National Library of Energy BETA

Sample records for radiometric cloud properties

  1. Estimation of the cloud transmittance from radiometric measurements at the ground level

    SciTech Connect (OSTI)

    Costa, Dario; Mares, Oana

    2014-11-24

    The extinction of solar radiation due to the clouds is more significant than due to any other atmospheric constituent, but it is always difficult to be modeled because of the random distribution of clouds on the sky. Moreover, the transmittance of a layer of clouds is in a very complex relation with their type and depth. A method for estimating cloud transmittance was proposed in Paulescu et al. (Energ. Convers. Manage, 75 690–697, 2014). The approach is based on the hypothesis that the structure of the cloud covering the sun at a time moment does not change significantly in a short time interval (several minutes). Thus, the cloud transmittance can be calculated as the estimated coefficient of a simple linear regression for the computed versus measured solar irradiance in a time interval ?t. The aim of this paper is to optimize the length of the time interval ?t. Radiometric data measured on the Solar Platform of the West University of Timisoara during 2010 at a frequency of 1/15 seconds are used in this study.

  2. Microwave and Millimeter-Wave Radiometric Studies of Temperature, Water Vapor and Clouds

    SciTech Connect (OSTI)

    Westwater, Edgeworth

    2011-05-06

    The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement (ARM) Program. At the North Slope of Alaska (NSA), both microwave radiometers (MWR) and the MWRProfiler (MWRP), been used operationally by ARM for passive retrievals of the quantities: Precipitable Water Vapor (PWV) and Liquid Water Path (LWP). However, it has been convincingly shown that these instruments are inadequate to measure low amounts of PWV and LWP. In the case of water vapor, this is especially important during the Arctic winter, when PWV is frequently less than 2 mm. For low amounts of LWP (< 50 g/m{sup 2}), the MWR and MWRP retrievals have an accuracy that is also not acceptable. To address some of these needs, in March-April 2004, NOAA and ARM conducted the NSA Arctic Winter Radiometric Experiment - Water Vapor Intensive Operational Period at the ARM NSA/Adjacent Arctic Ocean (NSA/AAO) site. After this experiment, the radiometer group at NOAA moved to the Center for Environmental Technology (CET) of the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. During this 2004 experiment, a total of 220 radiosondes were launched, and radiometric data from 22.235 to 380 GHz were obtained. Primary instruments included the ARM MWR and MWRP, a Global Positioning System (GPS), as well as the CET Ground-based Scanning Radiometer (GSR). We have analyzed data from these instruments to answer several questions of importance to ARM, including: (a) techniques for improved water vapor measurements; (b) improved calibration techniques during cloudy conditions; (c) the spectral response of radiometers to a variety of conditions: clear, liquid, ice, and mixed phase clouds; and (d) forward modeling of microwave and millimeter wave brightness temperatures from 22 to 380 GHz. Many of these results have been published in the open literature. During the third year of this contract, we participated in another ARM-sponsored experiment at the NSA during February-March 2007. This experiment is called the Radiative Heating in Underexplored Bands Campaign (RHUBC) and the GSR was operated successfully for the duration of the campaign. One of the principal goals of the experiment was to provide retrievals of water vapor during PWV amounts less than 2 mm and to compare GSR data with ARM radiometers and radiosondes. A secondary goal was to compare the radiometric response of the microwave and millimeter wavelength radiometers to water and ice clouds. In this final report, we will include the separate progress reports for each of the three years of the project and follow with a section on major accomplishments of the project.

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

    E-Print Network [OSTI]

    Hartmann, Dennis

    Computing and Partitioning Cloud Feedbacks Using Cloud Property Histograms. Part I: Cloud Radiative 2011) ABSTRACT This study proposes a novel technique for computing cloud feedbacks using histograms integrated cloud feedbacks computed in this manner agree remarkably well with the adjusted change in cloud

  4. CLOUD CLASSIFICATION AND CLOUD PROPERTY RETRIEVAL FROM MODIS , W. Paul Menzel

    E-Print Network [OSTI]

    Li, Jun

    6.4 CLOUD CLASSIFICATION AND CLOUD PROPERTY RETRIEVAL FROM MODIS AND AIRS Jun Li * , W. Paul Menzel Observing System's (EOS) Aqua satellite enable global monitoring of the distribution of clouds. The MODIS is able to provide at high spatial resolution (1 ~ 5km) a cloud mask, surface and cloud types, cloud phase

  5. Clouds 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    Uncertainties associated with the microphysical and radiative properties of ice clouds remain an active research area because of the importance these clouds have in atmospheric radiative transfer problems and the energy balance of the Earth...

  6. Cloud Property Retrieval Products for Graciosa Island, Azores

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

    Dong, Xiquan

    2014-05-05

    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.

  7. Cloud Property Retrieval Products for Graciosa Island, Azores

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

    Dong, Xiquan

    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.

  8. A 3D STOCHASTIC CLOUD MODEL FOR INVESTIGATING THE RADIATIVE PROPERTIES OF INHOMOGENEOUS CIRRUS CLOUDS

    E-Print Network [OSTI]

    Hogan, Robin

    A 3D STOCHASTIC CLOUD MODEL FOR INVESTIGATING THE RADIATIVE PROPERTIES OF INHOMOGENEOUS CIRRUS CLOUDS Robin J. Hogan and Sarah F. Kew ˇ Department of Meteorology, University of Reading, Reading, Berkshire, United Kingdom 1 INTRODUCTION The importance of ice clouds on the earth's radiation budget

  9. Cloud Properties and Radiative Heating Rates for TWP

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

    Comstock, Jennifer

    2013-11-07

    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.

  10. Cloud Properties and Radiative Heating Rates for TWP

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

    Comstock, Jennifer

    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.

  11. Cloud Scavenging Effects on Aerosol Radiative and Cloud-nucleating Properties - Final Technical Report

    SciTech Connect (OSTI)

    Ogren, John A.; Sheridan, Patrick S.; Andrews, Elisabeth

    2009-03-05

    The optical properties of aerosol particles are the controlling factors in determining direct aerosol radiative forcing. These optical properties depend on the chemical composition and size distribution of the aerosol particles, which can change due to various processes during the particles’ lifetime in the atmosphere. Over the course of this project we have studied how cloud processing of atmospheric aerosol changes the aerosol optical properties. A counterflow virtual impactor was used to separate cloud drops from interstitial aerosol and parallel aerosol systems were used to measure the optical properties of the interstitial and cloud-scavenged aerosol. Specifically, aerosol light scattering, back-scattering and absorption were measured and used to derive radiatively significant parameters such as aerosol single scattering albedo and backscatter fraction for cloud-scavenged and interstitial aerosol. This data allows us to demonstrate that the radiative properties of cloud-processed aerosol can be quite different than pre-cloud aerosol. These differences can be used to improve the parameterization of aerosol forcing in climate models.

  12. Computing and Partitioning Cloud Feedbacks Using Cloud Property Histograms. Part II: Attribution to Changes in Cloud Amount, Altitude, and Optical Depth

    E-Print Network [OSTI]

    Hartmann, Dennis

    Computing and Partitioning Cloud Feedbacks Using Cloud Property Histograms. Part II: Attribution to Changes in Cloud Amount, Altitude, and Optical Depth MARK D. ZELINKA Department of Atmospheric Sciences received 12 May 2011, in final form 15 November 2011) ABSTRACT Cloud radiative kernels and histograms

  13. Tropical Cloud Properties and Radiative Heating Profiles

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

    Mather, James

    2008-01-15

    We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.

  14. Tropical Cloud Properties and Radiative Heating Profiles

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

    Mather, James

    We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.

  15. The Structure of the Local Interstellar Medium IV: Dynamics, Morphology, Physical Properties, and Implications of Cloud-Cloud Interactions

    E-Print Network [OSTI]

    Seth Redfield; Jeffrey L. Linsky

    2007-09-27

    We present an empirical dynamical model of the local interstellar medium based on 270 radial-velocity measurements for 157 sight lines toward nearby stars. Physical-parameter measurements (i.e., temperature, turbulent velocity, depletions) are available for 90 components, or one-third of the sample, enabling initial characterizations of the physical properties of LISM clouds. The model includes 15 warm clouds located within 15 pc of the Sun, each with a different velocity vector. We derive projected morphologies of all clouds and estimate the volume filling factor of warm partially ionized material in the LISM to be between ~5.5% and 19%. Relative velocities of potentially interacting clouds are often supersonic, consistent with heating, turbulent, and metal-depletion properties. Cloud-cloud collisions may be responsible for the filamentary morphologies found in ~1/3 of LISM clouds, the distribution of clouds along the boundaries of the two nearest clouds (LIC and G), the detailed shape and heating of the Mic Cloud, the location of nearby radio scintillation screens, and the location of a LISM cold cloud. Contrary to previous claims, the Sun appears to be located in the transition zone between the LIC and G Clouds.

  16. Properties of the Molecular Clouds in NGC 205

    E-Print Network [OSTI]

    L. M. Young

    2000-07-12

    The nearby dwarf elliptical galaxy NGC 205 offers a unique opportunity for high resolution studies of the interstellar medium in an elliptical galaxy. This paper investigates the distribution of molecular gas, molecular line ratios, and the relationships between atomic gas, molecular gas, and dust in NGC 205. The line ratios 12CO(2-1)/(1-0) and 12CO(1-0)/13CO(1-0) in one of the molecular clouds in NGC 205 are consistent with the ratios found in other elliptical galaxies and in Galactic giant molecular clouds; they suggest that the CO in this cloud is probably subthermally excited. Atomic gas, molecular gas, and dust are very closely associated on scales of 100 pc; the atomic gas can be understood as photodissociated envelopes around the molecular clouds. The atomic column densities in this galaxy are quite low (10^20 cm^-2) because the interstellar UV field is relatively low. The total gas-to-dust column density ratios are consistent with Galactic gas-to-dust ratios. In short, the molecular gas in NGC 205 seems to have very similar properties to the familiar molecular clouds in our own Galaxy, except for the low atomic column densities.

  17. Cluster analysis of cloud properties : a method for diagnosing cloud-climate feedbacks

    E-Print Network [OSTI]

    Gordon, Neil D.

    2008-01-01

    Zhang (2004), Comparing clouds and their seasonal variationstropical greenhouse effect and cloud radiative forcing. J.thermodynamic components of cloud changes. Clim. Dyn. , 22,

  18. The roles of cloud drop effective radius and LWP in determining rain properties in marine stratocumulus

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    The roles of cloud drop effective radius and LWP in determining rain properties in marine that adding cloud condensation nuclei to marine stratocumulus can prevent their breakup from closed into open in terms of cloud drop effective radius (re). Rain is initiated when re near cloud top is around 12­14 mm

  19. On the Microphysical Properties of Ice Clouds as Inferred from the Polarization of Electromagnetic Waves 

    E-Print Network [OSTI]

    Cole, Benjamin

    2012-10-19

    Uncertainties associated with the microphysical and radiative properties of ice clouds remain an active research area because of the importance these clouds have in atmospheric radiative transfer problems and the energy balance of the Earth...

  20. Study of cloud properties from single-scattering, radiative forcing, and retrieval perspectives 

    E-Print Network [OSTI]

    Lee, Yong-Keun

    2009-06-02

    This dissertation reports on three different yet related topics in light scattering computation, radiative transfer simulation, and remote sensing implementation, regarding the cloud properties and the retrieval of cloud ...

  1. On the Feasibility of Precisely Measuring the Properties of a Precipitating Cloud with a Weather Radar 

    E-Print Network [OSTI]

    Runnels, R.C.

    1967-01-01

    In this paper the results of an investigation are presented that are concerned with the feasibility of employing a weather radar to make precise measurements of the properties of a precipitating cloud. A schematic cloud ...

  2. Radiometrics | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onRAPID/Geothermal/Exploration/Colorado <RAPID/Geothermal/Water Use/NevadaaToolsRadioactiveRadiometrics Jump to:

  3. ARM - Field Campaign - Cirrus Clouds and Aerosol Properties Campaign

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

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  4. ARM - PI Product - Cloud Property Retrieval Products for Graciosa Island,

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska OutreachCalendar NSA Related LinksOxidesProductsCloud Properties

  5. Clouds at Arctic Atmospheric Observatories. Part I: Occurrence and Macrophysical Properties

    E-Print Network [OSTI]

    Shupe, Matthew

    distributions, temperature, mi- crophysical properties, thickness, and phase composition. Arctic cloud to derive estimates of cloud occurrence fraction, vertical distribution, persistence in time, diurnal cycle seasons for which the sun is above the horizon for at least part of the day. 1. Introduction Clouds play

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

    E-Print Network [OSTI]

    Axisa, Duncan

    2011-02-22

    This research focuses on aircraft observational studies of aerosol-cloud interactions in cumulus clouds. The data were collected in the summer of 2004, the spring of 2007 and the mid-winter and spring of 2008 in Texas, ...

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

    E-Print Network [OSTI]

    Yi, Bingqi

    2013-07-09

    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...

  8. A Climatology of Midlatitude Continental Clouds from the ARM SGP Central Facility: Part I: Low-Level Cloud Macrophysical, Microphysical, and Radiative Properties

    E-Print Network [OSTI]

    Dong, Xiquan

    A Climatology of Midlatitude Continental Clouds from the ARM SGP Central Facility: Part I: Low Measurement (ARM) Southern Great Plains Central Facility (SCF). The cloud properties include liquid- phase.563 for daytime (nighttime). A new conceptual model of midlatitude continental low clouds at the ARM SGP site has

  9. ANALYSIS WITH RADIOACTIVE REAGENTS AND RADIOMETRIC TITRATION...

    Office of Scientific and Technical Information (OSTI)

    & Separations Chemistry-- Radiometric & Radiochemical Procedures; CHEMICAL ANALYSIS; COMPLEXES; DETERMINATION; PRECIPITATION; RADIOISOTOPES; SEPARATION PROCESSES; TITRATION...

  10. Cloud properties and associated radiative heating rates in the tropical western Pacific

    E-Print Network [OSTI]

    Cloud properties and associated radiative heating rates in the tropical western Pacific James H radiative fluxes and heating rates. Maxima in cloud occurrence are found in the boundary layer and the upper radiative heating rates in the tropical western Pacific, J. Geophys. Res., 112, D05201, doi:10.1029/2006JD

  11. Clouds

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

    the radiative influence of mixed-phase clouds. Further, its impact on the development and evaluation of retrieval schemes from ground- and satellite-based remote sensors is...

  12. High Cloud Properties from Three Years of MODIS Terra and Aqua Collection-4 Data over the Tropics

    E-Print Network [OSTI]

    Baum, Bryan A.

    High Cloud Properties from Three Years of MODIS Terra and Aqua Collection-4 Data over the Tropics) ABSTRACT This study surveys the optical and microphysical properties of high (ice) clouds over the Tropics on the gridded level-3 cloud products derived from the measurements acquired by the Moderate Resolution Imaging

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

    SciTech Connect (OSTI)

    Turner, David D.

    2003-06-01

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

  14. Retrieval of Cloud Microphysical Properties from MODIS and AIRS JUN LI,* HUNG-LUNG HUANG,* CHIAN-YI LIU,* PING YANG, TIMOTHY J. SCHMIT,# HELI WEI,

    E-Print Network [OSTI]

    Li, Jun

    Retrieval of Cloud Microphysical Properties from MODIS and AIRS JUN LI,* HUNG-LUNG HUANG,* CHIAN monitoring of the distribution of clouds during day and night. The MODIS is able to provide a high-spatial-resolution (1­5 km) cloud mask, cloud classification mask, cloud-phase mask, cloud-top pressure (CTP

  15. Retrieving Properties of Thin Clouds from Solar Aureole Measurements

    E-Print Network [OSTI]

    Joss, Paul C.

    This paper describes a newly designed Sun and Aureole Measurement (SAM) aureolegraph and the first results obtained with this instrument. SAM measurements of solar aureoles produced by cirrus and cumulus clouds were taken ...

  16. Cloud-Driven Changes in Aerosol Optical Properties - Final Technical Report

    SciTech Connect (OSTI)

    Ogren, John A.; Sheridan, Patrick S.; Andrews, Elisabeth

    2007-09-30

    The optical properties of aerosol particles are the controlling factors in determining direct aerosol radiative forcing. These optical properties depend on the chemical composition and size distribution of the aerosol particles, which can change due to various processes during the particles’ lifetime in the atmosphere. Over the course of this project we have studied how cloud processing of atmospheric aerosol changes the aerosol optical properties. A counterflow virtual impactor was used to separate cloud drops from interstitial aerosol and parallel aerosol systems were used to measure the optical properties of the interstitial and cloud-scavenged aerosol. Specifically, aerosol light scattering, back-scattering and absorption were measured and used to derive radiatively significant parameters such as aerosol single scattering albedo and backscatter fraction for cloud-scavenged and interstitial aerosol. This data allows us to demonstrate that the radiative properties of cloud-processed aerosol can be quite different than pre-cloud aerosol. These differences can be used to improve the parameterization of aerosol forcing in climate models.

  17. Properties of a Molecular Cloud in NGC 185

    E-Print Network [OSTI]

    L. M. Young

    2001-07-10

    The dwarf elliptical galaxy NGC 185- the closest early-type galaxy with detectable molecular gas- offers a unique opportunity for high angular resolution studies of the interstellar medium in early-type galaxies. I present interferometric images (17 pc $\\times$ 14 pc resolution) of CO emission from NGC 185. The majority of the molecular gas in NGC 185 is in one resolved cloud, closely associated with dust and an HI structure which may be a photodissociated envelope. The high spatial resolution also reveals a velocity gradient across the cloud, which allows a dynamical mass estimate independent of the H2/CO conversion factor or the virial theorem. The linear sizes, velocity gradients, and dynamical masses of the molecular clouds in NGC 185 and NGC 205, a similar dwarf elliptical, are comparable to those of the largest Galactic giant molecular clouds (GMCs). If the dynamical masses of the clouds are assumed to be good estimates of their true masses, the inferred H2/CO conversion factor in NGC 185 is at least eight times larger than a standard Galactic conversion factor, and the reasons for this difference are not yet understood. In any case, it seems clear that structures similar to Galactic GMCs can form in small elliptical or early type galaxies, even in the absence of spiral density waves.

  18. The impact of explicit cloud boundary information on ice cloud microphysical property retrievals from infrared radiances

    E-Print Network [OSTI]

    Stephens, Graeme L.

    from infrared radiances Steven J. Cooper, Tristan S. L'Ecuyer, and Graeme L. Stephens Department inclusion of explicit cloud boundary information from complementary sensors as well as providing a suite of diagnostic tools for evaluating the dominant sources of uncertainty in all retrieved quantities. Errors

  19. CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES

    E-Print Network [OSTI]

    influence the earth's radiation balance and climate directly, by scanering shortwave (solar) radiation in the earth radiation budget over the industrial period. exerting a radiative forcing that is of comparable. Keywords - Climate. aerosols. clouds, radiation INTRODUcnON In recent years awareness has increased

  20. Cluster analysis of cloud properties : a method for diagnosing cloud-climate feedbacks

    E-Print Network [OSTI]

    Gordon, Neil D.

    2008-01-01

    on computer models to understand the changes to cloudcloud properties with surface temperature from observations rather than from computer

  1. ARM - Publications: Science Team Meeting Documents: Cloud Property

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better AnodeThe Influence of Clouds, Aerosols,Comparison

  2. ARM - Field Campaign - Colorado: The Storm Peak Lab Cloud Property

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve4AJ01) (See22,Microphysical PropertiesgovCampaignsCloudSP2

  3. Solar differential rotation and properties of magnetic clouds

    E-Print Network [OSTI]

    K. Georgieva; B. Kirov; E. Gavruseva; J. Javaraiah

    2005-11-09

    The most geoeffective solar drivers are magnetic clouds - a subclass of coronal mass ejections (CME's) distinguished by the smooth rotation of the magnetic field inside the structure. The portion of CME's that are magnetic clouds is maximum at sunspot minimum and mimimum at sunspot maximum. This portion is determined by the amount of helicity carried away by CME's which in turn depends on the amount of helicity transferred from the solar interior to the surface, and on the surface differential rotation. The latter can increase or reduce, or even reverse the twist of emerging magnetic flux tubes, thus increasing or reducing the helicity in the corona, or leading to the violation of the hemispheric helicity rule, respectively. We investigate the CME's associated with the major geomagnetic storms in the last solar cycle whose solar sources have been identified, and find that in 10 out of 12 cases of violation of the hemispheric helicity rule or of highly geoeffective CME's with no magnetic field rotation, they originate from regions with "anti-solar" type of surface differential rotation.

  4. Comparison of marine boundary layer cloud properties from CERES-MODIS Edition 4 and DOE ARM

    E-Print Network [OSTI]

    Dong, Xiquan

    Comparison of marine boundary layer cloud properties from CERES-MODIS Edition 4 and DOE ARM AMF are compared with observations taken at the Department of Energy Atmospheric Radiation Measurement (ARM) Mobile from ARM ground-based observations were averaged over a 1h interval centered at the satellite overpass

  5. Study of Ice Cloud Properties from Synergetic Use of Satellite Observations and Modeling Capabilities 

    E-Print Network [OSTI]

    Xie, Yu

    2011-02-22

    Shaima Nasiri Gerald North Head of Department, Kenneth Bowman December 2010 Major Subject: Atmospheric Sciences iii ABSTRACT Study of Ice Cloud Properties from Synergetic Use of Satellite..., Shaima Nasiri, and Gerald North. Their detailed and constructive comments have been most helpful in shaping this dissertation. I also wish to acknowledge Drs. Patrick Minnis and Bryan Baum who gave me important guidance throughout this work...

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

    SciTech Connect (OSTI)

    Richard A. Ferrare; David D. Turner

    2011-09-01

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

  7. STORMVEX: The Storm Peak Lab Cloud Property Validation Experiment Science and Operations Plan

    SciTech Connect (OSTI)

    Mace, J; Matrosov, S; Shupe, M; Lawson, P; Hallar, G; McCubbin, I; Marchand, R; Orr, B; Coulter, R; Sedlacek, A; Avallone, L; Long, C

    2010-09-29

    During the Storm Peak Lab Cloud Property Validation Experiment (STORMVEX), a substantial correlative data set of remote sensing observations and direct in situ measurements from fixed and airborne platforms will be created in a winter season, mountainous environment. This will be accomplished by combining mountaintop observations at Storm Peak Laboratory and the airborne National Science Foundation-supported Colorado Airborne Multi-Phase Cloud Study campaign with collocated measurements from the second ARM Mobile Facility (AMF2). We describe in this document the operational plans and motivating science for this experiment, which includes deployment of AMF2 to Steamboat Springs, Colorado. The intensive STORMVEX field phase will begin nominally on 1 November 2010 and extend to approximately early April 2011.

  8. Using MSG-SEVIRI Cloud Physical Properties and Weather Radar Observations for the Detection of Cb/TCu Clouds

    E-Print Network [OSTI]

    Schmeits, Maurice

    , but the former shows a false-alarm ratio that is about 8% lower. Moreover, a big advantage of the newly developed, the energy supply industry, the construction industry, and farmers. The Cb and TCu clouds may pose a serious Society #12;wind shear, heavy precipitation, and lightning, that is associated with these clouds. Also

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

    SciTech Connect (OSTI)

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

    2011-07-06

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

  10. Observed and Simulated Cirrus Cloud Properties at the SGP CART Site

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeeding access to scienceSpeedingLightweightand Simulated Cirrus Cloud Properties

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska OutreachCalendar NSA Related LinksOxidesProductsCloud Properties and

  12. Investigation of the optical and cloud forming properties of pollution, biomass burning, and mineral dust aerosols 

    E-Print Network [OSTI]

    Lee, Yong Seob

    2006-08-16

    that were observed during this period. The predicted cloud condensation nuclei concentrations were used in a cloud model to determine the impact of the different aerosol types on the expected cloud droplet concentration. RH-dependent aerosol extinction...

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

    E-Print Network [OSTI]

    Meyer, Kerry Glynne

    2009-05-15

    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...

  14. Atmospheric Radiation Measurement (ARM) Data from Steamboat Springs, Colorado, for the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX)

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

    In October 2010, the initial deployment of the second ARM Mobile Facility (AMF2) took place at Steamboat Springs, Colorado, for the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX). The objective of this field campaign was to obtain data about liquid and mixed-phase clouds using AMF2 instruments in conjunction with Storm Peak Laboratory (located at an elevation of 3220 meters on Mt. Werner), a cloud and aerosol research facility operated by the Desert Research Institute. STORMVEX datasets are freely available for viewing and download. Users are asked to register with the ARM Archive; the user's email address is used from that time forward as the login name.

  15. The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds

    SciTech Connect (OSTI)

    Busha, Michael T.; Marshall, Philip J.; Wechsler, Risa H.; Klypin, Anatoly; Primack, Joel; /UC, Santa Cruz, Phys. Dept.

    2012-02-29

    We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a {Lambda}CDM universe. The large, high-resolution Bolshoi cosmological simulation of this universe provides a means to statistically sample the dynamical properties of bright satellite galaxies in a large population of dark matter halos. The observed properties of the MCs, including their circular velocity, distance from the center of the MW, and velocity within the MW halo, are used to evaluate the likelihood that a given halo would have each or all of these properties; the posterior probability distribution function (PDF) for any property of the MW system can thus be constructed. This method provides a constraint on the MW virial mass, 1.2{sup +0.7} - {sub 0.4}(stat.){sup +0.3} - {sub 0.3}(sys.) x 10{sup 12} M {circle_dot} (68% confidence), which is consistent with recent determinations that involve very different assumptions. In addition, we calculate the posterior PDF for the density profile of the MW and its satellite accretion history. Although typical satellites of 10{sup 12} M {circle_dot} halos are accreted over a wide range of epochs over the last 10 Gyr, we find a {approx}72% probability that the MCs were accreted within the last Gyr, and a 50% probability that they were accreted together.

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

    SciTech Connect (OSTI)

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

    2012-07-04

    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.

  17. Retrieval of optical and microphysical properties of ice clouds using Atmospheric Radiation Measurement (ARM) data 

    E-Print Network [OSTI]

    Kinney, Jacqueline Anne

    2005-11-01

    The research presented here retrieves the cloud optical thickness and particle effective size of cirrus clouds using surface radiation measurements obtained during the Atmospheric Radiation Measurement (ARM) field campaign. ...

  18. ESTABLISHMENT OF CLOUD REGIMES FOR SYSTEMATIC EVALUATION OF CLOUD MODELING

    E-Print Network [OSTI]

    ESTABLISHMENT OF CLOUD REGIMES FOR SYSTEMATIC EVALUATION OF CLOUD MODELING Wuyin Lin1 , Yangang Liu Distinct cloud regimes can exist locally and globally. Such cloud regimes usually have close association, the classification of cloud regimes may be based on cloud properties and/or meteorological conditions. This study

  19. At this meeting: Oral presentation: Cloud Properties From (A)ATSR (Caroline Poulsen)

    E-Print Network [OSTI]

    Oxford, University of

    sensors including radars, an infrared and microwave sounder unit, and microwave radiometer integrated vertically over each layer separated by cloud base. This strategy makes it possible to evaluate. Recent progress in satellite sensor technology, exempli- fied by hyperspectral sounders and cloud

  20. The Radiative Properties of Small Clouds: Multi-Scale Observations and Modeling

    SciTech Connect (OSTI)

    Feingold, Graham; McComiskey, Allison

    2013-09-25

    Warm, liquid clouds and their representation in climate models continue to represent one of the most significant unknowns in climate sensitivity and climate change. Our project combines ARM observations, LES modeling, and satellite imagery to characterize shallow clouds and the role of aerosol in modifying their radiative effects.

  1. Global Distribution and Climate Forcing of Marine Organic Aerosol - Part 2: Effects on Cloud Properties and Radiative Forcing

    SciTech Connect (OSTI)

    Gantt, Brett; Xu, Jun; Meskhidze, N.; Zhang, Yang; Nenes, Athanasios; Ghan, Steven J.; Liu, Xiaohong; Easter, Richard C.; Zaveri, Rahul A.

    2012-07-25

    A series of simulations with the Community Atmosphere Model version 5 (CAM5) with a 7-mode Modal Aerosol Model were conducted to assess the changes in cloud microphysical properties and radiative forcing resulting from marine organic aerosols. Model simulations show that the anthropogenic aerosol indirect forcing (AIF) predicted by CAM5 is decreased in absolute magnitude by up to 0.09 Wm{sup -2} (7 %) when marine organic aerosols are included. Changes in the AIF from marine organic aerosols are associated with small global increases in low-level incloud droplet number concentration and liquid water path of 1.3 cm{sup -3} (1.5 %) and 0.22 gm{sup -2} (0.5 %), respectively. Areas especially sensitive to changes in cloud properties due to marine organic aerosol include the Southern Ocean, North Pacific Ocean, and North Atlantic Ocean, all of which are characterized by high marine organic emission rates. As climate models are particularly sensitive to the background aerosol concentration, this small but non-negligible change in the AIF due to marine organic aerosols provides a notable link for ocean-ecosystem marine low-level cloud interactions and may be a candidate for consideration in future earth system models.

  2. A Radiometric All-Sky Infrared Camera (RASICAM) for DES/CTIO

    SciTech Connect (OSTI)

    Lewis, Peter M.; Rogers, Howard; Schindler, Rafe H.; /SLAC

    2010-08-25

    A novel radiometric all-sky infrared camera [RASICAM] has been constructed to allow automated real-time quantitative assessment of night sky conditions for the Dark Energy Camera [DECam] located on the Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile. The camera is optimized to detect the position, motion and optical depth of thin, high (8-10km) cirrus clouds and contrails by measuring their apparent temperature above the night sky background. The camera system utilizes a novel wide-field equiresolution catadioptic mirror system that provides sky coverage of 2{pi} azimuth and 14-90{sup o} from zenith. Several new technological and design innovations allow the RASICAM system to provide unprecedented cloud detection and IR-based photometricity quantification. The design of the RASICAM system is presented.

  3. Clouds and Chemistry: Ultracool Dwarf Atmospheric Properties from Optical and Infrared Colors

    E-Print Network [OSTI]

    M. S. Marley; S. Seager; D. Saumon; K. Lodders; A. S. Ackerman; R. Freedman; X Fan

    2001-11-16

    The optical and infrared colors of L and T dwarfs are sensitive to cloud sedimentation and chemical equilibrium processes in their atmospheres. The i'-z' vs. J-K color-color diagram provides a window into diverse atmospheric processes mainly because different chemical processes govern each color, and cloud opacity largely affects J-K but not i'-z'. Using theoretical atmosphere models that include for the first time a self-consistent treatment of cloud formation, we present an interpretation of the i'-z' vs. J-K color trends of known L and T dwarfs. We find that the i'-z' color is extremely sensitive to chemical equilibrium assumptions: chemical equilibrium models accounting for cloud sedimentation predict redder i'-z' colors--by up to 2 magnitudes--than models that neglect sedimentation. We explore the previously known J-K color trends where objects first become redder, then bluer with decreasing effective temperature. Only models that include sedimentation of condensates are able to reproduce these trends. We find that the exact track of a cooling brown in J-K (and i'-z') is very sensitive to the details of clouds, in particular to the efficiency of sedimentation of condensates in its atmosphere. We also find that clouds still affect the strength of the J, H, and K band fluxes of even the coolest T dwarfs. In addition, we predict the locus in the i'-z' vs. J-K color-color diagram of brown dwarfs cooler than yet discovered.

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

    E-Print Network [OSTI]

    September 2007; published 20 December 2007. [1] Measurements from the US Department of Energy Atmospheric or activation through cloud-phase chemistry could provide alternative explanations for M-PACE observations in general cir- culation models, the US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM

  5. IMPLICATIONS OF INFALLING Fe II-EMITTING CLOUDS IN ACTIVE GALACTIC NUCLEI: ANISOTROPIC PROPERTIES

    SciTech Connect (OSTI)

    Ferland, Gary J. [Department of Physics, University of Kentucky, Lexington, KY 40506 (United States); Hu Chen; Wang Jianmin [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Baldwin, Jack A. [Department of Physics and Astronomy, Michigan State University, Lansing, MI (United States); Porter, Ryan L. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Van Hoof, Peter A. M. [Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels (Belgium); Williams, R. J. R. [AWE plc, Aldermaston, Reading RG7 4PR (United Kingdom)

    2009-12-10

    We investigate consequences of the discovery that Fe II emission in quasars, one of the spectroscopic signatures of 'Eigenvector 1', may originate in infalling clouds. Eigenvector 1 correlates with the Eddington ratio L/L {sub Edd} so that Fe II/Hbeta increases as L/L {sub Edd} increases. We show that the 'force multiplier', the ratio of gas opacity to electron scattering opacity, is approx10{sup 3}-10{sup 4} in Fe II-emitting gas. Such gas would be accelerated away from the central object if the radiation force is able to act on the entire cloud. As had previously been deduced, infall requires that the clouds have large column densities so that a substantial amount of shielded gas is present. The critical column density required for infall to occur depends on L/L {sub Edd}, establishing a link between Eigenvector 1 and the Fe II/Hbeta ratio. We see predominantly the shielded face of the infalling clouds rather than the symmetric distribution of emitters that has been assumed. The Fe II spectrum emitted by the shielded face is in good agreement with observations thus solving several long-standing mysteries in quasar emission lines.

  6. THE HERSCHEL EXPLOITATION OF LOCAL GALAXY ANDROMEDA (HELGA). VI. THE DISTRIBUTION AND PROPERTIES OF MOLECULAR CLOUD ASSOCIATIONS IN M31

    SciTech Connect (OSTI)

    Kirk, J. M. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Gear, W. K.; Smith, M. W. L.; Ford, G.; Eales, S. A.; Gomez, H. L. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, Wales CF24 3AA (United Kingdom); Fritz, J.; Baes, M.; De Looze, I.; Gentile, G.; Gordon, K.; Verstappen, J.; Viaene, S. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bendo, G. J. [UK ALMA Regional Centre Node, Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); O'Halloran, B. [Astrophysics Group, Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Madden, S. C.; Lebouteiller, V. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, Irfu/Service, Paris, F-91190 Gif-sur-Yvette (France); Roman-Duval, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Boselli, A. [Laboratoire d'Astrophysique de Marseille, UMR 7326 CNRS, 38 rue F. Joliot-Curie, F-13388 Marseille (France); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); and others

    2015-01-01

    In this paper we present a catalog of giant molecular clouds (GMCs) in the Andromeda (M31) galaxy extracted from the Herschel Exploitation of Local Galaxy Andromeda (HELGA) data set. GMCs are identified from the Herschel maps using a hierarchical source extraction algorithm. We present the results of this new catalog and characterize the spatial distribution and spectral energy properties of its clouds based on the radial dust/gas properties found by Smith et al. A total of 326 GMCs in the mass range 10{sup 4}-10{sup 7} M {sub ?} are identified; their cumulative mass distribution is found to be proportional to M {sup –2.34}, in agreement with earlier studies. The GMCs appear to follow the same correlation of cloud mass to L {sub CO} observed in the Milky Way. However, comparison between this catalog and interferometry studies also shows that the GMCs are substructured below the Herschel resolution limit, suggesting that we are observing associations of GMCs. Following Gordon et al., we study the spatial structure of M31 by splitting the observed structure into a set of spiral arms and offset rings. We fit radii of 10.3 and 15.5 kpc to the two most prominent rings. We then fit a logarithmic spiral with a pitch angle of 8.°9 to the GMCs not associated with either ring. Last, we comment on the effects of deprojection on our results and investigate the effect different models for M31's inclination will have on the projection of an unperturbed spiral arm system.

