WorldWideScience

Sample records for sunshine cloud cover

  1. Cloud Cover

    Science.gov (United States)

    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…

  2. The SunCloud project: An initiative for a development of a worldwide sunshine duration and cloudiness observations dataset

    Science.gov (United States)

    Sanchez-Lorenzo, A.

    2010-09-01

    One problem encountered when establishing the causes of global dimming and brightening is the limited number of long-term solar radiation series with accurate and calibrated measurements. For this reason, the analysis is often supported and extended with the use of other climatic variables such as sunshine duration and cloud cover. Specifically, sunshine duration is defined as the amount of time usually expressed in hours that direct solar radiation exceeds a certain threshold (usually taken at 120 W m-2). Consequently, this variable can be considered as an excellent proxy measure of solar radiation at interannual and decadal time scales, with the advantage that measurements of this variable were initiated in the late 19th century in different, worldwide, main meteorological stations. Nevertheless, detailed and up-to-date analysis of sunshine duration behavior on global or hemispheric scales are still missing. Thus, starting on September 2010 in the framework of different research projects, we will engage a worldwide compilation of the longest daily or monthly sunshine duration series from the late 19th century until present. Several quality control checks and homogenization methods will be applied to the generated sunshine dataset. The relationship between the more precise downward solar radiation series from the Global Energy Balance Archive (GEBA) and the homogenized sunshine series will be studied in order to reconstruct global and regional solar irradiance at the Earth's surface since the late 19th century. Since clouds are the main cause of interannual and decadal variability of radiation reaching the Earth's surface, as a complement to the long-term sunshine series we will also compile worldwide surface cloudiness observations. With this presentation we seek to encourage the climate community to contribute with their own local datasets to the SunCloud project. The SunCloud Team: M. Wild, Institute for Atmospheric and Climate Science, ETH Zurich, Switzerland

  3. Seasonal cycle of cloud cover analyzed using Meteosat images

    OpenAIRE

    Massons, J.; Domingo, D.; Lorente, J.

    1998-01-01

    A cloud-detection method was used to retrieve cloudy pixels from Meteosat images. High spatial resolution (one pixel), monthly averaged cloud-cover distribution was obtained for a 1-year period. The seasonal cycle of cloud amount was analyzed. Cloud parameters obtained include the total cloud amount and the percentage of occurrence of clouds at three altitudes. Hourly variations of cloud cover are also analyzed. Cloud properties determined are coherent with those obtained in previous studies....

  4. Sky cover from MFRSR observations: cumulus clouds

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-01-01

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

  5. Reconstruction of effective cloud field geometry from series of sunshine number

    Science.gov (United States)

    Badescu, Viorel; Paulescu, Marius; Brabec, Marek

    2016-07-01

    A new method is proposed for extracting the parameters of effective cloud field models from time series of sunshine number (SSN). Data of SSN number and point cloudiness during 2009 and 2010 at Timisoara (Romania, South Eastern Europe; temperate continental climate) are used to illustrate the method. Two procedures of fitting the estimated point cloudiness to the observed point cloudiness data are proposed and tested. Seven simple effective cloud field models are analyzed. All models underestimate the point cloudiness. The MBE ranges between - 0.06 and - 0.23 while RMSE between 0.15 and 0.38, depending on the month and the duration of the SSN data averaging interval. The best model is based on a field of clouds of semicircle form. This agrees with previous results obtained in the semi-arid climate of Great South Plains in US. The dynamics of the effective cloud field is reconstructed during all months of 2010 at Timisoara. The time series of effective cloud fields are dominated by semicircle clouds but short episodes of semielliptic clouds, ellipsoid clouds, truncated cone clouds and cuboidal clouds are included in the series.

  6. Black carbon absorption effects on cloud cover, review and synthesis

    Directory of Open Access Journals (Sweden)

    D. Koch

    2010-03-01

    Full Text Available Absorbing aerosols (AA's such as black carbon (BC or dust absorb incoming solar radiation, perturb the temperature structure of the atmosphere, and influence cloud cover. Previous studies have described conditions where AA's either increase or decrease cloud cover. The effect depends on several factors, including the altitude of the AA relative to the cloud and on the cloud type. Cloud cover is decreased if the AA's are embedded in the cloud layer. AA's below cloud may enhance convection and cloud cover. AA's over cloud-level stabilize the underlying layer and tend to enhance stratocumulus clouds but may reduce cumulus clouds. AA's can also promote cloud cover in convergent regions as they enhance deep convection and low level convergence as it draws in moisture from ocean to land regions. Most global model studies indicate a regional variation in the cloud response but generally increased cloud cover over oceans and some land regions, with net increased low-level and/or reduced upper level cloud cover. The result is net negative radiative forcing from cloud response to AA's. In some of these climate model studies, the cooling effect of BC due to cloud changes was strong enough to essentially cancel the warming direct effects.

  7. Helix Nebula: sunshine and clouds on the CERN computing horizon

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    23 petabytes is how much data CERN recorded during 2011, and this number will rise in 2012. In order to respond to the challenge, the IT department is upping its game, amongst other things by participating in the Helix Nebula project, a public-private partnership to create a European cloud-computing platform, as announced in a recent CERN press release.   “We’re not replacing the Grid,” clarifies Bob Jones, responsible for CERN openlab who is also responsible for EC-funded projects in IT, “but looking at three complementary ways of increasing CERN’s computing capacity, so that as demand goes up we can continue to satisfy our users.” “First we are upgrading the electrical and cooling infrastructure of the computer centre in order to increase the availability of critical IT services needed for the Laboratory. This will also provide more floor space in the area called The Barn, allowing for more servers to fit in.”...

  8. Smoke and Pollution Aerosol Effect on Cloud Cover

    Science.gov (United States)

    Kaufman, Yoram J.; Koren, Ilan

    2006-01-01

    Pollution and smoke aerosols can increase or decrease the cloud cover. This duality in the effects of aerosols forms one of the largest uncertainties in climate research. Using solar measurements from Aerosol Robotic Network sites around the globe, we show an increase in cloud cover with an increase in the aerosol column concentration and an inverse dependence on the aerosol absorption of sunlight. The emerging rule appears to be independent of geographical location or aerosol type, thus increasing our confidence in the understanding of these aerosol effects on the clouds and climate. Preliminary estimates suggest an increase of 5% in cloud cover.

  9. Statistical cloud coverage as determined from sunshine duration: a model applicable in daylighting and solar energy forecasting

    Science.gov (United States)

    Kómar, Ladislav; Kocifaj, Miroslav

    2016-12-01

    A radiative/luminous energy budget is difficult to predict on a daily or hourly base if cloud coverage is obtained by subjective methods in discrete time points. A simple theoretical model that overcomes this shortcoming through interrelation of absolute cloud fraction and sunshine duration is presented. The latter is measured routinely at the meteorological stations worldwide. The model is based on statistical probability of clear line of sight, where Poisson spatial cloud distribution is analyzed for three different cloud shapes. A validation of the model using long-term measurements show a good correlation between experimentally determined and theoretically predicted data. The absolute cloud fraction obtained this way are a base for daylighting and solar energy applications including simulations of luminance/radiance sky distributions under different meteorological conditions. A simple calculation tool is developed and demonstrated on global horizontal illuminance (GHI).

  10. Observational evidence for cloud cover enhancement over western European forests

    Science.gov (United States)

    Teuling, Adriaan J.; Taylor, Christopher M.; Meirink, Jan Fokke; Melsen, Lieke A.; Miralles, Diego G.; van Heerwaarden, Chiel C.; Vautard, Robert; Stegehuis, Annemiek I.; Nabuurs, Gert-Jan; de Arellano, Jordi Vilà-Guerau

    2017-01-01

    Forests impact regional hydrology and climate directly by regulating water and heat fluxes. Indirect effects through cloud formation and precipitation can be important in facilitating continental-scale moisture recycling but are poorly understood at regional scales. In particular, the impact of temperate forest on clouds is largely unknown. Here we provide observational evidence for a strong increase in cloud cover over large forest regions in western Europe based on analysis of 10 years of 15 min resolution data from geostationary satellites. In addition, we show that widespread windthrow by cyclone Klaus in the Landes forest led to a significant decrease in local cloud cover in subsequent years. Strong cloud development along the downwind edges of larger forest areas are consistent with a forest-breeze mesoscale circulation. Our results highlight the need to include impacts on cloud formation when evaluating the water and climate services of temperate forests, in particular around densely populated areas.

  11. Discrete post-processing of total cloud cover ensemble forecasts

    Science.gov (United States)

    Hemri, Stephan; Haiden, Thomas; Pappenberger, Florian

    2017-04-01

    This contribution presents an approach to post-process ensemble forecasts for the discrete and bounded weather variable of total cloud cover. Two methods for discrete statistical post-processing of ensemble predictions are tested. The first approach is based on multinomial logistic regression, the second involves a proportional odds logistic regression model. Applying them to total cloud cover raw ensemble forecasts from the European Centre for Medium-Range Weather Forecasts improves forecast skill significantly. Based on station-wise post-processing of raw ensemble total cloud cover forecasts for a global set of 3330 stations over the period from 2007 to early 2014, the more parsimonious proportional odds logistic regression model proved to slightly outperform the multinomial logistic regression model. Reference Hemri, S., Haiden, T., & Pappenberger, F. (2016). Discrete post-processing of total cloud cover ensemble forecasts. Monthly Weather Review 144, 2565-2577.

  12. Cloud cover analysis over Tibet by Meteosat data

    Science.gov (United States)

    Fang, Yonghua; Bakan, Stephan

    2003-04-01

    The Tibet Plateau plays an important role in the general atmospheric circulation as a cold and heat source. In summer, the plateau is covered by active cumulus convection. So it is very important to understand the distribution of cloud over Tibet. In this paper, Meteosat image data is used to analyze the cloud cover over Tibet. The statistical method is used to perform cloud classification: first step, a two-dimensional frequency histogram is constructed from two channels images (VIS and IR); second step, dynamic clustering technique is used to automatically classify this two-dimensional histogram; third step, each pixel in original image is assigned to a cloud class. The classification results show clearly the distribution of cloud classes.

  13. Cloud cover estimation optical package: New facility, algorithms and techniques

    Science.gov (United States)

    Krinitskiy, Mikhail

    2017-02-01

    Short- and long-wave radiation is an important component of surface heat budget over sea and land. For estimating them accurate observations of the cloud cover are needed. While massively observed visually, for building accurate parameterizations cloud cover needs also to be quantified using precise instrumental measurements. Major disadvantages of the most of existing cloud-cameras are associated with their complicated design and inaccuracy of post-processing algorithms which typically result in the uncertainties of 20% to 30% in the camera-based estimates of cloud cover. The accuracy of these types of algorithm in terms of true scoring compared to human-observed values is typically less than 10%. We developed new generation package for cloud cover estimating, which provides much more accurate results and also allows for measuring additional characteristics. New algorithm, namely SAIL GrIx, based on routine approach, also developed for this package. It uses the synthetic controlling index ("grayness rate index") which allows to suppress the background sunburn effect. This makes it possible to increase the reliability of the detection of the optically thin clouds. The accuracy of this algorithm in terms of true scoring became 30%. One more approach, namely SAIL GrIx ML, we have used to increase the cloud cover estimating accuracy is the algorithm that uses machine learning technique along with some other signal processing techniques. Sun disk condition appears to be a strong feature in this kind of models. Artificial Neural Networks type of model demonstrates the best quality. This model accuracy in terms of true scoring increases up to 95,5%. Application of a new algorithm lets us to modify the design of the optical sensing package and to avoid the use of the solar trackers. This made the design of the cloud camera much more compact. New cloud-camera has already been tested in several missions across Atlantic and Indian oceans on board of IORAS research vessels.

  14. Clouds cover variability in São Paulo

    Directory of Open Access Journals (Sweden)

    Luciana Machado de Moura

    2016-11-01

    Full Text Available Clouds cover observations are performed by visual inspection which determines the fraction of the sky that is overcast. However, visual observation of clouds cover is a very subjective method, and can vary significantly among observers. This study examined the variability in clouds cover over the city of São Paulo between 1961 and 2013, using clouds cover fraction data observed at the weather station operated by IAG / USP. The study also used two techniques based on visible radiance data observed by the GOES-10 satellite in order to indirectly estimate clouds cover. In order to ensure consistency, the estimated and observed cloudiness was compared with the clearness index, which is the ratio between the total solar radiation observed at the weather station and the incoming solar irradiation at the top of atmosphere. The study found consistency between the various databases that showed similar behavior in all of the seasons of the year. The largest cloudiness values occurred in the summer and lowest in the winter.

  15. Cloud cover estimation: Use of GOES imagery in development of cloud cover data base for insolation assessment

    Science.gov (United States)

    Huning, J. R.; Logan, T. L.; Smith, J. H.

    1982-01-01

    The potential of using digital satellite data to establish a cloud cover data base for the United States, one that would provide detailed information on the temporal and spatial variability of cloud development are studied. Key elements include: (1) interfacing GOES data from the University of Wisconsin Meteorological Data Facility with the Jet Propulsion Laboratory's VICAR image processing system and IBIS geographic information system; (2) creation of a registered multitemporal GOES data base; (3) development of a simple normalization model to compensate for sun angle; (4) creation of a variable size georeference grid that provides detailed cloud information in selected areas and summarized information in other areas; and (5) development of a cloud/shadow model which details the percentage of each grid cell that is cloud and shadow covered, and the percentage of cloud or shadow opacity. In addition, comparison of model calculations of insolation with measured values at selected test sites was accomplished, as well as development of preliminary requirements for a large scale data base of cloud cover statistics.

  16. THE INFLUENCE OF NONUNIFORM CLOUD COVER ON TRANSIT TRANSMISSION SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Line, Michael R. [NASA Ames Research Center, Moffet Field, CA 94035 (United States); Parmentier, Vivien, E-mail: mrline@ucsc.edu [Department of Astronomy and Astrophysics, University of California–Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2016-03-20

    We model the impact of nonuniform cloud cover on transit transmission spectra. Patchy clouds exist in nearly every solar system atmosphere, brown dwarfs, and transiting exoplanets. Our major findings suggest that fractional cloud coverage can exactly mimic high mean molecular weight atmospheres and vice versa over certain wavelength regions, in particular, over the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) bandpass (1.1–1.7 μm). We also find that patchy cloud coverage exhibits a signature that is different from uniform global clouds. Furthermore, we explain analytically why the “patchy cloud-high mean molecular weight” degeneracy exists. We also explore the degeneracy of nonuniform cloud coverage in atmospheric retrievals on both synthetic and real planets. We find from retrievals on a synthetic solar composition hot Jupiter with patchy clouds and a cloud-free high mean molecular weight warm Neptune that both cloud-free high mean molecular weight atmospheres and partially cloudy atmospheres can explain the data equally well. Another key finding is that the HST WFC3 transit transmission spectra of two well-observed objects, the hot Jupiter HD 189733b and the warm Neptune HAT-P-11b, can be explained well by solar composition atmospheres with patchy clouds without the need to invoke high mean molecular weight or global clouds. The degeneracy between high molecular weight and solar composition partially cloudy atmospheres can be broken by observing the molecular Rayleigh scattering differences between the two. Furthermore, the signature of partially cloudy limbs also appears as a ∼100 ppm residual in the ingress and egress of the transit light curves, provided that the transit timing is known to seconds.

  17. Testing the proposed link between cosmic rays and cloud cover

    CERN Document Server

    Sloan, T

    2008-01-01

    A decrease in the globally averaged low level cloud cover, deduced from the ISCCP infra red data, as the cosmic ray intensity decreased during the solar cycle 22 was observed by two groups. The groups went on to hypothesise that the decrease in ionization due to cosmic rays causes the decrease in cloud cover, thereby explaining a large part of the presently observed global warming. We have examined this hypothesis to look for evidence to corroborate it. None has been found and so our conclusions are to doubt it. From the absence of corroborative evidence, we estimate that less than 23%, at the 95% confidence level, of the 11-year cycle change in the globally averaged cloud cover observed in solar cycle 22 is due to the change in the rate of ionization from the solar modulation of cosmic rays.

  18. On the correlation between cosmic ray intensity and cloud cover

    CERN Document Server

    Erlykin, A D; Kudela, K; Sloan, T; Wolfendale, A W

    2009-01-01

    Various aspects of the connection between cloud cover (CC) and cosmic rays (CR) are analysed. Many features of this connection indicate that there is no direct causal connection between low cloud cover (LCC) and CR in spite of the evident long-term correlation between them. However, most of these features are indirect. If only some part of the LCC is connected and varies with CR, then its value, obtained from the joint analysis of their 11-year variations, and averaged over the globe, should be most likely less than 20%. The most significant argument against a causal connection of CR and LCC is the anticorrelation between LCC and the medium cloud cover (MCC). The scenario of the parallel influence of the solar activity on the global temperature and CC on one side and CR on the other, which can lead to the observed correlations, is discussed and advocated.

  19. On the correlation between cosmic ray intensity and cloud cover

    OpenAIRE

    Erlykin, A. D.; Gyalai, G.; Kudela, K.; Sloan, T.; Wolfendale, A. W.

    2009-01-01

    Various aspects of the connection between cloud cover (CC) and cosmic rays (CR) are analysed. Many features of this connection indicate that there is no direct causal connection between low cloud cover (LCC) and CR in spite of the evident long-term correlation between them. However, most of these features are indirect. If only some part of the LCC is connected and varies with CR, then its value, obtained from the joint analysis of their 11-year variations, and averaged over the globe, should ...

  20. Clouds and relative humidity in climate models; or what really regulates cloud cover?

    Energy Technology Data Exchange (ETDEWEB)

    Walcek, C. [State Univ. of New York, Albany, NY (United States)

    1995-09-01

    The response and impact of clouds remains one of the largest outstanding questions in GCMs. Clouds are not homogeneous, though they are treated as such in the models. When averaged over areas typically used as numerical grid elements by GCMs, observations suggest that there are some clouds at all relative humidities. Fractional cloud cover at 100% relative humidity is rarely 100%, and totally clear skies rarely occur, even for low relative humidities. Relative humidity is the best single indicator of cloud coverage. However, if there is a relationship between cloud coverage and relative humidity, our current models and observations are inadequate to reveal exactly what that relationship is. It does appear that cloud coverage decreases exponentially as humidity falls below 100%. 2 refs., 2 figs.

  1. D Land Cover Classification Based on Multispectral LIDAR Point Clouds

    Science.gov (United States)

    Zou, Xiaoliang; Zhao, Guihua; Li, Jonathan; Yang, Yuanxi; Fang, Yong

    2016-06-01

    Multispectral Lidar System can emit simultaneous laser pulses at the different wavelengths. The reflected multispectral energy is captured through a receiver of the sensor, and the return signal together with the position and orientation information of sensor is recorded. These recorded data are solved with GNSS/IMU data for further post-processing, forming high density multispectral 3D point clouds. As the first commercial multispectral airborne Lidar sensor, Optech Titan system is capable of collecting point clouds data from all three channels at 532nm visible (Green), at 1064 nm near infrared (NIR) and at 1550nm intermediate infrared (IR). It has become a new source of data for 3D land cover classification. The paper presents an Object Based Image Analysis (OBIA) approach to only use multispectral Lidar point clouds datasets for 3D land cover classification. The approach consists of three steps. Firstly, multispectral intensity images are segmented into image objects on the basis of multi-resolution segmentation integrating different scale parameters. Secondly, intensity objects are classified into nine categories by using the customized features of classification indexes and a combination the multispectral reflectance with the vertical distribution of object features. Finally, accuracy assessment is conducted via comparing random reference samples points from google imagery tiles with the classification results. The classification results show higher overall accuracy for most of the land cover types. Over 90% of overall accuracy is achieved via using multispectral Lidar point clouds for 3D land cover classification.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-12-01

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

  3. Changes in atmospheric circulation and the Arctic Oscillation preserved within a millennial length reconstruction of summer cloud cover from northern Fennoscandia

    Energy Technology Data Exchange (ETDEWEB)

    Young, Giles H.F.; McCarroll, Danny; Loader, Neil J.; Gagen, Mary H.; Demmler, Joanne C. [Swansea University, Department of Geography, Swansea (United Kingdom); Kirchhefer, Andreas J. [University of Tromsoe, Department of Arctic and Marine Biology, Tromsoe (Norway); Dendrooekologen, Tromsoe (Norway)

    2012-07-15

    Cloud cover currently represents the single greatest source of uncertainty in General Circulation Models. Stable carbon isotope ratios ({delta}{sup 13}C) from tree-rings, in areas of low moisture stress, are likely to be primarily controlled by photosynthetically active radiation (PAR), and therefore should provide a proxy record for cloud cover or sunshine; indeed this association has previously been demonstrated experimentally for Scots pine in Fennoscandia, with sunlight explaining ca 90% of the variance in photosynthesis and temperature only ca 4%. We present a statistically verifiable 1011-year reconstruction of cloud cover from a well replicated, annually-resolved {delta}{sup 13}C record from Forfjord in coastal northwestern Norway. This reconstruction exhibits considerable variability in cloud cover over the past millennium, including extended sunny periods during the cool seventeenth and eighteenth centuries and warm cloudy periods during the eleventh, early fifteenth and twentieth centuries. We find that while a generally positive relationship persists between sunshine and temperature at high-frequency, at lower (multi-decadal) frequencies the relationship is more often a negative one, with cool periods being sunny (most notably the Little Ice Age period from 1600 to 1750 CE) and warm periods more cloudy (e.g. the mediaeval and the twentieth century). We conclude that these long-term changes may be caused by changes in the dominant circulation mode, likely to be associated with the Arctic Oscillation. There is also strong circumstantial evidence that prolonged periods of high summer cloud cover, with low PAR and probably high precipitation, may be in part responsible for major European famines caused by crop failures. (orig.)

  4. Marine ARM GPCI Investigation of Clouds Sunshine Pyranometer (SPN1) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, R. Michael [Remote Measurements & Research Company, Seattle, WA (United States); Long, Charles N. [National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.

    2016-01-10

    From the SPN1 manual, the SPN1 Sunshine Pyranometer is one sensor with three output channels: 1) total (global) solar radiation, 2) diffuse radiation, and 3) sunshine status. The SPN1 measures short-wave radiation between 400nm and 2700nm in W.m-2. The Direct beam component of solar radiation can be calculated from the Total minus the Diffuse component. The Sunshine status output indicates whether the energy in the direct beam exceeds the World Meteorological Organization (WMO) standard threshold value of 120 W.m-2, using an algorithm based on the Total radiation, and the ratio of Total to Diffuse radiation. The radiation outputs have a cosine-corrected response. The advantages of the SPN1 are 1) It matches the WMO ‘Good Quality’ pyranometer classification. 2) It requires no shadow band or solar tracker. 3) There are no moving parts. 4) It does not need to be adjusted or repositioned to track the sun—a distinct advantage over shade rings or mechanical trackers. 5) It does not need to be oriented towards north. It will work accurately in any orientation as long as it is mounted horizontally. 6) It does not require knowledge of the latitude or longitude, and can be used at any latitude or longitude. 7) It measures sunshine hours as well as Total and Diffuse radiation. 8) The built-in heater allows use in wet or icy conditions.

  5. Global patterns of solar influence on high cloud cover

    Science.gov (United States)

    Dima, Mihai; Voiculescu, Mirela

    2016-07-01

    One of the main sources of uncertainty in climate projections is represented by clouds, which have a profound influence on the Earth's radiation budget through the feedbacks in which they are involved. The improvement of clouds representation in General Circulation Models relies largely on constraints derived from observations and on correct identification of processes that influence cloud formation or lifetime. Here we identify solar forced high cloud cover (HCC) patterns in reanalysis and observed data extending over the 1871-2009 period, based on their associations with known fingerprints of the same forcing on surface air temperature, sea surface temperature (SST) and sea level pressure fields. The solar influence on HCC has maximum amplitudes over the Pacific basin, where HCC anomalies are distributed in bands of alternating polarities. The colocation of the HCC and SST anomalies bands indicates a thermal influence on high clouds through convection and an amplification of the HCC anomalies by a positive feedback of long-wave fluxes, which increases the solar signal. Consistent with numerical simulations, the solar forced HCC pattern appears to be generated through a constructive interference between the so-called "top-down" and "bottom-up" mechanisms of solar influence on climate and is amplified by ocean-atmosphere positive feedbacks.

  6. Statistical analysis of multivariate atmospheric variables. [cloud cover

    Science.gov (United States)

    Tubbs, J. D.

    1979-01-01

    Topics covered include: (1) estimation in discrete multivariate distributions; (2) a procedure to predict cloud cover frequencies in the bivariate case; (3) a program to compute conditional bivariate normal parameters; (4) the transformation of nonnormal multivariate to near-normal; (5) test of fit for the extreme value distribution based upon the generalized minimum chi-square; (6) test of fit for continuous distributions based upon the generalized minimum chi-square; (7) effect of correlated observations on confidence sets based upon chi-square statistics; and (8) generation of random variates from specified distributions.

  7. Black carbon semi-direct effects on cloud cover: review and synthesis

    Directory of Open Access Journals (Sweden)

    D. Koch

    2010-08-01

    Full Text Available Absorbing aerosols (AAs such as black carbon (BC or dust absorb incoming solar radiation, perturb the temperature structure of the atmosphere, and influence cloud cover. Previous studies have described conditions under which AAs either increase or decrease cloud cover. The effect depends on several factors, including the altitude of the AA relative to the cloud and the cloud type. We attempt to categorize the effects into several likely regimes. Cloud cover is decreased if the AAs are embedded in the cloud layer. AAs below cloud may enhance convection and cloud cover. AAs above cloud top stabilize the underlying layer and tend to enhance stratocumulus clouds but may reduce cumulus clouds. AAs can also promote cloud cover in convergent regions as they enhance deep convection and low level convergence as it draws in moisture from ocean to land regions. Most global model studies indicate a regional variation in the cloud response but generally increased cloud cover over oceans and some land regions, with net increased low-level and/or reduced upper level cloud cover. The result is a net negative semi-direct effect feedback from the cloud response to AAs. In some of these climate model studies, the cooling effect of BC due to cloud changes is strong enough to essentially cancel the warming direct effects.

  8. An Uneven Illumination Correction Algorithm for Optical Remote Sensing Images Covered with Thin Clouds

    National Research Council Canada - National Science Library

    Xiaole Shen; Qingquan Li; Yingjie Tian; Linlin Shen

    2015-01-01

    .... The imaging model of remote sensing images covered by thin clouds is analyzed. Due to the transmission attenuation, reflection, and scattering, the thin cloud cover usually increases region brightness and reduces saturation and contrast of the image...

  9. Correlation between atmospheric electric fields and cloud cover using a field mill and cloud observation data

    Science.gov (United States)

    Nakamori, Kota; Suzuki, Yasuki; Ohya, Hiroyo; Takano, Toshiaki; Kawamura, Yohei; Nakata, Hiroyuki; Yamashita, Kozo

    2017-04-01

    It is known that lightning and precipitations of rain droplets generated from thunderclouds are a generator of global atmospheric electric circuit. In the fair weather, the atmospheric electric fields (AEF) are downward (positive), while they are upward (negative) during lightning and precipitations. However, the correlations between the AEF, and the cloud parameters such as cloud cover, weather phenomenon, have been not revealed quantitatively yet. In this study, we investigate the correlations between the AEF and the cloud parameters, weather phenomenon using a field mill, the 95 GHz-FALCON (FMCW Radar for Cloud Observations)-I and all-sky camera observations. In this study, we installed a Boltek field mill on the roof of our building in Chiba University, Japan, (Geographic coordinate: 35.63 degree N, 140.10 degree E, the sea level: 55 m) on the first June, 2016. The sampling time of the AEF is 0.5 s. On the other hand, the FALCON-I has observed the cloud parameters far from about 76 m of the field mill throughout 24 hours every day. The vertical cloud profiles and the Doppler velocity of cloud particles can be derived by the FALCON-I with high distance resolutions (48.8 m) (Takano et al., 2010). In addition, the images of the clouds and precipitations are recorded with 30-s sampling by an all-sky camera using a CCD camera on the same roof during 05:00-22:00 LT every day. The distance between the field mill and the all-sky camera is 3.75 m. During 08:30 UT - 10:30 UT, on 4 July, 2016, we found the variation of the AEF due to the approach of thundercloud. The variation consisted of two patterns. One was slow variation due to the movement of thunderclouds, and the other was rapid variation associated with lightning discharges. As for the movement of thunderclouds, the AEF increased when the anvil was located over the field mill, which was opposite direction of the previous studies. This change might be due to the positive charges in the upper anvil more than 14 km

  10. Investigating a solar influence on cloud cover using the North American Regional Reanalysis data

    Directory of Open Access Journals (Sweden)

    Krahenbuhl Daniel Scott

    2015-01-01

    Full Text Available The controversial connection between cosmic rays, solar activity, and cloud cover is investigated using a climatological reconstructed reanalysis product: the North American Regional Reanalysis which provides high-resolution, low, mid-level, high, and total cloud cover data over a Lambert conformal conic projection permitting land/ocean discrimination. Pearson’s product-moment regional correlations were obtained between monthly cloud cover data and solar variability indicators, cosmic ray neutron monitors, several climatological indices, including the Atlantic Multidecadal Oscillation (AMO, and between cloud layers. Regions of the mid-latitude oceans exhibited a positive correlation with cosmic ray flux. Additionally, this maritime low cloud cover exhibits the only failed correlation significance with other altitudes. The cross correlation reveals that cloud cover is positively correlated everywhere but for ocean low cloud cover, supporting the unique response of the marine layer. The results of this investigation suggest that with the assumption that solar forcing does impact cloud cover, measurements of solar activity exhibits a slightly higher correlation than GCRs. The only instance where GCRs exhibit a positive regional correlation with cloud cover is for maritime low clouds. The AMO exerts the greatest control of cloud cover in the NARR domain.

  11. A new MODIS daily cloud free snow cover mapping algorithm on the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    XiaoDong Huang; XiaoHua Hao; QiSheng Feng; Wei Wang; TianGang Liang

    2014-01-01

    Because of similar reflective characteristics of snow and cloud, the weather status seriously affects snow monitoring using optical remote sensing data. Cloud amount analysis during 2010 to 2011 snow seasons shows that cloud cover is the major limitation for snow cover monitoring using MOD10A1 and MYD10A1. By use of MODIS daily snow cover products and AMSR-E snow wa-ter equivalent products (SWE), several cloud elimination methods were integrated to produce a new daily cloud free snow cover product, and information of snow depth from 85 climate stations in Tibetan Plateau area (TP) were used to validate the accuracy of the new composite snow cover product. The results indicate that snow classification accuracy of the new daily snow cover product reaches 91.7%when snow depth is over 3 cm. This suggests that the new daily snow cover mapping algorithm is suitable for monitoring snow cover dynamic changes in TP.

  12. Solar signal at regional scale: a study of possible solar impact upon cloud cover and associated climatic parameters in Romania

    Science.gov (United States)

    Sfica, Lucian; Iordache, Iulian; Voiculescu, Mirela

    2016-04-01

    consistent arguments for existing solar influence upon climate at global or hemispherical scale. Solar trademark was identified in pressure fields at tropospheric or stratospheric level, atmospheric circulation pattern, temperature variation or cloud cover, on different timescales. However, these are less clear at regional or local. In our study we try to investigate the solar impact upon the climate parameters on the level of Romanian territory. The ROCADA database (Bîrsan et al., 2014) was used for climate data for Romania. The database covers the 1961-2013 period for 9 climate parameters out of which we will focus on those which may help in understanding the cloud cover response to solar triggers: mean air temperature, maximum air temperature, minimum air temperature, relative humidity, cloud cover, atmospheric pressure, precipitation amount and sunshine duration. The data base is downloadable on a gridded dataset at daily level with a spatial resolution of 0,1 degree. For solar data a couple of proxy solar data were selected from NASA daily database - omniweb.gsfc.nasa.gov - concerning terrestrial magnetic field (BY, BZ), electric field (EF), solar wind speed (SW) or the more classical proxy of sunspots number. Climate Data Operator is used for extracting gridded data and ArcGis 10.3.1 and Qgis software packages for mapping the results. Data were statistically treated in order to eliminate the trend and the effect of seasonality. The results were organized for monthly, seasonal and yearly level. The methodology for detection of the solar signal on climate variables relies on interpreting the correlation maps between climate variables and solar proxies. Also, a composite analysis on the basis of separation of high and low solar activity at monthly level was performed. The main results leads to the idea that the solar signal can be detected primarly in the temporal variation of atmospheric pressure (positive correlation with solar wind speed), soil temperature

  13. Estimating solar resources in Mexico using cloud cover data

    Energy Technology Data Exchange (ETDEWEB)

    Renne, David; George, Ray; Brady, Liz; Marion, Bill [National Renewable Energy Laboratory, Colorado (United States); Estrada Cajigal, Vicente [Cuernavaca, Morelos (Mexico)

    2000-07-01

    This paper presents the results of applying the National Renewable Energy Laboratory's (NREL) Climatological Solar Radiation (CSR) model to Mexico to develop solar resource data. A major input to the CSR model is a worldwide surface and satellite-derived cloud cover database, called the Real Time Nephanalysis (RTNEPH). The RTNEPH is developed by the U.S. Air Force and distributed by the U.S. National Climatic Data Center. The RTNEPH combines routine ground-based cloud cover observations made every three hours at national weather centers throughout the world with satellite-derived cloud cover information developed from polar orbiting weather satellites. The data are geospatially digitized so that multilayerd cloud cover information is available on a grid of approximately 40-km to a side. The development of this database is an ongoing project that now covers more than twenty years of observations. For the North America analysis (including Mexico) we used an 8-year summarized histogram of the RTNEPH that provides monthly average cloud cover information for the period 1985-1992. The CSR model also accounts for attenuation of the solar beam due to aerosols, atmospheric trace gases, and water vapor. The CSR model outputs monthly average direct normal, global horizontal and diffuse solar information for each of the 40-km grid cells. From this information it is also possible to produce solar resource estimates for various solar collector types and orientations, such as flat plate collectors oriented at latitude tilt, or concentrating solar power collectors. Model results are displayed using Geographic Information System software. CSR model results for Mexico are presented here, along with a discussion of earlier solar resource assessment studies for Mexico, where both modeling approaches and measurement analyses have been used. [Spanish] Este articulo presenta los resultados de aplicar el modelo Radiacion Solar Climatologica CSR del NREL (National Renewable Energy

  14. Looking for the rainbow on exoplanets covered by liquid and icy water clouds

    CERN Document Server

    Karalidi, T; Hovenier, J W

    2012-01-01

    Looking for the primary rainbow in starlight that is reflected by exoplanets appears to be a promising method to search for liquid water clouds in exoplanetary atmospheres. Ice water clouds, that consist of water crystals instead of water droplets, could potentially mask the rainbow feature in the planetary signal by covering liquid water clouds. Here, we investigate the strength of the rainbow feature for exoplanets that have liquid and icy water clouds in their atmosphere, and calculate the rainbow feature for a realistic cloud coverage of Earth. We calculate flux and polarization signals of starlight that is reflected by horizontally and vertically inhomogeneous Earth--like exoplanets, covered by patchy clouds consisting of liquid water droplets or water ice crystals. The planetary surfaces are black. On a planet with a significant coverage of liquid water clouds only, the total flux signal shows a weak rainbow feature. Any coverage of the liquid water clouds by ice clouds, however, dampens the rainbow fea...

  15. Gridded sunshine duration climate data record for Germany based on combined satellite and in situ observations

    Science.gov (United States)

    Walawender, Jakub; Kothe, Steffen; Trentmann, Jörg; Pfeifroth, Uwe; Cremer, Roswitha

    2017-04-01

    The purpose of this study is to create a 1 km2 gridded daily sunshine duration data record for Germany covering the period from 1983 to 2015 (33 years) based on satellite estimates of direct normalised surface solar radiation and in situ sunshine duration observations using a geostatistical approach. The CM SAF SARAH direct normalized irradiance (DNI) satellite climate data record and in situ observations of sunshine duration from 121 weather stations operated by DWD are used as input datasets. The selected period of 33 years is associated with the availability of satellite data. The number of ground stations is limited to 121 as there are only time series with less than 10% of missing observations over the selected period included to keep the long-term consistency of the output sunshine duration data record. In the first step, DNI data record is used to derive sunshine hours by applying WMO threshold of 120 W/m2 (SDU = DNI ≥ 120 W/m2) and weighting of sunny slots to correct the sunshine length between two instantaneous image data due to cloud movement. In the second step, linear regression between SDU and in situ sunshine duration is calculated to adjust the satellite product to the ground observations and the output regression coefficients are applied to create a regression grid. In the last step regression residuals are interpolated with ordinary kriging and added to the regression grid. A comprehensive accuracy assessment of the gridded sunshine duration data record is performed by calculating prediction errors (cross-validation routine). "R" is used for data processing. A short analysis of the spatial distribution and temporal variability of sunshine duration over Germany based on the created dataset will be presented. The gridded sunshine duration data are useful for applications in various climate-related studies, agriculture and solar energy potential calculations.

  16. Enhancement of Cloud Cover and Suppression of Nocturnal Drizzle in Stratocumulus Polluted by Haze

    Science.gov (United States)

    Ackerman, Andrew S.; Toon, O. B.; Stevens, D. E.; Coakley, J. A., Jr.; Gore, Warren J. (Technical Monitor)

    2002-01-01

    Recent satellite observations indicate a significant decrease of cloud water in ship tracks, in contrast to an ensemble of in situ ship-track measurements that show no average change in cloud water relative to the surrounding clouds. We find through large-eddy simulations of stratocumulus that the trend in the satellite data is likely an artifact of sampling only overcast clouds. The simulations instead show cloud cover increasing with droplet concentrations. Our simulations also show that increases in cloud water from drizzle suppression (by increasing droplet concentrations) are favored at night or at extremely low droplet concentrations.

  17. Total cloud cover from satellite observations and climate models

    Directory of Open Access Journals (Sweden)

    P. Probst

    2010-09-01

    Full Text Available Global and zonal monthly means of cloud cover fraction for total cloudiness (CF from the ISCCP D2 dataset are compared to same quantity produced by the 20th century simulations of 21 climate models from the World Climate Research Programme's (WCRP's Coupled Model Intercomparison Project phase 3 (CMIP3 multi-model dataset archived by the Program for Climate Model Diagnosis and Intercomparison (PCMDI. The comparison spans the time frame from January 1984 to December 1999 and the global and zonal average of CF are studied. The restriction to total cloudiness depends on the output of some models that does not include the 3D cloud structure. It is shown that the global mean of CF for the PCMDI/CMIP3 models, averaged over the whole period, exhibits a considerable variance and generally underestimates the ISCCP value. Very large discrepancies among models, and between models and observations, are found in the polar areas, where both models and satellite observations are less reliable, and especially near Antarctica. For this reason the zonal analysis is focused over the 60° S–60° N latitudinal belt, which includes the tropical area and mid latitudes. The two hemispheres are analyzed separately to show the variation of the amplitude of the seasonal cycle. Most models overestimate the yearly averaged values of CF over all of the analysed areas, while differences emerge in their ability to capture the amplitude of the seasonal cycle. The models represent, in a qualitatively correct way, the magnitude and the weak sign of the seasonal cycle over the whole geographical domain, but overestimate the strength of the signal in the tropical areas and at mid-latitudes, when taken separately. The interannual variability of the two yearly averages and of the amplitude of the seasonal cycle is greatly underestimated by all models in each area analysed. This work shows that the climate models have an heterogeneous behaviour in simulating the CF over

  18. Looking for the rainbow on exoplanets covered by liquid and icy water clouds

    Science.gov (United States)

    Karalidi, T.; Stam, D. M.; Hovenier, J. W.

    2012-12-01

    Aims: Looking for the primary rainbow in starlight that is reflected by exoplanets appears to be a promising method to search for liquid water clouds in exoplanetary atmospheres. Ice water clouds, that consist of water crystals instead of water droplets, could potentially mask the rainbow feature in the planetary signal by covering liquid water clouds. Here, we investigate the strength of the rainbow feature for exoplanets that have liquid and icy water clouds in their atmosphere, and calculate the rainbow feature for a realistic cloud coverage of Earth. Methods: We calculate flux and polarization signals of starlight that is reflected by horizontally and vertically inhomogeneous Earth-like exoplanets, covered by patchy clouds consisting of liquid water droplets or water ice crystals. The planetary surfaces are black. Results: On a planet with a significant coverage of liquid water clouds only, the total flux signal shows a weak rainbow feature. Any coverage of the liquid water clouds by ice clouds, however, dampens the rainbow feature in the total flux, and thus the discovery of liquid water in the atmosphere. On the other hand, detecting the primary rainbow in the polarization signal of exoplanets appears to be a powerful tool for detecting liquid water in exoplanetary atmospheres, even when these clouds are partially covered by ice clouds. In particular, liquid water clouds covering as little as 10-20% of the planetary surface, with more than half of these covered by ice clouds, still create a polarized rainbow feature in the planetary signal. Indeed, calculations of flux and polarization signals of an exoplanet with a realistic Earth-like cloud coverage, show a strong polarized rainbow feature.

  19. Cloud Cover Increase with Increasing Aerosol Absorptivity: A Counterexample to the Conventional Semidirect Aerosol Effect

    Science.gov (United States)

    Perlwitz, Jan; Miller, Ron L.

    2010-01-01

    We reexamine the aerosol semidirect effect using a general circulation model and four cases of the single-scattering albedo of dust aerosols. Contrary to the expected decrease in low cloud cover due to heating by tropospheric aerosols, we find a significant increase with increasing absorptivity of soil dust particles in regions with high dust load, except during Northern Hemisphere winter. The strongest sensitivity of cloud cover to dust absorption is found over land during Northern Hemisphere summer. Here even medium and high cloud cover increase where the dust load is highest. The cloud cover change is directly linked to the change in relative humidity in the troposphere as a result of contrasting changes in specific humidity and temperature. More absorption by aerosols leads to larger diabatic heating and increased warming of the column, decreasing relative humidity. However, a corresponding increase in the specific humidity exceeds the temperature effect on relative humidity. The net effect is more low cloud cover with increasing aerosol absorption. The higher specific humidity where cloud cover strongly increases is attributed to an enhanced convergence of moisture driven by dust radiative heating. Although in some areas our model exhibits a reduction of low cloud cover due to aerosol heating consistent with the conventional description of the semidirect effect, we conclude that the link between aerosols and clouds is more varied, depending also on changes in the atmospheric circulation and the specific humidity induced by the aerosols. Other absorbing aerosols such as black carbon are expected to have a similar effect.

  20. Diurnal distribution of sunshine probability

    Energy Technology Data Exchange (ETDEWEB)

    Aydinli, S.

    1982-01-01

    The diurnal distribution of the sunshine probability is essential for the predetermination of average irradiances and illuminances by solar radiation on sloping surfaces. The most meteorological stations have only monthly average values of the sunshine duration available. It is, therefore, necessary to compute the diurnal distribution of sunshine probability starting from the average monthly values. It is shown how the symmetric component of the distribution of the sunshine probability which is a consequence of a ''sidescene effect'' of the clouds can be calculated. The asymmetric components of the sunshine probability depending on the location and the seasons and their influence on the predetermination of the global radiation are investigated and discussed.

  1. Multiple Satellite Observations of Cloud Cover in Extratropical Cyclones

    Science.gov (United States)

    Naud, Catherine M.; Booth, James F.; Posselt, Derek J.; van den Heever, Susan C.

    2013-01-01

    Using cloud observations from NASA Moderate Resolution Imaging Spectroradiometer, Multiangle Imaging Spectroradiometer, and CloudSat-CALIPSO, composites of cloud fraction in southern and northern hemisphere extratropical cyclones are obtained for cold and warm seasons between 2006 and 2010, to assess differences between these three data sets, and between summer and winter cyclones. In both hemispheres and seasons, over the open ocean, the cyclone-centered cloud fraction composites agree within 5% across the three data sets, but behind the cold fronts, or over sea ice and land, the differences are much larger. To supplement the data set comparison and learn more about the cyclones, we also examine the differences in cloud fraction between cold and warm season for each data set. The difference in cloud fraction between cold and warm season southern hemisphere cyclones is small for all three data sets, but of the same order of magnitude as the differences between the data sets. The cold-warm season contrast in northern hemisphere cyclone cloud fractions is similar for all three data sets: in the warm sector, the cold season cloud fractions are lower close to the low, but larger on the equator edge than their warm season counterparts. This seasonal contrast in cloud fraction within the cyclones warm sector seems to be related to the seasonal differences in moisture flux within the cyclones. Our analysis suggests that the three different data sets can all be used confidently when studying the warm sector and warm frontal zone of extratropical cyclones but caution should be exerted when studying clouds in the cold sector.

  2. Cloud cover diurnal cycles in satellite data and regional climate model simulations

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifroth, Uwe; Ahrens, Bodo [Frankfurt Univ., Frankfurt am Main (Germany). Inst. for Atmospheric and Environmental Sciences; Hollmann, Rainer [Deutscher Wetterdienst, Offenbach (Germany)

    2012-12-15

    The amount and diurnal cycle of cloud cover play an important role in the energy and water cycle of the earth-atmosphere system and influence the radiation budget of the earth. Due to its importance and the challenging nature of its quantification, cloud cover is considered the biggest uncertainty factor in climate modeling. There is a clear need for reliable cloud datasets suitable for climate model evaluation studies. This study analyzes two datasets of cloud cover and its diurnal cycle derived from satellite observations by the International Satellite Cloud Climatology Project (ISCCP) and by EUMETSAT's Satellite Application Facility on Climate Monitoring (CM SAF) in Africa and Europe. Two regions, Europe and the subtropical southern Atlantic Ocean, were identified as offering distinct cloud cover diurnal cycles reasonably observed by both satellite datasets. In these regions, simulations by the regional climate model COSMO-CLM (CCLM) were evaluated in terms of cloud cover and its diurnal cycle during the time period of 1990 to 2007. Results show that the satellite derived cloud diurnal cycles largely agree, while discrepancies occur under extreme conditions like in the Sahara region. The CCLM is able to simulate the diurnal cycle observed consistently in the two satellite datasets in the South-Atlantic ocean, but not in Europe. CCLM misses the afternoon maximum cloud cover in Summer in Europe, which implies deficiencies in the parameterization of convection and in the treatment of surface-atmosphere interactions. The simulation of the diurnal cycle of the more stratiform cloud cover over the subtropical Atlantic was satisfactory in CCLM. (orig.)

