol Spectrometer (CAS) and the Forward Scattering Probe (FSSP), between the one dimensional cloud imaging probe (1DC) and the two-dimensional cloud imaging probe (2DC), and between the bulk LWCs measured by the Gerber probe against those derived from the size resolved probes.

McFarquhar, Greg M.

2012-09-21T23:59:59.000Z

136

Laser-induced plasma cloud interaction and ice multiplication under cirrus cloud conditions  

Science Journals Connector (OSTI)

...electrode free by high-power ultrashort laser...AIDA). High-power lasers allow producing...above a critical power of 36 GW in air...respectively. (A) Chamber gas phase temperature...laser-induced ice generation is apparent from...s. The laser was fired at t = 400 s when the...

Thomas Leisner; Denis Duft; Ottmar Mhler; Harald Saathoff; Martin Schnaiter; Stefano Henin; Kamil Stelmaszczyk; Massimo Petrarca; Raphalle Delagrange; Zuoqiang Hao; Johannes Lder; Yannick Petit; Philipp Rohwetter; Jrme Kasparian; Jean-Pierre Wolf; Ludger Wste

2013-01-01T23:59:59.000Z

137

INVESTIGATION OF MOLECULAR CLOUD STRUCTURE AROUND INFRARED BUBBLES: CARMA OBSERVATIONS OF N14, N22, AND N74  

SciTech Connect (OSTI)

We present CARMA observations in 3.3 mm continuum and several molecular lines of the surroundings of N14, N22, and N74, three infrared bubbles from the GLIMPSE catalog. We have discovered 28 compact continuum sources and confirmed their associations with the bubbles using velocity information from HCO{sup +} and HCN. We have also mapped small-scale structures of N{sub 2}H{sup +} emission in the vicinity of the bubbles. By combining our data with survey data from GLIMPSE, MIPSGAL, BGPS, and MAGPIS, we establish about half of our continuum sources as star-forming cores. We also use survey data with the velocity information from our molecular line observations to describe the morphology of the bubbles and the nature of the fragmentation. We conclude from the properties of the continuum sources that N74 likely is at the near kinematic distance, which was previously unconfirmed. We also present tentative evidence of molecular clouds being more fragmented on bubble rims compared to dark clouds, suggesting that triggered star formation may occur, though our findings do not conform to a classic collect-and-collapse model.

Sherman, Reid A., E-mail: ras@oddjob.uchicago.edu [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)

2012-11-20T23:59:59.000Z

138

Cloud episode propagation over the Indonesian Maritime Continent from 10years of infrared brightness temperature observations  

Science Journals Connector (OSTI)

The cloud-top brightness temperature data from 2001 to 2010 are used to derive a climatology of deep convection duration, span, and propagation speed over the Indonesian Maritime Continent (10S10N, 80E160E). The full domain of study is divided into northern (010N) and southern (010S) regions to investigate the seasonal and latitudinal variabilities of cloud streaks. The ratio of westward- to eastward-propagating cloud streaks is found to be approximately 3:1. Westward-moving streaks generally have longer spans and faster speeds than eastward-moving systems. Coherent episodes of westward- (eastward-) propagating systems have 9.5 (7.5) h durations and 519 (378) km spans on average; most episodes have zonal phase speeds of 630ms?1. Median zonal phase speeds of 14.2 (westward) and 13.5ms?1 (eastward) are found for events with >1000km spans and >20h durations. The recurrence frequency, which is categorized from 1 event per day to 1 event per month, is also discussed. The latitudinal and seasonal dependences of statistical properties are strongly influenced by the Inter-Tropical Convergence Zone annual cycle. The number of westward-migrating systems is significant every month, while eastward-migrating systems strongly vary by season and latitude. Eastward migration is less frequent in the southern region during June, July and August (JJA) and in the northern region during December, January and February (DJF). In the northern region, the westward-propagating events' mean span is much longer during JJA, September, October, and November (SON) than the other periods; this effect is partially due to the favorable environmental shear conditions necessary to sustain a long-lived system. Eastward- and westward-propagating events are found during the shortwave heating and dissipation modes of diurnal cycle phase. Thus, thermal forcing, which is associated with the elevated terrain found over the islands and the landsea interface, is dominant on a daily basis. Several possible reasons behind the present results besides the environmental conditions are discussed. It is found that low-level wind may support the precipitation propagation speed, and its support may depend on the MaddenJulian Oscillation (MJO) phase. However, advection by wind alone is likely insufficient to propagate the precipitation as quickly, as our results show. The speed of precipitation migration particularly around Sumatra is similar to the values reported in the framework of propagating gravity waves and moist Kelvin waves.

Marzuki; Hiroyuki Hashiguchi; Masayuki K. Yamamoto; Mamoru Yamamoto; Shuichi Mori; Manabu D. Yamanaka; Richard E. Carbone; John D. Tuttle

2013-01-01T23:59:59.000Z

139

SUBMILLIMETER OBSERVATIONS OF DENSE CLUMPS IN THE INFRARED DARK CLOUD G049.40-00.01  

SciTech Connect (OSTI)

We obtained 350 and 850 {mu}m continuum maps of the infrared dark cloud G049.40-00.01. Twenty-one dense clumps were identified within G049.40-00.01 based on the 350 {mu}m continuum map with an angular resolution of about 9.''6. We present submillimeter continuum maps and report physical properties of the clumps. The masses of clumps range from 50 to 600 M{sub Sun }. About 70% of the clumps are associated with bright 24 {mu}m emission sources, and they may contain protostars. The two most massive clumps show extended, enhanced 4.5 {mu}m emission indicating vigorous star-forming activity. The clump-size-mass distribution suggests that many of them are forming high-mass stars. G049.40-00.01 contains numerous objects in various evolutionary stages of star formation, from pre-protostellar clumps to H II regions.

Kang, Miju; Choi, Minho [Korea Astronomy and Space Science Institute, 776 Daedeokdaero, Yuseong, Daejeon 305-348 (Korea, Republic of); Bieging, John H. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Rho, Jeonghee [SOFIA Science Center, USRA/NASA Ames Research Center, Moffet Field, CA 94035 (United States); Lee, Jeong-Eun [Department of Astronomy and Space Science, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Tsai, Chao-Wei, E-mail: mjkang@kasi.re.kr [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)

2011-12-20T23:59:59.000Z

140

Stratospheric background aerosol and polar cloud observations by laser backscattersonde within the framework  

E-Print Network [OSTI]

'Atmosfera'' launched nine laser backscattersondes (LABS) on board stratospheric balloons to make observations

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


141

E-Print Network 3.0 - area cirrus experiment Sample Search Results  

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

report Trinity 2006 Atmospheric, Oceanic & Planetary... whereby two models are used to produce global maps of aircraft induced cirrus. A contrail model... and coagulation. A...

142

Observations of the 3060 Day Oscillation in Zonal Mean Atmospheric Angular Momentum and High Cloud Cover  

Science Journals Connector (OSTI)

Data on zonally averaged atmospheric angular momentum and high cloud cover percent are analyzed for the periods AprilOctober 1979 and November 1982October 1983. The dominant periodicity in both momentum and cloud datasets was the so called 30...

James S. Risbey; Peter H. Stone

1988-07-01T23:59:59.000Z

143

A Bootstrap Technique for Testing the Relationship Between Local-Scale Radar Observations of Cloud Occurrence and Large-Scale Atmospheric Fields  

SciTech Connect (OSTI)

In this paper an atmospheric classification scheme based on fields that are resolved by global climate models (and numerical weather prediction models) is investigated as a mechanism to map the large-scale (synoptic-scale) atmospheric state to distributions of local-scale cloud properties. Using a bootstrap resampling technique, the temporal stability and distinctness of vertical profiles of cloud occurrence (obtained from a vertically pointing millimeter wavelength cloud-radar) are analyzed as a function of the atmospheric state. A stable class-based map from the large-scale to local-scale cloud properties could be of great utility in the analysis of GCM-predicted cloud properties, by providing a physical context from which to understand any differences between the model output and observations, as well as to separate differences (in total distribution) that are caused by having different weather regimes (or synoptic scale activity) rather than problems in the representation of clouds for a particular regime. Furthermore, if sufficiently robust mappings can be established, it could form the basis of a statistical GCM cloud parameterization.

Marchand, Roger T.; Beagley, Nathaniel; Thompson, Sandra E.; Ackerman, Thomas P.; Schultz, David M.

2006-11-01T23:59:59.000Z

144

A13B-0215: Case study of the 9 April 2009 `brown' cloud: Observations of unusually high cloud droplet concentrations in Saudi Arabia, David J Delene, University of North Dakota (delene@aero.und.edu; http://aerosol.atmos.und.edu)  

E-Print Network [OSTI]

' cloud: Observations of unusually high cloud droplet concentrations in Saudi Arabia, David J Delene accumulation on the unprotected leading edge of the aircraft's wing during the 9 April 2009 research in Saudi diameters compared to a normal cell. Cloud base CCN measurements in Saudi Arabia are variable with some

Delene, David J.

145

Reconciling Ground-Based and Space-Based Estimates of the Frequency of Occurrence and Radiative Effect of Clouds around Darwin, Australia  

SciTech Connect (OSTI)

The objective of this paper is to investigate whether estimates of the cloud frequency of occurrence and associated cloud radiative forcing as derived from ground-based and satellite active remote sensing and radiative transfer calculations can be reconciled over a well instrumented active remote sensing site located in Darwin, Australia, despite the very different viewing geometry and instrument characteristics. It is found that the ground-based radar-lidar combination at Darwin does not detect most of the cirrus clouds above 10 km (due to limited lidar detection capability and signal obscuration by low-level clouds) and that the CloudSat radar - Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) combination underreports the hydrometeor frequency of occurrence below 2 km height, due to instrument limitations at these heights. The radiative impact associated with these differences in cloud frequency of occurrence is large on the surface downwelling shortwave fluxes (ground and satellite) and the top-of atmosphere upwelling shortwave and longwave fluxes (ground). Good agreement is found for other radiative fluxes. Large differences in radiative heating rate as derived from ground and satellite radar-lidar instruments and RT calculations are also found above 10 km (up to 0.35 Kday-1 for the shortwave and 0.8 Kday-1 for the longwave). Given that the ground-based and satellite estimates of cloud frequency of occurrence and radiative impact cannot be fully reconciled over Darwin, caution should be exercised when evaluating the representation of clouds and cloud-radiation interactions in large-scale models and limitations of each set of instrumentation should be considered when interpreting model-observations differences.

Protat, Alain; Young, Stuart; McFarlane, Sally A.; L'Ecuyer, Tristan; Mace, Gerald G.; Comstock, Jennifer M.; Long, Charles N.; Berry, Elizabeth; Delanoe, Julien

2014-02-01T23:59:59.000Z

146

Multiple, distant (401) in situ observations of a magnetic cloud and a corotating interaction region complex  

E-Print Network [OSTI]

ejections (CMEs) were observed at the Sun; the energy densities of the solar wind, both magnetic as well Space Sciences Laboratory, University of Berkeley, Berkeley, USA a r t i c l e i n f o Article history report a comprehensive analysis of in situ observations made by Wind and the STEREO probes (STA, STB

California at Berkeley, University of

147

Observed scaling in clouds and precipitation and scale incognizance in regional to global atmospheric models  

E-Print Network [OSTI]

10.1175/2008JCLI2116.1. Hack, J. , J. Caron, G. Danabasoglu,Lin, C. S. Bretherton, J. J. Hack, and Rauscher, S. A. , T.balance) match observations (Hack et al. , 2006). It is

O'Brien, T.A.

2014-01-01T23:59:59.000Z

148

Retrieval of cloud-cleared atmospheric temperature profiles from hyperspectral infrared and microwave observations  

E-Print Network [OSTI]

This thesis addresses the problem of retrieving the temperature profile of the Earth's atmosphere from overhead infrared and microwave observations of spectral radiance in cloudy conditions. The contributions of the thesis ...

Blackwell, William Joseph, 1971-

2002-01-01T23:59:59.000Z

149

ARM - Measurement - Cloud fraction  

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

to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud fraction Fraction of sky covered by clouds, observed directly or derived from SW...

150

Patterns of satellite-viewed, subtropical, jet-stream clouds in relation to the observed wind field  

E-Print Network [OSTI]

constructed in which the mean velocity, height, temperature, and potential temperature of the jet core were determined. An excellent relationship between the cloud band orientation and velocity of propagation, and the subtropical, jet- stream, wind field... AND RESULTS Cases Selected. Cloud-Band Features 19 Cloud to Jet Velocity Ratio Maximum Wind Analyses Cross Section Analyses. Horizontal Wind Profile Vertical Wind Shear, Richardson Number and 19 23 27 Static Stability 30 IV CONCLUSIONS...

Vogt, Richard Joel

2012-06-07T23:59:59.000Z

151

KECK OBSERVATIONS OF THE GALACTIC CENTER SOURCE G2: GAS CLOUD OR STAR?  

SciTech Connect (OSTI)

We present new observations and analysis of G2-the intriguing red emission-line object which is quickly approaching the Galaxy's central black hole. The observations were obtained with the laser guide star adaptive optics systems on the W. M. Keck I and II telescopes (2006-2012) and include spectroscopy (R {approx} 3600) centered on the hydrogen Br{gamma} line as well as K' (2.1 {mu}m) and L' (3.8 {mu}m) imaging. Analysis of these observations shows the Br{gamma} line emission has a positional offset from the L' continuum. This offset is likely due to background source confusion at L'. We therefore present the first orbital solution derived from Br{gamma} line astrometry, which, when coupled with radial velocity measurements, results in a later time of closest approach (2014.21 {+-} 0.14), closer periastron (130 AU, 1600 R{sub s}), and higher eccentricity (0.9814 {+-} 0.0060) compared to a solution using L' astrometry. It is shown that G2 has no K' counterpart down to K' {approx} 20 mag. G2's L' continuum and the Br{gamma} line emission appears unresolved in almost all epochs, which implies that the bulk of the emission resides in a compact region. The observations altogether suggest that while G2 has a gaseous component that is tidally interacting with the central black hole, there is likely a central star providing the self-gravity necessary to sustain the compact nature of this object.

Phifer, K.; Meyer, L.; Ghez, A. M.; Witzel, G.; Yelda, S.; Boehle, A.; Morris, M. R.; Becklin, E. E. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Do, T. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, Ontario, M5S 3H4 (Canada); Lu, J. R. [Institute for Astronomy, University of Hawaii, Hilo, HI 96720 (United States); Matthews, K., E-mail: ghez@astro.ucla.edu [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

2013-08-10T23:59:59.000Z

152

Assessment of NASA GISS CMIP5 and Post-CMIP5 Simulated Clouds and TOA Radiation Budgets Using Satellite Observations. Part II: TOA Radiation Budget and CREs  

Science Journals Connector (OSTI)

In Part I of this study (Stanfield et al. 2014), the NASA GISS CMIP5 (C5) and Post-CMIP5 (P5) simulated cloud properties were assessed utilizing multiple satellite observations, with a particular focus on the southern mid-latitudes (SMLs). This ...

Ryan E. Stanfield; Xiquan Dong; Baike Xi; Anthony D. Del Genio; Patrick Minnis; David Doelling; Norman Loeb

153

Ship-based observation of drizzling stratocumulus clouds from EPIC to VOCALS Simon P. de Szoeke, Oregon State University, Corvallis, OR.  

E-Print Network [OSTI]

Ship-based observation of drizzling stratocumulus clouds from EPIC to VOCALS Simon P. de Szoeke, CO. W. Alan Brewer, NOAA ESRL Chemical Sciences Division, Boulder, CO. Extensive high-albedo marine influence on the top-of-atmosphere and surface radiation budgets. Feedbacks among upwelling, sea surface

Parker, Matthew D. Brown

154

Assessing the Radiative Impact of Clouds of Low Optical Depth  

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

155

Assessment of Uncertainty in Cloud Radiative Effects and Heating Rates through Retrieval Algorithm Differences: Analysis using 3-years of ARM data at Darwin, Australia  

SciTech Connect (OSTI)

Ground-based radar and lidar observations obtained at the Department of Energys Atmospheric Radiation Measurement Programs Tropical Western Pacific site located in Darwin, Australia are used to retrieve ice cloud properties in anvil and cirrus clouds. Cloud microphysical properties derived from four different retrieval algorithms (two radar-lidar and two radar only algorithms) are compared by examining mean profiles and probability density functions of effective radius (Re), ice water content (IWC), extinction, ice number concentration, ice crystal fall speed, and vertical air velocity. Retrieval algorithm uncertainty is quantified using radiative flux closure exercises. The effect of uncertainty in retrieved quantities on the cloud radiative effect and radiative heating rates are presented. Our analysis shows that IWC compares well among algorithms, but Re shows significant discrepancies, which is attributed primarily to assumptions of particle shape. Uncertainty in Re and IWC translates into sometimes-large differences in cloud radiative effect (CRE) though the majority of cases have a CRE difference of roughly 10 W m-2 on average. These differences, which we believe are primarily driven by the uncertainty in Re, can cause up to 2 K/day difference in the radiative heating rates between algorithms.

Comstock, Jennifer M.; Protat, Alain; McFarlane, Sally A.; Delanoe, Julien; Deng, Min

2013-05-22T23:59:59.000Z

156

SPITZER AND NEAR-INFRARED OBSERVATIONS OF A NEW BIPOLAR PROTOSTELLAR OUTFLOW IN THE ROSETTE MOLECULAR CLOUD  

SciTech Connect (OSTI)

We present and discuss Spitzer and near-infrared H{sub 2} observations of a new bipolar protostellar outflow in the Rosette Molecular Cloud. The outflow is seen in all four InfraRed Array Camera (IRAC) bands and partially as diffuse emission in the MIPS 24 {mu}m band. An embedded MIPS 24 {mu}m source bisects the outflow and appears to be the driving source. This source is coincident with a dark patch seen in absorption in the 8 {mu}m IRAC image. Spitzer IRAC color analysis of the shocked emission was performed from which thermal and column density maps of the outflow were constructed. Narrowband near-infrared (NIR) images of the flow reveal H{sub 2} emission features coincident with the high temperature regions of the outflow. This outflow has now been given the designation MHO 1321 due to the detection of NIR H{sub 2} features. We use these data and maps to probe the physical conditions and structure of the flow.

Ybarra, Jason E.; Lada, Elizabeth A.; Fleming, Scott W. [Department of Astronomy, University of Florida, Gainesville, FL 32605 (United States); Balog, Zoltan [Max-Planck-Institut fuer Astronomie, Heidelberg (Germany); Phelps, Randy L., E-mail: jybarra@astro.ufl.ed [National Science Foundation, Office of Integrative Activities, Arlington, VA 22230 (United States)

2010-05-01T23:59:59.000Z

157

Cloud Property Retrieval Products for Graciosa Island, Azores  

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

The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

Dong, Xiquan

158

Cloud Property Retrieval Products for Graciosa Island, Azores  

SciTech Connect (OSTI)

The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

Dong, Xiquan

2014-05-05T23:59:59.000Z

159

GREEN BANK TELESCOPE OBSERVATIONS OF THE NH{sub 3} (3, 3) AND (6, 6) TRANSITIONS TOWARD SAGITTARIUS A MOLECULAR CLOUDS  

SciTech Connect (OSTI)

Ammonia (3, 3) and (6, 6) transitions have been observed using the Green Bank Telescope toward the Sgr A region. The gas is mainly concentrated in 50 km s{sup -1} and 20 km s{sup -1} clouds located in a plane inclined to the galactic plane. These 'main' clouds appear to be virialized and influenced by the expansion of the supernova remnant Sgr A East. The observed emission shows very complicated features in the morphology and velocity structure. Gaussian multi-component fittings of the observed spectra revealed that various 'streaming' gas components exist all over the observed region. These components include those previously known as 'streamers' and 'ridges', but most of these components appear not to be directly connected to the major gas condensations (the 50 km s{sup -1} and 20 km s{sup -1} clouds). They are apparently located out of the galactic plane, and they may have a different origin than the major gas condensations. Some of the streaming components are expected to be sources that feed the circumnuclear disk of our Galactic center directly and episodically. They may also evolve differently than major gas condensations under the influence of the activities of the Galactic center.

Minh, Young Chol [Korea Astronomy and Space Science Institute, Daeduk-daero 776, Yuseong, Daejeon 305-348 (Korea, Republic of); Liu, Hauyu Baobab; Ho, Paul T. P.; Hsieh, Pei-Ying; Su, Yu-Nung [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Kim, Sungsoo S. [Department of Astronomy and Space Science, Kyung Hee University, Yongin, Kyungki-do 446-701 (Korea, Republic of); Wright, Melvyn [Radio Astronomy Laboratory, University of California, Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States)

2013-08-10T23:59:59.000Z

160

Observed Characteristics of Clouds and Precipitating Systems Associated with the Tropical Circulation in Global Models and Reanalyses  

E-Print Network [OSTI]

............................................................................ 90 a. Reanalysis Datasets .................................................................. 90 b. ISCCP Cloud Regimes ............................................................. 92 c. Model Setup... FIGURE Page A-1 Annual average, zonal mean meridional mass streamfunction values for each reanalysis dataset during the 1979-2008 period ............ 144 A-2 Same as Fig. A-1, but for JJA...

Stachnik, Justin Paul

2013-03-25T23:59:59.000Z

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


161

Attribution Analysis of Cloud Feedback  

E-Print Network [OSTI]

Uncertainty on cloud feedback is the primary contributor to the large spread of equilibrium climate sensitivity (ECS) in climate models. In this study, we compare the short-term cloud feedback in climate models with observations, and evaluate...

Zhou, Chen

2014-07-15T23:59:59.000Z

162

An investigation of time changes in clouds observed over the Gulf of Mexico and Caribbean Sea during the period 18 - 23 July 1961  

E-Print Network [OSTI]

are isopleths of eights of total sky cover. The data in brackets are 1200 GCT observations Daily 1200 GCT positions of Hurricane ANNA, 19 through 24 July 1961 Frame No. 31, Orbit 133T, TIROS III. This photograph was taken at 1544 GCT, 21 July 1961 ix.... The remaining system, somewhat less impressive than the first two, was a mass of cumulus or thick strato- cumulus lying over the higher terrain of north-central Mexico. Figures 7 through 9 depict these cloud masses. eD ?oo ~O 0& oo ~D 8 oo TEMPERATURE...

Cramer, William Paul

2012-06-07T23:59:59.000Z

163

Aerosol-Cloud-Precipitation Interactions in the Trade Wind Boundary Layer.  

E-Print Network [OSTI]

??This dissertation includes an overview of aerosol, cloud, and precipitation properties associated with shallow marine cumulus clouds observed during the Barbados Aerosol Cloud Experiment (BACEX, (more)

Jung, Eunsil

2012-01-01T23:59:59.000Z

164

Persistent Contrails and Contrail Cirrus. Part I: Large-Eddy Simulations from Inception to Demise  

Science Journals Connector (OSTI)

Large-eddy simulations with size-resolved microphysics are used to model persistent aircraft contrails and contrail-induced cirrus from a few wing spans behind the aircraft until their demise after many hours. Schemes for dynamic local ice binning ...

D. C. Lewellen; O. Meza; W. W. Huebsch

2014-12-01T23:59:59.000Z

165

A Study to Investigate Cloud Feedback Processes and Evaluate GCM Cloud Variations Using Statistical Cloud Property Composites From ARM Data  

SciTech Connect (OSTI)

The representation of clouds in Global Climate Models (GCMs) remains a major source of uncertainty in climate change simulations. Cloud climatologies have been widely used to either evaluate climate model cloud fields or examine, in combination with other data sets, climate-scale relationships between cloud properties and dynamical or microphysical parameters. Major cloud climatologies have been based either on satellite observations of cloud properties or on surface observers views of cloud type and amount. Such data sets provide either the top-down view of column-integrated cloud properties (satellites) or the bottom-up view of the cloud field morphology (surface observers). Both satellite-based and surface cloud climatologies have been successfully used to examine cloud properties, to support process studies, and to evaluate climate and weather models. However, they also present certain limitations, since the satellite cloud types are defined using radiative cloud boundaries and surface observations are based on cloud boundaries visible to human observers. As a result, these data sets do not resolve the vertical distribution of cloud layers, an issue that is important in calculating both the radiative and the hydrologic effects of the cloud field. Ground-based cloud radar observations, on the other hand, resolve with good accuracy the vertical distribution of cloud layers and could be used to produce cloud type climatologies with vertical layering information. However, these observations provide point measurements only and it is not immediately clear to what extent they are representative of larger regimes. There are different methods that can be applied to minimize this problem and to produce cloud layering climatologies useful for both cloud process and model evaluation studies. If a radar system is run continuously over a number of years, it eventually samples a large number of dynamical and microphysical regimes. If additional data sets are used to put the cloud layering information into the context of large-scale dynamical regimes, such information can be used to study interactions among cloud vertical distributions and dynamical and microphysical processes and to evaluate the ability of models to simulate those interactions. The U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program has established several Climate Research Facilities (ACRF) that provide continuous, long-term observations of clouds and radiation. ARM, with its overall goal of improving the treatment of radiation and clouds in climate models has provided unique observing systems for accelerating progress on the representation of cloud processes. In this project, six and a half years (January 1998 to June 2004) of cloud observations collected at the Southern Great Plains (SGP) Oklahoma ACRF were used to produce a cloud-type climatology. The climatology provides cloud amounts for seven different cloud types as well as information on the detailed structure of multi-layer cloud occurrences. Furthermore, the European Centre for Medium-Range Weather Forecasts (ECMWF) model output was used to define the dynamic regimes present during the observations of the cloud conditions by the vertically pointing radars at the SGP ACRF. The cloud-type climatology and the ECMWF SGP data set were then analyzed to examine and map dynamical conditions that favor the creation of single-layer versus multi-layer cloud structures as well as dynamical conditions that favor the occurrence of drizzle in continental stratus clouds. In addition, output from the ECMWF weather model forecasts was analyzed with the objective to compare model and radar derived cloud type statistics, in order to identify the major model deficiencies in cloud vertical distribution and map their seasonal variations. The project included two primary goals. The first was to create a cloud type climatology over the Southern Great Planes site that will show how cloud vertical distribution varies with dynamic and thermodynamic regime and how these variations would affect cloud climate fe

George Tselioudis

2009-08-11T23:59:59.000Z

166

7, 1711717146, 2007 Dependence of cloud  

E-Print Network [OSTI]

ACPD 7, 17117­17146, 2007 Dependence of cloud fraction and cloud height on temperature T. Wagner et a Creative Commons License. Atmospheric Chemistry and Physics Discussions Dependence of cloud fraction and cloud top height on surface temperature derived from spectrally resolved UV/vis satellite observations T

Paris-Sud XI, Université de

167

The low-mass pre-main sequence population of the stellar association LH 52 in the Large Magellanic Cloud discovered with Hubble Space Telescope WFPC2 Observations  

E-Print Network [OSTI]

We report on the serendipitous discovery of ~ 500 low-mass candidate PMS stars in the vicinity of the stellar association LH 52 in the Large Magellanic Cloud. We present evidence that the red faint sequence of these stars seen in the CMD of LH 52 from HST/WFPC2 observations belongs only to the association and follows almost perfectly isochrone models for PMS stars of masses down to ~ 0.3 M_solar. We find that this feature has a Galactic counterpart and that the mass spectrum of the candidate PMS stars in LH 52 seems to correspond to a Salpeter IMF with a slope Gamma ~ -1.26 in the mass range 0.8 - 1.4 M_solar.