  7. Thermal and Fragmentation Properties of Star-forming Clouds in Low-metallicity Environments

    E-Print Network [OSTI]

    K. Omukai; T. Tsuribe; R. Schneider; A. Ferrara

    2005-03-01

    The thermal and chemical evolution of star-forming clouds is studied for different gas metallicities, Z, using the model of Omukai (2000), updated to include deuterium chemistry and the effects of cosmic microwave background (CMB) radiation. HD-line cooling dominates the thermal balance of clouds when Z \\~ 10^{-5}-10^{-3} Z_sun and density ~10^{5} cm^{-3}. Early on, CMB radiation prevents the gas temperature to fall below T_CMB, although this hardly alters the cloud thermal evolution in low-metallicity gas. From the derived temperature evolution, we assess cloud/core fragmentation as a function of metallicity from linear perturbation theory, which requires that the core elongation E := (b-a)/a > E_NL ~ 1, where a (b) is the short (long) core axis length. The fragment mass is given by the thermal Jeans mass at E = E_NL. Given these assumptions and the initial (gaussian) distribution of E we compute the fragment mass distribution as a function of metallicity. We find that: (i) For Z=0, all fragments are very massive, > 10^{3}M_sun, consistently with previous studies; (ii) for Z>10^{-6} Z_sun a few clumps go through an additional high density (> 10^{10} cm^{-3}) fragmentation phase driven by dust-cooling, leading to low-mass fragments; (iii) The mass fraction in low-mass fragments is initially very small, but at Z ~ 10^{-5}Z_sun it becomes dominant and continues to grow as Z is increased; (iv) as a result of the two fragmentation modes, a bimodal mass distribution emerges in 0.01 0.1Z_sun, the two peaks merge into a singly-peaked mass function which might be regarded as the precursor of the ordinary Salpeter-like IMF.

  8. A five year global aerosol and cloud properties database from ATSR-2 data1 1 1 1 2 3

    E-Print Network [OSTI]

    Oxford, University of

    angle !Satellite zenith angle !Relative (satellite to Sun) azimuth angle !Value of the cost function !Cloud optical depth 1 !Cloud droplet effective radius 1 !Cloud top temperature 1 !Cloud top pressure 1 provides uncertainty estimates, and level 3 data provides variances, for all relevant parameters. Contact

  9. The effect of ice crystal surface roughness on the retrieval of ice cloud microphysical and optical properties 

    E-Print Network [OSTI]

    Xie, Yu

    2007-09-17

    ?µm). The discrete ordinates radiative transfer (DISORT) model is used to compute the radiances for a set of optical thicknesses, particle effective sizes, viewing and illumination angles, and cloud temperatures. A parameterization of cloud bi...

  10. Final Report - Satellite Calibration and Verification of Remotely Sensed Cloud and Radiation Properties Using ARM UAV Data (February 28, 1995 - February 28, 1998)

    SciTech Connect (OSTI)

    Minnis, Patrick

    1998-02-28

    The work proposed under this agreement was designed to validate and improve remote sensing of cloud and radiation properties in the atmosphere for climate studies with special emphasis on the use of satellites for monitoring these parameters to further the goals of the Atmospheric Radiation Measurement (ARM) Program.

  11. Comparison of CERES-MODIS stratus cloud properties with ground-based measurements at the DOE ARM Southern Great Plains site

    E-Print Network [OSTI]

    Dong, Xiquan

    Comparison of CERES-MODIS stratus cloud properties with ground- based measurements at the DOE ARM are compared with observations taken at the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains site from March 2000 through December 2004. Retrievals from ARM surface-based data

  12. Development of Cloud Microphysical Property Retrievals Using the University of Wisconsin Arctic High Spectral Resolution Lidar

    E-Print Network [OSTI]

    Eloranta, Edwin W.

    .6 2.8 1/(m str) 1e-14 1e-13 1e-12 1e-11 1e-10 1e-9 1e-8 1e-7 October 9,2004 Time (UT) Altitude:50 21:55 22:00 22:05 22:10 22:15 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 1/(m str) 1e-14 1e-13 1e-12 1e-11 1- eterization and Modeling Workgroup to increase our ability to simu- late mixed-phase boundary layer clouds

  13. Electron-Cloud Build-Up: Summary

    E-Print Network [OSTI]

    Furman, M.A.

    2007-01-01

    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

  14. A SYNERGY OF MICROWAVE CLOUD TOMOGRAPHY AND SCANNING RADAR: MOVING TOWARD A 3D VIEW OF CLOUDS

    E-Print Network [OSTI]

    A SYNERGY OF MICROWAVE CLOUD TOMOGRAPHY AND SCANNING RADAR: MOVING TOWARD A 3D VIEW OF CLOUDS D complementary techniques, i.e., cloud microwave tomography and scanning radar, to retrieve 3D cloud properties the sixth moment of cloud droplets, while cloud tomography, by remotely probing cloud microwave emission

  15. Challenge the future 1 Observations of aerosol-cloud-radiation

    E-Print Network [OSTI]

    Graaf, Martin de

    -road Industrial coal Residential solid fuel Biofuel cooking Biofuel heating Coal Open Burning Agricultural fields causes Differences in: · cloud properties · cloud fraction and location · aerosol properties · smoke

  16. The close binary properties of massive stars in the Milky Way and low-metallicity Magellanic Clouds

    SciTech Connect (OSTI)

    Moe, Maxwell; Di Stefano, Rosanne, E-mail: mmoe@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-10, Cambridge, MA 02138 (United States)

    2013-12-01

    In order to understand the rates and properties of Type Ia and Type Ib/c supernovae, X-ray binaries, gravitational wave sources, and gamma-ray bursts as a function of galactic environment and cosmic age, it is imperative that we measure how the close binary properties of O- and B-type stars vary with metallicity. We have studied eclipsing binaries with early B main-sequence primaries in three galaxies with different metallicities: the Large and Small Magellanic Clouds (LMC and SMC, respectively) and the Milky Way (MW). The observed fractions of early B stars that exhibit deep eclipses 0.25 < ?m (mag) < 0.65 and orbital periods 2 < P (days) < 20 in the MW, LMC, and SMC span a narrow range of (0.7-1.0)%, which is a model-independent result. After correcting for geometrical selection effects and incompleteness toward low-mass companions, we find for early B stars in all three environments (1) a close binary fraction of (22 ± 5)% across orbital periods 2 < P (days) < 20 and mass ratios q = M {sub 2}/M {sub 1} > 0.1, (2) an intrinsic orbital period distribution slightly skewed toward shorter periods relative to a distribution that is uniform in log P, (3) a mass-ratio distribution weighted toward low-mass companions, and (4) a small, nearly negligible excess fraction of twins with q > 0.9. Our fitted parameters derived for the MW eclipsing binaries match the properties inferred from nearby, early-type spectroscopic binaries, which further validates our results. There are no statistically significant trends with metallicity, demonstrating that the close binary properties of massive stars do not vary across metallicities –0.7 < log(Z/Z {sub ?}) < 0.0 beyond the measured uncertainties.

  17. Inverse modelling of cloud-aerosol interactions - Part 2: Sensitivity tests on liquid phase clouds using a Markov chain Monte Carlo based simulation approach

    E-Print Network [OSTI]

    Partridge, D. G; Vrugt, J. A; Tunved, P.; Ekman, A. M. L; Struthers, H.; Sorooshian, A.

    2012-01-01

    Seinfeld, J. H. : Aerosol, cloud drop concentration closureof aerosol composition on cloud droplet size distribution –aerosol properties on warm cloud droplet activation, At-

  18. The role of precipitation size distributions in km-scale NWP simulations of intense precipitation: Evaluation of cloud properties and surface precipitation

    SciTech Connect (OSTI)

    Van Weverberg K.; Vogelmann A.; van Lipzig, N. P. M.; Delobbec, L.

    2012-04-01

    We investigate the sensitivity of simulated cloud properties and surface precipitation to assumptions regarding the size distributions of the precipitating hydrometeors in a one-moment bulk microphysics scheme. Three sensitivity experiments were applied to two composites of 15 convective and 15 frontal stratiform intense precipitation events observed in a coastal midlatitude region (Belgium), which were evaluated against satellite-retrieved cloud properties and radar-rain-gauge derived surface precipitation. It is found that the cloud optical thickness distribution was well captured by all experiments, although a significant underestimation of cloudiness occurred in the convective composite. The cloud-top-pressure distribution was improved most by more realistic snow size distributions (including a temperature-dependent intercept parameter and non-spherical snow for the calculation of the slope parameter), due to increased snow depositional growth at high altitudes. Surface precipitation was far less sensitive to whether graupel or hail was chosen as the rimed ice species, as compared to previous idealized experiments. This smaller difference in sensitivity could be explained by the stronger updraught velocities and higher freezing levels in the idealized experiments compared to typical coastal midlatitude environmental conditions.

  19. Ice Nucleation of Bare and Sulfuric Acid-coated Mineral Dust Particles and Implication for Cloud Properties

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Sanders, Cassandra N.; Zhang, Kai; Liu, Xiaohong; Zhao, Chun

    2014-08-27

    Ice nucleation properties of different dust species coated with soluble material are not well understood. We determined the ice nucleation ability of bare and sulfuric acid coated mineral dust particles as a function of temperature (-25 to -35 deg C) and relative humidity with respect to water (RHw). Five different mineral dust species: Arizona test dust (ATD), illite, montmorillonite, quartz and kaolinite were dry dispersed and size-selected at 150 nm and exposed to sulfuric acid vapors in the coating apparatus. The condensed sulfuric acid soluble mass fraction per particle was estimated from the cloud condensation nuclei activated fraction measurements. The fraction of dust particles nucleating ice at various temperatures and RHw was determined using a compact ice chamber. In water-subsaturated conditions, compared to bare dust particles, we found that only coated ATD particles showed suppression of ice nucleation ability while other four dust species did not showed the effect of coating on the fraction of particles nucleating ice. The results suggest that interactions between the dust surface and sulfuric acid vapor are important, such that interactions may or may not modify the surface via chemical reactions with sulfuric acid. At water-supersaturated conditions we did not observed the effect of coating, i.e. the bare and coated dust particles had similar ice nucleation behavior.

  20. First observations of tracking clouds using scanning ARM cloud radars

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

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud fieldmore »and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.« less

  1. First observations of tracking clouds using scanning ARM cloud radars

    SciTech Connect (OSTI)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  2. Reply to Comments on ``Seasonal Variation of the Physical Properties of Marine Boundary Layer Clouds off the California Coast''

    E-Print Network [OSTI]

    Clouds off the California Coast'' WUYIN LIN* AND MINGHUA ZHANG School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York NORMAN G. LOEB NASA Langley Research Center, Hampton the Moderate Resolution Imaging Spectroradi- ometer­Clouds and the Earth's Radiant Energy System (MODIS

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

    E-Print Network [OSTI]

    Li, Yue

    2012-02-14

    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...

  4. Category:Radiometrics | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank,CammackFLIR Jump to:RAPID Roadmap Contact Properties Jump

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

    SciTech Connect (OSTI)

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

    2012-09-28

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

  6. A Herschel study of the properties of starless cores in the Polaris Flare dark cloud region using PACS and SPIRE

    E-Print Network [OSTI]

    Ward-Thompson, D; André, P; Saraceno, P; Didelon, P; Könyves, V; Schneider, N; Abergel, A; Baluteau, J -P; Bernard, J -Ph; Bontemps, S; Cambrésy, L; Cox, P; Di Francesco, J; Di Giorgio, A M; Griffin, M; Hargrave, P; Huang, M; Li, J Z; Martin, P; Men'shchikov, A; Minier, V; Molinari, S; Motte, F; Olofsson, G; Pezzuto, S; Russeil, D; Sauvage, M; Sibthorpe, B; Spinoglio, L; Testi, L; White, G; Wilson, C; Woodcraft, A; Zavagno, A

    2010-01-01

    The Polaris Flare cloud region contains a great deal of extended emission. It is at high declination and high Galactic latitude. It was previously seen strongly in IRAS Cirrus emission at 100 microns. We have detected it with both PACS and SPIRE on Herschel. We see filamentary and low-level structure. We identify the five densest cores within this structure. We present the results of a temperature, mass and density analysis of these cores. We compare their observed masses to their virial masses, and see that in all cases the observed masses lie close to the lower end of the range of estimated virial masses. Therefore, we cannot say whether they are gravitationally bound prestellar cores. Nevertheless, these are the best candidates to be potentialprestellar cores in the Polaris cloud region.

  7. Evaluating Radiometric Measurements Using a Fixed 45 Degrees Responsivity and Zenith Angle Dependent Responsivities (Poster)

    SciTech Connect (OSTI)

    Dooraghi, M.; Habte, A.; Reda, I.; Sengupta, M.; Gotseff, P.; Andreas, A.; Anderberg, M.

    2014-03-01

    This poster seeks to demonstrate the importance and application of an existing but unused approach that ultimately reduces the uncertainty of radiometric measurements. Current radiometric data is based on a single responsivity value that introduces significant uncertainty to the data, however, through using responsivity as a function of solar zenith angle, the uncertainty could be decreased by 50%.

  8. Uncertainty Estimation of Radiometric Data using a Guide to the Expression of Uncertainty in Measurement (GUM) Method

    SciTech Connect (OSTI)

    Habte, Aron

    2015-06-25

    This presentation summarizes uncertainty estimation of radiometric data using the Guide to the Expression of Uncertainty (GUM) method.

  9. Preface: Crowds and Clouds

    E-Print Network [OSTI]

    2012-01-01

    crowdsourcing, cloud computing, big data, and Internetdata include “cloud computing,” “algorithms,” “filters,” “cloud of claims about cloud computing and big data settle

  10. Analysis of Cloud-resolving Simulations of a Tropical Mesoscale Convective System Observed during TWP-ICE: Vertical Fluxes and Draft Properties in Convective and Stratiform Regions

    SciTech Connect (OSTI)

    Mrowiec, Agnieszka A.; Rio, Catherine; Fridlind, Ann; Ackerman, Andrew; Del Genio, Anthony D.; Pauluis, Olivier; Varble, Adam; Fan, Jiwen

    2012-10-02

    We analyze three cloud-resolving model simulations of a strong convective event observed during the TWP-ICE campaign, differing in dynamical core, microphysical scheme or both. Based on simulated and observed radar reflectivity, simulations roughly reproduce observed convective and stratiform precipitating areas. To identify the characteristics of convective and stratiform drafts that are difficult to observe but relevant to climate model parameterization, independent vertical wind speed thresholds are calculated to capture 90% of total convective and stratiform updraft and downdraft mass fluxes. Convective updrafts are fairly consistent across simulations (likely owing to fixed large-scale forcings and surface conditions), except that hydrometeor loadings differ substantially. Convective downdraft and stratiform updraft and downdraft mass fluxes vary notably below the melting level, but share similar vertically uniform draft velocities despite differing hydrometeor loadings. All identified convective and stratiform downdrafts contain precipitation below ~10 km and nearly all updrafts are cloudy above the melting level. Cold pool properties diverge substantially in a manner that is consistent with convective downdraft mass flux differences below the melting level. Despite differences in hydrometeor loadings and cold pool properties, convective updraft and downdraft mass fluxes are linearly correlated with convective area, the ratio of ice in downdrafts to that in updrafts is ~0.5 independent of species, and the ratio of downdraft to updraft mass flux is ~0.5-0.6, which may represent a minimum evaporation efficiency under moist conditions. Hydrometeor loading in stratiform regions is found to be a fraction of hydrometeor loading in convective regions that ranges from ~10% (graupel) to ~90% (cloud ice). These findings may lead to improved convection parameterizations.

  11. Cloud Properties Working Group Low Clouds Update

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclearDNP 20082 P r o j eCommittee of

  12. Design, manufacture, and calibration of infrared radiometric blackbody sources

    SciTech Connect (OSTI)

    Byrd, D.A.; Michaud, F.D.; Bender, S.C.

    1996-04-01

    A Radiometric Calibration Station (RCS) is being assembled at the Los Alamos National Laboratories (LANL) which will allow for calibration of sensors with detector arrays having spectral capability from about 0.4-15 {mu}m. The configuration of the LANL RCS. Two blackbody sources have been designed to cover the spectral range from about 3-15 {mu}m, operating at temperatures ranging from about 180-350 K within a vacuum environment. The sources are designed to present a uniform spectral radiance over a large area to the sensor unit under test. The thermal uniformity requirement of the blackbody cavities has been one of the key factors of the design, requiring less than 50 mK variation over the entire blackbody surface to attain effective emissivity values of about 0.999. Once the two units are built and verified to the level of about 100 mK at LANL, they will be sent to the National Institute of Standards and Technology (NIST), where at least a factor of two improvement will be calibrated into the blackbody control system. The physical size of these assemblies will require modifications of the existing NIST Low Background Infrared (LBIR) Facility. LANL has constructed a bolt-on addition to the LBIR facility that will allow calibration of our large aperture sources. Methodology for attaining the two blackbody sources at calibrated levels of performance equivalent to present state of the art will be explained in the following.

  13. DUST AND GAS IN THE MAGELLANIC CLOUDS FROM THE HERITAGE HERSCHEL KEY PROJECT. I. DUST PROPERTIES AND INSIGHTS INTO THE ORIGIN OF THE SUBMILLIMETER EXCESS EMISSION

    SciTech Connect (OSTI)

    Gordon, Karl D.; Roman-Duval, Julia; Meixner, Margaret; Bot, Caroline; Babler, Brian; Bernard, Jean-Philippe; Bolatto, Alberto; Jameson, Katherine; Boyer, Martha L.; Clayton, Geoffrey C.; Engelbracht, Charles; Fukui, Yasuo; Galametz, Maud; Galliano, Frederic; Hony, Sacha; Lebouteiller, Vianney; Indebetouw, Remy; Israel, Frank P.; Kawamura, Akiko; and others

    2014-12-20

    The dust properties in the Large and Small Magellanic clouds (LMC/SMC) are studied using the HERITAGE Herschel Key Project photometric data in five bands from 100 to 500 ?m. Three simple models of dust emission were fit to the observations: a single temperature blackbody modified by a power-law emissivity (SMBB), a single temperature blackbody modified by a broken power-law emissivity (BEMBB), and two blackbodies with different temperatures, both modified by the same power-law emissivity (TTMBB). Using these models, we investigate the origin of the submillimeter excess, defined as the submillimeter emission above that expected from SMBB models fit to observations <200 ?m. We find that the BEMBB model produces the lowest fit residuals with pixel-averaged 500 ?m submillimeter excesses of 27% and 43% for the LMC and SMC, respectively. Adopting gas masses from previous works, the gas-to-dust ratios calculated from our fitting results show that the TTMBB fits require significantly more dust than are available even if all the metals present in the interstellar medium (ISM) were condensed into dust. This indicates that the submillimeter excess is more likely to be due to emissivity variations than a second population of colder dust. We derive integrated dust masses of (7.3 ± 1.7) × 10{sup 5} and (8.3 ± 2.1) × 10{sup 4} M {sub ?} for the LMC and SMC, respectively. We find significant correlations between the submillimeter excess and other dust properties; further work is needed to determine the relative contributions of fitting noise and ISM physics to the correlations.

  14. Pre-Cloud Aerosol, Cloud Droplet Concentration, and Cloud Condensation Nuclei from the VAMOS Ocean-Cloud-Atmosphere Land Study (VOCALS) Field Campaign First Quarter 2010 ASR Program Metric Report

    SciTech Connect (OSTI)

    Kleinman, LI; Springston, SR; Daum, PH; Lee, Y-N; Sedlacek, AJ; Senum, G; Wang, J

    2011-08-31

    In this, the first of a series of Program Metric Reports, we (1) describe archived data from the DOE G-1 aircraft, (2) illustrate several relations between sub-cloud aerosol, CCN, and cloud droplets pertinent to determining the effects of pollutant sources on cloud properties, and (3) post to the data archive an Excel spreadsheet that contains cloud and corresponding sub-cloud data.

  15. The BLAST Survey of the Vela Molecular Cloud: Physical Properties of the Dense Cores in Vela-D

    E-Print Network [OSTI]

    Olmi, Luca; Angles-Alcazar, Daniel; Bock, James J; Chapin, Edward L; De Luca, Massimo; Devlin, Mark J; Dicker, Simon; Elia, Davide; Fazio, Giovanni G; Giannini, Teresa; Griffin, Matthew; Gundersen, Joshua O; Halpern, Mark; Hargrave, Peter C; Hughes, David H; Klein, Jeff; Lorenzetti, Dario; Marengo, Massimo; Marsden, Gaelen; Martin, Peter G; Massi, Fabrizio; Mauskopf, Philip; Netterfield, Calvin B; Patanchon, Guillaume; Rex, Marie; Salama, Alberto; Scott, Douglas; Semisch, Christopher; Smith, Howard A; Strafella, Francesco; Thomas, Nicholas; Truch, Matthew D P; Tucker, Carole; Tucker, Gregory S; Viero, Marco P; Wiebe, Donald V

    2009-01-01

    The Balloon-borne Large-Aperture Submillimeter Telescope (BLAST) carried out a 250, 350 and 500 micron survey of the galactic plane encompassing the Vela Molecular Ridge, with the primary goal of identifying the coldest, dense cores possibly associated with the earliest stages of star formation. Here we present the results from observations of the Vela-D region, covering about 4 square degrees, in which we find 141 BLAST cores. We exploit existing data taken with the Spitzer MIPS, IRAC and SEST-SIMBA instruments to constrain their (single-temperature) spectral energy distributions, assuming a dust emissivity index beta = 2.0. This combination of data allows us to determine the temperature, luminosity and mass of each BLAST core, and also enables us to separate starless from proto-stellar sources. We also analyze the effects that the uncertainties on the derived physical parameters of the individual sources have on the overall physical properties of starless and proto-stellar cores, and we find that there appe...

  16. Dispelling Clouds of Uncertainty

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

    Lewis, Ernie; Teixeira, Joăo

    2015-06-15

    How do you build a climate model that accounts for cloud physics and the transitions between cloud regimes? Use MAGIC.

  17. Cloud Computing Adam Barker

    E-Print Network [OSTI]

    St Andrews, University of

    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

  18. MODIS Global Cloud-Top Pressure and Amount Estimation: Algorithm Description and Results

    E-Print Network [OSTI]

    Baum, Bryan A.

    MODIS Global Cloud-Top Pressure and Amount Estimation: Algorithm Description and Results W. PAUL measurements for deriving global and regional cloud properties. MODIS has spectral coverage combined the capability for global cloud property retrievals. MODIS operational cloud products are derived globally

  19. THE MASS-LOSS RETURN FROM EVOLVED STARS TO THE LARGE MAGELLANIC CLOUD. II. DUST PROPERTIES FOR OXYGEN-RICH ASYMPTOTIC GIANT BRANCH STARS

    SciTech Connect (OSTI)

    Sargent, Benjamin A.; Meixner, M.; Gordon, Karl D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Srinivasan, S. [Institut d'Astrophysique de Paris, 98 bis, Boulevard Arago, Paris 75014 (France); Kemper, F.; Woods, Paul M. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Tielens, A. G. G. M. [Leiden Observatory, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Speck, A. K. [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States); Matsuura, M. [Institute of Origins, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Bernard, J.-Ph. [Centre d'Etude Spatiale des Rayonnements, 9 Av. du Colonel Roche, BP 44346, 31028 Toulouse Cedex 4 (France); Hony, S. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot DAPNIA/Service d'Astrophysique Bat. 709, CEA-Saclay F-91191 Gif-sur-Yvette Cedex (France); Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Marengo, M. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Sloan, G. C., E-mail: sargent@stsci.ed [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)

    2010-06-10

    We model multi-wavelength broadband UBVIJHK{sub s} and Spitzer IRAC and MIPS photometry and Infrared Spectrograph spectra from the SAGE and SAGE-Spectroscopy observing programs of two oxygen-rich asymptotic giant branch (O-rich AGB) stars in the Large Magellanic Cloud (LMC) using radiative transfer (RT) models of dust shells around stars. We chose a star from each of the bright and faint O-rich AGB populations found by earlier studies of the SAGE sample in order to derive a baseline set of dust properties to be used in the construction of an extensive grid of RT models of the O-rich AGB stars found in the SAGE surveys. From the bright O-rich AGB population, we chose HV 5715, and from the faint O-rich AGB population we chose SSTISAGE1C J052206.92-715017.6 (SSTSAGE052206). We found the complex indices of refraction of oxygen-deficient silicates from Ossenkopf et al. and a power law with exponential decay grain size distribution like what Kim et al. used but with {gamma} of -3.5, a {sub min} of 0.01 {mu}m, and a {sub 0} of 0.1 {mu}m to be reasonable dust properties for these models. There is a slight indication that the dust around the faint O-rich AGB may be more silica-rich than that around the bright O-rich AGB. Simple models of gas emission suggest a relatively extended gas envelope for the faint O-rich AGB star modeled, consistent with the relatively large dust shell inner radius for the same model. Our models of the data require the luminosity of SSTSAGE052206 and HV 5715 to be {approx}5100 L {sub sun} and {approx}36,000 L {sub sun}, respectively. This, combined with the stellar effective temperatures of 3700 K and 3500 K, respectively, that we find best fit the optical and near-infrared data, suggests stellar masses of {approx}3 M {sub sun} and {approx}7 M {sub sun}. This, in turn, suggests that HV 5715 is undergoing hot-bottom burning and that SSTSAGE052206 is not. Our models of SSTSAGE052206 and HV 5715 require dust shells of inner radius {approx}17 and {approx}52 times the stellar radius, respectively, with dust temperatures there of 900 K and 430 K, respectively, and with optical depths at 10 {mu}m through the shells of 0.095 and 0.012, respectively. The models compute the dust mass-loss rates for the two stars to be 2.0 x 10{sup -9} M{sub sun} yr{sup -1} and 2.3 x 10{sup -9} M{sub sun} yr{sup -1}, respectively. When a dust-to-gas mass ratio of 0.002 is assumed for SSTSAGE052206 and HV 5715, the dust mass-loss rates imply total mass-loss rates of 1.0 x 10{sup -6} M{sub sun} yr{sup -1} and 1.2 x 10{sup -6} M{sub sun} yr{sup -1}, respectively. These properties of the dust shells and stars, as inferred from our models of the two stars, are found to be consistent with properties observed or assumed by detailed studies of other O-rich AGB stars in the LMC and elsewhere.

  20. Cloud Tracking in Cloud-Resolving Models

    E-Print Network [OSTI]

    Plant, Robert

    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

  1. Acoustic clouds: standing sound waves around a black hole analogue

    E-Print Network [OSTI]

    Carolina L. Benone; Luis C. B. Crispino; Carlos Herdeiro; Eugen Radu

    2015-01-28

    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  2. Laser infrared photothermal radiometric depth profilometry of steels and its potential in rail track evaluation

    E-Print Network [OSTI]

    Mandelis, Andreas

    -scattering or in the transmission mode using a variety of sensor probes. In this work we used the infrared (IR) photothermal radioLaser infrared photothermal radiometric depth profilometry of steels and its potential in rail track evaluation A. Mandelis*, M. Munidasa, L. Nicolaides Photothermal and Optoelectronic Diagnostics

  3. Surface aerosol radiative forcing derived from collocated ground-based radiometric

    E-Print Network [OSTI]

    Liou, K. N.

    Surface aerosol radiative forcing derived from collocated ground-based radiometric observations-Filter Rotating Shadowband Radiometer data match closely with those from the Cimel sun- photometer data for two of the sunphotometer to retrieve aerosol optical depths, a, along with observed surface flux data from field campaigns

  4. Modelling the local and global cloud formation on HD 189733b

    E-Print Network [OSTI]

    Lee, G; Dobbs-Dixon, I; Juncher, D

    2015-01-01

    Context. Observations suggest that exoplanets such as HD 189733b form clouds in their atmospheres which have a strong feedback onto their thermodynamical and chemical structure, and overall appearance. Aims. Inspired by mineral cloud modelling efforts for Brown Dwarf atmospheres, we present the first spatially varying kinetic cloud model structures for HD 189733b. Methods. We apply a 2-model approach using results from a 3D global radiation-hydrodynamic simulation of the atmosphere as input for a detailed, kinetic cloud formation model. Sampling the 3D global atmosphere structure with 1D trajectories allows us to model the spatially varying cloud structure on HD 189733b. The resulting cloud properties enable the calculation of the scattering and absorption properties of the clouds. Results. We present local and global cloud structure and property maps for HD 189733b. The calculated cloud properties show variations in composition, size and number density of cloud particles which are strongest between the daysi...

  5. Toward Securing Sensor Clouds

    E-Print Network [OSTI]

    Router Cloud Computing Cloud Computing Cloud Computing Tower-mount Antenna Tower-mount Antenna Wireless-Features-1GHz-Tegra-2-HigherRes-Screen/ #12;Router Router Router Router Mini Computer Mini Computer Mini Computer Mini Computer External Storage External Storage Router Router Router Router Cloud Computing Cloud

  6. Atmospheric State, Cloud Microphysics and Radiative Flux

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

    Mace, Gerald

    2008-01-15

    Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

  7. Atmospheric State, Cloud Microphysics and Radiative Flux

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

    Mace, Gerald

    Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

  8. Ad hoc cloud computing 

    E-Print Network [OSTI]

    McGilvary, Gary Andrew

    2014-11-27

    Commercial and private cloud providers offer virtualized resources via a set of co-located and dedicated hosts that are exclusively reserved for the purpose of offering a cloud service. While both cloud models appeal to ...

  9. Eleventh ARM Science Team Meeting Proceedings, Atlanta, Georgia, March 19-23, 2001 Radar-based Retrievals of Cloud Properties in the Arctic

    E-Print Network [OSTI]

    Shupe, Matthew

    Eleventh ARM Science Team Meeting Proceedings, Atlanta, Georgia, March 19-23, 2001 1 Radar Radiation Measurement (ARM) program Cloud and Radiation Testbed (CART) sites, all techniques discussed here can be applied to measurements taken at the different ARM sites. Briefly summarized here

  10. CloudTransport: Using Cloud Storage for

    E-Print Network [OSTI]

    Houmansadr, Amir

    users' network traffic by tunneling it through a cloud storage ser- vice such as Amazon S3. The goal the bridge or identify other connections. CloudTransport can be used as a standalone service, a gateway

  11. TROPICAL CLOUD LIFE CYCLE AND OVERLAP STRUCTURE A. M. Vogelmann, M. P. Jensen, P. Kollias, and E. Luke

    E-Print Network [OSTI]

    TROPICAL CLOUD LIFE CYCLE AND OVERLAP STRUCTURE A. M. Vogelmann, M. P. Jensen, P. Kollias, and E.bnl.gov ABSTRACT The profile of cloud microphysical properties and how the clouds are overlapped within a vertical simulations. We will present how cloud microphysical properties and overlap structure retrieved at the ARM

  12. PUBBLICAZIONI SCIENTIFICHE CASTORINA F., PETRINI R. (1989). Radiometric geochronology: some constraints to the isochron method by an

    E-Print Network [OSTI]

    1989-01-01

    PUBBLICAZIONI SCIENTIFICHE ISI CASTORINA F., PETRINI R. (1989). Radiometric geochronology: some of geochronological and isotopic studies to volcanotectonics. Journal of Volcanology and Geothermal Research, vol. 75. (1998). Calcites at Vulcano island (Italy): isotopic and geochronological data bearing on the timing

  13. On Demand Surveillance Service in Vehicular Cloud

    E-Print Network [OSTI]

    Weng, Jui-Ting

    2013-01-01

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

  14. Cirrus cloud formation and the role of heterogeneous ice nuclei

    E-Print Network [OSTI]

    Froyd, Karl D.

    2013-01-01

    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 ...

  15. On Demand Surveillance Service in Vehicular Cloud

    E-Print Network [OSTI]

    Weng, Jui-Ting

    2013-01-01

    1.2 Cloud computing to Vehicular CloudM. Gerla. Vehicular Cloud Computing, VCA 2012 Proceedings,single vehicle cannot. Cloud computing to Vehicular Cloud

  16. Cloud Security by Max Garvey

    E-Print Network [OSTI]

    Tolmach, Andrew

    Cloud Security Survey by Max Garvey #12;Cloudy Cloud is Cloudy What is the cloud? On Demand Service, performance SECaaS - Cloud hosted security measures Certifications - measurements for cloud security. #12;Cloud Questions If you have $0 security budget, could cloud be a security improvement? Who owns the data

  17. Program Analyses for Cloud Computations

    E-Print Network [OSTI]

    Tetali, Sai Deep

    2015-01-01

    search. ” In CCSW 09: Cloud Computing Security Workshop, pp.ACM workshop on Cloud computing security workshop, CCSW ’11,aspects of cloud computing, including security, performance

  18. Characterizing synoptic and cloud variability in the Northern Atlantic using self-organizing maps

    E-Print Network [OSTI]

    Fish, Carly Sue

    2014-08-31

    Low ? level clouds have a significant influence on the Earth's radiation budget and it is thus imperative to understand their behavior within the marine boundary layer (MBL). The cloud properties in the Northeast ...