  3. Effect of retreating sea ice on Arctic cloud cover in simulated recent global warming

    Science.gov (United States)

    Abe, Manabu; Nozawa, Toru; Ogura, Tomoo; Takata, Kumiko

    2016-11-01

    This study investigates the effect of sea ice reduction on Arctic cloud cover in historical simulations with the coupled atmosphere-ocean general circulation model MIROC5. Arctic sea ice has been substantially retreating since the 1980s, particularly in September, under simulated global warming conditions. The simulated sea ice reduction is consistent with satellite observations. On the other hand, Arctic cloud cover has been increasing in October, with about a 1-month lag behind the sea ice reduction. The delayed response leads to extensive sea ice reductions because the heat and moisture fluxes from the underlying open ocean into the atmosphere are enhanced. Sensitivity experiments with the atmospheric part of MIROC5 clearly show that sea ice reduction causes increases in cloud cover. Arctic cloud cover increases primarily in the lower troposphere, but it decreases in the near-surface layers just above the ocean; predominant temperature rises in these near-surface layers cause drying (i.e., decreases in relative humidity), despite increasing moisture flux. Cloud radiative forcing due to increases in cloud cover in autumn brings an increase in the surface downward longwave radiation (DLR) by approximately 40-60 % compared to changes in clear-sky surface DLR in fall. These results suggest that an increase in Arctic cloud cover as a result of reduced sea ice coverage may bring further sea ice retreat and enhance the feedback processes of Arctic warming.

  4. A quantitative method for estimating cloud cover over tropical cyclones from satellite data

    OpenAIRE

    BALOGUN, E. E.

    2011-01-01

    A photometric method for quantifying cloud cover over tropical cyclones as observed from satellite photographs is presented. Two gridded photographs of tropical cyclones are analyzed by this method. On each photograph, nine concentric circles are drawn. The observed or reported centre of the cyclones is used as the centre for each set of concentric circles. Photometric estimates of cloud cover are made along the nine concentric circles. The principle of harmonic analysis is applied to the cl...

  5. Observational evidence for cloud cover enhancement over western European forests

    NARCIS (Netherlands)

    Teuling, A.J.; Taylor, C.; Meirink, J.F.; Melsen, L.A.; Miralles, D.G.; Heerwaarden, van C.C.; Vautard, R.; Stegehuis, A.I.; Nabuurs, G.J.; Vilà-Guerau De Arellano, J.

    2017-01-01

    Forests impact regional hydrology and climate directly by regulating water and heat fluxes. Indirect effects through cloud formation and precipitation can be important in facilitating continental-scale moisture recycling but are poorly understood at regional scales. In particular, the impact of

  6. Long-term summer sunshine/moisture stress reconstruction from tree-ring widths from Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    S. Poljanšek

    2013-01-01

    Full Text Available We present the first summer sunshine reconstruction from tree-ring data for the western part of the Balkan Peninsula. Summer sunshine is tightly connected with moisture stress in trees, because the moisture stress and therefore the width of annual tree-rings is under the influence of the direct and interactive effects of sunshine duration (temperature, precipitation, cloud cover and evapotranspiration. The reconstruction is based on a calibrated z-scored mean chronology, calculated from tree-ring width measurements from 7 representative black pine (Pinus nigra Arnold sites in Bosnia and Herzegovina (BiH. A combined regression and scaling approach was used for the reconstruction of the summer sunshine. We found a significant negative correlation (r = −0.54, p < 0.0001 with mean June–July sunshine hours from Osijek meteorological station (Croatia. The developed model was used for reconstruction of summer sunshine for the time period 1660–2010. We identified extreme summer events and compared them to available documentary historical sources of drought, volcanic eruptions and other reconstructions from the broader region. All extreme summers with low sunshine hours (1712, 1810, 1815, 1843, 1899 and 1966 are connected with volcanic eruptions.

  7. Nowcasting sunshine number using logistic modeling

    Science.gov (United States)

    Brabec, Marek; Badescu, Viorel; Paulescu, Marius

    2013-04-01

    In this paper, we present a formalized approach to statistical modeling of the sunshine number, binary indicator of whether the Sun is covered by clouds introduced previously by Badescu (Theor Appl Climatol 72:127-136, 2002). Our statistical approach is based on Markov chain and logistic regression and yields fully specified probability models that are relatively easily identified (and their unknown parameters estimated) from a set of empirical data (observed sunshine number and sunshine stability number series). We discuss general structure of the model and its advantages, demonstrate its performance on real data and compare its results to classical ARIMA approach as to a competitor. Since the model parameters have clear interpretation, we also illustrate how, e.g., their inter-seasonal stability can be tested. We conclude with an outlook to future developments oriented to construction of models allowing for practically desirable smooth transition between data observed with different frequencies and with a short discussion of technical problems that such a goal brings.

  8. Cloud cover typing from environmental satellite imagery. Discriminating cloud structure with Fast Fourier Transforms (FFT)

    Science.gov (United States)

    Logan, T. L.; Huning, J. R.; Glackin, D. L.

    1983-01-01

    The use of two dimensional Fast Fourier Transforms (FFTs) subjected to pattern recognition technology for the identification and classification of low altitude stratus cloud structure from Geostationary Operational Environmental Satellite (GOES) imagery was examined. The development of a scene independent pattern recognition methodology, unconstrained by conventional cloud morphological classifications was emphasized. A technique for extracting cloud shape, direction, and size attributes from GOES visual imagery was developed. These attributes were combined with two statistical attributes (cloud mean brightness, cloud standard deviation), and interrogated using unsupervised clustering amd maximum likelihood classification techniques. Results indicate that: (1) the key cloud discrimination attributes are mean brightness, direction, shape, and minimum size; (2) cloud structure can be differentiated at given pixel scales; (3) cloud type may be identifiable at coarser scales; (4) there are positive indications of scene independence which would permit development of a cloud signature bank; (5) edge enhancement of GOES imagery does not appreciably improve cloud classification over the use of raw data; and (6) the GOES imagery must be apodized before generation of FFTs.

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

    CERN Document Server

    Ye, Quanzhi

    2011-01-01

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

  10. Spatial Feature Reconstruction of Cloud-Covered Areas in Daily MODIS Composites

    Directory of Open Access Journals (Sweden)

    Stephan Paul

    2015-04-01

    Full Text Available The opacity of clouds is the main problem for optical and thermal space-borne sensors, like the Moderate-Resolution Imaging Spectroradiometer (MODIS. Especially during polar nighttime, the low thermal contrast between clouds and the underlying snow/ice results in deficiencies of the MODIS cloud mask and affected products. There are different approaches to retrieve information about frequently cloud-covered areas, which often operate with large amounts of days aggregated into single composites for a long period of time. These approaches are well suited for static-nature, slow changing surface features (e.g., fast-ice extent. However, this is not applicable to fast-changing features, like sea-ice polynyas. Therefore, we developed a spatial feature reconstruction to derive information for cloud-covered sea-ice areas based on the surrounding days weighted directly proportional with their temporal proximity to the initial day of interest. Its performance is tested based on manually-screened and artificially cloud-covered case studies of MODIS-derived polynya area data for the polynya in the Brunt Ice Shelf region of Antarctica. On average, we are able to completely restore the artificially cloud-covered test areas with a spatial correlation of 0.83 and a mean absolute spatial deviation of 21%.

  11. Improved identification of clouds and ice/snow covered surfaces in SCIAMACHY observations

    Directory of Open Access Journals (Sweden)

    J. M. Krijger

    2011-10-01

    Full Text Available In the ultra-violet, visible and near infra-red wavelength range the presence of clouds can strongly affect the satellite-based passive remote sensing observation of constituents in the troposphere, because clouds effectively shield the lower part of the atmosphere. Therefore, cloud detection algorithms are of crucial importance in satellite remote sensing. However, the detection of clouds over snow/ice surfaces is particularly difficult in the visible wavelengths as both clouds an snow/ice are both white and highly reflective. The SCIAMACHY Polarisation Measurement Devices (PMD Identification of Clouds and Ice/snow method (SPICI uses the SCIAMACHY measurements in the wavelength range between 450 nm and 1.6 μm to make a distinction between clouds and ice/snow covered surfaces, specifically developed to identify cloud-free SCIAMACHY observations. For this purpose the on-board SCIAMACHY PMDs are used because they provide higher spatial resolution compared to the main spectrometer measurements. In this paper we expand on the original SPICI algorithm (Krijger et al., 2005a to also adequately detect clouds over snow-covered forests which is inherently difficult because of the similar spectral characteristics. Furthermore the SCIAMACHY measurements suffer from degradation with time. This must be corrected for adequate performance of SPICI over the full SCIAMACHY time range. Such a correction is described here. Finally the performance of the new SPICI algorithm is compared with various other datasets, such as from FRESCO, MICROS and AATSR, focusing on the algorithm improvements.

  12. Wintertime Cloud Cover as a Contributor towards Inter-Annual Sea Ice Variability.

    Science.gov (United States)

    Letterly, A.; Key, J. R.

    2014-12-01

    The role of cloud forcing on Arctic sea ice is fundamental but also complex, serving as an accelerant or antagonist to ice growth on a hemispheric scale. Though sea ice decline in recent decades is largely attributed to arctic amplification, plunges in ice extent and restorative winter refreezes occurring on a year-to-year basis cannot be adequately explained by this general trend. For improved understanding and prediction of these inter-annual fluctuations in ice area, cloud forcing effects on surface energy budgets must be seen as an important factor for ice growth and melt. For example, the significant rebound of arctic sea ice from the record minimum of September 2012 was aided by the surface cooling effects of negative winter cloud cover anomalies (fewer clouds), according to a recent study using satellite and reanalysis data. For this study, the ERA-Interim reanalysis is used to diagnose and quantify the contribution of surface radiative forcing by wintertime cloud cover on sea ice during years with anomalous total ice areas. Comparisons between reanalysis of cloud forcing from September through March and passive microwave-derived ice concentrations in September demonstrate a significant inverse correlation between cloud cover during winter and the ice extent at the end of a melt season. Cloud re-emission of longwave radiation in winter months acts to curb the process by which polar seas radiatively cool to space and freeze, so that less winter cloud generally results in thicker sea ice. Here we investigate the role of winter cloud cover as a predictor and contributor to anomalous ice extent over the past 32 years. Our results stand to improve climate model projections of sea ice melt and assign some cause to large year-to-year ice area variability in a warming arctic regime.

  13. An Uneven Illumination Correction Algorithm for Optical Remote Sensing Images Covered with Thin Clouds

    Directory of Open Access Journals (Sweden)

    Xiaole Shen

    2015-09-01

    Full Text Available The uneven illumination phenomenon caused by thin clouds will reduce the quality of remote sensing images, and bring adverse effects to the image interpretation. To remove the effect of thin clouds on images, an uneven illumination correction can be applied. In this paper, an effective uneven illumination correction algorithm is proposed to remove the effect of thin clouds and to restore the ground information of the optical remote sensing image. The imaging model of remote sensing images covered by thin clouds is analyzed. Due to the transmission attenuation, reflection, and scattering, the thin cloud cover usually increases region brightness and reduces saturation and contrast of the image. As a result, a wavelet domain enhancement is performed for the image in Hue-Saturation-Value (HSV color space. We use images with thin clouds in Wuhan area captured by QuickBird and ZiYuan-3 (ZY-3 satellites for experiments. Three traditional uneven illumination correction algorithms, i.e., multi-scale Retinex (MSR algorithm, homomorphic filtering (HF-based algorithm, and wavelet transform-based MASK (WT-MASK algorithm are performed for comparison. Five indicators, i.e., mean value, standard deviation, information entropy, average gradient, and hue deviation index (HDI are used to analyze the effect of the algorithms. The experimental results show that the proposed algorithm can effectively eliminate the influences of thin clouds and restore the real color of ground objects under thin clouds.

  14. MODIS Snow Cover Mapping Decision Tree Technique: Snow and Cloud Discrimination

    Science.gov (United States)

    Riggs, George A.; Hall, Dorothy K.

    2010-01-01

    Accurate mapping of snow cover continues to challenge cryospheric scientists and modelers. The Moderate-Resolution Imaging Spectroradiometer (MODIS) snow data products have been used since 2000 by many investigators to map and monitor snow cover extent for various applications. Users have reported on the utility of the products and also on problems encountered. Three problems or hindrances in the use of the MODIS snow data products that have been reported in the literature are: cloud obscuration, snow/cloud confusion, and snow omission errors in thin or sparse snow cover conditions. Implementation of the MODIS snow algorithm in a decision tree technique using surface reflectance input to mitigate those problems is being investigated. The objective of this work is to use a decision tree structure for the snow algorithm. This should alleviate snow/cloud confusion and omission errors and provide a snow map with classes that convey information on how snow was detected, e.g. snow under clear sky, snow tinder cloud, to enable users' flexibility in interpreting and deriving a snow map. Results of a snow cover decision tree algorithm are compared to the standard MODIS snow map and found to exhibit improved ability to alleviate snow/cloud confusion in some situations allowing up to about 5% increase in mapped snow cover extent, thus accuracy, in some scenes.

  15. The Influence of Non-Uniform Cloud Cover on Transit Transmission Spectra

    CERN Document Server

    Line, Michael R

    2015-01-01

    We model the impact of non-uniform cloud cover on transit transmission spectra. Patchy clouds exist in nearly every solar system atmosphere, brown dwarfs, and transiting exoplanets. Our major findings suggest that fractional cloud coverage can exactly mimic high-metallicity atmospheres and vice-versa over certain wavelength regions, in particular, over the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) bandpass (1.1-1.7 $\\mu$m). We also find that patchy cloud coverage exhibits a signature that is different from uniform global clouds. We explore the additional degeneracy of non-uniform cloud coverage in atmospheric retrievals on both synthetic and real planets. We find from retrievals on a synthetic solar composition hot Jupiter with patchy clouds and a cloud free high mean molecular weight warm Neptune, that both cloud free high mean molecular weight atmospheres and partially cloudy atmospheres can explain the data equally well. Another key find is that the HST WFC3 transit transmission spectra of tw...

  16. Extrasolar Storms: Mapping Cloud Cover Evolution with Joint HST-Spitzer Observations

    Science.gov (United States)

    Apai, Daniel; Extrasolar Storms Team

    2017-01-01

    Observations of directly imaged and transiting exoplanets and brown dwarfs reveal the wide-spread presence of condensate clouds. These clouds profoundly influence the energy transport through ultracool atmospheres and impact their pressure-temperature profiles. Yet, the structure and properties of these cloud layers remain mostly unexplored and pose one of the great challenges to our understanding ultracool atmospheres. I will show how using HST and Spitzer jointly -- by exploiting their photometric stability and sensitivity and combining their wavelength ranges -- allows us to address this challenge. With time-resolved spectroscopy and photometry of rotating brown dwarfs - rotational phase mapping — we are exploring the longitudinal structure of condensate clouds and with multiple epoch observations we are following the evolution of the cloud cover. These new observations are opening a new window on the dynamics of ultracool atmospheres.

  17. Sensitivity Study of Cloud Cover and Ozone Modeling to Microphysics Parameterization

    Science.gov (United States)

    Wałaszek, Kinga; Kryza, Maciej; Szymanowski, Mariusz; Werner, Małgorzata; Ojrzyńska, Hanna

    2017-02-01

    Cloud cover is a significant meteorological parameter influencing the amount of solar radiation reaching the ground surface, and therefore affecting the formation of photochemical pollutants, most of all tropospheric ozone (O3). Because cloud amount and type in meteorological models are resolved by microphysics schemes, adjusting this parameterization is a major factor determining the accuracy of the results. However, verification of cloud cover simulations based on surface data is difficult and yields significant errors. Current meteorological satellite programs provide many high-resolution cloud products, which can be used to verify numerical models. In this study, the Weather Research and Forecasting model (WRF) has been applied for the area of Poland for an episode of June 17th-July 4th, 2008, when high ground-level ozone concentrations were observed. Four simulations were performed, each with a different microphysics parameterization: Purdue Lin, Eta Ferrier, WRF Single-Moment 6-class, and Morrison Double-Moment scheme. The results were then evaluated based on cloud mask satellite images derived from SEVIRI data. Meteorological variables and O3 concentrations were also evaluated. The results show that the simulation using Morrison Double-Moment microphysics provides the most and Purdue Lin the least accurate information on cloud cover and surface meteorological variables for the selected high ozone episode. Those two configurations were used for WRF-Chem runs, which showed significantly higher O3 concentrations and better model-measurements agreement of the latter.

  18. The impact of European forests on cloud cover: an observation-based study

    Science.gov (United States)

    Teuling, Ryan; Melsen, Lieke; Vila-Guerau de Arellano, Jordi; van Heerwaarden, Chiel; Miralles, Diego; Taylor, Chris; Stegehuis, Annemiek; Fokke Meirink, Jan; Nabuurs, Gert-Jan

    2016-04-01

    The impact of temperate forests on their environment is still uncertain [1]. While forests generally have a lower albedo, the flux partitioning over forests and its relation to weather conditions is still poorly understood [2,3], complicating attempts to study impacts of forest cover on atmospheric conditions through modeling. Effects of land surface conditions on boundary-layer humidity and cloud formation can also be very non-linear [4]. Furthermore, the study of hydrological and climate impacts of temperate European forests is complicated because forests are strongly fragmented and often can be found on hilly terrain, making it impossible to attribute differences in for instance cloud cover or runoff directly to forest cover. Only few regions exist where forests can be found in absence of strong topography of a size large enough to result in near-equilibrium between the atmospheric boundary layer and local surface conditions. In this study, we analyse 10 years (2004-2013) of cloud cover observations from the Meteosat Second Generation satellite platform at a 15-minute temporal resolution. These observations come from a physically-based cloud product at the 6 km resolution [5], and a statistical cloud product based on the high-resolution visible imagery (1 km resolution). We focus on two regions in France where large forests are found which satisfy the following criteria: a) absence of strong topography, and b) presence of sharp contrast between forest and non-forest regions. Cloud occurrence is expressed by the fraction of the daytime that clouds are detected within a pixel. We find that in particular in summer and late summer, clouds are much more likely to occur over forest than over the surrounding non-forest land (difference in the order of 0.2). An opposite signal, but of much weaker magnitude, is found during springtime, when clouds are less likely to develop over forest. Difference in cloud occurrence is consistent with MODIS-derived differences in EVI

  19. Development and Evaluation of a Cloud-Gap-Filled MODIS Daily Snow-Cover Product

    Science.gov (United States)

    Hall, Dorothy K.; Riggs, George A.; Foster, James L.; Kumar, Sujay V.

    2010-01-01

    The utility of the Moderate Resolution Imaging Spectroradiometer (MODIS) snow-cover products is limited by cloud cover which causes gaps in the daily snow-cover map products. We describe a cloud-gap-filled (CGF) daily snowcover map using a simple algorithm to track cloud persistence, to account for the uncertainty created by the age of the snow observation. Developed from the 0.050 resolution climate-modeling grid daily snow-cover product, MOD10C1, each grid cell of the CGF map provides a cloud-persistence count (CPC) that tells whether the current or a prior day was used to make the snow decision. Percentage of grid cells "observable" is shown to increase dramatically when prior days are considered. The effectiveness of the CGF product is evaluated by conducting a suite of data assimilation experiments using the community Noah land surface model in the NASA Land Information System (LIS) framework. The Noah model forecasts of snow conditions, such as snow-water equivalent (SWE), are updated based on the observations of snow cover which are obtained either from the MOD1 OC1 standard product or the new CGF product. The assimilation integrations using the CGF maps provide domain averaged bias improvement of -11 %, whereas such improvement using the standard MOD1 OC1 maps is -3%. These improvements suggest that the Noah model underestimates SWE and snow depth fields, and that the assimilation integrations contribute to correcting this systematic error. We conclude that the gap-filling strategy is an effective approach for increasing cloud-free observations of snow cover.

  20. Filling of Cloud-Induced Gaps for Land Use and Land Cover Classifications Around Refugee Camps

    Science.gov (United States)

    Braun, Andreas; Hagensieker, Ron; Hochschild, Volker

    2016-08-01

    Clouds cover is one of the main constraints in the field of optical remote sensing. Especially the use of multispectral imagery is affected by either fully obscured data or parts of the image which remain unusable. This study compares four algorithms for the filling of cloud induced gaps in classified land cover products based on Markov Random Fields (MRF), Random Forest (RF), Closest Spectral Fit (CSF) operators. They are tested on a classified image of Sentinel-2 where artificial clouds are filled by information derived from a scene of Sentinel-1. The approaches rely on different mathematical principles and therefore produced results varying in both pattern and quality. Overall accuracies for the filled areas range from 57 to 64 %. Best results are achieved by CSF, however some classes (e.g. sands and grassland) remain critical through all approaches.

  1. The detection of cloud-free snow-covered areas using AATSR measurements

    Directory of Open Access Journals (Sweden)

    L. G. Istomina

    2010-08-01

    Full Text Available A new method to detect cloud-free snow-covered areas has been developed using the measurements by the Advanced Along Track Scanning Radiometer (AATSR on board the ENVISAT satellite in order to discriminate clear snow fields for the retrieval of aerosol optical thickness or snow properties. The algorithm uses seven AATSR channels from visible (VIS to thermal infrared (TIR and analyses the spectral behaviour of each pixel in order to recognize the spectral signature of snow. The algorithm includes a set of relative thresholds and combines all seven channels into one flexible criterion, which allows us to filter out all the pixels with spectral behaviour similar to that of snow. The algorithm does not use any kind of morphological criteria and does not require the studied surface to have any special structure. The snow spectral shape criterion was determined by a comprehensive theoretical study, which included radiative transfer simulations for various atmospheric conditions as well as studying existing models and measurements of optical and physical properties of snow in different spectral bands. The method has been optimized to detect cloud-free snow-covered areas, and does not produce cloud/land/ocean/snow mask. However, the algorithm can be extended and able to discriminate various kinds of surfaces.

    The presented method has been validated against Micro Pulse Lidar data and compared to Moderate Resolution Imaging Spectroradiometer (MODIS cloud mask over snow-covered areas, showing quite good correspondence to each other.

    Comparison of both MODIS cloud mask and presented snow mask to AATSR operational cloud mask showed that in some cases of snow surface the accuracy of AATSR operational cloud mask is questionable.

  2. 3D LAND COVER CLASSIFICATION BASED ON MULTISPECTRAL LIDAR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    X. Zou

    2016-06-01

    Full Text Available Multispectral Lidar System can emit simultaneous laser pulses at the different wavelengths. The reflected multispectral energy is captured through a receiver of the sensor, and the return signal together with the position and orientation information of sensor is recorded. These recorded data are solved with GNSS/IMU data for further post-processing, forming high density multispectral 3D point clouds. As the first commercial multispectral airborne Lidar sensor, Optech Titan system is capable of collecting point clouds data from all three channels at 532nm visible (Green, at 1064 nm near infrared (NIR and at 1550nm intermediate infrared (IR. It has become a new source of data for 3D land cover classification. The paper presents an Object Based Image Analysis (OBIA approach to only use multispectral Lidar point clouds datasets for 3D land cover classification. The approach consists of three steps. Firstly, multispectral intensity images are segmented into image objects on the basis of multi-resolution segmentation integrating different scale parameters. Secondly, intensity objects are classified into nine categories by using the customized features of classification indexes and a combination the multispectral reflectance with the vertical distribution of object features. Finally, accuracy assessment is conducted via comparing random reference samples points from google imagery tiles with the classification results. The classification results show higher overall accuracy for most of the land cover types. Over 90% of overall accuracy is achieved via using multispectral Lidar point clouds for 3D land cover classification.

  3. Decreasing cloud cover drives the recent mass loss on the Greenland Ice Sheet.

    Science.gov (United States)

    Hofer, Stefan; Tedstone, Andrew J; Fettweis, Xavier; Bamber, Jonathan L

    2017-06-01

    The Greenland Ice Sheet (GrIS) has been losing mass at an accelerating rate since the mid-1990s. This has been due to both increased ice discharge into the ocean and melting at the surface, with the latter being the dominant contribution. This change in state has been attributed to rising temperatures and a decrease in surface albedo. We show, using satellite data and climate model output, that the abrupt reduction in surface mass balance since about 1995 can be attributed largely to a coincident trend of decreasing summer cloud cover enhancing the melt-albedo feedback. Satellite observations show that, from 1995 to 2009, summer cloud cover decreased by 0.9 ± 0.3% per year. Model output indicates that the GrIS summer melt increases by 27 ± 13 gigatons (Gt) per percent reduction in summer cloud cover, principally because of the impact of increased shortwave radiation over the low albedo ablation zone. The observed reduction in cloud cover is strongly correlated with a state shift in the North Atlantic Oscillation promoting anticyclonic conditions in summer and suggests that the enhanced surface mass loss from the GrIS is driven by synoptic-scale changes in Arctic-wide atmospheric circulation.

  4. Cloud obstruction and snow cover in Alpine areas from MODIS products

    Science.gov (United States)

    Da Ronco, P.; De Michele, C.

    2014-11-01

    Snow cover maps provide information of great practical interest for hydrologic purposes: when combined with point values of snow water equivalent (SWE), they enable estimation of the regional snow resource. In this context, Earth observation satellites are an interesting tool for evaluating large scale snow distribution and extension. MODIS (MODerate resolution Imaging Spectroradiometer on board Terra and Aqua satellites) daily Snow Covered Area product has been widely tested and proved to be appropriate for hydrologic applications. However, within a daily map the presence of cloud cover can hide the ground, thus obstructing snow detection. Here, we consider MODIS binary products for daily snow mapping over the Po River basin. Ten years (2003-2012) of MOD10A1 and MYD10A1 snow maps have been analysed and processed with the support of a 500 m resolution Digital Elevation Model (DEM). We first investigate the issue of cloud obstruction, highlighting its dependence on altitude and season. Snow maps seem to suffer the influence of overcast conditions mainly in mountain and during the melting period. Thus, cloud cover highly influences those areas where snow detection is regarded with more interest. In spring, the average percentages of area lying beneath clouds are in the order of 70%, for altitudes over 1000 m a.s.l. Then, starting from previous studies, we propose a cloud removal procedure and we apply it to a wide area, characterized by high geomorphological heterogeneity such as the Po River basin. In conceiving the new procedure, our first target was to preserve the daily temporal resolution of the product. Regional snow and land lines were estimated for detecting snow cover dependence on elevation. In cases when there was not enough information on the same day within the cloud-free areas, we used temporal filters with the aim of reproducing the micro-cycles which characterize the transition altitudes, where snow does not stand continually over the entire winter

  5. The detection of cloud free snow covered areas using AATSR measurements

    Directory of Open Access Journals (Sweden)

    L. G. Istomina

    2010-03-01

    Full Text Available A new method to detect cloud free snow covered areas is developed using the measurements by the Advanced Along Track Scanning Radiometer (AATSR on board the ENVISAT satellite in order to discriminate clear snow fields for the retrieval of aerosol optical thickness or snow properties. The algorithm uses seven AATSR channels from VIS to TIR and analyzes the spectral behavior of each pixel in order to recognize the spectral signature of snow. The algorithm includes a set of relative thresholds and combines all seven channels into one flexible criterion, which allows us to filter out all the pixels with spectral behavior similar to that of snow. The algorithm does not use any kind of morphological criteria and does not require the studied surface to have any special structure. The snow spectral shape criterion was determined by a comprehensive theoretical study, which included radiative transfer simulations for various atmospheric conditions as well as studying existing models and measurements of snow optical and physical properties in different spectral bands. The method has been optimized to detect cloud free snow covered areas, and does not produce cloud/land/ocean/snow mask. However, the algorithm can be extended and be able to discriminate various kinds of surfaces.

    The presented method has been validated against Micro Pulse Lidar data and compared to MODIS cloud mask over snow covered areas, showing quite good correspondence to each other.

  6. The Impact of Time Difference between Satellite Overpass and Ground Observation on Cloud Cover Performance Statistics

    Directory of Open Access Journals (Sweden)

    Jędrzej S. Bojanowski

    2014-12-01

    Full Text Available Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with the 3- or 6-h SYNOP frequency lead to collocation time differences of up to 3 h. The associated collocation error degrades the cloud cover performance statistics such as the Hanssen-Kuiper’s discriminant (HK by up to 45%. Limiting the time difference to 10 min, on the other hand, introduces a sampling error due to a lower number of corresponding satellite and SYNOP observations. This error depends on both the length of the validated time series and the SYNOP frequency. The trade-off between collocation and sampling error call for an optimum collocation time difference. It however depends on cloud cover characteristics and SYNOP frequency, and cannot be generalized. Instead, a method is presented to reconstruct the unbiased (true HK from HK affected by the collocation differences, which significantly (t-test p < 0.01 improves the validation results.

  7. Assimilation of ERBE data with a nonlinear programming technique to improve cloud-cover diagnosis

    Science.gov (United States)

    Wu, Xiangqian; Smith, William L.

    1992-01-01

    A method is developed to assimilate satellite data for the purpose of improving the diagnosis of fractional cloud cover within a numerical weather prediction model. The method makes use of a nonlinear programming technique to find a set of parameters for the cloud diagnosis that minimizes the difference between the observed and model-produced outgoing longwave radiation (OLR). The algorithm and theoretical basis of the method are presented. The method has been applied in two forecast experiments using a numerical weather prediction model. The results from a winter case demonstrate that the root-mean-square (rms) difference between the observed and forecasted OLR can be reduced by 50 percent when the optimized cloud diagnosis is used, with the remaining rms difference within the background noise.

  8. Assessment of cloud cover in climate models and reanalysis databases with ISCCP over the Mediterranean region

    Science.gov (United States)

    Enriquez, Aaron; Calbo, Josep; Gonzalez, Josep-Abel

    2013-04-01

    Clouds are an important regulator of climate due to their influence on the water balance of the atmosphere and their interaction with solar and infrared radiation. At any time, clouds cover a great percentage of the Earth's surface but their distribution is very irregular along time and space, which makes the evaluation of their influence on climate a difficult task. At present there are few studies related to cloud cover comparing current climate models with observational data. In this study, the database of monthly cloud cover provided by the International Satellite Cloud Climatology Project (ISCCP) has been chosen as a reference against which we compare the output of CMIP5 climate models and reanalysis databases, on the domain South-Europe-Mediterranean (SEM) established by the Intergovernmental Panel on Climate Change (IPCC) [1]. The study covers the period between 1984 and 2009, and the performance of cloud cover estimations for seasons has also been studied. To quantify the agreement between the databases we use two types of statistics: bias and SkillScore, which is based on the probability density functions (PDFs) of the databases [2]. We also use Taylor diagrams to visualize the statistics. Results indicate that there are areas where the models accurately describe what it is observed by ISCCP, for some periods of the year (e.g. Northern Africa, for autumn), compared to other areas and periods for which the agreement is lower (Iberian Peninsula in winter and the Black Sea for the summer months). However these differences should be attributed not only to the limitations of climate models, but possibly also to the data provided by ISCCP. References [1] Intergovernmental Panel on Climate Change (2007) Fourth Assessment Report: Climate Change 2007: Working Group I Report: The Physical Science Basis. [2] Ranking the AR4 climate models over the Murray Darling Basin using simulated maximum temperature, minimum temperature and precipitation. Int J Climatol 28

  9. Satellite-Based Sunshine Duration for Europe

    Directory of Open Access Journals (Sweden)

    Bodo Ahrens

    2013-06-01

    Full Text Available In this study, two different methods were applied to derive daily and monthly sunshine duration based on high-resolution satellite products provided by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT Satellite Application Facility on Climate Monitoring using data from Meteosat Second Generation (MSG SEVIRI (Spinning Enhanced Visible and Infrared Imager. The satellite products were either hourly cloud type or hourly surface incoming direct radiation. The satellite sunshine duration estimates were not found to be significantly different using the native 15-minute temporal resolution of SEVIRI. The satellite-based sunshine duration products give additional spatial information over the European continent compared with equivalent in situ-based products. An evaluation of the satellite sunshine duration by product intercomparison and against station measurements was carried out to determine their accuracy. The satellite data were found to be within ±1 h/day compared to high-quality Baseline Surface Radiation Network or surface synoptic observations (SYNOP station measurements. The satellite-based products differ more over the oceans than over land, mainly because of the treatment of fractional clouds in the cloud type-based sunshine duration product. This paper presents the methods used to derive the satellite sunshine duration products and the performance of the different retrievals. The main benefits and disadvantages compared to station-based products are also discussed.

  10. Beijing Sunshine Eternity Technology Co. Ltd.

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Founded on December 5, 2000,Beijing Sunshine Eternity Technology Co. Ltd. specializes in the research,production, trade and maintenance of telecommunication products. The main products cover information technology,

  11. Surface temperature sensitivities from cloud cover variations in the Hummel-Kuhn radiative—convective model with three different cloud approximations

    OpenAIRE

    HUMMEL, JOHN R.

    2011-01-01

    In modeling the thermal structure of the atmosphere, the role of clouds is critically important. Clouds modify the solar flux distribution throughout the atmosphere, radiate significantly in the infrared, and provide large thermal reservoirs because of the large latent heat of water. In the best current radiative convective one-dimensional models the global atmosphere is modeled as the sum of clear and cloudy sky parts weighted by a fractional cloud cover. In considering the cloudy sky part,...

  12. The detection of cloud-free snow-covered areas using AATSR measurements

    OpenAIRE

    2010-01-01

    A new method to detect cloud-free snow-covered areas has been developed using the measurements by the Advanced Along Track Scanning Radiometer (AATSR) on board the ENVISAT satellite in order to discriminate clear snow fields for the retrieval of aerosol optical thickness or snow properties. The algorithm uses seven AATSR channels from visible (VIS) to thermal infrared (TIR) and analyses the spectral behaviour of each pixel in order to recognize the spectral signature of snow. The algorithm in...

  13. The detection of cloud free snow covered areas using AATSR measurements

    OpenAIRE

    2010-01-01

    A new method to detect cloud free snow covered areas is developed using the measurements by the Advanced Along Track Scanning Radiometer (AATSR) on board the ENVISAT satellite in order to discriminate clear snow fields for the retrieval of aerosol optical thickness or snow properties. The algorithm uses seven AATSR channels from VIS to TIR and analyzes the spectral behavior of each pixel in order to recognize the spectral signature of snow. The algorithm includes a set of relative thresholds ...

  14. Interrelationship between cloud cover and sensible heat flux over land during MONTBLEX-1990

    Indian Academy of Sciences (India)

    T Venugopal; P Seetaramayya; A R Dhakate

    2005-08-01

    Micro-meteorological tower observations of MONTBLEX (Monsoon Trough Boundary Layer Experiment)-1990, combined with routine surface observations at Jodhpur in the dry convective sector of Indian summer monsoon trough are used to examine the interrelationship between total cloud cover (TCC) and surface sensible heat flux (SHF) during the summer monsoon of 1990. A significant inverse relationship between TCC and SHF is found during various Intensive Observation Periods of the experiment. This relationship holds for the various methods of estimation of SHF.

  15. Geo-spatial distribution of cloud cover and influence of cloud induced attenuation and noise temperature on satellite signal propagation over Nigeria

    Science.gov (United States)

    Ojo, Joseph Sunday

    2017-05-01

    The study of the influence of cloud cover on satellite propagation links is becoming more demanding due to the requirement of larger bandwidth for different satellite applications. Cloud attenuation is one of the major factors to consider for optimum performance of Ka/V and other higher frequency bands. In this paper, the geo-spatial distribution of cloud coverage over some chosen stations in Nigeria has been considered. The substantial scale spatial dispersion of cloud cover based on synoptic meteorological data and the possible impact on satellite communication links at higher frequency bands was also investigated. The investigation was based on 5 years (2008-2012) achieved cloud cover data collected by the Nigerian Meteorological Agency (NIMET) Federal Ministry of Aviation, Oshodi Lagos over four synoptic hours of the day covering day and night. The performances of satellite signals as they traverse through the cloud and cloud noise temperature at different seasons and over different hours of days at Ku/W-bands frequency are also examined. The overall result shows that the additional total atmospheric noise temperature due to the clear air effect and the noise temperature from the cloud reduces the signal-to-noise ratio of the satellite receiver systems, leading to more signal loss and if not adequately taken care of may lead to significant outage. The present results will be useful for Earth-space link budgeting, especially for the proposed multi-sensors communication satellite systems in Nigeria.

  16. A Satellite Survey of Cloud Cover and Water Vapor in the Southwestern USA and Northern Mexico

    Science.gov (United States)

    Carrasco, E.; Avila, R.; Erasmus, A.; Djorgovski, S. G.; Walker, A. R.; Blum, R.

    2017-03-01

    Cloud cover and water vapor conditions in the southwestern USA and northern Mexico were surveyed as a preparatory work for the Thirty Meter Telescope (TMT) in situ site testing program. Although the telescope site is already selected, the TMT site testing team decided to make public these results for its usefulness for the community. Using 58 months of meteorological satellite observations between 1993 July and 1999 September, different atmospheric parameters were quantified from data of the 10.7 μm and of 6.7 μm windows. In particular, cloud cover and water vapor conditions were identified in preferred areas. As a result of the aerial analysis, 15 sites of existing and potential telescope were selected, compared, and ranked in terms of their observing quality. The clearest sites are located along the spine of the Baja peninsula and into southern California on mountain peaks above the temperature inversion layer. A steep gradient of cloudiness was observed along the coast where coastal cloud and fog are trapped below the inversion layer. Moving from west to east over the continent, a significant increase in cloudiness was observed. The analysis shows that San Pedro Mártir, San Gorgonio Mountain and San Jacinto Peak have the largest fraction of clear sky conditions (∼74%). The site with the optimal combination of clear skies and low precipitable water vapor is Boundary Peak, Nevada. An approach based in satellite data provided a reliable method for sites comparison.

  17. Object-Based Analysis of Aerial Photogrammetric Point Cloud and Spectral Data for Land Cover Mapping

    Science.gov (United States)

    Debella-Gilo, M.; Bjørkelo, K.; Breidenbach, J.; Rahlf, J.

    2013-04-01

    The acquisition of 3D point data with the use of both aerial laser scanning (ALS) and matching of aerial stereo images coupled with advances in image processing algorithms in the past years provide opportunities to map land cover types with better precision than before. The present study applies Object-Based Image Analysis (OBIA) to 3D point cloud data obtained from matching of stereo aerial images together with spectral data to map land cover types of the Nord-Trøndelag county of Norway. The multi-resolution segmentation algorithm of the Definiens eCognition™ software is used to segment the scenes into homogenous objects. The objects are then classified into different land cover types using rules created based on the definitions given for each land cover type by the Norwegian Forest and Landscape Institute. The quality of the land cover map was evaluated using data collected in the field as part of the Norwegian National Forest Inventory. The results show that the classification has an overall accuracy of about 80% and a kappa index of about 0.65. OBIA is found to be a suitable method for utilizing 3D remote sensing data for land cover mapping in an effort to replace manual delineation methods.

  18. Cloud cover and solar disk state estimation using all-sky images: deep neural networks approach compared to routine methods

    Science.gov (United States)

    Krinitskiy, Mikhail; Sinitsyn, Alexey

    2017-04-01

    Shortwave radiation is an important component of surface heat budget over sea and land. To estimate them accurate observations of cloud conditions are needed including total cloud cover, spatial and temporal cloud structure. While massively observed visually, for building accurate SW radiation parameterizations cloud structure needs also to be quantified using precise instrumental measurements. While there already exist several state of the art land-based cloud-cameras that satisfy researchers needs, their major disadvantages are associated with inaccuracy of all-sky images processing algorithms which typically result in the uncertainties of 2-4 octa of cloud cover estimates with the resulting true-scoring cloud cover accuracy of about 7%. Moreover, none of these algorithms determine cloud types. We developed an approach for cloud cover and structure estimating, which provides much more accurate estimates and also allows for measuring additional characteristics. This method is based on the synthetic controlling index, namely the "grayness rate index", that we introduced in 2014. Since then this index has already demonstrated high efficiency being used along with the technique namely the "background sunburn effect suppression", to detect thin clouds. This made it possible to significantly increase the accuracy of total cloud cover estimation in various sky image states using this extension of routine algorithm type. Errors for the cloud cover estimates significantly decreased down resulting the mean squared error of about 1.5 octa. Resulting true-scoring accuracy is more than 38%. The main source of this approach uncertainties is the solar disk state determination errors. While the deep neural networks approach lets us to estimate solar disk state with 94% accuracy, the final result of total cloud estimation still isn`t satisfying. To solve this problem completely we applied the set of machine learning algorithms to the problem of total cloud cover estimation

  19. monthly probabilities for acquiring remote sensed data of indonesia with cloud cover less than 10 , 20 and 30 percent

    OpenAIRE

    J.P. Gastellu- Etcregorry

    2013-01-01

    The Indonesian spatiotemporal cloud cover distribution was quantified with the aid of GMS, Landsat and SPOT data. Iterative interactive factorial analyses grouped pixels with similar profiles into 18 classes for all land areas. For each class, statistics of Landsat and SPOT images, grouped by class, were used to verify, calibrate and improve class profiles. This led to quantified temporal profiles of probability of acquiring remotely sensed data with 10 , 20 and 30 percent cloud cover, for an...

  20. Influence of Reflectivity and Cloud Cover on the Optimal TiltAngle of Solar Panels

    Directory of Open Access Journals (Sweden)

    David J. Torres

    2015-09-01

    Full Text Available Determining the optimum angle for a solar panel is important if tracking systems are not used and a tilt angle remains constant. This article determines the sensitivity of the optimum angle to surface reflectivity at different latitudes using a mathematical model that accounts for direct, diffuse and reflected radiation. A quadratic correlation is also developed to compute the optimal angle and maximum energy as a function of latitude and reflectivity. We also seek to determine how sensitive the optimal tilt angle is to cloud cover using the 35° latitude of the Prosperity solar facility in Albuquerque, NM.

  1. An estimate of the temporal fraction of cloud cover at San Pedro M\\'artir Observatory

    CERN Document Server

    Carrasco, E; Sánchez, L J; Avila, R; Cruz-González, I

    2011-01-01

    San Pedro M\\'artir in the Northwest of Mexico is the site of the Observatorio Astron\\'omico Nacional. It was one of the five candidates sites for the Thirty Meter Telescope, whose site-testing team spent four years measuring the atmospheric properties on site with a very complete array of instrumentation. Using the public database created by this team, we apply a novel method to solar radiation data to estimate the daytime fraction of time when the sky is clear of clouds. We analyse the diurnal, seasonal and annual cycles of cloud cover. We find that 82.4 per cent of the time the sky is clear of clouds. Our results are consistent with those obtained by other authors, using different methods, adding support to this value and proving the potential of the applied method. The clear conditions at the site are particularly good showing that San Pedro M\\'artir is an excellent site for optical and infrared observations.

  2. Development of the Landsat Data Continuity Mission Cloud Cover Assessment Algorithms

    Science.gov (United States)

    Scaramuzza, Pat; Bouchard, M.A.; Dwyer, J.L.

    2012-01-01

    The upcoming launch of the Operational Land Imager (OLI) will start the next era of the Landsat program. However, the Automated Cloud-Cover Assessment (CCA) (ACCA) algorithm used on Landsat 7 requires a thermal band and is thus not suited for OLI. There will be a thermal instrument on the Landsat Data Continuity Mission (LDCM)-the Thermal Infrared Sensor-which may not be available during all OLI collections. This illustrates a need for CCA for LDCM in the absence of thermal data. To research possibilities for full-resolution OLI cloud assessment, a global data set of 207 Landsat 7 scenes with manually generated cloud masks was created. It was used to evaluate the ACCA algorithm, showing that the algorithm correctly classified 79.9% of a standard test subset of 3.95 109 pixels. The data set was also used to develop and validate two successor algorithms for use with OLI data-one derived from an off-the-shelf machine learning package and one based on ACCA but enhanced by a simple neural network. These comprehensive CCA algorithms were shown to correctly classify pixels as cloudy or clear 88.5% and 89.7% of the time, respectively.

  3. An estimate of the temporal fraction of cloud cover at San Pedro Mártir Observatory

    Science.gov (United States)

    Carrasco, E.; Carramiñana, A.; Sánchez, L. J.; Avila, R.; Cruz-González, I.

    2012-02-01

    San Pedro Mártir in the north-west of Mexico is the site of the Observatorio Astronómico Nacional. It was one of the five candidate sites for the Thirty Meter Telescope, whose site-testing team spent four years measuring the atmospheric properties on site with a very complete array of instrumentation. Using the public data base created by this team, we apply a novel method to solar radiation data to estimate the daytime fraction of time when the sky is clear of clouds. We analyse the diurnal, seasonal and annual cycles of cloud cover. We find that 82.4 per cent of the time the sky is clear of clouds. Our results are consistent with those obtained by other authors, using different methods, adding support to this value and proving the potential of the applied method. The clear conditions at the site are particularly good showing that San Pedro Mártir is an excellent site for optical and infrared observations.

  4. Improving rainfall estimation from commercial microwave links using METEOSAT SEVIRI cloud cover information

    Science.gov (United States)

    Boose, Yvonne; Doumounia, Ali; Chwala, Christian; Moumouni, Sawadogo; Zougmoré, François; Kunstmann, Harald

    2017-04-01

    The number of rain gauges is declining worldwide. A recent promising method for alternative precipitation measurements is to derive rain rates from the attenuation of the microwave signal between remote antennas of mobile phone base stations, so called commercial microwave links (CMLs). In European countries, such as Germany, the CML technique can be used as a complementary method to the existing gauge and radar networks improving their products, for example, in mountainous terrain and urban areas. In West African countries, where a dense gauge or radar network is absent, the number of mobile phone users is rapidly increasing and so are the CML networks. Hence, the CML-derived precipitation measurements have high potential for applications such as flood warning and support of agricultural planning in this region. For typical CML bandwidths (10-40 GHz), the relationship of attenuation to rain rate is quasi-linear. However, also humidity, wet antennas or electronic noise can lead to signal interference. To distinguish these fluctuations from actual attenuation due to rain, a temporal wet (rain event occurred)/ dry (no rain event) classification is usually necessary. In dense CML networks this is possible by correlating neighboring CML time series. Another option is to use the correlation between signal time series of different frequencies or bidirectional signals. The CML network in rural areas is typically not dense enough for correlation analysis and often only one polarization and one frequency are available along a CML. In this work we therefore use cloud cover information derived from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) radiometer onboard the geostationary satellite METEOSAT for a wet (pixels along link are cloud covered)/ dry (no cloud along link) classification. We compare results for CMLs in Burkina Faso and Germany, which differ meteorologically (rain rate and duration, droplet size distributions) and technically (CML frequencies

  5. Impact of Clouds on the Shortwave Radiation Budget of the Surface: Atmosphere System for Snow Covered Surfaces

    Science.gov (United States)

    Nemesure, Seth; Cess, Robert D.; Dutton, Ellsworth G.; DeLuisi, John J.; Li, Zhanqing; Leighton, Henry G.

    1994-01-01

    Recent data from the Earth Radiation Budget Experiment (ERBE) have raised the question as to whether or not the addition of clouds to the atmospheric column can decrease the top-of-the-atmosphere (TOA) albedo over bright snow-covered surfaces. To address this issue, ERBE shortwave pixel measurements have been collocated with surface insolation measurements made at two snow-covered locations: the South Pole and Saskatoon, Saskatchewan. Both collocated datasets show a negative correlation (with solar zenith angle variability removed) between TOA albedo and surface insolation. Because increased cloudiness acts to reduce surface insolation, these negative correlations demonstrate that clouds increase the TOA albedo at both snow-covered locations.

  6. Impact of clouds on the shortwave radiation budget of the surface-atmosphere system for snow-covered surfaces

    Science.gov (United States)

    Nemesure, Seth; Cess, Robert D.; Dutton, Ellsworth; Deluisi, John J.; Li, Zhanqing; Leighton, Henry G.

