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


1

Variations in Cloud Cover and Cloud Types over the Ocean from Surface Observations, 1954–2008  

Science Conference Proceedings (OSTI)

Synoptic weather observations from ships throughout the World Ocean have been analyzed to produce a climatology of total cloud cover and the amounts of nine cloud types. About 54 million observations contributed to the climatology, which now ...

Ryan Eastman; Stephen G. Warren; Carole J. Hahn

2011-11-01T23:59:59.000Z

2

Comparison of Cloud Cover from All-Sky Imager and Meteorological Observer  

Science Conference Proceedings (OSTI)

Naked-eye observation of cloud cover has widely resisted automation. Replacement of human observation by instruments is an inexorable trend for the development of ground-based macroscopic cloud observation. In this paper, cloud covers from an all-...

Juan Huo; Daren Lu

2012-08-01T23:59:59.000Z

3

A Survey of Changes in Cloud Cover and Cloud Types over Land from Surface Observations, 1971–96  

Science Conference Proceedings (OSTI)

From a dataset of weather observations from land stations worldwide, about 5400 stations were selected as having long periods of record with cloud-type information; they cover all continents and many islands. About 185 million synoptic reports ...

Stephen G. Warren; Ryan M. Eastman; Carole J. Hahn

2007-02-01T23:59:59.000Z

4

A Comparison of Ground and Satellite Observations of Cloud Cover  

Science Conference Proceedings (OSTI)

A processing scheme that determines cloud height and amount based on radiances from the Visible Infrared Spin Scan Radiometer Atmospheric Sounder (VAS) using a CO2 absorption technique has been installed on the National Environmental Satellite ...

Anthony J. Schreiner; Kathy I. Strabala; David A. Unger; W. Paul Menzel; Gary P. Ellrod; Jackson L. Pellet

1993-10-01T23:59:59.000Z

5

Evaluating the Cloud Cover Forecast of NCEP Global Forecast System with Satellite Observation  

E-Print Network (OSTI)

To assess the quality of daily cloud cover forecast generated by the operational global numeric model, the NCEP Global Forecast System (GFS), we compose a large sample with outputs from GFS model and satellite observations from the International Satellite Cloud Climatology Project (ISCCP) in the period of July 2004 to June 2008, to conduct a quantitative and systematic assessment of the performance of a cloud model that covers a relatively long range of time, basic cloud types, and in a global view. The evaluation has revealed the goodness of the model forecast, which further illustrates our completeness on understanding cloud generation mechanism. To quantity the result, we found a remarkably high correlation between the model forecasts and the satellite observations over the entire globe, with mean forecast error less than 15% in most areas. Considering a forecast within 30% difference to the observation to be a "good" one, we find that the probability for the GFS model to make good forecasts varies between...

Ye, Quanzhi

2011-01-01T23:59:59.000Z

6

Cloud-Cover Distributions and Correlations  

Science Conference Proceedings (OSTI)

Observations of cloud cover (in oktas or tenths) by ground-based observers have been studied to investigate the distribution of cloud-cover amounts and the correlation of cloud cover in time and space. The correlation between observations at the ...

P. A. Jones

1992-07-01T23:59:59.000Z

7

Short-Term Performance of MM5 with Cloud-Cover Assimilation from Satellite Observations  

Science Conference Proceedings (OSTI)

This study investigates the extent to which assimilating high-resolution remotely sensed cloud cover into the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) provides an ...

Ismail Yucel; W. James Shuttleworth; X. Gao; S. Sorooshian

2003-08-01T23:59:59.000Z

8

Temporal Changes in the Observed Relationship between Cloud Cover and Surface Air Temperature  

Science Conference Proceedings (OSTI)

The relationship between cloud cover and near-surface air temperature and its decadal changes are examined using the hourly synoptic data for the past four to six decades from five regions of the Northern Hemisphere: Canada, the United States, ...

Bomin Sun; Pavel Ya Groisman; Raymond S. Bradley; Frank T. Keimig

2000-12-01T23:59:59.000Z

9

Cloud Cover over the South Pole from Visual Observations, Satellite Retrievals, and Surface-Based Infrared Radiation Measurements  

Science Conference Proceedings (OSTI)

Estimates of cloud cover over the South Pole are presented from five different data sources: routine visual observations (1957–2004; Cvis), surface-based spectral infrared (IR) data (2001; CPAERI), surface-based broadband IR data (1994–2003; Cpyr)...

Michael S. Town; Von P. Walden; Stephen G. Warren

2007-02-01T23:59:59.000Z

10

The Diurnal Cycle of Cloud-Top Height and Cloud Cover over the Southeastern Pacific as Observed by GOES-10  

Science Conference Proceedings (OSTI)

The diurnal cycles in cloud-top height Htop and cloud fraction (CF) in the southeastern Pacific stratocumulus region were determined for October–November 2008 by analyzing data from Geostationary Operational Environmental Satellite-10 (GOES-10) ...

David Painemal; Patrick Minnis; Larry O'Neill

2013-08-01T23:59:59.000Z

11

Forecasting Cloud Cover and Atmospheric Seeing for Astronomical Observing: Application and Evaluation of the Global Forecast System  

E-Print Network (OSTI)

To explore the issue of performing a non-interactive numerical weather forecast with an operational global model in assist of astronomical observing, we use the Xu-Randall cloud scheme and the Trinquet-Vernin AXP seeing model with the global numerical output from the Global Forecast System to generate 3-72h forecasts for cloud coverage and atmospheric seeing, and compare them with sequence observations from 9 sites from different regions of the world with different climatic background in the period of January 2008 to December 2009. The evaluation shows that the proportion of prefect forecast of cloud cover forecast varies from ~50% to ~85%. The probability of cloud detection is estimated to be around ~30% to ~90%, while the false alarm rate is generally moderate and is much lower than the probability of detection in most cases. The seeing forecast has a moderate mean difference (absolute mean difference <0.3" in most cases) and root-mean-square-error or RMSE (0.2"-0.4" in most cases) comparing with the obs...

Ye, Q -z

2010-01-01T23:59:59.000Z

12

Cloud Cover and Climate Sensitivity  

Science Conference Proceedings (OSTI)

This study discusses how the sensitivity of climate may be affected by the variation of cloud cover based on the results from numerical experiments with a highly simplified, three-dimensional model of the atmospheric general circulation. The ...

Richard T. Wetherald; Syukuro Manabe

1980-07-01T23:59:59.000Z

13

Verification of Cloud Cover Forecast with Satellite Observation over West Africa  

Science Conference Proceedings (OSTI)

The 3-hourly brightness temperatures (BTs) at 10.8 ?m from the Meteosat Second Generation (MSG) satellite were used to document the cloud system variability over West Africa in the summer of 2006 and to evaluate the quality of the Méso-NH model ...

Nathalie Söhne; Jean-Pierre Chaboureau; Françoise Guichard

2008-11-01T23:59:59.000Z

14

Near-Global Observations of Low Clouds  

Science Conference Proceedings (OSTI)

This paper analyzes several near-global datasets of low cloud cover, including the the International Satellite Cloud Climatology Project (ISCCP) satellite observations, C. J. Hahn et al. surface-derived observations, and the National Centers for ...

Bryan C. Weare

2000-04-01T23:59:59.000Z

15

Tropical Thermostats and Low Cloud Cover  

Science Conference Proceedings (OSTI)

The ability of subtropical stratus low cloud cover to moderate or amplify the tropical response to climate forcing such as increased CO2 is considered. Cloud radiative forcing over the subtropics is parameterized using an empirical relation ...

R. L. Miller

1997-03-01T23:59:59.000Z

16

Two Years of Cloud Cover Statistics Using VAS  

Science Conference Proceedings (OSTI)

Statistics of cloud characteristics over North America have been accumulated for the past 2 yr. The frequency of cloud cover with the associated heights and infrared attenuation were charted using the C02 channel radiometric data from the VISSR ...

D. P. Wylie; W. P. Menzel

1989-04-01T23:59:59.000Z

17

“Overall” Cloud and Snow Cover Effects on Internal Climate Variables: The Use of Clear Sky Climatology  

Science Conference Proceedings (OSTI)

This paper is a continuation of empirical studies of cloud and snow cover effects on climate based on a blend of observational meteorological data for the past several decades. It employs the idea that the analysis of climate variability observed ...

Pavel Va Groisman; Eugene L. Genikhovich; Pan-Mao Zhai

1996-09-01T23:59:59.000Z

18

Climatological Data for Clouds Over the Globe from Surface Observations  

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

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

19

Atmospheric Moisture and Cloud Cover Characteristics Forecast by AMPS  

Science Conference Proceedings (OSTI)

Antarctic Mesoscale Prediction System (AMPS) forecasts of atmospheric moisture and cloud fraction (CF) are compared with observations at McMurdo and Amundsen–Scott South Pole station (hereafter, South Pole station) in Antarctica. Overall, it is ...

Ryan L. Fogt; David H. Bromwich

2008-10-01T23:59:59.000Z

20

On the Relationship between Stratiform Low Cloud Cover and Lower-Tropospheric Stability  

Science Conference Proceedings (OSTI)

Observations in subtropical regions show that stratiform low cloud cover is well correlated with the lower-troposphere stability (LTS), defined as the difference in potential temperature ? between the 700-hPa level and the surface. The LTS can be ...

Robert Wood; Christopher S. Bretherton

2006-12-01T23:59:59.000Z

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


21

Regional Cloud Cover Change Associated with Global Climate Change: Case Studies for Three Regions of the United States  

Science Conference Proceedings (OSTI)

Land-based observations of cloud cover, for the period 1900–87 and averaged over three geographical regions of the United States (coastal southwest, coastal northeast, and southern plains), show strong positive correlations with one estimate of ...

Meredith S. Croke; Robert D. Cess; Sultan Hameed

1999-07-01T23:59:59.000Z

22

Boundary Layer and Cloud Structure Controls on Tropical Low Cloud Cover Using A-Train Satellite Data and ECMWF Analyses  

Science Conference Proceedings (OSTI)

The Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), CloudSat radar, and the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud data on the A-Train constellation complemented with the European Centre for ...

Terence L. Kubar; Duane E. Waliser; J-L. Li

2011-01-01T23:59:59.000Z

23

Climatological Data For Clouds Over the Globe From Surface Observations,  

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

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

24

Accounting for Circumsolar and Horizon Cloud Determination Errors in Sky Image Inferral of Sky Cover  

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

Accounting for Circumsolar and Horizon Cloud Determination Errors in Sky Accounting for Circumsolar and Horizon Cloud Determination Errors in Sky Image Inferral of Sky Cover. C. N. Long, Pacific Northwest National Laboratory 1) Introduction In observing the cloudless sky, one can often notice that the area near the sun is whiter and brighter than the rest of the hemisphere. Additionally, even a slight haze will make a large angular area of the horizon whiter and brighter when the sun is low on the horizon. The human eye has an amazing ability to handle a range of light intensity spanning orders of magnitude. But one of the persistent problems in using sky images to infer fractional sky cover is the intensity range limitations of the camera detector. It is desirable to have bright enough images to be able to detect thin clouds, yet this often means the part of the image near the

25

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

Science Conference Proceedings (OSTI)

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

Adrian M. Tompkins

2002-06-01T23:59:59.000Z

26

Satellite-Observed Reflectance of Snow and Clouds  

Science Conference Proceedings (OSTI)

The effects of snow and cloud cover on bidirectional reflectance were examined using visible radiation (0.5–0.7 ?m) data measured by NOAA polar orbiting satellites between June 1974 and February 1978. Reflectances resulting from different cloud/...

Alan Robock; Dale Kaiser

1985-11-01T23:59:59.000Z

27

Observations of Liquid Water in Orographic Clouds over Elk Mountain  

Science Conference Proceedings (OSTI)

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

Marcia K. Politovich; Gabor Vali

1983-05-01T23:59:59.000Z

28

Cloud Top Liquid Water from Lidar Observations of Marine Stratocumulus  

Science Conference Proceedings (OSTI)

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

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

1989-02-01T23:59:59.000Z

29

ISCCP Cloud Properties Associated with Standard Cloud Types Identified in Individual Surface Observations  

Science Conference Proceedings (OSTI)

Individual surface weather observations from land stations and ships are compared with individual cloud retrievals of the International Satellite Cloud Climatology Project (ISCCP), stage C1, for an 8-yr period (1983–91) to relate cloud optical ...

Carole J. Hahn; William B. Rossow; Stephen G. Warren

2001-01-01T23:59:59.000Z

30

Observed Relationships between Arctic Longwave Cloud Forcing and Cloud Parameters Using a Neural Network  

Science Conference Proceedings (OSTI)

A neural network technique is used to quantify relationships involved in cloud–radiation feedbacks based on observations from the Surface Heat Budget of the Arctic (SHEBA) project. Sensitivities of longwave cloud forcing (CFL) to cloud parameters ...

Yonghua Chen; Filipe Aires; Jennifer A. Francis; James R. Miller

2006-08-01T23:59:59.000Z

31

More Observations of Small Funnel Clouds and Other Tubular Clouds  

Science Conference Proceedings (OSTI)

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

Howard B. Bluestein

2005-12-01T23:59:59.000Z

32

Observations of Cloud-Top Entrainment in Marine Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

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

Qing Wang; Bruce A. Albrecht

1994-06-01T23:59:59.000Z

33

Time-varying biases in U.S. total cloud cover data  

Science Conference Proceedings (OSTI)

This paper presents evidence of significant discontinuities in U. S. cloud cover data from the Integrated Surface Database (ISD) and its predecessor datasets. While long-term U.S. cloud records have some well-known homogeneity problems related to ...

Melissa Free; Bomin Sun

34

Impact of Ingesting Satellite-Derived Cloud Cover into the Regional Atmospheric Modeling System  

Science Conference Proceedings (OSTI)

This study investigates the extent to which assimilating high-resolution remotely sensed cloud cover into the Regional Atmospheric Modeling System (RAMS) provides an improved regional diagnosis of downward short- and longwave surface radiation ...

Ismail Yucel; W. James Shuttleworth; R. T. Pinker; L. Lu; S. Sorooshian

2002-03-01T23:59:59.000Z

35

The Influence of Changes in Cloud Cover on Recent Surface Temperature Trends in the Arctic  

Science Conference Proceedings (OSTI)

A method is presented to assess the influence of changes in Arctic cloud cover on the surface temperature trend, allowing for a more robust diagnosis of causes for surface warming or cooling. Seasonal trends in satellite-derived Arctic surface ...

Yinghui Liu; Jeffrey R. Key; Xuanji Wang

2008-02-01T23:59:59.000Z

36

Assimilation of ERBE Data with a Nonlinear Programming Technique to Improve Cloud-Cover Diagnosis  

Science Conference Proceedings (OSTI)

A method is developed to assimilate satellite data for the purpose of improving the diagnosis of fractional cloud cover within a numerical weather prediction model. The method makes use of a nonlinear programming technique to find a set of ...

Xiangqian Wu; William L. Smith

1992-09-01T23:59:59.000Z

37

Automatic Cloud Tracking Applied to GOES and METEOSAT Observations  

Science Conference Proceedings (OSTI)

Improvements to the SRI automatic cloud-tracking system are described that enable it to operate on multilayer clouds associated with severe storms. The improved method has been tested using rapid-scan observations of Hurricane Eloise obtained by ...

Roy M. Endlich; Daniel E. Wolf

1981-03-01T23:59:59.000Z

38

Combined Satellite- and Surface-Based Observations of Clouds  

Science Conference Proceedings (OSTI)

A new method for combining satellite and surface-based cloud observations into a self-consistent three-dimensional field is presented. This method derives the probabilities of the cloud states, which are most consistent with all of the ...

Bryan C. Weare

1999-03-01T23:59:59.000Z

39

Longwave Cloud Radiative Forcing as Determined from Nimbus-7 Observations  

Science Conference Proceedings (OSTI)

Collocated and coincident cloud and outgoing longwave radiation observations taken by experiments on board the Nimbus-7 satellite have been used to infer the daytime longwave cloud-radiative forcing. Through the specification of a time-series of ...

Philip E. Ardanuy; Larry L. Stowe; Arnold Gruber; Mitchell Weiss; Craig S. Long

1989-08-01T23:59:59.000Z

40

The Mysteries of Mammatus Clouds: Observations and Formation Mechanisms  

Science Conference Proceedings (OSTI)

Mammatus clouds are an intriguing enigma of atmospheric fluid dynamics and cloud physics. Most commonly observed on the underside of cumulonimbus anvils, mammatus also occur on the underside of cirrus, cirrocumulus, altocumulus, altostratus, and ...

David M. Schultz; Katharine M. Kanak; Jerry M. Straka; Robert J. Trapp; Brent A. Gordon; Dusan S. Zrni?; George H. Bryan; Adam J. Durant; Timothy J. Garrett; Petra M. Klein; Douglas K. Lilly

2006-10-01T23:59:59.000Z

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


41

Aircraft Observations of Ice Crystal Evolution in an Altostratus Cloud  

Science Conference Proceedings (OSTI)

Observations from a Lagrangian spiral descent within altostratus cloud associated with a cold front were used to study the evolution of ice particle spectra by following populations of ice crystals as they fell through the cloud. The flight track ...

Paul R. Field

1999-06-01T23:59:59.000Z

42

Relating Satellite-Observed Cloud Properties from MODIS to Meteorological Conditions for Marine Boundary Layer Clouds  

Science Conference Proceedings (OSTI)

This study examines 6 yr of cloud properties observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the NASA Terra satellite in five prominent marine boundary layer (MBL) cloud regions (California, Peru, Canary, Angola, ...

Guang J. Zhang; Andrew M. Vogelmann; Michael P. Jensen; William D. Collins; Edward P. Luke

2010-03-01T23:59:59.000Z

43

Properties of Tropical Cloud Ensembles Estimated Using a Cloud Model and an Observed Updraft Population  

Science Conference Proceedings (OSTI)

A simple cloud model is developed which is designed for both diagnostic studies and mesoscale cumulus parameterization experiments. The cloud model is combined with an observed population of tropical convective updrafts and used to examine the ...

William M. Frank; Charles Cohen

1985-09-01T23:59:59.000Z

44

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

Science Conference Proceedings (OSTI)

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

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

2003-02-01T23:59:59.000Z

45

The distribution of cloud cover over the former USSR as derived from the RIHMI 223-Station 3-hourly meteorological database  

SciTech Connect

In recent years a great deal of meteorological and climatological data has been exchanged between the two principal climate data centers of the United States and the former Soviet Union: the National Climatic Data Center (NCDC), in Asheville, North Carolina, and the Research Institute of Hydrometeorological Information (RIHMI) in Obninsk, Russia. This was accomplished via Working Group VIB (Influence of Environmental Changes on Climate) of the bilateral initiative known as the Agreement on Protection of the Environment, established on May 23, 1972 by the United States and the USSR. One of the key datasets compiled by RIHMI includes 3-hourly meteorological observations from 223 USSR stations for the period 1966-83. RIHMI has chosen to use daily and hourly data from these stations as the basis for considerable climate research efforts. These data (hereafter referred to as the RIHMI database) will soon be made available by both NCDC and the Department of Energy`s Carbon Dioxide Information Analysis Center (CDIAC) in Oak Ridge, Tennessee. The data have undergone extensive quality assurance checks at RIHMI, NCDC, and CDIAC. The data contain observations of some 22 meteorological variables, including near-surface air temperature, sea level pressure, precipitation amount, weather type, and total cloud cover. This study uses the RIHMI database to examine the spatial distribution of total cloud cover over the former USSR (hereafter referred to as the USSR). In this initial assessment, we focus on comparing our results with total cloud cover data presented in the atlas: Global Distribution of Total Cloud Cover and Cloud Type Amounts Over Land for the common data period 1971-81.

Kaiser, D.P.; Vose, R.S. [Oak Ridge National Lab., TN (United States); Karl, T.R. [National Climatic Data Center, Asheville, NC (United States); Razuvaev, V.N. [Research Institute of Hydrometeorological Information, Obninsk (Russian Federation)

1995-02-01T23:59:59.000Z

46

Observations of chemical differentiation in clumpy molecular clouds  

E-Print Network (OSTI)

We have extensively mapped a sample of dense molecular clouds (L1512, TMC-1C, L1262, Per 7, L1389, L1251E) in lines of HC3N, CH3OH, SO and C^{18}O. We demonstrate that a high degree of chemical differentiation is present in all of the observed clouds. We analyse the molecular maps for each cloud, demonstrating a systematic chemical differentiation across the sample, which we relate to the evolutionary state of the cloud. We relate our observations to the cloud physical, kinematical and evolutionary properties, and also compare them to the predictions of simple chemical models. The implications of this work for understanding the origin of the clumpy structures and chemical differentiation observed in dense clouds are discussed.

J. V. Buckle; S. D. Rodgers; E. S. Wirström; S. B. Charnley; A. J. Markwick-Kemper; H. M. Butner; S. Takakuwa

2007-04-09T23:59:59.000Z

47

Observations of Marine Stratocumulus Clouds During FIRE  

Science Conference Proceedings (OSTI)

During June and July 1987, a major collaborative experiment (part of The First ISCCP [International Satellite Cloud Climatology Project] Regional Experiment (FIRE) took place off the coast of California to study the extensive fields of ...

Bruce A. Albrecht; David A. Randall; Stephen Nicholls

1988-06-01T23:59:59.000Z

48

Estimating Cloud Type from Pyranometer Observations  

Science Conference Proceedings (OSTI)

In this paper the authors evaluate an inexpensive and automatable method to estimate cloud type at a given location during daylight hours using the time series of irradiance from a pyranometer. The motivation for this investigation is to provide ...

Claude E. Duchon; Mark S. O’Malley

1999-01-01T23:59:59.000Z

49

Cirriform Rotor Cloud Observed on a Canadian Arctic Ice Cap  

Science Conference Proceedings (OSTI)

A thin rotor cloud was observed on the lee side of Penny Ice Cap in the Canadian Arctic on 21 April 1996. The cloud consisted of thin cirriform layers, so that its motion was clearly observed. By means of time-lapse camera photography, the ...

Hisashi Ozawa; Kumiko Goto-Azuma; Koyuru Iwanami; Roy M. Koerner

1998-06-01T23:59:59.000Z

50

Radiosonde observations at Pt. Reyes and cloud properties retrieved from  

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

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

51

The Effect of Clouds on Air Showers Observation from Space  

E-Print Network (OSTI)

Issues relating to extensive air showers observation by a space-borne fluorescence detector and the effects of clouds on the observations are investigated using Monte Carlo simulation. The simulations assume the presence of clouds with varying altitudes and optical depths. Simulated events are reconstructed assuming a cloud-free atmosphere. While it is anticipated that auxiliary instruments, such as LIDAR (LIght Detection And Ranging), will be employed to measure the atmospheric conditions during actual observation, it is still possible that these instruments may fail to recognize the presence of a cloud in a particular shower observation. The purpose of this study is to investigate the effects on the reconstructed shower parameters in such cases. Reconstruction results are shown for both monocular and stereo detectors and for the two limiting cases of optically thin, and optically thick clouds.

T. Abu-Zayyad; C. C. H. Jui; E. C. Loh

2003-10-28T23:59:59.000Z

52

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

Science Conference Proceedings (OSTI)

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

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

1995-08-01T23:59:59.000Z

53

Seasonal and Diurnal Changes in Cirrus Clouds as Seen in Four Years of Observations with the VAS  

Science Conference Proceedings (OSTI)

GOES VAS multispectral observations in the carbon dioxide absorption band at 15 ?m have been used to compile cloud-cover statistics over the continental United States for the past 4 years. The CO2 technique calculates both cloud-top pressures and ...

W. P. Menzel; D. P. Wylie; K. I. Strabala

1992-04-01T23:59:59.000Z

54

Observed Microphysical Structure of Midlevel, Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

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

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

2002-06-01T23:59:59.000Z

55

Thunderstorm Cloud Top Observations Using Satellite Stereoscopy  

Science Conference Proceedings (OSTI)

GOES stereoscopy is applied to the study of severe squall line cells. Short interval (3 min) GOES stereoscopic data from the 2–3 May 1979 SESAME case were used to measure cloud top heights of growing storms as a function of time. A one-...

Robert A. Mack; A. F. Hasler; Robert F. Adler

1983-10-01T23:59:59.000Z

56

Relating Cirrus Cloud Properties to Observed Fluxes: A Critical Assessment  

Science Conference Proceedings (OSTI)

The accuracy needed in cirrus cloud scattering and microphysical properties is quantified such that the radiative effect on climate can he determined. Our ability to compute and observe these properties to within needed accuracies is assessed, ...

A. M. Vogelmann; T. P. Ackerman

1995-12-01T23:59:59.000Z

57

A 94-GHz Doppler Radar for Cloud Observations  

Science Conference Proceedings (OSTI)

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

Roger Lhermitte

1987-03-01T23:59:59.000Z

58

Observations of a Cloud Are Triggered by Thunderstorm Outflow  

Science Conference Proceedings (OSTI)

This paper presents aircraft, radar, satellite and rawinsonde observations which describe a cloud am formed by moist downdraft outflow from a cumulonimbus cluster in northwest Kansas. Aircraft cross sections are presented of four variables at 160 ...

David A. Matthews

1981-10-01T23:59:59.000Z

59

Combined System for Observations of Tropospheric and Stratospheric Thin Clouds  

Science Conference Proceedings (OSTI)

A balloonborne sonde and a polarization lidar have been developed to make combined observations of thin tropospheric and stratospheric clouds. In their first application these instruments have been used in a campaign organized to study Antarctic ...

A. Adriani; G. P. Gobbi; M. Viterbini; S. Ugazio

1993-02-01T23:59:59.000Z

60

Distribution and Validation of Cloud Cover Derived from AVHRR Data Over the Arctic Ocean During the SHEBA Year  

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

and Validation of Cloud Cover and Validation of Cloud Cover Derived from AVHRR Data Over the Arctic Ocean During the SHEBA Year P. Minnis National Aeronautics and Space Administration Langley Research Center Hampton, Virginia D. A. Spangenberg and V. Chakrapani Analytical Services and Materials, Inc. Hampton, Virginia Introduction Determination of cloud radiation interactions over large areas of the Arctic is possible only with the use of data from polar orbiting satellites. Cloud detection using satellite data is difficult in the Arctic due to the minimal contrast between clouds and the underlying snow surface in visible and infrared wavelengths. Polar clouds are frequently warmer or at the same brightness temperature as the background surface, complicating cloud detection. The brightness temperature differences between the

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


61

Cloud-state-dependent Sampling in AIRS Observations based on CloudSat Cloud Classification  

Science Conference Proceedings (OSTI)

The precision, accuracy, and potential sampling biases of temperature (T) and water vapor (q) vertical profiles obtained by satellite infrared sounding instruments are highly cloud-state dependent and poorly quantified. We describe progress ...

Qing Yue; Eric J. Fetzer; Brian H. Kahn; Sun Wong; Gerald Manipon; Alexandre Guillaume; Brian Wilson

62

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

E-Print Network (OSTI)

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

63

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

SciTech Connect

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

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

2005-03-18T23:59:59.000Z

64

Statistical Dependence of Albedo and Cloud Cover on Sea Surface Temperature for Two Tropical Marine Stratocumulus Regions  

Science Conference Proceedings (OSTI)

The relationship between sea surface temperature (SST) and albedo or cloud cover is examined for two tropical regions with high values of cloud radiative forcing and persistent marine stratocumulus (mSc)–one off the west coast of Peru, the other ...