  19. PC Windows Adobe Creative Cloud PC Windows Adobe Creative Cloud

    E-Print Network [OSTI]

    PC Windows Adobe Creative Cloud 1 PC Windows Adobe Creative Cloud 2015-05-25 1 Web Windows Adobe Creative Cloud PC | Creative Cloud https://helpx.adobe.com/jp/creative-cloud Adobe Creative Cloud 5.1 Web TTInstaller(Windows )() http://www.officesoft.gsic.titech.ac

  20. 660 VOLUME 21J O U R N A L O F A T M O S P H E R I C A N D O C E A N I C T E C H N O L O G Y Deriving Mixed-Phase Cloud Properties from Doppler Radar Spectra

    E-Print Network [OSTI]

    Shupe, Matthew

    the vertical air motion and to correct estimates of ice particle fall speeds. A mixed-phase cloud case study properties are such that they produce a bimodal Doppler velocity spectrum. Under these conditions, the Doppler spectrum moments of the distinct liquid and ice spectral modes may be computed independently

  1. Evaluation of Cloud-resolving and Limited Area Model Intercomparison Simulations using TWP-ICE Observations. Part 1: Deep Convective Updraft Properties

    SciTech Connect (OSTI)

    Varble, A. C.; Zipser, Edward J.; Fridlind, Ann; Zhu, Ping; Ackerman, Andrew; Chaboureau, Jean-Pierre; Collis, Scott M.; Fan, Jiwen; Hill, Adrian; Shipway, Ben

    2014-12-27

    Ten 3D cloud-resolving model (CRM) simulations and four 3D limited area model (LAM) simulations of an intense mesoscale convective system observed on January 23-24, 2006 during the Tropical Warm Pool – International Cloud Experiment (TWP-ICE) are compared with each other and with observed radar reflectivity fields and dual-Doppler retrievals of vertical wind speeds in an attempt to explain published results showing a high bias in simulated convective radar reflectivity aloft. This high bias results from ice water content being large, which is a product of large, strong convective updrafts, although hydrometeor size distribution assumptions modulate the size of this bias. Snow reflectivity can exceed 40 dBZ in a two-moment scheme when a constant bulk density of 100 kg m-3 is used. Making snow mass more realistically proportional to area rather than volume should somewhat alleviate this problem. Graupel, unlike snow, produces high biased reflectivity in all simulations. This is associated with large amounts of liquid water above the freezing level in updraft cores. Peak vertical velocities in deep convective updrafts are greater than dual-Doppler retrieved values, especially in the upper troposphere. Freezing of large rainwater contents lofted above the freezing level in simulated updraft cores greatly contributes to these excessive upper tropospheric vertical velocities. Strong simulated updraft cores are nearly undiluted, with some showing supercell characteristics. Decreasing horizontal grid spacing from 900 meters to 100 meters weakens strong updrafts, but not enough to match observational retrievals. Therefore, overly intense simulated updrafts may partly be a product of interactions between convective dynamics, parameterized microphysics, and large-scale environmental biases that promote different convective modes and strengths than observed.

  2. Hyperscale Cloud Technical White Paper

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    Hyperscale Cloud Technical White Paper Published: May 2015 Applies to: SQL Server 2016 CTP2, SQL in the cloud with greater scale and flexibility. Microsoft SQL Server is built for cloud integration--your organization can easily deploy SQL Server in a private cloud, hybrid cloud, or public cloud, and can use

  3. XSEDE Cloud Survey Report

    E-Print Network [OSTI]

    Chen, Tsuhan

    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

  4. Research Cloud Computing Recommendations

    E-Print Network [OSTI]

    Qian, Ning

    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

  5. Taiwan UniCloud: A Cloud Testbed with Collaborative Cloud Services Wu-Chun Chung*

    E-Print Network [OSTI]

    Chung, Yeh-Ching

    Taiwan UniCloud: A Cloud Testbed with Collaborative Cloud Services Wu-Chun Chung* , Po-Chi Shih}@cs.nthu.edu.tw Abstract--This paper introduces a prototype of Taiwan UniCloud, a community-driven hybrid cloud platform for academics in Taiwan. The goal is to leverage resources in multiple clouds among different organizations

  6. JUNE 2002 835F R I S C H E T A L . The Retrieval of Stratus Cloud Droplet Effective Radius with Cloud Radars

    E-Print Network [OSTI]

    Shupe, Matthew

    . (1999). Another retrieval for stratocumulus cloud properties using solar radiation, microwave ra obtained from a microwave radiometer; the second uses the radar reflectivity and an assumption

  7. Relationship between Cloud Condensation Nuclei and Satellite Retrievals of Cloud Droplet Effective Radius

    E-Print Network [OSTI]

    Delene, David J.

    ` Relationship between Cloud Condensation Nuclei and Satellite Retrievals of Cloud Droplet is the relationship between below cloud base cloud condensation nuclei (CCN) and satellite retrievals of cloud droplet cloud effective radius; however, satellites can not measure cloud condensation nuclei (CCN

  8. Community Cloud Computing

    E-Print Network [OSTI]

    Marinos, Alexandros

    2009-01-01

    Cloud Computing is rising fast, with its data centres growing at an unprecedented rate. However, this has come with concerns over privacy, efficiency at the expense of resilience, and environmental sustainability, because of the dependence on Cloud vendors such as Google, Amazon and Microsoft. Our response is an alternative model for the Cloud conceptualisation, providing a paradigm for Clouds in the community, utilising networked personal computers for liberation from the centralised vendor model. Community Cloud Computing (C3) offers an alternative architecture, created by combing the Cloud with paradigms from Grid Computing, principles from Digital Ecosystems, and sustainability from Green Computing, while remaining true to the original vision of the Internet. It is more technically challenging than Cloud Computing, having to deal with distributed computing issues, including heterogeneous nodes, varying quality of service, and additional security constraints. However, these are not insurmountable challenge...

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

    SciTech Connect (OSTI)

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

    2013-06-11

    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.

  10. Detection of Cb and TCu clouds Master Thesis

    E-Print Network [OSTI]

    Schmeits, Maurice

    : Meteosat HRV satellite image (edited) taken on 16 September 2009 at 18.00 UTC. c 2009 by lutz reflectances in the Visible (HRV) as well as weather radar data are used to de- velop a new Cb/TCu cloud regression model. Predictors for the mo- del have been derived from the cloud physical properties, HRV

  11. CLouds and Aerosol Radiative Interaction and Forcing Investigation

    E-Print Network [OSTI]

    Graaf, Martin de

    Radiative Interaction and Forcing Investigation Version 1.0 Date March 2012 Status Final #12;#12;CLARIFI, by absorbing and scattering solar radiation, and more importantly, by modifying cloud propertiesCLARIFI CLouds and Aerosol Radiative Interaction and Forcing Investigation M. de Graaf, L

  12. Federated Cloud Security Architecture for Secure and Agile Clouds

    E-Print Network [OSTI]

    Xu, Shouhuai

    Federated Cloud Security Architecture for Secure and Agile Clouds Weiliang Luo, Li Xu, Zhenxin Zhan. This chapter introduces the novel federated cloud security architecture that includes proactive cloud defense technologies for secure and agile cloud development. The federated security architecture consists of a set

  13. The proposed connection between clouds and cosmic rays: Cloud

    E-Print Network [OSTI]

    The proposed connection between clouds and cosmic rays: Cloud behaviour during the past 50 of cloud factors using both satellite and ground­based data. In particular, we search for evidence for the low cloud decrease predicted by the rising levels of solar activity and the low cloud­cosmic ray flux

  14. Tropical Warm Pool International Cloud Experiment TWP-ICE Cloud and rain characteristics in the Australian Monsoon

    SciTech Connect (OSTI)

    May, P.T., Jakob, C., and Mather, J.H.

    2004-05-31

    The impact of oceanic convection on its environment and the relationship between the characteristics of the convection and the resulting cirrus characteristics is still not understood. An intense airborne measurement campaign combined with an extensive network of ground-based observations is being planned for the region near Darwin, Northern Australia, during January-February, 2006, to address these questions. The Tropical Warm Pool International Cloud Experiment (TWP-ICE) will be the first field program in the tropics that attempts to describe the evolution of tropical convection, including the large scale heat, moisture, and momentum budgets, while at the same time obtaining detailed observations of cloud properties and the impact of the clouds on the environment. The emphasis will be on cirrus for the cloud properties component of the experiment. Cirrus clouds are ubiquitous in the tropics and have a large impact on their environment but the properties of these clouds are poorly understood. A crucial product from this experiment will be a dataset suitable to provide the forcing and testing required by cloud-resolving models and parameterizations in global climate models. This dataset will provide the necessary link between cloud properties and the models that are attempting to simulate them.

  15. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

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

  16. AN ARSCL-BASED CLOUD TYPE CLIMATOLOGY FROM RETRIEVALS AND IT'S USE IN MODEL EVALUATION STUDIES

    E-Print Network [OSTI]

    AN ARSCL-BASED CLOUD TYPE CLIMATOLOGY FROM RETRIEVALS AND IT'S USE IN MODEL EVALUATION STUDIES Laboratory P.O. Box, Upton, NY www.bnl.gov ABSTRACT A climatology of cloud types is developed using long in tandem with satellite observations for model cloud layering and property evaluation. Therefore, satellite

  17. An Autonomous Reliabilit Cloud Comput

    E-Print Network [OSTI]

    Buyya, Rajkumar

    An Autonomous Reliabilit Ami Cloud Comput Department of Computing and Informa Abstract--Cloud computing paradigm allo based access to computing and storages s Internet. Since with advances of Cloud. Keywords- Cloud computing; SLA negotiat I. INTRODUCTION Cloud computing has transferred the services

  18. Seasonal and optical characterisation of cirrus clouds over Indian sub-continent using LIDAR

    SciTech Connect (OSTI)

    Jayeshlal, G. S., E-mail: drssatyanarayana.malladi@gmail.com; Satyanarayana, Malladi, E-mail: drssatyanarayana.malladi@gmail.com; Dhaman, Reji K., E-mail: drssatyanarayana.malladi@gmail.com; Motty, G. S., E-mail: drssatyanarayana.malladi@gmail.com [Department of Optoelectronics, University of Kerala, Karyavattom, Trivandrum-695 581, Kerala (India)

    2014-10-15

    Light Detection and Ranging (LIDAR) is an important remote sensing technique to study about the cirrus clouds. The subject of cirrus clouds and related climate is challenging one. The received scattered signal from Lidar contains information on the physical and optical properties of cirrus clouds. The Lidar profile of the cirrus cloud provides information on the optical characteristics like depolarisation ratio, lidar ratio and optical depth, which give knowledge about possible phase, structure and orientation of cloud particle that affect the radiative budgeting of cirrus clouds. The findings from the study are subjected to generate inputs for better climatic modelling.

  19. Uncertainty Analysis for Broadband Solar Radiometric Instrumentation Calibrations and Measurements: An Update; Preprint

    SciTech Connect (OSTI)

    Myers, D. R.; Reda, I. M.; Wilcox, S. M.; Stoffel, T. L.

    2004-04-01

    The measurement of broadband solar radiation has grown in importance since the advent of solar renewable energy technologies in the 1970's, and the concern about the Earth's radiation balance related to climate change in the 1990's. In parallel, standardized methods of uncertainty analysis and reporting have been developed. Historical and updated uncertainties are based on the current international standardized uncertainty analysis method. Despite the fact that new and sometimes overlooked sources of uncertainty have been identified over the period 1988 to 2004, uncertainty in broadband solar radiometric instrumentation remains at 3% to 5% for pyranometers, and 2% to 3% for pyrheliometers. Improvements in characterizing correction functions for radiometer data may reduce total uncertainty. We analyze the theoretical standardized uncertainty sensitivity coefficients for the instrumentation calibration measurement equation and highlight the single parameter (thermal offset voltages), which contributes the most to the observed calibration responsivities.

  20. Radiometric and geometric analysis of hyperspectral imagery acquired from an unmanned aerial vehicle

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

    Hruska, Ryan; Mitchell, Jessica; Anderson, Matthew; Glenn, Nancy F.

    2012-09-17

    During the summer of 2010, an Unmanned Aerial Vehicle (UAV) hyperspectral in-flight calibration and characterization experiment of the Resonon PIKA II imaging spectrometer was conducted at the U.S. Department of Energy’s Idaho National Laboratory (INL) UAV Research Park. The purpose of the experiment was to validate the radiometric calibration of the spectrometer and determine the georegistration accuracy achievable from the on-board global positioning system (GPS) and inertial navigation sensors (INS) under operational conditions. In order for low-cost hyperspectral systems to compete with larger systems flown on manned aircraft, they must be able to collect data suitable for quantitative scientific analysis.more »The results of the in-flight calibration experiment indicate an absolute average agreement of 96.3%, 93.7% and 85.7% for calibration tarps of 56%, 24%, and 2.5% reflectivity, respectively. The achieved planimetric accuracy was 4.6 meters (based on RMSE).« less

  1. Radiometric and geometric analysis of hyperspectral imagery acquired from an unmanned aerial vehicle

    SciTech Connect (OSTI)

    Hruska, Ryan; Mitchell, Jessica; Anderson, Matthew; Glenn, Nancy F.

    2012-09-17

    During the summer of 2010, an Unmanned Aerial Vehicle (UAV) hyperspectral in-flight calibration and characterization experiment of the Resonon PIKA II imaging spectrometer was conducted at the U.S. Department of Energy’s Idaho National Laboratory (INL) UAV Research Park. The purpose of the experiment was to validate the radiometric calibration of the spectrometer and determine the georegistration accuracy achievable from the on-board global positioning system (GPS) and inertial navigation sensors (INS) under operational conditions. In order for low-cost hyperspectral systems to compete with larger systems flown on manned aircraft, they must be able to collect data suitable for quantitative scientific analysis. The results of the in-flight calibration experiment indicate an absolute average agreement of 96.3%, 93.7% and 85.7% for calibration tarps of 56%, 24%, and 2.5% reflectivity, respectively. The achieved planimetric accuracy was 4.6 meters (based on RMSE).

  2. Fig 2 -Cloud energy collect infrastructure Energy Efficient (Green) Cloud !

    E-Print Network [OSTI]

    Lefčvre, Laurent

    Fig 2 - Cloud energy collect infrastructure Energy Efficient (Green) Cloud ! The Compatible software components Energy Monitoring of physical and virtual resources Energy usage exposing for users and clouds managers Energy monitoring streams for upper layers software Design Energy aware software

  3. Finance Idol Word Cloud

    Broader source: Energy.gov [DOE]

    This word cloud represents the topics discussed during the Big and Small Ideas: How to Lower Solar Financing Costs breakout session at the SunShot Grand Challenge.

  4. Intercomparison of the Cloud Water Phase among Global Climate Models

    SciTech Connect (OSTI)

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

    2014-03-27

    Mixed-phase clouds (clouds that consist of both cloud droplets and ice crystals) are frequently present in the Earth’s atmosphere and influence the Earth’s 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.

  5. Program Analyses for Cloud Computations

    E-Print Network [OSTI]

    Tetali, Sai Deep

    2015-01-01

    search. ” In CCSW 09: Cloud Computing Security Workshop, pp.and M. Walfish. “Depot: Cloud storage with minimal trust. ”the 3rd ACM workshop on Cloud computing security workshop,

  6. Sensitivity of CAM5-Simulated Arctic Clouds and Radiation to Ice Nucleation Parameterization

    SciTech Connect (OSTI)

    Xie, Shaocheng; Liu, Xiaohong; Zhao, Chuanfeng; Zhang, Yuying

    2013-08-01

    Sensitivity of Arctic clouds and radiation in the Community Atmospheric Model version 5 to the ice nucleation process is examined by testing a new physically based ice nucleation scheme that links the variation of ice nuclei (IN) number concentration to aerosol properties. The default scheme parameterizes the IN concentration simply as a function of ice supersaturation. The new scheme leads to a significant reduction in simulated IN number concentrations at all latitudes while changes in cloud amount and cloud properties are mainly seen in high latitudes and middle latitude storm tracks. In the Arctic, there is a considerable increase in mid-level clouds and a decrease in low clouds, which result from the complex interaction among the cloud macrophysics, microphysics, and the large-scale environment. The smaller IN concentrations result in an increase in liquid water path and a decrease in ice water path due to the slow-down of the Bergeron-Findeisen process in mixed-phase clouds. Overall, there is an increase in the optical depth of Arctic clouds, which leads to a stronger cloud radiative forcing (net cooling) at the top of the atmosphere. The comparison with satellite data shows that the new scheme slightly improves low cloud simulations over most of the Arctic, but produces too many mid-level clouds. Considerable improvements are seen in the simulated low clouds and their properties when compared to Arctic ground-based measurements. Issues with the observations and the model-observation comparison in the Arctic region are discussed.

  7. Sandia Energy - Cloud Computing Services

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

    Services Home Stationary Power Safety, Security & Resilience of Energy Infrastructure Grid Modernization Cyber Security for Electric Infrastructure Cloud Computing Services Cloud...

  8. CONTRIBUTED Green Cloud Computing

    E-Print Network [OSTI]

    Tucker, Rod

    as well as data processing and data storage. We show that energy consumption in transport and switching | Cloud computing; core networks; data centers; energy consumption I. INTRODUCTION The increasing to energy consumption and cloud computing seems to be an alternative to office-based computing. By Jayant

  9. RELATIONSHIP BETWEEN CLOUD FRACTION AND CLOUD ALBEDO: COMBINED OBSERVATIONAL-MODELING-THEORETICAL INVESTIGATION

    E-Print Network [OSTI]

    RELATIONSHIP BETWEEN CLOUD FRACTION AND CLOUD ALBEDO: COMBINED OBSERVATIONAL of Energy Office of Science ABSTRACT Cloud fraction and cloud albedo have long occupied the central stage as key cloud quantities in studying cloud-climate interaction; however their quantitative relationship

  10. Cloud computing security.

    SciTech Connect (OSTI)

    Shin, Dongwan; Claycomb, William R.; Urias, Vincent E.

    2010-10-01

    Cloud computing is a paradigm rapidly being embraced by government and industry as a solution for cost-savings, scalability, and collaboration. While a multitude of applications and services are available commercially for cloud-based solutions, research in this area has yet to fully embrace the full spectrum of potential challenges facing cloud computing. This tutorial aims to provide researchers with a fundamental understanding of cloud computing, with the goals of identifying a broad range of potential research topics, and inspiring a new surge in research to address current issues. We will also discuss real implementations of research-oriented cloud computing systems for both academia and government, including configuration options, hardware issues, challenges, and solutions.

  11. INFERENCE OF INHOMOGENEOUS CLOUDS IN AN EXOPLANET ATMOSPHERE

    SciTech Connect (OSTI)

    Demory, Brice-Olivier; De Wit, Julien; Lewis, Nikole; Zsom, Andras; Seager, Sara; Fortney, Jonathan; Knutson, Heather; Desert, Jean-Michel; Heng, Kevin; Madhusudhan, Nikku; Gillon, Michael; Barclay, Thomas; Cowan, Nicolas B.

    2013-10-20

    We present new visible and infrared observations of the hot Jupiter Kepler-7b to determine its atmospheric properties. Our analysis allows us to (1) refine Kepler-7b's relatively large geometric albedo of Ag = 0.35 ± 0.02, (2) place upper limits on Kepler-7b thermal emission that remains undetected in both Spitzer bandpasses and (3) report a westward shift in the Kepler optical phase curve. We argue that Kepler-7b's visible flux cannot be due to thermal emission or Rayleigh scattering from H{sub 2} molecules. We therefore conclude that high altitude, optically reflective clouds located west from the substellar point are present in its atmosphere. We find that a silicate-based cloud composition is a possible candidate. Kepler-7b exhibits several properties that may make it particularly amenable to cloud formation in its upper atmosphere. These include a hot deep atmosphere that avoids a cloud cold trap, very low surface gravity to suppress cloud sedimentation, and a planetary equilibrium temperature in a range that allows for silicate clouds to potentially form in the visible atmosphere probed by Kepler. Our analysis does not only present evidence of optically thick clouds on Kepler-7b but also yields the first map of clouds in an exoplanet atmosphere.

  12. Convective Cloud Lifecycles Lunchtime seminar

    E-Print Network [OSTI]

    Plant, Robert

    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

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

    SciTech Connect (OSTI)

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

    2011-11-13

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

  14. Wind speed response of marine non-precipitating stratocumulus clouds over a diurnal cycle in cloud-system resolving simulations

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

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

    2015-10-21

    Observed and projected trends in large scale wind speed over the oceans prompt the question: how might marine stratocumulus clouds and their radiative properties respond to future changes in large scale wind speed? Wind speed drives the surface fluxes of sensible heat, moisture, and momentum, and thereby acts on cloud liquid water path (LWP) and cloud radiative properties. We present an investigation of the dynamical response of non-precipitating, overcast marine stratocumulus clouds to different wind speeds, all else equal. In cloud-system resolving simulations, we find that higher wind speed leads to faster boundary layer growth and stronger entrainment. The dynamicalmore »driver is enhanced buoyant production of turbulence kinetic energy (TKE) from latent heat release in cloud updrafts. LWP is enhanced during the night and in the morning at higher wind speed, and more strongly suppressed later in the day. Wind speed hence accentuates the diurnal LWP cycle by expanding the morning – afternoon contrast. The higher LWP at higher wind speed does not, however, enhance cloud top cooling because in clouds with LWP ⪆ 50 g m?2, long wave emissions are very insensitive to LWP. This leads to the more general conclusion that in sufficiently thick stratocumulus clouds, additional boundary layer growth and entrainment due to a boundary layer moistening arises by stronger production of TKE from latent heat release in cloud updrafts, rather than from enhanced longwave cooling. We find furthermore that large scale wind modulates boundary layer decoupling. At nighttime and at low wind speed during daytime, it enhances decoupling in part by faster boundary layer growth and stronger entrainment, and in part because circulation driven by shear from large scale wind in the sub-cloud layer hinders vertical moisture transport between the surface and cloud base. With increasing wind speed, however, in decoupled daytime conditions, shear-driven circulation due to large scale wind takes over from buoyancy-driven circulation in transporting moisture from the surface to cloud base, and thereby reduces decoupling and helps maintain LWP. The cloud radiative effect (CRE) responds to changes in LWP and cloud fraction, and higher wind speed translates to a stronger diurnally averaged CRE. However, the sensitivity of the diurnally averaged CRE to wind speed decreases with increasing wind speed.« less

  15. A developer's survey on different cloud platforms

    E-Print Network [OSTI]

    Doan, Dzung

    2009-01-01

    1 Introduction Cloud computing is a computing paradigm inFor this reason, cloud computing has also been describedparallel processing. Cloud computing can be contrasted with

  16. The Magellan Final Report on Cloud Computing

    E-Print Network [OSTI]

    Coghlan, Susan

    2013-01-01

    their research efforts in cloud security. Experiences andinvolving cloud resources and security guidance is thedynamic nature of cloud systems, the security controls must

  17. Migrating enterprise storage applications to the cloud

    E-Print Network [OSTI]

    Vrable, Michael Daniel

    2011-01-01

    outsourcing to the cloud and data security. Depending onconcerned about data security in the cloud. Data stored inrun in the cloud, while protecting data security guarantees.

  18. Migrating enterprise storage applications to the cloud

    E-Print Network [OSTI]

    Vrable, Michael Daniel

    2011-01-01

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

  19. Towards a Data-centric View of Cloud Security Wenchao Zhou Micah Sherr William R. Marczak Zhuoyao Zhang

    E-Print Network [OSTI]

    Ives, Zachary G.

    Towards a Data-centric View of Cloud Security Wenchao Zhou Micah Sherr William R. Marczak Zhuoyao@berkeley.edu ABSTRACT Cloud security issues have recently gained traction in the research community, with much of cloud security. In particular, we explore the secu- rity properties of secure data sharing between

  20. Scanning ARM Cloud Radars Part I: Operational Sampling Strategies

    SciTech Connect (OSTI)

    Kollias, Pavlos; Bharadwaj, Nitin; Widener, Kevin B.; Jo, Ieng; Johnson, Karen

    2014-03-01

    Probing clouds in three-dimensions has never been done with scanning millimeter-wavelength (cloud) radars in a continuous operating environment. The acquisition of scanning cloud radars by the Atmospheric Radiation Measurement (ARM) program and research institutions around the world generate the need for developing operational scan strategies for cloud radars. Here, the first generation of sampling strategies for the Scanning ARM Cloud Radars (SACRs) is discussed. These scan strategies are designed to address the scientific objectives of the ARM program, however, they introduce an initial framework for operational scanning cloud radars. While the weather community uses scan strategies that are based on a sequence of scans at constant elevations, the SACRs scan strategies are based on a sequence of scans at constant azimuth. This is attributed to the cloud properties that are vastly different for rain and snow shafts that are the primary target of precipitation radars. A “cloud surveillance” scan strategy is introduced (HS-RHI) based on a sequence of horizon-to-horizon Range Height Indicator (RHI) scans that sample the hemispherical sky (HS). The HS-RHI scan strategy is repeated every 30 min to provide a static view of the cloud conditions around the SACR location. Between HS-RHI scan strategies other scan strategies are introduced depending on the cloud conditions. The SACRs are pointing vertically in the case of measurable precipitation at the ground. The radar reflectivities are corrected for water vapor attenuation and non-meteorological detection are removed. A hydrometeor detection mask is introduced based on the difference of cloud and noise statistics is discussed.

  1. Cloud Properties Working Group Break Out Session

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclearDNP 20082 P r o j eCommittee of thePresence

  2. ARM Cloud Properties Working Group: Meeting Logistics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsicloudden Documentation Data Management Facility PlotsProducts (VAP) VAP38

  3. Storm Peak Lab Cloud Property Validation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect Photovoltaics -7541C.3X-rays3 Prepared

  4. Posters Cloud Microphysical and Radiative Properties Measured

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgram Guidelines This document outlines the majorL.Posters Posters513911

  5. Zenith Radiance Retrieval of Cloud Properties

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLos Alamos verifies largestnamed Electrochemical Society

  6. Lovelock black hole thermodynamics in a string cloud model

    E-Print Network [OSTI]

    Lee, Tae-Hun; Maharaj, Sunil D; Baboolal, Dharmanand

    2015-01-01

    The Lovelock theory is an extension of general relativity to higher dimensions. We study the Lovelock black hole for a string cloud model in arbitrary dimensional spacetime, and in turn also analyze its thermodynamical properties. Indeed, we compute the mass, temperature and entropy of the black hole and also perform a thermodynamical stability analysis. The phase structure suggests that the Hawking-Page phase transition is achievable. It turns out that the presence of the Lovelock terms and/or background string cloud completely changes the black hole thermodynamics. Interestingly, the entropy of a black hole is unaffected due to a background string cloud, but has a correction term due to Lovelock gravity.

  7. Is the Sun Embedded in a Typical Interstellar Cloud?

    E-Print Network [OSTI]

    P. C. Frisch

    2008-06-17

    The physical properties and kinematics of the partially ionized interstellar material near the Sun are typical of warm diffuse clouds in the solar vicinity. The interstellar magnetic field at the heliosphere and the kinematics of nearby clouds are naturally explained in terms of the S1 superbubble shell. The interstellar radiation field at the Sun appears to be harder than the field ionizing ambient diffuse gas, which may be a consequence of the low opacity of the tiny cloud surrounding the heliosphere. The spatial context of the Local Bubble is consistent with our location in the Orion spur.

  8. CloudSafe: Securing Data Processing within Vulnerable Virtualization Environments in the Cloud

    E-Print Network [OSTI]

    Ryder, Barbara G.

    CloudSafe: Securing Data Processing within Vulnerable Virtualization Environments in the Cloud large-scale cloud applications. Index Terms--cloud security, outsourced computation, side- channel, newly discovered vulnerabilities in cloud virtualization envi- ronment have threatened the security

  9. Cloud Based Applications and Platforms (Presentation)

    SciTech Connect (OSTI)

    Brodt-Giles, D.

    2014-05-15

    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.

  10. CloudMan: A Platform for Portable Cloud Manufacturing Services

    E-Print Network [OSTI]

    Dustdar, Schahram

    CloudMan: A Platform for Portable Cloud Manufacturing Services Soheil Qanbari, Samira Mahdi Zadeh Education (BIHE), Iran soroush.vedaeei@bihe.org Abstract--Cloud manufacturing refers to "as a Service" pro- duction model that exploits an on-demand access to a distributed pool of diversified manufacturing

  11. Attribution Analysis of Cloud Feedback 

    E-Print Network [OSTI]

    Zhou, Chen

    2014-07-15

    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...

  12. Software-Defined Mobile Cloud

    E-Print Network [OSTI]

    Ku, Ian

    2014-01-01

    M. Gerla. “Towards Software- Defined VANETs: ArchitectureI. Ku, Y. Lu, and M. Gerla. “Software-Defined Mobile Cloud:C. Peylo, “CloudMAC: towards software defined WLANs,” ACM

  13. Opaque cloud detection

    DOE Patents [OSTI]

    Roskovensky, John K. (Albuquerque, NM)

    2009-01-20

    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.

  14. The Tropical Warm Pool International Cloud Experiment

    SciTech Connect (OSTI)

    May, Peter T.; Mather, James H.; Vaughan, Geraint; Jakob, Christian; McFarquhar, Greg; Bower, Keith; Mace, Gerald G.

    2008-05-01

    One of the most complete data sets describing tropical convection ever collected will result from the upcoming Tropical Warm Pool International Cloud Experiment (TWP-ICE) in the area around Darwin, Northern Australia in January and February 2006. The aims of the experiment, which will be operated in conjunction with the DOE Atmospheric Radiation Measurement (ARM) site in Darwin, will be to examine convective cloud systems from their initial stages through to the decay of the cirrus generated and to measure their impact on the environment. The experiment will include an unprecedented network of ground-based observations (soundings, active and passive remote sensors) combined with low, mid and high altitude aircraft for in-situ and remote sensing measurements. A crucial outcome of the experiment will be a data set suitable to provide the forcing and evaluation data required by cloud resolving and single column models as well as global climate models (GCMs) with the aim to contribute to parameterization development. This data set will provide the necessary link between the observed cloud properties and the models that are attempting to simulate them. The experiment is a large multi-agency experiment including substantial contributions from the United States DOE ARM program, ARM-UAV program, NASA, the Australian Bureau of Meteorology, CSIRO, EU programs and many universities.

  15. CLOUD CHEMISTRY STEPHEN E. SCHWARTZ

    E-Print Network [OSTI]

    Schwartz, Stephen E.

    is considered bere to comprise both cloud composition and reactions that take place in clouds. Clouds are a very special subset of tbe atmosphere because they present substantial amounts of condensed-phase water (liquid, the examples developed bere focus on these chemical systems. However, much of the resulting undetstanding

  16. Cloud Formation, Evolution and Destruction

    E-Print Network [OSTI]

    Estalella, Robert

    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

  17. RISK ASSESSMENT CLOUD COMPUTING

    E-Print Network [OSTI]

    Columbia University

    SECURITY RESEARCH PRIVACY RISK ASSESSMENT AMC DATA FISMA CLOUD COMPUTING MOBILE DEVICES OPERATIONS PRACTICES TRENDS AUDITS policies #12;2 Privacy & Information Security Annual Update Thursday, June 20, 2013 of Breach statistics Plan to comply with requirements · Training and Education Information Security · Risk

  18. Scaling in stratocumulus fields: an emergent property

    E-Print Network [OSTI]

    Yuan, Tianle

    2015-01-01

    Marine stratocumulus clouds play a critical role in the Earth's climate system. They display an amazing array of complex behaviors at many different spatiotemporal scales. Precipitation in these clouds is in general very light, but it is vital for clouds' systematic evolution and organization. Here we identify areas of high liquid water path within these clouds as potentially precipitating, or pouches. They are breeding grounds for stratocumuli to change their organization form. We show, using different satellite data sets, that the size distribution of these pouches show a universal scaling. We argue that such scaling is an emergent property of the cloud system, which results from numbers interactions at the microscopic scale.

  19. DETECTABILITY OF OORT CLOUD OBJECTS USING KEPLER

    SciTech Connect (OSTI)

    Ofek, Eran O. [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Nakar, Ehud [School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel)

    2010-03-01

    The size distribution and total mass of objects in the Oort Cloud have important implications to the theory of planet formation, including the properties of, and the processes taking place in the early solar system. We discuss the potential of space missions, such as Kepler and CoRoT, designed to discover transiting exoplanets, to detect Oort Cloud, Kuiper Belt, and main belt objects by occultations of background stars. Relying on published dynamical estimates of the content of the Oort Cloud, we find that Kepler's main program is expected to detect between 0 and {approx}100 occultation events by deca-kilometer-sized Oort Cloud objects. The occultation rate depends on the mass of the Oort Cloud, the distance to its 'inner edge', and the size distribution of its objects. In contrast, Kepler is unlikely to find occultations by Kuiper Belt or main belt asteroids, mainly due to the fact that it is observing a high ecliptic latitude field. Occultations by solar system objects will appear as a photometric deviation in a single measurement, implying that the information regarding the timescale and light-curve shape of each event is lost. We present statistical methods that have the potential to verify the authenticity of occultation events by solar system objects, to estimate the distance to the occulting population, and to constrain their size distribution. Our results are useful for planning of future space-based exoplanet searches in a way that will maximize the probability of detecting solar system objects, without hampering the main science goals.

  20. MBL Drizzle Properties and Their Impact on Cloud Property Retrieval

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport) | SciTech ConnectFuture |0396THIN^J MASTER

  1. MAGIC: Marine ARM GPCI Investigation of Clouds

    SciTech Connect (OSTI)

    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

    2012-10-03

    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.

  2. Measuring photometric and spectral radiometric bi-directional transmission and reflection in a video-goniospectrometer

    E-Print Network [OSTI]

    Stokes, Eleanor (Eleanor Catherine)

    2008-01-01

    The effective use of complex fenestration systems (CFS) in buildings requires a detailed knowledge of their optical spectral and directional properties. Bidirectional scattering functions (BSDFs), either in transmission ...

  3. Simulations of Clouds and Sensitivity Study by Weather Research and Forecast Model for Atmospheric Radiation Measurement Case 4

    SciTech Connect (OSTI)

    Wu, J.; Zhang, M.

    2005-03-18

    One of the large errors in general circulation models (GCMs) cloud simulations is from the mid-latitude, synoptic-scale frontal cloud systems. Now, with the availability of the cloud observations from Atmospheric Radiation Measurement (ARM) 2000 cloud Intensive Operational Period (IOP) and other observational datasets, the community is able to document the model biases in comparison with the observations and make progress in development of better cloud schemes in models. Xie et al. (2004) documented the errors in midlatitude frontal cloud simulations for ARM Case 4 by single-column models (SCMs) and cloud resolving models (CRMs). According to them, the errors in the model simulated cloud field might be caused by following reasons: (1) lacking of sub-grid scale variability; (2) lacking of organized mesoscale cyclonic advection of hydrometeors behind a moving cyclone which may play important role to generate the clouds there. Mesoscale model, however, can be used to better under stand these controls on the subgrid variability of clouds. Few studies have focused on applying mesoscale models to the forecasting of cloud properties. Weaver et al. (2004) used a mesoscale model RAMS to study the frontal clouds for ARM Case 4 and documented the dynamical controls on the sub-GCM-grid-scale cloud variability.

  4. CloudAnalyst: A CloudSim-based Visual Modeller for Analysing Cloud Computing Environments and Applications

    E-Print Network [OSTI]

    Buyya, Rajkumar

    CloudAnalyst: A CloudSim-based Visual Modeller for Analysing Cloud Computing Environments and Applications Bhathiya Wickremasinghe1 , Rodrigo N. Calheiros2 , and Rajkumar Buyya1 1 The Cloud Computing and Distributed Systems (CLOUDS) Laboratory Department of Computer Science and Software Engineering The University

  5. Cloud in a Bottle Demonstrate how pressure relates to cloud formation by making a cloud in a soda bottle.

    E-Print Network [OSTI]

    Johnson, Cari

    Cloud in a Bottle Demonstrate how pressure relates to cloud formation by making a cloud in a soda doesn't escape. 5. Squeeze the soda bottle and release, repeating several times. Eventually, a cloud construction paper (or anything dark) on half of the bottle may make the cloud easier to see. What Happened

  6. Retrievals of cloud optical depth and effective radius from Thin-Cloud Rotating Shadowband Radiometer measurements

    E-Print Network [OSTI]

    Retrievals of cloud optical depth and effective radius from Thin-Cloud Rotating Shadowband December 2011. [1] A Thin-Cloud Rotating Shadowband Radiometer (TCRSR) was developed and deployed) through an optically thin cloud (optical depth

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

    SciTech Connect (OSTI)

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

    2014-04-16

    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.