    1994-01-01

    Recent data from the Earth Radiation Budget Experiment (ERBE) have raised the question as to whether or not the addition of clouds to the atmospheric column can decrease the top-of-the atmosphere (TOA) albedo over bright snow-covered surface. To address this issue, ERBE shortwave pixel measurements have been collected with surface insolation measurements made at two snow-covered locations: the South Pole and Saskatoon, Saskatchewan. Both collected datasets show a negative correlation (with solar zenith angle variability removed) between TOA albedo and surfaces insolation. Because increased cloudiness acts to reduce surface insolation, these negative correlations demonstrate that clouds increase the TOA albedo at both snow-covered locations.

  7. Partial covering of emission regions of Q 0528-250 by intervening H$_2$ clouds

    CERN Document Server

    Klimenko, V V; Ivanchik, A V; Ledoux, C; Noterdaeme, P; Petitjean, P; Srianand, R; Varshalovich, D A

    2015-01-01

    We present an analysis of the molecular hydrogen absorption system at z$_{\\rm abs}$ = 2.811 in the spectrum of the blazar Q0528-250. We demonstrate that the molecular cloud does not cover the background source completely. The partial coverage reveals itself as a residual flux in the bottom of saturated H_2 absorption lines. This amounts to about (2.22$\\pm$0.54)% of the continuum and does not depend on the wavelength. This value is small and it explains why this effect has not been detected in previous studies of this quasar spectrum. However, it is robustly detected and significantly higher than the zero flux level in the bottom of saturated lines of the Ly-alpha forest, (-0.21$\\pm$0.22)%. The presence of the residual flux could be caused by unresolved quasar multicomponents, by light scattered by dust, and/or by jet-cloud interaction. The H$_2$ absorption system is very well described by a two-component model without inclusion of additional components when we take partial coverage into account. The derived t...

  8. Global Distribution of Water Vapor and Cloud Cover--Sites for High Performance THz Applications

    CERN Document Server

    Suen, Jonathan Y; Lubin, Philip M

    2014-01-01

    Absorption of terahertz radiation by atmospheric water vapor is a serious impediment for radio astronomy and for long-distance communications. Transmission in the THz regime is dependent almost exclusively on atmospheric precipitable water vapor (PWV). Though much of the Earth has PWV that is too high for good transmission above 200 GHz, there are a number of dry sites with very low attenuation. We performed a global analysis of PWV with high-resolution measurements from the Moderate Resolution Imaging Spectrometer (MODIS) on two NASA Earth Observing System (EOS) satellites over the year of 2011. We determined PWV and cloud cover distributions and then developed a model to find transmission and atmospheric radiance as well as necessary integration times in the various windows. We produced global maps over the common THz windows for astronomical and satellite communications scenarios. Notably, we show that up through 1 THz, systems could be built in excellent sites of Chile, Greenland and the Tibetan Plateau, ...

  9. Quantifying nighttime cloud cover over Manila Observatory (14.64N, 121.07E) using a digital camera: red and blue difference algorithm and observations

    Science.gov (United States)

    Lagrosas, N.; Gacal, G. F. B.

    2016-12-01

    A digital camera is utilized to capture images of night sky for the purpose of quantifying cloud cover over the Manila Observatory (14.64N, 121.07E). The camera (Canon PowerShot 3200) is mounted on the rooftop of the Manila Observatory building and is programmed to capture images every 5 minutes. The analysis for cloud cover is accomplished by subtracting the matrix of the blue from the red component of the joint photographic experts group (JPEG) image. The difference, which is in 8 bit unsigned integer format, is converted to a double format. By examining the frequency distributions of various pixel values from images of clear and cloudy skies, clouds are detected if the pixel value is greater than the threshold pixel value of 0.02. Cloud cover at a particular time is defined as the ratio of the number of pixels with cloud to the total number of pixels in the image. Moon signals are automatically erased because the red and blue signals are of the same values for white color. However, a few artifacts are present on the rim of the moon signals that contribute to a few errors in the calculation of cloud cover. When this method is applied to data collected in the month of January 2016 (a relatively dry month), cloud cover at 5 minute interval is range from 0-100%. The cloud cover values, when plotted with time, show that, over the Manila Observatory, cloud cover values are mostly high before and at midnight. Cloud occurrence around 04:00 local time is low. The high and low cloud occurrence at midnight and early morning can be attributed to the urban heat effect, except for cases when there is rainfall during nighttime. In the early part of the night, the ground normally radiates thermal radiation. This increases the temperature of the atmosphere near the ground. Parcel of air with relatively high temperature tend to rise and can lead to cloud formation. Around early morning, when the ground is relatively cooler, possible less cloud formation is expected. Ambient

  10. Tropical Montane Cloud Forests: Hydrometeorological variability in three neighbouring catchments with different forest cover

    Science.gov (United States)

    Ramírez, Beatriz H.; Teuling, Adriaan J.; Ganzeveld, Laurens; Hegger, Zita; Leemans, Rik

    2017-09-01

    Mountain areas are characterized by a large heterogeneity in hydrological and meteorological conditions. This heterogeneity is currently poorly represented by gauging networks and by the coarse scale of global and regional climate and hydrological models. Tropical Montane Cloud Forests (TMCFs) are found in a narrow elevation range and are characterized by persistent fog. Their water balance depends on local and upwind temperatures and moisture, therefore, changes in these parameters will alter TMCF hydrology. Until recently the hydrological functioning of TMCFs was mainly studied in coastal regions, while continental TMCFs were largely ignored. This study contributes to fill this gap by focusing on a TMCF which is located on the northern eastern Andes at an elevation of 1550-2300 m asl, in the Orinoco river basin highlands. In this study, we describe the spatial and seasonal meteorological variability, analyse the corresponding catchment hydrological response to different land cover, and perform a sensitivity analysis on uncertainties related to rainfall interpolation, catchment area estimation and streamflow measurements. Hydro-meteorological measurements, including hourly solar radiation, temperature, relative humidity, wind speed, precipitation, soil moisture and streamflow, were collected from June 2013 to May 2014 at three gauged neighbouring catchments with contrasting TMCF/grassland cover and less than 250 m elevation difference. We found wetter and less seasonally contrasting conditions at higher elevations, indicating a positive relation between elevation and fog or rainfall persistence. This pattern is similar to that of other eastern Andean TMCFs, however, the study site had higher wet season rainfall and lower dry season rainfall suggesting that upwind contrasts in land cover and moisture can influence the meteorological conditions at eastern Andean TMCFs. Contrasting streamflow dynamics between the studied catchments reflect the overall system response

  11. Cloud Cover Assessment for Operational Crop Monitoring Systems in Tropical Areas

    Directory of Open Access Journals (Sweden)

    Isaque Daniel Rocha Eberhardt

    2016-03-01

    Full Text Available The potential of optical remote sensing data to identify, map and monitor croplands is well recognized. However, clouds strongly limit the usefulness of optical imagery for these applications. This paper aims at assessing cloud cover conditions over four states in the tropical and sub-tropical Center-South region of Brazil to guide the development of an appropriate agricultural monitoring system based on Landsat-like imagery. Cloudiness was assessed during overlapping four months periods to match the typical length of crop cycles in the study area. The percentage of clear sky occurrence was computed from the 1 km resolution MODIS Cloud Mask product (MOD35 considering 14 years of data between July 2000 and June 2014. Results showed high seasonality of cloud occurrence within the crop year with strong variations across the study area. The maximum seasonality was observed for the two states in the northern part of the study area (i.e., the ones closer to the Equator line, which also presented the lowest averaged values (15% of clear sky occurrence during the main (summer cropping period (November to February. In these locations, optical data faces severe constraints for mapping summer crops. On the other hand, relatively favorable conditions were found in the southern part of the study region. In the South, clear sky values of around 45% were found and no significant clear sky seasonality was observed. Results underpin the challenges to implement an operational crop monitoring system based solely on optical remote sensing imagery in tropical and sub-tropical regions, in particular if short-cycle crops have to be monitored during the cloudy summer months. To cope with cloudiness issues, we recommend the use of new systems with higher repetition rates such as Sentinel-2. For local studies, Unmanned Aircraft Vehicles (UAVs might be used to augment the observing capability. Multi-sensor approaches combining optical and microwave data can be another

  12. A comparison of ground and satellite observations of cloud cover to saturation pressure differences during a cold air outbreak

    Energy Technology Data Exchange (ETDEWEB)

    Alliss, R.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The role of clouds in the atmospheric general circulation and the global climate is twofold. First, clouds owe their origin to large-scale dynamical forcing, radiative cooling in the atmosphere, and turbulent transfer at the surface. In addition, they provide one of the most important mechanisms for the vertical redistribution of momentum and sensible and latent heat for the large scale, and they influence the coupling between the atmosphere and the surface as well as the radiative and dynamical-hydrological balance. In existing diagnostic cloudiness parameterization schemes, relative humidity is the most frequently used variable for estimating total cloud amount or stratiform cloud amount. However, the prediction of relative humidity in general circulation models (GCMs) is usually poor. Even for the most comprehensive GCMs, the predicted relative humidity may deviate greatly from that observed, as far as the frequency distribution of relative humidity is concerned. Recently, there has been an increased effort to improve the representation of clouds and cloud-radiation feedback in GCMs, but the verification of cloudiness parameterization schemes remains a severe problem because of the lack of observational data sets. In this study, saturation pressure differences (as opposed to relative humidity) and satellite-derived cloud heights and amounts are compared with ground determinations of cloud cover over the Gulf Stream Locale (GSL) during a cold air outbreak.

  13. Trends of six month nighttime ground-based cloud cover values over Manila Observatory (14.64N, 121.07E)

    Science.gov (United States)

    Gacal, G. F. B.; Lagrosas, N.

    2016-12-01

    The ground reflects thermal radiation during nighttime. Clouds reflect this radiation to the ground and cause increase in ambient temperature. In this study, trends of nighttime cloud cover are analyzed using a commercial camera (Canon Powershot A2300) that is operated continuously to capture images of clouds at 5 minute interval. The camera is situated inside a rain-proof box with a glass oculus and is placed on the rooftop of the Manila Observatory building. To detect pixels with clouds, the pictures are converted from its native JPEG format to grayscale format. The pixels are then screened for clouds by looking at the values of pixels with and without clouds. In grayscale format, pixels with clouds have greater pixel values than pixels without clouds. Based on the observations, a threshold pixel value of 17 is employed to discern pixels with clouds from pixels without clouds. When moon is present in the image, the grayscale image, which is in 8-bit unsigned integer format, is converted into double format. The moon signals are modelled using a two dimensional Gaussian function and is subtracted from the converted image (Gacal et al, 2016). This effectively removes the moon signals but preserves the cloud signals. This method is applied to the data collected from the months of January, February, March, October, November and December 2015. In Manila, dry months are from November to April. Wet months are from May to October. The trends of nighttime cloud cover values over Manila Observatory are shown in the figure below. Frequency distribution of cloud cover values of the first and last three months of the year show that dry and wet months have higher and lower frequency of low cloud cover values, respectively. The trend also exhibits a decrease of cloud cover from October to December but increases back from January until March. This is exhibited in the decrease in the frequency of cloud cover values in the 20%-100% range from October to December. This can be

  14. 西南地区云量变化特征%Variation Characteristics of Cloud Cover over Southwestern China

    Institute of Scientific and Technical Information of China (English)

    李慧晶; 刘建西; 刘东升; 王维佳; 林丹

    2014-01-01

    利用西南地区(云南、贵州、四川、重庆)记录较为完整的73个测站1956~2005年月平均云量资料,采用经验正交函数分析和Mann-Kendall突变检验方法,研究分析了西南地区云量的时空分布特征。结果表明:就全年而言,整个西南地区总云量的变化趋势一致,且存在着明显的年际变化特征,1990年代以后全年总云量表现出减少趋势;此外,总云量的分布在一定程度上受地形和区域气候的影响。从季节来看,夏、秋、冬季的总云量在西南地区为空间一致的变化趋势,而春季四川盆地北部总云量的变化趋势与其余地区相反;四季总云量也有明显的年际变化特征。低云量,全年和四季的时空变化特征相似,由于受地形起伏及区域气候差异的影响,川西高原东部和重庆地区的变化趋势与四川盆地的相反,且同样存在着明显的年际变化特征。另外,突变分析结果显示,西南地区的低云量近50 a来呈持续减少趋势,而总云量在1990年发生突变,突变前在0线附近震荡,突变后总云量持续减少。%Based on the monthly mean cloud cover data at 73 observation stations in Southwest China from 1956 to 2005,the spatial and temporal distributions of cloud cover were analyzed by using empirical orthogonal function (EOF)analysis and Mann-Kendall test. The results showed that the first eigenvectors of annual total cloud cover by EOF in Southwest China were negative consistently,and the temporal coefficient of the first eigenvector of annual total cloud cover decreased after the 1990s. This means that the change trends of annual total cloud cover were consistent,and the interannual variation was obvious. Moreover,the second eigenvectors of annual total cloud cover were different,and the eigenvector values in the east of Southwestern China were negative and positive in the west of South-western China. It means that the spatial

  15. The effects of moon illumination, moon angle, cloud cover, and sky glow on night vision goggle flight performance

    Science.gov (United States)

    Loro, Stephen Lee

    This study was designed to examine moon illumination, moon angle, cloud cover, sky glow, and Night Vision Goggle (NVG) flight performance to determine possible effects. The research was a causal-comparative design. The sample consisted of 194 Fort Rucker Initial Entry Rotary Wing NVG flight students being observed by 69 NVG Instructor Pilots. The students participated in NVG flight training from September 1992 through January 1993. Data were collected using a questionnaire. Observations were analyzed using a Kruskal-Wallis one-way analysis of variance and a Wilcox matched pairs signed-ranks test for difference. Correlations were analyzed using Pearson's r. The analyses results indicated that performance at high moon illumination levels is superior to zero moon illumination, and in most task maneuvers, superior to >0%--50% moon illumination. No differences were found in performance at moon illumination levels above 50%. Moon angle had no effect on night vision goggle flight performance. Cloud cover and sky glow have selective effects on different maneuvers. For most task maneuvers, cloud cover does not affect performance. Overcast cloud cover had a significant effect on seven of the 14 task maneuvers. Sky glow did not affect eight out of 14 task maneuvers at any level of sky glow.

  16. Increasing cloud cover in the 20th century: review and new findings in Spain

    Directory of Open Access Journals (Sweden)

    A. Sanchez-Lorenzo

    2012-04-01

    Full Text Available Visual observations of clouds have been performed since the establishment of meteorological observatories during the early instrumental period, and have become more systematic and reliable after the mid-19th century due to the establishment of the first national weather services. During the last decades a large number of studies have documented the trends of the total cloud cover (TCC and cloudy types; most of these studies are focused on the trends since the second half of the 20th century. Due to the lower reliability of former observations, and the fact that most of this data is not accessible in digital format, there is a lack of studies focusing on the trends of cloudiness since the mid-19th century. In the first part, this work attempts to review the previous studies analyzing TCC changes with information covering at least the first half of the 20th century. Then, the study analyses a database of cloudiness observations in Southern Europe (Spain since the second third of the 19th century. Specifically, monthly TCC series were reconstructed since 1866 by means of a so-called parameter of cloudiness, calculated from the number of cloudless and overcast days. This estimated TCC series show a high interannual and decadal correlation with the observed TCC series originally measured in oktas. After assessing the temporal homogeneity of the estimated TCC series, the mean annual and seasonal series for the whole of Spain and several subregions were calculated. The mean annual TCC shows a general tendency to increase from the beginning of the series until the 1960s; at this point, the trend becomes negative. The linear trend for the annual mean series, estimated over the 1866–2010 period, is a highly remarkable (and statistically significant increase of +0.44% per decade, which implies an overall increase of more than +6% during the analyzed period. These results are in line with the major part of the previous trends observed at many areas of the

  17. Increasing cloud cover in the 20th century: review and new findings in Spain

    Directory of Open Access Journals (Sweden)

    A. Sanchez-Lorenzo

    2012-07-01

    Full Text Available Visual observations of clouds have been performed since the establishment of meteorological observatories during the early instrumental period, and have become more systematic and reliable after the mid-19th century due to the establishment of the first national weather services. During the last decades a large number of studies have documented the trends of the total cloud cover (TCC and cloudy types; most of these studies focus on the trends since the second half of the 20th century. Due to the lower reliability of former observations, and the fact that most of this data is not accessible in digital format, there is a lack of studies focusing on the trends of cloudiness since the mid-19th century. In the first part, this work attempts to review previous studies analyzing TCC changes with information covering at least the first half of the 20th century. Then, the study analyses a database of cloudiness observations in Southern Europe (Spain since the second half of the 19th century. Specifically, monthly TCC series were reconstructed since 1866 by means of a so-called parameter of cloudiness, calculated from the number of cloudless and overcast days. These estimated TCC series show a high interannual and decadal correlation with the observed TCC series originally measured in oktas. After assessing the temporal homogeneity of the estimated TCC series, the mean annual and seasonal series for the whole of Spain and several subregions were calculated. The mean annual TCC shows a general tendency to increase from the beginning of the series until the 1960s; at this point, the trend becomes negative. The linear trend for the annual mean series, estimated over the 1866–2010 period, is a highly remarkable (and statistically significant increase of +0.44% per decade, which implies an overall increase of more than +6% during the analyzed period. These results are in line with the majority of the trends observed in many areas of the world in previous

  18. Increasing cloud cover in the 20th century: review and new findings in Spain

    Science.gov (United States)

    Sanchez-Lorenzo, A.; Calbó, J.; Wild, M.

    2012-07-01

    Visual observations of clouds have been performed since the establishment of meteorological observatories during the early instrumental period, and have become more systematic and reliable after the mid-19th century due to the establishment of the first national weather services. During the last decades a large number of studies have documented the trends of the total cloud cover (TCC) and cloudy types; most of these studies focus on the trends since the second half of the 20th century. Due to the lower reliability of former observations, and the fact that most of this data is not accessible in digital format, there is a lack of studies focusing on the trends of cloudiness since the mid-19th century. In the first part, this work attempts to review previous studies analyzing TCC changes with information covering at least the first half of the 20th century. Then, the study analyses a database of cloudiness observations in Southern Europe (Spain) since the second half of the 19th century. Specifically, monthly TCC series were reconstructed since 1866 by means of a so-called parameter of cloudiness, calculated from the number of cloudless and overcast days. These estimated TCC series show a high interannual and decadal correlation with the observed TCC series originally measured in oktas. After assessing the temporal homogeneity of the estimated TCC series, the mean annual and seasonal series for the whole of Spain and several subregions were calculated. The mean annual TCC shows a general tendency to increase from the beginning of the series until the 1960s; at this point, the trend becomes negative. The linear trend for the annual mean series, estimated over the 1866-2010 period, is a highly remarkable (and statistically significant) increase of +0.44% per decade, which implies an overall increase of more than +6% during the analyzed period. These results are in line with the majority of the trends observed in many areas of the world in previous studies, especially

  19. Sunshine and global solar radiation estimation at different sites in Egypt

    Science.gov (United States)

    El-Metwally, Mossad

    2005-09-01

    A simple non-linear method is proposed for estimating relative sunshine duration based on monthly mean daily maximum and minimum air temperatures and cloud cover fraction at six sites in Egypt, where long-term period (9 15 years) data were recorded. This method gives low errors (mean bias error is about -0.4% and root mean square is about 2.3% for pooled data), so it can be used in case of unavailability of sunshine duration data. Also, a non-linear equation has been proposed at the same sites to estimate monthly mean daily global radiation based on observed and estimated values of relative sunshine duration. This method was compared with linear Ångström Prescott and double linear of Garg Garg equation. These methods were tested seasonally and at different sky conditions (clear, partially cloudy and overcast skies). Also they have been tested against 32 stations dataset, at worldwide sites. The results show that the bias error for the proposed method is low, average values to mean bias error and root mean square error are around 0.1% and 6%, respectively, while they are around 3% and 7% to the other methods at pooled data. Generally, the proposed method preformed better than the others.

  20. Experimental evaluation of ALS point cloud ground extraction over different land cover in the Malopolska Province

    Science.gov (United States)

    Korzeniowska, Karolina; Mandlburger, Gottfried; Klimczyk, Agata

    2013-04-01

    The paper presents an evaluation of different terrain point extraction algorithms for Airborne Laser Scanning (ALS) point clouds. The research area covers eight test sites in the Małopolska Province (Poland) with varying point density between 3-15points/m² and surface as well as land cover characteristics. In this paper the existing implementations of algorithms were considered. Approaches based on mathematical morphology, progressive densification, robust surface interpolation and segmentation were compared. From the group of morphological filters, the Progressive Morphological Filter (PMF) proposed by Zhang K. et al. (2003) in LIS software was evaluated. From the progressive densification filter methods developed by Axelsson P. (2000) the Martin Isenburg's implementation in LAStools software (LAStools, 2012) was chosen. The third group of methods are surface-based filters. In this study, we used the hierarchic robust interpolation approach by Kraus K., Pfeifer N. (1998) as implemented in SCOP++ (Trimble, 2012). The fourth group of methods works on segmentation. From this filtering concept the segmentation algorithm available in LIS was tested (Wichmann V., 2012). The main aim in executing the automatic classification for ground extraction was operating in default mode or with default parameters which were selected by the developers of the algorithms. It was assumed that the default settings were equivalent to the parameters on which the best results can be achieved. In case it was not possible to apply an algorithm in default mode, a combination of the available and most crucial parameters for ground extraction were selected. As a result of these analyses, several output LAS files with different ground classification were achieved. The results were described on the basis of qualitative and quantitative analyses, both being in a formal description. The classification differences were verified on point cloud data. Qualitative verification of ground extraction was

  1. A Remote Sensing Model to Estimate Sunshine Duration in the Ningxia Hui Autonomous Region, China

    Institute of Scientific and Technical Information of China (English)

    朱晓晨; 邱新法; 曾燕; 高佳琦; 何永健

    2015-01-01

    Sunshine duration (SD) is strongly correlated with solar radiation, and is most widely used to estimate the latter. This study builds a remote sensing model on a 100 m × 100 m spatial resolution to estimate SD for the Ningxia Hui Autonomous Region, China. Digital elevation model (DEM) data are employed to refl ect topography, and moderate-resolution imaging spectroradiometer (MODIS) cloud products (Aqua MYD06−L2 and Terra MOD06−L2) are used to estimate sunshine percentage. Based on the terrain (e.g., slope, aspect, and terrain shadowing degree) and the atmospheric conditions (e.g., air molecules, aerosols, moisture, cloud cover, and cloud types), observation data from weather stations are also incorporated into the model. Verifi cation results indicate that the model simulations match reasonably with the observations, with the average relative error of the total daily SD being 2.21%. Further data analysis reveals that the variation of the estimated SD is consistent with that of the maximum possible SD; its spatial variation is so substantial that the estimated SD diff ers signifi cantly between the south-facing and north-facing slopes, and its seasonal variation is also large throughout the year.

  2. Quantifying the impact of cloud cover on ground radiation flux measurements using hemispherical images

    NARCIS (Netherlands)

    Roupioz, L.; Colin, J.; Jia, L.; Nerry, F.; Menenti, M.

    2015-01-01

    Linking observed or estimated ground incoming solar radiation with cloud coverage is difficult since the latter is usually poorly described in standard meteorological observation protocols. To investigate the benefits of detailed observation and characterization of cloud coverage and distribution

  3. Looking for the rainbow on exoplanets covered by liquid and icy water clouds

    NARCIS (Netherlands)

    Karalidi, T.; Stam, D.M.; Hovenier, J.W.

    2012-01-01

    Aims. Looking for the primary rainbow in starlight that is reflected by exoplanets appears to be a promising method to search for liquid water clouds in exoplanetary atmospheres. Ice water clouds, that consist of water crystals instead of water droplets, could potentially mask the rainbow feature in

  4. Looking for the rainbow on exoplanets covered by liquid and icy water clouds

    NARCIS (Netherlands)

    Karalidi, T.; Stam, D.M.; Hovenier, J.W.

    2012-01-01

    Aims. Looking for the primary rainbow in starlight that is reflected by exoplanets appears to be a promising method to search for liquid water clouds in exoplanetary atmospheres. Ice water clouds, that consist of water crystals instead of water droplets, could potentially mask the rainbow feature in

  5. Let Us Love the Sunshine

    Institute of Scientific and Technical Information of China (English)

    周寅婕

    2002-01-01

    If there is no sunshine, plants could not grow. If there is no sunshine, animals could not live. If there is no sunshine, we, the human beings could not develop or even survive. After years of adverse publicity(反面的宣伟), now researches suggest that sunshine does bathe us in favourable light.

  6. Interpreting the cloud cover – aerosol optical depth relationship found in satellite data using a general circulation model

    Directory of Open Access Journals (Sweden)

    J. Quaas

    2010-07-01

    Full Text Available Statistical analysis of satellite data shows a positive correlation between aerosol optical depth (AOD and total cloud cover (TCC. Reasons for this relationship have been disputed in recent literature. The aim of this study is to explore how different processes contribute to one model's analog of the positive correlation between aerosol optical depth and total cloud cover seen in the satellite retrievals. We compare the slope of the linear regression between the logarithm of TCC and the logarithm of AOD, or the strength of the relationship, as derived from three satellite data sets to the ones simulated by a global aerosol-climate model. We analyse model results from two different simulations with and without a parameterisation of aerosol indirect effects, and using dry compared to humidified AOD. Perhaps not surprisingly we find that no single one of the hypotheses discussed in the literature is able to uniquely explain the positive relationship. However the dominant contribution to the model's AOD-TCC relationship can be attributed to aerosol swelling in regions where humidity is high and clouds are coincidentally found. This finding leads us to hypothesise that much of the AOD-TCC relationship seen in the satellite data is also carried by such a process, rather than the direct effects of the aerosols on the cloud fields themselves.

  7. Atmospheric Correction Performance of Hyperspectral Airborne Imagery over a Small Eutrophic Lake under Changing Cloud Cover

    Directory of Open Access Journals (Sweden)

    Lauri Markelin

    2016-12-01

    Full Text Available Atmospheric correction of remotely sensed imagery of inland water bodies is essential to interpret water-leaving radiance signals and for the accurate retrieval of water quality variables. Atmospheric correction is particularly challenging over inhomogeneous water bodies surrounded by comparatively bright land surface. We present results of AisaFENIX airborne hyperspectral imagery collected over a small inland water body under changing cloud cover, presenting challenging but common conditions for atmospheric correction. This is the first evaluation of the performance of the FENIX sensor over water bodies. ATCOR4, which is not specifically designed for atmospheric correction over water and does not make any assumptions on water type, was used to obtain atmospherically corrected reflectance values, which were compared to in situ water-leaving reflectance collected at six stations. Three different atmospheric correction strategies in ATCOR4 was tested. The strategy using fully image-derived and spatially varying atmospheric parameters produced a reflectance accuracy of ±0.002, i.e., a difference of less than 15% compared to the in situ reference reflectance. Amplitude and shape of the remotely sensed reflectance spectra were in general accordance with the in situ data. The spectral angle was better than 4.1° for the best cases, in the spectral range of 450–750 nm. The retrieval of chlorophyll-a (Chl-a concentration using a popular semi-analytical band ratio algorithm for turbid inland waters gave an accuracy of ~16% or 4.4 mg/m3 compared to retrieval of Chl-a from reflectance measured in situ. Using fixed ATCOR4 processing parameters for whole images improved Chl-a retrieval results from ~6 mg/m3 difference to reference to approximately 2 mg/m3. We conclude that the AisaFENIX sensor, in combination with ATCOR4 in image-driven parametrization, can be successfully used for inland water quality observations. This implies that the need for in situ

  8. Object Based Image Analysis Combining High Spatial Resolution Imagery and Laser Point Clouds for Urban Land Cover

    Science.gov (United States)

    Zou, Xiaoliang; Zhao, Guihua; Li, Jonathan; Yang, Yuanxi; Fang, Yong

    2016-06-01

    With the rapid developments of the sensor technology, high spatial resolution imagery and airborne Lidar point clouds can be captured nowadays, which make classification, extraction, evaluation and analysis of a broad range of object features available. High resolution imagery, Lidar dataset and parcel map can be widely used for classification as information carriers. Therefore, refinement of objects classification is made possible for the urban land cover. The paper presents an approach to object based image analysis (OBIA) combing high spatial resolution imagery and airborne Lidar point clouds. The advanced workflow for urban land cover is designed with four components. Firstly, colour-infrared TrueOrtho photo and laser point clouds were pre-processed to derive the parcel map of water bodies and nDSM respectively. Secondly, image objects are created via multi-resolution image segmentation integrating scale parameter, the colour and shape properties with compactness criterion. Image can be subdivided into separate object regions. Thirdly, image objects classification is performed on the basis of segmentation and a rule set of knowledge decision tree. These objects imagery are classified into six classes such as water bodies, low vegetation/grass, tree, low building, high building and road. Finally, in order to assess the validity of the classification results for six classes, accuracy assessment is performed through comparing randomly distributed reference points of TrueOrtho imagery with the classification results, forming the confusion matrix and calculating overall accuracy and Kappa coefficient. The study area focuses on test site Vaihingen/Enz and a patch of test datasets comes from the benchmark of ISPRS WG III/4 test project. The classification results show higher overall accuracy for most types of urban land cover. Overall accuracy is 89.5% and Kappa coefficient equals to 0.865. The OBIA approach provides an effective and convenient way to combine high

  9. NH4SH and cloud cover in the atmospheres of the giant planets

    Science.gov (United States)

    Ibragimov, K. Iu.; Solodovnik, A. A.

    1991-02-01

    The probability of the formation of NH4SH and (NH4)2S is examined on the basis of the Le Chatelier principle. It is shown that it is very doubtful if NH4SH can be created in the atmospheres of the giant planets in quantities sufficient for cloud formation. Thus (NH4)2S is considered as a more likely candidate for cloud formation in the atmospheres of these planets, inasmuch as the conditions for its production there are more favorable.

  10. Can periodicity in low altitude cloud cover be induced by cosmic ray variability in the extragalactic shock model?

    CERN Document Server

    Atri, Dimitra; Melott, Adrian L; Kansas, University of; University, Washburn

    2010-01-01

    Variation in high energy cosmic rays (HECRs) has been proposed to explain a 62 My periodicity in terrestrial fossil biodiversity. It has been suggested that the infall of our galaxy toward the Virgo cluster could generate an extragalactic shock, accelerating charged particles and exposing the earth to a flux of high energy cosmic rays (HECRs). The oscillation of the Sun perpendicular to the galactic plane could induce 62 My periodicity in the HECR flux on the Earth, with a magnitude much higher than the Galactic cosmic ray change we see in a solar cycle. This mechanism could potentially explain the observed 62 My periodicity in terrestrial biodiversity over the past 500 My. In addition to direct effects on life from secondaries, HECRs induced air showers ionize the atmosphere leading to changes in atmospheric chemistry and microphysical processes that can lead to cloud formation including low altitude cloud cover. An increase in ionization changes the global electric circuit which could enhance the formation ...

  11. Climatic Characteristics of Sunshine Duration in the Tianshan Mountains of Xinjiang%新疆天山地区日照时数的气候特征

    Institute of Scientific and Technical Information of China (English)

    赵勇; 崔彩霞; 李扬

    2011-01-01

    Based on the daily sunshine duration data observed at 23 weather stations in the Tianshan Mountains during the period of 1961-2008,the spatiotemporal distribution and variation features of sunshine duration in the Tianshan Mountains were analyzed using some statistical methods,such as the simple linear regression and Mann-Kendall test.The results are as follows:(1) There was an obvious regional difference in climatic distribution of sunshine duration,and the sunshine duration increased from the west to the east and from the north to the south in the Tianshan Mountains;(2) The regional average sunshine duration was in a decrease trend,especially in winter and summer;(3) There was an obvious decadal variation trend of seasonal sunshine duration except that in spring,and a sharp decrease of seasonal sunshine duration occurred in winter 1987,summer 1978 and autumn 1980;(4) The sharp decrease of sunshine duration in winter and summer was related to the serious air pollution and the increase of cloud cover in recent 20 years.%基于1961-2008年新疆天山地区23站日照时数的逐日资料,使用一元线性方程和M-K检验等统计方法,分析天山地区日照时数的时空变化特征。结果表明:①日照时数的气候分布存在明显的空间差异,呈东多西少,南多北少的分布特征。②区域平均日照时数均呈减少趋势,尤其在冬季和夏季。③四季除春季外日照时数均存在明显的年代际变化特征,并发生了由多到少的气候突变,冬季在1987年,夏季在1978年,秋季在1980年左右。20世纪80年代中后期至今,冬、夏、秋三个季节日照时数减少的趋势显著。④冬季和夏季日照时数的较快减少与近

  12. Verification of cloud cover forecast with INSAT observation over western India

    Indian Academy of Sciences (India)

    Shivani Shah; B M Rao; Prashant Kumar; P K Pal

    2010-12-01

    Since the beginning of the summer monsoon 2009, experimental mesoscale weather forecasts in real time are being generated using WRF model by the Meteorology and Oceanography Group at the Space Applications Centre (ISRO)and are disseminated through MOSDAC (www.mosdac.gov.in) to various users. To begin with, the 12 h, 24 h and 48 h forecasts for the western India region are made available. A study is undertaken to comprehensively assess the cloudiness prediction performance of WRF model. The evaluations have been made over the three months period during monsoon 2009. INSAT cloud imagery data has been used as a reference for these evaluations. The verification strategy includes computation of various skill scores. It is seen that probability of detection (POD)of cloud is 84% and the false alarm rate (FAR) is around 18%. It is hoped that this assessment will provide information on the use of these forecasts in various applications.

  13. 3D LAND COVER CLASSIFICATION BASED ON MULTISPECTRAL LIDAR POINT CLOUDS

    OpenAIRE

    Zou, X; G. Zhao; Li, J.(Center for Underground Physics, Institute for Basic Science (IBS), Daejon, 305-811, Korea); Y. Yang; Fang, Y.

    2016-01-01

    Multispectral Lidar System can emit simultaneous laser pulses at the different wavelengths. The reflected multispectral energy is captured through a receiver of the sensor, and the return signal together with the position and orientation information of sensor is recorded. These recorded data are solved with GNSS/IMU data for further post-processing, forming high density multispectral 3D point clouds. As the first commercial multispectral airborne Lidar sensor, Optech Titan system is capable o...

  14. A study of the cloud cover and cloud top pressure weekly cycle over the region of Eastern Mediterranean with the use of MODIS satellite data

    Science.gov (United States)

    Dalampiras, Pashalis; Georgoulias, Aristeidis K.; Kourtidis, Konstantinos; Alexandri, Georgia; Meleti, Charoula

    2014-05-01

    In this work, the spatiotemporal variability of cloud cover (CC) and cloud top pressure (CTP) over the region of Eastern Mediterranean is presented. The analysis is based on level-2 data from MODIS TERRA and AQUA satellite sensors for the period 3/2000-12/2012 and 7/2002-12/2012, respectively. The data used here are from the 0.1-degree aerosol-cloud gridded dataset that was compiled within the framework of QUADIEEMS project for the investigation of the aerosol indirect effects. The Weekly Cycle Index (WCI) and the day of weekly maximum/minimum patterns are calculated on a seasonal basis and their possible connections with local aerosol sources and the regional aerosol patterns are investigated. To generalize our results, the day-of-the-week variability of CC and CTP for 9 sub-regions with different aerosol characteristics is examined. Among the most striking features is a summer CC midweek minimum over the Balkan Peninsula. Contrasting this, a weekend CC minimum appears over the Aegean and the Black Sea. In spring, we observe a statistically significant weekend CC maximum over the Balkan Peninsula and the sea regions around it. The synergistic use of various satellite, model and reanalysis products indicates that these regions are characterized by a strong presence of anthropogenic aerosols. The opposite behaviour is observed for CTP; however, the statistically significant weekly maxima and minima appear mostly over land. The QUADIEEMS project is co-financed by the European Social Fund (ESF) and national resources under the operational programme Education and Lifelong Learning (EdLL) within the framework of the Action "Supporting Postdoctoral Researchers".

  15. Assessing the performance of aerial image point cloud and spectral metrics in predicting boreal forest canopy cover

    Science.gov (United States)

    Melin, M.; Korhonen, L.; Kukkonen, M.; Packalen, P.

    2017-07-01

    Canopy cover (CC) is a variable used to describe the status of forests and forested habitats, but also the variable used primarily to define what counts as a forest. The estimation of CC has relied heavily on remote sensing with past studies focusing on satellite imagery as well as Airborne Laser Scanning (ALS) using light detection and ranging (lidar). Of these, ALS has been proven highly accurate, because the fraction of pulses penetrating the canopy represents a direct measurement of canopy gap percentage. However, the methods of photogrammetry can be applied to produce point clouds fairly similar to airborne lidar data from aerial images. Currently there is little information about how well such point clouds measure canopy density and gaps. The aim of this study was to assess the suitability of aerial image point clouds for CC estimation and compare the results with those obtained using spectral data from aerial images and Landsat 5. First, we modeled CC for n = 1149 lidar plots using field-measured CCs and lidar data. Next, this data was split into five subsets in north-south direction (y-coordinate). Finally, four CC models (AerialSpectral, AerialPointcloud, AerialCombi (spectral + pointcloud) and Landsat) were created and they were used to predict new CC values to the lidar plots, subset by subset, using five-fold cross validation. The Landsat and AerialSpectral models performed with RMSEs of 13.8% and 12.4%, respectively. AerialPointcloud model reached an RMSE of 10.3%, which was further improved by the inclusion of spectral data; RMSE of the AerialCombi model was 9.3%. We noticed that the aerial image point clouds managed to describe only the outermost layer of the canopy and missed the details in lower canopy, which was resulted in weak characterization of the total CC variation, especially in the tails of the data.

  16. Cloud cover climatologies in the Mediterranean obtained from satellites, surface observations, reanalyses, and CMIP5 simulations: validation and future scenarios

    Science.gov (United States)

    Enriquez-Alonso, Aaron; Sanchez-Lorenzo, Arturo; Calbó, Josep; González, Josep-Abel; Norris, Joel R.

    2016-07-01

    Clouds are an important regulator of climate due to their connection to the water balance of the atmosphere and their interaction with solar and infrared radiation. In this study, monthly total cloud cover (TCC) records from different sources have been inter-compared on annual and seasonal basis for the Mediterranean region and the period 1984-2005. Specifically, gridded databases from satellite projects (ISCCP, CLARA, PATMOS-x), from reanalysis products (ERA-Interim, MERRA), and from surface observations over land (EECRA) and ocean (ICOADS) have been examined. Then, simulations from 44 climate runs of the Coupled Model Intercomparison Project phase 5 corresponding to the historical scenario have been compared against the observations. Overall, we find good agreement between the mean values of TCC estimated from the three satellite products and from surface observations, while reanalysis products show much lower values across the region. Nevertheless, all datasets show similar behavior regarding the annual cycle of TCC. In addition, our results indicate an underestimation of TCC from climate model simulations as compared to the satellite products, especially during summertime, although the annual cycle is well simulated by most models. This result is quite general and apparently independent of the cloud parameterizations included in each particular model. Equally, similar results are obtained if the ISCCP simulator included in the Cloud Feedback Model Intercomparison Project Observation Simulator Package is considered, despite only few models provide the post-processed results. Finally, GCM projections of TCC over the Mediterranean are presented. These projections predict a reduction of TCC during the 21st century in the Mediterranean. Specifically, for an extreme emission scenario (RCP8.5) the projected relative rate of TCC decrease is larger than 10 % by the end of the century.

  17. Effects of an assumed cosmic ray-modulated low global cloud cover on the Earth's temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, J.; Mendoza, B. [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Mendoza, V.; Adem, J. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: victor@atmosfera.unam.mx

    2006-07-15

    We have used the Thermodynamic Model of the Climate to estimate the effect of variations in the low cloud cover on the surface temperature of the Earth in the Northern Hemisphere during the period 1984-1994. We assume that the variations in the low cloud cover are proportional to the variation of the cosmic ray flux measured during the same period. The results indicate that the effect in the surface temperature is more significant in the continents, where for July of 1991, we have found anomalies of the order of 0.7 degrees Celsius for the southeastern of Asia and 0.5 degrees Celsius for the northeast of Mexico. For an increase of 0.75% in the low cloud cover, the surface temperature computed by the model in the North Hemisphere presents a decrease of {approx} 0.11 degrees Celsius; however, for a decrease of 0.90% in the low cloud cover, the model gives an increase in the surface temperature of {approx} 0.15 degrees Celsius, these two cases correspond to a climate sensitivity factor for the case of forcing by duplication of atmospheric CO{sub 2}. These decreases or increases in surface temperature by increases of decreases in low clouds cover are ten times greater than the overall variability of the non-forced model time series. [Spanish] Hemos usado el Modelo Termodinamico del Clima para estimar el efecto de variaciones en la cubierta de nubes bajas sobre la temperatura superficial de la Tierra en el Hemisferio Norte durante el periodo 1984 - 1994. Suponemos que las variaciones en la cubierta de nubes bajas son proporcionales a las variaciones del flujo de rayos cosmicos medido durante el mismo periodo. Los resultados indican que el efecto en la temperatura es mas significativo en los continentes, donde para julio de 1991, hemos encontrado anomalias del orden de 0.7 grados Celsius sobre el sureste de Asia y 0.5 grados Celsius al noreste de Mexico. Para un incremento de 0.75% en la cubierta de nubes bajas, la temperatura de la superficie calculada por el modelo en

  18. An improved technique for global daily sunshine duration estimation using satellite imagery

    Institute of Scientific and Technical Information of China (English)

    Muhammad Ali SHAMIM; Renji REMESAN; Da-wei HAN; Naeem EJAZ; Ayub ELAHI

    2012-01-01

    This paper presents an improved model for global sunshine duration estimation.The methodology incorporates geostationary satellite images by including snow cover information,sun and satellite angles and a trend correction factor for seasons,for the determination of cloud cover index.The effectiveness of the proposed methodology has been tested using Meteosat geostationary satellite images in the visible band with a temporal resolution of 1 h and spatial resolution of 2.5 km×2.5 km,for the Brue Catchment in the southwest of England.Validation results show a significant improvement in the estimation of global sunshine duration by the proposed method as compared to its predecessor (R2 is improved from 0.68 to 0.83,root mean squared error (RMSE) from 2.37 h/d to 1.19 h/d and the mean biased error (MBE) from 0.21 h/d to 0.08 h/d).Further studies are needed to test this method in other parts of the world with different climate and geographical conditions.

  19. Cloud cover anomalies at middle latitudes: Links to troposphere dynamics and solar variability

    Science.gov (United States)

    Veretenenko, S.; Ogurtsov, M.

    2016-11-01

    In this work we study links between low cloud anomalies (LCA) at middle latitudes of the Northern and Southern hemispheres and galactic cosmic ray (GCR) variations used as a proxy of solar variability on the decadal time scale. It was shown that these links are not direct, but realized through GCR/solar activity phenomena influence on the development of extratropical baric systems (cyclones and troughs) which form cloud field. The violation of a positive correlation between LCA and GCR intensity which was observed in the 1980s-1990s occurred simultaneously in the Northern and Southern hemispheres in the early 2000s and coincided with the sign reversal of GCR effects on troposphere circulation. It was suggested that a possible reason for the correlation reversal between cyclonic activity at middle latitudes and GCR fluxes is the change of the stratospheric polar vortex intensity which influences significantly the troposphere-stratosphere coupling. The evidences for a noticeable weakening of the polar vortices in the Arctic and Antarctic stratosphere in the early 2000s are provided. The results obtained suggest an important role of the polar vortex evolution as a reason for a temporal variability of solar activity effects on the lower atmosphere.

  20. How to model moon signals using 2-dimensional Gaussian function: Classroom activity for measuring nighttime cloud cover

    Science.gov (United States)

    Gacal, G. F. B.; Lagrosas, N.

    2016-12-01

    used for quantifying cloud cover as captured by ordinary cameras (Gacal et al, 2016). Cloud cover can be defined as the ratio of number of pixels whose values exceeds 0.07 and the total number of pixels. In this particular image, cloud cover value is 0.67.

  1. Polar tropospheric BrO from GOME: timeseries and analysis of area covered by BrO 'clouds'

    Science.gov (United States)

    Hollwedel, J.; Beirle, S.; Frankenberg, C.; Grzegorski, M.; Khokhar, F.; Kühl, S.; Kraus, S.; Platt, U.; Wagner, T.; Wilms-Grabe, W.

    2003-04-01

    The GOME instrument aboard ERS-2 is measuring trace gases since 1995. With the DOAS method it is possible to extract vertical column densities of BrO (and other species) from the GOME spectra. The importance of BrO for the ozone depletion in the stratosphere is well known. BrO can also be liberated by heterogenous reactions on the surfaces of halogen rich aerosols, especially over the one year old sea ice. This mechanism is known as the Bromine explosion leading to the 'tropospheric ozone hole' in polar spring. Because of the global coverage and the long time series, comparisons of year-to-year variations are feasible. We focus especially on the comparison of the time and spatial variability of BrO events by analyzing time series and the extent of areas covered by BrO 'clouds'.

  2. Evaluating the “critical relative humidity” as a measure of subgrid-scale variability of humidity in general circulation model cloud cover parameterizations using satellite data

    OpenAIRE

    Quaas, Johannes

    2015-01-01

    A simple way to diagnose fractional cloud cover in general circulation models is to relate it to the simulated relative humidity, and allowing for fractional cloud cover above a “critical relative humidity” of less than 100%. In the formulation chosen here, this is equivalent to assuming a uniform “top-hat” distribution of subgrid-scale total water content with a variance related to saturation. Critical relative humidity has frequently been treated as a “tunable” constant, yet it is an observ...

  3. Analyzing the Effect of Intraseasonal Meteorological Variability and Land Cover on Aerosol-Cloud Interactions During the Amazonian Biomass Burning Season

    Science.gov (United States)

    TenHoeve, J. E.; Remer, L. A.; Jacobson, M. Z.

    2010-01-01

    pasture is not correlated with aerosol loading, supporting the assumption that temporal variation of column water vapor is primarily a function of the larger-scale meteorology. However, a difference in the response of cloud fraction to increasing AOD is observed between forest and pasture. This suggests that dissimilarities between other meteorological factors, such as atmospheric stability, are likely to have an impact on aerosol-cloud correlations between different land-cover types.