Lazaros Oreopoulos; Roger Davies

1993-12-01T23:59:59.000Z

65

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

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

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

66

Diagnosis of the Warm Rain Process in Cloud-Resolving Models Using Joint CloudSat and MODIS Observations  

Science Conference Proceedings (OSTI)

This study examines the warm rain formation process in global and regional cloud-resolving models. Methodologies developed to analyze CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations are employed to ...

Kentaroh Suzuki; Graeme L. Stephens; Susan C. van den Heever; Takashi Y. Nakajima

2011-11-01T23:59:59.000Z

67

Particle Growth and Drop Collection Efficiency of Warm Clouds as Inferred from Joint CloudSat and MODIS Observations  

Science Conference Proceedings (OSTI)

This study describes an approach for combining CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations to investigate the microphysical processes of warm clouds on the global scale. MODIS column optical thickness ...

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

2010-09-01T23:59:59.000Z

68

Cloud Diabatic Forcing of the Atmosphere, Estimated from Simultaneous ECMWF Diabatic Heating and ISCCP Cloud Amount Observations  

Science Conference Proceedings (OSTI)

The cloud diabatic forcing (CDF) of the atmosphere, defined as the difference between the diabatic heating in average and in clear-sky conditions is estimated from time series of simultaneous observations of diabatic heating and cloud amount. The ...

Peter Siegmund

1993-12-01T23:59:59.000Z

69

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

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

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

70

Observational and Model Estimates of Cloud Amount Feedback over the Indian and Pacific Oceans  

Science Conference Proceedings (OSTI)

Constraining intermodel spread in cloud feedback with observations is problematic because available cloud datasets are affected by spurious behavior in long-term variability. This problem is addressed by examining cloud amount in three independent ...

Katinka Bellomo; Amy C. Clement; Joel R. Norris; Brian J. Soden

2014-01-01T23:59:59.000Z

71

The Effect of Cloud Sides on Reflected Solar Radiation as Deduced from Satellite Observations  

Science Conference Proceedings (OSTI)

We report the observation of a feature that is characteristic of the reflection of solar radiation from absorbing, finite clouds. When absorption takes place, more radiation can be reflected by broken cloud fields than by extensive unbroken cloud ...

James A. Coakley Jr.; Roger Davies

1986-05-01T23:59:59.000Z

72

HIGH-RESOLUTION CH OBSERVATIONS OF TWO TRANSLUCENT MOLECULAR CLOUDS  

SciTech Connect

We present high-resolution (1.'3 x 1.'6) observations of the CH {sup 2}{pi}{sub 1/2} (F = 1-1) emission line at 3335 MHz in two high-latitude translucent clouds, MBM 3 and 40. At the assumed cloud distances, the angular resolution corresponds to {approx}0.05 pc, nearly an order of magnitude better than previous studies. Comparisons of the CH emission with previously obtained CO(1-0) data are difficult to interpret: the CO and CH line emission correlates in MBM 40 but not in MBM 3. In both clouds, there is a spatial offset in the peak emission, and perhaps in velocity for MBM 40. The difference in emission characteristics for the two tracers are noticeable in these two nearby clouds because of the high spatial resolution. Since both CH and CO are deemed to be reliable tracers of H{sub 2}, our results indicate that more care should be taken when using one of these tracers to determine the mass of a nearby molecular cloud.

Chastain, Raymond J. [Department of Physics and Astronomy, Louisiana State University, 368 Nicholson Hall, Tower Dr. Baton Rouge, LA 70803 (United States); Cotten, David; Magnani, Loris [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

2010-01-15T23:59:59.000Z

73

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

E-Print Network (OSTI)

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, central Saudi Arabia and Istanbul, Turkey, respectively. A set of 24 pairs of sub-cloud aerosol and cloud penetration data are analyzed. Measurements of fine and coarse mode aerosol concentrations from 3 different instruments were combined and fitted with lognormal distributions. The fit parameters of the lognormal distributions are compared with cloud droplet effective radii retrieved from 260 cloud penetrations. Cloud condensation nuclei (CCN) measurements for a subset of 10 cases from the Istanbul region are compared with concentrations predicted from aerosol size distributions. Ammonium sulfate was assumed to represent the soluble component of aerosol with dry sizes smaller than 0.5 mm and sodium chloride for aerosol larger than 0.5 mm. The measured CCN spectrum was used to estimate the soluble fraction. The correlations of the measured CCN concentration with the predicted CCN concentration were strong (R2 > 0.89) for supersaturations of 0.2, 0.3 and 0.6%. The measured concentrations were typically consistent with an aerosol having a soluble fraction between roughly 0.5 and 1.0, suggesting a contribution of sulfate or some other similarly soluble inorganic compound. The predicted CCN were found to vary by +or-3.7% when the soluble fraction was varied by 0.1. Cumulative aerosol concentrations at cutoff dry diameters of 1.1, 0.1 and 0.06 mm were found to be correlated with cloud condensation nuclei concentrations but not with maximum cloud base droplet concentrations. It is also shown that in some cases the predominant mechanisms involved in the formation of precipitation were altered and modified by the aerosol properties. This study suggests that CCN-forced variations in cloud droplet number concentration can change the effective radius profile and the type of precipitation hydrometeors. These differences may have a major impact on the global hydrological cycle and energy budget.

Axisa, Duncan

2009-12-01T23:59:59.000Z

74

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

Science Conference Proceedings (OSTI)

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

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

2010-06-01T23:59:59.000Z

75

Variations in Low Cloud Cover over the United States during the Second Half of the Twentieth Century  

Science Conference Proceedings (OSTI)

Several changes in U.S. observational practice [in particular, the introduction of the Automated Surface Observing System (ASOS) in the early 1990s] have led to a challenging heterogeneity of time series of most ground-based cloud observations. ...

Bomin Sun; Pavel Ya Groisman

2004-05-01T23:59:59.000Z

76

A Comparison of Cloud Cover Statistics from the GLAS Lidar with HIRS  

Science Conference Proceedings (OSTI)

The cloud dataset from the Geoscience Laser Altimeter System (GLAS) lidar on the Ice, Cloud, and Land Elevation Satellite (ICESat) spacecraft is compared to the cloud analysis of the Wisconsin NOAA High Resolution Infrared Radiation Sounder (HIRS)...

Donald Wylie; Edwin Eloranta; James D. Spinhirne; Steven P. Palm

2007-10-01T23:59:59.000Z

77

Estimating Three-Dimensional Cloud Structure via Statistically Blended Satellite Observations  

Science Conference Proceedings (OSTI)

The launch of the NASA CloudSat in April 2006 enabled the first satellite-based global observation of vertically-resolved cloud information. However, CloudSat’s non-scanning W-band (94 GHz) Cloud Profiling Radar (CPR) provides only a nadir cross-...

Steven D. Miller; John M. Forsythe; Philip T. Partain; John M. Haynes; Richard L. Bankert; Manajit Sengupta; Cristian Mitrescu; Jeffrey D. Hawkins; Thomas H. Vonder Haar

78

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

E-Print Network (OSTI)

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

79

Racoro Extended-Term Aircraft Observations of Boundary Layer Clouds  

Science Conference Proceedings (OSTI)

A first-of-a-kind, extended-term cloud aircraft campaign was conducted to obtain an in situ statistical characterization of continental boundary layer clouds needed to investigate cloud processes and refine retrieval algorithms. Coordinated by the ...

Andrew M. Vogelmann; Greg M. McFarquhar; John A. Ogren; David D. Turner; Jennifer M. Comstock; Graham Feingold; Charles N. Long; Haflidi H. Jonsson; Anthony Bucholtz; Don R. Collins; Glenn S. Diskin; Hermann Gerber; R. Paul Lawson; Roy K. Woods; Elisabeth Andrews; Hee-Jung Yang; J. Christine Chiu; Daniel Hartsock; John M. Hubbe; Chaomei Lo; Alexander Marshak; Justin W. Monroe; Sally A. McFarlane; Beat Schmid; Jason M. Tomlinson; Tami Toto

2012-06-01T23:59:59.000Z

80

Aerosol Remote Sensing over Clouds Using A-Train Observations  

Science Conference Proceedings (OSTI)

The detection of aerosol above clouds is critical for the estimate of both the aerosol and cloud radiative impacts. In this study, the authors present a new method to retrieve the aerosol properties over clouds that uses the multiangle ...

F. Waquet; J. Riedi; L. C. Labonnote; P. Goloub; B. Cairns; J-L. Deuzé; D. Tanré

2009-08-01T23:59:59.000Z

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


81

Low Cloud Type over the Ocean from Surface Observations. Part II: Geographical and Seasonal Variations  

Science Conference Proceedings (OSTI)

Synoptic surface cloud observations primarily made by volunteer observing ships are used to construct global climatologies of the frequency of occurrence of individual low cloud types over the ocean for daytime during summer and winter seasons ...

Joel R. Norris

1998-03-01T23:59:59.000Z

82

Comparison of an Experimental NOAA AVHRR Cloud Dataset with Other Observed and Forecast Cloud Datasets  

Science Conference Proceedings (OSTI)

CLAVR [cloud from AVHRR (Advanced Very High Resolution Radiometer)] is a global cloud dataset under development at NOAA/NESDIS (National Environmental Satellite, Data, and Information Service). Total cloud amount from two experimental cases, 9 ...

Yu-Tai Hou; Kenneth A. Campana; Kenneth E. Mitchell; Shi-Keng Yang; Larry L. Stowe

1993-12-01T23:59:59.000Z

83

LIRAD Observations of Tropical Cirrus Clouds in MCTEX. Part II: Optical Properties and Base Cooling in Dissipating Storm Anvil Clouds  

Science Conference Proceedings (OSTI)

During the Maritime Continent Thunderstorm Experiment (MCTEX), several decaying storm anvils were observed. The anvil clouds exhibited typical patterns of fallout and decay over a number of hours of observation. The anvil bases were initially ...

C. M. R. Platt; R. T. Austin; S. A. Young; A. J. Heymsfield

2002-11-01T23:59:59.000Z

84

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

SciTech Connect

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

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

2008-02-27T23:59:59.000Z

85

High and Dry: New Observations of Tropospheric and Cloud Properties above the Greenland Ice Sheet  

Science Conference Proceedings (OSTI)

Cloud and atmospheric properties strongly influence the mass and energy budgets of the Greenland Ice Sheet (GIS). To address critical gaps in the understanding of these systems, a new suite of cloud- and atmosphere-observing instruments has been installed ...

Matthew D. Shupe; David D. Turner; Von P. Walden; Ralf Bennartz; Maria P. Cadeddu; Benjamin B. Castellani; Christopher J. Cox; David R. Hudak; Mark S. Kulie; Nathaniel B. Miller; Ryan R. Neely; III; William D. Neff; Penny M. Rowe

2013-02-01T23:59:59.000Z

86

On the Observed Near Cancellation between Longwave and Shortwave Cloud Forcing in Tropical Regions  

Science Conference Proceedings (OSTI)

Observations based on Earth Radiation Budget Experiment (ERBE) satellite data indicate that there is a near cancellation between tropical longwave and shortwave cloud forcing in regions of deep convective activity. Cloud forcing depends on both ...

J. T. Kiehl

1994-04-01T23:59:59.000Z

87

A Cirrus-Cloud Experiment: Intensive Field Observations Planned for Fire  

Science Conference Proceedings (OSTI)

Plans for an intensive cirrus-cloud field experiment are described. The Cirrus Intensive Field Observations (Citrus IFO) is a major component of the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE). The ...

David O'C. Starr

1987-02-01T23:59:59.000Z

88

Calculating Monthly Radiative Fluxes and Heating Rates fromMonthly Cloud Observations  

Science Conference Proceedings (OSTI)

The radiative transfer model from NCAR’s general circulation model CCM3 is modified to calculate monthly radiative fluxes and heating rates from monthly observations of cloud properties from the International Satellite Cloud Climatology Project ...

John W. Bergman; Harry H. Hendon

1998-12-01T23:59:59.000Z

89

Retrieval of Aerosol Optical Depth above Clouds from OMI Observations: Sensitivity Analysis and Case Studies  

Science Conference Proceedings (OSTI)

A large fraction of the atmospheric aerosol load reaching the free troposphere is frequently located above low clouds. Most commonly observed aerosols above clouds are carbonaceous particles generally associated with biomass burning and boreal ...

Omar Torres; Hiren Jethva; P. K. Bhartia

2012-03-01T23:59:59.000Z

90

The Refractive Index Spectra within Clouds from Forward-Scatter Radar Observations  

Science Conference Proceedings (OSTI)

When long-wavelength radars are used to observe the atmosphere, there are occasions when radar return from a volume of cloud is unexpectedly large relative to that predicted by the classical incoherent scatter from individual cloud droplets. The ...

Earl E. Gossard; Richard G. Strauch

1981-02-01T23:59:59.000Z

91

Multiyear Observations of Cloud Lines Associated with the Chesapeake and Delaware Bays  

Science Conference Proceedings (OSTI)

Satellite and corresponding near-surface in situ observations have been made of single- and dual-band cloud events [dubbed anomalous cloud lines (ACLs)] associated with the Chesapeake and Delaware Bays. A previous study developed the basis for ...

Todd D. Sikora; David M. Halverson

2002-08-01T23:59:59.000Z

92

Size Distributions and Dynamical Properties of Shallow Cumulus Clouds from Aircraft Observations and Satellite Data  

Science Conference Proceedings (OSTI)

In this paper aircraft observations of shallow cumulus over Florida during the Small Cumulus Microphysics Study (SCMS) are analyzed. Size distributions of cloud fraction, mass flux, and in-cloud buoyancy flux are derived. These distributions ...

Stefaan M. A. Rodts; Peter G. Duynkerke; Harm J. J. Jonker

2003-08-01T23:59:59.000Z

93

Cluster Analysis of Cloud Properties over the Southern European Mediterranean Area in Observations and a Model  

Science Conference Proceedings (OSTI)

This paper demonstrates how satellite observations of the cloudiness over a complex area such as the European Mediterranean area can be classified into distinct cloud regimes by application of a K-means clustering algorithm to pixel-level cloud ...

Frédérique Chéruy; Filipe Aires

2009-10-01T23:59:59.000Z

94

Observations and Model Simulations of Transport and Precipitation Development in a Seeded Cumulus Congestus Cloud  

Science Conference Proceedings (OSTI)

Observations made by three instrumented aircraft, a Doppler radar, and other data sources were used to follow the initiation and development of precipitation in a small cumulus congestus cloud. The cloud was seeded at its base using an airborne ...

Michael W. Huston; Andrew G. Detwiler; Fred J. Kopp; Jeffrey L. Stith

1991-10-01T23:59:59.000Z

95

Evaluation of MM5 Optically Thin Clouds over Europe in Fall Using ICESat Lidar Spaceborne Observations  

Science Conference Proceedings (OSTI)

The description of clouds in mesoscale models has progressed significantly during recent years by improving microphysical schemes with more physical parameterizations deduced from observations. Recently, the first lidar in space, the Ice, Cloud, ...

H. Chepfer; M. Chiriaco; R. Vautard; J. Spinhirne

2007-07-01T23:59:59.000Z

96

Observation of Magnetic Resonances in Electron Clouds in a Positron Storage Ring  

SciTech Connect

The first experimental observation of magnetic resonances in electron clouds is reported. The resonance was observed as a modulation in cloud intensity for uncoated as well as TiN-coated aluminum surfaces in the positron storage ring of the PEP-II collider at SLAC. Electron clouds frequently arise in accelerators of positively charged particles, and severely impact the machines performance. The TiN coating was found to be an effective remedy, reducing the cloud intensity by three orders of magnitude.

Pivi, M.T.F.; Ng, J.S.T.; Cooper, F.; Kharakh, D.; King, F.; Kirby, R.E.; Kuekan, B.; Spencer, Cherrill M.; Raubenheimer, T.O.; Wang, L.F.; /SLAC

2011-08-24T23:59:59.000Z

97

Alteration of Atmospheric Solar Absorption by Clouds: Simulation and Observation  

Science Conference Proceedings (OSTI)

This study investigated theoretically and experimentally two parameters employed in recent attempts to address cloud absorption anomaly. One is the ratio, R, of shortwave cloud radiative forcing (CRF) at the surface to that at the top of the ...

Zhanqing Li; Louis Moreau

1996-05-01T23:59:59.000Z

98

Aircraft Observations of Transport and Diffusion in Cumulus Clouds  

Science Conference Proceedings (OSTI)

A gaseous tracer, sulfur hexafluoride, was used to follow the path of two different AgI cloud seeding aerosols in cumulus clouds. The materials were released at cloud base or midlevels. Plumes sampled at midlevels were found to be relatively ...

Jeffrey L. Stith; Don A. Griffith; R. Lynn Rose; John A. Flueck; James R. Miller Jr.; Paul L. Smith

1986-12-01T23:59:59.000Z

99

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

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

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

100

Reconciling Simulated and Observed Views of Clouds: MODIS, ISCCP, and the Limits of Instrument Simulators  

Science Conference Proceedings (OSTI)

The properties of clouds that may be observed by satellite instruments, such as optical thickness and cloud-top pressure, are only loosely related to the way clouds are represented in models of the atmosphere. One way to bridge this gap is through ...

Robert Pincus; Steven Platnick; Steven A. Ackerman; Richard S. Hemler; Robert J. Patrick Hofmann

2012-07-01T23:59:59.000Z

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


101

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

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

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

102

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

SciTech Connect

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

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

2008-02-27T23:59:59.000Z

103

Assessment of Cloud Cover Characteristics in Satellite Datasets and Reanalysis Products for Greenland  

Science Conference Proceedings (OSTI)

Clouds have an important controlling influence on the radiation balance, and hence surface melting, over the Greenland ice sheet and need to be classified to derive reliable albedo estimates from visible imagery. Little is known, however, about ...

J. A. Griggs; J. L. Bamber

2008-05-01T23:59:59.000Z

104

Impact of Cloud Cover on Solar Radiative Biases in Deep Convective Regimes  

Science Conference Proceedings (OSTI)

Conflicting claims have been made concerning the magnitude of the bias in solar radiative transfer calculations when horizontal photon transport is neglected for deep convective scenarios. The difficulty of obtaining a realistic set of cloud ...

F. Di Giuseppe; A. M. Tompkins

2005-06-01T23:59:59.000Z

105

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

SciTech Connect

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

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

2011-06-16T23:59:59.000Z

106

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

SciTech Connect

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

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

2009-02-02T23:59:59.000Z

107

Global Observation of Forest and Land Cover Dynamics (GOFC-GOLD) | Open  

Open Energy Info (EERE)

of Forest and Land Cover Dynamics (GOFC-GOLD) of Forest and Land Cover Dynamics (GOFC-GOLD) Jump to: navigation, search Name Global Observation of Forest and Land Cover Dynamics (GOFC-GOLD) Agency/Company /Organization World Meteorological Organization, United Nations Educational Scientific and Cultural Organization, United Nations Environment Programme, International Council for Science, Food and Agriculture Organization of the United Nations Sector Land, Climate Focus Area Biomass, Forestry, Agriculture Topics GHG inventory Resource Type Software/modeling tools Website http://www.fao.org/gtos/gofc-g References Global Observation of Forest and Land Cover Dynamics (GOFC-GOLD)[1] Global Observation of Forest and Land Cover Dynamics (GOFC-GOLD) Screenshot "Global Observation of Forest and Land Cover Dynamics (GOFC-GOLD) is a

108

Validation of Satellite-Based Objective Overshooting Cloud-Top Detection Methods Using CloudSat Cloud Profiling Radar Observations  

Science Conference Proceedings (OSTI)

Two satellite infrared-based overshooting convective cloud-top (OT) detection methods have recently been described in the literature: 1) the 11-?m infrared window channel texture (IRW texture) method, which uses IRW channel brightness temperature (...

Kristopher M. Bedka; Richard Dworak; Jason Brunner; Wayne Feltz

2012-10-01T23:59:59.000Z

109

Observations of Cloud Microstructure at the Centimeter Scale  

Science Conference Proceedings (OSTI)

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

Jean-Louis Brenguier

1993-04-01T23:59:59.000Z

110

Comparison of Aircraft Observations with Mixed-Phase Cloud Simulations  

Science Conference Proceedings (OSTI)

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

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

2003-04-01T23:59:59.000Z

111

Satellite-Observed Characteristics of Winter Monsoon Cloud Clusters  

Science Conference Proceedings (OSTI)

An objective algorithm is devised which is capable of touting tropical cloud clusters at the point of initiation, tracking them to the paint of dissipation and thereby accumulating statistics on their size distributions and preferred geographical ...

Mark Williams; Robert A. Houze Jr.

1987-02-01T23:59:59.000Z

112

Marine Boundary Layer Cloud Observations in the Azores  

Science Conference Proceedings (OSTI)

The recent deployment of the Atmospheric Radiation Measurement Program (ARM) Mobile Facility at Graciosa Island, Azores, in the context of the Clouds, Aerosol and Precipitation in the Marine Boundary Layer (CAP-MBL) field campaign added the most ...

Jasmine Rémillard; Pavlos Kollias; Edward Luke; Robert Wood

2012-11-01T23:59:59.000Z

113

What Controls Stratocumulus Radiative Properties? Lagrangian Observations of Cloud Evolution  

Science Conference Proceedings (OSTI)

Marine stratocumulus clouds have a large impact on the earth’s radiation budget. Their optical properties vary on two distinct timescales, one associated with the diurnal cycle of solar insolation and another with the downstream transition to ...

Robert Pincus; Marcia B. Baker; Christopher S. Bretherton

1997-09-01T23:59:59.000Z

114

Cloud Activating Properties of Aerosol Observed during CELTIC  

Science Conference Proceedings (OSTI)

Measurements of aerosol size distribution, chemical composition, and cloud condensation nuclei (CCN) concentration were performed during the Chemical Emission, Loss, Transformation, and Interactions with Canopies (CELTIC) field program at Duke ...

Craig A. Stroud; Athanasios Nenes; Jose L. Jimenez; Peter F. DeCarlo; J. Alex Huffman; Roelof Bruintjes; Eiko Nemitz; Alice E. Delia; Darin W. Toohey; Alex B. Guenther; Sreela Nandi

2007-02-01T23:59:59.000Z

115

Identification of Small Ice Cloud Particles Using Passive Radiometric Observations  

Science Conference Proceedings (OSTI)

There is currently significant uncertainty about the extent to which cirrus clouds are composed of “small” ice crystals smaller than about 20-?m effective radius. This is due in part to concerns that in situ measurements from aircraft are plagued ...

Steven J. Cooper; Timothy J. Garrett

2010-11-01T23:59:59.000Z

116

Lidar Observations of the Fine-Scale Variability of Marine Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

A Nd:YAG lidar system was flown aboard NASA's ER-2 high altitude aircraft. Observations of cloud top height were made with 70 m along-track and 7.5 m vertical-height resolution. The lidar data observed from an East Pacific stratocumulus cloud ...

Reinout Boers; James D. Spinhirne; William D. Hart

1988-07-01T23:59:59.000Z

117

A Comparison of TWP-ICE Observational Data with Cloud-Resolving Model Results  

SciTech Connect

Observations made during the TWP-ICE campaign are used to drive and evaluate thirteen cloud-resolving model simulations with periodic lateral boundary conditions. The simulations employ 2D and 3D dynamics, one- and two-moment microphysics, several variations on large-scale forcing, and the use of observationally derived aerosol properties to prognose droplet numbers. When domain means are averaged over a 6-day active monsoon period, all simulations reproduce observed surface precipitation rate but not its structural distribution. Simulated fractional areas covered by convective and stratiform rain are uncorrelated with one another, and are both variably overpredicted by up to a factor of {approx}2. Stratiform area fractions are strongly anticorrelated with outgoing longwave radiation (OLR) but are negligibly correlated with ice water path (IWP), indicating that ice spatial distribution controls OLR more than mean IWP. Overpredictions of OLR tend to be accompanied by underpredictions of reflected shortwave radiation (RSR). When there are two simulations differing only in microphysics scheme or large-scale forcing, the one with smaller stratiform area tends to exhibit greater OLR and lesser RSR by similar amounts. After {approx}10 days, simulations reach a suppressed monsoon period with a wide range of mean precipitable water vapor, attributable in part to varying overprediction of cloud-modulated radiative flux divergence compared with observationally derived values. Differences across the simulation ensemble arise from multiple sources, including dynamics, microphysics, and radiation treatments. Close agreement of spatial and temporal averages with observations may not be expected, but the wide spreads of predicted stratiform fraction and anticorrelated OLR indicate a need for more rigorous observation-based evaluation of the underlying micro- and macrophysical properties of convective and stratiform structures.

Fridlind, A. M.; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Grabowski, Wojciech W.; Hill, A.; Jones, T. R.; Khaiyer, M. M.; Liu, G.; Minnis, Patrick; Morrison, H.; Nguyen, L.; Park, S.; Petch, Jon C.; Pinty, Jean-Pierre; Schumacher, Courtney; Shipway, Ben; Varble, A. C.; Wu, Xiaoqing; Xie, Shaocheng; Zhang, Minghua

2012-03-13T23:59:59.000Z

118

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

SciTech Connect

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

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

2011-12-24T23:59:59.000Z

119

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

SciTech Connect

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

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

2011-12-24T23:59:59.000Z

120

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

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

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

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121

Cloud Layer Thicknesses from a Combination of Surface and Upper-Air Observations  

Science Conference Proceedings (OSTI)

Cloud layer thicknesses are derived from base and top altitudes by combining 14 years (1975–1988) of surface and upper-air observations at 63 sites in the Northern Hemisphere. Rawinsonde observations are employed to determine the locations of ...

Kirk D. Poore; Junhong Wang; William B. Rossow

1995-03-01T23:59:59.000Z

122

Simulated Doppler Radar Observations of Inhomogeneous Clouds: Application to the EarthCARE Space Mission  

Science Conference Proceedings (OSTI)

A new simulation technique for spaceborne Doppler radar observations that was developed specifically for inhomogeneous targets is presented. Cloud inhomogeneity affects Doppler observations in two ways. First, line-of-sight velocities within the ...

N. A. J. Schutgens

2008-01-01T23:59:59.000Z

123

Precipitation and Cloud Structure in Midlatitude Cyclones  

Science Conference Proceedings (OSTI)

Composite mean fields and probability distribution functions (PDFs) of rain rate, cloud type and cover, cloud-top temperature, surface wind velocity, and water vapor path (WVP) are constructed using satellite observations of midlatitude cyclones ...

Paul R. Field; Robert Wood

2007-01-01T23:59:59.000Z

124

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

Science Conference Proceedings (OSTI)

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

Robert J. Curran; Man-Li C. Wu

1982-03-01T23:59:59.000Z

125

Comparison of Monte Carlo Calculations with Observations of Light Scattering in Finite Clouds  

Science Conference Proceedings (OSTI)

Two experimental data sets have been compared with calculations of solar radiation scattered by finite cumulus clouds. The first approach was to observe the radiation exiting the sides of cumulus clouds from 0.8 to 3.0 km in vertical thickness as ...