  8. Use of the ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes & Aerosol-Cloud Interaction

    SciTech Connect (OSTI)

    Alexander Marshak; Warren Wiscombe; Yuri Knyazikhin; Christine Chiu

    2011-05-24

    We proposed a variety of tasks centered on the following question: what can we learn about 3D cloud-radiation processes and aerosol-cloud interaction from rapid-sampling ARM measurements of spectral zenith radiance? These ARM measurements offer spectacular new and largely unexploited capabilities in both the temporal and spectral domains. Unlike most other ARM instruments, which average over many seconds or take samples many seconds apart, the new spectral zenith radiance measurements are fast enough to resolve natural time scales of cloud change and cloud boundaries as well as the transition zone between cloudy and clear areas. In the case of the shortwave spectrometer, the measurements offer high time resolution and high spectral resolution, allowing new discovery-oriented science which we intend to pursue vigorously. Research objectives are, for convenience, grouped under three themes: â?˘ Understand radiative signature of the transition zone between cloud-free and cloudy areas using data from ARM shortwave radiometers, which has major climatic consequences in both aerosol direct and indirect effect studies. â?˘ Provide cloud property retrievals from the ARM sites and the ARM Mobile Facility for studies of aerosol-cloud interactions. â?˘ Assess impact of 3D cloud structures on aerosol properties using passive and active remote sensing techniques from both ARM and satellite measurements.

  9. Microphysical Consequences of the Spatial Distribution of Ice Nucleation in Mixed-Phase Stratiform Clouds

    SciTech Connect (OSTI)

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

    2014-07-28

    Mixed-phase stratiform clouds can persist even with steady ice precipitation fluxes, and the origin and microphysical properties of the ice crystals are of interest. Vapor deposition growth and sedimentation of ice particles along with a uniform volume source of ice nucleation, leads to a power law relation between ice water content wi and ice number concentration ni with exponent 2.5. The result is independent of assumptions about the vertical velocity structure of the cloud and is therefore more general than the related expression of Yang et al. [2013]. The sensitivity of the wi-ni relationship to the spatial distribution of ice nucleation is confirmed by Lagrangian tracking and ice growth with cloud-volume, cloud-top, and cloud-base sources of ice particles through a time-dependent cloud field. Based on observed wi and ni from ISDAC, a lower bound of 0.006 m^3/s is obtained for the ice crystal formation rate.

  10. Minimalist Model of Ice Microphysics in Mixed-phase Stratiform Clouds

    SciTech Connect (OSTI)

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

    2013-07-28

    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.

  11. Model-Driven Integration for a Service Placement Optimizer in a Sustainable Cloud of Clouds

    E-Print Network [OSTI]

    Suzuki, Jun

    --"Cloud of clouds" (or federated cloud) is an emerg- ing style of software deployment and execution to interoperate, federated clouds, model-driven system integration and sustainable clouds I. INTRODUCTION Cloud computing, cost effective (e.g., energy effi- cient) service/data placement and avoidance of "lock

  12. PC Mac OS Adobe Creative Cloud PC Mac OS Adobe Creative Cloud

    E-Print Network [OSTI]

    PC Mac OS Adobe Creative Cloud 1 PC Mac OS Adobe Creative Cloud 2015-05-25 1 Web Mac OS Adobe Creative Cloud PC | Creative Cloud https://helpx.adobe.com/jp/creative-cloud Adobe Creative Cloud 5.1 Web TTInstaller (Mac OS X )() http://www.officesoft.gsic.titech.ac.jp/pdf

  13. Relative humidity and its effect on aerosol optical depth in the vicinity of convective clouds

    E-Print Network [OSTI]

    Altaratz, O

    The hygroscopic growth of aerosols is controlled by the relative humidity (RH) and changes the aerosols' physical and hence optical properties. Observational studies of aerosol–cloud interactions evaluate the aerosol ...

  14. Determination of temperature and concentration from radiometric measurements in combustion systems

    E-Print Network [OSTI]

    Ren, Tao

    2015-01-01

    order to reduce heat transfer by radiation from the sampleinfrared radiation of gases, Journal of Heat Transfer 89 (and radiation properties of strongly radiating buoyant flames, ASME J Heat Transfer

  15. GMCs scaling relations: role of the cloud definition

    E-Print Network [OSTI]

    Khoperskov, S A; Ladeyschikov, D A; Sobolev, A M; Khoperskov, A V

    2015-01-01

    We investigate physical properties of molecular clouds in the disc galaxies with different morphologies: a galaxy without prominent structure, a spiral barred galaxy and a galaxy with flocculent structure. Our $N$-body/hydrodynamical simulations take into account non-equilibrium H$_2$ and CO chemical kinetics, self-gravity, star formation and feedback processes. For simulated galaxies the scaling relations of giant molecular clouds or so called Larson's relations are studied for two types of a cloud definition: the first is based on the total column density position-position (PP) datasets and the second is indicated by the CO~(1-0) line emission used position-position-velocity (PPV) data. We find that the cloud populations obtained by using both cloud extraction methods generally have similar physical parameters. Note that for the CO line data analysis the mass spectrum of clouds has a tail with low-massive objects $M\\sim 10^3-10^4$~\\Msun. In the case of variation of the column density threshold the significa...

  16. EVALUATING CLOUD RETRIEVAL ALGORITHMS WITH THE ARM BBHRP FRAMEWORK

    E-Print Network [OSTI]

    ) and the North Slope of Alaska (NSA) sites. These retrieval methods span a range of assumptions concerning demonstrated significant residuals. As an alternative to Microbase at NSA, the Shupe- Turner cloud property- 98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript

  17. Effects of aerosols on deep convective cumulus clouds 

    E-Print Network [OSTI]

    Fan, Jiwen

    2009-05-15

    in the droplet size. Ice processes are more sensitive to the changes of aerosol chemical properties than the warm rain processes. The most noticeable effect of increasing aerosol number concentrations is an increase of CDNC and cloud water content but a decrease...

  18. Tropical Warm Pool International Cloud Experiment (TWP-ICE): Cloud and Rain Characteristics in the Australian Monsoon

    SciTech Connect (OSTI)

    PT May; C Jakob; JH Mather

    2004-05-30

    The impact of oceanic convection on its environment and the relationship between the characteristics of the convection and the resulting cirrus characteristics is still not understood. An intense airborne measurement campaign combined with an extensive network of ground-based observations is being planned for the region near Darwin, Northern Australia, during January-February, 2006, to address these questions. The Tropical Warm Pool – International Cloud Experiment (TWP-ICE) will be the first field program in the tropics that attempts to describe the evolution of tropical convection, including the large scale heat, moisture, and momentum budgets, while at the same time obtaining detailed observations of cloud properties and the impact of the clouds on the environment. The emphasis will be on cirrus for the cloud properties component of the experiment. Cirrus clouds are ubiquitous in the tropics and have a large impact on their environment but the properties of these clouds are poorly understood. A crucial product from this experiment will be a dataset suitable to provide the forcing and testing required by cloud-resolving models and parameterizations in global climate models. This dataset will provide the necessary link between cloud properties and the models that are attempting to simulate them. The experiment is a collaboration between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program, the Bureau of Meteorology (BoM), the National Aeronautics and Space Administration (NASA), the European Commission DG RTD-1.2, and several United States, Australian, Canadian, and European Universities. This experiment will be undertaken over a 4-week period in early 2006. January and February corresponds to the wet phase of the Australia monsoon. This season has been selected because, despite Darwin’s coastal location, the convection that occurs over and near Darwin at this time is largely of maritime origin with a large fetch over water. Based on previous experiments, the convection appears typical of maritime convection with widespread convection that has complex organization, but is not as deep or as intense as continental or coastal convection. Therefore, it is expected that the convection and cloud characteristics will be representative of conditions typical for wide areas of the tropics.

  19. Embracing the Cloud for Better Cyber Security

    SciTech Connect (OSTI)

    Shue, Craig A; Lagesse, Brent J

    2011-01-01

    The future of cyber security is inextricably tied to the future of computing. Organizational needs and economic factors will drive computing outcomes. Cyber security researchers and practitioners must recognize the path of computing evolution and position themselves to influence the process to incorporate security as an inherent property. The best way to predict future computing trends is to look at recent developments and their motivations. Organizations are moving towards outsourcing their data storage, computation, and even user desktop environments. This trend toward cloud computing has a direct impact on cyber security: rather than securing user machines, preventing malware access, and managing removable media, a cloud-based security scheme must focus on enabling secure communication with remote systems. This change in approach will have profound implications for cyber security research efforts. In this work, we highlight existing and emerging technologies and the limitations of cloud computing systems. We then discuss the cyber security efforts that would support these applications. Finally, we discuss the implications of these computing architecture changes, in particular with respect to malware and social engineering.

  20. Polluting of Winter Convective Clouds upon Transition from Ocean Inland Over Central California: Contrasting Case Studies

    SciTech Connect (OSTI)

    Rosenfeld, Daniel; Chemke, Rei; Prather, Kimberly; Suski, Kaitlyn; Comstock, Jennifer M.; Schmid, Beat; Tomlinson, Jason M.; Jonsson, Haf

    2014-01-01

    In-situ aircraft measurements of aerosol chemical and cloud microphysical properties were conducted during the CalWater campaign in February and March 2011 over the Sierra Nevada Mountains and the coastal waters of central California. The main objective was to elucidate the impacts of aerosol properties on clouds and precipitation forming processes. In order to accomplish this, we compared contrasting cases of clouds that ingested aerosols from different sources. The results showed that clouds containing pristine oceanic air had low cloud drop concentrations and started to develop rain 500 m above their base. This occurred both over the ocean and over the Sierra Nevada, mainly in the early morning when the radiatively cooled stable continental boundary layer was decoupled from the cloud base. Supercooled rain dominated the precipitation that formed in growing convective clouds in the pristine air, up to the -21°C isotherm level. A contrasting situation was documented in the afternoon over the foothills of the Sierra Nevada, when the clouds ingested high pollution aerosol concentrations produced in the Central Valley. This led to slow growth of the cloud drop effective radius with height and suppressed and even prevented the initiation of warm rain while contributing to the development of ice hydrometeors in the form of graupel. Our results show that cloud condensation and ice nuclei were the limiting factors that controlled warm rain and ice processes, respectively, while the unpolluted clouds in the same air mass produced precipitation quite efficiently. These findings provide the motivation for deeper investigations into the nature of the aerosols seeding clouds.

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

    SciTech Connect (OSTI)

    2013-10-18

    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').

  2. Migrating enterprise storage applications to the cloud

    E-Print Network [OSTI]

    Vrable, Michael Daniel

    2011-01-01

    1.1 Cloud Computing Applications 1.2Zaharia. A view of cloud computing. Communications of theM. Voelker, Co-Chair Cloud computing has emerged as a model

  3. The Magellan Final Report on Cloud Computing

    E-Print Network [OSTI]

    Coghlan, Susan

    2013-01-01

    4.3.1 Cloud Computing Attractive Features . 4.3.2A berkeley view of cloud computing. Technical Report UCB/matching computations on cloud computing platforms and hpc

  4. The Cloud Computing and Other Variables

    E-Print Network [OSTI]

    Borjon-Kubota, Martha Estela

    2011-01-01

    12. Fragments in Six 13. Cloud Computing 14. Phase 15.Note 48. Devoured vi Cloud Computing and other Variables I.CALIFORNIA RIVERSIDE Cloud Computing and Other Variables A

  5. Magellan: experiences from a Science Cloud

    E-Print Network [OSTI]

    Ramakrishnan, Lavanya

    2013-01-01

    the security implications of user-controlled cloud images?key security practices and policies on private clouds, suchand security poli- cies will remain, and sites moving to cloud

  6. Trusted Cloud: Microsoft Azure Security, Privacy,

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    Trusted Cloud: Microsoft Azure Security, Privacy, and Compliance April 2015 #12;Trusted Cloud................................................................. 18 #12;Trusted Cloud: Microsoft Azure Security, Privacy, and Compliance | April, 2015 Introduction: Microsoft Azure Security, Privacy, and Compliance | April, 2015 #12;3 Contents Introduction

  7. Cicada: Predictive Guarantees for Cloud Network Bandwidth

    E-Print Network [OSTI]

    LaCurts, Katrina

    2014-03-24

    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 ...

  8. Magellan: experiences from a Science Cloud

    E-Print Network [OSTI]

    Ramakrishnan, Lavanya

    2013-01-01

    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

  9. The Mechanism of First Raindrops Formation in Deep Convective Clouds

    SciTech Connect (OSTI)

    Khain, Alexander; Prabha, Thara; Benmoshe, Nir; Pandithurai, G.; Ovchinnikov, Mikhail

    2013-08-22

    The formation of first raindrops in deep convective clouds is investigated. A combination of observational data analysis and 2-D and 3-D numerical bin microphysical simulations of deep convective clouds suggests that the first raindrops form at the top of undiluted or slightly diluted cores. It is shown that droplet size distributions in these regions are wider and contain more large droplets than in diluted volumes. The results of the study indicate that the initial raindrop formation is determined by the basic microphysical processes within ascending adiabatic volumes. It allows one to predict the height of the formation of first raindrops considering the processes of nucleation, diffusion growth and collisions. The results obtained in the study explain observational results reported by Freud and Rosenfeld (2012) according to which the height of first raindrop formation depends linearly on the droplet number concentration at cloud base. The results also explain why a simple adiabatic parcel model can reproduce this dependence. The present study provides a physical basis for retrieval algorithms of cloud microphysical properties and aerosol properties using satellites proposed by Rosenfeld et al. ( 2012). The study indicates that the role of mixing and entrainment in the formation of the first raindrops is not of crucial importance. It is also shown that low variability of effective and mean volume radii along horizontal traverses, as regularly observed by in situ measurements, can be simulated by high-resolution cloud models, in which mixing is parameterized by a traditional 1.5 order turbulence closure scheme.

  10. Effects of Ocean Ecosystem on Marine Aerosol-Cloud Interaction

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

    Meskhidze, Nicholas; Nenes, Athanasios

    2010-01-01

    Using satellite data for the surface ocean, aerosol optical depth (AOD), and cloud microphysical parameters, we show that statistically significant positive correlations exist between ocean ecosystem productivity, the abundance of submicron aerosols, and cloud microphysical properties over different parts of the remote oceans. The correlation coefficient for remotely sensed surface chlorophyll a concentration ([Chl- a ]) and liquid cloud effective radii over productive areas of the oceans varies between ? 0.2 and ? 0.6 . Special attention is given to identifying (and addressing) problems from correlation analysis used in the previousmore »studies that can lead to erroneous conclusions. A new approach (using the difference between retrieved AOD and predicted sea salt aerosol optical depth, AOD diff ) is developed to explore causal links between ocean physical and biological systems and the abundance of cloud condensation nuclei (CCN) in the remote marine atmosphere. We have found that over multiple time periods, 550?nm AOD diff (sensitive to accumulation mode aerosol, which is the prime contributor to CCN) correlates well with [Chl- a ] over the productive waters of the Southern Ocean. Since [Chl- a ] can be used as a proxy of ocean biological productivity, our analysis demonstrates the role of ocean ecology in contributing CCN, thus shaping the microphysical properties of low-level marine clouds. « less

  11. Bringing Clouds into Focus

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransen Plasma Asher An O2 RFand1120019Bringing Clouds into

  12. Digital Ecosystems in the Clouds: Towards Community Cloud Computing

    E-Print Network [OSTI]

    Briscoe, Gerard

    2009-01-01

    Cloud Computing is rising fast, with its data centres growing at an unprecedented rate. However, this has come with concerns of privacy, efficiency at the expense of resilience, and environmental sustainability, because of the dependence on Cloud vendors such as Google, Amazon, and Microsoft. Community Cloud Computing makes use of the principles of Digital Ecosystems to provide a paradigm for Clouds in the community, offering an alternative architecture for the use cases of Cloud Computing. Its more technically challenging, dealing with issues of distributed computing, such as latency, differential resource management, and additional security requirements. However, these are not insurmountable challenges, and with the need to retain control over our digital lives and the potential environmental consequences, its one we must pursue.

  13. Cloud Computing and Validation of Expandable In Silico Livers

    E-Print Network [OSTI]

    Ropella, Glen EP; Hunt, C Anthony

    2010-01-01

    with access to computer clusters. Cloud technology coupledto computer clusters. The availability of cloud technology

  14. UNDERSTANDING TRENDS ASSOCIATED WITH CLOUDS IN IRRADIATED EXOPLANETS

    SciTech Connect (OSTI)

    Heng, Kevin; Demory, Brice-Olivier E-mail: demory@mit.edu

    2013-11-10

    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.

  15. The Magellan Final Report on Cloud Computing

    E-Print Network [OSTI]

    Coghlan, Susan

    2013-01-01

    of computer security are evolving for cloud computingcomputer forensic space a way to integrate their tools with the cloudthe cloud business model. In addition to answering computer

  16. WEATHER MODIFICATION BY AIRCRAFT CLOUD SEEDING

    E-Print Network [OSTI]

    Vali, Gabor

    WEATHER MODIFICATION BY AIRCRAFT CLOUD SEEDING BERYULEV G.P. Head, Department of Cloud Physics and Weather Modification Central Aerological Observatory Rosgidromet, Russian Federation #12

  17. Cloud Seeding By: Julie Walter

    E-Print Network [OSTI]

    Toohey, Darin W.

    , smoke, that then are cooled because of the high altitudes. As the water or condensation nuclei cool more titled "Cat's Cradle" a young scientist has in his possession an ice crystal that has the power to freeze of those clouds. Winds can form suddenly and blow clouds away from the targeted area. Some experiments show

  18. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

    SciTech Connect (OSTI)

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; Miller, Matthew; Mechem, David; Tselioudis, George; Chiu, Christine; Mann, Julia; O Connor, Ewan; Hogan, Robin; Dong, Xiquan; Miller, Mark; Ghate, Virendra; Jefferson, Anne; Min, Qilong; Minnis, Patrick; Palinkonda, Rabindra; Albrecht, Bruce; Hannay, Cecile; Lin, Yanluan

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.

  19. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

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

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; et al

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulusmore »and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.« less

  20. Draft NISTIR 80061 NIST Cloud Computing2

    E-Print Network [OSTI]

    Draft NISTIR 80061 NIST Cloud Computing2 Forensic Science Challenges NIST Cloud Computing Forensic Computing11 Forensic Science Challenges 12 NIST Cloud Computing Forensic Science Working Group13 Information challenges77 faced by experts when responding to incidents that have occurred in a cloud-computing ecosystem

  1. Secure Cloud Computing With Brokered Trusted

    E-Print Network [OSTI]

    Secure Cloud Computing With Brokered Trusted Sensor Networks Profs. Steven Myers,Apu Kapadia, Xiao-mount Antenna Tower-mount Antenna Wireless Bridge Security Threats 1. Cloud or Grid 2. Communication Channels 3 Computing Cloud Computing Cloud Computing Tower-mount Antenna Tower-mount Antenna Wireless Bridge Security

  2. An Architecture for Trusted Clouds Mike Burmester

    E-Print Network [OSTI]

    Burmester, Mike

    reasoning will play a major role. In this paper we analyze the cloud paradigm from a security point of view, but it is also technically easier to secure. Finally, the Cloud has a dark side, at least from a security point regulatory and security policies; and hybrid clouds. Services. There are three basic cloud on demand

  3. Why the network matters in cloud computing

    E-Print Network [OSTI]

    Greenberg, Albert

    this promise, and security concerns still loom AT&T NetBond AT&T network enabled cloud computing provides highly-secure access, with the cloud functioning just like another MPLS VPN site. It also allowsWhy the network matters in cloud computing The promise of cloud hinges on flexibility, agility

  4. NIST Cloud Computing Forum and Workshop VIII

    E-Print Network [OSTI]

    NIST Cloud Computing Forum and Workshop VIII Kevin Mills, NIST July 9, 2015 #12;NIST Cloud Project Research Goals Kevin Mills, NIST #12;NIST Cloud Computing Forum and Workshop VIII July 2 015 failure scenarios in a cloud system · Ongoing work on run-time methods · Where to find more information 3

  5. Parameterizations of Cloud Microphysics and Indirect Aerosol Effects

    SciTech Connect (OSTI)

    Tao, Wei-Kuo

    2014-05-19

    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

  6. EWI PDS A.Iosup Research Cloud Computing Cloud Computing Research, PDS Group, TU Delft

    E-Print Network [OSTI]

    Iosup, Alexandru

    EWI PDS A.Iosup Research Cloud Computing Cloud Computing Research, PDS Group, TU Delft Cloud Computing Research http://www.pds.ewi.tudelft.nl/~iosup/research_cloud.html Rationale why and how is this work relevant? Cloud computing is an emerging commercial infrastructure paradigm that promises

  7. Storm Clouds Rising: Security Challenges for IaaS Cloud Computing

    E-Print Network [OSTI]

    Bishop, Matt

    Storm Clouds Rising: Security Challenges for IaaS Cloud Computing Brian Hay Kara Nance Matt Bishop on security concerns for computational cloud computing from the perspectives of cloud service users, cloud.hay@alaska.edu klnance@alaska.edu bishop@cs.ucdavis.edu Abstract Securing our digital assets has become increasingly

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

    E-Print Network [OSTI]

    Zhong, Lin

    General Terms Algorithms, Design, Human Factors, Languages, Performance, Security Keywords Camera, cloudVision: 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

  9. EVALUATION OF INTERNATIONAL SATELLITE CLOUD CLIMATOLOGY PROJECT (ISCCP) D2 CLOUD AMOUNT CHANGES AND THEIR CONNECTIONS

    E-Print Network [OSTI]

    Schubert, Wayne H.

    EVALUATION OF INTERNATIONAL SATELLITE CLOUD CLIMATOLOGY PROJECT (ISCCP) D2 CLOUD AMOUNT CHANGES #12;ii #12;iii ABSTRACT EVALUATION OF INTERNATIONAL SATELLITE CLOUD CLIMATOLOGY PROJECT (ISCCP) D2 Climatology Project (ISCCP) D2 dataset exhibits a 2.6% per decade decrease in the global all-cloud cloud

  10. Decomposing aerosol cloud radiative effects into cloud cover, liquid water path and Twomey components

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    Decomposing aerosol cloud radiative effects into cloud cover, liquid water path and Twomey December 2013 A method for separating the three components of the marine stratocumulus (MSC) aerosol cloud interactions radiative effects, i.e., the cloud cover, liquid water path (LWP) and cloud drop radius (Twomey

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

    E-Print Network [OSTI]

    Iosup, Alexandru

    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

  12. 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

  13. Cloud water contents and hydrometeor sizes during the FIRE Arctic Clouds Experiment

    E-Print Network [OSTI]

    Shupe, Matthew

    Cloud water contents and hydrometeor sizes during the FIRE Arctic Clouds Experiment Matthew D a 35-GHz cloud radar and the DOE Atmospheric Radiation Measurement Program operated a suite Clouds Experiment took place during April­July 1998, with the primary goal of investigating cloud

  14. A CloudSat cloud object partitioning technique and assessment and integration of deep

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    A CloudSat cloud object partitioning technique and assessment and integration of deep convective, USA Abstract A cloud object partitioning algorithm is developed to provide a widely useful database of deep convective clouds. It takes contiguous CloudSat cloudy regions and identifies various length

  15. Non-invasive hyperthermia apparatus including coaxial applicator having a non-invasive radiometric receiving antenna incorporated therein and method of use thereof

    DOE Patents [OSTI]

    Ross, M.P.

    1996-08-27

    A coaxial hyperthermia applicator is disclosed for applying non-invasively electromagnetic energy to a body against which it is placed. The coaxial applicator antenna has formed integrally within it a non-invasive radiometric antenna for receiving thermoelectromagnetic emissions. The coaxial-configured applicator produces a bell-shaped radiation pattern symmetric about the axis of symmetry of the coaxial applicator. Integrating the radiometric antenna within the coaxial applicator produces a single device that performs dual functions. The first function is to transmit non-invasively energy for heating a subcutaneous tumor. The second function is to receive non-invasively thermal electromagnetic radiation from the tumor by which temperature is sensed and fed back to control the output of the coaxial applicator. 11 figs.

  16. Non-invasive hyperthermia apparatus including coaxial applicator having a non-invasive radiometric receiving antenna incorporated therein and method of use thereof

    DOE Patents [OSTI]

    Ross, Michael P. (Albquuerque, NM)

    1996-01-01

    A coaxial hyperthermia applicator for applying non-invasively electromagnetic energy to a body against which it is placed. The coaxial applicator antenna has formed integrally within it a non-invasive radiometric antenna for receiving thermoelectromagnetic emissions. The coaxial-configured applicator produces a bell-shaped radiation pattern symmetric about the axis of symmetry of the coaxial applicator. Integrating the radiometric antenna within the coaxial applicator produces a single device that performs dual functions. The first function is to transmit non-invasively energy for heating a subcutaneous tumor. The second function is to receive non-invasively thermal electromagnetic radiation from the tumor by which temperature is sensed and fed back to control the output of the coaxial applicator.

  17. RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations

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

    Endo, Satoshi; Fridlind, Ann M.; Lin, Wuyin; Vogelmann, Andrew M.; Toto, Tami; Ackerman, Andrew S.; McFarquhar, Greg M.; Jackson, Robert C.; Jonsson, Haflidi H.; Liu, Yangang

    2015-06-19

    A 60-hour case study of continental boundary layer cumulus clouds is examined using two large-eddy simulation (LES) models. The case is based on observations obtained during the RACORO Campaign (Routine Atmospheric Radiation Measurement [ARM] Aerial Facility [AAF] Clouds with Low Optical Water Depths [CLOWD] Optical Radiative Observations) at the ARM Climate Research Facility's Southern Great Plains site. The LES models are driven by continuous large-scale and surface forcings, and are constrained by multi-modal and temporally varying aerosol number size distribution profiles derived from aircraft observations. We compare simulated cloud macrophysical and microphysical properties with ground-based remote sensing and aircraft observations.more »The LES simulations capture the observed transitions of the evolving cumulus-topped boundary layers during the three daytime periods, and generally reproduce variations of droplet number concentration with liquid water content (LWC), corresponding to the gradient between the cloud centers and cloud edges at given heights. The observed LWC values fall within the range of simulated values; the observed droplet number concentrations are commonly higher than simulated, but differences remain on par with potential estimation errors in the aircraft measurements. Sensitivity studies examine the influences of bin microphysics versus bulk microphysics, aerosol advection, supersaturation treatment, and aerosol hygroscopicity. Simulated macrophysical cloud properties are found to be insensitive in this non-precipitating case, but microphysical properties are especially sensitive to bulk microphysics supersaturation treatment and aerosol hygroscopicity.« less

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

    SciTech Connect (OSTI)

    Dana E. Veron

    2012-04-09

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

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

    E-Print Network [OSTI]

    I. Pashalidis; H. Tsertos

    2003-04-28

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

  20. Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c

    E-Print Network [OSTI]

    Prather, MJ

    2015-01-01

    Collins, W. : Effect of clouds on photolysis and oxidants insimulation of in- and below-cloud photolysis in troposphericS. , and Liu, X. : Effects of cloud overlap in photochemical

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

    SciTech Connect (OSTI)

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

    2012-01-16

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

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

    SciTech Connect (OSTI)

    Wu, Xiaoqing

    2014-02-25

    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.

  3. Redefining the Cloud based on Beneficial Service Characteristics A New Cloud Taxonomy Leads to Economically Reasonable Semi-cloudification

    E-Print Network [OSTI]

    Redefining the Cloud based on Beneficial Service Characteristics A New Cloud Taxonomy Leads, Germany kemmler@lrz.de Keywords: Cloud, Semi-cloud, Service, Cloud Service, Semi-cloud Service, Service Management. Abstract: Cloud services promise benefits for customers and providers such as scalability

  4. Resource Allocation and Scheduling in Heterogeneous Cloud Environments

    E-Print Network [OSTI]

    Lee, Gunho

    2012-01-01

    1] Open Cirrus cloud computing testbed. http://10] Early experiments in cloud computing. http://on Hot topics in cloud computing, pages 12–12, 2009. [29

  5. Cloud Computing and Validation of Expandable In Silico Livers

    E-Print Network [OSTI]

    Ropella, Glen EP; Hunt, C Anthony

    2010-01-01

    benefit analysis of cloud computing versus desktop grids.as: Ropella and Hunt: Cloud computing and validation ofCloud computing and validation of expandable in silico

  6. RFID Asset Management Solution with Cloud Computation Service

    E-Print Network [OSTI]

    Chattopadhyay, Arunabh

    2012-01-01

    A berkeley view of cloud computing”, EECS Department,and S. Sarma, “Cloud computing, rest and mashups to simplifyand/or frameworks. Cloud computing can be defined as

  7. Simulations of Midlatitude Frontal Clouds by Single-Column and...

    Office of Scientific and Technical Information (OSTI)

    and 4 cloud resolving models (CRMs) in simulating a strong midlatitude frontal cloud system taken from the Spring 2000 Cloud Intensive Observational Period at the ARM Southern...

  8. Intercomparison of model simulations of mixed-phase clouds observed...

    Office of Scientific and Technical Information (OSTI)

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

  9. DEVELOPMENT OF IMPROVED TECHNIQUES FOR SATELLITE REMOTE SENSING OF CLOUDS AND RADIATION USING ARM DATA, FINAL REPORT

    SciTech Connect (OSTI)

    Minnis, Patrick

    2013-06-28

    During the period, March 1997 – February 2006, the Principal Investigator and his research team co-authored 47 peer-reviewed papers and presented, at least, 138 papers at conferences, meetings, and workshops that were supported either in whole or in part by this agreement. We developed a state-of-the-art satellite cloud processing system that generates cloud properties over the Atmospheric Radiation (ARM) surface sites and surrounding domains in near-real time and outputs the results on the world wide web in image and digital formats. When the products are quality controlled, they are sent to the ARM archive for further dissemination. These products and raw satellite images can be accessed at http://cloudsgate2.larc.nasa.gov/cgi-bin/site/showdoc?docid=4&cmd=field-experiment-homepage&exp=ARM and are used by many in the ARM science community. The algorithms used in this system to generate cloud properties were validated and improved by the research conducted under this agreement. The team supported, at least, 11 ARM-related or supported field experiments by providing near-real time satellite imagery, cloud products, model results, and interactive analyses for mission planning, execution, and post-experiment scientific analyses. Comparisons of cloud properties derived from satellite, aircraft, and surface measurements were used to evaluate uncertainties in the cloud properties. Multiple-angle satellite retrievals were used to determine the influence of cloud structural and microphysical properties on the exiting radiation field.

  10. Star Formation in Disk Galaxies. III. Does stellar feedback result in cloud death?

    E-Print Network [OSTI]

    Tasker, Elizabeth J; Pudritz, Ralph

    2015-01-01

    Stellar feedback, star formation and gravitational interactions are major controlling forces in the evolution of Giant Molecular Clouds (GMCs). To explore their relative roles, we examine the properties and evolution of GMCs forming in an isolated galactic disk simulation that includes both localised thermal feedback and photoelectric heating. The results are compared with the three previous simulations in this series which consists of a model with no star formation, star formation but no form of feedback and star formation with photoelectric heating in a set with steadily increasing physical effects. We find that the addition of localised thermal feedback greatly suppresses star formation but does not destroy the surrounding GMC, giving cloud properties closely resembling the run in which no stellar physics is included. The outflows from the feedback reduce the mass of the cloud but do not destroy it, allowing the cloud to survive its stellar children. This suggests that weak thermal feedback such as the low...

  11. The Evolution of Cloud Computing in ATLAS

    E-Print Network [OSTI]

    Taylor, Ryan P.; The ATLAS collaboration; Love, Peter; Leblanc, Matthew Edgar; Di Girolamo, Alessandro; Paterson, Michael; Gable, Ian; Sobie, Randall; Field, Laurence

    2015-01-01

    The ATLAS experiment has successfully incorporated cloud computing technology and cloud resources into its primarily grid-based model of distributed computing. Cloud R&D activities continue to mature and transition into stable production systems, while ongoing evolutionary changes are still needed to adapt and refine the approaches used, in response to changes in prevailing cloud technology. In addition, completely new developments are needed to handle emerging requirements. This work will describe the overall evolution of cloud computing in ATLAS. The current status of the VM management systems used for harnessing IAAS resources will be discussed. Monitoring and accounting systems tailored for clouds are needed to complete the integration of cloud resources within ATLAS' distributed computing framework. We are developing and deploying new solutions to address the challenge of operation in a geographically distributed multi-cloud scenario, including a system for managing VM images across multiple clouds, ...

  12. Cirrus cloud-temperature interactions over a tropical station, Gadanki from lidar and satellite observations

    SciTech Connect (OSTI)

    S, Motty G, E-mail: mottygs@gmail.com; Satyanarayana, M., E-mail: mottygs@gmail.com; Krishnakumar, V., E-mail: mottygs@gmail.com; Dhaman, Reji k., E-mail: mottygs@gmail.com [Department of Optoelectronics, University of Kerala, Kariavattom, Trivandrum-695 581, Kerala (India)

    2014-10-15

    The cirrus clouds play an important role in the radiation budget of the earth's atmospheric system and are important to characterize their vertical structure and optical properties. LIDAR measurements are obtained from the tropical station Gadanki (13.5{sup 0} N, 79.2{sup 0} E), India, and meteorological indicators derived from Radiosonde data. Most of the cirrus clouds are observed near to the tropopause, which substantiates the strength of the tropical convective processes. The height and temperature dependencies of cloud height, optical depth, and depolarization ratio were investigated. Cirrus observations made using CALIPSO satellite are compared with lidar data for systematic statistical study of cirrus climatology.