D. Gouliermis; W. Brandner; Th. Henning

2005-12-05T23:59:59.000Z

168

Understanding the AIRS, ARM, and MODIS cloud products by cross-comparison  

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

Understanding the AIRS, ARM, and MODIS cloud products by cross-comparison Understanding the AIRS, ARM, and MODIS cloud products by cross-comparison Kahn, Brian Jet Propulsion Laboratory Eldering, Annmarie Jet Propulsion Laboratory Category: Cloud Properties We present comparisons of the Atmospheric Infrared Sounder (AIRS) operational cloud top height (CTH) to the active surface-based measurements of the Atmospheric Radiation Measurement (ARM) program sites in the tropical Western Pacific. The agreement is found to be consistent to other comparisons of passive IR-derived CTH from other measurement platforms despite the nominal footprint size of 45 km at nadir view. Independent comparisons of CTH to the millimeter-wave cloud radar at Manus Island and the micropulse lidar at Nauru Island indicate that the CTH retrieved by AIRS is statistically significant at the 5% level or less for cirrus cases

169

Cloud Computing  

SciTech Connect (OSTI)

Chicago Matters: Beyond Burnham (WTTW). Chicago has become a world center of "cloud computing." Argonne experts Pete Beckman and Ian Foster explain what "cloud computing" is and how you probably already use it on a daily basis.

Pete Beckman and Ian Foster

2009-12-04T23:59:59.000Z

170

A Balloon Observation of the Thermal Radiation from the Circumsolar Dust Cloud in the 1983 Total Eclipse  

Science Journals Connector (OSTI)

During the totality on June 11, 1983 in East Java, Indonesia, a near infrared photometric observation of the solar corona was made using a stratospheric balloon, which was successfully launched by a joint...? fro...

T. Maihara; K. Mizutani; N. Hiromoto

1985-01-01T23:59:59.000Z

171

Cloud Computing at NERSC  

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

Home R & D Archive Cloud Computing Cloud Computing Cloud computing is gaining a foothold in the business world, but can clouds meet the specialized needs of scientists?...

172

Cloud radar Doppler spectra in drizzling stratiform clouds: 1. Forward modeling and remote sensing applications  

E-Print Network [OSTI]

Cloud radar Doppler spectra in drizzling stratiform clouds: 1. Forward modeling and remote sensing broadening and drizzle growth in shallow liquid clouds remain not well understood. Detailed, cloudscale. Profiling, millimeterwavelength (cloud) radars can provide such observations. In particular, the first three

173

The low-mass initial mass function of the field population in the Large Magellanic Cloud with Hubble Space Telescope WFPC2 Observations  

E-Print Network [OSTI]

We present V- and I-equivalent HST/WFPC2 stellar photometry of an area in the Large Magellanic Cloud (LMC), located on the western edge of the bar of the galaxy, which accounts for the general background field of its inner disk. The WFPC2 observations reach magnitudes as faint as V=25 mag, and the large sample of more than 80,000 stars allows us to determine in detail the Present-Day Mass Function (PDMF) of the detected main-sequence stars, which is identical to the Initial Mass Function (IMF) for masses M <~ 1 M_solar. The low-mass main-sequence mass function of the LMC field is found not to have a uniform slope throughout the observed mass range, i.e. the slope does not follow a single power law. This slope changes at about 1 M_solar to become more shallow for stars with smaller masses down to the lowest observed mass of ~ 0.7 M_solar, giving clear indications of flattening for even smaller masses. We verified statistically that for stars with M <~ 1 M_solar the IMF has a slope Gamma around -2, with an indicative slope Gamma =~ -1.4 for 0.7 <~ M/M_solar <~ 0.9, while for more massive stars the main-sequence mass function becomes much steeper with Gamma =~ -5. The main-sequence luminosity function (LF) of the observed field is in very good agreement with the Galactic LF as it was previously found. Taking into account several assumptions concerning evolutionary effects, which should have changed through time the stellar content of the observed field, we reconstruct qualitatively its IMF for the whole observed mass range (0.7 <~ M/M_solar <~ 2.3) and we find that the number of observed evolved stars is not large enough to have affected significantly the form of the IMF, which thus is found almost identical to the observed PDMF.

D. Gouliermis; W. Brandner; Th. Henning

2005-08-31T23:59:59.000Z

174

Q. J. R. Meteorol. Soc. (2005), 129, pp. 1999 A 3D stochastic cloud model  

E-Print Network [OSTI]

the field is scaled to produce the observed mean and fractional standard deviation of ice water content the cirrus parameters of interest. It is found that horizontal power spectra of the logarithm of ice water of the fallstreaks may be predicted from the profile of mean wind and mean ice fall speed. We then describe

Hogan, Robin

175

The Initial Mass Function toward the low-mass end in the Large Magellanic Cloud with HST/WFPC2 Observations  

E-Print Network [OSTI]

We present V and I equivalent HST/WFPC2 photometry of two areas in the Large Magellanic Cloud: The southern part of the stellar association LH 52, located on the western edge of the super-shell LMC 4, and a field between two associations, which is located on the southwestern edge of the shell, and which accounts for the general background field of the galaxy. The HST/WFPC2 observations reach magnitudes as faint as V=25 mag, much deeper than have been observed earlier in stellar associations in the LMC. We determine the MF for main-sequence stars in the areas. Its slope (Gamma) in both areas is steeper for stars with masses M 2 M_solar (-1 5 M_solar. We conclude that this seems to be also the case toward lower masses down to M ~ 1 M_solar. Our data allow to construct the field-subtracted, incompleteness-corrected, main-sequence MF of the southwestern part of the young stellar association LH 52, which accounts for the Initial Mass Function (IMF) of the system. Its mean slope is found to be comparable, but still more shallow than a typical Salpeter IMF (Gamma = -1.12 +/- 0.24) for masses down to ~ 1 M_solar. We found indications that the IMF of the association probably is ``top-heavy'', due to the large number of intermediate-mass stars in the field of the system, while the general LMC field is found to be responsible for the low-mass population, with M < 2 M_solar, observed in both fields.

D. Gouliermis; W. Brandner; Th. Henning

2004-11-16T23:59:59.000Z

176

Cloud Computing.  

E-Print Network [OSTI]

?? Cloud computing has been given a great deal of attention during recent years. Almost all the technology market leaders and leading hosting service providers (more)

Siddiqui, Muhammad Anas

2013-01-01T23:59:59.000Z

177

ARM - Publications: Science Team Meeting Documents  

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

Cirrus Cloud Statistics from a Cloud-Resolving Model Simulation Compared to Cirrus Cloud Statistics from a Cloud-Resolving Model Simulation Compared to Cloud Radar Observations Krueger, S.K. (a), Luo, Y. (a), Mace, G.G. (a), and Xu, K.-M. (b), University of Utah (a), NASA Langley Research Center (b) Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting Mace, Clothiaux, and Ackerman (2000; MCA) determined the properties of cirrus clouds derived from one year (December 1996 to November 1997) of MMCR data collected at the SGP ARM site in Oklahoma. They also used additional measurements to retrieve the bulk microphysical properties of thin cirrus cloud layers. We sampled CRM results in a way that allows direct comparison to MCA's observations and retrievals of cirrus cloud properties. This allows evaluation, in a statistical sense, of the CRM's

178

Warm Core Structures in Organized Cloud Clusters Developing or Not Developing into Tropical Storms Observed by the Advanced Microwave Sounding Unit  

Science Journals Connector (OSTI)

The temperature profiles of organized cloud clusters developing or not developing (nondeveloping) into tropical storms (TSs; maximum surface wind >34 kt) over the western North Pacific in 2004 were investigated using Advanced Microwave Sounding ...

Kotaro Bessho; Tetsuo Nakazawa; Shuji Nishimura; Koji Kato

2010-07-01T23:59:59.000Z

179

Kinematical relations among radar-observed water concentrations, vertical motions, and liquid-water drop-size spectra in convective clouds  

E-Print Network [OSTI]

and liquid- water concentration, a one-dimensional (vertical) continuity equation for water substance is considered. Atmospheric values of parameters which appear in the continuity equation are determined from radar reflectivity measurements. Empirical... viii I INTRODUCTION Cloud Motions in General Equations Governing Cloud Parameters A Kinematical Equation Based on the Continuity of Water Substance Determinati. on of the Values of the Atmospheric Variables Appearing in the Kinematical Equation...

Runnels, Robert Clayton

2012-06-07T23:59:59.000Z

180

Cloud Computing Fundamentals  

Science Journals Connector (OSTI)

In the introductory chapter we define the concept of cloud computing and cloud services, and we introduce layers and types of cloud computing. We discuss the differences between cloud computing and cloud servi...

Borko Furht

2010-01-01T23:59:59.000Z

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


181

The Role of Gravity Waves in the Formation and Organization of Clouds during TWPICE  

SciTech Connect (OSTI)

All convective clouds emit gravity waves. While it is certain that convectively-generated waves play important parts in determining the climate, their precise roles remain uncertain and their effects are not (generally) represented in climate models. The work described here focuses mostly on observations and modeling of convectively-generated gravity waves, using the intensive observations from the DoE-sponsored Tropical Warm Pool International Cloud Experiment (TWP-ICE), which took place in Darwin, from 17 January to 13 February 2006. Among other things, the research has implications the part played by convectively-generated gravity waves in the formation of cirrus, in the initiation and organization of further convection, and in the subgrid-scale momentum transport and associated large-scale stresses imposed on the troposphere and stratosphere. The analysis shows two groups of inertia-gravity waves are detected: group L in the middle stratosphere during the suppressed monsoon period, and group S in the lower stratosphere during the monsoon break period. Waves belonging to group L propagate to the south-east with a mean intrinsic period of 35 h, and have vertical and horizontal wavelengths of about 5-6 km and 3000-6000 km, respectively. Ray tracing calculations indicate that these waves originate from a deep convective region near Indonesia. Waves belonging to group S propagate to the south-south-east with an intrinsic period, vertical wavelength and horizontal wavelength of about 45 h, 2 km and 2000-4000 km, respectively. These waves are shown to be associated with shallow convection in the oceanic area within about 1000 km of Darwin. The intrinsic periods of high-frequency waves are estimated to be between 20-40 minutes. The high-frequency wave activity in the stratosphere, defined by mass-weighted variance of the vertical motion of the sonde, has a maximum following the afternoon local convection indicating that these waves are generated by local convection. The wave activity is strongest in the lower stratosphere below 22 km and, during the suppressed monsoon period, is modulated with a 3-4-day period. The concentration of the wave activity in the lower stratosphere is consistent with the properties of the environment in which these waves propagate, whereas its 3-4-day modulation is explained by the variation of the convection activity in the TWP-ICE domain. At low rainfall intensity the wave activity increases as rainfall intensity increases. At high values of rainfall intensity, however, the wave activity associated with deep convective clouds is independent of the rainfall intensity. The convection and gravity waves observed during TWP-ICE are simulated with the Weather Research and Forecasting (WRF) Model. These simulations are compared with radiosonde observations described above and are used to determine some of the properties of convectively generated gravity waves. The gravity waves appear to be well simulated by the model. The model is used to explore the relationships between the convection, the gravity waves and cirrus.

Reeder, Michael J. [Monash University; Lane, Todd P. [University of Melbourne; Hankinson, Mai Chi Nguyen [Monash University

2013-09-27T23:59:59.000Z

182

Cumulus Clouds and Reflected Sunlight  

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

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

183

Cloud Microphysics Spring 2013 **odd years?**  

E-Print Network [OSTI]

ATS724 Cloud Microphysics (2-0-0) Spring 2013 **odd years?** Prerequisites: ATS620, ATS621; Ph, as the class will involve designing and building a simple cloud microphysical model. Course Description: **Sue and observations of nucleation, mechanisms of cloud droplet-spectra broadening, precipitation particle growth

184

A Case Study of Radar Observations and WRF LES Simulations of the Impact of Ground-Based Glaciogenic Seeding on Orographic Clouds and Precipitation. Part I: Observations and Model Validations  

Science Journals Connector (OSTI)

Profiling airborne radar data and accompanying large-eddy-simulation (LES) modeling are used to examine the impact of ground-based glaciogenic seeding on cloud and precipitation in a shallow stratiform orographic winter storm. This storm occurred ...

Xia Chu; Lulin Xue; Bart Geerts; Roy Rasmussen; Daniel Breed

2014-10-01T23:59:59.000Z

185

ARM - Measurement - Cloud condensation nuclei  

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

condensation nuclei condensation nuclei ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud condensation nuclei Small particles (typically 0.0002 mm, or 1/100 th the size of a cloud droplet) about which cloud droplets coalesce. Categories Aerosols, Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CCN : Cloud Condensation Nuclei Particle Counter Field Campaign Instruments AOS : Aerosol Observing System

186

Dynamic Cloud Infrastructure.  

E-Print Network [OSTI]

??This thesis will explore and investigate the possibility of implementing nested clouds to increase flexibility. A nested cloud is a private cloud running inside another (more)

Gundersen, Espen

2012-01-01T23:59:59.000Z

187

Securing Cloud Storage Service.  

E-Print Network [OSTI]

?? Cloud computing brought flexibility, scalability, and capital cost savings to the IT industry. As more companies turn to cloud solutions, securing cloud based services (more)

Zapolskas, Vytautas

2012-01-01T23:59:59.000Z

188

Liquid layers were observed in the Mixed-Phase Arctic Cloud Experiment (M-PACE) at temperatures down to 30C.  

E-Print Network [OSTI]

down to ­30°C. S ignificant and interrelated atmospheric, oceanic, and terrestrial changes have been to be related to complex feedback processes unique to the Arctic. Arctic clouds have been identified | #12;playing a central role in several hypothesized feed- back processes (Curry et al. 1996; Vavrus

Eloranta, Edwin W.

189

ARM - Field Campaign - Spring Cloud IOP  

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

190

A Global Climatology of Single-Layer and Overlapped Clouds and their Optical Properties Developed Using a New Algorithm Applied to Terra/MODIS Data  

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

Global Climatology of Single-Layer and Overlapped Global Climatology of Single-Layer and Overlapped Clouds and their Optical Properties Developed Using a New Algorithm Applied to Terra/MODIS Data 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 To date, weather satellites are the only tool to measure cloud and climate variables on a global scale, an objective addressed by the International Satellite Cloud Climatology Project (ISCCP) (Rossow and Schiffer 1991; Rossow and Schiffer 1999). However, there is a dearth of information concerning the global climatology of cloud vertical structure and cirrus cloud properties. This is because the often-used

191

Satellite-based remote sensing of cirrus clouds: hyperspectral radiative transfer modeling, analysis of uncertainties in in-situ cloud extinction measurements and intercomparison of cirrus retrievals from a-train instruments  

E-Print Network [OSTI]

, 2007 (UTC time 18:45).......................... 93 4.6 GOES-12 and GOES-10 merged infrared (11mm) color images over Central America for a) 10:45 b) 12:45 c) 14:28 d) 16:45 e) 18:45 and f) 20:28 UTC, on July 22, 2007............................................................................................. 106 4.14 Same as Fig. 4.10 for the ratio ! c A / MODIS . ......................................... 109 4.15 Same as Fig. 4.10 for the ratio B ?????????????. 111 4.16 Same as Fig. 4.10 for the ratio c C / A ?????????????. 113 4.17 The left...

Zhang, Zhibo

2009-05-15T23:59:59.000Z

192

Cloud Computing Adam Barker  

E-Print Network [OSTI]

Cloud Computing 1 Adam Barker #12;Overview · Introduction to Cloud computing · Enabling technologies · Di erent types of cloud: IaaS, PaaS and SaaS · Cloud terminology · Interacting with a cloud: management consoles · Launching an instance · Connecting to an instance · Running your application · Clouds

St Andrews, University of

193

ARM - Publications: Science Team Meeting Documents  

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

by deep convection, were observed about 30 percent of the time by the cloud radar. To produce cirrus statistics from the SCM results that are comparable to the cloud radar...

194

Cloud Controlling Factors --Low Clouds BJORN STEVENS,  

E-Print Network [OSTI]

Cloud Controlling Factors -- Low Clouds BJORN STEVENS, Department of Atmospheric and Oceanic) clouds is reviewed, with an emphasis on factors that may be expected to change in a changing climate of low-cloud control- ling processes are offered: these include renewing our focus on theory, model

Stevens, Bjorn

195

Cloud Tracking in Cloud-Resolving Models  

E-Print Network [OSTI]

Cloud Tracking in Cloud-Resolving Models RMetS Conference 4th September 2007 Bob Plant Department of Meteorology, University of Reading, UK #12;Introduction Obtain life cycle statistics for clouds in CRM simulations What is the distribution of cloud lifetimes? What factors determine the lifetime of an individual

Plant, Robert

196

Cloud Controlling Factors --Low Clouds BJORN STEVENS,  

E-Print Network [OSTI]

Cloud Controlling Factors -- Low Clouds BJORN STEVENS, Department of Atmospheric and Oceanic conspire to determine the statistics and cli- matology of layers of shallow (boundary layer) clouds of low-cloud control- ling processes are offered: these include renewing our focus on theory, model

Stevens, Bjorn

197

Cloud Computing: Rain-Clouds System  

E-Print Network [OSTI]

Abstract Cloud Computing is the on demand service can be provided to the users at any time. It delivers the software, data access, computing as a service rather than the product. The Cloud application simplifies the computing technology by providing pay-per-use customer relationship. It is the theory that familiar to cheaper devices with low processing power, lower storage capacities, great flexibility and many more things. The security of cloud computing is a major factor as users store sensitive and confidential information with cloud storage providers. The range of these providers may be un trusted and harmful. The purpose of adopting cloud computing in an organization is to decide between a public cloud ? and private cloud ? by means of privacy. Public clouds often known as provider clouds are administrated by third parties and services are offered on pay-per-use basis. Private clouds or internal clouds are owned by the single firm but it has some metrics such as lacking of availability of services (such as memory, server) and network resources which leads it to down. Due to this, technology moves toward the concept of Multi clouds or Rain Clouds. This paper displays the use of multi-clouds or rain clouds due to its ability to handle the huge amount of data traffic that affect the cloud computing user.

Harinder Kaur

198

Research Highlight  

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

The Evolution and Distribution of Water Vapor and Microphysical Properties The Evolution and Distribution of Water Vapor and Microphysical Properties in Cirrus Clouds Download a printable PDF Submitter: Comstock, J. M., Pacific Northwest National Laboratory Area of Research: Radiation Processes Working Group(s): Cloud Modeling, Cloud Properties Journal Reference: Comstock JM, R Lin, DO Starr, and P Yang. 2008. "Understanding ice supersaturation, particle growth, and number concentration in cirrus clouds." Journal of Geophysical Research - Atmospheres, 113, D23211, doi:10.1029/2008JD010332. Vertical velocity (Vm) derived from millimeter cloud radar (MMCR) Doppler velocity measurements in cirrus clouds observed over the ACRF SGP site. Cloud model simulations of cirrus clouds using large-scale forcing (left panel) and cloud-scale forcing (right panel).

199

Cloud Security by Max Garvey  

E-Print Network [OSTI]

Cloud Security Survey by Max Garvey #12;Cloudy Cloud is Cloudy What is the cloud? On Demand Service Network access Resource pooling Elasticity of Resources Measured Service #12;Cloud Types/Variants Iaa Cloud Public Cloud Hybrid Cloud combination. Private cloud with overflow going to public cloud. #12

Tolmach, Andrew

200

Towards a Characterization of Arctic Mixed-Phase Clouds  

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

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

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


201

Cloud Computing For Bioinformatics  

E-Print Network [OSTI]

Cloud Computing For Bioinformatics #12;Cloud Computing: what is it? · Cloud Computing is a distributed infrastructure where resources, software, and data are provided in an on-demand fashion. · Cloud Computing abstracts infrastructure from application. · Cloud Computing should save you time the way software

Ferrara, Katherine W.

202

Cloud Computing og availability  

E-Print Network [OSTI]

Cloud Computing og availability Projekt i pålidelighed Henrik Lavdal - 20010210 Søren Bardino Kaa - 20011654 Gruppe 8 19-03-2010 #12;Cloud Computing og availability Side 2 af 28 Indholdsfortegnelse ...........................................................................................5 Cloud computing

Christensen, Henrik Bærbak

203

Federal Cloud Computing: The Definitive Guide for Cloud Service Providers  

Science Journals Connector (OSTI)

Federal Cloud Computing: The Definitive Guide for Cloud Service Providers offers an in-depth look at topics surrounding federal cloud computing within the federal government, including the Federal Cloud Computing Strategy, Cloud Computing Standards, ...

Matthew Metheny

2012-12-01T23:59:59.000Z

204

On Demand Surveillance Service in Vehicular Cloud  

E-Print Network [OSTI]

Toward Vehicular Service Cloud . . . . . . . . . . . . . . .4.2 Open Mobile Cloud Requirement . . . . .3.1 Mobile Cloud

Weng, Jui-Ting

2013-01-01T23:59:59.000Z

205

2, 20952131, 2002 Below-cloud aerosol  

E-Print Network [OSTI]

). In addition, the understanding of wet removal processes remains crucial in local and regional pollutionACPD 2, 2095­2131, 2002 Below-cloud aerosol removal C. Andronache Title Page Abstract Introduction-cloud aerosol removal by rainfall for observed aerosol size distributions C. Andronache Boston College, Chestnut

Paris-Sud XI, Université de

206

Cloud Computing For Bioinformatics  

E-Print Network [OSTI]

Cloud Computing For Bioinformatics EC2 and AMIs #12;Quick-starting an EC2 instance (let's get our feet wet!) Cloud Computing #12;Cloud Computing: EC2 instance Quick Start · On EC2 console, we can click on Launch Instance · This will let us get up and going quickly #12;Cloud Computing: EC2 instance

Ferrara, Katherine W.

207

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 40, NO. 2, FEBRUARY 2002 405 Cloud Tracking by Scale Space Classification  

E-Print Network [OSTI]

relevance to the analysis of cloud life cycles and to the detection of cloud motion vectors (CMVs to cloud motion vector (CMV) studies and spatio­temporal analysis of cloud life cycles. The spatio­tem- poral life cycle includes the generation, dissipation and assim- ilation of clouds that can be observed

Acton, Scott

208

Nailing Down Ice in a Cloud Model  

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

Nailing Down Ice in a Cloud Model Nailing Down Ice in a Cloud Model For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight A research team led by scientists at Pacific Northwest National Laboratory identified specific strengths and weaknesses of four different ice cloud retrieval algorithms. Their comparisons tested the ability of the algorithms to obtain cloud properties from radar and lidar observational measurements. The team noted the sometimes large variances in heating/cooling measurements compared to the observed data. Identifying specific weaknesses will help scientists improve our understanding of cloud properties in the atmosphere, which can be used for climate model development and evaluation. "Measuring the effective size and mass of ice crystals impacts our understanding

209

1  

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

Cirrus Maintenance Cirrus Maintenance M. T. Boehm and J. Verlinde The Pennsylvania State University University Park, Pennsylvania Introduction Data from the Atmospheric Radiation Measurement (ARM) Program sites on Manus Island and Nauru in the tropical western Pacific reveal the frequent occurrence of high cirrus layers with lifetimes of several hours to several days. We are investigating the processes responsible for the development and maintenance of these clouds using observations and a cirrus cloud model. In a recent article we described results of a series of model runs designed to test the hypothesis that cloud circulations associated with radiative destabilization of the layer are responsible for the maintenance of high tropical cirrus (Boehm et al. 1999). In spite of significant differences in cloud circulation strength among the

210

Section 2  

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

JACCS/MRI Cirrus Group: S. Asano (Leader), A. Uchiyama, M. Shiobara, M. Fukabori, M. Murakami, H. Mizuno, JACCS/MRI Cirrus Group: S. Asano (Leader), A. Uchiyama, M. Shiobara, M. Fukabori, M. Murakami, H. Mizuno, Y. Yamada, N. Orikasa, A. Yamamoto, M. Hirota, T. Nagai, T. Fujimoto, T. Kobayashi, H. Nirasawa. 5 Ground-Based Cirrus Observation in the Japanese Cloud and Climate Study: A Sonde System for Radiation and Cloud Microphysics Measurement S. Asano and JACCS Cirrus Group (a) Meteorological Research Institute Tsukuba, Ibaraki 305 Japan Introduction Ground-Based Cirrus Clouds play a crucial role in radiative energy budget and water cycle in the earth-atmosphere system. In order to understand processes such as global warming and to improve assessment of climate change, it is necessary to develop climate models which properly take into account radiation and cloud

211

Satellite Remote Sensing of Mid-level Clouds  

E-Print Network [OSTI]

, the International Satellite Cloud Cli- matology Project (ISCCP, Rossow and Schi er 1999) and TIROS-N Observational Vertical Sounders Path-B (TOVS-B, Stubenrauch et al. 2006) are both long-term global climatologies that de ne mid-level clouds as having cloud top... devoted to establishing global cloud climatolo- gies, however, working de nitions or the classi cation of mid-level clouds vary with observational technique, region, and purpose (Poore et al. 1995; Hahn and Warren 1999; Rossow and Schi er 1999; Hahn...

Jin, Hongchun 1980-

2012-11-07T23:59:59.000Z

212

SURFACE CLOUD RADIATIVE FORCING, CLOUD FRACTION AND CLOUD ALBEDO: THEIR RELATIONSHIP AND MULTISCALE VARIATION  

E-Print Network [OSTI]

SURFACE CLOUD RADIATIVE FORCING, CLOUD FRACTION AND CLOUD ALBEDO: THEIR RELATIONSHIP AND MULTISCALE/Atmospheric Sciences Division Brookhaven National Laboratory P.O. Box, Upton, NY www.bnl.gov ABSTRACT Cloud-induced climate change. Cloud-radiative forcing, cloud fraction, and cloud albedo are three key quantities

213

Observations of the Variation in Aerosol and Cloud Microphysics along the 20S Transect on 13 November 2008 during VOCALS-REx  

Science Journals Connector (OSTI)

Observations are presented of the structure of the marine boundary layer (MBL) in the southeastern Pacific made with the U.K. BAe 146 aircraft on 13 November 2008 as it flew at a variety of altitudes along 20S between the coast of Chile and a ...