Thomas B. McKee; Mark DeMaria; James A. Kuenning; Stephen K. Cox

1983-04-01T23:59:59.000Z

126

Evaluation of Cloud-Resolving Model Intercomparison Simulations Using TWP-ICE Observations: Precipitation and Cloud Structure  

SciTech Connect

The Tropical Warm Pool – International Cloud Experiment (TWP-ICE) provided high quality model forcing and observational datasets through which detailed model and observational intercomparisons could be performed. In this first of a two part study, precipitation and cloud structures within nine cloud-resolving model simulations are compared with scanning radar reflectivity and satellite infrared brightness temperature observations during an active monsoon period from 19 to 25 January 2006. Most simulations slightly overestimate volumetric convective rainfall. Overestimation of simulated convective area by 50% or more in several simulations is somewhat offset by underestimation of mean convective rain rates. Stratiform volumetric rainfall is underestimated by 13% to 53% despite overestimation of stratiform area by up to 65% because stratiform rain rates in every simulation are much lower than observed. Although simulations match the peaked convective radar reflectivity distribution at low levels, they do not reproduce the peaked distributions observed above the melting level. Simulated radar reflectivity aloft in convective regions is too high in most simulations. In stratiform regions, there is a large spread in model results with none resembling observed distributions. Above the melting level, observed radar reflectivity decreases more gradually with height than simulated radar reflectivity. A few simulations produce unrealistically uniform and cold 10.8-?m infrared brightness temperatures, but several simulations produce distributions close to observed. Assumed ice particle size distributions appear to play a larger role than ice water contents in producing incorrect simulated radar reflectivity distributions aloft despite substantial differences in mean graupel and snow water contents across models.

Varble, Adam; Fridlind, Ann; Zipser, Edward J.; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Hill, Adrian; McFarlane, Sally A.; Pinty, Jean-Pierre; Shipway, Ben

2011-10-04T23:59:59.000Z

127

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

E-Print Network (OSTI)

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

Shupe, Matthew

128

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

E-Print Network (OSTI)

Ice clouds occur quite frequently, yet so much about these clouds is unknown. In recent years, numerous investigations and field campaigns have been focused on the study of ice clouds, all with the ultimate goal of gaining a better understanding of microphysical and optical properties, as well as determining the radiative impact. Perhaps one of the most recognized instruments used for such research is the Moderate-resolution Imaging Spectroradiometer (MODIS), carried aboard the NASA EOS satellites Terra and Aqua. The present research aims to support ongoing efforts in the field of ice cloud research by use of observations obtained from Terra and Aqua MODIS. First, a technique is developed to infer ice cloud optical depth from the MODIS cirrus reflectance parameter. This technique is based on a previous method developed by Meyer et al. (2004). The applicability of the algorithm is demonstrated with retrievals from level-2 and -3 MODIS data. The technique is also evaluated with the operational MODIS cloud retrieval product and a method based on airborne ice cloud observations. From this technique, an archive of daily optical depth retrievals is constructed. Using simple statistics, the global spatial and temporal distributions of ice clouds are determined. Research has found that Aqua MODIS observes more frequent ice clouds and larger optical depths and ice water paths than does Terra MODIS. Finally, an analysis of the time series of daily optical depth values revealed that ice clouds at high latitudes, which are most likely associated with synoptic scale weather sytems, persist long enough to move with the upper level winds. Tropical ice clouds, however, dissipate more rapidly, and are in all likelihood associated with deep convective cells.

Meyer, Kerry Glynne

2007-08-01T23:59:59.000Z

129

Cloud and Radiative Characteristics of Tropical Deep Convective Systems in Extended Cloud Objects from CERES Observations  

Science Conference Proceedings (OSTI)

The physical and radiative properties of tropical deep convective systems for the period from January to August 1998 are examined with the use of Clouds and the Earth’s Radiant Energy System Single-Scanner Footprint (SSF) data from the Tropical ...

Zachary A. Eitzen; Kuan-Man Xu; Takmeng Wong

2009-11-01T23:59:59.000Z

130

WHAM Observations of H-alpha from High-Velocity Clouds Are They Galactic or Extragalactic?  

E-Print Network (OSTI)

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the H-alpha line of high velocity clouds selected as the most likely candidates for being at larger than average distances. We have found H-alpha emission from 4 out of 5 of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group.

Tufte, S L; Madsen, G J; Haffner, L M; Reynolds, R J

2002-01-01T23:59:59.000Z

131

WHAM Observations of H-alpha from High-Velocity Clouds: Are They Galactic or Extragalactic?  

E-Print Network (OSTI)

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the H-alpha line of high velocity clouds selected as the most likely candidates for being at larger than average distances. We have found H-alpha emission from 4 out of 5 of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group.

S. L. Tufte; J. D. Wilson; G. J. Madsen; L. M. Haffner; R. J. Reynolds

2002-06-12T23:59:59.000Z

132

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

Science Conference Proceedings (OSTI)

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

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

2009-01-13T23:59:59.000Z

133

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

SciTech Connect

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

Turner, David D.

2003-06-01T23:59:59.000Z

134

Comparison of Simulated and Observed Continental Tropical Anvil Clouds and Their Radiative Heating Profiles  

Science Conference Proceedings (OSTI)

Vertically pointing millimeter-wavelength radar observations of anvil clouds extending from mesoscale convective systems (MCSs) that pass over an Atmospheric Radiation Measurement Program (ARM) field site in Niamey, Niger, are compared to anvil ...

Scott W. Powell; Robert A. Houze Jr.; Anil Kumar; Sally A. McFarlane

2012-09-01T23:59:59.000Z

135

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

Science Conference Proceedings (OSTI)

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

C. Rathke; J. Fischer

2000-11-01T23:59:59.000Z

136

Model Rain and Clouds over Oceans: Comparison with SSM/I Observations  

Science Conference Proceedings (OSTI)

A comparison of global model cloud and rain parameterization output with satellite observed radiances was carried out. Hydrometeor profiles from ECMWF operational short-range forecasts were combined with a microwave radiative transfer model to ...

Frédéric Chevallier; Peter Bauer

2003-07-01T23:59:59.000Z

137

Observations of Record Cold Cloud-Top Temperatures in Tropical Cyclone Hilda (1990)  

Science Conference Proceedings (OSTI)

A detailed analysis is made of the development of a region of cold cloud-top temperatures in Tropical Cyclone Hilda (1990) in the Coral Sea off eastern Australia. Observed temperatures of approximately 173 K (?100°C) from two independent ...

Elizabeth E. Ebert; Greg J. Holland

1992-10-01T23:59:59.000Z

138

Cloud-to-Ground Lightning Observations from TOGA COARE: Selected Results and Lightning Location Algorithms  

Science Conference Proceedings (OSTI)

Recently, observations of electrified oceanic convection and associated cloud-to-ground (CG) lightning were obtained over the tropical western Pacific Ocean during TOGA COARE (Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response ...

Walter A. Petersen; Steven A. Rutledge; Richard E. Orville

1996-04-01T23:59:59.000Z

139

A Clustering Approach to Compare Cloud Model Simulations to Satellite Observations  

Science Conference Proceedings (OSTI)

Cloud-resolving models (CRMs) offer an important pathway to interpret satellite observations of microphysical properties of storms. High-frequency microwave brightness temperatures (Tbs) respond to precipitating-sized ice particles and can ...

Fang Wang; Christian Kummerow

2012-11-01T23:59:59.000Z

140

The Turbulence Structure in a Continental Stratocumulus Cloud from Millimeter-Wavelength Radar Observations  

Science Conference Proceedings (OSTI)

The turbulent-scale vertical velocity structure in a continental stratocumulus cloud is studied using a 3-mm wavelength Doppler radar operating in a vertically pointing mode. The radar observations provided 30-m sampling in the vertical with 2-s ...

Pavlos Kollias; Bruce Albrecht

2000-08-01T23:59:59.000Z

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


141

Ground-Based and Satellite Observations of Cloud Fields in the Netherlands  

Science Conference Proceedings (OSTI)

A study is performed on the combination of ground-based and satellite observations for the derivation of cloud properties. Ground-based measurements from a lidar ceilometer and an infrared radiometer were combined with measurements of the NOAA ...

Arnout Feut; André van Lammeren

1996-09-01T23:59:59.000Z

142

Photographic Documentation of Some Distinctive Cloud Forms Observed Beneath a Large Cumulonimbus  

Science Conference Proceedings (OSTI)

Photographs of some variform cloud features observed in the inflow sector of an intense thunderstorm that occurred in southeastern Montana on 11 July 1981 are described. Associated meteorological conditions are interpreted within the context of ...

J. C. Fankhauser; G. M. Barnes; L. J. Miller; P. M. Roskowski

1983-05-01T23:59:59.000Z

143

Melting Layer Cloud Observed during R/V Mirai Cruise MR01-K05  

Science Conference Proceedings (OSTI)

In this study, cloud profiling radar and lidar were used to determine the frequency distribution of the base heights of cloudy layers with little (or no) falling condensate particles. The data were obtained from stationary observations conducted ...

Kazuaki Yasunaga; Kunio Yoneyama; Hisayuki Kubota; Hajime Okamoto; Atsushi Shimizu; Hiroshi Kumagai; Masaki Katsumata; Nobuo Sugimoto; Ichiro Matsui

2006-11-01T23:59:59.000Z

144

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

Science Conference Proceedings (OSTI)

We use observations of robust scaling behavior in clouds and precipitation to derive constraints on how partitioning of precipitation should change with model resolution. Our analysis indicates that 90–99% of stratiform precipitation should occur ...

Travis A. O’Brien; Fuyu Li; William D. Collins; Sara A. Rauscher; Todd D. Ringler; Mark Taylor; Samson M. Hagos; L. Ruby Leung

145

RACORO Extended-Term Aircraft Observations of Boundary-Layer Clouds  

SciTech Connect

A first-of-a-kind, extended-term cloud aircraft campaign was conducted to obtain an in-situ statistical characterization of boundary-layer clouds needed to investigate cloud processes and refine retrieval algorithms. Coordinated by the Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF), the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign operated over the ARM Southern Great Plains (SGP) site from 22 January to 30 June 2009, collecting 260 h of data during 59 research flights. A comprehensive payload aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft measured cloud microphysics, solar and thermal radiation, aerosol properties, and atmospheric state parameters. Proximity to the SGP's extensive complement of surface measurements provides ancillary data that supports modeling studies and enables evaluating a variety of surface retrieval algorithms. The five-month duration enabled sampling a range of conditions associated with the seasonal transition from winter to summer. Although about two-thirds of the cloud flights occurred in May and June, boundary-layer cloud fields were sampled under a variety of environmental and aerosol conditions, with about 75% of the flights occurring in cumulus and stratocumulus. Preliminary analyses show how these data are being used to analyze cloud-aerosol relationships, determine the aerosol sizes that are responsible for nucleating cloud drops, characterize the horizontal variability of the cloud radiative impacts, and evaluate air-borne and surface-based cloud property retrievals. We discuss how conducting an extended-term campaign requires a simplified operating paradigm that is different from that used for typical, short-term, intensive aircraft field programs.

Vogelmann, A. M.; McFarquhar, Greg; Ogren, John A.; Turner, David D.; Comstock, Jennifer M.; Feingold, G.; Long, Charles N.; Jonsson, Haf; Bucholtz, Anthony; Collins, Donald R.; Diskin, G. S.; Gerber, H.; Lawson, Paul; Woods, Roy; Andrews, Elizabeth; Yang, Hee-Jung; Chiu, Christine J.; Hartsock, Daniel; Hubbe, John M.; Lo, Chaomei; Marshak, A.; Monroe, Justin; McFarlane, Sally A.; Schmid, Beat; Tomlinson, Jason M.; Toto, Tami

2012-06-30T23:59:59.000Z

146

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

Science Conference Proceedings (OSTI)

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

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

2012-08-15T23:59:59.000Z

147

Evaluation of Cloud-Resolving Model Intercomparison Simulations Using TWP-ICE Observations: Precipitation and Cloud Structure  

SciTech Connect

The Tropical Warm Pool - International Cloud Experiment (TWP-ICE) provided high quality model forcing and observational datasets through which detailed model and observational intercomparisons could be performed. In this first of a two part study, precipitation and cloud structures within nine cloud-resolving model simulations are compared with scanning radar reflectivity and satellite infrared brightness temperature observations during an active monsoon period from 19 to 25 January 2006. Most simulations slightly overestimate volumetric convective rainfall. Overestimation of simulated convective area by 50% or more in several simulations is somewhat offset by underestimation of mean convective rain rates. Stratiform volumetric rainfall is underestimated by 13% to 53% despite overestimation of stratiform area by up to 65% because stratiform rain rates in every simulation are much lower than observed. Although simulations match the peaked convective radar reflectivity distribution at low levels, they do not reproduce the peaked distributions observed above the melting level. Simulated radar reflectivity aloft in convective regions is too high in most simulations. 29 In stratiform regions, there is a large spread in model results with none resembling 30 observed distributions. Above the melting level, observed radar reflectivity decreases 31 more gradually with height than simulated radar reflectivity. A few simulations produce 32 unrealistically uniform and cold 10.8-?m infrared brightness temperatures, but several 33 simulations produce distributions close to observed. Assumed ice particle size 34 distributions appear to play a larger role than ice water contents in producing incorrect 35 simulated radar reflectivity distributions aloft despite substantial differences in mean 36 graupel and snow water contents across models. 37

Varble, Adam C.; Fridlind, Ann; Zipser, Ed; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Hill, Adrian; McFarlane, Sally A.; Pinty, Jean-Pierre; Shipway, Ben

2011-06-24T23:59:59.000Z

148

On the Use of Pyrgeometers in Cloud  

Science Conference Proceedings (OSTI)

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

S. G. Bradley; R. G. Gibson

1982-08-01T23:59:59.000Z

149

Clouds  

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

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

150

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

SciTech Connect

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

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

2011-11-04T23:59:59.000Z

151

Lidar Observation of the Cirrus Cloud in the Tropopause at Chung-Li (25°N, 121°E)  

Science Conference Proceedings (OSTI)

The authors have detected a cirrus cloud near the tropopause by using a lidar system located at Chung-Li, Taiwan (25°N, 121°E). The cloud usually appeared between the month of May and September. In 1993–95, the cloud was observed almost 50% of ...

J. B. Nee; C. N. Len; W. N. Chen; C. I. Lin

1998-06-01T23:59:59.000Z

152

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

E-Print Network (OSTI)

The dissertation first investigates the single-scattering properties of inhomogeneous ice crystals containing air bubbles. Specifically, a combination of the ray-tracing technique and the Monte Carlo method is used to simulate the scattering of light by randomly oriented large hexagonal ice crystals containing spherical or spheroidal air bubbles. The effect of the air bubbles within ice crystals is to smooth the phase functions, diminish the 22° and 46° halo peaks, and reduce the backscatter in comparison with the case of bubble-free ice crystals. Cloud reflectance look-up tables were generated at the wavelengths of 0.65 ?m and 2.13 ?m to examine the impact of accounting for air bubbles in ice crystal morphology on the retrieval of ice cloud optical thickness and effective particle size. To investigate the effect of the representation of aggregates on electromagnetic scattering calculations, an algorithm is developed to efficiently specify the geometries of aggregates and to compute some of their geometric parameters such as the projected area. Based on in situ observations, aggregates are defined as clusters of hexagonal plates with a chain-like overall shape. An aggregate model is developed with 10 ensemble members, each consisting of between 4-12 hexagonal plates. The scattering properties of an individual aggregate ice particle are computed using the discrete dipole approximation or an Improved Geometric Optics Method, depending upon the size parameter. The aggregate model provides an accurate and computationally efficient way to represent all aggregates occurring within ice clouds. We developed an algorithm to determine an appropriate ice cloud model for application to satellite-based retrieval of ice cloud properties. Collocated Moderate Resolution Imaging Spectroradiometer and Multi-angle Imaging SpectroRadiometer (MISR) data are used to retrieve the optical thicknesses of ice clouds as a function of scattering angle in the nine MISR viewing directions. The difference between cloud optical thickness and its averaged value over the nine viewing angles can be used to validate the ice cloud models. Using the data obtained on 2 July 2009, an appropriate ice cloud model is determined. With the presence of all the uncertainties in the current operational satellite-based retrievals of ice cloud properties, this ice cloud model has excellent performance in terms of consistency in cloud property retrievals with the nine MISR viewing angles.

Xie, Yu

2010-12-01T23:59:59.000Z

153

Cloud Model-Based Simulation of Spaceborne Radar Observations  

Science Conference Proceedings (OSTI)

Simulations of observations from potential spaceborne radars are made based on storm structure generated from the three-dimensional (3D) Goddard cumulus ensemble model simulation of an intense overland convective system. Five frequencies of 3, 10,...

H-Y. M. Yeh; N. Prasad; R. Meneghini; W-K. Tao; J. A. Jones; R. F. Adler

1995-01-01T23:59:59.000Z

154

Sampling Errors and Bias in Satellite-Derived Fractional Cloud Cover Estimates from Exponential and Deterministic Cloud Fields as a Consequence of Instrument Pixel Size and Number  

Science Conference Proceedings (OSTI)

The proposed European Space Agency’s cloud profiling radar Millimetre Active Cloud Structure Imaging Mission is a nadir-pointing radar with a 1-km footprint; it will need to integrate the received signal power for a reasonable amount of time (1.4–...

Ivan Astin

1997-10-01T23:59:59.000Z

155

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

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

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

156

Stratocumulus Cloud Field Reflected Fluxes: The Effect of Cloud Shape  

Science Conference Proceedings (OSTI)

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

R. M. Welch; B. A. Wielicki

1984-11-01T23:59:59.000Z

157

Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

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

Robert Wood

2012-08-01T23:59:59.000Z

158

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

Science Conference Proceedings (OSTI)

A new automated daytime cumulonimbus/towering cumulus (Cb/TCu) cloud detection method for the months of May–September is presented that combines information on cloud physical properties retrieved from the Spinning Enhanced Visible and Infrared ...

Cintia Carbajal Henken; Maurice J. Schmeits; Hartwig Deneke; Rob A. Roebeling

2011-07-01T23:59:59.000Z

159

In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part I: Wave Clouds  

Science Conference Proceedings (OSTI)

The microphysical properties of wave clouds based on data collected during 17 missions flown by a Learjet research aircraft are presented and discussed. This extensive dataset expands upon previous aircraft studies of wave clouds and introduces ...

Brad A. Baker; R. Paul Lawson

2006-12-01T23:59:59.000Z

160

Cloud Droplet Residual Particle Microphysics in Marine Stratocumulus Clouds Observed during the Monterey Area Ship Track Experiment  

Science Conference Proceedings (OSTI)

The effect of marine boundary layer pollution level (as determined by the aerosol particle number concentration) on the size distribution of aerosol particles that formed cloud droplets in marine stratiform clouds is examined. In situ ...

Elisabeth Öström; Kevin J. Noone; Robert A. Pockalny

2000-08-01T23:59:59.000Z

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


161

In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part II: Cirrus Clouds  

Science Conference Proceedings (OSTI)

A Learjet research aircraft was used to collect microphysical data, including cloud particle imager (CPI) measurements of ice particle size and shape, in 22 midlatitude cirrus clouds. The dataset was collected while the aircraft flew 104 ...

R. Paul Lawson; Brad Baker; Bryan Pilson; Qixu Mo

2006-12-01T23:59:59.000Z

162

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

SciTech Connect

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

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

2011-11-10T23:59:59.000Z

163

Comparison between Observed Convective Cloud-Base Heights and Lifting Condensation Level for Two Different Lifted Parcels  

Science Conference Proceedings (OSTI)

Approximately 400 Automated Surface Observing System (ASOS) observations of convective cloud-base heights at 2300 UTC were collected from April through August of 2001. These observations were compared with lifting condensation level (LCL) heights ...

Jeffrey P. Craven; Ryan E. Jewell; Harold E. Brooks

2002-08-01T23:59:59.000Z

164

Climatology of High Cloud Dynamics Using Profiling ARM Doppler Radar Observations  

Science Conference Proceedings (OSTI)

Ice cloud properties are influenced by cloud-scale vertical air motion. Dynamical properties of ice clouds can be determined via Doppler measurements from ground-based, profiling cloud radars. Here, the decomposition of the Doppler velocities into ...

Heike Kalesse; Pavlos Kollias

165

VLT-FLAMES observations of young stellar clusters in the Magellanic Clouds  

E-Print Network (OSTI)

We introduce our VLT-FLAMES survey of massive stars in the Galaxy and the Magellanic Clouds, giving details of the observations in our younger fields in the LMC and SMC. In particular we highlight a new O2.5-type star discovered in N11, and Be-type stars in NGC 346 with permitted Fe II emission lines in their spectra. We give an overview of the distribution of spectral types in these fields and summarize the observed binary fraction.

C. J. Evans; D. J. Lennon; S. J. Smartt

2005-08-30T23:59:59.000Z

166

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

SciTech Connect

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

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

2012-10-01T23:59:59.000Z

167

Analysis of Aircraft, Radiosonde, and Radar Observations in Cirrus Clouds Observed during FIRE II: The Interactions between Environmental Structure, Turbulence, and Cloud Microphysical Properties  

Science Conference Proceedings (OSTI)

Ways to determine the turbulence intensity and the horizontal variability in cirrus clouds have been investigated using First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment II aircraft, radiosonde, and radar data. ...

Samantha A. Smith; Anthony D. DelGenio

2001-03-01T23:59:59.000Z

168

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

SciTech Connect

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

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

2008-08-15T23:59:59.000Z

169

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

SciTech Connect

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

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

2008-08-15T23:59:59.000Z

170

In Situ Observations of Cirrus Cloud Microphysical Properties Using the Counterflow Virtual Impactor  

Science Conference Proceedings (OSTI)

This study presents a new technique for making in situ measurements of cirrus cloud microphysical properties. Sampling of cirrus clouds was performed using a counterflow virtual impactor (CVI). The CVI was used to sample cloud elements larger ...

K. B. Noone; K. J. Noone; J. Heintzenberg; J. Ström; J. A. Ogren

1993-06-01T23:59:59.000Z

171

Comparison of Simulated and Observed Continental Tropical Anvil Clouds and Their Radiative Heating Profiles  

Science Conference Proceedings (OSTI)

Vertically pointing millimeter-wavelength radar observations of anvil clouds extending from mesoscale convective systems (MCSs) that pass over an Atmospheric Radiation Measurement Program (ARM) field site in Niamey, Niger, are compared to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model using six different microphysical schemes. The radar data provide the statistical distribution of the radar reflectivity values as a function of height and anvil thickness. These statistics are compared to the statistics of the modeled anvil cloud reflectivity at all altitudes. Requiring the model to be statistically accurate at all altitudes is a stringent test of the model performance. The typical vertical profile of radiative heating in the anvil clouds is computed from the radar observations. Variability of anvil structures from the different microphysical schemes provides an estimate of the inherent uncertainty in anvil radiative heating profiles. All schemes underestimate the optical thickness of thin anvils and cirrus, resulting in a bias of excessive net anvil heating in all of the simulations.

Powell, Scott W.; Houze, R.; Kumar, Anil; McFarlane, Sally A.

2012-09-06T23:59:59.000Z

172

accepted to The Astrophysical Journal Letters WHAM Observations of H? from High Velocity Clouds: Are They Galactic or Extragalactic?  

E-Print Network (OSTI)

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the H? line of high velocity clouds selected as the most likely candidates for being at larger than average distances. We have found H? emission from 4 out of 5 of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group.

S. L. Tufte; J. D. Wilson; G. J. Madsen; L. M. Haffner; R. J. Reynolds

2002-01-01T23:59:59.000Z

173

Increase of Cloud Droplet Size with Aerosol Optical Depth: An Observational and Modeling Study  

SciTech Connect

Cloud droplet effective radius (DER) is generally negatively correlated with aerosol optical depth (AOD) as a proxy of cloud condensation nuclei. In this study, cases of positive correlation were found over certain portions of the world by analyzing the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite products, together with a general finding that DER may increase or decrease with aerosol loading depending on environmental conditions. The slope of the correlation between DER and AOD is driven primarily by water vapor amount, which explains 70% of the variance in our study. Various potential artifacts that may cause the positive relation are investigated including water vapor swelling, partially cloudy, atmospheric dynamics, cloud three-dimensional (3-D) and surface influence effects. None seems to be the primary cause for the observed phenomenon, although a certain degree of influence exists for some of the factors. Analyses are conducted over seven regions around the world representing different types of aerosols and clouds. Only two regions show positive dependence of DER on AOD, near coasts of the Gulf of Mexico and South China Sea, which implies physical processes may at work. Using a 2-D spectral-bin microphysics Goddard Cumulus Ensemble model (GCE) which incorporated a reformulation of the Köhler theory, two possible physical mechanisms are hypothesized. They are related to the effects of slightly soluble organics (SSO) particles and giant CCNs. Model simulations show a positive correlation between DER and AOD, due to a decrease in activated aerosols with an increasing SSO content. Addition of a few giant CCNs also increases the DER. Further investigations are needed to fully understand and clarify the observed phenomenon.

Yuan, Tianle; Li, Zhanqing; Zhang, Renyi; Fan, Jiwen

2008-02-21T23:59:59.000Z

174

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

Science Conference Proceedings (OSTI)

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

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

2008-01-01T23:59:59.000Z

175

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

E-Print Network (OSTI)

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

Droegemeier, Kelvin K.

176

Improving the representation of low clouds and drizzle in the ECMWF model based on ARM observations from the Azores.  

Science Conference Proceedings (OSTI)

In this study, the representation of marine boundary layer cloud is investigated in the ECMWF model using observations from the Atmospheric Radiation Measurement (ARM) mobile facility deployment to Graciosa Island in the North Atlantic. Systematic ...

Maike Ahlgrimm; Richard Forbes

177

Cloud-Resolving Hurricane Initialization and Prediction through Assimilation of Doppler Radar Observations with an Ensemble Kalman Filter  

Science Conference Proceedings (OSTI)

This study explores the assimilation of Doppler radar radial velocity observations for cloud-resolving hurricane analysis, initialization, and prediction with an ensemble Kalman filter (EnKF). The case studied is Hurricane Humberto (2007), the ...

Fuqing Zhang; Yonghui Weng; Jason A. Sippel; Zhiyong Meng; Craig H. Bishop

2009-07-01T23:59:59.000Z

178

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

Science Conference Proceedings (OSTI)

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

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

2003-09-01T23:59:59.000Z

179

An Artificial Neural Network model to reduce false alarms in satellite precipitation products using MODIS and CloudSat observations  

Science Conference Proceedings (OSTI)

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

Nasrin Nasrollahi; Kuolin Hsu; Soroosh Sorooshian

180

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

Science Conference Proceedings (OSTI)

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

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

2009-08-01T23:59:59.000Z

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


181

Comparison of High-Cloud Characteristics as Estimated by Selected Spaceborne Observations and Ground-Based Lidar Datasets  

Science Conference Proceedings (OSTI)

The characterization of high clouds as performed from selected spaceborne observations is assessed in this article by employing a number of worldwide ground-based lidar multiyear datasets as reference. Among the latter, the ground lidar ...