  13. PROGRESS REPORT OF FY 2004 ACTIVITIES: IMPROVED WATER VAPOR AND CLOUD RETRIEVALS AT THE NSA/AAO

    SciTech Connect (OSTI)

    E. R. Westwater; V. V. Leuskiy; M. Klein; A. J. Gasiewski; and J. A. Shaw

    2004-11-01

    The basic goals of the research are to develop and test algorithms and deploy instruments that improve measurements of water vapor, cloud liquid, and cloud coverage, with a focus on the Arctic conditions of cold temperatures and low concentrations of water vapor. The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement Program. Although several technologies have been investigated to measure these column amounts, microwave radiometers (MWR) have been used operationally by the ARM program for passive retrievals of these quantities: precipitable water vapor (PWV) and integrated water liquid (IWL). The technology of PWV and IWL retrievals has advanced steadily since the basic 2-channel MWR was first deployed at ARM CART sites Important advances are the development and refinement of the tipcal calibration method [1,2], and improvement of forward model radiative transfer algorithms [3,4]. However, the concern still remains that current instruments deployed by ARM may be inadequate to measure low amounts of PWV and IWL. In the case of water vapor, this is especially important because of the possibility of scaling and/or quality control of radiosondes by the water amount. Extremely dry conditions, with PWV less than 3 mm, commonly occur in Polar Regions during the winter months. Accurate measurements of the PWV during such dry conditions are needed to improve our understanding of the regional radiation energy budgets. The results of a 1999 experiment conducted at the ARM North Slope of Alaska/Adjacent Arctic Ocean (NSA/AAO) site during March of 1999 [5] have shown that the strength associated with the 183 GHz water vapor absorption line makes radiometry in this frequency regime suitable for measuring low amounts of PWV. As a portion of our research, we conducted another millimeter wave radiometric experiment at the NSA/AAO in March-April 2004. This experiment relied heavily on our experiences of the 1999 experiment. Particular attention was paid to issues of radiometric calibration and radiosonde intercomparisons. Our theoretical and experimental work also supplements efforts by industry (F. Solheim, Private Communication) to develop sub-millimeter radiometers for ARM deployment. In addition to quantitative improvement of water vapor measurements at cold temperature, the impact of adding millimeter-wave window channels to improve the sensitivity to arctic clouds was studied. We also deployed an Infrared Cloud Imager (ICI) during this experiment, both for measuring continuous day-night statistics of the study of cloud coverage and identifying conditions suitable for tipcal analysis. This system provided the first capability of determining spatial cloud statistics continuously in both day and night at the NSA site and has been used to demonstrate that biases exist in inferring cloud statistics from either zenith-pointing active sensors (lidars or radars) or sky imagers that rely on scattered sunlight in daytime and star maps at night [6].

  14. An Inter-Cloud Architecture for Future Internet Infrastructures

    E-Print Network [OSTI]

    Petrakis, Euripides G.M.

    An Inter-Cloud Architecture for Future Internet Infrastructures STELIOS SOTIRIADIS, Technical, Technical University of Crete, Greece Iaan latest years, the concept of interconnecting clouds to allow of cloud resources from Internet users. An efficient common management between different clouds

  15. Disruptive technology business models in cloud computing

    E-Print Network [OSTI]

    Krikos, Alexis Christopher

    2010-01-01

    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 ...

  16. The Evolution of Cloud Computing in ATLAS

    E-Print Network [OSTI]

    Taylor, Ryan P; The ATLAS collaboration; Brasolin, Franco; Cordeiro, Cristovao; Desmarais, Ron; Field, Laurence; Gable, Ian; Giordano, Domenico; Di Girolamo, Alessandro; Hover, John; Leblanc, Matthew Edgar; Love, Peter; Paterson, Michael; Sobie, Randall; Zaytsev, Alexandr

    2015-01-01

    The ATLAS experiment has successfully incorporated cloud computing technology and cloud resources into its primarily grid-based model of distributed computing. Cloud R&D activities continue to mature and transition into stable production systems, while ongoing evolutionary changes are still needed to adapt and refine the approaches used, in response to changes in prevailing cloud technology. In addition, completely new developments are needed to handle emerging requirements. This paper describes the overall evolution of cloud computing in ATLAS. The current status of the virtual machine (VM) management systems used for harnessing infrastructure as a service (IaaS) resources are discussed. Monitoring and accounting systems tailored for clouds are needed to complete the integration of cloud resources within ATLAS' distributed computing framework. We are developing and deploying new solutions to address the challenge of operation in a geographically distributed multi-cloud scenario, including a system for ma...

  17. VOLUMETRIC SNAPPING: WATERTIGHT TRIANGULATION OF POINT CLOUDS

    E-Print Network [OSTI]

    Floater, Michael S.

    VOLUMETRIC SNAPPING: WATERTIGHT TRIANGULATION OF POINT CLOUDS Tim Volodine KULeuven, Department: meshing, surface reconstruction, volumetric grid, contouring, point clouds. Abstract: We propose, a volumetric method that does not rely on a signed distance function was proposed recently by Hornung

  18. Changes in high cloud conditions 

    E-Print Network [OSTI]

    Himebrook, Richard Frank

    1974-01-01

    of contrails, while in a more humid environment contrails wi. ll form. ilovis et al. (1970) showed that, over the 0. 68-2. 4p wavelength interval, "naturally" formed ice clouds and a fresh contrail show different signatures (which could be observed... prime cause for a change in the amount of high clouds, the Location of stations with respect to the jet routes was also reviewed. Atlanta, Ceorgia, was selected because it is a ma ~or air Lr r- minal and its upper-air liow advects jet...

  19. AnonymousCloud: A Data Ownership Privacy Provider Framework in Cloud Computing

    E-Print Network [OSTI]

    Hamlen, Kevin W.

    AnonymousCloud: A Data Ownership Privacy Provider Framework in Cloud Computing Safwan Mahmud Khan their computation results are ultimately delivered. To provide this data ownership privacy, the cloud's distributed-anonymity; authentication; cloud computing; in- formation security; privacy; Tor I. INTRODUCTION Revolutionary advances

  20. CloudHKA: A Cryptographic Approach for Hierarchical Access Control in Cloud Computing

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    CloudHKA: A Cryptographic Approach for Hierarchical Access Control in Cloud Computing Yi-Ruei Chen1, cloud computing, proxy re-encryption 1 Introduction Outsourcing data to cloud server (CS) becomes , Cheng-Kang Chu2 , Wen-Guey Tzeng3 , and Jianying Zhou4 1,3 Department of Computer Science, National

  1. CLOUD COMPUTING AND INFORMATION POLICY 1 Cloud Computing and Information Policy

    E-Print Network [OSTI]

    Daume III, Hal

    . Keywords: cloud computing, information policy, rechnology policy, grid computing, security, privacyCLOUD 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

  2. IsYour Network Cloud Ready? Network EnableYour Cloud With MPLSVPNs

    E-Print Network [OSTI]

    Greenberg, Albert

    -enabled cloud that is highly-secure and reliable. It is critical for enterprises to evaluate a network, but the high level of shared infrastructure creates concerns about security risks.As a result, the public cloudIsYour Network Cloud Ready? Network EnableYour Cloud With MPLSVPNs A FROST & SULLIVAN EXECUTIVE

  3. Home is Safer than the Cloud! Privacy Concerns for Consumer Cloud Storage

    E-Print Network [OSTI]

    for sensitive data over cloud storage. However, users desire better security and are ready to pay for services storage systems. General Terms Human Factors, Security, Privacy. Keywords Cloud Storage, Social FactorsHome is Safer than the Cloud! Privacy Concerns for Consumer Cloud Storage Iulia Ion , Niharika

  4. CloudWatcher: Network Security Monitoring Using OpenFlow in Dynamic Cloud Networks

    E-Print Network [OSTI]

    Gu, Guofei

    CloudWatcher: Network Security Monitoring Using OpenFlow in Dynamic Cloud Networks (or: How to Provide Security Monitoring as a Service in Clouds?) Seungwon Shin SUCCESS Lab Texas A&M University Email, basically, we can employ existing network security devices, but applying them to a cloud network requires

  5. StressCloud: A Tool for Analysing Performance and Energy Consumption of Cloud Applications

    E-Print Network [OSTI]

    Yang, Yun

    StressCloud: A Tool for Analysing Performance and Energy Consumption of Cloud Applications Feifei. It requires the evaluation of system performance and energy consumption under a wide variety of realistic and energy consumption analysis tool for cloud applications in real-world cloud environments. Stress

  6. THREE-DIMENSIONAL CLOUD STRUCTURE OBSERVED DURING DOE ARM'S 2009 CLOUD TOMOGRAPHY FIELD EXPERIMENT

    E-Print Network [OSTI]

    THREE-DIMENSIONAL CLOUD STRUCTURE OBSERVED DURING DOE ARM'S 2009 CLOUD TOMOGRAPHY FIELD EXPERIMENT on Cloud Physics, Portland, OR June 28-July 2, 2010 Environmental Sciences Department/Atmospheric Sciences Atmospheric Radiation Measurement (ARM)'s cloud tomography Intensive Observation Period (IOP

  7. 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

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

    E-Print Network [OSTI]

    Miami, University of

    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

  9. Cloud Verifier: Verifiable Auditing Service for IaaS Clouds Joshua Schiffman

    E-Print Network [OSTI]

    Jaeger, Trent

    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

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

    E-Print Network [OSTI]

    Plant, Robert

    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

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

    E-Print Network [OSTI]

    Sommerville, Ian

    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

  12. Comparison of MISR and MODIS cloud-top heights in the presence of cloud overlap

    E-Print Network [OSTI]

    Baum, Bryan A.

    Comparison of MISR and MODIS cloud-top heights in the presence of cloud overlap C.M. Naud a, , B July 2006; accepted 3 September 2006 Abstract Coincident MISR and MODIS cloud-top heights retrieved March 2000 and October 2003. The difference between MODIS and MISR cloud-top heights is assessed

  13. Ralf Klessen: PPV, Oct. 24, 2005 Molecular CloudMolecular Cloud

    E-Print Network [OSTI]

    Klessen,Ralf

    Ralf Klessen: PPV, Oct. 24, 2005 Molecular CloudMolecular Cloud Turbulence and Star formation three ,,steps" of star formation: 1.1. formation of molecular clouds in the disk of ourformation of molecular clouds in the disk of our galaxygalaxy 2.2. formation of protostellar coresformation

  14. Moving magnetic cloud -1Moving magnetic cloud -1 "Double change of frame" calculation...

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    #12;19 Moving magnetic cloud - 1Moving magnetic cloud - 1 "Double change of frame" calculation... #12;eb. 2005 -- Cosmic-rays & Particle Acceleration -- E. Parizot (IPN Orsay) 21 Moving magnetic cloud - 2Moving magnetic cloud - 2 #12;Karlsruhe, 23-25 Feb. 2005 -- Cosmic-rays & Particle Acceleration

  15. To Cloud or Not to Cloud: Measuring the Performance of Mobile Gaming

    E-Print Network [OSTI]

    Chen, Sheng-Wei

    To Cloud or Not to Cloud: Measuring the Performance of Mobile Gaming Chun-Ying Huang Department Tsing-Hua University Hsinchu, Taiwan chsu@cs.nthu.edu.tw ABSTRACT Mobile cloud gaming allows gamers an open source cloud gaming platform to conduct extensive experiments on real mobile clients. Our

  16. Determination of cloud liquid water distribution using 3D cloud tomography

    E-Print Network [OSTI]

    Determination of cloud liquid water distribution using 3D cloud tomography Dong Huang,1 Yangang Liu; published 2 July 2008. [1] The cloud microwave tomography method for remotely retrieving 3D distributions of cloud Liquid Water Content (LWC) was originally proposed by Warner et al. in the 1980s but has lain

  17. CloudTracker: Using Execution Provenance to Optimize the Cost of Cloud Use

    E-Print Network [OSTI]

    Bigelow, Stephen

    CloudTracker: Using Execution Provenance to Optimize the Cost of Cloud Use Geoffrey Douglas, Brian simulations using commercial clouds. We present a framework, called CLOUDTRACKER, that transparently records information from a simula- tion that is executed in a commercial cloud so that it may be "replayed" exactly

  18. The Open Cloud Testbed: A Wide Area Testbed for Cloud Computing Utilizing

    E-Print Network [OSTI]

    Grossman, Robert

    The Open Cloud Testbed: A Wide Area Testbed for Cloud Computing Utilizing High Performance Network of cloud platforms and services have been developed for data intensive computing, including Hadoop, Sector, CloudStore (formerly KFS), HBase, and Thrift. In order to benchmark the performance of these systems

  19. The Cloud Computing and Other Variables

    E-Print Network [OSTI]

    Borjon-Kubota, Martha Estela

    2011-01-01

    bodies. Saturated. We watch clouds simmer over the stillnessnoise like a fountain spring simmers between your thighs. A

  20. THE TRANSIT LIGHT CURVE OF AN EXOZODIACAL DUST CLOUD

    SciTech Connect (OSTI)

    Stark, Christopher C.

    2011-10-15

    Planets embedded within debris disks gravitationally perturb nearby dust and can create clumpy, azimuthally asymmetric circumstellar ring structures that rotate in lock with the planet. The Earth creates one such structure in the solar zodiacal dust cloud. In an edge-on system, the dust 'clumps' periodically pass in front of the star as the planet orbits, occulting and forward-scattering starlight. In this paper, we predict the shape and magnitude of the corresponding transit signal. To do so, we model the dust distributions of collisional, steady-state exozodiacal clouds perturbed by planetary companions. We examine disks with dusty ring structures formed by the planet's resonant trapping of in-spiraling dust for a range of planet masses and semi-major axes, dust properties, and disk masses. We synthesize edge-on images of these models and calculate the transit signatures of the resonant ring structures. The transit light curves created by dusty resonant ring structures typically exhibit two broad transit minima that lead and trail the planetary transit. We find that Jupiter-mass planets embedded within disks hundreds of times denser than our zodiacal cloud can create resonant ring structures with transit depths up to {approx}10{sup -4}, possibly detectable with Kepler. Resonant rings produced by planets more or less massive than Jupiter produce smaller transit depths. Observations of these transit signals may provide upper limits on the degree of asymmetry in exozodiacal clouds.

  1. Auditing the Structural Reliability of the Clouds

    E-Print Network [OSTI]

    Haller, Gary L.

    . Icebergs in the Clouds: the Other Risks of Cloud Computing. In HotCloud, 2012. #12;Correlated Failures of occurrences. #12;Talk Outline Challenges Our approach Evaluation #12;Talk Outline Challenges Our approach Evaluation #12;Challenges 1. How to acquire dependency information automatically? 2. How to organize

  2. Towards a Ubiquitous Cloud Computing Infrastructure

    E-Print Network [OSTI]

    van der Merwe, Kobus

    Towards a Ubiquitous Cloud Computing Infrastructure Jacobus Van der Merwe, K.K. Ramakrishnan of a number of cloud computing use cases. We specifically consider cloudbursting and follow-the-sun and focus that are also network service providers. I. INTRODUCTION Cloud computing is rapidly gaining acceptance

  3. Cloud Security: Issues and Concerns Pierangela Samarati*

    E-Print Network [OSTI]

    Samarati, Pierangela

    1 Cloud Security: Issues and Concerns Authors Pierangela Samarati* Universitŕ 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

  4. Security Architecture for Federated Mobile Cloud Computing

    E-Print Network [OSTI]

    Xu, Shouhuai

    Security Architecture for Federated Mobile Cloud Computing Shouhuai Xu and E. Paul Ratazzi, federated mobile cloud computing imposes a diverse set of new chal- lenges, especially from a security clouds for security purposes? How should we deal with the tar- geted attackers that attempt to launch

  5. VULCAN: Vulnerability Assessment Framework for Cloud Computing

    E-Print Network [OSTI]

    Kavi, Krishna

    services on Cloud is complex because the security depends on the vulnerability of infrastructure, platform services on Cloud is complex because the security depends on the vulnerability of infrastruc- ture?". Or "I want to host this software application in this cloud environment, what security vulnerabilities I

  6. Cloud Enterprise Storage and Data Migration

    E-Print Network [OSTI]

    Christensen, Henrik Bćrbak

    Cloud Enterprise Storage and Data Migration 20097733 Bobby Nielsen, 20003686 Frederik Kierbye}@cs.au.dk 20130324 Abstract This document presents a research in Enterprise Cloud Storage and Data Migration. The hypothesis is that, it is easy to migrate data between cloud platforms, including changing api

  7. MEBSURIXG CLOUD MOVEMENTS A Science Service Feature

    E-Print Network [OSTI]

    -.- - MEBSURIXG CLOUD MOVEMENTS I A Science Service Feature Released upon receist but intended on Meteorology Vatching the clouds drift by, a traditional pastime of idle people, i s part Of the professional his head. He makes his cloud observations w i t h the aid of an instrument known as a nei

  8. Unlocking the Secrets of Clouds

    Broader source: Energy.gov [DOE]

    Clouds may look soft, fluffy and harmless to the untrained eye, but to an expert climate model scientist they represent great challenges. Fortunately the Atmospheric Radiation Measurement (ARM) Climate and Research Facility is kicking off a five-month study which should significantly clear the air.

  9. POTENTIAL OF CLOUD-BASED

    E-Print Network [OSTI]

    Lee, Jason R.

    .!! Cover!photos!courtesy!of!the!National!Energy!Research!Scientific!Computing!Center!and!Google.! #12;! ! ! The Energy Efficiency Potential of Cloud-Based Software: A U.S. Case Study ! Lawrence Berkeley National Laboratory June, 2013 Research Team Eric!Masanet! Arman!Shehabi! Jiaqi!Liang! Lavanya!Ramakrishnan! Xiao

  10. ARM Data for Cloud Parameterization

    SciTech Connect (OSTI)

    Xu, Kuan-Man

    2006-10-02

    The PI's ARM investigation (DE-IA02-02ER633 18) developed a physically-based subgrid-scale saturation representation that fully considers the direct interactions of the parameterized subgrid-scale motions with subgrid-scale cloud microphysical and radiative processes. Major accomplishments under the support of that interagency agreement are summarized in this paper.

  11. Accounting for Unresolved Spatial Variability in Large Scale Models: Development and Evaluation of a Statistical Cloud Parameterization with Prognostic Higher Order Moments

    SciTech Connect (OSTI)

    Robert Pincus

    2011-05-17

    This project focused on the variability of clouds that is present across a wide range of scales ranging from the synoptic to the millimeter. In particular, there is substantial variability in cloud properties at scales smaller than the grid spacing of models used to make climate projections (GCMs) and weather forecasts. These models represent clouds and other small-scale processes with parameterizations that describe how those processes respond to and feed back on the largescale state of the atmosphere.

  12. New Mexico cloud super cooled liquid water survey final report 2009.

    SciTech Connect (OSTI)

    Beavis, Nick; Roskovensky, John K.; Ivey, Mark D.

    2010-02-01

    Los Alamos and Sandia National Laboratories are partners in an effort to survey the super-cooled liquid water in clouds over the state of New Mexico in a project sponsored by the New Mexico Small Business Assistance Program. This report summarizes the scientific work performed at Sandia National Laboratories during the 2009. In this second year of the project a practical methodology for estimating cloud super-cooled liquid water was created. This was accomplished through the analysis of certain MODIS sensor satellite derived cloud products and vetted parameterizations techniques. A software code was developed to analyze multiple cases automatically. The eighty-one storm events identified in the previous year effort from 2006-2007 were again the focus. Six derived MODIS products were obtained first through careful MODIS image evaluation. Both cloud and clear-sky properties from this dataset were determined over New Mexico. Sensitivity studies were performed that identified the parameters which most influenced the estimation of cloud super-cooled liquid water. Limited validation was undertaken to ensure the soundness of the cloud super-cooled estimates. Finally, a path forward was formulized to insure the successful completion of the initial scientific goals which include analyzing different of annual datasets, validation of the developed algorithm, and the creation of a user-friendly and interactive tool for estimating cloud super-cooled liquid water.

  13. Ice Concentration Retrieval in Stratiform Mixed-phase Clouds Using Cloud Radar Reflectivity Measurements and 1D Ice Growth Model Simulations

    SciTech Connect (OSTI)

    Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Luo, Tao

    2014-10-01

    Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculated from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.

  14. The Spitzer survey of interstellar clouds in the gould belt. VI. The Auriga-California molecular cloud observed with IRAC and MIPS

    SciTech Connect (OSTI)

    Broekhoven-Fiene, Hannah; Matthews, Brenda C. [Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8W 3P6 (Canada); Harvey, Paul M. [Astronomy Department, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Gutermuth, Robert A. [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); Huard, Tracy L.; Miller, Jennifer F. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Tothill, Nicholas F. H. [School of Computing, Engineering and Mathematics, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751 (Australia); Nutter, David [School of Physics and Astronomy, Cardiff University, Queen's Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Bourke, Tyler L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); DiFrancesco, James [National Research Council Herzberg Astronomy and Astrophysics, Victoria, BC, V9E 2E7 (Canada); Jřrgensen, Jes K. [Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-DK-2100 Copenhagen Ř. (Denmark); Allen, Lori E. [National Optical Astronomy Observatories, Tucson, AZ (United States); Chapman, Nicholas L. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Dunham, Michael M. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Merín, Bruno [Herschel Science Centre, ESAC-ESA, P.O. Box 78, E-28691 Villanueva de la Cańada, Madrid (Spain); Terebey, Susan [Department of Physics and Astronomy PS315, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States); Peterson, Dawn E. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); and others

    2014-05-01

    We present observations of the Auriga-California Molecular Cloud (AMC) at 3.6, 4.5, 5.8, 8.0, 24, 70, and 160 ?m observed with the IRAC and MIPS detectors as part of the Spitzer Gould Belt Legacy Survey. The total mapped areas are 2.5 deg{sup 2} with IRAC and 10.47 deg{sup 2} with MIPS. This giant molecular cloud is one of two in the nearby Gould Belt of star-forming regions, the other being the Orion A Molecular Cloud (OMC). We compare source counts, colors, and magnitudes in our observed region to a subset of the SWIRE data that was processed through our pipeline. Using color-magnitude and color-color diagrams, we find evidence for a substantial population of 166 young stellar objects (YSOs) in the cloud, many of which were previously unknown. Most of this population is concentrated around the LkH? 101 cluster and the filament extending from it. We present a quantitative description of the degree of clustering and discuss the relative fraction of YSOs in earlier (Class I and F) and later (Class II) classes compared to other clouds. We perform simple SED modeling of the YSOs with disks to compare the mid-IR properties to disks in other clouds and identify 14 classical transition disk candidates. Although the AMC is similar in mass, size, and distance to the OMC, it is forming about 15-20 times fewer stars.

  15. How Long Can Tiny HI Clouds Survive?

    E-Print Network [OSTI]

    Masahiro Nagashima; Shu-ichiro Inutsuka; Hiroshi Koyama

    2006-03-10

    We estimate the evaporation timescale for spherical HI clouds consisting of the cold neutral medium surrounded by the warm neutral medium. We focus on clouds smaller than 1pc, which corresponds to tiny HI clouds recently discovered by Braun & Kanekar and Stanimirovi{\\'c} & Heiles. By performing one-dimensional spherically symmetric numerical simulations of the two-phase interstellar medium (ISM), we derive the timescales as a function of the cloud size and of pressure of the ambient warm medium. We find that the evaporation timescale of the clouds of 0.01 pc is about 1Myr with standard ISM pressure, $p/k_{B}\\sim 10^{3.5}$ K cm$^{-3}$, and for clouds larger than about 0.1 pc it depends strongly on the pressure. In high pressure cases, there exists a critical radius for clouds growing as a function of pressure, but the minimum critical size is $\\sim$ 0.03 pc for a standard environment. If tiny HI clouds exist ubiquitously, our analysis suggests two implications: tiny HI clouds are formed continuously with the timescale of 1Myr, or the ambient pressure around the clouds is much higher than the standard ISM pressure. We also find that the results agree well with those obtained by assuming quasi-steady state evolution. The cloud-size dependence of the timescale is well explained by an analytic approximate formula derived by Nagashima, Koyama & Inutsuka. We also compare it with the evaporation rate given by McKee & Cowie.

  16. Scale dependence of entrainment-mixing mechanisms in cumulus clouds

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

    Lu, Chunsong [Nanjing Univ. of Information Science and Technology (China). Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters; Chinese Acadamy of Sciences, Beijing (China); Brookhaven National Laboratory (BNL), Upton, NY (United States). Biological, Environmental and Climate Science Dept.; Liu, Yangang [Brookhaven National Laboratory (BNL), Upton, NY (United States). Biological, Environmental and Climate Science Dept.; Niu, Shengjie [Nanjing Univ. of Information Science and Technology (China). Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters; Endo, Satoshi [Brookhaven National Laboratory (BNL), Upton, NY (United States). Biological, Environmental and Climate Science Dept.

    2014-12-27

    This work empirically examines the dependence of entrainment-mixing mechanisms on the averaging scale in cumulus clouds using in situ aircraft observations during the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. A new measure of homogeneous mixing degree is defined that can encompass all types of mixing mechanisms. Analysis of the dependence of the homogenous mixing degree on the averaging scale shows that, on average, the homogenous mixing degree decreases with increasing averaging scales, suggesting that apparent mixing mechanisms gradually approach from homogeneous mixing to extreme inhomogeneous mixing with increasing scales. The scale dependence can be well quantified by an exponential function, providing first attempt at developing a scale-dependent parameterization for the entrainment-mixing mechanism. The influences of three factors on the scale dependence are further examined: droplet-free filament properties (size and fraction), microphysical properties (mean volume radius and liquid water content of cloud droplet size distributions adjacent to droplet-free filaments), and relative humidity of entrained dry air. It is found that the decreasing rate of homogeneous mixing degree with increasing averaging scales becomes larger with larger droplet-free filament size and fraction, larger mean volume radius and liquid water content, or higher relative humidity. The results underscore the necessity and possibility of considering averaging scale in representation of entrainment-mixing processes in atmospheric models.

  17. Scale dependence of entrainment-mixing mechanisms in cumulus clouds

    SciTech Connect (OSTI)

    Lu, Chunsong; Liu, Yangang; Niu, Shengjie; Endo, Satoshi

    2014-12-17

    This work empirically examines the dependence of entrainment-mixing mechanisms on the averaging scale in cumulus clouds using in situ aircraft observations during the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. A new measure of homogeneous mixing degree is defined that can encompass all types of mixing mechanisms. Analysis of the dependence of the homogenous mixing degree on the averaging scale shows that, on average, the homogenous mixing degree decreases with increasing averaging scales, suggesting that apparent mixing mechanisms gradually approach from homogeneous mixing to extreme inhomogeneous mixing with increasing scales. The scale dependence can be well quantified by an exponential function, providing first attempt at developing a scale-dependent parameterization for the entrainment-mixing mechanism. The influences of three factors on the scale dependence are further examined: droplet-free filament properties (size and fraction), microphysical properties (mean volume radius and liquid water content of cloud droplet size distributions adjacent to droplet-free filaments), and relative humidity of entrained dry air. It is found that the decreasing rate of homogeneous mixing degree with increasing averaging scales becomes larger with larger droplet-free filament size and fraction, larger mean volume radius and liquid water content, or higher relative humidity. The results underscore the necessity and possibility of considering averaging scale in representation of entrainment-mixing processes in atmospheric models.

  18. Scale dependence of entrainment-mixing mechanisms in cumulus clouds

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

    Lu, Chunsong; Liu, Yangang; Niu, Shengjie; Endo, Satoshi

    2014-12-17

    This work empirically examines the dependence of entrainment-mixing mechanisms on the averaging scale in cumulus clouds using in situ aircraft observations during the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. A new measure of homogeneous mixing degree is defined that can encompass all types of mixing mechanisms. Analysis of the dependence of the homogenous mixing degree on the averaging scale shows that, on average, the homogenous mixing degree decreases with increasing averaging scales, suggesting that apparent mixing mechanisms gradually approach from homogeneous mixing to extreme inhomogeneous mixing with increasingmore »scales. The scale dependence can be well quantified by an exponential function, providing first attempt at developing a scale-dependent parameterization for the entrainment-mixing mechanism. The influences of three factors on the scale dependence are further examined: droplet-free filament properties (size and fraction), microphysical properties (mean volume radius and liquid water content of cloud droplet size distributions adjacent to droplet-free filaments), and relative humidity of entrained dry air. It is found that the decreasing rate of homogeneous mixing degree with increasing averaging scales becomes larger with larger droplet-free filament size and fraction, larger mean volume radius and liquid water content, or higher relative humidity. The results underscore the necessity and possibility of considering averaging scale in representation of entrainment-mixing processes in atmospheric models.« less

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

    E-Print Network [OSTI]

    Klein, Stephen A.

    2009-01-01

    humidity above stratiform clouds on indirect aerosol climateOverview of Arctic cloud and radiation characteristics. J.of Arctic low-level clouds observed during the FIRE Arctic

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

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan

    2013-01-01

    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

  1. Secure Cloud Computing with a Virtualized Network Infrastructure

    E-Print Network [OSTI]

    Akella, Aditya

    Secure Cloud Computing with a Virtualized Network Infrastructure Fang Hao, T.V. Lakshman, Sarit the rapid development in the field of cloud com- puting, security is still one of the major hurdles to cloud to users. At the other end of the spectrum, highly secured cloud services (e.g. Google "government cloud

  2. Fog Computing: Mitigating Insider Data Theft Attacks in the Cloud

    E-Print Network [OSTI]

    Keromytis, Angelos D.

    approach for securing data in the cloud using offensive decoy technology. We monitor data access security in a Cloud environment. I. INTRODUCTION Businesses, especially startups, small and medium busi. This is considered as one of the top threats to cloud computing by the Cloud Security Alliance [1]. While most Cloud

  3. Page 1Securing the Microsoft Cloud Securing the

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    Page 1Securing the Microsoft Cloud Securing the Microsoft Cloud #12;Page 2Securing the Microsoft to have confidence in Microsoft as their preferred cloud provider. Our security policies and practices their security and compliance related needs. Securing the Microsoft Cloud #12;Page 3Securing the Microsoft Cloud

  4. Organizational challenges in cloud adoption and enablers of cloud transition program

    E-Print Network [OSTI]

    Rajendran, Sneha

    2013-01-01

    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 ...

  5. Assessing Cloud Spatial and Vertical Distribution with Infrared Cloud Analyzer

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O DBiomass and Biofuels BiomassAssembly of aCloud Spatial and

  6. Fragmentation in rotating isothermal protostellar clouds

    SciTech Connect (OSTI)

    Bodenheimer, P.; Tohline, J.E.; Black, D.C.

    1980-01-01

    Results of an extensive set of 3-D hydrodynamic calculations that have been performed to investigate the susceptibility of rotating clouds to gravitational fragmentation are presented. (GHT)

  7. Interstellar Turbulence, Cloud Formation and Pressure Balance

    E-Print Network [OSTI]

    Enrique Vazquez-Semadeni

    1998-10-23

    We discuss HD and MHD compressible turbulence as a cloud-forming and cloud-structuring mechanism in the ISM. Results from a numerical model of the turbulent ISM at large scales suggest that the phase-like appearance of the medium, the typical values of the densities and magnetic field strengths in the intercloud medium, as well as Larson's velocity dispersion-size scaling relation in clouds may be understood as consequences of the interstellar turbulence. However, the density-size relation appears to only hold for the densest simulated clouds, there existing a large population of small, low-density clouds, which, on the other hand, are hardest to observe. We then discuss several tests and implications of a fully dynamical picture of interstellar clouds. The results imply that clouds are transient, constantly being formed, distorted and disrupted by the turbulent velocity field, with a fraction of these fluctuations undergoing gravitational collapse. Simulated line profiles and estimated cloud lifetimes are consistent with observational data. In this scenario, we suggest it is quite unlikely that quasi-hydrostatic structures on any scale can form, and that the near pressure balance between clouds and the intercloud medium is an incidental consequence of the density field driven by the turbulence and in the presence of appropriate cooling, rather than a driving or confining mechanism.

  8. CHARACTERIZATION OF CLOUDS IN TITAN'S TROPICAL ATMOSPHERE

    SciTech Connect (OSTI)

    Griffith, Caitlin A.; Penteado, Paulo; Rodriguez, Sebastien; Baines, Kevin H.; Buratti, Bonnie; Sotin, Christophe; Clark, Roger; Nicholson, Phil; Jaumann, Ralf

    2009-09-10

    Images of Titan's clouds, possible over the past 10 years, indicate primarily discrete convective methane clouds near the south and north poles and an immense stratiform cloud, likely composed of ethane, around the north pole. Here we present spectral images from Cassini's Visual Mapping Infrared Spectrometer that reveal the increasing presence of clouds in Titan's tropical atmosphere. Radiative transfer analyses indicate similarities between summer polar and tropical methane clouds. Like their southern counterparts, tropical clouds consist of particles exceeding 5 {mu}m. They display discrete structures suggestive of convective cumuli. They prevail at a specific latitude band between 8 deg. - 20 deg. S, indicative of a circulation origin and the beginning of a circulation turnover. Yet, unlike the high latitude clouds that often reach 45 km altitude, these discrete tropical clouds, so far, remain capped to altitudes below 26 km. Such low convective clouds are consistent with the highly stable atmospheric conditions measured at the Huygens landing site. Their characteristics suggest that Titan's tropical atmosphere has a dry climate unlike the south polar atmosphere, and despite the numerous washes that carve the tropical landscape.

  9. Modeling microwave/electron-cloud interaction

    E-Print Network [OSTI]

    Mattes, M; Zimmermann, F

    2013-01-01

    Starting from the separate codes BI-RME and ECLOUD or PyECLOUD, we are developing a novel joint simulation tool, which models the combined effect of a charged particle beam and of microwaves on an electron cloud. Possible applications include the degradation of microwave transmission in tele-communication satellites by electron clouds; the microwave-transmission tecchniques being used in particle accelerators for the purpose of electroncloud diagnostics; the microwave emission by the electron cloud itself in the presence of a magnetic field; and the possible suppression of electron-cloud formation in an accelerator by injecting microwaves of suitable amplitude and frequency. A few early simulation results are presented.

  10. April 12, 2014: The Era of Cloud Computing is coming Headline: The Era of Cloud Computing is coming

    E-Print Network [OSTI]

    Buyya, Rajkumar

    April 12, 2014: The Era of Cloud Computing is coming #12;Headline: The Era of Cloud Computing of Cloud Computing at a seminar in MANIT and RGPV on Saturday. Inset headline: This is the right time to build a career in Cloud Computing Article: Prof. Rajkumar Buyya gave guidance to students about Cloud

  11. IEEE TRANSACTIONS ON CLOUD COMPUTING, VOL. XX, NO. X, XXXX 1 Cloud Federations in the Sky: Formation Game

    E-Print Network [OSTI]

    Grosu, Daniel

    IEEE TRANSACTIONS ON CLOUD COMPUTING, VOL. XX, NO. X, XXXX 1 Cloud Federations in the Sky for cloud resources. The cloud providers' available resources may not be sufficient enough to cope with such demands. Therefore, the cloud providers need to reshape their business structures and seek to improve

  12. RETRIEVALS OF CLOUD OPTICAL DEPTH AND EFFECTIVE RADIUS FROM A THIN-CLOUD ROTATING SHADOWBAND RADIOMETER (TC-RSR)

    E-Print Network [OSTI]

    RETRIEVALS OF CLOUD OPTICAL DEPTH AND EFFECTIVE RADIUS FROM A THIN-CLOUD ROTATING SHADOWBAND Division Brookhaven National Laboratory U.S. Department of Energy Office of Science ABSTRACT A thin cloud cloud. We applied Min and Duan's retrieval algorithm to the field measurements of TC-RSR to derive cloud

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

    SciTech Connect (OSTI)

    Korolev, A; Shashkov, A; Barker, H

    2012-03-06

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

  14. Aircraft Microphysical Documentation from Cloud Base to Anvils of Hailstorm Feeder Clouds in Argentina

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    in Argentina DANIEL ROSENFELD The Hebrew University of Jerusalem, Jerusalem, Israel WILLIAM L. WOODLEY Woodley, Argentina, with a cloud-physics jet aircraft penetrating the major feeder clouds from cloud base to the 45°C. Introduction The province of Mendoza in western Argentina (32°S, 68°W), which is known worldwide for its wine

  15. CloudBridge: A Cloud-Powered System Enabling Mobile Devices to Control Peripherals Without Drivers

    E-Print Network [OSTI]

    Young, R. Michael

    , CloudBridge. CloudBridge user ap- plication running on a smart device works as a TCP bridge relaying on the other. Through the bridge, it is possible to issue operations from a smart device without having network Figure 1: The smart device in the middle works as a bridge connecting a cloud server

  16. Cloud K-SVD: Computing data-adaptive representations in the cloud

    E-Print Network [OSTI]

    Bajwa, Waheed U.

