Science.gov

Sample records for clouds

  1. Clouds

    NASA Image and Video Library

    2010-09-14

    Clouds are common near the north polar caps throughout the spring and summer. The clouds typically cause a haze over the extensive dune fields. This image from NASA Mars Odyssey shows the edge of the cloud front.

  2. Search Cloud

    MedlinePlus

    ... this page: https://medlineplus.gov/cloud.html Search Cloud To use the sharing features on this page, ... chest pa and lateral Share the MedlinePlus search cloud with your users by embedding our search cloud ...

  3. Neptune Clouds

    NASA Image and Video Library

    1999-10-14

    The bright cirrus-like clouds of Neptune change rapidly, often forming and dissipating over periods of several to tens of hours. In this sequence NASA Voyager 2 observed cloud evolution in the region around the Great Dark Spot GDS.

  4. Cloud Computing

    SciTech Connect

    Pete Beckman and Ian Foster

    2009-12-04

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

  5. Cloud Control

    ERIC Educational Resources Information Center

    Weinstein, Margery

    2012-01-01

    Your learning curriculum needs a new technological platform, but you don't have the expertise or IT equipment to pull it off in-house. The answer is a learning system that exists online, "in the cloud," where learners can access it anywhere, anytime. For trainers, cloud-based coursework often means greater ease of instruction resulting in greater…

  6. Arctic Clouds

    Atmospheric Science Data Center

    2013-04-19

    ...   View Larger Image Stratus clouds are common in the Arctic during the summer months, and are important modulators of ... from MISR's two most obliquely forward-viewing cameras. The cold, stable air causes the clouds to persist in stratified layers, and this ...

  7. Cloud Computing

    DTIC Science & Technology

    2009-11-12

    Eucalyptus Systems • Provides an open-source application that can be used to implement a cloud computing environment on a datacenter • Trying to establish an...edgeplatform.html • Amazon Elastic Compute Cloud (EC2): http://aws.amazon.com/ec2/ • Amazon Simple Storage Solution (S3): http://aws.amazon.com/s3/ • Eucalyptus

  8. Cloud Modeling

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Moncrieff, Mitchell; Einaud, Franco (Technical Monitor)

    2001-01-01

    Numerical cloud models have been developed and applied extensively to study cloud-scale and mesoscale processes during the past four decades. The distinctive aspect of these cloud models is their ability to treat explicitly (or resolve) cloud-scale dynamics. This requires the cloud models to be formulated from the non-hydrostatic equations of motion that explicitly include the vertical acceleration terms since the vertical and horizontal scales of convection are similar. Such models are also necessary in order to allow gravity waves, such as those triggered by clouds, to be resolved explicitly. In contrast, the hydrostatic approximation, usually applied in global or regional models, does allow the presence of gravity waves. In addition, the availability of exponentially increasing computer capabilities has resulted in time integrations increasing from hours to days, domain grids boxes (points) increasing from less than 2000 to more than 2,500,000 grid points with 500 to 1000 m resolution, and 3-D models becoming increasingly prevalent. The cloud resolving model is now at a stage where it can provide reasonably accurate statistical information of the sub-grid, cloud-resolving processes poorly parameterized in climate models and numerical prediction models.

  9. Thin Clouds

    Atmospheric Science Data Center

    2013-04-18

    ... their delicate appearance, thin, feathery clouds of ice crystals called cirrus may contribute to global warming. Some scientists ... minutes after MISR imaged the cloud from space. At the same time, another NASA high-altitude jet, the WB-57, flew right through the ...

  10. Cloud Control

    ERIC Educational Resources Information Center

    Weinstein, Margery

    2012-01-01

    Your learning curriculum needs a new technological platform, but you don't have the expertise or IT equipment to pull it off in-house. The answer is a learning system that exists online, "in the cloud," where learners can access it anywhere, anytime. For trainers, cloud-based coursework often means greater ease of instruction resulting in greater…

  11. Cloud Control

    ERIC Educational Resources Information Center

    Ramaswami, Rama; Raths, David; Schaffhauser, Dian; Skelly, Jennifer

    2011-01-01

    For many IT shops, the cloud offers an opportunity not only to improve operations but also to align themselves more closely with their schools' strategic goals. The cloud is not a plug-and-play proposition, however--it is a complex, evolving landscape that demands one's full attention. Security, privacy, contracts, and contingency planning are all…

  12. Cloud Cover

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2012-01-01

    This article features a major statewide initiative in North Carolina that is showing how a consortium model can minimize risks for districts and help them exploit the advantages of cloud computing. Edgecombe County Public Schools in Tarboro, North Carolina, intends to exploit a major cloud initiative being refined in the state and involving every…

  13. Cloud Control

    ERIC Educational Resources Information Center

    Ramaswami, Rama; Raths, David; Schaffhauser, Dian; Skelly, Jennifer

    2011-01-01

    For many IT shops, the cloud offers an opportunity not only to improve operations but also to align themselves more closely with their schools' strategic goals. The cloud is not a plug-and-play proposition, however--it is a complex, evolving landscape that demands one's full attention. Security, privacy, contracts, and contingency planning are all…

  14. Cloud Cover

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2012-01-01

    This article features a major statewide initiative in North Carolina that is showing how a consortium model can minimize risks for districts and help them exploit the advantages of cloud computing. Edgecombe County Public Schools in Tarboro, North Carolina, intends to exploit a major cloud initiative being refined in the state and involving every…

  15. Screaming Clouds

    NASA Astrophysics Data System (ADS)

    Fikke, Svein; Egill Kristjánsson, Jón; Nordli, Øyvind

    2017-04-01

    "Mother-of-pearl clouds" appear irregularly in the winter stratosphere at high northern latitudes, about 20-30 km above the surface of the Earth. The size range of the cloud particles is near that of visible light, which explains their extraordinary beautiful colours. We argue that the Norwegian painter Edvard Munch could well have been terrified when the sky all of a sudden turned "bloodish red" after sunset, when darkness was expected. Hence, there is a high probability that it was an event of mother-of-pearl clouds which was the background for Munch's experience in nature, and for his iconic Scream. Currently, the leading hypothesis for explaining the dramatic colours of the sky in Munch's famous painting is that the artist was captivated by colourful sunsets following the enormous Krakatoa eruption in 1883. After carefully considering the historical accounts of some of Munch's contemporaries, especially the physicist Carl Störmer, we suggest an alternative hypothesis, namely that Munch was inspired by spectacular occurrences of mother-of-pearl clouds. Such clouds, which have a wave-like structure akin to that seen in the Scream were first observed and described only a few years before the first version of this motive was released in 1892. Unlike clouds related to conventional weather systems in the troposphere, mother-of-pearl clouds appear in the stratosphere, where significantly different physical conditions prevail. This result in droplet sizes within the range of visible light, creating the spectacular colour patterns these clouds are famous for. Carl Störmer observed such clouds, and described them in minute details at the age of 16, but already with a profound interest in science. He later noted that "..these mother-of-pearl clouds was a vision of indescribable beauty!" The authors find it logical that the same vision could appear scaring in the sensible mind of a young artist unknown to such phenomena.

  16. Complex Clouds

    Atmospheric Science Data Center

    2013-04-16

    ...     View Larger Image The complex structure and beauty of polar clouds are highlighted by these images acquired ... MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center in Hampton, VA. Image ...

  17. Polar Clouds

    NASA Image and Video Library

    2012-02-27

    With the changing of seasons comes changes in weather. This image from NASA 2001 Mars Odyssey spacecraft shows clouds in the north polar region. The surface is just barely visible in part of the image.

  18. Deep Clouds

    NASA Image and Video Library

    2008-05-27

    Bright puffs and ribbons of cloud drift lazily through Saturn's murky skies. In contrast to the bold red, orange and white clouds of Jupiter, Saturn's clouds are overlain by a thick layer of haze. The visible cloud tops on Saturn are deeper in its atmosphere due to the planet's cooler temperatures. This view looks toward the unilluminated side of the rings from about 18 degrees above the ringplane. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera on April 15, 2008 at a distance of approximately 1.5 million kilometers (906,000 miles) from Saturn. Image scale is 84 kilometers (52 miles) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA09910

  19. Curious Clouds

    NASA Image and Video Library

    2006-06-13

    Saturn atmosphere produces beautiful and sometimes perplexing features. Is the bright feature below center a rare crossing of a feature from a zone to a belt, or is it an illusion created by different cloud layers at different levels?

  20. Cloud Formation

    NASA Astrophysics Data System (ADS)

    Graham, Mark Talmage

    2004-05-01

    Cloud formation is crucial to the heritage of modern physics, and there is a rich literature on this important topic. In 1927, Charles T.R. Wilson was awarded the Nobel Prize in physics for applications of the cloud chamber.2 Wilson was inspired to study cloud formation after working at a meteorological observatory on top of the highest mountain in Scotland, Ben Nevis, and testified near the end of his life, "The whole of my scientific work undoubtedly developed from the experiments I was led to make by what I saw during my fortnight on Ben Nevis in September 1894."3 To form clouds, Wilson used the sudden expansion of humid air.4 Any structure the cloud may have is spoiled by turbulence in the sudden expansion, but in 1912 Wilson got ion tracks to show up by using strobe photography of the chamber immediately upon expansion.5 In the interim, Millikan's study in 1909 of the formation of cloud droplets around individual ions was the first in which the electron charge was isolated. This study led to his famous oil drop experiment.6 To Millikan, as to Wilson, meteorology and physics were professionally indistinct. With his meteorological physics expertise, in WWI Millikan commanded perhaps the first meteorological observation and forecasting team essential to military operation in history.7 But even during peacetime meteorology is so much of a concern to everyone that a regular news segment is dedicated to it. Weather is the universal conversation topic, and life on land could not exist as we know it without clouds. One wonders then, why cloud formation is never covered in physics texts.

  1. Neptune's clouds

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The bright cirrus-like clouds of Neptune change rapidly, often forming and dissipating over periods of several to tens of hours. In this sequence Voyager 2 observed cloud evolution in the region around the Great Dark Spot (GDS). The surprisingly rapid changes which occur separating each panel shows that in this region Neptune's weather is perhaps as dynamic and variable as that of the Earth. However, the scale is immense by our standards -- the Earth and the GDS are of similar size -- and in Neptune's frigid atmosphere, where temperatures are as low as 55 degrees Kelvin (-360 F), the cirrus clouds are composed of frozen methane rather than Earth's crystals of water ice. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications

  2. CLOUD CHEMISTRY.

    SciTech Connect

    SCHWARTZ,S.E.

    2001-03-01

    Clouds present substantial concentrations of liquid-phase water, which can potentially serve as a medium for dissolution and reaction of atmospheric gases. The important precursors of acid deposition, SO{sub 2} and nitrogen oxides NO and NO{sub 2} are only sparingly soluble in clouds without further oxidation to sulfuric and nitric acids. In the case of SO{sub 2} aqueous-phase reaction with hydrogen peroxide, and to lesser extent ozone, are identified as important processes leading to this oxidation, and methods have been described by which to evaluate the rates of these reactions. The limited solubility of the nitrogen oxides precludes significant aqueous-phase reaction of these species, but gas-phase reactions in clouds can be important especially at night.

  3. Our World: Cool Clouds

    NASA Image and Video Library

    Learn how clouds are formed and watch an experiment to make a cloud using liquid nitrogen. Find out how scientists classify clouds according to their altitude and how clouds reflect and absorb ligh...

  4. Cloud Arcs

    Atmospheric Science Data Center

    2013-04-19

    ... a sinking motion elsewhere, are very common, the degree of organization exhibited here is relatively rare, as the wind field at different altitudes usually disrupts such patterns. The degree of self organization of this cloud image, whereby three or four such circular events ...

  5. Cloud Front

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02171 Cloud Front

    These clouds formed in the south polar region. The faintness of the cloud system likely indicates that these are mainly ice clouds, with relatively little dust content.

    Image information: VIS instrument. Latitude -86.7N, Longitude 212.3E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  6. Cloud vortices

    NASA Image and Video Library

    2015-11-02

    Cloud vortices off Heard Island, south Indian Ocean. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image of sea ice off Heard Island on Nov 2, 2015 at 5:02 AM EST (09:20 UTC). Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team

  7. Southern Clouds

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03026 Southern Clouds

    This image shows a system of clouds just off the margin of the South Polar cap. Taken during the summer season, these clouds contain both water-ice and dust.

    Image information: VIS instrument. Latitude 80.2S, Longitude 57.6E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  8. Linear Clouds

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03667 Linear Clouds

    These clouds are located near the edge of the south polar region. The cloud tops are the puffy white features in the bottom half of the image.

    Image information: VIS instrument. Latitude -80.1N, Longitude 52.1E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. Cloud Interactions

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 1 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere.

    Image information: VIS instrument. Latitude 68.4, Longitude 258.8 East (101.2 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration

  10. Estimating Cloud Cover

    ERIC Educational Resources Information Center

    Moseley, Christine

    2007-01-01

    The purpose of this activity was to help students understand the percentage of cloud cover and make more accurate cloud cover observations. Students estimated the percentage of cloud cover represented by simulated clouds and assigned a cloud cover classification to those simulations. (Contains 2 notes and 3 tables.)

  11. Estimating Cloud Cover

    ERIC Educational Resources Information Center

    Moseley, Christine

    2007-01-01

    The purpose of this activity was to help students understand the percentage of cloud cover and make more accurate cloud cover observations. Students estimated the percentage of cloud cover represented by simulated clouds and assigned a cloud cover classification to those simulations. (Contains 2 notes and 3 tables.)

  12. Martian Clouds

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 28 June 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image was acquired during early spring near the North Pole. The linear 'ripples' are transparent water-ice clouds. This linear form is typical for polar clouds. The black regions on the margins of this image are areas of saturation caused by the build up of scattered light from the bright polar material during the long image exposure.

    Image information: VIS instrument. Latitude 68.1, Longitude 147.9 East (212.1 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS

  13. Martian Clouds

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 28 June 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image was acquired during early spring near the North Pole. The linear 'ripples' are transparent water-ice clouds. This linear form is typical for polar clouds. The black regions on the margins of this image are areas of saturation caused by the build up of scattered light from the bright polar material during the long image exposure.

    Image information: VIS instrument. Latitude 68.1, Longitude 147.9 East (212.1 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS

  14. Mapping Titan Cloud Coverage

    NASA Image and Video Library

    2010-09-21

    This graphic, constructed from data obtained by NASA Cassini spacecraft, shows the percentage of cloud coverage across the surface of Saturn moon Titan. The color scale from black to yellow signifies no cloud coverage to complete cloud coverage.

  15. Crater Clouds

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA06085 Crater Clouds

    The crater on the right side of this image is affecting the local wind regime. Note the bright line of clouds streaming off the north rim of the crater.

    Image information: VIS instrument. Latitude -78.8N, Longitude 320.0E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. Cloud-Top Entrainment in Stratocumulus Clouds

    NASA Astrophysics Data System (ADS)

    Mellado, Juan Pedro

    2017-01-01

    Cloud entrainment, the mixing between cloudy and clear air at the boundary of clouds, constitutes one paradigm for the relevance of small scales in the Earth system: By regulating cloud lifetimes, meter- and submeter-scale processes at cloud boundaries can influence planetary-scale properties. Understanding cloud entrainment is difficult given the complexity and diversity of the associated phenomena, which include turbulence entrainment within a stratified medium, convective instabilities driven by radiative and evaporative cooling, shear instabilities, and cloud microphysics. Obtaining accurate data at the required small scales is also challenging, for both simulations and measurements. During the past few decades, however, high-resolution simulations and measurements have greatly advanced our understanding of the main mechanisms controlling cloud entrainment. This article reviews some of these advances, focusing on stratocumulus clouds, and indicates remaining challenges.

  17. Automatic Cloud Bursting under FermiCloud

    SciTech Connect

    Wu, Hao; Shangping, Ren; Garzoglio, Gabriele; Timm, Steven; Bernabeu, Gerard; Kim, Hyun Woo; Chadwick, Keith; Jang, Haengjin; Noh, Seo-Young

    2013-01-01

    Cloud computing is changing the infrastructure upon which scientific computing depends from supercomputers and distributed computing clusters to a more elastic cloud-based structure. The service-oriented focus and elasticity of clouds can not only facilitate technology needs of emerging business but also shorten response time and reduce operational costs of traditional scientific applications. Fermi National Accelerator Laboratory (Fermilab) is currently in the process of building its own private cloud, FermiCloud, which allows the existing grid infrastructure to use dynamically provisioned resources on FermiCloud to accommodate increased but dynamic computation demand from scientists in the domains of High Energy Physics (HEP) and other research areas. Cloud infrastructure also allows to increase a private cloud’s resource capacity through “bursting” by borrowing or renting resources from other community or commercial clouds when needed. This paper introduces a joint project on building a cloud federation to support HEP applications between Fermi National Accelerator Laboratory and Korea Institution of Science and Technology Information, with technical contributions from the Illinois Institute of Technology. In particular, this paper presents two recent accomplishments of the joint project: (a) cloud bursting automation and (b) load balancer. Automatic cloud bursting allows computer resources to be dynamically reconfigured to meet users’ demands. The load balance algorithm which the cloud bursting depends on decides when and where new resources need to be allocated. Our preliminary prototyping and experiments have shown promising success, yet, they also have opened new challenges to be studied

  18. The Oort cloud

    NASA Technical Reports Server (NTRS)

    Marochnik, Leonid S.; Mukhin, Lev M.; Sagdeev, Roald Z.

    1991-01-01

    Views of the large-scale structure of the solar system, consisting of the Sun, the nine planets and their satellites, changed when Oort demonstrated that a gigantic cloud of comets (the Oort cloud) is located on the periphery of the solar system. The following subject areas are covered: (1) the Oort cloud's mass; (2) Hill's cloud mass; (3) angular momentum distribution in the solar system; and (4) the cometary cloud around other stars.

  19. Jovian clouds and haze

    NASA Astrophysics Data System (ADS)

    West, Robert A.; Baines, Kevin H.; Friedson, A. James; Banfield, Don; Ragent, Boris; Taylor, Fred W.

    Tropospheric clouds: thermochemical equilibrium theory and cloud microphysical theory, condensate cloud microphysics, tropospheric cloud and haze distribution - observations, results from the Galileo probe experiments, Galileo NIMS observations and results, Galileo SSE observations and results, recent analyses of ground-based and HST data; Tropospheric clouds and haze: optical and physical properties: partical composition, particle optical properties, size and shape, chromophores; Stratospheric haze: particle distribution, optical properties, size and shape, particle formation.

  20. Ice Clouds

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Heavy water ice clouds almost completely obscure the surface in Vastitas Borealis.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 69.5, Longitude 283.6 East (76.4 West). 19 meter/pixel resolution.

  1. Limits to Cloud Susceptibility

    NASA Technical Reports Server (NTRS)

    Coakley, James A., Jr.

    2002-01-01

    1-kilometer AVHRR observations of ship tracks in low-level clouds off the west coast of the U S. were used to determine limits for the degree to which clouds might be altered by increases in anthropogenic aerosols. Hundreds of tracks were analyzed to determine whether the changes in droplet radii, visible optical depths, and cloud top altitudes that result from the influx of particles from underlying ships were consistent with expectations based on simple models for the indirect effect of aerosols. The models predict substantial increases in sunlight reflected by polluted clouds due to the increases in droplet numbers and cloud liquid water that result from the elevated particle concentrations. Contrary to the model predictions, the analysis of ship tracks revealed a 15-20% reduction in liquid water for the polluted clouds. Studies performed with a large-eddy cloud simulation model suggested that the shortfall in cloud liquid water found in the satellite observations might be attributed to the restriction that the 1-kilometer pixels be completely covered by either polluted or unpolluted cloud. The simulation model revealed that a substantial fraction of the indirect effect is caused by a horizontal redistribution of cloud water in the polluted clouds. Cloud-free gaps in polluted clouds fill in with cloud water while the cloud-free gaps in the surrounding unpolluted clouds remain cloud-free. By limiting the analysis to only overcast pixels, the current study failed to account for the gap-filling predicted by the simulation model. This finding and an analysis of the spatial variability of marine stratus suggest new ways to analyze ship tracks to determine the limit to which particle pollution will alter the amount of sunlight reflected by clouds.

  2. Cloud Processed CCN Affect Cloud Microphysics

    NASA Astrophysics Data System (ADS)

    Hudson, J. G.; Noble, S. R., Jr.; Tabor, S. S.

    2015-12-01

    Variations in the bimodality/monomodality of CCN spectra (Hudson et al. 2015) exert opposite effects on cloud microphysics in two aircraft field projects. The figure shows two examples, droplet concentration, Nc, and drizzle liquid water content, Ld, against classification of CCN spectral modality. Low ratings go to balanced separated bimodal spectra, high ratings go to single mode spectra, strictly monomodal 8. Intermediate ratings go merged modes, e.g., one mode a shoulder of another. Bimodality is caused by mass or hygroscopicity increases that go only to CCN that made activated cloud droplets. In the Ice in Clouds Experiment-Tropical (ICE-T) small cumuli with lower Nc, greater droplet mean diameters, MD, effective radii, re, spectral widths, σ, cloud liquid water contents, Lc, and Ld were closer to more bimodal (lower modal ratings) below cloud CCN spectra whereas clouds with higher Nc, smaller MD, re, σ, and Ld were closer to more monomodal CCN (higher modal ratings). In polluted stratus clouds of the MArine Stratus/Stratocumulus Experiment (MASE) clouds that had greater Nc, and smaller MD, re, σ, Lc, and Ld were closer to more bimodal CCN spectra whereas clouds with lower Nc, and greater MD, re, σ, Lc, and Ld were closer to more monomodal CCN. These relationships are opposite because the dominant ICE-T cloud processing was coalescence whereas chemical transformations (e.g., SO2 to SO4) were dominant in MASE. Coalescence reduces Nc and thus also CCN concentrations (NCCN) when droplets evaporate. In subsequent clouds the reduced competition increases MD and σ, which further enhance coalescence and drizzle. Chemical transformations do not change Nc but added sulfate enhances droplet and CCN solubility. Thus, lower critical supersaturation (S) CCN can produce more cloud droplets in subsequent cloud cycles, especially for the low W and effective S of stratus. The increased competition reduces MD, re, and σ, which inhibit coalescence and thus reduce drizzle

  3. Northern Clouds in Motion

    NASA Image and Video Library

    2011-03-17

    Clouds move above Titan large methane lakes and seas near the moon north pole in this image from NASA Cassini spacecraft. Methane clouds in the troposphere, the lowest part of the atmosphere, appear white here.

  4. Equatorial Titan Clouds

    NASA Image and Video Library

    2011-03-17

    NASA Cassini spacecraft chronicles the change of seasons as it captures clouds concentrated near the equator of Saturn largest moon, Titan. Methane clouds in the troposphere, the lowest part of the atmosphere, appear white here.

  5. Cloud Computing for radiologists

    PubMed Central

    Kharat, Amit T; Safvi, Amjad; Thind, SS; Singh, Amarjit

    2012-01-01

    Cloud computing is a concept wherein a computer grid is created using the Internet with the sole purpose of utilizing shared resources such as computer software, hardware, on a pay-per-use model. Using Cloud computing, radiology users can efficiently manage multimodality imaging units by using the latest software and hardware without paying huge upfront costs. Cloud computing systems usually work on public, private, hybrid, or community models. Using the various components of a Cloud, such as applications, client, infrastructure, storage, services, and processing power, Cloud computing can help imaging units rapidly scale and descale operations and avoid huge spending on maintenance of costly applications and storage. Cloud computing allows flexibility in imaging. It sets free radiology from the confines of a hospital and creates a virtual mobile office. The downsides to Cloud computing involve security and privacy issues which need to be addressed to ensure the success of Cloud computing in the future. PMID:23599560

  6. Noctilucent Cloud Sightings

    NASA Image and Video Library

    Polar Mesospheric Clouds form during each polar region's summer months in the coldest place in the atmosphere, 50 miles above Earth's surface. Noctilucent Clouds were first observed in 1885 by an a...

  7. South Polar Clouds

    NASA Image and Video Library

    2011-04-06

    Polar surface winds can reach high velocities. These winds can cause clouds to form when the winds flow into troughs and become chaotic. This image from NASA Mars Odyssey shows trough clouds as linear bands.

  8. Cloud Computing for radiologists.

    PubMed

    Kharat, Amit T; Safvi, Amjad; Thind, Ss; Singh, Amarjit

    2012-07-01

    Cloud computing is a concept wherein a computer grid is created using the Internet with the sole purpose of utilizing shared resources such as computer software, hardware, on a pay-per-use model. Using Cloud computing, radiology users can efficiently manage multimodality imaging units by using the latest software and hardware without paying huge upfront costs. Cloud computing systems usually work on public, private, hybrid, or community models. Using the various components of a Cloud, such as applications, client, infrastructure, storage, services, and processing power, Cloud computing can help imaging units rapidly scale and descale operations and avoid huge spending on maintenance of costly applications and storage. Cloud computing allows flexibility in imaging. It sets free radiology from the confines of a hospital and creates a virtual mobile office. The downsides to Cloud computing involve security and privacy issues which need to be addressed to ensure the success of Cloud computing in the future.

  9. Comparing Point Clouds

    DTIC Science & Technology

    2004-04-01

    Point clouds are one of the most primitive and fundamental surface representations. A popular source of point clouds are three dimensional shape...acquisition devices such as laser range scanners. Another important field where point clouds are found is in the representation of high-dimensional...framework for comparing manifolds given by point clouds is presented in this paper. The underlying theory is based on Gromov-Hausdorff distances, leading

  10. Computer animation of clouds

    SciTech Connect

    Max, N.

    1994-01-28

    Computer animation of outdoor scenes is enhanced by realistic clouds. I will discuss several different modeling and rendering schemes for clouds, and show how they evolved in my animation work. These include transparency-textured clouds on a 2-D plane, smooth shaded or textured 3-D clouds surfaces, and 3-D volume rendering. For the volume rendering, I will present various illumination schemes, including the density emitter, single scattering, and multiple scattering models.

  11. Cloud Forensics Issues

    DTIC Science & Technology

    2014-07-01

    encryption is needed and the need for a comprehensive key management process for public key infrastructure, as well as session and other cryptologic keys...In a community cloud, a group of organizations with similar interests or needs share a cloud infrastructure. That infrastructure is not open to the...since it is unlikely that a large proportion of cloud consumers will simultaneously have high utilization needs . The cloud environment can

  12. Cloud Computing Explained

    ERIC Educational Resources Information Center

    Metz, Rosalyn

    2010-01-01

    While many talk about the cloud, few actually understand it. Three organizations' definitions come to the forefront when defining the cloud: Gartner, Forrester, and the National Institutes of Standards and Technology (NIST). Although both Gartner and Forrester provide definitions of cloud computing, the NIST definition is concise and uses…

  13. Climate Cloud Height

    Atmospheric Science Data Center

    2017-05-16

    article title:  Is Climate Changing Cloud Heights? Too Soon to Say Climate change may eventually change global cloud heights, but scientists need ... whether that's happening already. For details see: Is Climate Changing Cloud Heights? Too Soon to Say . Climate ...

  14. Security in the cloud.

    PubMed

    Degaspari, John

    2011-08-01

    As more provider organizations look to the cloud computing model, they face a host of security-related questions. What are the appropriate applications for the cloud, what is the best cloud model, and what do they need to know to choose the best vendor? Hospital CIOs and security experts weigh in.

  15. Clouds in Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    West, R.

    1999-01-01

    In the terrestrial atmosphere clouds are familiar as vast collections of small water drops or ice cyrstals suspended in the air. The study of clouds touches on many facets of armospheric science. The chemistry of clouds is tied to the chemistry of the surrounding atmosphere.

  16. Cloud Computing Explained

    ERIC Educational Resources Information Center

    Metz, Rosalyn

    2010-01-01

    While many talk about the cloud, few actually understand it. Three organizations' definitions come to the forefront when defining the cloud: Gartner, Forrester, and the National Institutes of Standards and Technology (NIST). Although both Gartner and Forrester provide definitions of cloud computing, the NIST definition is concise and uses…

  17. Cloud microstructure studies

    NASA Technical Reports Server (NTRS)

    Blau, H. H., Jr.; Fowler, M. G.; Chang, D. T.; Ryan, R. T.

    1972-01-01

    Over two thousand individual cloud droplet size distributions were measured with an optical cloud particle spectrometer flown on the NASA Convair 990 aircraft. Representative droplet spectra and liquid water content, L (gm/cu m) were obtained for oceanic stratiform and cumuliform clouds. For non-precipitating clouds, values of L range from 0.1 gm/cu m to 0.5 gm/cu m; with precipitation, L is often greater than 1 gm/cu m. Measurements were also made in a newly formed contrail and in cirrus clouds.

  18. Intergalactic HI Clouds

    NASA Astrophysics Data System (ADS)

    Briggs, F. H.

    2004-06-01

    Neutral intergalactic clouds are so greatly out numbered by galaxies that their integral HI content is negligible in comparison to that contained in optically luminous galaxies. In fact, no HI cloud that is not associated with a galaxy or grouping of galaxies has yet been identified. This points to a causal relationship that relies on gravitational potentials that bind galaxies also being responsible for confining HI clouds to sufficient density that they can become self-shielding to the ionizing background radiation. Unconfined clouds of low density become ionized, but confined clouds find themselves vulnerable to instability and collapse, leading to star formation.

  19. Clouds Over 'Endurance'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Clouds in the martian sky above 'Endurance Crater' in this image from NASA's Mars Exploration Rover Opportunity can remind the viewer that Mars, our celestial neighbor, is subject to weather. On Earth, clouds like these would be referred to as 'cirrus' or theaptly nicknamed 'mares' tails.' These clouds occur in a region of strong vertical shear. The cloud particles (ice in this martiancase) fall out, and get dragged along away from the location where they originally condensed, forming characteristic streamers. Opportunity took this picture with its navigation camera during the rover's 282nd martian day (Nov. 8, 2004).

    The mission's atmospheric science team is studying cloud observations to deduce seasonal and time-of-day behavior of the clouds. This helps them gain a better understanding of processes that control cloud formation.

  20. THE CALIFORNIA MOLECULAR CLOUD

    SciTech Connect

    Lada, Charles J.; Lombardi, Marco; Alves, Joao F. E-mail: mlombard@eso.or

    2009-09-20

    We present an analysis of wide-field infrared extinction maps of a region in Perseus just north of the Taurus-Auriga dark cloud complex. From this analysis we have identified a massive, nearby, but previously unrecognized, giant molecular cloud (GMC). Both a uniform foreground star density and measurements of the cloud's velocity field from CO observations indicate that this cloud is likely a coherent structure at a single distance. From comparison of foreground star counts with Galactic models, we derive a distance of 450 +- 23 pc to the cloud. At this distance the cloud extends over roughly 80 pc and has a mass of {approx} 10{sup 5} M{sub sun}, rivaling the Orion (A) molecular cloud as the largest and most massive GMC in the solar neighborhood. Although surprisingly similar in mass and size to the more famous Orion molecular cloud (OMC) the newly recognized cloud displays significantly less star formation activity with more than an order of magnitude fewer young stellar objects than found in the OMC, suggesting that both the level of star formation and perhaps the star formation rate in this cloud are an order of magnitude or more lower than in the OMC. Analysis of extinction maps of both clouds shows that the new cloud contains only 10% the amount of high extinction (A{sub K} > 1.0 mag) material as is found in the OMC. This, in turn, suggests that the level of star formation activity and perhaps the star formation rate in these two clouds may be directly proportional to the total amount of high extinction material and presumably high density gas within them and that there might be a density threshold for star formation on the order of n(H{sub 2}) {approx} a few x 10{sup 4} cm{sup -3}.

  1. Interpretation of MODIS Cloud Images by CloudSat/CALIPSO Cloud Vertical Profiles

    NASA Astrophysics Data System (ADS)

    Wang, T.; Fetzer, E. J.; Wong, S.; Yue, Q.

    2015-12-01

    Clouds observed by passive remote-sensing imager (Aqua-MODIS) are collocated to cloud vertical profiles observed by active profiling sensors (CloudSat radar and CALIPSO lidar) at the pixel-scale. By comparing different layers of cloud types classified in the 2B-CLDCLASS-LIDAR product from CloudSat+CALIPSO to those cloud properties observed by MODIS, we evaluate the occurrence frequencies of cloud types and cloud-overlap in CloudSat+CALIPSO for each MODIS cloud regime defined by cloud optical depth (τ) and cloud-top pressure (P) histograms. We find that about 70% of MODIS clear sky agrees with the clear category in CloudSat+CALIPSO; whereas the remainder is either single layer (~25%) cirrus (Ci), low-level cumulus (Cu), stratocumulus (Sc), or multi-layer (<5%) clouds in CloudSat+CALIPSO. Under MODIS cloudy conditions, 60%, 28%, and 8% of the occurrences show single-, double-, and triple-layer clouds, respectively in CloudSat+CALIPSO. When MODIS identifies single-layer clouds, 50-60% of the MODIS low-level clouds are categorized as stratus (Sc) in CloudSat+CALIPSO. Over the tropics, ~70% of MODIS high and optically thin clouds (considered as cirrus in the histogram) is also identified as Ci in CloudSat+CALIPSO, and ~40% of MODIS high and optically thick clouds (considered as convective in the histogram) agrees with CloudSat+CALIPSO deep convections (DC). Over mid-latitudes these numbers drop to 45% and 10%, respectively. The best agreement occurs in tropical single-layer cloud regimes, where 90% of MODIS high-thin clouds are identified as Ci by CloudSat+CALIPSO and 60% of MODIS high-thick clouds are identified as DC. Worst agreement is found for multi-layer clouds, where cirrus on top of low- and mid-level clouds in MODIS are frequently categorized as high-thick clouds by passive imaging - among these only 5-12% are DC in CloudSat+CALIPSO. It is encouraging that both MODIS low-level clouds (regardless of optical thickness) and high-level thin clouds are consistently

  2. Silicon photonics cloud (SiCloud)

    NASA Astrophysics Data System (ADS)

    DeVore, Peter T. S.; Jiang, Yunshan; Lynch, Michael; Miyatake, Taira; Carmona, Christopher; Chan, Andrew C.; Muniam, Kuhan; Jalali, Bahram

    2015-02-01

    We present SiCloud (Silicon Photonics Cloud), the first free, instructional web-based research and education tool for silicon photonics. SiCloud's vision is to provide a host of instructional and research web-based tools. Such interactive learning tools enhance traditional teaching methods by extending access to a very large audience, resulting in very high impact. Interactive tools engage the brain in a way different from merely reading, and so enhance and reinforce the learning experience. Understanding silicon photonics is challenging as the topic involves a wide range of disciplines, including material science, semiconductor physics, electronics and waveguide optics. This web-based calculator is an interactive analysis tool for optical properties of silicon and related material (SiO2, Si3N4, Al2O3, etc.). It is designed to be a one stop resource for students, researchers and design engineers. The first and most basic aspect of Silicon Photonics is the Material Parameters, which provides the foundation for the Device, Sub-System and System levels. SiCloud includes the common dielectrics and semiconductors for waveguide core, cladding, and photodetection, as well as metals for electrical contacts. SiCloud is a work in progress and its capability is being expanded. SiCloud is being developed at UCLA with funding from the National Science Foundation's Center for Integrated Access Networks (CIAN) Engineering Research Center.

  3. What is a Cloud?

    NASA Astrophysics Data System (ADS)

    Long, C. N.; Wu, W.

    2013-12-01

    There are multiple factors that cause disagreements between differing methods using differing instruments to infer cloud amounts. But along with these issues is a fundamental concern that has permeated all comparisons and supersedes such questions as what are the uncertainty estimates of a given retrieval. To wit: what is a cloud? How can uncertainty of a cloud amount measurement be determined when there is no absolute 'truth' on what defines a cloud, as opposed to cloud-free? Recent research comparing a decade of surface- and satellite-based retrievals of cloud amount for the ARM Southern Great Plains site shows significant disagreements. While Total Sky Imager 100-degree FOV, Shortwave (SW) Radiative Flux Analysis, GOES satellite and PATMOS-x satellite amounts agree relatively well, ISCCP satellite and ARSCL time-series cloud amounts are significantly greater, 15% (ISCCP) and 8% (ARSCL) larger in average diurnal variations. In both cases, it appears that optically thin high ice is counted as 'cloud' in ARSCL and ISCCP that is not categorized as cloud by all the others. Additionally, cloud amounts from three methods (ISCCP, ARSCL, and GOES) show an overall increase of 8%-10% in the annually averaged cloud fractions from 1998 to 2009, while those from the other three (TSI, SWFA, PATMOS-x) show little trend for this period. So one wonders: are cloud amounts increasing or not over this period? The SW Flux Analysis used sky imager retrievals as 'truth' in development of the methodology (Long et al, 2006a), where sky imagery itself used human observations as the model (Long et al., 2006b). Min et al. (2008) then used SW Flux Analysis retrievals as 'truth' to develop an MFRSR-based spectral SW retrieval method. Dupont et al. (2008) show that the SW-based retrievals allow up to a visible optical depth of 0.15 (95% of occurrences) under the 'clear-sky' category which primarily consists of sub-visual cirrus, which by ancestry applies to spectral SW, sky imager and human

  4. Titan's South Polar Cloud

    NASA Astrophysics Data System (ADS)

    Toledo, D.; Rannou, P.; West, R. A.; Lavvas, P.; Del Genio, A. D.; Barbara, J. M.; Roy, M.; Turtle, E. P.

    2014-04-01

    Cassini/ISS cameras detected a newly formed large cloud in the south polar region of Titan on 2012-178 (June 27). Images of this cloud in the continuum filters at 889 nm (MT3) and 935 nm (CB3) clearly reveal different characteristics relative to the'detached haze' layer that extends over all south latitudes. Figure 1 shows I/F at 889 nm, where the cloud patch is observed beyond the latitude -77º and with values of the SZA higher than 90º. In this work, we analyze different MT3/CB3 images taken by ISS cameras, in order to characterize the optical properties of this cloud as well as its altitude. We first analyze images in the MT3 filter at different angles of observation in order to have some constraints on the altitude of the cloud, and subsequently the cloud optical properties are estimated by using radiative transfer simulations.

  5. Cryptographic Cloud Storage

    NASA Astrophysics Data System (ADS)

    Kamara, Seny; Lauter, Kristin

    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 non-standard cryptographic primitives in order to achieve our goal. We survey the benefits such an architecture would provide to both customers and service providers and give an overview of recent advances in cryptography motivated specifically by cloud storage.

  6. Ammonia Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Ammonia Ice Clouds on Jupiter

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds (appearing as bright blue areas) as they form and disperse over five successive Jupiter 'days.' Scientists noted how the larger cloud travels along with a small, local deep hole.

  7. Ammonia Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Ammonia Ice Clouds on Jupiter

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds (appearing as bright blue areas) as they form and disperse over five successive Jupiter 'days.' Scientists noted how the larger cloud travels along with a small, local deep hole.

  8. JINR cloud infrastructure evolution

    NASA Astrophysics Data System (ADS)

    Baranov, A. V.; Balashov, N. A.; Kutovskiy, N. A.; Semenov, R. N.

    2016-09-01

    To fulfil JINR commitments in different national and international projects related to the use of modern information technologies such as cloud and grid computing as well as to provide a modern tool for JINR users for their scientific research a cloud infrastructure was deployed at Laboratory of Information Technologies of Joint Institute for Nuclear Research. OpenNebula software was chosen as a cloud platform. Initially it was set up in simple configuration with single front-end host and a few cloud nodes. Some custom development was done to tune JINR cloud installation to fit local needs: web form in the cloud web-interface for resources request, a menu item with cloud utilization statistics, user authentication via Kerberos, custom driver for OpenVZ containers. Because of high demand in that cloud service and its resources over-utilization it was re-designed to cover increasing users' needs in capacity, availability and reliability. Recently a new cloud instance has been deployed in high-availability configuration with distributed network file system and additional computing power.

  9. Cloud Computing: An Overview

    NASA Astrophysics Data System (ADS)

    Qian, Ling; Luo, Zhiguo; Du, Yujian; Guo, Leitao

    In order to support the maximum number of user and elastic service with the minimum resource, the Internet service provider invented the cloud computing. within a few years, emerging cloud computing has became the hottest technology. From the publication of core papers by Google since 2003 to the commercialization of Amazon EC2 in 2006, and to the service offering of AT&T Synaptic Hosting, the cloud computing has been evolved from internal IT system to public service, from cost-saving tools to revenue generator, and from ISP to telecom. This paper introduces the concept, history, pros and cons of cloud computing as well as the value chain and standardization effort.

  10. SparkClouds: visualizing trends in tag clouds.

    PubMed

    Lee, Bongshin; Riche, Nathalie Henry; Karlson, Amy K; Carpendale, Sheelash

    2010-01-01

    Tag clouds have proliferated over the web over the last decade. They provide a visual summary of a collection of texts by visually depicting the tag frequency by font size. In use, tag clouds can evolve as the associated data source changes over time. Interesting discussions around tag clouds often include a series of tag clouds and consider how they evolve over time. However, since tag clouds do not explicitly represent trends or support comparisons, the cognitive demands placed on the person for perceiving trends in multiple tag clouds are high. In this paper, we introduce SparkClouds, which integrate sparklines into a tag cloud to convey trends between multiple tag clouds. We present results from a controlled study that compares SparkClouds with two traditional trend visualizations—multiple line graphs and stacked bar charts—as well as Parallel Tag Clouds. Results show that SparkClouds ability to show trends compares favourably to the alternative visualizations.

  11. HI clouds in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Kim, S.

    We present HI and Halpha surveys of the Large Magellanic Cloud (LMC) with the Australia Telescope Compact Array, the Parkes multibeam receiver, and the 16 inch optical telescope at the Siding Spring Observatory (SSO). Using a Fourier-plane technique, we have merged both ATCA and Parkes observations, providing an accurate set of images of the LMC sensitive to structure on scales of 9 pc upward. The spatial dynamic range (2.8 orders of magnitude), velocity resolution (1.649 km/sec per channel) allow for studies of phenomena ranging from the galaxy-wide interaction of the LMC with its close neighbors to the small-scale injection of energy from supernovae and stellar associations into the ISM of the LMC. On the large scale, the HI disk appears to be remarkably symmetric and to have a well-organized and orderly, if somewhat complex, rotational field. The bulk of the HI resides in a disk of 7.3 kpc in diameter. The mass of disk component of the LMC is 2.5 x10^9 M[sun ]and the mass within a radius of 4 kpc is about 3.5 x 10^9 M[sun ]. The structure of the neutral atomic ISM in the LMC is dominated by HI filaments combined with numerous shell, holes, and HI clouds. 23 HI supergiant shells and 103 giant shells are catalogued. Supergiant shells are defined as those regions whose extent is much larger than the HI scale height. The size distribution of HI shells follows a crude power law, N(log R) =AR^-1.5 . The HI clouds have been identified by defining a cloud to be an object composed of all pixels in right ascension, declination, and velocity that are connected and that lie above the threshold brightness temperature. The size spectrum of HI clouds is similar to the typical size spectrum of holes and shells in the HI distribution. The relationship between the size and the velocity dispersion of HI cloud is found to have the power law relationship so called as Larson's scaling law. A slope of the power law varies from 1.2 to 1.6. The virial masses of HI clouds range from 10

  12. Lost in Cloud

    NASA Technical Reports Server (NTRS)

    Maluf, David A.; Shetye, Sandeep D.; Chilukuri, Sri; Sturken, Ian

    2012-01-01

    Cloud computing can reduce cost significantly because businesses can share computing resources. In recent years Small and Medium Businesses (SMB) have used Cloud effectively for cost saving and for sharing IT expenses. With the success of SMBs, many perceive that the larger enterprises ought to move into Cloud environment as well. Government agency s stove-piped environments are being considered as candidates for potential use of Cloud either as an enterprise entity or pockets of small communities. Cloud Computing is the delivery of computing as a service rather than as a product, whereby shared resources, software, and information are provided to computers and other devices as a utility over a network. Underneath the offered services, there exists a modern infrastructure cost of which is often spread across its services or its investors. As NASA is considered as an Enterprise class organization, like other enterprises, a shift has been occurring in perceiving its IT services as candidates for Cloud services. This paper discusses market trends in cloud computing from an enterprise angle and then addresses the topic of Cloud Computing for NASA in two possible forms. First, in the form of a public Cloud to support it as an enterprise, as well as to share it with the commercial and public at large. Second, as a private Cloud wherein the infrastructure is operated solely for NASA, whether managed internally or by a third-party and hosted internally or externally. The paper addresses the strengths and weaknesses of both paradigms of public and private Clouds, in both internally and externally operated settings. The content of the paper is from a NASA perspective but is applicable to any large enterprise with thousands of employees and contractors.

  13. Clouds in Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    West, R.; Murdin, P.

    2000-11-01

    What are clouds? The answer to that question is both obvious and subtle. In the terrestrial atmosphere clouds are familiar as vast collections of small water drops or ice crystals suspended in the air. In the atmospheres of Venus, Mars, Jupiter, Saturn, Saturn's moon Titan, Uranus, Neptune, and possibly Pluto, they are composed of several other substances including sulfuric acid, ammonia, hydroge...

  14. Cloud Scene Simulation Modeling

    DTIC Science & Technology

    1991-11-20

    PL-M-91-2295 AD-A256 689 CLOUD SCENE SIMULATION MODELING M.E. Cianciolo J.S. Hersh M.R Ramos-Johnson TASC 55 Walkers Brook Drive Reading...1991 Scientific No. 1 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Cloud Scene Simulation Modeling PE 62101F PR 6670 TA 09 WU BE 6. AUTHOR(S) Contract

  15. Learning in the Clouds?

    ERIC Educational Resources Information Center

    Butin, Dan W.

    2013-01-01

    Engaged learning--the type that happens outside textbooks and beyond the four walls of the classroom--moves beyond right and wrong answers to grappling with the uncertainties and contradictions of a complex world. iPhones back up to the "cloud." GoogleDocs is all about "cloud computing." Facebook is as ubiquitous as the sky.…

  16. Weather Fundamentals: Clouds. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

  17. Learning in the Clouds?

    ERIC Educational Resources Information Center

    Butin, Dan W.

    2013-01-01

    Engaged learning--the type that happens outside textbooks and beyond the four walls of the classroom--moves beyond right and wrong answers to grappling with the uncertainties and contradictions of a complex world. iPhones back up to the "cloud." GoogleDocs is all about "cloud computing." Facebook is as ubiquitous as the sky.…

  18. Weather Fundamentals: Clouds. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

  19. Titan Lingering Clouds

    NASA Image and Video Library

    2009-06-03

    Lots of clouds are visible in this infrared image of Saturn's moon Titan. These clouds form and move much like those on Earth, but in a much slower, more lingering fashion, new results from NASA's Cassini spacecraft show. Scientists have monitored Titan's atmosphere for three-and-a-half years, between July 2004 and December 2007, and observed more than 200 clouds. The way these clouds are distributed around Titan matches scientists' global circulation models. The only exception is timing—clouds are still noticeable in the southern hemisphere while fall is approaching. Three false-color images make up this mosaic and show the clouds at 40 to 50 degrees mid-latitude. The images were taken by Cassini's visual and infrared mapping spectrometer during a close flyby of Titan on Sept. 7, 2006, known as T17. For a similar view see PIA12005. Each image is a color composite, with red shown at the 2-micron wavelength, green at 1.6 microns, and blue at 2.8 microns. An infrared color mosaic is also used as a background (red at 5 microns, green at 2 microns and blue at 1.3 microns). The characteristic elongated mid-latitude clouds, which are easily visible in bright bluish tones are still active even late into 2006-2007. According to climate models, these clouds should have faded out since 2005. http://photojournal.jpl.nasa.gov/catalog/PIA12004

  20. On Cloud Nine

    ERIC Educational Resources Information Center

    McCrea, Bridget; Weil, Marty

    2011-01-01

    Across the U.S., innovative collaboration practices are happening in the cloud: Sixth-graders participate in literary salons. Fourth-graders mentor kindergarteners. And teachers use virtual Post-it notes to advise students as they create their own television shows. In other words, cloud computing is no longer just used to manage administrative…

  1. Cloud Resolving Modeling

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2007-01-01

    One of the most promising methods to test the representation of cloud processes used in climate models is to use observations together with cloud-resolving models (CRMs). CRMs use more sophisticated and realistic representations of cloud microphysical processes, and they can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems (with sizes ranging from about 2-200 km). CRMs also allow for explicit interaction between clouds, outgoing longwave (cooling) and incoming solar (heating) radiation, and ocean and land surface processes. Observations are required to initialize CRMs and to validate their results. This paper provides a brief discussion and review of the main characteristics of CRMs as well as some of their major applications. These include the use of CRMs to improve our understanding of: (1) convective organization, (2) cloud temperature and water vapor budgets, and convective momentum transport, (3) diurnal variation of precipitation processes, (4) radiative-convective quasi-equilibrium states, (5) cloud-chemistry interaction, (6) aerosol-precipitation interaction, and (7) improving moist processes in large-scale models. In addition, current and future developments and applications of CRMs will be presented.

  2. On Cloud Nine

    ERIC Educational Resources Information Center

    McCrea, Bridget; Weil, Marty

    2011-01-01

    Across the U.S., innovative collaboration practices are happening in the cloud: Sixth-graders participate in literary salons. Fourth-graders mentor kindergarteners. And teachers use virtual Post-it notes to advise students as they create their own television shows. In other words, cloud computing is no longer just used to manage administrative…

  3. Cloud Onboarding with NGAP

    NASA Technical Reports Server (NTRS)

    Newman, Douglas

    2016-01-01

    Deployment of applications to the cloud, as opposed to on-premises, presents a number of new challenges to operations. Using an EOSDIS application deployed to NGAP as an example, we outline the commonality and differences you need to be aware of to successfully operate your application on the cloud.

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

    SciTech Connect

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

    2011-07-21

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

  5. Cloud computing security.

    SciTech Connect

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

    2010-10-01

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

  6. Polarization of clouds

    NASA Astrophysics Data System (ADS)

    Goloub, Philippe; Herman, Maurice; Parol, Frederic

    1995-12-01

    This paper reports the main results concerning polarization by clouds derived from POLDER (polarization and directionality of earth's reflectances) airborne version. These results tend to confirm the high information content in the polarization (phase, altimetry). The preliminary results of EUCREX'94 (European Cloud Radiation Experiment) evidenced the drastically different polarized signatures for ice crystals and water droplets. Here we report systematic and statistically significative observations over the whole EUCREX data set. The results show that the cirrus exhibit their own signature. Preliminary observations performed during CLEOPATRA'91 (Cloud Experiment Ober Pfaffenhofen And Transport) and EUCREX'94 campaigns have shown the feasibility of cloud altimetry using spectral information (443 nm and 865 nm) of the polarized light over liquid water droplets clouds. Altimetry technique has been generalized on ASTEX-SOFIA'92 and EUCREX'94 data sets. All these results are presented and discussed in this paper.

  7. Prebiotic chemistry in clouds

    NASA Technical Reports Server (NTRS)

    Oberbeck, Verne R.; Marshall, John; Shen, Thomas

    1991-01-01

    The chemical evolution hypothesis of Woese (1979), according to which prebiotic reactions occurred rapidly in droplets in giant atmospheric reflux columns was criticized by Scherer (1985). This paper proposes a mechanism for prebiotic chemistry in clouds that answers Scherer's concerns and supports Woese's hypothesis. According to this mechanism, rapid prebiotic chemical evolution was facilitated on the primordial earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by, or synthesized during entry of meteorites, comets, and interplanetary dust, would have been scavenged by cloud drops containing clay condensation nuclei and would be polymerized within cloud systems during cycles of condensation, freezing, melting, and evaporation of cloud drops.

  8. Computing and Partitioning Cloud Feedbacks using Cloud Property Histograms

    NASA Astrophysics Data System (ADS)

    Zelinka, M. D.; Klein, S. A.; Hartmann, D. L.

    2011-12-01

    In this study we propose a novel technique for computing cloud feedbacks using histograms of cloud fraction as joint functions of cloud top pressure and optical depth generated by the International Satellite Cloud Climatology Project (ISCCP) simulator, which was incorporated into the climate models that took part in the Cloud Feedback Model Intercomparison Project. We use a radiative transfer model to compute top of atmosphere (TOA) flux sensitivities to cloud fraction perturbations in each bin of the ISCCP simulator histogram, which we refer to as a cloud radiative kernel. Multiplying the cloud radiative kernel histogram with the histogram of actual cloud top fraction changes per unit of global warming simulated by each model produces an estimate of cloud feedback. Both the spatial structures and globally integrated values of cloud feedbacks computed in this manner agree remarkably well with those computed by adjusting the change in cloud radiative forcing for clear-sky effects as in Soden et al. (2008). The technique allows us to quantitatively partition cloud feedbacks into contributions from changes in cloud amount, height, and optical depth. We show that rising clouds are the dominant contributor to the positive LW cloud feedback, and that the extra-tropical contribution is approximately 70% as large as the tropical contribution. In the ensemble mean, the positive impact of rising clouds is 50% larger than the negative impact of reductions in cloud amount on LW cloud feedback, but the degree to which reductions in cloud fraction offset the effect of rising clouds varies considerably across models. In contrast, reductions in cloud fraction make a large and virtually unopposed positive contribution to SW cloud feedback, though the inter-model spread is greater than for any other individual feedback component. In general, models exhibiting greater reductions in subtropical marine boundary layer cloudiness tend to have larger positive SW cloud feedbacks, in

  9. Cirrus cloud retrieval using infrared sounding data: Multilevel cloud errors

    NASA Technical Reports Server (NTRS)

    Baum, Bryan A.; Wielicki, Bruce A.

    1994-01-01

    In this study we perform an error analysis for cloud-top pressure retrieval using the High-Resolution Infrared Radiometric Sounder (HIRS/2) 15-microns CO2 channels for the two-layer case of transmissive cirrus overlying an overcast, opaque stratiform cloud. This analysis includes standard deviation and bias error due to instrument noise and the presence of two cloud layers, the lower of which is opaque. Instantaneous cloud pressure retrieval errors are determined for a range of cloud amounts (0.1-1.0) and cloud-top pressures (850-250 mb). Large cloud-top pressure retrieval errors are found to occur when a lower opaque layer is present underneath an upper transmissive cloud layer in the satellite field of view (FOV). Errors tend to increase with decreasing upper-cloud effective cloud amount and with decreasing cloud height (increasing pressure). Errors in retrieved upper-cloud pressure result in corresponding errors in derived effective cloud amount. For the case in which a HIRS FOV has two distinct cloud layers, the difference between the retrieved and actual cloud-top pressure is positive in all cases, meaning that the retrieved upper-cloud height is lower than the actual upper-cloud height. In addition, errors in retrieved cloud pressure are found to depend upon the lapse rate between the low-level cloud top and the surface. We examined which sounder channel combinations would minimize the total errors in derived cirrus cloud height caused by instrument noise and by the presence of a lower-level cloud. We find that while the sounding channels that peak between 700 and 1000 mb minimize random errors, the sounding channels that peak at 300-500 mb minimize bias errors. For a cloud climatology, the bias errors are most critical.

  10. Making and Breaking Clouds

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-10-01

    Molecular clouds which youre likely familiar with from stunning popular astronomy imagery lead complicated, tumultuous lives. A recent study has now found that these features must be rapidly built and destroyed.Star-Forming CollapseA Hubble view of a molecular cloud, roughly two light-years long, that has broken off of the Carina Nebula. [NASA/ESA, N. Smith (University of California, Berkeley)/The Hubble Heritage Team (STScI/AURA)]Molecular gas can be found throughout our galaxy in the form of eminently photogenic clouds (as featured throughout this post). Dense, cold molecular gas makes up more than 20% of the Milky Ways total gas mass, and gravitational instabilities within these clouds lead them to collapse under their own weight, resulting in the formation of our galaxys stars.How does this collapse occur? The simplest explanation is that the clouds simply collapse in free fall, with no source of support to counter their contraction. But if all the molecular gas we observe collapsed on free-fall timescales, star formation in our galaxy would churn a rate thats at least an order of magnitude higher than the observed 12 solar masses per year in the Milky Way.Destruction by FeedbackAstronomers have theorized that there may be some mechanism that supports these clouds against gravity, slowing their collapse. But both theoretical studies and observations of the clouds have ruled out most of these potential mechanisms, and mounting evidence supports the original interpretation that molecular clouds are simply gravitationally collapsing.A sub-mm image from ESOs APEX telescope of part of the Taurus molecular cloud, roughly ten light-years long, superimposed on a visible-light image of the region. [ESO/APEX (MPIfR/ESO/OSO)/A. Hacar et al./Digitized Sky Survey 2. Acknowledgment: Davide De Martin]If this is indeed the case, then one explanation for our low observed star formation rate could be that molecular clouds are rapidly destroyed by feedback from the very stars

  11. Community Cloud Computing

    NASA Astrophysics Data System (ADS)

    Marinos, Alexandros; Briscoe, Gerard

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

  12. Clouds in GEOS-5

    NASA Technical Reports Server (NTRS)

    Bacmeister, Julio; Rienecker, Michele; Suarez, Max; Norris, Peter

    2007-01-01

    The GEOS-5 atmospheric model is being developed as a weather-and-climate capable model. It must perform well in assimilation mode as well as in weather and climate simulations and forecasts and in coupled chemistry-climate simulations. In developing GEOS-5, attention has focused on the representation of moist processes. The moist physics package uses a single phase prognostic condensate and a prognostic cloud fraction. Two separate cloud types are distinguished by their source: "anvil" cloud originates in detraining convection, and large-scale cloud originates in a PDF-based condensation calculation. Ice and liquid phases for each cloud type are considered. Once created, condensate and fraction from the anvil and statistical cloud types experience the same loss processes: evaporation of condensate and fraction, auto-conversion of liquid or mixed phase condensate, sedimentation of frozen condensate, and accretion of condensate by falling precipitation. The convective parameterization scheme is the Relaxed Arakawa-Schubert, or RAS, scheme. Satellite data are used to evaluate the performance of the moist physics packages and help in their tuning. In addition, analysis of and comparisons to cloud-resolving models such as the Goddard Cumulus Ensemble model are used to help improve the PDFs used in the moist physics. The presentation will show some of our evaluations including precipitation diagnostics.