  4. Monitoring snow cover variability (2000-2014) in the Hengduan Mountains based on cloud-removed MODIS products with an adaptive spatio-temporal weighted method

    Science.gov (United States)

    Li, Xinghua; Fu, Wenxuan; Shen, Huanfeng; Huang, Chunlin; Zhang, Liangpei

    2017-08-01

    Monitoring the variability of snow cover is necessary and meaningful because snow cover is closely connected with climate and ecological change. In this work, 500 m resolution MODIS daily snow cover products from 2000 to 2014 were adopted to analyze the status in Hengduan Mountains. In order to solve the spatial discontinuity caused by clouds in the products, we propose an adaptive spatio-temporal weighted method (ASTWM), which is based on the initial result of a Terra and Aqua combination. This novel method simultaneously considers the temporal and spatial correlations of the snow cover. The simulated experiments indicate that ASTWM removes clouds completely, with a robust overall accuracy (OA) of above 93% under different cloud fractions. The spatio-temporal variability of snow cover in the Hengduan Mountains was investigated with two indices: snow cover days (SCD) and snow fraction. The results reveal that the annual SCD gradually increases and the coefficient of variation (CV) decreases with elevation. The pixel-wise trends of SCD first rise and then drop in most areas. Moreover, intense intra-annual variability of the snow fraction occurs from October to March, during which time there is abundant snow cover. The inter-annual variability, which mainly occurs in high elevation areas, shows an increasing trend before 2004/2005 and a decreasing trend after 2004/2005. In addition, the snow fraction responds to the two climate factors of air temperature and precipitation. For the intra-annual variability, when the air temperature and precipitation decrease, the snow cover increases. Besides, precipitation plays a more important role in the inter-annual variability of snow cover than temperature.

  5. Singular Value Decomposition Analysis of Cloud Fraction Cover and Sea Ice Concentration over the Arctic Region, 1982-2009

    Science.gov (United States)

    Boccolari, Mauro; Parmiggiani, Flavio

    2016-08-01

    In this study, the coupled spatial and temporal variability between seasonal data of Cloud Fraction Cover (CFC) and Sea Ice Concentration (SIC) in the Arctic Ocean for the 1982-2009 period were investigated by using the Singular Value Decomposition (SVD) method.The spatial patterns of CFCs related to the first mode of co-variability, identify the maximum covariance, for all seasons, in the Barents Sea and in the Arctic Ocean Canada, while the SIC and 'found in the Chukchi Sea in autumn (in according to the maximum sea ice melting) and the Barents sea during both the winter and spring.CFC spatial patterns related to the first mode of co- variability, locate maximum covariance, for all seasons, in the Barents Sea and in the Canadian side of the Arctic Ocean, while for SIC is found in the Chukchi Sea during autumn (corresponding to the maximum sea ice melting) and in the Barents Sea during both the winter and spring.Finally, the correlation between the seasonal time series of expansion coefficients derived from the SVD analysis, for both CFC and SIC fields, with the seasonal time series of some relevant climate indices for the Arctic (NAO, AO, PDO and PNA). Statistically significant values for both fields were found during summer with the AO, and during autumn with the PNA.

  6. 秦岭南北日照时数时空变化及突变特征%Spatial-temporal variations and mutations of sunshine hours in the northern and southern regions of the Qinling Mountains

    Institute of Scientific and Technical Information of China (English)

    蒋冲; 刘晓磊; 程楠楠; 梁宁霞; 王飞; 刘思杰; 穆兴民

    2013-01-01

    98% of stations were in decrease of sunshine hours in winter and summer,respectively.However,characteristics of change in sunshine hours and its spatial distribution were without an obvious regularity.The downward trend in winter sunshine hours is probably due to dust-floating increasing in the atmosphere because a large amount of coal is being consumed by human being in winter.(3)The abrupt change in annual,spring and summer sunshine hours happened between 1979 and 1981 and there were no obvious abrupt change points in autumn or winter,which may be due to the urbanization development and cloud cover increasing.(4)Wind speed and maximum temperature are positively correlated with sunshine hours,while precipitation and relative humidity are passively correlated with sunshine hours.There was no a clear relationship between minimum or mean temperature and sunshine hours.%根据秦岭南北47个气象站1960-2011年逐月数据,采用样条曲线插值法(Spline)、气候倾向率、Pettitt突变点检测、相关分析等方法对该区日照时数的时空变化特征以及影响其变化的气象要素进行了分析.结果表明:(1)研究区多年平均日照时数为1 838.7h,空间分布呈东北向西南递减格局,按各分区日照长短排序为秦岭以北>秦岭南坡>汉水流域>巴巫谷地.四季日照时数分布特征与年尺度上的结论基本一致,4个季节按其大小排序为夏季>春季>秋季>冬季,四季均以秦岭以北的日照时数最大.(2)近52a各区年日照时数变化趋势较为一致,绝大部分站点呈下降趋势.下降的站点占本区站点总数的比例排序为巴巫谷地>汉水流域>秦岭以北>秦岭南坡,秦岭以南的广大地区相对于秦岭以北日照下降更明显.春季47%的站点呈上升趋势,显著上升的站点集中于中部地区;夏季98%的站点呈显著下降趋势;秋季和冬季变化特征及其空间分布无明显规律.(3)年尺度、春季

  7. FCC and the Sunshine Act.

    Science.gov (United States)

    Weiss, Kenneth

    The Sunshine Act, designed to encourage open meetings to increase public understanding of the governmental decision-making process, went into effect in March 1977. A total of 50 agencies, including the Federal Communications Commission (FCC), are subject to the provisions of the Sunshine Act. The act lists 10 exemptions, any of which can result in…

  8. Worldwide cloud cover model

    Science.gov (United States)

    Smith, O. E.; Sommerville, P. N.

    1979-01-01

    Classifying worldwide cloudiness into homogeneous regions, using a satellite data set containing day IR, night IR, incoming, and absorbed solar radiation measurements on a 2.5-degree latitude-longitude grid is considered. Methods of analysis are presented.

  9. Sensitivity of the southern West African mean atmospheric state to variations in low-level cloud cover as simulated by ICON

    Science.gov (United States)

    Kniffka, Anke; Knippertz, Peter; Fink, Andreas

    2017-04-01

    This contribution presents first results of numerical sensitivity experiments that are carried out in the framework of the project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa). DACCIWA aims to investigate the impact of the drastic increase in anthropogenic emissions in West Africa on the local weather and climate, for example through cloud-aerosol interactions or impacts on radiation and stability. DACCIWA organised a major international field campaign in West Africa in June-July 2016 and involves a wide range of modelling activities. Several studies have shown - and first results of the DACCIWA campaign confirm - that extensive ultra-low stratus clouds form in the southern parts of West Africa (8°W-8°E, 5-10°N) at night in connection with strong nocturnal low-level jets. The clouds persist long after sunrise and have therefore a substantial impact on the surface radiation budget and consequently on the diurnal evolution of the daytime, convectively mixed boundary layer. The objective of this study is to investigate the sensitivity of the West African monsoon system and its diurnal cycle to the radiative effects of these low clouds. The study is based on a series of daily 5-day sensitivity simulations using ICON, the operational numerical weather prediction model of the German Weather Service during the months July - September 2006. In these simulations, low clouds are made transparent, by artificially lowering the optical thickness information passed on to the model's radiation scheme. Results reveal a noticeable influence of the low-level cloud cover on the atmospheric mean state of our region of interest and beyond. Also the diurnal development of the convective boundary layer is influenced by the cloud modification. In the transparent-cloud experiments, the cloud deck tends to break up later in the day and is shifted to a higher altitude, thereby causing a short-lived intensification around 11 LT. The average rainfall patterns are

  10. Crickets in Sunshine.

    Science.gov (United States)

    Remmert, Hermann

    1985-12-01

    1. A method is described which makes the registration of body temperatures possible without disturbing the animals. Thus it is possible to observe and quantify the effect of basking on the development of a population. 2. In crickets (Gryllus bimaculatus) the time of development is drastically reduced by the possibility to bask in sunshine at self-determined intervals. The old rule of temperature-sums is demonstrated to be invalid in this case; the changing body temperature acts as a signal to unknown processes which speed up the development of the animal.

  11. Influence of atmospheric circulation patterns on local cloud and solar variability in Bergen, Norway

    Science.gov (United States)

    Parding, Kajsa; Olseth, Jan Asle; Liepert, Beate G.; Dagestad, Knut-Frode

    2016-08-01

    In a previous paper, we have shown that long-term cloud and solar observations (1965-2013) in Bergen, Norway (60.39°N, 5.33°E) are compatible with a largely cloud dominated radiative climate. Here, we explicitly address the relationship between the large scale circulation over Europe and local conditions in Bergen, identifying specific circulation shifts that have contributed to the observed cloud and solar variations. As a measure of synoptic weather patterns, we use the Grosswetterlagen (GWL), a daily classification of European weather for 1881-2013. Empirical models of cloud cover, cloud base, relative sunshine duration, and normalised global irradiance are constructed based on the GWL frequencies, extending the observational time series by more than 70 years. The GWL models successfully reproduce the observed increase in cloud cover and decrease in solar irradiance during the 1970s and 1980s. This cloud-induced dimming is traced to an increasing frequency of cyclonic and decreasing frequency of anticyclonic weather patterns over northern Europe. The changing circulation patterns in winter can be understood as a shift from the negative to the positive phase of the North Atlantic and Arctic Oscillation. A recent period of increasing solar irradiance is observed but not reproduce by the GWL models, suggesting this brightening is associated with factors other than large scale atmospheric circulation, possibly decreasing aerosol loads and local cloud shifts.

  12. Toward advanced daily cloud-free snow cover and snow water equivalent products from Terra-Aqua MODIS and Aqua AMSR-E measurements

    Science.gov (United States)

    Gao, Yang; Xie, Hongjie; Lu, Ning; Yao, Tandong; Liang, Tiangang

    2010-05-01

    SummaryBy taking advantage of the high spatial resolution of optical sensors and cloud penetration of a passive microwave sensor, a method is developed to generate new daily cloud-free snow cover (SC) and snow water equivalent (SWE) products, both in 500 m spatial resolution, utilizing daily Terra-Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and Aqua Advanced Microwave Scanning Radiometer for NASA's Earth Observing System (AMSR-E) snow products. This method was tested in Fairbanks and Upper Susitna Valley, Alaska area for one hydrological year (October 2006-September 2007). The results confirm that daily MODIS products and Terra-Aqua MODIS combined products have similar and high classification accuracy (91-94%) in cloud-free conditions and that the daily combination can reduce cloud cover ˜10%. The results also show the snow accuracy of the new SC products is 86%, which is much higher than the 31%, 45%, and 49% of the Terra, Aqua, and Terra/Aqua combined snow cover products (in all weather conditions), respectively. The validation demonstrates that the accuracy of AMSR-E SWE products is 68.5% and they tend to overestimate SWE. Redistribution of SWE, based on sub-pixel analysis of AMSR-E pixels, not only generates the new product at higher spatial resolution, now more suitable for basin and regional monitoring and modeling, but also slightly increases the accuracy of the SWE estimations. This method can also be used in merging other optical data such as AVHRR, Landsat with passive microwave data such as SSMR, SSM/I, and for future NPP and NPOESS missions.

  13. Reliable Averages and Risky Extremes - Analysis of spatio-temporal variability in solar irradiance and persistent cloud cover patterns over Switzerland

    Science.gov (United States)

    Kahl, Annelen; Nguyen, Viet-Anh; Sarrasin, Karine; Lehning, Michael

    2016-04-01

    With the perspective of Switzerland's phase-out from nuclear energy, solar energy potential may take a leading role for the country's future in renewable energy. Unlike nuclear power stations, photovoltaic (PV) production is prone to intermittency as it depends on the immediate solar irradiance, which fluctuates in space and time. If a large percentage of Switzerland's electricity was to be derived from solar radiation, stochastic fluctuations pose a risk to the robust supply and healthy function of the electricity network. For most efficient PV planning and siting, it is hence imperative to understand and quantify this variability in solar radiation, in order to anticipate average production as well as worst-case scenarios. Based on 12 years of satellite derived, spatially distributed data of daily average surface incoming shortwave radiation (SIS) this work analyses standard statistics, spatial correlation patterns and extreme conditions of cloud cover over Switzerland. Having compared different irradiance products, we decided to use the SIS product captured on the Meteosat Second Generation satellites, because it provides the most reliable snow/cloud discrimination, which is essential for spatial analysis over alpine terrain. Particularly in regions with high elevation differences, correlation between cloud cover and elevation undergo an annual cycle. In winter more clouds are found in the valleys, while in summer convective clouds dominate at higher elevations. The highest average irradiance values occur in the southern parts of the country, and make the cantons of Vallais, Tessin and Grison ideal candidate locations for PV installations. Simultaneously the Tessin shows a higher risk of periods with long lasting cloud cover, which would discourage from relying too much on solar power in that area. However looking at the question of suitability by studying spatial and temporal correlations of extremes, we see that the Tessin appears to be comparably decoupled

  14. Tracking Land Use/Land Cover Dynamics in Cloud Prone Areas Using Moderate Resolution Satellite Data: A Case Study in Central Africa

    Directory of Open Access Journals (Sweden)

    Bikash Basnet

    2015-05-01

    Full Text Available Tracking land surface dynamics over cloud prone areas with complex mountainous terrain is an important challenge facing the Earth Science community. One such region is the Lake Kivu region in Central Africa. We developed a processing chain to systematically monitor the spatio-temporal land use/land cover dynamics of this region over the years 1988, 2001, and 2011 using Landsat data, complemented by ancillary data. Topographic compensation was performed on Landsat reflectances to avoid the strong illumination angle impacts and image compositing was used to compensate for frequent cloud cover and thus incomplete annual data availability in the archive. A systematic supervised classification was applied to the composite Landsat imagery to obtain land cover thematic maps with overall accuracies of 90% and higher. Subsequent change analysis between these years found extensive conversions of the natural environment as a result of human related activities. The gross forest cover loss for 1988–2001 and 2001–2011 period was 216.4 and 130.5 thousand hectares, respectively, signifying significant deforestation in the period of civil war and a relatively stable and lower deforestation rate later, possibly due to conservation and reforestation efforts in the region. The other dominant land cover changes in the region were aggressive subsistence farming and urban expansion displacing natural vegetation and arable lands. Despite limited data availability, this study fills the gap of much needed detailed and updated land cover change information for this biologically important region of Central Africa. These multi-temporal datasets will be a valuable baseline for land use managers in the region interested in developing ecologically sustainable land management strategies and measuring the impacts of biodiversity conservation efforts.

  15. 1961-2010年河北省日照变化分析%Analysis on Change of Sunshine Duration in Hebei Province during the Period from 1961 to 2010

    Institute of Scientific and Technical Information of China (English)

    向亮; 胡波; 谷永利

    2012-01-01

    In this paper, the change of annual sunshine duration in Hebei Provinc during the period of 1961 - 2010 was analyzed using EOF, maximum entropy spectrum and Lepage test. The results showed that the difference of spatial distribution of annual sunshine duration was significant in the province. Holistically, annual sunshine duration was decreased from the north to the south of the province, it was in a downtrend in most areas of the province, the downtrend was more obvious in most parts of the central-southern area than that in most parts of the northern area, and the downtrend of annual sunshine duration was extremely significant. The spatial distribution of annual sunshine duration was not only similar, but also varied from the south to the north. Temporally, the decrease of annual, seasonal and monthly sunshine duration was extremely significant except that in few months. Lepage test revealed that there was a sharp change of annual sunshine duration in 1972 and 2001. The analyzed results also showed that the there was a significant change and 4.2-year periodicity of annual sunshine duration in the province. The further analyzed results revealed that the main factors resulting in the reduction of annual sunshine duration was cloud cover and fog, and floating dust was not the main reason causing the reduction of annual sunshine duration.%利用EOF、最大熵谱分析、Lepage突变性检验等方法,分析河北省1961-2010年日照时数的变化情况。结果表明:河北省日照时数空间分布差异较大,整体上表现为由北向南呈递减趋势,各区日照时数普遍呈下降趋势,其中中南大部地区下降趋势较为明显,而北部地区日照时数下降趋势相对较小,年13照时数下降趋势异常显著;空间分布上既有“一致型”,也存在“南中北型”;从时间变化上看,除个别月份外,其他年、季、月日照时数下降趋势均异常显著;Lepage突

  16. A Simple Solar, Spectral Model for Studying the Effects of Cloud Cover and Surface Albedo on the Incoming Solar Radiation.

    Science.gov (United States)

    1986-01-01

    designed for particular locations ( Barbaro , 1979), clear sky cases only (Bird, 1984), for slopes of different orientation (Temps and Coulson, 1977...not desirable. In late 1982, a volcano (El Chichon) erupted in Mexico and spewed ash and other constituents into the atmosphere. The volcanic cloud...April 1981, pp. 889-894. Barbaro , S.; Coppolino, S.; Leone, C.; and Sinagra, E. "An Atmospheric Model For computing Direct and Diffuse Solar Radiation

  17. Japan's Sunshine Project

    Science.gov (United States)

    1992-07-01

    A report summary of the results obtained on geothermal energies in the Sunshine Project during the fiscal year 1991 are presented. The report items include the following: studies on technologies to explore great-depth geothermal energy resources and technologies to evaluate nationwide geothermal energy resources; studies on geothermal well drilling technologies; studies on developing geothermally usable materials; studies on technologies to extract fracture heat from high-temperature rocks; studies on technologies to utilize completely geothermally hot water; comprehensive surveys on nationwide geothermal energy resources; analyses and evaluations on methods to explore fracture type reservoir beds; development of binary cycle power generation plants (developments of 10-MW class plants); down hole pumps; technologies to increase minable resources; technologies to prevent water leakage from geothermal wells; and systems to detect shaft-bottom information during geothermal well drilling); development of elementary technologies for hot rock power generation; analyses and evaluations on systems to extract heat from hot rocks; and analyses and evaluations on data associated with developing technologies to increase minable resources.

  18. The Covering Test of Embedded Software Based on Cloud Platform%嵌入式软件的云平台覆盖测试

    Institute of Scientific and Technical Information of China (English)

    朴希望

    2016-01-01

    本文介绍的是一种针对嵌入式软件的基于云平台的覆盖率测试方法,以及相关工具的应用。通过工具将插桩编译后的软件装载到目标机上运行,黑盒手工执行测试,白盒显示函数调用图和控制流程图,同时将执行和未执行代码分颜色显示,对未执行的代码进行人工分析,可以通过增加测试用例来提高覆盖率。%This paper discusses the covering testing tool based on cloud platform for embedded software. The principle and covering type of this tool and how to use the tool in practice are described in this paper. Instrumented and compiled program is operated on the target machine with the tool, and manual black box test and white box test are executed to make clear function call and control process. Codes tested and not been tested are labeled by different colors. Codes not been tested are analyzed by hand to improve covering rate by increasing test use cases.

  19. 基于GeoSOT网格的遥感影像云量信息精细描述模型%A Model of Remote Sensing Image Cloud-Cover Fine Description Based on GeoSOT Global Subdivsion Grid

    Institute of Scientific and Technical Information of China (English)

    席福彪; 程承旗; 冯洋

    2014-01-01

    针对现有遥感影像缺乏精细化云量描述手段的问题,提出了一种基于GeoSOT网格的遥感影像云量信息精细描述模型。模型建立了遥感影像与GeoSOT网格空间上的映射关系,通过记录每个网格内的影像是否含云,在一定精度上描述云在空间上的分布情况和云量的大小。试验结果表明:该模型能够精细地描述遥感影像云量信息,可实现对影像区域的云量高效检索,提高有云影像使用的效率和影像的可用性。%A model of remote sensing image cloud-cover fine description based on global subdivsion grid was proposed, which is able to cope with the problem of lacking fine description of remote sensing image cloud-cover. This model established a geospatial mapping between remote sensing image and GeoSOT grid. By recording each grid whether or not containing clouds, to describe the cloud-cover on the geospatial distribution. Experimental results show that this model can finely describe cloud-cover on the remote sensing image, achieve efficient retrieval of cloud-cover information, and improved efficiency and availability of cloud images usage.

  20. 78 FR 67144 - Sunshine Act Notice

    Science.gov (United States)

    2013-11-08

    ... 2. National Origin Discrimination in Today's Workplace. Note: In accordance with the Sunshine Act... information on these meetings. The EEOC provides sign language interpretation and Communication...

  1. 近46年西南地区云量的时空变化特征%Temporal and Spatial Distributions of Cloud Cover over Southwest China in Recent 46 Years

    Institute of Scientific and Technical Information of China (English)

    张琪; 李跃清; 陈权亮; 任景轩

    2011-01-01

    Through the wavelet analysis, linear trend analysis and SVD trend analysis methods and so on, the characteristics such as temporal and spatial distributions, variation tendency of cloud cover are analyzed, using the monthly mean cloud data at 85 observation stations in the Southwest China during the period from 1960 to 2005. The results show that the total cloud cover and the low cloud cover have obvious seasonal variations in southwest China. And in spring, autumn and winter, they are excessive in east and few in west. But the opposite is existent in summer. It can be also found that the total cloud cover and low cloud cover decrease in the past 46 years. And they have a quasi-eight-year changes in cycle. Additional,the annual mean total cloud cover and summer total cloud cover are yearly to decrease over the most of regions. The total cloud cover decrease in northwest of the West Sichuan Plateau, the south and east of Yunnan Province. At the same time, the low cloud cover decrease in Sichuan basin. The SVD analysis between temperature and total cloud cover shows that there is obvious negative correlation between temperature and total cloud in Southwest China, but the correlation between temperature and low cloud is not significant.%利用中国西南地区85个测站1960-2005年的月半均云量资料,采用小波分析、线性趋势分析和SVD分析等方法,分析了我国西南地区云量的时空分布和变化趋势等特征.结果表明,西南地区云量变化具有明显的季节特征,冬、春和秋季总云量和低云量分布均呈"东多西少"型,夏季相反,呈"东少西多"型;总云量和低云量均呈减少趋势,并存在较明显的准8年周期变化.年平均总云量及夏季总云量在西南大部分地区呈逐年递减趋势,冬季总云量在川西高原西北部和云南南部、东部呈减少趋势.而低云量的变化趋势比较一致,主要在四川盆地呈减少趋势;西南地区的温度场与总

  2. Advanced Understanding of Convection Initiation and Optimizing Cloud Seeding by Advanced Remote Sensing and Land Cover Modification over the United Arab Emirates

    Science.gov (United States)

    Wulfmeyer, V.; Behrendt, A.; Branch, O.; Schwitalla, T.

    2016-12-01

    A prerequisite for significant precipitation amounts is the presence of convergence zones. These are due to land surface heterogeneity, orography as well as mesoscale and synoptic scale circulations. Only, if these convergence zones are strong enough and interact with an upper level instability, deep convection can be initiated. For the understanding of convection initiation (CI) and optimal cloud seeding deployment, it is essential that these convergence zones are detected before clouds are developing in order to preempt the decisive microphysical processes for liquid water and ice formation. In this presentation, a new project on Optimizing Cloud Seeding by Advanced Remote Sensing and Land Cover Modification (OCAL) is introduced, which is funded by the United Arab Emirates Rain Enhancement Program (UAEREP). This project has two research components. The first component focuses on an improved detection and forecasting of convergence zones and CI by a) operation of scanning Doppler lidar and cloud radar systems during two seasonal field campaigns in orographic terrain and over the desert in the UAE, and b) advanced forecasting of convergence zones and CI with the WRF-NOAHMP model system. Nowcasting to short-range forecasting of convection will be improved by the assimilation of Doppler lidar and the UAE radar network data. For the latter, we will apply a new model forward operator developed at our institute. Forecast uncertainties will be assessed by ensemble simulations driven by ECMWF boundaries. The second research component of OCAL will study whether artificial modifications of land surface heterogeneity are possible through plantations or changes of terrain, leading to an amplification of convergence zones. This is based on our pioneering work on high-resolution modeling of the impact of plantations on weather and climate in arid regions. A specific design of the shape and location of plantations can lead to the formation of convergence zones, which can

  3. Creation and conservation of energy in Japan. [Sunshine and Moonlight Projects

    Energy Technology Data Exchange (ETDEWEB)

    Hoashi, K.

    1980-03-15

    Japan needs to increase alternatve energy supply by the year 2000. For the development of new energy sources, the Sunshine Project was initiated; it covers solar, geothermal, and coal liquefaction. For conservation of energy, the Moonlight Project was also begun. Some data on the schedules and budgets are given. 4 tables. (DLC)

  4. Current status and future tasks of the Sunshine Project. (Development of new energy technology)

    Energy Technology Data Exchange (ETDEWEB)

    Takada, T.

    1983-01-01

    Since its inception in 1974, the Sunshine Project has involved advances in new energy technology in many areas. The present report covers the principal areas of activity in 1980, examining the development status of solar energy, goethermal energy, coal liquefaction and gasification, hydrogen energy, wind power, ocean thermal energy conversion, etc. Future trends and tasks of new energy technology development are discussed. (In Japanese)

  5. 75 FR 44852 - Community Reinvestment Act Sunshine

    Science.gov (United States)

    2010-07-29

    ... Office of Thrift Supervision Community Reinvestment Act Sunshine AGENCY: Office of Thrift Supervision... collection. Title of Proposal: Community Reinvestment Act Sunshine. OMB Number: 1550-0105. Form Number: N/A... agreements that are in fulfillment of the Community Reinvestment Act of 1977 to be disclosed to the...

  6. 78 FR 64556 - Sunshine Act Meeting

    Science.gov (United States)

    2013-10-29

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Sunshine Act Meeting Notice is hereby given, pursuant to the provisions of the Government in the Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold a Closed Meeting...

  7. 78 FR 74196 - Sunshine Act Meeting

    Science.gov (United States)

    2013-12-10

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Sunshine Act Meeting Notice is hereby given, pursuant to the provisions of the Government in the Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold a Closed Meeting...

  8. 78 FR 72133 - Sunshine Act Meeting.

    Science.gov (United States)

    2013-12-02

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Sunshine Act Meeting. Notice is hereby given, pursuant to the provisions of the Government in the Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold a Closed Meeting...

  9. 78 FR 63528 - Sunshine Act Meeting

    Science.gov (United States)

    2013-10-24

    ... COMMISSION Sunshine Act Meeting Notice is hereby given, pursuant to the provisions of the Government in the Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold an Open Meeting on... sale of securities through crowdfunding pursuant to Section 4(a)(6) of the Securities Act of 1933,...

  10. Climatic sensitivity of the cloud cover and radiation balances over the North Slope of Alaska due to declining sea ice coverage

    Science.gov (United States)

    Cai, L.; Alexeev, V. A.; Arp, C. D.; Jones, B. M.

    2016-12-01

    In order to study the climatic impacts due to declining arctic sea ice in the Beaufort Sea and Chukchi Sea on the North Slope of Alaska in a decadal time scale, and to build a basis for further studying the climatic impacts by the potential lake ice melt in 21st century, a sensitivity experiment is designed originated from the dynamical downscaling of the Community Earth System Model (CESM1) by Weather Research & Forecast model with polar optimization (Polar WRF). The modeling domain has 119×99 grid points, with a 20 km grid spacing and the center latitude and longitude of 72°N and 155°W. Two decades respectively from the historical simulation and the RCP4.5 projection are chosen, which are the 1970's and the 2040's. Within the study area, the 2040's case produced up to 70% less sea ice extent compared with that in the 1970's case. Two sensitivity cases are also designed by switching the sea ice coverage between the historical and projected cases. The sea surface temperature (SST) is also revised to prevent unreasonable physics. This experiment results in the North Slope of Alaska being impacted by more precipitation, higher temperature, and more humid land surface in low sea ice coverage cases compared with the corresponding high sea ice coverage cases, and these differences reach their maximums in early winter. More in depth analysis on radiation balance found an abruptly increasing difference of the monthly mean downward longwave radiation flux (2 W/m2 vs. 13 W/m2) in early winter. The downward shortwave radiation flux, however, are less apparent during the summer months, with much smaller magnitude than longwave radiation flux. More variables like cloud fraction, as well as the cloud water and ice mix ratios on pressure levels are therefore involved to help portray the climatology of cloud cover and the impact to radiation balance over the North Slope of Alaska as the sea ice declining.

  11. Considerations for Cloud Security Operations

    OpenAIRE

    Cusick, James

    2016-01-01

    Information Security in Cloud Computing environments is explored. Cloud Computing is presented, security needs are discussed, and mitigation approaches are listed. Topics covered include Information Security, Cloud Computing, Private Cloud, Public Cloud, SaaS, PaaS, IaaS, ISO 27001, OWASP, Secure SDLC.

  12. The CLOUD experiment

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The Cosmics Leaving Outdoor Droplets (CLOUD) experiment as shown by Jasper Kirkby (spokesperson). Kirkby shows a sketch to illustrate the possible link between galactic cosmic rays and cloud formations. The CLOUD experiment uses beams from the PS accelerator at CERN to simulate the effect of cosmic rays on cloud formations in the Earth's atmosphere. It is thought that cosmic ray intensity is linked to the amount of low cloud cover due to the formation of aerosols, which induce condensation.

  13. Sr/Ca and stable isotopes in a coral from the Venezuelan coast: A record of 20th-century changes in SST, SSS and cloud cover?

    Science.gov (United States)

    Hetzinger, S.; Pfeiffer, M.; Dullo, W.; Zinke, J.; Garbe-Schoenberg, C.

    2011-12-01

    We present a record of monthly δ18O and Sr/Ca variations in coral aragonite from a massive Diploria strigosa colony retrieved from a coastal NW-Venezuelan reef site (10.55°N, 67.24°W; 1940-2004). Linear regression of coral proxies to high resolution satellite sea surface temperature (SST) data (NASA OBPG MODIS-Aqua, 9-km resolution) demonstrates that both geochemical proxies record seasonal temperature variability in ambient seawater (Sr/Ca: r=-0.68 monthly, r=-0.60 annual; δ18O: r=-0.57 monthly, r=-0.46 annual; 1985-2004). On longer time scales both proxies record local as well as regional SST dynamics in the southeastern Caribbean and northern North Tropical Atlantic. A statistically significant relationship is observed between coral δ18O and local air temperature (r=-0.56; 1951-2002), while correspondence of δ18O to SST products (e.g. ERSST, SODA reanalysis) is lower than for Sr/Ca ratios. However, coral δ18O is a function of both temperature and δ18Oseawater and δ18Oseawater in turn is dependent on salinity. A comparison of δ18O to sea surface salinity (SSS) data confirms the existence of a strong salinity component in coral δ18O on annual and longer time scales (SODA reanalysis, r=0.65 for annual means, r=0.84 for 3-year average; 1958-2001). A decreasing trend from the mid-1980s onwards is evident in both SSS and coral δ18O, corresponding to trends seen in other Caribbean studies. Further, both geochemical proxies show a significant negative correlation to cloud cover averaged over a regional box (r=-0.66 for Sr/Ca; r=-0.48 for δ18O; 1941-2003). A significant drop in cloud cover is seen around the year 1947, which is displayed in both proxies as a distinct positive peak and coincides with a drop in instrumental SST. Interestingly, a marked decrease in annual coral growth rate is observed in the uppermost years of the core (1999 to 2004), as well as a reduced seasonal amplitude in δ18O variability and a trend to more negative δ18O-values at the

  14. 76 FR 16016 - Sunshine Federal Register Notice

    Science.gov (United States)

    2011-03-22

    .... ] Briefing on Small Modular Reactors (Public Meeting) (Contact: Stephanie Coffin, 301-415-6877) This meeting... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Federal Register Notice AGENCY HOLDING THE MEETINGS: Nuclear Regulatory Commission,...

  15. 76 FR 14107 - Sunshine Federal Register Notice

    Science.gov (United States)

    2011-03-15

    .... Briefing on Small Modular Reactors (Public Meeting). (Contact: Stephanie Coffin, 301-415-6877). This... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Federal Register Notice AGENCY HOLDING THE MEETINGS: Nuclear Regulatory Commission....

  16. 76 FR 61346 - Sunshine Act Notice

    Science.gov (United States)

    2011-10-04

    ... Administration (NNSA) actions to address Plutonium Facility seismic vulnerabilities that lead to severe... From the Federal Register Online via the Government Publishing Office DEFENSE NUCLEAR FACILITIES SAFETY BOARD Sunshine Act Notice AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Notice of...

  17. Adaptively Spatio-temporal Weighted Method for Removing Cloud Obscuration from MODIS Daily Snow Cover Products%时空自适应加权的MODIS积雪产品去云方法

    Institute of Scientific and Technical Information of China (English)

    付文轩; 沈焕锋; 李星华; 黄春林; 侯金亮

    2016-01-01

    Due to the cloud obscuration,MODIS snow cover products are subjected to spatially discontinuous issues,which decrease the application potential.Therefore,this work proposed an adaptively spatio-temporal weighted method for alleviating the trouble.This method simultaneously took the spatial and temporal correlations of snow cover into consideration,and weighted their contributions to snow distribution automatically.Based on simulated experiments and daily snow depth data at climate stations,we evaluated its accuracy in Ili river basin of Xinjiang.The results indicated that our proposed method can remove cloud obscuration completely,with overall accuracy above 90% under different cloud coverages.Since the cloud-free snow cover maps reflect the real distribution of snow cover,they can be widely used for monitoring snow.%鉴于MODIS积雪产品存在的空间不连续降低了数据的应用潜力,该文提出一种时空自适应加权的去云方法,同时顾及积雪在空间和时间上的相关性,自适应地衡量两者对积雪分布的影响.以新疆伊犁河流域为实验区,进行了模拟验证和基于气象台站数据的真实验证.结果表明:该方法能完全去除云覆盖,去云精度可达到90%以上,且对不同云量的修复都有较好的鲁棒性,能真实地反映地面积雪覆盖情况,可为积雪监测研究提供数据保障.

  18. Geometric characteristics of clouds from ceilometer measurements and radiosounding methods

    OpenAIRE

    Costa Surós, Montse

    2014-01-01

    Improving methods for automatic and continuous description of cloud has a huge importance in order to determine the role of clouds in climate and their contribution to climate change. The geometric characteristics of clouds, such as the cloud cover and the cloud vertical structure (CVS), including the cloud base height (CBH) which is linked to cloud type, are very important for describing the impact clouds have on the atmosphere. It is presented a complete study of the cloud cover and the...

  19. Hybrid cloud for dummies

    CERN Document Server

    Hurwitz, Judith; Halper, Fern; Kirsch, Dan

    2012-01-01

    Understand the cloud and implement a cloud strategy for your business Cloud computing enables companies to save money by leasing storage space and accessing technology services through the Internet instead of buying and maintaining equipment and support services. Because it has its own unique set of challenges, cloud computing requires careful explanation. This easy-to-follow guide shows IT managers and support staff just what cloud computing is, how to deliver and manage cloud computing services, how to choose a service provider, and how to go about implementation. It also covers security and

  20. Cloud Detection with MATLAB

    OpenAIRE

    P. Shrivastava

    2013-01-01

    The accurate detection of clouds in satellite imagery is important in research and operational applications. Cloud cover influences the distribution of solar radiation reaching the ground where it is absorbed. Resulting fluxes of sensible and latent heat are critical to the accurate characterization of boundary layer behavior and mesoscale circulations that often lead to convective development. Therefore the spatial and temporal variation in cloud cover can greatly affect regional an...

  1. sunshine

    African Journals Online (AJOL)

    determine which of the Triandis variables (perceived consequences, affect, social factors) are associated with this ... studies on rickets in Ethiopia (2-5) showed that ... sun', and 'skin getting darker'. ... indicated that fear of the 'evil eye' or a 'bad.

  2. Cloud Formation

    Science.gov (United States)

    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.

  3. The Research of Removing the Affect of Clouds Cover by Combining the Mulit-Sensor lmages%联合应用多传感器影象消除云层遮挡影响的研究

    Institute of Scientific and Technical Information of China (English)

    方勇; 常本义

    2001-01-01

    In the process of mapping using optical remote sensing images, due to the limit of the conditions obtaining the remote sensing data and the affect of weather, the obtained images often are covered by clouds, which causes the losing of the information in local area and affects the quality of image map in some degree. In this paper, a method is proposed by fusion of multi-sensor images collected at different date to remove the affect due to cloud cover. It consists in two steps: firstly the auto registration is done around the region with clouds. In this step area-based grey match is used to get tie point, and statistical relational matching is done iterative to adjust the initial match result more reliable. So the two image can be registrated local area with high accuracy according to the final matching points. Secondly the image with cloud is replaced automatically by the other sensor image which has been radiation corrected through histogram matching so as to prevent the false edge from emerging during image mosaicing. At last, the test that SPOT image with clouds is replaced by TM image is done. The result demonstrates that the proposed method is possible and valuable, and the information in cloud area is recovered properly.%在利用光学遥感影象进行制图的过程中,由于受到获取遥感资料技术条件的限制,所获取的影象常常受到云层遮挡的影响,而造成局部地区信息丢失,针对此问题,提出了一种联合使用多传感器在不同时间段接收的影象,以消除云层遮挡影响的方法.该方法主要分为两个步骤,即首先是对云层覆盖地区不同时间的影象进行自动配准;然后对用来替换云层覆盖地区的影象进行辐射改正,以消除替换过程中出现的接缝.同时利用SPOT和TM影象进行了实验,实验结果表明该方法是有效的、可行的,能够较好地恢复云层遮挡地区的信息.

  4. 75 FR 13296 - Sunshine Act Meetings

    Science.gov (United States)

    2010-03-19

    ... BOARD MEETING Sunshine Act Meetings TIME AND DATE: March 29, 2010; 9:00 a.m.-1 :30 p.m. PLACE: 901 N... Minutes of the December 14, 2009, Meeting of the Board of Directors Resolution Honoring Gary Bryner... Advisory Council Membership and Attendance at Meetings Status of Upcoming Meetings Status of...

  5. 78 FR 70598 - Sunshine Act Meetings Notice

    Science.gov (United States)

    2013-11-26

    ... COMMISSION Sunshine Act Meetings Notice DATES: Weeks of November 25, December 2, 9, 16, 23, 30, 2013. PLACE... November 25, 2013 There are no meetings scheduled for the week of November 25, 2013. Week of December 2, 2013--Tentative There are no meetings scheduled for the week of December 2, 2013. Week of December...

  6. 76 FR 15991 - Sunshine Act Meetings

    Science.gov (United States)

    2011-03-22

    ... BOARD MEETING Sunshine Act Meetings TIME AND DATE: March 28, 2011, 9 a.m.-1:30 p.m. PLACE: 901 N. Stuart... of the Minutes of the December 13, 2010, Meeting of the Board of Directors President's Report...EAm rica Website Demonstration Next Meetings PORTIONS TO BE OPEN TO THE PUBLIC: Approval of...

  7. 75 FR 74071 - Sunshine Act Meetings

    Science.gov (United States)

    2010-11-30

    ... BOARD MEETING Sunshine Act Meetings TIME AND DATE: December 13, 2010, 9 a.m.-2 p.m. PLACE: 901 N. Stuart... March 29, 2010, Meeting of the Board of Directors. Advisory Council Report and Recommendations. Role of... Approval of the Minutes of the March 29, 2010, Meeting of the Board of Directors. Advisory Council...

  8. 78 FR 25309 - Sunshine Act Meeting

    Science.gov (United States)

    2013-04-30

    ... SAFETY BOARD Sunshine Act Meeting TIME AND DATE: 9:30 a.m., Tuesday, May 14, 2013. PLACE: NTSB Conference.... MATTERS TO BE CONSIDERED: 8482 Safety Report--Reaching Zero: Actions to Eliminate Alcohol- Impaired Driving 8417A Marine Accident Report--Allision of the Cargo Vessel M/V Delta Mariner with Eggner's Ferry...

  9. 78 FR 66893 - Sunshine Act Notice

    Science.gov (United States)

    2013-11-07

    ... Sunshine Act Notice AGENCY: United States Commission on Civil Rights. ACTION: Notice of Business Meeting..., Washington, DC 20425. Meeting Agenda I. Approval of Agenda II. Office of General Counsel Ethics Training: Expiration of Appointments and Applicable Ethics Rules III. Program Planning Review and Vote on the Proposed...

  10. 76 FR 10410 - Sunshine Federal Register Notice

    Science.gov (United States)

    2011-02-24

    ... March 28, 2011--Tentative Tuesday, March 29, 2011 9 a.m. Briefing on Small Modular Reactors (Public... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Federal Register Notice AGENCY: Nuclear Regulatory Commission. DATES: Weeks of...

  11. 76 FR 11290 - Sunshine Federal Register Notice

    Science.gov (United States)

    2011-03-01

    ... Tuesday, March 29, 2011 9 a.m. Briefing on Small Modular Reactors (Public Meeting) (Contact: Stephanie... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Federal Register Notice AGENCY HOLDING THE MEETINGS: Nuclear Regulatory Commission....

  12. 76 FR 12768 - Sunshine Act Notice

    Science.gov (United States)

    2011-03-08

    ... . Week of March 28, 2011--Tentative Tuesday, March 29, 2011 9 a.m. Briefing on Small Modular Reactors... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Act Notice AGENCY HOLDING THE MEETINGS: Nuclear Regulatory Commission. DATES: Weeks...

  13. 76 FR 17460 - SUNSHINE FEDERAL REGISTER NOTICE

    Science.gov (United States)

    2011-03-29

    ... Tuesday, March 29, 2011 9 a.m. Briefing on Small Modular Reactors (Public Meeting); (Contact: Stephanie... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION SUNSHINE FEDERAL REGISTER NOTICE AGENCY HOLDING THE MEETINGS: Nuclear Regulatory Commission...

  14. 75 FR 65674 - Sunshine Act Meetings

    Science.gov (United States)

    2010-10-26

    ... on international activities. 3. Review of active cases. 4. Report on recent activities of the Joint... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION Sunshine Act Meetings TIME AND DATE: Wednesday, November 3, 2010, at 11 a.m. PLACE: Commission hearing...

  15. 77 FR 32637 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2012-06-01

    ... capital requirements for savings and loan holding companies. 2. Final interagency rulemaking: Market risk... From the Federal Register Online via the Government Publishing Office FEDERAL RESERVE SYSTEM Sunshine Act Meeting Notice AGENCY: Board of Governors of the Federal Reserve System. Time and Date: 3:30 p...

  16. 77 FR 10529 - Sunshine Act Meeting

    Science.gov (United States)

    2012-02-22

    ... From the Federal Register Online via the Government Publishing Office FEDERAL RETIREMENT THRIFT INVESTMENT BOARD Sunshine Act Meeting TIME AND DATE: 9 a.m. (Eastern Time) February 27, 2012. PLACE: 2nd.... Legislative Report 3. Review of Audit Recommendations 4. Audit Reports 5. Department of Labor Audit...

  17. 78 FR 33134 - Sunshine Act Meetings

    Science.gov (United States)

    2013-06-03

    ... Investment Company Act that govern the operation of money market funds and related amendments to Form PF... Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold an Open Meeting on Wednesday, June 5, 2013 at 10:00 a.m., in the Auditorium, Room L-002. The subject matter of the Open...

  18. 76 FR 71968 - Sunshine Act Meeting

    Science.gov (United States)

    2011-11-21

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Sunshine Act Meeting AGENCY: Federal Election Commission. DATES: Date & Time: Wednesday, November 16, 2011... disclosure of which would be likely to have a considerable adverse effect on the implementation of a...

  19. 77 FR 8258 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2012-02-14

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Sunshine Act Meeting Notice AGENCY: Federal Election Commission. DATE AND TIME: Monday, February 13, 2012... likely to have a considerable adverse effect on the implementation of a proposed Commission...

  20. 75 FR 1608 - Sunshine Act Meetings

    Science.gov (United States)

    2010-01-12

    ... From the Federal Register Online via the Government Publishing Office COMMODITY FUTURES TRADING... the Government in the Sunshine Act, Public Law 94-409, 5 U.S.C. 552b. Agency Holding the Meeting... exchanges, derivatives transaction execution facilities and electronic trading facilities. Contact Person...

  1. 75 FR 38492 - Sunshine Act Meetings

    Science.gov (United States)

    2010-07-02

    ... COMMISSION Sunshine Act Meetings TIME AND DATE: Wednesday, June 30, 2010, 2 p.m.-3 p.m. PLACE: Hearing Room... the Public. ] MATTERS TO BE CONSIDERED: 1. Accreditation for Third Party Conformity Assessment Bodies for Testing for Children's Products: Carpets and Rugs. 2. Accreditation for Third Party...

  2. 78 FR 5212 - Sunshine Act Meetings

    Science.gov (United States)

    2013-01-24

    ... Udall Foundation audit; and (10) Possible action on the Organizational Development Consultants Report... Interior's Inspector General regarding the Udall Foundation audit. ] CONTACT PERSON FOR MORE INFORMATION... L. UDALL FOUNDATION Sunshine Act Meetings TIME AND DATE: 9:00 a.m. to 5:00 p.m., Thursday,...

  3. 78 FR 29697 - Sunshine Act Meetings

    Science.gov (United States)

    2013-05-21

    ... Interior's Inspector General regarding the Udall Foundation audit. PORTIONS OPEN TO THE PUBLIC: All agenda... Inspector General regarding the Udall Foundation audit. CONTACT PERSON FOR MORE INFORMATION: Philip J... K. UDALL AND STEWART L. UDALL FOUNDATION Sunshine Act Meetings TIME AND DATE: 12:00 p.m. to 5:00...

  4. 77 FR 54910 - Sunshine Act Meeting

    Science.gov (United States)

    2012-09-06

    ...) before or after the meeting. If any person wishes auxiliary aids (such as a sign language interpreter) or... UNITED STATES Sunshine Act Meeting ACTION: Notice of Open Special Meeting of the Sub-Saharan Africa... Room 326, 811 Vermont Avenue NW., Washington, DC 20571. SUMMARY: The Sub-Saharan Africa Advisory...

  5. 78 FR 62588 - Sunshine Act Meeting

    Science.gov (United States)

    2013-10-22

    ... From the Federal Register Online via the Government Publishing Office CONSUMER PRODUCT SAFETY COMMISSION Sunshine Act Meeting TIME AND DATE: Tuesday, October 22, 2013, 10 a.m.-12 p.m. PLACE: Hearing Room 420, Bethesda Towers, 4330 East-West Highway, Bethesda, Maryland. STATUS: Commission Meeting--Open...

  6. 78 FR 64555 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2013-10-29

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Act Meeting Notice DATES: Weeks of October 28, November 4, 11, 18, 25, December 2, 2013. PLACE: Commissioners' Conference Room, 11555 Rockville Pike, Rockville, Maryland. STATUS: Public...

  7. 78 FR 66768 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2013-11-06

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Sunshine Act Meeting Notice AGENCY HOLDING THE MEETING: United States International Trade Commission. TIME AND DATE: November 7, 2013 at 11:00 a.m. PLACE: Room 101, 500 E Street SW., Washington,...

  8. 78 FR 74129 - Sunshine Act Meeting

    Science.gov (United States)

    2013-12-10

    ... From the Federal Register Online via the Government Publishing Office FEDERAL MARITIME COMMISSION Sunshine Act Meeting AGENCY: Federal Maritime Commission. DATES: December 10, 2013. PLACE: 800 N. Capitol Street NW., First Floor Hearing Room, Washington, DC. STATUS: The meeting will be held in Closed...

  9. 78 FR 64498 - Sunshine Act Meeting

    Science.gov (United States)

    2013-10-29

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Sunshine Act Meeting AGENCY: Federal Election Commission. DATE AND TIME: Thursday, October 31, 2013 at 10:00 a.m. PLACE: 999 E Street NW., Washington, DC (Ninth Floor). STATUS: This meeting will be open...

  10. 78 FR 77736 - Sunshine Act Meetings

    Science.gov (United States)

    2013-12-24

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Act Meetings DATE: Weeks of December 23, 30, 2013, January 6, 13, 20, 27, 2014. PLACE: Commissioners' Conference Room, 11555 Rockville Pike, Rockville, Maryland. STATUS: Public and Closed. Week...