    Cloud K-SVD: Computing data-adaptive representations in the cloud Haroon Raja and Waheed U. Bajwa Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ 08854 Emails: haroon a distributed algorithm, termed as cloud K-SVD, for learning a UoS structure underlying distributed data

  17. A Study of Entropy Sources in Cloud Random Number Generation on Cloud Hosts

    E-Print Network [OSTI]

    Chen, Yu

    A Study of Entropy Sources in Cloud Computers: Random Number Generation on Cloud Hosts Brendan Kerrigan and Yu Chen Dept. of Electrical and Computer Engineering, SUNY - Binghamton Abstract. Cloud security practices are based on assumptions that hold true for physical machines, but don't translate

  18. JP2.3 CLOUD RADIATIVE HEATING RATE FORCING FROM PROFILES OF RETRIEVED ARCTIC CLOUD MICROPHYSICS

    E-Print Network [OSTI]

    Shupe, Matthew

    JP2.3 CLOUD RADIATIVE HEATING RATE FORCING FROM PROFILES OF RETRIEVED ARCTIC CLOUD MICROPHYSICS). This data allows for observationally-based calculations ofradiative heating rate profiles within the Arctic atmosphere. In this paper we define cloud radiative heating rate forcing (CRHF) as the difference between

  19. ENTRAINMENT AND MIXING AND THEIR EFFECTS ON CLOUD DROPLET SIZE DISTRIBUTIONS OF THE STRATOCUMULUS CLOUDS OBSERVED

    E-Print Network [OSTI]

    ENTRAINMENT AND MIXING AND THEIR EFFECTS ON CLOUD DROPLET SIZE DISTRIBUTIONS OF THE STRATOCUMULUS clouds due to entrainment and mixing of the clear air, which then affect the cloud droplet size distribution. How the entrained clear air mixes with cloudy air has been of great interest for the last several

  20. The Physical Conditions in a Pre Super Star Cluster Molecular Cloud in the Antennae Galaxies

    E-Print Network [OSTI]

    Johnson, K E; Indebetouw, R; Brogan, C L; Whitmore, B C; Hibbard, J; Sheth, K; Evans, A

    2015-01-01

    We present an analysis of the physical conditions in an extreme molecular cloud in the Antennae merging galaxies. This cloud has properties consistant with those required to form a globular cluster. We have obtained ALMA CO and 870$\\mu$m observations of the Antennae galaxy system with $\\sim 0".5$ resolution. This cloud stands out in the data with a radius of $\\lesssim 24$~pc and mass of $>5\\times 10^6$~M$_\\odot$. The cloud appears capable of forming a globular cluster, but the lack of associated thermal radio emission indicates that star formation has not yet altered the environment. The lack of thermal radio emission places the cloud in an early stage of evolution, which we expect to be short-lived ($\\lesssim 1$~Myr) and thus rare. Given its mass and kinetic energy, for the cloud to be confined (as its appearance strongly suggests) it must be subject to an external pressure of P/$k_B \\gtrsim 10^8$~K~cm$^{-3}$ -- 10,000 times higher than typical interstellar pressure. This would support theories that high pre...

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

    SciTech Connect (OSTI)

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

    2013-10-01

    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.

  2. Low virial parameters in molecular clouds: Implications for high-mass star formation and magnetic fields

    SciTech Connect (OSTI)

    Kauffmann, Jens; Pillai, Thushara [Astronomy Department, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Goldsmith, Paul F., E-mail: jens.kauffmann@astro.caltech.edu, E-mail: tpillai@astro.caltech.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Boulevard, Pasadena, CA 91109 (United States)

    2013-12-20

    Whether or not molecular clouds and embedded cloud fragments are stable against collapse is of utmost importance for the study of the star formation process. Only 'supercritical' cloud fragments are able to collapse and form stars. The virial parameter ? = M {sub vir}/M, which compares the virial mass to the actual mass, provides one way to gauge stability against collapse. Supercritical cloud fragments are characterized by ? ? 2, as indicated by a comprehensive stability analysis considering perturbations in pressure and density gradients. Past research has suggested that virial parameters ? ? 2 prevail in clouds. This would suggest that collapse toward star formation is a gradual and relatively slow process and that magnetic fields are not needed to explain the observed cloud structure. Here, we review a range of very recent observational studies that derive virial parameters <<2 and compile a catalog of 1325 virial parameter estimates. Low values of ? are in particular observed for regions of high-mass star formation (HMSF). These observations may argue for a more rapid and violent evolution during collapse. This would enable 'competitive accretion' in HMSF, constrain some models of 'monolithic collapse', and might explain the absence of high-mass starless cores. Alternatively, the data could point at the presence of significant magnetic fields ?1 mG at high gas densities. We examine to what extent the derived observational properties might be biased by observational or theoretical uncertainties. For a wide range of reasonable parameters, our conclusions appear to be robust with respect to such biases.

  3. Airborne cloud condensation nuclei measurements during the 2006 Texas Air Quality Study

    E-Print Network [OSTI]

    Jimenez, Jose-Luis

    Administration WP3D platform during the 2006 Texas Air Quality Study/Gulf of Mexico Atmospheric Composition indirectly influence climate through their impact on cloud radiative properties and the hydro- logical cycle and Environmental Engineering, Bourns College of EngineeringCenter for Environmental Research and Techno

  4. DROP-SCALE NUMERICAL MODELING OF CHEMICAL PARTITIOING DURING CLOUD HYDROMETEOR FREEZING

    E-Print Network [OSTI]

    Stuart, Amy L.

    DROP-SCALE NUMERICAL MODELING OF CHEMICAL PARTITIOING DURING CLOUD HYDROMETEOR FREEZING A.L. Stuart freezing provide greatly varying estimates of the retention efficiency of volatile solutes (e.g., Lamb understanding of the dependence of partitioning on chemical properties and freezing conditions (Stuart

  5. Shortwave aerosol radiative forcing over cloud-free oceans from Terra: 1. Angular models for aerosols

    E-Print Network [OSTI]

    Christopher, Sundar A.

    Sensor Microwave Imager (SSM/I) data to obtain near surface wind speed. The new aerosol ADMs are built to obtain aerosol properties within a Clouds and Earth Radiant Energy System (CERES) footprint and Special as functions of near-surface ocean wind speed and MODIS aerosol optical depth at 0.55 mm (t0.55). Among the new

  6. Consistent cloud computing storage as the basis for distributed applications

    E-Print Network [OSTI]

    Anderson, James William

    2011-01-01

    Messaging in Cloud Computing . . . . . . . . . .7 1.4Eucalyptus Open—Source Cloud—Computing System. In C'C&#http://www.eweek.com/c/a/Cloud-Computing/Amazons—Head—Start—

  7. A Framework for Secure Cloud-Empowered Mobile Biometrics

    E-Print Network [OSTI]

    Valenti, Matthew C.

    1 A Framework for Secure Cloud-Empowered Mobile Biometrics A. A framework for secure cloud biometrics 4. System analysis 5. Conclusion #12;3 3 for secure cloud biometrics 4. System analysis 5. Conclusion #12;4 4 Introduc

  8. ISMS for Microsoft's Cloud Infrastructure 1 Information Security Management System

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    ISMS for Microsoft's Cloud Infrastructure 1 Information Security Management System for Microsoft's Cloud Infrastructure Online Services Security and Compliance Executive summary This paper describes the Microsoft Cloud Infrastructure and Operations (MCIO) Information Security Management System (ISMS) program

  9. E-Cloud Build-up in Grooved Chambers

    E-Print Network [OSTI]

    Venturini, Marco

    2007-01-01

    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,

  10. Deriving cloud velocity from an array of solar radiation measurements

    E-Print Network [OSTI]

    Bosch, J.L.; Zheng, Y.; Kleissl, J.

    2013-01-01

    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);

  11. A cloud-assisted design for autonomous driving

    E-Print Network [OSTI]

    Suresh Kumar, Swarun

    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 ...

  12. QUANTITATIVELY ASSESSING THE ROLE OF CLOUDS IN THE TRANSMISSION SPECTRUM OF GJ 1214b

    SciTech Connect (OSTI)

    Morley, Caroline V.; Fortney, Jonathan J.; Kempton, Eliza M.-R.; Marley, Mark S.; Zahnle, Kevin; Vissher, Channon

    2013-09-20

    Recent observations of the super-Earth GJ 1214b show that it has a relatively featureless transmission spectrum. One suggestion is that these observations indicate that the planet's atmosphere is vertically compact, perhaps due to a water-rich composition that yields a large mean molecular weight. Another suggestion is that the atmosphere is hydrogen/helium-rich with clouds that obscure predicted absorption features. Previous models that incorporate clouds have included their effect without a strong physical motivation for their existence. Here, we present model atmospheres of GJ 1214b that include physically motivated clouds of two types. We model the clouds that are present in chemical equilibrium, as has been suggested to occur on brown dwarfs, which include KCl and ZnS for this planet. We also include clouds that form as a result of photochemistry, forming a hydrocarbon haze layer. We use a photochemical kinetics model to understand the vertical distribution and available mass of haze-forming molecules. We model both solar and enhanced-metallicity cloudy models and determine the cloud properties necessary to match observations. In enhanced-metallicity atmospheres, we find that the equilibrium clouds can match the observations of GJ 1214b if they are lofted high into the atmosphere and have a low sedimentation efficiency (f{sub sed} = 0.1). We find that models with a variety of hydrocarbon haze properties can match the observations. Particle sizes from 0.01 to 0.25 ?m can match the transmission spectrum with haze-forming efficiencies as low as 1%-5%.

  13. Electron Cloud Effects in Accelerators

    SciTech Connect (OSTI)

    Furman, M.A.

    2012-11-30

    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].

  14. Clouds, Aerosols and Precipitation in

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclearDNP 20082 P r o j eCommitteeCloud-Resolving3

  15. ARM - Lesson Plans: Making Clouds

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Room News PublicationsClimate inMaking Clouds Outreach

  16. Sandia Energy - Cloud Computing Services

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumniProjects Caterpillar, Sandia CRADAChemistryCloud

  17. Cloud activating properties of aerosol observed during CELTIC

    E-Print Network [OSTI]

    2007-01-01

    the secondary organic aero- sol contribution to PM2.5 usingthe EC tracer method. Aero- sol Sci. Technol. , 38 (S1),to represent 15% of submicron aero- sol mass. The large

  18. Testing AGCM-Predicted Cloud and Radiation Properties with ARM...

    Office of Scientific and Technical Information (OSTI)

    Conference: Proceedings of the 15th American Meteorological Society Symposium on Global Change and Climate Variations, Paper No. 6.3 Publisher: American Meteorological Society,...

  19. CLOUD MICROPHYSICAL PROPERTIES, PROCESSES, AND RAINFALL ESTIMATION OPPORTUNITIES

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    , and a formulation of the RDSD into the simplest free parameters of the rain intensity R, rain water content W intensity R, rain water content W and median volume drop diameter D0. This is accomplished through-R relationships is explored from the combined approach of rain-forming physical processes that shape the RDSD

  20. Study of ice cloud properties using infrared spectral data 

    E-Print Network [OSTI]

    Garrett, Kevin James

    2009-05-15

    fulfilment of the requirements for the degre of MASTER OF SCIENCE Approved by: Chair of Commite, Ping Yang Commite Members, Shaima L. Nasiri Gerald R. North George Katawar Head of Department, Richard E. Orvile August 2007... Nasiri for her support, encouragement and technical guidance, Dr. Gerald North for his advice and encouragement prior to my applying as a post- bacalaureate and throughout, and Dr. George Katawar. Also, I would like to acknowledge and thank Dr. Don...

  1. Cloud properties derived from the High Spectral Resolution Lidar during

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclearDNP 20082 P r o j eCommittee offromandMPACE

  2. ARM - Evaluation Product - Cloud Optical Properties from MFRSR Using Min

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments? WeDatastreamstps DocumentationAtlanticENA Contacts ENA RelatedProductsCalibrated KAZR

  3. ARM - PI Product - Tropical Cloud Properties and Radiative Heating Profiles

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska OutreachCalendar NSAProductsMerged

  4. Posters Ship-Based Measurements of Cloud Optical Properties

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgram Guidelines This document outlines the majorL.Posters955 Posters77

  5. Radiosonde observations at Pt. Reyes and cloud properties retrieved from

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on GlobalRachel2 Radiometer CharacterizationGOES-WEST

  6. Impact of Ice Crystal Roughness on Satellite Retrieved Cloud Properties

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATION PLAN FOR THE SITE- SPECIFIC SAVINGS PORTFOLIOImpactIce

  7. Clock-Based Proxy Re-encryption Scheme inClock-Based Proxy Re-encryption Scheme inClock-Based Proxy Re-encryption Scheme inClock-Based Proxy Re-encryption Scheme in Unreliable CloudsUnreliable CloudsUnreliable CloudsUnreliable Clouds

    E-Print Network [OSTI]

    Wu, Jie

    International Workshop on Security in Cloud Computing (CloudSecInternational Workshop on Security in Cloud Computing (CloudSecInternational Workshop on Security in Cloud Computing (CloudSecInternational Workshop on Security in Cloud Computing (CloudSec 2012)2012)2012)2012) [1] Central South University, China [2] Temple

  8. RFID Asset Management Solution with Cloud Computation Service

    E-Print Network [OSTI]

    Chattopadhyay, Arunabh

    2012-01-01

    Gadh, “Web based RFID asset management solution establishedLos Angeles RFID Asset Management Solution with CloudTHE DISSERTATION RFID Asset Management Solution with Cloud

  9. Testing Cloud Microphysics Parameterizations in NCAR CAM5 with...

    Office of Scientific and Technical Information (OSTI)

    fraction for single-layer boundary layer mixed-phase stratocumulus, and multilayer or deep frontal clouds. However, for low-level clouds, the model significantly underestimates...

  10. Direct Numerical Simulations and Robust Predictions of Cloud...

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

    cloud. Credit: Computational Science and Engineering Laboratory, ETH Zurich, Switzerland Direct Numerical Simulations and Robust Predictions of Cloud Cavitation Collapse PI Name:...

  11. Compression of Antiproton Clouds for Antihydrogen Trapping

    E-Print Network [OSTI]

    G. B. Andresen; W. Bertsche; P. D. Bowe; C. C. Bray; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; J. Fajans; M. C. Fujiwara; R. Funakoshi; D. R. Gill; J. S. Hangst; W. N. Hardy; R. S. Hayano; M. E. Hayden; R. Hydomako; M. J. Jenkins; L. V. Jorgensen; L. Kurchaninov; R. Lambo; N. Madsen; P. Nolan; K. Olchanski; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; S. Seif El Nasr; D. M. Silveira; J. W. Storey; R. I. Thompson; D. P. van der Werf; J. S. Wurtele; Y. Yamazaki

    2008-06-30

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.

  12. The CloudNets Network Virtualization Architecture

    E-Print Network [OSTI]

    Schmid, Stefan

    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

  13. Pricing Cloud Bandwidth Reservations under Demand Uncertainty

    E-Print Network [OSTI]

    Li, Baochun

    Pricing Cloud Bandwidth Reservations under Demand Uncertainty Di Niu, Chen Feng, Baochun Li's utility depends not only on its bandwidth usage, but more importantly on the portion of its demand that can be made by all tenants and the cloud provider, even with the presence of demand uncertainty

  14. Secure Storage in Cloud Computing Abbas Amini

    E-Print Network [OSTI]

    i Secure Storage in Cloud Computing Abbas Amini Kongens Lyngby 2012 IMM-M.Sc.-2012-39 #12;ii In this Master's thesis a security solution for data storage in cloud computing is examined. The solution encompasses confidentiality and integrity of the stored data, as well as a secure data sharing mechanism

  15. Dynamics of Clouds Fall Semester 2012

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    -2pm Course Description: This class focuses on the general dynamics of cloud systems. Models of fog, vertical velocities, and liquid water contents 1 1 Fogs and Stratocumulus Clouds · Types of fog and formation mechanisms · Radiation fog and physics and dynamics · Valley fog · Marine fog · Stratocumulus

  16. Public Cloud B CarbonEmission

    E-Print Network [OSTI]

    Buyya, Rajkumar

    Programming Environment and Tools: Green Profiler, Power Capping, Green Compiler, Workflow Cloud Hosting Sensors, Demand Prediction Power Capping, Green Software Services such as energy-efficient scientific information Green Offer Directory 2) Request any `Green Offer' Routers Internet Green Broker #12;Cloud

  17. Deuteration in infrared dark clouds

    E-Print Network [OSTI]

    Lackington, Matias; Pineda, Jaime E; Garay, Guido; Peretto, Nicolas; Traficante, Alessio

    2015-01-01

    Much of the dense gas in molecular clouds has a filamentary structure but the detailed structure and evolution of this gas is poorly known. We have observed 54 cores in infrared dark clouds (IRDCs) using N$_2$H$^+$ (1-0) and (3-2) to determine the kinematics of the densest material, where stars will form. We also observed N$_2$D$^+$ (3-2) towards 29 of the brightest peaks to analyse the level of deuteration which is an excellent probe of the quiescent of the early stages of star formation. There were 13 detections of N$_2$D$^+$ (3-2). This is one of the largest samples of IRDCs yet observed in these species. The deuteration ratio in these sources ranges between 0.003 and 0.14. For most of the sources the material traced by N$_2$D$^+$ and N$_2$H$^+$ (3-2) still has significant turbulent motions, however three objects show subthermal N$_2$D$^+$ velocity dispersion. Surprisingly the presence or absence of an embedded 70 $\\mu$m source shows no correlation with the detection of N$_2$D$^+$ (3-2), nor does it correl...

  18. The Magellanic Stream and debris clouds

    SciTech Connect (OSTI)

    For, B.-Q.; Staveley-Smith, L. [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); Matthews, D. [Centre for Materials and Surface Science, La Trobe University, Melbourne, VIC 3086 (Australia); McClure-Griffiths, N. M., E-mail: biqing.for@icrar.org [CSIRO Astronomy and Space Science, Epping, NSW 1710 (Australia)

    2014-09-01

    We present a study of the discrete clouds and filaments in the Magellanic Stream using a new high-resolution survey of neutral hydrogen (H I) conducted with the H75 array of the Australia Telescope Compact Array, complemented by single-dish data from the Parkes Galactic All-Sky Survey. From the individual and combined data sets, we have compiled a catalog of 251 clouds and listed their basic parameters, including a morphological description useful for identifying cloud interactions. We find an unexpectedly large number of head-tail clouds in the region. The implication for the formation mechanism and evolution is discussed. The filaments appear to originate entirely from the Small Magellanic Cloud and extend into the northern end of the Magellanic Bridge.

  19. Cloud Computing Security in Business Information Systems

    E-Print Network [OSTI]

    Ristov, Sasko; Kostoska, Magdalena

    2012-01-01

    Cloud computing providers' and customers' services are not only exposed to existing security risks, but, due to multi-tenancy, outsourcing the application and data, and virtualization, they are exposed to the emergent, as well. Therefore, both the cloud providers and customers must establish information security system and trustworthiness each other, as well as end users. In this paper we analyze main international and industrial standards targeting information security and their conformity with cloud computing security challenges. We evaluate that almost all main cloud service providers (CSPs) are ISO 27001:2005 certified, at minimum. As a result, we propose an extension to the ISO 27001:2005 standard with new control objective about virtualization, to retain generic, regardless of company's type, size and nature, that is, to be applicable for cloud systems, as well, where virtualization is its baseline. We also define a quantitative metric and evaluate the importance factor of ISO 27001:2005 control objecti...

  20. The frequency of tropical precipitating clouds as observed by the TRMM PR and ICESat/GLAS 

    E-Print Network [OSTI]

    Casey, Sean Patrick

    2009-06-02

    Convective clouds in the tropics can be grouped into three categories: shallow clouds with cloud-top heights near 2 km above the surface, mid-level congestus clouds with tops near the 0°C level, and deep convective clouds ...

  1. The Musca cloud: a 6 pc-long velocity-coherent, sonic filament

    E-Print Network [OSTI]

    Hacar, A; Tafalla, M; Beuther, H; Alves, J

    2015-01-01

    Filaments play a key role in the molecular clouds' evolution, but their internal dynamical properties remain poorly characterized. To further explore the physical state of these structures, we have investigated the kinematic properties of the Musca cloud. We have sampled the main axis of this filamentary cloud in $^{13}$CO and C$^{18}$O (2--1) lines using APEX observations. The different line profiles in Musca shows that this cloud presents a continuous and quiescent velocity field along its $\\sim$6.5 pc of length. With an internal gas kinematics dominated by thermal motions (i.e. $\\sigma_{NT}/c_s\\lesssim1$) and large-scale velocity gradients, these results reveal Musca as the longest velocity-coherent, sonic-like object identified so far in the ISM. The (tran-)sonic properties of Musca present a clear departure from the predicted supersonic velocity dispersions expected in the Larson's velocity dispersion-size relationship, and constitute the first observational evidence of a filament fully decoupled from th...

  2. Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c

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

    Prather, M. J.

    2015-08-14

    A new approach for modeling photolysis rates (J values) in atmospheres with fractional cloud cover has been developed and is implemented as Cloud-J – a multi-scattering eight-stream radiative transfer model for solar radiation based on Fast-J. Using observations of the vertical correlation of cloud layers, Cloud-J 7.3c provides a practical and accurate method for modeling atmospheric chemistry. The combination of the new maximum-correlated cloud groups with the integration over all cloud combinations by four quadrature atmospheres produces mean J values in an atmospheric column with root mean square (rms) errors of 4 % or less compared with 10–20 % errorsmore »using simpler approximations. Cloud-J is practical for chemistry–climate models, requiring only an average of 2.8 Fast-J calls per atmosphere vs. hundreds of calls with the correlated cloud groups, or 1 call with the simplest cloud approximations. Another improvement in modeling J values, the treatment of volatile organic compounds with pressure-dependent cross sections, is also incorporated into Cloud-J.« less

  3. Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3

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

    Prather, M. J.

    2015-05-27

    A new approach for modeling photolysis rates (J values) in atmospheres with fractional cloud cover has been developed and implemented as Cloud-J – a multi-scattering eight-stream radiative transfer model for solar radiation based on Fast-J. Using observed statistics for the vertical correlation of cloud layers, Cloud-J 7.3 provides a practical and accurate method for modeling atmospheric chemistry. The combination of the new maximum-correlated cloud groups with the integration over all cloud combinations represented by four quadrature atmospheres produces mean J values in an atmospheric column with root-mean-square errors of 4% or less compared with 10–20% errors using simpler approximations. Cloud-Jmore »is practical for chemistry-climate models, requiring only an average of 2.8 Fast-J calls per atmosphere, vs. hundreds of calls with the correlated cloud groups, or 1 call with the simplest cloud approximations. Another improvement in modeling J values, the treatment of volatile organic compounds with pressure-dependent cross sections is also incorporated into Cloud-J.« less

  4. Modeling Incoherent Electron Cloud Effects

    SciTech Connect (OSTI)

    Vay, Jean-Luc; Benedetto, E.; Fischer, W.; Franchetti, G.; Ohmi, K.; Schulte, D.; Sonnad, K.; Tomas, R.; Vay, J.-L.; Zimmermann, F.; Rumolo, G.; Pivi, M.; Raubenheimer, T.

    2007-06-18

    Incoherent electron effects could seriously limit the beam lifetime in proton or ion storage rings, such as LHC, SPS, or RHIC, or blow up the vertical emittance of positron beams, e.g., at the B factories or in linear-collider damping rings. Different approaches to modeling these effects each have their own merits and drawbacks. We describe several simulation codes which simplify the descriptions of the beam-electron interaction and of the accelerator structure in various different ways, and present results for a toy model of the SPS. In addition, we present evidence that for positron beams the interplay of incoherent electron-cloud effects and synchrotron radiation can lead to a significant increase in vertical equilibrium emittance. The magnitude of a few incoherent e+e- scattering processes is also estimated. Options for future code development are reviewed.

  5. Scanning ARM Cloud Radar Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N; Johnson, K

    2012-06-18

    The scanning ARM cloud radar (SACR) is a polarimetric Doppler radar consisting of three different radar designs based on operating frequency. These are designated as follows: (1) X-band SACR (X-SACR); (2) Ka-band SACR (Ka-SACR); and (3) W-band SACR (W-SACR). There are two SACRs on a single pedestal at each site where SACRs are deployed. The selection of the operating frequencies at each deployed site is predominantly determined by atmospheric attenuation at the site. Because RF attenuation increases with atmospheric water vapor content, ARM's Tropical Western Pacific (TWP) sites use the X-/Ka-band frequency pair. The Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites field the Ka-/W-band frequency pair. One ARM Mobile Facility (AMF1) has a Ka/W-SACR and the other (AMF2) has a X/Ka-SACR.

  6. ARM - Midlatitude Continental Convective Clouds

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

    Jensen, Mike; Bartholomew, Mary Jane; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

    2012-01-19

    Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current 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 important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

  7. ARM - Midlatitude Continental Convective Clouds

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

    Jensen, Mike; Bartholomew, Mary Jane; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

    Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current 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 important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

  8. Optical Properties of Saharan Dust and Asian Dust: Application to Radiative Transfer Simulations 

    E-Print Network [OSTI]

    Fang, Guangyang

    2012-07-16

    an important role in climate change, the majorities of aerosols are natural ones and can impact cloud properties, convective cloud dynamics, and the development of tropical storms (Jones et al. 2004). The optical properties of mineral dust aerosols... dusts from the Rayleigh regime to the geometric optics regime. A database of the optical properties of randomly oriented spheroids has been developed. 4.1 Geometry of the dust particle model The geometry of the spheroidal model used is shown...

  9. The potential impact of turbulent velocity fluctuations on drizzle formation in Cumulus clouds in an idealized 2D setup

    E-Print Network [OSTI]

    Andrejczuk, M; Blyth, A

    2015-01-01

    This article discusses a potential impact of turbulent velocity fluctuations of the air on a drizzle formation in Cumulus clouds. Two different representations of turbulent velocity fluctuations for a microphysics formulated in a Lagrangian framework are discussed - random walk model and the interpolation, and its effect on microphysical properties of the cloud investigated. Turbulent velocity fluctuations significantly enhances velocity differences between colliding droplets, especially those having small sizes. As a result drizzle forms faster in simulations including a representation of turbulence. Both representations of turbulent velocity fluctuations, random walk and interpolation, have similar effect on droplet spectrum evolution, but interpolation of the velocity does account for a possible anisotropy in the air velocity. All discussed simulations show relatively large standard deviation ($\\sim$1${\\mu}m$) of the cloud droplet distribution from the onset of cloud formation is observed. Because coalesen...

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

    SciTech Connect (OSTI)

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

    2014-09-23

    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.

  11. Comparing VM-Placement Algorithms for On-Demand Clouds

    E-Print Network [OSTI]

    Comparing VM-Placement Algorithms for On-Demand Clouds Feb. 14, 2012 NIST Presentation to LSN Kevin. Dabrowski, "Comparing VM-Placement Algorithms for On-Demand Clouds", Proceedings of IEEE CloudCom 2011, Nov VM- placement algorithms through simulation of large, on-demand infrastructure clouds. Demonstrate

  12. Fault-Tolerant and Reliable Computation in Cloud Computing

    E-Print Network [OSTI]

    Deng, Jing

    Fault-Tolerant and Reliable Computation in Cloud Computing Jing Deng Scott C.-H. Huang Yunghsiang S, Taipei, 106 Taiwan. § Intelligent Automation, Inc., Rockville, MD, USA. Abstract-- Cloud computing of scientific computation in cloud computing. We investigate a cloud selection strategy to decompose the matrix

  13. Compute and Storage Clouds Using Wide Area High Performance Networks

    E-Print Network [OSTI]

    Grossman, Robert

    Compute and Storage Clouds Using Wide Area High Performance Networks Robert L. Grossman Yunhong Gu. The infrastructure consists of a storage cloud called Sector and a compute cloud called Sphere. We describe two (record- based, column-based or object-based services); and a compute cloud provides computational

  14. GamingAnywhere: An Open-Source Cloud Gaming Testbed

    E-Print Network [OSTI]

    Chen, Sheng-Wei

    the latest computer games. Cloud gaming is an alternative way to deliver high-quality gaming experience: A cloud gaming service based on GamingAny- where. In a cloud gaming system, computer games run on power to game servers. With cloud gaming, gamers can play the latest computer games anywhere and anytime, while

  15. Designing SCIT Architecture Pattern in a Cloud-based Environment

    E-Print Network [OSTI]

    Sood, Arun K.

    and storage size. However, Cloud security is a challenge. In this paper, we leverage Cloud services to designDesigning SCIT Architecture Pattern in a Cloud-based Environment Quyen L. Nguyen and Arun Sood {qnguyeng@gmu.edu, asood@gmu.edu} Abstract--Cloud Computing has gained momentum in the IT world, due to its

  16. Accountability in Cloud Computing and Distributed Computer Systems Hongda Xiao

    E-Print Network [OSTI]

    Feigenbaum, Joan

    a mechanism for holding cloud-service providers accountable but also an interesting application of secure be applicable to other aspects of data- center and cloud security. #12;Accountability in Cloud ComputingAbstract Accountability in Cloud Computing and Distributed Computer Systems Hongda Xiao 2014

  17. Information Flow Auditing In the Cloud Angeliki Zavou

    E-Print Network [OSTI]

    Keromytis, Angelos D.

    towards cloud computing. The many examples of security breaches in major cloud services, that reach to address security issues and concerns that affect cloud-hosted web services, whose providers do not have and accidental data leaks. My approach was inspired by the observation that cloud users' security concerns could

  18. HI CLOUDS BEYOND THE GALACTIC DISK Felix J. Lockman

    E-Print Network [OSTI]

    Groppi, Christopher

    HI CLOUDS BEYOND THE GALACTIC DISK Felix J. Lockman National Radio Astronomy Observatory, Green parts of the Milky Way the disk­halo interface is composed of many discrete HI clouds. The clouds lie: the structure of the ISM at the disk­halo interface, and a high­velocity HI cloud which appears

  19. Thin Cloud Length Scales Using CALIPSO and CloudSat Data 

    E-Print Network [OSTI]

    Solbrig, Jeremy E.

    2010-10-12

    of the requirements for the degree of MASTER OF SCIENCE Approved by: Co-Chairs of Committee, Andrew Dessler Shaima Nasiri Committee Members, Ping Chang R. Saravanan Head of Department Kenneth Bowman August 2009 Major Subject: Atmospheric Sciences... iii ABSTRACT Thin Cloud Length Scales Using CALIPSO and CloudSat Data. (August 2009) Jeremy Edward Solbrig, B.S., University of Northern Colorado Co-Chairs of Advisory Committee, Dr. Andrew Dessler Dr. Shaima Nasiri Thin clouds...

  20. Evaluation of ECMWF cloud type simulations at the ARM Southern Great Plains site using a new cloud type climatology

    E-Print Network [OSTI]

    Evaluation of ECMWF cloud type simulations at the ARM Southern Great Plains site using a new cloud; accepted 13 December 2006; published 3 February 2007. [1] A new method to derive a cloud type climatology is applied to cloud observations over the Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM

  1. Star Formation triggered by cloud-cloud collisions

    E-Print Network [OSTI]

    Balfour, S K; Hubber, D A; Jaffa, S E

    2015-01-01

    We present the results of SPH simulations in which two clouds, each having mass $M_{_{\\rm{o}}}\\!=\\!500\\,{\\rm M}_{_\\odot}$ and radius $R_{_{\\rm{o}}}\\!=\\!2\\,{\\rm pc}$, collide head-on at relative velocities of $\\Delta v_{_{\\rm{o}}} =2.4,\\;2.8,\\;3.2,\\;3.6\\;{\\rm and}\\;4.0\\,{\\rm km}\\,{\\rm s}^{-1}$. There is a clear trend with increasing $\\Delta v_{_{\\rm{o}}}$. At low $\\Delta v_{_{\\rm{o}}}$, star formation starts later, and the shock-compressed layer breaks up into an array of predominantly radial filaments; stars condense out of these filaments and fall, together with residual gas, towards the centre of the layer, to form a single large-$N$ cluster, which then evolves by competitive accretion, producing one or two very massive protostars and a diaspora of ejected (mainly low-mass) protostars; the pattern of filaments is reminiscent of the hub and spokes systems identified recently by observers. At high $\\Delta v_{_{\\rm{o}}}$, star formation occurs sooner and the shock-compressed layer breaks up into a network of f...

  2. ARM Cloud Retrieval Ensemble Data Set (ACRED)

    SciTech Connect (OSTI)

    Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z

    2011-09-12

    This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.

  3. EVENT CLOUDS : lighter than air architectural structures

    E-Print Network [OSTI]

    Peydro Duclos, Ignacio

    2014-01-01

    EVENT CLOUD is a versatile covering system that allows events to happen independently to weather conditions. It consists of a lighter than air pneumatic structure, filled either with helium or hot air, that covers spaces ...

  4. QER- Comment of Cloud Peak Energy Inc

    Office of Energy Efficiency and Renewable Energy (EERE)

    Dear Ms Pickett Please find attached comments from Cloud Peak Energy as input to the Department of Energy’s Quadrennial Energy Review. If possible I would appreciate a confirmation that this email has been received Thank you.

  5. HPC CLOUD APPLIED TO LATTICE OPTIMIZATION

    SciTech Connect (OSTI)

    Sun, Changchun; Nishimura, Hiroshi; James, Susan; Song, Kai; Muriki, Krishna; Qin, Yong

    2011-03-18

    As Cloud services gain in popularity for enterprise use, vendors are now turning their focus towards providing cloud services suitable for scientific computing. Recently, Amazon Elastic Compute Cloud (EC2) introduced the new Cluster Compute Instances (CCI), a new instance type specifically designed for High Performance Computing (HPC) applications. At Berkeley Lab, the physicists at the Advanced Light Source (ALS) have been running Lattice Optimization on a local cluster, but the queue wait time and the flexibility to request compute resources when needed are not ideal for rapid development work. To explore alternatives, for the first time we investigate running the Lattice Optimization application on Amazon's new CCI to demonstrate the feasibility and trade-offs of using public cloud services for science.

  6. Carbon monoxide in collapsing interstellar clouds

    E-Print Network [OSTI]

    De Jong, T.; Chu, Shih-I; Dalgarno, A.