Zhiqiang Cui; Alan Gadian; Alan Blyth; Jonathan Crosier; Ian Crawford

2014-08-01T23:59:59.000Z

214

Hydrated sulphuric acid in dense molecular clouds  

Science Journals Connector (OSTI)

......anthropogenically from combustion of fuels. Oxidized...forms readily in hydrocarbon combustion where sulphur is...dense clouds. From heat of vaporization...3 Observational Data Absorption spectra...peak absorption data in mum (cm1) for......

Flavio Scappini; Cesare Cecchi-Pestellini; Harvey Smith; William Klemperer; Alexander Dalgarno

2003-05-11T23:59:59.000Z

215

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

SciTech Connect (OSTI)

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

216

Magnetic reconnection as a possible heating mechanism of the local high temperature protons within magnetic clouds  

Science Journals Connector (OSTI)

Magnetic clouds have the outstanding observational features of low proton temperature and plasma beta value, but numerous observations show that some magnetic clouds often have local high temperature phenomena...

HengQiang Feng; JieMin Wang

2014-08-01T23:59:59.000Z

217

Atmospheric Rivers Coming to a Cloud Near You  

SciTech Connect (OSTI)

Learn about the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) field campaign in this short video. Ruby Leung, PNNL's lead scientist on this campaign's observational strategy to monitor precipitation.

Leung, Ruby

2014-03-29T23:59:59.000Z

218

Cloud Detection over Snow and Ice Using MISR Data , Eugene E. Clothiaux  

E-Print Network [OSTI]

Cloud Detection over Snow and Ice Using MISR Data Tao Shi , Bin Yu , Eugene E. Clothiaux , and Amy J. Braverman Abstract Clouds play a major role in Earth's climate and cloud detection prediction and global climate model studies. To advance the observational capabilities of detecting clouds

Yu, Bin

219

Global distribution of total cloud cover and cloud type amounts over the ocean  

SciTech Connect (OSTI)

This is the fourth of a series of atlases to result from a study of the global cloud distribution from ground-based observations. The first two atlases (NCAR/TN-201+STR and NCAR/TN-241+STR) described the frequency of occurrence of each cloud type and the co-occurrence of different types, but included no information about cloud amounts. The third atlas (NCAR/TN-273+STR) described, for the land areas of the earth, the average total cloud cover and the amounts of each cloud type, and their geographical, diurnal, seasonal, and interannual variations, as well as the average base heights of the low clouds. The present atlas does the same for the ocean areas of the earth.

Warren, S.G.; Hahn, C.J.; London, J.; Chervin, R.M.; Jenne, R.L. (Washington Univ., Seattle, WA (USA). Dept. of Atmospheric Sciences; Colorado Univ., Boulder, CO (USA). Cooperative Inst. for Research in Environmental Sciences; Colorado Univ., Boulder, CO (USA). Dept. of Astrophysical, Planetary, and Atmospheric Sciences; National Center for Atmospheric Research, Boulder, CO (USA))

1988-12-01T23:59:59.000Z

220

THE GALFA-H I COMPACT CLOUD CATALOG  

SciTech Connect (OSTI)

We present a catalog of 1964 isolated, compact neutral hydrogen clouds from the Galactic Arecibo L-Band Feed Array Survey Data Release One. The clouds were identified by a custom machine-vision algorithm utilizing the difference of Gaussian kernels to search for clouds smaller than 20'. The clouds have velocities typically between |V{sub LSR}| =20 and 400 km s{sup -1}, line widths of 2.5-35 km s{sup -1}, and column densities ranging from 1 to 35 Multiplication-Sign 10{sup 18} cm{sup -2}. The distances to the clouds in this catalog may cover several orders of magnitude, so the masses may range from less than a solar mass for clouds within the Galactic disk, to greater than 10{sup 4} M{sub Sun} for high-velocity clouds (HVCs) at the tip of the Magellanic Stream. To search for trends, we separate the catalog into five populations based on position, velocity, and line width: HVCs; galaxy candidates; cold low-velocity clouds (LVCs); warm, low positive-velocity clouds in the third Galactic quadrant; and the remaining warm LVCs. The observed HVCs are found to be associated with previously identified HVC complexes. We do not observe a large population of isolated clouds at high velocities as some models predict. We see evidence for distinct histories at low velocities in detecting populations of clouds corotating with the Galactic disk and a set of clouds that is not corotating.

Saul, Destry R.; Peek, J. E. G.; Grcevich, J.; Putman, M. E.; Brown, A. R. H.; Hamden, E. T. [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Douglas, K. A. [Physics and Astronomy, University of Calgary/Dominion Radio Astrophysical Observatory, P.O. Box 248, Penticton, BC V2A 6J9 (Canada); Korpela, E. J. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Stanimirovic, S.; Lee, M.; Burkhart, B.; Pingel, N. M. [Department of Astronomy, University of Wisconsin, Madison, 475 N Charter St, Madison, WI 53703 (United States); Heiles, C. [Radio Astronomy Lab, UC Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States); Gibson, S. J. [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101 (United States); Begum, A. [Indian Institute of Science Education and Research, ITI Campus (Gas Rahat) Building, Govindpura, Bhopal-23 (India); Tonnesen, S. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2012-10-10T23:59:59.000Z

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


221

ARM - Measurement - Cloud size  

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

to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud size Information about the physical dimensions of a cloud, including such measurements...

222

North Australian Cloud Lines  

Science Journals Connector (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

223

Infrared Optical Constants of Highly Diluted Sulfuric Acid Solution Droplets at Cirrus Temperatures  

Science Journals Connector (OSTI)

The data evaluation procedure, previously developed for open-path TDLAS measurements in combustion processes,(28) water sprays,(29) and on stratospheric balloon platforms,(30) ensured a precise correction of the broadband optical scattering losses caused by the aerosol and cloud particles along the absorption path, as well as the pressure and temperature changes during the expansion. ...

Robert Wagner; Stefan Benz; Helmut Bunz; Ottmar Mhler; Harald Saathoff; Martin Schnaiter; Thomas Leisner; Volker Ebert

2008-10-22T23:59:59.000Z

224

Marine cloud brightening  

Science Journals Connector (OSTI)

...will not be as effective in marine stratocumulus clouds that are...Engineering steps to implement marine cloud brightening (a) Introduction...brightening by increasing the CCN of marine stratus clouds (by way of...vessel and the optimum means of propulsion. In fact, both these aspects...

2012-01-01T23:59:59.000Z

225

XSEDE Cloud Survey Report  

E-Print Network [OSTI]

XSEDE Cloud Survey Report David Lifka, Cornell Center for Advanced Computing Ian Foster, ANL, ANL and The University of Chicago A National Science Foundation-sponsored cloud user survey was conducted from September 2012 to April 2013 by the XSEDE Cloud Integration Investigation Team to better

Walter, M.Todd

226

Research Cloud Computing Recommendations  

E-Print Network [OSTI]

Research Cloud Computing Recommendations SRCPAC December 3, 2014 #12;Mandate and Membership SRCPAC convened this committee in Sept 2014 to investigate the role that cloud computing should play in our & Academic Affairs (Social Work) #12;Questions discussed · What cloud resources are available? · Which kinds

Qian, Ning

227

An enigmatic HI cloud  

E-Print Network [OSTI]

The discovery of an HI cloud with peculiar properties at equatorial coordinates (J2000) ra=07h49m, dec=04d30m is presented. The HI object was detected at 21cm using the 300-m NAIC Arecibo telescope. Subsequent follow-up high-resolution observations with the NRAO Very Large Array (VLA) telescope at L-Band revealed more details about its morphology. The most intriguing aspect of the object is the clear velocity gradient of 1 km/s, which is present in the data, an indication of either rotation or expansion. The gas appears to be cold, and its morphology is somewhat elliptical with clumpy substructure. Assuming disk rotation, the dynamical mass could be determined as a function of distance.Depending on the exact nature of the velocity gradient in the HI cloud, we can reach some preliminary conclusions about the nature of the object. Expansion would imply association with a circumstellar envelope of an evolved AGB star, while in the case of rotation, a comparison between the visible and the dynamical mass can lead...

Dedes, L; Kalberla, P W M

2008-01-01T23:59:59.000Z

228

An enigmatic HI cloud  

E-Print Network [OSTI]

The discovery of an HI cloud with peculiar properties at equatorial coordinates (J2000) ra=07h49m, dec=04d30m is presented. The HI object was detected at 21cm using the 300-m NAIC Arecibo telescope. Subsequent follow-up high-resolution observations with the NRAO Very Large Array (VLA) telescope at L-Band revealed more details about its morphology. The most intriguing aspect of the object is the clear velocity gradient of 1 km/s, which is present in the data, an indication of either rotation or expansion. The gas appears to be cold, and its morphology is somewhat elliptical with clumpy substructure. Assuming disk rotation, the dynamical mass could be determined as a function of distance.Depending on the exact nature of the velocity gradient in the HI cloud, we can reach some preliminary conclusions about the nature of the object. Expansion would imply association with a circumstellar envelope of an evolved AGB star, while in the case of rotation, a comparison between the visible and the dynamical mass can lead to some preliminary conclusions. A common feature of those conclusions is the presence of a gravitational potential well, which is required to account for the rotation of the trapped HI gas. This potential well could be associated with a dark galaxy or some other exotic object.

L. Dedes; C. Dedes; P. W. M Kalberla

2008-10-21T23:59:59.000Z

229

Migrating enterprise storage applications to the cloud  

E-Print Network [OSTI]

hybrid cloud combines aspects of public and private clouds: a company may build a compute cloud own its own infrastructure,

Vrable, Michael Daniel

2011-01-01T23:59:59.000Z

230

ARM - Publications: Science Team Meeting Documents  

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

Retrieval of Cirrus Particle Sizes Using a Spit-Window Technique: A Retrieval of Cirrus Particle Sizes Using a Spit-Window Technique: A Sensitivity Study Fu, Q. (a) and Sun, W.B. (b), University of Washington (a), Dalhousie University (b) Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting The 8 - 12 um atmospheric window is an important spectral region for the remote sensing of the earth-atmosphere system. Since clouds are the major regulator of the global radiative energy budget, numerous methods have been developed to detect clouds and cloud properties based on satellite observations. Among them are the split-window techniques which are particularly useful for remote sensing of cirrus clouds. Owing to the large spectral variation of ice's imaginary refractive index over the atmospheric window, one can infer the effective ice particle sizes of cirrus clouds

231

Cloud Properties Working Group Low Clouds Update  

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

232

Evaluation of tropical cloud and precipitation statistics of CAM3 using CloudSat and CALIPSO data  

SciTech Connect (OSTI)

The combined CloudSat and CALIPSO satellite observations provide the first simultaneous measurements of cloud and precipitation vertical structure, and are used to examine the representation of tropical clouds and precipitation in the Community Atmosphere Model Version 3 (CAM3). A simulator package utilizing a model-to-satellite approach facilitates comparison of model simulations to observations, and a revised clustering method is used to sort the subgrid-scale patterns of clouds and precipitation into principal cloud regimes. Results from weather forecasts performed with CAM3 suggest that the model underestimates the horizontal extent of low and mid-level clouds in subsidence regions, but overestimates that of high clouds in ascending regions. CAM3 strongly overestimates the frequency of occurrence of the deep convection with heavy precipitation regime, but underestimates the horizontal extent of clouds and precipitation at low and middle levels when this regime occurs. This suggests that the model overestimates convective precipitation and underestimates stratiform precipitation consistent with a previous study that used only precipitation observations. Tropical cloud regimes are also evaluated in a different version of the model, CAM3.5, which uses a highly entraining plume in the parameterization of deep convection. While the frequency of occurrence of the deep convection with heavy precipitation regime from CAM3.5 forecasts decreases, the incidence of the low clouds with precipitation and congestus regimes increases. As a result, the parameterization change does not reduce the frequency of precipitating convection that is far too high relative to observations. For both versions of CAM, clouds and precipitation are overly reflective at the frequency of the CloudSat radar and thin clouds that could be detected by the lidar only are underestimated.

Zhang, Y; Klein, S; Boyle, J; Mace, G G

2008-11-20T23:59:59.000Z

233

BNL | Cloud Lifecycle Infrastructure  

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

234

Cloud Model Evaluation Using Radiometric Measurements from the Airborne Multiangle Imaging Spectroradiometer (AirMISR)  

SciTech Connect (OSTI)

Detailed information on cloud properties is needed to vigorously test retrieval algorithms for satellite and ground-based remote sensors. The inherent complexity of clouds makes this information difficult to obtain from observations alone and cloud resolving models are often used to generating synthetic datasets that can be used as proxies for real data. We test the ability of a cloud resolving model to reproduce cloud structure in a case study of low-level clouds observed by the Earth Observing System (EOS) validation program in north central Oklahoma on March 3, 2000. A three-dimensional radiative transfer model is applied to synthetic cloud properties generated by a high-resolution three-dimensional cloud model in order to simulate the top of atmosphere radiances. These synthetic radiances are then compared with observations from the airborne Multiangle Imaging SpectroRadiometer (AirMISR), flown on the NASA ER-2 high-altitude aircraft.

Ovtchinnikov, Mikhail; Marchand, Roger T.

2007-03-01T23:59:59.000Z

235

METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics  

E-Print Network [OSTI]

METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics CLASS: Monday as atmospheric electricity and optics. Specific topics that will be covered are as follows: Cloud physics: Review Observation studies Atmospheric electricity: Electrostatics Electromagnetic wave Thunderstorm charging

Droegemeier, Kelvin K.

236

Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences  

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

237

Intercomparison of the Cloud Water Phase among Global Climate Models  

SciTech Connect (OSTI)

Mixed-phase clouds (clouds that consist of both cloud droplets and ice crystals) are frequently present in the Earths atmosphere and influence the Earths energy budget through their radiative properties, which are highly dependent on the cloud water phase. In this study, the phase partitioning of cloud water is compared among six global climate models (GCMs) and with Cloud and Aerosol Lidar with Orthogonal Polarization retrievals. It is found that the GCMs predict vastly different distributions of cloud phase for a given temperature, and none of them are capable of reproducing the spatial distribution or magnitude of the observed phase partitioning. While some GCMs produced liquid water paths comparable to satellite observations, they all failed to preserve sufficient liquid water at mixed-phase cloud temperatures. Our results suggest that validating GCMs using only the vertically integrated water contents could lead to amplified differences in cloud radiative feedback. The sensitivity of the simulated cloud phase in GCMs to the choice of heterogeneous ice nucleation parameterization is also investigated. The response to a change in ice nucleation is quite different for each GCM, and the implementation of the same ice nucleation parameterization in all models does not reduce the spread in simulated phase among GCMs. The results suggest that processes subsequent to ice nucleation are at least as important in determining phase and should be the focus of future studies aimed at understanding and reducing differences among the models.

Komurcu, Muge; Storelvmo, Trude; Tan, Ivy; Lohmann, U.; Yun, Yuxing; Penner, Joyce E.; Wang, Yong; Liu, Xiaohong; Takemura, T.

2014-03-27T23:59:59.000Z

238

The Roles of Cloud Drop Effective Radius and LWP in Determining Rain Properties in Marine Stratocumulus  

SciTech Connect (OSTI)

Numerical simulations described in previous studies showed that adding cloud condensation nuclei to marine stratocumulus can prevent their breakup from closed into open cells. Additional analyses of the same simulations show that the suppression of rain is well described in terms of cloud drop effective radius (re). Rain is initiated when re near cloud top is around 12-14 um. Cloud water starts to get depleted when column-maximum rain intensity (Rmax) exceeds 0.1 mm h-1. This happens when cloud-top re reaches 14 um. Rmax is mostly less than 0.1 mm h-1 at re<14 um, regardless of the cloud water path, but increases rapidly when re exceeds 14 um. This is in agreement with recent aircraft observations and theoretical observations in convective clouds so that the mechanism is not limited to describing marine stratocumulus. These results support the hypothesis that the onset of significant precipitation is determined by the number of nucleated cloud drops and the height (H) above cloud base within the cloud that is required for cloud drops to reach re of 14 um. In turn, this can explain the conditions for initiation of significant drizzle and opening of closed cells providing the basis for a simple parameterization for GCMs that unifies the representation of both precipitating and non-precipitating clouds as well as the transition between them. Furthermore, satellite global observations of cloud depth (from base to top), and cloud top re can be used to derive and validate this parameterization.

Rosenfeld, Daniel; Wang, Hailong; Rasch, Philip J.

2012-07-04T23:59:59.000Z

239

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

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

Dispersion of Cloud Droplet Size Distributions, Cloud Parameterizations, and Indirect Aerosol Effects P. H. Daum and Y. Liu Brookhaven National Laboratory Upton, New York...

240

ARM - Measurement - Cloud top height  

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

to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud top height For a given cloud or cloud layer, the highest level of the atmosphere where...

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


241

Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo  

SciTech Connect (OSTI)

This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surface-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fraction, and cloud albedo. The analytical expression is then used to deduce a new approach for inferring cloud albedo from concurrent surface-based measurements of downwelling surface shortwave radiation and cloud fraction. High-resolution decade-long data on cloud albedos are obtained by use of this surface-based approach over the US Department of Energy's Atmospheric Radiaton Measurement (ARM) Program at the Great Southern Plains (SGP) site. The surface-based cloud albedos are further compared against those derived from the coincident GOES satellite measurements. The three long-term (1997-2009) sets of hourly data on shortwave cloud radiative forcing, cloud fraction and cloud albedo collected over the SGP site are analyzed to explore the multiscale (diurnal, annual and inter-annual) variations and covariations. The analytical formulation is useful for diagnosing deficiencies of cloud-radiation parameterizations in climate models.

Liu, Y.; Wu, W.; Jensen, M. P.; Toto, T.

2011-07-21T23:59:59.000Z

242

Cloud Computing: An Architectural Perspective .  

E-Print Network [OSTI]

??Cloud Computing is a term heavily used in today's world. Not even a day passes by without hearing the words "Cloud Computing". It has become (more)

Pandya, Hetalben

2013-01-01T23:59:59.000Z

243

Profiling clouds' inner life | EMSL  

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

inner life Subgrid modeling pinpoints cloud transformation to uncover true reflective power An accurate understanding of clouds over the ocean is important for climate change...

244

BNL | Aerosol, Cloud, Precipitation Interactions  

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

245

ARM - Measurement - Cloud extinction  

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

246

ARM - Publications: Science Team Meeting Documents: Cloud Radiative Forcing  

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

Cloud Radiative Forcing at the ARM Climate Research Facility: Part 2. The Cloud Radiative Forcing at the ARM Climate Research Facility: Part 2. The Vertical Redistribution of Radiant Energy by Clouds. Mace, Gerald University of Utah Benson, Sally University of Utah Kato, Seiji Hampton University/NASA Langley Research Center Documentation with data of the effects of clouds on the radiant energy balance of the surface and atmosphere represent a critical shortcoming in the set of observations that are needed to ascertain the validity of model simulations of the earth's climate. While clouds are known to cool the climate system from TOA radiation budget studies, the redistribution of energy between the surface and atmosphere and within the atmosphere by clouds has not been examined in detail. Using data collected at the Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP)

247

1  

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

Cirrus cloud inhomogeneity occurs at scales greater than the cirrus radiative smoothing scale (100 m), but less than typical global climate model resolutions (300...

248

Long-lived artificial ion clouds in the earth's ionosphere  

SciTech Connect (OSTI)

The authors report on two observations made over the Caribbean during the summer of 1991 of barium ion cloud releases, ten hours after the clouds were released. One release was made in the morning twilight, and one in the evening twilight, and each was observed again in the following twilight period by a low light level TV imager and a TV spectrograph onboard a Russian research vessel. These observations were very surprising at the time, but the authors present arguments as to why in retrospect they may not be so unusual in practise. Such cloud releases may provide very sensitive tests of ionspheric convection models.

Milinevsky, G.P. (Kiev Univ., Ukraine (Russian Federation)); Kashirin, A.I. (NPO Typhoon, Obninsk (Russian Federation)); Romanovsky, Yu.A. (Institute of Applied Geophysics, Moscow (Russian Federation)); Stenbaek-Nielson, H.C. (Univ. of Alaska, Fairbanks (United States)); Kelley, M.C. (Cornell Univ., Ithaca, NY (United States))

1993-06-07T23:59:59.000Z

249

Cloud Computing Synopsis and Recommendations  

Science Journals Connector (OSTI)

This document reprises the NIST-established definition of cloud computing, describes cloud computing benefits and open issues, presents an overview of major classes of cloud technology, and provides guidelines and recommendations on how organizations ... Keywords: cloud computing, computer security, virtualization

Mark Lee Badger; Timothy Grance; Robert Patt-Corner; Jeffery M, Voas

2012-05-01T23:59:59.000Z

250

Convective Cloud Lifecycles Lunchtime seminar  

E-Print Network [OSTI]

Convective Cloud Lifecycles Lunchtime seminar 19th May 2009 Bob Plant Department of Meteorology, University of Reading, UK #12;Introduction Obtain life cycle statistics for clouds in CRM simulations Why Conclusions Convective Cloud Lifecycles ­ p.1/3 #12;Why bother? Convective Cloud Lifecycles ­ p.2/3 #12;Some

Plant, Robert

251

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

SciTech Connect (OSTI)

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

252

3. New Cloud Climatology  

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

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

253

In Clouds We Trust  

Science Journals Connector (OSTI)

......can bring. Many have realised that giving a third party control of part of the IT infrastructure can help reduce capital expenditure and maximise asset utilisation to provide a quantitative return on investment (ROI). Cloud can also remove resource......

Jim Damoulakis

2010-03-01T23:59:59.000Z

254

Moving into the Cloud.  

E-Print Network [OSTI]

??Cloud computing is the notion of abstracting and outsourcing hardware or software resources over the Internet, often to a third party on a pay-as-you-go basis. (more)

Mikalsen, Christian

2009-01-01T23:59:59.000Z

255

Simulation of the Extinction Efficiency, the Absorption Efficiency and the Asymmetry Factor of Ice Crystals and Relevant Applications to the Study of Cirrus Cloud Radiative Properties  

E-Print Network [OSTI]

The single-scattering properties of six non-spherical ice crystals, droxtals, plates, solid columns, hollow columns, aggregates and 6-branch bullet rosettes are simulated. The anomalous diffraction theory (ADT) is applied to the simulation...

Lu, Kai

2010-10-12T23:59:59.000Z

256

Cloud Properties and Radiative Heating Rates for TWP  

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

A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

Comstock, Jennifer

257

Cloud Properties and Radiative Heating Rates for TWP  

SciTech Connect (OSTI)

A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

Comstock, Jennifer

2013-11-07T23:59:59.000Z

258

Migrating enterprise storage applications to the cloud  

E-Print Network [OSTI]

2.1 Cloud Providers . . . . . . . . . . . .2.1.1 Cloud Storage . . . . . . . . .2.1.2 Cloud Computation . . . . . . 2.2 Enterprise Storage

Vrable, Michael Daniel

2011-01-01T23:59:59.000Z

259

Detection of CFIRB with AKARI/FIS Deep Observations  

E-Print Network [OSTI]

The Cosmic Far-Infrared Background (CFIRB) contains information about the number and distribution of contributing sources and thus gives us an important key to understand the evolution of galaxies. Using a confusion study to set a fundamental limit to the observations, we investigate the potential to explore the CFIRB with AKARI/FIS deep observations. The Far-Infrared Surveyor (FIS) is one of the focal-plane instruments on the AKARI (formerly known as ASTRO-F) satellite, which was launched in early 2006. Based upon source distribution models assuming three different cosmological evolutionary scenarios (no evolution, weak evolution, and strong evolution), an extensive model for diffuse emission from infrared cirrus, and instrumental noise estimates, we present a comprehensive analysis for the determination of the confusion levels for deep far-infrared observations. We use our derived sensitivities to suggest the best observational strategy for the AKARI/FIS mission to detect the CFIRB fluctuations. If the source distribution follows the evolutionary models, observations will be mostly limited by source confusion. We find that we will be able to detect the CFIRB fluctuations and that these will in turn provide information to discriminate between the evolutionary scenarios of galaxies in most low-to-medium cirrus regions.

Woong-Seob Jeong; Chris P. Pearson; Hyung Mok Lee; Shuji Matsuura; Mitsunobu Kawada; Takao Nakagawa; Sang Hoon Oh; Mai Shirahata; Sungho Lee; Ho Seong Hwang; Hideo Matsuhara

2007-05-14T23:59:59.000Z

260

Supernova remnants in the Magellanic Clouds. III  

SciTech Connect (OSTI)

As part of a continuing study of supernova remnants in the Magellanic Clouds, narrow-band optical images were obtained of seven SNR candidates in the LMC selected on the basis of radio and/or X-ray observations. Four of the candidates are confirmed as new SNRs. The object 0536-692 appears to be a superbubble resulting from one or more supernovae and the stellar winds from the large OB stellar association, NGC 2044, within its interior. The latest results bring the total number of SNRs with optical identifications in the Large Magellanic Cloud to 32. 16 references.

Mathewson, D.S.; Ford, V.L.; Tuohy, I.R.; Mills, B.Y.; Turtle, A.J.; Helfand, D.J.

1985-06-01T23:59:59.000Z

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


261

Prospects of the WSR-88D Radar for Cloud Studies  

E-Print Network [OSTI]

Sounding of nonprecipitating clouds with the 10-cm wavelength Weather Surveillance Radar-1988 Doppler (WSR-88D) is discussed. Readily available enhancements to signal processing and volume coverage patterns of the WSR-88D allow observations of a...

Melnikov, Valery M.; Zrni?, Dusan S.; Doviak, Richard J.; Chilson, Phillip B.; Mechem, David B.; Kogan, Yefim L.

2011-04-01T23:59:59.000Z

262

Mass loss from red giants in the Magellanic Clouds  

E-Print Network [OSTI]

The Magellanic Clouds provide the ideal laboratory for the study of mass loss and molecule and dust formation in red giants as a function of luminosity and metal abundance. I present some recent observational work.

Jacco Th. van Loon

2005-03-02T23:59:59.000Z

263

Finite Cloud Effects at the ACRF TWP Site Patrick Taylor and...  

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

Finite Cloud Effects at the ACRF TWP Site Patrick Taylor and Robert G. Ellingson Dept. of Meteorology, Florida State University, Tallahassee, FL 32306 Data: Observations are...