Artemio Plana-Fattori; Gérard Brogniez; Patrick Chervet; Martial Haeffelin; Olga Lado-Bordowsky; Yohann Morille; Frédéric Parol; Jacques Pelon; Antoine Roblin; Genevičve Sčze; Claudia Stubenrauch

2009-06-01T23:59:59.000Z

182

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

Science Conference Proceedings (OSTI)

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

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

2008-04-01T23:59:59.000Z

183

Developing an Index to Measure Urban Heat Island Effect Using Satellite Land Skin Temperature and Land Cover Observations  

Science Conference Proceedings (OSTI)

A new index of calculating the intensity of urban heat island effects (UHI) for a city using satellite skin temperature and land cover observations is recommended. UHI, the temperature difference between urban and rural regions, is traditionally ...

Menglin S. Jin

2012-09-01T23:59:59.000Z

184

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

E-Print Network (OSTI)

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

Klein, Stephen A.

2009-01-01T23:59:59.000Z

185

AMI OBSERVATIONS OF THE ANOMALOUS MICROWAVE EMISSION IN THE PERSEUS MOLECULAR CLOUD  

SciTech Connect

We present observations of the known anomalous microwave emission region, G159.6-18.5, in the Perseus molecular cloud at 16 GHz performed with the Arcminute Microkelvin Imager Small Array. These are the highest angular resolution observations of G159.6-18.5 at microwave wavelengths. By combining these microwave data with infrared observations between 5.8 and 160 {mu}m from the Spitzer Space Telescope, we investigate the existence of a microwave-infrared correlation on angular scales of {approx}2'. We find that the overall correlation appears to increase toward shorter infrared wavelengths, which is consistent with the microwave emission being produced by electric dipole radiation from small, spinning dust grains. We also find that the microwave-infrared correlation peaks at 24 {mu}m (6.7{sigma}), suggesting that the microwave emission is originating from a population of stochastically heated small interstellar dust grains rather than polycyclic aromatic hydrocarbons.

Tibbs, C. T. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Scaife, A. M. M. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Dickinson, C.; Davies, R. D.; Davis, R. J.; Watson, R. A. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Paladini, R. [NASA Herschel Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Grainge, K. J. B., E-mail: ctibbs@ipac.caltech.edu [Astrophysics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2013-05-10T23:59:59.000Z

186

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

Science Conference Proceedings (OSTI)

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

R. A. Roebeling; E. van Meijgaard

2009-04-01T23:59:59.000Z

187

A Land and Ocean Microwave Cloud Classification Algorithm Derived from AMSU-A and -B, Trained Using MSG-SEVIRI Infrared and Visible Observations  

Science Conference Proceedings (OSTI)

A statistical cloud classification and cloud mask algorithm is developed based on Advanced Microwave Sounding Unit (AMSU-A and -B) microwave (MW) observations. The visible and infrared data from the Meteosat Third Generation-Spinning Enhanced ...

Filipe Aires; Francis Marquisseau; Catherine Prigent; Genevičve Sčze

2011-08-01T23:59:59.000Z

188

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

SciTech Connect

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

Liu, X; Ghan, SJ; Xie, S

2007-04-01T23:59:59.000Z

189

ORIGINAL PAPER MODIS/Terra observed snow cover over the Tibet Plateau  

E-Print Network (OSTI)

exerts a profound dynamic and thermal forcing on the regional atmospheric circulation (Yeh et al. 1979 cover will influence the energy and water exchange between the land surfaces and the lower troposphere by modulating radiation, water and heat flux (Cohen and Rind 1991). Therefore, snow cover anomalies have been

Pu, Zhaoxia

190

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

Science Conference Proceedings (OSTI)

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

Frédéric Burnet; Jean-Louis Brenguier

2007-06-01T23:59:59.000Z

191

Ship-Based Observations of the Diurnal Cycle of Southeast Pacific Marine Stratocumulus Clouds and Precipitation  

Science Conference Proceedings (OSTI)

The diurnal cycle of marine stratocumulus in cloud-topped boundary layers is examined using ship-based meteorological data obtained during the 2008 VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx). The high temporal and ...

Casey D. Burleyson; Simon P. de Szoeke; Sandra E. Yuter; Matt Wilbanks; W. Alan Brewer

192

On the Modification Potential of Illinois Summertime Convective Clouds, with Comparisons to Florida and FACE Observations  

Science Conference Proceedings (OSTI)

The potential for enhancing rain output over central Illinois through modification of summertime convective clouds was investigated by use of model predictions of cumulus growth, as well as direct, internal measurements of cloud physical ...

Victor Wiggert; Robert I. Sax; Ronald L. Holle

1982-09-01T23:59:59.000Z

193

Clouds and the Earth's Radiant Energy System (CERES): An Earth Observing System Experiment  

Science Conference Proceedings (OSTI)

Clouds and the Earth's Radiant Energy System (CERES) is an investigation to examine the role of cloud/radiation feedback in the Earth's climate system. The CERES broadband scanning radiometers are an improved version of the Earth Radiation Budget ...

Bruce A. Wielicki; Bruce R. Barkstrom; Edwin F. Harrison; Robert B. Lee III; G. Louis Smith; John E. Cooper

1996-05-01T23:59:59.000Z

194

Dynamical Characteristics of Cirrus Clouds from Aircraft and Radar Observations in Micro and Meso-? Scales  

Science Conference Proceedings (OSTI)

Cirrus clouds that formed on 26 November and 6 December 1991 during the First International Satellite Cloud Climatology Project Regional Experiment (FIRE) II, which took place over the Kansas region. are studied because of significant dynamic ...

I. Gultepe; D. O'C. Starr; A. J. Heymsfield; T. Uttal; T. P. Ackerman; D. L. WestPhal

1995-12-01T23:59:59.000Z

195

Microphysical and Radar Observations of Seeded and Nonseeded Continental Cumulus Clouds  

Science Conference Proceedings (OSTI)

Controlled cloud seeding experiments were conducted near Bethlehem, South Africa during the summer of 1984–85. The experimental unit was the semi-isolated cumulus congestus cloud. Microphysical measurements were obtained by three instrumented ...

T. W. Krauss; R. T. Bruintjes; J. Verlinde

1987-05-01T23:59:59.000Z

196

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

Science Conference Proceedings (OSTI)

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

Lazaros Oreopoulos; Robert F. Cahalan; Steven Platnick

2007-10-01T23:59:59.000Z

197

Observational and Theoretical Studies of Solar Radiation in Arctic Stratus Clouds  

Science Conference Proceedings (OSTI)

A series of clouds-radiation experiments was carried out in June 1980 in Arctic stratus clouds occurring over the Beaufort Sea using the NCAR Electra aircraft. This paper is an analysis of the hemispheric radiation fields obtained with Eppley ...

G. F. Herman; J. A. Curry

1984-01-01T23:59:59.000Z

198

Cloud-Resolving Satellite Data Assimilation: Information Content of IR Window Observations and Uncertainties in Estimation  

Science Conference Proceedings (OSTI)

This study addresses the problem of four-dimensional (4D) estimation of a cloudy atmosphere on cloud-resolving scales using satellite remote sensing measurements. The motivation is to develop a methodology for accurate estimation of cloud ...

T. Vukicevic; M. Sengupta; A. S. Jones; T. Vonder Haar

2006-03-01T23:59:59.000Z

199

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

Science Conference Proceedings (OSTI)

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

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

1989-06-01T23:59:59.000Z

200

Scale Dependence of the Thermodynamic Forcing of Tropical Monsoon Clouds: Results from TRMM Observations  

Science Conference Proceedings (OSTI)

Clouds exert a thermodynamic forcing on the ocean–atmosphere column through latent heating, owing to the production of rain, and through cloud radiative forcing, owing to the absorption of terrestrial infrared energy and the reflection of solar ...

Eric M. Wilcox; V. Ramanathan

2001-04-01T23:59:59.000Z

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


201

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

SciTech Connect

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

Howard Barker; Jason Cole

2012-05-17T23:59:59.000Z

202

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

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

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

203

COLLABORATIVE RESEARCH:USING ARM OBSERVATIONS & ADVANCED STATISTICAL TECHNIQUES TO EVALUATE CAM3 CLOUDS FOR DEVELOPMENT OF STOCHASTIC CLOUD-RADIATION  

SciTech Connect

The long-range goal of several past and current projects in our DOE-supported research has been the development of new and improved parameterizations of cloud-radiation effects and related processes, using ARM data, and the implementation and testing of these parameterizations in global models. The main objective of the present project being reported on here has been to develop and apply advanced statistical techniques, including Bayesian posterior estimates, to diagnose and evaluate features of both observed and simulated clouds. The research carried out under this project has been novel in two important ways. The first is that it is a key step in the development of practical stochastic cloud-radiation parameterizations, a new category of parameterizations that offers great promise for overcoming many shortcomings of conventional schemes. The second is that this work has brought powerful new tools to bear on the problem, because it has been a collaboration between a meteorologist with long experience in ARM research (Somerville) and a mathematician who is an expert on a class of advanced statistical techniques that are well-suited for diagnosing model cloud simulations using ARM observations (Shen).

Somerville, Richard

2013-08-22T23:59:59.000Z

204

Improvements of a Mixed-Phase Cloud Scheme Using Aircraft Observations  

Science Conference Proceedings (OSTI)

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

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

2003-04-01T23:59:59.000Z

205

Aerosol, Cloud, and Climate: From Observation to Model (457th Brookhaven Lecture)  

Science Conference Proceedings (OSTI)

In the last 100 years, the Earth has warmed by about 1şF, glaciers and sea ice have been melting more quickly than previously, especially during the past decade, and the level of the sea has risen about 6-8 inches worldwide. Scientists have long been investigating this phenomenon of “global warming,” which is believed to be at least partly due to the increased carbon dioxide (CO2) concentration in the air from burning fossil fuels. Funded by DOE, teams of researchers from BNL and other national labs have been gathering data in the U.S. and internationally to build computer models of climate and weather to help in understanding general patterns, causes, and perhaps, solutions. Among many findings, researchers observed that atmospheric aerosols, minute particles in the atmosphere, can significantly affect global energy balance and climate. Directly, aerosols scatter and absorb sunlight. Indirectly, increased aerosol concentration can lead to smaller cloud droplets, changing clouds in ways that tend to cool global climate and potentially mask overall warming from man-made CO2.

Wang, Jian (Ph.D., Environmental Sciences Department)

2010-05-12T23:59:59.000Z

206

Insights into Cloud-Top Height and Dynamics from the Seasonal Cycle of Cloud-Top Heights Observed by MISR in the West Pacific Region  

Science Conference Proceedings (OSTI)

The connection between environmental stability and the height of tropical deep convective clouds is analyzed using stereo cloud height data from the Multiangle Imaging Spectroradiometer (MISR), focusing on the seasonal cycle of clouds over the ...

Jung Hyo Chae; Steven C. Sherwood

2010-01-01T23:59:59.000Z

207

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

Science Conference Proceedings (OSTI)

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

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

2010-06-01T23:59:59.000Z

208

Influence of the Eurasian snow cover on the Indian summer monsoon variability in observed climatologies and CMIP3  

E-Print Network (OSTI)

Influence of the Eurasian snow cover on the Indian summer monsoon variability in observed using sev- eral statistical tools including a maximum covariance analysis. The snow­monsoon relationship between an east­west snow dipole over Eurasia and the Indian summer monsoon precipitation. However, our

209

Influence of the Eurasian snow cover on the Indian summer monsoon variability in observed climatologies and CMIP3  

E-Print Network (OSTI)

Influence of the Eurasian snow cover on the Indian summer monsoon variability in observed statistical tools including a maximum covariance analysis. The snow­monsoon relationship is explored using an east­west snow dipole over Eurasia and the Indian summer monsoon precipitation. However, our results

210

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

SciTech Connect

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

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

2007-12-14T23:59:59.000Z

211

Quantifying tropical cyclone cloud cover using Envisat retrievals – an example of a recent severe tropical cyclone, ‘Thane’  

Science Conference Proceedings (OSTI)

The eastern coast of peninsular India routinely receives the onslaught of devastating cyclonic storms. We suggest a novel method involving Envisat retrievals followed by application of the European Space Agency's ESA's Earth Observation Link Stand-Alone ...

Ishan Saini, Pranav Chandramouli, Arkayan Samaddar, Satyajit Ghosh

2013-07-01T23:59:59.000Z

212

Observation of femtosecond laser-induced nanostructure-covered large scale waves on metals  

SciTech Connect

Following femtosecond (fs) laser pulse irradiation, we produce a type of periodic surface structure with a period tens of times greater than the laser wavelength and densely covered by an iterating pattern that consists of stripes of nanostructures and microscale cellular structures. The morphology of this large scale wave pattern crucially depends on laser fluence and the number of laser pulses, but not on the laser wavelength. Our study suggests that this large scale wave is initiated by fs laser induced surface unevenness followed by periodically distributed nonuniform surface heating from fs pulse irradiation.

Hwang, Taek Yong; Guo Chunlei [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

2011-04-15T23:59:59.000Z

213

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

E-Print Network (OSTI)

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

214

Feasibility of Determining Cloud-Top Heights Using the Backscattered Ultraviolet Satellite Observation Technique  

Science Conference Proceedings (OSTI)

A technique for determining cloud-top height by means of backscattered ultraviolet (BUV) solar radiation is presented. Cloud-top heights can be inferred using this technique if both the BUV radiance and its degree of polarization are measured by ...

Tadashi Aruga; Kaichi Maeda; Donald F. Heath

1984-05-01T23:59:59.000Z

215

Observations of Cloud, Radiation, and Surface Forcing in the Equatorial Eastern Pacific  

Science Conference Proceedings (OSTI)

In this paper the authors report on a study of cloud and surface flux processes in the tropical eastern Pacific Ocean based on a series of ship-based cloud and flux measurements made during fall (1999–2002) and spring (2000–02) maintenance ...

C. W. Fairall; Taneil Uttal; Duane Hazen; Jeffrey Hare; Meghan F. Cronin; Nicholas Bond; Dana E. Veron

2008-02-01T23:59:59.000Z

216

WHAM Observations of H-alpha Emission from High Velocity Clouds in the M, A, and C Complexes  

E-Print Network (OSTI)

The first observations of the recently completed Wisconsin H-Alpha Mapper (WHAM) facility include a study of emission lines from high velocity clouds in the M, A, and C complexes, with most of the observations on the M I cloud. We present results including clear detections of H-alpha emission from all three complexes with intensities ranging from 0.06 R to 0.20 R. In every observed direction where there is significant high velocity H I gas seen in the 21 cm line we have found associated ionized hydrogen emitting the H-alpha line. The velocities of the H-alpha and 21 cm emission are well correlated in every case except one, but the intensities are not correlated. There is some evidence that the ionized gas producing the H-alpha emission envelopes the 21 cm emitting neutral gas but the H-alpha "halo", if present, is not large. If the H-alpha emission arises from the photoionization of the H I clouds, then the implied Lyman continuum flux F_{LC} at the location of the clouds ranges from 1.3 to 4.2 x 10^5 photons cm^{-2} s^{-1}. If, on the other hand, the ionization is due to a shock arising from the collision of the high-velocity gas with an ambient medium in the halo, then the density of the pre-shocked gas can be constrained. We have also detected the [S II] 6716 angstrom line from the M I cloud and have evidence that the [S II] to H-alpha ratio varies with location on the cloud.

S. L. Tufte; R. J. Reynolds; L. M. Haffner

1998-07-15T23:59:59.000Z

217

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

Science Conference Proceedings (OSTI)

Widespread stratocumulus clouds were observed on nine transects from seven research cruises to the southeastern tropical Pacific Ocean along 20°S, 75°–85°W in October–November of 2001–08. The nine transects sample a unique combination of synoptic ...

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

2012-12-01T23:59:59.000Z

218

A Climatology of Warm-Season Cloud Patterns over East Asia Based on GMS Infrared Brightness Temperature Observations  

Science Conference Proceedings (OSTI)

In the present study, hourly infrared (IR) brightness temperatures observed by the Geostationary Meteorological Satellite (GMS) over the region 20°–40°N, 95°–145°E in May–August 1998–2001 are used to compile a climatology of warm-season cloud/...

Chung-Chieh Wang; George Tai-Jen Chen; Richard E. Carbone

2004-07-01T23:59:59.000Z

219

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

Science Conference Proceedings (OSTI)

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

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

1994-03-01T23:59:59.000Z

220

Phenomenological Description of Tropical Clouds Using CloudSat Cloud Classification  

Science Conference Proceedings (OSTI)

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

Ali Behrangi; Terry Kubar; Bjorn Lambrigtsen

2012-10-01T23:59:59.000Z

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


221

WHAM Observations of H$\\alpha$ Emission from High Velocity Clouds in the M, A, and C Complexes  

E-Print Network (OSTI)

The first observations of the recently completed Wisconsin H-Alpha Mapper (WHAM) facility include a study of emission lines from high velocity clouds in the M, A, and C complexes, with most of the observations on the M I cloud. We present results including clear detections of H-alpha emission from all three complexes with intensities ranging from 0.06 R to 0.20 R. In every observed direction where there is significant high velocity H I gas seen in the 21 cm line we have found associated ionized hydrogen emitting the H-alpha line. The velocities of the H-alpha and 21 cm emission are well correlated in every case except one, but the intensities are not correlated. There is some evidence that the ionized gas producing the H-alpha emission envelopes the 21 cm emitting neutral gas but the H-alpha "halo", if present, is not large. If the H-alpha emission arises from the photoionization of the H I clouds, then the implied Lyman continuum flux F_{LC} at the location of the clouds ranges from 1.3 to 4.2 x 10^5 photons...

Tufte, S L; Haffner, L M

1998-01-01T23:59:59.000Z

222

Observations of ground-state OH in the Large Magellanic Cloud  

E-Print Network (OSTI)

We have carried out a series of observations of the 1665- and 1667-MHz transitions of the 2Pi_3/2, J=3/2 OH ground state towards six selected HII regions in the Large Magellanic Cloud (IRAS 05011-6815 and MRC 0510-689, 0513-694B, 0539-691, 0540-696B, 0540-697A) using the Australia Telescope Compact Array. The study has provided the first accurate positions for known 1665- and 1667-MHz OH masers as well as detecting several new masers. The regions all contain H_2O or CH_3OH masers but OH masers were detected in only four. The 1.6-GHz continuum emission was also imaged to investigate its spatial relationship to the associated OH maser. Although some masers are close to compact continuum components, in other cases they are near the continuum distribution boundaries and perhaps have been created as a result of the HII region interacting with the surrounding interstellar medium.

K. J. Brooks; J. B. Whiteoak

1997-10-16T23:59:59.000Z

223

VERY LARGE ARRAY OBSERVATIONS OF THE INFRARED DARK CLOUD G19.30+0.07  

SciTech Connect

We present Very Large Array observations of ammonia (NH{sub 3}) (1,1), (2,2), and dicarbon sulfide (CCS) (2{sub 1}-1{sub 0}) emission toward the infrared dark cloud (IRDC) G19.30+0.07 at {approx}22 GHz. The NH{sub 3} emission closely follows the 8 {mu}m extinction. The NH{sub 3} (1,1) and (2,2) lines provide diagnostics of the temperature and density structure within the IRDC, with typical rotation temperatures of {approx}10-20 K and NH{sub 3} column densities of {approx}10{sup 15} cm{sup -2}. The estimated total mass of G19.30+0.07 is {approx}1130 M{sub sun}. The cloud comprises four compact NH{sub 3} clumps of mass {approx}30-160 M{sub sun}. Two coincide with 24 {mu}m emission, indicating heating by protostars, and show evidence of outflow in the NH{sub 3} emission. We report a water maser associated with a third clump; the fourth clump is apparently starless. A non-detection of 8.4 GHz emission suggests that the IRDC contains no bright H II regions and places a limit on the spectral type of an embedded zero-age main-sequence star to early-B or later. From the NH{sub 3} emission, we find that G19.30+0.07 is composed of three distinct velocity components or 'subclouds'. One velocity component contains the two 24 {mu}m sources and the starless clump, another contains the clump with the water maser, while the third velocity component is diffuse, with no significant high-density peaks. The spatial distribution of NH{sub 3} and CCS emission from G19.30+0.07 is highly anti-correlated, with the NH{sub 3} predominantly in the high-density clumps and the CCS tracing lower-density envelopes around those clumps. This spatial distribution is consistent with theories of evolution for chemically young low-mass cores, in which CCS has not yet been processed to other species and/or depleted in high-density regions.

Devine, K. E.; Churchwell, E. [Department of Astronomy, University of Wisconsin, 475 N. Charter Street, Madison, WI 53703 (United States); Chandler, C. J.; Borg, K. J. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Brogan, C.; Indebetouw, R. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Shirley, Y., E-mail: kdevine@collegeofidaho.edu [Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States)

2011-05-20T23:59:59.000Z

224

Observed and Simulated Cirrus Cloud Properties at the SGP CART Site  

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

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

225

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

Science Conference Proceedings (OSTI)

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

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

2008-02-01T23:59:59.000Z

226

Cloud Variability over the Indian Monsoon Region as Observed from Satellites  

Science Conference Proceedings (OSTI)

This study focuses on documenting the seasonal progression of the Asian monsoon by analyzing clouds and convection in the pre-, peak-, and postmonsoon seasons. This effort was possible as a result of the movement of Meteosat-5 over the Indian ...

Margaret M. Wonsick; Rachel T. Pinker; Yves Govaerts

2009-09-01T23:59:59.000Z

227

Cloud Phase Determination Using Ground-Based AERI Observations at SHEBA  

Science Conference Proceedings (OSTI)

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

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

2003-06-01T23:59:59.000Z

228

Multiwavelength Observations of a Developing Cloud System: The FIRE II 26 November 1991 Case Study  

Science Conference Proceedings (OSTI)

Simultaneous multiwavelength measurements of a developing cloud system were obtained by NOAA Doppler lidar, Doppler radar, Fourier transform infrared interferometer, and microwave and infrared radiometers on 26 November 1991. The evolution of the ...

J. M. Intrieri; W. L. Eberhard; T. Uttal; J. A. Shaw; J. B. Snider; Y. Han; B. W. Orr; S. Y. Matrosov

1995-12-01T23:59:59.000Z

229

AMSU-B Observations of Mixed-Phase Clouds over Land  

Science Conference Proceedings (OSTI)

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

M. N. Deeter; J. Vivekanandan

2005-01-01T23:59:59.000Z

230

Further Observations of the Production of Ice Particles in Clouds by Aircraft  

Science Conference Proceedings (OSTI)

Evidence is presented for the production of high concentrations of rather uniformly-sized ice crystals in a supercooled stratus cloud by a commercial, turbine, propeller-driven aircraft.

Arthur L. Rangno; Peter V. Hobbs

1984-06-01T23:59:59.000Z

231

Investigation of Regional and Seasonal Variations in Marine Boundary Layer Cloud Properties from MODIS Observations  

Science Conference Proceedings (OSTI)

To aid in understanding the role that marine boundary layer (MBL) clouds play in climate and assist in improving their representations in general circulation models (GCMs), their long-term microphysical and macroscale characteristics are ...

Michael P. Jensen; Andrew M. Vogelmann; William D. Collins; Guang J. Zhang; Edward P. Luke

2008-10-01T23:59:59.000Z

232

Distributions of Liquid, Vapor, and Ice in an Orographic Cloud from Field Observations  

Science Conference Proceedings (OSTI)

The phase distribution of the water mass of a cold orographic cloud into vapor, liquid, and ice is calculated from measurements made from an instrumented aircraft. The vapor values are calculated from thermodynamic measurements, and the liquid is ...

Taneil Uttal; Robert M. Rauber; Lewis O. Grant

1988-04-01T23:59:59.000Z

233

Radar Observations of Transport and Diffusion in Clouds and Precipitation Using TRACIR  

Science Conference Proceedings (OSTI)

A remote-sensing technique called TRACIR (tracking air with circular-polarization radar) was developed recently for studying air-parcel trajectories in clouds. The technique uses a dual-circular-polarization radar to detect microwave chaff fibers ...

Brooks E. Martner; Robert A. Kropfli; John D. Marwitz

1992-06-01T23:59:59.000Z

234

Comparisons between Model Forecast and Observed Boundary Layer Profiles and Related Comments on Cloud Prediction  

Science Conference Proceedings (OSTI)

In this study comparisons are made between Met Office mesoscale model boundary layer profiles, and radiosonde data collected in the central United Kingdom during three intensive boundary layer cloud experiments. Significant differences between ...

J. D. Price; M. R. Bush

2004-12-01T23:59:59.000Z

235

Numerical Simulations of Observed Arctic Stratus Clouds Using a Second-Order Turbulence Closure Model  

Science Conference Proceedings (OSTI)

A high-resolution one-dimensional version of a second-order turbulence closure radiative-convective model, developed at Los Alamos National Laboratory, is used to simulate the interactions among turbulence, radiation, and bulk cloud parameters in ...

W. S. Smith; C-Y. J. Kao

1996-01-01T23:59:59.000Z

236

Relationships between Arctic Sea Ice and Clouds during Autumn  

Science Conference Proceedings (OSTI)

The connection between sea ice variability and cloud cover over the Arctic seas during autumn is investigated by analyzing the 40-yr ECMWF Re-Analysis (ERA-40) products and the Television and Infrared Observation Satellite (TIROS) Operational ...

Axel J. Schweiger; Ron W. Lindsay; Steve Vavrus; Jennifer A. Francis

2008-09-01T23:59:59.000Z

237

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

SciTech Connect

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

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

2007-09-30T23:59:59.000Z

238

Weather at Sierra Negra: 7.3-year statistics and a new method to estimate the temporal fraction of cloud cover  

E-Print Network (OSTI)

Sierra Negra, one of the highest peaks in central Mexico, is the site of the Large Millimeter Telescope. We describe the first results of a comprehensive analysis of the weather data measured in situ from October 2000 to February 2008 to be used as a reference for future activity in the site. We compare the data from two different stations at the summit considering the accuracy of both instruments. We analysed the diurnal, seasonal and annual cycles for all the parameters. The thermal stability is remarkably good, crucial for a good performance of the telescopes. From the solar radiation data we developed a new method to estimate the fraction of time when the sky is clear of clouds. We show that our measurements are consistent with a warm standard atmosphere model. The conditions at the site are benign and stable given its altitude, showing that Sierra Negra is a extremely good site for millimeter and high energy observations.

Carrasco, E; Avila, R; Gutiérrez, C; Avilés, J L; Reyes, J; Meza, J; Yam, O

2009-01-01T23:59:59.000Z

239

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

Science Conference Proceedings (OSTI)

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

Roger Marchand; Thomas Ackerman

2011-05-01T23:59:59.000Z

240

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

Science Conference Proceedings (OSTI)

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

Jun Yang; Weitao Lu; Ying Ma; Wen Yao

2012-04-01T23:59:59.000Z

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


241

An Evaluation of WRF Simulations of Clouds over the Southern Ocean with A-Train Observations  

Science Conference Proceedings (OSTI)

The representation of the marine boundary layer (BL) clouds remains a formidable challenge for start-of-the-art simulations. A recent study by Bodas-Salcedo et al. (2012) using the UK Met Office Unified Model highlights that the underprediction of ...

Yi Huang; Steven T. Siems; Michael J. Manton; Gregory Thompson

242

profiles of optical Extinction Coefficients Calculated from Droplet Spectra Observed in Marine Stratus Cloud Layers  

Science Conference Proceedings (OSTI)

Airborne measurements of droplet spectra n(r) where r is droplet radius were made in stratus cloud layers over the ocean 130 km southwest of San Diego. Optical extinction coefficients ?e were calculated at selected wavelengths (?= 0.53, 3.75 and ...