  13. Interstellar molecular clouds

    NASA Astrophysics Data System (ADS)

    Bally, J.

    1986-04-01

    The physical properties of the molecular phase of the interstellar medium are studied with regard to star formation and the structure of the Galaxy. Most observations of molecular clouds are made with single-dish, high-surface precision radio telescopes, with the best resolution attainable at 0.2 to 1 arcmin; the smallest structures that can be resolved are of order 10 to the 17th cm in diameter. It is now believed that: (1) most of the mass of the Galaxy is in the form of giant molecular clouds; (2) the largest clouds and those responsible for most massive star formation are concentrated in spiral arms; (3) the molecular clouds are the sites of perpetual star formation, and are significant in the chemical evolution of the Galaxy; (4) giant molecular clouds determine the evolution of the kinematic properties of galactic disk stars; (5) the total gas content is diminishing with time; and (6) most clouds have supersonic internal motions and do not form stars on a free-fall time scale. It is concluded that though progress has been made, more advanced instruments are needed to inspect the processes operating within stellar nurseries and to study the distribution of the molecular clouds in more distant galaxies. Instruments presently under construction which are designed to meet these ends are presented.

  14. Diagnosing AIRS Sampling with CloudSat Cloud Classes

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric; Yue, Qing; Guillaume, Alexandre; Kahn, Brian

    2011-01-01

    AIRS yield and sampling vary with cloud state. Careful utilization of collocated multiple satellite sensors is necessary. Profile differences between AIRS and ECMWF model analyses indicate that AIRS has high sampling and excellent accuracy for certain meteorological conditions. Cloud-dependent sampling biases may have large impact on AIRS L2 and L3 data in climate research. MBL clouds / lower tropospheric stability relationship is one example. AIRS and CloudSat reveal a reasonable climatology in the MBL cloud regime despite limited sampling in stratocumulus. Thermodynamic parameters such as EIS derived from AIRS data map these cloud conditions successfully. We are working on characterizing AIRS scenes with mixed cloud types.

  15. Cloud Distribution Statistics from LITE

    NASA Technical Reports Server (NTRS)

    Winker, David M.

    1998-01-01

    The Lidar In-Space Technology Experiment (LITE) mission has demonstrated the utility of spaceborne lidar in observing multilayer clouds and has provided a dataset showing the distribution of tropospheric clouds and aerosols. These unambiguous observations of the vertical distribution of clouds will allow improved verification of current cloud climatologies and GCM cloud parameterizations. Although there is now great interest in cloud profiling radar, operating in the mm-wave region, for the spacebased observation of cloud heights the results of the LITE mission have shown that satellite lidars can also make significant contributions in this area.

  16. Cloud Types and Services

    NASA Astrophysics Data System (ADS)

    Jin, Hai; Ibrahim, Shadi; Bell, Tim; Gao, Wei; Huang, Dachuan; Wu, Song

    The increasing popularity of Internet services such as the Amazon Web Services, Google App Engine and Microsoft Azure have drawn a lot of attention to the Cloud Computing paradigm. Although the term "Cloud Computing" is new, the technology is an extension of the remarkable achievements of grid, virtualization, Web 2.0 and Service Oriented Architecture (SOA) technologies, and the convergence of these technologies. Moreover, interest in Cloud Computing has been motivated by many factors such as the prevalence of multi-core processors and the low cost of system hardware, as well as the increasing cost of the energy needed to operate them. As a result, Cloud Computing, in just three years, has risen to the top of the IT revolutionary technologies, and has been announced as the top technology to watch in the year 2010.

  17. GEOS-5 Modeled Clouds

    NASA Image and Video Library

    This visualization shows clouds from a simulation using the Goddard Earth Observing System Model, Verison 5 (GEOS-5). The global atmospheric simulation covers a period from Feb 3, 2010 through Feb ...

  18. Methanol in dark clouds

    NASA Technical Reports Server (NTRS)

    Friberg, P.; Hjalmarson, A.; Madden, S. C.; Irvine, W. M.

    1988-01-01

    The first observation of methanol in cold dark clouds TMC 1, L 134 N, and B 335 is reported. In all three clouds, the relative abundance of methanol was found to be in the range of 10 to the -9th (i.e., almost an order of magnitude more abundant than acetaldehyde), with no observable variation between the clouds. Methanol emission showed a complex velocity structure; in TMC 1, clear indications of non-LTE were observed. Dimethyl ether was searched for in L 134 N; the upper limit of the column density of dimethyl ether in L 134 N was estimated to be 4 x 10 to the 12th/sq cm, assuming 5 K rotation temperature and LTE. This limit makes the abundance ratio (CH3)2O/CH3OH not higher than 1/5, indicating that dimethyl ether is not overabundant in this dark cloud.

  19. Noctilucent Clouds in Motion

    NASA Image and Video Library

    Swedish photographer Peter Rosén took this close-up, time-lapse movieof Noctilucent Clouds (NLCs) over Stockholm, Sweden on the evening ofJuly 16, 2012. "What looked like a serene view from a di...

  20. Closed Large Cell Clouds

    Atmospheric Science Data Center

    2013-04-19

    article title:  Closed Large Cell Clouds in the South Pacific     ... unperturbed by cyclonic or frontal activity. When the cell centers are cloudy and the main sinking motion is concentrated at cell ...

  1. Dusty Space Cloud

    NASA Image and Video Library

    2012-01-10

    This image shows the Large Magellanic Cloud galaxy in infrared light as seen by ESA Herschel Space Observatory and NASA Spitzer Space Telescope. The brightest center-left region is called 30 Doradus, or the Tarantula Nebula.

  2. Ammonia Clouds on Jupiter

    NASA Image and Video Library

    2007-10-09

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds appearing as bright blue areas as they form and disperse.

  3. Trigger-Happy Cloud

    NASA Image and Video Library

    2009-08-12

    This composite image, combining data from NASA Chandra X-ray Observatory and Spitzer Space Telescope shows the star-forming cloud Cepheus B, located in our Milky Way galaxy about 2,400 light years from Earth

  4. My NASA Data Clouds

    NASA Image and Video Library

    This lesson has two activities that help students develop a basic understanding of the relationship between cloud type and the form of precipitation and the relationship between the amount of water...

  5. Clouds over Tharsis

    NASA Image and Video Library

    1998-03-13

    Color composite of condensate clouds over Tharsis made from red and blue images with a synthesized green channel. Mars Orbiter Camera wide angle frames from Orbit 48. http://photojournal.jpl.nasa.gov/catalog/PIA00812

  6. Methanol in dark clouds

    NASA Technical Reports Server (NTRS)

    Friberg, P.; Hjalmarson, A.; Madden, S. C.; Irvine, W. M.

    1988-01-01

    The first observation of methanol in cold dark clouds TMC 1, L 134 N, and B 335 is reported. In all three clouds, the relative abundance of methanol was found to be in the range of 10 to the -9th (i.e., almost an order of magnitude more abundant than acetaldehyde), with no observable variation between the clouds. Methanol emission showed a complex velocity structure; in TMC 1, clear indications of non-LTE were observed. Dimethyl ether was searched for in L 134 N; the upper limit of the column density of dimethyl ether in L 134 N was estimated to be 4 x 10 to the 12th/sq cm, assuming 5 K rotation temperature and LTE. This limit makes the abundance ratio (CH3)2O/CH3OH not higher than 1/5, indicating that dimethyl ether is not overabundant in this dark cloud.

  7. Reconfigurable Martian Data Cloud

    NASA Astrophysics Data System (ADS)

    Sheldon, D. J.; Moeller, R. C.; Pingree, P.; Lay, N.; Reeves, G.

    2012-06-01

    The objective is to develop a constellation of small satellites in orbit around Mars that would provide a highly scalable and dynamically allocatable high performance computing resource. Key is use of Field Programmable Gate Arrays for the cloud.

  8. Electromagnetic scattering in clouds

    NASA Technical Reports Server (NTRS)

    Solakiewicz, Richard

    1992-01-01

    Techniques used to explain the nature of the optical effects of clouds on the light produced by lightning include a Monte Carlo simulation, an equivalent medium approach, and methods based on Boltzmann transport theory. A cuboidal cloud has been considered using transform methods and a diffusion approximation. Many simplifying assumptions have been used by authors to make this problem tractable. In this report, the cloud will have a spherical shape and its interior will consist of a uniform distribution of identical spherical water droplets. The source will be modeled as a Hertz dipole, electric or magnetic, inside or outside the cloud. An impulsive source is used. Superposition may be employed to obtain a sinusoid within an envelope which describes a lightning event. The problem is investigated by transforming to the frequency domain, obtaining Green's functions, and then using the Cagniard-DeHoop method to symbolically recover the time domain solution.

  9. Digital Forensics in the Cloud

    DTIC Science & Technology

    2013-10-01

    Birmingham Abstract. Today’s cloud computing architectures often lack support for computer forensic investigations. Besides this, the existing digital... forensics tools cannot cope with the dynamic nature of the cloud. This paper explores the challenges of digital forensics in the cloud, possible...attacks on cloud-evidence, and mitigation strategies against those challenges. Digital Forensics in the Cloud To identify the actual attacker in the

  10. Marine cloud brightening.

    PubMed

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; 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, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-09-13

    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, seed-particle 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 100×100 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.

  11. Marine Cloud Brightening

    SciTech Connect

    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

    2012-09-07

    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.

  12. Cloud Inhomogeneity from MODIS

    NASA Technical Reports Server (NTRS)

    Oreopoulos, Lazaros; Cahalan, Robert F.

    2004-01-01

    Two full months (July 2003 and January 2004) of MODIS Atmosphere Level-3 data from the Terra and Aqua satellites are analyzed in order to characterize the horizontal variability of cloud optical thickness and water path at global scales. Various options to derive cloud variability parameters are discussed. The climatology of cloud inhomogeneity is built by first calculating daily parameter values at spatial scales of l degree x 1 degree, and then at zonal and global scales, followed by averaging over monthly time scales. Geographical, diurnal, and seasonal changes of inhomogeneity parameters are examined separately for the two cloud phases, and separately over land and ocean. We find that cloud inhomogeneity is weaker in summer than in winter, weaker over land than ocean for liquid clouds, weaker for local morning than local afternoon, about the same for liquid and ice clouds on a global scale, but with wider probability distribution functions (PDFs) and larger latitudinal variations for ice, and relatively insensitive to whether water path or optical thickness products are used. Typical mean values at hemispheric and global scales of the inhomogeneity parameter nu (roughly the mean over the standard deviation of water path or optical thickness), range from approximately 2.5 to 3, while for the inhomogeneity parameter chi (the ratio of the logarithmic to linear mean) from approximately 0.7 to 0.8. Values of chi for zonal averages can occasionally fall below 0.6 and for individual gridpoints below 0.5. Our results demonstrate that MODIS is capable of revealing significant fluctuations in cloud horizontal inhomogenity and stress the need to model their global radiative effect in future studies.

  13. FIRE Arctic Clouds Experiment

    NASA Technical Reports Server (NTRS)

    Curry, J. A.; Hobbs, P. V.; King, M. D.; Randall, D. A.; Minnis, P.; Issac, G. A.; Pinto, J. O.; Uttal, T.; Bucholtz, A.; Cripe, D. G.; hide

    1998-01-01

    An overview is given of the First ISCCP Regional Experiment (FIRE) Arctic Clouds Experiment that was conducted in the Arctic during April through July, 1998. The principal goal of the field experiment was to gather the data needed to examine the impact of arctic clouds on the radiation exchange between the surface, atmosphere, and space, and to study how the surface influences the evolution of boundary layer clouds. The observations will be used to evaluate and improve climate model parameterizations of cloud and radiation processes, satellite remote sensing of cloud and surface characteristics, and understanding of cloud-radiation feedbacks in the Arctic. The experiment utilized four research aircraft that flew over surface-based observational sites in the Arctic Ocean and Barrow, Alaska. In this paper we describe the programmatic and science objectives of the project, the experimental design (including research platforms and instrumentation), conditions that were encountered during the field experiment, and some highlights of preliminary observations, modelling, and satellite remote sensing studies.

  14. Absorption in Extended Inhomogeneous Clouds

    NASA Technical Reports Server (NTRS)

    Joiner, Joanna; Vasilkov, Alexander; Spurr, Robert; Bhartia, P. K.; Krotkov, Nick

    2008-01-01

    The launch of several different sensors, including CloudSat, into the A-train constellation of satellites allows us for the first time to compute absorption that can occur in realistic vertically inhomogeneous clouds including multiple cloud decks. CloudSat data show that these situations are common. Therefore, understanding vertically inhomogeneous clouds is important from both climate and satellite atmospheric composition remote sensing perspectives. Satellite passive sensors that operate from the near IR to the UV often rely on radiative cloud pressures derived from absorption in oxygen bands (A, B, gamma, or O2-O2 bands) or from rotational-Raman scattering in order to retrieve information about atmospheric trace gases. The radiative cloud pressure is distinct from the physical cloud top derived from thermal infrared measurements. Therefore, the combination of information from different passive sensors yields some information about the cloud vertical profile. When either or both the clouds or atmospheric absorbers (trace gases and aerosols) are vertically inhomogeneous, the use of an effective cloud pressure derived from these approaches may lead to errors. Here, we focus on several scenarios (deep convective clouds and distinct two layer clouds) based on realistic cloud optical depth vertical profiles derived from the CloudSatfMODIS combination. We focus on implications for trace-gas column amount retrievals (specifically ozone and NO2) and derived surface UV irradiance from the Ozone Monitoring Instrument (OMI) on the Atrain Aura platform.

  15. Formation of Massive Molecular Cloud Cores by Cloud-Cloud Collision

    NASA Astrophysics Data System (ADS)

    Inoue, Tsuyoshi; Fukui, Yasuo

    2013-09-01

    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.

  16. FORMATION OF MASSIVE MOLECULAR CLOUD CORES BY CLOUD-CLOUD COLLISION

    SciTech Connect

    Inoue, Tsuyoshi; Fukui, Yasuo

    2013-09-10

    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.

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

    SciTech Connect

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

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

  18. Titan Mystery Clouds

    NASA Image and Video Library

    2016-12-21

    This comparison of two views from NASA's Cassini spacecraft, taken fairly close together in time, illustrates a peculiar mystery: Why would clouds on Saturn's moon Titan be visible in some images, but not in others? In the top view, a near-infrared image from Cassini's imaging cameras, the skies above Saturn's moon Titan look relatively cloud free. But in the bottom view, at longer infrared wavelengths, Cassini sees a large field of bright clouds. Even though these views were taken at different wavelengths, researchers would expect at least a hint of the clouds to show up in the upper image. Thus they have been trying to understand what's behind the difference. As northern summer approaches on Titan, atmospheric models have predicted that clouds will become more common at high northern latitudes, similar to what was observed at high southern latitudes during Titan's late southern summer in 2004. Cassini's Imaging Science Subsystem (ISS) and Visual and Infrared Mapping Spectrometer (VIMS) teams have been observing Titan to document changes in weather patterns as the seasons change, and there is particular interest in following the onset of clouds in the north polar region where Titan's lakes and seas are concentrated. Cassini's "T120" and "T121" flybys of Titan, on June 7 and July 25, 2016, respectively, provided views of high northern latitudes over extended time periods -- more than 24 hours during both flybys. Intriguingly, the ISS and VIMS observations appear strikingly different from each other. In the ISS observations (monochrome image at top), surface features are easily identifiable and only a few small, isolated clouds were detected. In contrast, the VIMS observations (color image at bottom) suggest widespread cloud cover during both flybys. The observations were made over the same time period, so differences in illumination geometry or changes in the clouds themselves are unlikely to be the cause for the apparent discrepancy: VIMS shows persistent

  19. GEWEX Cloud Systems Study (GCSS)

    NASA Technical Reports Server (NTRS)

    Moncrieff, Mitch

    1993-01-01

    The Global Energy and Water Cycle Experiment (GEWEX) Cloud Systems Study (GCSS) program seeks to improve the physical understanding of sub-grid scale cloud processes and their representation in parameterization schemes. By improving the description and understanding of key cloud system processes, GCSS aims to develop the necessary parameterizations in climate and numerical weather prediction (NWP) models. GCSS will address these issues mainly through the development and use of cloud-resolving or cumulus ensemble models to generate realizations of a set of archetypal cloud systems. The focus of GCSS is on mesoscale cloud systems, including precipitating convectively-driven cloud systems like MCS's and boundary layer clouds, rather than individual clouds, and on their large-scale effects. Some of the key scientific issues confronting GCSS that particularly relate to research activities in the central U.S. are presented.

  20. Marine cloud brightening

    PubMed Central

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; 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, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-01-01

    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, seed-particle 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 100×100 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

  1. Stratocumulus cloud evolution

    SciTech Connect

    Yang, X.; Rogers, D.P.; Norris, P.M.; Johnson, D.W.; Martin, G.M.

    1994-12-31

    The structure and evolution of the extra-tropical marine atmospheric boundary layer (MABL) depends largely on the variability of stratus and stratocumulus clouds. The typical boundary-layer is capped by a temperature inversion that limits exchange with the free atmosphere. Cloud-top is usually coincident with the base of the inversion. Stratus clouds are generally associated with a well-mixed MABL, whereas daytime observations of stratocumulus-topped boundary-layers indicate that the cloud and subcloud layers are often decoupled due to shortwave radiative heating of the cloud layer. In this case the surface-based mixed layer is separated from the base of the stratocumulus (Sc) by a layer that is stable to dry turbulent mixing. This is sometimes referred to as the transition layer. Often cumulus clouds (Cu) develop in the transition layer. The cumulus tops may remain below the Sc base or they may penetrate into the Sc layer and occasionally through the capping temperature inversion. While this cloud structure is characteristic of the daytime MABL, it may persist at night also. The Cu play an important role in connecting the mixed layer to the Sc layer. If the Cu are active they transport water vapor from the sea surface that maintains the Sc against the dissipating effects of shortwave heating. The Cu, however, are very sensitive to small changes in the heat and moisture in the boundary-layer and are transient features. Here the authors discuss the effect of these small Cu on the turbulent structure of the MABL.

  2. Send in the Clouds

    NASA Image and Video Library

    2017-01-02

    Floating high above the hydrocarbon lakes, wispy clouds have finally started to return to Titan's northern latitudes Clouds like these disappeared from Titan's (3,200 miles or 5,150 kilometers across) northern reaches for several years (from about 2010 to 2014). Now they have returned, but in far smaller numbers than expected. Since clouds can quickly appear and disappear, Cassini scientists regularly monitor the large moon, in the hopes of observing cloud activity. They are especially interested in comparing these observations to predictions of how cloud cover should change with Saturn's seasons. Titan's clear skies are not what researchers expected. This view looks toward the Saturn-facing side of Titan. North on Titan is up and rotated 3 degrees to the left. The image was taken with the Cassini spacecraft narrow-angle camera on Oct. 29, 2016 using a spectral filter that preferentially admits wavelengths of near-infrared light centered at 938 nanometers. The view was obtained at a distance of approximately 545,000 miles (878,000 kilometers) from Titan. Image scale is 3 miles (5 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20516

  3. A Flexible Cloud Generator

    NASA Astrophysics Data System (ADS)

    Benassi, A.; Deguy, S.; Szczap, F.

    2001-05-01

    In this work we propose a flexible cloud generating model as well as a software. This model depends upon 5 quantities: -the cloud fractional coverage -the spectral slope -the mean value -the variance -the internal heterogeneity (intermittency). All these quantities are independantly identifiable on the base of mathematical proofs. This model also depends on a given function, called "morphlet", and on the law of a random variables family. In order to get a positive water contain inside the cloud,we ask the morphlet and the random variables to be positives. The structure of the model is hierarchycal. The vertebral column of this model is a tree: the basic encoding tree of the space where the cloud lives. At each edge of the tree is attached: -a Bernoulli random variable,this for tuning the fractional cover and the intermittency, -a rate of energy loose,giving the spectral slope, -a dilated morphlet. The word flexible is justified by the fact that we can choose to modify some objets on the basic tree in order to adjust the caracteristics of the desired cloud.

  4. Microphysics of Pyrocumulonimbus Clouds

    NASA Technical Reports Server (NTRS)

    Jensen, Eric; Ackerman, Andrew S.; Fridlind, Ann

    2004-01-01

    The intense heat from forest fires can generate explosive deep convective cloud systems that inject pollutants to high altitudes. Both satellite and high-altitude aircraft measurements have documented cases in which these pyrocumulonimbus clouds inject large amounts of smoke well into the stratosphere (Fromm and Servranckx 2003; Jost et al. 2004). This smoke can remain in the stratosphere, be transported large distances, and affect lower stratospheric chemistry. In addition recent in situ measurements in pyrocumulus updrafts have shown that the high concentrations of smoke particles have significant impacts on cloud microphysical properties. Very high droplet number densities result in delayed precipitation and may enhance lightning (Andrew et al. 2004). Presumably, the smoke particles will also lead to changes in the properties of anvil cirrus produces by the deep convection, with resulting influences on cloud radiative forcing. In situ sampling near the tops of mature pyrocumulonimbus is difficult due to the high altitude and violence of the storms. In this study, we use large eddy simulations (LES) with size-resolved microphysics to elucidate physical processes in pyrocumulonimbus clouds.

  5. Microphysics of Pyrocumulonimbus Clouds

    NASA Technical Reports Server (NTRS)

    Jensen, Eric; Ackerman, Andrew S.; Fridlind, Ann

    2004-01-01

    The intense heat from forest fires can generate explosive deep convective cloud systems that inject pollutants to high altitudes. Both satellite and high-altitude aircraft measurements have documented cases in which these pyrocumulonimbus clouds inject large amounts of smoke well into the stratosphere (Fromm and Servranckx 2003; Jost et al. 2004). This smoke can remain in the stratosphere, be transported large distances, and affect lower stratospheric chemistry. In addition recent in situ measurements in pyrocumulus updrafts have shown that the high concentrations of smoke particles have significant impacts on cloud microphysical properties. Very high droplet number densities result in delayed precipitation and may enhance lightning (Andrew et al. 2004). Presumably, the smoke particles will also lead to changes in the properties of anvil cirrus produces by the deep convection, with resulting influences on cloud radiative forcing. In situ sampling near the tops of mature pyrocumulonimbus is difficult due to the high altitude and violence of the storms. In this study, we use large eddy simulations (LES) with size-resolved microphysics to elucidate physical processes in pyrocumulonimbus clouds.

  6. Cloud top entrainment instability and cloud top distributions

    NASA Technical Reports Server (NTRS)

    Boers, Reinout; Spinhirne, James D.

    1990-01-01

    Classical cloud-top entrainment instability condition formulation is discussed. A saturation point diagram is used to investigate the details of mixing in cases where the cloud-top entrainment instability criterion is satisfied.

  7. Cloud profiling radar for the CloudSat Mission

    NASA Technical Reports Server (NTRS)

    Im, Eastwood; Wu, Chialin; Durden, Stephen L.

    2005-01-01

    The CloudSat Mission is a new satellite mission jointly developed by NASA, JPL, the Canadian Agency, Colorado State University, and the US AirForce to acquire a global data set of vertical cloud structure and its variability.

  8. Cloud condensation nucleus-sulfate mass relationship and cloud albedo

    NASA Technical Reports Server (NTRS)

    Hegg, Dean A.

    1994-01-01

    Analysis of previously published, simultaneous measurements of cloud condensation nucleus number concentration and sulfate mass concentration suggest a nonlinear relationship between the two variables. This nonlinearity reduces the sensitivity of cloud albedo to changes in the sulfur cycle.

  9. Cloud condensation nucleus-sulfate mass relationship and cloud albedo

    NASA Technical Reports Server (NTRS)

    Hegg, Dean A.

    1994-01-01

    Analysis of previously published, simultaneous measurements of cloud condensation nucleus number concentration and sulfate mass concentration suggest a nonlinear relationship between the two variables. This nonlinearity reduces the sensitivity of cloud albedo to changes in the sulfur cycle.

  10. Reconstruction of cloud geometry using a scanning cloud radar

    NASA Astrophysics Data System (ADS)

    Ewald, F.; Winkler, C.; Zinner, T.

    2015-06-01

    Clouds are one of the main reasons of uncertainties in the forecasts of weather and climate. In part, this is due to limitations of remote sensing of cloud microphysics. Present approaches often use passive spectral measurements for the remote sensing of cloud microphysical parameters. Large uncertainties are introduced by three-dimensional (3-D) radiative transfer effects and cloud inhomogeneities. Such effects are largely caused by unknown orientation of cloud sides or by shadowed areas on the cloud. Passive ground-based remote sensing of cloud properties at high spatial resolution could be crucially improved with this kind of additional knowledge of cloud geometry. To this end, a method for the accurate reconstruction of 3-D cloud geometry from cloud radar measurements is developed in this work. Using a radar simulator and simulated passive measurements of model clouds based on a large eddy simulation (LES), the effects of different radar scan resolutions and varying interpolation methods are evaluated. In reality, a trade-off between scan resolution and scan duration has to be found as clouds change quickly. A reasonable choice is a scan resolution of 1 to 2°. The most suitable interpolation procedure identified is the barycentric interpolation method. The 3-D reconstruction method is demonstrated using radar scans of convective cloud cases with the Munich miraMACS, a 35 GHz scanning cloud radar. As a successful proof of concept, camera imagery collected at the radar location is reproduced for the observed cloud cases via 3-D volume reconstruction and 3-D radiative transfer simulation. Data sets provided by the presented reconstruction method will aid passive spectral ground-based measurements of cloud sides to retrieve microphysical parameters.

  11. Factors Controlling Cloud Droplet Number Concentrations in Continental Convective Clouds

    NASA Astrophysics Data System (ADS)

    Gong, W.; Leaitch, W. R.; Strapp, J. W.; MacDonald, A. M.; Hayden, K. L.; Toom-Sauntry, D.; Anlauf, K. G.; Leithead, A.; Li, S.; Shantz, N.; Couture, M. D.

    2006-12-01

    One of the key processes in aerosol-cloud interactions is aerosol activation. It controls cloud droplet number concentration, which has direct implication on cloud optical properties and cloud microphysical processes (e.g., precipitation formation). It also determines where the aerosol mass addition due to in-cloud production (e.g., of sulfate) will reside after cloud evaporation and, hence, the cloud processed aerosol size spectrum, which will again impact aerosol optical properties and potentially activation in subsequent cloud cycles [Feingold and Kreidenweis, 2000]. A number of factors, (dynamical, microphysical, and chemical), affect the ability of aerosols to take up water and act as cloud condensation nuclei. There have been numerous studies devoted to the effect of aerosol physical and chemical properties on droplet activation (see McFiggans et al., 2005 for an in-depth review). As part of the ICARTT 2004 campaign, an aircraft study of Chemical transformation and Transport by Clouds (CTC) was conducted by Canadian government and university scientists. Measurements of trace gases, aerosol particle physics and chemistry, and cloud microphysics and dynamics were made (below and in clouds) from the NRCC Convair 580 aircraft between July 20 and August 18, 2004 over southwestern Ontario, northern Ohio, and eastern Michigan. In this study, the observed cloud droplet number concentrations in non- precipitating towering cumulus clouds are compared with the predictions from a detailed aerosol parcel model, which solves the diffusional growth equation for condensation of water on aerosol particles following an air parcel during its adiabatic ascend. The parcel model is also coupled with a size-resolved aqueous-phase chemistry module to allow the interaction between aerosol water uptake and aqueous-phase chemistry (mass transfer and oxidation). Effects of updraft velocity, below-cloud aerosol properties (number concentration, size distribution, and composition), and

  12. Making clouds in Spacelab

    NASA Technical Reports Server (NTRS)

    Duncan, C.

    1978-01-01

    Improvements in the accuracy of weather predictions and possibilities for changing the weather might depend on a better understanding of the microphysical processes which take place within clouds. A study of these processes on the surface of the earth is difficult in connection with gravitational disturbances. An Atmospheric Cloud Physics Laboratory (ACPL), which is currently being developed, is to be carried into space in the Spacelab in the early 1980's. This facility will provide scientists, for the first time, with the opportunity to study cloud physics without the disturbing gravitational effects. In the ACPL facility, a microscopic element can be suspended without support. The processes of freezing, thawing, collision, electric charging, and temperature changes can be observed and photographed as many times and for as long as necessary.

  13. Winter Clouds Over Mie

    NASA Technical Reports Server (NTRS)

    2004-01-01

    12 March 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) red wide angle image shows late winter clouds over the 104 km (65 mi) diameter crater, Mie. Cellular clouds occur in the lower martian atmosphere, surrounding Mie Crater. Their cloudtops are at an altitude that is below the crater rim. Higher than the crater rim occurs a series of lee wave clouds, indicating air circulation moving from west/northwest (left) toward the east/southeast (right). Mie Crater is located in Utopia Planitia, not too far from the Viking 2 landing site, near 48.5 N, 220.4 W. Sunlight illuminates this January 2004 scene from the lower left.

  14. Ash cloud aviation advisories

    SciTech Connect

    Sullivan, T.J.; Ellis, J.S.; Schalk, W.W.; Nasstrom, J.S.

    1992-06-25

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

  15. Cloud Based Applications and Platforms (Presentation)

    SciTech Connect

    Brodt-Giles, D.

    2014-05-15

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

  16. MISR Level 2 Cloud Product Versioning

    Atmospheric Science Data Center

    2016-11-04

      MISR Level 2 Cloud Product Versioning MISR Level 2 Cloud Product Processing Status ESDT Product File ... Quality Designations MIL2TCSP MISR_AM1_TC_CLOUD Stage 3 Validated:  Cloud Top Heights (Without Wind ...

  17. Real World: Global Cloud Observation Day

    NASA Image and Video Library

    Learn about precipitation and how clouds are formed. Find out why scientists study clouds and how you can help NASA collect cloud observation data as part of the Students' Cloud Observation OnLine,...

  18. Can cloud-top entrainment promote cloud growth?

    NASA Technical Reports Server (NTRS)

    Randall, D. A.

    1984-01-01

    The primary significance of Cloud Deepening through Entrainment (CDE) is that it can prevent the cloud top entrainment instability from destroying a cloud deck. Without suppressing the instability, CDE transforms it from a cloud destroyer to a cloud builder. The analysis does not depend on an entrainment hypothesis. Moreover, it is not restricted to PBL stratocumulus sheets. Stratiform clouds in the free atmosphere can be subject to CDE we need only reinterpret Ps as the pressure at the base of an elevated turbulent mixed layer. Modest departures from well mixedness will alter the results quantitatively but not qualitatively. Processes other than entrainment, such as surface evaporation, radiative cooling, and advection will often work with CDE to build a cloud layer; but of course they can also oppose CDE by reducing the relative humidity. If we make the weak assumption that the deepening of a cloud layer favors an increase in the cloud top entrainment rate (without specifying any particular functional relationship) we are led to speculate that CDE can cause runaway cloud growth, even in the absence of cloud top entrainment instability. through CDE entrainment leads to a deeper cloud, which leads to stronger entrainment.

  19. The Oort cloud

    NASA Technical Reports Server (NTRS)

    Wessman, Paul R.

    1990-01-01

    Although the outermost planet, Pluto, is 6 x 10 to the 9th km from the sun, the sun's gravitational sphere of influence extends much further, out to about 2 x 10 to the 13th km. This space is occupied by the Oort cloud, comprising 10 to the 12th-10 to the 13th cometary nuclei, formed in the primordial solar nebula. Observations and computer modeling have contributed to a detailed understanding of the structure and dynamics of the cloud, which is thought to be the source of the long-period comets and possibly comet showers.

  20. Automatic cloud cover mapping.

    NASA Technical Reports Server (NTRS)

    Strong, J. P., III; Rosenfeld, A.

    1971-01-01

    A method of converting a picture into a 'cartoon' or 'map' whose regions correspond to differently textured regions is described. Texture edges in the picture are detected, and solid regions surrounded by these (usually broken) edges are 'colored in' using a propagation process. The resulting map is cleaned by comparing the region colors with the textures of the corresponding regions in the picture, and also by merging some regions with others according to criteria based on topology and size. The method has been applied to the construction of cloud cover maps from cloud cover pictures obtained by satellites.

  1. The Oort cloud

    NASA Astrophysics Data System (ADS)

    Weissman, Paul R.

    1990-04-01

    Although the outermost planet, Pluto, is 6 x 10 to the 9th km from the sun, the sun's gravitational sphere of influence extends much further, out to about 2 x 10 to the 13th km. This space is occupied by the Oort cloud, comprising 10 to the 12th-10 to the 13th cometary nuclei, formed in the primordial solar nebula. Observations and computer modeling have contributed to a detailed understanding of the structure and dynamics of the cloud, which is thought to be the source of the long-period comets and possibly comet showers.

  2. The Oort cloud

    NASA Technical Reports Server (NTRS)

    Wessman, Paul R.

    1990-01-01

    Although the outermost planet, Pluto, is 6 x 10 to the 9th km from the sun, the sun's gravitational sphere of influence extends much further, out to about 2 x 10 to the 13th km. This space is occupied by the Oort cloud, comprising 10 to the 12th-10 to the 13th cometary nuclei, formed in the primordial solar nebula. Observations and computer modeling have contributed to a detailed understanding of the structure and dynamics of the cloud, which is thought to be the source of the long-period comets and possibly comet showers.

  3. Opaque cloud detection

    DOEpatents

    Roskovensky, John K.

    2009-01-20

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

  4. Animated View of Noctilucent Cloud

    NASA Image and Video Library

    Polar mesospheric clouds, as they are known to those who study them from satellite observations, are also often called "noctilucent," or night shining, clouds as seen by ground-based observers. Bec...

  5. G2 Gas Cloud Simulation

    NASA Image and Video Library

    This simulation shows the future behavior of the G2 gas cloud now approaching Sgr A*, the supermassive black hole at the center of the Milky Way. X-ray emission from the cloud's tidal interaction w...

  6. Active Imaging through Cirrus Clouds.

    PubMed

    Landesman, B; Kindilien, P; Pierson, R; Matson, C; Mosley, D

    1997-11-24

    The presence of clouds of ice particles in the uplink and downlink path of an illumination beam can severely impede the performance of an active imaging system. Depending on the optical depth of the cloud, i.e., its density and depth, the beam can be completely scattered and extinguished, or the beam can pass through the cloud with some fraction attenuated, scattered, and depolarized. In particular, subvisual cirrus clouds, i.e., high, thin cirrus clouds that cannot be observed from the ground, can affect the properties and alignment of both uplink and downlink beams. This paper discusses the potential for active imaging in the presence of cirrus clouds. We document field data results from an active imaging experiment conducted several years ago, which the authors believe to show the effects of cirrus clouds on an active imaging system. To verify these conclusions, we include the results of a simulation of the interaction of a coherent illumination scheme with a cirrus cloud.

  7. Physical View of Cloud Seeding

    ERIC Educational Resources Information Center

    Tribus, Myron

    1970-01-01

    Reviews experimental data on various aspects of climate control. Includes a discussion of (1) the physics of cloud seeding, (2) the applications of cloud seeding, and (3) the role of statistics in the field of weather modification. Bibliography. (LC)

  8. Physical View of Cloud Seeding

    ERIC Educational Resources Information Center

    Tribus, Myron

    1970-01-01

    Reviews experimental data on various aspects of climate control. Includes a discussion of (1) the physics of cloud seeding, (2) the applications of cloud seeding, and (3) the role of statistics in the field of weather modification. Bibliography. (LC)

  9. Applications: Cloud Height at Night.

    ERIC Educational Resources Information Center

    Mathematics Teacher, 1980

    1980-01-01

    The method used at airports in determining the cloud height at night is presented. Several problems, the equation used, and a simple design of an alidade (an instrument that shows cloud heights directly) are also included. (MP)

  10. Discovery of Leonid Meteoric Cloud

    DTIC Science & Technology

    2007-11-02

    as a local enhancement in sky brightness during the meteor shower in 1998. The radius of the trail, deduced from the spatial extent of the cloud, is...A meteoric cloud is a faint glow of sunlight scattered by the small meteoroids in the trail along a parent comets orbit. Here we report the first...detection of the meteoric cloud associated with the Leonid meteor stream. Our photometric observations, performed on Mauna Kea, Hawaii, reveal the cloud

  11. Cloud computing basics for librarians.

    PubMed

    Hoy, Matthew B

    2012-01-01

    "Cloud computing" is the name for the recent trend of moving software and computing resources to an online, shared-service model. This article briefly defines cloud computing, discusses different models, explores the advantages and disadvantages, and describes some of the ways cloud computing can be used in libraries. Examples of cloud services are included at the end of the article. Copyright © Taylor & Francis Group, LLC

  12. Coherent Radiation of Electron Cloud

    SciTech Connect

    Heifets, S.

    2004-11-02

    The electron cloud in positron storage rings is pinched when a bunch passes by. For short bunches, the radiation due to acceleration of electrons of the cloud is coherent. Detection of such radiation can be used to measure the density of the cloud. The estimate of the power and the time structure of the radiated signal is given in this paper.

  13. A View from the Clouds

    ERIC Educational Resources Information Center

    Chudnov, Daniel

    2010-01-01

    Cloud computing is definitely a thing now, but it's not new and it's not even novel. Back when people were first learning about the Internet in the 1990s, every diagram that one saw showing how the Internet worked had a big cloud in the middle. That cloud represented the diverse links, routers, gateways, and protocols that passed traffic around in…

  14. A View from the Clouds

    ERIC Educational Resources Information Center

    Chudnov, Daniel

    2010-01-01

    Cloud computing is definitely a thing now, but it's not new and it's not even novel. Back when people were first learning about the Internet in the 1990s, every diagram that one saw showing how the Internet worked had a big cloud in the middle. That cloud represented the diverse links, routers, gateways, and protocols that passed traffic around in…

  15. The Basics of Cloud Computing

    ERIC Educational Resources Information Center

    Kaestner, Rich

    2012-01-01

    Most school business officials have heard the term "cloud computing" bandied about and may have some idea of what the term means. In fact, they likely already leverage a cloud-computing solution somewhere within their district. But what does cloud computing really mean? This brief article puts a bit of definition behind the term and helps one…

  16. The Basics of Cloud Computing

    ERIC Educational Resources Information Center

    Kaestner, Rich

    2012-01-01

    Most school business officials have heard the term "cloud computing" bandied about and may have some idea of what the term means. In fact, they likely already leverage a cloud-computing solution somewhere within their district. But what does cloud computing really mean? This brief article puts a bit of definition behind the term and helps one…

  17. AceCloud: Molecular Dynamics Simulations in the Cloud.

    PubMed

    Harvey, M J; De Fabritiis, G

    2015-05-26

    We present AceCloud, an on-demand service for molecular dynamics simulations. AceCloud is designed to facilitate the secure execution of large ensembles of simulations on an external cloud computing service (currently Amazon Web Services). The AceCloud client, integrated into the ACEMD molecular dynamics package, provides an easy-to-use interface that abstracts all aspects of interaction with the cloud services. This gives the user the experience that all simulations are running on their local machine, minimizing the learning curve typically associated with the transition to using high performance computing services.

  18. Cloud water chemistry and the production of sulfates in clouds

    NASA Technical Reports Server (NTRS)

    Hegg, D. A.; Hobbs, P. V.

    1981-01-01

    Measurements are presented of the pH and ionic content of water collected in clouds over western Washington and the Los Angeles Basin. Evidence for sulfate production in some of the clouds is presented. Not all of the sulfur in the cloud water was in the form of sulfate. However, the measurements indicate that the production of sulfate in clouds is of considerable significance in the atmosphere. Comparison of field measurements with model results show reasonable agreement and suggest that the production of sulfate in cloud water is a consequence of more than one conversion mechanism.

  19. Cloud water chemistry and the production of sulfates in clouds

    NASA Technical Reports Server (NTRS)

    Hegg, D. A.; Hobbs, P. V.

    1981-01-01

    Measurements are presented of the pH and ionic content of water collected in clouds over western Washington and the Los Angeles Basin. Evidence for sulfate production in some of the clouds is presented. Not all of the sulfur in the cloud water was in the form of sulfate. However, the measurements indicate that the production of sulfate in clouds is of considerable significance in the atmosphere. Comparison of field measurements with model results show reasonable agreement and suggest that the production of sulfate in cloud water is a consequence of more than one conversion mechanism.

  20. Model Cloud Relationships.

    DTIC Science & Technology

    1983-10-30

    nucleation due tovi Brownian diffusion (NNUB .), thermophoresis (NNUC .) andVi Vi diffusiophoresis (NNUD .). Finally, production of specific Vi...Young (1974) referred to as model A. Young considers contact by Brownian diffusion, thermophoresis and diffusiophoresis. Brownian- diftusion contact...nucleation results from the random collision of aerosol particles with cloud droplets. Thermophoresis contact nucleation occurs due to the attraction

  1. Computing in the Clouds

    ERIC Educational Resources Information Center

    Johnson, Doug

    2010-01-01

    Web-based applications offer teachers, students, and school districts a convenient way to accomplish a wide range of tasks, from accounting to word processing, for free. Cloud computing has the potential to offer staff and students better services at a lower cost than the technology deployment models they're using now. Saving money and improving…

  2. Interstellar molecular clouds.

    PubMed

    Bally, J

    1986-04-11

    The interstellar medium in our galaxy contains matter in a variety of states ranging from hot plasma to cold and dusty molecular gas. The molecular phase consists of giant clouds, which are the largest gravitationally bound objects in the galaxy, the primary reservoir of material for the ongoing birth of new stars, and the medium regulating the evolution of galactic disks.

  3. Training in the Clouds

    ERIC Educational Resources Information Center

    Pretlow, Cassi; Jayroe, Tina

    2010-01-01

    In this article, the authors share how cloud-based applications, such as Google Calendar, Wikidot, Google Docs, Google Sites, YouTube, and Craigslist, played a big part in the success of their plan of implementing a technology training program for customers and employees. A few years ago the Denver Public Library, where the authors work, developed…

  4. Cloud Forecast Simulation Model.

    DTIC Science & Technology

    1981-10-01

    forecasts is described in terms of their "skill." The skill of weather forecasts varies according to the type of forecast being made (e.g., tornado warnings...are more difficult to make than cloud forecasts) and according to the location and time-of-year (because clima - tology exerts such a strong influence

  5. Uranus Cloud Movement

    NASA Image and Video Library

    1996-10-23

    These time-lapse images of Uranus. taken by NASA Voyager 2 on Jan. 14, 1986, show the movement of two small, bright, streaky clouds -- the first such features ever seen on the planet. http://photojournal.jpl.nasa.gov/catalog/PIA00369

  6. Seeding the Cloud

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2013-01-01

    For any institution looking to shift enterprise resource planning (ERP) systems to the cloud, big savings can be achieved--but only if the school has properly prepped "before" negotiations begin. These three steps can help: (1) Mop up the mess first; (2) Understand the true costs for services; and (3) Calculate the cost of transition.

  7. Seeding the Cloud

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2013-01-01

    For any institution looking to shift enterprise resource planning (ERP) systems to the cloud, big savings can be achieved--but only if the school has properly prepped "before" negotiations begin. These three steps can help: (1) Mop up the mess first; (2) Understand the true costs for services; and (3) Calculate the cost of transition.

  8. Data in the Cloud

    ERIC Educational Resources Information Center

    Bull, Glen; Garofalo, Joe

    2010-01-01

    The ability to move from one representation of data to another is one of the key characteristics of expert mathematicians and scientists. Cloud computing will offer more opportunities to create and display multiple representations of data, making this skill even more important in the future. The advent of the Internet led to widespread…

  9. Invisible Cirrus Clouds

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Moderate-resolution Imaging Spectroradiometer's (MODIS') cloud detection capability is so sensitive that it can detect clouds that would be indistinguishable to the human eye. This pair of images highlights MODIS' ability to detect what scientists call 'sub-visible cirrus.' The image on top shows the scene using data collected in the visible part of the electromagnetic spectrum-the part our eyes can see. Clouds are apparent in the center and lower right of the image, while the rest of the image appears to be relatively clear. However, data collected at 1.38um (lower image) show that a thick layer of previously undetected cirrus clouds obscures the entire scene. These kinds of cirrus are called 'sub-visible' because they can't be detected using only visible light. MODIS' 1.38um channel detects electromagnetic radiation in the infrared region of the spectrum. These images were made from data collected on April 4, 2000. Image courtesy Mark Gray, MODIS Atmosphere Team

  10. Training in the Clouds

    ERIC Educational Resources Information Center

    Pretlow, Cassi; Jayroe, Tina

    2010-01-01

    In this article, the authors share how cloud-based applications, such as Google Calendar, Wikidot, Google Docs, Google Sites, YouTube, and Craigslist, played a big part in the success of their plan of implementing a technology training program for customers and employees. A few years ago the Denver Public Library, where the authors work, developed…

  11. Uranus - Discrete Cloud

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This false-color Voyager picture of Uranus shows a discrete cloud seen as a bright streak near the planet's limb. The picture is a highly processed composite of three images obtained Jan. 14, 1986, when the spacecraft was 12.9 million kilometers (8.0 million miles) from the planet. The cloud visible here is the most prominent feature seen in a series of Voyager images designed to track atmospheric motions. (The occasional donut-shaped features, including one at the bottom, are shadows cast by dust in the camera optics; the processing necessary to bring out the faint features on the planet also brings out these camera blemishes.) Three separate images were shuttered through violet, blue and orange filters. Each color image showed the cloud to a different degree; because they were not exposed at exactly the same time, the images were processed to provide a correction for a good spatial match. In a true-color image, the cloud would be barely discernible; the false color helps bring out additional details. The different colors imply variations in vertical structure, but as yet is not possible to be specific about such differences. One possibility is that the Uranian atmosphere contains smog-like constituents, in which case some color differences may represent differences in how these molecules are distributed. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  12. Stratified Arctic Clouds

    NASA Image and Video Library

    2003-01-02

    Stratus clouds are common in the Arctic during the summer months, and are important modulators of the arctic climate as seen in this anaglyph from the MISR instrument aboard NASA Terra spacecraft. 3D glasses are necessary to view this image.

  13. Optical Transmission through Clouds

    DTIC Science & Technology

    1989-09-01

    radiative transfer in clouds is carried out by the .1,nte Carlo method. In a Monte Carlo computation one photon...has some advantages over other computational methods for radiative transfer , namely * any phase function can be used * can include polarization (with...APPENDIX A. Monte Carlo Simulation if Radiative Transfer APPENDIX B. Intensity Reference Method for Radiative Transfer APPENDIX C.

  14. Living under a Cloud.

    ERIC Educational Resources Information Center

    Gursky, Daniel

    1991-01-01

    This article examines the efforts of three high school teachers at Richland High School in Richland (Washington) to change the school logo from a mushroom cloud, the symbol for a nuclear explosion. Opposition to these teachers' efforts has come from school administrators and fellow teachers, students, alumnae, and community residents. (IAH)

  15. Ice Crystal Cloud Research

    NASA Image and Video Library

    2016-07-11

    NASA Glenn’s Propulsion Systems Lab (PSL) is conducting research to characterize ice crystal clouds that can create a hazard to aircraft engines under certain conditions. The isokinetic probe (in gold) samples particles and another series of probes can measure everything from humidity to air pressure.

  16. Multiscale Cloud System Modeling

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Moncrieff, Mitchell W.

    2009-01-01

    The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.

  17. Living under a Cloud.

    ERIC Educational Resources Information Center

    Gursky, Daniel

    1991-01-01

    This article examines the efforts of three high school teachers at Richland High School in Richland (Washington) to change the school logo from a mushroom cloud, the symbol for a nuclear explosion. Opposition to these teachers' efforts has come from school administrators and fellow teachers, students, alumnae, and community residents. (IAH)

  18. Jupiter Clouds in Depth

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site] 619 nm [figure removed for brevity, see original site] 727 nm [figure removed for brevity, see original site] 890 nm

    Images from NASA's Cassini spacecraft using three different filters reveal cloud structures and movements at different depths in the atmosphere around Jupiter's south pole.

    Cassini's cameras come equipped with filters that sample three wavelengths where methane gas absorbs light. These are in the red at 619 nanometer (nm) wavelength and in the near-infrared at 727 nm and 890 nm. Absorption in the 619 nm filter is weak. It is stronger in the 727 nm band and very strong in the 890 nm band where 90 percent of the light is absorbed by methane gas. Light in the weakest band can penetrate the deepest into Jupiter's atmosphere. It is sensitive to the amount of cloud and haze down to the pressure of the water cloud, which lies at a depth where pressure is about 6 times the atmospheric pressure at sea level on the Earth). Light in the strongest methane band is absorbed at high altitude and is sensitive only to the ammonia cloud level and higher (pressures less than about one-half of Earth's atmospheric pressure) and the middle methane band is sensitive to the ammonia and ammonium hydrosulfide cloud layers as deep as two times Earth's atmospheric pressure.

    The images shown here demonstrate the power of these filters in studies of cloud stratigraphy. The images cover latitudes from about 15 degrees north at the top down to the southern polar region at the bottom. The left and middle images are ratios, the image in the methane filter divided by the image at a nearby wavelength outside the methane band. Using ratios emphasizes where contrast is due to methane absorption and not to other factors, such as the absorptive properties of the cloud particles, which influence contrast at all wavelengths.

    The most prominent feature seen in all three filters is the polar stratospheric haze that makes Jupiter

  19. Multiscale Cloud System Modeling

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Moncrieff, Mitchell W.

    2009-01-01

    The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.

  20. Multiple Scattering in Clouds

    DTIC Science & Technology

    1979-09-01

    Equation .................................. 35 Boundary Conditions ................................ 37SIrradiance at Cloud Exit...mathematical description of the multiple scatter- ing problem is given by the nonstationary radiative transport equation of Chandrasekhar [2]. Written in...function, S0 is the source function, and X is the single-scatter albedo. Unfortunately, the nonstationary transport equation has not been solved in a

  1. Venus: Tickling the clouds

    NASA Astrophysics Data System (ADS)

    Marcq, Emmanuel

    2017-08-01

    Even though a thick atmosphere stands between Venus's cloud top and its surface, recent observations now establish the impact of Venus's topography on its upper atmospheric dynamics. Understanding how this is possible will lead to substantial progress in atmospheric computer models.

  2. Data Products on Cloud

    NASA Technical Reports Server (NTRS)

    Ly, Vuong T.; Mandl, Daniel J.

    2014-01-01

    This presentation lays out the data processing products that exist and are planned for the Matsu cloud for Earth Observing 1. The presentation focuses on a new feature called co-registration of Earth Observing 1 with Landsat Global Land Survey chips.

  3. Prebiotic chemistry in clouds.

    PubMed

    Oberbeck, V R; Marshall, J; Shen, T

    1991-01-01

    In the traditional concept for the origin of life as proposed by Oparin and Haldane in the 1920s, prebiotic reactants became slowly concentrated in the primordial oceans and life evolved slowly from a series of highly protracted chemical reactions during the first billion years of Earth's history. However, chemical evolution may not have occurred continuously because planetesimals and asteroids impacted the Earth many times during the first billion years, may have sterilized the Earth, and required the process to start over. A rapid process of chemical evolution may have been required in order that life appeared at or before 3.5 billion years ago. Thus, a setting favoring rapid chemical evolution may be required. A chemical evolution hypothesis set forth by Woese in 1979 accomplished prebiotic reactions rapidly in droplets in giant atmospheric reflux columns. However, in 1985 Scherer raised a number of objections to Woese's hypothesis and concluded that it was not valid. We propose a mechanism for prebiotic chemistry in clouds that satisfies Scherer's concerns regarding the Woese hypothesis and includes advantageous droplet chemistry. Prebiotic reactants were supplied to the atmosphere by comets, meteorites, and interplanetary dust or synthesized in the atmosphere from simple compounds using energy sources such as ultraviolet light, corona discharge, or lightning. These prebiotic monomers would have first encountered moisture in cloud drops and precipitation. We propose that rapid prebiotic chemical evolution was facilitated on the primordial Earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by , or synthesized during entry of, meteorites, comets, and interplanetary dust would have been scavenged by cloud drops containing clay condensation nuclei. Polymerization would have occurred within cloud systems during cycles of condensation, freezing, melting, and

  4. Uranus Cloud Movement

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Time-lapse Voyager 2 images of Uranus show the movement of two small, bright, streaky clouds -- the first such features ever seen on the planet. The clouds were detected in this series of orange-filtered images taken Jan. 14, 1986, over a 4.6-hour interval (from top to bottom). At the time, the spacecraft was about 12.9 million kilometers (8.0 million miles) from the planet, whose pole of rotation is near the center of each disk. Uranus, which is tipped on its side with respect to the other planets, is rotating in a counterclockwise direction, as are the two clouds seen here as bright streaks. (The occasional donut-shaped features that show up are shadows cast by dust in the camera optics. The processing necessary to bring out the faint features on the planet also brings out these camera blemishes.) The larger of the two clouds is at a latitude of 33 degrees; the smaller cloud, seen faintly in the three lower images, lies at 26 degrees (a lower latitude and hence closer to the limb). Their counterclockwise periods of rotation are 16.2 and 16.9 hours, respectively. This difference implies that the lower-latitude feature is lagging behind the higher-latitude feature at a speed of almost 100 meters per second (220 mph). Latitudinal bands are also visible in these images. The faint bands, more numerous now than in previous Voyager images from longer range, are concentric with the pole of rotation -- that is, they circle the planet in lines of constant latitude. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  5. Overlap Properties of Clouds Generated by a Cloud Resolving Model

    NASA Technical Reports Server (NTRS)

    Oreopoulos, L.; Khairoutdinov, M.

    2002-01-01

    In order for General Circulation Models (GCMs), one of our most important tools to predict future climate, to correctly describe the propagation of solar and thermal radiation through the cloudy atmosphere a realistic description of the vertical distribution of cloud amount is needed. Actually, one needs not only the cloud amounts at different levels of the atmosphere, but also how these cloud amounts are related, in other words, how they overlap. Currently GCMs make some idealized assumptions about cloud overlap, for example that contiguous cloud layers overlap maximally and non-contiguous cloud layers overlap in a random fashion. Since there are difficulties in obtaining the vertical profile of cloud amount from observations, the realism of the overlap assumptions made in GCMs has not been yet rigorously investigated. Recently however, cloud observations from a relatively new type of ground radar have been used to examine the vertical distribution of cloudiness. These observations suggest that the GCM overlap assumptions are dubious. Our study uses cloud fields from sophisticated models dedicated to simulate cloud formation, maintenance, and dissipation called Cloud Resolving Models . These models are generally considered capable of producing realistic three-dimensional representation of cloudiness. Using numerous cloud fields produced by such a CRM we show that the degree of overlap between cloud layers is a function of their separation distance, and is in general described by a combination of the maximum and random overlap assumption, with random overlap dominating as separation distances increase. We show that it is possible to parameterize this behavior in a way that can eventually be incorporated in GCMs. Our results seem to have a significant resemblance to the results from the radar observations despite the completely different nature of the datasets. This consistency is encouraging and will promote development of new radiative transfer codes that will

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

    DOE PAGES

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

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

  7. AIRS Subpixel Cloud Characterization Using MODIS Cloud Products.

    NASA Astrophysics Data System (ADS)

    Li, Jun; Menzel, W. Paul; Sun, Fengying; Schmit, Timothy J.; Gurka, James

    2004-08-01

    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 able to provide, at high spatial resolution (1 5 km), a cloud mask, surface and cloud types, cloud phase, cloud-top pressure (CTP), effective cloud amount (ECA), cloud particle size (CPS), and cloud optical thickness (COT). AIRS is able to provide CTP, ECA, CPS, and COT at coarser spatial resolution (13.5 km at nadir) but with much better accuracy using its high-spectral-resolution measurements. The combined MODIS AIRS system offers the opportunity for improved cloud products over those possible from either system alone. The key steps for synergistic use of imager and sounder radiance measurements are 1) collocation in space and time and 2) imager cloud amount, type, and phase determination within the sounder pixel. The MODIS and AIRS measurements from the EOS Aqua satellite provide the opportunity to study the synergistic use of advanced imager and sounder measurements. As the first step, the MODIS classification procedure is applied to identify various surface and cloud types within an AIRS footprint. Cloud-layer information (lower, midlevel, or high clouds) and phase information (water, ice, or mixed-phase clouds) within the AIRS footprint are sorted and characterized using MODIS 1-km-spatial-resolution data. The combined MODIS and AIRS data for various scenes are analyzed to study the utility of the synergistic use of high-spatial-resolution imager products and high-spectral-resolution sounder radiance measurements. There is relevance to the optimal use of data from the Advanced Baseline Imager (ABI) and Hyperspectral Environmental Suite (HES) systems, which are to fly on the Geostationary Operational Environmental Satellite (GOES)-R.