  11. 78 FR 77450 - Sunshine Act Meeting

    Science.gov (United States)

    2013-12-23

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Sunshine Act Meeting AGENCY: Federal Election Commission. FEDERAL REGISTER CITATION OF PREVIOUS ANNOUNCEMENT--78 FR 75568 (December 12, 2013). DATE AND TIME: Tuesday, December 17, 2013 at the conclusion...

  12. 78 FR 72096 - Sunshine Act Meetings

    Science.gov (United States)

    2013-12-02

    ... From the Federal Register Online via the Government Publishing Office INTER-AMERICAN FOUNDATION Sunshine Act Meetings TIME AND DATE: December 9, 2013, 9:00 a.m.-1:00 p.m. PLACE: Baker & McKenzie, 815 Connecticut Avenue NW., Washington, DC 20006. STATUS: Open session. MATTERS TO BE CONSIDERED: Approval of...

  13. 78 FR 74162 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2013-12-10

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Sunshine Act Meeting Notice AGENCY HOLDING THE MEETING: United States International Trade Commission TIME AND DATE: December 12, 2013 at 11:00 a.m. PLACE: Room 101, 500 E Street SW., Washington,...

  14. 78 FR 64535 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2013-10-29

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Sunshine Act Meeting Notice AGENCY HOLDING THE MEETING: United States International Trade Commission. TIME AND DATE: November 1, 2013 at 11:00 a.m. PLACE: Room 101, 500 E Street SW., Washington,...

  15. 78 FR 71611 - Sunshine Act Meeting

    Science.gov (United States)

    2013-11-29

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Sunshine Act Meeting AGENCY: Federal Election Commission. DATE & TIME: Tuesday, December 3, 2013 at 10:00 a.m. PLACE: 999 E Street NW., Washington, DC. STATUS: This meeting will be closed to the public....

  16. 78 FR 72086 - Sunshine Act Meetings

    Science.gov (United States)

    2013-12-02

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Sunshine Act Meetings AGENCY: Federal Election Commission. DATE & TIME: Thursday, December 5, 2013 at 10:00 a.m. PLACE: 999 E Street NW., Washington, DC (Ninth Floor). STATUS: This meeting will be open to...

  17. 78 FR 63493 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2013-10-24

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Sunshine Act Meeting Notice AGENCY HOLDING THE MEETING: United States International Trade Commission. TIME AND DATE: October 29, 2013 at 11:00 a.m. PLACE: Room 101, 500 E Street SW., Washington,...

  18. 78 FR 64541 - Sunshine Act Meeting

    Science.gov (United States)

    2013-10-29

    ... From the Federal Register Online via the Government Publishing Office ] NATIONAL TRANSPORTATION SAFETY BOARD Sunshine Act Meeting TIME AND DATE: 9:30 a.m., Tuesday, November 5, 2013 PLACE: NTSB Conference Center, 429 L'Enfant Plaza SW., Washington, DC 20594. STATUS: The one item is open to the...

  19. 78 FR 74188 - Sunshine Act Meetings Notice

    Science.gov (United States)

    2013-12-10

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Sunshine Act Meetings Notice DATE: Weeks of December 9, 16, 23, 30, 2013, January 6, 13, 2014. PLACE: Commissioners' Conference Room, 11555 Rockville Pike, Rockville, Maryland. STATUS: Public...

  20. 75 FR 39053 - Sunshine Act Meetings

    Science.gov (United States)

    2010-07-07

    ... initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings Time and Dates: All meetings are held at 2:30 p.m. Wednesday, July 7...

  1. 75 FR 75703 - Sunshine Act Meetings

    Science.gov (United States)

    2010-12-06

    ... arbitration, or the initiation, conduct, or disposition * * * of particular representation or unfair labor... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings Time and Dates All meetings are held at 2:30 p.m. Wednesday, December 1...

  2. 77 FR 60146 - Sunshine Act Meetings

    Science.gov (United States)

    2012-10-02

    ... initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings TIME AND DATES: All meetings are held at 2:30 p.m. Tuesday, October 2...

  3. 76 FR 75881 - Sunshine Act Meeting

    Science.gov (United States)

    2011-12-05

    ... Sunshine Act Meeting AGENCY HOLDING THE MEETING: Federal Maritime Commission. TIME AND DATE: December 8... Proposal of the Ministry of Transport of the People's Republic of China for Adjustment of the Amount for... the Liner Shipping Conference Exemption from Competition Laws-Discussion of Bureau of Trade...

  4. 75 FR 31760 - Sunshine Act Meeting

    Science.gov (United States)

    2010-06-04

    ... INVESTIGATION BOARD Sunshine Act Meeting In connection with its investigation into the natural gas explosion that occurred at the Kleen Energy power plant in Middletown, Connecticut, the United States Chemical... fueled power plant under construction in Middletown, Connecticut, experienced a catastrophic natural...

  5. 75 FR 39205 - Sunshine Act Notice

    Science.gov (United States)

    2010-07-08

    ... From the Federal Register Online via the Government Publishing Office COMMISSION ON CIVIL RIGHTS Sunshine Act Notice AGENCY: United States Commission on Civil Rights. ACTION: Notice of meeting. DATE AND.... Program Planning Approval of Recommendations for Briefing Report on Encouraging Minority Students...

  6. 77 FR 51073 - Sunshine Act Meeting

    Science.gov (United States)

    2012-08-23

    ... solicitation and general advertising in securities offerings conducted pursuant to Rule 506 of Regulation D... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE... Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold an Open Meeting...

  7. 78 FR 41132 - Sunshine Act Meeting

    Science.gov (United States)

    2013-07-09

    ... against general solicitation and general advertising in certain securities offerings conducted pursuant to... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE... Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold an Open Meeting...

  8. 76 FR 20050 - Sunshine Act Meetings

    Science.gov (United States)

    2011-04-11

    ... From the Federal Register Online via the Government Publishing Office LEGAL SERVICES CORPORATION Sunshine Act Meetings Notice DATE AND TIME: The Legal Services Corporation Board of Directors and its... Committee 5. Development Committee Saturday, April 16, 2011 1. Governance & Performance Review 9 a.m...

  9. 75 FR 50782 - Sunshine Act Meeting Notice

    Science.gov (United States)

    2010-08-17

    ... From the Federal Register Online via the Government Publishing Office LEGAL SERVICES CORPORATION Sunshine Act Meeting Notice Time and Date: The Legal Services Corporation Board of Directors' Governance... Services Corporation, 3333 K Street, NW., Washington, DC 20007. Status of Meeting: Open. Public Observation...

  10. 75 FR 48729 - Sunshine Act Meeting; Notice

    Science.gov (United States)

    2010-08-11

    ... From the Federal Register Online via the Government Publishing Office LEGAL SERVICES CORPORATION Sunshine Act Meeting; Notice TIME AND DATE: The Legal Services Corporation Board of Directors' Operations...: Legal Services Corporation, 3333 K Street, NW., Washington, DC 20007. STATUS OF MEETING: Open, except...

  11. 75 FR 78675 - Sunshine Act Notice

    Science.gov (United States)

    2010-12-16

    ... Sunshine Act Notice AGENCY: United States Commission on Civil Rights. ACTION: Notice of Meeting... Discrimination in Liberal Arts College Admissions. Eminent Domain Project. NBPP. V. State Advisory Committee Issues: Update on status of North Dakota, Illinois and Minnesota SACs. Update on Vermont SAC. VI...

  12. 77 FR 10784 - Sunshine Act Meeting

    Science.gov (United States)

    2012-02-23

    ... CORPORATION Finance, Budget & Program Committee of the Board of Directors; Sunshine Act Meeting DATES: Time..., Washington, DC 20005. Status: Open. CONTACT PERSON FOR MORE INFORMATION: Erica Hall, Assistant Corporate... Report IV. NFMC Interest Income Budget V. Lease Update VI. Corporate Scorecard & Dashboard VII. NFMC...

  13. 76 FR 72220 - Sunshine Act Meetings

    Science.gov (United States)

    2011-11-22

    ... Instructor, The Elizabeth M. Boggs Center on Developmental Disabilities, University of Medicine & Dentistry... DISABILITY Sunshine Act Meetings TIME AND DATES: The Members of the National Council on Disability (NCD) will... Supports (CLASS) Program; effective communication strategies for people with disabilities before,...

  14. 78 FR 26667 - Sunshine Act Meeting

    Science.gov (United States)

    2013-05-07

    ... encouraging unsolicited ratings of asset-backed securities. The third panel will focus on other potential... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE... Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold a credit ratings...

  15. 76 FR 44057 - Sunshine Act Meeting.

    Science.gov (United States)

    2011-07-22

    ...-propose rules related to shelf-eligibility for asset-backed securities and request additional comment on... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE... Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold an Open Meeting on...

  16. 76 FR 17174 - Sunshine Act Meeting

    Science.gov (United States)

    2011-03-28

    ... risk retention by securitizers of asset-backed securities. Item 2: The Commission will consider whether... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE... Sunshine Act, Public Law 94-409, that the Securities and Exchange Commission will hold an Open Meeting on...

  17. 75 FR 8416 - Sunshine Act Meeting

    Science.gov (United States)

    2010-02-24

    ... COMMISSION Sunshine Act Meeting Notice is hereby given, pursuant to the provisions of the Government in the... statement regarding its continued support for a single-set of high-quality globally accepted accounting standards and its ongoing consideration of incorporating International Financial Reporting Standards...

  18. 75 FR 39576 - Sunshine Act; Board Meeting

    Science.gov (United States)

    2010-07-09

    ... From the Federal Register Online via the Government Publishing Office INTER-AMERICAN FOUNDATION Sunshine Act; Board Meeting Time and Date: July 12, 2010; 2 p.m.-3:30 p.m. ] Place: 901 N. Stuart Street, Tenth Floor, Arlington, Virginia 22203. Status: Closed session as provided in 22 CFR 1004.4(f)....

  19. 77 FR 71611 - Sunshine Act; Board Meeting

    Science.gov (United States)

    2012-12-03

    ... Sunshine Act; Board Meeting TIME AND DATE: December 10, 2012. 9:00 a.m.-12:45 p.m. PLACE: Woodrow Wilson... September 24, 2012, Meeting of the Board of Directors Presentation of Resolution Honoring Service of Kay Arnold Carrying Out the IAF's Strategic Plan Management Report Setting Next Board Meetings PORTIONS TO...

  20. 基于EOF方法的华中五省近47年总云量变化分析%Analysis on Total Cloud Cover Change of Five Provinces in Central China Last 47 Years Based on EOF Method

    Institute of Scientific and Technical Information of China (English)

    徐琼芳; 高庆九; 石燕; 潘洪祥

    2011-01-01

    选用华中五省(河南、湖北、湖南、安徽、江西)20个全球交换站1959 - 2005年逐月云量观测资料,用EOF方法分析了近47a来华中五省总云量的年、季节变化规律及其地域分布特征,以期对气候模式开发和模拟研究提供参考,并为华中五省气候变化和农业生产区划提供数据支持.结果表明:近47a来,华中五省平均年、季总云量总体呈减少趋势.总云量变化地区差异较大,主要有2种典型时空分布.第一典型场中,年、季均为正值,且均由南向北呈现出低-高的差异,中心位于华中五省中偏北部地区.对应时间系数中,年、春、秋季1959 -2005年总体呈明显波动下降趋势,可得出年、春、秋季总云量近47a呈减少趋势,夏季无明显变化,冬季变化趋势也不明显.第二典型场中,年、四季均大体以长江为界呈反向变化,对应时间系数以年际变化为主.%Based on monthly cloud cover observation data from 20 global exchange stations of five provinces ( Henan, Hubei, Hunan, Anhui and Jiangxi province) in central China during 1959 -2005, the seasonal/annual variation and regional distribution of total cloud cover in last 47 years were analyzed. The results showed that both of average annual and seasonal total cloud cover in central China decreased in last 47 years. Variation of total cloud cover changed among different regions, and there were two kinds of typical space - time distribution. One was positive variation for both annual and seasonal, and increasing from south to north. Its center located in the northern-middle part of central China. The cloud cover of spring and autumn declined and there was no obvious change in summer and winter from 1959 to 2005. The other was reverse variation on the two sides of the Yangtze river, obvious in annual variation.

  1. Encyclopedia of cloud computing

    CERN Document Server

    Bojanova, Irena

    2016-01-01

    The Encyclopedia of Cloud Computing provides IT professionals, educators, researchers and students with a compendium of cloud computing knowledge. Authored by a spectrum of subject matter experts in industry and academia, this unique publication, in a single volume, covers a wide range of cloud computing topics, including technological trends and developments, research opportunities, best practices, standards, and cloud adoption. Providing multiple perspectives, it also addresses questions that stakeholders might have in the context of development, operation, management, and use of clouds. Furthermore, it examines cloud computing's impact now and in the future. The encyclopedia presents 56 chapters logically organized into 10 sections. Each chapter covers a major topic/area with cross-references to other chapters and contains tables, illustrations, side-bars as appropriate. Furthermore, each chapter presents its summary at the beginning and backend material, references and additional resources for further i...

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

    CERN Document Server

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

    2009-01-01

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

  3. 中国干旱区积雪面积产品去云处理方法验证与评估%Validation and Assessment of Cloud Obscuration Reduction of Snow Cover Products in Arid Areas in China

    Institute of Scientific and Technical Information of China (English)

    王增艳; 车涛

    2012-01-01

    Cloud coverage in daily snow cover products is a main obstacle in using Moderate Resolution Imaging Spectroradiometer(MODIS).In this study,the multi-temporal and multi-sensor combination approaches are applied to reduce cloud obscuration with Aqua Advanced Microwave Scanning Radiometer for NASA'S Earth Observing System(AMSR-E) snow depth products introduced as the auxiliary data to develop 6 new kinds of snow cover products.Different snow cover duration days(SCD) maps are developed from these combined products.The results are as follows:(1) MODIS and AMSR-E 4-day threshold-combined snow cover product performed well in algorithm efficiency,cloud-reducing effect and capability in maintaining relatively high spatiotemporal resolutions;(2) Under all weather conditions,the overall,snow and land accuracies of the resulted cloud-free products were 96%,80% and 99%,and they were significantly higher than 64%,32% and 70% of the original MODIS Terra and Aqua combination product,respectively;(3) The SCD map generated from this product could not only maintain a high spatial resolution of the original MODIS product,but also could precisely reflect the spatial distribution of the snow cover status in the study area.%针对MODIS每日积雪产品中云覆盖现象严重这一问题,以中国干旱区作为研究对象,结合AMSR-E被动微波雪深数据,采用多时相、多传感器数据融合的方法进行去云处理,获取MODIS每日,4 d,8 d和MODIS与AM-SR-E融合后的每日,4 d与8 d共6种新的积雪产品,并分别提取其积雪持续日数(SCD)。对比结果显示,MODIS与AMSR-E多传感器的阈值法4日融合产品在融合算法效率、云去除效果和融合后保持较高分类精度方面均有较好表现,其融合后的无云产品在全天气条件下具有96%的整体分类精度、80%的雪分类精度和99%的陆地分类精度,大大高于研究区原MODIS Terra-Aqua每日融合积雪产品全天候条件下64%,32%

  4. Variation of sunshine hours and related driving forces in southwestern China%中国西南地区日照时数变化及影响因素

    Institute of Scientific and Technical Information of China (English)

    杨小梅; 安文玲; 张薇; 常丽; 王亚敏

    2012-01-01

    With various methods, the temporal and spatial vaiation of sunshine hours over southwestern China during 1961—2009 were analyzed based on data collected from 110 standard meteorological stations. The results showed that annual mean sunshine hours was 1 894 h, and the higher values were distributed in the Tibetan plateau, Hengduan mountains and Yunnan plateau, whereas the lower values were located at Guizhou plateau and Sichuan basin. Annual and seasonal sunshine hours decreased before 1990 and increased after that. Spatially, statistically significant decreases of sunshine hours mainly occurred in lower altitude regions, especially in the Sichuan basin and Guizhou plateau, whiles there were increases or smaller decreases at higher altitudes regions. Wind speed was the main reason for the changed sunshine hours. It showed a closely temporal and spatial correlation between wind speed and sunshine hours in 1969—2009, and the decreasing magnitudes was larger in 1969—2000 than in 2001—2009 with the same spatial pattern, and a larger decreasing trend displayed a declining trend in non-windy days than in windy days with the exception of spring and autumn. The relative humidity was the secondary influencing factor for the changed sunshine hours, and this could be reflected by a significant negative correlation and a reverse trend between the two variables. In addition, the surface downward solar radiation flux, cloud cover, cloud water content and precipitation also made some contribution to a rise of sunshine hours during 1991—2009, which especially caused an obvious variation in the 1970s and 1990s.%运用多种方法,对中国西南地区110个气象站1961-2009年日照时数变化的研究发现,该区年均日照时数为1894 h,日照时数的较大值主要分布在海拔较高的西藏高原、横断山区和云南高原,而贵州高原和四川盆地日照时数相对较少.研究区年和季节日照时数在1990年之前降低,此后明显增

  5. Variability analysis of the reconstructed daily global solar radiation under all-sky and cloud-free conditions in Madrid during the period 1887-1950

    Science.gov (United States)

    Antón, M.; Román, R.; Sanchez-Lorenzo, A.; Calbó, J.; Vaquero, J. M.

    2017-07-01

    This study focuses on the analysis of the daily global solar radiation (GSR) reconstructed from sunshine duration measurements at Madrid (Spain) from 1887 to 1950. Additionally, cloud cover information recorded simultaneously by human observations for the study period was also analyzed and used to select cloud-free days. First, the day-to-day variability of reconstructed GSR data was evaluated, finding a strong relationship between GSR and cloudiness. The second step was to analyze the long-term evolution of the GSR data which exhibited two clear trends with opposite sign: a marked negative trend of - 36 kJ/m2 per year for 1887-1915 period and a moderate positive trend of + 13 kJ/m2 per year for 1916-1950 period, both statistically significant at the 95% confidence level. Therefore, there is evidence of ;early dimming; and ;early brightening; periods in the reconstructed GSR data for all-sky conditions in Madrid from the late 19th to the mid-20th centuries. Unlike the long-term evolution of GSR data, cloud cover showed non-statistically significant trends for the two analyzed sub-periods, 1887-1915 and 1916-1950. Finally, GSR trends were analyzed exclusively under cloud-free conditions in summer by means of the determination of the clearness index for those days with all cloud cover observations equal to zero oktas. The long-term evolution of the clearness index was in accordance with the ;early dimming; and ;early brightening; periods, showing smaller trends but still statistically significant. This result points out that aerosol load variability could have had a non-negligible influence on the long-term evolution of GSR even as far as from the late 19th century.

  6. Comparison of sunshine duration measurements from Campbell-Stokes sunshine recorder and CSD1 sensor

    Science.gov (United States)

    Urban, Grzegorz; Zając, Ireneusz

    2017-07-01

    Paper presents comparative analysis of sunshine duration measurement results obtained using Campbell-Stokes sunshine recorder (CS) and electronic sensor (CSD1). The comparison is based on data from 2009 to 2010 collected at seven weather stations (Leszno, Wrocław-Strachowice, Legnica, Opole, Zielona Góra, Jelenia Góra, Kłodzko) operated by the Institute of Meteorology and Water Management—National Research Institute (IMWM-NRI) in south-western Poland. Results obtained in Opole and Legnica stations are erroneous. In case of other stations, the relationship between daily total sunshine duration as measured by CS and CSD1 was strong. Coefficients of determination were 0.96-0.97. Mean differences in daily totals of sunshine duration were ±0.3 h. Differences of mean monthly and annual totals were both positive and negative with no pattern of occurrences. Implementation of permanent corrections is not possible. The highest consistency between both measurement devices was found during winter months.

  7. Comparison of sunshine duration measurements from Campbell-Stokes sunshine recorder and CSD1 sensor

    Science.gov (United States)

    Urban, Grzegorz; Zając, Ireneusz

    2016-03-01

    Paper presents comparative analysis of sunshine duration measurement results obtained using Campbell-Stokes sunshine recorder (CS) and electronic sensor (CSD1). The comparison is based on data from 2009 to 2010 collected at seven weather stations (Leszno, Wrocław-Strachowice, Legnica, Opole, Zielona Góra, Jelenia Góra, Kłodzko) operated by the Institute of Meteorology and Water Management—National Research Institute (IMWM-NRI) in south-western Poland. Results obtained in Opole and Legnica stations are erroneous. In case of other stations, the relationship between daily total sunshine duration as measured by CS and CSD1 was strong. Coefficients of determination were 0.96-0.97. Mean differences in daily totals of sunshine duration were ±0.3 h. Differences of mean monthly and annual totals were both positive and negative with no pattern of occurrences. Implementation of permanent corrections is not possible. The highest consistency between both measurement devices was found during winter months.

  8. Stochastic modeling of sunshine number data

    Energy Technology Data Exchange (ETDEWEB)

    Brabec, Marek, E-mail: mbrabec@cs.cas.cz [Department of Nonlinear Modeling, Institute of Computer Science, Academy of Sciences of the Czech Republic, Pod Vodarenskou vezi 2, 182 07 Prague 8 (Czech Republic); Paulescu, Marius [Physics Department, West University of Timisoara, V. Parvan 4, 300223 Timisoara (Romania); Badescu, Viorel [Candida Oancea Institute, Polytechnic University of Bucharest, Spl. Independentei 313, 060042 Bucharest (Romania)

    2013-11-13

    In this paper, we will present a unified statistical modeling framework for estimation and forecasting sunshine number (SSN) data. Sunshine number has been proposed earlier to describe sunshine time series in qualitative terms (Theor Appl Climatol 72 (2002) 127-136) and since then, it was shown to be useful not only for theoretical purposes but also for practical considerations, e.g. those related to the development of photovoltaic energy production. Statistical modeling and prediction of SSN as a binary time series has been challenging problem, however. Our statistical model for SSN time series is based on an underlying stochastic process formulation of Markov chain type. We will show how its transition probabilities can be efficiently estimated within logistic regression framework. In fact, our logistic Markovian model can be relatively easily fitted via maximum likelihood approach. This is optimal in many respects and it also enables us to use formalized statistical inference theory to obtain not only the point estimates of transition probabilities and their functions of interest, but also related uncertainties, as well as to test of various hypotheses of practical interest, etc. It is straightforward to deal with non-homogeneous transition probabilities in this framework. Very importantly from both physical and practical points of view, logistic Markov model class allows us to test hypotheses about how SSN dependents on various external covariates (e.g. elevation angle, solar time, etc.) and about details of the dynamic model (order and functional shape of the Markov kernel, etc.). Therefore, using generalized additive model approach (GAM), we can fit and compare models of various complexity which insist on keeping physical interpretation of the statistical model and its parts. After introducing the Markovian model and general approach for identification of its parameters, we will illustrate its use and performance on high resolution SSN data from the Solar

  9. Computing study on holistic aerodynamics of chaff cloud covering various flow regimes%箔条云跨流域整体气动特性计算研究

    Institute of Scientific and Technical Information of China (English)

    李志辉; 梁杰; 李四新; 王鹿受

    2011-01-01

    The statistical simulation technique in random sample for the numerous chaffs and chaff- cloud released by the aerocraft is founded on the theory of stochastic dynamics and statistical diffusive sampling. Based on the aerodynamic theory and computing technique established in the recent years, the evaluating algorithm for the aerodynamic characteristic of chaff bodies with the high long and slender ratio has been developed for various altitudes, flying angles and Mach numbers from rarefied free - molecular flow to continuum flow regimes. The numerical method of trajectory flying mechanics is studied and applied to calculate the space situation and velocity of the flying chaff groups at any time. The holistic performance of the chaff cloud is analyzed and studied in mathematical modeling and simulation by developing the weighted technique of stochastic dynamics and statistical distribution theory. As a result, the statistical simulating method on the holistic aerodynamics and covering range of chaff cloud from various flow regimes has been founded. The holistic flying characteristic of the numerous chaffs and chaff clouds released by aerocraft is computed and analyzed as the primary application of the present method. The present simulating results are tallied with the theoretical forecast and experiment testing, which displays the engineering practicality and reliability of the present method in simulating the flying contrail, overcast range and holistic aerodynamics of the chaff cloud including space position, number density, flying gesture and velocity across the atmosphere inside and outside.%研究随机动力学理论与统计散布取样技术,提出对飞行器抛撤"海量"箔条及形成箔条云有限分组随机统计模拟方法;采用所建立空气动力学理论与计算技术,提出可有效模拟稀薄流到连续流不同高度、马赫数、攻角与侧滑角及极高长细比箔条气动特性计算方法;研制飞行力学数值方法,计算确

  10. VMware private cloud computing with vCloud director

    CERN Document Server

    Gallagher, Simon

    2013-01-01

    It's All About Delivering Service with vCloud Director Empowered by virtualization, companies are not just moving into the cloud, they're moving into private clouds for greater security, flexibility, and cost savings. However, this move involves more than just infrastructure. It also represents a different business model and a new way to provide services. In this detailed book, VMware vExpert Simon Gallagher makes sense of private cloud computing for IT administrators. From basic cloud theory and strategies for adoption to practical implementation, he covers all the issues. You'll lea

  11. JINR cloud infrastructure evolution

    Science.gov (United States)

    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.

  12. Cover Story

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Monopoly Cause of Unsafe Mining Conditions;Disputes Cloud Public Servants Law;Four Tried in Wenzhou Corruption Probe;Chinese Banks Get Foreign Investment;Harbin Pharmaceutical Buyout to Help Nanfang Securities;

  13. Cloud database development and management

    CERN Document Server

    Chao, Lee

    2013-01-01

    Nowadays, cloud computing is almost everywhere. However, one can hardly find a textbook that utilizes cloud computing for teaching database and application development. This cloud-based database development book teaches both the theory and practice with step-by-step instructions and examples. This book helps readers to set up a cloud computing environment for teaching and learning database systems. The book will cover adequate conceptual content for students and IT professionals to gain necessary knowledge and hands-on skills to set up cloud based database systems.

  14. 部分云覆盖下红外辐射传输模型及对火山灰云的敏感性研究%Study of an Infrared Radiative Transfer Model under Partially Cloud-Covered and Its Sensitivity to Volcanic Ash Cloud

    Institute of Scientific and Technical Information of China (English)

    赵营营; 朱琳; 孙文彬; 李文杰

    2016-01-01

    针对我国新一代地球同步气象卫星FY-4的预期发射和数据应用,本文借助与FY-4卫星成像仪类似的Meteosat-8卫星的SEVIRI仪器数据资料开展先期研究,建立了一种部分云覆盖条件下红外辐射传输模型,模拟了不同大气条件、火山灰云高度、有效云量和观测天顶角情况下卫星观测的红外通道的亮度温度的变化.美国标准气候态大气廓线和火山灰区实时大气廓线两种模拟结果都表明,模型模拟的8.3~9.1μm,9.8~11.8μm,11~13μm,12.4~14.4μm的入瞳亮度温度对云高度、有效云量较为敏感,基本呈线性相关;卫星天顶角对模拟的辐射亮温的影响相对较小.通过不同大气廓线状态和火山灰云发射率情景下的测试结果表明,只有同时考虑大气条件和火山灰云通道发射率的差异后,模式才能够较好地模拟出火山爆发情景下火山灰云中酸性物质在11μm和12μm的反吸收特性.与大气条件相比,通道的发射率差异对火山灰云的遥感建模更为重要.因此,可在传统的分裂窗通道的基础上,通过热红外多通道亮温及亮温差异信息联合反演火山灰云高度和有效云量等因子,提高部分覆盖下火山灰云的微物理参数的反演精度.本研究为建立基于我国新一代静止气象卫星FY-4数据的火山灰云浓度定量反演模型提供了理论基础.%Based on instrument spectral response characteristics of Meteosat-8 SEVIRI which is adopted as a proxy of the FY-4 Imager which will be launched next year, an infrared radiative transfer model under partially cloud-covered is established. Observed brightness temperatures of SEVIRI infrared spectral bands (with 8.3-9.1μm, 9.8-11.8μm, 11-13μm and 12.4-14.4μm, respectively) under different atmospheric conditions, volcanic ash cloud heights, effective ash cloud emissivity and observation zenith angles are simulated. We found that no matter whether under U.S. standard atmosphere or

  15. Solar variability and clouds

    CERN Document Server

    Kirkby, Jasper

    2000-01-01

    Satellite observations have revealed a surprising imprint of the 11- year solar cycle on global low cloud cover. The cloud data suggest a correlation with the intensity of Galactic cosmic rays. If this apparent connection between cosmic rays and clouds is real, variations of the cosmic ray flux caused by long-term changes in the solar wind could have a significant influence on the global energy radiation budget and the climate. However a direct link between cosmic rays and clouds has not been unambiguously established and, moreover, the microphysical mechanism is poorly understood. New experiments are being planned to find out whether cosmic rays can affect cloud formation, and if so how. (37 refs).

  16. Cloud computing basics

    CERN Document Server

    Srinivasan, S

    2014-01-01

    Cloud Computing Basics covers the main aspects of this fast moving technology so that both practitioners and students will be able to understand cloud computing. The author highlights the key aspects of this technology that a potential user might want to investigate before deciding to adopt this service. This book explains how cloud services can be used to augment existing services such as storage, backup and recovery. Addressing the details on how cloud security works and what the users must be prepared for when they move their data to the cloud. Also this book discusses how businesses could prepare for compliance with the laws as well as industry standards such as the Payment Card Industry.

  17. Search Cloud

    Science.gov (United States)

    ... of this page: https://medlineplus.gov/cloud.html Search Cloud To use the sharing features on this ... of Top 110 zoster vaccine Share the MedlinePlus search cloud with your users by embedding our search ...

  18. A Preliminary View on the Estimation of Land Surface Temperature Under Cloud Cover from Thermal Remote Sensing Data%热红外遥感图像中云覆盖像元地表温度估算初论

    Institute of Scientific and Technical Information of China (English)

    周义; 覃志豪; 包刚

    2013-01-01

    Land surface temperature (LST) is a very important parameter controlling the energy and water balance between atmosphere and land surface. Since it is difficult to obtain such information from ground-based measurements, it appears to be very attractive by using satellite thermal infrared measurements to estimate LST since it can be used for estimating surface temperature at global or local scale. Moreover, the estimation of LST by using satellite remote sensing data is feasible. Cloud cover is a major obstacle to thermal infrared remote sensing applications and remote sensing quantitative retrieval of land surface temperature. Furthermore, cloud frequently exists in most time and covers roughly half the surface of the Earth even if the sky is clear. This is the case especially in some regions of high latitudes in the north hemisphere, e.g. the tropics are covered by cloud for about 60% of the time. Therefore, the influence of clouds on LST deserves more discussion and how to estimate LST of pixels covered by cloud on thermal remotely sensed imagery is one of the cutting-edge research problems. In this article, based on the theory of surface energy balance (SEB), three methods, which are spatial interpretation adjustment method, the adjustment method by correlations between LST and Vegetation Indices (VIs) and improved surface energy balance method, have been put forward for the estimation of LST when the sky is cloudy. Moreover, the lowland effect of LST spatial distribution under cloud cover and the method for the calculation of its intensity (denoted as SE) were also discussed. Generally speaking, when SE equals to 1, it means that SE reaches its maximum due to thick cloud cover .While SE equals to 0, it means that there is no lowland effect in clear sky. SE is strongly affected by the cloud and surface conditions. That is to say, SE is influenced greatly by cloud properties such as the time it appears and lasts, its shape, thickness and height and surface

  19. Trusted cloud computing

    CERN Document Server

    Krcmar, Helmut; Rumpe, Bernhard

    2014-01-01

    This book documents the scientific results of the projects related to the Trusted Cloud Program, covering fundamental aspects of trust, security, and quality of service for cloud-based services and applications. These results aim to allow trustworthy IT applications in the cloud by providing a reliable and secure technical and legal framework. In this domain, business models, legislative circumstances, technical possibilities, and realizable security are closely interwoven and thus are addressed jointly. The book is organized in four parts on "Security and Privacy", "Software Engineering and

  20. Land Cover

    Data.gov (United States)

    Kansas Data Access and Support Center — The Land Cover database depicts 10 general land cover classes for the State of Kansas. The database was compiled from a digital classification of Landsat Thematic...

  1. Cloud speed sensor

    Directory of Open Access Journals (Sweden)

    V. Fung

    2013-10-01

    Full Text Available Changing cloud cover is a major source of solar radiation variability and poses challenges for the integration of solar energy. A compact and economical system that measures cloud motion vectors to estimate power plant ramp rates and provide short term solar irradiance forecasts is presented. The Cloud Speed Sensor (CSS is constructed using an array of luminance sensors and high-speed data acquisition to resolve the progression of cloud passages across the sensor footprint. An embedded microcontroller acquires the sensor data and uses a cross-correlation algorithm to determine cloud motion vectors. The CSS was validated against an artificial shading test apparatus, an alternative method of cloud motion detection from ground measured irradiance (Linear Cloud Edge, LCE, and a UC San Diego Sky Imager (USI. The CSS detected artificial shadow directions and speeds to within 15 and 6% accuracy, respectively. The CSS detected (real cloud directions and speeds without average bias and with average weighted root mean square difference of 22° and 1.9 m s−1 when compared to USI and 33° and 1.5 m s−1 when compared to LCE results.

  2. Lsst cloud cover measurement for observation scheduling

    Directory of Open Access Journals (Sweden)

    J. Sebag

    2007-01-01

    Full Text Available Las especificaciones científicas del Large Synoptic Survey Telescope (LSST requieren de una operación por 10 años para realizar un reconocimiento del cielo visible en múltiples filtros con revisitas frecuentes. Durante la operación nocturna regular se utilizaría un programador de observaciones para seleccionar los campos a observar con una cadencia de uno cada 30 segundos. Para maximizar la eficiencia del reconocimiento, se realizarían ajustes en tiempo real al programa de observación utilizando parámetros como la nubosidad. El LSST está evaluando la utilización de cámaras tipo all-sky |con cobertura amplia del cielo e imágenes de satélites como información para el proceso de programación de tiempo. Cámaras tipo all-sky en el visible están en operación en la mayor__a de los observatorios y se han desarrollado rutinas para cuantificar automáticamente la fotometría de las imágenes. Se realizó una comparación preliminar entre las imágenes all-sky y datos satelitales contemporáneos. La evaluación de las técnicas de detección de nubes también incluye una cámara infrarroja tipo all-sky que se espera inicie operación a mediados del 2007

  3. Little Miss Sunshine et le road movie

    Directory of Open Access Journals (Sweden)

    Anne Paupe

    2007-01-01

    Full Text Available Little Miss Sunshine est un road movie bien particulier : s’il relève assurément de ce genre, puisqu’il est essentiellement consacré au périple entrepris par ses protagonistes afin d’emmener, envers et contre tout, la petite Olive au concours de beauté qui l’attend en Californie, le film de Jonathan Dayton et Valerie Faris retient surtout l’attention par son humour satirique. Un rapide tour d’horizon de sa réception critique confirme qu’il a été rangé simultanément dans deux catégories généri...

  4. Global solar radiation estimation using sunshine duration in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Almorox, J.; Hontoria, C. [Universidad Politecnica de Madrid (Spain). Dpto. de Edafologia

    2004-06-01

    Several equations were employed to estimate global solar radiation from sunshine hours for 16 meteorological stations in Spain, using only the relative duration of sunshine. These equations included the original Angstrom-Prescott linear regression and modified functions (quadratic, third degree, logarithmic and exponential functions). Estimated values were compared with measured values in terms of the coefficient of determination, standard error of the estimate and mean absolute error. All the models fitted the data adequately and can be used to estimate global solar radiation from sunshine hours. This study finds that the third degree models performed better than the other models, but the linear model is preferred due to its greater simplicity and wider application. It is also found that seasonal partitioning does not significantly improve the estimation of global radiation. (author)

  5. Cloud Governance

    DEFF Research Database (Denmark)

    Berthing, Hans Henrik

    Denne præsentation beskriver fordele og værdier ved anvendelse af Cloud Computing. Endvidere inddrager resultater fra en række internationale analyser fra ISACA om Cloud Computing.......Denne præsentation beskriver fordele og værdier ved anvendelse af Cloud Computing. Endvidere inddrager resultater fra en række internationale analyser fra ISACA om Cloud Computing....

  6. Benthic Cover

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic cover (habitat) maps are derived from aerial imagery, underwater photos, acoustic surveys, and data gathered from sediment samples. Shallow to moderate-depth...

  7. Global solar radiation estimation from relative sunshine hours in Yemen

    Energy Technology Data Exchange (ETDEWEB)

    Abdul-Aziz, J.; A-Nagi, A.; Zumailan, A.A.R. (Aden Univ. (Yemen, Republic of))

    1993-01-01

    The existing measurements of global solar radiation and sunshine duration for Yemen are examined. The errors of estimating global solar radiation from sunshine hour measurements using Angstrom's relation are evaluated. As a simple predictor for global solar radiation, an average Angstrom relation in the form H-bar/H[sub o] = 0.3518 + 0.3162 n/N for all stations is evaluated. Other Angstrom correlation relations are also proposed by classifying the stations under study into four groups. The estimated results are compared and seem to be satisfactory in the latter case. (Author)

  8. Cloud optics

    CERN Document Server

    Kokhanovsky, A

    2006-01-01

    Clouds affect the climate of the Earth, and they are an important factor in the weather. Therefore, their radiative properties must be understood in great detail. This book summarizes current knowledge on cloud optical properties, for example their ability to absorb, transmit, and reflect light, which depends on the clouds' geometrical and microphysical characteristics such as sizes of droplets and crystals, their shapes, and structures. In addition, problems related to the image transfer through clouds and cloud remote sensing are addressed in this book in great detail. This book can be an im

  9. Land cover changes and their biogeophysical effects on climate

    National Research Council Canada - National Science Library

    Mahmood, Rezaul; Pielke, Roger A; Hubbard, Kenneth G; Niyogi, Dev; Dirmeyer, Paul A; McAlpine, Clive; Carleton, Andrew M; Hale, Robert; Gameda, Samuel; Beltrán‐Przekurat, Adriana; Baker, Bruce; McNider, Richard; Legates, David R; Shepherd, Marshall; Du, Jinyang; Blanken, Peter D; Frauenfeld, Oliver W; Nair, U.S; Fall, Souleymane

    2014-01-01

    Land cover changes ( LCCs ) play an important role in the climate system. Research over recent decades highlights the impacts of these changes on atmospheric temperature, humidity, cloud cover, circulation, and precipitation...

  10. Marine Cloud Brightening

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Marine cloud brightening.

    Science.gov (United States)

    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.

  12. 76 FR 57068 - Board Meeting; Sunshine Act Meetings

    Science.gov (United States)

    2011-09-15

    ... Board Meeting; Sunshine Act Meetings TIME AND DATE: September 26, 2011, 9 a.m.-1:30 p.m. PLACE: 901 N...: Approval of the Minutes of the June 6, 2011, Meeting of the Board of Directors Strategic Planning President and Management Report Communications Strategy Advisory Council Next Meetings PORTIONS TO BE OPEN...

  13. 75 FR 47312 - Board Meeting; Sunshine Act Meetings

    Science.gov (United States)

    2010-08-05

    ... From the Federal Register Online via the Government Publishing Office INTER-AMERICAN FOUNDATION Board Meeting; Sunshine Act Meetings Time and Date: August 9, 2010, 8:30 a.m.-5:30 p.m.. Place: 101 Constitution Avenue, Washington, DC 20001. Status: Closed session as provided in 22 CFR 1004.4(f). Matters...

  14. 77 FR 15382 - Notice of Sunshine Act Meetings

    Science.gov (United States)

    2012-03-15

    ... BOARD MEETING Notice of Sunshine Act Meetings TIME AND DATE: March 26, 2012, 9 a.m.-1:30 p.m. PLACE: 901... the Minutes of the December 12, 2011, Meeting of the Board of Directors Management Report IAF Fellows Mid-Year Conference Grantee Perception Report Next Meetings Executive Session PORTIONS TO BE OPEN...

  15. 75 FR 34487 - Sunshine Act Meetings (by Conference Call)

    Science.gov (United States)

    2010-06-17

    ... From the Federal Register Online via the Government Publishing Office NATIONAL COUNCIL ON DISABILITY Sunshine Act Meetings (by Conference Call) DATE AND TIMES: June 25, 2010, 1 p.m.-3 p.m. PLACE: NCD, 1331 F Street, NW., Suite 850, Washington, DC 20004. STATUS: Open to the public. MATTERS TO...

  16. 76 FR 28243 - Sunshine Act; Notice of Agency Meeting

    Science.gov (United States)

    2011-05-16

    ... From the Federal Register Online via the Government Publishing Office NATIONAL CREDIT UNION ADMINISTRATION Sunshine Act; Notice of Agency Meeting TIME AND DATE: 10 a.m., Thursday, May 19, 2011. PLACE... and Regulations, Accuracy of Advertising and Notice of Insured Status. 2. Final Rule--Part 745 of...

  17. Insolation-sunshine relation with site elevation and latitude

    Energy Technology Data Exchange (ETDEWEB)

    Raja, I.A. (Univ. of Balochistan, Quetta (Pakistan))

    1994-07-01

    Data from six meteorological stations dispersed widely over Pakistan have been used to produce a correlation between the monthly means of easily measured sunshine duration and the less frequently recorded global solar radiation, taking into account the site elevation above sea level and the latitude. The relation is shown to be valuable for other regions too.

  18. 77 FR 65416 - Notice of Sunshine Act Meetings

    Science.gov (United States)

    2012-10-26

    ... regarding the Udall Foundation audit; and (7) Personnel matters. PORTIONS OPEN TO THE PUBLIC: All agenda... from the U.S. Department of the Interior's Inspector General regarding the Udall Foundation audit and... L. UDALL FOUNDATION Notice of Sunshine Act Meetings TIME AND DATE: 9:00 a.m. to 5:00 p.m.,...

  19. 76 FR 51064 - National Science Board; Sunshine Act Meetings; Notice

    Science.gov (United States)

    2011-08-17

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION National Science Board; Sunshine Act Meetings; Notice The National Science Board (NSB) Committee on Audit... 614), the National Science Foundation Act, as amended (42 U.S.C. 1862n-5), and the Government in...

  20. 76 FR 29727 - Sunshine Act Meeting-Change of Time

    Science.gov (United States)

    2011-05-23

    ...; May 27, 2011.\\1\\ \\1\\ These meetings were announced previously at 76 FR 24463. June 3, 2011; June 10, 2011; June 17, 2011; June 24, 2011.\\2\\ \\2\\ These meetings were announced previously at 76 FR 28425... COMMISSION Sunshine Act Meeting--Change of Time The following notice of a time change for scheduled...

  1. 78 FR 72131 - Sunshine Act Meeting; Board of Governors

    Science.gov (United States)

    2013-12-02

    ... From the Federal Register Online via the Government Publishing Office POSTAL SERVICE Sunshine Act Meeting; Board of Governors DATES AND TIMES: December 10, 2013, at 11:00 a.m. PLACE: Washington, DC, via Teleconference. STATUS: Closed. MATTERS TO BE CONSIDERED: Tuesday, December 10, 2013 at 11:00 a.m. 1....

  2. 76 FR 24541 - Board of Governors; Sunshine Act Meeting

    Science.gov (United States)

    2011-05-02

    ... From the Federal Register Online via the Government Publishing Office POSTAL SERVICE Board of Governors; Sunshine Act Meeting DATE AND TIMES: Tuesday, May 10, 2011, at 8 a.m. and 2 p.m. PLACE: Washington, DC, at U.S. Postal Service Headquarters, 475 L'Enfant Plaza, SW., in the Benjamin Franklin...

  3. 77 FR 32151 - Sunshine Act Meeting; Board of Governors

    Science.gov (United States)

    2012-05-31

    ... From the Federal Register Online via the Government Publishing Office POSTAL SERVICE Sunshine Act Meeting; Board of Governors DATES AND TIMES: Thursday, June 14, 2012, at 10 a.m. PLACE: Washington, DC, at U.S. Postal Service Headquarters, 475 L'Enfant Plaza SW., in the Benjamin Franklin Room....

  4. 77 FR 13159 - Sunshine Act Meeting Notice: Board of Governors

    Science.gov (United States)

    2012-03-05

    ... From the Federal Register Online via the Government Publishing Office POSTAL SERVICE Sunshine Act Meeting Notice: Board of Governors Dates and Times: Wednesday, March 21, 2012, at 10 a.m. Place: Washington, DC, at U.S. Postal Service Headquarters, 475 L'Enfant Plaza SW., in the Benjamin Franklin...

  5. 77 FR 52074 - Board of Governors; Sunshine Act Meeting

    Science.gov (United States)

    2012-08-28

    ... From the Federal Register Online via the Government Publishing Office POSTAL SERVICE Board of Governors; Sunshine Act Meeting DATES AND TIMES: Thursday, September 13, 2012, at 10:00 a.m. PLACE: Washington, DC, at U.S. Postal Service Headquarters, 475 L'Enfant Plaza SW., in the Benjamin Franklin...

  6. 77 FR 32496 - Government in the Sunshine Act Meeting Notice

    Science.gov (United States)

    2012-06-01

    ... limiting spending on travel and conferences. The BBG will recognize the anniversaries of Agency language... From the Federal Register Online via the Government Publishing Office BROADCASTING BOARD OF GOVERNORS Government in the Sunshine Act Meeting Notice DATE AND TIME: Thursday, June 7, 2012, 10:00...

  7. 78 FR 15745 - Sunshine Act Meetings: March 2013

    Science.gov (United States)

    2013-03-12

    ... BOARD Sunshine Act Meetings: March 2013 TIME AND DATES: All meetings are held at 2:00 p.m. Thursday, March 7; Wednesday, March 13; Thursday, March 14; Wednesday, March 20; Thursday, March 21; Wednesday, March 27; Thursday, March 28. PLACE: Board Agenda Room, No. 11820, 1099 14th St. NW., Washington,...

  8. 77 FR 14047 - Sunshine Act Meetings Notice; March 2012

    Science.gov (United States)

    2012-03-08

    ... BOARD Sunshine Act Meetings Notice; March 2012 TIME AND DATES: All meetings are held at 2:30 p.m. Wednesday, March 7; Thursday, March 8; Tuesday, March 13; Wednesday, March 14; Thursday, March 15; Tuesday, March 20; Wednesday, March 21; Thursday, March 22; Tuesday, March 27; Wednesday, March 28;...

  9. 76 FR 67484 - Sunshine Act Meetings: November 2011

    Science.gov (United States)

    2011-11-01

    ... arbitration, or the initiation, conduct, or disposition * * * of particular representation or unfair labor... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: November 2011 TIME AND DATES: All meetings are held at 2:30 p.m. Tuesday...

  10. 77 FR 45381 - Sunshine Act Meetings: August 2012

    Science.gov (United States)

    2012-07-31

    ... initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: August 2012 TIME AND DATES: All meetings are held at 2:30 p.m. Wednesday...