V. Ray Noonkester

1985-06-01T23:59:59.000Z

243

The Segregation of Aerosols by Cloud-Nucleating Activity. Part II: Observation of an Urban Aerosol  

Science Conference Proceedings (OSTI)

The submicron aerosol of metropolitan Seattle was segregated into CCN and non-CCN fractions by a high-flux thermal diffusion cloud chamber in series with a dichotomous separator. Each segregated fraction of the five-hour daily sample was ...

Lee Harrison

1985-04-01T23:59:59.000Z

244

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

E-Print Network (OSTI)

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

Magee, Nathan

2011-01-01T23:59:59.000Z

245

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

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

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

246

The 13–14 December 2001 IMPROVE-2 Event. Part II: Comparisons of MM5 Model Simulations of Clouds and Precipitation with Observations  

Science Conference Proceedings (OSTI)

This paper compares airborne in situ observations of cloud microphysical parameters with the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) simulations, using the Reisner-2 ...

Matthew F. Garvert; Christopher P. Woods; Brian A. Colle; Clifford F. Mass; Peter V. Hobbs; Mark T. Stoelinga; Justin B. Wolfe

2005-10-01T23:59:59.000Z

247

Surface Solar Radiation Flux and Cloud Radiative Forcing for the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP): A Satellite, Surface Observations, and Radiative Transfer Model Study  

Science Conference Proceedings (OSTI)

This study presents surface solar radiation flux and cloud radiative forcing results obtained by using a combination of satellite and surface observations interpreted by means of a simple plane-parallel radiative transfer model called 2001. This ...

Catherine Gautier; Martin Landsfeld

1997-05-01T23:59:59.000Z

248

THE GALFA-H I COMPACT CLOUD CATALOG  

Science Conference Proceedings (OSTI)

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

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

2012-10-10T23:59:59.000Z

249

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

E-Print Network (OSTI)

This dissertation focuses on the global investigation of optically thin cirrus cloud optical thickness (tau) and microphysical properties, such as, effective particle size (D_(eff)) and ice crystal habits (shapes), based on the global satellite observations and fast radiative transfer models (RTMs). In the first part, we develop two computationally efficient RTMs simulating satellite observations under cloudy-sky conditions in the visible/shortwave infrared (VIS/SWIR) and thermal inferred (IR) spectral regions, respectively. To mitigate the computational burden associated with absorption, thermal emission and multiple scattering, we generate pre-computed lookup tables (LUTs) using two rigorous models, i.e., the line-by-line radiative transfer model (LBLRTM) and the discrete ordinates radiative transfer model (DISORT). The second part introduces two methods (i.e., VIS/SWIR- and IR-based methods) to retrieve tau and D_(eff) from satellite observations in corresponding spectral regions of the two RTMs. We discuss the advantages and weakness of the two methods by estimating the impacts from different error sources on the retrievals through sensitivity studies. Finally, we develop a new method to infer the scattering phase functions of optically thin cirrus clouds in a water vapor absorption channel (1.38-µm). We estimate the ice crystal habits and surface structures by comparing the inferred scattering phase functions and numerically simulated phase functions calculated using idealized habits.

Wang, Chenxi

2013-08-01T23:59:59.000Z

250

Very Large Array Observations of Ammonia in Infrared-Dark Clouds II: Internal Kinematics  

E-Print Network (OSTI)

Infrared-dark clouds (IRDCs) are believed to be the birthplaces of rich clusters and thus contain the earliest phases of high-mass star formation. We use the Green Bank Telescope (GBT) and Very Large Array (VLA) maps of ammonia (NH3) in six IRDCs to measure their column density and temperature structure (Paper 1), and here, we investigate the kinematic structure and energy content. We find that IRDCs overall display organized velocity fields, with only localized disruptions due to embedded star formation. The local effects seen in NH3 emission are not high velocity outflows but rather moderate (few km/s) increases in the line width that exhibit maxima near or coincident with the mid-infrared emission tracing protostars. These line width enhancements could be the result of infall or (hidden in NH3 emission) outflow. Not only is the kinetic energy content insufficient to support the IRDCs against collapse, but also the spatial energy distribution is inconsistent with a scenario of turbulent cloud support. We co...

Ragan, Sarah E; Bergin, Edwin A; Wilner, David

2012-01-01T23:59:59.000Z

251

Cloud-Base-Height Estimation from Paired Ground-Based Hemispherical Observations  

Science Conference Proceedings (OSTI)

Total-sky imager (TSI) and hemispheric-sky imager (HSI) each have a hemispherical field of view, and many TSIs are now deployed. These instruments have been used routinely to provide a time series of the fractional sky cover only. In this study, ...

Evgueni Kassianov; Charles N. Long; Jason Christy

2005-08-01T23:59:59.000Z

252

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

Science Conference Proceedings (OSTI)

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

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

2011-12-20T23:59:59.000Z

253

Spatial and Temporal Scales of Precipitating Tropical Cloud Systems in Satellite Imagery and the NCAR CCM3  

Science Conference Proceedings (OSTI)

Testing general circulation model parameterizations against observations is traditionally done by comparing simulated and observed, time-averaged quantities, such as monthly mean cloud cover, evaluated on a stationary grid. This approach ignores ...

Eric M. Wilcox

2003-11-01T23:59:59.000Z

254

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

Science Conference Proceedings (OSTI)

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

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

2008-04-01T23:59:59.000Z

255

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

Science Conference Proceedings (OSTI)

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

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

256

Relative Humidity and Temperature Influences on Cirrus Formation and Evolution: Observations from Wave Clouds and FIRE II  

Science Conference Proceedings (OSTI)

Measurements in orographic wave clouds. and in cirrus sampled during FIRE II, are used to investigate ice nucleation in the upper troposphere. The dynamically and microphysically simpler quasi-steady-state wave clouds provide relatively ideal ...

Andrew J. Heymsfield; Larry M. Miloshevich

1995-12-01T23:59:59.000Z

257

Marine Stratocumulus Cloud Fields off the Coast of Southern California Observed Using LANDSAT Imagery. Part II: Textural Analysis  

Science Conference Proceedings (OSTI)

Statistical measures of the spatial distributions of gray levels (cloud reflectivities) are determined for LANDSAT Multispectral Scanner digital data. Textural properties for twelve stratocumulus cloud fields, seven cumulus fields, and two cirrus ...

R. M. Welch; S. K. Sengupta; K. S. Kuo

1988-04-01T23:59:59.000Z

258

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

Science Conference Proceedings (OSTI)

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

Soline Bielli; Frank Roux

1999-06-01T23:59:59.000Z

259

A Simple Method for the Assessment of the Cloud Cover State in High-Latitude Regions by a Ground-Based Digital Camera  

Science Conference Proceedings (OSTI)

This work describes the development of a simple method of field estimating the sky cloud coverage percentage for several applications at the Brazilian Antarctic Station, Ferraz (62°05?S, 58°23.5?W). The database of this method was acquired by a ...

M. P. Souza-Echer; E. B. Pereira; L. S. Bins; M. A. R. Andrade

2006-03-01T23:59:59.000Z

260

Satellite-Based Imagery Techniques for Daytime Cloud/Snow Delineation from MODIS  

Science Conference Proceedings (OSTI)

This paper presents two multispectral enhancement techniques for distinguishing between regions of cloud and snow cover using optical spectrum passive radiometer satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS)...

Steven D. Miller; Thomas F. Lee; Robert L. Fennimore

2005-07-01T23:59:59.000Z

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


261

Remote Sensing of Cloud Parameters  

Science Conference Proceedings (OSTI)

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

Moustafa T. Chahine

1982-01-01T23:59:59.000Z

262

GFDL ARM Project Technical Report: Using ARM Observations to Evaluate Cloud and Convection Parameterizations & Cloud-Convection-Radiation Interactions in the GFDL Atmospheric General Circulation Model  

SciTech Connect

This report briefly summarizes the progress made by ARM postdoctoral fellow, Yanluan Lin, at GFDL during the period from October 2008 to present. Several ARM datasets have been used for GFDL model evaluation, understanding, and improvement. This includes a new ice fall speed parameterization with riming impact and its test in GFDL AM3, evaluation of model cloud and radiation diurnal and seasonal variation using ARM CMBE data, model ice water content evaluation using ARM cirrus data, and coordination of the TWPICE global model intercomparison. The work illustrates the potential and importance of ARM data for GCM evaluation, understanding, and ultimately, improvement of GCM cloud and radiation parameterizations. Future work includes evaluation and improvement of the new dynamicsPDF cloud scheme and aerosol activation in the GFDL model.

V. Ramaswamy; L. J. Donner; J-C. Golaz; S. A. Klein

2010-06-17T23:59:59.000Z

263

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

Science Conference Proceedings (OSTI)

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

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

2011-06-01T23:59:59.000Z

264

A Cloud and Precipitation Feature Database from Nine Years of TRMM Observations  

Science Conference Proceedings (OSTI)

An event-based method of analyzing the measurements from multiple satellite sensors is presented by using observations of the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR), Microwave Imager (TMI), Visible and Infrared ...

Chuntao Liu; Edward J. Zipser; Daniel J. Cecil; Stephen W. Nesbitt; Steven Sherwood

2008-10-01T23:59:59.000Z

265

XMM-Newton observations of the Small Magellanic Cloud: X-ray outburst of the 6.85 s pulsar XTE J0103-728  

E-Print Network (OSTI)

A bright X-ray transient was seen during an XMM-Newton observation in the direction of the Small Magellanic Cloud (SMC) in October 2006. The EPIC data allow us to accurately locate the source and to investigate its temporal and spectral behaviour. X-ray spectra covering 0.2-10 keV and pulse profiles in different energy bands were extracted from the EPIC data. The detection of 6.85 s pulsations in the EPIC-PN data unambiguously identifies the transient with XTE J0103-728, discovered as 6.85 s pulsar by RXTE. The X-ray light curve during the XMM-Newton observation shows flaring activity of the source with intensity changes by a factor of two within 10 minutes. Modelling of pulse-phase averaged spectra with a simple absorbed power-law indicates systematic residuals which can be accounted for by a second emission component. For models implying blackbody emission, thermal plasma emission or emission from the accretion disk (disk-blackbody), the latter yields physically sensible parameters. The photon index of the power-law of ~0.4 indicates a relatively hard spectrum. The 0.2-10 keV luminosity was 2x10^{37} with a contribution of ~3% from the disk-blackbody component. A likely origin for the excess emission is reprocessing of hard X-rays from the neutron star by optically thick material near the inner edge of an accretion disk. From a timing analysis we determine the pulse period to 6.85401(1) s indicating an average spin-down of ~0.0017 s per year since the discovery of XTE J0103-728 in May 2003. The X-ray properties and the identification with a Be star confirm XTE J0103-728 as Be/X-ray binary transient in the SMC.

F. Haberl; W. Pietsch

2008-01-30T23:59:59.000Z

266

Possible Observations of Noctilucent Clouds by Thomas Romney Robinson C. J. Butler  

E-Print Network (OSTI)

.They are believed to be composed of ice crystals which reflect the light of the Sun shining from below the observer to be composed of extra-terrestrial particles which, as they descend through the atmosphere to the vicinity Observatory, best known by meteorologists for his Cup Anemometer. From a painting by Maud Humphrey

267

Simulation of microphysical structure associated with tropical cloud clusters using mesoscale model and comparison with TRMM observations  

Science Conference Proceedings (OSTI)

An attempt has been made in the present study to examine the microphysical structure of a non-squall Tropical Cloud Cluster (TCC). Three-dimensional model simulations of cloud microphysical structure associated with a non-squall TCC occurred on 26 October ...

S. Abhilash; K. Mohankumar; S. Das

2008-04-01T23:59:59.000Z

268

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

E-Print Network (OSTI)

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

Solomon, Amy

269

Fault Tolerance and Scaling in e-Science Cloud Applications: Observations from the Continuing Development of MODISAzure  

Science Conference Proceedings (OSTI)

It can be natural to believe that many of the traditional issues of scale have been eliminated or at least greatly reduced via cloud computing. That is, if one can create a seemingly wellfunctioning cloud application that operates correctly on small or moderate-sized problems, then the very nature of cloud programming abstractions means that the same application will run as well on potentially significantly larger problems. In this paper, we present our experiences taking MODISAzure, our satellite data processing system built on the Windows Azure cloud computing platform, from the proof-of-concept stage to a point of being able to run on significantly larger problem sizes (e.g., from national-scale data sizes to global-scale data sizes). To our knowledge, this is the longest-running eScience application on the nascent Windows Azure platform. We found that while many infrastructure-level issues were thankfully masked from us by the cloud infrastructure, it was valuable to design additional redundancy and fault-tolerance capabilities such as transparent idempotent task retry and logging to support debugging of user code encountering unanticipated data issues. Further, we found that using a commercial cloud means anticipating inconsistent performance and black-box behavior of virtualized compute instances, as well as leveraging changing platform capabilities over time. We believe that the experiences presented in this paper can help future eScience cloud application developers on Windows Azure and other commercial cloud providers.

Li, Jie; Humphrey, Marty; Cheah, You-Wei; Ryu, Youngryel; Agarwal, Deb; Jackson, Keith; Ingen, Catharine van

2010-04-01T23:59:59.000Z

270

Temporal and Vertical Distribution of Acidity and Ionic Composition in Clouds: Comparison between Modeling Results and Observations  

Science Conference Proceedings (OSTI)

Cyclic temporal variations of pH and ionic concentration in sampled clouds which traversed the Mt. Mitchell State Park site (35°44?05?N, 82°17?15?W, 2006 m MSL) during the summers of 1986, 1987 and 1988 are reported. These clouds typically had a ...

T. P. DeFelice; V. K. Saxena

1990-05-01T23:59:59.000Z

271

Spitzer Infrared Spectrograph Observations of Magellanic Cloud Planetary Nebulae: the nature of dust in low metallicity circumstellar ejecta  

E-Print Network (OSTI)

We present 5 - 40 micron spectroscopy of 41 planetary nebulae (PNe) in the Magellanic Clouds, observed with the Infrared Spectrograph on board the Spitzer Space Telescope. The spectra show the presence of a combination of nebular emission lines and solid-state features from dust, superimposed on the thermal IR continuum. By analyzing the 25 LMC and 16 SMC PNe in our sample we found that the IR spectra of 14 LMC and 4 SMC PNe are dominated by nebular emission lines, while the other spectra show solid-state features. We observed that the solid-state features are compatible with carbon-rich dust grains (SiC, polycyclic aromatic hydrocarbons (PAHs), etc.) in most cases, except in three PNe showing oxygen-rich dust features. The frequency of carbonaceous dust features is generally higher in LMC than in SMC PNe. The spectral analysis allowed the correlations of the dust characteristics with the gas composition and morphology, and the properties of the central stars. We found that: 1) all PNe with carbonaceous dust features have C/O>1, none of these being bipolar or otherwise highly asymmetric; 2) all PNe with oxygen-rich dust features have C/Oproduction efficiency depends on metallicity, with low metallicity environments not favoring dust production.

L. Stanghellini; P. Garcia-Lario; D. A. Garcia-Hernandez; J. V. Perea-Calderon; J. E. Davies; A. Manchado; E. Villaver; R. A. Shaw

2007-09-04T23:59:59.000Z

272

Determination of the Optical Thickness and Effective Particle Radius of Clouds from Reflected Solar Radiation Measurements. Part II: Marine Stratocumulus Observations  

Science Conference Proceedings (OSTI)

A multispectral scanning radiometer has been used to obtain measurements of the reflection function of marine stratocumulus clouds at 0.75, 1.65 and 2.16 ?m. These observations were obtained from the NASA ER-2 aircraft as part of the First ISCCP [...

Teruyuki Nakajima; Michael D. King; James D. Spinhirne; Lawrence F. Radke

1991-03-01T23:59:59.000Z

273

The Retrieval of Marine Stratiform Cloud Properties from Multiple Observations in the 3.9-µm Window under Conditions of Varying Solar Illumination  

Science Conference Proceedings (OSTI)

Radiometric observations in the 3.9-µm region have been used by a number of investigators for the determination of cloud parameters or sea surface temperature at night. Only a few attempts have been made to perform quantitative assessments of ...

Thomas J. Kleespies

1995-07-01T23:59:59.000Z

274

Testing a New Cirrus Cloud Parameterizaton  

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

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

275

Observational Analyses of North Atlantic Tropical Cyclones from NOAA Polar-Orbiting Satellite Microwave Data  

Science Conference Proceedings (OSTI)

Passive microwave observations from the current NOAA series of polar-orbiting satellites of a large sample of North Atlantic tropical cyclones are qualitatively and quantitatively analyzed. Microwave observations can penetrate the cloud cover ...

Christopher S. Velden

1989-01-01T23:59:59.000Z

276

Radiative Transfer Simulations Using Mesoscale Cloud Model Outputs: Comparisons with Passive Microwave and Infrared Satellite Observations for Midlatitudes  

Science Conference Proceedings (OSTI)

Real midlatitude meteorological cases are simulated over western Europe with the cloud mesoscale model Méso-NH, and the outputs are used to calculate brightness temperatures at microwave frequencies with the Atmospheric Transmission at Microwave (...

Ingo Meirold-Mautner; Catherine Prigent; Eric Defer; Juan R. Pardo; Jean-Pierre Chaboureau; Jean-Pierre Pinty; Mario Mech; Susanne Crewell

2007-05-01T23:59:59.000Z

277

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

Science Conference Proceedings (OSTI)

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

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

2009-10-01T23:59:59.000Z

278

Comparison of Four Cloud Schemes in Simulating the Seasonal Mean Field Forced by the Observed Sea Surface Temperature  

Science Conference Proceedings (OSTI)

The impacts of four stratiform cloud parameterizations on seasonal mean fields are investigated using the global version of the Experimental Climate Prediction Center (ECPC) global-to-regional forecast system (G-RSM). The simulated fields are ...

Akihiko Shimpo; Masao Kanamitsu; Sam F. Iacobellis; Song-You Hong

2008-07-01T23:59:59.000Z

279

Evaluating Cloud Contamination in Clear-Sky MODIS Terra Daytime Land Surface Temperatures Using Ground-Based Meteorology Station Observations  

Science Conference Proceedings (OSTI)

Environment Canada meteorological station hourly sampled air temperatures Tair at four stations in the southwest Yukon were used to identify cloud contamination in the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra clear-sky daytime ...

Scott N. Williamson; David S. Hik; John A. Gamon; Jeffrey L. Kavanaugh; Saewan Koh

2013-03-01T23:59:59.000Z

280

A Study of the Aerosol Effect on a Cloud Field with Simultaneous Use of GCM Modeling and Satellite Observation  

Science Conference Proceedings (OSTI)

The indirect effect of aerosols was simulated by a GCM for nonconvective water clouds and was compared with remote sensing results from the Advanced Very High Resolution Radiometer (AVHRR) satellite-borne sensor for January, April, July, and ...

Kentaroh Suzuki; Teruyuki Nakajima; Atusi Numaguti; Toshihiko Takemura; Kazuaki Kawamoto; Akiko Higurashi

2004-01-01T23:59:59.000Z

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


281

Marine Stratocumulus Cloud Fields off the Coast of Southern California Observed Using LANDSAT Imagery. Part I: Structural Characteristics  

Science Conference Proceedings (OSTI)

The structural characteristics of stratocumulus cloud fields off the coast of southern California are investigated using LANDSAT Multispectral Scanner (MSS) imagery. Twelve scenes in this area are examined along with three other stratocumulus ...

R. M. Welch; K. S. Kuo; B. A. Wielicki; S. K. Sengupta; L. Parker

1988-04-01T23:59:59.000Z

282

The Retrieval of Profiles of Particulate Extinction from Cloud-Aerosol Lidar Infrared Pathfinder Satellite Observations (CALIPSO) Data: Algorithm Description  

Science Conference Proceedings (OSTI)

This work describes the algorithms used for the fully automated retrieval of profiles of particulate extinction coefficients from the attenuated backscatter data acquired by the lidar on board the Cloud-Aerosol Lidar Infrared Pathfinder Satellite ...

Stuart A. Young; Mark A. Vaughan

2009-06-01T23:59:59.000Z

283

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

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

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

284

A Simulation of a Squall Line Using a Nonhydrostatic Cloud Model with a 5-km Horizontal Grid  

Science Conference Proceedings (OSTI)

A three-dimensional nonhydrostatic cloud model is used to simulate the squall line observed in central Texas on 11 April 1979. The cloud model covers an area 400 × 400 km2 with a 5-km horizontal resolution and is supplied initial and boundary ...

Richard S. Hemler; Frank B. Lipps; Bruce B. Ross

1991-12-01T23:59:59.000Z

285

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

SciTech Connect

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

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

2013-08-10T23:59:59.000Z

286

Reflected Fluxes for Broken Clouds over a Lambertian Surface  

Science Conference Proceedings (OSTI)

Reflected fluxes are calculated for broken cloudiness (i.e., nonplane parallel) as a function of cloud cover, cloud optical depth, solar zenith angle and surface albedo. These calculations extend previous results for broken cloud reflected fluxes ...

Ronald M. Welch; Bruce A. Wielicki

1989-05-01T23:59:59.000Z

287

Cloud Predictions Diagnosed from Global Weather Model Forecasts  

Science Conference Proceedings (OSTI)

The U.S. Air Force has a long history of investment in cloud analysis and prediction operations. Their need for accurate cloud cover information has resulted in routine production of global cloud analyses (from their RTNEPH analysis model) and ...

Donald C. Norquist

2000-10-01T23:59:59.000Z

288

Four Years of Global Cirrus Cloud Statistics Using HIRS  

Science Conference Proceedings (OSTI)

Trends in global upper-tropospheric transmissive cirrus cloud cover are beginning to emerge from a four-year cloud climatology using NOAA polar-orbiting High-Resolution Infrared Radiation Sounder (HIRS) multispectral data. Cloud occurrence, ...

Donald P. Wylie; W. Paul Menzel; Harold M. Woolf; Kathleen I. Strabala

1994-12-01T23:59:59.000Z

289

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

Science Conference Proceedings (OSTI)

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

Bryan C. Weare

1994-02-01T23:59:59.000Z

290

Turbulent molecular clouds  

E-Print Network (OSTI)

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

Hennebelle, Patrick

2012-01-01T23:59:59.000Z

291

IC cloud: Enabling compositional cloud  

Science Conference Proceedings (OSTI)

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

Yi-Ke Guo; Li Guo

2011-08-01T23:59:59.000Z

292

Comparison of ISCCP and Other Cloud Amounts  

Science Conference Proceedings (OSTI)

A new 8-year global cloud climatology has been produced by the International Satellite Cloud Climatology Project (ISCCP) that provides information every 3 h at 280-km spatial resolution covering the period from July 1983 through June 1991. If ...

William B. Rossow; Alison W. Walker; Leonid C. Garder

1993-12-01T23:59:59.000Z

293

Observations of the Cross-Lake Cloud and Snow Evolution in a Lake-Effect Snow Event  

Science Conference Proceedings (OSTI)

While the total snowfall produced in lake-effect storms can be considerable, little is known about how clouds and snow evolve within lake-effect boundary layers. Data collected over Lake Michigan on 10 January 1998 during the Lake-Induced ...

Faye E. Barthold; David A. R. Kristovich

2011-08-01T23:59:59.000Z

294

Classification of Ice Crystal Shapes in Midlatitude Ice Clouds from Three Years of Lidar Observations over the SIRTA Observatory  

Science Conference Proceedings (OSTI)

This paper presents a study of ice crystal shapes in midlatitude ice clouds inferred from a technique based on the comparison of ray-tracing simulations with lidar depolarization ratio measured at 532 nm. This technique is applied to three years ...

Vincent Noel; Helene Chepfer; Martial Haeffelin; Yohann Morille

2006-11-01T23:59:59.000Z

295

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

Science Conference Proceedings (OSTI)

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

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

2005-04-01T23:59:59.000Z

296

Polarimetric Radar Observations in the Ice Region of Precipitating Clouds at C-Band and X-Band Radar Frequencies  

Science Conference Proceedings (OSTI)

Data collected by C-band and X-band radars in northwestern Italy are analyzed to study the behavior of the polarimetric variables in the ice region of precipitating clouds, with special emphasis on the specific differential phase Kdp. It is found ...

R. Bechini; L. Baldini; V. Chandrasekar

2013-05-01T23:59:59.000Z

297

Polar Stratospheric Cloud Observations in the 2006/07 Arctic Winter by Using an Improved Micropulse Lidar  

Science Conference Proceedings (OSTI)

The potential of a new improved version of micropulse lidar (MPL-4) on polar stratospheric cloud (PSC) detection is evaluated in the Arctic over Ny-Ĺlesund (79°N, 12°E), Norway. The campaign took place from January to February 2007 in the frame ...

Carmen Cordoba-Jabonero; Manuel Gil; Margarita Yela; Marion Maturilli; Roland Neuber

2009-10-01T23:59:59.000Z

298

Nimbus-7 Global Cloud Climatology. Part II: First Year Results  

Science Conference Proceedings (OSTI)

Regional and seasonal variations in global cloud cover observed by the Nimbus-7 satellite over 1 year are analyzed by examining the 4 midseason months—April, July and October 1979 and January 1980. The Nimbus-7 data set is generated from the ...

Larry L. Stowe; H. Y. Michael Yeh; Thomas F. Eck; Charlie G. Wellemeyer; H. Lee Kyle; The Nimbus-7 Cloud Data Processing Team

1989-07-01T23:59:59.000Z

299

Window coverings  

SciTech Connect

This brochure discusses the following: how heat loss and gain occurs, moisture problems, conventional coverings seldom save energy, plastic window sheets, insulated window coverings, and what to look for. (MHR)

1981-01-01T23:59:59.000Z

300

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

SciTech Connect

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

Michael R. Poellot

2009-01-09T23:59:59.000Z

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


301

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

E-Print Network (OSTI)

CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder Stellite Observations (CALIPSO). J. Geophys

302

CALIPSO/CALIOP Cloud Phase Discrimination Algorithm  

Science Conference Proceedings (OSTI)

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

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

2009-11-01T23:59:59.000Z

303

Observations of tornadoes and wall clouds with a portable FM-CW Doppler radar: 1989--1990 results  

SciTech Connect

The purpose of this paper is to report on our progress using a portable, 1 W,FM (frequency modulated)-CW (continuous wave) Doppler radar developed at the Los Alamos National Laboratory (LANL), to make measurements of the wind field in tornadoes and wall clouds along with simultaneous visual documentation. Results using a CW version of the radar in 1987--1988 are given in Bluestein and Unruh (1989). 18 refs., 2 figs., 1 tab.

Bluestein, H.B. (Oklahoma Univ., Norman, OK (USA). School of Meteorology); Unruh, W.P. (Los Alamos National Lab., NM (USA))

1990-01-01T23:59:59.000Z

304

A Critical Review of the Australian Experience in Cloud Seeding  

Science Conference Proceedings (OSTI)

From 1947 to 1994 a number of cloud-seeding experiments were done in Australia based on the static cloud-seeding hypothesis. A critical analysis of these successive cloud-seeding experiments, coupled with microphysical observations of the clouds, ...