  8. Cloud Computing Security Issue: Survey

    NASA Astrophysics Data System (ADS)

    Kamal, Shailza; Kaur, Rajpreet

    2011-12-01

    Cloud computing is the growing field in IT industry since 2007 proposed by IBM. Another company like Google, Amazon, and Microsoft provides further products to cloud computing. The cloud computing is the internet based computing that shared recourses, information on demand. It provides the services like SaaS, IaaS and PaaS. The services and recourses are shared by virtualization that run multiple operation applications on cloud computing. This discussion gives the survey on the challenges on security issues during cloud computing and describes some standards and protocols that presents how security can be managed.

  9. Formation of giant molecular clouds in global spiral structures: The role of orbital dynamics and cloud-cloud collisions

    NASA Technical Reports Server (NTRS)

    Roberts, W. W., Jr.; Stewart, G. R.

    1987-01-01

    The different roles played by orbital dynamics and dissipative cloud-cloud collisions in the formation of giant molecular clouds (GMCs) in a global spiral structure are investigated. The interstellar medium (ISM) is simulated by a system of particles, representing clouds, which orbit in a spiral-perturbed, galactic gravitational field. The overall magnitude and width of the global cloud density distribution in spiral arms is very similar in the collisional and collisionless simulations. The results suggest that the assumed number density and size distribution of clouds and the details of individual cloud-cloud collisions have relatively little effect on these features. Dissipative cloud-cloud collisions play an important steadying role for the cloud system's global spiral structure. Dissipative cloud-cloud collisions also damp the relative velocity dispersion of clouds in massive associations and thereby aid in the effective assembling of GMC-like complexes.

  10. Fractal statistics of cloud fields

    NASA Technical Reports Server (NTRS)

    Cahalan, Robert F.; Joseph, Joachim H.

    1989-01-01

    Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM) data, with 80 and 30 m spatial resolution, respectively, have been employed to study the spatial structure of boundary-layer and intertropical convergence zone (ITCZ) clouds. The probability distributions of cloud areas and cloud perimeters are found to approximately follow a power-law, with a different power (i.e., fractal dimension) for each cloud type. They are better approximated by a double power-law behavior, indicating a change in the fractal dimension at a characteristic size which depends upon cloud type. The fractal dimension also changes with threshold. The more intense cloud areas are found to have a higher perimeter fractal dimension, perhaps indicative of the increased turbulence at cloud top. A detailed picture of the inhomogeneous spatial structure of various cloud types will contribute to a better understanding of basic cloud processes, and also has implications for the remote sensing of clouds, for their effects on remote sensing of other parameters, and for the parameterization of clouds in general circulation models, all of which rely upon plane-parallel radiative transfer algorithms.

  11. Sahara Dust Cloud

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Dust Particles Click on the image for Quicktime movie from 7/15-7/24

    A continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean.

    These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward.

    In a sequence of images created by data acquired by the Earth-orbiting Atmospheric Infrared Sounder ranging from July 15 through July 24, we see the distribution of the cloud in the atmosphere as it swirls off of Africa and heads across the ocean to the west. Using the unique silicate spectral signatures of dust in the thermal infrared, AIRS can detect the presence of dust in the atmosphere day or night. This detection works best if there are no clouds present on top of the dust; when clouds are present, they can interfere with the signal, making it much harder to detect dust as in the case of July 24, 2005.

    In the Quicktime movie, the scale at the bottom of the images shows +1 for dust definitely detected, and ranges down to -1 for no dust detected. The plots are averaged over a number of AIRS observations falling within grid boxes, and so it is possible to obtain fractional numbers. [figure removed for brevity, see original site] Total Water Vapor in the Atmosphere Around the Dust Cloud Click on the image for Quicktime movie

    The dust cloud is contained within a dry adiabatic layer which originates over the Sahara Desert. This Saharan Air Layer (SAL) advances Westward over the Atlantic Ocean, overriding the cool, moist air nearer the surface. This burst of very dry air is visible in the

  12. Sahara Dust Cloud

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Dust Particles Click on the image for Quicktime movie from 7/15-7/24

    A continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean.

    These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward.

    In a sequence of images created by data acquired by the Earth-orbiting Atmospheric Infrared Sounder ranging from July 15 through July 24, we see the distribution of the cloud in the atmosphere as it swirls off of Africa and heads across the ocean to the west. Using the unique silicate spectral signatures of dust in the thermal infrared, AIRS can detect the presence of dust in the atmosphere day or night. This detection works best if there are no clouds present on top of the dust; when clouds are present, they can interfere with the signal, making it much harder to detect dust as in the case of July 24, 2005.

    In the Quicktime movie, the scale at the bottom of the images shows +1 for dust definitely detected, and ranges down to -1 for no dust detected. The plots are averaged over a number of AIRS observations falling within grid boxes, and so it is possible to obtain fractional numbers. [figure removed for brevity, see original site] Total Water Vapor in the Atmosphere Around the Dust Cloud Click on the image for Quicktime movie

    The dust cloud is contained within a dry adiabatic layer which originates over the Sahara Desert. This Saharan Air Layer (SAL) advances Westward over the Atlantic Ocean, overriding the cool, moist air nearer the surface. This burst of very dry air is visible in the

  13. Cloud boundaries during FIRE 2

    NASA Technical Reports Server (NTRS)

    Uttal, Taneil; Shaver, Scott M.; Clothiaux, Eugene E.; Ackerman, Thomas P.

    1993-01-01

    To our knowledge, previous observations of cloud boundaries have been limited to studies of cloud bases with ceilometers, cloud tops with satellites, and intermittent reports by aircraft pilots. Comprehensive studies that simultaneously record information of cloud top and cloud base, especially in multiple layer cases, have been difficult, and require the use of active remote sensors with range-gated information. In this study, we examined a 4-week period during which the NOAA Wave Propagation Laboratory (WPL) 8-mm radar and the Pennsylvania State University (PSU) 3-mm radar operated quasi-continuously, side by side. By quasi-continuously, we mean that both radars operated during all periods when cloud was present, during both daytime and nighttime hours. Using this data, we develop a summary of cloud boundaries for the month of November for a single location in the mid-continental United States.

  14. Cloud Radiative Effect in dependence on Cloud Type

    NASA Astrophysics Data System (ADS)

    Aebi, Christine; Gröbner, Julian; Kämpfer, Niklaus; Vuilleumier, Laurent

    2015-04-01

    Radiative transfer of energy in the atmosphere and the influence of clouds on the radiation budget remain the greatest sources of uncertainty in the simulation of climate change. Small changes in cloudiness and radiation can have large impacts on the Earth's climate. In order to assess the opposing effects of clouds on the radiation budget and the corresponding changes, frequent and more precise radiation and cloud observations are necessary. The role of clouds on the surface radiation budget is studied in order to quantify the longwave, shortwave and the total cloud radiative forcing in dependence on the atmospheric composition and cloud type. The study is performed for three different sites in Switzerland at three different altitude levels: Payerne (490 m asl), Davos (1'560 m asl) and Jungfraujoch (3'580 m asl). On the basis of data of visible all-sky camera systems at the three aforementioned stations in Switzerland, up to six different cloud types are distinguished (Cirrus-Cirrostratus, Cirrocumulus-Altocumulus, Stratus-Altostratus, Cumulus, Stratocumulus and Cumulonimbus-Nimbostratus). These cloud types are classified with a modified algorithm of Heinle et al. (2010). This cloud type classifying algorithm is based on a set of statistical features describing the color (spectral features) and the texture of an image (textural features) (Wacker et al. (2015)). The calculation of the fractional cloud cover information is based on spectral information of the all-sky camera data. The radiation data are taken from measurements with pyranometers and pyrgeometers at the different stations. A climatology of a whole year of the shortwave, longwave and total cloud radiative effect and its sensitivity to integrated water vapor, cloud cover and cloud type will be calculated for the three above-mentioned stations in Switzerland. For the calculation of the shortwave and longwave cloud radiative effect the corresponding cloud-free reference models developed at PMOD/WRC will be

  15. From airborne cloud remote sensing observations to cloud regime classification

    NASA Astrophysics Data System (ADS)

    Konow, Heike; Ament, Felix

    2017-04-01

    The representation of cloud and precipitation processes is one of the largest sources of uncertainty in climate and weather predictions. To validate model predictions of convective processes over the Atlantic ocean, usually satellite data are used. However, satellite products provide just a coarse view with poor temporal resolution of convective maritime clouds. Aircraft-based observations such as the cloud remote sensing configuration NARVAL (Next-generation Aircraft Remote-Sensing for Validation Studies) on the German research aircraft HALO (High Altitude Long Range Research Aircraft) offer a more detailed insight due to lower altitude and higher sampling rates than satellite data. Part of the NARVAL payload on HALO is the HALO Microwave Package (HAMP) which consists a suite of passive microwave radiometers with 26 frequencies in different bands between 22.24 and 183.31 ± 12.5 GHz and a cloud radar at 36 GHz. This payload was flown on HALO between 2013 and 2016 on several campaigns: NARVAL-I (2013 and 2014), NARVAL-II (2016), NAWDEX (2016, North Atlantic Waveguide and Downstream Impact Experiment). Cloud regimes can be characterized by cloud macrophysical parameters such as cloud fraction, cloud top height, cloud length, etc. During all campaigns, a range of different cloud regimes were investigated. For example, during NARVAL-I (South) and NARVAL-II, cloud fraction observed by HAMP instruments ranged between 10 % and 40 % over the duration of the individual flights. During NARVAL-I (North) and NAWDEX, cloud fraction was between 50 % and 80 %. This shows the range of cloud parameters in different regimes. Cloud regime classification can be approached in two different ways: regimes can be deduced by analyzing a priori information such as atmospheric thermodynamic profiles and satellite data and then infer the cloud characteristics in these conditions. The second, inductive, approach is to characterize cloudy scenes by cloud macrophysical parameters. We will

  16. Jupiter Clouds in Depth

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site] 619 nm [figure removed for brevity, see original site] 727 nm [figure removed for brevity, see original site] 890 nm

    Images from NASA's Cassini spacecraft using three different filters reveal cloud structures and movements at different depths in the atmosphere around Jupiter's south pole.

    Cassini's cameras come equipped with filters that sample three wavelengths where methane gas absorbs light. These are in the red at 619 nanometer (nm) wavelength and in the near-infrared at 727 nm and 890 nm. Absorption in the 619 nm filter is weak. It is stronger in the 727 nm band and very strong in the 890 nm band where 90 percent of the light is absorbed by methane gas. Light in the weakest band can penetrate the deepest into Jupiter's atmosphere. It is sensitive to the amount of cloud and haze down to the pressure of the water cloud, which lies at a depth where pressure is about 6 times the atmospheric pressure at sea level on the Earth). Light in the strongest methane band is absorbed at high altitude and is sensitive only to the ammonia cloud level and higher (pressures less than about one-half of Earth's atmospheric pressure) and the middle methane band is sensitive to the ammonia and ammonium hydrosulfide cloud layers as deep as two times Earth's atmospheric pressure.

    The images shown here demonstrate the power of these filters in studies of cloud stratigraphy. The images cover latitudes from about 15 degrees north at the top down to the southern polar region at the bottom. The left and middle images are ratios, the image in the methane filter divided by the image at a nearby wavelength outside the methane band. Using ratios emphasizes where contrast is due to methane absorption and not to other factors, such as the absorptive properties of the cloud particles, which influence contrast at all wavelengths.

    The most prominent feature seen in all three filters is the polar stratospheric haze that makes Jupiter

  17. Cloud-Vegetation Interaction: Use of Normalized Difference Cloud Index for Estimation of Cloud Optical Thickness

    NASA Technical Reports Server (NTRS)

    Marshak, A.; Knyazikhint, Y.; Davis, A.; Wiscombe, W.; Pilewskie, P.

    1999-01-01

    A new technique to retrieve cloud optical depth for broken clouds above green vegetation using ground-based zenith radiance measurements is developed. By analogy with the Normalized Difference Vegetation Index NDVI), the Normalized Difference Cloud Index (NDCI) is defined as a ratio between the difference and the sum of two zenith radiances measured for two narrow spectral bands in the visible and near-IR regions. The very different spectral behavior of cloud liquid water drops and green vegetation is the key physics behind the NDCI. It provides extra tools to remove the radiative effects of the 3D cloud structure. Numerical calculations based on fractal clouds and real measurements of NDCI and cloud liquid water path confirm the improvements.

  18. Sahara Dust Cloud

    NASA Image and Video Library

    2005-07-15

    In July of 2005, a continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean, captured by the Atmospheric Infrared Sounder onboard NASA Aqua satellite. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean. These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward. http://photojournal.jpl.nasa.gov/catalog/PIA00448

  19. Jupiter's Bands of Clouds

    NASA Image and Video Library

    2017-06-22

    This enhanced-color image of Jupiter's bands of light and dark clouds was created by citizen scientists Gerald Eichstädt and Seán Doran using data from the JunoCam imager on NASA's Juno spacecraft. Three of the white oval storms known as the "String of Pearls" are visible near the top of the image. Each of the alternating light and dark atmospheric bands in this image is wider than Earth, and each rages around Jupiter at hundreds of miles (kilometers) per hour. The lighter areas are regions where gas is rising, and the darker bands are regions where gas is sinking. Juno acquired the image on May 19, 2017, at 11:30 a.m. PST (2:30 p.m. EST) from an altitude of about 20,800 miles (33,400 kilometers) above Jupiter's cloud tops. https://photojournal.jpl.nasa.gov/catalog/PIA21393

  20. Cloud Computing Strategy

    DTIC Science & Technology

    2012-07-01

    the use of  available cloud and  shared   services .”     Federal Risk and Authorization Management Program (FedRAMP):  FedRAMP (See  Appendix B...governance processes will promote and enable the use of standardized SLAs  that facilitate the adoption of  shared   services  and virtual computing...Services,  shared   services  (cloud services offered by other  Components, the Federal Government, mission partners) and commercial vendors that meet

  1. The Clouds of Isidore

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These views of Hurricane Isidore were acquired by the Multi-angle Imaging SpectroRadiometer (MISR) on September 20, 2002. After bringing large-scale flooding to western Cuba, Isidore was upgraded (on September 21) from a tropical storm to a category 3hurricane. Sweeping westward to Mexico's Yucatan Peninsula, the hurricane caused major destruction and left hundreds of thousands of people homeless. Although weakened after passing over the Yucatan landmass, Isidore regained strength as it moved northward over the Gulf of Mexico.

    At left is a colorful visualization of cloud extent that superimposes MISR's radiometric camera-by-camera cloud mask (RCCM) over natural-color radiance imagery, both derived from data acquired with the instrument's vertical-viewing (nadir) camera. Using brightness and statistical metrics, the RCCM is one of several techniques MISR uses to determine whether an area is clear or cloudy. In this rendition, the RCCM has been color-coded, and purple = cloudy with high confidence, blue = cloudy with low confidence, green = clear with low confidence, and red = clear with high confidence.

    In addition to providing information on meteorological events, MISR's data products are designed to help improve our understanding of the influences of clouds on climate. Cloud heights and albedos are among the variables that govern these influences. (Albedo is the amount of sunlight reflected back to space divided by the amount of incident sunlight.) The center panel is the cloud-top height field retrieved using automated stereoscopic processing of data from multiple MISR cameras. Areas where heights could not be retrieved are shown in dark gray. In some areas, such as the southern portion of the image, the stereo retrieval was able to detect thin, high clouds that were not picked up by the RCCM's nadir view. Retrieved local albedo values for Isidore are shown at right. Generation of the albedo product is dependent upon observed cloud radiances as a function

  2. The Clouds of Isidore

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These views of Hurricane Isidore were acquired by the Multi-angle Imaging SpectroRadiometer (MISR) on September 20, 2002. After bringing large-scale flooding to western Cuba, Isidore was upgraded (on September 21) from a tropical storm to a category 3hurricane. Sweeping westward to Mexico's Yucatan Peninsula, the hurricane caused major destruction and left hundreds of thousands of people homeless. Although weakened after passing over the Yucatan landmass, Isidore regained strength as it moved northward over the Gulf of Mexico.

    At left is a colorful visualization of cloud extent that superimposes MISR's radiometric camera-by-camera cloud mask (RCCM) over natural-color radiance imagery, both derived from data acquired with the instrument's vertical-viewing (nadir) camera. Using brightness and statistical metrics, the RCCM is one of several techniques MISR uses to determine whether an area is clear or cloudy. In this rendition, the RCCM has been color-coded, and purple = cloudy with high confidence, blue = cloudy with low confidence, green = clear with low confidence, and red = clear with high confidence.

    In addition to providing information on meteorological events, MISR's data products are designed to help improve our understanding of the influences of clouds on climate. Cloud heights and albedos are among the variables that govern these influences. (Albedo is the amount of sunlight reflected back to space divided by the amount of incident sunlight.) The center panel is the cloud-top height field retrieved using automated stereoscopic processing of data from multiple MISR cameras. Areas where heights could not be retrieved are shown in dark gray. In some areas, such as the southern portion of the image, the stereo retrieval was able to detect thin, high clouds that were not picked up by the RCCM's nadir view. Retrieved local albedo values for Isidore are shown at right. Generation of the albedo product is dependent upon observed cloud radiances as a function

  3. Point clouds in BIM

    NASA Astrophysics Data System (ADS)

    Antova, Gergana; Kunchev, Ivan; Mickrenska-Cherneva, Christina

    2016-10-01

    The representation of physical buildings in Building Information Models (BIM) has been a subject of research since four decades in the fields of Construction Informatics and GeoInformatics. The early digital representations of buildings mainly appeared as 3D drawings constructed by CAD software, and the 3D representation of the buildings was only geometric, while semantics and topology were out of modelling focus. On the other hand, less detailed building representations, with often focus on ‘outside’ representations were also found in form of 2D /2,5D GeoInformation models. Point clouds from 3D laser scanning data give a full and exact representation of the building geometry. The article presents different aspects and the benefits of using point clouds in BIM in the different stages of a lifecycle of a building.

  4. High Resolution Cloud Microphysics and Radiation Studies

    DTIC Science & Technology

    2011-06-16

    characteristics of mid level altocumulus clouds and upper level visible and subvisual cirrus clouds The MPL lidar provided information about the temporal...balloon, lidar, and radar study of cirrus and altocumulus clouds to further investigate the presence of multi- cloud and nearly cloud -free layers...data set of the clouds and thermodynanuc structure to build a mesoscale and LF.S test-bed for cirrus and altocumulus cloud layers. The project was

  5. Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The larger of two nearby companions of the Milky Way Galaxy that can be seen with the naked eye in the southern hemisphere sky and which are named after the Portuguese navigator, Ferdinand Magellan, who observed them in 1519 during his circumnavigation of the world. Located in the constellation of Dorado, at a distance of about 170 000 light-years, the Large Magellanic Cloud (LMC) has an overall ...

  6. Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The smaller of two nearby companions of the Milky Way Galaxy that can be seen with the naked eye in the southern hemisphere sky and which are named after the Portuguese navigator, Ferdinand Magellan. Located in the constellation of Tucana, at a distance of about 190 000 light-years, the Small Magellanic Cloud (SMC) has an angular diameter of about three degrees, about half the apparent diameter o...

  7. Clouds over Mars!

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the first color image ever taken from the surface of Mars of an overcast sky. Featured are pink stratus clouds coming from the northeast at about 15 miles per hour (6.7 meters/second) at an approximate height of ten miles (16 kilometers) above the surface. The clouds consist of water ice condensed on reddish dust particles suspended in the atmosphere. Clouds on Mars are sometimes localized and can sometimes cover entire regions, but have not yet been observed to cover the entire planet. The image was taken about an hour and forty minutes before sunrise by the Imager for Mars Pathfinder (IMP) on Sol 16 at about ten degrees up from the eastern Martian horizon.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages and Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  8. Clouds over Mars!

    NASA Image and Video Library

    1997-08-01

    This is the first color image ever taken from the surface of Mars of an overcast sky. Featured are pink stratus clouds coming from the northeast at about 15 miles per hour (6.7 meters/second) at an approximate height of ten miles (16 kilometers) above the surface. The clouds consist of water ice condensed on reddish dust particles suspended in the atmosphere. Clouds on Mars are sometimes localized and can sometimes cover entire regions, but have not yet been observed to cover the entire planet. The image was taken about an hour and forty minutes before sunrise by the Imager for Mars Pathfinder (IMP) on Sol 16 at about ten degrees up from the eastern Martian horizon. Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA00796

  9. Chemistry and microphysics of polar stratospheric clouds and cirrus clouds.

    PubMed

    Zondlo, M A; Hudson, P K; Prenni, A J; Tolbert, M A

    2000-01-01

    Ice particles found within polar stratospheric clouds (PSCs) and upper tropospheric cirrus clouds can dramatically impact the chemistry and climate of the Earth's atmosphere. The formation of PSCs and the subsequent chemical reactions that occur on their surfaces are key components of the massive ozone hole observed each spring over Antarctica. Cirrus clouds also provide surfaces for heterogeneous reactions and significantly modify the Earth's climate by changing the visible and infrared radiation fluxes. Although the role of ice particles in climate and chemistry is well recognized, the exact mechanisms of cloud formation are still unknown, and thus it is difficult to predict how anthropogenic activities will change cloud abundances in the future. This article focuses on the nucleation, chemistry, and microphysical properties of ice particles composing PSCs and cirrus clouds. A general overview of the current state of research is presented along with some unresolved issues facing scientists in the future.

  10. Clouds on Hot Jupiters Illustration

    NASA Image and Video Library

    2016-10-18

    Hot Jupiters are exoplanets that orbit their stars so tightly that their temperatures are extremely high, reaching over 2,400 degrees Fahrenheit (1600 Kelvin). They are also tidally locked, so one side of the planet always faces the sun and the other is in permanent darkness. Research suggests that the "dayside" is largely free of clouds, while the "nightside" is heavily clouded. This illustration represents how hot Jupiters of different temperatures and different cloud compositions might appear to a person flying over the dayside of these planets on a spaceship, based on computer modeling. Cooler planets are entirely cloudy, whereas hotter planets have morning clouds only. Clouds of different composition have different colors, whereas the clear sky is bluer than on Earth. For the hottest planets, the atmosphere is hot enough on the evening side to glow like a charcoal. Figure 1 shows an approximation of what various hot Jupiters might look like based on a combination of computer modeling and data from NASA's Kepler Space Telescope. From left to right it shows: sodium sulfide clouds (1000 to 1200 Kelvin), manganese sulfide clouds (1200 to 1600 Kelvin), magnesium silicate clouds (1600 to 1800 Kelvin), magnesium silicate and aluminum oxide clouds (1800 Kelvin) and clouds composed of magnesium silicate, aluminum oxide, iron and calcium titanate (1900 to 2200 Kelvin). http://photojournal.jpl.nasa.gov/catalog/PIA21074

  11. Cumulus cloud formulations for longwave radiation calculations

    SciTech Connect

    Han, D.; Ellingson, R.G.

    1999-03-15

    Longwave radiative transfer under broken cloud conditions is often treated as a problem in cloud bulk geometry, especially for cumulus clouds, because individual clouds are nearly black. However, climate models ignore cloud geometry and estimate the effects of broken cumulus clouds as the cloud amount weighted average of clear and black cloud overcast conditions. To overcome the simplicity of the black plate approximation, the authors developed a more generalized form of cloud geometrical effects on the effective cloud fraction. Following previous work, this form includes parameters that allow a more precise specification of cloud size and spatial distributions. The sensitivity of the generalized form to the variation in cloud bulk geometrical shapes, aspect ratio, size distribution, and side inclination angle are the primary factors significantly affecting the effective cloud fraction. These parameters are important at all cloud amounts with greatest sensitivity when the cloud amount is between 0.2 and 0.8. On the other hand, cloud spatial distributions do not significantly influence the effective cloud fraction when absolute cloud amount is less than 0.2 and/or when the cloud aspect ratio is less than 0.5. However, in the range of greatest sensitivity with large aspect ratio and absolute amount, model comparisons show large intermodel differences. The model discussed herein is cloud size dependent and applies most directly to small cumulus clouds.

  12. Cloud Simulation Warm Cloud Experiments: Droplet Growth and Aerosol Scavenging.

    DTIC Science & Technology

    1988-03-02

    cloud simulation facility capabilities and experiments (Hagen, Alcorn, Alofs, Anderson, Carstens, Hopkins, Salk , Schmitt, Trueblood, White) 4. Conference...Snowmass, CO, AMS, 145-148. Jonas , P.R., and B.J. Mason, 1982: Entrainment and the droplet spectrumin cumulus clouds. Quart. J. Roy. Meteor. Soc. 108...distribution near the base of cumulus clouds. Quart. J. Roy. Meteor. Soc. 108, 917-928. Mason, B.J., and P.R. Jonas , 1984: The evolution of droplet

  13. Clouds and Dust Storms

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 2 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere.

    Image information: VIS instrument. Latitude 68.4, Longitude 180 East (180 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with

  14. CLOUD PARAMETERIZATIONS, CLOUD PHYSICS, AND THEIR CONNECTIONS: AN OVERVIEW.

    SciTech Connect

    LIU,Y.; DAUM,P.H.; CHAI,S.K.; LIU,F.

    2002-02-12

    This paper consists of three parts. The first part is concerned with the parameterization of cloud microphysics in climate models. We demonstrate the crucial importance of spectral dispersion of the cloud droplet size distribution in determining radiative properties of clouds (e.g., effective radius), and underline the necessity of specifying spectral dispersion in the parameterization of cloud microphysics. It is argued that the inclusion of spectral dispersion makes the issue of cloud parameterization essentially equivalent to that of the droplet size distribution function, bringing cloud parameterization to the forefront of cloud physics. The second part is concerned with theoretical investigations into the spectral shape of droplet size distributions in cloud physics. After briefly reviewing the mainstream theories (including entrainment and mixing theories, and stochastic theories), we discuss their deficiencies and the need for a paradigm shift from reductionist approaches to systems approaches. A systems theory that has recently been formulated by utilizing ideas from statistical physics and information theory is discussed, along with the major results derived from it. It is shown that the systems formalism not only easily explains many puzzles that have been frustrating the mainstream theories, but also reveals such new phenomena as scale-dependence of cloud droplet size distributions. The third part is concerned with the potential applications of the systems theory to the specification of spectral dispersion in terms of predictable variables and scale-dependence under different fluctuating environments.

  15. CloudSat: the Cloud Profiling Radar Mission

    NASA Technical Reports Server (NTRS)

    Im, Eastwood; Durden, Stephen L.; Tanelli, Simone

    2006-01-01

    The Cloud Profiling Radar (CPR), the primary science instrument of the CloudSat Mission, is a 94-GHz nadir-looking radar that measures the power backscattered by clouds as a function of distance from the radar. This instrument will acquire a global time series of vertical cloud structure at 500-m vertical resolution and 1.4-km horizontal resolution. CPR will operate in a short-pulse mode and will yield measurements at a minimum detectable sensitivity of -28 dBZ.

  16. TURBULENCE DECAY AND CLOUD CORE RELAXATION IN MOLECULAR CLOUDS

    SciTech Connect

    Gao, Yang; Law, Chung K.; Xu, Haitao

    2015-02-01

    The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in which star formation can occur. On the other hand, without a continuous external energy source maintaining the turbulence, such as in molecular clouds, the turbulence decays with an energy dissipation time comparable to the dynamic timescale of clouds, which could change the size limits obtained from Jean's criterion by assuming constant turbulence intensities. Here we adopt scaling relations of physical variables in decaying turbulence to analyze its specific effects on the formation of stars. We find that the decay of turbulence provides an additional approach for Jeans' criterion to be achieved, after which gravitational infall governs the motion of the cloud core. This epoch of turbulence decay is defined as cloud core relaxation. The existence of cloud core relaxation provides a more complete understanding of the effect of the competition between turbulence and gravity on the dynamics of molecular cloud cores and star formation.

  17. Cloud effects on ultraviolet photoclimatology

    NASA Technical Reports Server (NTRS)

    Green, A. E. S.; Spinhirne, J. D.

    1978-01-01

    The purpose of this study is to quantify for the needs of photobiology the influence of clouds upon the ultraviolet spectral irradiance reaching the ground. Towards this end, analytic formulas are developed which approximately characterize the influence of clouds upon total solar radiation. These may be used in conjunction with a solar pyranometer to assign an effective visual optical depth for the cloud cover. A formula is also developed which characterizes the influence of the optical depth of clouds upon the UV spectral irradiance in the 280-340 nm region. Thus total solar energy observations to assign cloud optical properties can be used to calculate the UV spectral irradiance at the ground in the presence of these clouds. As incidental by-products of this effort, convenient formulas are found for the direct and diffuse components of total solar energy.

  18. Exoplanet Clouds in the Laboratory

    NASA Astrophysics Data System (ADS)

    Johnson, Alexandria; Cziczo, Daniel J.; Seager, Sara; Charbonneau, David; Bauer, Amy J. R.

    2015-12-01

    The lack of strong spectral features of some exoplanet atmospheres may suggest the presence of a cloud layer and poses great challenges for atmospheric characterization. We aim to address these observations and the challenges by leveraging lab-based terrestrial cloud particle instrumentation as a means of investigating how particles representative of those in exoplanet atmospheres interact with incoming radiation. In the end we hope to achieve two goals - First, to better understand the observable properties of cloud particles in exoplanet atmospheres. Second, to determine how these clouds might directly limit our ability to observe and characterize the atmosphere below.In this presentation I will discuss the cloud chamber used for this work, how we leverage terrestrial based cloud knowledge, our initial investigation of the light scattered by ammonium nitrate (NH4NO3) across temperature and relative humidity dependent phase changes, and future work with suspected exoplanet atmospheric condensates under various atmospheric compositions, pressures, and temperatures.

  19. Cloud Vertical Structure variability within MODIS Cloud Regimes according to CloudSat-CALIPSO

    NASA Astrophysics Data System (ADS)

    Cho, N.; Oreopoulos, L.; Lee, D.

    2016-12-01

    To advance the understanding of the relationships and associations between active and passive views of cloud systems systematic comparisons are needed. We take advantage of A-Train's capability to collect a multitude of coincident measurements of atmospheric hydrometeors to develop a framework for examining cloud vertical structure (CVS). The backbone of our comparisons are cloud regimes (CRs) derived from co-varying cloud optical thickness and cloud top pressure retrieved from the MODIS radiometer. CloudSat and CALIPSO observations containing information about cloud occurrence throughout atmospheric layers are segregated and composited according to the MODIS regime classification for Aqua-only CR occurrences. With this approach, vertical profiles of cloud systems are organized in a way that allows them to be thoroughly studied and compared. We examine the frequency of occurrence within each MODIS CR of coarsely resolved CVS permutations (namely the possible combinations of clouds occurring at high, middle, and low altitudes either in isolation or in various configurations of contiguous or non-contiguous overlap). We look for similarities and extreme contrasts in CVS among MODIS CRs, dependence of CVS on the degree of deviation from the CR centroid, and regional dependences within the occurrences of the same CR. The presentation aims to demonstrate pathways towards a better knowledge of the information content of each type (i.e., active/passive) of measurement and to expose categories of cloud systems where the combination of measurements with different strengths and sensitivities is helping rather than confounding interpretations of the nature of cloudiness.

  20. Biogeography, Cloud Base Heights and Cloud Immersion in Tropical Montane Cloud Forests

    NASA Astrophysics Data System (ADS)

    Welch, R. M.; Asefi, S.; Zeng, J.; Nair, U. S.; Lawton, R. O.; Ray, D. K.; Han, Q.; Manoharan, V. S.

    2007-05-01

    Tropical Montane Cloud Forests (TMCFs) are ecosystems characterized by frequent and prolonged immersion within orographic clouds. TMCFs often lie at the core of the biological hotspots, areas of high biodiversity, whose conservation is necessary to ensure the preservation of a significant amount of the plant and animal species in the world. TMCFs support islands of endemism dependent on cloud water interception that are extremely susceptible to environmental and climatic changes at regional or global scales. Due to the ecological and hydrological importance of TMCFs it is important to understand the biogeographical distribution of these ecosystems. The best current list of TMCFs is a global atlas compiled by the United Nations Environmental Program (UNEP). However, this list is incomplete, and it does not provide information on cloud immersion, which is the defining characteristic of TMCFs and sorely needed for ecological and hydrological studies. The present study utilizes MODIS satellite data both to determine orographic cloud base heights and then to quantify cloud immersion statistics over TMCFs. Results are validated from surface measurements over Northern Costa Rica for the month of March 2003. Cloud base heights are retrieved with approximately 80m accuracy, as determined at Monteverde, Costa Rica. Cloud immersion derived from MODIS data is also compared to an independent cloud immersion dataset created using a combination of GOES satellite data and RAMS model simulations. Comparison against known locations of cloud forests in Northern Costa Rica shows that the MODIS-derived cloud immersion maps successfully identify these cloud forest locations, including those not included in the UNEP data set. Results also will be shown for cloud immersion in Hawaii. The procedure appears to be ready for global mapping.

  1. Evaluation of Passive Multilayer Cloud Detection Using Preliminary CloudSat and CALIPSO Cloud Profiles

    NASA Astrophysics Data System (ADS)

    Minnis, P.; Sun-Mack, S.; Chang, F.; Huang, J.; Nguyen, L.; Ayers, J. K.; Spangenberg, D. A.; Yi, Y.; Trepte, C. R.

    2006-12-01

    During the last few years, several algorithms have been developed to detect and retrieve multilayered clouds using passive satellite data. Assessing these techniques has been difficult due to the need for active sensors such as cloud radars and lidars that can "see" through different layers of clouds. Such sensors have been available only at a few surface sites and on aircraft during field programs. With the launch of the CALIPSO and CloudSat satellites on April 28, 2006, it is now possible to observe multilayered systems all over the globe using collocated cloud radar and lidar data. As part of the A- Train, these new active sensors are also matched in time ad space with passive measurements from the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer - EOS (AMSR-E). The Clouds and the Earth's Radiant Energy System (CERES) has been developing and testing algorithms to detect ice-over-water overlapping cloud systems and to retrieve the cloud liquid path (LWP) and ice water path (IWP) for those systems. One technique uses a combination of the CERES cloud retrieval algorithm applied to MODIS data and a microwave retrieval method applied to AMSR-E data. The combination of a CO2-slicing cloud retireval technique with the CERES algorithms applied to MODIS data (Chang et al., 2005) is used to detect and analyze such overlapped systems that contain thin ice clouds. A third technique uses brightness temperature differences and the CERES algorithms to detect similar overlapped methods. This paper uses preliminary CloudSat and CALIPSO data to begin a global scale assessment of these different methods. The long-term goals are to assess and refine the algorithms to aid the development of an optimal combination of the techniques to better monitor ice 9and liquid water clouds in overlapped conditions.

  2. Particle cloud mixing in microgravity

    NASA Technical Reports Server (NTRS)

    Ross, H.; Facca, L.; Tangirala, V.; Berlad, A. L.

    1989-01-01

    Quasi-steady flame propagation through clouds of combustible particles requires quasi-steady transport properties and quasi-steady particle number density. Microgravity conditions may be employed to help achieve the conditions of quiescent, uniform clouds needed for such combustion studies. Joint experimental and theoretical NASA-UCSD studies were concerned with the use of acoustic, electrostatic, and other methods of dispersion of fuel particulates. Results of these studies are presented for particle clouds in long cylindrical tubes.

  3. Shape of fair weather clouds.

    PubMed

    Wang, Yong; Zocchi, Giovanni

    2010-03-19

    We introduce a model which accounts for the shape of cumulus clouds exclusively in terms of thermal plumes or thermals. The plumes are explicitly represented by a simple potential flow generated by singularities (sources and sinks) and are thus laminar, but with their motion create a field which supports the cloud. We compare this model with actual clouds by means of various shape descriptors including the fractal dimension, and find agreement.

  4. Cloud droplet size distributions in low-level stratiform clouds

    SciTech Connect

    Miles, N.L.; Verlinde, J.; Clothiaux, E.E.

    2000-01-15

    A database of stratus cloud droplet size distribution parameters, derived from in situ data reported in the existing literature, was created, facilitating intercomparison among datasets and quantifying typical values and their variability. From the datasets, which were divided into marine and continental groups, several parameters are presented, including the total number concentration, effective diameter, mean diameter, standard deviation of the droplet diameters about the mean diameter, and liquid water content, as well as the parameters of modified gamma and lognormal distributions. In light of these results, the appropriateness of common assumptions used in remote sensing of cloud droplet size distributions is discussed. For example, vertical profiles of mean diameter, effective diameter, and liquid water content agreed qualitatively with expectations based on the current paradigm of cloud formation. Whereas parcel theory predicts that the standard deviation about the mean diameter should decrease with height, the results illustrated that the standard deviation generally increases with height. A feature common to all marine clouds was their approximately constant total number concentration profiles; however, the total number concentration profiles of continental clouds were highly variable. Without cloud condensation nuclei spectra, classification of clouds into marine and continental groups is based on indirect methods. After reclassification of four sets of measurements in the database, there was a fairly clear dichotomy between marine and continental clouds, but a great deal of variability within each classification. The relevant applications of this study lie in radiative transfer and climate issues, rather than in cloud formation and dynamics. Techniques that invert remotely sensed measurements into cloud droplet size distributions frequently rely on a priori assumptions, such as constant number concentration profiles and constant spectral width. The

  5. Empirical data from Oort's cloud

    NASA Technical Reports Server (NTRS)

    Desemme, A. H.

    1985-01-01

    Empirical evidence on the size and origin of the Oort cloud of comets is compared with theories on the origin of the Oort cloud. Data on the binding energy of the very long period comets indicate that the Oort cloud is five times smaller than previously thought and that the mean velocity perturbation introduced by stellar passages is smaller than Oort believed. The bimodal brightness distribution of 'new' comets indicates that their formation mechanism is straightforward accretion without later fragmentation. Data on retrograde versus prograde orbits and their relevance to the rotation of the Oort cloud are examined. Models of the solar nebula are discussed in the light of the foregoing evidence.

  6. Cloud/climate sensitivity experiments

    NASA Technical Reports Server (NTRS)

    Roads, J. O.; Vallis, G. K.; Remer, L.

    1982-01-01

    A study of the relationships between large-scale cloud fields and large scale circulation patterns is presented. The basic tool is a multi-level numerical model comprising conservation equations for temperature, water vapor and cloud water and appropriate parameterizations for evaporation, condensation, precipitation and radiative feedbacks. Incorporating an equation for cloud water in a large-scale model is somewhat novel and allows the formation and advection of clouds to be treated explicitly. The model is run on a two-dimensional, vertical-horizontal grid with constant winds. It is shown that cloud cover increases with decreased eddy vertical velocity, decreased horizontal advection, decreased atmospheric temperature, increased surface temperature, and decreased precipitation efficiency. The cloud field is found to be well correlated with the relative humidity field except at the highest levels. When radiative feedbacks are incorporated and the temperature increased by increasing CO2 content, cloud amounts decrease at upper-levels or equivalently cloud top height falls. This reduces the temperature response, especially at upper levels, compared with an experiment in which cloud cover is fixed.

  7. Chemical evolution of dense clouds

    NASA Technical Reports Server (NTRS)

    Chappelle, E. W.; Donn, B. D.; Payne, W. A., Jr.; Stief, L. J.

    1972-01-01

    Chemical processes that could determine the molecular composition of the cloud during the several stages of its evolution are considered. Reactions at the relatively interstellar densities are emphasized.

  8. The Ethics of Cloud Computing.

    PubMed

    de Bruin, Boudewijn; Floridi, Luciano

    2017-02-01

    Cloud computing is rapidly gaining traction in business. It offers businesses online services on demand (such as Gmail, iCloud and Salesforce) and allows them to cut costs on hardware and IT support. This is the first paper in business ethics dealing with this new technology. It analyzes the informational duties of hosting companies that own and operate cloud computing datacentres (e.g., Amazon). It considers the cloud services providers leasing 'space in the cloud' from hosting companies (e.g., Dropbox, Salesforce). And it examines the business and private 'clouders' using these services. The first part of the paper argues that hosting companies, services providers and clouders have mutual informational (epistemic) obligations to provide and seek information about relevant issues such as consumer privacy, reliability of services, data mining and data ownership. The concept of interlucency is developed as an epistemic virtue governing ethically effective communication. The second part considers potential forms of government restrictions on or proscriptions against the development and use of cloud computing technology. Referring to the concept of technology neutrality, it argues that interference with hosting companies and cloud services providers is hardly ever necessary or justified. It is argued, too, however, that businesses using cloud services (e.g., banks, law firms, hospitals etc. storing client data in the cloud) will have to follow rather more stringent regulations.

  9. Cloud formation in substellar atmospheres

    NASA Astrophysics Data System (ADS)

    Helling, Christiane

    2009-02-01

    Clouds seem like an every-day experience. But-do we know how clouds form on brown dwarfs and extra-solar planets? How do they look like? Can we see them? What are they composed of? Cloud formation is an old-fashioned but still outstanding problem for the Earth atmosphere, and it has turned into a challenge for the modelling of brown dwarf and exo-planetary atmospheres. Cloud formation imposes strong feedbacks on the atmospheric structure, not only due to the clouds own opacity, but also due to the depletion of the gas phase, possibly leaving behind a dynamic and still supersaturated atmosphere. I summarise the different approaches taken to model cloud formation in substellar atmospheres and workout their differences. Focusing on the phase-non-equilibrium approach to cloud formation, I demonstrate the inside we gain from detailed microphysical modelling on for instance the material composition and grain size distribution inside the cloud layer on a Brown Dwarf atmosphere. A comparison study on four different cloud approaches in Brown Dwarf atmosphere simulations demonstrates possible uncertainties in interpretation of observational data.

  10. Using Cloud Computing infrastructure with CloudBioLinux, CloudMan and Galaxy

    PubMed Central

    Afgan, Enis; Chapman, Brad; Jadan, Margita; Franke, Vedran; Taylor, James

    2012-01-01

    Cloud computing has revolutionized availability and access to computing and storage resources; making it possible to provision a large computational infrastructure with only a few clicks in a web browser. However, those resources are typically provided in the form of low-level infrastructure components that need to be procured and configured before use. In this protocol, we demonstrate how to utilize cloud computing resources to perform open-ended bioinformatics analyses, with fully automated management of the underlying cloud infrastructure. By combining three projects, CloudBioLinux, CloudMan, and Galaxy into a cohesive unit, we have enabled researchers to gain access to more than 100 preconfigured bioinformatics tools and gigabytes of reference genomes on top of the flexible cloud computing infrastructure. The protocol demonstrates how to setup the available infrastructure and how to use the tools via a graphical desktop interface, a parallel command line interface, and the web-based Galaxy interface. PMID:22700313

  11. Using cloud computing infrastructure with CloudBioLinux, CloudMan, and Galaxy.

    PubMed

    Afgan, Enis; Chapman, Brad; Jadan, Margita; Franke, Vedran; Taylor, James

    2012-06-01

    Cloud computing has revolutionized availability and access to computing and storage resources, making it possible to provision a large computational infrastructure with only a few clicks in a Web browser. However, those resources are typically provided in the form of low-level infrastructure components that need to be procured and configured before use. In this unit, we demonstrate how to utilize cloud computing resources to perform open-ended bioinformatic analyses, with fully automated management of the underlying cloud infrastructure. By combining three projects, CloudBioLinux, CloudMan, and Galaxy, into a cohesive unit, we have enabled researchers to gain access to more than 100 preconfigured bioinformatics tools and gigabytes of reference genomes on top of the flexible cloud computing infrastructure. The protocol demonstrates how to set up the available infrastructure and how to use the tools via a graphical desktop interface, a parallel command-line interface, and the Web-based Galaxy interface.

  12. Eyesafe laser cloud mapper

    NASA Astrophysics Data System (ADS)

    Woodall, Milton A., II; Minch, J. R.; Nunez, J.; Keeter, Howard S.; Johnson, Anthony M.

    1990-07-01

    The performance of eyesafe erbium:glass lasers operating at a wavelength of 1. 54 urn has been tested under various natural and manmade obscurants. To obtain the maximum amount of information two distinct system configurations were employed. The first a laser cloud mapper was designed to provide a direct depth profile of smoke density and reflectivity as well as target position. The second configuration was a production military laser rangefinder. It is representative of systems currently incorporated in tactical armored vehicles and was used to provide a direct indication of target range. 1.

  13. Martian Clouds Data Workshop

    NASA Technical Reports Server (NTRS)

    Lee, Steven (Editor)

    1987-01-01

    The major topics covered were a discussion of the structure of relational data base systems and features of the Britton Lee Relational Data Base Management System (RDBMS); a discussion of the workshop's objectives, approach, and research scenarios; and an overview of the Atmospheres Node User's Guide, which details the datasets stored on the Britton Lee, the structure of the query and data analysis system, and examples of the exact menu screens encountered. Also discussed were experience with the system, review of the system performance, and a strategy to produce queries and performance data retrievals of mutual interest. The goals were defined as examining correlations between cloud occurrence, water vapor abundance, and surface properties.

  14. Ion Cloud Modeling

    DTIC Science & Technology

    1977-11-11

    FORM I -i TRIRUTON S2TEEN GOVT tCESeO NO.rr- enteredPINT’ CATLO NUMBE.R dfern e Reot -3 :z SUPLMNTR NOTE Lewi KE ORS(C inson eeeeNAe fneeeay ndien6f y ... y of the released gas is specified, the snowplow model for the expansion of a gas cloud determines the time-dependence of the radius R(t) of the...ito t/a and the diffusion is assumed to commence at t = tD For a gas with y = 5/3 which is appropriate for barium atom vapor, we show the resulting

  15. A Simple Cloud Reflectance Model for Ship Tracks in Clouds

    DTIC Science & Technology

    1991-11-01

    A Simple Cloud Reflectance Model 01 for Ship Tracks in Clouds I OTIOSt 9L1, FIF MAR 16 1992J R. A. Siquig Forecast Guidance and Naval Systems...because of increased absorption. Note that this is based on the results for four wavelengths. Because of the undulatory nature of the imaginary part of

  16. Alterations of Cloud Microphysics Due to Cloud Processed CCN

    NASA Astrophysics Data System (ADS)

    Hudson, J. G.; Tabor, S. S.; Noble, S. R., Jr.

    2015-12-01

    High-resolution CCN spectra have revealed bimodality (Hudson et al. 2015) similar to aerosol size spectra (e.g., Hoppel et al. 1985). Bimodality is caused by chemical and physical cloud processes that increase mass or hygroscopicity of only CCN that produced activated cloud droplets. Bimodality is categorized by relative CCN concentrations (NCCN) within the two modes, Nu-Np; i.e., NCCN within the higher critical supersaturation, Sc, mode that did not undergo cloud processing minus NCCN within the lower Sc mode that was cloud processed. Lower, especially negative, Nu-Np designates greater processing. The table shows regressions between Nu-Np and characteristics of clouds nearest the CCN measurements. ICE-T MASE parameter R SL R SL Nc 0.17 93.24 -0.26 98.65 MD -0.31 99.69 0.33 99.78 σ -0.27 99.04 0.48 100.00 Ld -0.31 99.61 0.38 99.96 Table. Correlation coefficients, R, and one-tailed significance levels in percent, SL, for Nu-Np with microphysics of the clouds closest to each CCN measurement, 75 ICE-T and 74 MASE cases. Nc is cloud droplet concentration, MD is cloud droplet mean diameter, σ is standard deviation of cloud droplet spectra, Ldis drizzle drop LWC. Two aircraft field campaigns, Ice in Clouds Experiment-Tropical (ICE-T) and Marine Stratus/Stratocumulus Experiment (MASE) show opposite R signs because coalescence dominated cloud processing in low altitude ICE-T cumuli whereas chemical transformations predominated in MASE low altitude polluted stratus. Coalescence reduces Nc and NCCN, which thus increases MD, and σ, which promote Ld. Chemical transformations, e.g., SO2 to SO4, increase CCN hygroscopicity, thus reducing Sc, but not affecting Nc or NCCN. Lower Sc CCN are capable of producing greater Nc in subsequent cloud cycles, which leads to lower MD and σ which reduce Ld (figure). These observations are consistent with cloud droplet growth models for the higher vertical wind (W) of cumuli and lower W of stratus. Coalescence thus reduces the indirect

  17. Watching Summer Clouds on Titan

    NASA Image and Video Library

    2016-11-04

    NASA's Cassini spacecraft watched clouds of methane moving across the far northern regions of Saturn's largest moon, Titan, on Oct. 29 and 30, 2016. Several sets of clouds develop, move over the surface and fade during the course of this movie sequence, which spans 11 hours, with one frame taken every 20 minutes. Most prominent are long cloud streaks that lie between 49 and 55 degrees north latitude. While the general region of cloud activity is persistent over the course of the observation, individual streaks appear to develop then fade. These clouds are measured to move at a speed of about 14 to 22 miles per hour (7 to 10 meters per second). There are also some small clouds over the region of small lakes farther north, including a bright cloud between Neagh Lacus and Punga Mare, which fade over the course of the movie. This small grouping of clouds is moving at a speed of about 0.7 to 1.4 miles per hour (1 to 2 meters per second). Time-lapse movies like this allow scientists to observe the dynamics of clouds as they develop, move over the surface and fade. A time-lapse movie can also help to distinguish between noise in images (for example from cosmic rays hitting the detector) and faint clouds or fog. In 2016, Cassini has intermittently observed clouds across the northern mid-latitudes of Titan, as well as within the north polar region -- an area known to contain numerous methane/ethane lakes and seas see PIA19657 and PIA17655. However, most of this year's observations designed for cloud monitoring have been short snapshots taken days, or weeks, apart. This observation provides Cassini's best opportunity in 2016 to study short-term cloud dynamics. Models of Titan's climate have predicted more cloud activity during early northern summer than what Cassini has observed so far, suggesting that the current understanding of the giant moon's changing seasons is incomplete. The mission will continue monitoring Titan's weather around the 2017 summer solstice in Titan

  18. Cloud-free resolution element statistics program

    NASA Technical Reports Server (NTRS)

    Liley, B.; Martin, C. D.

    1971-01-01

    Computer program computes number of cloud-free elements in field-of-view and percentage of total field-of-view occupied by clouds. Human error is eliminated by using visual estimation to compute cloud statistics from aerial photographs.

  19. CloudSat View of Flossie

    NASA Image and Video Library

    CloudSat passed directly over Tropical Storm Flossie on July 29 and showed cumulus and stratocumulus clouds in northern Hawaii and cumulonimbus clouds over the southern part. Large amounts of liqui...

  20. Reviewing Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Fernandez Lopez, Manuel

    2017-07-01

    The star formation process involves a wide range of spatial scales, densities and temperatures. Herschel observations of the cold and low density molecular gas extending tens of parsecs, that constitutes the bulk of the molecular clouds of the Milky Way, have shown a network of dense structures in the shape of filaments. These filaments supposedly condense into higher density clumps to form individual stars or stellar clusters. The study of the kinematics of the filaments through single-dish observations suggests the presence of gas flows along the filaments, oscillatory motions due to gravity infall, and the existence of substructure inside filaments that may be threaded by twisted fibers. A few molecular clouds have been mapped with interferometric resolutions bringing more insight into the filament structure. Compression due to large-scale supersonic flows is the preferred mechanism to explain filament formation although the exact nature of the filaments, their origin and evolution are still not well understood. Determining the turbulence drivers behind the origin of the filaments, the relative importance of turbulence, gravity and magnetic fields on regulating the filament structure and evolution, and providing detailed insight on the substructure inside the filaments are among the current open questions in this research area.

  1. Storm and Clouds

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Yesterday's storm front was moving westward, today's moves eastward. Note the thick cloud cover and beautifully delineated cloud tops.

    Image information: VIS instrument. Latitude 72.1, Longitude 308.3 East (51.7 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. Measuring Cloud Properties from UAVs

    NASA Astrophysics Data System (ADS)

    Nicoll, K.; Harrison, R. G.; Roberts, G.

    2014-12-01

    Observations of in-situ cloud properties are an essential aspect of cloud microphysics studies. UAVs readily provide a platform from which high resolution cloud measurements can be made, both in the vertical and horizontal directions. Currently, however, one limiting factor in the use of UAVs for cloud studies is the lack of availability of lightweight, low power sensors. This work describes a number of small, disposable sensors for cloud droplet detection and electrical charge measurements, which have been flown on both free balloon and UAV platforms. The cloud droplet detector utilises optical reflection, combining a low power, high brightness LED as the optical source with a semiconductor photodiode as the detector. During daylight conditions, the photodiode detector also provides a measurement of broadband solar radiation, allowing an estimate of extinction within the cloud to be derived. The current consumption of the sensor is <30mA, and it has worked reliably in both day and night time conditions. Multiple flights of these sensors onboard UAVs with wingspan <2m (including Funjet and Easystar aircraft), made from southern France through a variety of cloud types will be presented.

  3. Teaching Cybersecurity Using the Cloud

    ERIC Educational Resources Information Center

    Salah, Khaled; Hammoud, Mohammad; Zeadally, Sherali

    2015-01-01

    Cloud computing platforms can be highly attractive to conduct course assignments and empower students with valuable and indispensable hands-on experience. In particular, the cloud can offer teaching staff and students (whether local or remote) on-demand, elastic, dedicated, isolated, (virtually) unlimited, and easily configurable virtual machines.…

  4. A Tale of Two Clouds

    ERIC Educational Resources Information Center

    Gray, Terry

    2010-01-01

    The University of Washington (UW) adopted a dual-provider cloud-computing strategy, focusing initially on software as a service. The original project--to replace an obsolete alumni e-mail system--resulted in a cloud solution that soon grew to encompass the entire campus community. The policies and contract terms UW developed, focusing on…

  5. Apollo 7 Mission,Clouds

    NASA Image and Video Library

    1968-10-11

    Apollo 7,Cumulus,alto-cumulus,cirrus clouds. Very high oblique. Cloud Cover 50%. Original film magazine was labeled S. Camera Data: Hasselblad 500-C; Lens: Zeiss Planar,F/2.8,80mm; Film Type: Kodak SO-121,Aerial Ektachrome; Filter: Wratten 2A. Flight Date: October 11-12. 1968.

  6. Chemical evolution of molecular clouds

    NASA Technical Reports Server (NTRS)

    Prasad, Sheo S.; Tarafdar, Sankar P.; Villere, Karen R.; Huntress, Wesley T., Jr.

    1987-01-01

    The principles behind the coupled chemical-dynamical evolution of molecular clouds are described. Particular attention is given to current problems involving the simplest species (i.e., C. CO, O2, and H2) in quiescent clouds. The results of a comparison made between the molecular abundances in the Orion ridge and the hot core (Blake, 1986) are presented.

  7. The Evolution of Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Wannier, Peter

    2002-07-01

    How is the evolution of dense clouds affected by their surrounding, more diffuse gas? Without an answer, it is not possible to understand the evolution of the ISM. Dense clouds can end their lives through the combined actions of star formation, violent disruption, and ablation. If ablation is an important process, then it is not a foregone conclusion that the dense clouds we see today will ever form stars. We will learn about the ablation process using STIS observations toward 18 stars for which we have existing FUSE observations, sightlines selected to lie behind the extended halos of four widely separated, molecular clouds. Our primary goal is to measure the gas pressure, the key to driving gas flows; secondary goals are to estimate the prevailing radiation and the CO column density. We have completed a pilot study of three stars in B5/Perseus, which enabled us to infer the presence near that cloud, of an isobaric, evaporative outflow, probably driven by UV irradiation. The 18 proposed sightlines lie near four dense clouds which have been well studied at radio, mm and far-IR wavelengths, providing needed auxiliary information about morphology and kinematics. The clouds {1} are nearby, {2} are unperturbed by massive star formation, and {3} sample a range of external environments. The combined STIS, FUSE and ground-based results will yield information needed to understand the role of ablation in the evolution of the central clouds.