264

DOE/SC-ARM-12-020 MAGIC: Marine ARM GPCI Investigation of Clouds  

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

essential to have complementary observations from the surface, both in situ as well as remote sensed, such as surface fluxes (radiation, latent and sensible heat); cloud...

265

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

SciTech Connect (OSTI)

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.; Delano, J.; Deng, M.; Hogan, R. J.; Huang, D.; Jensen, M. P.; Mace, G. G.; McCoy, R.; OConnor, E. J.; Turner, D. D.; Wang, Z.

2012-05-30T23:59:59.000Z

266

Ice Heating Up Cold Clouds | EMSL  

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

Ice Heating Up Cold Clouds Ice Heating Up Cold Clouds In a heated battle, ice crystals win the competition for cloud water vapor The mighty cloud ice crystal appears deceptively...

267

Cloud Based Applications and Platforms (Presentation)  

SciTech Connect (OSTI)

Presentation to the Cloud Computing East 2014 Conference, where we are highlighting our cloud computing strategy, describing the platforms on the cloud (including Smartgrid.gov), and defining our process for implementing cloud based applications.

Brodt-Giles, D.

2014-05-15T23:59:59.000Z

268

Cloud Condensation Nuclei Retrievals at Cloud Base in North Dakota  

E-Print Network [OSTI]

Cloud Condensation Nuclei Retrievals at Cloud Base in North Dakota · Mariusz Starzec #12;Motivation Compare University of Wyoming (UWyo) and Droplet Measurement Technologies (DMT) cloud condensation nuclei condensation nuclei concentration (CCNC) at any supersaturation (SS) #12;Background Aerosols act as nuclei

Delene, David J.

269

HNCO in molecular clouds  

SciTech Connect (OSTI)

In a survey of 18 molecular clouds, HNCO J/sub K/-1K1..-->..J'/sub K/'-1K'1 = 5/sub 05/..-->..4/sub 05/ and 4/sub 04/..-->..3/sub 03/ emission was etected in seven clouds, and possibly in one other. Emission in these transitions originates in high-density regions (n> or approx. =10/sup 6/ cm/sup -3/). The molecule's excitation requirements allow us to derive limits to excitation temperatures an optical depths. We discuss the possibility of clumping with respect to the beam and compare our results with data from other molecular species. The HNCO emission from Sgr A is an ordder of magnitude larger than the other detected sources as is the ratio ..delta..T +- /sub A/(HNCO 5/sub 05/..-->..4/sub 04/)/..delta..T +- /sub A/(C/sup 18/O 1..-->..0). HNCO is probably a constituent of most molecular clouds.

Jackson, J.M.; Armstrong, J.T.; Barrett, A.H.

1984-05-15T23:59:59.000Z

270

Cometary Origin of the Zodiacal Cloud and Carbonaceous Micrometeorites  

E-Print Network [OSTI]

The zodiacal cloud is a thick circumsolar disk of small debris particles produced by asteroid collisions and comets. The relative proportion in which these two source populations contribute to the zodiacal cloud and the exact physical mechanism that generates the bulk of observed dust were unknown. Here we model the IRAS observations of thermal emission from asteroid and cometary particles to explain the origin of the zodiacal cloud. We find that >90% of the observed mid-infrared emission is produced by particles from the Jupiter-family comets (JFCs). We suggest that spontaneous disruptions of JFCs, rather than the usual cometary activity driven by sublimating volatiles, is the main mechanism that liberates cometary particles into the zodiacal cloud. Our results imply that JFC particles dominate the accretion rate of micrometeorites by Earth. Since their atmospheric entry speeds are typically low, many large JFC grains should survive frictional heating and land on the Earth's surface. This explains why most a...

Nesvorny, David; Levison, Harold F; Bottke, William F; Vokrouhlicky, David

2009-01-01T23:59:59.000Z

271

Constrained water cloud generator  

Science Journals Connector (OSTI)

The fast generation of large cloudy volumes with imposed cloud cover fractions and ambient vertical profiles is very important for the realistic simulation of atmospheric scenes. The model proposed here is the second step of a two-step model composed on the one hand of a volume generator based on a Fourier filtering method and on the other hand of a physical generator filling the volume with physical parameters. After a description of the general generation scheme, this paper focuses on the simulation of vertical profiles of water content (liquid, vapour) coupled with other state parameters (temperature, pressure, vertical velocity) via thermodynamic and hydrodynamic equations by local forcing of ambient conditions. The method for solving these equations is explained and applied to practical cases. First, by assuming that the actual temperature at the cloud base is equal to the dew temperature and by imposing a moist pseudo-adiabatic temperature gradient between the cloud top and bottom, the temperature profile in the cloud is found. When conditional instability occurs, the initial temperature profile between the ground and the cloud base is iteratively shifted to lower values until absolute stability is reached. Then the liquid water content is calculated by integrating the equation of water conservation, and the water vapour content by assuming that the cloud is everywhere saturated. Eventually, the vertical velocity is estimated by integration of the momentum equation. This method gives results in good agreement with published measurements, analytical and numerical models. Eventually, further developments of the column model, including the effects of phase transitions, turbulence, horizontal motions and mixing with the surrounding medium, are proposed in the concluding section.

Roland P.H. Berton

2008-01-01T23:59:59.000Z

272

Opaque cloud detection  

DOE Patents [OSTI]

A method of detecting clouds in a digital image comprising, for an area of the digital image, determining a reflectance value in at least three discrete electromagnetic spectrum bands, computing a first ratio of one reflectance value minus another reflectance value and the same two values added together, computing a second ratio of one reflectance value and another reflectance value, choosing one of the reflectance values, and concluding that an opaque cloud exists in the area if the results of each of the two computing steps and the choosing step fall within three corresponding predetermined ranges.

Roskovensky, John K. (Albuquerque, NM)

2009-01-20T23:59:59.000Z

273

5, 60136039, 2005 FRESCO cloud  

E-Print Network [OSTI]

ACPD 5, 6013­6039, 2005 FRESCO cloud algorithm N. Fournier et al. Title Page Abstract Introduction cloud information over deserts from SCIAMACHY O2 A-band N. Fournier 1 , P. Stammes 1 , M. de Graaf 1 , R, 6013­6039, 2005 FRESCO cloud algorithm N. Fournier et al. Title Page Abstract Introduction Conclusions

Paris-Sud XI, Université de

274

8, 96979729, 2008 FRESCO+ cloud  

E-Print Network [OSTI]

ACPD 8, 9697­9729, 2008 FRESCO+ cloud retrieval algorithm P. Wang et al. Title Page Abstract Chemistry and Physics Discussions FRESCO+: an improved O2 A-band cloud retrieval algorithm for tropospheric on behalf of the European Geosciences Union. 9697 #12;ACPD 8, 9697­9729, 2008 FRESCO+ cloud retrieval

Paris-Sud XI, Université de

275

Cloud Formation, Evolution and Destruction  

E-Print Network [OSTI]

Chapter 4 Cloud Formation, Evolution and Destruction We now begin to trace the journey towards a star. How long does this take? The answer is surprisingly short: a good many clouds already contain new stars and these stars tend to be young. The typical cloud cannot spend long, if any time at all

Estalella, Robert

276

Who is this cloud?  

Science Journals Connector (OSTI)

WHO IS THIS CLOUD? is a generative artwork in progress. It is a piece of art dedicated to the memory of a loved one and the idea of existence and transformation. The computer "Beings" will be animated according to their inner program, to weather sensors ... Keywords: Turing pattern, artificial life art, cellular automata, generative art, transhumanism

Lola B. Deswarte; Alain Lioret; Barbara Tannery

2012-03-01T23:59:59.000Z

277

Exploring parameterization for turbulent entrainmentmixing processes in clouds  

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

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

278

Molecular Cloud Evolution. III. Accretion Versus Stellar Feedback  

Science Journals Connector (OSTI)

We numerically investigate the effect of feedback from the ionization heating from massive stars on the evolution of giant molecular clouds (GMCs) and their star formation efficiency (SFE), which we treat as an instantaneous, time-dependent quantity. We follow the GMCs' evolution from their formation to advanced star-forming stages. After an initial period of contraction, the collapsing clouds begin forming stars, whose feedback evaporates part of the clouds' mass, opposing the continuing accretion from the infalling gas. Our results are as follows: (1) in the presence of feedback, the clouds attain levels of the SFE that are consistent at all times with observational determinations for regions of comparable star formation rates. (2) However, the dense gas mass is larger in general in the presence of feedback, while the total mass (dense gas + stars) is nearly insensitive to the presence of feedback, suggesting that it is determined mainly by the accretion, while the feedback inhibits mainly the conversion of dense gas to stars, because it acts directly to reheat and disperse the gas that is directly on its way to forming stars. (3) The factor by which the SFE is reduced upon the inclusion of feedback is a decreasing function of the cloud's mass, for clouds of size ~10pc. This naturally explains the larger observed SFEs of massive-star-forming regions. (4) The clouds may attain a pseudo-virialized state, with a value of the virial mass very similar to the actual cloud mass. However, this state differs from true virialization in that the clouds, rather than being equilibrium entities, are the centers of a larger-scale collapse, in which accretion replenishes the mass consumed by star formation. (5) The higher-density regions within the clouds are in a similar situation, accreting gas infalling from the less-dense, more extended regions of the clouds. (6) The density probability density functions of the regions containing the clouds in general exhibit a shape characteristic of thermally bistable flows, and extend down to densities corresponding to the warm atomic medium, because the warm gas interpenetrates the clouds. The general picture arising from our simulations is that the gas involved in the gravitational contraction leading to star formation extends to large scales and is not confined to the local environment of the final collapse, where the effect of the feedback is active, in agreement with recent proposals of a gravitationally driven mass cascade from large to small scales.

Enrique Vzquez-Semadeni; Pedro Coln; Gilberto C. Gmez; Javier Ballesteros-Paredes; Alan W. Watson

2010-01-01T23:59:59.000Z

279

MAGIC: Marine ARM GPCI Investigation of Clouds  

SciTech Connect (OSTI)

The second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF2) will be deployed aboard the Horizon Lines cargo container ship merchant vessel (M/V) Spirit for MAGIC, the Marine ARM GPCI1 Investigation of Clouds. The Spirit will traverse the route between Los Angeles, California, and Honolulu, Hawaii, from October 2012 through September 2013 (except for a few months in the middle of this time period when the ship will be in dry dock). During this field campaign, AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be two intensive observational periods (IOPs), one in January 2013 and one in July 2013, during which more detailed measurements of the atmospheric structure will be made.

Lewis, ER; Wiscombe, WJ; Albrecht, BA; Bland, GL; Flagg, CN; Klein, SA; Kollias, P; Mace, G; Reynolds, RM; Schwartz, SE; Siebesma, AP; Teixeira, J; Wood, R; Zhang, M

2012-10-03T23:59:59.000Z

280

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network [OSTI]

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Lockman, Felix J; Heroux, A J; Langston, Glen I

2008-01-01T23:59:59.000Z

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


281

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network [OSTI]

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Felix J. Lockman; Robert A. Benjamin; A. J. Heroux; Glen I. Langston

2008-04-25T23:59:59.000Z

282

ARM - Field Campaign - Ground-based Cloud Tomography Experiment at SGP  

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

govCampaignsGround-based Cloud Tomography Experiment at SGP govCampaignsGround-based Cloud Tomography Experiment at SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Ground-based Cloud Tomography Experiment at SGP 2009.05.26 - 2009.07.17 Lead Scientist : Dong Huang For data sets, see below. Description Knowledge of 3D cloud properties is pressingly needed in many research fields. One of the problems encountered when trying to represent 3D cloud fields in numerical models is that the existing techniques cannot provide necessary observations at the required spatial scale and resolution. We tested a new promising technique for measuring 3D cloud microphysical structure, called cloud microwave tomography, at the Southern Great Plains (SGP) site for one month in late April 2009. Five microwave scanning

283

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

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

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

284

ARM - PI Product - Cloud Properties and Radiative Heating Rates for TWP  

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

ProductsCloud Properties and Radiative Heating Rates for ProductsCloud Properties and Radiative Heating Rates for TWP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud Properties and Radiative Heating Rates for TWP 2002.01.01 - 2012.02.08 Site(s) TWP General Description A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote

285

Using ARM data to correct plane-parallel satellite retrievals of cloud  

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

Using ARM data to correct plane-parallel satellite retrievals of cloud Using ARM data to correct plane-parallel satellite retrievals of cloud properties Dong, Xiquan University of North Dakota Minnis, Patrick NASA Langley Research Center Xi, Baike University of North Dakota Khaiyer, Mandana Analytical Services and Material, Inc. Category: Cloud Properties The angular variations of cloud properties derived from GOES data are examined using simultaneously collocated ARM surface observations/retrievals at the DOE ARM SGP site during the 6-yr period from January 1997 to December 2002. The dependencies of GOES cloud retrievals on solar zenith angle (SZA), scattering angle (SCA), and relative azimuth angle (RZA) are investigated for single-layer and overcast low-level stratus clouds. The GOES-retrieved cloud-droplet effective radius (re),

286

A Catalog of HI Clouds in the Large Magellanic Cloud  

E-Print Network [OSTI]

A 21 cm neutral hydrogen interferometric survey of the Large Magellanic Cloud (LMC) combined with the Parkes multi-beam HI single-dish survey clearly shows that the HI gas is distributed in the form of clumps or clouds. The HI clouds and clumps have been identified using a thresholding method with three separate brightness temperature thresholds ($T_b$). Each catalog of HI cloud candidates shows a power law relationship between the sizes and the velocity dispersions of the clouds roughly following the Larson Law scaling $\\sigma_v \\propto R^{0.5}$, with steeper indices associated with dynamically hot regions. The clouds in each catalog have roughly constant virial parameters as a function mass suggesting that that the clouds are all in roughly the same dynamical state, but the values of the virial parameter are significantly larger than unity showing that turbulent motions dominate gravity in these clouds. The mass distribution of the clouds is a power law with differential indices between -1.6 and -2.0 for the three catalogs. In contrast, the distribution of mean surface densities is a log-normal distribution.

S. Kim; E. Rosolowsky; Y. Lee; Y. Kim; Y. C. Jung; M. A. Dopita; B. G. Elmegreen; K. C. Freeman; R. J. Sault; M. J. Kesteven; D. McConnell; Y. -H. Chu

2007-06-28T23:59:59.000Z

287

Size of Cloud from Shadow  

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

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

288

ARM - Measurement - Total cloud water  

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

289

ARM - Measurement - Cloud droplet size  

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

droplet size droplet size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud droplet size Linear size (e.g. radius or diameter) of a cloud particle Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments CPI : Cloud Particle Imager CVI-AIR : Counterflow Virtual Impactor MIRAI : JAMSTEC Research Vessel Mirai PDI : Phase Doppler Interferometer UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments SPEC-CPI : Stratton Park Engineering Company - Cloud particle imager

290

Millimeter and Near-Infrared Observations of Neptune's Atmospheric Dynamics  

E-Print Network [OSTI]

B Near-Infrared Radiative Transfer Model B.15 Near-Infrared Observations of Neptunes Clouds with the133 6.2 Near-infrared spectroscopy . . . . . .

Cook, Statia Honora Luszcz

2012-01-01T23:59:59.000Z

291

Climate zones for maritime clouds  

SciTech Connect (OSTI)

In this paper we use a commercially available lidar ceilometer to investigate how the basic structure of marine boundary-layer clouds varies for four different marine climate regimes. We obtained most of the data used in this analysis from ship-based ceilometer measurements recorded during several different atmospheric and oceanographic field programs conducted in the Atlantic and Pacific oceans. For comparison, we show the results obtained at a mid-latitude continental location and at an ice camp on the Arctic ice shelf. For each analyzed case, we use an extended time series to generate meaningful cloud base and cloud fraction statistics. The Vaisala CT 12K ceilometer uses a GaAs diode laser to produce short (150 ns), high-intensity pulses of infrared radiation (904 nm wavelength). The return signals from a large number of consecutive pulses are coherently summed to boost the signal-to-noise ratio. Each resulting 30-s profile of backscattered power (15-m resolution) is analyzed to detect cloud layers using a specified cloud detection limit. In addition to measurements of cloud base, the ceilometer can also provide information on cloud fraction using a time series of the {open_quotes}cloud{close_quotes} or {open_quotes} no cloud{close_quotes} status reported in the 30-s data.

White, A.B.; Ruffieux, D. [Univ. of Colorado, Boulder, CO (United States); [National Oceanic and Atmospheric Administration, Boulder, CO (United States); Fairall, C.W. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)

1995-04-01T23:59:59.000Z

292

TC_CLOUD_REGIME.cdr  

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

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

293

Declarative Automated Cloud Resource Orchestration  

E-Print Network [OSTI]

orchestration · Cloud resource orchestration constraint optimization problems 4 Provider operational] · Orchestration procedures Transactions · Either commit or abort Distributed communication and optimization

Plotkin, Joshua B.

294

The Near-infrared Period-luminosity Relations of Cepheids in the Large Magellanic Cloud  

E-Print Network [OSTI]

We present near-infrared (J & Ks) observations of Cepheids in the Large Magellanic Cloud. The goals of these observations are to better characterize the Cepheid Period-Luminosity relation at these wavelengths, especially for periods below 10 days...

Mahzooni, Salma

2011-08-08T23:59:59.000Z

295

Posters Parameterization of Thin Mid-Level Stratiform Clouds  

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

1 1 Posters Parameterization of Thin Mid-Level Stratiform Clouds S. K. Krueger Department of Meteorology University of Utah Salt Lake City, Utah Thin mid-level stratiform ("altocumulus") clouds have received little attention from either modelers or observational programs, yet these clouds cover large portions of the earth and significantly affect the radiation fields. Since altocumulus are vertically sub-grid scale in general circulation models (GCMs), they have either been neglected or represented implicitly through a "fractional cloudiness" scheme. Such schemes are not suitable for climate modeling because they lack theoretical foundations that indicate their limits of applicability. The Atmospheric Radiation Measurement (ARM) Cloud and Radiation Testbed (CART) program offers an

296

ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds and Climate:  

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

govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: Snowfall govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: Snowfall Experiment Related Campaigns Biogenic Aerosols- Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: Snowfall Experiment 2014.02.01 - 2014.04.30 Lead Scientist : Dmitri Moisseev Description The snowfall measurement campaign, which will take place during AMF2 deployment in Finland, will focus on understanding snowfall microphysics and characterizing performance of surface based snowfall measurement instruments. This will be achieved by combining triple frequency (X, Ka, W -band) radar observations of vertical structure of the precipitation,

297

ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds and Climate:  

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

govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 Related Campaigns Biogenic Aerosols- Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 2014.04.01 - 2014.06.01 Lead Scientist : Joel Thornton Description The ultimate goal of this work is to connect field and laboratory observations of organic aerosol chemical and physical properties during the nascent growth stage to the diurnal and vertical distributions of aerosol abundance measured over the boreal forest by the ARM Mobile Facility 2

298

ARM - Evaluation Product - CMWG Data - SCM-Forcing Data, Cloud  

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

ProductsCMWG Data - SCM-Forcing Data, Cloud ProductsCMWG Data - SCM-Forcing Data, Cloud Microphysical Properties and Radiative Heating Profiles Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : CMWG Data - SCM-Forcing Data, Cloud Microphysical Properties and Radiative Heating Profiles Site(s) GAN HFE NSA SGP TWP General Description SCM-forcing data are derived from the ARM Program observational data using the constrained variational analysis approach (Zhang and Lin 1997 and Zhang et al. 2001). The resulting products include both the large-scale forcing terms and the evaluation fields, which can be used for driving the Single-Column Models (SCMs) and Cloud Resolving Models (CRMs) and validating model simulations. Results from our studies are then used to

299

Cicada: Predictive Guarantees for Cloud Network Bandwidth  

E-Print Network [OSTI]

In cloud-computing systems, network-bandwidth guarantees have been shown to improve predictability of application performance and cost. Most previous work on cloud-bandwidth guarantees has assumed that cloud tenants know ...

LaCurts, Katrina

2014-03-24T23:59:59.000Z

300

DIRSIG Cloud Modeling Capabilities; A Parametric Study  

E-Print Network [OSTI]

1 DIRSIG Cloud Modeling Capabilities; A Parametric Study Kristen Powers powers:................................................................................................................... 13 Calculation of Sensor Reaching Radiance Truth Values for Cloudless & Stratus Cloud Scenes and Atmospheric Database Creation for Stratus Cloud Scene & Calculation of Associated Sensor Reaching Radiance

Salvaggio, Carl

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


301

Magellan: experiences from a Science Cloud  

E-Print Network [OSTI]

2010. From Clusters To Clouds: xCAT 2 Is Out Of The Bag.Cost of Doing Science on the Cloud: The Montage Example. Incost of doing science on the cloud: the montage example. In

Ramakrishnan, Lavanya

2013-01-01T23:59:59.000Z

302

Electron-Cloud Build-Up: Summary  

E-Print Network [OSTI]

Properties In?uencing Electron Cloud Phenomena, Appl. Surf.Dissipation of the Electron Cloud, Proc. PAC03 (Portland,is no signi?cant electron-cloud under nominal operating

Furman, M.A.

2007-01-01T23:59:59.000Z

303

Ship-Track Clouds, Aerosol, and Ship Dynamic Effects; A Climate Perspective from Ship-Based Measurements  

SciTech Connect (OSTI)

Ship-track clouds are marine boundary layer clouds that form behind ocean ships and are observed from satellites in the visible and near infrared. Ship-track clouds provide a rare opportunity to connect aerosol cloud condensation nuclei (CCN) emissions and observable changes in marine stratiform clouds. A very small change in the reflectivity of these eastern Pacific and Atlantic clouds (about 4%) provides a climate feedback of similar magnitude to doubling CO{sub 2} (increasing cloud reflectivity corresponds to global cooling). The Department of Energy sponsored research from 1991 to 1995 to study ship-track clouds including two ocean-based experiments in the summers of 1991 and 1994. These experiments showed that ship-track cloud properties were often more complex those related to a reduction of droplet size with an increase in number associated with increasing CCN from the ship's plume. The clouds showed evidence of morphological changes more likely to be associated with cloud dynamic effects either initiated by the increased CCN or directly by the ship's heat output or turbulent air wake. The fact that marine stratiform clouds, that are susceptible to ship track formation, are starved for both CCN and convective turbulence complicates the separation of the two effects.

Porch, W.M.

1998-10-13T23:59:59.000Z

304

OVERVIEW OF SATURN LIGHTNING OBSERVATIONS  

E-Print Network [OSTI]

OVERVIEW OF SATURN LIGHTNING OBSERVATIONS G. Fischer* , U. A. Dyudina , W. S. Kurth , D. A. Gurnett The lightning activity in Saturn's atmosphere has been monitored by Cassini for more than six years favorably with imaging observa- tions of related cloud features as well as direct observations of flash

Gurnett, Donald A.

305

The magnetic cloud of January 10, 1997  

Science Journals Connector (OSTI)

The magnetic cloud of January 1011, 1997, was observed by SOHO and WIND spacecraft ahead of the Earth's magnetosphere. Plasma parameters registered by their instrumentation show remarkable differences in the solar wind speed, proton density and tempersture that is difficult to explain taking into account simply their distance. The interplanetary magnetic field (measured on board WIND only), would be fitted nearly equivalently by both cylindrical and spherical models. In order to explain observed divergences we speculate on possible model of a poloidal spheromak that develops into a toroid during its propagation.

A. Geranios; S. Fischer; M. Vandas; G. Zastenker

1999-01-01T23:59:59.000Z

306

Section 70  

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

Figure 1. Cutaway view of the new version of HYVIS. Figure 1. Cutaway view of the new version of HYVIS. Microphysical Properties of Mid-latitude Cirrus Clouds Observed with Hydrometeor Videosonde N. Orikasa, M. Murakami, H. Mizuno, Y. Yamada and M. Miyao Meteorological Research Institute Tsukuba 305, Japan Introduction High-level ice clouds play a complex role in the global energy budget by affecting infrared radiation emitted by the earth's surface. In order to understand the climate system, it is necessary to increase our knowledge about the microphysical, radiative, and optical properties of cirrus clouds. In situ measurements on microphysical structures of cirrus clouds have been made by using special, high-altitude flying aircraft. Limited studies have been made to date. Two-dimensional optical array probes, which are often used for aircraft

307

A TRUSTED STORAGE SYSTEM FOR THE CLOUD.  

E-Print Network [OSTI]

??Data stored in third party storage systems like the cloud might not be secure since confidentiality and integrity of data are not guaranteed. Though cloud (more)

Karumanchi, Sushama

2010-01-01T23:59:59.000Z

308

Fraunhofer ISST CLOUD COMPUTING APPLICATIONS  

E-Print Network [OSTI]

#12;© Fraunhofer ISST Fraunhofer Innovation Cluster »Cloud Computing for Logistics« Budget 3 * 3 Mio© Fraunhofer ISST CLOUD COMPUTING APPLICATIONS FOR LOGISTICS Jakob Rehof Professor, Chair of Software Engineering, Technical University of Dortmund Director, Fraunhofer-ISST Dortmund and Berlin First

Rajamani, Sriram K.

309

Convective Cells in Altocumulus Observed with a High-Resolution Radar  

Science Journals Connector (OSTI)

Very-high-resolution Doppler radar observations are used together with aircraft measurements to document the dynamic and thermodynamic structure of a dissipating altocumulus cloud system associated with a deep virga layer. The cloud layer ...