Brian F. Ryan; Warren D. King

1997-02-01T23:59:59.000Z

305

Evaluation of AIRS cloud thermodynamic phase determination with CALIPSO  

Science Conference Proceedings (OSTI)

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

Hongchun Jin; Shaima L. Nasiri

306

On the Use of Cloud Forcing to Estimate Cloud Feedback  

Science Conference Proceedings (OSTI)

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

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

2004-10-01T23:59:59.000Z

307

FORMATION OF MASSIVE MOLECULAR CLOUD CORES BY CLOUD-CLOUD COLLISION  

SciTech Connect

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

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

2013-09-10T23:59:59.000Z

308

Supersaturation Intermittency in Turbulent Clouds  

Science Conference Proceedings (OSTI)

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

Raymond A. Shaw

2000-10-01T23:59:59.000Z

309

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

SciTech Connect

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

Luke,E.; Kollias, P.

2007-08-06T23:59:59.000Z

310

Posters Parameterization of Thin Mid-Level Stratiform Clouds  

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

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

311

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

Science Conference Proceedings (OSTI)

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

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

1994-09-01T23:59:59.000Z

312

Evaluating the Performance of Planetary Boundary Layer and Cloud Microphysical Parameterization Schemes in Convection-Permitting Ensemble Forecasts using Synthetic GOES-13 Satellite Observations  

Science Conference Proceedings (OSTI)

In this study, the ability of several cloud microphysical and planetary boundary layer parameterization schemes to accurately simulate cloud characteristics within 4-km-grid-spacing ensemble forecasts over the contiguous U.S. was evaluated through ...

Rebecca Cintineo; Jason A. Otkin; Ming Xue; Fanyou Kong

313

Retrieval of Thermal and Microphysical Variables in Observed Convective Storms. Part II: Sensitivity of Cloud Processes to Variation of the Microphysical Parameterization  

Science Conference Proceedings (OSTI)

The hydrometeor content and thermal fields in a thunderstorm are estimated from a three-dimensional kinematic cloud model employing Doppler wind fields and parameterized microphysical processes. The sensitivity of the cloud model calculations to ...

Conrad L. Ziegler

1988-03-01T23:59:59.000Z

314

Evaluation of Model-Predicted Top-of-Atmosphere Radiation and Cloud Parameters over Africa with Observations from GERB and SEVIRI  

Science Conference Proceedings (OSTI)

This study compared the Regional Atmospheric Climate Model version 2 (RACMO) with satellite data by simultaneously looking at cloud properties and top-of-atmosphere (TOA) fluxes. This study used cloud properties retrieved from Spinning Enhanced ...

Wouter Greuell; Erik van Meijgaard; Nicolas Clerbaux; Jan Fokke Meirink

2011-08-01T23:59:59.000Z

315

Cirrus Cloud Radiative and Microphysical Properties from Ground Observations and In Situ Measurements during FIRE 1991 and Their Application to Exhibit Problems in Cirrus Solar Radiative Transfer Modeling  

Science Conference Proceedings (OSTI)

Measurements from the FIRE 1991 cirrus cloud field experiment in the central United States are presented and analyzed.

S. Kinne; T. P. Ackerman; M. Shiobara; A. Uchiyama; A. J. Heymsfield; L. Miloshevich; J. Wendell; E. Eloranta; C. Purgold; R. W. Bergstrom

1997-09-01T23:59:59.000Z

316

Covered Bridges  

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

Covered Bridges Covered Bridges Nature Bulletin No. 644 June 3, 1961 Forest Preserve District of Cook County John J. Duffy, President Roberts Mann, Conservation Editor David H. Thompson, Senior Naturalist COVERED BRIDGES Covered bridges have a peculiar fascination for most of us. W e wish they could talk. Many of them are truly historic landmarks. Each one is a unique and picturesque relic of the days when .America was a young country. As a locality became more thickly settled the people demanded roads, improved roads, with bridges across creeks and rivers where fords or ferries had been the only means of crossing. There were no steel mills. But there were skilled woodsmen and virgin forests with huge trees from which they could fashion timbers of any dimension and length desired. Equally important, in certain regions there were master builders: craftsmen with shrewd knowledge of stresses and strains in trusses and arches. That is why covered bridges were and are so numerous in Vermont, New Hampshire, Pennsylvania, Ohio and Indiana. Lack of such men may explain the absence of those structures in Minnesota and other states where timber was plentiful.

317

In Situ Observation of Cirrus Scattering Phase Functions with 22° and 46° Halos: Cloud Field Study on 19 February 1998  

Science Conference Proceedings (OSTI)

Observations of halos and related phenomena due to ice crystals are commonly reported from ground observations and presented in the literature. Nevertheless, ice crystal characteristics have only been poorly documented from in situ measurements ...

Frederique Auriol; Jean-François Gayet; Guy Febvre; Olivier Jourdan; Laurent Labonnote; Gerard Brogniez

2001-11-01T23:59:59.000Z

318

Multiview Cloud-Top Height and Wind Retrieval with Photogrammetric Methods: Application to Meteosat-8 HRV Observations  

Science Conference Proceedings (OSTI)

The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) currently operates three geostationary satellites: Meteosat-5, Meteosat-7, and Meteosat-8. Observations by Meteosat-5 can be combined with observations from ...

Gabriela Seiz; Stephen Tjemkes; Philip Watts

2007-08-01T23:59:59.000Z

319

COLORS OF A SECOND EARTH. II. EFFECTS OF CLOUDS ON PHOTOMETRIC CHARACTERIZATION OF EARTH-LIKE EXOPLANETS  

SciTech Connect

As a test bed for future investigations of directly imaged terrestrial exoplanets, we present the recovery of the surface components of the Earth from multi-band diurnal light curves obtained with the EPOXI spacecraft. We find that the presence and longitudinal distribution of ocean, soil, and vegetation are reasonably well reproduced by fitting the observed color variations with a simplified model composed of a priori known albedo spectra of ocean, soil, vegetation, snow, and clouds. The effect of atmosphere, including clouds, on light scattered from surface components is modeled using a radiative transfer code. The required noise levels for future observations of exoplanets are also determined. Our model-dependent approach allows us to infer the presence of major elements of the planet (in the case of the Earth, clouds, and ocean) with observations having signal-to-noise ratio (S/N) {approx}> 10 in most cases and with high confidence if S/N {approx}> 20. In addition, S/N {approx}> 100 enables us to detect the presence of components other than ocean and clouds in a fairly model-independent way. Degradation of our inversion procedure produced by cloud cover is also quantified. While cloud cover significantly dilutes the magnitude of color variations compared with the cloudless case, the pattern of color changes remains. Therefore, the possibility of investigating surface features through light-curve fitting remains even for exoplanets with cloud cover similar to Earth's.

Fujii, Yuka; Suto, Yasushi; Turner, Edwin L. [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Kawahara, Hajime [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Fukuda, Satoru; Nakajima, Teruyuki [Center of Climate System Research, The University of Tokyo, Kashiwa 277-8568 (Japan); Livengood, Timothy A., E-mail: yuka.fujii@utap.phys.s.u-tokyo.ac.jp [NASA/Goddard Space Flight Center Greenbelt, MD 20771 (United States)

2011-09-10T23:59:59.000Z

320

The computation of cloud base height from paired whole-sky imaging cameras  

SciTech Connect

A major goal for global change studies is to improve the accuracy of general circulation models (GCMs) capable of predicting the timing and magnitude of greenhouse gas-induced global warming. Research has shown that cloud radiative feedback is the single most important effect determining the magnitude of possible climate responses to human activity. Of particular value to reducing the uncertainties associated with cloud-radiation interactions is the measurement of cloud base height (CBH), both because it is a dominant factor in determining the infrared radiative properties of clouds with respect to the earth`s surface and lower atmosphere and because CBHs are essential to measuring cloud cover fraction. We have developed a novel approach to the extraction of cloud base height from pairs of whole sky imaging (WSI) cameras. The core problem is to spatially register cloud fields from widely separated WSI cameras; this complete, triangulation provides the CBH measurements. The wide camera separation (necessary to cover the desired observation area) and the self-similarity of clouds defeats all standard matching algorithms when applied to static views of the sky. To address this, our approach is based on optical flow methods that exploit the fact that modern WSIs provide sequences of images. We will describe the algorithm and present its performance as evaluated both on real data validated by ceilometer measurements and on a variety of simulated cases.

Allmen, M.C.; Kegelmeyer, W.P. Jr.

1994-03-01T23:59:59.000Z

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


321

CDIAC Cloud Data Sets  

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

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

322

More Frequent Cloud-Free Sky and Less Surface Solar Radiation in China from 1955 to 2000  

SciTech Connect

Newly available data from extended weather stations and time period reveal that much of China has experienced statistically significant decreases in total cloud cover and low cloud cover over roughly the last half of the Twentieth century. This conclusion is supported by our recent analysis of the more reliably observed frequency of cloud-free sky and overcast sky. The total cloud cover and low cloud cover have decreased 0.88% and 0.33% per decade, respectively, and cloud-free days have increased 0.60% and overcast days decreased 0.78% per decade in China from 1954-2001. Meanwhile, both solar radiation and pan evaporation have decreased in most parts of China, with solar radiation decreasing 3.1 W/m2 and pan evaporation decreasing 39 mm per decade. Combined with other evidences documented in previous studies, we conjectured that increased air pollution may have produced a fog-like haze that reflected/absorbed radiation from the sun and resulted in less solar radiation reaching the surface, despite concurrent upward trends in cloud-free skies over China.

Qian, Yun; Kaiser, Dale P.; Leung, Lai R.; Xu, Ming

2006-01-11T23:59:59.000Z

323

Simultaneous Occurrence of Different Cloud Types  

Science Conference Proceedings (OSTI)

Cloud observations from land stations and from ships in the ocean are used to investigate the frequency of observation and the co-occurrence of different cloud types, and the geographical and seasonal variations of these co-occurrences. Ground-...

Stephen G. Warren; Carole J. Hahn; Julius London

1985-07-01T23:59:59.000Z

324

Evaluation and Intercomparison of Cloud Fraction and Radiative Fluxes in Recent Reanalyses over the Arctic Using BSRN Surface Observations  

Science Conference Proceedings (OSTI)

With continual advancements in data assimilation systems, new observing systems, and improvements in model parameterizations, several new atmospheric reanalysis datasets have recently become available. Before using these new reanalyses it is ...

Behnjamin J. Zib; Xiquan Dong; Baike Xi; Aaron Kennedy

2012-04-01T23:59:59.000Z

325

Assimilation of Satellite Imager Data and Surface Observations to Improve Analysis of Circulations Forced by Cloud Shading Contrasts  

Science Conference Proceedings (OSTI)

An assimilation system that performs continuous assimilation of satellite imager data and intermittent assimilation of hourly surface observations is described. The system was applied to a case study of the southeast United States that was ...

Frank H. Ruggiero; George D. Modica; Alan E. Lipton

2000-02-01T23:59:59.000Z

326

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

Science Conference Proceedings (OSTI)

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

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

2009-08-01T23:59:59.000Z

327

Climatology of Surface Meteorology, Surface Fluxes, Cloud Fraction, and Radiative Forcing over the Southeast Pacific from Buoy Observations  

Science Conference Proceedings (OSTI)

A 5-yr climatology of the meteorology, including boundary layer cloudiness, for the southeast Pacific region is presented using observations from a buoy located at 20°S, 85°W. The sea surface temperature and surface air temperature exhibit a ...

Virendra P. Ghate; Bruce A. Albrecht; Christopher W. Fairall; Robert A. Weller

2009-10-01T23:59:59.000Z

328

The Impact of humidity above stratiform clouds on indirect aerosol climate forcing  

SciTech Connect

Some of the global warming effect of anthropogenic greenhouse gases is offset by increased solar reflection from clouds with smaller droplets that form on increased numbers of cloud condensation nuclei in polluted air. The global magnitude of the resulting indirect aerosol climate forcing is estimated to be comparable (and opposed) to the anthropogenic carbon dioxide forcing, but estimates are highly uncertain because of complexities in characterizing the physical process that determine global aerosol and cloud populations and their interactions. Beyond reflecting sunlight more effectively, smaller droplets are less efficient at producing precipitation, and decreased precipitation is expected to result in increased cloud water and cloud cover, further increasing the indirect forcing. Yet polluted marine boundary-layer clouds are not generally observed to hold more water. Here we use model simulations of stratocumulus clouds to show that suppression of precipitation from increased droplet concentrations leads to increased cloud water only when sufficient precipitation reaches the surface, a condition favored when the overlying air is moist. Otherwise, aerosol induced suppression of precipitation enhances entrainment of overlying dry air, thereby reducing cloud water and diminishing the indirect climate forcing.

Ackerman, A S; Kirkpatrick, M P; Stevens, D E; Toon, O B

2004-12-20T23:59:59.000Z

329

Variations in Nimbus-7 Cloud Estimates. Part II: Regional Changes  

Science Conference Proceedings (OSTI)

Regional estimates of low, middle, high, and total cloud amounts derived from bispectral measurements from Nimbus-7 have been analyzed for the six-year period April 1979 through March 1985. Fractional cloud cover for the three height categories ...

Bryan C. Weare

1992-12-01T23:59:59.000Z

330

Tropospheric Influence on Solar Ultraviolet Radiation: The Role of Clouds  

Science Conference Proceedings (OSTI)

Measurements obtained from several Robertson-Berger (RB) meters over the course of one year define the role of cloud cover in moderating biologically effective ultraviolet radiation at the Earth's surface. In an annual mean sense, clouds reduce ...

John E. Frederick; Hilary E. Snell

1990-03-01T23:59:59.000Z

331

Cloud-Tracked Winds from Pioneer Venus OCPP Images  

Science Conference Proceedings (OSTI)

Analysis of ultraviolet image sequences, obtained from the Pioneer Venus Orbiter Cloud Photopolarimeter and covering five 80-day periods from 1979–1985, provides the first climatological description of the cloud top circulation on Venus. The ...

William B. Rossow; Anthony D. Del Genio; Timothy Eichler

1990-09-01T23:59:59.000Z

332

Marine Cloud Brightening  

Science Conference Proceedings (OSTI)

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

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

2012-09-07T23:59:59.000Z

333

Estimating Probabilities of Cloud-Free Fields-of-View From the Earth Through the Atmosphere  

Science Conference Proceedings (OSTI)

A model for estimating the probability of obtaining a cloud-free field-of-view as a function of ground-observer-reported total sky cover is presented for earth-to-space viewing applications. The development of the model and examples of its ...

Iver A. Lund; Donald D. Grantham; Richard E. Davis

1980-04-01T23:59:59.000Z

334

Assessment of Global Cloud Datasets from Satellites: Project and Database Initiated by the GEWEX Radiation Panel  

Science Conference Proceedings (OSTI)

Clouds cover about 70% of Earth's surface and play a dominant role in the energy and water cycle of our planet. Only satellite observations provide a continuous survey of the state of the atmosphere over the entire globe and across the wide range of ...

C. J. Stubenrauch; W. B. Rossow; S. Kinne; S. Ackerman; G. Cesana; H. Chepfer; L. Di Girolamo; B. Getzewich; A. Guignard; A. Heidinger; B. C. Maddux; W. P. Menzel; P. Minnis; C. Pearl; S. Platnick; C. Poulsen; J. Riedi; S. Sun-Mack; A. Walther; D. Winker; S. Zeng; G. Zhao

2013-07-01T23:59:59.000Z

335

OPTICAL-TO-NEAR-INFRARED SIMULTANEOUS OBSERVATIONS FOR THE HOT URANUS GJ3470b: A HINT OF A CLOUD-FREE ATMOSPHERE  

SciTech Connect

We present optical (g', R{sub c}, and I{sub c}) to near-infrared (J) simultaneous photometric observations for a primary transit of GJ3470b, a Uranus-mass transiting planet around a nearby M dwarf, by using the 50 cm MITSuME telescope and the 188 cm telescope, both at the Okayama Astrophysical Observatory. From these data, we derive the planetary mass, radius, and density as 14.1 {+-} 1.3 M{sub Circled-Plus }, 4.32{sup +0.21}{sub -0.10} R{sub Circled-Plus }, and 0.94 {+-} 0.12 g cm{sup -3}, respectively, thus confirming the low density that was reported by Demory et al. based on the Spitzer/IRAC 4.5 {mu}m photometry (0.72{sup +0.13}{sub -0.12} g cm{sup -3}). Although the planetary radius is about 10% smaller than that reported by Demory et al., this difference does not alter their conclusion that the planet possesses a hydrogen-rich envelope whose mass is approximately 10% of the planetary total mass. On the other hand, we find that the planet-to-star radius ratio (R{sub p} /R{sub s} ) in the J band (0.07577{sup +0.00072}{sub -0.00075}) is smaller than that in the I{sub c} (0.0802 {+-} 0.0013) and 4.5 {mu}m (0.07806{sup +0.00052}{sub -0.00054}) bands by 5.8% {+-} 2.0% and 2.9% {+-} 1.1%, respectively. A plausible explanation for the differences is that the planetary atmospheric opacity varies with wavelength due to absorption and/or scattering by atmospheric molecules. Although the significance of the observed R{sub p} /R{sub s} variations is low, if confirmed, this fact would suggest that GJ3470b does not have a thick cloud layer in the atmosphere. This property would offer a wealth of opportunity for future transmission-spectroscopic observations of this planet to search for certain molecular features, such as H{sub 2}O, CH{sub 4}, and CO, without being prevented by clouds.

Fukui, Akihiko; Yanagisawa, Kenshi; Kuroda, Daisuke; Shimizu, Yasuhiro; Izumiura, Hideyuki [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan); Narita, Norio; Takahashi, Yasuhiro H.; Kawauchi, Kiyoe; Nagayama, Shogo [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kurosaki, Kenji; Ikoma, Masahiro [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-0033 (Japan); Ohnuki, Hiroshi [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Onitsuka, Masahiro; Suenaga, Takuya [The Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirano, Teruyuki [Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ohta, Kouji [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake, Sakyo, Kyoto 606-8502 (Japan); Yoshida, Michitoshi [Hiroshima Astrophysical Science Center, Hiroshima University 1-3-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kawai, Nobuyuki, E-mail: afukui@oao.nao.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro, Tokyo 152-8551 (Japan)

2013-06-20T23:59:59.000Z

336

Fine Structure of Cloud Droplet Concentration as Seen from the Fast-FSSP Measurements. Part II: Results of In Situ Observations  

Science Conference Proceedings (OSTI)

A new feature of cloud structure has been discovered while analyzing the measurements obtained in situ in 57 clouds by the Fast Forward-Scattering Spectrometer Probe (FSSP). By means of a novel technique of statistical analysis, it is shown that ...

M. Pinsky; A. Khain

2003-01-01T23:59:59.000Z

337

Solar Radiative Transfer in Clouds with Vertical Internal Inhomogeneity  

Science Conference Proceedings (OSTI)

To investigate the photon transport in inhomogeneous clouds, a Monte Carlo cloud model with internal variation of optical properties is developed. The data for cloud vertical internal inhomogeneity are chosen from published observations. ...

J. Li; D. J. W. Geldart; Petr Chýlek

1994-09-01T23:59:59.000Z

338

On the Relationship between Thermodynamic Structure and Cloud Top, and Its Climate Significance in the Arctic  

Science Conference Proceedings (OSTI)

Cloud and thermodynamic characteristics from three Arctic observation sites are investigated to understand the collocation between low-level clouds and temperature inversions. A regime where cloud top was 100–200 m above the inversion base [cloud ...

Joseph Sedlar; Matthew D. Shupe; Michael Tjernström

2012-04-01T23:59:59.000Z

339

Cloud-Base Height Estimates Using a Combination of Meteorological Satellite Imagery and Surface Reports  

Science Conference Proceedings (OSTI)

This paper describes how the combination of a satellite-derived cloud classification with surface observations can improve analysis of cloud-base height. A cloud-base retrieval that combines a cloud classification derived from visible and ...

John M. Forsythe; Thomas H. Vonder Haar; Donald L. Reinke

2000-12-01T23:59:59.000Z

340

Cloud Chmabers  

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

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

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


341

Cloud Detection with MODIS. Part II: Validation  

Science Conference Proceedings (OSTI)

An assessment of the performance of the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask algorithm for Terra and Aqua satellites is presented. The MODIS cloud mask algorithm output is compared with lidar observations from ground [...

S. A. Ackerman; R. E. Holz; R. Frey; E. W. Eloranta; B. C. Maddux; M. McGill

2008-07-01T23:59:59.000Z

342

Cloud Color and Ocean Radiant Heating  

Science Conference Proceedings (OSTI)

It is well recognized that clouds regulate the flux of solar radiation reaching the sea surface. Clouds also affect the spectral distribution of incident irradiance. Observations of spectral and total incident solar irradiance made from the ...

David A. Siegel; Toby K. Westberry; J. Carter Ohlmann

1999-04-01T23:59:59.000Z

343

Radar and Radiation Properties of Ice Clouds  

Science Conference Proceedings (OSTI)

The authors derive relations of the equivalent radar reflectivity Ze and extinction coefficient ? of ice clouds and confirm the theory by in situ aircraft observations during the First International Satellite Cloud Climatology Project Regional ...

David Atlas; Sergey Y. Matrosov; Andrew J. Heymsfield; Ming-Dah Chou; David B. Wolff

1995-11-01T23:59:59.000Z

344

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

SciTech Connect

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

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

2011-11-01T23:59:59.000Z

345

A Tropical "NAT-like" belt observed from space  

E-Print Network (OSTI)

The optical properties of cold tropical tropopause clouds are examined on a global scale, using two years of space-borne lidar observations from CALIPSO (June 2006 ? May 2008). The linear depolarization ratio, color ratio and backscatter signal are analyzed in tropical clouds colder than 200 K in a way similar to recent studies of Polar Stratospheric Clouds (PSCs). It is found that the three categories of particles encountered in PSC (Ice, Sulfate Ternary Solutions or STS, and Nitric Acid Trihydrate or NAT) do also occur in tropical cold cloud layers. Particles with optical properties similar to NAT are few, but they cover the tropical belt and represent about 20% of cold cloud tropical particles. The optical behavior of these particles requires them to be small, non-spherical, optically thin, and persistent in the TTL at temperatures colder than 200 K; NAT particles and very small ice crystals meet these criteria.

Chepfer, Hélčne; 10.1029/2008GL036289

2009-01-01T23:59:59.000Z

346

Cellular clouds  

Science Conference Proceedings (OSTI)

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

Tim Forde; Linda Doyle

2013-03-01T23:59:59.000Z

347

Comparison of Model-Predicted Transport and Diffusion of Seeding Material with NOAA Satellite-Observed Seeding Track in Supercooled Layer Clouds  

Science Conference Proceedings (OSTI)

From 0615 to 0749 UTC 14 March 2000, an operation of cloud seeding for precipitation enhancement by aircraft was carried out in the middle part of Shaanxi Province, China. National Oceanic and Atmospheric Administration (NOAA)-14 satellite ...

Xing Yu; Jin Dai; Daniel Rosenfeld; Hengchi Lei; Xiaohong Xu; Peng Fan; Zhengqi Chen

2005-06-01T23:59:59.000Z

348

Obtaining Best Estimates for the Microphysical and Radiative Properties of Tropical Ice Clouds from TWP-ICE In Situ Microphysical Observations  

Science Conference Proceedings (OSTI)

Best estimates of the bulk microphysical and radiative properties (ice water content, visible extinction, effective radius, and total concentration) are derived for three case studies of tropical ice clouds sampled during the Tropical Warm Pool ...

A. Protat; G. M. McFarquhar; J. Um; J. Delanoë

2011-04-01T23:59:59.000Z

349

Full-Time, Eye-Safe Cloud and Aerosol Lidar Observation at Atmospheric Radiation Measurement Program Sites: Instruments and Data Processing  

Science Conference Proceedings (OSTI)

Atmospheric radiative forcing, surface radiation budget, and top-of-the-atmosphere radiance interpretation involve knowledge of the vertical height structure of overlying cloud and aerosol layers. During the last decade, the U.S. Department of ...

James R. Campbell; Dennis L. Hlavka; Ellsworth J. Welton; Connor J. Flynn; David D. Turner; James D. Spinhirne; V. Stanley Scott III; I. H. Hwang

2002-04-01T23:59:59.000Z

350

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

Science Conference Proceedings (OSTI)

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

Kotaro Bessho; Tetsuo Nakazawa; Shuji Nishimura; Koji Kato

2010-07-01T23:59:59.000Z

351

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

Science Conference Proceedings (OSTI)

A classification scheme is created to map the synoptic-scale (large scale) atmospheric state to distributions of local-scale cloud properties. This mapping is accomplished by a neural network that classifies 17 months of synoptic-scale initial ...

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

2006-11-01T23:59:59.000Z

352

An Investigation with a General Circulation Model of the Climatic Effects of Cloud Albedo Changes Caused by Atmospheric Pollution  

Science Conference Proceedings (OSTI)

A hemispheric general circulation model, with fixed zonally averaged cloud cover, was used to investigate the climatic impact of increased albedo of low-level clouds caused by atmospheric pollution. The albedo of these clouds was increased from ...

B. G. Hunt

1982-08-01T23:59:59.000Z

353

Microphysical Observations of Tropical Clouds  

Science Conference Proceedings (OSTI)

The results from airborne in situ sampling of convective tropical storms in the Amazon and Kwajalein are presented. Three cases from the Amazon and two from Kwajalein are compared and provide examples of the much larger dataset that was obtained ...

Jeffrey L. Stith; James E. Dye; Aaron Bansemer; Andrew J. Heymsfield; Cedric A. Grainger; Walter A. Petersen; Robert Cifelli

2002-02-01T23:59:59.000Z

354

Cumulus Clouds and Reflected Sunlight  

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

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

355

Thin Cloud Length Scales Using CALIPSO and CloudSat Data  

E-Print Network (OSTI)

Thin clouds are the most difficult cloud type to observe. The recent availability of joint cloud products from the active remote sensing instruments aboard CloudSat and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) facilitates the study of these clouds. Using one of these joint cloud products, 2B-GEOPROF-Lidar, and a post-processing algorithm designed to find horizontally continuous thin clouds within the cloud product, the locations, length scales, and vertical distributions by length of thin clouds are determined. It is found that thin clouds vary in length from a few km to over 2900 km and tend to be longer in the tropical upper troposphere than lower in the atmosphere and at higher latitudes. In the upper troposphere between 0° and 40°N, over 20% of all thin cloud measurements in the 2B-GEOPROF-Lidar product are contributed by thin clouds that are longer than 500 km. In fact, in this latitude range, over 65% of all thin cloud measurements are contributed by clouds longer than 100 km. Also, thin cloud length and frequency differ between the four seasons in the year of data used here.

Solbrig, Jeremy E.