  8. Architectural Implications of Cloud Computing

    DTIC Science & Technology

    2011-10-24

    Mellon University Final Thoughts 1 Cloud Computing is in essence an economic model • It is a different way to acquire and manage IT resources...Cloud (EC2): http://aws.amazon.com/ec2/ • Amazon Simple Storage Solution (S3): http://aws.amazon.com/s3/ • Eucalyptus Systems: http

  9. Chemical evolution of molecular clouds

    NASA Technical Reports Server (NTRS)

    Prasad, Sheo S.; Tarafdar, Sankar P.; Villere, Karen R.; Huntress, Wesley T., Jr.

    1987-01-01

    The principles behind the coupled chemical-dynamical evolution of molecular clouds are described. Particular attention is given to current problems involving the simplest species (i.e., C. CO, O2, and H2) in quiescent clouds. The results of a comparison made between the molecular abundances in the Orion ridge and the hot core (Blake, 1986) are presented.

  10. A Tale of Two Clouds

    ERIC Educational Resources Information Center

    Gray, Terry

    2010-01-01

    The University of Washington (UW) adopted a dual-provider cloud-computing strategy, focusing initially on software as a service. The original project--to replace an obsolete alumni e-mail system--resulted in a cloud solution that soon grew to encompass the entire campus community. The policies and contract terms UW developed, focusing on…

  11. Climate Effects of Cloud Modified CCN-Cloud Interactions

    NASA Astrophysics Data System (ADS)

    Noble, S. R., Jr.; Hudson, J. G.

    2015-12-01

    Cloud condensation nuclei (CCN) play an important role in the climate system through the indirect aerosol effect (IAE). IAE is one of the least understood aspects of the climate system as many cloud processes are complicated. Many studies of aerosol-cloud interaction involve CCN interaction with cloud droplet concentrations (Nc), cloud microphysics, and radiative properties. However, fewer studies investigate how cloud processes modify CCN. Upon evaporation from non-precipitating clouds, CCN distributions develop bimodal shaped distributions (Hoppel et al. 1986). Activated CCN participate in cloud processing that is either chemical: aqueous oxidation; or physical: Brownian scavenging, collision and coalescence. Chemical processing does not change CCN concentration (NCCN) but reduces critical supersaturations (Sc; larger size) (Feingold and Kreidenweis, 2000) while physical processing reduces NCCN and Sc. These processes create the minima in the bimodal CCN distributions (Hudson et al., 2015). Updraft velocity (W) and NCCN are major factors on how these modified CCN distributions affect clouds. Panel a shows two nearby CCN distributions in the MArine Stratus/stratocumulus Experiment (MASE), which have similar concentrations, but the bimodal one (red) has been modified by cloud processing. In a simplified cloud droplet model, the modified CCN then produces higher Nc (panel b) and smaller droplet mean diameters (MD; panel c) when compared to the unmodified CCN (black) for W lower than 50 cm/s. The better CCN (lower Sc) increase competition among droplets reducing MD and droplet distribution spread (σ) which acts to reduce drizzle. Competition is created by limited available condensate due to lower S created by the low W (<50 cm/s) typical of stratus. The increased Nc of the modified CCN in stratus then increases IAE in the climate system. At higher W (>50 cm/s) typical of cumuli, Ncis reduced and MD is increased from the modified CCN distribution (panels b & c). Here

  12. Comparison of Cirrus Cloud Models: A Project of the GEWEX Cloud System Study (GCSS) Working Group on Cirrus Cloud Systems

    NASA Technical Reports Server (NTRS)

    Starr, David O'C.; Benedetti, Angela; Boehm, Matt; Brown, Philip R. A.; Gierens, Klaus M.; Girard, Eric; Giraud, Vincent; Jakob, Christian; Jensen, Eric

    2000-01-01

    The GEWEX Cloud System Study (GCSS, GEWEX is the Global Energy and Water Cycle Experiment) is a community activity aiming to promote development of improved cloud parameterizations for application in the large-scale general circulation models (GCMs) used for climate research and for numerical weather prediction. The GCSS strategy is founded upon the use of cloud-system models (CSMs). These are "process" models with sufficient spatial and temporal resolution to represent individual cloud elements, but spanning a wide range of space and time scales to enable statistical analysis of simulated cloud systems. GCSS also employs single-column versions of the parametric cloud models (SCMs) used in GCMs. GCSS has working groups on boundary-layer clouds, cirrus clouds, extratropical layer cloud systems, precipitating deep convective cloud systems, and polar clouds.

  13. Comparison of Cirrus Cloud Models: A Project of the GEWEX Cloud System Study (GCSS) Working Group on Cirrus Cloud Systems

    NASA Technical Reports Server (NTRS)

    Starr, David OC.; Benedetti, Angela; Boehm, Matt; Brown, Philip R. A.; Gierens, Klaus M.; Girard, Eric; Giraud, Vincent; Jakob, Christian; Jensen, Eric; Khvorostyanov, Vitaly; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The GEWEX Cloud System Study (GCSS, GEWEX is the Global Energy and Water Cycle Experiment) is a community activity aiming to promote development of improved cloud parameterizations for application in the large-scale general circulation models (GCMs) used for climate research and for numerical weather prediction (Browning et al, 1994). The GCSS strategy is founded upon the use of cloud-system models (CSMs). These are "process" models with sufficient spatial and temporal resolution to represent individual cloud elements, but spanning a wide range of space and time scales to enable statistical analysis of simulated cloud systems. GCSS also employs single-column versions of the parametric cloud models (SCMs) used in GCMs. GCSS has working groups on boundary-layer clouds, cirrus clouds, extratropical layer cloud systems, precipitating deep convective cloud systems, and polar clouds.

  14. [Multifractal cloud properties data assessment

    SciTech Connect

    Gautier, C.; Ricchiazzi, P.; Peterson, P.; Lavallee, D.; Frouin, R.; Lubin, D.; Lovejoy, S.; Schertzer, D.

    1992-05-06

    Our group has been very active over the last year, analyzing a number of data sets to characterize multifractal cloud properties and assess the effects of clouds on surface radiation properties (spectral and broadband). The data sets analyzed include: AVHRR observations of clouds over the ocean, SPOT observations of clouds over the ocean, SSM/I observations of clouds over the ocean, pyranometer data with all-sky photographs, pyrgeometer data all-sky photographs, and spectral surface irradiance all-sky photographs. A number of radiative transfer computations have been performed to help in the interpretation of these observations or provide theoretical guidance for their analysis. Finally 4 number of radiative transfer models have been acquired and tested to prepare for the interpretation of ARM/CART data.

  15. Trusted Computing Strengthens Cloud Authentication

    PubMed Central

    2014-01-01

    Cloud computing is a new generation of technology which is designed to provide the commercial necessities, solve the IT management issues, and run the appropriate applications. Another entry on the list of cloud functions which has been handled internally is Identity Access Management (IAM). Companies encounter IAM as security challenges while adopting more technologies became apparent. Trust Multi-tenancy and trusted computing based on a Trusted Platform Module (TPM) are great technologies for solving the trust and security concerns in the cloud identity environment. Single sign-on (SSO) and OpenID have been released to solve security and privacy problems for cloud identity. This paper proposes the use of trusted computing, Federated Identity Management, and OpenID Web SSO to solve identity theft in the cloud. Besides, this proposed model has been simulated in .Net environment. Security analyzing, simulation, and BLP confidential model are three ways to evaluate and analyze our proposed model. PMID:24701149

  16. Trusted computing strengthens cloud authentication.

    PubMed

    Ghazizadeh, Eghbal; Zamani, Mazdak; Ab Manan, Jamalul-lail; Alizadeh, Mojtaba

    2014-01-01

    Cloud computing is a new generation of technology which is designed to provide the commercial necessities, solve the IT management issues, and run the appropriate applications. Another entry on the list of cloud functions which has been handled internally is Identity Access Management (IAM). Companies encounter IAM as security challenges while adopting more technologies became apparent. Trust Multi-tenancy and trusted computing based on a Trusted Platform Module (TPM) are great technologies for solving the trust and security concerns in the cloud identity environment. Single sign-on (SSO) and OpenID have been released to solve security and privacy problems for cloud identity. This paper proposes the use of trusted computing, Federated Identity Management, and OpenID Web SSO to solve identity theft in the cloud. Besides, this proposed model has been simulated in .Net environment. Security analyzing, simulation, and BLP confidential model are three ways to evaluate and analyze our proposed model.

  17. [Multifractal cloud properties data assessment

    SciTech Connect

    Gautier, C.; Ricchiazzi, P.; Peterson, P.; Lavallee, D. ); Frouin, R.; Lubin, D. ); Lovejoy, S. ); Schertzer, D. )

    1992-05-06

    Our group has been very active over the last year, analyzing a number of data sets to characterize multifractal cloud properties and assess the effects of clouds on surface radiation properties (spectral and broadband). The data sets analyzed include: AVHRR observations of clouds over the ocean, SPOT observations of clouds over the ocean, SSM/I observations of clouds over the ocean, pyranometer data with all-sky photographs, pyrgeometer data all-sky photographs, and spectral surface irradiance all-sky photographs. A number of radiative transfer computations have been performed to help in the interpretation of these observations or provide theoretical guidance for their analysis. Finally 4 number of radiative transfer models have been acquired and tested to prepare for the interpretation of ARM/CART data.

  18. Cloud regimes as phase transitions

    NASA Astrophysics Data System (ADS)

    Stechmann, Samuel N.; Hottovy, Scott

    2016-06-01

    Clouds are repeatedly identified as a leading source of uncertainty in future climate predictions. Of particular importance are stratocumulus clouds, which can appear as either (i) closed cells that reflect solar radiation back to space or (ii) open cells that allow solar radiation to reach the Earth's surface. Here we show that these clouds regimes -- open versus closed cells -- fit the paradigm of a phase transition. In addition, this paradigm characterizes pockets of open cells as the interface between the open- and closed-cell regimes, and it identifies shallow cumulus clouds as a regime of higher variability. This behavior can be understood using an idealized model for the dynamics of atmospheric water as a stochastic diffusion process. With this new conceptual viewpoint, ideas from statistical mechanics could potentially be used for understanding uncertainties related to clouds in the climate system and climate predictions.

  19. Physical conditions in molecular clouds

    NASA Technical Reports Server (NTRS)

    Evans, Neal J., II

    1989-01-01

    Recent developments have complicated the picture of the physical conditions in molecular clouds. The discoveries of widespread emission from high-J lines of CD and 12-micron IRAS emission have revealed the presence of considerably hotter gas and dust near the surfaces of molecular clouds. These components can complicate interpretation of the bulk of the cloud gas. Commonly assumed relations between column density or mean density and cloud size are called into question by conflicting results and by consideration of selection effects. Analysis of density and density structure through molecular excitation has shown that very high densities exist in star formation regions, but unresolved structure and possible chemical effects complicate the interpretation. High resolution far-IR and submillimeter observations offer a complementary approach and are beginning to test theoretical predictions of density gradients in clouds.

  20. Physical conditions in molecular clouds

    NASA Technical Reports Server (NTRS)

    Evans, Neal J., II

    1989-01-01

    Recent developments have complicated the picture of the physical conditions in molecular clouds. The discoveries of widespread emission from high-J lines of CD and 12-micron IRAS emission have revealed the presence of considerably hotter gas and dust near the surfaces of molecular clouds. These components can complicate interpretation of the bulk of the cloud gas. Commonly assumed relations between column density or mean density and cloud size are called into question by conflicting results and by consideration of selection effects. Analysis of density and density structure through molecular excitation has shown that very high densities exist in star formation regions, but unresolved structure and possible chemical effects complicate the interpretation. High resolution far-IR and submillimeter observations offer a complementary approach and are beginning to test theoretical predictions of density gradients in clouds.

  1. Tropical deep convective cloud morphology

    NASA Astrophysics Data System (ADS)

    Igel, Matthew R.

    A cloud-object partitioning algorithm is developed. It takes contiguous CloudSat cloudy regions and identifies various length scales of deep convective clouds from a tropical, oceanic subset of data. The methodology identifies a level above which anvil characteristics become important by analyzing the cloud object shape. Below this level in what is termed the pedestal region, convective cores are identified based on reflectivity maxima. Identifying these regions allows for the assessment of length scales of the anvil and pedestal of the deep convective clouds. Cloud objects are also appended with certain environmental quantities from the ECMWF reanalysis. Simple geospatial and temporal assessments show that the cloud object technique agrees with standard observations of local frequency of deep-convective cloudiness. Additionally, the nature of cloud volume scale populations is investigated. Deep convection is seen to exhibit power-law scaling. It is suggested that this scaling has implications for the continuous, scale invariant, and random nature of the physics controlling tropical deep convection and therefore on the potentially unphysical nature of contemporary convective parameterizations. Deep-convective clouds over tropical oceans play important roles in Earth's climate system. The response of tropical, deep convective clouds to sea surface temperatures (SSTs) is investigated using this new data set. Several previously proposed feedbacks are examined: the FAT hypothesis, the Iris hypothesis, and the Thermostat hypothesis. When the data are analyzed per cloud object, each hypothesis is broadly found to correctly predict cloud behavior in nature, although it appears that the FAT hypothesis needs a slight modification to allow for cooling cloud top temperatures with increasing SSTs. A new response that shows that the base temperature of deep convective anvils remains approximately constant with increasing SSTs is introduced. These cloud-climate feedbacks are

  2. Population Dynamics and Convective Cloud Fields

    NASA Astrophysics Data System (ADS)

    Nober, F. J.; Graf, H.-F.

    2003-04-01

    A cumulus cloud field model has been coupled to an atmospheric general circulation model (AGCM). The results, which show a good performance of the model within the AGCM and a qualitative good agreement to observation concerning the statistical information of cloud fields are presented. While most of the current cumulus convection parameterisations are formulated as massflux schemes (determing the overall massflux of all cumulus clouds in one AGCM grid column) the presented cloud field model determines for each AGCM grid column, where convection takes place, an explicit spectrum of different clouds. Therefore the information about the actual cumulus convection state in a grid column is not restricted to an avereged massflux but includes the number of different cloud types which in principle are able to develope under the given vertical condition. The degree to which part each cloud type participates in the whole cloud field is determined by the cloud field model with respect to the special vertical state in the grid column. The choice of the cloud model to define the different cloud types is very flexible. Very simple cloud models are possible but also more complex ones that describe more realistic clouds (including dynamic and microphysical information) than simple massflux approaches do. The cloud field model takes into account the interaction between all non-convective processes calculated by the AGCM and (which makes the procedure self constistent) the cloud-cloud interaction between each cloud type and each other. The final calculation of the cloud field is done following an approach from population dynamics (Lotka-Volterra-Equation). The tests of the model in the ECHAM5 AGCM (running in single column mode) shows that the model produces reliable convective feedbacks (i.e. integral convective heating, convective transport, etc.). The additional information of the cloud field structure (power law behavior of cloud size distribution, cloud tops for each cloud type

  3. EDITORIAL: Focus on Cloud Physics FOCUS ON CLOUD PHYSICS

    NASA Astrophysics Data System (ADS)

    Falkovich, Gregory; Malinowski, Szymon P.

    2008-07-01

    Cloud physics has for a long time been an important segment of atmospheric science. It is common knowledge that clouds are crucial for our understanding of weather and climate. Clouds are also interesting by themselves (not to mention that they are beautiful). Complexity is hidden behind the common picture of these beautiful and interesting objects. The typical school textbook definition that a cloud is 'a set of droplets or particles suspended in the atmosphere' is not adequate. Clouds are complicated phenomena in which dynamics, turbulence, microphysics, thermodynamics and radiative transfer interact on a wide range of scales, from sub-micron to kilometres. Some of these interactions are subtle and others are more straightforward. Large and small-scale motions lead to activation of cloud condensation nuclei, condensational growth and collisions; small changes in composition and concentration of atmospheric aerosol lead to significant differences in radiative properties of the clouds and influence rainfall formation. It is justified to look at a cloud as a composite, nonlinear system which involves many interactions and feedback. This system is actively linked into a web of atmospheric, oceanic and even cosmic interactions. Due to the complexity of the cloud system, present-day descriptions of clouds suffer from simplifications, inadequate parameterizations, and omissions. Sometimes the most fundamental physics hidden behind these simplifications and parameterizations is not known, and a wide scope of view can sometimes prevent a 'microscopic', deep insight into the detail. Only the expertise offered by scientists focused on particular elementary processes involved in this complicated pattern of interactions allows us to shape elements of the puzzle from which a general picture of clouds can be created. To be useful, every element of the puzzle must be shaped precisely. This often creates problems in communication between the sciences responsible for shaping

  4. Galaxy CloudMan: delivering cloud compute clusters.

    PubMed

    Afgan, Enis; Baker, Dannon; Coraor, Nate; Chapman, Brad; Nekrutenko, Anton; Taylor, James

    2010-12-21

    Widespread adoption of high-throughput sequencing has greatly increased the scale and sophistication of computational infrastructure needed to perform genomic research. An alternative to building and maintaining local infrastructure is "cloud computing", which, in principle, offers on demand access to flexible computational infrastructure. However, cloud computing resources are not yet suitable for immediate "as is" use by experimental biologists. We present a cloud resource management system that makes it possible for individual researchers to compose and control an arbitrarily sized compute cluster on Amazon's EC2 cloud infrastructure without any informatics requirements. Within this system, an entire suite of biological tools packaged by the NERC Bio-Linux team (http://nebc.nerc.ac.uk/tools/bio-linux) is available for immediate consumption. The provided solution makes it possible, using only a web browser, to create a completely configured compute cluster ready to perform analysis in less than five minutes. Moreover, we provide an automated method for building custom deployments of cloud resources. This approach promotes reproducibility of results and, if desired, allows individuals and labs to add or customize an otherwise available cloud system to better meet their needs. The expected knowledge and associated effort with deploying a compute cluster in the Amazon EC2 cloud is not trivial. The solution presented in this paper eliminates these barriers, making it possible for researchers to deploy exactly the amount of computing power they need, combined with a wealth of existing analysis software, to handle the ongoing data deluge.

  5. Putting the clouds back in aerosol-cloud interactions

    NASA Astrophysics Data System (ADS)

    Gettelman, A.

    2015-11-01

    Aerosol-cloud interactions (ACI) are the consequence of perturbed aerosols affecting cloud drop and crystal number, with corresponding microphysical and radiative effects. ACI are sensitive to both cloud microphysical processes (the "C" in ACI) and aerosol emissions and processes (the "A" in ACI). This work highlights the importance of cloud microphysical processes, using idealized and global tests of a cloud microphysics scheme used for global climate prediction. Uncertainties in key cloud microphysical processes examined with sensitivity tests cause uncertainties of nearly -30 to +60 % in ACI, similar to or stronger than uncertainties identified due to natural aerosol emissions (-30 to +30 %). The different dimensions and sensitivities of ACI to microphysical processes identified in previous work are analyzed in detail, showing that precipitation processes are critical for understanding ACI and that uncertain cloud lifetime effects are nearly one-third of simulated ACI. Buffering of different processes is important, as is the mixed phase and coupling of the microphysics to the condensation and turbulence schemes in the model.

  6. Cloud-Ground Interaction

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 30 June 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image of the North Polar water-ice clouds shows how surface topography can affect the linear form. Notice that the crater at the bottom of the image is causing a deflection in the linear form.

    Image information: VIS instrument. Latitude 68.4, Longitude 100.7 East (259.3 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the

  7. Cloud microphysical background for the Israel-4 cloud seeding experiment

    NASA Astrophysics Data System (ADS)

    Freud, Eyal; Koussevitzky, Hagai; Goren, Tom; Rosenfeld, Daniel

    2015-05-01

    The modest amount of rainfall in Israel occurs in winter storms that bring convective clouds from the Mediterranean Sea when the cold post frontal air interacts with its relatively warm surface. These clouds were seeded in the Israel-1 and Israel-2 cloud glaciogenic seeding experiments, which have shown statistically significant positive effect of added rainfall of at least 13% in northern Israel, whereas the Israel-3 experiment showed no added rainfall in the south. This was followed by operational seeding in the north since 1975. The lack of physical evidence for the causes of the positive effects in the north caused a lack of confidence in the statistical results and led to the Israel-4 randomized seeding experiment in northern Israel. This experiment started in the winter of 2013/14. The main difference from the previous experiments is the focus on the orographic clouds in the catchment of the Sea of Galilee. The decision to commence the experiment was partially based on evidence supporting the existence of seeding potential, which is reported here. Aircraft and satellite microphysical and dynamic measurements of the clouds document the critical roles of aerosols, especially sea spray, on cloud microstructure and precipitation forming processes. It was found that the convective clouds over sea and coastal areas are naturally seeded hygroscopically by sea spray and develop precipitation efficiently. The diminution of the large sea spray aerosols farther inland along with the increase in aerosol concentrations causes the clouds to develop precipitation more slowly. The short time available for the precipitation forming processes in super-cooled orographic clouds over the Golan Heights farthest inland represents the best glaciogenic seeding potential.

  8. ASTER cloud coverage reassessment using MODIS cloud mask products

    NASA Astrophysics Data System (ADS)

    Tonooka, Hideyuki; Omagari, Kunjuro; Yamamoto, Hirokazu; Tachikawa, Tetsushi; Fujita, Masaru; Paitaer, Zaoreguli

    2010-10-01

    In the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) Project, two kinds of algorithms are used for cloud assessment in Level-1 processing. The first algorithm based on the LANDSAT-5 TM Automatic Cloud Cover Assessment (ACCA) algorithm is used for a part of daytime scenes observed with only VNIR bands and all nighttime scenes, and the second algorithm based on the LANDSAT-7 ETM+ ACCA algorithm is used for most of daytime scenes observed with all spectral bands. However, the first algorithm does not work well for lack of some spectral bands sensitive to cloud detection, and the two algorithms have been less accurate over snow/ice covered areas since April 2008 when the SWIR subsystem developed troubles. In addition, they perform less well for some combinations of surface type and sun elevation angle. We, therefore, have developed the ASTER cloud coverage reassessment system using MODIS cloud mask (MOD35) products, and have reassessed cloud coverage for all ASTER archived scenes (>1.7 million scenes). All of the new cloud coverage data are included in Image Management System (IMS) databases of the ASTER Ground Data System (GDS) and NASA's Land Process Data Active Archive Center (LP DAAC) and used for ASTER product search by users, and cloud mask images are distributed to users through Internet. Daily upcoming scenes (about 400 scenes per day) are reassessed and inserted into the IMS databases in 5 to 7 days after each scene observation date. Some validation studies for the new cloud coverage data and some mission-related analyses using those data are also demonstrated in the present paper.

  9. Photogrammetry and photo interpretation applied to analyses of cloud cover, cloud type, and cloud motion

    NASA Technical Reports Server (NTRS)

    Larsen, P. A.

    1972-01-01

    A determination was made of the areal extent of terrain obscured by clouds and cloud shadows on a portion of an Apollo 9 photograph at the instant of exposure. This photogrammetrically determined area was then compared to the cloud coverage reported by surface weather observers at approximately the same time and location, as a check on result quality. Stereograms prepared from Apollo 9 vertical photographs, illustrating various percentages of cloud coverage, are presented to help provide a quantitative appreciation of the degradation of terrain photography by clouds and their attendant shadows. A scheme, developed for the U.S. Navy, utilizing pattern recognition techniques for determining cloud motion from sequences of satellite photographs, is summarized. Clouds, turbulence, haze, and solar altitude, four elements of our natural environment which affect aerial photographic missions, are each discussed in terms of their effects on imagery obtained by aerial photography. Data of a type useful to aerial photographic mission planners, expressing photographic ground coverage in terms of flying height above terrain and camera focal length, for a standard aerial photograph format, are provided. Two oblique orbital photographs taken during the Apollo 9 flight are shown, and photo-interpretations, discussing the cloud types imaged and certain visible geographical features, are provided.

  10. Mesoscale cloud phenomena observed by LANDSAT

    NASA Technical Reports Server (NTRS)

    Ormsby, J. P.

    1977-01-01

    Examples of certain mesoscale cloud features - jet cirrus, eddies/vortices, cloud banding, and wave clouds - were collected from LANDSAT imagery and placed into Mason's four groups of causes of cloud formation based on the mechanism of vertical motion which produces condensation. These groups are as follows: (1) layer clouds formed by widespread regular ascent; (2) layer clouds caused by irregular stirring motions; (3) convective clouds; and (4) clouds formed by orographic disturbances. These mechanisms explain general cloud formation. Once formed, other forces may play a role in the deformation of a cloud or cloud mass into unusual and unique meso- and microscale patterns. Each example presented is followed by a brief discussion describing the synoptic situation, and some inference into the formation and occurrence of the more salient features. No major attempt was made to discuss in detail the meteorological and topographic interplay producing these mesoscale features.

  11. Under Jupiter's Cloud Tops

    NASA Image and Video Library

    2017-05-25

    NASA's Juno spacecraft carries an instrument called the Microwave Radiometer, which examines Jupiter's atmosphere beneath the planet's cloud tops. This image shows the instrument's view of the outer part of Jupiter's atmosphere. Before Juno began using this instrument, scientists expected the atmosphere to be uniform at depths greater than 60 miles (100 kilometers). But with the Microwave Radiometer, scientists have discovered that the atmosphere has variations down to at least 220 miles (350 kilometers), as deep as the instrument can see. In the cut-out image to the right, orange signifies high ammonia abundance and blue signifies low ammonia abundance. Jupiter appears to have a band around its equator high in ammonia abundance, with a column shown in orange. This is contrary to scientists' expectations that ammonia would be uniformly mixed. https://photojournal.jpl.nasa.gov/catalog/PIA21642

  12. Clouds Near Mie Crater

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-572, 12 December 2003

    Mie Crater, a large basin formed by asteroid or comet impact in Utopia Planitia, lies at the center of this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) red wide angle image. The crater is approximately 104 km (65 mi) across. To the east and southeast (toward the lower right) of Mie, in this 5 December 2003 view, are clouds of dust and water ice kicked up by local dust storm activity. It is mid-winter in the northern hemisphere of Mars, a time when passing storms are common on the northern plains of the red planet. Sunlight illuminates this image from the lower left; Mie Crater is located at 48.5oN, 220.3oW. Viking 2 landed west/southwest of Mie Crater, off the left edge of this image, in September 1976.

  13. Ionospheric plasma cloud dynamics

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Measurements of the thermospheric neutral wind and ionospheric drift made at Eglin AFB, Florida and Kwajalein Atoll are discussed. The neutral wind measurements at Eglin had little variation over a period of four years for moderate magnetic activity (Kp 4); the ionospheric drifts are small. Evidence is presented that indicates that increased magnetic activity has a significant effect on the neutral wind magnitude and direction at this midlatitude station. The neutral wind at dusk near the equator is generally small although in one case out of seven it was significantly larger. It is described how observations of large barium releases can be used to infer the degree of electrodynamic coupling of ion clouds to the background ionosphere. Evidence is presented that indicates that large barium releases are coupled to the conjugate ionosphere at midlatitudes.

  14. W3 molecular cloud

    SciTech Connect

    Thronson, H.A.,JR.; Lada, C.J.; Hewagama, T.

    1985-10-01

    Extensive J = 1 to 0 (C-12)(O-16) and (C-13)(O-16) observations of the W3 molecular cloud and the surrounding region are presented and discussed. The velocity structure in the region is strongly suggestive of a model of large-scale, externally induced star formation. It is shown that star formation occurred in W3 and the nearby star-forming region W3(OH) after the gas within which they lie was swept up by the expanding W4 ionization front. Two condensations dominate the mass structure of the core of W3, one associated with IRS 4 and the other with IRS 5 and 1. A velocity difference between the two condensations is interpreted as indicating the two sources actually are discrete knots. 31 references.

  15. Horizontal distribution of mixed cloud type scene

    NASA Astrophysics Data System (ADS)

    Guillaume, A.; Kahn, B. H.; Yue, Q.; Wong, S.; Manipon, G.; Hua, H.; Wilson, B. D.; Wang, T.; Fetzer, E. J.

    2016-12-01

    We describe a novel method to uniquely characterize and quantify the scale dependence of mixed cloud scene geometry using cloud type classification reported with the 94GHz CloudSat radar. Only a fraction of all possible combinations of cloud types are observed at any along-track length scale considered. Cloud scenes most frequently contain only one or two cloud types. We show how cloud occurrence depends on the grid cell spatial resolution used to define cloud scenes. A maximum number of observed cloud scenes occur near 100 km with fewer cloud type combinations at smaller and larger scales. We then quantify the cloud lengths along the CloudSat track using both the cloud top classification and the vertical structure of cloud classification separately for each of the nine cloud types defined by CloudSat and for all clouds considered independent of cloud type. While the individual cloud types do not follow a clear power law behavior as a function of horizontal or vertical scale, a robust power law scaling of cloud geometry is observed when cloud type is not considered. The power law scaling exponent of horizontal length is approximated by β ≈ -5/3 over two to three orders of magnitude. The power law scaling exponent of vertical length is approximated by β ≈ -7/3 over two orders of magnitude. These exponents are in agreement with previous studies using numerical models, satellite, and in situ aircraft observations. In particular, the anisotropy in the horizontal and vertical scaling are nearly identical to recent aircraft observations of wind kinetic energy spectra, suggesting the underlying three-dimensional cloud geometry is strongly related to kinetic energy spectra.

  16. Aerosol cloud generation experiments

    NASA Astrophysics Data System (ADS)

    Ratzel, A. C.; Constantineau, E. J.

    This paper provides results from an experimental study performed to evaluate the use of homogeneous and granulated explosive mixture concepts for creating spherical aerosol clouds. In the explosive mixture concept, a small mass of explosive is added to a larger mass of fine inert particulate, and the blend is hand-tamped into a confining cylindrical or spherical structure thereby creating a bed of explosive mixture. The mixture proportions are selected such that the mixture is able to sustain a reaction, be it a detonation or deflagration, throughout the bed. This approach generates gas for aerosol dispersal throughout the bed rather than from the center of the bed (as from a center-driven concept device). As such, a uniformly dispersed aerosol, rather than a thin shell of aerosol, would be expected to be dispersed. The two mixture concepts considered in this work differed only in the assembly and blending of the inert and explosive. Of interest in this work was the evaluation of the explosive mixture concepts relative to providing uniform spherical clouds of fine oxide aerosols of characteristic dimension less than 10 microns. Programmatic constraints dictated that the mass and quantity of extraneous materials such as the external structure and other peripherals associated with initiation also be minimized. Experiments were conducted in air with spherical devices ranging in size from 3 to 15 in. in diameter and with cylindrical and conical shotgun devices of length 4 to 7 inches. The latter test were performed to assess reaction sustainability for different explosive mixture ratios. Trends obtained from the studies as well as an assessment of the explosive mixture dispersal concept are included.

  17. Statistical analysis of an LES shallow cumulus cloud ensemble using a cloud tracking algorithm

    NASA Astrophysics Data System (ADS)

    Dawe, J. T.; Austin, P. H.

    2012-01-01

    A technique for the tracking of individual clouds in a Large Eddy Simulation (LES) is presented. We use this technique on an LES of a shallow cumulus cloud field based upon the Barbados Oceanographic and Meteorological Experiment (BOMEX) to calculate statistics of cloud height, lifetime, and other physical properties for individual clouds in the model. We also examine the question of nature versus nurture in shallow cumulus clouds: do properties at cloud base determine the upper-level properties of the clouds (nature), or are cloud properties determined by the environmental conditions they encounter (nurture). We find that clouds which ascend through an environment that has been pre-moistened by previous cloud activity are no more likely to reach the inversion than clouds that ascend through a drier environment. Cloud base thermodynamic properties are uncorrelated with upper-level cloud properties, while mean fractional entrainment and detrainment rates display moderate correlations with cloud properties up to the inversion. Conversely, cloud base area correlates well with upper-level cloud area and maximum cloud height. We conclude that cloud thermodynamic properties are primarily influenced by entrainment and detrainment processes, cloud area and height are primarily influenced by cloud base area, and thus nature and nurture both play roles in the dynamics of BOMEX shallow cumulus clouds.

  18. Statistical analysis of a LES shallow cumulus cloud ensemble using a cloud tracking algorithm

    NASA Astrophysics Data System (ADS)

    Dawe, J. T.; Austin, P. H.

    2011-08-01

    A technique for the tracking of individual clouds in a Large Eddy Simulation (LES) is presented. We use this technique on a LES of a shallow cumulus cloud field based upon the Barbados Oceanographic and Meteorological Experiment (BOMEX) to calculate statistics of cloud height, lifetime, and other physical properties for individual clouds in the model. We also examine the question of nature versus nurture in shallow cumulus clouds: do properties at cloud base determine the upper-level properties of the clouds (nature), or are cloud properties determined by the environmental conditions they encounter (nurture). We find that clouds which ascend through an environment that has been pre-moistened by previous cloud activity are no more likely to reach the inversion than clouds that ascend through a drier environment. Cloud base thermodynamic properties are uncorrelated with upper-level cloud properties, while mean fractional entrainment and detrainment rate displays moderate correlations with cloud properties up to the inversion. Conversely, cloud base area correlates well with upper-level cloud area and maximum cloud height. We conclude that cloud thermodynamic properties are primarily influenced by entrainment and detrainment processes, cloud area and height are primarily influenced by cloud base area, and thus nature and nurture both play roles in the dynamics of BOMEX shallow cumulus clouds.

  19. New Perspectives on Processes Responsible for Cloud Feedback: Beyond Warm Low Clouds

    NASA Astrophysics Data System (ADS)

    Gettelman, A.; Sherwood, S. C.

    2016-12-01

    Cloud feedbacks are the largest uncertainty in constraining climate sensitivity. Cloud feedbacks are determined by a series of interacting processes that have different relevance in different cloud regimes. Recent work is extending the consensus on the large scale controls for cloud feedback. Beyond shallow warm clouds there are several other regimes where critical processes influence cloud feedbacks. Cloud microphysics is important for cloud feedback in mixed phase cloud regimes in middle and high latitudes. Aerosol mediated effects on cloud feedback need to be accounted for and may contribute to spread of cloud feedback in model simulations. The role of cloud microphysics in setting and altering deep convective precipitation efficiency may also be important for cloud feedback. Examples and some new work will illustrate these processes and their effect on cloud feedback. In this paradigm, narrowing the spread of cloud feedbacks involves focusing on key regimes and trying to simulate critical cloud processes with high fidelity. Focusing on regimes leads naturally to a physical basis for understanding emergent constraints on clouds in the present day. Future studies will need to account for the diversity of cloud microphysical and aerosol processes in models. Narrowing the spread of cloud feedbacks may require better accounting for the diversity of processes that contribute to cloud feedbacks, such as different treatments of the mixed phase regime, different complexity of microphysics in convective cloud, or different aerosol processes.

  20. Creating cloud-free Landsat ETM+ data sets in tropical landscapes: cloud and cloud-shadow removal

    Treesearch

    Sebastián Martinuzzi; William A. Gould; Olga M. Ramos Gonzalez

    2007-01-01

    Clouds and cloud shadows are common features of visible and infrared remotelysensed images collected from many parts of the world, particularly in humid and tropical regions. We have developed a simple and semiautomated method to mask clouds and shadows in Landsat ETM+ imagery, and have developed a recent cloud-free composite of multitemporal images for Puerto Rico and...

  1. Relation of Cloud Occurrence Frequency, Overlap, and Effective Thickness Derived from CALIPSO and CloudSat Merged Cloud Vertical Profiles

    NASA Technical Reports Server (NTRS)

    Kato, Seiji; Sun-Mack, Sunny; Miller, Walter F.; Rose, Fred G.; Chen, Yan; Minnis, Patrick; Wielicki, Bruce A.

    2009-01-01

    A cloud frequency of occurrence matrix is generated using merged cloud vertical profile derived from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Cloud Profiling Radar (CPR). The matrix contains vertical profiles of cloud occurrence frequency as a function of the uppermost cloud top. It is shown that the cloud fraction and uppermost cloud top vertical pro les can be related by a set of equations when the correlation distance of cloud occurrence, which is interpreted as an effective cloud thickness, is introduced. The underlying assumption in establishing the above relation is that cloud overlap approaches the random overlap with increasing distance separating cloud layers and that the probability of deviating from the random overlap decreases exponentially with distance. One month of CALIPSO and CloudSat data support these assumptions. However, the correlation distance sometimes becomes large, which might be an indication of precipitation. The cloud correlation distance is equivalent to the de-correlation distance introduced by Hogan and Illingworth [2000] when cloud fractions of both layers in a two-cloud layer system are the same.

  2. Molecular clouds without detectable CO

    NASA Technical Reports Server (NTRS)

    Blitz, Leo; Bazell, David; Desert, F. Xavier

    1990-01-01

    The clouds identified by Desert, Bazell, and Boulanger (DBB clouds) in their search for high-latitude molecular clouds were observed in the CO (J = 1-0) line, but only 13 percent of the sample was detected. The remaining 87 percent are diffuse molecular clouds with CO abundances of about 10 to the -6th, a typical value for diffuse clouds. This hypothesis is shown to be consistent with Copernicus data. The DBB clouds are shown to ben an essentially complete catalog of diffuse molecular clouds in the solar vicinity. The total molecular surface density in the vicinity of the sun is then only about 20 percent greater than the 1.3 solar masses/sq pc determined by Dame et al. (1987). Analysis of the CO detections indicates that there is a sharp threshold in extinction of 0.25 mag before CO is detectable and is derived from the IRAS I(100) micron threshold of 4 MJy/sr. This threshold is presumably where the CO abundance exhibits a sharp increase

  3. Molecular clouds without detectable CO

    NASA Astrophysics Data System (ADS)

    Blitz, Leo; Bazell, David; Desert, F. Xavier

    1990-03-01

    The clouds identified by Desert, Bazell, and Boulanger (DBB clouds) in their search for high-latitude molecular clouds were observed in the CO (J = 1-0) line, but only 13 percent of the sample was detected. The remaining 87 percent are diffuse molecular clouds with CO abundances of about 10 to the -6th, a typical value for diffuse clouds. This hypothesis is shown to be consistent with Copernicus data. The DBB clouds are shown to ben an essentially complete catalog of diffuse molecular clouds in the solar vicinity. The total molecular surface density in the vicinity of the sun is then only about 20 percent greater than the 1.3 solar masses/sq pc determined by Dame et al. (1987). Analysis of the CO detections indicates that there is a sharp threshold in extinction of 0.25 mag before CO is detectable and is derived from the IRAS I(100) micron threshold of 4 MJy/sr. This threshold is presumably where the CO abundance exhibits a sharp increase

  4. Titan South Polar Cloud Burst

    NASA Image and Video Library

    2009-06-03

    This infrared image of Saturn's moon Titan shows a large burst of clouds in the moon's south polar region. These clouds form and move much like those on Earth, but in a much slower, more lingering fashion, new results from NASA's Cassini Spacecraft show. This image is a color composite, with red shown at a 5-micron wavelength, green at 2.7 microns, and blue at 2 microns. An infrared color mosaic is also used as a background image (red at 5 microns, green at 2 microns, blue at 1.3 microns). The images were taken by Cassini's visual and infrared mapping spectrometer during a flyby of Titan on March 26, 2007, known as T27. For a similar view see PIA12004. Titan's southern hemisphere still shows a very active meteorology (the cloud appears in white-reddish tones) even in 2007. According to climate models, these clouds should have faded out since 2005. Scientists have monitored Titan's atmosphere for three-and-a-half years, between July 2004 and December 2007, and observed more than 200 clouds. The way these clouds are distributed around Titan matches scientists' global circulation models. The only exception is timing—clouds are still noticeable in the southern hemisphere while fall is approaching. http://photojournal.jpl.nasa.gov/catalog/PIA12005

  5. Chemistry in dynamically evolving clouds

    NASA Technical Reports Server (NTRS)

    Tarafdar, S. P.; Prasad, S. S.; Huntress, W. T., Jr.; Villere, K. R.; Black, D. C.

    1985-01-01

    A unified model of chemical and dynamical evolution of isolated, initially diffuse and quiescent interstellar clouds is presented. The model uses a semiempirically derived dependence of the observed cloud temperatures on the visual extinction and density. Even low-mass, low-density, diffuse clouds can collapse in this model, because the inward pressure gradient force assists gravitational contraction. In contrast, previous isothermal collapse models required the low-mass diffuse clouds to be unrealistically cold before gravitational contraction could start. Theoretically predicted dependences of the column densities of various atoms and molecules, such as C and CO, on visual extinction in diffuse clouds are in accord with observations. Similarly, the predicted dependences of the fractional abundances of various chemical species (e.g., CO, H2CO, HCN, HCO(+)) on the total hydrogen density in the core of the dense clouds also agree with observations reported to date in the literature. Compared with previous models of interstellar chemistry, the present model has the potential to explain the wide spectrum of chemical and physical properties of both diffuse and dense clouds with a common formalism employing only a few simple initial conditions.

  6. Chemical composition of Venus clouds

    NASA Astrophysics Data System (ADS)

    Krasnopolsky, V. A.

    1985-01-01

    From estimates of drying effect in the cloud layer, data of the Venera 14 X-ray fluorescent spectroscopy, and evaluation of photochemical production of sulfuric acid, it follows that sulfuric acid and/or products of its further conversion should constitute not only the Mode 2 particles but most of the Mode 3 particles as well. The eddy mixing coefficient equal 20,000 sq cm per sec in the cloud layer. The presence of ferric chloride in the cloud layer is indicated by the Venus u.v. absorption spectrum in the range of 3200-5000 A, by the Venera 12 X-ray fluorescent spectrum, by the coincidence of the calculated FeCl3 condensate density profile and that of the Mode 1 in the middle and lower cloud layer, as well as by the upward flux of FeCl3 from the middle cloud layer which provides the necessary concentration of FeCl3 in H2SO4 solution. FeCl3 as the second absorber explains the localization of absorption in the upper cloud layer due to the FeCl3 conversion to ferric sulfate near the boundary between the upper and middle cloud layers. Other possible absorbers such as sulfur, ammonium pyrosulfite, nitrosylsulfuric acid, etc. are discussed.

  7. Chemistry in dynamically evolving clouds

    NASA Technical Reports Server (NTRS)

    Tarafdar, S. P.; Prasad, S. S.; Huntress, W. T., Jr.; Villere, K. R.; Black, D. C.

    1985-01-01

    A unified model of chemical and dynamical evolution of isolated, initially diffuse and quiescent interstellar clouds is presented. The model uses a semiempirically derived dependence of the observed cloud temperatures on the visual extinction and density. Even low-mass, low-density, diffuse clouds can collapse in this model, because the inward pressure gradient force assists gravitational contraction. In contrast, previous isothermal collapse models required the low-mass diffuse clouds to be unrealistically cold before gravitational contraction could start. Theoretically predicted dependences of the column densities of various atoms and molecules, such as C and CO, on visual extinction in diffuse clouds are in accord with observations. Similarly, the predicted dependences of the fractional abundances of various chemical species (e.g., CO, H2CO, HCN, HCO(+)) on the total hydrogen density in the core of the dense clouds also agree with observations reported to date in the literature. Compared with previous models of interstellar chemistry, the present model has the potential to explain the wide spectrum of chemical and physical properties of both diffuse and dense clouds with a common formalism employing only a few simple initial conditions.

  8. Analytical optical scattering in clouds

    NASA Technical Reports Server (NTRS)

    Phanord, Dieudonne D.

    1989-01-01

    An analytical optical model for scattering of light due to lightning by clouds of different geometry is being developed. The self-consistent approach and the equivalent medium concept of Twersky was used to treat the case corresponding to outside illumination. Thus, the resulting multiple scattering problem is transformed with the knowledge of the bulk parameters, into scattering by a single obstacle in isolation. Based on the size parameter of a typical water droplet as compared to the incident wave length, the problem for the single scatterer equivalent to the distribution of cloud particles can be solved either by Mie or Rayleigh scattering theory. The super computing code of Wiscombe can be used immediately to produce results that can be compared to the Monte Carlo computer simulation for outside incidence. A fairly reasonable inverse approach using the solution of the outside illumination case was proposed to model analytically the situation for point sources located inside the thick optical cloud. Its mathematical details are still being investigated. When finished, it will provide scientists an enhanced capability to study more realistic clouds. For testing purposes, the direct approach to the inside illumination of clouds by lightning is under consideration. Presently, an analytical solution for the cubic cloud will soon be obtained. For cylindrical or spherical clouds, preliminary results are needed for scattering by bounded obstacles above or below a penetrable surface interface.

  9. Mixed phase clouds, cloud electrification and remote sensing.

    SciTech Connect

    Chylek, P.; Borel, C. C.; Klett, James

    2004-01-01

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

  10. Water in dense molecular clouds

    NASA Technical Reports Server (NTRS)

    Wannier, P. G.; Kuiper, T. B. H.; Frerking, M. A.; Gulkis, S.; Pickett, H. M.; Wilson, W. J.; Pagani, L.; Lecacheux, A.; Encrenaz, P.

    1991-01-01

    The G.P. Kuiper Airborne Observatory (KAO) was used to make initial observations of the half-millimeter ground-state transition of water in seven giant molecular clouds and in two late-type stars. No significant detections were made, and the resulting upper limits are significantly below those expected from other, indirect observations and from several theoretical models. The implied interstellar H2O/CO abundance is less than 0.003 in the cores of three giant molecular clouds. This value is less than expected from cloud chemistry models and also than estimates based on HDO and H3O(+) observations.

  11. Water in dense molecular clouds

    NASA Technical Reports Server (NTRS)

    Wannier, P. G.; Kuiper, T. B. H.; Frerking, M. A.; Gulkis, S.; Pickett, H. M.; Wilson, W. J.; Pagani, L.; Lecacheux, A.; Encrenaz, P.

    1991-01-01

    The G.P. Kuiper Airborne Observatory (KAO) was used to make initial observations of the half-millimeter ground-state transition of water in seven giant molecular clouds and in two late-type stars. No significant detections were made, and the resulting upper limits are significantly below those expected from other, indirect observations and from several theoretical models. The implied interstellar H2O/CO abundance is less than 0.003 in the cores of three giant molecular clouds. This value is less than expected from cloud chemistry models and also than estimates based on HDO and H3O(+) observations.

  12. Discrete cloud structure on Neptune

    NASA Technical Reports Server (NTRS)

    Hammel, H. B.

    1989-01-01

    Recent CCD imaging data for the discrete cloud structure of Neptune shows that while cloud features at CH4-band wavelengths are manifest in the southern hemisphere, they have not been encountered in the northern hemisphere since 1986. A literature search has shown the reflected CH4-band light from the planet to have come from a single discrete feature at least twice in the last 10 years. Disk-integrated photometry derived from the imaging has demonstrated that a bright cloud feature was responsible for the observed 8900 A diurnal variation in 1986 and 1987.

  13. Infrasound absorption by atmospheric clouds

    NASA Astrophysics Data System (ADS)

    Baudoin, Michael; Coulouvrat, Francois; Thomas, Jean-Louis

    2010-05-01

    A model is developed for the absorption of infrasound by atmospheric clouds made of a suspension of liquid water droplets within a gaseous mixture of water vapor and air. The model is based on the work of D.A. Gubaidullin and R.I. Nigmatulin [Int. J. Multiphase Flow, 26, 207-228, 2000], which is applied to atmospheric clouds. Three physical mechanisms are included : unsteady viscous drag associated with momentum transfers due to the translation of water droplets, unsteady thermal transfers between the liquid and gaseous phases, and mass transfers due to the evaporation or condensation of the water phase. For clouds, in the infrasonic frequency range, phase changes are the dominant mechanisms (around 1 Hz), while viscous and heat transfers become significant only around 100 Hz. Mass transfers involve two physical effects : evaporation and condensation of the water phase at the droplet surface, and diffusion of the water vapor within the gaseous phase. The first one is described through the Hertz-Knudsen-Langmuir theory based on kinetic theory. It involves a little known coefficient known as coefficient of accommodation. The second one is the classical Fick diffusion. For clouds, and unless the coefficient of accommodation is very small (far from the generally recommended value is close to one), diffusion is the main limiting effects for mass transfers. In a second stage, the sound and infrasound absorption is evaluated for various typical clouds up to about 4 km altitude. Above this altitude, the ice content of clouds is dominant compared to their water content, and the present model is not applicable. Cloud thickness, water content, and droplets size distribution are shown to be the major factors influencing the infrasound absorption. A variety of clouds have been analyzed. In most cases, it is shown that infrasound absorption within clouds is several orders larger than classical absorption (due to molecular relaxation of nitrogen and oxygen molecules in presence

  14. "Plane tracks" in cirrus clouds

    NASA Astrophysics Data System (ADS)

    Tesche, M.; Achtert, P.; Glantz, P.; Noone, K. J.

    2015-12-01

    Determining the effects of aircraft emissions on cirrus clouds already present in the atmosphere has proven to be challenging. Quantifying any such effects is necessary if we are to properly account for the influence of aviation on climate. Here we quantify the effect of aircraft on the optical thickness of already-existing cirrus clouds by matching actual aircraft flight tracks to satellite lidar measurements. We show that there are systematic, statistically significant increases in normalized cirrus cloud optical thickness inside mid-latitude flight corridors compared with adjacent areas immediately outside the corridors.

  15. Chemical evolution of dense clouds

    NASA Technical Reports Server (NTRS)

    Chapelle, E. W.; Donn, B. D.; Payne, W. A., Jr.; Stief, L. J.

    1973-01-01

    Attention is given to chemical processes which could determine the molecular composition of the cloud during the several stages of its evolution, taking into account thermal reactions at the relatively high interstellar densities expected during the processes. The origin of the observed molecules is discussed together with questions of molecular evolution during collapse of the cloud and the role of organic molecules in planetary chemical evolution. A number of experiments are also considered along with the application of the experimental results to cloud equilibrium problems.

  16. Cloud Thickness from Diffusion of Lidar Pulses in Clouds

    NASA Technical Reports Server (NTRS)

    Cahalan, Robert F.; Davis, A.; McGill, Matthew

    1999-01-01

    Measurements of the distribution of reflected light from a laser beam incident on an aqueous suspension of particles or "cloud" with known thickness and particle size distribution are reported. The distribution is referred to as the "cloud radiative Green's function", G. In the diffusion domain, G is sensitive to cloud thickness, allowing that important quantity to be retrieved. The goal of the laboratory simulation is to provide preliminary estimates of sensitivity of G to cloud thickness,for use in the optimal design of an offbeam Lidar instrument for remote sensing of cloud thickness (THOR, Thickness from Offbeam Returns). These clouds of polystyrene microspheres suspended in water are analogous to real clouds of water droplets suspended in air. The microsphere size distribution is roughly lognormal, from 0.5 microns to 25 microns, similar to real clouds. Density of suspended spheres is adjusted so mean-free-path of visible photons is about 10 cm, approximately 1000 times smaller than in real clouds. The light source is a ND:YAG laser at 530 nm. Detectors are flux and photon-counting Photomultiplier Tube (PMTS), with a glass probe for precise positioning. A Labview 5 VI controls positioning, and data acquisition, via an NI Motion Control board connected to a stepper motor driving an Edmund linear slider, and a 16-channel 16-bit NI-DAQ board. The stepper motor is accurate to 10 microns, and step size is selectable from the VI software. Far from the incident beam, the rate of exponential increase as the direction of the incident beam is approached scales as expected from diffusion theory, linearly with the cloud thickness, and inversely as the square root of the reduced optical thickness, and is independent of particle size. Near the beam the signal begins to increase faster than exponential, due to single and low-order scattering near the backward direction, and here the distribution depends on particle size. Results are being used to verify 3D Monte Carlo

  17. Ice cloud microphysical properties in tropical Pacific regions derived from CloudSat and CALIPSO measurements

    NASA Astrophysics Data System (ADS)

    Takahashi, Naoya; Hayasaka, Tadahiro; Okamoto, Hajime

    2017-02-01

    We revealed the difference in tropical ice cloud microphysical properties between the western Pacific (WP) and the eastern Pacific (EP), based on satellite retrievals. Vertical profile of effective particle radius of ice cloud (re) was estimated from active sensors on board CloudSat and CALIPSO satellites. In this study, we focused only on ice cloud which is defined as clouds with the cloud top temperature lower than 0°C. To investigate the relationship between cloud optical properties and cloud vertical structures, these ice clouds were classified into five types based on cloud optical thickness values. Compared the vertical profile of re in WP with that in the EP, re around the freezing level within convective cloud in EP slightly larger than that in WP. This analysis also shows that re of optically thick cloud is larger than that of optically thin cloud. The difference in re may be caused by differences in moisture convergence, upward motion, aerosols.

  18. Volcanic Plume from Mt. Unzen, Dust Cloud, cloud Vortices

    NASA Image and Video Library

    1991-12-01

    Stable, south flowing air over the western Pacific Ocean (26.0N, 131.0E) is disturbed by islands south of Korea, resulting in sinuous clouds known as von Karman vortices. The smoke plume from Japan's Mount Unzen Volcano on Kyushu, is visible just west of the large cloud mass and extending southward. A very large, purple tinged dust pall, originating in Mongolia, can be seen on the Earth's Limb, covering eastern China and extending into the East China Sea.

  19. Clouds and Storms on Earth and Titan

    NASA Astrophysics Data System (ADS)

    Rafkin, S. C.; Barth, E.

    2006-12-01

    Due to the dense predominately nitrogen atmosphere and the stability of all phases of methane in its atmosphere, Titan's atmosphere and methane cycle have often been cited as an analogy to the atmospheric reservoir of Earth's hydrologic cycle. In this talk, we explore the extent to which this analogy is appropriate, with a focus on comparative cloud structure and dynamics gleaned from observations and recent explicit cloud modeling studies. Furthermore, we attempt to classify the clouds that have been observed on Titan and make a clear distinction between clouds and haze. On Earth, clouds are classified according to their altitude (low, middle, high, or extensive vertical development) with further refinement based on appearance and dynamical underpinnings (stratiform or convective) or rain production (using the suffix -nimbus). Earth has clouds that populate every category. While Titan may have clouds in each cloud category, only a few cloud types have been observed. The first are the south polar clouds that have most commonly been likened to cumulonimbi (thunderstorms) on Earth. The nature and dynamics of terrestrial thunderstorms are described and compared to Titan's putative south polar storm clouds. Layered (stratiform) clouds that can be optically thin or thick and appear at a variety of altitudes have also been observed on Titan. These clouds have been likened to a variety of Earth cloud types, sometimes incorrectly. The classification of Titan's clouds is more than just an exercise in semantics; cloud types immediately convey information about the mechanism and physics of the clouds and the nature of the cloud environment, which we discuss. Distinct from clouds are hazes, which are composed of energetically metastable aerosols. While the Earth community recognizes the inherent physical differences between cloud and haze, this is not the case for Titan where the distinction is blurred. The distinction of haze from cloud is physically meaningful and provides

  20. Cloud microphysics - Analysis of the clouds of Earth, Venus, Mars, and Jupiter

    NASA Technical Reports Server (NTRS)

    Rossow, W. B.

    1978-01-01

    The probable microphysics of a cloud is deduced by a described method which requires information on cloud particle mean size, composition, number density, and atmospheric structure, but does not require any additional information. The analysis is applied to the sulfuric acid clouds of Venus, the water ice and dust clouds of Mars, and the ammonia-water and ammonia ice clouds of Jupiter. The Venus cloud layer is found to have some resemblance to smog and haze layers on earth. The water ice clouds on Mars resemble tenuous nonprecipitating cirrus clouds on earth. Precipitation, vertical distribution of gases, and vertical transport of heat in the clouds on Jupiter are considered.

  1. Implications of using transmitted vs. reflected light for determining cloud properties, cloud radiative effects and aerosol-cloud-interactions

    NASA Astrophysics Data System (ADS)

    LeBlanc, S. E.; Redemann, J.; Segal-Rosenhaimer, M.; Kacenelenbogen, M. S.; Shinozuka, Y.; Flynn, C. J.; Schmidt, S.; Pilewskie, P.; Song, S.; Woods, S.; Lawson, P.; Nenes, A.; Lin, J. J.; Ziemba, L. D.