Jerome M. Schmidt; Piotr J. Flatau; Robert D. Yates

2014-06-01T23:59:59.000Z

310

ARM - Measurement - Cloud ice particle  

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

ice particle ice particle ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud ice particle Particles made of ice found in clouds. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments MET : Surface Meteorological Instrumentation Field Campaign Instruments REPLICATOR : Balloon-borne Ice Crystal Replicator CPI : Cloud Particle Imager CVI-AIR : Counterflow Virtual Impactor LEARJET : Lear Jet PARTIMG : Particle imager UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments

311

TWP Island Cloud Trail Studies  

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

Pacific Island Cloud Trail Studies Pacific Island Cloud Trail Studies W. M. Porch Los Alamos National Laboratory Los Alamos, New Mexico S. Winiecki University of Chicago Chicago, Illinois Introduction Images and surface temperature measurements from the U.S. Department of Energy (DOE) Multi- spectral Thermal Imaging (MTI) satellite are combined with geostationary meteorological satellite (GMS) images during 2000 and 2001 to better understand cloud trail formation characteristics from the Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) site. Figure 1 shows a comparison on two consecutive days in December 2000. The day for which a cloud trail developed was more moist and cooler at the altitude the cloud developed (about 600 m) and there was very little

312

ARM - Measurement - Cloud base height  

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

base height base height ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud base height For a given cloud or cloud layer, the lowest level of the atmosphere where cloud properties are detectable. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments BLC : Belfort Laser Ceilometer MPL : Micropulse Lidar MWRP : Microwave Radiometer Profiler RL : Raman Lidar VCEIL : Vaisala Ceilometer External Instruments NOAASURF : NOAA Surface Meteorology Data, collected by NWS and NCDC

313

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

SciTech Connect (OSTI)

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

314

Zenith Radiance Retrieval of Cloud Properties  

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

retrievals of cloud properties retrievals of cloud properties from the AMF/COPS campaign Preliminary retrievals of cloud properties from the AMF/COPS campaign Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC The cloud optical properties of interest are: The cloud optical properties of interest are: * Cloud optical depth τ - the great unknown * Radiative cloud fraction * Cloud effective drop size, r eff * Cloud optical depth τ - the great unknown * Radiative cloud fraction * Cloud effective drop size, r eff τ = 3 2 LWP r eff r eff in μm, LWP in g/m 2 The 2-ch narrow-field-of-view radiometer (2NFOV) The 2-ch narrow-field-of-view radiometer

315

MAGNETIZED GAS IN THE SMITH HIGH VELOCITY CLOUD  

SciTech Connect (OSTI)

We report the first detection of magnetic fields associated with the Smith High Velocity Cloud. We use a catalog of Faraday rotation measures toward extragalactic radio sources behind the Smith Cloud, new H I observations from the Robert C. Byrd Green Bank Telescope, and a spectroscopic map of H? from the Wisconsin H-Alpha Mapper Northern Sky Survey. There are enhancements in rotation measure (RM) of ?100 rad m{sup 2} which are generally well correlated with decelerated H? emission. We estimate a lower limit on the line-of-sight component of the field of ?8 ?G along a decelerated filament; this is a lower limit due to our assumptions about the geometry. No RM excess is evident in sightlines dominated by H I or H? at the velocity of the Smith Cloud. The smooth H? morphology of the emission at the Smith Cloud velocity suggests photoionization by the Galactic ionizing radiation field as the dominant ionization mechanism, while the filamentary morphology and high (?1 Rayleigh) H? intensity of the lower-velocity magnetized ionized gas suggests an ionization process associated with shocks due to interaction with the Galactic interstellar medium. The presence of the magnetic field may contribute to the survival of high velocity clouds like the Smith Cloud as they move from the Galactic halo to the disk. We expect these data to provide a test for magnetohydrodynamic simulations of infalling gas.

Hill, Alex S.; McClure-Griffiths, Naomi M. [CSIRO Astronomy and Space Science, Marsfield, NSW (Australia); Mao, S. A. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI (United States); Benjamin, Robert A. [Department of Physics, University of Wisconsin-Whitewater, Whitewater, WI (United States); Lockman, Felix J., E-mail: alex.hill@csiro.au, E-mail: naomi.mcclure-griffiths@csiro.au, E-mail: mao@astro.wisc.edu, E-mail: benjamir@uww.edu, E-mail: jlockman@nrao.edu [National Radio Astronomy Observatory, Green Bank, WV (United States)

2013-11-01T23:59:59.000Z

316

ARM - Evaluation Product - Active Remote Sensing of Clouds from Ka-band ARM  

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

ProductsActive Remote Sensing of Clouds from Ka-band ProductsActive Remote Sensing of Clouds from Ka-band ARM Zenith Radars Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Active Remote Sensing of Clouds from Ka-band ARM Zenith Radars Site(s) GAN SGP General Description The Ka-band ARM Zenith Radars (KAZRs) have replaced the long-serving Millimeter Cloud Radars, or MMCRs. Accordingly, the primary MMCR Value Added Product (VAP), the Active Remote Sensing of CLouds (ARSCL) product, is being replaced by a KAZR-based version, the KAZR-ARSCL VAP. KAZR-ARSCL provides cloud boundaries and best-estimate time-height fields of radar moments. KAZR observations are corrected for water vapor attenuation and velocity aliasing and significant detection masks are produced. KAZR-ARSCL

317

Historical Sunshine and Cloud Data in the United States (revised 1991)  

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

Historical Sunshine and Cloud Data in the United States (revised 1991) Historical Sunshine and Cloud Data in the United States (revised 1991) (NDP-021) DOI: 10.3334/CDIAC/cli.ndp021 data Data Investigators P. M. Steurer and T. R. Karl This data base presents monthly sunshine data from 240 U.S. stations (including Puerto Rico and nine Pacific Islands) and monthly cloud amount data from 197 U.S. stations. The longest periods of record are 1891 through 1987 for the sunshine data and 1871 through 1987 for the cloud data. The sunshine data were derived from measurements taken by a variety of sunshine-recording instruments. The cloud data were derived from land-based estimates of fractional cloud amount, which were made with observation practices that have varied during the period of record. Station number, station name, latitude, and longitude are given for all stations in each

318

Minimalist Model of Ice Microphysics in Mixed-phase Stratiform Clouds  

SciTech Connect (OSTI)

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

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

2013-07-28T23:59:59.000Z

319

EVALUATION OF NUMERICAL WEATHER PREDICTION IN MODELING CLOUD-RADIATION INTERACTIONS OVER THE SOUTHERN GREAT PLAINS  

E-Print Network [OSTI]

EVALUATION OF NUMERICAL WEATHER PREDICTION IN MODELING CLOUD- RADIATION INTERACTIONS OVER.bnl.gov ABSTRACT Numerical weather prediction (NWP) is the basis for present-day weather forecasts, and NWP- and satellite- based observations over the Southern Great Plains to evaluate how well cloud

Johnson, Peter D.

320

METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics  

E-Print Network [OSTI]

METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics CLASS: Monday of the physical states and processes of clouds and precipitation as well as atmospheric electricity and optics and results Radar observation and estimation Atmospheric electricity: Electrostatics Electromagnetic wave

Droegemeier, Kelvin K.

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


321

Radio Planetary Nebulae in the Magellanic Clouds  

E-Print Network [OSTI]

We report the extragalactic radio-continuum detection of 15 planetary nebulae (PNe) in the Magellanic Clouds (MCs) from recent Australia Telescope Compact Array+Parkes mosaic surveys. These detections were supplemented by new and high resolution radio, optical and IR observations which helped to resolve the true nature of the objects. Four of the PNe are located in the Small Magellanic Cloud (SMC) and 11 are located in the Large Magellanic Cloud (LMC). Based on Galactic PNe the expected radio flux densities at the distance of the LMC/SMC are up to ~2.5 mJy and ~2.0 mJy at 1.4 GHz, respectively. We find that one of our new radio PNe in the SMC has a flux density of 5.1 mJy at 1.4 GHz, several times higher than expected. We suggest that the most luminous radio PN in the SMC (N S68) may represent the upper limit to radio peak luminosity because it is ~3 times more luminous than NGC 7027, the most luminous known Galactic PN. We note that the optical diameters of these 15 MCs PNe vary from very small (~0.08 pc or ...

Filipovi?, M D; Reid, W A; Payne, J L; Parker, Q A; Crawford, E J; Boji?i?, I S; De Horta, A Y; Hughes, A; Dickel, J; Stootman, F

2009-01-01T23:59:59.000Z

322

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

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

323

THE MAGELLANIC INTER-CLOUD PROJECT (MAGIC). I. EVIDENCE FOR INTERMEDIATE-AGE STELLAR POPULATIONS IN BETWEEN THE MAGELLANIC CLOUDS  

SciTech Connect (OSTI)

The origin of the gas in between the Magellanic Clouds (MCs)-known as the ''Magellanic Bridge'' (MB)-is puzzling. Numerical simulations suggest that the MB formed from tidally stripped gas and stars in a recent interaction between the MCs. However, the apparent lack of stripped intermediate- or old-age stars associated with the MB is at odds with this picture. In this paper, we present the first results from the MAGellanic Inter-Cloud program (MAGIC) aimed at probing the stellar populations in the inter-Cloud region. We present observations of the stellar populations in two large fields located in between the Large and Small Magellanic Clouds (LMC/SMC), secured using the WFI camera on the 2.2 m telescope in La Silla. Using a synthetic color-magnitude diagram technique, we present the first quantitative evidence for the presence of intermediate-age and old stars in the inter-Cloud region. The intermediate-age stars-which make up {approx}28% of all stars in the region-are not present in fields at a similar distance from the SMC in a direction pointing away from the LMC. This provides potential evidence that these intermediate-age stars could have been tidally stripped from the SMC. However, spectroscopic studies will be needed to confirm or rule out the tidal origin for the inter-Cloud gas and stars.

Noeel, N. E. D.; Read, J. I. [ETH Zuerich, Institute for Astronomy, Wolfgang-Pauli-Strasse 27, CH-8093 Zuerich (Switzerland); Conn, B. C.; Rix, H.-W. [Max Planck Institut fuer Astronomie, Koenigstuhl 17, D-69117, Heidelberg (Germany); Carrera, R. [Instituto de Astrofisica de Canarias, C/Via Lactea s/n, E-38200, La Laguna, Tenerife (Spain); Dolphin, A., E-mail: noelia@phys.ethz.ch [Raytheon Company, P.O. Box 11337, Tucson, AZ 85734-1337 (United States)

2013-05-10T23:59:59.000Z

324

ARM - Publications: Science Team Meeting Documents: Observations of Natural  

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

Observations of Natural Variability in Marine Stratocumulus Clouds Observations of Natural Variability in Marine Stratocumulus Clouds Albrecht, Bruce University of Miami Kollias, Pavlos RSMAS/University of Miami Jo, Ieng Rosentiel School of Marine & Atmospheric Science Ghate, Virendra RSMAS/Univ. Miami Serpetzoglou, Efthymious Minnis, Patrick NASA Langley Research Center Sun-Mack, Szedung SAIC Large to mesoscale features affecting the albedo of marine stratocumulus clouds are observed frequently and can have a substantial impact on the overall albedo of the subtropical cloud decks. One such naturally occurring feature-defined as a cloud rift-is characterized as a large-scale, persistent area of broken, low reflectivity stratocumulus clouds usually surrounded by a solid deck of stratocumulus. We review results from a

325

ATLAS Cloud R&D  

E-Print Network [OSTI]

The computing model of the ATLAS experiment was designed around the concept of grid computing and, since the start of data taking, this model has proven very successful. However, new cloud computing technologies bring attractive features to improve the operations and elasticity of scientific distributed computing. ATLAS sees grid and cloud computing as complementary technologies that will coexist at different levels of resource abstraction, and two years ago created an R&D working group to investigate the different integration scenarios. The ATLAS Cloud Computing R&D has been able to demonstrate the feasibility of offloading work from grid to cloud sites and, as of today, is able to integrate transparently various cloud resources into the PanDA workload management system. The ATLAS Cloud Computing R&D is operating various PanDA queues on private and public resources and has provided several hundred thousand CPU days to the experiment. As a result, the ATLAS Cloud Computing R&D group has gained...

Panitkin, S; The ATLAS collaboration; Caballero Bejar, J; Benjamin, D; DiGirolamo, A; Gable, I; Hendrix, V; Hover, J; Kucharczuk, K; Medrano LLamas, R; Love, P; Ohman, H; Paterson, M; Sobie, R; Taylor, R; Walker, R; Zaytsev, A

2013-01-01T23:59:59.000Z

326

Empirical relationship between entrainment rate and microphysics in cumulus clouds  

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

327

Update of the Electron Cloud Simulations for DAFNE  

SciTech Connect (OSTI)

A strong horizontal instability, limiting the positron current at I {approx} 500mA, has been observed at DAFNE since the installation of the FINUDA detector in 2003. Experiments and simulations seem to provide evidence that the electron cloud build-up in the wigglers and bending magnets of the DAFNE positron ring induces coupled bunch instability with features compatible with observations. Recently the installation of a new horizontal feedback system allowed to control the instability for value of the positron current as high as possible (I {approx} 1000mA). To better understand the electron cloud effects and possibly to find a remedy, a detailed simulation study is undergoing. In this communication we present recent simulation results relative to the single bunch instability induced by an electron cloud interacting with the beam.

Demma, Theo; /Frascati; Pivi, Mauro T.F.; /SLAC

2012-04-12T23:59:59.000Z

328

IBM Software Solution Brief Safeguarding the cloud  

E-Print Network [OSTI]

IBM Software Solution Brief Safeguarding the cloud with IBM Security solutions Maintain visibility and control with proven security solutions for public, private and hybrid clouds Highlights Address cloud internal and external users, data, applications and workloads as they move to and from the cloud Regain

329

CLOUD COMPUTING INFRASTRUCTURE AND OPERATIONS PROGRAM  

E-Print Network [OSTI]

CLOUD COMPUTING INFRASTRUCTURE AND OPERATIONS PROGRAM A six-week in-depth program in the architectures, infrastructure, and operations of Cloud Computing DePaul University's Cloud Computing Infrastructure and Operations Program provides specialized knowledge in Cloud infrastructure with emphasis

Schaefer, Marcus

330

Locus Technologies 2014 Lost in the Cloud?  

E-Print Network [OSTI]

© Locus Technologies 2014 Lost in the Cloud? There's an App for That David McConaughy Locus Technologies 1997-2014 4 #12;Cloud-based EMIS 2014© Locus Technologies 1997-2014 5 #12; Cloud Synch data back to EIM cloud for analysis 2014© Locus Technologies 1997-2014 9 #12;Mobile Apps for Data

Illinois at Urbana-Champaign, University of

331

Cloud Computing An enterprise perspective Raghavan Subramanian  

E-Print Network [OSTI]

Cloud Computing ­ An enterprise perspective Raghavan Subramanian Infosys Technologies Limited #12;2Infosys Confidential Overview of cloud computing? Cloud computing* Computing in which dynamically scalable of cloud computing 1. On-demand self-service 2. Ubiquitous network access 3. Location independent resource

Rajamani, Sriram K.

332

Cloud Futures Workshop 2010 Cloud Computing Support for Massively Social Gaming Alexandru Iosup  

E-Print Network [OSTI]

1 Cloud Futures Workshop 2010 ­ Cloud Computing Support for Massively Social Gaming Alexandru Iosup Pierre (Vrije U.). Cloud Computing Support for Massively Social Gaming (Rain for the Thirsty) #12;Cloud Futures Workshop 2010 ­ Cloud Computing Support for Massively Social Gaming 2 Intermezzo: Tips on how

Iosup, Alexandru

333

Vision: Cloud-Powered Sight for All Showing the Cloud What You See  

E-Print Network [OSTI]

Vision: Cloud-Powered Sight for All Showing the Cloud What You See Paramvir Bahl Matthai Philipose argue that for computers to do more for us, we need to show the cloud what we see and embrace cloud General Terms Algorithms, Design, Human Factors, Languages, Performance, Security Keywords Camera, cloud

Zhong, Lin

334

Section 110  

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

3 3 The Optical Properties of Tropical Cirrus Clouds in the Maritime Continent Thunderstorm Experiment from Lidar and Infrared Radiometer Retrievals C.M.R. Platt, S. A. Young, R. T. Austin, G. R. Patterson and S. C. Marsden CSIRO, Division of Atmospheric Research Aspendale, Victoria, Australia Introduction Observations of the optical and structural properties of equa- torial cirrus clouds were made previously in the Atmospheric Radiation Measurement (ARM) Program's Pilot Radiation Observation Experiment (PROBE) in 1993 and were reported in Platt et al. (1996). The results are presented in final form in Platt et al. (1997). The Maritime Continent Thunderstorm Experiment (MCTEX) provided another opportunity to study tropical cirrus and anvil clouds. The component of the experiment that included the

335

Cloud Occurrence Frequency at the Barrow, Alaska, ARM Climate Research Facility for 2008 Third Quarter 2009 ARM and Climate Change Prediction Program Metric Report  

SciTech Connect (OSTI)

Clouds represent a critical component of the Earths atmospheric energy balance as a result of their interactions with solar and terrestrial radiation and a redistribution of heat through convective processes and latent heating. Despite their importance, clouds and the processes that control their development, evolution and lifecycle remain poorly understood. Consequently, the simulation of clouds and their associated feedbacks is a primary source of inter-model differences in equilibrium climate sensitivity. An important step in improving the representation of cloud process simulations is an improved high-resolution observational data set of the cloud systems including their time evolution. The first order quantity needed to understand the important role of clouds is the height of cloud occurrence and how it changes as a function of time. To this end, the Atmospheric Radiation Measurement (ARM) Climate Research Facilities (ACRF) suite of instrumentation has been developed to make the observations required to improve the representation of cloud systems in atmospheric models.

M Jensen; K Johnson; JH Mather

2009-07-14T23:59:59.000Z

336

Cloud Feedbacks on Climate: A Challenging Scientific Problem  

SciTech Connect (OSTI)

One reason it has been difficult to develop suitable social and economic policies to address global climate change is that projected global warming during the coming century has a large uncertainty range. The primary physical cause of this large uncertainty range is lack of understanding of the magnitude and even sign of cloud feedbacks on the climate system. If Earth's cloudiness responded to global warming by reflecting more solar radiation back to space or allowing more terrestrial radiation to be emitted to space, this would mitigate the warming produced by increased anthropogenic greenhouse gases. Contrastingly, a cloud response that reduced solar reflection or terrestrial emission would exacerbate anthropogenic greenhouse warming. It is likely that a mixture of responses will occur depending on cloud type and meteorological regime, and at present, we do not know what the net effect will be. This presentation will explain why cloud feedbacks have been a challenging scientific problem from the perspective of theory, modeling, and observations. Recent research results on observed multidecadal cloud-atmosphere-ocean variability over the Pacific Ocean will also be shown, along with suggestions for future research.

Norris, Joel (Scripps Institution of Oceanography, UC San Diego) [Scripps Institution of Oceanography, UC San Diego

2010-05-10T23:59:59.000Z

337

Eight billion asteroids in the Oort cloud  

E-Print Network [OSTI]

this and the observed population of small bodies is pretty good, although our non-migratory Neptune fails to capture Plutinos and other resonant objects, and the question of what eliminates the inner Solar system bodies remains open. found the total mass of Oort cloud... Lewis A. R., Quinn T., Kaib N. A., 2013, AJ, 146, 16 Malhotra R., 1993, Nature, 365, 819 Marsden B. G., Steel D. I., 1994, in Gehrels T., Matthews M. S., Schumann A. M., eds, Hazards Due to Comets and Asteroids. Kluwer, Dordrecht, p. 221 Martin R. G...

Shannon, Andrew; Jackson, Alan P.; Veras, Dimitri; Wyatt, Mark

2014-11-25T23:59:59.000Z

338

Millimeter Wave Cloud Radar (MMCR) Handbook  

SciTech Connect (OSTI)

The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

KB Widener; K Johnson

2005-01-30T23:59:59.000Z

339

Evaluating regional cloud-permitting simulations of the WRF model for the Tropical Warm Pool International Cloud Experiment (TWP-ICE, Darwin 2006)  

SciTech Connect (OSTI)

Data from the Tropical Warm Pool I5 nternational Cloud Experiment (TWPICE) were used to evaluate two suites of high-resolution (4-7 km, convection-resolving) simulations of the Advanced Research Weather Research and Forecasting (WRF) model with a focus on the performance of different cloud microphysics (MP) schemes. The major difference between these two suites of simulations is with and without the reinitializing process. Whenreinitialized every three days, the four cloud MP schemes evaluated can capture the general profiles of cloud fraction, temperature, water vapor, winds, and cloud liquid and ice water content (LWC and IWC, respectively). However, compared with surface measurements of radiative and moisture fluxes and satellite retrieval of top-of-the-atmosphere (TOA) fluxes, disagreements do exist. Large discrepancies with observed LWC and IWC and derived radiative heating profiles can be attributed to both the limitations of the cloud property retrievals and model performance. The simulated precipitation also shows a wide range of uncertainty as compared with observations, which could be caused by the cloud MP schemes, complexity of land-sea configuration, and the high temporal and spatial variability. In general, our result indicates the importance of large-scale initial and lateral boundary conditions in re-producing basic features of cloudiness and its vertical structures. Based on our case study, we find overall the six-hydrometer single-moment MP scheme(WSM6) [Hong and Lim, 2006] in the WRF model si25 mulates the best agree- ment with the TWPICE observational analysis.

Wang, Yi; Long, Charles N.; Leung, Lai-Yung R.; Dudhia, Jimy; McFarlane, Sally A.; Mather, James H.; Ghan, Steven J.; Liu, Xiaodong

2009-11-05T23:59:59.000Z

340

Properties of tropical convection observed by ARM millimeter-radars  

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

Properties of tropical convection observed by ARM millimeter-radars Properties of tropical convection observed by ARM millimeter-radars Haynes, John Colorado State University Stephens, Graeme Colorado State University Category: Cloud Properties The results of an analysis of tropical cloud systems observed from a variety of vertically pointing radar systems are described. In particular, observations taken during five years of operation of the ARM millimeter wavelength radar system (MMCR) at Manus Island in the Tropical West Pacific region are characterized into cloud classes according to the radar reflectivity structures of these cloud systems, associated rainfall, and surface radiative properties. These observations of cloud properties are composited with respect to various phases of the Madden Julian Oscillation, which is a dominant mode of variability at Manus Island. A method of better

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341

ARM - Field Campaign - Cloud IOP  

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

govCampaignsCloud IOP govCampaignsCloud IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Cloud IOP 1998.04.27 - 1998.05.17 Lead Scientist : Gerald Mace For data sets, see below. Summary Monday, April 27, 1998 IOP Opening Activities: Heavy rain (nearly 2.5" since 12Z 4/26/98) at the central facility (CF) dominated the first day of the Cloud Physics/Single Column Model IOP and limited the daily activities. A 1430 GMT sonde launch commenced the 3-hour sonde launch schedule at the CF and 4 boundary facilities (BFs). Scientists/Instrumentation on Site: Citation: Has arrived and is located at the Ponca City Airport. No flights are currently planned. Flights are tentatively planned for stratus sampling when precipitation ends.

342

Clouds, Aerosols and Precipitation in  

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

the Marine Boundary Layer (CAP-MBL) Graciosa Island, Azores, NE Atlantic Ocean Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010 May 2009-December 2010 Rob Wood, University of Washington Rob Wood, University of Washington AMF Deployment Team Thanks to Mark Miller: AMF Site Scientist Mark Miller: AMF Site Scientist Kim Nitschke: AMF Site Manager CAP-MBL Proposal Team Importance of Low-Clouds for Climate Imperative that we understand the processes controlling the formation, maintenance and dissipation of low clouds in order to formation, maintenance and dissipation of low clouds in order to improve their representation in climate models. Which clouds matter for climate sensitivity? Cli t F db k

343

Cloud Computing for Telecom Systems.  

E-Print Network [OSTI]

??Context: Cloud computing is reshaping the service-delivery and business-models in Information and Communications Technology (ICT). The Information Technology (IT) sector has benefited from it in (more)

Sapkota, Sagar

2011-01-01T23:59:59.000Z

344

Energy-Efficient Cloud Computing  

Science Journals Connector (OSTI)

......Centre & IT Equipment Energy Use. Proc. Digital Power...2007. pp. 1323. ACM, New York. [7] Energy Star, http://www...pp. 164177. ACM, New York. [32] Pratt, I...Vol. 53 No. 7, 2010 Energy-Efficient Cloud Computing......