2009-08-01T23:59:59.000Z

356

ARM - Publications: Science Team Meeting Documents: Clouds in the Darwin  

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

Clouds in the Darwin area and their relation to large-scale conditions Clouds in the Darwin area and their relation to large-scale conditions Jakob, Christian BMRC Hoeglund, Sofia Lulea University of Technology This poster shows a climatological overview of the cloud cover in the Darwin region (location of a TWP ARM site) in the very north of Australia. Information on optical thickness and cloud top pressure from the ISCCP Stage D1 product over the time period 1985 to 2000 has been used to examine how the cloud cover changes over the course of a year, and also how it is affected by the seasonal changes in the region. The most remarkable changes can be seen during the wet (summer) season, when wet westerly winds sweep in over Darwin and dramatically change the weather conditions. By dividing the cloud cover into cloud regimes, one can also see an

357

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

Science Conference Proceedings (OSTI)

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

Robert Wood; Paul R. Field

2000-06-01T23:59:59.000Z

358

ARM - Measurement - Cloud condensation nuclei  

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

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

359

A study of the link between cosmic rays and clouds with a cloud chamber at the CERN PS  

E-Print Network (OSTI)

Recent satellite data have revealed a surprising correlation between galactic cosmic ray (GCR) intensity and the fraction of the Earth covered by clouds. If this correlation were to be established by a causal mechanism, it could provide a crucial step in understanding the long-sought mechanism connecting solar and climate variability. The Earth's climate seems to be remarkably sensitive to solar activity, but variations of the Sun's electromagnetic radiation appear to be too small to account for the observed climate variability. However, since the GCR intensity is strongly modulated by the solar wind, a GCR-cloud link may provide a sufficient amplifying mechanism. Moreover if this connection were to be confirmed, it could have profound consequences for our understanding of the solar contributions to the current global warming. The CLOUD (Cosmics Leaving OUtdoor Droplets) project proposes to test experimentally the existence a link between cosmic rays and cloud formation, and to understand the microphysical mechanism. CLOUD plans to perform detailed laboratory measurements in a particle beam at CERN, where all the parameters can be precisely controlled and measured. The beam will pass through an expansion cloud chamber and a reactor chamber where the atmosphere is to be duplicated by moist air charged with selected aerosols and trace condensable vapours. An array of external detectors and mass spectrometers is used to analyse the physical and chemical characteristics of the aerosols and trace gases during beam exposure. Where beam effects are found, the experiment will seek to evaluate their significance in the atmosphere by incorporating them into aerosol and cloud models.

The Cloud Collaboration

2001-04-16T23:59:59.000Z

360

AIRS Subpixel Cloud Characterization Using MODIS Cloud Products  

Science Conference Proceedings (OSTI)

The Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS) measurements from the Earth Observing System's (EOS's) Aqua satellite enable improved global monitoring of the distribution of clouds. MODIS is ...

Jun Li; W. Paul Menzel; Fengying Sun; Timothy J. Schmit; James Gurka

2004-08-01T23:59:59.000Z

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


361

Microphysical Effects of Wintertime Cloud Seeding with Silver Iodide over the Rocky Mountains. Part III: Observations over the Grand Mesa, Colorado  

Science Conference Proceedings (OSTI)

During March 1986, several airborne and ground-based silver iodide (AgI) seeding experiments were conducted over the Grand Mesa, Colorado, during a three-day period of northerly flow and shallow orographic cloud. While little natural snowfall was ...

Arlin B. Super; Bruce A. Boe

1988-10-01T23:59:59.000Z

362

Cloud-to-Ground Lightning Activity in the 10–11 June 1985 Mesoscale Convective System Observed during the Oklahoma–Kansas PRE-STORM Project  

Science Conference Proceedings (OSTI)

As part of the field program for the Oklahoma–Kansas PRE-STORM Project conducted in May–June 1985, a network of electromagnetic direction-finders was deployed to locate and detect the polarity of cloud-to-ground (CG) lighting flashes associated ...

Steven A. Rutledge; Donald R. MacGorman

1988-07-01T23:59:59.000Z

363

The Effect of Shape and Spatial Distribution of Cumulus Clouds on Longwave Irradiance  

Science Conference Proceedings (OSTI)

In the longwave part of the spectrum, clouds are generally modeled in GCMs as flat black plates. The true effective cloud cover for transmittance of infrared radiation may be larger or smaller than the fractional cloud cover normal to the surface ...

Rosemary M. Killen; Robert G. Ellingson

1994-07-01T23:59:59.000Z

364

Cloud computing beyond objects: seeding the cloud  

Science Conference Proceedings (OSTI)

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

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

2009-10-01T23:59:59.000Z

365

Interannual Variations of Arctic Cloud Types in Relation to Sea Ice  

Science Conference Proceedings (OSTI)

Sea ice extent and thickness may be affected by cloud changes, and sea ice changes may in turn impart changes to cloud cover. Different types of clouds have different effects on sea ice. Visual cloud reports from land and ocean regions of the ...

Ryan Eastman; Stephen G. Warren

2010-08-01T23:59:59.000Z

366

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

Science Conference Proceedings (OSTI)

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

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

2010-09-28T23:59:59.000Z

367

ARM - Field Campaign - Spring Cloud IOP  

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

govCampaignsSpring Cloud IOP govCampaignsSpring Cloud IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Spring Cloud IOP 2000.03.01 - 2000.03.26 Lead Scientist : Gerald Mace For data sets, see below. Summary The Atmospheric Radiation Measurement (ARM) Program conducted a Cloud Intensive Operational Period (IOP) in March 2000 that was the first-ever effort to document the 3-dimensional cloud field from observational data. Prior numerical studies of solar radiation propagation through the atmosphere in the presence of clouds have been limited by the necessity to use theoretical representations of clouds. Three-dimensional representations of actual clouds and their microphysical properties, such as the distribution of ice and water, had previously not been possible

368

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

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

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

369

Clouds as Seen by Satellite Sounders (3I) and Imagers (ISCCP). Part II: A New Approach for Cloud Parameter Determination in the 3I Algorithms  

Science Conference Proceedings (OSTI)

First comparisons of improved initialization inversion (3I) cloud parameters determined from TIROS-N Operational Vertical Sounder observations with time–space-collocated clouds from the recently reprocessed International Satellite Cloud ...

C. J. Stubenrauch; A. Chédin; R. Armante; N. A. Scott

1999-08-01T23:59:59.000Z

370

A Pattern Recognition Technique for Distinguishing Surface and Cloud Types in the Polar Regions  

Science Conference Proceedings (OSTI)

Measurement of polar cloud cover is important because of its strong radiative influence on the energy balance of the snow and ice surface. Conventional satellite cloud detection schemes often fail in the polar regions because the visible and ...

Elizabeth Ebert

1987-10-01T23:59:59.000Z

371

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

SciTech Connect

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

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

2011-02-01T23:59:59.000Z

372

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

Science Conference Proceedings (OSTI)

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

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

2010-09-01T23:59:59.000Z

373

An Unattended Cloud-Profiling Radar for Use in Climate Research  

Science Conference Proceedings (OSTI)

A new millimeter-wave cloud radar (MMCR) has been designed to provide detailed, long-term observations of nonprecipitating and weakly precipitating clouds at Cloud and Radiation Testbed (CART) sites of the Department of Energy's Atmospheric ...

Kenneth P. Moran; Brooks E. Martner; M. J. Post; Robert A. Kropfli; David C. Welsh; Kevin B. Widener

1998-03-01T23:59:59.000Z

374

Limitations of Bispectral Infrared Cloud Phase Determination and Potential for Improvement  

Science Conference Proceedings (OSTI)

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

Shaima L. Nasiri; Brian H. Kahn

2008-11-01T23:59:59.000Z

375

A Test of the Simulation of Tropical Convective Cloudiness by a Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

A methodology is described for testing the simulation of tropical convective clouds by models through comparison with observations of clouds and precipitation from earth-orbiting satellites. Clouds are divided into categories that represent ...

Mario A. Lopez; Dennis L. Hartmann; Peter N. Blossey; Robert Wood; Christopher S. Bretherton; Terence L. Kubar

2009-06-01T23:59:59.000Z

376

Modeling Study of Ice Formation in Warm-Based Precipitating Shallow Cumulus Clouds  

Science Conference Proceedings (OSTI)

Observations of large concentrations of ice particles in the dissipating stage of warm-based precipitating shallow cumulus clouds point to the limitations of scientists’ understanding of the physics of such clouds and the possible role of cloud ...

Jiming Sun; Parisa A. Ariya; Henry G. Leighton; Man Kong Yau

2012-11-01T23:59:59.000Z

377

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

Science Conference Proceedings (OSTI)

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

R. Wood

2005-09-01T23:59:59.000Z

378

A Multisensor Perspective on the Radiative Impacts of Clouds and Aerosols  

Science Conference Proceedings (OSTI)

The launch of CloudSat and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) in 2006 provided the first opportunity to incorporate information about the vertical distribution of cloud and aerosols directly into global ...

David S. Henderson; Tristan L’Ecuyer; Graeme Stephens; Phil Partain; Miho Sekiguchi

2013-04-01T23:59:59.000Z

379

The CALIPSO Lidar Cloud and Aerosol Discrimination: Version 2 Algorithm and Initial Assessment of Performance  

Science Conference Proceedings (OSTI)

The Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite was launched in April 2006 to provide global vertically resolved measurements of clouds and aerosols. Correct discrimination between clouds and aerosols ...

Zhaoyan Liu; Mark Vaughan; David Winker; Chieko Kittaka; Brian Getzewich; Ralph Kuehn; Ali Omar; Kathleen Powell; Charles Trepte; Chris Hostetler

2009-07-01T23:59:59.000Z

380

Entrainment and the Temporal Development of the Microphysies of Convective Clouds  

Science Conference Proceedings (OSTI)

This paper addresses the question of time changes in the cloud parcels comprising a cumulus cloud. Observations are analyzed which show how a cloud parcel begins its life on the upshear side of the cloud. As the cloud as a whole continues to ...

David P. Rogers; James W. Telford; Steven K. Chai

1985-09-01T23:59:59.000Z

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


381

Cloud Computing Operations Research  

Science Conference Proceedings (OSTI)

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

Ilyas Iyoob, Emrah Zarifoglu, A. B. Dieker

2013-06-01T23:59:59.000Z

382

Ice Cloud Particle Size Distributions and Pressure-Dependent Terminal Velocities from In Situ Observations at Temperatures from 0 to ?86 C  

Science Conference Proceedings (OSTI)

The primary goal of this study is to derive ice particle terminal velocities from micron to cm sizes and for atmospheric pressures covering the range 200–1000 hPa from data spanning a wide range of locations, temperatures, and altitudes and to ...

Andrew J. Heymsfield; Carl Schmitt; Aaron Bansemer

383

Towards a Characterization of Arctic Mixed-Phase Clouds  

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

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

384

Vehicle body cover  

SciTech Connect

This patent describes a vehicle body covered with a vehicle body cover which comprises: a front cover part, a rear cover part, a pair of side cover parts, and a roof cover part: the front cover part having portions adapted to cover only a hood, an area around a windshield and tops of front fenders of a vehicle body. The portion covering the hood is separated from the portions covering the tops of the fenders by cuts in the front cover part, the front cover part having an un-cut portion corresponding to a position at which the hood is hinged to the car body. The front cover part has a cut-out at a position corresponding to the windshield of the vehicle body and the front cover part has at least one cut-out at a position corresponding to where a rear view mirror is attached to the vehicle body; and the rear cover part having portions adapted to cover an area around a rear window, a trunk lid and a rear end of the vehicle body, the portion covering the trunk lid separated from the rest of the rear cover part by cuts corresponding to three sides of the trunk lid and an un-cut portion corresponding to a position at which the trunk lid is hinged to the vehicle body. The rear cover part has a hole at position corresponding to a trunk lid lock, a cut-out portion at a position corresponding to the rear window of the vehicle body, a cut-out at a position corresponding to a license plate of the vehicle body and cut-outs at positions corresponding to rear taillights of the vehicle body.

Hirose, T.

1987-01-13T23:59:59.000Z

385

Cloud Condensation Nuclei  

Science Conference Proceedings (OSTI)

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

James G. Hudson

1993-04-01T23:59:59.000Z

386

Forecasting of Supercooled Clouds  

Science Conference Proceedings (OSTI)

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

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

1995-07-01T23:59:59.000Z

387

Multiple layer insulation cover  

DOE Patents (OSTI)

A multiple layer insulation cover for preventing heat loss in, for example, a greenhouse, is disclosed. The cover is comprised of spaced layers of thin foil covered fabric separated from each other by air spaces. The spacing is accomplished by the inflation of spaced air bladders which are integrally formed in the cover and to which the layers of the cover are secured. The bladders are inflated after the cover has been deployed in its intended use to separate the layers of the foil material. The sizes of the material layers are selected to compensate for sagging across the width of the cover so that the desired spacing is uniformly maintained when the cover has been deployed. The bladders are deflated as the cover is stored thereby expediting the storage process and reducing the amount of storage space required.

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

1981-11-03T23:59:59.000Z

388

Analysis of Tools Used to Quantify Droplet Clustering in Clouds  

Science Conference Proceedings (OSTI)

The spacing of cloud droplets observed along an approximately horizontal line through a cloud may be analyzed using a variety of techniques to reveal structure on small scales, sometimes called clustering, if such structure exists. A number of ...

Brad Baker; R. Paul Lawson

2010-10-01T23:59:59.000Z

389

Cloud Properties inferred from 8?12-µm Data  

Science Conference Proceedings (OSTI)

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

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

1994-02-01T23:59:59.000Z

390

Vertical Motions in Arctic Mixed-Phase Stratiform Clouds  

Science Conference Proceedings (OSTI)

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

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

2008-04-01T23:59:59.000Z

391

Assimilation of Global Cloud Imagery from Multiple Satellites  

Science Conference Proceedings (OSTI)

Synoptic images of the global cloud field have been created from measurements of infrared radiation taken aboard four geostationary and two polar-orbiting platforms simultaneously observing the earth's cloud field. A series of spatial and ...

Ken Tanaka; Karen Woodberry; Harry Hendon; Murry Salby

1991-10-01T23:59:59.000Z

392

Physically Retrieving Cloud and Thermodynamic Parameters from Ultraspectral IR Measurements  

Science Conference Proceedings (OSTI)

A physical inversion scheme has been developed dealing with cloudy as well as cloud-free radiance observed with ultraspectral infrared sounders to simultaneously retrieve surface, atmospheric thermodynamic, and cloud microphysical parameters. A ...

Daniel K. Zhou; William L. Smith Sr.; Xu Liu; Allen M. Larar; Stephen A. Mango; Hung-Lung Huang

2007-03-01T23:59:59.000Z

393

Drizzle in Stratiform Boundary Layer Clouds. Part II: Microphysical Aspects  

Science Conference Proceedings (OSTI)

This is the second of two observational papers examining drizzle in stratiform boundary layer clouds. Part I details the vertical and horizontal structure of cloud and drizzle parameters, including some bulk microphysical variables. In this paper,...

R. Wood

2005-09-01T23:59:59.000Z

394

A Cloud Climatology of the Southern Great Plains ARM CART  

Science Conference Proceedings (OSTI)

Cloud amount statistics from three different sources were processed and compared. Surface observations from a National Centers for Environmental Prediction dataset were used. The data (Edited Cloud Report; ECR) consist of synoptic weather reports ...

Steven M. Lazarus; Steven K. Krueger; Gerald G. Mace

2000-05-01T23:59:59.000Z

395

TWP-ICE Data from the GEWEX Cloud System Study: Data Integration for Model Evaluation (GCSSDIME)  

DOE Data Explorer (OSTI)

One of the most complete data sets of tropical cirrus and convection observations resulted from the Tropical Warm Pool - International Cloud Experiment (TWP-ICE) in the area around Darwin, Australia. The aim of the experiment is to examine convective cloud systems from their initial stages through the decaying and thin high level cirrus and measure their impact on the environment. The experiment design includes an unprecedented array of soundings and other information to support cloud resolving and other modeling studies as well as a large range of in-situ and remotely sensed observation platforms. A key component of the field campaign is a fleet of aircraft including the Dornier, Dimona, Egrett, Twin Otter, and Proteus. Together, these aircraft collected measurements of cloud properties and the meteorological environment from the planetary boundary layer up to 15 km high. The extensive ground network of cloud sensing radar, lidar and passive instruments are located on a ship and several ground sites throughout the experimental domain. This case study presents data from 19 Jan 2006 to 28 Feb 2006 and covers a region from 25S to 10S latitude and from 125E to 140E longitude.[Copied from http://gcss-dime.giss.nasa.gov/twp-ice/twp-ice.html

396

ARM - Measurement - Cloud phase  

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

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

397

Glossary Term - Cloud Chamber  

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

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

398

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

Science Conference Proceedings (OSTI)

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

Zhian Sun; Keith P. Shine

1995-07-01T23:59:59.000Z

399

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

Science Conference Proceedings (OSTI)

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

H. Morrison; J. O. Pinto

2006-07-01T23:59:59.000Z

400

Subsiding Shells around Shallow Cumulus Clouds  

Science Conference Proceedings (OSTI)

In this study large-eddy simulations (LES) are used to gain more knowledge on the shell of subsiding air that is frequently observed around cumulus clouds. First, a detailed comparison between observational and numerical results is presented to ...

Thijs Heus; Harm J. J. Jonker

2008-03-01T23:59:59.000Z

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


401

Numerical Simulation of Ice-Phase Convective Cloud Seeding  

Science Conference Proceedings (OSTI)

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

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

1980-08-01T23:59:59.000Z

402

On the Climatology of Upper-Layer Clouds  

Science Conference Proceedings (OSTI)

Unique data obtained from a regular aircraft sounding network that operated in the Soviet Union from 1957 through 1963 were used to estimate the potential accuracy of the cirrus cloud cover climatology based on routine ground-based weather ...

Ilia P. Mazin; Svetlana N. Burkovskaya; Elvira T. Ivanova

1993-09-01T23:59:59.000Z

403

Estimation of Ultraviolet-B Irradiance under Variable Cloud Conditions  

Science Conference Proceedings (OSTI)

Methods to estimate the irradiance of ultraviolet-B (UVB; 280–320 nm) radiation are needed to assess biological effects of changes in atmospheric composition. Measurements of the spatial distribution of sky cloud cover, temporal variability of ...

Richard H. Grant; Gordon M. Heisler

2000-06-01T23:59:59.000Z

404

Methodologies and Comparisons for Lund's Two Methods for Calculating Probability of Cloud-Free Line-of-Sight  

Science Conference Proceedings (OSTI)

To help in the implementation of Lund's probability of cloud-free line-of-sight (PCFLOS) calculations (method A and method B) for limited altitudes, a methodology for cumulative cloud cover calculation (required for both methods) is introduced ...

Shawn Yu; Kenneth E. Case; Julian Chernick

1986-03-01T23:59:59.000Z

405

Tamper resistant choke cover  

Science Conference Proceedings (OSTI)

A carburetor improvement is described for inhibiting tampering with a thermostatic choke coil after carburetor manufacture. A cover (3) fits over a choke coil housing (H) to enclose a choke lever, the thermostatic coil being mounted inside the cover. The cover has a circumferential flange (5) which abuts the outer surface of the housing, the flange having a notch (9) formed therein and the cover being rotatable about the outer surface of the housing to position one end of the coil relative to the choke lever. A retainer (7) locks the cover in a fixed position once the one end of the coil is located with respect to the choke lever. The retainer has a tab (11) insertable in the notch to prevent further rotation of the cover. A screw (15) having a detachable head (17) unremovably secures the retainer to the carburetor whereby once the retainer is secured, further movement of the cover is prevented.

Kneipkamp, L.E.

1981-12-29T23:59:59.000Z

406

Molecular Clouds and Millimetre Michael Burton  

E-Print Network (OSTI)

Molecular Clouds and Millimetre Astronomy Michael Burton School of Physics, University of New South of the Astronomical Society of Australia July 21, 1995 Abstract A condensed summary of molecular cloud astrophysics is presented. Some examples of the power of combining near--IR and mm molecular line observations are given

Burton, Michael

407

Lightning Frequency and Microphysical Properties of Precipitating Clouds over the Western North Pacific during Winter as Derived from TRMM Multisensor Observations  

Science Conference Proceedings (OSTI)

Tropical Rainfall Measuring Mission observations from multiple sensors including precipitation radar, microwave and infrared radiometers, and a lightning sensor were used to describe precipitation, lightning frequency, and microphysical ...

Yasu-Masa Kodama; Haruna Okabe; Yukie Tomisaka; Katsuya Kotono; Yoshimi Kondo; Hideyuki Kasuya

2007-06-01T23:59:59.000Z

408

Automatic Detection of Cloud Cover over the Baltic Sea  

Science Conference Proceedings (OSTI)

A simple detection method was proposed to increase the efficiency of automatic classification of a satellite image cell (clear/cloudy). A method is described on the basis of the Advanced Very High Resolution Radiometer (AVHRR) data, with a focus ...

Adam Kr??el; Marcin Paszkuta

2011-09-01T23:59:59.000Z

409

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

E-Print Network (OSTI)

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

Zuidema, Paquita

410

Roundness and Aspect Ratio of Particles in Ice Clouds  

Science Conference Proceedings (OSTI)

The frequency of occurrence of the aspect ratio and roundness of particles in ice clouds from aircraft observations have been examined. Images of cloud particles were measured by a cloud particle imager (CPI) at 2.3-?m resolution, installed on ...

Alexei Korolev; George Isaac

2003-08-01T23:59:59.000Z

411

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

DOE Green Energy (OSTI)

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

Kuo-Nan Liou

2003-12-29T23:59:59.000Z

412

ICE AND DUST IN THE PRESTELLAR DARK CLOUD LYNDS 183: PREPLANETARY MATTER AT THE LOWEST TEMPERATURES  

Science Conference Proceedings (OSTI)

Dust grains are nucleation centers and catalysts for the growth of icy mantles in quiescent interstellar clouds, the products of which may accumulate into preplanetary matter when new stars and solar systems form within the clouds. In this paper, we present the first spectroscopic detections of silicate dust and the molecular ices H{sub 2}O, CO, and CO{sub 2} in the vicinity of the prestellar core L183 (L134N). An infrared photometric survey of the cloud was used to identify reddened background stars, and we present spectra covering solid-state absorption features in the wavelength range 2-20 {mu}m for nine of them. The mean composition of the ices in the best-studied line of sight (toward J15542044-0254073) is H{sub 2}O:CO:CO{sub 2} Almost-Equal-To 100:40:24. The ices are amorphous in structure, indicating that they have been maintained at low temperature ({approx}ice column density N(H{sub 2}O) correlates with reddening by dust, exhibiting a threshold effect that corresponds to the transition from unmantled grains in the outer layers of the cloud to ice-mantled grains within, analogous to that observed in other dark clouds. A comparison of results for L183 and the Taurus and IC 5146 dark clouds suggests common behavior, with mantles first appearing in each case at a dust column corresponding to a peak optical depth {tau}{sub 9.7} = 0.15 {+-} 0.03 in the silicate feature. Our results support a previous conclusion that the color excess E{sub J-K} does not obey a simple linear correlation with the total dust column in lines of sight that intercept dense clouds. The most likely explanation is a systematic change in the optical properties of the dust as the density increases.

Whittet, D. C. B.; Poteet, C. A.; Bajaj, V. M.; Horne, D. [Department of Physics, Applied Physics and Astronomy and New York Center for Astrobiology, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180 (United States); Chiar, J. E. [SETI Institute, Carl Sagan Center, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Pagani, L. [LERMA, UMR 8112 du CNRS, Observatoire de Paris, 61 Av. de l'Observatoire, F-75014 Paris (France); Shenoy, S. S. [SOFIA Science Center, NASA Ames Research Center, MS 232-12, Moffett Field, CA 94035 (United States); Adamson, A. J. [Gemini Observatory, Southern Operations Center, Casilla 603, La Serena (Chile)

2013-09-10T23:59:59.000Z

413

Nailing Down Ice in a Cloud Model  

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

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

414

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

Science Conference Proceedings (OSTI)

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

Paul J. DeMott; David C. Rogers

1990-05-01T23:59:59.000Z

415

Factors Controlling the Vertical Extent of Fair-Weather Shallow Cumulus Clouds over Land: Investigation of Diurnal-Cycle Observations Collected at the ARM Southern Great Plains Site  

Science Conference Proceedings (OSTI)

Summertime observations for 13 yr at the Atmospheric Radiation Measurement Southern Great Plains site are used to study fair-weather shallow cumuli (ShCu). To roughly separate forced from active ShCu, days are categorized into “thin-” or “thick-” ...

Yunyan Zhang; Stephen A. Klein

2013-04-01T23:59:59.000Z

416

NERSC Journal Cover Stories  

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

NatureCoverLarge.png NatureCoverLarge.png High-quality electron beams from a laser wakefield accelerator using plasma-channel guiding September 30, 2004 | Author(s): C. G. R. Geddes, Cs. Toth, J. van Tilborg, E. Esarey, C. B. Schroeder, D. Bruhwiler, C. Nieter, J. Cary & W. P. Leemans | Source: Nature | Category: Fusion Energy | URL: http://dx.doi.org/10.1038/nature02900 Download Image: NatureCoverLarge.png | png | 2.7 MB 30 September 2004, Vol. 431, pp. 541-544 PhysTodayCoverLarge.png Integrated Simulation of Fusion Plasmas February 1, 2005 | Author(s): Donald B. Batchelor | Source: Physics Today | Category: Fusion Energy | URL: http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_58/iss_2/35_1.shtml Download Image: PhysTodayCoverLarge.png | png | 329 KB February 2005, Vol. 58 (2), pp. 35-40

417

NERSC Journal Cover Stories  

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

CEN-Cover.png CEN-Cover.png Graphene Moves Toward Applications November 21, 2011 | Author(s): Donghai Mei, et al. | Category: Chemistry | URL: http://dx.doi.org/10.1021/nl203332e Download Image: CEN-Cover.png | png | 986 KB Hierarchically Porous Graphene as a Lithium-Air Battery Electrode. See also http://pubs.acs.org/NanoLett (2011) 11, 5071-5078 SotirisCoverJPCBLarge.jpg Computational Investigation of the First Solvation Shell Structure of Interfacial and Bulk Aqueous Chloride and Iodide Ions November 14, 2008 | Author(s): Collin D. Wick, and Sotiris S. Xantheas | Source: The Journal of Physical Chemistry B | Category: Chemistry | URL: http://dx.doi.org/10.1021/jp806782r Download Image: SotirisCoverJPCBLarge.jpg | jpg | 1.1 MB 2009, Vol. 113 (13), pp. 4141-4146 ACSCatalysis2013Mei.png

418

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

SciTech Connect

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

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

2005-03-18T23:59:59.000Z

419

Measuring Cloud Properties from Space: A Review  

Science Conference Proceedings (OSTI)

A brief review of observations of clouds using satellites highlights open issues and directions for future studies. The key one is improved treatment of the effects of small-scale spatial inhomogeneity in remote sensing data analyses and in the ...