  11. 77 FR 39270 - Sunshine Act Meetings: July 2012

    Science.gov (United States)

    2012-07-02

    ... arbitration, or the initiation, conduct, or disposition * * * of particular representation or unfair labor... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: July 2012 TIME AND DATES: All meetings are held at 2:30 p.m. Tuesday, July...

  12. 77 FR 4584 - Sunshine Act Meetings: February 2012

    Science.gov (United States)

    2012-01-30

    ... initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: February 2012 Time and Dates: All meetings are held at 2:30 p.m. Wednesday...

  13. 77 FR 2571 - Sunshine Act Meetings: January 2012

    Science.gov (United States)

    2012-01-18

    ... initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: January 2012 TIME AND DATES: All meetings are held at 2:30 p.m. Tuesday...

  14. 76 FR 75566 - Sunshine Act Meetings: December 2011

    Science.gov (United States)

    2011-12-02

    ... arbitration, or the initiation, conduct, or disposition * * * of particular representation or unfair labor... From the Federal Register Online via the Government Publishing Office ] NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: December 2011 TIME AND DATES: All meetings are held at 2:30 p.m. Thursday...

  15. 76 FR 55421 - Sunshine Act Meetings: September 2011

    Science.gov (United States)

    2011-09-07

    ... initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: September 2011 Time and Dates: All meetings are held at 2:30 p.m. Tuesday...

  16. 75 FR 68008 - Sunshine Act Meetings: November 2010

    Science.gov (United States)

    2010-11-04

    ... Doc No: 2010-28052] NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: November 2010 Time and Dates... proceeding or an arbitration, or the initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings under section 8, 9, or 10 of the [National Labor Relations] Act...

  17. 78 FR 26089 - Sunshine Act Meetings: May 2013

    Science.gov (United States)

    2013-05-03

    ... initiation, conduct, or disposition * * * of particular representation or unfair labor practice proceedings... From the Federal Register Online via the Government Publishing Office NATIONAL LABOR RELATIONS BOARD Sunshine Act Meetings: May 2013 TIME AND DATES: All meetings are held at 2:00 p.m. Wednesday, May...

  18. Is a little sunshine all we need? On the impact of sunshine regulation on profits, productivity and prices in the Dutch drinking water sector

    NARCIS (Netherlands)

    de Witte, K.; Saal, D.S.

    2008-01-01

    This paper analyzes the conduct of publicly owned monopolistic utilities regulated by a voluntary sunshine regulatory model (i.e. publication of the performances of utilities). In particular, we examine the behaviour of Dutch drinking water utilities before and after the introduction of the sunshine

  19. Is a little sunshine all we need? On the impact of sunshine regulation on profits, productivity and prices in the Dutch drinking water sector

    NARCIS (Netherlands)

    K. de Witte; D.S. Saal

    2008-01-01

    This paper analyzes the conduct of publicly owned monopolistic utilities regulated by a voluntary sunshine regulatory model (i.e. publication of the performances of utilities). In particular, we examine the behaviour of Dutch drinking water utilities before and after the introduction of the sunshine

  20. Insights from a refined decomposition of cloud feedbacks

    Science.gov (United States)

    Zelinka, Mark D.; Zhou, Chen; Klein, Stephen A.

    2016-09-01

    Decomposing cloud feedback into components due to changes in several gross cloud properties provides valuable insights into its physical causes. Here we present a refined decomposition that separately considers changes in free tropospheric and low cloud properties, better connecting feedbacks to individual governing processes and avoiding ambiguities present in a commonly used decomposition. It reveals that three net cloud feedback components are robustly nonzero: positive feedbacks from increasing free tropospheric cloud altitude and decreasing low cloud cover and a negative feedback from increasing low cloud optical depth. Low cloud amount feedback is the dominant contributor to spread in net cloud feedback but its anticorrelation with other components damps overall spread. The ensemble mean free tropospheric cloud altitude feedback is roughly 60% as large as the standard cloud altitude feedback because it avoids aliasing in low cloud reductions. Implications for the "null hypothesis" climate sensitivity from well-understood and robustly simulated feedbacks are discussed.

  1. Reimagining liquid transportation fuels : sunshine to petrol.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry Alan (Sandia National Laboratories, Livermore, CA); Hogan, Roy E., Jr.; McDaniel, Anthony H. (Sandia National Laboratories, Livermore, CA); Siegel, Nathan Phillip; Dedrick, Daniel E. (Sandia National Laboratories, Livermore, CA); Stechel, Ellen Beth; Diver, Richard B., Jr.; Miller, James Edward; Allendorf, Mark D. (Sandia National Laboratories, Livermore, CA); Ambrosini, Andrea; Coker, Eric Nicholas; Staiger, Chad Lynn; Chen, Ken Shuang; Ermanoski, Ivan; Kellog, Gary L.

    2012-01-01

    Two of the most daunting problems facing humankind in the twenty-first century are energy security and climate change. This report summarizes work accomplished towards addressing these problems through the execution of a Grand Challenge LDRD project (FY09-11). The vision of Sunshine to Petrol is captured in one deceptively simple chemical equation: Solar Energy + xCO{sub 2} + (x+1)H{sub 2}O {yields} C{sub x}H{sub 2x+2}(liquid fuel) + (1.5x+.5)O{sub 2} Practical implementation of this equation may seem far-fetched, since it effectively describes the use of solar energy to reverse combustion. However, it is also representative of the photosynthetic processes responsible for much of life on earth and, as such, summarizes the biomass approach to fuels production. It is our contention that an alternative approach, one that is not limited by efficiency of photosynthesis and more directly leads to a liquid fuel, is desirable. The development of a process that efficiently, cost effectively, and sustainably reenergizes thermodynamically spent feedstocks to create reactive fuel intermediates would be an unparalleled achievement and is the key challenge that must be surmounted to solve the intertwined problems of accelerating energy demand and climate change. We proposed that the direct thermochemical conversion of CO{sub 2} and H{sub 2}O to CO and H{sub 2}, which are the universal building blocks for synthetic fuels, serve as the basis for this revolutionary process. To realize this concept, we addressed complex chemical, materials science, and engineering problems associated with thermochemical heat engines and the crucial metal-oxide working-materials deployed therein. By project's end, we had demonstrated solar-driven conversion of CO{sub 2} to CO, a key energetic synthetic fuel intermediate, at 1.7% efficiency.

  2. Antarctic clouds

    OpenAIRE

    Lachlan-Cope, Tom

    2010-01-01

    Sensitivity studies with global climate models show that, by their influence on the radiation balance, Antarctic clouds play a major role in the climate system, both directly at high southern latitudes and indirectly globally, as the local circulation changes lead to global teleconnections. Unfortunately, observations of cloud distribution in the Antarctic are limited and often of low quality because of the practical difficulty in observing clouds in the harsh Antarctic environment. The best ...

  3. Cloud Computing

    CERN Document Server

    Antonopoulos, Nick

    2010-01-01

    Cloud computing has recently emerged as a subject of substantial industrial and academic interest, though its meaning and scope is hotly debated. For some researchers, clouds are a natural evolution towards the full commercialisation of grid systems, while others dismiss the term as a mere re-branding of existing pay-per-use technologies. From either perspective, 'cloud' is now the label of choice for accountable pay-per-use access to third party applications and computational resources on a massive scale. Clouds support patterns of less predictable resource use for applications and services a

  4. Cloud ERP and Cloud Accounting Software in Romania

    Directory of Open Access Journals (Sweden)

    Gianina MIHAI

    2015-05-01

    Full Text Available Nowadays, Cloud Computing becomes a more and more fashionable concept in the IT environment. There is no unanimous opinion on the definition of this concept, as it covers several versions of the newly emerged stage in the IT. But in fact, Cloud Computing should not suggest anything else than simplicity. Thus, in short, simple terms, Cloud Computing can be defined as a solution to use external IT resources (servers, storage media, applications and services, via Internet. Cloud computing is nothing more than the promise of an easy accessible technology. If the promise will eventually turn into something certain yet remains to be seen. In our opinion it is too early to make an assertion. In this article, our purpose is to find out what is the Romanian offer of ERP and Accounting software applications in Cloud and / or as services in SaaS version. Thus, we conducted an extensive study whose results we’ll present in the following.

  5. Risk of field cultivation of pickling cucumber caused by unfavorable sunshine duration conditions

    OpenAIRE

    2011-01-01

    Solar energy, accessible to plants during sunshine from the sunrise to the sunset is of key importance in productivity of agrocenoses. The aim of the work was to determine risk of pickling cucumber cultivation caused by an unfavorable course of sunshine duration in Poland on the basis of a 40-year research period 1966-2005. The research into the subject was undertaken due to frequent occurrence of sunshine deficiency in Poland and its high temporal and spatial variability. Effect of solar con...

  6. Brightening up: the effect of the Physician Payment Sunshine Act on existing regulation of pharmaceutical marketing.

    Science.gov (United States)

    Gorlach, Igor; Pham-Kanter, Genevieve

    2013-01-01

    With the passage of the Physician Payment Sunshine Act as part of the federal health care reform law, pharmaceutical manufacturers are now required to disclose a wide range of payments made by manufacturers to physicians. We review current state regulation of pharmaceutical marketing and consider how the federal sunshine provision will affect existing marketing regulation. We analyze the legal and practical implications of the Physician Payment Sunshine Act.

  7. Atmospheric Profiles, Clouds, and the Evolution of Sea Ice Cover in the Beaufort and Chukchi Seas: Atmospheric Observations and Modeling as Part of the Seasonal Ice Zone Reconnaissance Surveys

    Science.gov (United States)

    2015-09-30

    gliding unmanned aerial vehicle ( UAV ) that can also be dropped from a manned aircraft, but then can be guided to areas of interest (e.g. seasonal ice...APPLICATIONS The vertical structure of the atmospheric profiles and cloud are regulated by the synoptic conditions. Using our k-mean classification

  8. The Relationship Between Surface Temperature Anomaly Time Series and those of OLR, Water Vapor, and Cloud Cover as Observed Using Nine Years of AIRS Version-5 Level-3 Products

    Science.gov (United States)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena

    2011-01-01

    Outline: (1) Comparison of AIRS and CERES anomaly time series of outgoing longwave radiation (OLR) and OLR(sub CLR), i.e. Clear Sky OLR (2) Explanation of recent decreases in global and tropical mean values of OLR (3) AIRS "Short-term" Longwave Cloud Radiative Feedback -- A new product

  9. High performance cloud auditing and applications

    CERN Document Server

    Choi, Baek-Young; Song, Sejun

    2014-01-01

    This book mainly focuses on cloud security and high performance computing for cloud auditing. The book discusses emerging challenges and techniques developed for high performance semantic cloud auditing, and presents the state of the art in cloud auditing, computing and security techniques with focus on technical aspects and feasibility of auditing issues in federated cloud computing environments.   In summer 2011, the United States Air Force Research Laboratory (AFRL) CyberBAT Cloud Security and Auditing Team initiated the exploration of the cloud security challenges and future cloud auditing research directions that are covered in this book. This work was supported by the United States government funds from the Air Force Office of Scientific Research (AFOSR), the AFOSR Summer Faculty Fellowship Program (SFFP), the Air Force Research Laboratory (AFRL) Visiting Faculty Research Program (VFRP), the National Science Foundation (NSF) and the National Institute of Health (NIH). All chapters were partially suppor...

  10. Analysis on the Variation Characteristics of Sunshine Hours in Puyang City

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The research aimed to analyze the variation characteristics of sunshine hours in Puyang City in recent 51 years.[Method] Based on the monthly sunshine hours in five meteorological stations of Puyang City during 1960-2010,the annual,seasonal and monthly variation trends of sunshine hours,mutation time node were analyzed by using the climate trend coefficient,climate tendency rate,sliding average method,SNR and so on.The objective fact and rule of sunshine variation in Puyang in recent 51 years we...

  11. Variation Characteristics of Sunshine Hours and Its Reason Analysis over Loess Plateau of Shaanxi

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The research aimed to study variation characteristics of sunshine hours over Loess Plateau of Shaanxi during 1961-2010.[Method] By using the climate tendency rate,climate trend coefficient and linear correlation,the temporal and spatial variation characteristics of sunshine hours in Loess Plateau of Shaanxi in recent 50 years were analyzed.Moreover,the main reason for inducing variation of sunshine hours in the zone was discussed.[Result] In recent 50 years,the variation of annual sunshine hours...

  12. Managing Clouds in Cloud Platforms

    CERN Document Server

    Ahmat, Kamal A

    2010-01-01

    Managing cloud services is a fundamental challenge in todays virtualized environments. These challenges equally face both providers and consumers of cloud services. The issue becomes even more challenging in virtualized environments that support mobile clouds. Cloud computing platforms such as Amazon EC2 provide customers with flexible, on demand resources at low cost. However, they fail to provide seamless infrastructure management and monitoring capabilities that many customers may need. For instance, Amazon EC2 doesn't fully support cloud services automated discovery and it requires a private set of authentication credentials. Salesforce.com, on the other hand, do not provide monitoring access to their underlying systems. Moreover, these systems fail to provide infrastructure monitoring of heterogenous and legacy systems that don't support agents. In this work, we explore how to build a cloud management system that combines heterogeneous management of virtual resources with comprehensive management of phys...

  13. Behavior of cloud base height from ceilometer measurements

    OpenAIRE

    Costa Surós, Montse; Calbó Angrill, Josep; González Gutiérrez, Josep Abel; Martin-Vide, Javier

    2013-01-01

    Given the importance of clouds in the climate, and the difficulty in determining their behavior and their contribution to climate change, there is a need for improvement of methods for automatic and continuous description of cloud characteristics. Ceilometers constitute a priori a reliable instrumental method for sounding the atmosphere and describing cloudiness, specifically cloud base height (CBH), cloud cover, and even cloud vertical structure. In the present study, the behavior of CBH at ...

  14. Parameterization of clouds and radiation in climate models

    Energy Technology Data Exchange (ETDEWEB)

    Roeckner, E. [Max Planck Institute for Meterology, Hamburg (Germany)

    1995-09-01

    Clouds are a very important, yet poorly modeled element in the climate system. There are many potential cloud feedbacks, including those related to cloud cover, height, water content, phase change, and droplet concentration and size distribution. As a prerequisite to studying the cloud feedback issue, this research reports on the simulation and validation of cloud radiative forcing under present climate conditions using the ECHAM general circulation model and ERBE top-of-atmosphere radiative fluxes.

  15. Marine cloud brightening

    Science.gov (United States)

    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

  16. Cloud Control

    Science.gov (United States)

    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…

  17. Cloud Computing

    CERN Document Server

    Mirashe, Shivaji P

    2010-01-01

    Computing as you know it is about to change, your applications and documents are going to move from the desktop into the cloud. I'm talking about cloud computing, where applications and files are hosted on a "cloud" consisting of thousands of computers and servers, all linked together and accessible via the Internet. With cloud computing, everything you do is now web based instead of being desktop based. You can access all your programs and documents from any computer that's connected to the Internet. How will cloud computing change the way you work? For one thing, you're no longer tied to a single computer. You can take your work anywhere because it's always accessible via the web. In addition, cloud computing facilitates group collaboration, as all group members can access the same programs and documents from wherever they happen to be located. Cloud computing might sound far-fetched, but chances are you're already using some cloud applications. If you're using a web-based email program, such as Gmail or Ho...

  18. Screaming Clouds

    Science.gov (United States)

    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.

  19. Securing Cloud from Cloud Drain

    Directory of Open Access Journals (Sweden)

    Niva Das

    2014-09-01

    Full Text Available Today, in the world of communication, connected systems is growing at a rapid pace. To accommodate this growth the need for computational power and storage is also increasing at a similar rate. Companies are investing a large amount of resources in buying, maintaining and ensuring availability of the system to their customers. To mitigate these issues, cloud computing is playing a major role [1]. The underlying concept of cloud computing dates back to the ‘50s but the term entering into widespread usage can be traced to 2006 when Amazon.com announced the Elastic Compute Cloud. In this paper, we will discuss about cloud security approaches. We have used the term “CloudDrain” to define data leakage in case of security compromise.

  20. ASTER cloud coverage reassessment using MODIS cloud mask products

    Science.gov (United States)

    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.

  1. A Warm Reading of Sunshine Sketches of a Little Town

    Institute of Scientific and Technical Information of China (English)

    刘翠萍

    2014-01-01

    Stephen Leacock(1869-1944) is one of the founding parents of Canadian letters and literature. In the early 20th centu-ry, his reputation as a humorist and a political economist was not limited by the boundaries of Canada but spread around the world. As one of his works, Sunshine Sketches of a Little Town has attracted world-wide admiration. It is a series of vignettes dra-matizing the comedy of day-to-day life in Mariposa. It is bathed in the warm sunshine for all of us to laugh at as one of us re-members the little towns we might have known or come from. As a matter of fact, Leacock employs several techniques in his writing for humorous effect. This paper elaborates on the auther and the work, and makes an analysis on the character-Smith.

  2. Cloud migration

    CERN Document Server

    Höllwarth, Tobias

    2012-01-01

    This book is designed for managers and entrepreneurs, who are considering improving the economics and flexibility of their IT solutions and infrastructures. The book is also for readers who wish to learn more about the Cloud, but do not want to become specialists.This book discusses the technical, legal, fiscal, economic, organisational and environmental aspects of Cloud services. If you are looking for practical advice on vendor selection and certification, as well as real world Cloud project case studies, this is the book to consult.It is the result of a highly cooper

  3. Cloud Computing

    CERN Document Server

    Baun, Christian; Nimis, Jens; Tai, Stefan

    2011-01-01

    Cloud computing is a buzz-word in today's information technology (IT) that nobody can escape. But what is really behind it? There are many interpretations of this term, but no standardized or even uniform definition. Instead, as a result of the multi-faceted viewpoints and the diverse interests expressed by the various stakeholders, cloud computing is perceived as a rather fuzzy concept. With this book, the authors deliver an overview of cloud computing architecture, services, and applications. Their aim is to bring readers up to date on this technology and thus to provide a common basis for d

  4. Fuzzy cloud concepts for assessing radiation feedbacks

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, H. [Univ. of Colorado, Boulder, CO (United States)

    1995-09-01

    The importance of clouds in the climate system is well-known but poorly understood. Modeling and observational studies have suggested that there may be positive feedbacks associated with certain cloud processes, but it is not known how strong these feedbacks are in the context of the overall system. Examples include ice microphysics feedback, as shown by Liou`s model, and the relationship between SST and cloud cover in the tropics, which is the focus of this research. 2 refs., 3 figs.

  5. Air Pollution Contributes in Sunshine Dimming in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The research team led by Professor Yang Yonghui of Center for Agricultural Resources Research, In- stitute of Genetics and Developmental Biology, CAS, have revealed the magnitude and physical mechanism of the effect of air pollution on sunshine hours in 38 big cities across China. These results have recently been published in Journal of Geophysical Research-Atmospheres (VOL. 117, D00V14, doi. 10. 1029/ 2011JD016753). It was funded by international collaborative proiect from MOST and NSFC.

  6. Sganzerla Cover

    Directory of Open Access Journals (Sweden)

    Victor da Rosa

    2014-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7917.2014v19n1p158 Neste artigo, realizo uma leitura do cinema de Rogério Sganzerla, desde o clássico O bandido da luz vermelha até os documentários filmados na década de oitenta, a partir de duas noções centrais: cover e over. Para isso, parto de uma controvérsia com o ensaio de Ismail Xavier, Alegorias do subdesenvolvimento, em que o crítico realiza uma leitura do cinema brasileiro da década de sessenta através do conceito de alegoria; depois releio uma série de textos críticos do próprio Sganzerla, publicados em Edifício Sganzerla, procurando repensar as ideias de “herói vazio” ou “cinema impuro” e sugerindo assim uma nova relação do seu cinema com o tempo e a representação; então busco articular tais ideias com certos procedimentos de vanguarda, como a falsificação, a cópia, o clichê e a colagem; e finalmente procuro mostrar que, no cinema de Sganzerla, a partir principalmente de suas reflexões sobre Orson Welles, a voz é usada de maneira a deformar a interpretação naturalista.

  7. Cover Picture.

    Science.gov (United States)

    Breuning; Ruben; Lehn; Renz; Garcia; Ksenofontov; Gütlich; Wegelius; Rissanen

    2000-07-17

    The cover picture shows how both, fine arts and science, avail themselves of a system of intertwined symbolic and iconic languages. They make use of a common set of abstracted signs to report on their results. Thus, already in 1925, Wassily Kandinsky painted a masterpiece (bottom), which now, 75 years later, might be regarded as a blueprint for a scientific project. In his painting, Kandinsky pictured a grid-shaped sign that resembles in effect an actual molecular switch. Apparently following an enigmatic protocol, the groups of Lehn and Gütlich (see p. 2504 ff. for more details) constructed a grid-type inorganic architecture that operates as a three-level magnetic switch (center) triggered by three external perturbations (p, T, hnu). The switching principle is based on the spin-crossover phenomenon of Fe(II) ions and can be monitored by Mössbauer spectroscopy (left) and magnetic measurements (rear). Maybe not by chance, the English translation of the title of the painting "signs" is a homonym of "science", since both presented works are a product of the insatiable curiosity of man and his untiring desire to recognize his existence.

  8. 78 FR 72123 - Sunshine Act Cancellation Notice-OPIC December 4, 2013 Public Hearing

    Science.gov (United States)

    2013-12-02

    ... From the Federal Register Online via the Government Publishing Office OVERSEAS PRIVATE INVESTMENT CORPORATION Sunshine Act Cancellation Notice--OPIC December 4, 2013 Public Hearing OPIC's Sunshine Act notice of its Public Hearing in Conjunction with each Board meeting was published in the Federal...

  9. Daytime Land Cloud Detection Enhancements For The VIIRS Cloud Mask

    Science.gov (United States)

    Frey, R. A.; Heidinger, A. K.; Hutchinson, K. D.; Iisager, B.

    2005-12-01

    The first in a new series of polar-orbiting satellites, National Polar-Orbiting Operational Satellite System (NPOESS), is scheduled to be launched in 2008. The Visible/Infrared Imager/Radiometer Suite (VIIRS) is a major component of the series and will replace the AVHRR instrument on operational polar orbiters. A crucial piece of the VIIRS data processing chain is the VIIRS Cloud Mask (VCM). A high quality cloud detection system is necessary as a first step for most if not all of the algorithms which produce the 18 EDRs (Environmental Data Records) from VIIRS. A cloud detection scheme similar to the one developed for MODIS data (MOD35) will be implemented for VIIRS, but several enhancements have been investigated for daytime land scenes. During daylight hours over vegetated surfaces and in the absence of snow cover, use of the high contrast between clouds and surface in visible wavelengths offers the most sensitive clear/cloud discrimination. However, visible surface reflectances vary from about 10% over tropical rain forests to as high as 50% in arid regions, making the use of a single cloud test threshold very difficult. A set of reflectance thresholds based on NDVI and scattering angle has been developed from historical AVHRR data. Clear-sky NDVIs were accumulated as a function of scattering angle over a multi-year period and from morning and afternoon satellites, from which cloud test thresholds were developed. The thresholds were then tested on several AVHRR scenes. For extremely arid scenes, where visible reflectances from clouds and surface are similar, a cloud test using 0.4 μm data has been devised. This poster describes the development of both new cloud tests and associated thresholds, from initial tests using MODIS data to the calculation and implementation of the thresholds.

  10. Clouds over Mars!

    Science.gov (United States)

    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.

  11. Satellite Regional Cloud Climatology over the Great Lakes

    Directory of Open Access Journals (Sweden)

    Steven A. Ackerman

    2013-11-01

    Full Text Available Thirty-one years of imager data from polar orbiting satellites are composited to produce a satellite climate data set of cloud amount for the Great Lakes region. A trend analysis indicates a slight decreasing trend in cloud cover over the region during this time period. The trend is significant and largest (~2% per decade over the water bodies. A strong seasonal cycle of cloud cover is observed over both land and water surfaces. Winter cloud amounts are greater over the water bodies than land due to heat and moisture flux into the atmosphere. Late spring through early autumn cloud amounts are lower over the water bodies than land due to stabilization of the boundary layer by relatively cooler lake waters. The influence of the lakes on cloud cover also extends beyond their shores, affecting cloud cover and properties far down wind. Cloud amount composited by wind direction demonstrate that the increasing cloud amounts downwind of the lakes is greatest during autumn and winter. Cold air flows over relatively warm lakes in autumn and winter generate wind parallel convective cloud bands. The cloud properties of these wind parallel cloud bands over the lakes during winter are presented.

  12. Security of Data Stored in the Cloud

    OpenAIRE

    Vrhovec, Andraž

    2016-01-01

    The goal of this diploma thesis is to give an overview of data security in cloud systems. The first part covers basics of cloud and security. Additionally it identifies some risks arising from the use of cloud computing. The second part focuses on cryptography, especially on ciphers, as a tool for mitigation of those risks. We try to convey some recent ideas (especially those interesting in the context of cloud computing) from the cryptographic world to the reader in an easy manner. We conclu...

  13. Cloudonomics the business value of cloud computing

    CERN Document Server

    Weinman, Joe

    2012-01-01

    The ultimate guide to assessing and exploiting the customer value and revenue potential of the Cloud A new business model is sweeping the world—the Cloud. And, as with any new technology, there is a great deal of fear, uncertainty, and doubt surrounding cloud computing. Cloudonomics radically upends the conventional wisdom, clearly explains the underlying principles and illustrates through understandable examples how Cloud computing can create compelling value—whether you are a customer, a provider, a strategist, or an investor. Cloudonomics covers everything you need to consider f

  14. Implementing and developing cloud computing applications

    CERN Document Server

    Sarna, David E Y

    2010-01-01

    From small start-ups to major corporations, companies of all sizes have embraced cloud computing for the scalability, reliability, and cost benefits it can provide. It has even been said that cloud computing may have a greater effect on our lives than the PC and dot-com revolutions combined.Filled with comparative charts and decision trees, Implementing and Developing Cloud Computing Applications explains exactly what it takes to build robust and highly scalable cloud computing applications in any organization. Covering the major commercial offerings available, it provides authoritative guidan

  15. Low cloud properties influenced by cosmic rays

    CERN Document Server

    Marsh, N D; Marsh, Nigel D; Svensmark, Henrik

    2000-01-01

    The influence of solar variability on climate is currently uncertain. Recent observations have indicated a possible mechanism via the influence of solar modulated cosmic rays on global cloud cover. Here we show that the influence of solar variability is strongest in low clouds (<= 3.2km). These are liquid water clouds which points to a microphysical mechanism involving enhanced aerosol formation. If confirmed it suggests that the average state of the Heliosphere is important for climate on Earth. The estimated response in low clouds due to a doubling of solar activity is a 1.4 W/m2 warming.

  16. Ontology-based Cloud Services Representation

    Directory of Open Access Journals (Sweden)

    Abdullah Ali

    2014-07-01

    Full Text Available The advancement of cloud computing has enabled service providers to provide diversity of cloud services to users with different attributes at a range of costs. Finding the suitable service from the increasing numbers of cloud services that satisfy the user requirements such as performance, cost and security has become a big challenge. The variety on services description none uniformed naming conventions and the heterogeneous types and features of cloud services led to make the cloud service discovery a hard problem. Therefore, an intelligent service discovery system is necessary for searching and retrieving appropriate services accurately and quickly. Many studies have been conducted to discover the cloud services using different techniques, such as ontology model and agents technology. The existing ontology for cloud services does not cover the cloud concepts and it is intended to be used for specific tasks only. This study represents the cloud concepts in a comprehensive way that can be used for cloud services discovery or cloud computing management.

  17. Mobile Clouds

    DEFF Research Database (Denmark)

    Fitzek, Frank; Katz, Marcos

    users in very different ways and for various purposes. The book provides many stimulating examples of resource-sharing applications. Enabling technologies for mobile clouds are also discussed, highlighting the key role of network coding. Mobile clouds have the potential to enhance communications...... of resource sharing takes a wider and deeper meaning, creating the foundations for a global real-time multidimensional resource pool, the underlying infrastructure for shareconomy. Above all, this is an inspiring book for anyone who is concerned about the future of wireless and mobile communications networks...... and their relationship with Social networks. Key Features: Provides fundamental ideas and promising concepts for exploiting opportunistic cooperation and cognition in wireless and mobile networks Gives clear definitions of mobile clouds from different perspectives Associates mobile and wireless networks with social...

  18. Comparative study of the feasibility of cloud removal methods based on MODIS seasonal snow cover data over the Tibetan Plateau%基于MODIS的青藏高原季节性积雪去云方法可行性比较研究

    Institute of Scientific and Technical Information of China (English)

    张欢; 邱玉宝; 郑照军; 除多; 杨煜丹

    2016-01-01

    The Tibetan Plateau is located in a mid-latitude area,where seasonal snow cover scatters spatially and climate stations is not enough. Moderate Resolution Imaging Spectrometer(MODIS)provides daily products of snow cover for this region. However,cloud cover is the major limitation to optical remote sensing observation. In order to analyze the applicability of the cloud removal methods,the methods are generalized into five catego-ries according to their principles,and then comparative analysis is carried out to search their "hidden assump-tions". The result demonstrates that methods based on time continuity is well applied and has obvious cloud re-moval effect. The consistency rate of Terra and Aqua is 72.5%on average. While the consistency of 2-days to 5-days ranges from 5.6%to 43%,of which the reliability is poor. The adjacent pixels method combination is able to remove a little cloud,with a high correct rate of 95.5%,but the removed cloud amount is only a little. The method based on altitude is well applied in high mountain areas,while it is not working well in plateau hinter-land due to its small slopes. Passive microwave remote sensing data for cloud removal are dependent on the rec-ognition rate of microwave on cloud,which brings about larger error. Other mathematical method is of weak physical significance in the Tibetan Plateau,where snowfall and snowmelt is frequently and snow cover is scat-tered. By comparing and analyzing the methods above,it is acquired that regional advantages and characteristics of the Tibetan Plateau should be considered into cloud removal,in order to gradually improve the MODIS daily snow cover product.%青藏高原地处中纬度地区,季节性积雪分布破碎,地面观测站点稀少,中分辨率成像光谱仪(MODIS)可为该地区提供每日积雪监测数据,然而云是光学遥感最大的影响因素,为研究MODIS每日积雪产品去云方法在青藏高原的适用性,根据原理将去云方法归纳

  19. Cloud radiative properties and aerosol - cloud interaction

    Science.gov (United States)

    Viviana Vladutescu, Daniela; Gross, Barry; Li, Clement; Han, Zaw

    2015-04-01

    The presented research discusses different techniques for improvement of cloud properties measurements and analysis. The need for these measurements and analysis arises from the high errors noticed in existing methods that are currently used in retrieving cloud properties and implicitly cloud radiative forcing. The properties investigated are cloud fraction (cf) and cloud optical thickness (COT) measured with a suite of collocated remote sensing instruments. The novel approach makes use of a ground based "poor man's camera" to detect cloud and sky radiation in red, green, and blue with a high spatial resolution of 30 mm at 1km. The surface-based high resolution photography provides a new and interesting view of clouds. As the cloud fraction cannot be uniquely defined or measured, it depends on threshold and resolution. However as resolution decreases, cloud fraction tends to increase if the threshold is below the mean, and vice versa. Additionally cloud fractal dimension also depends on threshold. Therefore these findings raise concerns over the ability to characterize clouds by cloud fraction or fractal dimension. Our analysis indicate that Principal Component analysis may lead to a robust means of quantifying cloud contribution to radiance. The cloud images are analyzed in conjunction with a collocated CIMEL sky radiometer, Microwave Radiometer and LIDAR to determine homogeneity and heterogeneity. Additionally, MFRSR measurements are used to determine the cloud radiative properties as a validation tool to the results obtained from the other instruments and methods. The cloud properties to be further studied are aerosol- cloud interaction, cloud particle radii, and vertical homogeneity.

  20. Cloud essentials CompTIA authorized courseware for exam CLO-001

    CERN Document Server

    Hausman, Kirk; Sampaio, Telmo

    2013-01-01

    CompTIA-Authorized courseware for the Cloud Essentials Exam (CLO-001) What better way to get up to speed on cloud computing than with this new book in the popular Sybex Essentials series? Cloud Essentials covers the basics of cloud computing and its place in the modern enterprise. Explore public and private clouds; contrast the ""as a service"" models for PaaS, SaaS, IaaS, or XaaS platforms; plan security; and more. In addition, the book covers the exam objectives for the both the CompTIA Cloud Essentials (Exam CLO-001) exam and the EXIN Cloud Computing Foundation (EX0-1

  1. Mapping in the cloud

    CERN Document Server

    Peterson, Michael P

    2014-01-01

    This engaging text provides a solid introduction to mapmaking in the era of cloud computing. It takes students through both the concepts and technology of modern cartography, geographic information systems (GIS), and Web-based mapping. Conceptual chapters delve into the meaning of maps and how they are developed, covering such topics as map layers, GIS tools, mobile mapping, and map animation. Methods chapters take a learn-by-doing approach to help students master application programming interfaces and build other technical skills for creating maps and making them available on the Internet. Th

  2. Cosmic rays, cloud condensation nuclei and clouds – a reassessment using MODIS data

    Directory of Open Access Journals (Sweden)

    J. E. Kristjánsson

    2008-12-01

    Full Text Available The response of clouds to sudden decreases in the flux of galactic cosmic rays (GCR – Forbush decrease events – has been investigated using cloud products from the space-borne MODIS instrument, which has been in operation since 2000. By focusing on pristine Southern Hemisphere ocean regions we examine areas where we believe that a cosmic ray signal should be easier to detect than elsewhere. While previous studies have mainly considered cloud cover, the high spatial and spectral resolution of MODIS allows for a more thorough study of microphysical parameters such as cloud droplet size, cloud water content and cloud optical depth, in addition to cloud cover. Averaging the results from the 22 Forbush decrease events that were considered, no statistically significant correlations were found between any of the four cloud parameters and GCR, when autocorrelations were taken into account. Splitting the area of study into six domains, all of them have a negative correlation between GCR and cloud droplet size, in agreement with a cosmic ray – cloud coupling, but in only one of the domains (eastern Atlantic Ocean was the correlation statistically significant. Conversely, cloud optical depth is mostly negatively correlated with GCR, and in the eastern Atlantic Ocean domain that correlation is statistically significant. For cloud cover and liquid water path, the correlations with GCR are weaker, with large variations between the different domains. When only the six Forbush decrease events with the largest amplitude (more than 10% decrease were studied, the correlations fit the hypothesis slightly better, with 16 out of 24 correlations having the expected sign, although many of the correlations are quite weak. Introducing a time lag of a few days for clouds to respond to the cosmic ray signal the correlations tend to become weaker and even to change sign.

  3. Cloud removal of remote sensing image based on multi-output suppor t vector regression

    Institute of Scientific and Technical Information of China (English)

    Gensheng Hu; Xiaoqi Sun; Dong Liang; Yingying Sun

    2014-01-01

    Removal of cloud cover on the satel ite remote sens-ing image can effectively improve the availability of remote sensing images. For thin cloud cover, support vector value contourlet trans-form is used to achieve multi-scale decomposition of the area of thin cloud cover on remote sensing images. Through enhancing coefficients of high frequency and suppressing coefficients of low frequency, the thin cloud is removed. For thick cloud cover, if the areas of thick cloud cover on multi-source or multi-temporal remote sensing images do not overlap, the multi-output support vector regression learning method is used to remove this kind of thick clouds. If the thick cloud cover areas overlap, by using the multi-output learning of the surrounding areas to predict the sur-face features of the overlapped thick cloud cover areas, this kind of thick cloud is removed. Experimental results show that the pro-posed cloud removal method can effectively solve the problems of the cloud overlapping and radiation difference among multi-source images. The cloud removal image is clear and smooth.

  4. Mobile Clouds

    DEFF Research Database (Denmark)

    Fitzek, Frank; Katz, Marcos

    examples of mobile clouds applications, based on both existing commercial initiatives as well as proof-of-concept test-beds. Visions and prospects are also discussed, paving the way for further development. As mobile networks and social networks become more and more reliant on each other, the concept...

  5. Soft Clouding

    DEFF Research Database (Denmark)

    Søndergaard, Morten; Markussen, Thomas; Wetton, Barnabas;

    2012-01-01

    Soft Clouding is a blended concept, which describes the aim of a collaborative and transdisciplinary project. The concept is a metaphor implying a blend of cognitive, embodied interaction and semantic web. Furthermore, it is a metaphor describing our attempt of curating a new semantics of sound...

  6. Cloud a particle beam facility to investigate the influence of cosmic rays on clouds

    CERN Document Server

    Kirkby, Jasper

    2001-01-01

    Palaeoclimatic data provide extensive evidence for solar forcing of the climate during the Holocene and the last ice age, but the underlying mechanism remains a mystery. However recent observations suggest that cosmic rays may play a key role. Satellite data have revealed a surprising correlation between cosmic ray intensity and the fraction of the Earth covered by low clouds \\cite{svensmark97,marsh}. Since the cosmic ray intensity is modulated by the solar wind, this may be an important clue to the long-sought mechanism for solar-climate variability. In order to test whether cosmic rays and clouds are causally linked and, if so, to understand the microphysical mechanisms, a novel experiment known as CLOUD\\footnotemark\\ has been proposed \\cite{cloud_proposal}--\\cite{cloud_addendum_2}. CLOUD proposes to investigate ion-aerosol-cloud microphysics under controlled laboratory conditions using a beam from a particle accelerator, which provides a precisely adjustable and measurable artificial source of cosmic rays....

  7. Hidden in the Clouds: New Ideas in Cloud Computing

    CERN Document Server

    CERN. Geneva

    2013-01-01

    Abstract: Cloud computing has become a hot topic. But 'cloud' is no newer in 2013 than MapReduce was in 2005: We've been doing both for years. So why is cloud more relevant today than it ever has been? In this presentation, we will introduce the (current) central thesis of cloud computing, and explore how and why (or even whether) the concept has evolved. While we will cover a little light background, our primary focus will be on the consequences, corollaries and techniques introduced by some of the leading cloud developers and organizations. We each have a different deployment model, different applications and workloads, and many of us are still learning to efficiently exploit the platform services offered by a modern implementation. The discussion will offer the opportunity to share these experiences and help us all to realize the benefits of cloud computing to the fullest degree. Please bring questions and opinions, and be ready to share both!   Bio: S...

  8. Brief introduction to Beijing Sunshine Eternity Technology Co.Ltd

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Beijing Sunshine Eternity Technology Co.Ltd is an enterprise specializ- ing in import and export,as well as processing of high-quality sheepskins. Combining traditional Chinese and international leading technologies,we have developed a series of sheared sheepskin products,including cushions,automo- bile seat backs,baby sacks,fur & leather indoor shoes and shoe lining leathers and bed blankets of all sizes.Our products are popular in the United Kingdom, Belgium,Italy,Russia,Germany,India and Japan,as well as on the domestic

  9. Cloud computing and ROI a new framework for it strategy

    CERN Document Server

    Mohapatra, Sanjay

    2014-01-01

    This book develops an IT strategy for cloud computing that helps businesses evaluate their readiness for cloud services and calculate the ROI. The framework provided helps reduce risks involved in transitioning from traditional "on site" IT strategy to virtual "cloud computing." Since the advent of cloud computing, many organizations have made substantial gains implementing this innovation. Cloud computing allows companies to focus more on their core competencies, as IT enablement is taken care of through cloud services. Cloud Computing and ROI includes case studies covering retail, automobile and food processing industries. Each of these case studies have successfully implemented the cloud computing framework and their strategies are explained. As cloud computing may not be ideal for all businesses, criteria?are also offered to help determine if this strategy should be adopt.

  10. Bigdata Driven Cloud Security: A Survey

    Science.gov (United States)

    Raja, K.; Hanifa, Sabibullah Mohamed

    2017-08-01

    Cloud Computing (CC) is a fast-growing technology to perform massive-scale and complex computing. It eliminates the need to maintain expensive computing hardware, dedicated space, and software. Recently, it has been observed that massive growth in the scale of data or big data generated through cloud computing. CC consists of a front-end, includes the users’ computers and software required to access the cloud network, and back-end consists of various computers, servers and database systems that create the cloud. In SaaS (Software as-a-Service – end users to utilize outsourced software), PaaS (Platform as-a-Service-platform is provided) and IaaS (Infrastructure as-a-Service-physical environment is outsourced), and DaaS (Database as-a-Service-data can be housed within a cloud), where leading / traditional cloud ecosystem delivers the cloud services become a powerful and popular architecture. Many challenges and issues are in security or threats, most vital barrier for cloud computing environment. The main barrier to the adoption of CC in health care relates to Data security. When placing and transmitting data using public networks, cyber attacks in any form are anticipated in CC. Hence, cloud service users need to understand the risk of data breaches and adoption of service delivery model during deployment. This survey deeply covers the CC security issues (covering Data Security in Health care) so as to researchers can develop the robust security application models using Big Data (BD) on CC (can be created / deployed easily). Since, BD evaluation is driven by fast-growing cloud-based applications developed using virtualized technologies. In this purview, MapReduce [12] is a good example of big data processing in a cloud environment, and a model for Cloud providers.

  11. A comparison of long-term parallel measurements of sunshine duration obtained with a Campbell-Stokes sunshine recorder and two automated sunshine sensors

    Science.gov (United States)

    Baumgartner, D. J.; Pötzi, W.; Freislich, H.; Strutzmann, H.; Veronig, A. M.; Foelsche, U.; Rieder, H. E.

    2017-06-01

    In recent decades, automated sensors for sunshine duration (SD) measurements have been introduced in meteorological networks, thereby replacing traditional instruments, most prominently the Campbell-Stokes (CS) sunshine recorder. Parallel records of automated and traditional SD recording systems are rare. Nevertheless, such records are important to understand the differences/similarities in SD totals obtained with different instruments and how changes in monitoring device type affect the homogeneity of SD records. This study investigates the differences/similarities in parallel SD records obtained with a CS and two automated SD sensors between 2007 and 2016 at the Kanzelhöhe Observatory, Austria. Comparing individual records of daily SD totals, we find differences of both positive and negative sign, with smallest differences between the automated sensors. The larger differences between CS-derived SD totals and those from automated sensors can be attributed (largely) to the higher sensitivity threshold of the CS instrument. Correspondingly, the closest agreement among all sensors is found during summer, the time of year when sensitivity thresholds are least critical. Furthermore, we investigate the performance of various models to create the so-called sensor-type-equivalent (STE) SD records. Our analysis shows that regression models including all available data on daily (or monthly) time scale perform better than simple three- (or four-) point regression models. Despite general good performance, none of the considered regression models (of linear or quadratic form) emerges as the "optimal" model. Although STEs prove useful for relating SD records of individual sensors on daily/monthly time scales, this does not ensure that STE (or joint) records can be used for trend analysis.

  12. Jupiter Clouds in Depth

    Science.gov (United States)

    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 nmImages 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 bright near the pole

  13. Cloud management and security

    CERN Document Server

    Abbadi, Imad M

    2014-01-01

    Written by an expert with over 15 years' experience in the field, this book establishes the foundations of Cloud computing, building an in-depth and diverse understanding of the technologies behind Cloud computing. In this book, the author begins with an introduction to Cloud computing, presenting fundamental concepts such as analyzing Cloud definitions, Cloud evolution, Cloud services, Cloud deployment types and highlighting the main challenges. Following on from the introduction, the book is divided into three parts: Cloud management, Cloud security, and practical examples. Part one presents the main components constituting the Cloud and federated Cloud infrastructure(e.g., interactions and deployment), discusses management platforms (resources and services), identifies and analyzes the main properties of the Cloud infrastructure, and presents Cloud automated management services: virtual and application resource management services. Part two analyzes the problem of establishing trustworthy Cloud, discuss...

  14. Sky cover from MFRSR observations

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-07-01

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

  15. A 6-year global cloud climatology from the Atmospheric InfraRed Sounder AIRS and a statistical analysis in synergy with CALIPSO and CloudSat

    Directory of Open Access Journals (Sweden)

    C. J. Stubenrauch

    2010-03-01

    Full Text Available We present a six-year global climatology of cloud properties, obtained from observations of the Atmospheric Infrared Sounder (AIRS onboard the NASA Aqua satellite. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO combined with CloudSat observations, both missions launched as part of the A-Train in 2006, provide a unique opportunity to evaluate the retrieved AIRS cloud properties such as cloud amount and height as well as to explore the vertical structure of different cloud types. AIRS-LMD cloud detection agrees with CALIPSO about 85% over ocean and about 75% over land. Global cloud amount has been estimated as about 66% to 74%, depending on the weighting of not cloudy AIRS footprints by partial cloud cover (0 or 0.3. 40% of all clouds are high clouds, and about 44% of all clouds are single layer low-level clouds. The "radiative" cloud height determined by the AIRS-LMD retrieval corresponds well to the height of the maximum backscatter signal and of the "apparent middle" of the cloud. Whereas the real cloud thickness of high opaque clouds often fills the whole troposphere, their "apparent" cloud thickness (at which optical depth reaches about 5 is on average only 2.5 km. The real geometrical thickness of optically thin cirrus as identified by AIRS-LMD is identical to the "apparent" cloud thickness with an average of about 2.5 km in the tropics and midlatitudes. High clouds in the tropics have slightly more diffusive cloud tops than at higher latitudes. In general, the depth of the maximum backscatter signal increases nearly linearly with increasing "apparent" cloud thickness. For the same "apparent" cloud thickness optically thin cirrus show a maximum backscatter about 10% deeper inside the cloud than optically thicker clouds. We also show that only the geometrically thickest opaque clouds and (the probably surrounding anvil cirrus penetrate the stratosphere in the tropics.

  16. A 6-year global cloud climatology from the Atmospheric InfraRed Sounder AIRS and a statistical analysis in synergy with CALIPSO and CloudSat

    Directory of Open Access Journals (Sweden)

    S. Cros

    2010-08-01

    Full Text Available We present a six-year global climatology of cloud properties, obtained from observations of the Atmospheric Infrared Sounder (AIRS onboard the NASA Aqua satellite. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO combined with CloudSat observations, both missions launched as part of the A-Train in 2006, provide a unique opportunity to evaluate the retrieved AIRS cloud properties such as cloud amount and height. In addition, they permit to explore the vertical structure of different cloud types. AIRS-LMD cloud detection agrees with CALIPSO about 85% over ocean and about 75% over land. Global cloud amount has been estimated from 66% to 74%, depending on the weighting of not cloudy AIRS footprints by partial cloud cover from 0 to 0.3. 42% of all clouds are high clouds, and about 42% of all clouds are single layer low-level clouds. The "radiative" cloud height determined by the AIRS-LMD retrieval corresponds well to the height of the maximum backscatter signal and of the "apparent middle" of the cloud. Whereas the real cloud thickness of high opaque clouds often fills the whole troposphere, their "apparent" cloud thickness (at which optical depth reaches about 5 is on average only 2.5 km. The real geometrical thickness of optically thin cirrus as identified by AIRS-LMD is identical to the "apparent" cloud thickness with an average of about 2.5 km in the tropics and midlatitudes. High clouds in the tropics have slightly more diffusive cloud tops than at higher latitudes. In general, the depth of the maximum backscatter signal increases nearly linearly with increasing "apparent" cloud thickness. For the same "apparent" cloud thickness optically thin cirrus show a maximum backscatter about 10% deeper inside the cloud than optically thicker clouds. We also show that only the geometrically thickest opaque clouds and (the probably surrounding anvil cirrus penetrate the stratosphere in the tropics.