Andreas Berl; Erol Gelenbe; Marco Di Girolamo; Giovanni Giuliani; Hermann De Meer; Minh Quan Dang; Kostas Pentikousis

2010-09-01T23:59:59.000Z

345

Jacob P. Fugal, Scott Spuler Earth Observing Laboratory NCAR, Boulder, CO USA  

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

airborne digital holographic airborne digital holographic instrument for measuring the spatial distribution and local size distributions of cloud particles: Holographic Detector for Clouds 2 (HOLODEC 2) Jacob P. Fugal, Scott Spuler Earth Observing Laboratory NCAR, Boulder, CO USA & Raymond A. Shaw Physics Department, michigan Tech Houghton, MI USA C-130 Hercules Q HIAPER Gulfstream GV HOLODEC (Holographic Detector for Clouds) is an airborne instrument that measures the size, shape, and relative 3D position of cloud particles using digital in- line holography. Science Questions for HOLODEC 2 * How do local cloud particle size distributions vary inside cloud regions (edge, top, core, base), by cloud age, cloud type? * How are cloud particles spatially distributed on sub-cm scales due to mixing, entrainment, and

346

Parameterizations of Cloud Microphysics and Indirect Aerosol Effects  

SciTech Connect (OSTI)

1. OVERVIEW Aerosols and especially their effect on clouds are one of the key components of the climate system and the hydrological cycle [Ramanathan et al., 2001]. Yet, the aerosol effect on clouds remains largely unknown and the processes involved not well understood. A recent report published by the National Academy of Science states "The greatest uncertainty about the aerosol climate forcing - indeed, the largest of all the uncertainties about global climate forcing - is probably the indirect effect of aerosols on clouds [NRC, 2001]." The aerosol effect on clouds is often categorized into the traditional "first indirect (i.e., Twomey)" effect on the cloud droplet sizes for a constant liquid water path [Twomey, 1977] and the "semi-direct" effect on cloud coverage [e.g., Ackerman et al., 2000]. Enhanced aerosol concentrations can also suppress warm rain processes by producing a narrow droplet spectrum that inhibits collision and coalescence processes [e.g., Squires and Twomey, 1961; Warner and Twomey, 1967; Warner, 1968; Rosenfeld, 1999]. The aerosol effect on precipitation processes, also known as the second type of aerosol indirect effect [Albrecht, 1989], is even more complex, especially for mixed-phase convective clouds. Table 1 summarizes the key observational studies identifying the microphysical properties, cloud characteristics, thermodynamics and dynamics associated with cloud systems from high-aerosol continental environments. For example, atmospheric aerosol concentrations can influence cloud droplet size distributions, warm-rain process, cold-rain process, cloud-top height, the depth of the mixed phase region, and occurrence of lightning. In addition, high aerosol concentrations in urban environments could affect precipitation variability by providing an enhanced source of cloud condensation nuclei (CCN). Hypotheses have been developed to explain the effect of urban regions on convection and precipitation [van den Heever and Cotton, 2007 and Shepherd, 2005]. Recently, a detailed spectral-bin microphysical scheme was implemented into the Goddard Cumulus Ensemble (GCE) model. Atmospheric aerosols are also described using number density size-distribution functions. A spectral-bin microphysical model is very expensive from a computational point of view and has only been implemented into the 2D version of the GCE at the present time. The model is tested by studying the evolution of deep tropical clouds in the west Pacific warm pool region and summertime convection over a mid-latitude continent with different concentrations of CCN: a low "clean" concentration and a high "dirty" concentration. The impact of atmospheric aerosol concentration on cloud and precipitation will be investigated. 2. MODEL DESCRIPTION AND CASE STUDIES 2.1 GCE MODEL The model used in this study is the 2D version of the GCE model. Modeled flow is anelastic. Second- or higher-order advection schemes can produce negative values in the solution. Thus, a Multi-dimensional Positive Definite Advection Transport Algorithm (MPDATA) has been implemented into the model. All scalar variables (potential temperature, water vapor, turbulent coefficient and all five hydrometeor classes) use forward time differencing and the MPDATA for advection. Dynamic variables, u, v and w, use a second-order accurate advection scheme and a leapfrog time integration (kinetic energy semi-conserving method). Short-wave (solar) and long-wave radiation as well as a subgrid-scale TKE turbulence scheme are also included in the model. Details of the model can be found in Tao and Simpson (1993) and Tao et al. (2003). 2.2 Microphysics (Bin Model) The formulation of the explicit spectral-bin microphysical processes is based on solving stochastic kinetic equations for the size distribution functions of water droplets (cloud droplets and raindrops), and six types of ice particles: pristine ice crystals (columnar and plate-like), snow (dendrites and aggregates), graupel and frozen drops/hail. Each type is described by a special size distribution function containing 33 categories (bin

Tao, Wei-Kuo [NASA/GSFC] [NASA/GSFC

2014-05-19T23:59:59.000Z

347

A Comparison of Multiscale Variations of Decade-long Cloud Fractions from Six Different Platforms over the Southern Great Plains in the United States  

SciTech Connect (OSTI)

This study investigates 1997-2011 observationally based cloud fraction estimates from different platforms over the Southern Great Plains, United States, including three ground-based estimates and three satellite-based estimates at multiple temporal and spatial scales. They are: 1) the Active Remotely Sensed Clouds Locations (ARSCL); 2) the Total Sky Imager (TSI); 3) the Radiative Flux Analysis (RFA); 4) Geostationary Operational Environmental Satellite (GOES); 5) the International Satellite Cloud Climatology Project (ISCCP); and 6) Advanced Very High Resolution Radiometer Pathfinder Atmospheres Extended (PATMOS-x). A substantial disagreement is evident among different estimates, especially for ISCCP and ARSCL with statistically significant larger cloud fractions than the other estimates. For example, ISCCP and ARSCL mean cloud fractions in January are ~21% and 8% larger than the average from all the other estimates, respectively. Three estimates (ISCCP, ARSCL, GOES) exhibit an 8%-10% overall increase in the annually averaged cloud fractions from 1998 to 2009; the other three estimates (TSI, RFA, and PATMOS-x) exhibit no significant tendency of increase in this decade. Monthly cloud fractions from all the estimates exhibit Gaussian-like distributions while the distributions of daily cloud fractions are dependent on spatial scales. Investigations of high-resolution cloud fractions reveal that the differences stem from the inconsistent definitions of cloud fraction. Findings from this study suggest caution when using observationally based cloud fraction estimates for climate studies, highlighting that the consistency in defining cloud fraction between models and observations is crucial for studying the Earths climate.

Wu, Wei; Liu, Yangang; Jensen, Michael; Toto, Tami; Foster, Michael J.; Long, Charles N.

2014-03-27T23:59:59.000Z

348

Research Highlight  

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

Cloud Observations at Niamey During the AMF Deployment Cloud Observations at Niamey During the AMF Deployment Submitter: Kollias, P., McGill University Area of Research: Cloud Distributions/Characterizations Working Group(s): Cloud Properties Journal Reference: Kollias, P. and M. A. Miller, 2007: Cloud and Precipitation Observations at Niamey During the 2006 ARM Mobile Facility Deployment. Submitted to Geophysical Research Letters. Daily observed cloud fraction in Niamey during the AMF deployment. The cloud fraction is derived using measurements from the 94-GHz radar, the MPL, and the ceilometer. The vertical resolution is 260 m, and a 5-day temporal filter is applied to the daily cloud fraction profiles. (a) Monthly-averaged cloud and precipitation fraction. The monthly mean and standard deviation of cirrus cloud top (white line), middle cloud tops

349

Title: Networking the Cloud: Enabling Enterprise Computing and Storage Cloud computing has been changing how enterprises run and manage their IT systems. Cloud  

E-Print Network [OSTI]

Title: Networking the Cloud: Enabling Enterprise Computing and Storage Abstract: Cloud computing has been changing how enterprises run and manage their IT systems. Cloud computing platforms provide introduction on Cloud Computing. We propose a Virtual Cloud Pool abstraction to logically unify cloud

350

Measurements with an Automatically Recording Inverted Echo Sounder; ARIES and the Bubble Clouds  

Science Journals Connector (OSTI)

We report here analysis of the first observations with a new instrument, ARIES, designed to record the acoustic backscatter from bubble clouds at several levels below the surface of the ocean. The instrument is deployed on a subsurface mooring ...

S. A. Thorpe

1986-08-01T23:59:59.000Z

351

Prediction of In-Cloud Icing Conditions at Ground Level Using the WRF Model  

Science Journals Connector (OSTI)

In-cloud icing on aircraft and ground structures can be observed every winter in many countries. In extreme cases ice can cause accidents and damage to infrastructure such as power transmission lines, telecommunication towers, wind turbines, ski ...

Bjrn Egil Kringlebotn Nygaard; Jn Egill Kristjnsson; Lasse Makkonen

2011-12-01T23:59:59.000Z

352

Development and Testing of a Life Cycle Model and a Parameterization of Thin Mid-level Stratiform Clouds  

SciTech Connect (OSTI)

We used a cloud-resolving model (a detailed computer model of cloud systems) to evaluate and improve the representation of clouds in global atmospheric models used for numerical weather prediction and climate modeling. We also used observations of the atmospheric state, including clouds, made at DOE's Atmospheric Radiation Measurement (ARM) Program's Climate Research Facility located in the Southern Great Plains (Kansas and Oklahoma) during Intensive Observation Periods to evaluate our detailed computer model as well as a single-column version of a global atmospheric model used for numerical weather prediction (the Global Forecast System of the NOAA National Centers for Environmental Prediction). This so-called Single-Column Modeling approach has proved to be a very effective method for testing the representation of clouds in global atmospheric models. The method relies on detailed observations of the atmospheric state, including clouds, in an atmospheric column comparable in size to a grid column used in a global atmospheric model. The required observations are made by a combination of in situ and remote sensing instruments. One of the greatest problems facing mankind at the present is climate change. Part of the problem is our limited ability to predict the regional patterns of climate change. In order to increase this ability, uncertainties in climate models must be reduced. One of the greatest of these uncertainties is the representation of clouds and cloud processes. This project, and ARM taken as a whole, has helped to improve the representation of clouds in global atmospheric models.

Krueger, Steven K.

2008-03-03T23:59:59.000Z

353

The Sensitivity of Radiative Fluxes to Parameterized Cloud Microphysics  

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

Sensitivity of Radiative Fluxes to Sensitivity of Radiative Fluxes to Parameterized Cloud Microphysics S. F. Iacobellis and R. C. J. Somerville Scripps Institution of Oceanography University of California San Diego, California G. M. McFarquhar University of Illinois at Urbana-Champaign Urbana, Illinois D. L. Mitchell Desert Research Institute Las Vegas, Nevada Introduction We have used a single-column model (SCM) to examine the sensitivity of fundamental quantities such as atmospheric radiative heating rates and surface and top of atmosphere (TOA) radiative fluxes to various parameterizations of clouds and cloud microphysics. When an SCM, which consists of one isolated column of a global atmospheric model, is forced with observational estimates of horizontal advection terms, the parameterizations within the SCM produce time-dependent fields which can be

354

Collision of two spin-polarized fermionic clouds  

SciTech Connect (OSTI)

We study the collision of two spin-polarized Fermi clouds in a harmonic trap using a simulation of the Boltzmann equation. As observed in recent experiments, we find three distinct regimes of behavior. For weak interactions the clouds pass through each other. If interactions are increased they approach each other exponentially and for strong interactions they bounce off each other several times. We thereby demonstrate that all these phenomena can be reproduced using a semiclassical collisional approach and that these changes in behavior are associated with an increasing collision rate. We then show that the oscillation of the clouds in the bounce regime is an example of an unusual case in quantum gases: a nonlinear coupling between collective modes, namely, the spin dipole mode and the axial breathing mode, which is enforced by collisions. We also determine the frequency of the bounce as a function of the final temperature of the equilibrated system.

Goulko, O. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Centre for Mathematical Sciences, Cambridge CB3 0WA (United Kingdom); Chevy, F. [Laboratoire Kastler Brossel, Ecole Normale Superieure, 24 rue Lhomond, F-75231 Paris Cedex 05 (France); Lobo, C. [School of Mathematics, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)

2011-11-15T23:59:59.000Z

355

Atmospheric Radiation Measurement Tropical Warm Pool International Cloud Experiment  

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

Tropical Warm Pool Tropical Warm Pool International Cloud Experiment General Description The Tropical Warm Pool - International Cloud Experiment (TWP-ICE) was a collaborative effort led by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Program and the Australian Bureau of Meteorology. Beginning January 21 and ending February 14, 2006, the experiment was conducted in the region near the ARM Climate Research Facility in Darwin, Northern Australia. This permanent facility is fully equipped with sophisticated instruments for measuring cloud and other atmospheric properties to provide a long-term record of continuous observational data. Measurements obtained from the other experiment components (explained below) will complement this dataset to provide a detailed description of the tropical atmosphere.

356

Experiments on Electron Cloud Mitigation at PEP-II  

SciTech Connect (OSTI)

The electron cloud effect has been observed at many accelerator facilities. It has been the subject of many workshops and reviews. An electron cloud is formed when low energy photoelectrons released from the vacuum chamber surfaces and ionized residual gas molecules, driven by the beam fields of passing positively charged bunches, impinge on the chamber walls and create secondary emission. It is an important issue for many currently operating facilities and the damping rings of the proposed International Linear Collider (ILC) because beam-cloud interaction can severely impact the machines performance. Systematic studies on the electron cloud effect, and its possible remedies, have been carried out in many laboratories. At SLAC, the effort has been concentrated on theoretical understanding with the aid of computer simulations, and experimental measurements with high intensity positron beams at PEP-II. Computer simulation results have been presented at ECLOUD07 and in an earlier article in this journal. In this article, we present recent results from electron cloud experiments at the positron storage ring of PEP-II. In particular, we discuss the performance of various mitigation techniques.

Ng, Johnny S.T.; Pivi, Mauro T.F.; /SLAC

2011-11-22T23:59:59.000Z

357

Sky Cover from MFRSR Observations  

SciTech Connect (OSTI)

The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their model clear-sky counterparts are two main components of a new method for estimating the fractional sky cover of different cloud types, including cumulus clouds. The performance of this method is illustrated using 1-min resolution data from ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR). The MFRSR data are collected at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during the summer of 2007 and represent 13 days with cumulus clouds. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

Kassianov, Evgueni I.; Barnard, James C.; Berg, Larry K.; Flynn, Connor J.; Long, Charles N.

2011-07-01T23:59:59.000Z

358

Aerosol Observing System (AOS) Handbook  

SciTech Connect (OSTI)

The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earths radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

Jefferson, A

2011-01-17T23:59:59.000Z

359

Electricity in Volcanic Clouds  

Science Journals Connector (OSTI)

...jets was often about 150 m/sec. From aerial views of the crater we have estimated...from Bjornsson's observations, so the aerial and surface observations immediately downwind...1958); T. Nagata, K. Hirao, N. Fukushima, T. Takashima, Bull. EarthquakeRes...

Robert Anderson; Stuart Gathman; James Hughes; Sveinbjrn Bjrnsson; Sigurgeir Jnasson; Duncan C. Blanchard; Charles B. Moore; Henry J. Survilas; Bernard Vonnegut

1965-05-28T23:59:59.000Z

360

The Cloud Project Climate Research with Accelerators  

E-Print Network [OSTI]

The current understanding of climate change in the in- dustrial age is that it is predominantly caused by anthro- pogenic greenhouse gases, with relatively small natural contributions due to solar irradiance and volcanoes. How- ever, palaeoclimatic reconstructions show that the climate has frequently varied on 100-year time scales during the Holocene (last 10 kyr) by amounts comparable to the present warmingand yet the mechanism is not under- stood. Estimated changes of solar irradiance on these time scales are too small to account for the climate observations. This raises the question of whether cosmic rays, which are modulated by the solar wind, may be directly affect- ing the climate, providing an effective indirect solar forcing mechanism. Indeed recent satellite observationsalthough disputedsuggest that cosmic rays may affect clouds un- der certain conditions. However, given the many sources of variability in the atmosphere and the lack of control of the cosmic ray flux, demonstrating overall ca...

Kirkby, Jasper

2010-01-01T23:59:59.000Z

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


361

ARM - PI Product - SGP and TWP (Manus) Ice Cloud Vertical Velocities  

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

ProductsSGP and TWP (Manus) Ice Cloud Vertical ProductsSGP and TWP (Manus) Ice Cloud Vertical Velocities Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : SGP and TWP (Manus) Ice Cloud Vertical Velocities 1997.01.01 - 2010.12.31 Site(s) SGP TWP General Description Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Lower level clouds are removed, however a multi-layer flag is included.

362

Detecting Drizzle in Marine Warm Clouds Using Visible, Infrared, and Microwave Satellite Data  

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

Drizzle in Marine Warm Clouds Drizzle in Marine Warm Clouds Using Visible, Infrared, and Microwave Satellite Data H. Shao and G. Liu Florida State University Tallahassee, Florida Introduction Determining the radiative effects of aerosols is one of the most important areas in climate research. There are observational evidences showing that aerosols can affect the radiative balance of the earth indirectly - as the number of aerosols increases, water in the cloud spreads over many more particles. Large concentrations of small droplets not only make the cloud more reflective, but also reduce the probability of rainfall and prolong cloud lifetime, because small droplets have less efficiency of coalescence (e.g., Albrecht 1989, Rosenfeld 2000). Since precipitation is a key component in

363

Behavior of nanoparticle clouds around a magnetized microsphere under magnetic and flow fields  

E-Print Network [OSTI]

When a micron-sized magnetizable particle is introduced into a suspension of nanosized magnetic particles, the nanoparticles accumulate around the microparticle and form thick anisotropic clouds extended in the direction of the applied magnetic field. This phenomenon promotes colloidal stabilization of bimodal magnetic suspensions and allows efficient magnetic separation of nanoparticles used in bioanalysis and water purification. In the present work, size and shape of nanoparticle clouds under the simultaneous action of an external uniform magnetic field and the flow have been studied in details. In experiments, dilute suspension of iron oxide nanoclusters (of a mean diameter of 60 nm) was pushed through a thin slit channel with the nickel microspheres (of a mean diameter of 50$\\mu$m) attached to the channel wall. The behavior of nanocluster clouds was observed in the steady state using an optical microscope. In the presence of strong enough flow, the size of the clouds monotonically decreases with increasing flow speed in both longitudinal and transverse magnetic fields. This is qualitatively explained by enhancement of hydrodynamic forces washing the nanoclusters away from the clouds. In the longitudinal field, the flow induces asymmetry of the front and the back clouds. To explain the flow and the field effects on the clouds, we have developed a simple model based on the balance of the stresses and particle fluxes on the cloud surface. This model, applied to the case of the magnetic field parallel to the flow, captures reasonably well the flow effect on the size and shape of the cloud and reveals that the only dimensionless parameter governing the cloud size is the ratio of hydrodynamic-to-magnetic forces - the Mason number. At strong magnetic interactions considered in the present work (dipolar coupling parameter $\\alpha \\geq 2$), the Brownian motion seems not to affect the cloud behavior.

Ccilia Magnet; Pavel Kuzhir; Georges Bossis; Alain Meunier; Sebastien Nave; Andrey Zubarev; Claire Lomenech; Victor Bashtovoi

2014-04-14T23:59:59.000Z

364

ARM - Measurement - Cloud optical depth  

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

optical depth optical depth ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud optical depth Amount of light cloud droplets or ice particles prevent from passing through a column of atmosphere. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. External Instruments GOES : Geostationary Operational Environmental Satellites Field Campaign Instruments EC-CONVAIR580-BULK : Environment Canada Convair 580 Bulk Parameters GOES : Geostationary Operational Environmental Satellites

365

Space observations of cold-cloud phase change  

Science Journals Connector (OSTI)

...Planetary Sciences, Massachusetts Institute of Technology...be suitable for the solar insolation used...global and annual mean solar radiation value, 340...smoke and dust upon solar radiation...Planetary Sciences, Massachusetts Institute of Technology...

Yong-Sang Choi; Richard S. Lindzen; Chang-Hoi Ho; Jinwon Kim

2010-01-01T23:59:59.000Z

366

Ground-based Microwave Cloud Tomography  

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

367

Widget:LogoCloud | Open Energy Information  

Open Energy Info (EERE)

Widget Edit History Facebook icon Twitter icon Widget:LogoCloud Jump to: navigation, search This widget adds css selectors and javascript for the Template:LogoCloud. For...

368

Multiscale Models for Cumulus Cloud Dynamics  

Science Journals Connector (OSTI)

Cumulus clouds involve processes on a vast range of scalesincluding cloud droplets, turbulent mixing, and updrafts and downdraftsand it is often difficult to determine how processes on different scales interact with each other. In this article, ...

Samuel N. Stechmann; Bjorn Stevens

2010-10-01T23:59:59.000Z

369

Template:LogoCloud | Open Energy Information  

Open Energy Info (EERE)

TODO: Would be nice if logos could be vertically centered within each line of the cloud TODO: Provide a way to toggle the mouse-over behavior Usage For rendering a cloud of logos....

370

IBM research division cloud computing initiative  

Science Journals Connector (OSTI)

Cloud computing represents the latest phase in the evolution of Internet-based computing. In this paper, we describe the fundamental building blocks of cloud computing and the initiative undertaken by the IBM Research Division in this area, which includes ...

M. Naghshineh; R. Ratnaparkhi; D. Dillenberger; J. R. Doran; C. Dorai; L. Anderson; G. Pacifici; J. L. Snowdon; A. Azagury; M. VanderWiele; Y. Wolfsthal

2009-07-01T23:59:59.000Z

371

Disruptive technology business models in cloud computing  

E-Print Network [OSTI]

Cloud computing, a term whose origins have been in existence for more than a decade, has come into fruition due to technological capabilities and marketplace demands. Cloud computing can be defined as a scalable and flexible ...

Krikos, Alexis Christopher

2010-01-01T23:59:59.000Z

372

Cloud seeding as a technique for studying aerosol-cloud interactions in marine stratocumulus  

E-Print Network [OSTI]

Cloud seeding as a technique for studying aerosol-cloud interactions in marine stratocumulus hygroscopic aerosols were introduced into a solid marine stratocumulus cloud (200 m thick) by burning hygroscopic flares mounted on an aircraft. The cloud microphysical response in two parallel seeding plumes

Miami, University of

373

Cloud Service Security Requirements Questionnaire 1. What Cloud service will you be providing  

E-Print Network [OSTI]

Cloud Service Security Requirements Questionnaire Exhibit G 1. What Cloud service will you) as Low/Moderate/High? If so, which? 4. Has your cloud service been audited by any eternal agencies for security and quality control? If so, please provide evidence. 5. Has your cloud service been industry

374

Cloud Tracking in Cloud-Resolving Models R. S. Plant1  

E-Print Network [OSTI]

Cloud Tracking in Cloud-Resolving Models R. S. Plant1 1 Department of Meteorology, University. INTRODUCTION In recent years Cloud Resolving Models (CRMs) have become an increasingly important tool for CRM data, which allows one to investigate statistical prop- erties of the lifecycles of the "clouds

Plant, Robert

375

HPI Cloud Symposium ,Operating The Cloud` 25.09.2013, Hasso-Plattner-Institut, Auditorium Building  

E-Print Network [OSTI]

Agenda HPI Cloud Symposium ,Operating The Cloud` 25.09.2013, Hasso-Plattner-Institut, Auditorium Building 09:30h Registration 10:00h Opening Prof. Dr. Christoph Meinel, HPI Potsdam 10:30h Cloud-RAID: Eine Methode zur Bereitstellung zuverlässiger Speicherressourcen in ?ffentlichen Clouds Maxim Schnajkin, HPI

Weske, Mathias

376

The Cloud Adoption Toolkit: Supporting Cloud Adoption Decisions in the Enterprise  

E-Print Network [OSTI]

1 The Cloud Adoption Toolkit: Supporting Cloud Adoption Decisions in the Enterprise Ali Khajeh-Hosseini, David Greenwood, James W. Smith, Ian Sommerville Cloud Computing Co-laboratory, School of Computer Science University of St Andrews, UK {akh, dsg22, jws7, ifs}@cs.st-andrews.ac.uk Abstract Cloud computing

Sommerville, Ian

377

Cloud Verifier: Verifiable Auditing Service for IaaS Clouds Joshua Schiffman  

E-Print Network [OSTI]

Cloud Verifier: Verifiable Auditing Service for IaaS Clouds Joshua Schiffman Security Architecture University Park, PA, USA yus138,hvijay,tjaeger@cse.psu.edu Abstract--Cloud computing has commoditized compute paradigm, its adoption has been stymied by cloud platform's lack of trans- parency, which leaves customers

Jaeger, Trent

378

CLOUD COMPUTING AND INFORMATION POLICY 1 Cloud Computing and Information Policy  

E-Print Network [OSTI]

CLOUD COMPUTING AND INFORMATION POLICY 1 Cloud Computing and Information Policy: Computing in a Policy Cloud? Forthcoming in the Journal of Information Technology and Politics, 5(3). Paul T. Jaeger University of Maryland Jimmy Lin University of Maryland Justin M. Grimes University of Maryland #12;CLOUD

Lin, Jimmy

379

Cloud networking and communications Cloud computing is having an important impact on  

E-Print Network [OSTI]

Editorial Cloud networking and communications Cloud computing is having an important impact attention has been devoted to system aspects of Cloud computing. More recently, however, the focus is shifting towards Cloud net- working and communications with evolutionary and revo- lutionary propositions

Boutaba, Raouf

380

Securely Managing Cryptographic Keys used within a Cloud Environment  

E-Print Network [OSTI]

to rapidly develop/host cloud applications Infrastructure as a Service (Iaas) - Networked access to processing power, storage Cloud Deployment Models Public Cloud Private Cloud Community Cloud Hybrid administers the Cloud Infrastructure? Who has access to my data? My activity history? Key Management Where

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


381

Refinement, Validation and Application of Cloud-Radiation Parameterization in a GCM  

SciTech Connect (OSTI)

The research performed under this award was conducted along 3 related fronts: (1) Refinement and assessment of parameterizations of sub-grid scale radiative transport in GCMs. (2) Diagnostic studies that use ARM observations of clouds and convection in an effort to understand the effects of moist convection on its environment, including how convection influences clouds and radiation. This aspect focuses on developing and testing methodologies designed to use ARM data more effectively for use in atmospheric models, both at the cloud resolving model scale and the global climate model scale. (3) Use (1) and (2) in combination with both models and observations of varying complexity to study key radiation feedback Our work toward these objectives thus involved three corresponding efforts. First, novel diagnostic techniques were developed and applied to ARM observations to understand and characterize the effects of moist convection on the dynamical and thermodynamical environment in which it occurs. Second, an in house GCM radiative transfer algorithm (BUGSrad) was employed along with an optimal estimation cloud retrieval algorithm to evaluate the ability to reproduce cloudy-sky radiative flux observations. Assessments using a range of GCMs with various moist convective parameterizations to evaluate the fidelity with which the parameterizations reproduce key observable features of the environment were also started in the final year of this award. The third study area involved the study of cloud radiation feedbacks and we examined these in both cloud resolving and global climate models.

Dr. Graeme L. Stephens

2009-04-30T23:59:59.000Z

382

Aircraft Observations of Sub-cloud Aerosol and Convective Cloud Physical Properties  

E-Print Network [OSTI]

nucleation and Aitken modes. Backtrajectories of Central Mediterranean origin contain a high accumulation mode but low nucleation mode. Eastern Europe backtrajectories have the lowest nucleation mode but exhibit a broad accumulation mode which... are shaped by complex nonlinear processes that are difficult to represent numerically. These processes include nucleation of new particles and evaporation, growth and coagulation of existing particles. Most current models explicitly represent the ASD...

Axisa, Duncan

2011-02-22T23:59:59.000Z

383

Case study of the 9 April 2009 `brown' cloud: Observations of Unusually High Cloud  

E-Print Network [OSTI]

Saudi Arabia field project was funded by the Kingdom of Saudi Arabia through a contract with Weather Concentrations in Saudi Arabia David J. Delene Atmospheric Sciences Department University of North Dakota #12;Research Motivation for Weather Modification Water Resource Stresses Severe Weather Hazards Inadvertent

Delene, David J.

384

6, 93519388, 2006 Aerosol-cloud  

E-Print Network [OSTI]

ACPD 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al Chemistry and Physics Discussions Aerosol-cloud interaction inferred from MODIS satellite data and global 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al. Title

Paris-Sud XI, Université de

385

Level Set Implementations on Unstructured Point Cloud  

E-Print Network [OSTI]

Level Set Implementations on Unstructured Point Cloud by HO, Hon Pong A Thesis Submitted;Level Set Implementations on Unstructured Point Cloud by HO, Hon Pong This is to certify that I have implementations on unstructured point cloud 15 3.1 Level set initialization

Duncan, James S.