William B. Rossow

1989-03-01T23:59:59.000Z

420

A tropical « NAT-like » belt observed from space  

E-Print Network (OSTI)

The optical properties of cold tropical tropopause clouds are examined on a global scale, using two years of space-borne lidar observations from CALIPSO (June 2006- May 2008). The linear depolarization ratio, color ratio and backscatter signal are analyzed in tropical clouds colder than 200 K in a way similar to recent studies of Polar Stratospheric Clouds (PSCs). It is found that the three categories of particles encountered in PSC (Ice, Sulfate Ternary Solutions or STS, and Nitric Acid Trihydrate or NAT) do also occur in tropical cold cloud layers. Particles with optical properties similar to NAT are few, but they cover the hal-00439695, version 1- 8 Dec 2009 tropical belt and represent about 20 % of cold cloud tropical particles all year long. The optical behavior of these particles requires them to be very small, non-spherical, optically thin, and persistent in the TTL at temperatures colder than 200 K; NAT particles and very small ice crystals meet these criteria and are right now the best candidates to explain the presented observations. 2

unknown authors

2009-01-01T23:59:59.000Z

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


421

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

SciTech Connect

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

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

2001-06-01T23:59:59.000Z

422

STAR FORMATION RATES IN MOLECULAR CLOUDS AND THE NATURE OF THE EXTRAGALACTIC SCALING RELATIONS  

SciTech Connect

In this paper, we investigate scaling relations between star formation rates and molecular gas masses for both local Galactic clouds and a sample of external galaxies. We specifically consider relations between the star formation rates and measurements of dense, as well as total, molecular gas masses. We argue that there is a fundamental empirical scaling relation that directly connects the local star formation process with that operating globally within galaxies. Specifically, the total star formation rate in a molecular cloud or galaxy is linearly proportional to the mass of dense gas within the cloud or galaxy. This simple relation, first documented in previous studies, holds over a span of mass covering nearly nine orders of magnitude and indicates that the rate of star formation is directly controlled by the amount of dense molecular gas that can be assembled within a star formation complex. We further show that the star formation rates and total molecular masses, characterizing both local clouds and galaxies, are correlated over similarly large scales of mass and can be described by a family of linear star formation scaling laws, parameterized by f{sub DG}, the fraction of dense gas contained within the clouds or galaxies. That is, the underlying star formation scaling law is always linear for clouds and galaxies with the same dense gas fraction. These considerations provide a single unified framework for understanding the relation between the standard (nonlinear) extragalactic Schmidt-Kennicutt scaling law, that is typically derived from CO observations of the gas, and the linear star formation scaling law derived from HCN observations of the dense gas.

Lada, Charles J.; Forbrich, Jan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Lombardi, Marco [Department of Physics, University of Milan, via Celoria 16, I-20133 Milan (Italy); Alves, Joao F., E-mail: clada@cfa.harvard.edu, E-mail: jforbrich@cfa.harvard.edu, E-mail: marco.lombardi@gmail.com, E-mail: joao.alves@univie.ac.at [Institute for Astronomy, University of Vienna, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria)

2012-02-01T23:59:59.000Z

423

Global Circuit Model with Clouds  

Science Conference Proceedings (OSTI)

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

Limin Zhou; Brian A. Tinsley

2010-04-01T23:59:59.000Z

424

Cloud classification using whole-sky imager data  

SciTech Connect

Clouds are one of the most important moderators of the earth radiation budget and one of the least understood. The effect that clouds have on the reflection and absorption of solar and terrestrial radiation is strongly influenced by their shape, size, and composition. Physically accurate parameterization of clouds is necessary for any general circulation model (GCM) to yield meaningful results. The work presented here is part of a larger project that is aimed at producing realistic three-dimensional (3D) volume renderings of cloud scenes, thereby providing the important shape information for parameterizing GCMs. The specific goal of the current study is to develop an algorithm that automatically classifies (by cloud type) the clouds observed in the scene. This information will assist the volume rendering program in determining the shape of the cloud. Much work has been done on cloud classification using multispectral satellite images. Most of these references use some kind of texture measure to distinguish the different cloud types and some also use topological features (such as cloud/sky connectivity or total number of clouds). A wide variety of classification methods has been used, including neural networks, various types of clustering, and thresholding. The work presented here utilizes binary decision trees to distinguish the different cloud types based on cloud feature vectors.

Buch, K.A. Jr.; Sun, Chen-Hui

1995-02-01T23:59:59.000Z

425

Cloud Computing Forum & Workshop II  

Science Conference Proceedings (OSTI)

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

2013-08-07T23:59:59.000Z

426

ISCCP Cloud Algorithm Intercomparison  

Science Conference Proceedings (OSTI)

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

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

1985-09-01T23:59:59.000Z

427

ARM - Measurement - Cloud type  

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

type ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud type Cloud type such as...

428

Entrainment in Cumulus Clouds  

Science Conference Proceedings (OSTI)

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

Alan M. Blyth

1993-04-01T23:59:59.000Z

429

Automated cloud resource orchestration  

Science Conference Proceedings (OSTI)

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

Changbin Liu / Boon Thau Loo

2012-01-01T23:59:59.000Z

430

North Australian Cloud Lines  

Science Conference Proceedings (OSTI)

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

W. Drosdowsky; G. J. Holland

1987-11-01T23:59:59.000Z

431

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

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

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

432

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

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

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

433

Impact of cloud microphysics on squall line organization  

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

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

434

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

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

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

435

3.9 Query Cloud-Provider Capabilities and Capacities  

Science Conference Proceedings (OSTI)

... response, either through an automated program or human review, and ... cloud-user observes request failure and consequent error messages and ...

2010-11-01T23:59:59.000Z

436

Cloud Computing at NERSC  

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

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

437

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

Science Conference Proceedings (OSTI)

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

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

2012-06-01T23:59:59.000Z

438

Assessment of the Quality of MODIS Cloud Products from Radiance Simulations  

Science Conference Proceedings (OSTI)

Observations made by the Moderate Resolution Imaging Spectroradiometer (MODIS), the Atmospheric Infrared Sounder (AIRS), the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), and CloudSat are synergistically used to ...

Seung-Hee Ham; Byung-Ju Sohn; Ping Yang; Bryan A. Baum

2009-08-01T23:59:59.000Z

439

EMSL: Publications - Journal Covers  

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

Journal Cover Gallery Journal Cover Gallery Here are a few of the scientific journal covers that feature outstanding research done at EMSL. Where available, additional information is hyperlinked from the date above the cover. 2013 April 2013 [Enlarge Image] Microscopy and Microanalysis January 2013 [Enlarge Image] Molecular BioSystems January 2013 [Enlarge Image] Molecular BioSystems 2012 May 2012 [Enlarge Image] Chemical Science March 7 2012 [Enlarge Image] Physical Chemistry Chemical Physics February 28 2012 [Enlarge Image] Physical Chemistry Chemical Physics February 21 2012 [Enlarge Image] Physical Chemistry Chemical Physics 2011 December 15, 2011 [Enlarge Image] Analytical Chemistry September 14, 2011 [Enlarge Image] The Journal of American Chemical Society July 20, 2011 [Enlarge Image]

440

Cover Heated, Open Vessels  

SciTech Connect

This revised ITP steam tip sheet on covering heated, open vessels provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

2006-01-01T23:59:59.000Z

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


441

WATER COOLED RETORT COVER  

DOE Patents (OSTI)

A retort cover is designed for use in the production of magnesium metal by the condensation of vaporized metal on a collecting surface. The cover includes a condensing surface, insulating means adjacent to the condensing surface, ind a water-cooled means for the insulating means. The irrangement of insulation and the cooling means permits the magnesium to be condensed at a high temperature and in massive nonpyrophoric form. (AEC)

Ash, W.J.; Pozzi, J.F.

1962-05-01T23:59:59.000Z

442

Rope Cloud over Land  

Science Conference Proceedings (OSTI)

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

Von S. Woods

1983-03-01T23:59:59.000Z

443

User Centric Community Clouds  

Science Conference Proceedings (OSTI)

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

Joăo Paulo Barraca; Alfredo Matos; Rui L. Aguiar

2011-05-01T23:59:59.000Z

444

Optical-to-Near-Infrared Simultaneous Observations for the Hot Uranus GJ3470b: A Hint for Cloud-free Atmosphere  

E-Print Network (OSTI)

We present optical (g', R_c, and I_c) to near-infrared (J) simultaneous photometric observations for a primary transit of GJ3470b, the second lowest-mass planet among transiting planets around nearby M dwarfs, by using the 50-cm MITSuME telescope and the 188-cm telescope both at Okayama Astrophysical Observatory. From these data, we derive the planetary mass, radius, and density as 14.1 \\pm 1.3 M_earth, 4.32^{+0.21}_{-0.10} R_earth, and 0.94 \\pm 0.12 g cm^{-3}, respectively, thus confirming the low density that was reported by Demory et al. based on the Spitzer/IRAC 4.5-micron photometry (0.72^{+0.13}_{-0.12} g cm^{-3}). Although the planetary radius is about 10% smaller than that reported by Demory et al., this difference does not alter their conclusion that the planet possesses a hydrogen-rich envelope whose mass is approximately 10% of the planetary total mass. On the other hand, we find that the planet-to-star radius ratio (R_p/R_s) in the J band (0.07577^{+0.00072}_{-0.00075}) is smaller than that in the...

Fukui, Akihiko; Kurosaki, Kenji; Ikoma, Masahiro; Yanagisawa, Kenshi; Kuroda, Daisuke; Shimizu, Yasuhiro; Takahashi, Yasuhiro H; Ohnuki, Hiroshi; Onitsuka, Masahiro; Hirano, Teruyuki; Suenaga, Takuya; Kawauchi, Kiyoe; Nagayama, Shogo; Ohta, Kouji; Yoshida, Michitoshi; Kawai, Nobuyuki; Izumiura, Hideyuki

2013-01-01T23:59:59.000Z

445

Performance Characteristics of Distinct Lightning Detection Networks Covering Belgium  

Science Conference Proceedings (OSTI)

This study reports results from electric field measurements coupled to high-speed camera observations of cloud-to-ground lightning to test the performance of lightning location networks in terms of its detection efficiency and location accuracy. ...

Dieter R. Poelman; Wolfgang Schulz; Christian Vergeiner

2013-05-01T23:59:59.000Z

446

National Land Cover Data  

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

National Land Cover Data National Land Cover Data Metadata also available as Metadata: q Identification_Information q Data_Quality_Information q Spatial_Data_Organization_Information q Spatial_Reference_Information q Entity_and_Attribute_Information q Distribution_Information q Metadata_Reference_Information Identification_Information: Citation: Citation_Information: Originator: United States Geological Survey Publication_Date: Unpublished Material Title: National Land Cover Data Edition: 01 Geospatial_Data_Presentation_Form: raster digital data Other_Citation_Details: Classification and processing of the orginal remote sensing products was done by the Multi-Resolution Land Characterization Consortium and EROS Data Center (U.S. Geological Survey). The Consortium includes the

447

ARM - Midlatitude Continental Convective Clouds - Single Column Model Forcing (xie-scm_forcing)  

Science Conference Proceedings (OSTI)

The constrained variational objective analysis approach described in Zhang and Lin [1997] and Zhang et al. [2001]was used to derive the large-scale single-column/cloud resolving model forcing and evaluation data set from the observational data collected during Midlatitude Continental Convective Clouds Experiment (MC3E), which was conducted during April to June 2011 near the ARM Southern Great Plains (SGP) site. The analysis data cover the period from 00Z 22 April - 21Z 6 June 2011. The forcing data represent an average over the 3 different analysis domains centered at central facility with a diameter of 300 km (standard SGP forcing domain size), 150 km and 75 km, as shown in Figure 1. This is to support modeling studies on various-scale convective systems.

Shaocheng Xie; Renata McCoy; Yunyan Zhang

2012-10-25T23:59:59.000Z

448

ARM - Midlatitude Continental Convective Clouds - Single Column Model Forcing (xie-scm_forcing)  

DOE Data Explorer (OSTI)

The constrained variational objective analysis approach described in Zhang and Lin [1997] and Zhang et al. [2001]was used to derive the large-scale single-column/cloud resolving model forcing and evaluation data set from the observational data collected during Midlatitude Continental Convective Clouds Experiment (MC3E), which was conducted during April to June 2011 near the ARM Southern Great Plains (SGP) site. The analysis data cover the period from 00Z 22 April - 21Z 6 June 2011. The forcing data represent an average over the 3 different analysis domains centered at central facility with a diameter of 300 km (standard SGP forcing domain size), 150 km and 75 km, as shown in Figure 1. This is to support modeling studies on various-scale convective systems.

Shaocheng Xie; Renata McCoy; Yunyan Zhang

449

Cloud Properties Working Group Low Clouds Update  

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

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

450

Cloud displays for mobile users in a display cloud  

Science Conference Proceedings (OSTI)

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

Lars Tiede; John Markus Bjřrndalen; Otto J. Anshus

2013-02-01T23:59:59.000Z

451

Validation of Cloud-Resolving Model Background Data for Cloud Data Assimilation  

Science Conference Proceedings (OSTI)

Results from a cloud-resolving model are systematically compared with a variety of observations, both ground based and satellite, in order to better understand the mean background errors and their correlations. This is a step in the direction of ...

Rosanne Polkinghorne; Tomislava Vukicevic; K. Franklin Evans

2010-03-01T23:59:59.000Z

452

A Revised Cloud Overlap Scheme for Fast Microwave Radiative Transfer in Rain and Cloud  

Science Conference Proceedings (OSTI)

The assimilation of cloud- and precipitation-affected observations into weather forecasting systems requires very fast calculations of radiative transfer in the presence of multiple scattering. At the European Centre for Medium-Range Weather ...

Alan J. Geer; Peter Bauer; Christopher W. O’Dell

2009-11-01T23:59:59.000Z

453

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

Science Conference Proceedings (OSTI)

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

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

2012-01-01T23:59:59.000Z

454

BNL | Cloud Lifecycle Infrastructure  

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

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

455

Cover Crops for the Garden  

E-Print Network (OSTI)

photosynthesis. When the cover crops decompose, the nitrogenthe nodules becomes available for growing crops to draw on.to a fall planting of cover crops. Cover crops are grown not

2008-01-01T23:59:59.000Z

456

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

SciTech Connect

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

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

2008-11-20T23:59:59.000Z

457

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

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

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

458

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

SciTech Connect

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

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

2010-03-15T23:59:59.000Z

459

New Geostationary Satellite–Based Snow-Cover Algorithm  

Science Conference Proceedings (OSTI)

Snow cover plays an important role in the climate system by changing the energy and mass transfer between the atmosphere and the surface. Reliable observations of the snow cover are difficult to obtain without satellites. This paper introduces a ...

Niilo Siljamo; Otto Hyvärinen

2011-06-01T23:59:59.000Z

460

BNL | Cloud Lifecycle Research  

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

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

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


461

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

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

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

462

Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences  

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

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

463

Cloud Classification Before Luke Howard  

Science Conference Proceedings (OSTI)

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

Stanely David Gedzelman

1989-04-01T23:59:59.000Z

464

Radar Reflectivity of Cumulus Clouds  

Science Conference Proceedings (OSTI)

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

Henri Sauvageot; Jilani Omar

1987-06-01T23:59:59.000Z

465

Cumulus Cloud Field Morphology and Spatial Patterns Derived from High Spatial Resolution Landsat Imagery  

Science Conference Proceedings (OSTI)

Detailed observations of cumulus cloud scales and processes are an essential ingredient in models that deal with (i) high spatial resolution cumulus ensembles; and (ii) parameterization of cloud radiative processes. The present investigation ...

S. K. Sengupta; R. M. Welch; M. S. Navar; T. A. Berendes; D. W. Chen

1990-12-01T23:59:59.000Z

466

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

Science Conference Proceedings (OSTI)

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

Katrin Lehmann; Holger Siebert; Raymond A. Shaw

2009-12-01T23:59:59.000Z

467

Analysis of Spatial Inhomogeneities in Cumulus Clouds Using High Spatial Resolution Landsat Data  

Science Conference Proceedings (OSTI)

Aircraft observations and high resolution Landsat Multispectral Scanner digital data are used to determine the sizes of spatial inhomogeneities (“holes”) in cumulus clouds. The majority of holes are found near cloud edges, but the larger holes ...

Lindsay Parker; R. M. Welch; D. J. Musil

1986-10-01T23:59:59.000Z

468

Intercomparison of Cloud Imagery from the DMSP OLS, NOAA AVHRR, GOES VISSR, and Landsat MSS  

Science Conference Proceedings (OSTI)

Concurrent visible and infrared imagery from four satellite sensors (DMSP OLS, NOAA AVHRR, GOES VISSR, Landsat MSS) have been intercompared. Inherent differences in observed cloud properties and cloud field analyses are noted due to individual ...

R. G. Isaacs; J. C. Barnes

1987-12-01T23:59:59.000Z

469

The Interaction of Clouds and Dry Air in the Eastern Tropical Pacific  

Science Conference Proceedings (OSTI)

Cloud radar observations of eastern Pacific intertropical convergence zone cloud vertical structure are interpreted in light of soundings, 100-km-scale divergence profiles calculated from precipitation radar Doppler velocities, and surface rain ...

Paquita Zuidema; Brian Mapes; Jialin Lin; Chris Fairall; Gary Wick

2006-09-01T23:59:59.000Z

470

A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part III: Radiative Properties  

Science Conference Proceedings (OSTI)

In Part III of a series of papers describing the extended time high-cloud observations from the University of Utah Facility for Atmospheric Remote Sensing (FARS) supporting the First International Satellite Cloud Climatology Project (ISCCP) ...

Kenneth Sassen; Jennifer M. Comstock

2001-08-01T23:59:59.000Z

471

On the Nucleation of Ice in Highly Supersaturated Regions of Clouds  

Science Conference Proceedings (OSTI)

We simply but quantitatively analyze the hypothesis that the common observation, that ice crystal concentrations in clouds often far exceed measured ice nucleus concentrations, can be explained by our inability to reproduce cloud supersaturations ...

Bradley A. Baker

1991-08-01T23:59:59.000Z

472

Precipitation Characteristics of Trade Wind Clouds during RICO Derived from Radar, Satellite, and Aircraft Measurements  

Science Conference Proceedings (OSTI)

Precipitation characteristics of trade wind clouds over the Atlantic Ocean near Barbuda are derived from radar and aircraft data and are compared with satellite-observed cloud fields collected during the Rain in Cumulus over the Ocean (RICO) ...

Eric R. Snodgrass; Larry Di Girolamo; Robert M. Rauber

2009-03-01T23:59:59.000Z

473

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

Science Conference Proceedings (OSTI)

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

Anthony D. Del Genio; Audrey B. Wolf

2000-10-01T23:59:59.000Z

474

Variability of Microphysical Parameters in High-Altitude Ice Clouds: Results of the Remote Sensing Method  

Science Conference Proceedings (OSTI)

The remote sensing method for retrieving vertical profiles of microphysical parameters in ice clouds from ground-based measurements taken by the Doppler radar and IR radiometer was applied to several cloud cases observed during different field ...

Sergey Y. Matrosov

1997-06-01T23:59:59.000Z

475

Microphysical Structure and Evolution of a Central Sierra Nevada Orographic Cloud System  

Science Conference Proceedings (OSTI)

This paper describes complex microphysical interactions observed within an orographic cloud system over the central Sierra Nevada of California. Measurements of the physical structure and microphysical characteristics of this cloud system were ...

Robert M. Rauber

1992-01-01T23:59:59.000Z

476

Factors Determining the Impact of Aerosols on Surface Precipitation from Clouds: An Attempt at Classification  

Science Conference Proceedings (OSTI)

The simulation of the dynamics and the microphysics of clouds observed during the Large-Scale Biosphere–Atmosphere Experiment in Amazonia—Smoke, Aerosols, Clouds, Rainfall, and Climate (LBA–SMOCC) campaign, as well as extremely continental and ...

A. P. Khain; N. BenMoshe; A. Pokrovsky

2008-06-01T23:59:59.000Z

477

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

Science Conference Proceedings (OSTI)

Cloud observations over the past decade from six Arctic atmospheric observatories are investigated to derive estimates of cloud occurrence fraction, vertical distribution, persistence in time, diurnal cycle, and boundary statistics. Each ...

Matthew D. Shupe; Von P. Walden; Edwin Eloranta; Taneil Uttal; James R. Campbell; Sandra M. Starkweather; Masataka Shiobara

2011-03-01T23:59:59.000Z

478

Solar Activity and Cloud Opacity Variations: A Modulated Cosmic Ray Ionization Model  

Science Conference Proceedings (OSTI)

The observed correlation between global low cloud amount and the flux of high energy cosmic rays supports the idea that ionization plays a crucial role in tropospheric cloud formation. This idea is explored quantitatively with a simple model ...

David Marsden; Richard E. Lingenfelter

2003-02-01T23:59:59.000Z

479

BNL | Aerosol, Cloud, Precipitation Interactions  

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

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

480

Cloud Computing Forum & Workshop IV  

Science Conference Proceedings (OSTI)

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

2013-08-07T23:59:59.000Z

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


481

cover_booked.indd  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Management. The point of contact for this document is Paul Bosco, who can be reached at Management. The point of contact for this document is Paul Bosco, who can be reached at (202) 586-3524 or by e-mail to paul.bosco@hq.doe.gov. Cover Photo: Night, in the form of a crescent moon, overtakes the fading light of day beyond Wilson Hall at Fermi National Accelerator Laboratory. i TABLE OF CONTENTS PAGE BACKGROUND ........................................................................................................... 1 ABOUT DOE ......................................................................................................... 1 DOE REAL PROPERTY ............................................................................................... 2 REAL PROPERTY ASSETS VISION.......................................................................................

482

CONTRIBUTED Green Cloud Computing  

E-Print Network (OSTI)

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

Tucker, Rod

483

Cryptographic cloud storage  

Science Conference Proceedings (OSTI)

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

Seny Kamara; Kristin Lauter

2010-01-01T23:59:59.000Z

484

Dynamical and Microphysical Characteristics of Arctic Clouds during BASE  

Science Conference Proceedings (OSTI)

In this study, observations from aircraft, Doppler radar, and LANDSAT are used to better understand dynamical and microphysical characteristics of low-level Arctic clouds for climate change studies. Observations during the Beaufort and Arctic ...

I. Gultepe; G. Isaac; D. Hudak; R. Nissen; J. W. Strapp

2000-04-01T23:59:59.000Z

485

ARM - Measurement - Cloud extinction  

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

extinction extinction ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud extinction The removal of radiant energy from an incident beam by the process of cloud absorption and/or scattering. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments NEPHELOMETER : Nephelometer Field Campaign Instruments CEP : Cloud Extinction Probe CLDAEROSMICRO : Cloud and Aerosol Microphysical Properties EC-CONVAIR580-BULK : Environment Canada Convair 580 Bulk Parameters

486

Small Cloud Particle Shapes in Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

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

Greg M. McFarquhar; Junshik Um; Robert Jackson

2013-05-01T23:59:59.000Z

487

Cover, IG-0620  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Department's Unclassified Cyber Department's Unclassified Cyber Security Program-2003 DOE/IG-0620 September 2003 -2- The evaluation disclosed that in many instances, the Department had not acted to identify, track, and correct previously reported issues in a timely manner. Management also had not established program-level performance metrics to guide cyber security program execution or evaluate performance. As a result, the Department's unclassified information systems remain vulnerable to attacks that may affect the availability or integrity of its information assets. In addition to sites and systems specifically covered during this evaluation, the Office of Inspector General has done extensive work in the area of cyber security and performance management at locations throughout the Department of Energy. Where relevant, we have

488

Book cover 1  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Civil Rights Civil Rights Employee Concerns Program Fiscal Year 2008 Activity Report Message from the Director... The Employee Concerns Program was established as part of a Secretarial Initiative in 1996 to handle concerns filed by employees on a variety of issues ranging from health and safety to waste, fraud and abuse. This report covering fiscal year (FY) 2008 marks the thirteenth consecutive year the Department of Energy's (DOE) Employee Concerns Program (ECP) has produced and issued an Annual Report reviewing the complex-wide activity of the ECP. These reports provide an overview of important progress made during the year advancing the work and mission of the ECP, as well as highlighting trends of interest to Department administrators. In Fiscal Year 2008, 643 employees utilized the program, and filed 362 new concerns. Combined with a carry-

489

An Earth Outgoing Longwave Radiation Climate Model. Part II: Radiation with Clouds Included  

Science Conference Proceedings (OSTI)

An Earth outgoing longwave radiation (OLWR) climate model was constructed for radiation budget studies. The model consists of the upward radiative transfer parameterization of Thompson and Warren, the cloud cover model of Sherr et al., and a ...

Shi-Keng Yang; G. Louis Smith; Fred L. Bartman

1988-10-01T23:59:59.000Z

490

A Sensitivity Study of Convective Cloud Formation by Vegetation Forcing with Different Atmospheric Conditions  

Science Conference Proceedings (OSTI)

Variable vegetation cover is a possible trigger for convection, especially in semiarid areas due to differential surface forcing. A two-dimensional numerical model with explicit cloud physics and a detailed vegetation parameterization scheme is ...

Xiaodong Hong; Martin J. Leach; Sethu Raman

1995-09-01T23:59:59.000Z

491

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

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

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

492

Ozone Destruction in Continental Stratus Clouds: An Aircraft Case Study  

Science Conference Proceedings (OSTI)

Apparent depletion of ozone in a cold (0°C), continental stratus cloud system was observed during in situ data collection on 30 April 1994 at the Department of Energy Clouds and Radiation Test Bed site in northern Oklahoma. Analyses of the ...

Zhien Wang; Kenneth Sassen

2000-06-01T23:59:59.000Z

493

Cloud Computing Forensic Science Workshop  

Science Conference Proceedings (OSTI)

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

2013-09-05T23:59:59.000Z

494

A marketplace for cloud resources  

Science Conference Proceedings (OSTI)

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

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

2010-10-01T23:59:59.000Z

495

NERSC Journal Cover Stories  

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

Liu2010.jpg Liu2010.jpg Methanol Synthesis from H2 and CO2 on a Mo6S8 Cluster: A Density Functional Study October 30, 2009 | Author(s): Ping Liu, YongMan Choi, Y. Yang and M. G. White | Source: J. Phys. Chem. A | Category: Chemistry | URL: http://dx.doi.org/10.1021/jp906780a Download Image: Liu2010.jpg | jpg | 2.1 MB J. Phys. Chem. A, 2010, 114 (11), pp 3888-3895 Ott2006.jpg A New Mechanism for Gravitational-Wave Emission in Core-Collapse Supernovae May 26, 2006 | Author(s): Christian D. Ott, Adam Burrows, Luc Dessart, and Eli Livne | Source: Physical Review Letters | Category: Astrophysics | URL: http://link.aps.org/abstract/PRL/v96/e201102 Download Image: Ott2006.jpg | jpg | 111 KB Phys. Rev. Lett. » Volume 96 » Issue 20 DaughtonCoverPOP2013.png A review of pressure anisotropy caused by electron trapping in

496

3. New Cloud Climatology  

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

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

497

ISCCP Cloud Data Products  

Science Conference Proceedings (OSTI)

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

William B. Rossow; Robert A. Schiffer

1991-01-01T23:59:59.000Z

498

Cloud Transmissivities for Canada  

Science Conference Proceedings (OSTI)

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

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

1985-03-01T23:59:59.000Z

499

Can Fully Accounting for Clouds in Data Assimilation Improve Short-Term Forecasts by Global Models?  

Science Conference Proceedings (OSTI)

This paper explores the degree to which short-term forecasts with global models might be improved if clouds were fully included in a data assimilation system, so that observations of clouds affected all parts of the model state and cloud ...

Robert Pincus; Robert J. Patrick Hofmann; Jeffrey L. Anderson; Kevin Raeder; Nancy Collins; Jeffrey S. Whitaker

2011-03-01T23:59:59.000Z

500

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

SciTech Connect

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

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

2012-05-30T23:59:59.000Z

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