    2015-12-01

    Light transmitted through clouds is sensitive to a different cloud volume than reflected light at cloud top. This difference in sampling volumes has implications when calculating the radiative effects of clouds (CRE) and aerosol-cloud-interactions (ACI). We present a comparison of retrieved cloud properties and the corresponding CRE and ACI based on transmitted and reflected light for a cloud sampled during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, 2013) field campaign. Measurements of zenith radiances were obtained from the NASA DC-8 aircraft using the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) instrument. 4STAR was deployed on an airborne platform during SEAC4RS alongside the Solar Spectral Flux Radiometer (SSFR). To retrieve cloud properties from transmitted shortwave radiation, we use a retrieval utilizing spectrally resolved measurements. Spectral features in shortwave radiation transmitted through clouds are sensitive to changes in cloud optical thickness, effective radius, and thermodynamic phase. The spectral features due to absorption and scattering processes by liquid water and ice cloud particles include shifts in spectral slopes, curvatures, maxima, and minima of cloud-transmitted radiance. These spectral features have been quantified by 15 parameters used to retrieve cloud properties from the 4STAR zenith radiances. Retrieved cloud optical thicknesses and effective radii based on transmitted shortwave radiation are compared to their counterparts obtained from reflected shortwave radiation measured above cloud with MODIS and with the enhanced MODIS Airborne Simulator (eMAS), the Research Scanning Polarimeter (RSP), and SSFR operating aboard the NASA ER-2 aircraft. Remotely sensed cloud particle effective radius are combined with in situ measurements of cloud and aerosol particles from the NASA Langley Aerosol Research Group Experiment (LARGE) CCN Counter

  2. When STAR meets the Clouds - Virtualization & Cloud Computing Experiences

    NASA Astrophysics Data System (ADS)

    Lauret, J.; Walker, M.; Goasguen, S.; Stout, L.; Fenn, M.; Balewski, J.; Hajdu, L.; Keahey, K.

    2011-12-01

    In recent years, Cloud computing has become a very attractive paradigm and popular model for accessing distributed resources. The Cloud has emerged as the next big trend. The burst of platform and projects providing Cloud resources and interfaces at the very same time that Grid projects are entering a production phase in their life cycle has however raised the question of the best approach to handling distributed resources. Especially, are Cloud resources scaling at the levels shown by Grids? Are they performing at the same level? What is their overhead on the IT teams and infrastructure? Rather than seeing the two as orthogonal, the STAR experiment has viewed them as complimentary and has studied merging the best of the two worlds with Grid middleware providing the aggregation of both Cloud and traditional resources. Since its first use of Cloud resources on Amazon EC2 in 2008/2009 using a Nimbus/EC2 interface, the STAR software team has tested and experimented with many novel approaches: from a traditional, native EC2 approach to the Virtual Organization Cluster (VOC) at Clemson University and Condor/VM on the GLOW resources at the University of Wisconsin. The STAR team is also planning to run as part of the DOE/Magellan project. In this paper, we will present an overview of our findings from using truly opportunistic resources and scaling-out two orders of magnitude in both tests and practical usage.

  3. Continuous growth of cloud droplets in cumulus cloud

    NASA Astrophysics Data System (ADS)

    Gotoh, Toshiyuki; Suehiro, Tamotsu; Saito, Izumi

    2016-04-01

    A new method to seamlessly simulate the continuous growth of droplets advected by turbulent flow inside a cumulus cloud was developed from first principle. A cubic box ascending with a mean updraft inside a cumulus cloud was introduced and the updraft velocity was self-consistently determined in such a way that the mean turbulent velocity within the box vanished. All the degrees of freedom of the cloud droplets and turbulence fields were numerically integrated. The box ascended quickly inside the cumulus cloud due to the updraft and the mean radius of the droplets grew from 10 to 24 μm for about 10 min. The turbulent flow tended to slow down the time evolutions of the updraft velocity, the box altitude and the mean cloud droplet radius. The size distribution of the cloud droplets in the updraft case was narrower than in the absence of the updraft. It was also found that the wavenumeber spectra of the variances of the temperature and water vapor mixing ratio were nearly constant in the low wavenumber range. The future development of the new method was argued.

  4. CALIPSO Observations of Near-Cloud Aerosol Properties as a Function of Cloud Fraction

    NASA Technical Reports Server (NTRS)

    Yang, Weidong; Marshak, Alexander; Varnai, Tamas; Wood, Robert

    2015-01-01

    This paper uses spaceborne lidar data to study how near-cloud aerosol statistics of attenuated backscatter depend on cloud fraction. The results for a large region around the Azores show that: (1) far-from-cloud aerosol statistics are dominated by samples from scenes with lower cloud fractions, while near-cloud aerosol statistics are dominated by samples from scenes with higher cloud fractions; (2) near-cloud enhancements of attenuated backscatter occur for any cloud fraction but are most pronounced for higher cloud fractions; (3) the difference in the enhancements for different cloud fractions is most significant within 5km from clouds; (4) near-cloud enhancements can be well approximated by logarithmic functions of cloud fraction and distance to clouds. These findings demonstrate that if variability in cloud fraction across the scenes used to composite aerosol statistics are not considered, a sampling artifact will affect these statistics calculated as a function of distance to clouds. For the Azores-region dataset examined here, this artifact occurs mostly within 5 km from clouds, and exaggerates the near-cloud enhancements of lidar backscatter and color ratio by about 30. This shows that for accurate characterization of the changes in aerosol properties with distance to clouds, it is important to account for the impact of changes in cloud fraction.

  5. CALIPSO observations of near-cloud aerosol properties as a function of cloud fraction

    NASA Astrophysics Data System (ADS)

    Yang, Weidong; Marshak, Alexander; Várnai, Tamás.; Wood, Robert

    2014-12-01

    This paper uses spaceborne lidar data to study how near-cloud aerosol statistics of attenuated backscatter depend on cloud fraction. The results for a large region around the Azores show that (1) far-from-cloud aerosol statistics are dominated by samples from scenes with lower cloud fractions, while near-cloud aerosol statistics are dominated by samples from scenes with higher cloud fractions; (2) near-cloud enhancements of attenuated backscatter occur for any cloud fraction but are most pronounced for higher cloud fractions; (3) the difference in the enhancements for different cloud fractions is most significant within 5 km from clouds; (4) near-cloud enhancements can be well approximated by logarithmic functions of cloud fraction and distance to clouds. These findings demonstrate that if variability in cloud fraction across the scenes used for composite aerosol statistics is not considered, a sampling artifact will affect these statistics calculated as a function of distance to clouds. For the Azores region data set examined here, this artifact occurs mostly within 5 km from clouds and exaggerates the near-cloud enhancements of lidar backscatter and color ratio by about 30%. This shows that for accurate characterization of the changes in aerosol properties with distance to clouds, it is important to account for the impact of changes in cloud fraction.

  6. Characterization of Cloud Water-Content Distribution

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon

    2010-01-01

    The development of realistic cloud parameterizations for climate models requires accurate characterizations of subgrid distributions of thermodynamic variables. To this end, a software tool was developed to characterize cloud water-content distributions in climate-model sub-grid scales. This software characterizes distributions of cloud water content with respect to cloud phase, cloud type, precipitation occurrence, and geo-location using CloudSat radar measurements. It uses a statistical method called maximum likelihood estimation to estimate the probability density function of the cloud water content.

  7. Raman lidar observations of cloud liquid water.

    PubMed

    Rizi, Vincenzo; Iarlori, Marco; Rocci, Giuseppe; Visconti, Guido

    2004-12-10

    We report the design and the performances of a Raman lidar for long-term monitoring of tropospheric aerosol backscattering and extinction coefficients, water vapor mixing ratio, and cloud liquid water. We focus on the system's capabilities of detecting Raman backscattering from cloud liquid water. After describing the system components, along with the current limitations and options for improvement, we report examples of observations in the case of low-level cumulus clouds. The measurements of the cloud liquid water content, as well as the estimations of the cloud droplet effective radii and number densities, obtained by combining the extinction coefficient and cloud water content within the clouds, are critically discussed.

  8. Research computing in a distributed cloud environment

    NASA Astrophysics Data System (ADS)

    Fransham, K.; Agarwal, A.; Armstrong, P.; Bishop, A.; Charbonneau, A.; Desmarais, R.; Hill, N.; Gable, I.; Gaudet, S.; Goliath, S.; Impey, R.; Leavett-Brown, C.; Ouellete, J.; Paterson, M.; Pritchet, C.; Penfold-Brown, D.; Podaima, W.; Schade, D.; Sobie, R. J.

    2010-11-01

    The recent increase in availability of Infrastructure-as-a-Service (IaaS) computing clouds provides a new way for researchers to run complex scientific applications. However, using cloud resources for a large number of research jobs requires significant effort and expertise. Furthermore, running jobs on many different clouds presents even more difficulty. In order to make it easy for researchers to deploy scientific applications across many cloud resources, we have developed a virtual machine resource manager (Cloud Scheduler) for distributed compute clouds. In response to a user's job submission to a batch system, the Cloud Scheduler manages the distribution and deployment of user-customized virtual machines across multiple clouds. We describe the motivation for and implementation of a distributed cloud using the Cloud Scheduler that is spread across both commercial and dedicated private sites, and present some early results of scientific data analysis using the system.

  9. Cloud computing in medical imaging.

    PubMed

    Kagadis, George C; Kloukinas, Christos; Moore, Kevin; Philbin, Jim; Papadimitroulas, Panagiotis; Alexakos, Christos; Nagy, Paul G; Visvikis, Dimitris; Hendee, William R

    2013-07-01

    Over the past century technology has played a decisive role in defining, driving, and reinventing procedures, devices, and pharmaceuticals in healthcare. Cloud computing has been introduced only recently but is already one of the major topics of discussion in research and clinical settings. The provision of extensive, easily accessible, and reconfigurable resources such as virtual systems, platforms, and applications with low service cost has caught the attention of many researchers and clinicians. Healthcare researchers are moving their efforts to the cloud, because they need adequate resources to process, store, exchange, and use large quantities of medical data. This Vision 20/20 paper addresses major questions related to the applicability of advanced cloud computing in medical imaging. The paper also considers security and ethical issues that accompany cloud computing.

  10. Clouds and radiation: A primier

    SciTech Connect

    Zachariasen, F.

    1993-02-25

    This paper addresses a previously unknown complex interdisciplinary process providing a feedback loop which may have a major impact on the effect on global climate of the steadily increasing growth of greenhouse gases in the atmosphere.... Solar radiation, Cloud condensation.

  11. Zero-gravity cloud physics.

    NASA Technical Reports Server (NTRS)

    Hollinden, A. B.; Eaton, L. R.; Vaughan, W. W.

    1972-01-01

    The first results of an ongoing preliminary-concept and detailed-feasibility study of a zero-gravity earth-orbital cloud physics research facility are reviewed. Current planning and thinking are being shaped by two major conclusions of this study: (1) there is a strong requirement for and it is feasible to achieve important and significant research in a zero-gravity cloud physics facility; and (2) some very important experiments can be accomplished with 'off-the-shelf' type hardware by astronauts who have no cloud-physics background; the most complicated experiments may require sophisticated observation and motion subsystems and the astronaut may need graduate level cloud physics training; there is a large number of experiments whose complexity varies between these two extremes.

  12. Zero-gravity cloud physics.

    NASA Technical Reports Server (NTRS)

    Hollinden, A. B.; Eaton, L. R.; Vaughan, W. W.

    1972-01-01

    The first results of an ongoing preliminary-concept and detailed-feasibility study of a zero-gravity earth-orbital cloud physics research facility are reviewed. Current planning and thinking are being shaped by two major conclusions of this study: (1) there is a strong requirement for and it is feasible to achieve important and significant research in a zero-gravity cloud physics facility; and (2) some very important experiments can be accomplished with 'off-the-shelf' type hardware by astronauts who have no cloud-physics background; the most complicated experiments may require sophisticated observation and motion subsystems and the astronaut may need graduate level cloud physics training; there is a large number of experiments whose complexity varies between these two extremes.

  13. Ultraviolet Mars Reveals Cloud Formation

    NASA Image and Video Library

    Images from MAVEN's Imaging UltraViolet Spectrograph were used to make this movie of rapid cloud formation on Mars on July 9-10, 2016. The ultraviolet colors of the planet have been rendered in fal...

  14. Unidata Cyberinfrastructure in the Cloud

    NASA Astrophysics Data System (ADS)

    Ramamurthy, M. K.; Young, J. W.

    2016-12-01

    Data services, software, and user support are critical components of geosciences cyber-infrastructure to help researchers to advance science. With the maturity of and significant advances in cloud computing, it has recently emerged as an alternative new paradigm for developing and delivering a broad array of services over the Internet. Cloud computing is now mature enough in usability in many areas of science and education, bringing the benefits of virtualized and elastic remote services to infrastructure, software, computation, and data. Cloud environments reduce the amount of time and money spent to procure, install, and maintain new hardware and software, and reduce costs through resource pooling and shared infrastructure. Given the enormous potential of cloud-based services, Unidata has been moving to augment its software, services, data delivery mechanisms to align with the cloud-computing paradigm. To realize the above vision, Unidata has worked toward: * Providing access to many types of data from a cloud (e.g., via the THREDDS Data Server, RAMADDA and EDEX servers); * Deploying data-proximate tools to easily process, analyze, and visualize those data in a cloud environment cloud for consumption by any one, by any device, from anywhere, at any time; * Developing and providing a range of pre-configured and well-integrated tools and services that can be deployed by any university in their own private or public cloud settings. Specifically, Unidata has developed Docker for "containerized applications", making them easy to deploy. Docker helps to create "disposable" installs and eliminates many configuration challenges. Containerized applications include tools for data transport, access, analysis, and visualization: THREDDS Data Server, Integrated Data Viewer, GEMPAK, Local Data Manager, RAMADDA Data Server, and Python tools; * Leveraging Jupyter as a central platform and hub with its powerful set of interlinking tools to connect interactively data servers

  15. Millimeter Wave Cloud Radar (MMCR) Handbook

    SciTech Connect

    KB Widener; K Johnson

    2005-01-30

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

  16. Clouds of high contrast on Uranus.

    PubMed

    Karkoschka, E

    1998-04-24

    Near-infrared images of Uranus taken with the Hubble Space Telescope in July and October 1997 revealed discrete clouds with contrasts exceeding 10 times the highest contrast observed before with other techniques. At visible wavelengths, these 10 clouds had lower contrasts than clouds seen by Voyager 2 in 1986. Uranus' rotational rates for southern latitudes were identical in 1986 and 1997. Clouds in northern latitudes rotate slightly more slowly than clouds in opposite southern latitudes.

  17. Cloud Security: Issues and Research Directions

    DTIC Science & Technology

    2014-11-18

    al. present two storage isolation schemes that enable cloud users with high security requirements to verify that their disk storage is isolated from...Proof of Isolation for Cloud Storage Zhan Wang, Kun Sun, Sushil Jajodia, and Jiwu Jing 6. Selective and Fine-Grained Access to Data in the Cloud ... Cloud Security: Issues and Research Directions We organized an invitational workshop at George Mason University on Cloud Security: Issues and Research

  18. Cloud Computing for DoD

    DTIC Science & Technology

    2012-05-01

    cloud computing 17 NASA Nebula Platform •  Cloud computing pilot program at NASA Ames •  Integrates open-source components into seamless, self...Mission support •  Education and public outreach (NASA Nebula , 2010) 18 NSF Supported Cloud Research •  Support for Cloud Computing in...Mell, P. & Grance, T. (2011). The NIST Definition of Cloud Computing. NIST Special Publication 800-145 •  NASA Nebula (2010). Retrieved from

  19. Physical processes in polar stratospheric ice clouds

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Ferry, G.; Turco, R. P.; Jordan, J.; Goodman, J.

    1989-01-01

    The formulation and evolution of polar stratospheric ice clouds are simulated using a one-dimensional model of cloud microphysics. It is found that the optical thickness and particle size of ice clouds depend on the cooling rate of the air in which the cloud formed. It is necessary that there be an energy barrier to ice nucleation upon the preexisting aerosols in order to account for the cooling rate dependence of the cloud properties.

  20. Cloud Radiative Forcing in the Tropics

    NASA Technical Reports Server (NTRS)

    Christopher, Sundar Anand

    1995-01-01

    Understanding the role of clouds is one of the highest priority science objectives in the global climate change program. In particular there has been a renewed interest in understanding the cloud radiative interactions in the tropical regions. Although a number of studies have emphasized the importance of cloud optical properties on the earth's radiative energy balance, information concerning cloud optical depth and particle size as a function of cloud type is lacking.

  1. Pluvial Inhibition by Urban Cloud Condensation Nuclei

    NASA Astrophysics Data System (ADS)

    Hudson, J. G.; Yum, S. S.

    2002-05-01

    Cloud microphysics and sub-cloud aerosol measurements in urban and cleaner air masses showed the effects of anthropogenic air pollution. Cloud condensation nuclei (CCN) measurements in three different parts of the world displayed typical urban/clean air mass differences in concentrations. Near-simultaneous cloud droplet measurements (diameter < 50 micrometers) showed the higher concentrations and smaller sizes expected for higher CCN concentrations. The commensurate lower concentrations of large cloud droplets (30-50 micrometers) in urban air indicated that the higher CCN concentrations were responsible for the order(s) of magnitude lower drizzle drop (diameter > 50 micrometers) concentrations in the urban-influenced clouds. The similarity of the clean and urban- influenced cloud droplet spectra near cloud base suggested no differences in giant nuclei concentrations that have been suggested to be responsible for greater precipitation in cleaner clouds. This suppression of warm rain by higher CCN concentrations occurred hundreds of km from the urban sources. Similar effects were found for three different cloud types in these three field projects: 1) stratocumulus clouds in the eastern Atlantic (ASTEX); 2) small cumulus clouds in eastern Florida (SCMS); and small trade wind cumuli in the Indian Ocean (INDOEX). Comparisons of CCN and cloud droplet concentrations in the three projects showed a more-or-less linear relationship between CCN and cloud droplet concentrations. Comparisons of CCN and cloud droplet spectra showed that supersaturations were lower in the urban-influenced clouds due to greater competition for condensed water. This means that a smaller percentage of the higher urban CCN concentrations actually produced cloud droplets. However, the supersaturation suppression was smaller because droplet sizes were so reduced that many urban cloud droplets escaped detection. This underestimation of cloud droplet concentrations suggested a greater suppression of

  2. Cloud Radiative Forcing in the Tropics

    NASA Technical Reports Server (NTRS)

    Christopher, Sundar Anand

    1995-01-01

    Understanding the role of clouds is one of the highest priority science objectives in the global climate change program. In particular there has been a renewed interest in understanding the cloud radiative interactions in the tropical regions. Although a number of studies have emphasized the importance of cloud optical properties on the earth's radiative energy balance, information concerning cloud optical depth and particle size as a function of cloud type is lacking.

  3. Titan's Mid-latitude Clouds

    NASA Astrophysics Data System (ADS)

    Roe, Henry G.; Schaller, E. L.; Trujillo, C. A.; Brown, M. E.

    2007-10-01

    In the first few years of spatially resolved observations of Titan's tropospheric methane clouds (2001-2003) all of the clouds were clustered in the south polar region. This time period coincided with the southern summer solstice (October 2002) and these south polar clouds are almost certainly a seasonal phenomenon. Starting in December 2003 we began seeing clouds in a narrow latitude range centered at 40°S latitude. In Roe et al. (2005a) we published this initial discovery and speculated that the clouds might be due either to changes in the seasonal circulation pattern or a process linked to surface geography. Further observations soon revealed that the clouds were significantly clustered over one region of longitude (near 350°W), strongly suggesting a geographically controlled origin (Roe et al. 2005b), although Cassini observations suggest a circulation-induced convergence origin (Griffith et al. 2005). The actual answer is most likely a combination of geographic surface effects with the atmospheric circulation. We report here on our continuing ground-based observation campaign, including observations on 65 nights in the 2006-2007 apparition with the Gemini 8-m telescope. With two more years of observations since the data shown in Roe et al. (2005b) we now have much firmer conclusions with respect to the spatial distribution and temporal characteristics of the mid-latitude clouds. We will present our latest understanding of Titan's mid-latitude clouds given the entire dataset now available to us. References Griffith, C.A., & 26 co-authors 2005. Science, 310, 474. Roe, H.G., A.H. Bouchez, C.A. Trujillo, E.L. Schaller, & M.E. Brown 2005a. ApJL, 618, 49. Roe, H.G., M.E. Brown, E.L. Schaller, A.H. Bouchez, & C.A. Trujillo 2005b. Science, 310, 477. This work is supported by NASA under Grant #NNX07AK74G issued through the Planetary Astronomy Program.

  4. Liquid Cloud Responses to Soot

    NASA Astrophysics Data System (ADS)

    Koch, D. M.

    2010-12-01

    Although soot absorption warms the atmosphere, soot may cause climate cooling due to its effects on liquid clouds, including contribution to cloud condensation nuclei (CCN) and semi-direct effects. Six global models that include aerosol microphysical schemes conducted three soot experiments. The average model cloud radiative response to biofuel soot (black and organic carbon), including both indirect and semi-direct effects, is -0.12 Wm-2, comparable in size but opposite in sign to the respective direct atmospheric warming. In a more idealized fossil fuel black carbon only experiment, some models calculated a positive cloud response because the soot provided a deposition sink for sulfate, decreasing formation of more viable CCN. Biofuel soot particles were typically assumed to be larger and more hygroscopic than for fossil fuel soot and therefore caused more negative forcing, as also found in previous studies. Diesel soot (black and organic carbon) experiments had relatively smaller cloud impacts with five of the models < ±0.06 Wm-2 from clouds. The net semi-direct effect alone may also be negative in global models, as found by several previous studies. The soot-cloud effects are quite uncertain. The range of model responses was large and interrannual variability for each model can also be large. Furthermore the aerosol microphysical schemes are poorly constrained, and the non-linearities resulting from the competition of opposing effects on the CCN population make it difficult to extrapolate from idealized experiments to likely impacts of realistic potential emission changes. However, results so far suggest that soot-induced cloud-cooling effects are comparable in magnitude to the direct warming effects from soot absorption.

  5. "Cloud" health-care workers.

    PubMed Central

    Sherertz, R. J.; Bassetti, S.; Bassetti-Wyss, B.

    2001-01-01

    Certain bacteria dispersed by health-care workers can cause hospital infections. Asymptomatic health-care workers colonized rectally, vaginally, or on the skin with group A streptococci have caused outbreaks of surgical site infection by airborne dispersal. Outbreaks have been associated with skin colonization or viral upper respiratory tract infection in a phenomenon of airborne dispersal of Staphylococcus aureus called the "cloud" phenomenon. This review summarizes the data supporting the existence of cloud health-care workers. PMID:11294715

  6. Neptune Clouds Showing Vertical Relief

    NASA Image and Video Library

    1996-01-29

    NASA's Voyager 2 high resolution color image, taken 2 hours before closest approach, provides obvious evidence of vertical relief in Neptune's bright cloud streaks. These clouds were observed at a latitude of 29 degrees north near Neptune's east terminator. The linear cloud forms are stretched approximately along lines of constant latitude and the sun is toward the lower left. The bright sides of the clouds which face the sun are brighter than the surrounding cloud deck because they are more directly exposed to the sun. Shadows can be seen on the side opposite the sun. These shadows are less distinct at short wavelengths (violet filter) and more distinct at long wavelengths (orange filter). This can be understood if the underlying cloud deck on which the shadow is cast is at a relatively great depth, in which case scattering by molecules in the overlying atmosphere will diffuse light into the shadow. Because molecules scatter blue light much more efficiently than red light, the shadows will be darkest at the longest (reddest) wavelengths, and will appear blue under white light illumination. The resolution of this image is 11 kilometers (6.8 miles per pixel) and the range is only 157,000 kilometers (98,000 miles). The width of the cloud streaks range from 50 to 200 kilometers (31 to 124 miles), and their shadow widths range from 30 to 50 kilometers (18 to 31 miles). Cloud heights appear to be of the order of 50 kilometers (31 miles). This corresponds to 2 scale heights. http://photojournal.jpl.nasa.gov/catalog/PIA00058

  7. Cloud Top Scanning radiometer (CTS)

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A scanning radiometer to be used for measuring cloud radiances in each of three spectral regions is described. Significant features incorporated in the Cloud Top Scanner design are: (1) flexibility and growth potential through use of easily replaceable modular detectors and filters; (2) full aperture, multilevel inflight calibration; (3) inherent channel registration through employment of a single shared field stop; and (4) radiometric sensitivity margin in a compact optical design through use of Honeywell developed (Hg,Cd)Te detectors and preamplifiers.

  8. The effects of cloud inhomogeneities upon radiative fluxes, and the supply of a cloud truth validation dataset

    NASA Technical Reports Server (NTRS)

    Welch, Ronald M.

    1993-01-01

    A series of cloud and sea ice retrieval algorithms are being developed in support of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Science Team objectives. These retrievals include the following: cloud fractional area, cloud optical thickness, cloud phase (water or ice), cloud particle effective radius, cloud top heights, cloud base height, cloud top temperature, cloud emissivity, cloud 3-D structure, cloud field scales of organization, sea ice fractional area, sea ice temperature, sea ice albedo, and sea surface temperature. Due to the problems of accurately retrieving cloud properties over bright surfaces, an advanced cloud classification method was developed which is based upon spectral and textural features and artificial intelligence classifiers.

  9. Cloud streets in Davis Strait

    NASA Image and Video Library

    2017-09-27

    The late winter sun shone brightly on a stunning scene of clouds and ice in the Davis Strait in late February, 2013. The Moderate Resolution Imaging Spectroradiometer aboard NASA’s Aqua satellite captured this true-color image on February 22 at 1625 UTC. The Davis Strait connects the Labrador Sea (part of the Atlantic Ocean) in the south with Baffin Bay to the north, and separates Canada, to the west, from Greenland to the east. Strong, steady winds frequently blow southward from the colder Baffin Bay to the warmer waters of the Labrador Sea. Over ice, the air is dry and no clouds form. However, as the Arctic air moves over the warmer, open water the rising moist air and the temperature differential gives rise to lines of clouds. In this image, the clouds are aligned in a beautiful, parallel pattern. Known as “cloud streets”, this pattern is formed in a low-level wind, with the clouds aligning in the direction of the wind. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  10. Cloud computing for comparative genomics.

    PubMed

    Wall, Dennis P; Kudtarkar, Parul; Fusaro, Vincent A; Pivovarov, Rimma; Patil, Prasad; Tonellato, Peter J

    2010-05-18

    Large comparative genomics studies and tools are becoming increasingly more compute-expensive as the number of available genome sequences continues to rise. The capacity and cost of local computing infrastructures are likely to become prohibitive with the increase, especially as the breadth of questions continues to rise. Alternative computing architectures, in particular cloud computing environments, may help alleviate this increasing pressure and enable fast, large-scale, and cost-effective comparative genomics strategies going forward. To test this, we redesigned a typical comparative genomics algorithm, the reciprocal smallest distance algorithm (RSD), to run within Amazon's Elastic Computing Cloud (EC2). We then employed the RSD-cloud for ortholog calculations across a wide selection of fully sequenced genomes. We ran more than 300,000 RSD-cloud processes within the EC2. These jobs were farmed simultaneously to 100 high capacity compute nodes using the Amazon Web Service Elastic Map Reduce and included a wide mix of large and small genomes. The total computation time took just under 70 hours and cost a total of $6,302 USD. The effort to transform existing comparative genomics algorithms from local compute infrastructures is not trivial. However, the speed and flexibility of cloud computing environments provides a substantial boost with manageable cost. The procedure designed to transform the RSD algorithm into a cloud-ready application is readily adaptable to similar comparative genomics problems.

  11. Cloud computing for comparative genomics

    PubMed Central

    2010-01-01

    Background Large comparative genomics studies and tools are becoming increasingly more compute-expensive as the number of available genome sequences continues to rise. The capacity and cost of local computing infrastructures are likely to become prohibitive with the increase, especially as the breadth of questions continues to rise. Alternative computing architectures, in particular cloud computing environments, may help alleviate this increasing pressure and enable fast, large-scale, and cost-effective comparative genomics strategies going forward. To test this, we redesigned a typical comparative genomics algorithm, the reciprocal smallest distance algorithm (RSD), to run within Amazon's Elastic Computing Cloud (EC2). We then employed the RSD-cloud for ortholog calculations across a wide selection of fully sequenced genomes. Results We ran more than 300,000 RSD-cloud processes within the EC2. These jobs were farmed simultaneously to 100 high capacity compute nodes using the Amazon Web Service Elastic Map Reduce and included a wide mix of large and small genomes. The total computation time took just under 70 hours and cost a total of $6,302 USD. Conclusions The effort to transform existing comparative genomics algorithms from local compute infrastructures is not trivial. However, the speed and flexibility of cloud computing environments provides a substantial boost with manageable cost. The procedure designed to transform the RSD algorithm into a cloud-ready application is readily adaptable to similar comparative genomics problems. PMID:20482786

  12. Investigation of arc cloud lines

    NASA Technical Reports Server (NTRS)

    Purdom, J. F. W.; Sinclair, P. C.

    1984-01-01

    The natural mechanisms that lead to the development of deep convective storms through the integration of radio scan satellite data with research aircraft observations is discussed. The aircraft measurements are designed to provide detailed air motion and thermodynamic data near and in the arc cloud line region at the same time GOES rapid scan data is taken. Inspection of the data indicates: (1) Arc cloud lines are important in both the production of convergence and vorticity, and in the interaction with intense thunderstorms which may act to trigger tornado activity. (2) The lateral extent of the vertical motion field compared to the cloud scale indicates that the main driving force for the initial cloud development along the arc-line is controlled by the thunderstorm outflow(s) interacting with the convectively unstable air of the environment. (3) Arc cloud lines and their associated DSL region can pose extreme hazards to aircraft operations. (4) An arc cloud line's major threat to space shuttle operations lie in its ability to generate new thunderstorm activity along the shuttle glide path.

  13. VIIRS Cloud Mask Validation Exercises

    NASA Astrophysics Data System (ADS)

    Frey, R.; Heidinger, A. K.; Hutchison, K.; Dutcher, S.

    2011-12-01

    The NPP Satellite is scheduled for launch October 25, 2011. Included on the platform is the VIIRS (Visible/Infrared Imager/Suite) instrument which features 16 bands at about 0.75 m spatial resolution and 5 imager bands at roughly 0.375 m resolution. The basic VIIRS cloud mask (VCM) output is a flag that indicates one of four possible cloudy vs. clear conditions for each 0.75 m pixel: confident clear, probably clear, probably cloudy, and confident cloudy. Pre-launch assessment of the VCM algorithm has been performed with use of MODIS observations as proxy input. Several comparisons are shown between VCM results and cloud detection from other instruments and/or algorithms: MODIS cloud mask (MOD35) at the five-minute granule level (L2), global and regional monthly average cloud amounts from MODIS (MOD35) and MODIS-CERES, ISCCP, PATMOS-x (AVHRR), and CALIOP (lidar). In addition to overall results, collocated MODIS observations, CALIOP and VCM cloud determinations are used to evaluate VCM cloud test thresholds and other tunable parameters. The methods shown will be among those used during the Intensive Calibration and Validation period and beyond.

  14. Diurnal Variations of Clouds in Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Wu, Qiaoyan; Ruan, Zhenxin

    2016-04-01

    Using 14 years (2000-2013) of pixel-resolution infrared (IR) brightness temperature data and best track data, this study estimates the diurnal variations of convective systems in tropical cyclones (TCs) in the western North Pacific. The very cold cloud cover (IR brightness temperatures < 208 K) of TCs reaches a maximum areal extent in the early morning (0000-0300 LST) and then decreases after the sunrise. The decrease of very cold cloud cover is followed by an increase of cloud cover between 208 K and 240 K with a maximum areal extent in the afternoon (1500-1800 LST). TC IR cloud top temperatures < 240 K have minimum values in the morning (0300-0600 LST) , while TC IR cloud top temperatures > 240 K have mean minimum values in the afternoon (1500-1800 LST). The out-of-phase relation between different cloud conditions with IR cloud top temperatures < 240 K and IR cloud top temperatures > 240 K lead to radius-averaged IR temperature show two minima within a day. Different diurnal evolution under different cloud conditions suggests that TC convective systems are better described in terms of both areal extent and cloud-top temperature. The maximum cloud cover with IR cloud top temperatures colder than 208 K in the morning and the maximum cloud cover with IR cloud top temperatures between 208 K and 240 K in the afternoon suggest that two different mechanisms might be involved with the diurnal variations of these two types of TC cloud conditions.

  15. Contrasting Cloud Composition Between Coupled and Decoupled Marine Boundary Layer Clouds

    NASA Astrophysics Data System (ADS)

    WANG, Z.; Mora, M.; Dadashazar, H.; MacDonald, A.; Crosbie, E.; Bates, K. H.; Coggon, M. M.; Craven, J. S.; Xian, P.; Campbell, J. R.; AzadiAghdam, M.; Woods, R. K.; Jonsson, H.; Flagan, R. C.; Seinfeld, J.; Sorooshian, A.

    2016-12-01

    Marine stratocumulus clouds often become decoupled from the vertical layer immediately above the ocean surface. This study contrasts cloud chemical composition between coupled and decoupled marine stratocumulus clouds. Cloud water and droplet residual particle composition were measured in clouds off the California coast during three airborne experiments in July-August of separate years (E-PEACE 2011, NiCE 2013, BOAS 2015). Decoupled clouds exhibited significantly lower overall mass concentrations in both cloud water and droplet residual particles, consistent with reduced cloud droplet number concentration and sub-cloud aerosol (Dp > 100 nm) number concentration, owing to detachment from surface sources. Non-refractory sub-micrometer aerosol measurements show that coupled clouds exhibit higher sulfate mass fractions in droplet residual particles, owing to more abundant precursor emissions from the ocean and ships. Consequently, decoupled clouds exhibited higher mass fractions of organics, nitrate, and ammonium in droplet residual particles, owing to effects of long-range transport from more distant sources. Total cloud water mass concentration in coupled clouds was dominated by sodium and chloride, and their mass fractions and concentrations exceeded those in decoupled clouds. Conversely, with the exception of sea salt constituents (e.g., Cl, Na, Mg, K), cloud water mass fractions of all species examined were higher in decoupled clouds relative to coupled clouds. These results suggest that an important variable is the extent to which clouds are coupled to the surface layer when interpreting microphysical data relevant to clouds and aerosol particles.

  16. Evolution of molecular clouds

    NASA Technical Reports Server (NTRS)

    Sevenster, M.

    1993-01-01

    The evolution of interstellar molecular hydrogen was studied, with a special interest for the formation and evolution of molecular clouds and star formation within them, by a two-dimensional hydrodynamical simulation performed on a rectangular grid of physical sizes on the order of 100 pc. It is filled with an initial density of approx. 1 cm(exp -3), except for one cell (approx. 1 pc(exp 2)) at the center of the grid where an accretion core of 1-10(exp 3) solar masses is placed. The grid is co-moving with the gridcenter that is on a circular orbit around the Galactic center and that also is the guiding center of epicyclic approximation of orbits of the matter surrounding it. The initial radial velocity is zero; to account for differential rotation the initial tangential velocity (i.e. the movement around the galactic center) is proportional to the radial distance to the grid center. The rate is comparable to the rotation rate at the Local Standard of Rest. The influence of galactic rotation is noticed by spiral or elliptical forms, but on much longer time scales than self gravitation and cooling processes. Density and temperature are kept constant at the boundaries and no inflow is allowed along the tangential boundaries.

  17. Use of cloud observations and mesoscale meteorology models to evaluate and improve cloud parameterizations

    SciTech Connect

    Walcek, C.J.

    1992-10-30

    This research program utilizes satellite and surface-derived cloud observations together with standard meteorological measurements to evaluate and improve our ability to accurately diagnose cloud coverage. Results are to be used to compliment existing or future parameterizations of cloud effects in general circulation models, since nearly all cloud parameterizations must specify a fractional area of cloud coverage when calculating radiative or dynamic cloud effects, and current parameterizations rely on rather crude cloud cover estimates. We have compiled and reviewed a list of formulations used by various climate research groups to specify cloud cover. We find considerable variability between formulations used by various climate and meteorology models, and under some conditions, one formulation will produce a zero cloud amount, while an alternate formulation calculates 95% cloud cover under the same environmental conditions. All formulations hypothesize that cloud cover is predominantly determined by the average relative humidity, although some formulations allow local temperature lapse rates and vertical velocities to influence cloud amount.

  18. Development status of the cloud profiling radar for the CloudSat mission

    NASA Technical Reports Server (NTRS)

    Im, E.; Durden, S. L.; Wu, C.

    2003-01-01

    The Cloud Profiling Radar, the primary science instrument of the CloudSat Mission, is a 94-GHz nadir-looking radar that measures the power backscattered by clouds as a function of distance from the radar.

  19. Cloud-cloud collision in the Galactic center 50 km s-1 molecular cloud

    NASA Astrophysics Data System (ADS)

    Tsuboi, Masato; Miyazaki, Atsushi; Uehara, Kenta

    2015-12-01

    We performed a search of star-forming sites influenced by external factors, such as SNRs, H II regions, and cloud-cloud collisions (CCCs), to understand the star-forming activity in the Galactic center region using the NRO Galactic Center Survey in SiO v = 0, J = 2-1, H13CO+J = 1-0, and CS J = 1-0 emission lines obtained with the Nobeyama 45 m telescope. We found a half-shell-like feature (HSF) with a high integrated line intensity ratio of ∫TB(SiO v = 0, J = 2-1)dv/∫TB(H13CO+J = 1-0)dv ˜ 6-8 in the 50 km s-1 molecular cloud; the HSF is a most conspicuous molecular cloud in the region and harbors an active star-forming site where several compact H II regions can be seen. The high ratio in the HSF indicates that the cloud contains huge shocked molecular gas. The HSF can be also seen as a half-shell feature in the position-velocity diagram. A hypothesis explaining the chemical and kinetic properties of the HSF is that the feature originates from a CCC. We analyzed the CS J = 1-0 emission line data obtained with the Nobeyama Millimeter Array to reveal the relation between the HSF and the molecular cloud cores in the cloud. We made a cumulative core mass function (CMF) of the molecular cloud cores within the HSF. The CMF in the CCC region is not truncated at least up to ˜2500 M⊙, although the CMF of the non-CCC region reaches the upper limit of ˜1500 M⊙. Most massive molecular cores with Mgas > 750 M⊙ are located only around the ridge of the HSF and adjoin the compact H II region. These may be a sign of massive star formation induced by CCCs in the Galactic center region.

  20. Jupiter's Multi-level Clouds

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Clouds and hazes at various altitudes within the dynamic Jovian atmosphere are revealed by multi-color imaging taken by the Near-Infrared Mapping Spectrometer (NIMS) onboard the Galileo spacecraft. These images were taken during the second orbit (G2) on September 5, 1996 from an early-morning vantage point 2.1 million kilometers (1.3 million miles) above Jupiter. They show the planet's appearance as viewed at various near-infrared wavelengths, with distinct differences due primarily to variations in the altitudes and opacities of the cloud systems. The top left and right images, taken at 1.61 microns and 2.73 microns respectively, show relatively clear views of the deep atmosphere, with clouds down to a level about three times the atmospheric pressure at the Earth's surface.

    By contrast, the middle image in top row, taken at 2.17 microns, shows only the highest altitude clouds and hazes. This wavelength is severely affected by the absorption of light by hydrogen gas, the main constituent of Jupiter's atmosphere. Therefore, only the Great Red Spot, the highest equatorial clouds, a small feature at mid-northern latitudes, and thin, high photochemical polar hazes can be seen. In the lower left image, at 3.01 microns, deeper clouds can be seen dimly against gaseous ammonia and methane absorption. In the lower middle image, at 4.99 microns, the light observed is the planet's own indigenous heat from the deep, warm atmosphere.

    The false color image (lower right) succinctly shows various cloud and haze levels seen in the Jovian atmosphere. This image indicates the temperature and altitude at which the light being observed is produced. Thermally-rich red areas denote high temperatures from photons in the deep atmosphere leaking through minimal cloud cover; green denotes cool temperatures of the tropospheric clouds; blue denotes cold of the upper troposphere and lower stratosphere. The polar regions appear purplish, because small-particle hazes allow leakage and

  1. The Community Cloud Atlas - Building an Informed Cloud Watching Community

    NASA Astrophysics Data System (ADS)

    Guy, N.; Rowe, A.

    2014-12-01

    The sky is dynamic, from long lasting cloud systems to ethereal, fleeting formations. After years of observing the sky and growing our personal collections of cloud photos, we decided to take to social media to share pictures, as well as build and educate a community of cloud enthusiasts. We began a Facebook page, the Community Cloud Atlas, described as "...the place to show off your pictures of the sky, identify clouds, and to discuss how specific cloud types form and what they can tell you about current and future weather." Our main goal has been to encourage others to share their pictures, while we describe the scenes from a meteorological perspective and reach out to the general public to facilitate a deeper understanding of the sky. Nearly 16 months later, we have over 1400 "likes," spanning 45 countries with ages ranging from 13 to over 65. We have a consistent stream of submissions; so many that we decided to start a corresponding blog to better organize the photos, provide more detailed explanations, and reach a bigger audience. Feedback from users has been positive in support of not only sharing cloud pictures, but also to "learn the science as well as admiring" the clouds. As one community member stated, "This is not 'just' a place to share some lovely pictures." We have attempted to blend our social media presence with providing an educational resource, and we are encouraged by the response we have received. Our Atlas has been informally implemented into classrooms, ranging from a 6th grade science class to Meteorology courses at universities. NOVA's recent Cloud Lab also made use of our Atlas as a supply of categorized pictures. Our ongoing goal is to not only continue to increase understanding and appreciation of the sky among the public, but to provide an increasingly useful tool for educators. We continue to explore different social media options to interact with the public and provide easier content submission, as well as software options for

  2. Transport of infrared radiation in cuboidal clouds

    NASA Technical Reports Server (NTRS)

    HARSHVARDHAN; Weinman, J. A.; Davies, R.

    1981-01-01

    The transport of infrared radiation in a single cuboidal cloud using a vertical two steam approximation was modeled. The emittance of the top face of the model cloud is always less than that for a plane parallel cloud of the same optical depth. The hemisphere flux escaping from the cloud top has a gradient from the center to the edges which brighten when the cloud is over warmer ground. Cooling rate calculations in the 8 to 13.6 micrometer region show that there is cooling from the sides of the cloud at all levels even when there is heating of the core from the ground below. The radiances exiting from model cuboidal clouds were computed by path integration over the source function obtained with the two stream approximation. It is suggested that the brightness temperature measured from finite clouds will overestimate the cloud top temperature.

  3. A parameterization of cloud droplet nucleation

    SciTech Connect

    Ghan, S.J. ); Chuang, C.; Penner, J.E. )

    1993-01-01

    Droplet nucleation is a fundamental cloud process. The number of aerosols activated to form cloud droplets influences not only the number of aerosols scavenged by clouds but also the size of the cloud droplets. Cloud droplet size influences the cloud albedo and the conversion of cloud water to precipitation. Global aerosol models are presently being developed with the intention of coupling with global atmospheric circulation models to evaluate the influence of aerosols and aerosol-cloud interactions on climate. If these and other coupled models are to address issues of aerosol-cloud interactions, the droplet nucleation process must be adequately represented. Here we introduce a droplet nucleation parametrization that offers certain advantages over the popular Twomey (1959) parameterization.

  4. The clouds are hazes of Venus

    NASA Technical Reports Server (NTRS)

    Esposito, L. W.; Knollenberg, R. G.; Marov, M. IA.; Toon, O. B.; Turco, R. P.

    1983-01-01

    Pioneer Venus and Venera probe data for the clouds of Venus are considered. These clouds consist of a main cloud deck at 45-70 km altitude, with thinner hazes above and below, although the microphysical properties of the main cloud are further subdivided into upper, middle and lower cloud levels. Much of the cloud exhibits a multimodal particle size distribution, with the mode most visible from the earth being H2SO4 droplets having 2-3 micron diameters. Despite variations, the vertical structure of the clouds indicates persistent features at sites separated by years and by great distances. The clouds are more strongly affected by radiation than by latent heat release, and the small particle size and weak convective activity observed are incompatible with lightning of cloud origin.

  5. Automated Detection of Clouds in Satellite Imagery

    NASA Technical Reports Server (NTRS)

    Jedlovec, Gary

    2010-01-01

    Many different approaches have been used to automatically detect clouds in satellite imagery. Most approaches are deterministic and provide a binary cloud - no cloud product used in a variety of applications. Some of these applications require the identification of cloudy pixels for cloud parameter retrieval, while others require only an ability to mask out clouds for the retrieval of surface or atmospheric parameters in the absence of clouds. A few approaches estimate a probability of the presence of a cloud at each point in an image. These probabilities allow a user to select cloud information based on the tolerance of the application to uncertainty in the estimate. Many automated cloud detection techniques develop sophisticated tests using a combination of visible and infrared channels to determine the presence of clouds in both day and night imagery. Visible channels are quite effective in detecting clouds during the day, as long as test thresholds properly account for variations in surface features and atmospheric scattering. Cloud detection at night is more challenging, since only courser resolution infrared measurements are available. A few schemes use just two infrared channels for day and night cloud detection. The most influential factor in the success of a particular technique is the determination of the thresholds for each cloud test. The techniques which perform the best usually have thresholds that are varied based on the geographic region, time of year, time of day and solar angle.

  6. Fast Simulators for Satellite Cloud Optical Centroid Pressure Retrievals, 1. Evaluation of OMI Cloud Retrievals

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Vasilkov, A.; Gupta, P.; Bhartia, P. K.; Veefkind, P.; Sneep, M.; de Haan, J.; Polonsky, I.; Spurr, R.

    2012-01-01

    The cloud Optical Centroid Pressure (OCP), also known as the effective cloud pressure, is a satellite-derived parameter that is commonly used in trace-gas retrievals to account for the effects of clouds on near-infrared through ultraviolet radiance measurements. Fast simulators are desirable to further expand the use of cloud OCP retrievals into the operational and climate communities for applications such as data assimilation and evaluation of cloud vertical structure in general circulation models. In this paper, we develop and validate fast simulators that provide estimates of the cloud OCP given a vertical profile of optical extinction. We use a pressure-weighting scheme where the weights depend upon optical parameters of clouds and/or aerosol. A cloud weighting function is easily extracted using this formulation. We then use fast simulators to compare two different satellite cloud OCP retrievals from the Ozone Monitoring Instrument (OMI) with estimates based on collocated cloud extinction profiles from a combination of CloudS at radar and MODIS visible radiance data. These comparisons are made over a wide range of conditions to provide a comprehensive validation of the OMI cloud OCP retrievals. We find generally good agreement between OMI cloud OCPs and those predicted by CloudSat. However, the OMI cloud OCPs from the two independent algorithms agree better with each other than either does with the estimates from CloudSat/MODIS. Differences between OMI cloud OCPs and those based on CloudSat/MODIS may result from undetected snow/ice at the surface, cloud 3-D effects, low altitude clouds missed by CloudSat, and the fact that CloudSat only observes a relatively small fraction of an OMI field-of-view.

  7. Generalized scale invariance, clouds and radiative transfer on multifractal clouds

    SciTech Connect

    Lovejoy, S.; Schertzer, D.

    1995-09-01

    Recent systematic satellite studies (LANDSAT, AVHRR, METEOSAT) of cloud radiances using (isotropic) energy spectra have displayed excellent scaling from at least about 300m to about 4000km, even for individual cloud pictures. At first sight, this contradicts the observed diversity of cloud morphology, texture and type. The authors argue that the explanation of this apparent paradox is that the differences are due to anisotropy, e.g. differential stratification and rotation. A general framework for anisotropic scaling expressed in terms of isotropic self-similar scaling and fractals and multifractals is needed. Schertzer and Lovejoy have proposed Generalized Scale Invariance (GSI) in response to this need. In GSI, the statistics of the large and small scales of system can be related to each other by a scale changing operator T{sub {lambda}} which depends only on the scale ratio {lambda}{sub i} there is no characteristic size. 3 refs., 1 fig.

  8. Documenting the distribution of cloud layers within ISCCP-defined cloud types using CloudSat and CALIPSO data

    NASA Astrophysics Data System (ADS)

    Wrenn, F. J.; Mace, G. G.

    2011-12-01

    The multi-decadal and global ISCCP dataset has proven invaluable to the modeling community. ISCCP provides information only on the effective radiative top of cloud layers in a vertical column and the column-integrated optical depth. The effective radiative cloud top has been used to characterize cloudy pixels in terms of certain morphological types even though this is known to be wrong. In the presence of multiple clouds layers, such as cirrus boundary layer clouds, the effective radiative cloud top may have little to do with what is actually present. This ambiguity in the presence of multiple cloud layers leads to possible misinterpretations of ISCCP statistics when cast into the traditional cloud top pressure-optical depth classifications. CloudSat and CALIPSO provide detailed information regarding the vertical structure of clouds layers but on a much coarser temporal and spatial grid. Therefore, we use the detailed information from CloudSat and CALIPSO to document the actual distribution of cloud layers within the ISCCP cloud classifications. Cloud properties provided from CloudSat and CALIPSO combined with atmospheric state data from ECMWF and column optical depth from MODIS are input into an ISCCP simulator code to provide ISCCP-like cloud top pressures and the active remote sensing data are used to explore the vertical structure of cloud and precipitation layers within the standard nine ISCCP cloud top pressure-optical depth classifications. We will show that ISCCP-defined "types" defy a simple interpretation and are often ambiguous within a region and entirely non-unique between regions calling into question recent results that attempt to use ISCCP global statistics to evaluate model results.

  9. Clustering, randomness, and regularity in cloud fields: 2. Cumulus cloud fields

    NASA Astrophysics Data System (ADS)

    Zhu, T.; Lee, J.; Weger, R. C.; Welch, R. M.

    1992-12-01

    During the last decade a major controversy has been brewing concerning the proper characterization of cumulus convection. The prevailing view has been that cumulus clouds form in clusters, in which cloud spacing is closer than that found for the overall cloud field and which maintains its identity over many cloud lifetimes. This "mutual protection hypothesis" of Randall and Huffman (1980) has been challenged by the "inhibition hypothesis" of Ramirez et al. (1990) which strongly suggests that the spatial distribution of cumuli must tend toward a regular distribution. A dilemma has resulted because observations have been reported to support both hypotheses. The present work reports a detailed analysis of cumulus cloud field spatial distributions based upon Landsat, Advanced Very High Resolution Radiometer, and Skylab data. Both nearest-neighbor and point-to-cloud cumulative distribution function statistics are investigated. The results show unequivocally that when both large and small clouds are included in the cloud field distribution, the cloud field always has a strong clustering signal. The strength of clustering is largest at cloud diameters of about 200-300 m, diminishing with increasing cloud diameter. In many cases, clusters of small clouds are found which are not closely associated with large clouds. As the small clouds are eliminated from consideration, the cloud field typically tends towards regularity. Thus it would appear that the "inhibition hypothesis" of Ramirez and Bras (1990) has been verified for the large clouds. However, these results are based upon the analysis of point processes. A more exact analysis also is made which takes into account the cloud size distributions. Since distinct clouds are by definition nonoverlapping, cloud size effects place a restriction upon the possible locations of clouds in the cloud field. The net effect of this analysis is that the large clouds appear to be randomly distributed, with only weak tendencies towards

  10. Cirrus Cloud Modeling: Overview and Issues

    NASA Technical Reports Server (NTRS)

    Starr, David OC.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    A review of cirrus cloud modeling will be given with special attention to the role of dynamical processes in regulating cloud microphysical properties and the interactions with radiative process in determining cloud lifecycle. The talk will draw heavily on the papers by Starr and Quante, Quante and Starr and Demoz et al., as well as recent results from the GEWEX Cloud System Study (GCSS) Working Group on Cirrus Cloud Systems (WG2) Idealized Cirrus Model Comparison and Cirrus Parcel Model Comparison projects, as described in Starr et al. and Lin et al. Key issues in current cirrus cloud modeling will be described and discussed.

  11. Cloud observations with Nimbus-7 satellite data

    NASA Technical Reports Server (NTRS)

    Stowe, L. L.; Hwang, P. H.; Bhartia, P. K.; Eck, T. F.

    1983-01-01

    A Nimbus-7 Cloud Data Processing Team was established in 1982 in order to implement cloud-related studies for as long as the spacecraft's Temperature Humidity IR radiometer and Total Ozone Mapping Spectrometer continue to operate. It will soon be possible to correlate the Nimbus-7 cloud cover information with International Satellite Cloud Climatology results. The production of validated Nimbus-7 cloud products was scheduled to begin in November, 1983; each year of Nimbus-7 cloud data should take about four months to produce.

  12. Experiment S007: Cloud top spectrometry

    NASA Technical Reports Server (NTRS)

    Saiedy, F.; Wark, D. Q.; Morgan, W. A.

    1971-01-01

    During the Gemini 5 mission, 26 spectrographic observations on various cloud types were obtained using the oxygen A band (7600 A). An example of the types of spectrum and photograph involved represents a cloud in the intertropical convergence zone. Densitometer traces of the spectra of three types of clouds (high, medium, and low) are shown. It was apparent qualitatively that radiation transmission in the oxygen band for a high cloud was much greater than that for a low cloud. The results proved the feasibility of cloud altitude measurements from a spacecraft by this method.

  13. Grain Growth in Collapsing Clouds

    NASA Astrophysics Data System (ADS)

    Rossi, S. C. F.; Benevides-Soares, P.; Barbuy, B.

    1990-11-01

    RESUMEN. Se ha considerado un proceso de coagulaci6n de granos en nubes colapsantes de diferentes metalicidades. Se aplicaron los calculos al intervalo de densidades n = lO to , forrespondiendo a la fase isotermica de contracci6n de nubes. A lo largo de esta fase en el colap- so, la temperatura es por lo tanto constante, en donde se alcanza T Q lOKpara nubes de metalicidad solar y T 100 K para nubes de baja metalicidad. El tamano final del grano es mayor para las mayores metali- cidades. ABSTRACT. A process of grain coagulation in collapsing clouds of different metallicities is considered. The calculations are applied to the density range n = 1O to , corresponding to the isothermal phase of cloud contraction. Along this phase in the collapse, the temperature is thus a constant, where T % 10 K for solar-metallicity clouds, and T % 100 K for low metallicity clouds is reached. The final grain size is larger for the higher metallicities. Keq : INTERSTELLAR-CLOUDS - INTERSTELLAR-CRAINS

  14. Advances in the TRIDEC Cloud

    NASA Astrophysics Data System (ADS)

    Hammitzsch, Martin; Spazier, Johannes; Reißland, Sven

    2016-04-01

    The TRIDEC Cloud is a platform that merges several complementary cloud-based services for instant tsunami propagation calculations and automated background computation with graphics processing units (GPU), for web-mapping of hazard specific geospatial data, and for serving relevant functionality to handle, share, and communicate threat specific information in a collaborative and distributed environment. The platform offers a modern web-based graphical user interface so that operators in warning centres and stakeholders of other involved parties (e.g. CPAs, ministries) just need a standard web browser to access a full-fledged early warning and information system with unique interactive features such as Cloud Messages and Shared Maps. Furthermore, the TRIDEC Cloud can be accessed in different modes, e.g. the monitoring mode, which provides important functionality required to act in a real event, and the exercise-and-training mode, which enables training and exercises with virtual scenarios re-played by a scenario player. The software system architecture and open interfaces facilitate global coverage so that the system is applicable for any region in the world and allow the integration of different sensor systems as well as the integration of other hazard types and use cases different to tsunami early warning. Current advances of the TRIDEC Cloud platform will be summarized in this presentation.

  15. Ammonia Ice Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The top cloud layer on Jupiter is thought to consist of ammonia ice, but most of that ammonia 'hides' from spectrometers. It does not absorb light in the same way ammonia does. To many scientists, this implies that ammonia churned up from lower layers of the atmosphere 'ages' in some way after it condenses, possibly by being covered with a photochemically generated hydrocarbon mixture. The New Horizons Linear Etalon Imaging Spectral Array (LEISA), the half of the Ralph instrument that is able to 'see' in infrared wavelengths that are absorbed by ammonia ice, spotted these clouds and watched them evolve over five Jupiter days (about 40 Earth hours). In these images, spectroscopically identified fresh ammonia clouds are shown in bright blue. The largest cloud appeared as a localized source on day 1, intensified and broadened on day 2, became more diffuse on days 3 and 4, and disappeared on day 5. The diffusion seemed to follow the movement of a dark spot along the boundary of the oval region. Because the source of this ammonia lies deeper than the cloud, images like these can tell scientists much about the dynamics and heat conduction in Jupiter's lower atmosphere.

  16. Ammonia Ice Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The top cloud layer on Jupiter is thought to consist of ammonia ice, but most of that ammonia 'hides' from spectrometers. It does not absorb light in the same way ammonia does. To many scientists, this implies that ammonia churned up from lower layers of the atmosphere 'ages' in some way after it condenses, possibly by being covered with a photochemically generated hydrocarbon mixture. The New Horizons Linear Etalon Imaging Spectral Array (LEISA), the half of the Ralph instrument that is able to 'see' in infrared wavelengths that are absorbed by ammonia ice, spotted these clouds and watched them evolve over five Jupiter days (about 40 Earth hours). In these images, spectroscopically identified fresh ammonia clouds are shown in bright blue. The largest cloud appeared as a localized source on day 1, intensified and broadened on day 2, became more diffuse on days 3 and 4, and disappeared on day 5. The diffusion seemed to follow the movement of a dark spot along the boundary of the oval region. Because the source of this ammonia lies deeper than the cloud, images like these can tell scientists much about the dynamics and heat conduction in Jupiter's lower atmosphere.