386

Cloud Security: Issues and Concerns Pierangela Samarati*  

E-Print Network [OSTI]

1 Cloud Security: Issues and Concerns Authors Pierangela Samarati* Università degli Studi di Milano, Italy sabrina.decapitani@unimi.it Keywords cloud security confidentiality integrity availability secure data storage and processing Summary The cloud has emerged as a successful computing paradigm

Samarati, Pierangela

387

Cloud Computing: Centralization and Data Sovereignty  

E-Print Network [OSTI]

1 Cloud Computing: Centralization and Data Sovereignty Primavera De Filippi, Smari McCarthy Abstract: Cloud computing can be defined as the provision of computing resources on-demand over and elasticity of costs, problems arise concerning the collection of personal information in the Cloud

Paris-Sud XI, Université de

388

Alignment of Dust in Molecular Clouds  

E-Print Network [OSTI]

Polarimetry is one of the most informative techniques of studying magnetic fields in molecular clouds. How reliable the interpretation of the polarization maps in terms of magnetic fields is the issue that the grain alignment theory addresses. We show that grain alignment involves several processes acting simultaneously, but on different time-scales. We explain that rotating dust grains get substantial magnetic moment that allows them precess fast about magnetic field lines. As the result, grains preserve their orientation to magnetic field when the magnetic field direction fluctuates. We point out to the importance of internal alignment, i.e. the process forces grain axes to be aligned in respect to the grain angular momentum. We show that subtle quantum effects, in particular relaxation related to nuclear magnetic moments of atoms composing the grain, brings to live complex grain motions, e.g. flips. These flips substantially alter the dynamics of grain and limit the applicability of earlier theories that did not account for them. We also briefly review basic physical processes involved in the alignment of grain angular momentum in respect to interstellar magnetic field. We claim that the bulk of existing observational data is consistent with the radiative torque alignment mechanism. In particular, we show that large grains that are known to exist in the cores of molecular clouds may be aligned by the attenuated external interstellar radiation field.

A. Lazarian; J. Cho

2004-08-10T23:59:59.000Z

389

Testing the Probability of Clear Line of Sight Models with ARM Observations  

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

the Probability of Clear Line of Sight Models the Probability of Clear Line of Sight Models with ARM Observations Y. Ma Department of Meteorology University of Maryland College Park, Maryland R. G. Ellingson Department of Meteorology Florida State University Tallahassee, Florida Abstract Clouds play a major role in regulating Earth's climate. However, computer models of Earth's climate neglect the effects of cloud vertical extend in a broken cloud field. The vertical extent allows clouds to shade more of the atmosphere and allow radiative exchange over a larger temperature range. One way to parameterize this 3D cloud effect is to relate the various cloud properties, including the cloud vertical extent, to a statistical cloud field parameter called the probability of clear line of sight (PCLS) (see

390

ARM - Surface Aerosol Observing System  

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

FacilitiesSurface Aerosol Observing System FacilitiesSurface Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Surface Aerosol Observing System The ARM Mobile Facility (AMF) is equipped to quantify the interaction between clouds and aerosol particles. A counter-flow virtual impactor (CVI) is used to selectively sample cloud drops. The CVI takes advantage of the

391

The Temperature of Interstellar Clouds from Turbulent Heating  

E-Print Network [OSTI]

To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the dimension of the most dissipative structures. By comparing the model with the probability distribution of the turbulent dissipation rate in a simulation of supersonic and super-Alfvenic turbulence, we find a best-fit value of d=1.64. We apply this intermittency model to the computation of the mass-weighted probability distribution of the gas temperature of molecular clouds, high-mass star-forming cores, and cold diffuse HI clouds. Our main results are: i) The mean gas temperature in molecular clouds can be explained as the effect of turbulent heating alone, while cosmic ray heating may dominate only in regions where the turbulent heating is low; ii) The mean gas temperature in high-mass star-forming cores with typical FWHM of ~6 km/s (corresponding to a 1D rms velocity of 2.5 km/s) may be completely controlled by turbulent heating, which predicts a mean value of approximately 36 K, two to three times larger than the mean gas temperature in the absence of turbulent heating; iii) The intermittency of the turbulent heating can generate enough hot regions in cold diffuse HI clouds to explain the observed CH+ abundance, if the rms velocity on a scale of 1 pc is at least 3 km/s, in agreement with previous results based on incompressible turbulence. Because of its importance in the thermal balance of molecular clouds and high-mass star-forming cores, the process of turbulent heating may be central in setting the characteristic stellar mass and in regulating molecular chemical reactions.

Liubin Pan; Paolo Padoan

2008-06-30T23:59:59.000Z

392

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

SciTech Connect (OSTI)

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

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

2013-08-16T23:59:59.000Z

393

Research Highlight  

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

Structure of Cirrus Properties and Its Coupling with the State of the Structure of Cirrus Properties and Its Coupling with the State of the Large-Scale Atmosphere Download a printable PDF Submitter: Ivanova, K., Pennsylvania State University Ackerman, T. P., University of Washington Area of Research: Atmospheric Thermodynamics and Vertical Structures Working Group(s): Cloud Properties Journal Reference: Ivanova K and TP Ackerman. 2009. "Tracking nucleation-growth-sublimation in cirrus clouds using ARM millimeter wavelength radar observations." Journal of Geophysical Research - Atmospheres, , D06113, 10.1029/2008JD010271. Figure 1. Values of the drift and diffusion coefficients of the Fokker-Planck equation derived from the MMCR radar reflectivity observations. The diffusion coefficient characterizes the small scale, fast

394

Optical Emission Lines from Warm Interstellar Clouds - a Decisive Test of the Decaying Neutrino Theory  

E-Print Network [OSTI]

Recently developed instruments such as the Taurus Tunable Filter and WHAM should be able to detect some or all of the optical emission lines H$\\alpha$, [OI] $\\lambda$6300, [SII] $\\lambda$6717, [NI] $\\lambda$ 5200 and [NII] $\\lambda$6584 from warm interstellar clouds such as those observed by Spitzer $&$ Fitzpatrick (1993) (SF) along the line of sight to the halo star HD93521. The strengths of these lines should resolve the debate as to whether the free electrons, which SF held responsible for the observed excitation of CII in the clouds, are located mainly in the skins of the clouds or in their interiors. If the free electrons are indeed mainly located in the cloud interiors, then the substantial electron density derived by SF, and its constancy from cloud to cloud for the slow-moving clouds, when combined with their opacity to Lyman continuum radiation, lend strong support to the decaying neutrino theory for the ionisation of the interstellar medium (Sciama 1990, 1993 a, b, 1997). If the [OI] and [NI] lines are relatively strong but the [NII] line is weak, then this would lend further, decisive, support to this theory, since decay photons are unable to ionise N, although its ionisation potential is only 0.9 eV greater than that of H.

D. W. Sciama

1998-06-12T23:59:59.000Z

395

Separating Cloud Forming Nuclei from Interstitial Aerosol  

SciTech Connect (OSTI)

It has become important to characterize the physicochemical properties of aerosol that have initiated the warm and ice clouds. The data is urgently needed to better represent the aerosol-cloud interaction mechanisms in the climate models. The laboratory and in-situ techniques to separate precisely the aerosol particles that act as cloud condensation nuclei (CCN) and ice nuclei (IN), termed as cloud nuclei (CN) henceforth, have become imperative in studying aerosol effects on clouds and the environment. This review summarizes these techniques, design considerations, associated artifacts and challenges, and briefly discusses the need for improved designs to expand the CN measurement database.

Kulkarni, Gourihar R.

2012-09-12T23:59:59.000Z

396

Exploiting Virtualization and Cloud Computing in ATLAS  

E-Print Network [OSTI]

The ATLAS Computing Model was designed around the concept of grid computing; since the start of data-taking, this model has proven very successful in the federated operation of more than one hundred Worldwide LHC Computing Grid (WLCG) sites for offline data distribution, storage, processing and analysis. However, new paradigms in computing, namely virtualization and cloud computing, present improved strategies for managing and provisioning IT resources that could allow ATLAS to more flexibly adapt and scale its storage and processing workloads on varied underlying resources. In particular, ATLAS is developing a "grid-of-clouds" infrastructure in order to utilize WLCG sites that make resources available via a cloud API. This work will present the current status of the Virtualization and Cloud Computing R&D project in ATLAS Distributed Computing. First, strategies for deploying PanDA queues on cloud sites will be discussed, including the introduction of a "cloud factory" for managing cloud VM instances. Nex...

Barreiro Megino, FH; The ATLAS collaboration; De, K; Gable, I; Hendrix, V; Panitkin, S; Paterson, M; De Silva, A; van der Ster, D; Taylor, R; Vitillo, RA; Walker, R

2012-01-01T23:59:59.000Z

397

ARM - Publications: Science Team Meeting Documents  

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

The Association of the Cirrus Properties Over the Western Tropical Pacific The Association of the Cirrus Properties Over the Western Tropical Pacific with Tropical Deep Convection Deng, M.(a), Mace, G.G.(a), and Soden, B.J.(b), Univesity of Utah (a), Geophysical Fluid Dynamics Laboratory (b) The microphysical and radiative properties of upper tropospheric clouds in the tropics are known to have a substantial influence on climate. Observations from long term cloud radar measurements in the tropics show that upper tropospheric clouds are observed above 10 km as much as 40% of the time depending on location. By combining satellite observations with observations from the tropical ARM site on Nauru and Manus Islands we examine the macro and microphysical properties of these clouds in terms of their association with deep convection. The fundamental questions we will

398

EA-1852: Cloud County Community College Wind Energy Project, Cloud County,  

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

2: Cloud County Community College Wind Energy Project, Cloud 2: Cloud County Community College Wind Energy Project, Cloud County, Kansas EA-1852: Cloud County Community College Wind Energy Project, Cloud County, Kansas Summary This EA evaluates the environmental impacts of a proposal to authorize the expenditure of federal funds by Cloud County Community College (CCCC) for a wind energy project. CCCC has installed three wind turbines and proposes to install a fourth turbine on their campus in Concordia, Kansas, for use in their wind energy training curriculum and to provide electricity for their campus. Public Comment Opportunities No public comment opportunities available at this time. Documents Available for Download January 10, 2011 EA-1852: Notice of Scoping Cloud County Community College Wind Energy Technology Project, Cloud

399

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

SciTech Connect (OSTI)

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

400

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

SciTech Connect (OSTI)

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

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


401

Cloud speed impact on solar variability scaling ?? Application to the wavelet variability model  

E-Print Network [OSTI]

Kleissl, J. , 2013. Deriving cloud velocity from an array ofCloud Speed Impact on Solar Variability Scaling -this work, we determine from cloud speeds. Cloud simulator

Lave, Matthew; Kleissl, Jan

2013-01-01T23:59:59.000Z

402

1 DECEMBER 2004 4541L U O A N D R O S S O W 2004 American Meteorological Society  

E-Print Network [OSTI]

Tropical Cirrus Life Cycle, Evolution, and Interaction with Upper-Tropospheric Water Vapor Using Lagrangian Trajectory Analysis of Satellite Observations ZHENGZHAO LUO Cooperative Institute for Research, and the NCEP­NCAR reanalysis wind field. Building upon the existing International Satellite Cloud Climatology

403

commentary and analysis: Fallstreaks and Their Parent Generators  

Science Journals Connector (OSTI)

We present a comparatively rare photograph of cirrus uncinus (mare's tail cirrus) fallstreaks with supercooledcumuliform generating heads. The image demonstrates regeneration of the clouds to account for the extended lifetime of both the ...

D. Atlas

2001-03-01T23:59:59.000Z

404

Low?frequency sound radiation and scattering from bubble clouds.  

Science Journals Connector (OSTI)

Recent experimental evidence has shown that when wave breaking occurs low?frequency (LF?200 Hz) sound is produced and LF scatter has a different characteristic than expected from rough sea surface scattering. These effects have been attributed to the bubbles produced during wave breaking which are convected to depth by the breaking turbulence vorticity and Langmuir circulation as observed by Thorpe [S. Thorpe Oceanic White Caps edited by E. Monahan and G. MacNiocaill (Reidel Boston 1986) pp. 5758]. While the radiation and scatteringcharacteristics at frequencies greater than 1 kHz are explained by incoherent scatter from the observed bubble size and space distributions the lower frequency phenomena are not easily explained. However if bubble plumes and clouds produced in the wave breaking have appreciable volume fractions (?10?5) then LF sound radiation and scattering can be explained by classical theories. This paper reviews the scattering and radiation from bubbleclouds in water as a function of volume fraction. When the cloud is compact coherent and collective scatter are shown to occur. The natural frequency of radiation is shown to be described by a modified Minnaert result while the backscatter target strength is described by the first?order volume mode. These analytical results agree with experimental sound radiation and scatter measurements. Finally the collective radiation of bubble plumes and clouds is discussed as a possible explanation of the observed ocean low?frequency scattering and radiation phenomena. [Work sponsored by ONR 11250A and NUSC IR.

William M. Carey

1992-01-01T23:59:59.000Z

405

1  

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

Cirrus Extinction and Lidar Ratio Derived from Raman Cirrus Extinction and Lidar Ratio Derived from Raman Lidar Measurements at the Atmospheric Radiation Measurement Program Southern Site D. Petty and J. Comstock Pacific Northwest National Laboratory Richland, Washington D. Tuner Space Science Engineering Center, University of Wisconsin-Madison Madison, Wisconsin Introduction Range resolved microphysical properties and extinction coefficient in cirrus clouds are critical for assessing the impact of cirrus on climate. Vertical profiles of cirrus extinction are important parameters for radiative flux and heating rate calculations. The extinction-to-backscatter ratio (also called lidar ratio) provides information on the transmission and reflection properties of cirrus clouds and also on the

406

TROPIC: Transactional Resource Orchestration Platform In the Cloud  

E-Print Network [OSTI]

TROPIC: Transactional Resource Orchestration Platform In the Cloud Changbin Liu, Yun Mao*, Xu Chen ­ InfrastructureasaService (IaaS) Cloud · Provide cloud infrastructure services: virtual machines (VMs), virtual block devices, VPNs · Widely adopted, e.g. Amazon Elastic Compute Cloud (EC2) ­ Cloud resource

Plotkin, Joshua B.

407

International Cloud Workshop, Locarno, Switzerland, 3 Feb 2009  

E-Print Network [OSTI]

International Cloud Workshop, Locarno, Switzerland, 3 Feb 2009 Impact of broken and inhomogeneous clouds on satellite cloud-phase retrieval Erwin Wolters ­ KNMI Hartwig Deneke ­ KNMI/University of Bonn;Contents Introduction CM-SAF cloud-phase retrieval method The problem ­ research question Broken clouds

Haak, Hein

408

Interconnecting Federated Clouds by Using Publish-Subscribe Service  

Science Journals Connector (OSTI)

Cloud Federation is an emerging computing model where multiple resources from independent Cloud providers are leveraged to create large-scale distributed virtual computing clusters, operating as into a single Cloud organization. This model enables the ... Keywords: Cloud Computing, Cloud Federation, Denial of Service, Intercommunication, Publish/Subscribe Service, Reliability

Christian Esposito; Massimo Ficco; Francesco Palmieri; Aniello Castiglione

2013-12-01T23:59:59.000Z

409

ARM - Measurement - Cloud particle size distribution  

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

410

UNDERSTANDING TRENDS ASSOCIATED WITH CLOUDS IN IRRADIATED EXOPLANETS  

SciTech Connect (OSTI)

Unlike previously explored relationships between the properties of hot Jovian atmospheres, the geometric albedo and the incident stellar flux do not exhibit a clear correlation, as revealed by our re-analysis of Q0-Q14 Kepler data. If the albedo is primarily associated with the presence of clouds in these irradiated atmospheres, a holistic modeling approach needs to relate the following properties: the strength of stellar irradiation (and hence the strength and depth of atmospheric circulation), the geometric albedo (which controls both the fraction of starlight absorbed and the pressure level at which it is predominantly absorbed), and the properties of the embedded cloud particles (which determine the albedo). The anticipated diversity in cloud properties renders any correlation between the geometric albedo and the stellar flux weak and characterized by considerable scatter. In the limit of vertically uniform populations of scatterers and absorbers, we use an analytical model and scaling relations to relate the temperature-pressure profile of an irradiated atmosphere and the photon deposition layer and to estimate whether a cloud particle will be lofted by atmospheric circulation. We derive an analytical formula for computing the albedo spectrum in terms of the cloud properties, which we compare to the measured albedo spectrum of HD 189733b by Evans et al. Furthermore, we show that whether an optical phase curve is flat or sinusoidal depends on whether the particles are small or large as defined by the Knudsen number. This may be an explanation for why Kepler-7b exhibits evidence for the longitudinal variation in abundance of condensates, while Kepler-12b shows no evidence for the presence of condensates despite the incident stellar flux being similar for both exoplanets. We include an 'observer's cookbook' for deciphering various scenarios associated with the optical phase curve, the peak offset of the infrared phase curve, and the geometric albedo.

Heng, Kevin [University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Demory, Brice-Olivier, E-mail: kevin.heng@csh.unibe.ch, E-mail: demory@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

2013-11-10T23:59:59.000Z

411

Organizational challenges in cloud adoption and enablers of cloud transition program  

E-Print Network [OSTI]

With the proliferation of cloud computing, organizations have been able to get access to never seen before computing power and resources. Cloud computing has revolutionized the utilization of computing resources through ...

Rajendran, Sneha

2013-01-01T23:59:59.000Z

412

A Global Climatology of Outgoing Longwave Spectral Cloud Radiative Effect and Associated Effective Cloud Properties  

Science Journals Connector (OSTI)

Longwave (LW) spectral flux and cloud radiative effect (CRE) are important for understanding the earths radiation budget and cloudradiation interaction. Here, the authors extend their previous algorithms to collocated Atmospheric Infrared ...

Xianglei Huang; Xiuhong Chen; Gerald L. Potter; Lazaros Oreopoulos; Jason N. S. Cole; Dongmin Lee; Norman G. Loeb

2014-10-01T23:59:59.000Z

413

CloudML : A DSL for model-based realization of applications in the cloud.  

E-Print Network [OSTI]

??Cloud Computing offers a vast amount of resources, available for end users on a pay-as-you-go basis. The opportunity to choose between several cloud providers is (more)

Brandtzg, Eirik

2012-01-01T23:59:59.000Z

414

On the Usage of Spectral and Broadband Satellite Instrument Measurements to Differentiate Climate Models with Different Cloud Feedback Strengths  

Science Journals Connector (OSTI)

Top-of-atmosphere radiometric signals associated with different high- and low-cloudradiative feedbacks have been examined through the use of an observing system simulation experiment (OSSE). The OSSE simulates variations in the spectrally ...

Daniel R. Feldman; Daniel M. Coleman; William D. Collins

2013-09-01T23:59:59.000Z

415

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

Science Journals Connector (OSTI)

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

Richard M. Forbes; Maike Ahlgrimm

2014-09-01T23:59:59.000Z

416

A satellite view of the radiative impact of clouds on surface downward fluxes in the Tibetan Plateau  

Science Journals Connector (OSTI)

Using thirteen years of satellite observations for the Tibetan Plateau, we investigate and quantify the sensitivities (or partial derivatives) of daytime surface downward shortwave and longwave fluxes with respect to changes in cloud cover and ...

C. M. Naud; I. Rangwala; M. Xu; J. R. Miller

417

Simulations of electron cloud build-up and saturation in the APS  

SciTech Connect (OSTI)

In studies with positron beams in the Advanced Photon Source, a dramatic amplification was observed in the electron cloud for certain bunch current and bunch spacings. In modeling presented previously, we found qualitative agreement with the observed beam-induced multipacting condition, provided reasonable values were chosen for the secondary electron yield parameters, including the energy distribution. In this paper, we model and discuss the build-up and saturation process observed over long bunch trains at the resonance condition. Understanding this saturation mechanism in more detail may have implications for predicting electron cloud amplification, multipacting, and instabilities in future rings.

Harkay, K.C.; Rosenberg, R.A.; Furman, M.A.; Pivi, M.

2002-06-19T23:59:59.000Z

418

Prediction of Cloud Points of Biodiesel  

Science Journals Connector (OSTI)

Prediction of Cloud Points of Biodiesel ... Despite the lack of accurate data for the cloud points of biodiesel, the results obtained here allow for an adequate evaluation of the model proposed, showing that it can produce good predictions of the cloud points of mixtures of fatty acid esters. ... Because of its environmental benefits, resulting from a decrease in CO2 emissions, its origin from renewable resources, and the increase in crude oil costs, biodiesel is become increasingly attractive. ...

J. C. A. Lopes; L. Boros; M. A. Krhenbhl; A. J. A. Meirelles; J. L. Daridon; J. Pauly; I. M. Marrucho; J. A. P. Coutinho

2007-10-09T23:59:59.000Z

419

Analysis of cloud layer structure in Shouxian, China using RS92 radiosonde aided by 95 GHz cloud radar  

E-Print Network [OSTI]

Analysis of cloud layer structure in Shouxian, China using RS92 radiosonde aided by 95 GHz cloud to analyze cloud vertical structure over this area by taking advantage of the first direct measurements of cloud vertical layers from the 95 GHz radar. Singlelayer, twolayer, and threelayer clouds account for 28

Li, Zhanqing

420

Occlusion Effects and the Distribution of Interstellar Cloud Sizes and Masses  

E-Print Network [OSTI]

The frequency distributions of sizes of ``clouds" and ``clumps" within clouds are significantly flatter for extinction surveys than for CO spectral line surveys, even for comparable size ranges. A possible explanation is the blocking of extinction clouds by larger foreground clouds (occlusion), which should not affect spectral line surveys much because clouds are resolved in velocity space along a given line of sight. We present a simple derivation of the relation between the true and occluded size distributions, assuming clouds are uniformly distributed in space or the distance to a cloud comples is much greater than the size of the complex. Because the occlusion is dominated by the largest clouds, we find that occlusion does not affect the measured size distribution except for sizes comparable to the largest size, implying that occlusion is not responsible for the discrepancy if the range in sizes of the samples is large. However, we find that the range in sizes for many of the published observed samples is actually quite small, which suggests that occlusion does affect the extinction sample and/or that the discrepancy could arise from the different operational definitions and selection effects involved in the two samples. Size and mass spectra from an IRAS survey (Wood \\etal\\ 1994) suggest that selection effects play a major role in all the surveys. We conclude that a reliable determination of the ``true" size and mass spectra of clouds will require spectral line surveys with very high signal-to-noise and sufficient resolution and sampling to cover a larger range of linear sizes, as well as careful attention to selection effects.

J. Scalo; A. Lazarian

1995-08-15T23:59:59.000Z

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


421

Technical Sessions Parameterization of Convective Clouds, Mesoscale...  

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

and Convective-Generated Clouds W. R. Cotton Department of Atmospheric Science Colorado State University Fort Collins, CO 80523 This presentation is a summary of research...

422

Radiative Effects of Cloud Inhomogeneity and  

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

Radiative Effects of Cloud Inhomogeneity and Geometric Association Over the Tropical Western Pacific Warm Pool X. Wu National Center for Atmospheric Research (a) Boulder, Colorado...

423

The Magellan Final Report on Cloud Computing  

E-Print Network [OSTI]

supported images and site security policies. A cloud systemcertain implications on site security policies. Our securityactivitiesboth in terms of site security policy as well as

Coghlan, Susan

2013-01-01T23:59:59.000Z

424

An Analysis of Cloud Absorption During  

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

Analysis of Cloud Absorption During ARESE II (Spring 2000) D. M. Powell, R. T. Marchand, and T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington Introduction...

425

Automated Security Compliance Tool for the Cloud.  

E-Print Network [OSTI]

?? Security, especially security compliance, is a major concern that is slowing down the large scale adoption of cloud computing in the enterprise environment. Business (more)

Ullah, Kazi Wali

2012-01-01T23:59:59.000Z

426

Cloud Computing and Sustainability: Energy Efficiency Aspects.  

E-Print Network [OSTI]

?? Cloud computing promises a new era of service delivery and deployment in such a way that every person can access any kind of services (more)

Gholamhosseinian, Ashkan

2012-01-01T23:59:59.000Z

427

Tropical Cloud Life Cycle and Overlap Structure  

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

Tropical Cloud Life Cycle and Overlap Structure Vogelmann, Andrew Brookhaven National Laboratory Jensen, Michael Brookhaven National Laboratory Kollias, Pavlos Brookhaven National...

428

Cloud Computing Organizational Benefits: A Managerial concern.  

E-Print Network [OSTI]

??Context: Software industry is looking for new methods and opportunities to reduce the project management problems and operational costs. Cloud Computing concept is providing answers (more)

Mandala, Venkata

2012-01-01T23:59:59.000Z

429

Cloud Computing - Trends and Performance Issues.  

E-Print Network [OSTI]

??Context: Cloud Computing is a very fascinating concept these days, it is attracting so many organiza-tions to move their utilities and applications into a dedicated (more)

Al-Refai, Ali

2011-01-01T23:59:59.000Z

430

Migrating enterprise storage applications to the cloud.  

E-Print Network [OSTI]

??Cloud computing has emerged as a model for hosting computing infrastructure and outsourcing management of that infrastructure. It offers the promise of simplified provisioning and (more)

Vrable, Michael Daniel

2011-01-01T23:59:59.000Z

431

A COMPARISON OF CLOUD MICROPHYSICAL QUANTITIES WITH FORECASTS FROM CLOUD PREDICTION MODELS  

E-Print Network [OSTI]

of the Atmospheric System Research (ASR) Program, Bethesda, MD March 15-19, 2010 Environmental Sciences Department/Atmospheric Plains (SGP) site. Cloud forecasts generated by the models are compared with cloud microphysical and radiosonde) are used to derive the cloud microphysical quantities: ice water content, liquid water content

432

Testing a cloud application: IBM SmartCloud inotes: methodologies and tools  

Science Journals Connector (OSTI)

IBM SmartCloud is a branded collection of Cloud products and solutions from IBM. It includes Infrastructure as a Service (IaaS), Software as a Service (SaaS), and Platform as a Service (PaaS) offered through public, private and hybrid cloud delivery ... Keywords: Software testing, methodology, tool

Michael Lynch; Thomas Cerqueus; Christina Thorpe

2013-07-01T23:59:59.000Z

433

AirCloud: a cloud-based air-quality monitoring system for everyone  

Science Journals Connector (OSTI)

We present the design, implementation, and evaluation of AirCloud -- a novel client-cloud system for pervasive and personal air-quality monitoring at low cost. At the frontend, we create two types of Internet-connected particulate matter (PM2:5) ... Keywords: PM2.5, air quality, client-cloud calibration system

Yun Cheng, Xiucheng Li, Zhijun Li, Shouxu Jiang, Yilong Li, Ji Jia, Xiaofan Jiang

2014-11-01T23:59:59.000Z

434

Cloud-Top Temperatures for Precipitating Winter Clouds JAY W. HANNA  

E-Print Network [OSTI]

1 Cloud-Top Temperatures for Precipitating Winter Clouds JAY W. HANNA NOAA/NESDIS Satellite for each precipitation type, as well as light, moderate and heavy snow and rain. The light the cloud microphysics in producing precipitation. For example, ice will only nucleate from the vapor phase

Schultz, David

435

Derivation of Seasonal Cloud Properties at ARM-NSA from Multispectral MODIS Data  

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

Derivation of Seasonal Cloud Properties at ARM-NSA Derivation of Seasonal Cloud Properties at ARM-NSA from Multispectral MODIS Data D. A. Spangenberg Analytical Services and Materials, Inc. Hampton, Virginia P. Minnis National Aeronautics and Space Administration Langley Research Center Hampton, Virginia T. Uttal National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Q. Z. Trepte and S. S.-Mack Science Applications International Corporation Hampton, Virginia Introduction Improving climate model predictions over earth's Polar Regions requires a complete knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface observed in satellite data, especially for visible wavelengths. This makes it difficult to

436

A Simple Empirical Equation to Calculate Cloud Optical Thickness from Shortwave Broadband Measurements  

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

Simple Empirical Equation to Calculate Cloud Optical Simple Empirical Equation to Calculate Cloud Optical Thickness from Shortwave Broadband Measurements J. C. Barnard and C. N. Long Pacific Northwest National Laboratory Richland, Washington Introduction Observational studies of shortwave cloud optical thickness, c , play an important role in determining how clouds affect climate. Accordingly, considerable effort has been, and continues to be expended to characterize the spatial and temporal distribution of c over the globe. This effort involves satellite and ground-based measurements that infer c from measurements of the reflection or transmission of solar radiation. Transmitted solar radiation forms the basis of several important algorithms designed to calculate c ; these algorithms use either spectral irradiances (Min and Harrison 1996; henceforth referred

437

Beam-Induced Multipactoring and Electron-Cloud Effects in Particle Accelerators  

E-Print Network [OSTI]

In the beam pipe of high-energy proton or positron accelerators an electron cloud can be generated by a variety of processes, e.g. by residual-gas ionization, by photoemission from synchrotron radiation, and, most importantly, by secondary emission via a beam-induced multipactoring process. The electron cloud commonly leads to a degradation of the beam vacuum by several orders of magnitude, to fast beam instabilities, to beam-size increases, and to fast or slow beam losses. At the Large Hadron Collider (LHC), the cloud electrons could also give rise to an additional heat load inside cold superconducting magnets. In addition to the direct heat deposition from incoherently moving electrons, a potential magnetron effect has been conjectured, where electrons would radiate coherently when moving in a strong magnetic field under the simultaneous influence of a beam-induced electric wake field that may become resonant with the cyclotron frequency. Electron-cloud effects are already being observed w...