    1975-07-01

    Calculations are made for the energy loss rates, brightness temperatures, and line profiles of carbon monoxide in collapsing interstellar clouds. The most recent data for the H2-CO collision rates have been used in the calculations; a useful...

  7. Uranus at equinox: Cloud morphology and dynamics

    E-Print Network [OSTI]

    Sromovsky, Lawrence; Hammel, Heidi; Ahue, William; de Pater, Imke; Rages, Kathy; Showalter, Mark; van Dam, Marcos

    2015-01-01

    As the 7 December 2007 equinox of Uranus approached, ring and atmosphere observers produced a substantial collection of observations using the 10-m Keck telescope and the Hubble Space Telescope. Those spanning the period from 7 June 2007 through 9 September 2007 we used to identify and track cloud features, determine atmospheric motions, characterize cloud morphology and dynamics, and define changes in atmospheric band structure. We confirmed the existence of the suspected northern hemisphere prograde jet, locating its peak near 58 N, and extended wind speed measurements to 73 N. For 28 cloud features we obtained extremely high wind-speed accuracy through extended tracking times. The new results confirm a small N-S asymmetry in the zonal wind profile, and the lack of any change in the southern hemisphere between 1986 (near solstice) and 2007 (near equinox) suggests that the asymmetry may be permanent rather than seasonally reversing. In the 2007 images we found two prominent groups of discrete cloud features ...

  8. Factors shaping the future of Cloud Computing

    E-Print Network [OSTI]

    Francis, Steven (Steven Douglas)

    2011-01-01

    Many different forces are currently shaping the future of the Cloud Computing Market. End user demand and end user investment in existing technology are important drivers. Vendor innovation and competitive strategy are ...

  9. What Makes Clouds Grow and Die?

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

    fairly well." Based on these results, Hagos and his collaborators will next focus on cold pools and their role in growing small shallow clouds into large, deep ones. The team...

  10. A developer's survey on different cloud platforms

    E-Print Network [OSTI]

    Doan, Dzung

    2009-01-01

    5.5 SQL Services . . . . . . . . . . 5.6 Developerare made at the block level. SQL Services Besides storagethat lives in the cloud, called SQL Services. It’s based on

  11. On Demand Surveillance Service in Vehicular Cloud

    E-Print Network [OSTI]

    Weng, Jui-Ting

    2013-01-01

    as the combination of cloud com- puting and mobile devices.optimal bit rates for mobile devices to save energy. [48]The mobile devices are considered as clients and sensors,

  12. Exploiting weather forecast data for cloud detection 

    E-Print Network [OSTI]

    Mackie, Shona

    2009-01-01

    Accurate, fast detection of clouds in satellite imagery has many applications, for example Numerical Weather Prediction (NWP) and climate studies of both the atmosphere and of the Earth’s surface temperature. Most ...

  13. Electron-Cloud Build-Up: Summary

    SciTech Connect (OSTI)

    Furman, M.A.

    2007-06-18

    I present a summary of topics relevant to the electron-cloud build-up and dissipation that were presented at the International Workshop on Electron-Cloud Effects 'ECLOUD 07' (Daegu, S. Korea, April 9-12, 2007). This summary is not meant to be a comprehensive review of the talks. Rather, I focus on those developments that I found, in my personal opinion, especially interesting. The contributions, all excellent, are posted in http://chep.knu.ac.kr/ecloud07/.

  14. Adenine Abundance in a Collapsing Molecular Cloud

    E-Print Network [OSTI]

    Sandip K. Chakrabarti; Sonali Chakrabarti

    2000-03-18

    A vital ingredient of DNA molecule named adenine may be produced by successive addition of HCN during molecular cloud collapse and star formation. We compute its abundance in a collapsing cloud as a function of the reaction rate and show that in much of the circumstances the resulting amount may be sufficient to contaminate planets, comets and meteorites. We introduce a $f$-parameter which may be used to study the abundance where radiative association takes place.

  15. Secure Data Processing in a Hybrid Cloud

    E-Print Network [OSTI]

    Khadilkar, Vaibhav; Thuraisingham, Bhavani; Mehrotra, Sharad

    2011-01-01

    Cloud computing has made it possible for a user to be able to select a computing service precisely when needed. However, certain factors such as security of data and regulatory issues will impact a user's choice of using such a service. A solution to these problems is the use of a hybrid cloud that combines a user's local computing capabilities (for mission- or organization-critical tasks) with a public cloud (for less influential tasks). We foresee three challenges that must be overcome before the adoption of a hybrid cloud approach: 1) data design: How to partition relations in a hybrid cloud? The solution to this problem must account for the sensitivity of attributes in a relation as well as the workload of a user; 2) data security: How to protect a user's data in a public cloud with encryption while enabling query processing over this encrypted data? and 3) query processing: How to execute queries efficiently over both, encrypted and unencrypted data? This paper addresses these challenges and incorporates...

  16. Star formation relations in nearby molecular clouds

    SciTech Connect (OSTI)

    Evans, Neal J. II; Heiderman, Amanda; Vutisalchavakul, Nalin

    2014-02-20

    We test some ideas for star formation relations against data on local molecular clouds. On a cloud by cloud basis, the relation between the surface density of star formation rate and surface density of gas divided by a free-fall time, calculated from the mean cloud density, shows no significant correlation. If a crossing time is substituted for the free-fall time, there is even less correlation. Within a cloud, the star formation rate volume and surface densities increase rapidly with the corresponding gas densities, faster than predicted by models using the free-fall time defined from the local density. A model in which the star formation rate depends linearly on the mass of gas above a visual extinction of 8 mag describes the data on these clouds, with very low dispersion. The data on regions of very massive star formation, with improved star formation rates based on free-free emission from ionized gas, also agree with this linear relation.

  17. There are two types of cloud ratings currently in use: NUMERICAL--A cloud rating is manually assigned to each quadrant of the scene. 0 is

    E-Print Network [OSTI]

    Janée, Greg

    Clouds There are two types of cloud ratings currently in use: NUMERICAL-- A cloud rating is manually assigned to each quadrant of the scene. 0 is used for 0-10 percent clouds visible in a quadrant; 1 is used for 10-25 percent clouds visible in a quadrant; and 2 is used for over 25 percent clouds visible

  18. Triggering collapse of the presolar dense cloud core and injecting short-lived radioisotopes with a shock wave. III. Rotating three-dimensional cloud cores

    SciTech Connect (OSTI)

    Boss, Alan P.; Keiser, Sandra A.

    2014-06-10

    A key test of the supernova triggering and injection hypothesis for the origin of the solar system's short-lived radioisotopes is to reproduce the inferred initial abundances of these isotopes. We present here the most detailed models to date of the shock wave triggering and injection process, where shock waves with varied properties strike fully three-dimensional, rotating, dense cloud cores. The models are calculated with the FLASH adaptive mesh hydrodynamics code. Three different outcomes can result: triggered collapse leading to fragmentation into a multiple protostar system; triggered collapse leading to a single protostar embedded in a protostellar disk; or failure to undergo dynamic collapse. Shock wave material is injected into the collapsing clouds through Rayleigh-Taylor fingers, resulting in initially inhomogeneous distributions in the protostars and protostellar disks. Cloud rotation about an axis aligned with the shock propagation direction does not increase the injection efficiency appreciably, as the shock parameters were chosen to be optimal for injection even in the absence of rotation. For a shock wave from a core-collapse supernova, the dilution factors for supernova material are in the range of ?10{sup –4} to ?3 × 10{sup –4}, in agreement with recent laboratory estimates of the required amount of dilution for {sup 60}Fe and {sup 26}Al. We conclude that a type II supernova remains as a promising candidate for synthesizing the solar system's short-lived radioisotopes shortly before their injection into the presolar cloud core by the supernova's remnant shock wave.

  19. Scalable Networking for Cloud Datacenters

    E-Print Network [OSTI]

    CERN. Geneva

    2010-01-01

    Andy will discuss the architectural evolution of Ethernet networks and switch architectures as they are being designed to address much larger cloud networking applications that require predictable throughput and latency.About the speakerAs Chief Development Officer, Andy Bechtolsheim is responsible for the overall product development and technical direction of Arista Networks.Previously Andy was a Founder and Chief System Architect at Sun Microsystems, where most recently he was responsible for industry standard server architecture. Andy was also a Founder and President of Granite Systems, a Gigabit Ethernet startup acquired by Cisco Systems in 1996. From 1996 until 2003 Andy served as VP/GM of the Gigabit Systems Business Unit at Cisco that developed the very successful Catalyst 4500 family of switches. Andy was also a Founder and President of Kealia, a next generation server company acquired by Sun in 2004.Andy received an M.S. in Computer Engineering from Carnegie Mellon University in 1976 and was a Ph.D. ...

  20. The Energy Efficiency Potential of Cloud-Based Software: A U.S. Case Study

    E-Print Network [OSTI]

    Masanet, Eric

    2014-01-01

    Technology:  Can  Cloud  Computing  Enable  Carbon  environment/resources/Can_Cloud_Computing_Enable_Carbon_AbatTechnology:  Can  Cloud  Computing  Enable  Carbon  

  1. Simulation of a Feedback System for the Attenuation of e-Cloud Driven Instability

    E-Print Network [OSTI]

    Vay, J.-L.

    2010-01-01

    using computer simulations, electron cloud buildup in thebottom) from computer simulations of electron cloud drivenvia computer simulations the effect of electron clouds on a

  2. Theoretical Studies of TE-Wave Propagation as a Diagnostic for Electron Cloud

    E-Print Network [OSTI]

    Penn, Gregory E

    2011-01-01

    in WARP to model electron cloud measurements through TEMeasurement of Electron Clouds in Large Accelerators byof the Electron Cloud in the Cesr- TA Synchrotron Ring”,

  3. To Cloud or Not to Cloud: A Mobile Device Perspective on Energy Consumption of Applications

    E-Print Network [OSTI]

    Namboodiri, Vinod

    -based applications would be for mobile device users. For users of such battery life constrained devices, the most-based applications on battery life of mobile devices. It tries to answer the question: "For some user definedTo Cloud or Not to Cloud: A Mobile Device Perspective on Energy Consumption of Applications Vinod

  4. Analytic Approach to the Cloud-in-cloud Problem for Non-Gaussian Density Fluctuations

    E-Print Network [OSTI]

    Kaiki Taro Inoue; Masahiro Nagashima

    2002-03-28

    We revisit the cloud-in-cloud problem for non-Gaussian density fluctuations. We show that the extended Press-Schechter (EPS) formalism for non-Gaussian fluctuations has a flaw in describing mass functions regardless of type of filtering. As an example, we consider non-Gaussian models in which density fluctuations at a point obeys a \\chi^2 distribution with \

  5. Three Different Behaviors of Liquid Water Path of Water Clouds in Aerosol-Cloud Interactions

    E-Print Network [OSTI]

    Han, Quingyuan

    third of the cases, a minus one third (-1/3) power law relation between effective droplet radius droplet size and enhance evaporation just below cloud base, which decouples the cloud from the boundary explanation for the observed decrease of the diurnal temperature cycle (Hansen et al., 1997). Significant

  6. CloudVista: Interactive and Economical Visual Cluster Analysis for Big Data in the Cloud

    E-Print Network [OSTI]

    CloudVista: Interactive and Economical Visual Cluster Analysis for Big Data in the Cloud Huiqi Xu Analysis of big data has become an important problem for many business and scientific applications, among which clustering and visualizing clusters in big data raise some unique challenges. This demonstration

  7. CloudSim: A Novel Framework for Modeling and Simulation of Cloud Computing Infrastructures and Services

    E-Print Network [OSTI]

    Buyya, Rajkumar

    infrastructure (hardware, software, services) for different application and service models under varying load problem to tackle. To simplify this process, in this paper we propose CloudSim: a new generalized Cloud computing infrastructures and management services. The simulation framework has the following

  8. Binary Formation in Star-Forming Clouds with Various Metallicities

    E-Print Network [OSTI]

    Masahiro N. Machida

    2008-03-01

    Cloud evolution for various metallicities is investigated by three-dimensional nested grid simulations, in which the initial ratio of rotational to gravitational energy of the host cloud \\beta_0 (=10^-1 - 10^-6) and cloud metallicity Z (=0 - Z_\\odot) are parameters. Starting from a central number density of n = 10^4 cm^-3, cloud evolution for 48 models is calculated until the protostar is formed (n \\simeq 10^23 cm^-3) or fragmentation occurs. The fragmentation condition depends both on the initial rotational energy and cloud metallicity. Cloud rotation promotes fragmentation, while fragmentation tends to be suppressed in clouds with higher metallicity. Fragmentation occurs when \\beta_0 > 10^-3 in clouds with solar metallicity, while fragmentation occurs when \\beta_0 > 10^-5 in the primordial gas cloud. Clouds with lower metallicity have larger probability of fragmentation, which indicates that the binary frequency is a decreasing function of cloud metallicity. Thus, the binary frequency at the early universe (or lower metallicity environment) is higher than at present day (or higher metallicity environment). In addition, binary stars born from low-metallicity clouds have shorter orbital periods than those from high-metallicity clouds. These trends are explained in terms of the thermal history of the collapsing cloud.

  9. Polycylcic Aromatic Hydrocarbons (PAH's) in dense cloud chemistry

    E-Print Network [OSTI]

    Valentine Wakelam; Eric Herbst

    2008-02-26

    Virtually all detailed gas-phase models of the chemistry of dense interstellar clouds exclude polycyclic aromatic hydrocarbons (PAH's). This omission is unfortunate because from the few studies that have been done on the subject, it is known that the inclusion of PAH's can affect the gas-phase chemistry strongly. We have added PAH's to our network to determine the role they play in the chemistry of cold dense cores. In the models presented here, we include radiative attachment to form PAH-, mutual neutralization between PAH anions and small positively-charged ions, and photodetachment. We also test the sensitivity of our results to changes in the size and abundance of the PAH's. Our results confirm that the inclusion of PAH's changes many of the calculated abundances of smaller species considerably. In TMC-1, the general agreement with observations is significantly improved contrary to L134N. This may indicate a difference in PAH properties between the two regions. With the inclusion of PAH's in dense cloud chemistry, high-metal elemental abundances give a satisfactory agreement with observations. As a result, we do not need to decrease the observed elemental abundances of all metals and we do not need to vary the elemental C/O ratio in order to produce large abundances of carbon species in TMC-1 (CP).

  10. Chapter 3: Evaluating the impacts of carbonaceous aerosols on clouds and climate

    SciTech Connect (OSTI)

    Menon, Surabi; Del Genio, Anthony D.

    2007-09-03

    Any attempt to reconcile observed surface temperature changes within the last 150 years to changes simulated by climate models that include various atmospheric forcings is sensitive to the changes attributed to aerosols and aerosol-cloud-climate interactions, which are the main contributors that may well balance the positive forcings associated with greenhouse gases, absorbing aerosols, ozone related changes, etc. These aerosol effects on climate, from various modeling studies discussed in Menon (2004), range from +0.8 to -2.4 W m{sup -2}, with an implied value of -1.0 W m{sup -2} (range from -0.5 to -4.5 W m{sup -2}) for the aerosol indirect effects. Quantifying the contribution of aerosols and aerosol-cloud interactions remain complicated for several reasons some of which are related to aerosol distributions and some to the processes used to represent their effects on clouds. Aerosol effects on low lying marine stratocumulus clouds that cover much of the Earth's surface (about 70%) have been the focus of most of prior aerosol-cloud interaction effect simulations. Since cumulus clouds (shallow and deep convective) are short lived and cover about 15 to 20% of the Earth's surface, they are not usually considered as radiatively important. However, the large amount of latent heat released from convective towers, and corresponding changes in precipitation, especially in biomass regions due to convective heating effects (Graf et al. 2004), suggest that these cloud systems and aerosol effects on them, must be examined more closely. The radiative heating effects for mature deep convective systems can account for 10-30% of maximum latent heating effects and thus cannot be ignored (Jensen and Del Genio 2003). The first study that isolated the sensitivity of cumulus clouds to aerosols was from Nober et al. (2003) who found a reduction in precipitation in biomass burning regions and shifts in circulation patterns. Aerosol effects on convection have been included in other models as well (cf. Jacobson, 2002) but the relative impacts on convective and stratiform processes were not separated. Other changes to atmospheric stability and thermodynamical quantities due to aerosol absorption are also known to be important in modifying cloud macro/micro properties. Linkages between convection and boreal biomass burning can also impact the upper troposphere and lower stratosphere, radiation and cloud microphysical properties via transport of tropospheric aerosols to the lower stratosphere during extreme convection (Fromm and Servranckx 2003). Relevant questions regarding the impact of biomass aerosols on convective cloud properties include the effects of vertical transport of aerosols, spatial and temporal distribution of rainfall, vertical shift in latent heat release, phase shift of precipitation, circulation and their impacts on radiation. Over land surfaces, a decrease in surface shortwave radiation ({approx} 3-6 W m{sup -2} per decade) has been observed between 1960 to 1990, whereas, increases of 0.4 K in land temperature during the same period that occurred have resulted in speculations that evaporation and precipitation should also have decreased (Wild et al. 2004). However, precipitation records for the same period over land do not indicate any significant trend (Beck et al. 2005). The changes in precipitation are thought to be related to increased moisture advection from the oceans (Wild et al. 2004), which may well have some contributions from aerosol-radiation-convection coupling that could modify circulation patterns and hence moisture advection in specific regions. Other important aspects of aerosol effects, besides the direct, semi-direct, microphysical and thermodynamical impacts include alteration of surface albedos, especially snow and ice covered surfaces, due to absorbing aerosols. These effects are uncertain (Jacobson, 2004) but may produce as much as 0.3 W m{sup -2} forcing in the Northern hemisphere that could contribute to melting of ice and permafrost and change in the length of the season (e.g. early arrival of Spring

  11. Herschel observations of embedded protostellar clusters in the Rosette Molecular Cloud

    E-Print Network [OSTI]

    Hennemann, M; Bontemps, S; Schneider, N; Csengeri, T; Balog, Z; Di Francesco, J; Zavagno, A; André, Ph; Men'shchikov, A; Abergel, A; Ali, B; Baluteau, J -P; Bernard, J -Ph; Cox, P; Didelon, P; di Giorgio, A -M; Griffin, M; Hargrave, P; Hill, T; Horeau, B; Huang, M; Kirk, J; Leeks, S; Li, J Z; Marston, A; Martin, P; Molinari, S; Luong, Q Nguyen; Olofsson, G; Persi, P; Pezzuto, S; Russeil, D; Saraceno, P; Sauvage, M; Sibthorpe, B; Spinoglio, L; Testi, L; Ward-Thompson, D; White, G; Wilson, C; Woodcraft, A

    2010-01-01

    The Herschel OB young stellar objects survey (HOBYS) has observed the Rosette molecular cloud, providing an unprecedented view of its star formation activity. These new far-infrared data reveal a population of compact young stellar objects whose physical properties we aim to characterise. We compiled a sample of protostars and their spectral energy distributions that covers the near-infrared to submillimetre wavelength range. These were used to constrain key properties in the protostellar evolution, bolometric luminosity, and envelope mass and to build an evolutionary diagram. Several clusters are distinguished including the cloud centre, the embedded clusters in the vicinity of luminous infrared sources, and the interaction region. The analysed protostellar population in Rosette ranges from 0.1 to about 15 Msun with luminosities between 1 and 150 Lsun, which extends the evolutionary diagram from low-mass protostars into the high-mass regime. Some sources lack counterparts at near- to mid-infrared wavelengths...

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

    SciTech Connect (OSTI)

    Schumacher, Courtney

    2012-12-13

    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.

  13. Cloudy sounding and cloud-top height retrieval from AIRS alone single field-of-view radiance measurements

    E-Print Network [OSTI]

    Li, Jun

    to 15.4 mm). The spectral coverage includes strong CO2 absorption necessary for temperature profile and Ping Yang4 Received 3 April 2007; accepted 16 May 2007; published 20 June 2007. [1] High) Aqua satellite provide unique information about atmospheric state, surface and cloud properties

  14. HI-to-H2 transitions in the Perseus Molecular Cloud

    E-Print Network [OSTI]

    Bialy, Shmuel; Lee, Min-Young; Petit, Franck Le; Roueff, Evelyne

    2015-01-01

    We apply the Sternberg et al. (2014) theoretical model to analyze HI and H2 observations in the Perseus molecular cloud. We constrain the physical properties of the HI shielding envelopes and the nature of the HI-to-H2 transitions. Our analysis (Bialy et al. 2015) implies that in addition to cold neutral gas (CNM), less dense thermally-unstable gas (UNM) significantly contributes to the shielding of the H2 cores in Perseus.

  15. Cosmic ray penetration in diffuse clouds

    E-Print Network [OSTI]

    Morlino, G; Krause, J

    2015-01-01

    Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the $\\gamma$-ray flux produced by hadronic collisions between cosmic rays and cloud material. We study the spectrum of cosmic rays inside and outside of a diffuse cloud, by solving the stationary transport equation for cosmic rays including diffusion, advection and energy losses due to ionization of neutral hydrogen atoms. We found that the cosmic ray spectrum inside a diffuse cloud differs from the one in the interstellar medium (ISM) for energies smaller than $E_{br}\\approx 100$ MeV, irrespective of the model details. Below $E_{br}$, the spectrum is harder (softer) than that in the ISM if the latter is a power law $\\propto p^{-s}$ with $s$ larger (smaller) than $\\sim0.42$. As a consequence also the ionization rate due to CRs is strongly affected. Assuming an average Galactic spectrum similar to the one infe...

  16. Magellan: experiences from a Science Cloud

    SciTech Connect (OSTI)

    Ramakrishnan, Lavanya; Zbiegel, Piotr; Campbell, Scott; Bradshaw, Rick; Canon, Richard; Coghlan, Susan; Sakrejda, Iwona; Desai, Narayan; Declerck, Tina; Liu, Anping

    2011-02-02

    Cloud resources promise to be an avenue to address new categories of scientific applications including data-intensive science applications, on-demand/surge computing, and applications that require customized software environments. However, there is a limited understanding on how to operate and use clouds for scientific applications. Magellan, a project funded through the Department of Energy?s (DOE) Advanced Scientific Computing Research (ASCR) program, is investigating the use of cloud computing for science at the Argonne Leadership Computing Facility (ALCF) and the National Energy Research Scientific Computing Facility (NERSC). In this paper, we detail the experiences to date at both sites and identify the gaps and open challenges from both a resource provider as well as application perspective.

  17. Isolating signatures of major cloud-cloud collisions II: The lifetimes of broad bridge features

    E-Print Network [OSTI]

    Haworth, T J; Tasker, E J; Fukui, Y; Torii, K; Dale, J E; Takahira, K; Habe, A

    2015-01-01

    We investigate the longevity of broad bridge features in position-velocity diagrams that appear as a result of cloud-cloud collisions. Broad bridges will have a finite lifetime due to the action of feedback, conversion of gas into stars and the timescale of the collision. We make a series of analytic arguments with which to estimate these lifetimes. Our simple analytic arguments suggest that for collisions between clouds larger than R~10 pc the lifetime of the broad bridge is more likely to be determined by the lifetime of the collision rather than the radiative or wind feedback disruption timescale. However for smaller clouds feedback becomes much more effective. This is because the radiative feedback timescale scales with the ionising flux Nly as R^{7/4}Nly^{-1/4} so a reduction in cloud size requires a relatively large decrease in ionising photons to maintain a given timescale. We find that our analytic arguments are consistent with new synthetic observations of numerical simulations of cloud-cloud collisi...

  18. Simulation of e-cloud driven instability and its attenuation using a simulated feedback system in the CERN SPS

    E-Print Network [OSTI]

    Vay, J.-L.

    2011-01-01

    bottom) from computer simulations of electron cloud drivenusing computer simulations of electron cloud buildup in the

  19. E-Cloud Build-up in Grooved Chambers

    SciTech Connect (OSTI)

    Venturini, Marco

    2007-05-01

    We simulate electron cloud build-up in a grooved vacuumchamber including the effect of space charge from the electrons. Weidentify conditions for e-cloud suppression and make contact withprevious estimates of an effective secondary electron yield for groovedsurfaces.

  20. An electrodynamic balance (EDB) for extraterrestrial cloud formation studies

    E-Print Network [OSTI]

    Berlin, Shaena R. (Shaena Rochel)

    2014-01-01

    Ice clouds scatter and absorb solar radiation, affecting atmospheric and surface temperatures (Gettelman et al., 2012). On Mars, where ice contained in clouds makes up a large portion of total atmospheric water vapor, ice ...

  1. Transition to cloud computing in healthcare information systems

    E-Print Network [OSTI]

    Ren, Haiying, S.M. Massachusetts Institute of Technology

    2012-01-01

    This thesis is a study on the adoption of cloud computing in healthcare information technology industry. It provides a guideline for people who are trying to bring cloud computing into healthcare information systems through ...

  2. Resource Allocation and Scheduling in Heterogeneous Cloud Environments

    E-Print Network [OSTI]

    Lee, Gunho

    2012-01-01

    tation of private cloud computing on computer clusters. Itclouds. In Proceedings of the ACM Conference on Computer andCloud Environments by Gunho Lee Doctor of Philosophy in Computer

  3. SURGE : the Secure Cloud Storage and Collaboration Framework

    E-Print Network [OSTI]

    Schmahmann, Adin R

    2014-01-01

    SURGE is a Secure Cloud Storage and Collaboration Framework that is designed to be easy for application developers to use. The motivation is to allow application developers to mimic existing cloud based applications, but ...

  4. Consistent cloud computing storage as the basis for distributed applications

    E-Print Network [OSTI]

    Anderson, James William

    2011-01-01

    and authentication for security. Currently, cloud servicecloud computing applications share certain com- mon requirements of scalability, performance, availability, reliability, security,security, and e?iciency poses sig- ni?cant challenges. The cloud

  5. Simulation of E-Cloud Driven Instability And Its Attenuation...

    Office of Scientific and Technical Information (OSTI)

    Simulation of E-Cloud Driven Instability And Its Attenuation Using a Feedback System in the CERN SPS Citation Details In-Document Search Title: Simulation of E-Cloud Driven...

  6. I/O Performance of Virtualized Cloud Environments

    E-Print Network [OSTI]

    Ghoshal, Devarshi

    2013-01-01

    machine testbed runs the Eucalyptus 2.0 cloud software stackenvironment is based on Eucalyptus 2.0.5, an open sourcezations to clouds. Our Eucalyptus installation uses Kernel-

  7. Cloud computing : implications for enterprise software vendors (ESV)

    E-Print Network [OSTI]

    Francis, Leonard, S.M. Massachusetts Institute of Technology

    2009-01-01

    'Cloud computing', is a broad concept and in general is a term used for internet-based computing resources that are in an unspecified remote location or locations and that are flexible and fungible. Clouds provide a wide ...

  8. Cloud computing and its implications for organizational design and performance

    E-Print Network [OSTI]

    Farahani Rad, Ali

    2013-01-01

    Cloud computing has been at the center of attention for a while now. This attention is directed towards different aspects of this concept which concern different stakeholders from IT companies to cloud adopters to simple ...

  9. Cloud computing adoption model for governments and large enterprises

    E-Print Network [OSTI]

    Trivedi, Hrishikesh

    2013-01-01

    Cloud Computing has held organizations across the globe spell bound with its promise. As it moves from being a buzz word and hype into adoption, organizations are faced with question of how to best adopt cloud. Existing ...

  10. Intercomparison of model simulations of mixed-phase clouds observed...

    Office of Scientific and Technical Information (OSTI)

    with a cloud top temperature of -15C. While the cloud was water dominated, ice precipitation appears to have lowered the liquid water path to about 23 of the adiabatic value....

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

    SciTech Connect (OSTI)

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

    2013-01-31

    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.

  12. Radion clouds around evaporating black holes

    E-Print Network [OSTI]

    J. R. Morris

    2009-09-03

    A Kaluza-Klein model, with a matter source associated with Hawking radiation from an evaporating black hole, is used to obtain a simple form for the radion effective potential. The environmental effect generally causes a matter-induced shift of the radion vacuum, resulting in the formation of a radion cloud around the hole. There is an albedo due to the radion cloud, with an energy dependent reflection coefficient that depends upon the size of the extra dimensions and the temperature of the hole.

  13. Cloud-based Architecture Capabilities Summary Report

    SciTech Connect (OSTI)

    Vang, Leng; Prescott, Steven R; Smith, Curtis

    2014-09-01

    In collaborating scientific research arena it is important to have an environment where analysts have access to a shared of information documents, software tools and be able to accurately maintain and track historical changes in models. A new cloud-based environment would be accessible remotely from anywhere regardless of computing platforms given that the platform has available of Internet access and proper browser capabilities. Information stored at this environment would be restricted based on user assigned credentials. This report reviews development of a Cloud-based Architecture Capabilities (CAC) as a web portal for PRA tools.

  14. Simulations of the electron cloud buildups and suppressions in...

    Office of Scientific and Technical Information (OSTI)

    United States Language: English Subject: 43 PARTICLE ACCELERATORS; ACCELERATORS; BUILDUP; CLOUDS; ELECTRODES; ELECTRONS; FERMILAB TEVATRON; PROTONS; SOLENOIDS Accelerators...

  15. A Survey on Approaches for Interoperability and Portability of Cloud Computing Services

    E-Print Network [OSTI]

    Petrakis, Euripides G.M.

    A Survey on Approaches for Interoperability and Portability of Cloud Computing Services Kostas.sotiriadis, petrakis}@intelligence.tuc.gr Keywords: Cloud computing, cloud interoperability, cloud portability Abstract: Over the recent years, the rapid development of Cloud Computing has driven to a large market of cloud

  16. Simulations of the Electron Cloud Builld Up and Instabilities for Various ILC Damping Ring Configurations

    SciTech Connect (OSTI)

    Pivi, Mauro; Raubenheimer, Tor O.; Wang, Lanfa; Ohmi, Kazuhito; Wanzenberg, Rainer; Wolski, Andrzej; /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech.

    2007-03-12

    In the beam pipe of the positron damping ring of the International Linear Collider (ILC), an electron cloud may be first produced by photoelectrons and ionization of residual gases and then increased by the secondary emission process. This paper reports the assessment of electron cloud effects in a number of configuration options for the ILC baseline configuration. Careful estimates were made of the secondary electron yield (sometimes in the literature also referred as secondary emission yield SEY or {delta}, with a peak value {delta}{sub max}) threshold for electron cloud build-up, and the related single- and coupled-bunch instabilities, as a function of beam current and surface properties for a variety of optics designs. When the configuration for the ILC damping rings was chosen at the end of 2005, the results from these studies were important considerations. On the basis of the joint theoretical and experimental work, the baseline configuration currently specifies a pair of 6 km damping rings for the positron beam, to mitigate the effects of the electron cloud that could present difficulties in a single 6 km ring. However, since mitigation techniques are now estimated to be sufficiently mature, a reduced single 6-km circumference is presently under consideration so as to reduce costs.

  17. HIGH-VELOCITY CLOUDS IN THE GALACTIC ALL SKY SURVEY. I. CATALOG

    SciTech Connect (OSTI)

    Moss, V. A.; Kummerfeld, J. K.; McClure-Griffiths, N. M.; Murphy, T.; Pisano, D. J.; Curran, J. R.

    2013-11-01

    We present a catalog of high-velocity clouds (HVCs) from the Galactic All Sky Survey (GASS) of southern sky neutral hydrogen, which has 57 mK sensitivity and 1 km s{sup –1} velocity resolution and was obtained with the Parkes Telescope. Our catalog has been derived from the stray-radiation-corrected second release of GASS. We describe the data and our method of identifying HVCs and analyze the overall properties of the GASS population. We catalog a total of 1693 HVCs at declinations <0°, including 1111 positive velocity HVCs and 582 negative velocity HVCs. Our catalog also includes 295 anomalous velocity clouds (AVCs). The cloud line-widths of our HVC population have a median FWHM of ?19 km s{sup –1}, which is lower than that found in previous surveys. The completeness of our catalog is above 95% based on comparison with the HIPASS catalog of HVCs upon which we improve by an order of magnitude in spectral resolution. We find 758 new HVCs and AVCs with no HIPASS counterpart. The GASS catalog will shed unprecedented light on the distribution and kinematic structure of southern sky HVCs, as well as delve further into the cloud populations that make up the anomalous velocity gas of the Milky Way.