  17. Grains charges in interstellar clouds

    NASA Technical Reports Server (NTRS)

    Bel, N.; Lafon, J. P.; Viala, Y. P.

    1989-01-01

    The charge of cosmic grains could play an important role in many astrophysical phenomena. It probably has an influence on the coagulation of grains and more generally on grain-grain collisions, and on interaction between charged particles and grains which could lead to the formation of large grains or large molecules. The electrostatic charge of grains depends mainly on the nature of constitutive material of the grain and on the physical properties of its environment: it results from a delicate balance between the plasma particle collection and the photoelectron emission, both of them depending on each other. The charge of the grain is obtained in two steps: (1) using the numerical model the characteristics of the environment of the grain are computed; (2) the charge of a grain which is embedded in this environment is determined. The profile of the equilibrium charge of some typical grains through different types of interstellar clouds is obtained as a function of the depth of the cloud. It is shown that the grain charge can reach high values not only in hot diffuse clouds, but also in clouds with higher densities. The results are very sensitive to the mean UV interstellar radiation field. Three parameters appear to be essential but with different levels of sensitivity of the charge: the gas density, the temperature, and the total thickness of the cloud.

  18. Bubble and bubble cloud dynamics

    NASA Astrophysics Data System (ADS)

    Matsumoto, Yoichiro

    2000-07-01

    Cavitation bubbles are formed from small air bubbles, so-called nuclei, with the surrounding pressure reduction caused by the flow, and then, the bubbles shrink and collapse with the surrounding pressure rise. Such volumetric changes of bubbles are calculated in detail and it is found that they are significantly influenced by the internal phenomena, such as thermal diffusion, mist formation due to a homogeneous condensation, mass diffusion between vapor and noncondensable gas, heat and mass transfer through the bubble wall. The structure in cavitating flow interacts with the cavitation bubbles, and those bubbles form a cloud cavitation. It is well known that cloud cavitation is one of the most destructive forms. The behavior of bubble clouds is simulated numerically. An inward propagating shock wave is formed during the collapse of the bubble cloud, and the shock wave and its precursor are focused at the cloud center area. These phenomena associate high frequency pressure oscillations and violent bubble collapses. Those bubble collapses emit high pressure peaks, which are several hundreds times larger than that of a single bubble collapse.

  19. High Velocity Clouds

    NASA Technical Reports Server (NTRS)

    Wolfire, M. G.; McKee, C. F.; Hollenbach, D. J.; Tielens, A. G. G. M.; Morrison, David (Technical Monitor)

    1994-01-01

    We calculate the thermal equilibrium gas temperature of high velocity clouds (HVCs) in the Galactic Halo. Our method accounts for the photoelectric heating from small grains and PAHs, and includes a detailed treatment of the ionization rates and heating due to the soft X-ray background and due to cosmic rays. Phase diagrams (thermal pressure P versus gas density n) are presented for gas with a range of dust/gas ratios (D/G) and a range of metallicities (Z). Variations in D/G affect mainly the photoelectric heating rate, while variations in Z affect both the photoelectric heating and gas cooling. Curves are shown for D/G = 1 (local value) to D/G less than approx. equal to 0.005 and for Z=1 (local value) to Z= 0.005. We find that a two phase medium (CNM + WNM) can be in pressure equilibrium with a hot (T approximately 1-2 x 10(exp 6) K) halo within a range of permitted pressures, P(sup min) to P(sup max). We take halo parameters consistent with observed properties of the soft X-ray background. In general, both P(sup min) and P(sup max) decrease with lower D/G due to a drop in photoelectric heating from grains, while. P(sup min) and P(sup max) increase with lower Z due to a drop in gas coolants. We demonstrate that successful two phase models can be constructed with pressure in the range 10(exp 3) less than approximately equal to P/k less than approximately equal to 10(exp 4) K cm(exp -3) consistent with the thermal pressure in the Galactic disk. In addition, using the observed relation between CNM density and distance in HVCs, (n = 75/fDkpc cm(exp -3); Wakker & Schwarz 1991, AA, 250, 484) we show that our pressure curves constrain the allowed range of HVC heights to be between 0.3 - 16 kpc.

  20. High Velocity Clouds

    NASA Technical Reports Server (NTRS)

    Wolfire, M. G.; McKee, C. F.; Hollenbach, D. J.; Tielens, A. G. G. M.; Morrison, David (Technical Monitor)

    1994-01-01

    We calculate the thermal equilibrium gas temperature of high velocity clouds (HVCs) in the Galactic Halo. Our method accounts for the photoelectric heating from small grains and PAHs, and includes a detailed treatment of the ionization rates and heating due to the soft X-ray background and due to cosmic rays. Phase diagrams (thermal pressure P versus gas density n) are presented for gas with a range of dust/gas ratios (D/G) and a range of metallicities (Z). Variations in D/G affect mainly the photoelectric heating rate, while variations in Z affect both the photoelectric heating and gas cooling. Curves are shown for D/G = 1 (local value) to D/G less than approx. equal to 0.005 and for Z=1 (local value) to Z= 0.005. We find that a two phase medium (CNM + WNM) can be in pressure equilibrium with a hot (T approximately 1-2 x 10(exp 6) K) halo within a range of permitted pressures, P(sup min) to P(sup max). We take halo parameters consistent with observed properties of the soft X-ray background. In general, both P(sup min) and P(sup max) decrease with lower D/G due to a drop in photoelectric heating from grains, while. P(sup min) and P(sup max) increase with lower Z due to a drop in gas coolants. We demonstrate that successful two phase models can be constructed with pressure in the range 10(exp 3) less than approximately equal to P/k less than approximately equal to 10(exp 4) K cm(exp -3) consistent with the thermal pressure in the Galactic disk. In addition, using the observed relation between CNM density and distance in HVCs, (n = 75/fDkpc cm(exp -3); Wakker & Schwarz 1991, AA, 250, 484) we show that our pressure curves constrain the allowed range of HVC heights to be between 0.3 - 16 kpc.

  1. FAME-C: Retrieval of cloud top pressure with vertically inhomogeneous cloud profiles

    NASA Astrophysics Data System (ADS)

    Henken, Cintia Carbajal; Lindstrot, Rasmus; Filipitsch, Florian; Walther, Andi; Preusker, Rene; Fischer, Jürgen

    2013-05-01

    A synergistic FAME-C (Freie Universität Berlin AATSR-MERIS Cloud Retrieval) algorithm is developed within the frame of the ESA CCI Cloud project. Within FAME-C the ratio of two MERIS measurements (the Oxygen-A absorption channel and a window channel) is used to retrieve cloud top pressure. In case of high, extended clouds the retrieved cloud top pressure is generally too high. This can be understood as an overestimation of extinction in upper cloud layers due to the assumption of vertical homogeneous clouds in the radiative transfer simulations. To include more realistic cloud vertical profiles, one year of data from the Cloud Profiling Radar (CPR) onboard CloudSat has been used to determine average normalized cloud vertical extinction profiles with a fixed pressure thickness for nine cloud types. The nine cloud types are based on the ISCCP COT-CTP classification table. The retrieved cloud top pressure, now using CloudSat cloud profiles in the forward model, is compared to CPR reflectivities as well as the retrieved cloud top pressure using vertically homogeneous cloud profiles. In the first number of cases under examination the overestimation of cloud top pressure, and therefore the bias, is reduced by a large amount when using CloudSat vertical cloud profiles. Another advantage is that no assumption about the cloud geometrical thickness has to be made in the new retrieval. It should be noted that comparisons between FAME-C products and A-train products can only be made at high latitudes where A-train and ENVISAT have overlapping overflights.

  2. Southern Ocean Water Cloud Properties from Combined CALIOP, CloudSat and MODIS Measurements

    NASA Astrophysics Data System (ADS)

    Hu, Y.; ZENG, S.; Rodier, S. D.; Zhai, P.; Josset, D. B.; Liu, Z.; Lu, X.

    2013-12-01

    CALIOP, the dual wavelength, polarization sensitive lidar flying aboard the CALIPSO satellite, has been operating since June 2006 and is expected to continue for several more years. CALIOP provides accurate information about cloud top height and cloud thermodynamic phase information. Combining CALIOP measurements with collocated Cloudsat and MODIS measurements, we can estimate cloud properties such as 3-D structure of the clouds, cloud thermodynamic phase, cloud top extinction coefficient, cloud droplet number concentration (CDNC) and liquid water content (LWC) of water clouds. Cloud thermodynamics phase is derived from combined CALIOP and CloudSat measurements. Depolarization of backscatter by water clouds is due to multiple scattering, which depends strongly on cloud extinction coefficient. CDNC and LWC are derived from the CALIOP depolarization measurements and droplet size distribution information such as MODIS effective radius. The multi-instrument data analysis reviews unique properties of clouds in Southern oceans, e.g., frequent presence of supercooled liquid water clouds, large seasonal variations in water cloud droplet number concentrations (droplet number concentrations in summer is three times as large as winter time). We will present basic measurement concept and spatial/temporal statistics of these water cloud properties from measurements of the past seven years. We also attempt to assess seasonal and inter-annual variations of cloud microphysical properties using the past seven years' CALIPO/CloudSat measurements. CALIOP's depolarization ratio is one of the best calibrated measurements made by the A-Train sensors. Over the life of the CALIPSO mission, the stability of the CALIOP depolarization ratio calibration has remained within 1%. CALIOP's depolarization ratio measurements are used for studying changes in cloud thermodynamic phase and water cloud microphysical properties that are relevant to multiple scattering processes of water clouds

  3. Morning Clouds Atop Martian Mountain

    NASA Image and Video Library

    2015-06-19

    Seen shortly after local Martian sunrise, clouds gather in the summit pit, or caldera, of Pavonis Mons, a giant volcano on Mars, in this image from the Thermal Emission Imaging System (THEMIS) on NASA's Mars Odyssey orbiter. The clouds are mostly made of ice crystals. They appear blue in the image because the cloud particles scatter blue light more strongly than other colors. Pavonis Mons stands about nine miles (14 kilometers) high, and the caldera spans about 29 miles (47 kilometers) wide. This image was made by THEMIS through three of its visual-light filters plus a near-infrared filter, and it is approximately true in color. THEMIS and other instruments on Mars Odyssey have been studying Mars from orbit since 2001. http://photojournal.jpl.nasa.gov/catalog/PIA19675

  4. Microphysical Characteristics of Tropical Clouds

    NASA Technical Reports Server (NTRS)

    Grainger, Cedric A.; Anderson, Nicholas

    2004-01-01

    This report summarizes the analysis of data collected by the University of North Dakota Citation II measurement platform during three TRMM Field measurement campaigns. The Citation II made cloud measurements during TEFLUN B in Florida, the LBA program in Brazil, and KWAJEX in Kwajalein. The work performed can be divided into two parts. The first part consisted of reformatting the Citation data into a form more easily used to compare to the satellite information. The second part consisted of examination of the cloud data in order to characterize the properties of the tropical clouds. The reformatting of the Citation data was quite labor intensive and, due to the fact that the aircraft was involved in three of the field campaigns, it required a substantial number of person-hours to complete. Much of the analysis done on the second part was done in conjunction with the thesis work of Nicholas Anderson, then a graduate student at the University of North Dakota.

  5. Clouds of Neptune and Uranus

    NASA Technical Reports Server (NTRS)

    Atreya, Sushil K.; Wong, Ah-San

    2005-01-01

    We present results on the bases and concentrations of methane ice, ammonia ice, ammonium hydrosulfide-solid, water ice, and aqueous-ammonia solution (droplet) clouds of Neptune and Uranus, based on an equilibrium cloud condensation model. Due to their similar p-T structures, the model results for Neptune and Uranus are similar. Assuming 30-50x solar enhancement for the condensibles species, as expected from formation models, we find that the base of the droplet cloud is at the 370 bars for 30 solar, and at 500 bars for 50 solar cases. Despite this, entry probes need to be deployed to only 50-100 bars to obtain all the critical information needed to constrain models of the formation of these planets and their atmospheres.

  6. Wispy Blue Clouds Over Mars

    NASA Technical Reports Server (NTRS)

    1997-01-01

    These are more wispy blue clouds from Sol 39 as seen by the Imager for Mars Pathfinder (IMP). The bright clouds near the bottom are about 10 degrees above the horizon. The clouds are believed to be at an altitude of 10 to 15 km, and are thought to be made of small water ice particles. The picture was taken about 40 minutes before sunrise.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  7. Marine cloud brightening: regional applications.

    PubMed

    Latham, John; Gadian, Alan; Fournier, Jim; Parkes, Ben; Wadhams, Peter; Chen, Jack

    2014-12-28

    The general principle behind the marine cloud brightening (MCB) climate engineering technique is that seeding marine stratocumulus clouds with substantial concentrations of roughly monodisperse sub-micrometre-sized seawater particles might significantly enhance cloud albedo and longevity, thereby producing a cooling effect. This paper is concerned with preliminary studies of the possible beneficial application of MCB to three regional issues: (1) recovery of polar ice loss, (2) weakening of developing hurricanes and (3) elimination or reduction of coral bleaching. The primary focus is on Item 1. We focus discussion herein on advantages associated with engaging in limited-area seeding, regional effects rather than global; and the levels of seeding that may be required to address changing current and near-term conditions in the Arctic. We also mention the possibility that MCB might be capable of producing a localized cooling to help stabilize the West Antarctic Ice Sheet.

  8. The evolution of molecular clouds

    NASA Technical Reports Server (NTRS)

    Shu, Frank H.; Lizano, Susana

    1988-01-01

    The problem of the structure and evolution of molecular clouds is reviewed, with particular emphasis given to the relationship with star formation. The basic hypothesis is that magnetic fields are the primary agents for supporting molecular clouds, although damped Alfven waves may play an important role in the direction parallel to the field lines. This picture naturally leads to a conception of 'bimodal star formation'. It is proposed that high-mass stars form from the overall gravitational collapse of a supercritical cloud, whereas low-mass stars form from small individual cores that slowly condense by ambipolar diffusion from a more extended envelope until they pass the brink of graviational instability and begin to collapse dynamically from 'inside-out'. The evidence that the infall stage of protostellar evolution is terminated by the development of a powerful stellar wind is reviewed.

  9. Scientific Services on the Cloud

    NASA Astrophysics Data System (ADS)

    Chapman, David; Joshi, Karuna P.; Yesha, Yelena; Halem, Milt; Yesha, Yaacov; Nguyen, Phuong

    Scientific Computing was one of the first every applications for parallel and distributed computation. To this date, scientific applications remain some of the most compute intensive, and have inspired creation of petaflop compute infrastructure such as the Oak Ridge Jaguar and Los Alamos RoadRunner. Large dedicated hardware infrastructure has become both a blessing and a curse to the scientific community. Scientists are interested in cloud computing for much the same reason as businesses and other professionals. The hardware is provided, maintained, and administrated by a third party. Software abstraction and virtualization provide reliability, and fault tolerance. Graduated fees allow for multi-scale prototyping and execution. Cloud computing resources are only a few clicks away, and by far the easiest high performance distributed platform to gain access to. There may still be dedicated infrastructure for ultra-scale science, but the cloud can easily play a major part of the scientific computing initiative.

  10. Marine cloud brightening: regional applications

    PubMed Central

    Latham, John; Gadian, Alan; Fournier, Jim; Parkes, Ben; Wadhams, Peter; Chen, Jack

    2014-01-01

    The general principle behind the marine cloud brightening (MCB) climate engineering technique is that seeding marine stratocumulus clouds with substantial concentrations of roughly monodisperse sub-micrometre-sized seawater particles might significantly enhance cloud albedo and longevity, thereby producing a cooling effect. This paper is concerned with preliminary studies of the possible beneficial application of MCB to three regional issues: (1) recovery of polar ice loss, (2) weakening of developing hurricanes and (3) elimination or reduction of coral bleaching. The primary focus is on Item 1. We focus discussion herein on advantages associated with engaging in limited-area seeding, regional effects rather than global; and the levels of seeding that may be required to address changing current and near-term conditions in the Arctic. We also mention the possibility that MCB might be capable of producing a localized cooling to help stabilize the West Antarctic Ice Sheet. PMID:25404682

  11. The evolution of molecular clouds

    NASA Technical Reports Server (NTRS)

    Shu, Frank H.; Lizano, Susana

    1988-01-01

    The problem of the structure and evolution of molecular clouds is reviewed, with particular emphasis given to the relationship with star formation. The basic hypothesis is that magnetic fields are the primary agents for supporting molecular clouds, although damped Alfven waves may play an important role in the direction parallel to the field lines. This picture naturally leads to a conception of 'bimodal star formation'. It is proposed that high-mass stars form from the overall gravitational collapse of a supercritical cloud, whereas low-mass stars form from small individual cores that slowly condense by ambipolar diffusion from a more extended envelope until they pass the brink of graviational instability and begin to collapse dynamically from 'inside-out'. The evidence that the infall stage of protostellar evolution is terminated by the development of a powerful stellar wind is reviewed.

  12. Clouds Move Across Mars Horizon

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This sequence combines 32 images of clouds moving eastward across a Martian horizon. The Surface Stereo Imager on NASA's Phoenix Mars Lander took this set of images on Sept. 18, 2008, during early afternoon hours of the 113th Martian day of the mission.

    The view is toward the north. The actual elapsed time between the first image and the last image is nearly half an hour. The numbers inset at lower left are the elapsed time, in seconds, after the first image of the sequence. The particles in the clouds are water-ice, as in cirrus clouds on Earth.

    Phoenix landed in the northern region of Mars on May 25, 2008. The mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  13. A comparison of shock-cloud and wind-cloud interactions: the longer survival of clouds in winds

    NASA Astrophysics Data System (ADS)

    Goldsmith, K. J. A.; Pittard, J. M.

    2017-09-01

    The interaction of a hot, high-velocity wind with a cold, dense molecular cloud has often been assumed to resemble the evolution of a cloud embedded in a post-shock flow. However, no direct comparative study of these two processes currently exists in the literature. We present 2D adiabatic hydrodynamical simulations of the interaction of a Mach 10 shock with a cloud of density contrast χ = 10 and compare our results with those of a commensurate wind-cloud simulation. We then investigate the effect of varying the wind velocity, effectively altering the wind Mach number Mwind, on the cloud's evolution. We find that there are significant differences between the two processes: 1) the transmitted shock is much flatter in the shock-cloud interaction; 2) a low-pressure region in the wind-cloud case deflects the flow around the edge of the cloud in a different manner to the shock-cloud case; 3) there is far more axial compression of the cloud in the case of the shock. As Mwind increases, the normalized rate of mixing is reduced. Clouds in winds with higher Mwind also do not experience a transmitted shock through the cloud's rear and are more compressed axially. In contrast with shock-cloud simulations, the cloud mixing time normalized by the cloud-crushing time-scale tcc increases for increasing Mwind until it plateaus (at tmix ≃ 25 tcc) at high Mwind, thus demonstrating the expected Mach scaling. In addition, clouds in high Mach number winds are able to survive for long durations and are capable of being moved considerable distances.

  14. Rethinking a Mysterious Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Imara, N.

    2015-04-01

    I present high-resolution column density maps of two molecular clouds (MCs) having strikingly different star formation rates. To better understand the unusual, massive G216-2.5, an MC with no massive star formation, the distribution of its molecular gas is compared to that of the Rosette MC. Far-infrared data from Herschel are used to derive N(H2) maps of each cloud and are combined with {{I}CO} data to determine the CO-to-H2 ratio, {{X}CO}. In addition, the probability distribution functions (PDFs) and cumulative mass fractions of the clouds are compared. For G216-2.5, < N({{H}2})> =7.8× {{10}20} cm-2 and < {{X}CO}> =2.2× {{10}20} cm-2 (K km s-1)-1 for the Rosette, < N({{H}2})> =1.8× {{10}21} cm-2 and < {{X}CO}> =2.8× {{10}20} cm-2 (K km s-1)-1. The PDFs of both clouds are log-normal for extinctions below ˜2 mag and both show departures from log-normality at high extinctions. Although it is the less-massive cloud, the Rosette has a higher fraction of its mass in the form of dense gas and contains 1389 {{M}⊙ } of gas above the so-called extinction threshold for star formation, {{A}V}=7.3 mag. The G216-2.5 cloud has 874 {{M}⊙ } of dense gas above this threshold.

  15. Collisions in the Oort Cloud

    SciTech Connect

    Stern, S.A.

    1988-03-01

    The present assessment of the consequentiality of physical collisions between Oort Cloud objects by a first-generation model indicates that natural power-law population structures produce significant numbers of collisions between each comet and smaller objects over the age of the solar system. These collisions are held to constitute a feedback mechanism for small debris production. The impacts yield extensive comet surface evolution in the cloud, in conditions where the number of small orbiting objects conforms to the standard power-law populations. 16 references.

  16. Geometric Effects on Electron Cloud

    SciTech Connect

    Wang, L

    2007-07-06

    The development of an electron cloud in the vacuum chambers of high intensity positron and proton storage rings may limit the machine performances by inducing beam instabilities, beam emittance increase, beam loss, vacuum pressure increases and increased heat load on the vacuum chamber wall. The electron multipacting is a kind of geometric resonance phenomenon and thus is sensitive to the geometric parameters such as the aperture of the beam pipe, beam shape and beam bunch fill pattern, etc. This paper discusses the geometric effects on the electron cloud build-up in a beam chamber and examples are given for different beams and accelerators.

  17. Warm/cold cloud processes

    NASA Technical Reports Server (NTRS)

    Bowdle, D. A.

    1979-01-01

    Technical assistance continued in support of the Atmospheric Cloud Physics Laboratory is discussed. A study of factors affecting warm cloud formation showed that the time of formation during an arbitrary expansion is independent of carrier gas composition for ideal gases and independent of aerosol concentration for low concentrations of very small aerosols. Equipment and procedures for gravimetric evaluation of a precision saturator were laboratory tested. A numerical feasibility study was conducted for the stable levitation of charged solution droplets by an electric field in a one-g static diffusion chamber. The concept, operating principles, applications, limits, and sensitivity of the levitation technique are discussed.

  18. Cloud Offload in Hostile Environments

    DTIC Science & Technology

    2011-12-01

    5, 6, 7, 18, 21, 22, 25, 29, 44, 51]. Commercial applications that use cloud offload now exist: Apple’s Siri for speech recognition on the iPhone is...today’s smartphones are already powerful enough to sup- port this genre of applications without need for cloud offload. Android has supported built-in...face detection functionality for some time now. The APIs have been extended in Android 4.0 to support tracking of multiple faces and to give detailed

  19. Clouds Microphysics Analysis and Modeling.

    DTIC Science & Technology

    1986-07-01

    mesoscale cloud models and analyze data in support of such models. Results Of the BIGH-ILL and CCOPE experiment model runs and the transfer and implementation...model of cumulus clouds. the SNOW\\-11s’’.s’n analysi, STRATEX data analysis. UND data analysis of aircraft flight tapes, and program, for th4e anal...8217 (i\\ f P\\lS-’iU) mc Image Data . 20. OiSTRIBUTIONIAVAILABILiTY OF ABSTRACT 21 ABSTRACT SECURITY CLASSIFICATION UNCLASSIFIEO/UNLIMITEO [:(SAME AS RPT OTIC

  20. MedlinePlus FAQ: Search Cloud

    MedlinePlus

    ... faq/searchcloud.html Question: How does the search cloud work? To use the sharing features on this page, please enable JavaScript. Answer: The search cloud displays the top 100 search terms typed into ...

  1. NASA Now: A-Train: Clouds

    NASA Image and Video Library

    During this episode of NASA Now, you’ll meet NASA physical scientist Lin Chambers, learn about the role of clouds in the Earth's energy and water cycles, and find out how NASA collects cloud data...

  2. A surface-based cloud observing system

    NASA Technical Reports Server (NTRS)

    Albrecht, B. A.; Ackerman, T. P.; Thomson, D. W.; Mace, G.; Miller, M. A.; Peters, R. M.

    1991-01-01

    The paper describes a surface-based system, called the Cloud Observing System (COS), that was developed for measurements of the dynamical and thermodynamical properties of clouds and of their interaction with the large-scale environment, by combining several remote sensors and in situ systems. The atmospheric parameters that will be measured by COS include precipitation, the velocity and direction of wind, the cloud liquid water, the low-level winds and turbulence structure, integrated liquid and vapor quantities, the temperature and water profiles, the cloud radiance and the cloud base temperature, irradiances at the surface, the low-level temperature profile, the cloud-base height, and the cloud fraction; video cameras will provide visual records of clouds.

  3. MODIS Views Variations in Cloud Types

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This MODIS image, centered over the Great Lakes region in North America, shows a variety of cloud types. The clouds at the top of the image, colored pink, are cold, high-level snow and ice clouds, while the neon green clouds are lower-level water clouds. Because different cloud types reflect and emit radiant energy differently, scientists can use MODIS' unique data set to measure the sizes of cloud particles and distinguish between water, snow, and ice clouds. This scene was acquired on Feb. 24, 2000, and is a red, green, blue composite of bands 1, 6, and 31 (0.66, 1.6, and 11.0 microns, respectively). Image by Liam Gumley, Space Science and Engineering Center, University of Wisconsin-Madison

  4. Cloud Technology May Widen Genomic Bottleneck - TCGA

    Cancer.gov

    Computational biologist Dr. Ilya Shmulevich suggests that renting cloud computing power might widen the bottleneck for analyzing genomic data. Learn more about his experience with the Cloud in this TCGA in Action Case Study.

  5. Warming Ancient Mars with Water Clouds

    NASA Astrophysics Data System (ADS)

    Hartwick, V. L.; Toon, O. B.

    2017-10-01

    High altitude clouds in the present day Mars atmosphere may form on interplanetary dust particles (IDPs). Paleo fluences of IDPs were likely higher, and similar clouds are expected to influence the Mars paleo-climate.

  6. Reducing the uncertainty in subtropical cloud feedback

    NASA Astrophysics Data System (ADS)

    Myers, Timothy A.; Norris, Joel R.

    2016-03-01

    Large uncertainty remains on how subtropical clouds will respond to anthropogenic climate change and therefore whether they will act as a positive feedback that amplifies global warming or negative feedback that dampens global warming by altering Earth's energy budget. Here we reduce this uncertainty using an observationally constrained formulation of the response of subtropical clouds to greenhouse forcing. The observed interannual sensitivity of cloud solar reflection to varying meteorological conditions suggests that increasing sea surface temperature and atmospheric stability in the future climate will have largely canceling effects on subtropical cloudiness, overall leading to a weak positive shortwave cloud feedback (0.4 ± 0.9 W m-2 K-1). The uncertainty of this observationally based approximation of the cloud feedback is narrower than the intermodel spread of the feedback produced by climate models. Subtropical cloud changes will therefore complement positive cloud feedbacks identified by previous work, suggesting that future global cloud changes will amplify global warming.

  7. Analysis on the security of cloud computing

    NASA Astrophysics Data System (ADS)

    He, Zhonglin; He, Yuhua

    2011-02-01

    Cloud computing is a new technology, which is the fusion of computer technology and Internet development. It will lead the revolution of IT and information field. However, in cloud computing data and application software is stored at large data centers, and the management of data and service is not completely trustable, resulting in safety problems, which is the difficult point to improve the quality of cloud service. This paper briefly introduces the concept of cloud computing. Considering the characteristics of cloud computing, it constructs the security architecture of cloud computing. At the same time, with an eye toward the security threats cloud computing faces, several corresponding strategies are provided from the aspect of cloud computing users and service providers.

  8. Intensification of convective extremes driven by cloud-cloud interaction

    NASA Astrophysics Data System (ADS)

    Moseley, Christopher; Hohenegger, Cathy; Berg, Peter; Haerter, Jan O.

    2016-10-01

    In a changing climate, a key role may be played by the response of convective-type cloud and precipitation to temperature changes. Yet, it is unclear if convective precipitation intensities will increase mainly due to thermodynamic or dynamical processes. Here we perform large eddy simulations of convection by imposing a realistic diurnal cycle of surface temperature. We find convective events to gradually self-organize into larger cloud clusters and those events occurring late in the day to produce the highest precipitation intensities. Tracking rain cells throughout their life cycles, we show that events which result from collisions respond strongly to changes in boundary conditions, such as temperature changes. Conversely, events not resulting from collisions remain largely unaffected by the boundary conditions. Increased surface temperature indeed leads to more interaction between events and stronger precipitation extremes. However, comparable intensification occurs when leaving temperature unchanged but simply granting more time for self-organization. These findings imply that the convective field as a whole acquires a memory of past precipitation and inter-cloud dynamics, driving extremes. For global climate model projections, our results suggest that the interaction between convective clouds must be incorporated to simulate convective extremes and the diurnal cycle more realistically.

  9. Aerosol-Cloud-Drizzle-Turbulence Interactions in Boundary Layer Clouds

    DTIC Science & Technology

    2013-09-30

    Journal of Applied Meteorology and Climate (Jung et al., 2013). FIG.2. Schematic of the entrainment processes and in-cloud flow pattern for a...Coe, H., Allen, G., Vaughan, G., Daum, P., Fairall, C., Chand , D., Gallardo Klenner, L., Garreaud, R., Grados Quispe, C., Covert, D. S., Bates, T. S

  10. GCM Simulations of Cirrus Clouds and Cloud Feedbacks

    NASA Technical Reports Server (NTRS)

    DelGenio, Anthony D.

    1998-01-01

    Cirrus clouds are a particularly uncertain component of general circulation model (GCM simulations of long-term climate change for a variety of reasons: (1) They encompass a wide range of optical thicknesses and altitudes, from thin tropopause cirrus to thick anvil cirrus that descend to the freezing level, and thus can exert both positive and negative forcing and feedback on the climate; (2) The dynamical processes that create them are poorly resolved in climate GCMs and different in the tropics and midlatitudes; (3) Predictions of their formation and microphysical properties depend on the accuracy of dynamical transports of small concentrations of water vapor to and within the upper troposphere; (4) The relative humidity conditions at which they form depends on the nature and concentration of nucleating particles and is poorly understood; (5) They are more difficult to observe than other cloud types, and hence their parameterization is more loosely constrained by available data. We will illustrate the potential sensitivity of the perturbed climate to uncertainties in cirrus cloud formulation. We will also examine the processes that form cirrus in climate models and discuss the accuracy with which climate GCMs represent these processes. We will also discuss ways in which GCM grid-scale parameterizations might be derived from cloud-scale observations. Finally, we will emphasize the types of global observations needed to constrain parameterizations of cirrus in climate GCMs.

  11. Cloud Detection and Cloud Top Height Determination using the Hyperspectral Imaging Spectrometer specMACS

    NASA Astrophysics Data System (ADS)

    Höppler, Lucas; Gödde, Felix; Kölling, Tobias; Zinner, Tobias; Mayer, Bernhard; Groß, Silke; Gutleben, Manuel

    2017-04-01

    Diabatic heat released by clouds sometimes causes numerical weather forecast failures. Climate model predictions depend on radiative effects of tropical clouds in the trade winds. Both climate and global weather forecast models, therefore, need to be improved with respect to a proper representation of cloud microphysical and macrophysical properties. For this purpose, parameters describing the cloud geometry such as cloud fraction, cloud size and cloud top heights are important. These parameters are also important ingredients to accurately validate the results of previous and upcoming studies with cloud resolving models. A hyperspectral imaging spectrometer (specMACS) was operated aboard the research plane HALO in the NARVAL II and NAWDEX experiments. By combining the reflected radiance of the clouds and the signal of the water vapor absorption bands in the infrared part of the solar spectrum, an effective cloud mask was developed which is prerequisite for any further analysis. The method allows detecting clouds even over the bright sunglint. As a next step, cloud top heights are determined by comparing the measured radiance within and outside of the oxygen A-band with radiative transfer model calculations. Subsequently, the calculated cloud top heights are compared to LIDAR measurements. While this method works well for plane-parallel, homogeneous clouds, 3D radiative transfer effects cause artifacts at cloud edges and in cloud free areas which can lead to strongly miscalculated cloud top heights. These effects will be assessed and also evaluated. Deriving quantities such as cloud fraction, cloud size, and cloud structure is the basis for calculating cloud heating and cooling rates in upcoming studies.

  12. Evaluating stratiform cloud base charge remotely

    NASA Astrophysics Data System (ADS)

    Harrison, R. Giles; Nicoll, Keri A.; Aplin, Karen L.