  17. Cloud Computing

    DEFF Research Database (Denmark)

    Krogh, Simon

    2013-01-01

    The second half of the 20th century has been characterized by an explosive development in information technology (Maney, Hamm, & O'Brien, 2011). Processing power, storage capacity and network bandwidth have increased exponentially, resulting in new possibilities and shifting IT paradigms. In step...... with technological changes, the paradigmatic pendulum has swung between increased centralization on one side and a focus on distributed computing that pushes IT power out to end users on the other. With the introduction of outsourcing and cloud computing, centralization in large data centers is again dominating...... the IT scene. In line with the views presented by Nicolas Carr in 2003 (Carr, 2003), it is a popular assumption that cloud computing will be the next utility (like water, electricity and gas) (Buyya, Yeo, Venugopal, Broberg, & Brandic, 2009). However, this assumption disregards the fact that most IT production...

  18. 76 FR 55387 - Farm Credit Administration Board; Sunshine Act; Regular Meeting

    Science.gov (United States)

    2011-09-07

    ... From the Federal Register Online via the Government Publishing Office FARM CREDIT ADMINISTRATION Farm Credit Administration Board; Sunshine Act; Regular Meeting AGENCY: Farm Credit Administration... the regular meeting of the Farm Credit Administration Board (Board). DATE AND TIME: The regular...

  19. 77 FR 61751 - Farm Credit Administration Board; Sunshine Act; Regular Meeting

    Science.gov (United States)

    2012-10-11

    ... Mac Investment Management Bookletter--Providing Credit to Farmers and Ranchers Operating in Local... From the Federal Register Online via the Government Publishing Office FARM CREDIT ADMINISTRATION Farm Credit Administration Board; Sunshine Act; Regular Meeting AGENCY: Farm Credit...

  20. 78 FR 71708 - Sunshine Act Meeting; Unified Carrier Registration Plan Board of Directors

    Science.gov (United States)

    2013-11-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Motor Carrier Safety Administration Sunshine Act Meeting; Unified Carrier Registration Plan Board of Directors AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice...

  1. 78 FR 77773 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

    Science.gov (United States)

    2013-12-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Motor Carrier Safety Administration Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice...

  2. Satellite discrimination of snow/cloud surfaces

    Science.gov (United States)

    Crane, R. G.; Anderson, M. R.

    1984-01-01

    Differentiation between cloud cover and snow surfaces using remotely sensed data is complicated by the similarity of their radiative temperatures, and also by their similar reflectances at visible wavelengths. A method of cloud analysis over snow-covered regions is presented, using 1.51-1.63 micron data from an experimental sensor on board a U.S. Air Force Defense Meteorological Satellite Program platform. At these wavelengths, snow appears relatively 'black' while clouds are highly reflective. The spatial structure of the 1.51-1.63 micron reflectivity fields over a continuous snow surface are examined. Plots of mean reflectance against coefficients of variation for 4 x 4 pixel areas reveals a cluster of points have low reflectivity and low variability, corresponding to snow-covered (cloud free) areas, and a similar cluster with high reflectances corresponding to 100 per cent cloud cover. For the case of a single layered cloud, the radiances associated with partially filled fields of view are also inferred.

  3. Clouds and snowmelt on the north slope of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Stamnes, K.; Bowling, S.A. [Univ. of Alaska, Fairbanks, AK (United States)

    1996-04-01

    Clouds have a large effect on the radiation field. Consequently, possible changes in cloud properties may have a very substantial impact on climate. Of all natural surfaces, seasonal snow cover has the highest surface albedo, which is one of the most important components of the climatic system. Interactions between clouds and seasonal snow cover are expected to have a significant effect on climate and its change at high latitudes. The purpose of this paper is to investigate the sensitivity of the surface cloud-radiative forcing during the period of snowmelt at high latitudes. The primary variables investigated are cloud liquid path (LWP) and droplet equivalent radius (r{sub e}). We will also examine the sensitivity of the surface radiative fluxes to cloud base height and cloud base temperature.

  4. Land Cover - Minnesota Land Cover Classification System

    Data.gov (United States)

    Minnesota Department of Natural Resources — Land cover data set based on the Minnesota Land Cover Classification System (MLCCS) coding scheme. This data was produced using a combination of aerial photograph...

  5. Progress towards a Venus reference cloud model

    Science.gov (United States)

    Wilson, Colin; Ignatiev, Nikolay; Marcq, Emmanuel

    Venus is completely enveloped by clouds. The main cloud layers stretch from altitudes of 48 - 75 km, with additional tenuous hazes found at altitudes 30 - 100 km. Clouds play a crucial role in governing atmospheric circulation, chemistry and climate on all planets, but particularly so on Venus due to the optical thickness of the atmosphere. The European Space Agency’s Venus Express (VEx) satellite has carried out a wealth of observations of Venus clouds since its arrival at Venus in April 2006. Many VEx observations are relevant to cloud science - from imagers and spectrometers to solar, stellar and radio occultation - each covering different altitude ranges, spectral ranges and atmospheric constituents. We have formed an International Team at the International Space Science Institute to bring together scientists from each of the relevant Venus Express investigation teams as well as from previous missions, as well as those developing computational and analytical models of clouds and hazes. The aims of the project are (1) to create self-consistent reference cloud/haze models which capture not only a mean cloud structure but also its main modes of variability; and (2) to bring together modelers and observers, to reach an understanding of clouds and hazes on Venus which matches all observables and is physically consistent. Our approach is to first to assemble an averaged cloud profile for low latitudes, showing how cloud number abundances and other observables vary as a function of altitude, consistent with all available observations. In a second step, we will expand this work to produce a reference cloud profile which varies with latitude and local solar time, as well as optical thickness of the cloud. We will present our status in progressing towards this goal. We acknowledge the support of the International Space Science Institute of Berne, Switzerland, in hosting our Team’s meetings.

  6. Spectral Dependence of MODIS Cloud Droplet Effective Radius Retrievals for Marine Boundary Layer Clouds

    Science.gov (United States)

    Zhang, Zhibo; Platnick, Steven E.; Ackerman, Andrew S.; Cho, Hyoun-Myoung

    2014-01-01

    Low-level warm marine boundary layer (MBL) clouds cover large regions of Earth's surface. They have a significant role in Earth's radiative energy balance and hydrological cycle. Despite the fundamental role of low-level warm water clouds in climate, our understanding of these clouds is still limited. In particular, connections between their properties (e.g. cloud fraction, cloud water path, and cloud droplet size) and environmental factors such as aerosol loading and meteorological conditions continue to be uncertain or unknown. Modeling these clouds in climate models remains a challenging problem. As a result, the influence of aerosols on these clouds in the past and future, and the potential impacts of these clouds on global warming remain open questions leading to substantial uncertainty in climate projections. To improve our understanding of these clouds, we need continuous observations of cloud properties on both a global scale and over a long enough timescale for climate studies. At present, satellite-based remote sensing is the only means of providing such observations.

  7. Tuberculosis incidence correlates with sunshine: an ecological 28-year time series study.

    Directory of Open Access Journals (Sweden)

    Gavin C K W Koh

    Full Text Available BACKGROUND: Birmingham is the largest UK city after London, and central Birmingham has an annual tuberculosis incidence of 80 per 100,000. We examined seasonality and sunlight as drivers of tuberculosis incidence. Hours of sunshine are seasonal, sunshine exposure is necessary for the production of vitamin D by the body and vitamin D plays a role in the host response to tuberculosis. METHODS: We performed an ecological study that examined tuberculosis incidence in Birmingham from Dec 1981 to Nov 2009, using publicly-available data from statutory tuberculosis notifications, and related this to the seasons and hours of sunshine (UK Meteorological Office data using unmeasured component models. RESULTS: There were 9,739 tuberculosis cases over the study period. There was strong evidence for seasonality, with notifications being 24.1% higher in summer than winter (p<0.001. Winter dips in sunshine correlated with peaks in tuberculosis incidence six months later (4.7% increase in incidence for each 100 hours decrease in sunshine, p<0.001. DISCUSSION AND CONCLUSION: A potential mechanism for these associations includes decreased vitamin D levels with consequent impaired host defence arising from reduced sunshine exposure in winter. This is the longest time series of any published study and our use of statutory notifications means this data is essentially complete. We cannot, however, exclude the possibility that another factor closely correlated with the seasons, other than sunshine, is responsible. Furthermore, exposure to sunlight depends not only on total hours of sunshine but also on multiple individual factors. Our results should therefore be considered hypothesis-generating. Confirmation of a potential causal relationship between winter vitamin D deficiency and summer peaks in tuberculosis incidence would require a randomized-controlled trial of the effect of vitamin D supplementation on future tuberculosis incidence.

  8. Observational and model evidence for positive low-level cloud feedback.

    Science.gov (United States)

    Clement, Amy C; Burgman, Robert; Norris, Joel R

    2009-07-24

    Feedbacks involving low-level clouds remain a primary cause of uncertainty in global climate model projections. This issue was addressed by examining changes in low-level clouds over the Northeast Pacific in observations and climate models. Decadal fluctuations were identified in multiple, independent cloud data sets, and changes in cloud cover appeared to be linked to changes in both local temperature structure and large-scale circulation. This observational analysis further indicated that clouds act as a positive feedback in this region on decadal time scales. The observed relationships between cloud cover and regional meteorological conditions provide a more complete way of testing the realism of the cloud simulation in current-generation climate models. The only model that passed this test simulated a reduction in cloud cover over much of the Pacific when greenhouse gases were increased, providing modeling evidence for a positive low-level cloud feedback.

  9. Cloud Interactions

    Science.gov (United States)

    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 with Raytheon Santa Barbara

  10. Clouds at CTIO and the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, Jr., Eric [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-08-01

    An understanding of the weather patters at Cerro-Tololo Inter-American (CTIO) Observatory, the observing site for the Dark Energy Survey (DES), is important for assessing the efciency of DES operations in using observing time and for planning future operations. CTIO has maintained records of cloud-cover by quarters of nights since 1975. A comparison between these cloud records in the 2013-2014 DES observing season (DES year 1) and achieved observing efciency and exposure quality allows the DES collaboration to make better use of the historical records in survey planning. Plots and tables here relate human recorded cloud-cover to collection of good DES data, show the variation of typical cloud-cover by month, and evaluate the relationship between the El Niño weather pattern and cloud-cover at CTIO.

  11. Mapping known and potential mineral occurrences and host rocks in the Bonnifield Mining District using minimal cloud- and snow-cover ASTER data: Chapter E in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

    Science.gov (United States)

    Hubbard, Bernard E.; Dusel-Bacon, Cynthia; Rowan, Lawrence C.; Eppinger, Robert G.; Gough, Larry P.; Day, Warren C.

    2007-01-01

    On July 8, 2003, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor acquired satellite imagery of a 60-kilometer-wide swath covering a portion of the Bonnifield mining district within the southernmost part of the Tintina Gold Province, Alaska, under unusually favorable conditions of minimal cloud and snow cover. Although rocks from more than eight different lithotectonic terranes are exposed within the extended swath of data, we focus on volcanogenic massive sulfides (VMS) and porphyry deposits within the Yukon-Tanana terrane (YTT), the largest Mesozoic accretionary terrane exposed between the Denali fault system to the south of Fairbanks and the Tintina fault system to the north of Fairbanks. Comparison of thermal-infrared region (TIR) decorrelation stretch data to available geologic maps indicates that rocks from the YTT contain a wide range of rock types ranging in composition from mafic metavolcanic rocks to felsic rock types such as metarhyolites, pelitic schists, and quartzites. The nine-band ASTER visible-near-infrared region--short-wave infrared region (VNIR-SWIR) reflectance data and spectral matched-filter processing were used to map hydrothermal alteration patterns associated with VMS and porphyry deposit types. In particular, smectite, kaolinite, opaline silica, jarosite and (or) other ferric iron minerals defined narrow (less than 250-meter diameter) zonal patterns around Red Mountain and other potential VMS targets. Using ASTER we identified some of the known mineral deposits in the region, as well as mineralogically similar targets that may represent potential undiscovered deposits. Some known deposits were not identified and may have been obscured by vegetation or snow cover or were too small to be resolved.

  12. Low cloud properties influenced by cosmic rays

    DEFF Research Database (Denmark)

    Marsh, Nigel; Svensmark, Henrik

    2000-01-01

    The influence of solar variability on climate is currently uncertain. Recent observations have indicated a possible mechanism via the influence of solar modulated cosmic rays on global cloud cover. Surprisingly the influence of solar variability is strongest in low clouds (less than or equal to3 ......), which points to a microphysical mechanism involving aerosol formation that is enhanced by ionization due to cosmic rays. If confirmed it suggests that the average state of the heliosphere is important for climate on Earth.......The influence of solar variability on climate is currently uncertain. Recent observations have indicated a possible mechanism via the influence of solar modulated cosmic rays on global cloud cover. Surprisingly the influence of solar variability is strongest in low clouds (less than or equal to3 km...

  13. GASP cloud encounter statistics - Implications for laminar flow control flight

    Science.gov (United States)

    Jasperson, W. H.; Nastrom, G. D.; Davis, R. E.; Holdeman, J. D.

    1984-01-01

    The cloud observation archive from the NASA Global Atmospheric Sampling Program (GASP) is analyzed in order to derive the probability of cloud encounter at altitudes normally flown by commercial airliners, for application to a determination of the feasability of Laminar Flow Control (LFC) on long-range routes. The probability of cloud encounter is found to vary significantly with season. Several meteorological circulation features are apparent in the latitudinal distribution of cloud cover. The cloud encounter data are shown to be consistent with the classical midlatitude cyclone model with more clouds encountered in highs than in lows. Aircraft measurements of route-averaged time-in-clouds fit a gamma probability distribution model which is applied to estimate the probability of extended cloud encounter, and the associated loss of LFC effectiveness along seven high-density routes. The probability is demonstrated to be low.

  14. Long Term Cloud Property Datasets From MODIS and AVHRR Using the CERES Cloud Algorithm

    Science.gov (United States)

    Minnis, Patrick; Bedka, Kristopher M.; Doelling, David R.; Sun-Mack, Sunny; Yost, Christopher R.; Trepte, Qing Z.; Bedka, Sarah T.; Palikonda, Rabindra; Scarino, Benjamin R.; Chen, Yan; Hong, Gang; Bhatt, Rajendra

    2015-01-01

    Cloud properties play a critical role in climate change. Monitoring cloud properties over long time periods is needed to detect changes and to validate and constrain models. The Clouds and the Earth's Radiant Energy System (CERES) project has developed several cloud datasets from Aqua and Terra MODIS data to better interpret broadband radiation measurements and improve understanding of the role of clouds in the radiation budget. The algorithms applied to MODIS data have been adapted to utilize various combinations of channels on the Advanced Very High Resolution Radiometer (AVHRR) on the long-term time series of NOAA and MetOp satellites to provide a new cloud climate data record. These datasets can be useful for a variety of studies. This paper presents results of the MODIS and AVHRR analyses covering the period from 1980-2014. Validation and comparisons with other datasets are also given.

  15. The incidence and implications of clouds for cloud forest plant water relations.

    Science.gov (United States)

    Goldsmith, Gregory R; Matzke, Nicholas J; Dawson, Todd E

    2013-03-01

    Although clouds are the most recognisable and defining feature of tropical montane cloud forests, little research has focussed on how clouds affect plant functioning. We used satellite and ground-based observations to study cloud and leaf wetting patterns in contrasting tropical montane and pre-montane cloud forests. We then studied the consequences of leaf wetting for the direct uptake of water accumulated on leaf surfaces into the leaves themselves. During the dry season, the montane forest experienced higher precipitation, cloud cover and leaf wetting events of longer duration than the pre-montane forest. Leaf wetting events resulted in foliar water uptake in all species studied. The capacity for foliar water uptake differed significantly between the montane and pre-montane forest plant communities, as well as among species within a forest. Our results indicate that foliar water uptake is common in these forest plants and improves plant water status during the dry season.

  16. Martian Clouds

    Science.gov (United States)

    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 investigation is led by Dr. Philip

  17. 近40 a甘南高原日照时数变化趋势及影响因子%Variation Trend Analysis on Sunshine Duration and Its Impact Factors in Gannan Plateau in Recent 40 Years

    Institute of Scientific and Technical Information of China (English)

    王建兵; 敖泽建; 陈洋

    2014-01-01

    related with the temperature,water vapor pressure,cloud amount,precipitation and wind speed,and the different variation tendency of precipitation and wind speed was the main effecting factors on the different variation tendency of sunshine duration in the eastern part and the western part of the Gannan Plateau.%利用甘南高原8个气象站1971~2010年的日照时数地面观测资料,对其近40 a日照时数的时空变化特征进行了分析。发现:甘南高原年日照时数的空间分布特征呈西多东少;月际变化表现出明显的3峰3谷的特征;20世纪70~80年代是甘南高原日照时数最少的时期,而20世纪90年代日照时数明显增加,进入21世纪后,高原西部日照时数出现了减少的趋势,而东部仍以偏多为主。突变分析表明,甘南高原日照时数的变化可分为3种类型:第1类为出现增大突变,并且仍持续上升的,主要有卓尼、迭部;第2类为出现增大突变,但目前开始减少,主要有夏河、玛曲、舟曲;第3类为未出现突变的,有合作、碌曲、临潭。日照时数的变化与气温、水汽压、云量、降水和风速的变化密切相关,造成甘南高原西部与东部日照时数不同变化趋势的主要原因是降水量和风速的不同变化。

  18. Spatiotemporal Variations of Cloud Amount over the Yangtze River Delta, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wenjing,ZHANG Ning,; SUN Jianning

    2014-01-01

    Based on the NOAA’s Advanced Very High Resolution Radiometer (AVHRR) Pathfi nder Atmospheres Extended (PATMOS-x) monthly mean cloud amount data, variations of annual and seasonal mean cloud amount over the Yangtze River Delta (YRD), China were examined for the period 1982-2006 by using a linear regression analysis. Both total and high-level cloud amounts peak in June and reach minimum in December, mid-level clouds have a peak during winter months and reach a minimum in summer, and low-level clouds vary weakly throughout the year with a weak maximum from August to October. For the annual mean cloud amount, a slightly decreasing tendency (-0.6% sky cover per decade) of total cloud amount is observed during the studying period, which is mainly due to the reduction of annual mean high-level cloud amount (-2.2% sky cover per decade). Mid-level clouds occur least (approximately 15% sky cover) and remain invariant, while the low-level cloud amount shows a signifi cant increase during spring (1.5% sky cover per decade) and summer (3.0%sky cover per decade). Further analysis has revealed that the increased low-level clouds during the summer season are mainly impacted by the local environment. For example, compared to the low-level cloud amounts over the adjacent rural areas (e.g., cropland, large water body, and mountain areas covered by forest), those over and around urban agglomerations rise more dramatically.

  19. Do clouds save the great barrier reef? satellite imagery elucidates the cloud-SST relationship at the local scale.

    Directory of Open Access Journals (Sweden)

    Susannah M Leahy

    Full Text Available Evidence of global climate change and rising sea surface temperatures (SSTs is now well documented in the scientific literature. With corals already living close to their thermal maxima, increases in SSTs are of great concern for the survival of coral reefs. Cloud feedback processes may have the potential to constrain SSTs, serving to enforce an "ocean thermostat" and promoting the survival of coral reefs. In this study, it was hypothesized that cloud cover can affect summer SSTs in the tropics. Detailed direct and lagged relationships between cloud cover and SST across the central Great Barrier Reef (GBR shelf were investigated using data from satellite imagery and in situ temperature and light loggers during two relatively hot summers (2005 and 2006 and two relatively cool summers (2007 and 2008. Across all study summers and shelf positions, SSTs exhibited distinct drops during periods of high cloud cover, and conversely, SST increases during periods of low cloud cover, with a three-day temporal lag between a change in cloud cover and a subsequent change in SST. Cloud cover alone was responsible for up to 32.1% of the variation in SSTs three days later. The relationship was strongest in both El Niño (2005 and La Niña (2008 study summers and at the inner-shelf position in those summers. SST effects on subsequent cloud cover were weaker and more variable among study summers, with rising SSTs explaining up to 21.6% of the increase in cloud cover three days later. This work quantifies the often observed cloud cooling effect on coral reefs. It highlights the importance of incorporating local-scale processes into bleaching forecasting models, and encourages the use of remote sensing imagery to value-add to coral bleaching field studies and to more accurately predict risks to coral reefs.

  20. Do clouds save the great barrier reef? satellite imagery elucidates the cloud-SST relationship at the local scale.

    Science.gov (United States)

    Leahy, Susannah M; Kingsford, Michael J; Steinberg, Craig R

    2013-01-01

    Evidence of global climate change and rising sea surface temperatures (SSTs) is now well documented in the scientific literature. With corals already living close to their thermal maxima, increases in SSTs are of great concern for the survival of coral reefs. Cloud feedback processes may have the potential to constrain SSTs, serving to enforce an "ocean thermostat" and promoting the survival of coral reefs. In this study, it was hypothesized that cloud cover can affect summer SSTs in the tropics. Detailed direct and lagged relationships between cloud cover and SST across the central Great Barrier Reef (GBR) shelf were investigated using data from satellite imagery and in situ temperature and light loggers during two relatively hot summers (2005 and 2006) and two relatively cool summers (2007 and 2008). Across all study summers and shelf positions, SSTs exhibited distinct drops during periods of high cloud cover, and conversely, SST increases during periods of low cloud cover, with a three-day temporal lag between a change in cloud cover and a subsequent change in SST. Cloud cover alone was responsible for up to 32.1% of the variation in SSTs three days later. The relationship was strongest in both El Niño (2005) and La Niña (2008) study summers and at the inner-shelf position in those summers. SST effects on subsequent cloud cover were weaker and more variable among study summers, with rising SSTs explaining up to 21.6% of the increase in cloud cover three days later. This work quantifies the often observed cloud cooling effect on coral reefs. It highlights the importance of incorporating local-scale processes into bleaching forecasting models, and encourages the use of remote sensing imagery to value-add to coral bleaching field studies and to more accurately predict risks to coral reefs.

  1. The Clouds of Isidore

    Science.gov (United States)

    2002-01-01

    viewing angle as well as the height field. Note that over the short distances (2.2 kilometers) that the local albedo product is generated, values can be greater than 1.0 due to contributions from cloud sides. Areas where albedo could not be retrieved are shown in dark gray.The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 14669. The panels cover an area of about 380 kilometers x 704 kilometers, and utilize data from blocks 70 to 79within World Reference System-2 path 17.MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  2. Global cloud climatology from surface observations

    Energy Technology Data Exchange (ETDEWEB)

    Warren, S. [Univ. of Washington, Seattle, WA (United States)

    1995-09-01

    Surface weather observations from stations on land and ships in the ocean are used to obtain the global distribution, at 5{sup o}x5{sup o} latitude-longitude resolution, of total cloud cover and the average amounts of the different cloud types: cumulus, cumulonimbus, stratus, stratocumulus, nimbostratus, altostratus, altocumulus, cirrus, cirrostratus, cirrocumulus, and fog. Diurnal and seasonal variations are derived, as well as interannual variations and multi-year trends. 3 refs., 3 figs.

  3. Cloud Computing (4)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ 8 Case Study Cloud computing is still a new phenomenon. Although many IT giants are developing their own cloud computing infrastructures,platforms, software, and services, few have really succeeded in becoming cloud computing providers.

  4. Blue skies for CLOUD

    CERN Multimedia

    2006-01-01

    Through the recently approved CLOUD experiment, CERN will soon be contributing to climate research. Tests are being performed on the first prototype of CLOUD, an experiment designed to assess cosmic radiation influence on cloud formation.

  5. Quantitative Measures of Immersion in Cloud and the Biogeography of Cloud Forests

    Science.gov (United States)

    Lawton, R. O.; Nair, U. S.; Ray, D.; Regmi, A.; Pounds, J. A.; Welch, R. M.

    2010-01-01

    Sites described as tropical montane cloud forests differ greatly, in part because observers tend to differ in their opinion as to what constitutes frequent and prolonged immersion in cloud. This definitional difficulty interferes with hydrologic analyses, assessments of environmental impacts on ecosystems, and biogeographical analyses of cloud forest communities and species. Quantitative measurements of cloud immersion can be obtained on site, but the observations are necessarily spatially limited, although well-placed observers can examine 10 50 km of a mountain range under rainless conditions. Regional analyses, however, require observations at a broader scale. This chapter discusses remote sensing and modeling approaches that can provide quantitative measures of the spatiotemporal patterns of cloud cover and cloud immersion in tropical mountain ranges. These approaches integrate remote sensing tools of various spatial resolutions and frequencies of observation, digital elevation models, regional atmospheric models, and ground-based observations to provide measures of cloud cover, cloud base height, and the intersection of cloud and terrain. This combined approach was applied to the Monteverde region of northern Costa Rica to illustrate how the proportion of time the forest is immersed in cloud may vary spatially and temporally. The observed spatial variation was largely due to patterns of airflow over the mountains. The temporal variation reflected the diurnal rise and fall of the orographic cloud base, which was influenced in turn by synoptic weather conditions, the seasonal movement of the Intertropical Convergence Zone and the north-easterly trade winds. Knowledge of the proportion of the time that sites are immersed in clouds should facilitate ecological comparisons and biogeographical analyses, as well as land use planning and hydrologic assessments in areas where intensive on-site work is not feasible.

  6. Land cover changes and their biogeophysical effects on climate

    Science.gov (United States)

    Rezaul Mahmood; Roger A. Pielke; Kenneth G. Hubbard; Dev Niyogi; Paul A. Dirmeyer; Clive McAlpine; Andrew M. Carleton; Robert Hale; Samuel Gameda; Adriana Beltrán-Przekurat; Bruce Baker; Richard McNider; David R. Legates; Marshall Shepherd; Jinyang Du; Peter D. Blanken; Oliver W. Frauenfeld; U.S. Nair; Souleymane. Fall

    2013-01-01

    Land cover changes (LCCs) play an important role in the climate system. Research over recent decades highlights the impacts of these changes on atmospheric temperature, humidity, cloud cover, circulation, and precipitation. These impacts range from the local- and regional-scale to sub-continental and global-scale. It has been found that the impacts of regional-scale...

  7. Clouds and the Near-Earth Environment: Possible Links

    Directory of Open Access Journals (Sweden)

    Condurache-Bota Simona

    2015-12-01

    Full Text Available Climate variability is a hot topic not only for scientists and policy-makers, but also for each and every one of us. The anthropogenic activities are considered to be responsible for most climate change, however there are large uncertainties about the magnitude of effects of solar variability and other extraterrestrial influences, such as galactic cosmic rays on terrestrial climate. Clouds play an important role due to feedbacks of the radiation budget: variation of cloud cover/composition affects climate, which, in turn, affects cloud cover via atmospheric dynamics and sea temperature variations. Cloud formation and evolution are still under scientific scrutiny, since their microphysics is still not understood. Besides atmospheric dynamics and other internal climatic parameters, extraterrestrial sources of cloud cover variation are considered. One of these is the solar wind, whose effect on cloud cover might be modulated by the global atmospheric electrical circuit. Clouds height and composition, their seasonal variation and latitudinal distribution should be considered when trying to identify possible mechanisms by which solar energy is transferred to clouds. The influence of the solar wind on cloud formation can be assessed also through the ap index - the geomagnetic storm index, which can be readily connected with interplanetary magnetic field, IMF structure. This paper proposes to assess the possible relationship between both cloud cover and solar wind proxies, as the ap index, function of cloud height and composition and also through seasonal studies. The data covers almost three solar cycles (1984-2009. Mechanisms are looked for by investigating observed trends or correlation at local/seasonal scale

  8. Cloud computing for data-intensive applications

    CERN Document Server

    Li, Xiaolin

    2014-01-01

    This book presents a range of cloud computing platforms for data-intensive scientific applications. It covers systems that deliver infrastructure as a service, including: HPC as a service; virtual networks as a service; scalable and reliable storage; algorithms that manage vast cloud resources and applications runtime; and programming models that enable pragmatic programming and implementation toolkits for eScience applications. Many scientific applications in clouds are also introduced, such as bioinformatics, biology, weather forecasting and social networks. Most chapters include case studie

  9. Distribution of possible sunshine durations over rugged terrains of China

    Institute of Scientific and Technical Information of China (English)

    ZENG Yan; QIU Xinfa; MIAO Qilong; LIU Changming

    2003-01-01

    Based on the digital elevation model (DEM), a new model for calculating possible sunshine duration (PSD) is completely described. Using this model, monthly PSD with resolution of 1 km×1 km for the rugged topography of China is calculated. Results suggest that terrain has robust effect on PSD, particularly in winter when a lower sun elevation angle exists. Besides, the proposed model taking the DEM data as the input has an ability to process mass of data and is applicable to satellite image processing platforms or Geographic Information System (GIS). The PSD (in hours) is provided in the same way as other kinds of spatial information and can be employed as basic geographic data for relevant studies as well.

  10. Cloud-Top Entrainment in Stratocumulus Clouds

    Science.gov (United States)

    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.

  11. Cloud and Radiation Processes Simulated by a Coupled Atmosphere-Ocean Model

    Institute of Scientific and Technical Information of China (English)

    WANG Fang; DING Yihui; XU Ying

    2007-01-01

    Using NCC/IAP T63 coupled atmosphere-ocean general circulation model (AOGCM), two 20-yr integrations were processed, and their ability to simulate cloud and radiation was analysed in detail. The results show that the model can simulate the basic distribution of cloud cover, and however, obvious differences still exist compared with ISCCP satellite data and ERA reanalysis data. The simulated cloud cover is less in general, especially the abnormal low values in some regions of ocean. By improving the cloud cover scheme,simulated cloud cover in the eastern Pacific and Atlantic, summer hemisphere's oceans from subtropical to mid-latitude is considerably improved. But in the tropical Indian Ocean and West Pacific the cloud cover difference is still evident, mainly due to the deficiency of high cloud simulation in these regions resulting from deep cumulus convection. In terms of the analysis on radiation and cloud radiative forcing, we find that simulation on long wave radiation is better than short wave radiation. The simulation error of short wave radiation is caused mostly by the simulation difference in short wave radiative forcing, sea ice, and snow cover, and also by not involving aerosol's effect. The simulation error of long wave radiation is mainly resulting from deficiency in simulating cloud cover and underlying surface temperature. Corresponding to improvement of cloud cover, the simulated radiation (especially short wave radiation) in eastern oceans,summer hemisphere's oceans from subtropical to mid-latitude is remarkably improved. This also bring sobvious improvement to net radiation in these regions.

  12. Sunshine, Sea, and Season of Birth: MS Incidence in Wales.

    Directory of Open Access Journals (Sweden)

    Lloyd D Balbuena

    Full Text Available Maternal sun exposure in gestation and throughout the lifetime is necessary for vitamin D synthesis, and living near the sea is a population level index of seafood consumption. The aim of this study was to estimate the incidence rate of multiple sclerosis (MS in Wales and examine its association with sun exposure, coastal living, and latitude. The study used a database of MS hospital visits and admissions in Wales between 2002 and 2013. For the 1,909 lower layer super output areas (LSOAs in Wales, coastal status, population, longitude/latitude, and average sunshine hours per day were obtained. Age-specific and age-standardised MS incidence were calculated and modelled using Poisson regression. The distribution of births by month was compared between MS cases and the combined England and Wales population. There were 3,557 new MS cases between 2002 and 2013, with an average annual incidence of 8.14 (95% CI: 7.69-8.59 among males and 12.97 (95% CI: 12.44-13.50 among females per 100,000 population. The female-to-male ratio was 1.86:1. For both sexes combined, the average annual incidence rate was 9.10 (95% CI: 8.80-9.40. All figures are age-standardized to the 1976 European standard population. Compared to the combined England and Wales population, more people with MS were born in April, observed-to-expected ratio: 1.21 (95% CI: 1.08-1.36. MS incidence varied directly with latitude and inversely with sunshine hours. Proximity to the coast was associated with lower MS incidence only in easterly areas. This study shows that MS incidence rate in Wales is comparable to the rate in Scotland and is associated with environmental factors that probably represent levels of vitamin D.

  13. Silicon Photonics Cloud (SiCloud)

    DEFF Research Database (Denmark)

    DeVore, P. T. S.; Jiang, Y.; Lynch, M.;

    2015-01-01

    Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths.......Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths....

  14. Automatic Cloud Bursting under FermiCloud

    Energy Technology Data Exchange (ETDEWEB)

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

    1900-01-01

    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

  15. Automatic Cloud Bursting under FermiCloud

    Energy Technology Data Exchange (ETDEWEB)

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

    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

  16. Beam Measurements of a CLOUD (Cosmics Leaving OUtdoor Droplets) Chamber

    CERN Document Server

    Kirkby, Jasper

    2001-01-01

    A striking correlation has recently been observed between global cloud cover and the flux of incident cosmic rays. The effect of natural variations in the cosmic ray flux is large, causing estimated changes in the Earth's energy radiation balance that are comparable to those attributed to greenhouse gases from the burning of fossil fuels since the Industrial Revolution. However a direct link between cosmic rays and cloud formation has not been unambiguously established. We therefore propose to experimentally measure cloud (water droplet) formation under controlled conditions in a test beam at CERN with a CLOUD chamber, duplicating the conditions prevailing in the troposphere. These data, which have never been previously obtained, will allow a detailed understanding of the possible effects of cosmic rays on clouds and confirm, or otherwise, a direct link between cosmic rays, global cloud cover and the Earth's climate. The measurements will, in turn, allow more reliable calculations to be made of the residual e...

  17. What Medicare Covers

    Science.gov (United States)

    ... What Part A covers Medicare Part A hospital insurance covers inpatient hospital care, skilled nursing facility, hospice, lab tests, surgery, ... Medicare Covers Drug Coverage (Part D) Supplements & Other Insurance Claims & ... doctors, providers, hospitals & plans Where can I get covered medical items? ...

  18. Could cirrus clouds have warmed early Mars?

    Science.gov (United States)

    Ramirez, Ramses M.; Kasting, James F.

    2017-01-01

    The presence of the ancient valley networks on Mars indicates that the climate at 3.8 Ga was warm enough to allow substantial liquid water to flow on the martian surface for extended periods of time. However, the mechanism for producing this warming continues to be debated. One hypothesis is that Mars could have been kept warm by global cirrus cloud decks in a CO2sbnd H2O atmosphere containing at least 0.25 bar of CO2 (Urata and Toon, 2013). Initial warming from some other process, e.g., impacts, would be required to make this model work. Those results were generated using the CAM 3-D global climate model. Here, we use a single-column radioactive-convective climate model to further investigate the cirrus cloud warming hypothesis. Our calculations indicate that cirrus cloud decks could have produced global mean surface temperatures above freezing, but only if cirrus cloud cover approaches ∼75 - 100% and if other cloud properties (e.g., height, optical depth, particle size) are chosen favorably. However, at more realistic cirrus cloud fractions, or if cloud parameters are not optimal, cirrus clouds do not provide the necessary warming, suggesting that other greenhouse mechanisms are needed.

  19. Automatic cloud classification of whole sky images

    Directory of Open Access Journals (Sweden)

    A. Heinle

    2010-05-01

    Full Text Available The recently increasing development of whole sky imagers enables temporal and spatial high-resolution sky observations. One application already performed in most cases is the estimation of fractional sky cover. A distinction between different cloud types, however, is still in progress. Here, an automatic cloud classification algorithm is presented, based on a set of mainly statistical features describing the color as well as the texture of an image. The k-nearest-neighbour classifier is used due to its high performance in solving complex issues, simplicity of implementation and low computational complexity. Seven different sky conditions are distinguished: high thin clouds (cirrus and cirrostratus, high patched cumuliform clouds (cirrocumulus and altocumulus, stratocumulus clouds, low cumuliform clouds, thick clouds (cumulonimbus and nimbostratus, stratiform clouds and clear sky. Based on the Leave-One-Out Cross-Validation the algorithm achieves an accuracy of about 97%. In addition, a test run of random images is presented, still outperforming previous algorithms by yielding a success rate of about 75%, or up to 88% if only "serious" errors with respect to radiation impact are considered. Reasons for the decrement in accuracy are discussed, and ideas to further improve the classification results, especially in problematic cases, are investigated.

  20. Is a little sunshine all we need? On the impact of sunshine regulation on profits, productivity and prices in the Dutch drinking water sector

    NARCIS (Netherlands)

    de Witte, K.; Saal, D.S.

    2010-01-01

    This paper analyzes the performance of Dutch drinking water utilities before and after the introduction of sunshine regulation, which involves publication of the performance of utilities but no formal price regulation. By decomposing profit change into its economic drivers, our results suggest that,

  1. Snow cover data derived from MODIS for water balance applications

    Directory of Open Access Journals (Sweden)

    A. Gafurov

    2009-02-01

    Full Text Available Snow cover information is of central importance for the estimation of water storage in cold mountainous regions. It is difficult to assess distributed snow cover information in a catchment in order to estimate possible water resources. It is especially a challenge to obtain snow cover information for high mountainous areas. Usually, snow depth is measured at meteorological stations, and it is relatively difficult to extrapolate this spatially or temporally since it highly depends on available energy and topography. The snow coverage of a catchment gives detailed information about the catchment's potential source for water. Many regions lack meteorological stations that measure snow, and usually no stations are available at high elevations.

    Satellite information is a very valuable source for obtaining several environmental parameters. One of the advantages is that the data is mostly provided in a spatially distributed format. This study uses satellite data to estimate snow coverage on high mountainous areas. Moderate-resolution Imaging Spectroradiometer (MODIS snow cover data is used in the Kokcha Catchment located in the north-eastern part of Afghanistan. The main disadvantage of MODIS data that restricts its direct use in environmental applications is cloud coverage. This is why this study is focused on eliminating cloud covered cells and estimating cell information under cloud covered cells using six logical, spatial and temporal approaches. The results give total cloud removal and mapping of snow cover for the study areas.

  2. Snow cover data derived from MODIS for water balance applications

    Science.gov (United States)

    Gafurov, A.; Bárdossy, A.

    2009-02-01

    Snow cover information is of central importance for the estimation of water storage in cold mountainous regions. It is difficult to assess distributed snow cover information in a catchment in order to estimate possible water resources. It is especially a challenge to obtain snow cover information for high mountainous areas. Usually, snow depth is measured at meteorological stations, and it is relatively difficult to extrapolate this spatially or temporally since it highly depends on available energy and topography. The snow coverage of a catchment gives detailed information about the catchment's potential source for water. Many regions lack meteorological stations that measure snow, and usually no stations are available at high elevations. Satellite information is a very valuable source for obtaining several environmental parameters. One of the advantages is that the data is mostly provided in a spatially distributed format. This study uses satellite data to estimate snow coverage on high mountainous areas. Moderate-resolution Imaging Spectroradiometer (MODIS) snow cover data is used in the Kokcha Catchment located in the north-eastern part of Afghanistan. The main disadvantage of MODIS data that restricts its direct use in environmental applications is cloud coverage. This is why this study is focused on eliminating cloud covered cells and estimating cell information under cloud covered cells using six logical, spatial and temporal approaches. The results give total cloud removal and mapping of snow cover for the study areas.

  3. Driving Factors of the Decadal Variations in Sunshine Duration and Surface Solar Radiation in China

    Science.gov (United States)

    Wang, Y.; Yang, Y.; Wild, M.

    2016-12-01

    Solar radiation received at the Earth's surface has not been stable over time but underwent substantial decadal variations, popularly known as global dimming and brightening. Consistently in China, a reversal was noted in sunshine duration (SD), a widely used proxy for surface solar radiation (SSR), from dimming by -0.17 h d-1 decade-1 for the period 1960-1989 to leveling off by -0.01 h d-1 decade-1 for 1990-2013. SD declines covered about 85% of 344 examined sites across China in the dimming phase. By contrast, in the brightening phase, SD increased in about half of China, while continued to decrease in the other half, especially in central and north China. Through trend comparison and grey relational analysis, it was proven that the decadal changes in SD in China were driven by air pollution rather than cloud——the two most likely candidates for explaining global dimming and brightening. The air pollution effect on SD and SSR was then quantified under clear-sky conditions as follows: (1) on pristine days, SD is on average 1.1 h d-1 (12.4%) longer than on polluted days; and (2) on average, when air pollution increases by one level, i.e. the index for air pollution (API) increases by 50, SSR decreases by 6 W m-2. API was shown to be a useful indicator in studying the effects of aerosols on global dimming and brightening. Besides, air pollution has driven wind speed into a non-negligible regulator of SSR. The regulatory effect of wind speed on SSR starts to be important when API exceeds the level of 125. In addition, in the dimming phase without available API monitoring, urbanization can be used as an applicable proxy for anthropogenic pollution level. Urbanization has significantly affected SD trends in China until the brightening phase when pollution regulations became effective.

  4. Cloud Computing (1)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ Editor's Desk: Cloud computing is a topic of intense interest in the Internet field. Major IT giants have launched their own cloud computing products. This four-part lecture series will discuss cloud computing technology in the following aspects: The first part provides a brief description of the origin and characteristics of cloud computing from the users view of point; the other parts introduce typical applications of cloud computing, technically analyze the specific content within the cloud, its components, architecture and computational paradigm, compare cloud computing to other distributed computing technologies, and discuss its successful cases, commercial models, related technical and economic issues, and development trends.

  5. Cloud Computing (2)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ Editor's Desk: Cloud computing is a topic of intense interest in the Internet field. Major IT giants have launched their own cloud computing products. This four-part lecture series discusses cloud computing technology in the following aspects: The first part provided a brief description of the origin and characteristics of cloud computing from the users view of point; the other parts introduce typical applications of cloud computing, technically analyze the specific content within the cloud, its components, architecture and computational paradigm, compare cloud computing to other distributed computing technologies, and discuss its successful cases, commercial models, related technical and economic issues, and development trends.

  6. Cloud storage for dummies

    CERN Document Server

    Xu, Linda; Loughlin, Tanya

    2010-01-01

    Understand cloud computing and save your organization time and money! Cloud computing is taking IT by storm, but what is it and what are the benefits to your organization? Hitachi Data Systems' Cloud Storage For Dummies provides all the answers, With this book, you discover a clear explanation of cloud storage, and tips for how to choose the right type of cloud storage for your organization's needs. You also find out how cloud storage can free up valuable IT resources, saving time and money. Cloud Storage For Dummies presents useful information on setting up a

  7. Robots and sensor clouds

    CERN Document Server

    Shakshuki, Elhadi

    2016-01-01

    This book comprises four chapters that address some of the latest research in clouds robotics and sensor clouds. The first part of the book includes two chapters on cloud robotics. The first chapter introduces a novel resource allocation framework for cloud robotics and proposes a Stackelberg game model and the corresponding task oriented pricing mechanism for resource allocation. In the second chapter, the authors apply Cloud Computing for building a Cloud-Based 3D Point Cloud extractor for stereo images. Their objective is to have a dynamically scalable and applicable to near real-time scenarios.  .

  8. Deriving Snow Cover Metrics for Alaska from MODIS

    Directory of Open Access Journals (Sweden)

    Chuck Lindsay

    2015-09-01

    Full Text Available Moderate Resolution Imaging Spectroradiometer (MODIS daily snow cover products provide an opportunity for determining snow onset and melt dates across broad geographic regions; however, cloud cover and polar darkness are limiting factors at higher latitudes. This study presents snow onset and melt dates for Alaska, portions of western Canada and the Russian Far East derived from Terra MODIS snow cover daily 500 m grid data (MOD10A1 and evaluates our method for filling data gaps caused by clouds or polar darkness. Pixels classified as cloud or no data were reclassified by: spatial filtering using neighboring pixel values; temporal filtering using pixel values for days before/after cloud cover; and snow-cycle filtering based on a time series assessment of a pixel’s position within snow accumulation, cover or melt periods. During the 2012 snow year, these gap-filling methods reduced cloud pixels from 27.7% to 3.1%. A total of 12 metrics (e.g., date of first and last snow, date of persistent snow cover and periods of intermittence for each pixel were calculated by snow year. A comparison of MODIS-derived snow onset and melt dates with in situ observations from 244 weather stations generally showed an early bias in MODIS-derived dates and an effect of increasing cloudiness exacerbating bias. Our results show that mean regional duration of seasonal snow cover is 179–311 days/year and that snow cover is often intermittent, with 41% of the area experiencing ≥2 snow-covered periods during a snow season. Other regional-scale patterns in the timing of snow onset and melt are evident in the yearly 500 m gridded products publically available at http://static.gina.alaska.edu/NPS_products/MODIS_snow/.

  9. Physical-chemical processes in a protoplanetary cloud

    Science.gov (United States)

    Lavrukhina, Avgusta K.

    1991-01-01

    Physical-chemical processes in a protoplanetary cloud are discussed. The following subject areas are covered: (1) characteristics of the chemical composition of molecular interstellar clouds; (2) properties and physico-chemical process in the genesis of interstellar dust grains; and (3) the isotope composition of volatiles in bodies of the Solar System.

  10. Fluid Analysis of Network Content Dissemination and Cloud Systems

    Science.gov (United States)

    2017-03-06

    Final 3. DATES COVERED (From - To) 01 Sep 2015 to 30 Nov 2016 4. TITLE AND SUBTITLE Fluid analysis of network content dissemination and cloud systems...2015 to 30 Nov 2016 AFOSR GRANT NUMBER: FA9550-15-1-0183 TITLE: Fluid analysis of network content dissemination and cloud systems PI: Fernando

  11. A cosmic ray-climate link and cloud observations

    CERN Document Server

    Laken, Benjamin A; Calogovic, Jasa; Dunne, Eimear M; 10.1051/swsc/2012018

    2012-01-01

    Despite over 35 years of constant satellite-based measurements of cloud, reliable evidence of a long-hypothesized link between changes in solar activity and Earth's cloud cover remains elusive. This work examines evidence of a cosmic ray cloud link from a range of sources, including satellite-based cloud measurements and long-term ground-based climatological measurements. The satellite-based studies can be divided into two categories: 1) monthly to decadal timescale correlations, and 2) daily timescale epoch-superpositional (composite) analysis. The latter analyses frequently focus on high-magnitude reductions in the cosmic ray flux known as Forbush Decrease (FD) events. At present, two long-term independent global satellite cloud datasets are available (ISCCP and MODIS). Although the differences between them are considerable, neither shows evidence of a solar-cloud link at either long or short timescales. Furthermore, reports of observed correlations between solar activity and cloud over the 1983 to 1995 per...

  12. Sensitivity analysis of upwelling thermal radiance in presence of clouds

    Science.gov (United States)

    Subramanian, S. V.; Tiwari, S. N.; Suttles, J. T.