  18. ARM - Field Campaign - Cloud IOP

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve4AJ01) (See22,Microphysical Properties ofgovCampaignsCirrus

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

    SciTech Connect (OSTI)

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

    2011-11-01

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

  20. Fine-Grained Multi-Resource Scheduling in Cloud Datacenters

    E-Print Network [OSTI]

    Fu, Xiaoming

    Fine-Grained Multi-Resource Scheduling in Cloud Datacenters Yuan Zhang University of G--Cloud datacenters typically require tenants to spec- ify the resource demands for the virtual machines (VMs. Unfortunately, this leads to low resource utilization of cloud datacenters as tenants are obligated

  1. Cloud Storage Standards Overview and Research Ideas Brainstorm

    E-Print Network [OSTI]

    Cloud Storage Standards Overview and Research Ideas Brainstorm Mark Carlson, SNIA TC and Sun Chair, SNIA Cloud Storage TWG CMU SDI Lecture ­ 12th November 2009 #12;Insert tutorial title in footer © 2009 Storage Networking Industry Association.All Rights Reserved. Abstract ! Cloud Storage is a new business

  2. Design and Performance Guarantees in Cloud Computing: Challenges and Opportunities

    E-Print Network [OSTI]

    Como, Giacomo

    Design and Performance Guarantees in Cloud Computing: Challenges and Opportunities [Challenge.8 [Software Engineering]: Metrics--complexity mea- sures, performance measures Keywords Cloud computing Römers väg 1 Lund, Sweden alessandro.papadopoulos@control.lth.se ABSTRACT In the last years, cloud

  3. Controlling Data in the Cloud: Outsourcing Computation without Outsourcing Control

    E-Print Network [OSTI]

    Shi, Elaine

    Controlling Data in the Cloud: Outsourcing Computation without Outsourcing Control Richard Chow.fujitsu.com ABSTRACT Cloud computing is clearly one of today's most enticing technology areas due, at least in part, there are significant, persistent concerns about cloud computing that are impeding momentum and will eventually

  4. Socially Optimal Pricing of Cloud Computing Resources Ishai Menache

    E-Print Network [OSTI]

    Shimkin, Nahum

    Socially Optimal Pricing of Cloud Computing Resources Ishai Menache Microsoft Research New England The cloud computing paradigm offers easily accessible com- puting resources of variable size and capabilities. We con- sider a cloud-computing facility that provides simultaneous service to a heterogeneous

  5. Maestro: A cloud computing framework with automated locking (Invited Paper)

    E-Print Network [OSTI]

    Krovi, Venkat

    Maestro: A cloud computing framework with automated locking (Invited Paper) Murat Demirbas challenge for distributed systems programming and cloud computing. Using locks is the most common technique (shared-memory), Maestro improves productivity and lowers the cost of entry to cloud computing backend

  6. Cryptography Challenges for Computational Privacy in Public Clouds

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Cryptography Challenges for Computational Privacy in Public Clouds Sashank Dara Cisco Systems security but its readiness for this new generational shift of computing platform i.e. Cloud Computing into the underpinnings of Computational Privacy and lead to better solutions. I. INTRODUCTION Cloud computing came out

  7. Introduction to the IEEE Transactions on Cloud Computing

    E-Print Network [OSTI]

    Buyya, Rajkumar

    Introduction to the IEEE Transactions on Cloud Computing Rajkumar Buyya Welcome to the IEEE Transactions on Cloud Computing (TCC). It is my privilege and honor to serve as the inaugural Editor-in-Chief of TCC. I would like to thank the IEEE and the world-wide Cloud Computing community for giving me

  8. Differentiation factors between free and premium among different cloud computing

    E-Print Network [OSTI]

    Vellekoop, Michel

    Differentiation factors between free and premium among different cloud computing services Author for consumers among various cloud computing services. The design is a comparative case study by which Spotify, Freemium, Differentiation, Cloud computing services Permission to make digital or hard copies of all

  9. Security Models and Requirements for Healthcare Application Clouds

    E-Print Network [OSTI]

    Liu, Ling

    Security Models and Requirements for Healthcare Application Clouds Rui Zhang 1,2 and Ling Liu 1 1 clouds and analyze the arising security and privacy issues in access and management of EHRs. We describe an EHR security reference model for managing security issues in healthcare clouds, which highlights three

  10. Secure Cloud Manufacturing: Research Challenges and a Case Study

    E-Print Network [OSTI]

    Wang, Weichao

    Secure Cloud Manufacturing: Research Challenges and a Case Study Weichao Wang1 , Yu Wang2 , Wesley-floor will be injected into the system to assess its security. 1 Introduction With the fast development of cloud for the sustainability of US economy [14, 15]. To bridge this gap, we plan to investigate security of cloud manufacturing

  11. Efficient and Secure Data Storage Operations for Mobile Cloud Computing

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Efficient and Secure Data Storage Operations for Mobile Cloud Computing Zhibin Zhou and Dijiang, users' concerns about data security are the main obstacles that impede cloud computing from being widely architectures are needed to address the security concerns of users for using cloud computing techniques

  12. Secure and Constant Cost Public Cloud Storage Auditing with Deduplication

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Secure and Constant Cost Public Cloud Storage Auditing with Deduplication Jiawei Yuan Department and secure data integrity auditing with storage deduplication for cloud storage. In this paper we solve and storage efficiency are two important requirements for cloud storage. Proof of Retriev- ability (POR

  13. Towards a Discipline of Mission-Aware Cloud Computing

    E-Print Network [OSTI]

    Sandhu, Ravi

    Concerns: Dependability Security Cloud Computing Security Guess who wins?! © Ravi Sandhu World-Leading Research with Real Cloud Computing 3 Leading Research with Real-World Impact! #12;Cyber security has Information assurance Cyber Security Information assurance The cloud, or any other cyber infrastructure

  14. Privacy-Preserving Public Auditing for Secure Cloud Storage

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    1 Privacy-Preserving Public Auditing for Secure Cloud Storage Cong Wang, Student Member, IEEE burden to user. In this paper, we propose a secure cloud storage system supporting privacy for data integrity. Examples of outages and security breaches of noteworthy cloud services appear from time

  15. Authorization Federation in IaaS Multi Cloud Navid Pustchi

    E-Print Network [OSTI]

    Sandhu, Ravi

    Authorization Federation in IaaS Multi Cloud Navid Pustchi Institute for Cyber Security Department; Cloud Federation; Distributed Access Control; Security; Trust Management. 1. INTRODUCTION Cloud of Computer Science Univ of Texas at San Antonio tam498@my.utsa.edu Ram Krishnan Institute for Cyber Security

  16. Microsoft's Cloud Infrastructure Datacenters and Network Fact Sheet

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    Corp. delivers more than 200 cloud services, including Bing, MSN, Outlook.com, Office 365, One operations centers. This infrastructure is supported by one of the world's largest multi- terabit global and listen to our cloud energy strategist's presentation. #12;Microsoft's cloud infrastructure by the numbers

  17. Towards a New Execution Model for HPC Clouds Thomas Sterling

    E-Print Network [OSTI]

    Lumsdaine, Andrew

    Towards a New Execution Model for HPC Clouds Thomas Sterling Center for Research in Extreme Scale an alternative paradigm for bringing Clouds more closely aligned to Science, Technology, Engineering Execution Model for HPC Clouds Thomas Sterling 1. Introduction Even as HPC is transiting the pan

  18. Electron-Cloud Build-up: Summary M. A. Furman,

    E-Print Network [OSTI]

    Furman, Miguel

    LBNL-62849 Electron-Cloud Build-up: Summary M. A. Furman, Center for Beam Physics, LBNL, Berkeley, CA 94720-8211, USA Abstract I present a summary of topics relevant to the electron- cloud build-up and dissipation that were presented at the International Workshop on Electron-Cloud Effects "ECLOUD'07" (Daegu, S

  19. Energy Measurement for the Cloud Yi Yu, Saleem Bhatti

    E-Print Network [OSTI]

    Bhatti, Saleem N.

    Energy Measurement for the Cloud Yi Yu, Saleem Bhatti School of Computer Science, University of St important resource to consider is energy (or power). As cloud services are intended to be `always on' the energy costs of cloud service provision is already significant, and will continue to rise as global

  20. AEROSOLS AND CLOUDS IN CHEMICAL TRANSPORT MODELS AND CLIMATE MODELS

    E-Print Network [OSTI]

    of Earth's climate system. Clouds are highly reflective in the solar spectrum, yet strongly absorbingAEROSOLS AND CLOUDS IN CHEMICAL TRANSPORT MODELS AND CLIMATE MODELS Ulrike Lohmann1 and Stephen E Forum: Perturbed Clouds in the Climate System, Frankfurt, Germany March 2-7, 2008 Environmental Sciences

  1. A Survey on Cloud Interoperability: Taxonomies, Standards, and Practice

    E-Print Network [OSTI]

    Cheung, David Wai-lok

    A Survey on Cloud Interoperability: Taxonomies, Standards, and Practice Zhizhong Zhang, Chuan Wu:{zzzhang,cwu,dcheung}@cs.hku.hk ABSTRACT Cloud computing is a new computing paradigm that allows users with different computing demands, applications and services). Many commercial cloud providers have emerged in the past 6-7 years, and each

  2. Icy wave-cloud lunar corona and cirrus iridescence

    E-Print Network [OSTI]

    Shaw, Joseph A.

    Icy wave-cloud lunar corona and cirrus iridescence Joseph A. Shaw* and Nathan J. Pust Electrical to determine that iridescence in cirrus and a lunar corona in a thin wave cloud were caused by tiny ice conventional ice crystals. The iridescent cloud was located at the tropopause [11­13:6 km above mean sea level

  3. Growth of Cloud Droplets in a Turbulent Environment

    E-Print Network [OSTI]

    Wang, Lian-Ping

    Growth of Cloud Droplets in a Turbulent Environment Wojciech W. Grabowski1 and Lian-Ping Wang2 1 Keywords condensational growth, turbulent collision-coalescence, particle-laden flow, cloud microphysical concerning the growth of cloud droplets by water-vapor diffu- sion and by collision

  4. Cloud-Assisted Multiparty Computation from Fully Homomorphic Encryption

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Cloud-Assisted Multiparty Computation from Fully Homomorphic Encryption Adriana L´opez-Alt New York powerful party, namely the "cloud". Our protocols are simultaneously efficient in a number of metrics that of the cloud is linear in the size of the circuit computing f. In the semi-honest case, our protocol relies

  5. Scaling relations for molecular gas in the Large Magellanic Cloud

    E-Print Network [OSTI]

    Hardcastle, Martin

    Scaling relations for molecular gas in the Large Magellanic Cloud By A r t o H e i kk i l ¨a e (virial mass versus CO luminosity, luminosity versus size, linewidth versus size) for molecular clouds in the 30 Dor and N 159 regions in the Large Magel­ lanic Cloud. The analysis is based on CO J = 1 ! 0

  6. ENHANCED CLOUD REGIME CLASSIFICATION FOR EVALUATION OF MODEL FAST PHYSICS

    E-Print Network [OSTI]

    ENHANCED CLOUD REGIME CLASSIFICATION FOR EVALUATION OF MODEL FAST PHYSICS Wuyin Lin1 , Yangang Liu1 of Energy under Contract No. DE-AC02-98CH10886 ABSTRACT Distinct cloud regimes exist locally and globally helps identify the meteorological conditions that are closely associated with specific cloud regimes

  7. IMPACT OF AEROSOLS ON CONVECTIVE CLOUDS AND PRECIPITATION

    E-Print Network [OSTI]

    Zeng, Ning

    IMPACT OF AEROSOLS ON CONVECTIVE CLOUDS AND PRECIPITATION Wei-Kuo Tao,1 Jen-Ping Chen,2 Zhanqing Li effects on clouds could further extend to precipitation, both through the formation of cloud particles mechan- isms behind these effects, in particular, the ones connected to precipitation, are not yet well

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

    SciTech Connect (OSTI)

    Huang, Hsin-Yuan; Hall, Alex

    2013-07-24

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

  9. Mobilizing the Cloud: Enabling Multi-User Mobile Outsourcing in the Cloud Technical Report

    E-Print Network [OSTI]

    Weissman, Jon

    , resource-intensive applications. Mobile computation outsourcing to external resources has been proposed mobile application outsourcing platform, leveraging the cloud for scalability, elasticity, and multi, current battery technology can only support limited computational power in such a portable and lightweight

  10. Cost Efficient Datacenter Selection for Cloud Services

    E-Print Network [OSTI]

    Li, Baochun

    Cost Efficient Datacenter Selection for Cloud Services Hong Xu, Baochun Li henryxu, bli and performance. They need an effective way to direct the user requests to a suitable datacenter, in a cost efficient manner. Previ- ous work focused mostly on the electricity cost of datacenters. The approaches

  11. The Clouds Distributed Operating System * Partha Dasgupta

    E-Print Network [OSTI]

    Yeom, Heon Young

    The Clouds Distributed Operating System * Partha Dasgupta Dept. of Computer Science and Engg Ramachandran. College of Computing Georgia Tech, Atlanta, GA 30332 Keywords: Distributed Operating Systems operating system that runs on general purpose computers connected via a local­area network. The system

  12. On Robust Regression in Photogrammetric Point Clouds

    E-Print Network [OSTI]

    Schindler, Konrad

    On Robust Regression in Photogrammetric Point Clouds Konrad Schindler and Horst Bischof Institute,bischof}@icg.tu-graz.ac.at Abstract. Many applications in computer vision require robust linear regression on photogrammetrically for robust regression are based on distance measures from the regression surface to the points

  13. Higher-order closures and cloud parameterizations

    E-Print Network [OSTI]

    Higher-order closures and cloud parameterizations Jean-Christophe Golaz National Research Council moments directly. These prognostic equations introduce new terms that must be closed. #12;What't know whether to transport smoke up or down at the next timestep. Larson 1999 #12;Outline · What

  14. The Pion Cloud: Insights into Hadron Structure

    E-Print Network [OSTI]

    A. W. Thomas

    2007-11-14

    Modern nuclear theory presents a fascinating study in contrasting approaches to the structure of hadrons and nuclei. Nowhere is this more apparent than in the treatment of the pion cloud. As this discussion really begins with Yukawa, it is entirely appropriate that this invited lecture at the Yukawa Institute in Kyoto should deal with the issue.

  15. Efficient Resource Management for Cloud Computing Environments

    E-Print Network [OSTI]

    energy footprint. In order to correctly and completely unify a Green aspect to the next generation such as the relatively high operating cost for both public and private Clouds. The area of Green computing is also computational power. In this paper a new framework is presented that provides efficient green enhancements

  16. The Magellan Final Report on Cloud Computing

    SciTech Connect (OSTI)

    ,; Coghlan, Susan; Yelick, Katherine

    2011-12-21

    The goal of Magellan, a project funded through the U.S. Department of Energy (DOE) Office of Advanced Scientific Computing Research (ASCR), was to investigate the potential role of cloud computing in addressing the computing needs for the DOE Office of Science (SC), particularly related to serving the needs of mid- range computing and future data-intensive computing workloads. A set of research questions was formed to probe various aspects of cloud computing from performance, usability, and cost. To address these questions, a distributed testbed infrastructure was deployed at the Argonne Leadership Computing Facility (ALCF) and the National Energy Research Scientific Computing Center (NERSC). The testbed was designed to be flexible and capable enough to explore a variety of computing models and hardware design points in order to understand the impact for various scientific applications. During the project, the testbed also served as a valuable resource to application scientists. Applications from a diverse set of projects such as MG-RAST (a metagenomics analysis server), the Joint Genome Institute, the STAR experiment at the Relativistic Heavy Ion Collider, and the Laser Interferometer Gravitational Wave Observatory (LIGO), were used by the Magellan project for benchmarking within the cloud, but the project teams were also able to accomplish important production science utilizing the Magellan cloud resources.

  17. : a Cloud Perspective Pradeep B. Teregowda

    E-Print Network [OSTI]

    Giles, C. Lee

    as well as discuss the effort involved. 1 Introduction Digital library search engines have been retrieval systems. Particularly, Web based digital library search engines such as CiteSeerx can readily take applications are good candidates for hosting in a cloud infrastructure. CiteSeerx a digi- tal library

  18. Argonne's Magellan Cloud Computing Research Project

    ScienceCinema (OSTI)

    Beckman, Pete

    2013-04-19

    Pete Beckman, head of Argonne's Leadership Computing Facility (ALCF), discusses the Department of Energy's new $32-million Magellan project, which designed to test how cloud computing can be used for scientific research. More information: http://www.anl.gov/Media_Center/News/2009/news091014a.html

  19. Proof of Concept: Cloud Condensation Nucleus Counter

    E-Print Network [OSTI]

    Delene, David J.

    North Dakota project. The solid circle is the mean value, the horizontal line is the 50th percentile Price High Price #12;Research Applications · One commercially available cloud condensation nuclei (CCN) counter. · Available since 2002 · Sold over 100 Units, Mostly Labs · Price is Approximately $70

  20. DEPSKY: Dependable and Secure Storage in a Cloud-of-Clouds Alysson Bessani Miguel Correia Bruno Quaresma Fernando Andre Paulo Sousa

    E-Print Network [OSTI]

    Correia, Miguel

    DEPSKY: Dependable and Secure Storage in a Cloud-of-Clouds Alysson Bessani Miguel Correia Bruno of critical data that could be moved to the cloud. However, the reliability and security of data stored, Security Keywords Cloud computing, Cloud storage, Byzantine quorum systems 1. Introduction The increasing

  1. Enabling Security in Cloud Storage SLAs with CloudProof Raluca Ada Popa Jacob R. Lorch David Molnar Helen J. Wang Li Zhuang

    E-Print Network [OSTI]

    Enabling Security in Cloud Storage SLAs with CloudProof Raluca Ada Popa Jacob R. Lorch David Molnar,dmolnar,helenw,lizhuang}@microsoft.com ABSTRACT Several cloud storage systems exist today, but none of them provide security guaranteesProof, a secure storage system specifically de- signed for the cloud. In CloudProof, customers can not only detect

  2. NIST Cloud Computing Strategy working paper, April 2011 1 of 25 NIST Strategy to build a USG Cloud Computing

    E-Print Network [OSTI]

    of United States Government (USG) secure and effective adoption of the Cloud Computing2 model to reduce to datacenter and enterprise application design and management. While cloud computing is being used, security and security requirements. The roadmap document is the mechanism being developed by the NIST Cloud Computing

  3. Water clouds in Y dwarfs and exoplanets

    SciTech Connect (OSTI)

    Morley, Caroline V.; Fortney, Jonathan J.; Marley, Mark S.; Lupu, Roxana; Greene, Tom; Saumon, Didier; Lodders, Katharina

    2014-05-20

    The formation of clouds affects brown dwarf and planetary atmospheres of nearly all effective temperatures. Iron and silicate condense in L dwarf atmospheres and dissipate at the L/T transition. Minor species such as sulfides and salts condense in mid- to late T dwarfs. For brown dwarfs below T {sub eff} ? 450 K, water condenses in the upper atmosphere to form ice clouds. Currently, over a dozen objects in this temperature range have been discovered, and few previous theoretical studies have addressed the effect of water clouds on brown dwarf or exoplanetary spectra. Here we present a new grid of models that include the effect of water cloud opacity. We find that they become optically thick in objects below T {sub eff} ? 350-375 K. Unlike refractory cloud materials, water-ice particles are significantly nongray absorbers; they predominantly scatter at optical wavelengths through the J band and absorb in the infrared with prominent features, the strongest of which is at 2.8 ?m. H{sub 2}O, NH{sub 3}, CH{sub 4}, and H{sub 2} CIA are dominant opacity sources; less abundant species may also be detectable, including the alkalis, H{sub 2}S, and PH{sub 3}. PH{sub 3}, which has been detected in Jupiter, is expected to have a strong signature in the mid-infrared at 4.3 ?m in Y dwarfs around T {sub eff} = 450 K; if disequilibrium chemistry increases the abundance of PH{sub 3}, it may be detectable over a wider effective temperature range than models predict. We show results incorporating disequilibrium nitrogen and carbon chemistry and predict signatures of low gravity in planetary mass objects. Finally, we make predictions for the observability of Y dwarfs and planets with existing and future instruments, including the James Webb Space Telescope and Gemini Planet Imager.

  4. Cloud Computing and Grid Computing 360-Degree Compared

    E-Print Network [OSTI]

    Foster, Ian; Raicu, Ioan; Lu, Shiyong

    2009-01-01

    Cloud Computing has become another buzzword after Web 2.0. However, there are dozens of different definitions for Cloud Computing and there seems to be no consensus on what a Cloud is. On the other hand, Cloud Computing is not a completely new concept; it has intricate connection to the relatively new but thirteen-year established Grid Computing paradigm, and other relevant technologies such as utility computing, cluster computing, and distributed systems in general. This paper strives to compare and contrast Cloud Computing with Grid Computing from various angles and give insights into the essential characteristics of both.

  5. Operation Greenhouse. Scientific Director's report of atomic-weapon tests at Eniwetok, 1951. Annex 4. 1. Cloud studies. Part 1. Cloud physics. Part 2. Development of the atomic cloud. Part 3. Cloud-tracking photography

    SciTech Connect (OSTI)

    Anderson, C.E.; Gustafson, P.E.; Kellogg, W.W.; McKown, R.E.; McPherson, D.E.

    1985-09-01

    The cloud-physics project was primarily intended to fulfill a requirements for detailed information on the meteorological microstructure of atomic clouds. By means of a tracking and photographic network extending halfway around Eniwetok Atoll, the behavior of the first three clouds of Operation Greenhouse were observed and recorded. The rise of the fourth cloud was observed visually from only one site. The analysis of these observations, combined with information about the local weather conditions, gives a fairly complete picture of the development of each of the clouds. Particular emphasis was placed on the earlier phases of development, and the heights and sizes of the cloud parts have been determined as functions of time. A summary of important features of some previous atomic clouds are included for comparison.

  6. pCloud: A Cloud-based Power Market Simulation Environment

    SciTech Connect (OSTI)

    Rudkevich, Aleksandr; Goldis, Evgeniy

    2012-12-02

    This research conducted by the Newton Energy Group, LLC (NEG) is dedicated to the development of pCloud: a Cloud-based Power Market Simulation Environment. pCloud is offering power industry stakeholders the capability to model electricity markets and is organized around the Software as a Service (SaaS) concept -- a software application delivery model in which software is centrally hosted and provided to many users via the internet. During the Phase I of this project NEG developed a prototype design for pCloud as a SaaS-based commercial service offering, system architecture supporting that design, ensured feasibility of key architecture's elements, formed technological partnerships and negotiated commercial agreements with partners, conducted market research and other related activities and secured funding for continue development of pCloud between the end of Phase I and beginning of Phase II, if awarded. Based on the results of Phase I activities, NEG has established that the development of a cloud-based power market simulation environment within the Windows Azure platform is technologically feasible, can be accomplished within the budget and timeframe available through the Phase II SBIR award with additional external funding. NEG believes that pCloud has the potential to become a game-changing technology for the modeling and analysis of electricity markets. This potential is due to the following critical advantages of pCloud over its competition: - Standardized access to advanced and proven power market simulators offered by third parties. - Automated parallelization of simulations and dynamic provisioning of computing resources on the cloud. This combination of automation and scalability dramatically reduces turn-around time while offering the capability to increase the number of analyzed scenarios by a factor of 10, 100 or even 1000. - Access to ready-to-use data and to cloud-based resources leading to a reduction in software, hardware, and IT costs. - Competitive pricing structure, which will make high-volume usage of simulation services affordable. - Availability and affordability of high quality power simulators, which presently only large corporate clients can afford, will level the playing field in developing regional energy policies, determining prudent cost recovery mechanisms and assuring just and reasonable rates to consumers. - Users that presently do not have the resources to internally maintain modeling capabilities will now be able to run simulations. This will invite more players into the industry, ultimately leading to more transparent and liquid power markets.

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

    SciTech Connect (OSTI)

    Verschuur, Gerrit L.

    2013-04-01

    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.

  8. Anisotropic Formation of Magnetized Cores in Turbulent Clouds

    E-Print Network [OSTI]

    Chen, Che-Yu

    2015-01-01

    In giant molecular clouds (GMCs), shocks driven by converging turbulent flows create high-density, strongly-magnetized regions that are locally sheetlike. In previous work, we showed that within these layers, dense filaments and embedded self-gravitating cores form by gathering material along the magnetic field lines. Here, we extend the parameter space of our three-dimensional, turbulent MHD core formation simulations. We confirm the anisotropic core formation model we previously proposed, and quantify the dependence of median core properties on the pre-shock inflow velocity and upstream magnetic field strength. Our results suggest that bound core properties are set by the total dynamic pressure (dominated by large-scale turbulence) and thermal sound speed c_s in GMCs, independent of magnetic field strength. For models with Mach number between 5 and 20, the median core masses and radii are comparable to the critical Bonnor-Ebert mass and radius defined using the dynamic pressure for P_ext. Our results corres...

  9. The Lognormal Probability Distribution Function of the Perseus Molecular Cloud: A Comparison of HI and Dust

    E-Print Network [OSTI]

    Burkhart, Blakesley; Murray, Claire; Stanimirovic, Snezana

    2015-01-01

    The shape of the probability distribution function (PDF) of molecular clouds is an important ingredient for modern theories of star formation and turbulence. Recently, several studies have pointed out observational difficulties with constraining the low column density (i.e. Av HI data and compare the PDF shape and properties to the total gas PDF and the N(H2) PDF. We find that the shape of the PDF in the atomic medium of Perseus is well described by a lognormal distribution, and not by a power-law or bimodal distribution. The peak of the atomic gas PDF in and around Perseus lies at the HI-H2 transition column density for this cloud, past which the N(H2) PDF takes on a powerlaw form. We find that the PDF of the atomic gas is narrow and at column densities larger than...

  10. The road toward a full, high resolution Molecular Cloud catalog of the Galaxy

    E-Print Network [OSTI]

    Colombo, Dario; Ginsburg, Adam; Duarte-Cabral, Ana; Hughes, Annie

    2015-01-01

    The statistical description of Giant Molecular Cloud (GMC) properties relies heavily on the performance of automatic identification algorithms, which are often seriously affected by the survey design. The algorithm we designed, SCIMES (Spectral Clustering for Interstellar Molecular Emission Segmentation), is able to overcome some of these limitations by considering the cloud segmentation problem in the broad framework of the graph theory. The application of the code on the CO(3-2) High Resolution Survey (COHRS) data allowed for a robust decomposition of more than 12,000 objects in the Galactic Plane. Together with the wealth of Galactic Plane surveys of the recent years, this approach will help to open the door to a future, systematic cataloging of all discrete molecular features of our own Galaxy.

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

    SciTech Connect (OSTI)

    Wang, Minghuai; Penner, Joyce E.

    2010-06-21

    A statistical cirrus cloud scheme that accounts for mesoscale temperature perturbations is implemented in a coupled aerosol and atmospheric circulation model to better represent both subgrid-scale supersaturation and cloud formation. This new scheme treats the effects of aerosol on cloud formation and ice freezing in an improved manner, and both homogeneous freezing and heterogeneous freezing are included. The scheme is able to better simulate the observed probability distribution of relative humidity compared to the scheme that was implemented in an older version of the model. Heterogeneous ice nuclei (IN) are shown to decrease the frequency of occurrence of supersaturation, and improve the comparison with observations at 192 hPa. Homogeneous freezing alone can not reproduce observed ice crystal number concentrations at low temperatures (<205 K), but the addition of heterogeneous IN improves the comparison somewhat. Increases in heterogeneous IN affect both high level cirrus clouds and low level liquid clouds. Increases in cirrus clouds lead to a more cloudy and moist lower troposphere with less precipitation, effects which we associate with the decreased convective activity. The change in the net cloud forcing is not very sensitive to the change in ice crystal concentrations, but the change in the net radiative flux at the top of the atmosphere is still large because of changes in water vapor. Changes in the magnitude of the assumed mesoscale temperature perturbations by 25% alter the ice crystal number concentrations and the net radiative fluxes by an amount that is comparable to that from a factor of 10 change in the heterogeneous IN number concentrations. Further improvements on the representation of mesoscale temperature perturbations, heterogeneous IN and the competition between homogeneous freezing and heterogeneous freezing are needed.

  12. ARM - SGP Radiometric Calibration Facility

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska OutreachCalendarPressExtended Facility SGP Related

  13. Experiment to Characterize Tropical Cloud Systems

    SciTech Connect (OSTI)

    May, Peter T.; Mather, Jim H.; Jakob, Christian

    2005-08-02

    A major experiment to study tropical convective cloud systems and their impacts will take place around Darwin, Northern Australia in early 2006. The Tropical Warm Pool International Cloud Experiment (TWP-ICE) is a collaboration including the DOE ARM (Atmospheric Radiation Measurement) and ARM-UAV programs, NASA centers, the Australian Bureau of Meteorology, CSIRO, and universities in the USA, Australia, Japan, the UK, and Canada. TWP-ICE will be preceded in November/December 2004 by a collaborating European aircraft campaign involving the EU SCOUT-O3 and UK NERC ACTIVE projects. Detailed atmospheric measurements will be made in the Darwin area through the whole Austral summer, giving unprecedented coverage through the pre-monsoon and monsoon periods.

  14. Dust Emission from the Perseus Molecular Cloud

    E-Print Network [OSTI]

    S. Schnee; J. Li; A. A. Goodman; A. I. Sargent

    2008-05-27

    Using far-infrared emission maps taken by IRAS and Spitzer and a near-infrared extinction map derived from 2MASS data, we have made dust temperature and column density maps of the Perseus molecular cloud. We show that the emission from transiently heated very small grains and the big grain dust emissivity vary as a function of extinction and dust temperature, with higher dust emissivities for colder grains. This variable emissivity can not be explained by temperature gradients along the line of sight or by noise in the emission maps, but is consistent with grain growth in the higher density and lower temperature regions. By accounting for the variations in the dust emissivity and VSG emission, we are able to map the temperature and column density of a nearby molecular cloud with better accuracy than has previously been possible.

  15. Filaments in simulations of molecular cloud formation

    SciTech Connect (OSTI)

    Gómez, Gilberto C.; Vázquez-Semadeni, Enrique

    2014-08-20

    We report on the filaments that develop self-consistently in a new numerical simulation of cloud formation by colliding flows. As in previous studies, the forming cloud begins to undergo gravitational collapse because it rapidly acquires a mass much larger than the average Jeans mass. Thus, the collapse soon becomes nearly pressureless, proceeding along its shortest dimension first. This naturally produces filaments in the cloud and clumps within the filaments. The filaments are not in equilibrium at any time, but instead are long-lived flow features through which the gas flows from the cloud to the clumps. The filaments are long-lived because they accrete from their environment while simultaneously accreting onto the clumps within them; they are essentially the locus where the flow changes from accreting in two dimensions to accreting in one dimension. Moreover, the clumps also exhibit a hierarchical nature: the gas in a filament flows onto a main, central clump but other, smaller-scale clumps form along the infalling gas. Correspondingly, the velocity along the filament exhibits a hierarchy of jumps at the locations of the clumps. Two prominent filaments in the simulation have lengths ?15 pc and masses ?600 M {sub ?} above density n ? 10{sup 3} cm{sup –3} (?2 × 10{sup 3} M {sub ?} at n > 50 cm{sup –3}). The density profile exhibits a central flattened core of size ?0.3 pc and an envelope that decays as r {sup –2.5} in reasonable agreement with observations. Accretion onto the filament reaches a maximum linear density rate of ?30 M {sub ?} Myr{sup –1} pc{sup –1}.

  16. A Community Atmosphere Model with Superparameterized Clouds

    SciTech Connect (OSTI)

    Randall, David; Branson, Mark; Wang, Minghuai; Ghan, Steven J.; Craig, Cheryl; Gettelman, A.; Edwards, Jim

    2013-06-18

    In 1999, National Center for Atmospheric Research (NCAR) scientists Wojciech Grabowski and Piotr Smolarkiewicz created a "multiscale" atmospheric model in which the physical processes associated with clouds were represented by running a simple high-resolution model within each grid column of a lowresolution global model. In idealized experiments, they found that the multiscale model produced promising simulations of organized tropical convection, which other models had struggled to produce. Inspired by their results, Colorado State University (CSU) scientists Marat Khairoutdinov and David Randall created a multiscale version of the Community Atmosphere Model (CAM). They removed the cloud parameterizations of the CAM, and replaced them with Khairoutdinov's high-resolution cloud model. They dubbed the embedded cloud model a "super-parameterization," and the modified CAM is now called the "SP-CAM." Over the next several years, many scientists, from many institutions, have explored the ability of the SP-CAM to simulate tropical weather systems, the day-night changes of precipitation, the Asian and African monsoons, and a number of other climate processes. Cristiana Stan of the Center for Ocean-Land-Atmosphere Interactions found that the SP-CAM gives improved results when coupled to an ocean model, and follow-on studies have explored the SP-CAM's utility when used as the atmospheric component of the Community Earth System Model. Much of this research has been performed under the auspices of the Center for Multiscale Modeling of Atmospheric Processes, a National Science Foundation (NSF) Science and Technology Center for which the lead institution is CSU.

  17. A complex network approach to cloud computing

    E-Print Network [OSTI]

    Travieso, Gonzalo; Bruno, Odemir Martinez; Costa, Luciano da Fontoura

    2015-01-01

    Cloud computing has become an important means to speed up computing. One problem influencing heavily the performance of such systems is the choice of nodes as servers responsible for executing the users' tasks. In this article we report how complex networks can be used to model such a problem. More specifically, we investigate the performance of the processing respectively to cloud systems underlain by Erdos-Renyi and Barabasi-Albert topology containing two servers. Cloud networks involving two communities not necessarily of the same size are also considered in our analysis. The performance of each configuration is quantified in terms of two indices: the cost of communication between the user and the nearest server, and the balance of the distribution of tasks between the two servers. Regarding the latter index, the ER topology provides better performance than the BA case for smaller average degrees and opposite behavior for larger average degrees. With respect to the cost, smaller values are found in the BA ...

  18. Outflow Driven Turbulence in Molecular Clouds

    E-Print Network [OSTI]

    Jonathan J. Carroll; Adam Frank; Eric G. Blackman; Andrew J. Cunningham; Alice C. Quillen

    2008-05-30

    In this paper we explore the relationship between protostellar outflows and turbulence in molecular clouds. Using 3-D numerical simulations we focus on the hydrodynamics of multiple outflows interacting within a parsec scale volume. We explore the extent to which transient outflows injecting directed energy and momentum into a sub-volume of a molecular cloud can be converted into random turbulent motions. We show that turbulence can readily be sustained by these interactions and show that it is possible to broadly characterize an effective driving scale of the outflows. We compare the velocity spectrum obtained in our studies to that of isotropically forced hydrodynamic turbulence finding that in outflow driven turbulence a power law is indeed achieved. However we find a steeper spectrum (beta ~ 3) is obtained in outflow driven turbulence models than in isotropically forced simulations (beta ~ 2). We discuss possible physical mechanisms responsible for these results as well and their implications for turbulence in molecular clouds where outflows will act in concert with other processes such as gravitational collapse.

  19. Filament formation in wind-cloud interactions. I. Spherical clouds in uniform magnetic fields

    E-Print Network [OSTI]

    Banda-Barragán, Wladimir; Federrath, Christoph; Crocker, Roland; Bicknell, Geoffrey

    2015-01-01

    Filamentary structures are ubiquitous in the interstellar medium, yet their formation, internal structure, and longevity have not been studied in detail. We report the results from a comprehensive numerical study that investigates the characteristics, formation, and evolution of filaments arising from magnetohydrodynamic interactions between supersonic winds and dense clouds. Here we improve on previous simulations by utilising sharper density contrasts and higher numerical resolutions. By following multiple density tracers, we find that material in the envelopes of the clouds is removed and deposited downstream to form filamentary tails, while the cores of the clouds serve as footpoints and late-stage outer layers of these tails. Aspect ratios >12, subsonic velocity dispersions ~0.1-0.3 of the wind sound speed, and magnetic field amplifications ~100 are found to be characteristic of these filaments. We also report the effects of different magnetic field strengths and orientations. The magnetic field strength...

  20. Distances to Galactic high-velocity clouds. I. Cohen Stream, complex GCP, cloud g1

    E-Print Network [OSTI]

    B. P. Wakker; D. G. York; R. Wilhelm; J. C. Barentine; P. Richter; T. C. Beers; Z. Ivezic; J. C. Howk

    2007-09-12

    The high- and intermediate-velocity interstellar clouds (HVCs/IVCs) are tracers of energetic processes in and around the Milky Way. Clouds with near-solar metallicity about one kpc above the disk trace the circulation of material between disk and halo (the Galactic Fountain). The Magellanic Stream consists of gas tidally extracted from the SMC, tracing the dark matter potential of the Milky Way. Several other HVCs have low-metallicity and appear to trace the continuing accretion of infalling intergalactic gas. These assertions are supported by the metallicities (0.1 to 1 solar) measured for about ten clouds in the past decade. Direct measurements of distances to HVCs have remained elusive, however. In this paper we present four new distance brackets, using VLT observations of interstellar \\CaII H and K absorption toward distant Galactic halo stars. We derive distance brackets of 5.0 to 11.7 kpc for the Cohen Stream (likely to be an infalling low-metallicity cloud), 9.8 to 15.1 kpc for complex GCP (also known as the Smith Cloud or HVC40-15+100 and with still unknown origin), 1.0 to 2.7 kpc for an IVC that appears associated with the return flow of the Fountain in the Perseus Arm, and 1.8 to 3.8 kpc for cloud g1, which appears to be in the outflow phase of the Fountain. Our measurements further demonstrate that the Milky Way is accreting substantial amounts of gaseous material, which influences the Galaxy's current and future dynamical and chemical evolution.