    2017-06-01

    Stratiform clouds acquire charge at their upper and lower horizontal boundaries due to vertical current flow in the global electric circuit. Cloud charge is expected to influence microphysical processes, but understanding is restricted by the infrequent in situ measurements available. For stratiform cloud bases below 1 km in altitude, the cloud base charge modifies the surface electric field beneath, allowing a new method of remote determination. Combining continuous cloud height data during 2015-2016 from a laser ceilometer with electric field mill data, cloud base charge is derived using a horizontal charged disk model. The median daily cloud base charge density found was -0.86 nC m-2 from 43 days' data. This is consistent with a uniformly charged region 40 m thick at the cloud base, now confirming that negative cloud base charge is a common feature of terrestrial layer clouds. This technique can also be applied to planetary atmospheres and volcanic plumes.Plain Language SummaryThe idea that <span class="hlt">clouds</span> in the atmosphere can charge electrically has been appreciated since the time of Benjamin Franklin, but it is less widely recognized that it is not just thunderclouds which contain electric charge. For example, water droplets in simple layer <span class="hlt">clouds</span>, that are abundant and often responsible for an overcast day, carry electric charges. The droplet charging arises at the upper and lower edges of the layer <span class="hlt">cloud</span>. This occurs because the small droplets at the edges draw charge from the air outside the <span class="hlt">cloud</span>. Understanding how strongly layer <span class="hlt">clouds</span> charge is important in evaluating electrical effects on the development of such <span class="hlt">clouds</span>, for example, how thick the <span class="hlt">cloud</span> becomes and whether it generates rain. Previously, <span class="hlt">cloud</span> charge measurement has required direct measurements within the <span class="hlt">cloud</span> using weather balloons or aircraft. This work has monitored the lower <span class="hlt">cloud</span> charge continuously using instruments placed at the surface beneath</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950043413&hterms=sage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsage','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950043413&hterms=sage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsage"><span>Comparison between SAGE II and ISCCP high-level <span class="hlt">clouds</span>. 2: Locating <span class="hlt">clouds</span> tops</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liao, Xiaohan; Rossow, William B.; Rind, David</p> <p>1995-01-01</p> <p>A comparison is made of the vertical distribution of high-level <span class="hlt">cloud</span> tops derived from the Stratospheric Aerosol and Gas Experiment II (SAGE II) occultation measurements and from the International Satellite <span class="hlt">Cloud</span> Climatology Project (ISCCP) for all Julys and Januarys in 1985 to 1990. The results suggest that ISCCP overestimates the pressure of high-level <span class="hlt">clouds</span> by up to 50-150 mbar, particularly at low latitudes. This is caused by the frequent presence of <span class="hlt">clouds</span> with diffuse tops (greater than 50% time when cloudy events are observed). The averaged vertical extent of the diffuse top is about 1.5 km. At midlatitudes where the SAGE II and ISCCP <span class="hlt">cloud</span> top pressure agree best, <span class="hlt">clouds</span> with distinct tops reach a maximum relative proportion of the total level <span class="hlt">cloud</span> amount (about 30-40%), and diffuse-topped <span class="hlt">clouds</span> are reduced to their minimum (30-40%). The ISCCP-defined <span class="hlt">cloud</span> top pressure should be regarded not as the material physical height of the <span class="hlt">clouds</span> but as the level which emits the same infrared radiance as observed. SAGE II and ISCCP <span class="hlt">cloud</span> top pressures agree for <span class="hlt">clouds</span> with distinct tops. There is also an indication that the <span class="hlt">cloud</span> top pressures of optically thin <span class="hlt">clouds</span> not overlying thicker <span class="hlt">clouds</span> are poorly estimated by ISCCP at middle latitudes. The average vertical extent of these thin <span class="hlt">clouds</span> is about 2.5 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950043413&hterms=sage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsage','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950043413&hterms=sage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsage"><span>Comparison between SAGE II and ISCCP high-level <span class="hlt">clouds</span>. 2: Locating <span class="hlt">clouds</span> tops</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liao, Xiaohan; Rossow, William B.; Rind, David</p> <p>1995-01-01</p> <p>A comparison is made of the vertical distribution of high-level <span class="hlt">cloud</span> tops derived from the Stratospheric Aerosol and Gas Experiment II (SAGE II) occultation measurements and from the International Satellite <span class="hlt">Cloud</span> Climatology Project (ISCCP) for all Julys and Januarys in 1985 to 1990. The results suggest that ISCCP overestimates the pressure of high-level <span class="hlt">clouds</span> by up to 50-150 mbar, particularly at low latitudes. This is caused by the frequent presence of <span class="hlt">clouds</span> with diffuse tops (greater than 50% time when cloudy events are observed). The averaged vertical extent of the diffuse top is about 1.5 km. At midlatitudes where the SAGE II and ISCCP <span class="hlt">cloud</span> top pressure agree best, <span class="hlt">clouds</span> with distinct tops reach a maximum relative proportion of the total level <span class="hlt">cloud</span> amount (about 30-40%), and diffuse-topped <span class="hlt">clouds</span> are reduced to their minimum (30-40%). The ISCCP-defined <span class="hlt">cloud</span> top pressure should be regarded not as the material physical height of the <span class="hlt">clouds</span> but as the level which emits the same infrared radiance as observed. SAGE II and ISCCP <span class="hlt">cloud</span> top pressures agree for <span class="hlt">clouds</span> with distinct tops. There is also an indication that the <span class="hlt">cloud</span> top pressures of optically thin <span class="hlt">clouds</span> not overlying thicker <span class="hlt">clouds</span> are poorly estimated by ISCCP at middle latitudes. The average vertical extent of these thin <span class="hlt">clouds</span> is about 2.5 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1030103.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1030103.pdf"><span>Mobile <span class="hlt">Cloud</span> Learning for Higher Education: A Case Study of Moodle in the <span class="hlt">Cloud</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wang, Minjuan; Chen, Yong; Khan, Muhammad Jahanzaib</p> <p>2014-01-01</p> <p>Mobile <span class="hlt">cloud</span> learning, a combination of mobile learning and <span class="hlt">cloud</span> computing, is a relatively new concept that holds considerable promise for future development and delivery in the education sectors. <span class="hlt">Cloud</span> computing helps mobile learning overcome obstacles related to mobile computing. The main focus of this paper is to explore how <span class="hlt">cloud</span> computing…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9318F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9318F"><span>Delivering Unidata Technology via the <span class="hlt">Cloud</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fisher, Ward; Oxelson Ganter, Jennifer</p> <p>2016-04-01</p> <p>Over the last two years, Docker has emerged as the clear leader in open-source containerization. Containerization technology provides a means by which software can be pre-configured and packaged into a single unit, i.e. a container. This container can then be easily deployed either on local or remote systems. Containerization is particularly advantageous when moving software into the <span class="hlt">cloud</span>, as it simplifies the process. Unidata is adopting containerization as part of our commitment to migrate our technologies to the <span class="hlt">cloud</span>. We are using a two-pronged approach in this endeavor. In addition to migrating our data-portal services to a <span class="hlt">cloud</span> environment, we are also exploring new and novel ways to use <span class="hlt">cloud</span>-specific technology to serve our community. This effort has resulted in several new <span class="hlt">cloud</span>/Docker-specific projects at Unidata: "<span class="hlt">Cloud</span>Stream," "<span class="hlt">Cloud</span>IDV," and "<span class="hlt">Cloud</span>Control." <span class="hlt">Cloud</span>Stream is a docker-based technology stack for bringing legacy desktop software to new computing environments, without the need to invest significant engineering/development resources. <span class="hlt">Cloud</span>Stream helps make it easier to run existing software in a <span class="hlt">cloud</span> environment via a technology called "Application Streaming." <span class="hlt">Cloud</span>IDV is a <span class="hlt">Cloud</span>Stream-based implementation of the Unidata Integrated Data Viewer (IDV). <span class="hlt">Cloud</span>IDV serves as a practical example of application streaming, and demonstrates how traditional software can be easily accessed and controlled via a web browser. Finally, <span class="hlt">Cloud</span>Control is a web-based dashboard which provides administrative controls for running docker-based technologies in the <span class="hlt">cloud</span>, as well as providing user management. In this work we will give an overview of these three open-source technologies and the value they offer to our community.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA632313','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA632313"><span>Adopting <span class="hlt">Cloud</span> Computing in the Pakistan Navy</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-06-01</p> <p>Department of Defense, the U.S. Navy, and the National Institute of Standards and Technology <span class="hlt">cloud</span> architectures , a framework has been laid out for... architecture , DoD <span class="hlt">cloud</span> 15. NUMBER OF PAGES 83 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION...National Institute of Standards and Technology <span class="hlt">cloud</span> architectures , a framework has been laid out for adopting <span class="hlt">cloud</span> computing in the Pakistan Navy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870036309&hterms=lupus&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlupus','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870036309&hterms=lupus&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlupus"><span>CO observations of dark <span class="hlt">clouds</span> in Lupus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Murphy, D. C.; Cohen, R.; May, J.</p> <p>1986-01-01</p> <p>C-12O observations covering 170 square degrees toward the southern T Association Lupus have revealed the presence of an extended physically related complex of dark <span class="hlt">clouds</span> which have recently formed low mass stars. The estimated mass of the <span class="hlt">clouds</span> (about 30,000 solar masses) is comparable to that of the nearby Ophiuchus dust <span class="hlt">clouds</span>. The Lupus <span class="hlt">clouds</span> are projected onto a gap between two subgroups of the Scorpio-Centaurus OB association suggesting that this long accepted subgrouping may require reinterpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870036309&hterms=Lupus&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DLupus','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870036309&hterms=Lupus&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DLupus"><span>CO observations of dark <span class="hlt">clouds</span> in Lupus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Murphy, D. C.; Cohen, R.; May, J.</p> <p>1986-01-01</p> <p>C-12O observations covering 170 square degrees toward the southern T Association Lupus have revealed the presence of an extended physically related complex of dark <span class="hlt">clouds</span> which have recently formed low mass stars. The estimated mass of the <span class="hlt">clouds</span> (about 30,000 solar masses) is comparable to that of the nearby Ophiuchus dust <span class="hlt">clouds</span>. The Lupus <span class="hlt">clouds</span> are projected onto a gap between two subgroups of the Scorpio-Centaurus OB association suggesting that this long accepted subgrouping may require reinterpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27792377','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27792377"><span>Dispersion of Droplet <span class="hlt">Clouds</span> in Turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bocanegra Evans, Humberto; Dam, Nico; Bertens, Guus; van der Voort, Dennis; van de Water, Willem</p> <p>2016-10-14</p> <p>We measure the absolute dispersion of <span class="hlt">clouds</span> of monodisperse, phosphorescent droplets in turbulent air by means of high-speed image-intensified video recordings. Laser excitation allows the initial preparation of well-defined, pencil-shaped luminous droplet <span class="hlt">clouds</span> in a completely nonintrusive way. We find that the dispersion of the <span class="hlt">clouds</span> is faster than the dispersion of fluid elements. We speculate that preferential concentration of inertial droplet <span class="hlt">clouds</span> is responsible for the enhanced dispersion.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989JGR....9418521K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989JGR....9418521K"><span><span class="hlt">Cloud</span> cover analysis with Arctic AVHRR data: 1. <span class="hlt">Cloud</span> detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Key, J.; Barry, R. G.</p> <p>1989-12-01</p> <p>Automated analyses of satellite radiance data have concentrated heavily on low and middle latitude situations. Some of the design objectives for the International Satellite <span class="hlt">Cloud</span> Climatology Project (ISCCP) <span class="hlt">cloud</span> detection procedure such as space and time contrasts are used in a basic algorithm from which a polar <span class="hlt">cloud</span> detection algorithm is developed. This algorithm is applied to Arctic data for January and July conditions. Both advanced very high resolution radiometer (AVHRR) and scanning multichannel microwave radiometer (SMMR) data are utilized. Synthetic AVHRR and SMMR data for a 7-day analysis period are also generated to provide a data set with known characteristics on which to test and validate algorithms. Modifications to the basic algorithm for polar conditions include the use of SMMR and SMMR-derived data sets for the estimation of surface parameters, elimination of the spatial test for the warmest pixel, the use of AVHRR channels 1 (0.7 μm), 3 (3.7 μm), and 4 (11 μm) in the temporal tests and the final multispectral thresholding, and the use of surface class characteristic values when clear-sky values cannot be obtained. Additionally, the difference between channels 3 and 4 is included in the temporal test for the detection of optically thin <span class="hlt">cloud</span>. Greatest improvement in computed <span class="hlt">cloud</span> fraction is realized over snow and ice surfaces; over open water or snow-free land, all versions perform similarly. Since the inclusion of SMMR for surface analysis and additional spectral channels increases the computational burden, its use may be justified only over snow and ice-covered regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...847L..10M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...847L..10M"><span>Fast Molecular <span class="hlt">Cloud</span> Destruction Requires Fast <span class="hlt">Cloud</span> Formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mac Low, Mordecai-Mark; Burkert, Andreas; Ibáñez-Mejía, Juan C.</p> <p>2017-09-01</p> <p>A large fraction of the gas in the Galaxy is cold, dense, and molecular. If all this gas collapsed under the influence of gravity and formed stars in a local free-fall time, the star formation rate in the Galaxy would exceed that observed by more than an order of magnitude. Other star-forming galaxies behave similarly. Yet, observations and simulations both suggest that the molecular gas is indeed gravitationally collapsing, albeit hierarchically. Prompt stellar feedback offers a potential solution to the low observed star formation rate if it quickly disrupts star-forming <span class="hlt">clouds</span> during gravitational collapse. However, this requires that molecular <span class="hlt">clouds</span> must be short-lived objects, raising the question of how so much gas can be observed in the molecular phase. This can occur only if molecular <span class="hlt">clouds</span> form as quickly as they are destroyed, maintaining a global equilibrium fraction of dense gas. We therefore examine <span class="hlt">cloud</span> formation timescales. We first demonstrate that supernova and superbubble sweeping cannot produce dense gas at the rate required to match the <span class="hlt">cloud</span> destruction rate. On the other hand, Toomre gravitational instability can reach the required production rate. We thus argue that, although dense, star-forming gas may last only around a single global free-fall time; the dense gas in star-forming galaxies can globally exist in a state of dynamic equilibrium between formation by gravitational instability and disruption by stellar feedback. At redshift z ≳ 2, the Toomre instability timescale decreases, resulting in a prediction of higher molecular gas fractions at early times, in agreement with the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004GeoRL..3114111B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004GeoRL..3114111B"><span>Aircraft measurements of high average charges on <span class="hlt">cloud</span> drops in layer <span class="hlt">clouds</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beard, Kenneth V.; Ochs, Harry T.; Twohy, Cynthia H.</p> <p>2004-07-01</p> <p>The first reliable aircraft measurements of characteristic <span class="hlt">cloud</span> drop charges were obtained by utilizing a counterflow virtual impactor to substantially increase charge sensitivity and eliminate spurious contact charging that contaminated previous aircraft measurements. We find average drop charges more than an order of magnitude larger than expected from mountain surface measurements in similar <span class="hlt">clouds</span>. Our evaluation of the data indicates that the high average charges on <span class="hlt">cloud</span> drops originate in charge layers at the <span class="hlt">cloud</span> boundaries and are carried into the <span class="hlt">cloud</span> layer by vertical motions. These initial aircraft results demonstrate that <span class="hlt">cloud</span> drop charges in layer <span class="hlt">clouds</span> may be high enough to influence microphysical processes that promote precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880062158&hterms=minimum+data+set&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dminimum%2Bdata%2Bset','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880062158&hterms=minimum+data+set&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dminimum%2Bdata%2Bset"><span>Properties of deep convective <span class="hlt">clouds</span> in the ISCCP Pilot Data Set. [International Satellite <span class="hlt">Cloud</span> Climatology Project</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Del Genio, Anthony D.; Yao, Mao-Sung</p> <p>1987-01-01</p> <p>Statistics on tropical deep convective <span class="hlt">clouds</span> in the International Satellite <span class="hlt">Cloud</span> Climatology Project Pilot Data Set are compiled by binning daytime data over areas of 2 X 2.5, 4 X 5, and 8 X 10 degrees. To isolate the convective <span class="hlt">clouds</span>, only pixels with minimum visible optical thickness of 32 and maximum <span class="hlt">cloud</span> top pressure of 550 mb are considered. Maps of convective <span class="hlt">cloud</span> cover and frequency of convective events and frequency histograms of deep convective <span class="hlt">cloud</span> pixels and <span class="hlt">cloud</span> top pressures are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED544685.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED544685.pdf"><span><span class="hlt">Cloud</span> Computing. Technology Briefing. Number 1</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Alberta Education, 2013</p> <p>2013-01-01</p> <p><span class="hlt">Cloud</span> computing is Internet-based computing in which shared resources, software and information are delivered as a service that computers or mobile devices can access on demand. <span class="hlt">Cloud</span> computing is already used extensively in education. Free or low-cost <span class="hlt">cloud</span>-based services are used daily by learners and educators to support learning, social…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=hadoop&id=EJ996798','ERIC'); return false;" href="https://eric.ed.gov/?q=hadoop&id=EJ996798"><span>Introducing <span class="hlt">Cloud</span> Computing Topics in Curricula</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chen, Ling; Liu, Yang; Gallagher, Marcus; Pailthorpe, Bernard; Sadiq, Shazia; Shen, Heng Tao; Li, Xue</p> <p>2012-01-01</p> <p>The demand for graduates with exposure in <span class="hlt">Cloud</span> Computing is on the rise. For many educational institutions, the challenge is to decide on how to incorporate appropriate <span class="hlt">cloud</span>-based technologies into their curricula. In this paper, we describe our design and experiences of integrating <span class="hlt">Cloud</span> Computing components into seven third/fourth-year…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/985074','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/985074"><span>The Mixed-Phase Arctic <span class="hlt">Cloud</span> Experiment.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Verlinde, J.; Harrington, Jerry Y.; McFarquhar, Greg; Yannuzzi, V. T.; Avramov, Alexander; Greenburg, S.; Johnson, N.; Zhang, G.; Poellot, Michael; Mather, Jim H.; Turner, David D.; Eloranta, E. W.; Zak, Bernard D.; Prenni, Anthony J.; Daniel, J. S.; Kok, G. L.; Tobin, D. C.; Holz, R. E.; Sassen, Kenneth; Spangenberg, D.; Minnis, Patrick; Tooman, Tim P.; Ivey, Mark D.; Richardson, S. J.; Bahrmann, C. P.; Shupe, Matthew D.; DeMott, Paul J.; Heymsfield, Andrew J.; Schofield, R.</p> <p>2007-02-01</p> <p>In order to help bridge the gaps in our understanding of mixed-phase Arctic <span class="hlt">clouds</span>, the Department of Energy Atmospheric Radiation Measurement Program (DOE-ARM) funded an integrated, systematic observational study. The major objective of the Mixed-Phase Arctic <span class="hlt">Cloud</span> Experiment (M-PACE), conducted September 27–October 22, 2004 during the autumnal transition season, was to collect a focused set of observations needed to advance our understanding of the <span class="hlt">cloud</span> microphysics, <span class="hlt">cloud</span> dynamics, thermodynamics, radiative properties, and evolution of Arctic mixed-phase <span class="hlt">clouds</span>. These data would then be used to improve to both detailed models of Arctic <span class="hlt">clouds</span> and large-scale climate models. M-PACE successfully documented the microphysical structure of arctic mixed-phase <span class="hlt">clouds</span>, with multiple in situ profiles in both single-layer and multi-layer <span class="hlt">clouds</span>, over the two ground-based remote sensing sites at Barrow and Oliktok Point. Liquid was found in <span class="hlt">clouds</span> with temperatures down to -30C, the coldest <span class="hlt">cloud</span> top temperature below -40C sampled by the aircraft. The remote sensing instruments suggest that ice was present in low concentrations, mostly concentrated in precipitation shafts, although there are indications of light ice precipitation present below the optically thick single-layer <span class="hlt">clouds</span>. Flights into arctic cirrus <span class="hlt">clouds</span> revealed microphysics properties very similar to their mid-latitude in situ formed cousins, with dominant ice crystal habit bullet rosettes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DPS....4750404G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DPS....4750404G"><span>Microphysics of Exoplanet <span class="hlt">Clouds</span> and Hazes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Peter; Benneke, Björn; Knutson, Heather A.; Yung, Yuk L.</p> <p>2015-11-01</p> <p><span class="hlt">Clouds</span> and hazes are ubiquitous in the atmospheres of exoplanets. However, as most of these planets have temperatures between 600 and 2000 K, their <span class="hlt">clouds</span> and hazes are likely composed of exotic condensates such as silicates, metals, and salts. We currently lack a satisfactory understanding of the microphysical processes that govern the distribution of these <span class="hlt">clouds</span> and hazes, thus creating a gulf between the <span class="hlt">cloud</span> properties retrieved from observations and the <span class="hlt">cloud</span> composition predictions from condensation equilibrium models. In this work we present a 1D microphysical <span class="hlt">cloud</span> model that calculates, from first principles, the rates of condensation, evaporation, coagulation, and vertical transport of chemically mixed <span class="hlt">cloud</span> and haze particles in warm and hot exoplanet atmospheres. The model outputs the equilibrium number density of <span class="hlt">cloud</span> particles with altitude, the particle size distribution, and the chemical makeup of the <span class="hlt">cloud</span> particles as a function of altitude and particle mass. The model aims to (1) explain the observed variability in “cloudiness” of individual exoplanets, (2) assess whether the proposed <span class="hlt">cloud</span> materials are capable of forming the observed particle distributions, and (3) examine the role <span class="hlt">clouds</span> have in the transport of (<span class="hlt">cloud</span>-forming) heavy elements in exoplanet atmospheres.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22711204G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22711204G"><span>Microphysics of Exoplanet <span class="hlt">Clouds</span> and Hazes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Peter; Benneke, Björn; Knutson, Heather; Yung, Yuk</p> <p>2016-01-01</p> <p><span class="hlt">Clouds</span> and hazes are ubiquitous in the atmospheres of exoplanets. However, as most of these planets have temperatures between 600 and 2000 K, their <span class="hlt">clouds</span> and hazes are likely composed of exotic condensates such as silicates, metals, and salts. We currently lack a satisfactory understanding of the microphysical processes that govern the distribution of these <span class="hlt">clouds</span> and hazes, thus creating a gulf between the <span class="hlt">cloud</span> properties retrieved from observations and the <span class="hlt">cloud</span> composition predictions from condensation equilibrium models. In this work we present a 1D microphysical <span class="hlt">cloud</span> model that calculates, from first principles, the rates of condensation, evaporation, coagulation, and vertical transport of chemically mixed <span class="hlt">cloud</span> and haze particles in warm and hot exoplanet atmospheres. The model outputs the equilibrium number density of <span class="hlt">cloud</span> particles with altitude, the particle size distribution, and the chemical makeup of the <span class="hlt">cloud</span> particles as a function of altitude and particle mass. The model aims to (1) explain the observed variability in "cloudiness" of individual exoplanets, (2) assess whether the proposed <span class="hlt">cloud</span> materials are capable of forming the observed particle distributions, and (3) examine the role <span class="hlt">clouds</span> have in the transport of (<span class="hlt">cloud</span>-forming) heavy elements in exoplanet atmospheres.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ESS.....311107G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ESS.....311107G"><span>Microphysics of Exoplanet <span class="hlt">Clouds</span> and Hazes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Peter; Benneke, Björn; Knutson, Heather; Yung, Yuk</p> <p>2015-12-01</p> <p><span class="hlt">Clouds</span> and hazes are ubiquitous in the atmospheres of exoplanets. However, as most of these planets have temperatures between 600 and 2000 K, their <span class="hlt">clouds</span> and hazes are likely composed of exotic condensates such as silicates, metals, and salts. We currently lack a satisfactory understanding of the microphysical processes that govern the distribution of these <span class="hlt">clouds</span> and hazes, thus creating a gulf between the <span class="hlt">cloud</span> properties retrieved from observations and the <span class="hlt">cloud</span> composition predictions from condensation equilibrium models. In this work we present a 1D microphysical <span class="hlt">cloud</span> model that calculates, from first principles, the rates of condensation, evaporation, coagulation, and vertical transport of chemically mixed <span class="hlt">cloud</span> and haze particles in warm and hot exoplanet atmospheres. The model outputs the equilibrium number density of <span class="hlt">cloud</span> particles with altitude, the particle size distribution, and the chemical makeup of the <span class="hlt">cloud</span> particles as a function of altitude and particle mass. The model aims to (1) explain the observed variability in “cloudiness” of individual exoplanets, (2) assess whether the proposed <span class="hlt">cloud</span> materials are capable of forming the observed particle distributions, and (3) examine the role <span class="hlt">clouds</span> have in the transport of (<span class="hlt">cloud</span>-forming) heavy elements in exoplanet atmospheres.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJMPB..3144079Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJMPB..3144079Z"><span>Remote sensing imaging simulation and <span class="hlt">cloud</span> removal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Xifang; Wu, Feng; Wu, Tao; Zhao, Chunyu</p> <p>2017-07-01</p> <p><span class="hlt">Cloud</span> obstacles obscure ground information frequently during remote sensing imaging which leads to valuable information losses. Removing <span class="hlt">clouds</span> from a single image becomes challenging since no reference images containing <span class="hlt">cloud</span>-free regions are available. In order to study <span class="hlt">cloud</span> removal technologies and evaluate their performances, a method to simulate evenly and unevenly distributed <span class="hlt">clouds</span> was proposed by analyzing the physical model of remote sensing imaging. Dual tree complex wavelet transform (DTCWT) and its features were introduced briefly. According to the frequency relationships between <span class="hlt">clouds</span> and ground objects in remote sensing images, a novel <span class="hlt">cloud</span> removal algorithm was proposed. The algorithm divided the <span class="hlt">cloud</span>-contaminated image into low-level high frequency sub-bands, high-level high frequency sub-bands and low frequency sub-band by DTCWT. Low-level high frequency sub-bands were filtered to enhance the ground object information by Laplacian sharpening. The other two types of sub-bands were processed to remove <span class="hlt">clouds</span> by <span class="hlt">cloud</span> cover coefficient weighting (CCCW). The experiments were implemented to process <span class="hlt">cloud</span> disturbed images produced by the proposed simulation method. The results of <span class="hlt">cloud</span> removal from remote sensing images were analyzed. It proved the proposed algorithm is greatly superior to algorithms based on traditional wavelet transform and dark channel prior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Cloud+AND+chamber&id=EJ1001296','ERIC'); return false;" href="http://eric.ed.gov/?q=Cloud+AND+chamber&id=EJ1001296"><span>Simple <span class="hlt">Cloud</span> Chambers Using Gel Ice Packs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kamata, Masahiro; Kubota, Miki</p> <p>2012-01-01</p> <p>Although <span class="hlt">cloud</span> chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using <span class="hlt">cloud</span> chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive <span class="hlt">cloud</span> chamber that uses the contents of gel ice packs which can substitute for dry…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Particle+AND+physics+AND+educations&pg=5&id=EJ1001296','ERIC'); return false;" href="https://eric.ed.gov/?q=Particle+AND+physics+AND+educations&pg=5&id=EJ1001296"><span>Simple <span class="hlt">Cloud</span> Chambers Using Gel Ice Packs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kamata, Masahiro; Kubota, Miki</p> <p>2012-01-01</p> <p>Although <span class="hlt">cloud</span> chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using <span class="hlt">cloud</span> chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive <span class="hlt">cloud</span> chamber that uses the contents of gel ice packs which can substitute for dry…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA13124.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA13124.html"><span>WISE View of a Wispy <span class="hlt">Cloud</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2010-08-10</p> <p>NASA Wide-field Infrared Survey Explorer highlights the Small Magellanic <span class="hlt">Cloud</span>, a small galaxy about 200,000 light-years away. Located in the constellation Tucana, the Small Magellanic <span class="hlt">Cloud</span> looks like a wispy <span class="hlt">cloud</span> encircling the south celestial pole.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10991197','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10991197"><span>Anomalous scaling of cumulus <span class="hlt">cloud</span> boundaries</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Siebesma; Jonker</p> <p>2000-07-03</p> <p>The geometrical properties of cumulus <span class="hlt">clouds</span> modeled by a numerical technique called large-eddy simulation are investigated. Surface-volume analyses reconfirm previous scaling results based on satellite data. This technique allows for the first time a direct analysis of the scaling behavior of <span class="hlt">cloud</span> boundaries of individual <span class="hlt">clouds</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/news/misr-level-3-cloud-motion-vector','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/news/misr-level-3-cloud-motion-vector"><span>MISR Level 3 <span class="hlt">Cloud</span> Motion Vector</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2013-07-10</p> <p>MISR Level 3 <span class="hlt">Cloud</span> Motion Vector Level 3 Wednesday, November 7, 2012 ... A new version, F02_0002, of the MISR L3 CMV (<span class="hlt">Cloud</span> Motion Vector) data product is now available. This new release provides finer ... coverage. These enhancements are the result of reorganizing motion vector information present in the recent Level 2 <span class="hlt">Cloud</span> product as ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.664b2003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.664b2003B"><span>Scaling the CERN OpenStack <span class="hlt">cloud</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bell, T.; Bompastor, B.; Bukowiec, S.; Castro Leon, J.; Denis, M. K.; van Eldik, J.; Fermin Lobo, M.; Fernandez Alvarez, L.; Fernandez Rodriguez, D.; Marino, A.; Moreira, B.; Noel, B.; Oulevey, T.; Takase, W.; Wiebalck, A.; Zilli, S.</p> <p>2015-12-01</p> <p>CERN has been running a production OpenStack <span class="hlt">cloud</span> since July 2013 to support physics computing and infrastructure services for the site. In the past year, CERN <span class="hlt">Cloud</span> Infrastructure has seen a constant increase in nodes, virtual machines, users and projects. This paper will present what has been done in order to make the CERN <span class="hlt">cloud</span> infrastructure scale out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA08599.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA08599.html"><span><span class="hlt">Cloud</span>Sat Overflight of Hurricane Bud</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2006-07-13</p> <p>The image at the top of figure 1 is from a geostationary imager. The colors relate to the temperature of the <span class="hlt">clouds</span>. The higher the <span class="hlt">clouds</span>, the lower the temperature. The highest, coldest <span class="hlt">clouds</span> are located near the center of the hurricane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EntIS...9..186R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EntIS...9..186R"><span><span class="hlt">Cloud</span> manufacturing: from concept to practice</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Lei; Zhang, Lin; Tao, Fei; Zhao, Chun; Chai, Xudong; Zhao, Xinpei</p> <p>2015-02-01</p> <p>The concept of <span class="hlt">cloud</span> manufacturing is emerging as a new promising manufacturing paradigm, as well as a business model, which is reshaping the service-oriented, highly collaborative, knowledge-intensive and eco-efficient manufacturing industry. However, the basic concepts about <span class="hlt">cloud</span> manufacturing are still in discussion. Both academia and industry will need to have a commonly accepted definition of <span class="hlt">cloud</span> manufacturing, as well as further guidance and recommendations on how to develop and implement <span class="hlt">cloud</span> manufacturing. In this paper, we review some of the research work and clarify some fundamental terminologies in this field. Further, we developed a <span class="hlt">cloud</span> manufacturing systems which may serve as an application example. From a systematic and practical perspective, the key requirements of <span class="hlt">cloud</span> manufacturing platforms are investigated, and then we propose a <span class="hlt">cloud</span> manufacturing platform prototype, Mfg<span class="hlt">Cloud</span>. Finally, a public <span class="hlt">cloud</span> manufacturing system for small- and medium-sized enterprises (SME) is presented. This paper presents a new perspective for <span class="hlt">cloud</span> manufacturing, as well as a <span class="hlt">cloud</span>-to-ground solution. The integrated solution proposed in this paper, including the terminology, Mfg<span class="hlt">Cloud</span>, and applications, can push forward this new paradigm from concept to practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1072691.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1072691.pdf"><span>The Education Value of <span class="hlt">Cloud</span> Computing</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Katzan, Harry, Jr.</p> <p>2010-01-01</p> <p><span class="hlt">Cloud</span> computing is a technique for supplying computer facilities and providing access to software via the Internet. <span class="hlt">Cloud</span> computing represents a contextual shift in how computers are provisioned and accessed. One of the defining characteristics of <span class="hlt">cloud</span> software service is the transfer of control from the client domain to the service provider.…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/version/pge12b','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/version/pge12b"><span>MISR Level 3 Albedo and <span class="hlt">Cloud</span> Versioning</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2016-11-04</p> <p>  MISR Level 3 Albedo and <span class="hlt">Cloud</span> Versioning Component Global Albedo Product (CGAL) and Component Global <span class="hlt">Cloud</span> Product (CGCL) - Daily, ...  <span class="hlt">CLOUD</span> - Wind Vectors, Height Histogram Stage 1:  ALBEDO - Expansive, Restrictive and Local Albedo (except over snow and ice) ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=hadoop&id=EJ996798','ERIC'); return false;" href="http://eric.ed.gov/?q=hadoop&id=EJ996798"><span>Introducing <span class="hlt">Cloud</span> Computing Topics in Curricula</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chen, Ling; Liu, Yang; Gallagher, Marcus; Pailthorpe, Bernard; Sadiq, Shazia; Shen, Heng Tao; Li, Xue</p> <p>2012-01-01</p> <p>The demand for graduates with exposure in <span class="hlt">Cloud</span> Computing is on the rise. For many educational institutions, the challenge is to decide on how to incorporate appropriate <span class="hlt">cloud</span>-based technologies into their curricula. In this paper, we describe our design and experiences of integrating <span class="hlt">Cloud</span> Computing components into seven third/fourth-year…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800007391','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800007391"><span>In situ exhaust <span class="hlt">cloud</span> measurements. [particle size distribution and <span class="hlt">cloud</span> physics of rocket exhaust <span class="hlt">clouds</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wornom, D.</p> <p>1980-01-01</p> <p>Airborne in situ exhaust <span class="hlt">cloud</span> measurements were conducted to obtain definitions of <span class="hlt">cloud</span> particle size range, Cl2 content, and HCl partitioning. Particle size distribution data and Cl2 measurements were made during the May, August, and September 1977 Titan launches. The measurements of three basic effluents - HCl, NO sub X, and particles - against minutes after launch are plotted. The maximum observed HCl concentration to the maximum Cl2 concentration are compared and the ratios of the Cl2 to the HCl is calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9159E..02F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9159E..02F"><span>Recognition methods on <span class="hlt">cloud</span> amount, movement of <span class="hlt">clouds</span>, and rain <span class="hlt">clouds</span> for rainfall prediction using whole sky images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fujinuma, Kazuma; Arai, Masayuki</p> <p>2014-04-01</p> <p>The final target of our research is to develop a system for forecasting local concentrated heavy rain, such as guerrilla rainstorms, by using whole sky images taken on the ground. To construct this system, this paper proposes the following recognition methods: <span class="hlt">cloud</span> amount, movement of <span class="hlt">clouds</span>, and rain <span class="hlt">clouds</span>. The experimental results show that red/blue (R/B) values are efficient for measuring the <span class="hlt">cloud</span> amount. However, using the gravity of images and the difference among time-sequenced images is insufficient to recognize the movement of <span class="hlt">clouds</span> and does not correlate well with the R/B values and rain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=peroxide&id=EJ1016988','ERIC'); return false;" href="http://eric.ed.gov/?q=peroxide&id=EJ1016988"><span>The "Mushroom <span class="hlt">Cloud</span>" Demonstration Revisited</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Panzarasa, Guido; Sparnacci, Katia</p> <p>2013-01-01</p> <p>A revisitation of the classical "mushroom <span class="hlt">cloud</span>" demonstration is described. Instead of aniline and benzoyl peroxide, the proposed reaction involves household chemicals such as alpha-pinene (turpentine oil) and trichloroisocyanuric acid ("Trichlor") giving an impressive demonstration of oxidation and combustion reactions that…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870024645&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DOort%2Bcloud','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870024645&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DOort%2Bcloud"><span>The Oort <span class="hlt">cloud</span> in transition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weissman, P. R.</p> <p>1986-01-01</p> <p>The evolution of theoretical and empirical models of the Oort <span class="hlt">cloud</span> (OC) since it was first proposed by Oort in 1950 is traced, and the main features of current models are discussed, in a general review. Consideration is given to work on the classical OC (Monte Carlo simulations of OC evolution, population and mass estimates, and OC perturbation by passing stars and giant molecular <span class="hlt">clouds</span>), models of a massive inner OC (simulations of planetesimal-swarm evolution in the Uranus-Neptune zone and IRAS observations of circumstellar dust shells), evidence for random and/or periodic comet showers, and the possible role of the Galactic missing mass. The current OC model comprises an almost spherical outer (10,000-100,000-AU) <span class="hlt">cloud</span> of mass 7-8 earth mass and population (1.4-2.3) x 10 to the 12th, and a flat disklike inner (40-10,000 AU) <span class="hlt">cloud</span> of mass 100-200 earth mass and population (1-10) x 10 to the 13th.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840006538','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840006538"><span>Space shuttle exhaust <span class="hlt">cloud</span> properties</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, B. J.; Keller, V. W.</p> <p>1983-01-01</p> <p>A data base describing the properties of the exhaust <span class="hlt">cloud</span> produced by the launch of the Space Transportation System and the acidic fallout observed after each of the first four launches was assembled from a series of ground and aircraft based measurements made during the launches of STS 2, 3, and 4. Additional data were obtained from ground-based measurements during firings of the 6.4 percent model of the Solid Rocket Booster at the Marshall Center. Analysis indicates that the acidic fallout is produced by atomization of the deluge water spray by the rocket exhaust on the pad followed by rapid scavening of hydrogen chloride gas aluminum oxide particles from the Solid Rocket Boosters. The atomized spray is carried aloft by updrafts created by the hot exhaust and deposited down wind. Aircraft measurements in the STS-3 ground <span class="hlt">cloud</span> showed an insignificant number of ice nuclei. Although no measurements were made in the column <span class="hlt">cloud</span>, the possibility of inadvertent weather modification caused by the interaction of ice nuclei with natural <span class="hlt">clouds</span> appears remote.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010hocc.book..493B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010hocc.book..493B"><span>HPC on Competitive <span class="hlt">Cloud</span> Resources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bientinesi, Paolo; Iakymchuk, Roman; Napper, Jeff</p> <p></p> <p>Computing as a utility has reached the mainstream. Scientists can now easily rent time on large commercial clusters that can be expanded and reduced on-demand in real-time. However, current commercial <span class="hlt">cloud</span> computing performance falls short of systems specifically designed for scientific applications. Scientific computing needs are quite different from those of the web applications that have been the focus of <span class="hlt">cloud</span> computing vendors. In this chapter we demonstrate through empirical evaluation the computational efficiency of high-performance numerical applications in a commercial <span class="hlt">cloud</span> environment when resources are shared under high contention. Using the Linpack benchmark as a case study, we show that cache utilization becomes highly unpredictable and similarly affects computation time. For some problems, not only is it more efficient to underutilize resources, but the solution can be reached sooner in realtime (wall-time). We also show that the smallest, cheapest (64-bit) instance on the studied environment is the best for price to performance ration. In light of the high-contention we witness, we believe that alternative definitions of efficiency for commercial <span class="hlt">cloud</span> environments should be introduced where strong performance guarantees do not exist. Concepts like average, expected performance and execution time, expected cost to completion, and variance measures--traditionally ignored in the high-performance computing context--now should complement or even substitute the standard definitions of efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=cloud+AND+storage&id=EJ919565','ERIC'); return false;" href="http://eric.ed.gov/?q=cloud+AND+storage&id=EJ919565"><span><span class="hlt">Cloud</span>-Based Data Storage</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Waters, John K.</p> <p>2011-01-01</p> <p>The vulnerability and inefficiency of backing up data on-site is prompting school districts to switch to more secure, less troublesome <span class="hlt">cloud</span>-based options. District auditors are pushing for a better way to back up their data than the on-site, tape-based system that had been used for years. About three years ago, Hendrick School District in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=peroxides&id=EJ1016988','ERIC'); return false;" href="https://eric.ed.gov/?q=peroxides&id=EJ1016988"><span>The "Mushroom <span class="hlt">Cloud</span>" Demonstration Revisited</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Panzarasa, Guido; Sparnacci, Katia</p> <p>2013-01-01</p> <p>A revisitation of the classical "mushroom <span class="hlt">cloud</span>" demonstration is described. Instead of aniline and benzoyl peroxide, the proposed reaction involves household chemicals such as alpha-pinene (turpentine oil) and trichloroisocyanuric acid ("Trichlor") giving an impressive demonstration of oxidation and combustion reactions that…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18268731','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18268731"><span>Can cirrus <span class="hlt">clouds</span> produce glories?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sassen, K; Arnott, W P; Barnett, J M; Aulenbach, S</p> <p>1998-03-20</p> <p>A vague glory display was photographed over central Utah from an airplane beginning its descent through a cirrus <span class="hlt">cloud</span> layer with an estimated <span class="hlt">cloud</span> top temperature of -45 and -55 degrees C. Photographic analysis reveals a single reddish-brown ring of 2.5-3.0 degrees radius around the antisolar point, although a second ring appeared visually to have been present over the brief observation period. Mie and approximate nonspherical theory scattering simulations predict a population of particles with modal diameters between 9 and 15 mum. Although it is concluded that multiple-ringed glories can be accounted for only through the backscattering of light from particles that are strictly spherical in shape, the poor glory colorization in this case could imply the presence of slightly aspherical ice particles. The location of this display over mountainous terrain suggests that it was generated by an orographic wave <span class="hlt">cloud</span>, which we speculate produced numerous frozen <span class="hlt">cloud</span> droplets that only gradually took on crystalline characteristics during growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=generator&pg=4&id=EJ1101126','ERIC'); return false;" href="https://eric.ed.gov/?q=generator&pg=4&id=EJ1101126"><span>More than a Word <span class="hlt">Cloud</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Filatova, Olga</p> <p>2016-01-01</p> <p>Word <span class="hlt">cloud</span> generating applications were originally designed to add visual attractiveness to posters, websites, slide show presentations, and the like. They can also be an effective tool in reading and writing classes in English as a second language (ESL) for all levels of English proficiency. They can reduce reading time and help to improve…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC31I..02G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC31I..02G"><span>Limits of cirrus <span class="hlt">cloud</span> seeding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gasparini, B.; Münch, S.; Lohmann, U.</p> <p>2016-12-01</p> <p>The net warming effect of cirrus <span class="hlt">clouds</span> has driven part of the geoengineering research toward the idea of decreasing cirrus occurrence by seeding them with effective ice nucleating particles (INP). However, recent studies disagree whether such a measure would be effective. We used the ECHAM-HAM GCM to simulate a globally uniform scenario of cirrus seeding by effective INP with a radius of 0.5 μm. In our simulations cirrus seeding has no significant climatic effects, due to two main limiting factors: ice crystal radius decrease and <span class="hlt">cloud</span> cover increase. Nevertheless, by increasing the seeding ice nucleating particle radius from 0.5 to 50 μm we obtain a negative top-of-the-atmosphere radiative anomaly of up to -1 W/m2. Idealised scenarios with increased sedimentation velocity, which we found to be a good proxy for seeding, decrease the radiative balance by up to -2.3 W/m2. The negative anomaly is in both cases a result of decreases in cirrus <span class="hlt">cloud</span> frequency, upper tropospheric ice water content, and ice crystal number. Our simulations assume ice nucleating particles being able to nucleate ice crystals only at temperatures below -35°C. Additional inclusion of the impacts of seeded particles on mixed-phase <span class="hlt">clouds</span> partially counteracts the seeding effects for INP concentrations larger than 3 L-1 due to their glaciation effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22875554','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22875554"><span>DICOM relay over the <span class="hlt">cloud</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Silva, Luís A Bastião; Costa, Carlos; Oliveira, José Luis</p> <p>2013-05-01</p> <p>Healthcare institutions worldwide have adopted picture archiving and communication system (PACS) for enterprise access to images, relying on Digital Imaging Communication in Medicine (DICOM) standards for data exchange. However, communication over a wider domain of independent medical institutions is not well standardized. A DICOM-compliant bridge was developed for extending and sharing DICOM services across healthcare institutions without requiring complex network setups or dedicated communication channels. A set of DICOM routers interconnected through a public <span class="hlt">cloud</span> infrastructure was implemented to support medical image exchange among institutions. Despite the advantages of <span class="hlt">cloud</span> computing, new challenges were encountered regarding data privacy, particularly when medical data are transmitted over different domains. To address this issue, a solution was introduced by creating a ciphered data channel between the entities sharing DICOM services. Two main DICOM services were implemented in the bridge: Storage and Query/Retrieve. The performance measures demonstrated it is quite simple to exchange information and processes between several institutions. The solution can be integrated with any currently installed PACS-DICOM infrastructure. This method works transparently with well-known <span class="hlt">cloud</span> service providers. <span class="hlt">Cloud</span> computing was introduced to augment enterprise PACS by providing standard medical imaging services across different institutions, offering communication privacy and enabling creation of wider PACS scenarios with suitable technical solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMIN21B1731C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMIN21B1731C"><span>The AIST Managed <span class="hlt">Cloud</span> Environment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cook, S.</p> <p>2016-12-01</p> <p>ESTO is currently in the process of developing and implementing the AIST Managed <span class="hlt">Cloud</span> Environment (AMCE) to offer <span class="hlt">cloud</span> computing services to ESTO-funded PIs to conduct their project research. AIST will provide projects access to a <span class="hlt">cloud</span> computing framework that incorporates NASA security, technical, and financial standards, on which project can freely store, run, and process data. Currently, many projects led by research groups outside of NASA do not have the awareness of requirements or the resources to implement NASA standards into their research, which limits the likelihood of infusing the work into NASA applications. Offering this environment to PIs will allow them to conduct their project research using the many benefits of <span class="hlt">cloud</span> computing. In addition to the well-known cost and time savings that it allows, it also provides scalability and flexibility. The AMCE will facilitate infusion and end user access by ensuring standardization and security. This approach will ultimately benefit ESTO, the science community, and the research, allowing the technology developments to have quicker and broader applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770000275&hterms=Cloud+chamber&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DCloud%2Bchamber','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770000275&hterms=Cloud+chamber&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DCloud%2Bchamber"><span>Fast-response <span class="hlt">cloud</span> chamber</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fogal, G. L.</p> <p>1977-01-01</p> <p>Wall structure keeps chambers at constant, uniform temperature, yet allows them to be cooled rapidly if necessary. Wall structure, used in fast-response <span class="hlt">cloud</span> chamber, has surface heater and coolant shell separated by foam insulation. It is lightweight and requires relatively little power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Traction+AND+storage&id=EJ919565','ERIC'); return false;" href="https://eric.ed.gov/?q=Traction+AND+storage&id=EJ919565"><span><span class="hlt">Cloud</span>-Based Data Storage</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Waters, John K.</p> <p>2011-01-01</p> <p>The vulnerability and inefficiency of backing up data on-site is prompting school districts to switch to more secure, less troublesome <span class="hlt">cloud</span>-based options. District auditors are pushing for a better way to back up their data than the on-site, tape-based system that had been used for years. About three years ago, Hendrick School District in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA00063.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA00063.html"><span>Neptune - True Color of <span class="hlt">Clouds</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1996-01-29</p> <p>This image of Neptune was taken by NASA Voyager 2 wide-angle camera; small trails of similar <span class="hlt">clouds</span> trending east to west and large scale structure east of the Great Dark Spot all suggest that waves are present in the atmosphere and play a large role. http://photojournal.jpl.nasa.gov/catalog/PIA00063</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003nrao.pres....1.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003nrao.pres....1."><span><span class="hlt">Clouds</span> Dominate the Galactic Halo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p>2003-01-01</p> <p>Using the exquisite sensitivity of the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT), astronomer Jay Lockman of the National Radio Astronomy Observatory (NRAO) in Green Bank, W. Va., has produced the best cross-section ever of the Milky Way Galaxy's diffuse halo of hydrogen gas. This image confirms the presence of discrete hydrogen <span class="hlt">clouds</span> in the halo, and could help astronomers understand the origin and evolution of the rarefied atmosphere that surrounds our Galaxy. Lockman presented his findings at the American Astronomical Society meeting in Seattle, WA. Hydrogen <span class="hlt">Clouds</span> Graphic Artist's Rendering of the Milky Way (background) with insert showing GBT image of cross-section of neutral atomic Hydrogen Credit: Kirk Woellert/National Science Foundation Patricia Smiley, NRAO. "The first observations with the Green Bank Telescope suggested that the hydrogen in the lower halo, the transition zone between the Milky Way and intergalactic space, is very clumpy," said Lockman. "The latest data confirm these results and show that instead of trailing away smoothly from the Galactic plane, a significant fraction of the hydrogen gas in the halo is concentrated in discrete <span class="hlt">clouds</span>. There are even some filaments." Beyond the star-filled disk of the Milky Way, there exists an extensive yet diffuse halo of hydrogen gas. For years, astronomers have speculated about the origin and structure of this gas. "Even the existence of neutral hydrogen in the halo has been somewhat of a puzzle," Lockman remarked. "Unlike the Earth's atmosphere, which is hot enough to hold itself up against the force of gravity, the hydrogen in the halo is too cool to support itself against the gravitational pull of the Milky Way." Lockman points out that some additional factor has to be involved to get neutral hydrogen to such large distances from the Galactic plane. "This force could be cosmic rays, a supersonic wind, the blast waves from supernovae, or something we have not thought of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.448.2634B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.448.2634B"><span>Violent relaxation of ellipsoidal <span class="hlt">clouds</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benhaiem, David; Sylos Labini, Francesco</p> <p>2015-04-01</p> <p>An isolated, initially cold and ellipsoidal <span class="hlt">cloud</span> of self-gravitating particles represents a relatively simple system in which to study the effects of deviations from spherical symmetry in the mechanism of violent relaxation. Initial deviations from spherical symmetry are shown to play a dynamical role that is equivalent to that of density fluctuations in the case of an initially spherical <span class="hlt">cloud</span>. Indeed, these deviations control the amount of particle-energy change and thus determine the properties of the final energy distribution, particularly the appearance of two species of particles: bound and free. Ejection of mass and energy from the system, together with the formation of a density profile decaying as ρ(r) ˜ r-4 and a Keplerian radial velocity dispersion profile, are prominent features similar to those observed after the violent relaxation of spherical <span class="hlt">clouds</span>. In addition, we find that ejected particles are characterized by highly non-spherical shapes, the features of which can be traced in the initial deviations from spherical symmetry that are amplified during the dynamical evolution: particles can indeed form anisotropic configurations, like bars and/or discs, even though the initial <span class="hlt">cloud</span> was very close to spherical.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=generator&pg=4&id=EJ1101126','ERIC'); return false;" href="http://eric.ed.gov/?q=generator&pg=4&id=EJ1101126"><span>More than a Word <span class="hlt">Cloud</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Filatova, Olga</p> <p>2016-01-01</p> <p>Word <span class="hlt">cloud</span> generating applications were originally designed to add visual attractiveness to posters, websites, slide show presentations, and the like. They can also be an effective tool in reading and writing classes in English as a second language (ESL) for all levels of English proficiency. They can reduce reading time and help to improve…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820014881','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820014881"><span>Ground <span class="hlt">cloud</span> air quality effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brubaker, K. L.</p> <p>1980-01-01</p> <p>The effects of the ground <span class="hlt">cloud</span> associated with launching of a large rocket on air quality are discussed. The ground <span class="hlt">cloud</span> consists of the exhaust emitted by the rocket during the first 15 to 25 seconds following ignition and liftoff, together with a large quantity of entrained air, cooling water, dust and other debris. Immediately after formation, the ground <span class="hlt">cloud</span> rises in the air due to the buoyant effect of its high thermal energy content. Eventually, at an altitude typically between 0.7 and 3 km, the <span class="hlt">cloud</span> stabilizes and is carried along by the prevailing wind at that altitude. For the use of heavy lift launch vehicles small quantities of nitrogen oxides, primarily nitric oxide and nitrogen dioxide, are expected to be produced from a molecular nitrogen impurity in the fuel or liquid oxygen, or from entrainment and heating of ambient air in the hot rocket exhaust. In addition, possible impurities such as sulfur in the fuel would give rise to a corresponding amount of oxidation products such as sulfur dioxide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080008148&hterms=pollution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dpollution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080008148&hterms=pollution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dpollution"><span>Study Pollution Impacts on Upper-Tropospheric <span class="hlt">Clouds</span> with Aura, <span class="hlt">Cloud</span>Sat, and CALIPSO Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, Dong</p> <p>2007-01-01</p> <p>This viewgraph presentation reviews the impact of pollution on <span class="hlt">clouds</span> in the Upper Troposphere. Using the data from the Aura Microwave Limb Sounder (MLS), <span class="hlt">Cloud</span>Sat, CALIPSO the presentation shows signatures of pollution impacts on <span class="hlt">clouds</span> in the upper troposphere. The presentation demonstrates the complementary sensitivities of MLS , <span class="hlt">Cloud</span>Sat and CALIPSO to upper tropospheric <span class="hlt">clouds</span>. It also calls for careful analysis required to sort out microphysical changes from dynamical changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080008148&hterms=aura&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Daura','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080008148&hterms=aura&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Daura"><span>Study Pollution Impacts on Upper-Tropospheric <span class="hlt">Clouds</span> with Aura, <span class="hlt">Cloud</span>Sat, and CALIPSO Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, Dong</p> <p>2007-01-01</p> <p>This viewgraph presentation reviews the impact of pollution on <span class="hlt">clouds</span> in the Upper Troposphere. Using the data from the Aura Microwave Limb Sounder (MLS), <span class="hlt">Cloud</span>Sat, CALIPSO the presentation shows signatures of pollution impacts on <span class="hlt">clouds</span> in the upper troposphere. The presentation demonstrates the complementary sensitivities of MLS , <span class="hlt">Cloud</span>Sat and CALIPSO to upper tropospheric <span class="hlt">clouds</span>. It also calls for careful analysis required to sort out microphysical changes from dynamical changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-GSFC_20170927_Archive_e001970.jpg.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-GSFC_20170927_Archive_e001970.jpg.html"><span>Winter <span class="hlt">Cloud</span> Streets, North Atlantic</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-09-28</p> <p>NASA image acquired January 24, 2011 What do you get when you mix below-freezing air temperatures, frigid northwest winds from Canada, and ocean temperatures hovering around 39 to 40 degrees Fahrenheit (4 to 5 degrees Celsius)? Paved highways of <span class="hlt">clouds</span> across the skies of the North Atlantic. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite collected this natural-color view of New England, the Canadian Maritimes, and coastal waters at 10:25 a.m. U.S. Eastern Standard Time on January 24, 2011. Lines of <span class="hlt">clouds</span> stretch from northwest to southeast over the North Atlantic, while the relatively cloudless skies over land afford a peek at the snow that blanketed the Northeast just a few days earlier. <span class="hlt">Cloud</span> streets form when cold air blows over warmer waters, while a warmer air layer—or temperature inversion—rests over top of both. The comparatively warm water of the ocean gives up heat and moisture to the cold air mass above, and columns of heated air—thermals—naturally rise through the atmosphere. As they hit the temperature inversion like a lid, the air rolls over like the circulation in a pot of boiling water. The water in the warm air cools and condenses into flat-bottomed, fluffy-topped cumulus <span class="hlt">clouds</span> that line up parallel to the wind. Though they are easy to explain in a broad sense, <span class="hlt">cloud</span> streets have a lot of mysteries on the micro scale. A NASA-funded researcher from the University of Wisconsin recently observed an unusual pattern in <span class="hlt">cloud</span> streets over the Great Lakes. <span class="hlt">Cloud</span> droplets that should have picked up moisture from the atmosphere and grown in size were instead shrinking as they moved over Lake Superior. Read more in an interview at What on Earth? NASA image by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Michael Carlowicz. Instrument: Terra - MODIS Credit: NASA Earth Observatory NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860051498&hterms=cumulus+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcumulus%2Bcloud','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860051498&hterms=cumulus+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcumulus%2Bcloud"><span>Cumulus <span class="hlt">cloud</span> properties derived using Landsat satellite data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wielicki, B. A.; Welch, R. M.</p> <p>1986-01-01</p> <p>Landsat Multispectral Scanner (MSS) digital data are used to remotely sense cumulus <span class="hlt">cloud</span> properties such as <span class="hlt">cloud</span> fraction and <span class="hlt">cloud</span> reflectance, along with the distribution of <span class="hlt">cloud</span> number and <span class="hlt">cloud</span> fraction as a function of <span class="hlt">cloud</span> size. The analysis is carried out for four cumulus fields covering regions approximately 150 km square. Results for these initial <span class="hlt">cloud</span> fields indicate that: (1) the common intuitive model of <span class="hlt">clouds</span> as nearly uniform reflecting surfaces is a poor representation of cumulus <span class="hlt">clouds</span>, (2) the cumulus <span class="hlt">clouds</span> were often multicelled, even for <span class="hlt">clouds</span> as small as 1 km in diameter, (3) <span class="hlt">cloud</span> fractional coverage derived using a simple reflectance threshold is sensitive to the chosen threshold even for 57-meter resolution Landsat data, (4) the sensitivity of <span class="hlt">cloud</span> fraction to changes in satellite sensor resolution is less sensitive than suggested theoretically, and (5) the Landsat derived <span class="hlt">cloud</span> size distributions show encouraging similarities among the <span class="hlt">cloud</span> fields examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A21D0085R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A21D0085R"><span>Death of an Arctic Mixed Phase <span class="hlt">Cloud</span>: How Changes in the Arctic Environment Influence <span class="hlt">Cloud</span> Properties and <span class="hlt">Cloud</span> Radiative Feedbacks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roesler, E. L.; Posselt, D. J.</p> <p>2012-12-01</p> <p>Arctic mixed phase stratocumulus <span class="hlt">clouds</span> exert an important influence on the radiative budget over the Arctic ocean and sea ice. Field programs and numerical experiments have shown the properties of these <span class="hlt">clouds</span> to be sensitive to changes in the surface properties, thermodynamic environment, and aerosols. While it is clear that Arctic mixed-phase <span class="hlt">clouds</span> respond to changes in the Arctic environment, uncertainty remains as to how climate warming will affect the <span class="hlt">cloud</span> micro- and macrophysical properties. This is in no small part due to the fact that there are nonlinear interactions between changes in atmospheric and surface properties and changes in <span class="hlt">cloud</span> characteristics. In this study, large-eddy simulations are performed of an arctic mixed phase <span class="hlt">cloud</span> observed during the Indirect and Semi-Direct Aerosol Campaign. A parameter-space-filling uncertainty quantification technique is used to rigorously explore how simulated arctic mixed phase <span class="hlt">clouds</span> respond to changes in the properties of the environment. Specifically, the <span class="hlt">cloud</span> ice and aerosol concentration, surface sensible and latent heat fluxes, and large scale temperature, water vapor, and vertical motion are systematically changed, and the properties of the resulting <span class="hlt">clouds</span> are examined. It is found that Arctic mixed phase <span class="hlt">clouds</span> exhibit four characteristic behaviors: stability, growth, decay, and dissipation. Sets of environmental and surface properties that lead to the emergence of each type of behavior are presented, and the implications for the response of Arctic <span class="hlt">clouds</span> to changes in climate are explored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007MNRAS.378..893B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007MNRAS.378..893B"><span>CaFe interstellar <span class="hlt">clouds</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bondar, A.; Kozak, M.; Gnaciński, P.; Galazutdinov, G. A.; Beletsky, Y.; Krełowski, J.</p> <p>2007-07-01</p> <p>A new kind of interstellar <span class="hlt">cloud</span> is proposed. These are rare (just a few examples among ~300 lines of sight) objects with the CaI 4227-Å, FeI 3720-Å and 3860-Å lines stronger than those of KI (near 7699 Å) and NaI (near 3302 Å). We propose the name `CaFe' for these <span class="hlt">clouds</span>. Apparently they occupy different volumes from the well-known interstellar HI <span class="hlt">clouds</span> where the KI and ultraviolet NaI lines are dominant features. In the CaFe <span class="hlt">clouds</span> we have not found either detectable molecular features (CH, CN) or diffuse interstellar bands which, as commonly believed, are carried by some complex, organic molecules. We have found the CaFe <span class="hlt">clouds</span> only along sightlines toward hot, luminous (and thus distant) objects with high rates of mass loss. In principle, the observed gas-phase interstellar abundances reflect the combined effects of the nucleosynthetic history of the material, the depletion of heavy elements into dust grains and the ionization state of these elements which may depend on irradiation by neighbouring stars. Based on data collected using the Maestro spectrograph at the Terskol 2-m telescope, Russia; and on data collected using the ESO Feros spectrograph; and on data obtained from the ESO Science Archive Facility acquired with the UVES spectrograph, Chile. E-mail: `arctur'@rambler.ru (AB); marizak@astri.uni.torun.pl (MK); pg@iftia.univ.gda.pl (PG); gala@boao.re.kr (GAG); ybialets@eso.org (YB); jacek@astri.uni.torun.pl (JK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.B42A..09V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.B42A..09V"><span>Diurnal and Seasonal <span class="hlt">Cloud</span> Base Patterns Highlight Small-Mountain Tropical <span class="hlt">Cloud</span> Forest Vulnerability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Van Beusekom, A.; Gonzalez, G.; Scholl, M. A.</p> <p>2016-12-01</p> <p>The degree to which <span class="hlt">cloud</span> immersion sustains tropical montane <span class="hlt">cloud</span> forests (TMCFs) during rainless periods and the amount these <span class="hlt">clouds</span> are affected by urban areas is not well understood, as <span class="hlt">cloud</span> base is rarely quantified near mountains. We found that a healthy small-mountain TMCF in Puerto Rico had lowest <span class="hlt">cloud</span> base during the mid-summer dry season. In addition, we observed that <span class="hlt">cloud</span> bases were lower than the mountaintops as often in the winter dry season as in the wet seasons, based on 2.5 years of direct and 16 years of indirect observations. The low <span class="hlt">clouds</span> during dry season appear to be explained by proximity to the oceanic <span class="hlt">cloud</span> system where lower <span class="hlt">clouds</span> are seasonally invariant in altitude and cover; along with orographic lifting and trade-wind control over <span class="hlt">cloud</span> formation. These results suggest that climate change impacts on small-mountain TMCFs may not be limited to the dry season; changes in regional-scale patterns that cause drought periods during the wet seasons will likely have higher <span class="hlt">cloud</span> base, and thus may threaten <span class="hlt">cloud</span> water support to sensitive mountain ecosystems. Strong El Niño's can cause drought in Puerto Rico; we will report results from the summer of 2015 that examined El Niño effects on <span class="hlt">cloud</span> base altitudes. Looking at regionally collected airport <span class="hlt">cloud</span> data, we see indicators that diurnal urban effects may already be raising the low <span class="hlt">cloud</span> bases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812368W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812368W"><span>Comparison of different <span class="hlt">cloud</span> types from surface and satellite <span class="hlt">cloud</span> classification products over China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Minyan; Zeng, Le; Wang, Shengjie; Gu, Junxia; Yang, Runzhi</p> <p>2016-04-01</p> <p>Different <span class="hlt">cloud</span> types usually have different <span class="hlt">cloud</span> dynamic process and micro-physical characteristics, and the relative <span class="hlt">cloud</span> radiation forcing effects vary much. In recent years, the focus of <span class="hlt">cloud</span> classification is the algorithm development, as well as the analysis on total <span class="hlt">cloud</span> amount, high/middle/low <span class="hlt">cloud</span> amount. While, research on the different <span class="hlt">cloud</span> types (like cirrus, stratus, and cumulonimbus) is not enough. In this research, we use multi-resources <span class="hlt">cloud</span> classification products including FY-2, Cloudsat and surface observation to obtain the temporal-spatial distribution characteristics and evolvement of different <span class="hlt">cloud</span> types in different regions of China, analyze the quantitative difference of multi-source products and the reasons. According to the temporal and spatial scales of <span class="hlt">cloud</span>, and temporal-spatial representation of <span class="hlt">cloud</span> classification products based on <span class="hlt">Cloud</span>Sat, etc, the scaling is necessary to explore in temporal-spatial matching/validation research. This research have important scientific significances on understanding the regional characteristics of different <span class="hlt">cloud</span> types in China, improving the remote sensing retrieve algorithms on <span class="hlt">cloud</span> classification, temporal-spatial matching/validation techniques of satellite data, and <span class="hlt">cloud</span> vertical structure parameterized methods in numerical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900031740&hterms=Physical+Chemistry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhysical%2BChemistry','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900031740&hterms=Physical+Chemistry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhysical%2BChemistry"><span>Diffuse <span class="hlt">cloud</span> chemistry. [in interstellar matter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Van Dishoeck, Ewine F.; Black, John H.</p> <p>1988-01-01</p> <p>The current status of models of diffuse interstellar <span class="hlt">clouds</span> is reviewed. A detailed comparison of recent gas-phase steady-state models shows that both the physical conditions and the molecular abundances in diffuse <span class="hlt">clouds</span> are still not fully understood. Alternative mechanisms are discussed and observational tests which may discriminate between the various models are suggested. Recent developments regarding the velocity structure of diffuse <span class="hlt">clouds</span> are mentioned. Similarities and differences between the chemistries in diffuse <span class="hlt">clouds</span> and those in translucent and high latitude <span class="hlt">clouds</span> are pointed out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015amos.confE..82M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015amos.confE..82M"><span>Comparison of IR and Visible <span class="hlt">Cloud</span> Imagers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mandeville, W.; McLaughlin, T.; Bygren, S.; Randell, C.</p> <p></p> <p>This paper presents a comparison between the Infrared <span class="hlt">Cloud</span> Imager (IRCI) used at Ground-based Electro-Optical Deep Space Surveillance (GEODSS) sites and the Visible <span class="hlt">Cloud</span> Imager (VCI) developed using a COTS all-sky camera. The <span class="hlt">cloud</span> imagers are used to create exclusion maps for GEODSS observations based on detected <span class="hlt">cloud</span> locations. Excluding observation attempts in obscured areas of the sky is done to improve the allocation of sensor resources. Estimates are made for atmospheric extinction across the entire sky by comparing known star brightness to measured brightness. Data for the comparison were collected at the GEODSS test site located in Yoder, Colorado for a variety of <span class="hlt">cloud</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8386E..0AL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8386E..0AL"><span>Transitioning ISR architecture into the <span class="hlt">cloud</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lash, Thomas D.</p> <p>2012-06-01</p> <p>Emerging <span class="hlt">cloud</span> computing platforms offer an ideal opportunity for Intelligence, Surveillance, and Reconnaissance (ISR) intelligence analysis. <span class="hlt">Cloud</span> computing platforms help overcome challenges and limitations of traditional ISR architectures. Modern ISR architectures can benefit from examining commercial <span class="hlt">cloud</span> applications, especially as they relate to user experience, usage profiling, and transformational business models. This paper outlines legacy ISR architectures and their limitations, presents an overview of <span class="hlt">cloud</span> technologies and their applications to the ISR intelligence mission, and presents an idealized ISR architecture implemented with <span class="hlt">cloud</span> computing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EntIS...8..167Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EntIS...8..167Z"><span><span class="hlt">Cloud</span> manufacturing: a new manufacturing paradigm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Lin; Luo, Yongliang; Tao, Fei; Li, Bo Hu; Ren, Lei; Zhang, Xuesong; Guo, Hua; Cheng, Ying; Hu, Anrui; Liu, Yongkui</p> <p>2014-03-01</p> <p>Combining with the emerged technologies such as <span class="hlt">cloud</span> computing, the Internet of things, service-oriented technologies and high performance computing, a new manufacturing paradigm - <span class="hlt">cloud</span> manufacturing (CMfg) - for solving the bottlenecks in the informatisation development and manufacturing applications is introduced. The concept of CMfg, including its architecture, typical characteristics and the key technologies for implementing a CMfg service platform, is discussed. Three core components for constructing a CMfg system, i.e. CMfg resources, manufacturing <span class="hlt">cloud</span> service and manufacturing <span class="hlt">cloud</span> are studied, and the constructing method for manufacturing <span class="hlt">cloud</span> is investigated. Finally, a prototype of CMfg and the existing related works conducted by the authors' group on CMfg are briefly presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880001353','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880001353"><span>Solar activity, magnetic <span class="hlt">clouds</span>, and geomagnetic storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>1987-01-01</p> <p>Associational aspects of magnetic <span class="hlt">clouds</span> and solar activity, and of magnetic <span class="hlt">clouds</span> and geomagentic storms are described. For example, recent research has shown associations to exist between the launch of magnetic <span class="hlt">clouds</span> directed Earthward from the Sun and, in particular, two forms of solar activity: flare-related, type II metric radio bursts and disappearing filaments (prominences). Furthermore, recent research has shown an association to exist between the onset of magnetic <span class="hlt">clouds</span> on Earth and the initiation of geomagnetic storms. Based on these findings, STIP Intervals XV-XIX are examined for possible occurrences of Earthward-directed magnetic <span class="hlt">clouds</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1093516','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1093516"><span>Separating <span class="hlt">Cloud</span> Forming Nuclei from Interstitial Aerosol</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kulkarni, Gourihar R.