Caspers, Friedhelm; Scandale, Walter; Zimmermann, F

2009-01-01T23:59:59.000Z

438

Analysis of Cloud Variability and Sampling Errors in Surface and Satellite Mesurements  

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

Analysis of Cloud Variability and Sampling Errors in Analysis of Cloud Variability and Sampling Errors in Surface and Satellite Measurements Z. Li, M. C. Cribb, and F.-L. Chang Earth System Science Interdisciplinary Center University of Maryland College Park, Maryland A. P. Trishchenko and Y. Luo Canada Centre for Remote Sensing Ottawa, Ontario, Canada Introduction Radiation measurements have been widely employed for evaluating cloud parameterization schemes and model simulation results. As the most comprehensive program aiming to improve cloud parameteri- zation schemes, the Atmospheric Radiation Measurement (ARM) Program has an essential goal to make observations on the scale of a general circulation model gridbox, so as to define the physics underlying some of the important parameterizations in the general circulation models used in climate change

439

Searching for Dark Matter Annihilation in the Smith High-Velocity Cloud  

E-Print Network [OSTI]

Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith Cloud make it a tempting target for the indirect detection of dark matter annihilation. We argue that the Smith Cloud may be a better target than some Milky Way dwarf spheroidal satellite galaxies and use gamma-ray observations from the Fermi Large Area Telescope to search for a dark matter annihilation signal. No significant gamma-ray excess is found coincident with the Smith Cloud, and we set strong limits on the dark matter annihilation cross section assuming a spatially-extended dark matter profile consistent with dynamical modeling of the Smith Cloud. Notably, these limits exclude the canonical thermal relic cross section ($\\sim 3\\times10^{-26}{\\rm cm}^{3}{\\rm s}^{-1}$) for dark matter masses $\\lesssim 30$ GeV annihilating via the $b \\bar b$ or $\\tau^{+}\\tau^{-}$ channels for certain assumptions of the dark matter density profile; however, uncertainties in the dark matter content of the Smith Cloud may significantly weaken these constraints.

Alex Drlica-Wagner; German A. Gomez-Vargas; John W. Hewitt; Tim Linden; Luigi Tibaldo

2014-06-30T23:59:59.000Z

440

On the Relationship between Thermodynamic Structure and Cloud Top, and Its Climate Significance in the Arctic  

E-Print Network [OSTI]

inside inversion (CII)] was frequently observed at central Arctic Ocean sites, while observations from- nitudes of surface cloud warming and cooling are de- pendent upon the solar zenith angle, surface albedo-D-11-00186.1 ? 2012 American Meteor

Shupe, Matthew

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


441

Contribution of Microbial Activity to Carbon Chemistry in Clouds  

Science Journals Connector (OSTI)

...of their atmospheric transport that atmospheric particles...undergo several condensation-evaporation...in cloud water. Clouds...of cloud water, precipitation...Microbiology and atmospheric processes...resource recovery. IWA Publishing...

Mickal Vatilingom; Pierre Amato; Martine Sancelme; Paolo Laj; Maud Leriche; Anne-Marie Delort

2009-10-23T23:59:59.000Z

442

V-041: Red Hat CloudForms Multiple Vulnerabilities | Department...  

Energy Savers [EERE]

V-041: Red Hat CloudForms Multiple Vulnerabilities V-041: Red Hat CloudForms Multiple Vulnerabilities December 6, 2012 - 4:01am Addthis PROBLEM: Red Hat CloudForms Multiple...

443

Building mobile multimedia services: a hybrid cloud computing approach  

Science Journals Connector (OSTI)

Second, we use a hybrid cloud computing...strategy. That means the i5Cloud takes advantage of in-house commodity hardware infrastructure which is usually available in most organizations, ... , i5Cloud can automat...

Dejan Kovachev; Yiwei Cao; Ralf Klamma

2014-05-01T23:59:59.000Z

444

E-Cloud Build-up in Grooved Chambers  

E-Print Network [OSTI]

and F. Zimmermann, LC e-Cloud Activities at CERN, talkal. , Simulations of the Electron Cloud for Vari- ous Con?E-CLOUD BUILD-UP IN GROOVED CHAMBERS ? M. Venturini LBNL,

Venturini, Marco

2007-01-01T23:59:59.000Z

445

A cloud-assisted design for autonomous driving  

E-Print Network [OSTI]

This paper presents Carcel, a cloud-assisted system for autonomous driving. Carcel enables the cloud to have access to sensor data from autonomous vehicles as well as the roadside infrastructure. The cloud assists autonomous ...

Suresh Kumar, Swarun

446

Deriving cloud velocity from an array of solar radiation measurements  

E-Print Network [OSTI]

K. , 2011. US20110060475. Cloud tracking. U.S. Patent Bedka,technique for obtaining cloud motion from geosynchronouson advection of a frozen cloud field (Chow et al. (2011);

Bosch, J.L.; Zheng, Y.; Kleissl, J.

2013-01-01T23:59:59.000Z

447

ARM - Field Campaign - Midlatitude Continental Convective Clouds Experiment  

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

Experiment Experiment (MC3E): Multi-Frequency Profilers Related Campaigns Midlatitude Continental Convective Clouds Experiment (MC3E) 2011.04.22, Jensen, SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers 2011.04.22 - 2011.06.06 Lead Scientist : Christopher Williams For data sets, see below. Description The scientific focus was to study the vertical structure of precipitation in a vertical column over the SGP Central Facility. These multi-frequency profiler observations enabled directly measuring the vertical air motion and retrieving the raindrop size distributions from near the surface to just under the freezing level. These profilers were deployed during MC3E

448

Cloud point determination using a thickness shear mode resonator  

SciTech Connect (OSTI)

Crude oils and crude oil products contain substantial amounts of petroleum waxes, consisting of a distribution of high molecular weight hydrocarbons. These waxes or paraffins have limited solubility in oil and tend to precipitate out at a temperature determined by the concentration and constituents of the wax. Precipitation and deposition of wax results in narrowing of pipelines, making crude oil recovery difficult. A parameter of practical importance is the wax precipitation temperature, traditionally known as the cloudpoint, at which visible crystallization occurs. Deposition problems arise in oil field operations at or below this temperature. Several techniques can be used to determine the cloud point: (1) visual observation, (2) viscosity measurement, (3) differential thermal analysis, and (4) pulsed nuclear magnetic resonance. This report describes a method for determination of cloud point with the use of a thickness shear mode resonator.

Spates, J.J. [Ktech Corp., Albuquerque, NM (United States); Martin, S.J.; Mansure, A.J. [Sandia National Lab., Albuquerque, NM (United States); Germer, J.W. [Petrolite Corp., St. Louis, MO (United States)

1995-12-31T23:59:59.000Z

449

SGP Cloud and Land Surface Interaction Campaign (CLASIC): Measurement Platforms  

SciTech Connect (OSTI)

The Cloud and Land Surface Interaction Campaign (CLASIC) will be conducted from June 8 to June 30, 2007, at the U.S. Department of Energys Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. Data will be collected using eight aircraft equipped with a variety of specialized sensors, four specially instrumented surface sites, and two prototype surface radar systems. The architecture of CLASIC includes a high-altitude surveillance aircraft and enhanced vertical thermodynamic and wind profile measurements that will characterize the synoptic scale structure of the clouds and the land surface within the ACRF SGP site. Mesoscale and microscale structures will be sampled with a variety of aircraft, surface, and radar observations. An overview of the measurement platforms that will be used during the CLASIC are described in this report. The coordination of measurements, especially as it relates to aircraft flight plans, will be discussed in the CLASIC Implementation Plan.

MA Miller; R Avissar; LK Berg; SA Edgerton; ML Fischer; TJ Jackson; B. Kustas; PJ Lamb; G McFarquhar; Q Min; B Schmid; MS Torn; DD Tuner

2007-06-01T23:59:59.000Z

450

Electron Cloud Effects in Accelerators  

SciTech Connect (OSTI)

Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

Furman, M.A.

2012-11-30T23:59:59.000Z

451

Tracking tropical cloud systems for the diagnosis of simulations by the weather research and forecasting (WRF) model  

SciTech Connect (OSTI)

To aid in improving model parameterizations of clouds and convection, we examine the capability of models, using explicit convection, to simulate the life cycle of tropical cloud systems in the tropical warm pool. The cloud life cycle is determined using a satellite cloud tracking algorithm (Boer and Ramanathan, J. Geophys. Res., 1997), and the statistics are compared to those of simulations using the Weather Research and Forecasting (WRF) Model. Using New York Blue, a Blue Gene/L supercomputer that is co-operated by Brookhaven and Stony Brook, simulations are run at a resolution comparable to the observations. Initial results suggest that the organization of the mesoscale convective systems is particularly sensitive to the cloud microphysics parameterization used.

Vogelmann, A.M.; Lin, W.; Cialella, A.; Luke, E. P.; Jensen, M. P.; Zhang, M. H.; Boer, E.

2010-06-27T23:59:59.000Z

452

THE GALACTIC CENTER CLOUD G0.253+0.016: A MASSIVE DENSE CLOUD WITH LOW STAR FORMATION POTENTIAL  

SciTech Connect (OSTI)

We present the first interferometric molecular line and dust emission maps for the Galactic Center (GC) cloud G0.253+0.016, observed using CARMA and the SMA. This cloud is very dense, and concentrates a mass exceeding the Orion Molecular Cloud Complex (2 Multiplication-Sign 10{sup 5} M{sub Sun }) into a radius of only 3 pc, but it is essentially starless. G0.253+0.016 therefore violates ''star formation laws'' presently used to explain trends in galactic and extragalactic star formation by a factor {approx}45. Our observations show a lack of dense cores of significant mass and density, thus explaining the low star formation activity. Instead, cores with low densities and line widths {approx}< 1 km s{sup -1}-probably the narrowest lines reported for the GC region to date-are found. Evolution over several 10{sup 5} yr is needed before more massive cores, and possibly an Arches-like stellar cluster, could form. Given the disruptive dynamics of the GC region, and the potentially unbound nature of G0.253+0.016, it is not clear that this evolution will happen.

Kauffmann, Jens; Pillai, Thushara [Astronomy Department, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Zhang Qizhou, E-mail: jens.kauffmann@astro.caltech.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS78, Cambridge, MA 02138 (United States)

2013-03-10T23:59:59.000Z

453

Sulfate aerosols and polar stratospheric cloud formation  

SciTech Connect (OSTI)

Before the discovery of the Antarctic ozone hole, it was generally assumed that gas-phase chemical reactions controlled the abundance of stratospheric ozone. However, the massive springtime ozone losses over Antarctica first reported by Farman et al in 1985 could not be explained on the basis of gas-phase chemistry alone. In 1986, Solomon et al suggested that chemical reactions occurring on the surfaces of polar stratospheric clouds (PSCs) could be important for the observed ozone losses. Since that time, an explosion of laboratory, field, and theoretical research in heterogeneous atmospheric chemistry has occurred. Recent work has indicated that the most important heterogeneous reaction on PSCs is ClONO[sub 2] + HCl [yields] Cl[sub 2] + HNO[sub 3]. This reaction converts inert chlorine into photochemically active Cl[sub 2]. Photolysis of Cl[sub 2] then leads to chlorine radicals capable of destroying ozone through very efficient catalytic chain reactions. New observations during the second Airborne Arctic Stratospheric Expedition found stoichiometric loss of ClONO[sub 2] and HCl in air processed by PSCs in accordance with reaction 1. Attention is turning toward understanding what kinds of aerosols form in the stratospheric, their formation mechanism, surface area, and specific chemical reactivity. Some of the latest findings, which underline the importance of aerosols, were presented at a recent National Aeronautics and Space Administration workshop in Boulder, Colorado.

Tolbert, M.A. (Univ. of Colorado, Boulder, CO (United States))

1994-04-22T23:59:59.000Z

454

Network Performance of a Video Application in the Cloud.  

E-Print Network [OSTI]

??Cloud computing is a technology that uses the internet and central remote servers to maintain data and applications. There are different cloud services of which (more)

NARISETTY, SHRAVAN

2012-01-01T23:59:59.000Z

455

Overview of the COPS Aerosol and Cloud Microphysics (ACM) Subgroup...  

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

properties of orographically induced clouds and how do these depend on dynamics, thermodynamics, and aerosol microphysics? * What is the role of aerosols and changing cloud...

456

Direct Numerical Simulations and Robust Predictions of Cloud...  

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

the center of the bubble cloud. Credit: Computational Science and Engineering Laboratory, ETH Zurich, Switzerland Direct Numerical Simulations and Robust Predictions of Cloud...

457

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

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

458

Smoking Rain Clouds over the Amazon  

Science Journals Connector (OSTI)

...processes affect the water cycle, the pollution...the dynamics of atmospheric circulation. Several...concentrations of cloud condensation nuclei (CCN) in the...transport cloud water in deep convection...concentrations result in recovery of drop size. However...background. Stronger atmospheric instability and a...

M. O. Andreae; D. Rosenfeld; P. Artaxo; A. A. Costa; G. P. Frank; K. M. Longo; M. A. F. Silva-Dias

2004-02-27T23:59:59.000Z

459

Atmospheric chemistry: Thwarting the seeds of clouds  

Science Journals Connector (OSTI)

... The ephemeral cloud of tiny drops that you see above the spout of your teapot forms in the same way as clouds in the sky by the condensation of ... the number of nanometre-sized particles formed through nucleation, similar to what happens above the teapot, except that organic molecules rather than water molecules are involved. ...

Paul J. Ziemann

2009-09-16T23:59:59.000Z

460

Public Cloud B CarbonEmission  

E-Print Network [OSTI]

Sensors, Demand Prediction Power Capping, Green Software Services such as energy-efficient scientific) Request a Cloud service 4) Allocate service 5) Request service allocation 3) Request energy efficiency information Green Offer Directory 2) Request any `Green Offer' Routers Internet Green Broker #12;Cloud

Buyya, Rajkumar

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


461

The CloudNets Network Virtualization Architecture  

E-Print Network [OSTI]

Nets Network Virtualization Architecture Johannes Grassler jgrassler@inet.tu-berlin.de 05. Februar, 2014 Johannes Grassler jgrassler@inet.tu-berlin.de The CloudNets Network Virtualization Architecture #12;..... . .... . .... . ..... . .... . .... . .... . ..... . .... . .... . .... . ..... . .... . .... . .... . ..... . .... . ..... . .... . .... . Johannes Grassler jgrassler@inet.tu-berlin.de The CloudNets Network Virtualization Architecture #12

Schmid, Stefan

462

ARM - Field Campaign - Boundary Layer Cloud IOP  

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

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

463

GALACTIC ALL-SKY SURVEY HIGH-VELOCITY CLOUDS IN THE REGION OF THE MAGELLANIC LEADING ARM  

SciTech Connect (OSTI)

We present a catalog of high-velocity clouds in the region of the Magellanic Leading Arm. The catalog is based on neutral hydrogen (H I) observations from the Parkes Galactic All-Sky Survey. Excellent spectral resolution allows clouds with narrow-line components to be resolved. The total number of detected clouds is 419. We describe the method of cataloging and present the basic parameters of the clouds. We discuss the general distribution of the high-velocity clouds and classify the clouds based on their morphological type. The presence of a significant number of head-tail clouds and their distribution in the region is discussed in the context of Magellanic System simulations. We suggest that ram-pressure stripping is a more important factor than tidal forces for the morphology and formation of the Magellanic Leading Arm and that different environmental conditions might explain the morphological difference between the Magellanic Leading Arm and Magellanic Stream. We also discuss a newly identified population of clouds that forms the LA IV and a new diffuse bridge-like feature connecting the LA II and III complexes.

For, Bi-Qing; Staveley-Smith, Lister [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia)] [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); McClure-Griffiths, N. M., E-mail: biqing.for@uwa.edu.au [Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710 (Australia)

2013-02-10T23:59:59.000Z

464

Midlatitude Continental Convective Clouds Experiment (MC3E)  

SciTech Connect (OSTI)

Convective processes play a critical role in the Earths energy balance through the redistribution of heat and moisture in the atmosphere and subsequent impacts on the hydrologic cycle. Global observation and accurate representation of these processes in numerical models is vital to improving our current understanding and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales that are associated with convective and stratiform precipitation processes; therefore, they must turn to parameterization schemes to represent these processes. In turn, the physical basis for these parameterization schemes needs to be evaluated for general application under a variety of atmospheric conditions. Analogously, space-based remote sensing algorithms designed to retrieve related cloud and precipitation information for use in hydrological, climate, and numerical weather prediction applications often rely on physical parameterizations that reliably translate indirectly related instrument measurements to the physical quantity of interest (e.g., precipitation rate). Importantly, both spaceborne retrieval algorithms and model convective parameterization schemes traditionally rely on field campaign data sets as a basis for evaluating and improving the physics of their respective approaches. The Midlatitude Continental Convective Clouds Experiment (MC3E) will take place in central Oklahoma during the AprilMay 2011 period. The experiment is a collaborative effort between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Aeronautics and Space Administrations (NASA) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The field campaign leverages the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors, and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal is to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that have never before been available. Several different components of convective cloud and precipitation processes tangible to both the convective parameterization and precipitation retrieval algorithm problem are targeted, such as preconvective environment and convective initiation, updraft/downdraft dynamics, condensate transport and detrainment, precipitation and cloud microphysics, spatial and temporal variability of precipitation, influence on the environment and radiation, and a detailed description of the large-scale forcing.

Jensen, MP; Petersen, WA; Del Genio, AD; Giangrande, SE; Heymsfield, A; Heymsfield, G; Hou, AY; Kollias, P; Orr, B; Rutledge, SA; Schwaller, MR; Zipser, E

2010-04-01T23:59:59.000Z

465

Multi Cloud Architecture to Provide Data Security And Integrity  

E-Print Network [OSTI]

Abstract-- Cloud servers are being used to store data and application but its security is a major issue in current context. To solve the data security problems in public environment we propose an effective model for security and integrity of data stored in a cloud, through data segmentation followed by data encryption programs in a multiple cloud architecture. This architecture forms a multi cloud system where primary cloud is available for multiple users for data storage offering lesser load on client systems thereby using the cloud computing architecture. This architecture introduces a secondary cloud controlled by a single administrator which provides the data backup for primary cloud after undergoing specific segmentation and encryption algorithms to ensure security and integrity of data. The proposed system also offers protection against virus attacks by using linux as the base OS. Keywords-- Encryption, Linux, Multi cloud system, Primary cloud, Secondary cloud, Segmentation.

Nikhil Dutta; Himanshu Bakshi; Mujammill Mulla; Viraj Shinde

466

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

SciTech Connect (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, 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

467

Posters Ground-Based Radiometric Observations  

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

7 7 Posters Ground-Based Radiometric Observations of Atmospheric Water for Climate Research J. B. Snider, D. A. Hazen, A. J. Francavilla, W. B. Madsen, and M. D. Jacobson National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction Surface-based microwave and infrared radiometers have been employed by the National Oceanic and Atmospheric Administration's Environmental Technology Laboratory (NOAA/ETL) in climate research since 1987. The ability of these systems to operate continuously and unattended for extended periods of time has provided significant new information on atmospheric water vapor and cloud liquid. These data are being employed to improve our understanding of cloud-radiation feedback mechanisms, an understanding

468

THE MAGELLANIC QUASARS SURVEY. III. SPECTROSCOPIC CONFIRMATION OF 758 ACTIVE GALACTIC NUCLEI BEHIND THE MAGELLANIC CLOUDS  

SciTech Connect (OSTI)

The Magellanic Quasars Survey (MQS) has now increased the number of quasars known behind the Magellanic Clouds by almost an order of magnitude. All survey fields in the Large Magellanic Cloud (LMC) and 70% of those in the Small Magellanic Cloud (SMC) have been observed. The targets were selected from the third phase of the Optical Gravitational Lensing Experiment (OGLE-III) based on their optical variability, mid-IR, and/or X-ray properties. We spectroscopically confirmed 758 quasars (565 in the LMC and 193 in the SMC) behind the clouds, of which 94% (527 in the LMC and 186 in the SMC) are newly identified. The MQS quasars have long-term (12 yr and growing for OGLE), high-cadence light curves, enabling unprecedented variability studies of quasars. The MQS quasars also provide a dense reference grid for measuring both the internal and bulk proper motions of the clouds, and 50 quasars are bright enough (I ?< 18 mag) for absorption studies of the interstellar/intergalactic medium of the clouds.

Koz?owski, Szymon; Udalski, Andrzej; Szyma?ski, M. K.; Kubiak, M.; Pietrzy?ski, G.; Soszy?ski, I.; Wyrzykowski, ?.; Ulaczyk, K.; Poleski, R.; Pietrukowicz, P.; Skowron, J. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Onken, Christopher A. [Research School of Astronomy and Astrophysics, The Australian National University, Canberra 2611 (Australia); Kochanek, Christopher S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Bonanos, A. Z., E-mail: simkoz@astrouw.edu.pl, E-mail: onken@mso.anu.edu.au, E-mail: ckochanek@astronomy.ohio-state.edu [National Observatory of Athens, Institute of Astronomy, Astrophysics, Space Applications and Remote Sensing, I. Metaxa and Vas. Pavlou St., Palaia Penteli, 15236 Athens (Greece); Collaboration: OGLE Collaboration

2013-10-01T23:59:59.000Z

469

Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics  

SciTech Connect (OSTI)

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

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

2013-10-01T23:59:59.000Z

470

Remote Sensing Observations from MTI Satellites and GMS Over Tropical Island of Nauru  

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

Remote Sensing Observations from MTI Satellites and Remote Sensing Observations from MTI Satellites and GMS Over Tropical Island of Nauru W. M. Porch, P. Chylek, and B. Henderson Los Alamos National Laboratory Los Alamos, New Mexico Introduction The observations of island cloud trails have revealed a strong relationship between the character and frequency of occurrence of island cloud trails and the Tropical Ocean Southern Oscillation (MacFarlane et al. 2004 a, b). Island cloud trails from the U.S. Department of Energy's (DOE) Atmospheric and Radiation Measurement (ARM) facility of Nauru persist for more than 50 km (Nordeen et al. 2001) and resemble ship trail clouds found in the Eastern Ocean Margins (Porch et al. 1999). Island trail clouds are much more frequently observed during La Niña periods than El Niño periods (Figure 1). This

471

The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign  

SciTech Connect (OSTI)

The ALTOS campaign focuses on operating a tethered observing system for routine in situ sampling of low-level (< 2 km) Arctic clouds. It has been a long-term hope to fly tethered systems at Barrow, Alaska, but it is clear that the Federal Aviation Administration (FAA) will not permit in-cloud tether systems at Barrow, even if unmanned aerial vehicle (UAV) operations are allowed in the future. We have provided the scientific rationale for long-term, routine in situ measurements of cloud and aerosol properties in the Arctic. The existing restricted air space at Oliktok offers an opportunity to do so.

Verlinde, J

2010-10-18T23:59:59.000Z

472

Multi-Phase Galaxy Formation: High Velocity Clouds and the Missing Baryon Problem  

E-Print Network [OSTI]

The standard treatment of cooling in Cold Dark Matter halos assumes that all of the gas within a ``cooling radius'' cools and contracts monolithically to fuel galaxy formation. Here we take into account the expectation that the hot gas in galactic halos is thermally unstable and prone to fragmentation during cooling and show that the implications are more far-reaching than previously expected: allowing multi-phase cooling fundamentally alters expectations about gas infall in halos and naturally explains the bright-end cutoff in the galaxy luminosity function. We argue that cooling should proceed via the formation of high-density, 10^4 K clouds, pressure-confined within a hot gas background. The background medium has a low density, and can survive as a stable corona with a long cooling time. The fraction of baryons contained in the residual hot core grows with halo mass because the cooling density increases, and this leads to an upper-mass limit in quiescent, non-merged galaxies of ~10^11 Msun. In this scenario, galaxy formation is fueled by the infall of pressure-supported clouds. For Milky-Way-size systems, clouds of mass ~ 5x10^6 Msun that formed or merged within the last several Gyrs should still exist as a residual population in the halo, with a total mass in clouds of ~ 2 x 10^10 Msun. The mass of the Milky Way galaxy is explained naturally in this model, and is a factor of two smaller than would result in the standard treatment without feedback. We expect clouds in galactic halos to be ~ 1 kpc in size and to extend ~150 kpc from galactic centers. The predicted properties of clouds match well the observed radial velocities, angular sizes, column densities, and velocity widths of High Velocity Clouds around our Galaxy. The clouds also explain high-ion absorption systems at z<1.

Ariyeh H. Maller; James S. Bullock

2004-06-28T23:59:59.000Z