</p> <p>2012-09-12</p> <p>It has become important to characterize the physicochemical properties of aerosol that have initiated the warm and ice <span class="hlt">clouds</span>. The data is urgently needed to better represent the aerosol-<span class="hlt">cloud</span> interaction mechanisms in the climate models. The laboratory and in-situ techniques to separate precisely the aerosol particles that act as <span class="hlt">cloud</span> condensation nuclei (CCN) and ice nuclei (IN), termed as <span class="hlt">cloud</span> nuclei (CN) henceforth, have become imperative in studying aerosol effects on <span class="hlt">clouds</span> and the environment. This review summarizes these techniques, design considerations, associated artifacts and challenges, and briefly discusses the need for improved designs to expand the CN measurement database.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993LNP...416...44I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993LNP...416...44I"><span>Ionized carbon (CII) in the Magellanic <span class="hlt">Clouds</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Israel, F. P.; Maloney, P. R.</p> <p></p> <p>We present preliminary results of recently obtained observations of the important cooling line of singly ionized carbon in the Magellanic <span class="hlt">Clouds</span>. Three large Magellanic <span class="hlt">Cloud</span> (LMC) and six HII region/CO <span class="hlt">cloud</span> complexes have been detected and mapped. Comparison shows that the strength and distribution of (CII) regions is well-correlated with those of dust complexes emitting far-infrared radiation, but not with molecular <span class="hlt">cloud</span> complexes traced by CO emission. The results confirm that photo-dissociation processes are of relatively greater importance in Magellanic <span class="hlt">Cloud</span> star formation regions than in Galactic regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160006542','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160006542"><span>Potential New Lidar Observations for <span class="hlt">Cloud</span> Studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winker, Dave; Hu, Yong; Narir, Amin; Cai, Xia</p> <p>2015-01-01</p> <p>The response of <span class="hlt">clouds</span> to global warming represents a major uncertainty in estimating climate sensitivity. These uncertainties have been tracked to shallow marine <span class="hlt">clouds</span> in the tropics and subtropics. CALIOP observations have already been used extensively to evaluate model predictions of shallow <span class="hlt">cloud</span> fraction and top height (Leahy et al. 2013; Nam et al 2012). Tools are needed to probe the lowest levels of the troposphere. The large footprint of satellite lidars gives large multiple scattering from <span class="hlt">clouds</span> which presents new possibilities for <span class="hlt">cloud</span> retrievals to constrain model predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010050107&hterms=Gore&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DGore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010050107&hterms=Gore&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DGore"><span>Precipitating Condensation <span class="hlt">Clouds</span> in Substellar Atmospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ackerman, Andrew S.; Marley, Mark S.; Gore, Warren J. (Technical Monitor)</p> <p>2000-01-01</p> <p>We present a method to calculate vertical profiles of particle size distributions in condensation <span class="hlt">clouds</span> of giant planets and brown dwarfs. The method assumes a balance between turbulent diffusion and precipitation in horizontally uniform <span class="hlt">cloud</span> decks. Calculations for the Jovian ammonia <span class="hlt">cloud</span> are compared with previous methods. An adjustable parameter describing the efficiency of precipitation allows the new model to span the range of predictions from previous models. Calculations for the Jovian ammonia <span class="hlt">cloud</span> are found to be consistent with observational constraints. Example calculations are provided for water, silicate, and iron <span class="hlt">clouds</span> on brown dwarfs and on a cool extrasolar giant planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010050107&hterms=Condensation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DCondensation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010050107&hterms=Condensation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DCondensation"><span>Precipitating Condensation <span class="hlt">Clouds</span> in Substellar Atmospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ackerman, Andrew S.; Marley, Mark S.; Gore, Warren J. (Technical Monitor)</p> <p>2000-01-01</p> <p>We present a method to calculate vertical profiles of particle size distributions in condensation <span class="hlt">clouds</span> of giant planets and brown dwarfs. The method assumes a balance between turbulent diffusion and precipitation in horizontally uniform <span class="hlt">cloud</span> decks. Calculations for the Jovian ammonia <span class="hlt">cloud</span> are compared with previous methods. An adjustable parameter describing the efficiency of precipitation allows the new model to span the range of predictions from previous models. Calculations for the Jovian ammonia <span class="hlt">cloud</span> are found to be consistent with observational constraints. Example calculations are provided for water, silicate, and iron <span class="hlt">clouds</span> on brown dwarfs and on a cool extrasolar giant planet.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/962208','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/962208"><span>A Study to Investigate <span class="hlt">Cloud</span> Feedback Processes and Evaluate GCM <span class="hlt">Cloud</span> Variations Using Statistical <span class="hlt">Cloud</span> Property Composites From ARM Data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>George Tselioudis</p> <p>2009-08-11</p> <p>The representation of <span class="hlt">clouds</span> in Global Climate Models (GCMs) remains a major source of uncertainty in climate change simulations. <span class="hlt">Cloud</span> climatologies have been widely used to either evaluate climate model <span class="hlt">cloud</span> fields or examine, in combination with other data sets, climate-scale relationships between <span class="hlt">cloud</span> properties and dynamical or microphysical parameters. Major <span class="hlt">cloud</span> climatologies have been based either on satellite observations of <span class="hlt">cloud</span> properties or on surface observers views of <span class="hlt">cloud</span> type and amount. Such data sets provide either the top-down view of column-integrated <span class="hlt">cloud</span> properties (satellites) or the bottom-up view of the <span class="hlt">cloud</span> field morphology (surface observers). Both satellite-based and surface <span class="hlt">cloud</span> climatologies have been successfully used to examine <span class="hlt">cloud</span> properties, to support process studies, and to evaluate climate and weather models. However, they also present certain limitations, since the satellite <span class="hlt">cloud</span> types are defined using radiative <span class="hlt">cloud</span> boundaries and surface observations are based on <span class="hlt">cloud</span> boundaries visible to human observers. As a result, these data sets do not resolve the vertical distribution of <span class="hlt">cloud</span> layers, an issue that is important in calculating both the radiative and the hydrologic effects of the <span class="hlt">cloud</span> field. Ground-based <span class="hlt">cloud</span> radar observations, on the other hand, resolve with good accuracy the vertical distribution of <span class="hlt">cloud</span> layers and could be used to produce <span class="hlt">cloud</span> type climatologies with vertical layering information. However, these observations provide point measurements only and it is not immediately clear to what extent they are representative of larger regimes. There are different methods that can be applied to minimize this problem and to produce <span class="hlt">cloud</span> layering climatologies useful for both <span class="hlt">cloud</span> process and model evaluation studies. If a radar system is run continuously over a number of years, it eventually samples a large number of dynamical and microphysical regimes. If additional data sets are used to put the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080000873&hterms=austin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D60%26Ntt%3Daustin','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080000873&hterms=austin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D60%26Ntt%3Daustin"><span>Comparison of <span class="hlt">Cloud</span> Properties from CALIPSO-<span class="hlt">Cloud</span>Sat and Geostationary Satellite Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nguyen, L.; Minnis, P.; Chang, F.; Winker, D.; Sun-Mack, S.; Spangenberg, D.; Austin, R.</p> <p>2007-01-01</p> <p><span class="hlt">Cloud</span> properties are being derived in near-real time from geostationary satellite imager data for a variety of weather and climate applications and research. Assessment of the uncertainties in each of the derived <span class="hlt">cloud</span> parameters is essential for confident use of the products. Determination of <span class="hlt">cloud</span> amount, <span class="hlt">cloud</span> top height, and <span class="hlt">cloud</span> layering is especially important for using these real -time products for applications such as aircraft icing condition diagnosis and numerical weather prediction model assimilation. Furthermore, the distribution of <span class="hlt">clouds</span> as a function of altitude has become a central component of efforts to evaluate climate model <span class="hlt">cloud</span> simulations. Validation of those parameters has been difficult except over limited areas where ground-based active sensors, such as <span class="hlt">cloud</span> radars or lidars, have been available on a regular basis. Retrievals of <span class="hlt">cloud</span> properties are sensitive to the surface background, time of day, and the <span class="hlt">clouds</span> themselves. Thus, it is essential to assess the geostationary satellite retrievals over a variety of locations. The availability of <span class="hlt">cloud</span> radar data from <span class="hlt">Cloud</span>Sat and lidar data from CALIPSO make it possible to perform those assessments over each geostationary domain at 0130 and 1330 LT. In this paper, <span class="hlt">Cloud</span>Sat and CALIPSO data are matched with contemporaneous Geostationary Operational Environmental Satellite (GOES), Multi-functional Transport Satellite (MTSAT), and Meteosat-8 data. Unlike comparisons with <span class="hlt">cloud</span> products derived from A-Train imagers, this study considers comparisons of nadir active sensor data with off-nadir retrievals. These matched data are used to determine the uncertainties in <span class="hlt">cloud</span>-top heights and <span class="hlt">cloud</span> amounts derived from the geostationary satellite data using the <span class="hlt">Clouds</span> and the Earth s Radiant Energy System (CERES) <span class="hlt">cloud</span> retrieval algorithms. The CERES multi-layer <span class="hlt">cloud</span> detection method is also evaluated to determine its accuracy and limitations in the off-nadir mode. The results will be useful for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009seao.book...81Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009seao.book...81Y"><span>Global Software Development with <span class="hlt">Cloud</span> Platforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yara, Pavan; Ramachandran, Ramaseshan; Balasubramanian, Gayathri; Muthuswamy, Karthik; Chandrasekar, Divya</p> <p></p> <p>Offshore and outsourced distributed software development models and processes are facing challenges, previously unknown, with respect to computing capacity, bandwidth, storage, security, complexity, reliability, and business uncertainty. <span class="hlt">Clouds</span> promise to address these challenges by adopting recent advances in virtualization, parallel and distributed systems, utility computing, and software services. In this paper, we envision a <span class="hlt">cloud</span>-based platform that addresses some of these core problems. We outline a generic <span class="hlt">cloud</span> architecture, its design and our first implementation results for three <span class="hlt">cloud</span> forms - a compute <span class="hlt">cloud</span>, a storage <span class="hlt">cloud</span> and a <span class="hlt">cloud</span>-based software service- in the context of global distributed software development (GSD). Our ”compute cloud” provides computational services such as continuous code integration and a compile server farm, ”storage cloud” offers storage (block or file-based) services with an on-line virtual storage service, whereas the on-line virtual labs represent a useful <span class="hlt">cloud</span> service. We note some of the use cases for <span class="hlt">clouds</span> in GSD, the lessons learned with our prototypes and identify challenges that must be conquered before realizing the full business benefits. We believe that in the future, software practitioners will focus more on these <span class="hlt">cloud</span> computing platforms and see <span class="hlt">clouds</span> as a means to supporting a ecosystem of clients, developers and other key stakeholders.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997JCli...10...52L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997JCli...10...52L"><span>Global <span class="hlt">Cloud</span> Liquid Water Path Simulations(.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lemus, Lilia; Rikus, Lawrie; Martin, C.; Platt, R.</p> <p>1997-01-01</p> <p>A new parameterization of <span class="hlt">cloud</span> liquid water and ice content has been included in the Bureau of Meteorology Global Assimilation and Prediction System. The <span class="hlt">cloud</span> liquid water content is derived from the mean <span class="hlt">cloud</span> temperatures in the model using an empirical relationship based on observations. The results from perpetual January and July simulations are presented and show that the total <span class="hlt">cloud</span> water path steadily decreases toward high latitudes, with two relative maxima at midlatitudes and a peak at low latitudes. To validate the scheme, the simulated fields need to be processed to produce liquid water paths that can be directly compared with the corresponding field derived from Special Sensor Microwave/Imager (SSM/I) data. This requires the identification of <span class="hlt">cloud</span> ice water content within the parameterization and a prescription to account for the treatment of strongly precipitating subgrid-scale <span class="hlt">cloud</span>. The resultant <span class="hlt">cloud</span> liquid water paths agree qualitatively with the SSM/I data but show some systematic errors that are attributed to corresponding errors in the model's simulation of <span class="hlt">cloud</span> amounts. Given that a more quantitative validation requires substantial improvement in the model's diagnostic <span class="hlt">cloud</span> scheme, the comparison with the SSM/I data indicates that the <span class="hlt">cloud</span> water path, derived from the <span class="hlt">cloud</span> liquid water content parameterization introduced in this paper, is consistent with the observations and can be usefully incorporated in the prediction system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A41F..04Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A41F..04Z"><span>Constraints on the Longwave <span class="hlt">Cloud</span> Altitude Feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zelinka, M. D.; Klein, S. A.</p> <p>2011-12-01</p> <p><span class="hlt">Cloud</span> feedback represents the source of largest spread among global climate model projections of future climate change. Though most studies to date have focused on the large spread in <span class="hlt">cloud</span> feedback that arises from disparate responses of subtropical low <span class="hlt">clouds</span>, we show using a new technique for quantifying the contribution to <span class="hlt">cloud</span> feedback from individual <span class="hlt">cloud</span> types that a significant spread exists in the response of high <span class="hlt">clouds</span>, with implications for both longwave and shortwave feedbacks. In this talk, we focus on the inter-model spread in longwave altitude feedback, defined as the impact on top of atmosphere longwave fluxes due solely to changes in the vertical distribution of <span class="hlt">clouds</span>, holding both the total amount and the optical depth distribution fixed. Among the ten models analyzed, this feedback varies from 0.06 to 0.80 W m-2 K-1. We show that the magnitude of this feedback is dependent on two key variables: the effective high <span class="hlt">cloud</span> amount in the control climate and the change in mean <span class="hlt">cloud</span> top pressure under doubling of CO2. The latter component is governed by the degree to which the troposphere deepens under doubling of CO2, suggesting an inverse relationship with the lapse rate feedback. To the extent that realistic bounds can be placed on effective high <span class="hlt">cloud</span> amount using observations, the range of plausible longwave <span class="hlt">cloud</span> altitude feedback magnitudes can be further reduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890005165','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890005165"><span>Physical processes in polar stratospheric ice <span class="hlt">clouds</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Toon, Owen B.; Turco, Richard; Jordan, Joseph</p> <p>1988-01-01</p> <p>A one dimensional model of <span class="hlt">cloud</span> microphysics was used to simulate the formation and evolution of polar stratospheric ice <span class="hlt">clouds</span>. Some of the processes which are included in the model are outlined. It is found that the <span class="hlt">clouds</span> must undergo preferential nucleation upon the existing aerosols just as do tropospheric cirrus <span class="hlt">clouds</span>. Therefore, there is an energy barrier between stratospheric nitric acid particles and ice particles implying that nitric acid does not form a continuous set of solutions between the trihydrate and ice. The Kelvin barrier is not significant in controlling the rate of formation of ice particles. It was found that the <span class="hlt">cloud</span> properties are sensitive to the rate at which the air parcels cool. In wave <span class="hlt">clouds</span>, with cooling rates of hundreds of degrees per day, most of the existing aerosols nucleate and become ice particles. Such <span class="hlt">clouds</span> have particles with sizes on the order of a few microns, optical depths on order of unity and are probably not efficient at removing materials from the stratosphere. In <span class="hlt">clouds</span> which form with cooling rates of a few degrees per day or less, only a small fraction of the aerosols become <span class="hlt">cloud</span> particles. In such <span class="hlt">clouds</span> the particle radius is larger than 10 microns, the optical depths are low and water vapor is efficiently removed. Seasonal simulations show that the lowest water vapor mixing ratio is determined by the lowest temperature reached, and that the time when <span class="hlt">clouds</span> disappear is controlled by the time when temperatures begin to rise above the minimum values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27655341','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27655341"><span>Automating NEURON Simulation Deployment in <span class="hlt">Cloud</span> Resources.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stockton, David B; Santamaria, Fidel</p> <p>2017-01-01</p> <p>Simulations in neuroscience are performed on local servers or High Performance Computing (HPC) facilities. Recently, <span class="hlt">cloud</span> computing has emerged as a potential computational platform for neuroscience simulation. In this paper we compare and contrast HPC and <span class="hlt">cloud</span> resources for scientific computation, then report how we deployed NEURON, a widely used simulator of neuronal activity, in three <span class="hlt">clouds</span>: Chameleon <span class="hlt">Cloud</span>, a hybrid private academic <span class="hlt">cloud</span> for <span class="hlt">cloud</span> technology research based on the OpenStack software; Rackspace, a public commercial <span class="hlt">cloud</span>, also based on OpenStack; and Amazon Elastic <span class="hlt">Cloud</span> Computing, based on Amazon's proprietary software. We describe the manual procedures and how to automate <span class="hlt">cloud</span> operations. We describe extending our simulation automation software called NeuroManager (Stockton and Santamaria, Frontiers in Neuroinformatics, 2015), so that the user is capable of recruiting private <span class="hlt">cloud</span>, public <span class="hlt">cloud</span>, HPC, and local servers simultaneously with a simple common interface. We conclude by performing several studies in which we examine speedup, efficiency, total session time, and cost for sets of simulations of a published NEURON model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.664b2038T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.664b2038T"><span>The Evolution of <span class="hlt">Cloud</span> Computing in ATLAS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, Ryan P.; Berghaus, Frank; Brasolin, Franco; Domingues Cordeiro, Cristovao Jose; Desmarais, Ron; Field, Laurence; Gable, Ian; Giordano, Domenico; Di Girolamo, Alessandro; Hover, John; LeBlanc, Matthew; Love, Peter; Paterson, Michael; Sobie, Randall; Zaytsev, Alexandr</p> <p>2015-12-01</p> <p>The ATLAS experiment at the LHC has successfully incorporated <span class="hlt">cloud</span> computing technology and <span class="hlt">cloud</span> resources into its primarily grid-based model of distributed computing. <span class="hlt">Cloud</span> R&D activities continue to mature and transition into stable production systems, while ongoing evolutionary changes are still needed to adapt and refine the approaches used, in response to changes in prevailing <span class="hlt">cloud</span> technology. In addition, completely new developments are needed to handle emerging requirements. This paper describes the overall evolution of <span class="hlt">cloud</span> computing in ATLAS. The current status of the virtual machine (VM) management systems used for harnessing Infrastructure as a Service resources are discussed. Monitoring and accounting systems tailored for <span class="hlt">clouds</span> are needed to complete the integration of <span class="hlt">cloud</span> resources within ATLAS' distributed computing framework. We are developing and deploying new solutions to address the challenge of operation in a geographically distributed multi-<span class="hlt">cloud</span> scenario, including a system for managing VM images across multiple <span class="hlt">clouds</span>, a system for dynamic location-based discovery of caching proxy servers, and the usage of a data federation to unify the worldwide grid of storage elements into a single namespace and access point. The usage of the experiment's high level trigger farm for Monte Carlo production, in a specialized <span class="hlt">cloud</span> environment, is presented. Finally, we evaluate and compare the performance of commercial <span class="hlt">clouds</span> using several benchmarks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020079970','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020079970"><span><span class="hlt">Cloud</span> Thickness from Offbeam Returns - Thor Lidar</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cahalan, R.; Kolasinski, J.; McGill, M.; Lau, William K. M. (Technical Monitor)</p> <p>2002-01-01</p> <p>Physical thickness of a <span class="hlt">cloud</span> layer, and sometimes multiple <span class="hlt">cloud</span> layers, can be estimated from the time delay of off-beam returns from a pulsed laser source illuminating one side of the <span class="hlt">cloud</span> layer. In particular, the time delay of light returning from the outer diffuse halo of light surrounding the beam entry point, relative to the time delay at beam center, determines the <span class="hlt">cloud</span> physical thickness. The delay combined with the pulse stretch gives the optical thickness. The halo method works best for thick <span class="hlt">cloud</span> layers, typically optical thickness exceeding 2, and thus compliments conventional lidar which cannot penetrate thick <span class="hlt">clouds</span>. <span class="hlt">Cloud</span> layer top and base have been measured independently over the ARM/SGP site using conventional laser ranging (lidar) and the top minus base thickness are compared with a <span class="hlt">cloud</span> top halo estimate obtained from the NASA/Goddard THOR System (THOR = THickness from Offbeam Returns). THOR flies on the NASA P3, and measures the halo timings from several km above <span class="hlt">cloud</span> top, at the same time providing conventional lidar <span class="hlt">cloud</span> top height. The ARM/SGP micropulse lidar provides <span class="hlt">cloud</span> base height for validation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..120.3436H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..120.3436H"><span><span class="hlt">Cloud</span> supersaturations from CCN spectra Hoppel minima</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hudson, James G.; Noble, Stephen; Tabor, Samantha</p> <p>2015-04-01</p> <p>High-resolution <span class="hlt">cloud</span> condensation nucleus (CCN) spectral measurements in two aircraft field projects, Marine Stratus/Stratocumulus Experiment (MASE) and Ice in <span class="hlt">Clouds</span> Experiment-Tropical (ICE-T), often showed bimodality that had previously been observed in submicrometer aerosol size distributions obtained by differential mobility analyzers. However, a great deal of spectral shape variability from very bimodal to very monomodal was observed in close proximity. <span class="hlt">Cloud</span> supersaturation (S) estimates based on critical S, Sc, at minimal CCN concentrations between two modes (Hoppel minima) were ascertained for 63% of 325 measured spectra. These <span class="hlt">cloud</span> S were lower than effective S (Seff) determined by comparing ambient CCN spectra with nearby <span class="hlt">cloud</span> droplet concentrations (Nc). Averages for the polluted MASE stratus were 0.15 and 0.23% and for the cumulus <span class="hlt">clouds</span> of ICE-T 0.44 and 1.03%. This <span class="hlt">cloud</span> S disagreement between the two methods might in part be due to the fact that Hoppel minima include the effects of <span class="hlt">cloud</span> processing, which push CCN spectra toward lower S. Furthermore, there is less <span class="hlt">cloud</span> processing by the smaller <span class="hlt">cloud</span> droplets, which might be related to smaller droplets evaporating more readily. Significantly lower concentrations within the more bimodal spectra compared with the monomodal spectra indicated active physical processes: Brownian capture of interstitial CCN and droplet coalescence. Chemical <span class="hlt">cloud</span> processing also contributed to bimodality, especially in MASE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960008695','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960008695"><span>Modeling and parameterization of horizontally inhomogeneous <span class="hlt">cloud</span> radiative properties</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Welch, R. M.</p> <p>1995-01-01</p> <p>One of the fundamental difficulties in modeling <span class="hlt">cloud</span> fields is the large variability of <span class="hlt">cloud</span> optical properties (liquid water content, reflectance, emissivity). The stratocumulus and cirrus <span class="hlt">clouds</span>, under special consideration for FIRE, exhibit spatial variability on scales of 1 km or less. While it is impractical to model individual <span class="hlt">cloud</span> elements, the research direction is to model a statistical ensembles of <span class="hlt">cloud</span> elements with mean-<span class="hlt">cloud</span> properties specified. The major areas of this investigation are: (1) analysis of <span class="hlt">cloud</span> field properties; (2) intercomparison of <span class="hlt">cloud</span> radiative model results with satellite observations; (3) radiative parameterization of <span class="hlt">cloud</span> fields; and (4) development of improved <span class="hlt">cloud</span> classification algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930029573&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DOort%2Bcloud','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930029573&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DOort%2Bcloud"><span>Dynamical history of the Oort <span class="hlt">cloud</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weissman, Paul R.</p> <p>1991-01-01</p> <p>An overview of recent dynamical studies on the Oort <span class="hlt">cloud</span> of comets surrounding the solar system is presented. Cometary orbits in the <span class="hlt">cloud</span> evolve under the complex interaction of stellar, galactic, and giant molecular <span class="hlt">cloud</span> perturbations, as well as planetary and nongravitational perturbations when the orbits reenter the planetary region. There is mounting evidence for a dense, inner Oort <span class="hlt">cloud</span> of comets which acts as a reservoir to replenish the outer <span class="hlt">cloud</span> as comets there are stripped away. A ring of comets beyond the orbit of Neptune, which may be the source of the short-period comets, is also likely. Temporal variations in the flux of comets from the Oort <span class="hlt">cloud</span> into the planetary region by a factor of 50 percent are typical, and by factors of 20 to 200 are possible. Comets in the Oort <span class="hlt">cloud</span> are processed by galactic cosmic rays, heated by nearby supernovae, eroded by interstellar dust impacts, and disrupted by mutual collisions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010073053&hterms=contour+detection&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcontour%2Bdetection','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010073053&hterms=contour+detection&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcontour%2Bdetection"><span>Operational <span class="hlt">Cloud</span> Detection in GEOS Imagery</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jedlovec, Gary J.; Laws, Kevin; Arnold, James E. (Technical Monitor)</p> <p>2001-01-01</p> <p>The bispectral spatial coherence approach for the detection and masking of <span class="hlt">clouds</span> is revisited with modifications for operational applications to Geostationary Operational Environmental Satellite (GOES) Imager and Sounder data. The approach applies an edge detection algorithm to a "difference" image to identify the edges or contours of the <span class="hlt">clouds</span>. The difference image is generated as the difference between the 3.9 and 11 micrometer channels of the GOES sensors. This difference image better highlights <span class="hlt">cloud</span> edges than either image alone and draws upon the emissivity differences in the various channels. The <span class="hlt">cloud</span> contours are "filled-in" by referencing the thermal gradients in the 11-micrometer channel or difference image associated with the <span class="hlt">cloud</span> edge. This paper and associate poster will present a preliminary validation of the bispectral spatial coherence approach and will compare the <span class="hlt">cloud</span> masks generated with this approach to the National Oceanic and Atmospheric Administration/National Environmental Satellite, Data, and Information Service (NOAA/NESDIS) operational <span class="hlt">cloud</span> products.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14988556','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14988556"><span>Smoking rain <span class="hlt">clouds</span> over the Amazon.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andreae, M O; Rosenfeld, D; Artaxo, P; Costa, A A; Frank, G P; Longo, K M; Silva-Dias, M A F</p> <p>2004-02-27</p> <p>Heavy smoke from forest fires in the Amazon was observed to reduce <span class="hlt">cloud</span> droplet size and so delay the onset of precipitation from 1.5 kilometers above <span class="hlt">cloud</span> base in pristine <span class="hlt">clouds</span> to more than 5 kilometers in polluted <span class="hlt">clouds</span> and more than 7 kilometers in pyro-<span class="hlt">clouds</span>. Suppression of low-level rainout and aerosol washout allows transport of water and smoke to upper levels, where the <span class="hlt">clouds</span> appear "smoking" as they detrain much of the pollution. Elevating the onset of precipitation allows invigoration of the updrafts, causing intense thunderstorms, large hail, and greater likelihood for overshooting <span class="hlt">cloud</span> tops into the stratosphere. There, detrained pollutants and water vapor would have profound radiative impacts on the climate system. The invigorated storms release the latent heat higher in the atmosphere. This should substantially affect the regional and global circulation systems. Together, these processes affect the water cycle, the pollution burden of the atmosphere, and the dynamics of atmospheric circulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860046872&hterms=Evolution+Molecular&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DEvolution%252C%2BMolecular','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860046872&hterms=Evolution+Molecular&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DEvolution%252C%2BMolecular"><span>Molecular <span class="hlt">cloud</span> evolution and star formation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Silk, J.</p> <p>1985-01-01</p> <p>The present state of knowledge of the relationship between molecular <span class="hlt">clouds</span> and young stars is reviewed. The determination of physical parameters from molecular line observations is summarized, and evidence for fragmentation of molecular <span class="hlt">clouds</span> is discussed. Hierarchical fragmentation is reviewed, minimum fragment scales are derived, and the stability against fragmentation of both spherically and anisotropically collapsing <span class="hlt">clouds</span> is discussed. Observational evidence for high-velocity flows in <span class="hlt">clouds</span> is summarized, and the effects of winds from pre-main sequence stars on molecular gas are discussed. The triggering of <span class="hlt">cloud</span> collapse by enhanced pressure is addressed, as is the formation of dense shells by spherical outflows and their subsequent breakup. A model for low-mass star formation is presented, and constraints on star formation from the initial mass function are examined. The properties of giant molecular <span class="hlt">clouds</span> and massive star formation are described. The implications of magnetic fields for <span class="hlt">cloud</span> evolution and star formation are addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880058797&hterms=warm+global&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dwarm%2Bglobal','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880058797&hterms=warm+global&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dwarm%2Bglobal"><span>The Nimbus-7 Global <span class="hlt">Cloud</span> Climatology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hwang, Paul H.; Kyle, H. Lee; Stowe, Larry L.; Pellegrino, P. P.; Yeh, H. Y. Michael</p> <p>1988-01-01</p> <p>The Nimbus-7 Global <span class="hlt">Cloud</span> Climatology (N7GCC) has been produced from measurements made between April 1979 and March 1985 using the Temperature Humidity IR Radiometer and the Total Ozone Mapping Spectrometer on the Nimbus-7 satellite. The N7GCC gives, near local noon and midnight, the fractional area covered by high-level, middle-level, and low-altitude <span class="hlt">clouds</span>, and the total fractional area covered by all <span class="hlt">clouds</span>. Statistics for cirrus, deep convective, and warm low-altitude <span class="hlt">clouds</span> and the <span class="hlt">cloud</span> and clear-sky radiances with correlative surface temperatures are also included. The N7GCC is compared with other <span class="hlt">cloud</span> data sets, including the International Satellite <span class="hlt">Cloud</span> Climatology Project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860046872&hterms=evolution+Molecular&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Devolution%2BMolecular','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860046872&hterms=evolution+Molecular&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Devolution%2BMolecular"><span>Molecular <span class="hlt">cloud</span> evolution and star formation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Silk, J.</p> <p>1985-01-01</p> <p>The present state of knowledge of the relationship between molecular <span class="hlt">clouds</span> and young stars is reviewed. The determination of physical parameters from molecular line observations is summarized, and evidence for fragmentation of molecular <span class="hlt">clouds</span> is discussed. Hierarchical fragmentation is reviewed, minimum fragment scales are derived, and the stability against fragmentation of both spherically and anisotropically collapsing <span class="hlt">clouds</span> is discussed. Observational evidence for high-velocity flows in <span class="hlt">clouds</span> is summarized, and the effects of winds from pre-main sequence stars on molecular gas are discussed. The triggering of <span class="hlt">cloud</span> collapse by enhanced pressure is addressed, as is the formation of dense shells by spherical outflows and their subsequent breakup. A model for low-mass star formation is presented, and constraints on star formation from the initial mass function are examined. The properties of giant molecular <span class="hlt">clouds</span> and massive star formation are described. The implications of magnetic fields for <span class="hlt">cloud</span> evolution and star formation are addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150008652&hterms=Simone&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSimone','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150008652&hterms=Simone&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSimone"><span>Next-Generation Spaceborne <span class="hlt">Cloud</span> Profiling Radars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tanelli, Simone; Durden, Stephen L.; Im, Eastwood; Heymsfield, Gerald M.; Racette, Paul; Starr, Dave O.</p> <p>2009-01-01</p> <p>One of the instruments recommended for deployment on the Aerosol/<span class="hlt">Cloud</span>/Echosystems (ACE) mission is a new advanced <span class="hlt">Cloud</span> Profiling Radar (ACE-CPR). The atmospheric sciences community has initiated the effort to define the scientific requirements for this instrument. Initial studies focusing on system configuration, performance and feasibility start from the successful experience of the <span class="hlt">Cloud</span> Profiling Radar on <span class="hlt">Cloud</span>Sat Mission (CS-CPR), the first 94-GHz nadir-looking spaceborne radar which has been acquiring global time series of vertical <span class="hlt">cloud</span> structure since June 2, 2006. In this paper we address the significance of <span class="hlt">Cloud</span>Sat's accomplishments in regards to the design and development of radars for future <span class="hlt">cloud</span> profiling missions such as EarthCARE and ACE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150008798&hterms=springer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dspringer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150008798&hterms=springer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dspringer"><span>Enabling Earth Science Through <span class="hlt">Cloud</span> Computing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hardman, Sean; Riofrio, Andres; Shams, Khawaja; Freeborn, Dana; Springer, Paul; Chafin, Brian</p> <p>2012-01-01</p> <p><span class="hlt">Cloud</span> Computing holds tremendous potential for missions across the National Aeronautics and Space Administration. Several flight missions are already benefiting from an investment in <span class="hlt">cloud</span> computing for mission critical pipelines and services through faster processing time, higher availability, and drastically lower costs available on <span class="hlt">cloud</span> systems. However, these processes do not currently extend to general scientific algorithms relevant to earth science missions. The members of the Airborne <span class="hlt">Cloud</span> Computing Environment task at the Jet Propulsion Laboratory have worked closely with the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) mission to integrate <span class="hlt">cloud</span> computing into their science data processing pipeline. This paper details the efforts involved in deploying a science data system for the CARVE mission, evaluating and integrating <span class="hlt">cloud</span> computing solutions with the system and porting their science algorithms for execution in a <span class="hlt">cloud</span> environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880058797&hterms=nimbus+cloud&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnimbus%2Bcloud','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880058797&hterms=nimbus+cloud&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnimbus%2Bcloud"><span>The Nimbus-7 Global <span class="hlt">Cloud</span> Climatology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hwang, Paul H.; Kyle, H. Lee; Stowe, Larry L.; Pellegrino, P. P.; Yeh, H. Y. Michael</p> <p>1988-01-01</p> <p>The Nimbus-7 Global <span class="hlt">Cloud</span> Climatology (N7GCC) has been produced from measurements made between April 1979 and March 1985 using the Temperature Humidity IR Radiometer and the Total Ozone Mapping Spectrometer on the Nimbus-7 satellite. The N7GCC gives, near local noon and midnight, the fractional area covered by high-level, middle-level, and low-altitude <span class="hlt">clouds</span>, and the total fractional area covered by all <span class="hlt">clouds</span>. Statistics for cirrus, deep convective, and warm low-altitude <span class="hlt">clouds</span> and the <span class="hlt">cloud</span> and clear-sky radiances with correlative surface temperatures are also included. The N7GCC is compared with other <span class="hlt">cloud</span> data sets, including the International Satellite <span class="hlt">Cloud</span> Climatology Project.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150008798&hterms=computing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcomputing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150008798&hterms=computing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcomputing"><span>Enabling Earth Science Through <span class="hlt">Cloud</span> Computing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hardman, Sean; Riofrio, Andres; Shams, Khawaja; Freeborn, Dana; Springer, Paul; Chafin, Brian</p> <p>2012-01-01</p> <p><span class="hlt">Cloud</span> Computing holds tremendous potential for missions across the National Aeronautics and Space Administration. Several flight missions are already benefiting from an investment in <span class="hlt">cloud</span> computing for mission critical pipelines and services through faster processing time, higher availability, and drastically lower costs available on <span class="hlt">cloud</span> systems. However, these processes do not currently extend to general scientific algorithms relevant to earth science missions. The members of the Airborne <span class="hlt">Cloud</span> Computing Environment task at the Jet Propulsion Laboratory have worked closely with the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) mission to integrate <span class="hlt">cloud</span> computing into their science data processing pipeline. This paper details the efforts involved in deploying a science data system for the CARVE mission, evaluating and integrating <span class="hlt">cloud</span> computing solutions with the system and porting their science algorithms for execution in a <span class="hlt">cloud</span> environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT........26M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT........26M"><span>Microphysics and Southern Ocean <span class="hlt">Cloud</span> Feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCoy, Daniel T.</p> <p></p> <p>Global climate models (GCMs) change their <span class="hlt">cloud</span> properties in the Southern Ocean (SO) with warming in a qualitatively consistent fashion. <span class="hlt">Cloud</span> albedo increases in the mid-latitudes and <span class="hlt">cloud</span> fraction decreases in the subtropics. This creates a distinctive 'dipole' structure in the SW <span class="hlt">cloud</span> feedback. However, the shape of the dipole varies from model to model. In this thesis we discuss the microphysical mechanisms underlying the SW <span class="hlt">cloud</span> feedback over the mid-latitude SO. We will focus on the negative lobe of the dipole. The negative SW <span class="hlt">cloud</span> feedback in the mid-latitudes is created by transitions from ice to liquid in models. If ice transitions to liquid in mixed-phase <span class="hlt">clouds</span> the <span class="hlt">cloud</span> albedo increases because ice crystals are larger than liquid droplets and therefore more reflective for a constant mass of water. Decreases in precipitation efficiency further enhance this effect by decreasing sinks of <span class="hlt">cloud</span> water. This transition is dependent on the mixed-phase <span class="hlt">cloud</span> parameterization. Parameterizations vary wildly between models and GCMs disagree by up to 35 K on the temperature where ice and liquid are equally prevalent. This results in a wide spread in the model predictions of the increase in liquid water path (LWP, where the path is the vertically integrated mass of water) with warming that drives the negative optical depth <span class="hlt">cloud</span> feedback. It is found that this disagreement also results in a wide array of climate mean-states as models that create liquid at lower temperatures have a higher mean-state LWP, lower ice water path (IWP), and higher condensed (ice and liquid) water path (CWP). This presents a problem in climate models. GCMs need to have a reasonable planetary albedo in their climate mean-state. We show evidence that GCMs have tuned <span class="hlt">cloud</span> fraction to compensate for the variation in mid-latitude <span class="hlt">cloud</span> albedo driven by the mixed-phase <span class="hlt">cloud</span> parameterization. This tuning results in mid-latitude <span class="hlt">clouds</span> that are both too few and too bright as well as a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRD..12114636C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRD..12114636C"><span>Aerosol indirect effect dictated by liquid <span class="hlt">clouds</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Christensen, Matthew W.; Chen, Yi-Chun; Stephens, Graeme L.</p> <p>2016-12-01</p> <p>Anthropogenic aerosols have been shown to enhance the solar reflection from warm liquid <span class="hlt">clouds</span> and mask part of the warming due to the buildup of greenhouse gases. However, very little is known about the effects of aerosol on mixed-phase stratiform <span class="hlt">clouds</span> as well as other <span class="hlt">cloud</span> regimes including cumulus, altocumulus, nimbostratus, deep convection, and anvil cirrus. These additional <span class="hlt">cloud</span> categories are ubiquitous and typically overlooked in satellite-based assessments of the global aerosol indirect forcing. Here we provide their contribution to the aerosol indirect forcing estimate using satellite data collected from several colocated sensors in the A-train for the period 2006-2010. <span class="hlt">Cloud</span> type is determined according to the 2B-CLDCLASS-LIDAR <span class="hlt">Cloud</span>Sat product, and the observations are matched to the radiative flux measurements from CERES (<span class="hlt">Clouds</span> and the Earth's Radiant Energy System) and aerosol retrievals from MODIS (MODerate resolution Imaging Spectroradiometer). The oceanic mean aerosol indirect forcing is estimated to be -0.20 ± 0.31 W m-2 with warm low-level <span class="hlt">cloud</span> largely dictating the strength of the response (-0.36 ± 0.21 W m-2) due to their abundance and strong <span class="hlt">cloud</span> albedo effect. Contributions from mixed-phase low-level <span class="hlt">cloud</span> (0.01 ± 0.06 W m-2) and convective <span class="hlt">cloud</span> (0.15 ± 0.23 W m-2) are positive and buffer the system due to strong aerosol-<span class="hlt">cloud</span> feedbacks that reduce the <span class="hlt">cloud</span> albedo effect and/or lead to convective invigoration causing a countering positive longwave warming response. By combining all major <span class="hlt">cloud</span> categories together, aerosol indirect forcing decreases and now contains positive values in the uncertainty estimate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ShWav..23..233K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ShWav..23..233K"><span>Spherical combustion <span class="hlt">clouds</span> in explosions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuhl, A. L.; Bell, J. B.; Beckner, V. E.; Balakrishnan, K.; Aspden, A. J.</p> <p>2013-05-01</p> <p>This study explores the properties of spherical combustion <span class="hlt">clouds</span> in explosions. Two cases are investigated: (1) detonation of a TNT charge and combustion of its detonation products with air, and (2) shock dispersion of aluminum powder and its combustion with air. The evolution of the blast wave and ensuing combustion <span class="hlt">cloud</span> dynamics are studied via numerical simulations with our adaptive mesh refinement combustion code. The code solves the multi-phase conservation laws for a dilute heterogeneous continuum as formulated by Nigmatulin. Single-phase combustion (e.g., TNT with air) is modeled in the fast-chemistry limit. Two-phase combustion (e.g., Al powder with air) uses an induction time model based on Arrhenius fits to Boiko's shock tube data, along with an ignition temperature criterion based on fits to Gurevich's data, and an ignition probability model that accounts for multi-particle effects on <span class="hlt">cloud</span> ignition. Equations of state are based on polynomial fits to thermodynamic calculations with the Cheetah code, assuming frozen reactants and equilibrium products. Adaptive mesh refinement is used to resolve thin reaction zones and capture the energy-bearing scales of turbulence on the computational mesh (ILES approach). Taking advantage of the symmetry of the problem, azimuthal averaging was used to extract the mean and rms fluctuations from the numerical solution, including: thermodynamic profiles, kinematic profiles, and reaction-zone profiles across the combustion <span class="hlt">cloud</span>. Fuel consumption was limited to ˜ 60-70 %, due to the limited amount of air a spherical combustion <span class="hlt">cloud</span> can entrain before the turbulent velocity field decays away. Turbulent kinetic energy spectra of the solution were found to have both rotational and dilatational components, due to compressibility effects. The dilatational component was typically about 1 % of the rotational component; both seemed to preserve their spectra as they decayed. Kinetic energy of the blast wave decayed due to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA01096&hterms=url&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Durl','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA01096&hterms=url&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Durl"><span>Jovian Lightning and Moonlit <span class="hlt">Clouds</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>Jovian lightning and moonlit <span class="hlt">clouds</span>. These two images, taken 75 minutes apart, show lightning storms on the night side of Jupiter along with <span class="hlt">clouds</span> dimly lit by moonlight from Io, Jupiter's closest moon. The images were taken in visible light and are displayed in shades of red. The images used an exposure time of about one minute, and were taken when the spacecraft was on the opposite side of Jupiter from the Earth and Sun. Bright storms are present at two latitudes in the left image, and at three latitudes in the right image. Each storm was made visible by multiple lightning strikes during the exposure. Other Galileo images were deliberately scanned from east to west in order to separate individual flashes. The images show that Jovian and terrestrial lightning storms have similar flash rates, but that Jovian lightning strikes are a few orders of magnitude brighter in visible light.<p/>The moonlight from Io allows the lightning storms to be correlated with visible <span class="hlt">cloud</span> features. The latitude bands where the storms are seen seem to coincide with the 'disturbed regions' in daylight images, where short-lived chaotic motions push <span class="hlt">clouds</span> to high altitudes, much like thunderstorms on Earth. The storms in these images are roughly one to two thousand kilometers across, while individual flashes appear hundreds of kilometer across. The lightning probably originates from the deep water <span class="hlt">cloud</span> layer and illuminates a large region of the visible ammonia <span class="hlt">cloud</span> layer from 100 kilometers below it.<p/>There are several small light and dark patches that are artifacts of data compression. North is at the top of the picture. The images span approximately 50 degrees in latitude and longitude. The lower edges of the images are aligned with the equator. The images were taken on October 5th and 6th, 1997 at a range of 6.6 million kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft.<p/>The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA01096&hterms=dark+web&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddark%2Bweb','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA01096&hterms=dark+web&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddark%2Bweb"><span>Jovian Lightning and Moonlit <span class="hlt">Clouds</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>Jovian lightning and moonlit <span class="hlt">clouds</span>. These two images, taken 75 minutes apart, show lightning storms on the night side of Jupiter along with <span class="hlt">clouds</span> dimly lit by moonlight from Io, Jupiter's closest moon. The images were taken in visible light and are displayed in shades of red. The images used an exposure time of about one minute, and were taken when the spacecraft was on the opposite side of Jupiter from the Earth and Sun. Bright storms are present at two latitudes in the left image, and at three latitudes in the right image. Each storm was made visible by multiple lightning strikes during the exposure. Other Galileo images were deliberately scanned from east to west in order to separate individual flashes. The images show that Jovian and terrestrial lightning storms have similar flash rates, but that Jovian lightning strikes are a few orders of magnitude brighter in visible light.<p/>The moonlight from Io allows the lightning storms to be correlated with visible <span class="hlt">cloud</span> features. The latitude bands where the storms are seen seem to coincide with the 'disturbed regions' in daylight images, where short-lived chaotic motions push <span class="hlt">clouds</span> to high altitudes, much like thunderstorms on Earth. The storms in these images are roughly one to two thousand kilometers across, while individual flashes appear hundreds of kilometer across. The lightning probably originates from the deep water <span class="hlt">cloud</span> layer and illuminates a large region of the visible ammonia <span class="hlt">cloud</span> layer from 100 kilometers below it.<p/>There are several small light and dark patches that are artifacts of data compression. North is at the top of the picture. The images span approximately 50 degrees in latitude and longitude. The lower edges of the images are aligned with the equator. The images were taken on October 5th and 6th, 1997 at a range of 6.6 million kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft.<p/>The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA05391.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA05391.html"><span>Bands of <span class="hlt">Clouds</span> and Lace</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2004-05-13</p> <p>As Cassini nears its rendezvous with Saturn, new detail in the banded <span class="hlt">clouds</span> of the planet's atmosphere are becoming visible. Cassini began the journey to the ringed world of Saturn nearly seven years ago and is now less than two months away from orbit insertion on June 30. Cassini’s narrow-angle camera took this image on April 16, 2004, when the spacecraft was 38.5 million kilometers (23.9 million miles) from Saturn. Dark regions are generally areas free of high <span class="hlt">clouds</span>, and bright areas are places with high, thick <span class="hlt">clouds</span> which shield the view of the darker areas below. A dark spot is visible at the south pole, which is remarkable to scientists because it is so small and centered. The spot could be affected by Saturn's magnetic field, which is nearly aligned with the planet's rotation axis, unlike the magnetic fields of Jupiter and Earth. From south to north, other notable features are the two white spots just above the dark spot toward the right, and the large dark oblong-shaped feature that extends across the middle. The darker band beneath the oblong-shaped feature has begun to show a lacy pattern of lighter-colored, high altitude <span class="hlt">clouds</span>, indicative of turbulent atmospheric conditions. The <span class="hlt">cloud</span> bands move at different speeds, and their irregularities may be due to either the different motions between them or to disturbances below the visible <span class="hlt">cloud</span> layer. Such disturbances might be powered by the planet's internal heat; Saturn radiates more energy than it receives from the Sun. The moon Mimas (396 kilometers, 245 miles across) is visible to the left of the south pole. Saturn currently has 31 known moons. Since launch, 13 new moons have been discovered by ground-based telescopes. Cassini will get a closer look and may discover new moons, perhaps embedded within the planet’s magnificent rings. This image was taken using a filter sensitive to light near 727 nanometers, one of the near-infrared absorption bands of methane gas, which is one of the ingredients in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000025312','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000025312"><span><span class="hlt">Cloud</span> Statistics for NASA Climate Change Studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wylie, Donald P.</p> <p>1999-01-01</p> <p>The Principal Investigator participated in two field experiments and developed a global data set on cirrus <span class="hlt">cloud</span> frequency and optical depth to aid the development of numerical models of climate. Four papers were published under this grant. The accomplishments are summarized: (1) In SUCCESS (SUbsonic aircraft: Contrail & <span class="hlt">Cloud</span> Effects Special Study) the Principal Investigator aided weather forecasters in the start of the field program. A paper also was published on the <span class="hlt">clouds</span> studied in SUCCESS and the use of the satellite stereographic technique to distinguish <span class="hlt">cloud</span> forms and heights of <span class="hlt">clouds</span>. (2) In SHEBA (Surface Heat Budget in the Arctic) FIRE/ACE (Arctic <span class="hlt">Cloud</span> Experiment) the Principal Investigator provided daily weather and <span class="hlt">cloud</span> forecasts for four research aircraft crews, NASA's ER-2, UCAR's C-130, University of Washington's Convert 580, and the Canadian Atmospheric Environment Service's Convert 580. Approximately 105 forecasts were written. The Principal Investigator also made daily weather summaries with calculations of air trajectories for 54 flight days in the experiment. The trajectories show where the air sampled during the flights came from and will be used in future publications to discuss the origin and history of the air and <span class="hlt">clouds</span> sampled by the aircraft. A paper discussing how well the FIRE/ACE data represent normal climatic conditions in the arctic is being prepared. (3) The Principal Investigator's web page became the source of information for weather forecasting by the scientists on the SHEBA ship. (4) Global Cirrus frequency and optical depth is a continuing analysis of global <span class="hlt">cloud</span> cover and frequency distribution are being made from the NOAA polar orbiting weather satellites. This analysis is sensitive to cirrus <span class="hlt">clouds</span> because of the radiative channels used. During this grant three papers were published which describe <span class="hlt">cloud</span> frequencies, their optical properties and compare the Wisconsin FM <span class="hlt">Cloud</span> Analysis to other global <span class="hlt">cloud</span> data such as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRD..12111620W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRD..12111620W"><span>Validation of MODIS <span class="hlt">cloud</span> mask and multilayer flag using <span class="hlt">Cloud</span>Sat-CALIPSO <span class="hlt">cloud</span> profiles and a cross-reference of their <span class="hlt">cloud</span> classifications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Tao; Fetzer, Eric J.; Wong, Sun; Kahn, Brian H.; Yue, Qing</p> <p>2016-10-01</p> <p>Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 <span class="hlt">cloud</span> observations (MYD06) at 1 km are collocated with daytime <span class="hlt">CloudSat-Cloud</span>-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) (C-C) <span class="hlt">cloud</span> vertical structures (2B-CLDCLASS-LIDAR). For 2007-2010, over 267 million C-C <span class="hlt">cloud</span> profiles are used to (1) validate MODIS <span class="hlt">cloud</span> mask and <span class="hlt">cloud</span> multilayer flag and (2) cross-reference between C-C <span class="hlt">cloud</span> types and MODIS <span class="hlt">cloud</span> regimes defined by joint histograms of <span class="hlt">cloud</span> top pressure (CTP) and <span class="hlt">cloud</span> optical depth (τ). Globally, of total observations, C-C reports 27.1% clear and 72.9% cloudy, whereas MODIS reports 30.0% confidently clear and 58.7% confidently cloudy, with the rest 7.1% as probably clear and 4.2% as probably cloudy. Agreement between MODIS and C-C is 77.8%, with 20.9% showing both clear and 56.9% showing both cloudy. The 9.1% of observations are clear in MODIS but cloudy in C-C, indicating <span class="hlt">clouds</span> missed by MODIS; 1.8% of observations are cloudy in MODIS but clear in C-C, likely due to aerosol/dust or surface snow layers misidentified by MODIS. C-C reports 47.4/25.5% single-layer/multilayer <span class="hlt">clouds</span>, while MODIS reports 26.7/14.0%. For C-C single-layer <span class="hlt">clouds</span>, 90% of tropical MODIS high (CTP < 440 hPa) and optically thin (τ < 3.6) <span class="hlt">clouds</span> are identified as cirrus and 60% of high and optically thick (τ > 23) <span class="hlt">clouds</span> are recognized as deep convective in C-C. Approximately 70% of MODIS low-level (CTP > 680 hPa) <span class="hlt">clouds</span> are classified as stratocumulus in C-C regardless of region and optical thickness. No systematic relationship exists between MODIS middle-level (680 < CTP < 440 hPa) <span class="hlt">clouds</span> and C-C <span class="hlt">cloud</span> types, largely due to different definitions adopted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000031600&hterms=weather+types&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dweather%2Btypes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000031600&hterms=weather+types&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dweather%2Btypes"><span>ISCCP <span class="hlt">Cloud</span> Properties Associated with Standard <span class="hlt">Cloud</span> Types Identified in Individual Surface Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hahn, Carole J.; Rossow, William B.; Warren, Stephen G.</p> <p>1999-01-01</p> <p>Individual surface weather observations from land stations and ships are compared with individual <span class="hlt">cloud</span> retrievals of the International Satellite <span class="hlt">Cloud</span> Climatology Project (ISCCP), Stage C1, for an 8-year period (1983-1991) to relate <span class="hlt">cloud</span> optical thicknesses and <span class="hlt">cloud</span>-top pressures obtained from satellite data to the standard <span class="hlt">cloud</span> types reported in visual observations from the surface. Each surface report is matched to the corresponding ISCCP-C1 report for the time of observation for the 280x280-km grid-box containing that observation. Classes of the surface reports are identified in which a particular <span class="hlt">cloud</span> type was reported present, either alone or in combination with other <span class="hlt">clouds</span>. For each class, <span class="hlt">cloud</span> amounts from both surface and C1 data, base heights from surface data, and the frequency-distributions of <span class="hlt">cloud</span>-top pressure (p(sub c) and optical thickness (tau) from C1 data are averaged over 15-degree latitude zones, for land and ocean separately, for 3-month seasons. The frequency distribution of p(sub c) and tau is plotted for each of the surface-defined <span class="hlt">cloud</span> types occurring both alone and with other <span class="hlt">clouds</span>. The average <span class="hlt">cloud</span>-top pressures within a grid-box do not always correspond well with values expected for a reported <span class="hlt">cloud</span> type, particularly for the higher <span class="hlt">clouds</span> Ci, Ac, and Cb. In many cases this is because the satellites also detect <span class="hlt">clouds</span> within the grid-box that are outside the field of view of the surface observer. The highest average <span class="hlt">cloud</span> tops are found for the most extensive <span class="hlt">cloud</span> type, Ns, averaging 7 km globally and reaching 9 km in the ITCZ. Ns also has the greatest average retrieved optical thickness, tau approximately equal 20. Cumulonimbus <span class="hlt">clouds</span> may actually attain far greater heights and depths, but do not fill the grid-box. The tau-p(sub c) distributions show features that distinguish the high, middle, and low <span class="hlt">clouds</span> reported by the surface observers. However, the distribution patterns for the individual low <span class="hlt">cloud</span> types (Cu, Sc, St</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AtmRe.183..191S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AtmRe.183..191S"><span>Space-borne observations of aerosol - <span class="hlt">cloud</span> relations for <span class="hlt">cloud</span> systems of different heights</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stathopoulos, S.; Georgoulias, A. K.; Kourtidis, K.</p> <p>2017-01-01</p> <p>Here, we examine the aerosol - <span class="hlt">cloud</span> relations over three major urban clusters of China, representative of three different climatic regimes, under different water vapor conditions and <span class="hlt">cloud</span> heights, using Aerosol Optical Depth at 550 nm (AOD), <span class="hlt">Cloud</span> Fraction (CC), <span class="hlt">Cloud</span> Optical Depth (COD), Water Vapor (WV) and <span class="hlt">Cloud</span> Top Pressure (CTP) data from the MODIS instrument. Over all regions and for all seasons, CC is found to increase with increasing AOD, WV and <span class="hlt">cloud</span> height. Aerosols, at low WV environments and under constant CTP, have less impact on CC than at high WV environments. Furthermore, AOD has a varying influence on COD depending on CTP. Finally, COD is found to increase with height for low and middle height <span class="hlt">clouds</span>, and with increasing AOD, especially at low AOD. Our results demonstrate that the role of WV in the observed satellite-based aerosol - <span class="hlt">cloud</span> relations is significant for all <span class="hlt">cloud</span> heights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160006617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160006617"><span>Comparison Between CCCM and <span class="hlt">Cloud</span>Sat Radar-Lidar (RL) <span class="hlt">Cloud</span> and Radiation Products</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ham, Seung-Hee; Kato, Seiji; Rose, Fred G.; Sun-Mack, Sunny</p> <p>2015-01-01</p> <p>To enhance <span class="hlt">cloud</span> properties, LaRC and CIRA developed each combination algorithm for obtained properties from passive, active and imager in A-satellite constellation. When comparing global <span class="hlt">cloud</span> fraction each other, LaRC-produced CERES-CALIPSO-<span class="hlt">Cloud</span>Sat-MODIS (CCCM) products larger low-level <span class="hlt">cloud</span> fraction over tropic ocean, while CIRA-produced Radar-Lidar (RL) shows larger mid-level <span class="hlt">cloud</span> fraction for high latitude region. The reason for different low-level <span class="hlt">cloud</span> fraction is due to different filtering method of lidar-detected <span class="hlt">cloud</span> layers. Meanwhile difference in mid-level <span class="hlt">clouds</span> is occurred due to different priority of <span class="hlt">cloud</span> boundaries from lidar and radar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1203854','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1203854"><span>Quantifying Diurnal <span class="hlt">Cloud</span> Radiative Effects by <span class="hlt">Cloud</span> Type in the Tropical Western Pacific</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.</p> <p>2015-06-01</p> <p><span class="hlt">Cloud</span> radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, <span class="hlt">cloud</span> populations, and <span class="hlt">cloud</span> radiative effects by partitioning the data by <span class="hlt">cloud</span> type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate <span class="hlt">cloud</span> radiative effects down by <span class="hlt">cloud</span> type across the diurnal cycle. The Nauru <span class="hlt">cloud</span> populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the <span class="hlt">cloud</span> populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective <span class="hlt">clouds</span> have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave <span class="hlt">cloud</span> radiative effects at all three sites comes from low <span class="hlt">clouds</span>. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean <span class="hlt">cloud</span> frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of <span class="hlt">cloud</span> frequency. Our results provide solid benchmarks to evaluate model simulations of <span class="hlt">cloud</span> radiative effects in the tropics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040171505&hterms=fractions+keep&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dfractions%2Bkeep','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040171505&hterms=fractions+keep&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dfractions%2Bkeep"><span><span class="hlt">Clouds</span> Aerosols Internal Affaires: Increasing <span class="hlt">Cloud</span> Fraction and Enhancing the Convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koren, Ilan; Kaufman, Yoram; Remer, Lorraine; Rosenfeld, Danny; Rudich, Yinon</p> <p>2004-01-01</p> <p><span class="hlt">Clouds</span> developing in a polluted environment have more numerous, smaller <span class="hlt">cloud</span> droplets that can increase the <span class="hlt">cloud</span> lifetime and liquid water content. Such changes in the <span class="hlt">cloud</span> droplet properties may suppress low precipitation allowing development of a stronger convection and higher freezing level. Delaying the washout of the <span class="hlt">cloud</span> water (and aerosol), and the stronger convection will result in higher <span class="hlt">clouds</span> with longer life time and larger anvils. We show these effects by using large statistics of the new, 1km resolution data from MODIS on the Terra satellite. We isolate the aerosol effects from meteorology by regression and showing that aerosol microphysical effects increases <span class="hlt">cloud</span> fraction by average of 30 presents for all <span class="hlt">cloud</span> types and increases convective <span class="hlt">cloud</span> top pressure by average of 35mb. We analyze the aerosol <span class="hlt">cloud</span> interaction separately for high pressure trade wind <span class="hlt">cloud</span> systems and separately for deep convective <span class="hlt">cloud</span> systems. The resultant aerosol radiative effect on climate for the high pressure <span class="hlt">cloud</span> system is: -10 to -13 W/sq m at the top of the atmosphere (TOA) and -11 to -14 W/sq m at the surface. For deeper convective <span class="hlt">clouds</span> the forcing is: -4 to -5 W/sq m at the TOA and -6 to -7 W/sq m at the surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890012054','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890012054"><span>Operational implications of a <span class="hlt">cloud</span> model simulation of space shuttle exhaust <span class="hlt">clouds</span> in different atmospheric conditions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zak, J. A.</p> <p>1989-01-01</p> <p>A three-dimensional <span class="hlt">cloud</span> model was used to characterize the dominant influence of the environment on the Space Shuttle exhaust <span class="hlt">cloud</span>. The model was modified to accept the actual heat and moisture from rocket exhausts and deluge water as initial conditions. An upper-air sounding determined the ambient atmosphere in which the <span class="hlt">cloud</span> would grow. The model was validated by comparing simulated <span class="hlt">clouds</span> with observed <span class="hlt">clouds</span> from four actual Shuttle launches. Results are discussed with operational weather forecasters in mind. The model successfully produced <span class="hlt">clouds</span> with dimensions, rise, decay, liquid water contents, and vertical motion fields very similar to observed <span class="hlt">clouds</span> whose dimensions were calculated from 16 mm film frames. Once validated, the model was used in a number of different atmospheric conditions ranging from very unstable to very stable. Wind shear strongly affected the appearance of both the ground <span class="hlt">cloud</span> and vertical column <span class="hlt">cloud</span>. The ambient low-level atmospheric moisture governed the amount of <span class="hlt">cloud</span> water in model <span class="hlt">clouds</span>. Some dry atmospheres produced little or no <span class="hlt">cloud</span> water. An empirical forecast technique for Shuttle <span class="hlt">cloud</span> rise is presented and differences between natural atmospheric convection and exhaust <span class="hlt">clouds</span> are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23841397','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23841397"><span>[Analysis of <span class="hlt">cloud</span> spectral structure characteristics based on <span class="hlt">cloud</span> profile radar data].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Han, Yong; Lü, Da-Ren</p> <p>2013-04-01</p> <p><span class="hlt">Cloud</span> plays a very important role in the earth-atmosphere system. However, the current climate models are still lacking data about internal fine structure of <span class="hlt">cloud</span>. And when the traditional passive satellite radiometer is used for remote sense, a plentiful information of the vertical distribution of <span class="hlt">cloud</span> layer will be lost. For these reasons, NASA proposed the launch project of <span class="hlt">Cloud</span>Sat, Whose purpose is to provide the necessary observation, and then allow us to understand better the internal structure of the <span class="hlt">cloud</span>. <span class="hlt">Cloud</span>Sat was successfully launched on April 28, 2006. It carried the first <span class="hlt">cloud</span> profile radar (CPR) with W band (94 GHz), which can provide continuous and global time sequence vertical structure and characteristics of <span class="hlt">cloud</span>. In the present paper, using <span class="hlt">Cloud</span>Sat satellite data, we analyzed the 8th "Morakot" and 15th " Koppu" typhoon <span class="hlt">cloud</span> systems. According to the "typhoon" <span class="hlt">cloud</span> detection results, the radar reflectivity, <span class="hlt">cloud</span> types and optical thickness successive variation of <span class="hlt">cloud</span> layer were gotten, which will provide a reference for studying optical properties of typhoon <span class="hlt">cloud</span> system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A33I0381R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A33I0381R"><span>Large Eddy Simulation Study on Arctic Marine <span class="hlt">Clouds</span>: the Effect of Aerosol-<span class="hlt">Cloud</span> Interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raatikainen, T.; Ahola, J.; Tonttila, J.; Romakkaniemi, S.; Laaksonen, A.; Korhonen, H.</p> <p>2016-12-01</p> <p>Dynamics of marine stratocumulus <span class="hlt">clouds</span> depend on radiative cooling from <span class="hlt">cloud</span> tops, turbulent transport of moisture and heat from the sea surface, and the availability of atmospheric aerosols to act as <span class="hlt">cloud</span> condensation nuclei (CCN). These processes and especially aerosol-<span class="hlt">cloud</span> interactions can be examined with a recently developed Large Eddy Simulation (LES) model UCLALES-SALSA (Tonttila et al., Geosci. Model Dev. Discuss., 2016). Unlike most other LES models, UCLALES-SALSA has fully interactive sectional description for aerosols and liquid and frozen <span class="hlt">cloud</span> species. UCLALES-SALSA simulations are initialized using atmospheric observations from the Arctic Summer <span class="hlt">Cloud</span> Ocean Study (ASCOS). First, the model is used to examine the effects of initial total aerosol number concentration on <span class="hlt">cloud</span> properties. In agreement with several observations, lowering aerosol number concentration decreases <span class="hlt">cloud</span> lifetime by increasing drizzle and precipitation rates, which further decreases aerosol number concentration. The second test includes comparison between model versions with different microphysics. The new sectional approach seems to produce thicker and more persistent <span class="hlt">clouds</span> than a two moment model version (Stevens et al., J. Atmos. Sci., 1999) even when the models are tuned to have equal <span class="hlt">cloud</span> droplet number concentrations. The third part of the study is focused on the effect of ice on <span class="hlt">cloud</span> properties. Preliminary results indicate that the current <span class="hlt">cloud</span> case is so warm that the liquid phase dominates, but further studies are ongoing. In general, the results show that <span class="hlt">cloud</span> evolution depends on aerosol-<span class="hlt">cloud</span> interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050180543','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050180543"><span>Validation of AIRS/AMSU <span class="hlt">Cloud</span> Retrievals Using MODIS <span class="hlt">Cloud</span> Analyses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Molnar, Gyula I.; Susskind, Joel</p> <p>2005-01-01</p> <p>The AIRS/AMSU (flying on the EOS-AQUA satellite) sounding retrieval methodology allows for the retrieval of key atmospheric/surface parameters under partially cloudy conditions (Susskind et al.). In addition, <span class="hlt">cloud</span> parameters are also derived from the AIRS/AMSU observations. Within each AIRS footprint, <span class="hlt">cloud</span> parameters at up to 2 <span class="hlt">cloud</span> layers are determined with differing <span class="hlt">cloud</span> top pressures and effective (product of infrared emissivity at 11 microns and physical <span class="hlt">cloud</span> fraction) <span class="hlt">cloud</span> fractions. However, so far the AIRS <span class="hlt">cloud</span> product has not been rigorously evaluated/validated. Fortunately, collocated/coincident radiances measured by MODIS/AQUA (at a much lower spectral resolution but roughly an order of-magnitude higher spatial resolution than that of AIRS) are used to determine analogous <span class="hlt">cloud</span> products from MODIS. This allows us for a rather rare and interesting possibility: the intercomparisons and mutual validation of imager vs. sounder-based <span class="hlt">cloud</span> products obtained from the same satellite positions. First, we present results of small-scale (granules) instantaneous intercomparisons. Next, we will evaluate differences of temporally averaged (monthly) means as well as the representation of inter-annual variability of <span class="hlt">cloud</span> parameters as presented by the two <span class="hlt">cloud</span> data sets. In particular, we present statistical differences in the retrieved parameters of <span class="hlt">cloud</span> fraction and <span class="hlt">cloud</span> top pressure. We will investigate what type of <span class="hlt">cloud</span> systems are retrieved most consistently (if any) with both retrieval schemes, and attempt to assess reasons behind statistically significant differences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040171505&hterms=jerusalem&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Djerusalem','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040171505&hterms=jerusalem&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Djerusalem"><span><span class="hlt">Clouds</span> Aerosols Internal Affaires: Increasing <span class="hlt">Cloud</span> Fraction and Enhancing the Convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koren, Ilan; Kaufman, Yoram; Remer, Lorraine; Rosenfeld, Danny; Rudich, Yinon</p> <p>2004-01-01</p> <p><span class="hlt">Clouds</span> developing in a polluted environment have more numerous, smaller <span class="hlt">cloud</span> droplets that can increase the <span class="hlt">cloud</span> lifetime and liquid water content. Such changes in the <span class="hlt">cloud</span> droplet properties may suppress low precipitation allowing development of a stronger convection and higher freezing level. Delaying the washout of the <span class="hlt">cloud</span> water (and aerosol), and the stronger convection will result in higher <span class="hlt">clouds</span> with longer life time and larger anvils. We show these effects by using large statistics of the new, 1km resolution data from MODIS on the Terra satellite. We isolate the aerosol effects from meteorology by regression and showing that aerosol microphysical effects increases <span class="hlt">cloud</span> fraction by average of 30 presents for all <span class="hlt">cloud</span> types and increases convective <span class="hlt">cloud</span> top pressure by average of 35mb. We analyze the aerosol <span class="hlt">cloud</span> interaction separately for high pressure trade wind <span class="hlt">cloud</span> systems and separately for deep convective <span class="hlt">cloud</span> systems. The resultant aerosol radiative effect on climate for the high pressure <span class="hlt">cloud</span> system is: -10 to -13 W/sq m at the top of the atmosphere (TOA) and -11 to -14 W/sq m at the surface. For deeper convective <span class="hlt">clouds</span> the forcing is: -4 to -5 W/sq m at the TOA and -6 to -7 W/sq m at the surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUSM.H22A..22H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUSM.H22A..22H"><span><span class="hlt">Cloud</span> Classification and Rainfall Estimation using GOES Infrared Imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>hong, y</p> <p>2002-05-01</p> <p>The high-resolution <span class="hlt">cloud</span> infrared images from geostationary satellites (approximately 4 km x 4 km and 30 minutes) provide information of <span class="hlt">cloud</span> structure and evolution, such information can be useful to improve the satellite rainfall estimation. An algorithm is developed to process the <span class="hlt">cloud</span> images and to enhance the <span class="hlt">cloud</span> features, which includes: 1) the Seeded Region Growing Segmentation (SRGS) scheme which divides a large scope of <span class="hlt">cloud</span> images into "<span class="hlt">cloud</span> patches" according to the "topography" of <span class="hlt">cloud</span>-top; 2) calculating <span class="hlt">cloud</span> features of physics (temperature and dynamics), geometry (shape and size), texture (surface gradient) for each <span class="hlt">cloud</span> patch; 3) categorizing <span class="hlt">cloud</span> patches into clusters based on the extracted features (a Self-Organization Feature Mapping scheme); and 4) relating <span class="hlt">cloud</span> clusters to the NEXRAD rainfall maps to display the different <span class="hlt">cloud</span>-rainfall relationships. The results of this <span class="hlt">cloud</span> analysis program will be demonstrated and the potential use of <span class="hlt">cloud</span>-patch analysis for rainfall estimation will be discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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