    1981-01-01

    Total upwelling radiance at the top of the atmosphere is evaluated theoretically in the presence of clouds. The influence of cloud heights, thicknesses and different cloud covers on the upwelling radiance is also investigated. The characteristics of the two cloud types considered in this study closely correspond to altocumulus and cirrus with the cloud emissivity as a function of its liquid water (or ice) content. For calculation of the integrated transmittance of atmospheric gases such as, H2O, CO2, O3, and N2O, the Quasi Random Band (QRB) model approach is adopted. Results are obtained in three different spectral ranges and are compared with the clearsky radiance results. It is found that the difference between the clearsky and cloudy radiance increases with increasing cloud height and liquid water content. This difference also decreases as the surface temperature approaches the value of the cloud top temperature.

  13. THE GALFA-H I COMPACT CLOUD CATALOG

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-10

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

  14. Cloud Computing (3)

    Institute of Scientific and Technical Information of China (English)

    Wang Bai; Xu Liutong

    2010-01-01

    @@ Editor's Desk: In the preceding two parts of this series, several aspects of cloud computing-including definition, classification, characteristics, typical applications, and service levels-were discussed. This part continues with a discussion of Cloud Computing Oopen Architecture and Market-Oriented Cloud. A comparison is made between cloud computing and other distributed computing technologies, and Google's cloud platform is analyzed to determine how distributed computing is implemented in its particular model.

  15. Cloud Robotics Platforms

    Directory of Open Access Journals (Sweden)

    Busra Koken

    2015-01-01

    Full Text Available Cloud robotics is a rapidly evolving field that allows robots to offload computation-intensive and storage-intensive jobs into the cloud. Robots are limited in terms of computational capacity, memory and storage. Cloud provides unlimited computation power, memory, storage and especially collaboration opportunity. Cloud-enabled robots are divided into two categories as standalone and networked robots. This article surveys cloud robotic platforms, standalone and networked robotic works such as grasping, simultaneous localization and mapping (SLAM and monitoring.

  16. An Observational Study of the Relationship between Cloud, Aerosol and Meteorology in Broken Low-Level Cloud Conditions

    Science.gov (United States)

    Loeb, Norman G.; Schuster, Gregory L.

    2008-01-01

    Global satellite analyses showing strong correlations between aerosol optical depth and 3 cloud cover have stirred much debate recently. While it is tempting to interpret the results as evidence of aerosol enhancement of cloud cover, other factors such as the influence of meteorology on both the aerosol and cloud distributions can also play a role, as both aerosols and clouds depend upon local meteorology. This study uses satellite observations to examine aerosol-cloud relationships for broken low-level cloud regions off the coast of Africa. The analysis approach minimizes the influence of large-scale meteorology by restricting the spatial and temporal domains in which the aerosol and cloud properties are compared. While distributions of several meteorological variables within 5deg 5deg latitude-longitude regions are nearly identical under low and high aerosol optical depth, the corresponding distributions of single-layer low cloud properties and top-of-atmosphere radiative fluxes differ markedly, consistent with earlier studies showing increased cloud cover with aerosol optical depth. Furthermore, fine-mode fraction and Angstrom Exponent are also larger in conditions of higher aerosol optical depth, even though no evidence of systematic latitudinal or longitudinal gradients between the low and high aerosol optical depth populations are observed. When the analysis is repeated for all 5deg 5deg latitude-longitude regions over the global oceans (after removing cases in which significant meteorological differences are found between the low and high aerosol populations), results are qualitatively similar to those off the coast of Africa.

  17. Sensor Data Fusion for Accurate Cloud Presence Prediction Using Dempster-Shafer Evidence Theory

    Directory of Open Access Journals (Sweden)

    Jesse S. Jin

    2010-10-01

    Full Text Available Sensor data fusion technology can be used to best extract useful information from multiple sensor observations. It has been widely applied in various applications such as target tracking, surveillance, robot navigation, signal and image processing. This paper introduces a novel data fusion approach in a multiple radiation sensor environment using Dempster-Shafer evidence theory. The methodology is used to predict cloud presence based on the inputs of radiation sensors. Different radiation data have been used for the cloud prediction. The potential application areas of the algorithm include renewable power for virtual power station where the prediction of cloud presence is the most challenging issue for its photovoltaic output. The algorithm is validated by comparing the predicted cloud presence with the corresponding sunshine occurrence data that were recorded as the benchmark. Our experiments have indicated that comparing to the approaches using individual sensors, the proposed data fusion approach can increase correct rate of cloud prediction by ten percent, and decrease unknown rate of cloud prediction by twenty three percent.

  18. Sensor data fusion for accurate cloud presence prediction using Dempster-Shafer evidence theory.

    Science.gov (United States)

    Li, Jiaming; Luo, Suhuai; Jin, Jesse S

    2010-01-01

    Sensor data fusion technology can be used to best extract useful information from multiple sensor observations. It has been widely applied in various applications such as target tracking, surveillance, robot navigation, signal and image processing. This paper introduces a novel data fusion approach in a multiple radiation sensor environment using Dempster-Shafer evidence theory. The methodology is used to predict cloud presence based on the inputs of radiation sensors. Different radiation data have been used for the cloud prediction. The potential application areas of the algorithm include renewable power for virtual power station where the prediction of cloud presence is the most challenging issue for its photovoltaic output. The algorithm is validated by comparing the predicted cloud presence with the corresponding sunshine occurrence data that were recorded as the benchmark. Our experiments have indicated that comparing to the approaches using individual sensors, the proposed data fusion approach can increase correct rate of cloud prediction by ten percent, and decrease unknown rate of cloud prediction by twenty three percent.

  19. Automated satellite cloud analysis: a multispectral approach to the problem of snow/cloud discrimination

    OpenAIRE

    Allen, Robert C. Jr.

    1987-01-01

    Approved for public release; distribution is unlimited An algorithm is developed and evaluated for discriminating among clouds, snow cover and clear land. The multispectral technique uses daytime images of AVHRR channels 1 (0.63^m). 3 (3.7jim) and 4 (11.0[im). Reflectance is derived for channel 3 by using the channel 4 emission temperature to estimate and remove the channel 3 thermal emission. Separation of clouds from snow and land is based primarily on this derived channel...

  20. Effective cloud optical depth and enhancement effects for broken liquid water clouds in Valencia (Spain)

    Science.gov (United States)

    Marín, M. J.; Serrano, D.; Utrillas, M. P.; Núñez, M.; Martínez-Lozano, J. A.

    2017-10-01

    Partly cloudy skies with liquid water clouds have been analysed, founding that it is essential to distinguish data if the Sun is obstructed or not by clouds. Both cases can be separated considering simultaneously the Cloud Modification Factor (CMF) and the clearness index (kt). For partly cloudy skies and the Sun obstructed the effective cloud optical depth (τ) has been obtained by the minimization method for overcast skies. This method was previously developed by the authors but, in this case, taking into account partial cloud cover. This study has been conducted for the years 2011-2015 with the multiple scattering model SBDART and irradiance measurements for the UV Erythemal Radiation (UVER) and the broadband ranges. Afterwards a statistical analysis of τ has shown that the maximum value is much lower than for overcast skies and there is more discrepancy between the two spectral ranges regarding the results for overcast skies. In order to validate these results the effective cloud optical depth has been correlated with several transmission factors, giving similar fit parameters to those obtained for overcast skies except for the clearness index in the UVER range. As our method is not applicable for partly cloudy skies with the visible Sun, the enhancement of radiation caused by clouds when the Sun is visible has been studied. Results show that the average enhancement CMF values are the same for both ranges although enhancement is more frequent for low cloud cover in the UVER and medium-high cloud cover in the broadband range and it does not depend on the solar zenith angle.

  1. Cloud and circulation feedbacks in a near-global aquaplanet cloud-resolving model

    Science.gov (United States)

    Narenpitak, Pornampai; Bretherton, Christopher S.; Khairoutdinov, Marat F.

    2017-06-01

    A near-global aquaplanet cloud-resolving model (NGAqua) with fixed meridionally varying sea-surface temperature (SST) is used to investigate cloud feedbacks due to three climate perturbations: a uniform 4 K SST increase, a quadrupled-CO2 concentration, and both combined. NGAqua has a horizontal resolution of 4 km with no cumulus parameterization. Its domain is a zonally periodic 20,480 km-long tropical channel, spanning 46°S-N. It produces plausible mean distributions of clouds, rainfall, and winds. After spin-up, 80 days are analyzed for the control and increased-SST simulations, and 40 days for those with quadrupled CO2. The Intertropical Convergence Zone width and tropical cloud cover are not strongly affected by SST warming or CO2 increase, except for the expected upward shift in high clouds with warming, but both perturbations weaken the Hadley circulation. Increased SST induces a statistically significant increase in subtropical low cloud fraction and in-cloud liquid water content but decreases midlatitude cloud, yielding slightly positive domain-mean shortwave cloud feedbacks. CO2 quadrupling causes a slight shallowing and a statistically insignificant reduction of subtropical low cloud fraction. Warming-induced low cloud changes are strongly correlated with changes in estimated inversion strength, which increases modestly in the subtropics but decreases in the midlatitudes. Enhanced clear-sky boundary layer radiative cooling in the warmer climate accompanies the robust subtropical low cloud increase. The probability distribution of column relative humidity across the tropics and subtropics is compared between the control and increased-SST simulations. It shows no evidence of bimodality or increased convective aggregation in a warmer climate.

  2. Cloud Statistics and Discrimination in the Polar Regions

    Science.gov (United States)

    Chan, M.; Comiso, J. C.

    2012-12-01

    Despite their important role in the climate system, cloud cover and their statistics are poorly known, especially in the polar regions, where clouds are difficult to discriminate from snow covered surfaces. The advent of the A-train, which included Aqua/MODIS, CALIPSO/CALIOP and CloudSat/CPR sensors has provided an opportunity to improve our ability to accurately characterize the cloud cover. MODIS provides global coverage at a relatively good temporal and spatial resolution while CALIOP and CPR provide limited nadir sampling but accurate characterization of the vertical structure and phase of the cloud cover. Over the polar regions, cloud detection from a passive sensors like MODIS is challenging because of the presence of cold and highly reflective surfaces such as snow, sea-ice, glaciers, and ice-sheet, which have surface signatures similar to those of clouds. On the other hand, active sensors such as CALIOP and CPR are not only very sensitive to the presence of clouds but can also provide information about its microphysical characteristics. However, these nadir-looking sensors have sparse spatial coverage and their global data can have data spatial gaps of up to 100 km. We developed a polar cloud detection system for MODIS that is trained using collocated data from CALIOP and CPR. In particular, we employ a machine learning system that reads the radiative profile observed by MODIS and determine whether the field of view is cloudy or clear. Results have shown that the improved cloud detection scheme performs better than typical cloud mask algorithms using a validation data set not used for training. A one-year data set was generated and results indicate that daytime cloud detection accuracies improved from 80.1% to 92.6% (over sea-ice) and 71.2% to 87.4% (over ice-sheet) with CALIOP data used as the baseline. Significant improvements are also observed during nighttime, where cloud detection accuracies increase by 19.8% (over sea-ice) and 11.6% (over ice

  3. Cloud detection method for Chinese moderate high resolution satellite imagery (Conference Presentation)

    Science.gov (United States)

    Zhong, Bo; Chen, Wuhan; Wu, Shanlong; Liu, Qinhuo

    2016-10-01

    Cloud detection of satellite imagery is very important for quantitative remote sensing research and remote sensing applications. However, many satellite sensors don't have enough bands for a quick, accurate, and simple detection of clouds. Particularly, the newly launched moderate to high spatial resolution satellite sensors of China, such as the charge-coupled device on-board the Chinese Huan Jing 1 (HJ-1/CCD) and the wide field of view (WFV) sensor on-board the Gao Fen 1 (GF-1), only have four available bands including blue, green, red, and near infrared bands, which are far from the requirements of most could detection methods. In order to solve this problem, an improved and automated cloud detection method for Chinese satellite sensors called OCM (Object oriented Cloud and cloud-shadow Matching method) is presented in this paper. It firstly modified the Automatic Cloud Cover Assessment (ACCA) method, which was developed for Landsat-7 data, to get an initial cloud map. The modified ACCA method is mainly based on threshold and different threshold setting produces different cloud map. Subsequently, a strict threshold is used to produce a cloud map with high confidence and large amount of cloud omission and a loose threshold is used to produce a cloud map with low confidence and large amount of commission. Secondly, a corresponding cloud-shadow map is also produced using the threshold of near-infrared band. Thirdly, the cloud maps and cloud-shadow map are transferred to cloud objects and cloud-shadow objects. Cloud and cloud-shadow are usually in pairs; consequently, the final cloud and cloud-shadow maps are made based on the relationship between cloud and cloud-shadow objects. OCM method was tested using almost 200 HJ-1/CCD images across China and the overall accuracy of cloud detection is close to 90%.

  4. Sensitivity of PARASOL multi-angle photopolarimetric aerosol retrievals to cloud contamination

    NARCIS (Netherlands)

    Stap, F. A.; Hasekamp, O. P.; Roeckmann, Thomas

    2015-01-01

    An important problem in satellite remote sensing of aerosols is related to the need to perform an adequate cloud screening. If a cloud screening is applied that is not strict enough, the ground scene has the probability of residual cloud cover which causes large errors on the retrieved aerosol param

  5. Sensitivity of PARASOL multi-angle photopolarimetric aerosol retrievals to cloud contamination

    NARCIS (Netherlands)

    Stap, F. A.; Hasekamp, O. P.; Roeckmann, Thomas

    2015-01-01

    An important problem in satellite remote sensing of aerosols is related to the need to perform an adequate cloud screening. If a cloud screening is applied that is not strict enough, the ground scene has the probability of residual cloud cover which causes large errors on the retrieved aerosol

  6. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    1999-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

  7. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    2002-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

  8. Scientific Data Storage for Cloud Computing

    Science.gov (United States)

    Readey, J.

    2014-12-01

    Traditionally data storage used for geophysical software systems has centered on file-based systems and libraries such as NetCDF and HDF5. In contrast cloud based infrastructure providers such as Amazon AWS, Microsoft Azure, and the Google Cloud Platform generally provide storage technologies based on an object based storage service (for large binary objects) complemented by a database service (for small objects that can be represented as key-value pairs). These systems have been shown to be highly scalable, reliable, and cost effective. We will discuss a proposed system that leverages these cloud-based storage technologies to provide an API-compatible library for traditional NetCDF and HDF5 applications. This system will enable cloud storage suitable for geophysical applications that can scale up to petabytes of data and thousands of users. We'll also cover other advantages of this system such as enhanced metadata search.

  9. The Aerosol, Clouds and Ecosystem (ACE) Mission

    Science.gov (United States)

    Schoeberl, M.; Remer, L.; Kahn, R.; Starr, D.; Hildebrand, P.; Colarco, P.; Diner, D.; Vane, D.; Im, E.; Behrenfeld, M.; Stephens, G.; Maring, H.; Bontempi, P.; Martins, J. V.

    2008-12-01

    The Aerosol, Clouds and Ecosystem (ACE) Mission is a second tier Decadal Survey mission designed to characterize the role of aerosols in climate forcing, especially their impact on precipitation and cloud formation. ACE also includes ocean biosphere measurements (chlorophyll and dissolved organic materials) which will be greatly improved by simultaneous measurements of aerosols. The nominal ACE payload includes lidar and multiangle spectropolarimetric polarimetric measurements of aerosols, radar measurements of clouds and multi-band spectrometer for the measurement of ocean ecosystems. An enhancement to ACE payload under consideration includes µ-wave radiometer measurements of cloud ice and water outside the nadir path of the radar/lidar beams. This talk will cover ACE instrument and science options, updates on the science team definition activity and science potential.

  10. Determinants of geographic patterns of diseases: interaction of lactose/lactase status and sunshine exposure.

    Science.gov (United States)

    Szilagyi, Andrew

    2010-11-01

    Geographic patterns of diseases depend on multilayered causes. However, the division of the world's population into two phenotypes regarding lactose digestion and sunshine exposure to fixed areas of the globe are two relatively slow changing variables. It is hypothesized that it is a vectorial interaction between these two variables that provide a backbone to risk modification of many diseases. Lactase non persistence status tends to follow sunshine exposure particularly in Europe but Lactase persistence status is also been shown to be related to pastoral life styles in spotty regions of Africa, Middle East and China. Current emphasis of research favours the modifying role of vitamin D and sunshine. Nevertheless it was demonstrated that national digester/nondigester status has mathematical relationships to geographic distribution of some diseases. These relationships are also similar to that described for the effects of latitude through sunshine and vitamin D. This observation raises a question as to how each one affects disease outcome. In this paper lactose/lactase interactions are first reviewed for eight exemplary diseases. Based on population findings and corroborative meta-analyses gleaned from the literature 6 types of interactions may be classified. Then in a preliminary fashion lactose digester and maldigester status are related to relative annual sunshine exposure. Further the relative national annual sunshine exposure is evaluated to outcomes of the same exemplary diseases. The patterns related to sunshine reflect that obtained with national lactase status proportions and also corroborate a literature review. However, correlations are weak to moderate and only ovarian cancer reached conventional statistical significance. Because these comparisons are based on modest number of national data firm conclusions cannot be made. However, it is argued that evolutionary pressures exerted by regional sunshine exposure may have had influence on a number of relevant

  11. Grids and clouds in the Czech NGI

    Science.gov (United States)

    Kundrát, Jan; Adam, Martin; Adamová, Dagmar; Chudoba, Jiří; Kouba, Tomáš; Lokajíček, Miloš; Mikula, Alexandr; Říkal, Václav; Švec, Jan; Vohnout, Rudolf

    2016-09-01

    There are several infrastructure operators within the Czech Republic NGI (National Grid Initiative) which provide users with access to high-performance computing facilities over a grid and cloud interface. This article focuses on those where the primary author has personal first-hand experience. We cover some operational issues as well as the history of these facilities.

  12. VMware vCloud Director essentials

    CERN Document Server

    Pal, Lipika

    2014-01-01

    If you are a technical professional with system administration knowledge, then this book is for you. The book also covers areas of importance if you are a virtualization engineer, consultant, architect, senior system engineer, or senior system analyst. You should possess core vSphere platform knowledge necessary to serve as a base to learn vCloud Director and its associated components.

  13. Sensitivity of PARASOL multi-angle photo-polarimetric aerosol retrievals to cloud contamination

    Science.gov (United States)

    Stap, F. A.; Hasekamp, O.; Röckmann, T.

    2014-10-01

    An important problem in satellite remote sensing of aerosols is related to the need to perform an adequate cloud screening. If a cloud screening is applied that is not strict enough, the ground scene has the probability of residual cloud cover which causes large errors on the retrieved aerosol parameters. On the other hand, if the cloud screening procedure is too strict, too many clear sky cases, especially near-cloud scenes, will falsely be flagged cloudy. The detrimental effects of cloud contamination as well as the importance of aerosol cloud interactions that can be studied in these near-cloud scenes call for new approaches to cloud screening. Multi-angle, multi-wavelength photo-polarimetric measurements have a unique capability to distinguish between scattering by (liquid) cloud droplets and aerosol particles. In this paper the sensitivity of aerosol retrievals from multi-angle, photo-polarimetric measurements to cloud contamination is investigated and the ability to intrinsically filter the cloud contaminated scenes based on a goodness-of-fit criteria is evaluated. Hereto, an aerosol retrieval algorithm is applied to a partially clouded, synthetic data-set including partial cloud cover as well as non-cloud screened POLDER-3/PARASOL observations It is found that a goodness-of-fit filter, together with a filter on the coarse mode refractive index (mrcoarse > 1.335) and a cirrus screening adequately reject the cloud contaminated scenes. No bias nor larger SD are found in the retrieved parameters for this intrinsic cloud filter compared to the parameters retrieved in a priori cloud screened data-set (using MODIS/AQUA cloud masks) of PARASOL observations. Moreover, less high aerosol load scenes are misinterpreted as cloud contaminated. The retrieved aerosol optical thickness, single scattering albedo and Ångström exponent show good agreement with AERONET observations. Furthermore, the synthetic retrievals give confidence in the ability of the algorithm to

  14. Pequena Miss Sunshine: para além de uma subjetividade exterior Little Miss Sunshine: beyond external subjectivity

    Directory of Open Access Journals (Sweden)

    Rosa Maria Bueno Fischer

    2008-08-01

    Full Text Available O artigo discute as relações entre cultura do sucesso e sexualidade, com foco na infância - tema caro às diferentes mídias, como a televisão e o cinema. Faz-se uma análise do filme Pequena Miss Sunshine, a partir de autores como Foucault, Alain Badiou, Ismail Xavier e Jurandir Costa, com ênfase nos conceitos de modos de subjetivação, imagem fílmica e subjetividade exterior. O objetivo é pensar questões de gênero e sexualidade na cultura do espetáculo, a partir de uma narrativa cinematográfica em que tais valores são questionados. A ênfase é dada à análise do olhar e do corpo infantil, na figura da personagem Olive, de modo a pensar a gestualidade própria da criança, em seu silêncio, enigma e mistério, mais do que mera revelação de sentidos. O texto aponta que tal exercício pode sugerir outros modos de pensar as relações entre mídia, infância e questões de gênero e sexualidade.This article explores the relations between the culture of success and sexuality, with a focus on childhood as an important issue for the different kinds of media, such as television and the cinema. An analysis of the movie Little Miss Sunshine is developed, with the use of theoretical references from Foucault, Alain Badiou, Jurandir Costa and Ismail Xavier, about the concepts of audiovisual images, ways of subjectivation and external subjectivity. The aim of the study is to reflect on gender and sexuality issues in a spectacle culture, from a movie narrative in which such values are questioned. There is an analysis of children's bodies and their way of seeing the world, as expressed by the character Olive, with gestures, silence and mystery, rather than a revelation of senses. Such practices may suggest other ways of considering the relations between media, childhood and gender and sexuality issues.

  15. Secure cloud computing

    CERN Document Server

    Jajodia, Sushil; Samarati, Pierangela; Singhal, Anoop; Swarup, Vipin; Wang, Cliff

    2014-01-01

    This book presents a range of cloud computing security challenges and promising solution paths. The first two chapters focus on practical considerations of cloud computing. In Chapter 1, Chandramouli, Iorga, and Chokani describe the evolution of cloud computing and the current state of practice, followed by the challenges of cryptographic key management in the cloud. In Chapter 2, Chen and Sion present a dollar cost model of cloud computing and explore the economic viability of cloud computing with and without security mechanisms involving cryptographic mechanisms. The next two chapters addres

  16. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... such as lowpermeability clay soils and geomembranes are required. The avoidance of water input to organic waste may impede the microbial stabilization processes including gas generation. Therefore watertight top covers may be in conflict with the purposes of reactor landfills (see Chapter 10.6). At some sites covers...... sometimes are made to include components for recirculation of landfill leachate (see Section 10.9.2 for more details). The top cover is an important factor in the water management of landfills. Details about water infiltration through top covers and its influence on the hydrology of the landfill is covered...

  17. Global surface-based cloud observation for ISCCP

    Science.gov (United States)

    1994-01-01

    Visual observations of cloud cover are hindered at night due to inadequate illumination of the clouds. This usually leads to an underestimation of the average cloud cover at night, especially for the amounts of middle and high clouds, in climatologies on surface observations. The diurnal cycles of cloud amounts, if based on all the surface observations, are therefore in error, but they can be obtained more accurately if the nighttime observations are screened to select those made under sufficient moonlight. Ten years of nighttime weather observations from the northern hemisphere in December were classified according to the illuminance of moonlight or twilight on the cloud tops, and a threshold level of illuminance was determined, above which the clouds are apparently detected adequately. This threshold corresponds to light from a full moon at an elevation angle of 6 degrees or from a partial moon at higher elevation, or twilight from the sun less than 9 degrees below the horizon. It permits the use of about 38% of the observations made with the sun below the horizon. The computed diurnal cycles of total cloud cover are altered considerably when this moonlight criterion is imposed. Maximum cloud cover over much of the ocean is now found to be at night or in the morning, whereas computations obtained without benefit of the moonlight criterion, as in our published atlases, showed the time of maximum to be noon or early afternoon in many regions. Cloud cover is greater at night than during the day over the open oceans far from the continents, particularly in summer. However, near noon maxima are still evident in the coastal regions, so that the global annual average oceanic cloud cover is still slightly greater during the day than at night, by 0.3%. Over land, where daytime maxima are still obtained but with reduced amplitude, average cloud cover is 3.3% greater during the daytime. The diurnal cycles of total cloud cover we obtain are compared with those of ISCCP for a

  18. Research for logistics distribution center location-distribution problem based on maximal covering in cloud logistics mode%云物流模式下基于最大覆盖配送中心的选址-分配问题研究

    Institute of Scientific and Technical Information of China (English)

    毕娅; 梁晓磊; 赵韦; 王勋; 李文锋

    2012-01-01

    In order to improve the logistics resource utilization rate and reduce the logistics cost, under the guidance of the "cloud" thought, this paper constructed a new multi-objective and non-linear location-distribution model with certain assumptions as premises. The model aimed to the maximal covering demand, the optimal distribution and the lowest cost of the supply chain. It designed the heuristic algorithm based on GA and PSO for the model according to the specific structure of the model' s decision-making space. The numerical calculation was performed to solve the arithmetic problem in practical investigation. It shows that the decision model is practical and the algorithm is valid.%为了实现物流资源利用率的提高和物流成本的降低,根据“云”的思想,建立了云物流下基于最大覆盖的选址—分配的多目标非线性决策模型,该模型的目标是配送中心的选址优化和整体需求覆盖最大化.设计了基于遗传和粒子群的组合式启发式算法,对算法的性能进行了Benchmark测试.通过大量算例和对比分析,验证了模型和算法的有效性和稳定性.

  19. Installing and Scaling out Ubuntu Enterprise Cloud in Virtual Environment

    DEFF Research Database (Denmark)

    Pantić, Zoran; Ali Babar, Muhammad

    This document contains the supplemental material to the book “Guidelines for Building a Private Cloud Infrastructure”. This document provides guidance on how to install Ubuntu Enterprise Cloud in virtual environment, and afterwards how to scale out when needed. The purpose of this supplemental book...... is to provide a practical, step-by-step, detailed guide on how to dimension and install the machines and network. Some initial steps of configuring the cloud are also covered. The installation is performed in a virtual environment based on Windows 7 and VMware Workstation 7. The cloud installation is performed...

  20. Cloud computing and digital media fundamentals, techniques, and applications

    CERN Document Server

    Li, Kuan-Ching; Shih, Timothy K

    2014-01-01

    Cloud Computing and Digital Media: Fundamentals, Techniques, and Applications presents the fundamentals of cloud and media infrastructure, novel technologies that integrate digital media with cloud computing, and real-world applications that exemplify the potential of cloud computing for next-generation digital media. It brings together technologies for media/data communication, elastic media/data storage, security, authentication, cross-network media/data fusion, interdevice media interaction/reaction, data centers, PaaS, SaaS, and more.The book covers resource optimization for multimedia clo

  1. Cloud Processed CCN Affect Cloud Microphysics

    Science.gov (United States)

    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

  2. Moving towards Cloud Security

    Directory of Open Access Journals (Sweden)

    Edit Szilvia Rubóczki

    2015-01-01

    Full Text Available Cloud computing hosts and delivers many different services via Internet. There are a lot of reasons why people opt for using cloud resources. Cloud development is increasing fast while a lot of related services drop behind, for example the mass awareness of cloud security. However the new generation upload videos and pictures without reason to a cloud storage, but only few know about data privacy, data management and the proprietary of stored data in the cloud. In an enterprise environment the users have to know the rule of cloud usage, however they have little knowledge about traditional IT security. It is important to measure the level of their knowledge, and evolve the training system to develop the security awareness. The article proves the importance of suggesting new metrics and algorithms for measuring security awareness of corporate users and employees to include the requirements of emerging cloud security.

  3. In the clouds

    NARCIS (Netherlands)

    Wassink, J.

    2012-01-01

    Clouds always used to be the least understood element of the weather system, but that is rapidly changing . Computer clouds increasingly correspond with those in the sky, which promises weather forecasts at street level and more accurate climate scenarios.

  4. Cloud Computing for radiologists.

    Science.gov (United States)

    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.

  5. Bulk meteorological parameters for diagnosing cloudiness in the stochastic cloud forecast model

    OpenAIRE

    Leach, Ryan N.

    2006-01-01

    The three dimensional distribution of clouds is of great interest to the Air Force, and to the aviation community in general. The Stochastic Cloud Forecast Model (SCFM) is a novel, global cloud model currently operated at the Air Force Weather Agency (AFWA) which diagnoses cloud cover statistically using a minimal set of predictors from global numerical forecasts. Currently the four predictors are pressure, temperature, vertical velocity, and relative humidity. In this thesis, 330 sets of...

  6. Computer animation of clouds

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Computer animation of clouds

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Comparing Point Clouds

    Science.gov (United States)

    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

  9. Cloud computing strategies

    CERN Document Server

    Chorafas, Dimitris N

    2011-01-01

    A guide to managing cloud projects, Cloud Computing Strategies provides the understanding required to evaluate the technology and determine how it can be best applied to improve business and enhance your overall corporate strategy. Based on extensive research, it examines the opportunities and challenges that loom in the cloud. It explains exactly what cloud computing is, what it has to offer, and calls attention to the important issues management needs to consider before passing the point of no return regarding financial commitments.

  10. Airborne Cloud Computing Environment (ACCE)

    Science.gov (United States)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  11. Airborne Cloud Computing Environment (ACCE)

    Science.gov (United States)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  12. Governmental Cloud - Part of Cloud Computing

    Directory of Open Access Journals (Sweden)

    Cristian IVANUS

    2014-01-01

    Full Text Available Large IT (Information Technology companies propose cloud government's (G-Cloud development model through investment from the private sector, which will facilitate the access of users from public sector to the new generation IT services. Through the G-Cloud private operators that operate governmental cloud infrastructure by adding specific SaaS (Software as a Service functionalities, proposed model by big companies, supports public institutions in optimizing costs and increased operational efficiency, bringing tangible benefits in relation with citizens and thus with the whole society. These optimizations are achieved by moving the initial investment to the private sector, through type subscription model cost by eliminating dependency on human factors (technical and by providing a low cost [1]. This paper aims to bring to the attention of specialists, some aspects of Governmental Cloud from the European Union (EU countries to be understood and implemented in Romania.

  13. CLOUD DETECTION OF OPTICAL SATELLITE IMAGES USING SUPPORT VECTOR MACHINE

    Directory of Open Access Journals (Sweden)

    K.-Y. Lee

    2016-06-01

    Full Text Available Cloud covers are generally present in optical remote-sensing images, which limit the usage of acquired images and increase the difficulty of data analysis, such as image compositing, correction of atmosphere effects, calculations of vegetation induces, land cover classification, and land cover change detection. In previous studies, thresholding is a common and useful method in cloud detection. However, a selected threshold is usually suitable for certain cases or local study areas, and it may be failed in other cases. In other words, thresholding-based methods are data-sensitive. Besides, there are many exceptions to control, and the environment is changed dynamically. Using the same threshold value on various data is not effective. In this study, a threshold-free method based on Support Vector Machine (SVM is proposed, which can avoid the abovementioned problems. A statistical model is adopted to detect clouds instead of a subjective thresholding-based method, which is the main idea of this study. The features used in a classifier is the key to a successful classification. As a result, Automatic Cloud Cover Assessment (ACCA algorithm, which is based on physical characteristics of clouds, is used to distinguish the clouds and other objects. In the same way, the algorithm called Fmask (Zhu et al., 2012 uses a lot of thresholds and criteria to screen clouds, cloud shadows, and snow. Therefore, the algorithm of feature extraction is based on the ACCA algorithm and Fmask. Spatial and temporal information are also important for satellite images. Consequently, co-occurrence matrix and temporal variance with uniformity of the major principal axis are used in proposed method. We aim to classify images into three groups: cloud, non-cloud and the others. In experiments, images acquired by the Landsat 7 Enhanced Thematic Mapper Plus (ETM+ and images containing the landscapes of agriculture, snow area, and island are tested. Experiment results demonstrate

  14. Cloud Detection of Optical Satellite Images Using Support Vector Machine

    Science.gov (United States)

    Lee, Kuan-Yi; Lin, Chao-Hung

    2016-06-01

    Cloud covers are generally present in optical remote-sensing images, which limit the usage of acquired images and increase the difficulty of data analysis, such as image compositing, correction of atmosphere effects, calculations of vegetation induces, land cover classification, and land cover change detection. In previous studies, thresholding is a common and useful method in cloud detection. However, a selected threshold is usually suitable for certain cases or local study areas, and it may be failed in other cases. In other words, thresholding-based methods are data-sensitive. Besides, there are many exceptions to control, and the environment is changed dynamically. Using the same threshold value on various data is not effective. In this study, a threshold-free method based on Support Vector Machine (SVM) is proposed, which can avoid the abovementioned problems. A statistical model is adopted to detect clouds instead of a subjective thresholding-based method, which is the main idea of this study. The features used in a classifier is the key to a successful classification. As a result, Automatic Cloud Cover Assessment (ACCA) algorithm, which is based on physical characteristics of clouds, is used to distinguish the clouds and other objects. In the same way, the algorithm called Fmask (Zhu et al., 2012) uses a lot of thresholds and criteria to screen clouds, cloud shadows, and snow. Therefore, the algorithm of feature extraction is based on the ACCA algorithm and Fmask. Spatial and temporal information are also important for satellite images. Consequently, co-occurrence matrix and temporal variance with uniformity of the major principal axis are used in proposed method. We aim to classify images into three groups: cloud, non-cloud and the others. In experiments, images acquired by the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and images containing the landscapes of agriculture, snow area, and island are tested. Experiment results demonstrate the detection

  15. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    is landscaped in order to fit into the surrounding area/environment or meet specific plans for the final use of the landfill. To fulfill the above listed requirements landfill covers are often multicomponent systems which are placed directly on top of the waste. The top cover may be placed immediately after...... the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... however, top covers may be the only environmental protection measure. In some landfill regulations (for instance the Subtitle D landfills receiving municipal solid waste in the USA) it is required to minimize infiltration into the waste layers. Therefore top covers containing liner components...

  16. Comprehensive Radar Observations of Clouds and Precipitation over the Tibetan Plateau and Preliminary Analysis of Cloud Properties

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Intensive fi eld experiment is an important approach to obtain microphysical information about clouds and precipitation. From 1 July to 31 August 2014, the third Tibetan Plateau Atmospheric Science Experiment was carried out and comprehensive measurements of water vapor, clouds, and precipitation were conducted at Naqu. The most advanced radars in China, such as Ka-band millimeter-wave cloud radar, Ku-band micro-rain radar, C-band continuous-wave radar and lidar, and microwave radiometer and disdrometer were deployed to observe high spatial-temporal vertical structures of clouds and precipitation. The C-band dual-linear polarization radar was coordinated with the China new generation weather radar to constitute a dual-Doppler radar system for the measurements of three-dimensional wind fi elds within convective precipitations and the structure and evolution of hydrometeors related to precipitation process. Based on the radar measurements in this experiment, the diurnal variations of several important cloud properties were analyzed, including cloud top and base, cloud depth, cloud cover, number of cloud layers, and their vertical structures during summertime over Naqu. The features of refl ectivity, velocity, and depolarization ratio for diff erent types of clouds observed by cloud radar are discussed. The results indicate that the cloud properties were successfully measured by using various radars in this fi eld experiment. During the summertime over Naqu, most of the clouds were located above 6 km and below 4 km above ground level. Statistical analysis shows that total amounts of clouds, the top of high-level clouds, and cloud depth, all demonstrated a distinct diurnal variation. Few clouds formed at 1000 LST (local standard time), whereas large amounts of clouds formed at 2000 LST. Newly formed cumulus and stratus clouds were often found at 3-km height, where there existed signifi cant updrafts. Deep convection reached up to 16.5 km (21 km above the mean sea level

  17. Security in the cloud.

    Science.gov (United States)

    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.

  18. On clocks and clouds

    Directory of Open Access Journals (Sweden)

    M. K. Witte

    2013-09-01

    Full Text Available Cumulus clouds exhibit a life cycle that consists of: (a the growth phase (increasing size, most notably in the vertical direction; (b the mature phase (growth ceases; any precipitation that develops is strongest during this period; and (c the dissipation phase (cloud dissipates because of precipitation and/or entrainment; no more dynamical support. Although radar can track clouds over time and give some sense of the age of a cloud, most aircraft in situ measurements lack temporal context. We use large eddy simulations of trade wind cumulus cloud fields from cases during the Barbados Oceanographic and Meteorological Experiment (BOMEX and Rain In Cumulus over the Ocean (RICO campaigns to demonstrate a potential cumulus cloud "clock". We find that the volume-averaged total water mixing ratio rt is a useful cloud clock for the 12 clouds studied. A cloud's initial rt is set by the subcloud mixed-layer mean rt and decreases monotonically from the initial value due primarily to entrainment. The clock is insensitive to aerosol loading, environmental sounding and extrinsic cloud properties such as lifetime and volume. In some cases (more commonly for larger clouds, multiple pulses of buoyancy occur, which complicate the cumulus clock by replenishing rt. The clock is most effectively used to classify clouds by life phase.

  19. Cloud Computing Explained

    Science.gov (United States)

    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…

  20. Cloud Computing Explained

    Science.gov (United States)

    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…

  1. On CLOUD nine

    CERN Multimedia

    2009-01-01

    The team from the CLOUD experiment - the world’s first experiment using a high-energy particle accelerator to study the climate - were on cloud nine after the arrival of their new three-metre diameter cloud chamber. This marks the end of three years’ R&D and design, and the start of preparations for data taking later this year.

  2. Use of A-train satellite observations (CALIPSO-PARASOL) to evaluate tropical cloud properties in the LMDZ5 GCM

    Science.gov (United States)

    Konsta, D.; Dufresne, J.-L.; Chepfer, H.; Idelkadi, A.; Cesana, G.

    2016-08-01

    The evaluation of key cloud properties such as cloud cover, vertical profile and optical depth as well as the analysis of their intercorrelation lead to greater confidence in climate change projections. In addition, the comparison between observations and parameterizations of clouds in climate models is improved by using collocated and instantaneous data of cloud properties. Simultaneous and independent observations of the cloud cover and its three-dimensional structure at high spatial and temporal resolutions are made possible by the new space-borne multi-instruments observations collected with the A-train. The cloud cover and its vertical structure observed by CALIPSO and the visible directional reflectance (a surrogate for the cloud optical depth) observed by PARASOL, are used to evaluate the representation of cloudiness in two versions of the atmospheric component of the IPSL-CM5 climate model (LMDZ5). A model-to-satellite approach, applying the CFMIP Observation Simulation Package (COSP), is used to allow a quantitative comparison between model results and observations. The representation of clouds in the two model versions is first evaluated using monthly mean data. This classical approach reveals biases of different magnitudes in the two model versions. These biases consist of (1) an underestimation of cloud cover associated to an overestimation of cloud optical depth, (2) an underestimation of low- and mid-level tropical clouds and (3) an overestimation of high clouds. The difference in the magnitude of these biases between the two model versions clearly highlights the improvement of the amount of boundary layer clouds, the improvement of the properties of high-level clouds, and the improvement of the simulated mid-level clouds in the tropics in LMDZ5B compared to LMDZ5A, due to the new convective, boundary layer, and cloud parametrizations implemented in LMDZ5B. The correlation between instantaneous cloud properties allows for a process-oriented evaluation

  3. 78 FR 70964 - Sunshine Act Meeting; Audit Committee of the Board of Directors

    Science.gov (United States)

    2013-11-27

    ... Litigation & Management Internal Operations Review V. Internal Audit Reports with Management's Response VI. Internal Audit Status Reports VII. MHA/NFMC/EHLP Compliance VIII. Annual Audit Update & Other External... CORPORATION Sunshine Act Meeting; Audit Committee of the Board of Directors TIME & DATE: 3:30 p.m.,...

  4. Generation of hourly solar radiation for inclined surfaces using monthly mean sunshine duration in Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Mefti, A.; Bouroubi, M.Y. [Centre of Development of Renewable Energy, Lab. of Energy Resources, Algiers (Algeria); Adane, A. [Univ. of Science and Technology of Algiers (U.S.T.H.B.), Lab. of Image Processing and Radiation, Algiers (Algeria)

    2003-11-01

    Hourly global solar radiation flux incident on an inclined surface is evaluated in any site of Algeria using monthly mean daily sunshine duration measurements. The methodology used consists of successive transformations of solar data, respectively, based on the exponential probability distribution of daily sunshine duration, Angstrom equation, beta probability distribution of hourly global solar radiation flux, polynomial correlations of hourly direct and diffuse radiation with global solar radiation and the Klucher model. Monthly mean values of daily sunshine duration data recorded in 54 meteorological stations of Algeria and hourly solar radiation data collected in Algiers, Bechar and Tamanrasset are available for this study. Knowing the monthly mean daily sunshine duration measurements, the hourly global solar radiation data are then obtained on a tilted surface for the locations of Algiers, Tamanrasset and Bechar. The monthly mean hourly global solar radiation data estimated for Algiers are in reasonably good agreement with the experimental ones. Associated with the principal component analysis, the above method has been extended to all the other meteorological stations, and monthly mean values of hourly global solar radiation flux incident on an inclined surface have been simulated for every site of Algeria. This yields an important database useful for solar energy applications. (Author)

  5. 76 FR 55710 - Sunshine Act Meeting of LSC Board of Directors Finance Committee

    Science.gov (United States)

    2011-09-08

    ... Sunshine Act Meeting of LSC Board of Directors Finance Committee TIME AND DATE: The Legal Services Corporation (``LSC'' or ``Corporation'') Board of Directors (``Board'') Finance Committee will meet...: Finance Committee Agenda Open Session 1. Approval of agenda. 2. Consider and act on LSC Management's...

  6. 75 FR 56580 - Sunshine Act Meeting of LSC Board of Directors and Its Finance Committee

    Science.gov (United States)

    2010-09-16

    ... Sunshine Act Meeting of LSC Board of Directors and Its Finance Committee TIME AND DATE: The Legal Services Corporation (``LSC'' or ``Corporation'') Board of Directors (``Board'') and its Finance Committee will meet consecutively on September 21, 2010, with the Finance Committee convening at 10 a.m., Eastern Time, and...

  7. 76 FR 67764 - Finance, Budget & Program Committee Board of Directors Meeting; Sunshine Act

    Science.gov (United States)

    2011-11-02

    ... From the Federal Register Online via the Government Publishing Office NEIGHBORHOOD REINVESTMENT CORPORATION Finance, Budget & Program Committee Board of Directors Meeting; Sunshine Act Time & Date: 10 a.m., Thursday, November 3, 2011. Place: 1325 G Street, NW., Suite 800, Boardroom, Washington, DC 20005....

  8. 76 FR 55125 - Finance, Budget & Program Committee Meeting of the Board of Directors; Sunshine Act

    Science.gov (United States)

    2011-09-06

    ... From the Federal Register Online via the Government Publishing Office NEIGHBORHOOD REINVESTMENT CORPORATION Finance, Budget & Program Committee Meeting of the Board of Directors; Sunshine Act TIME AND DATE: 2 p.m., Wednesday, September 7, 2011 PLACE: 1325 G Street, NW., Suite 800, Boardroom, Washington,...

  9. 77 FR 56238 - Finance, Budget & Program. Committee Meeting of the Board of Directors; Sunshine Act

    Science.gov (United States)

    2012-09-12

    ... From the Federal Register Online via the Government Publishing Office NEIGHBORHOOD REINVESTMENT CORPORATION Finance, Budget & Program. Committee Meeting of the Board of Directors; Sunshine Act TIME & DATE: 3 p.m., Thursday, September 20, 2012. PLACE: 1325 G Street NW., Suite 800, Boardroom, Washington,...

  10. 76 FR 55124 - Audit Committee Meeting of the Board of Directors; Sunshine Act

    Science.gov (United States)

    2011-09-06

    ... CORPORATION Audit Committee Meeting of the Board of Directors; Sunshine Act TIME AND DATE: 11:00 a.m...; ehall@nw.org . AGENDA: I. CALL TO ORDER II. Executive Session with Internal Audit Director III. Internal Audit Report with Management's Response IV. FY `11 and `12 Risk Assessments and Internal Audit Plans...

  11. 78 FR 54925 - Audit Committee Meeting of The Board of Directors; Sunshine Act Meeting

    Science.gov (United States)

    2013-09-06

    ... CORPORATION Audit Committee Meeting of The Board of Directors; Sunshine Act Meeting TIME AND DATE: 10:00 a.m... Secretary, (202) 760-4104; ehall@nw.org . AGENDA: I. CALL TO ORDER II. Executive Session With Internal Audit Director III. Title Change of the Internal Audit Director IV. Executive Session With Officers:...

  12. Egg saprolegniasis in a commercial sunshine bass hatchery: Control regime developed using copper sulfate

    Science.gov (United States)

    An obstacle to sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) larval production is fungal growth on eggs caused by the water-mold Saprolegnia spp. Copper sulfate (CuSO4) is commonly used for fungus control in troughs of catfish hatcheries, but the effectiveness o...

  13. 77 FR 24741 - Sunshine Act Meeting; National Museum and Library Services Board

    Science.gov (United States)

    2012-04-25

    ... ARTS AND THE HUMANITIES Sunshine Act Meeting; National Museum and Library Services Board AGENCY: Institute of Museum and Library Services (IMLS), NFAH. ACTION: Notice of meeting. SUMMARY: This notice sets forth the agenda of the forthcoming meeting of the National Museum and Library Services Board....

  14. 78 FR 8193 - Sunshine Act Meeting; Audit Committee Meeting of the Board of Directors

    Science.gov (United States)

    2013-02-05

    ... External Auditors IV. Executive Session: Audit Committee V. Executive Session with Internal Audit Director VI. Executive Session with Officers VII. Acceptance of the FY2012 Audited Financial Statements VIII... CORPORATION Sunshine Act Meeting; Audit Committee Meeting of the Board of Directors TIME & DATE: 2:00...

  15. The Relationship Between Temperature & Sunshine and Spring-Sown Wheat Quality

    Institute of Scientific and Technical Information of China (English)

    CAO Guang-cai; LI Meng; WU Dong-bing; SUN Qun; QIANG Xiao-lin; CHEN He-qin; DONG Mei; KOU Hao; WANG Jian-lin; HOU Li-bai

    2003-01-01

    In order to study the relationship between temperature&sunshine and spring-sown wheat qua lity,a spring-sown experiment with 3 wheat varieties was conducted in Rikaze,Lasa,Linzhi,Beijing and Shenyang from 1998 to 2001.The results indicated that significant difference on some quality characteristics of experimental wheat varieties were observed from different locations and different years.The results also showed:protein content was positively correlated with wet gluten content,falling number,the average day temperature and sunshine hours from heading to maturation;and negatively correlated with the growing days and the average diurnal temperature difference from sowing to maturation;wet gluten content was positively correlated with the average day temperature and sunshine hours during the same period.Sedimentation value and falling number were positively correlated with the average sunshine hours from sowing to maturation.The basic way of wheat production in Tibet was as follows:mainly developing medium gluten wheat varieties,suitably planting weak gluten wheat varieties,introducing some inland excellent varieties.

  16. 78 FR 19708 - Farm Credit Administration Board; Sunshine Act; Regular Meeting

    Science.gov (United States)

    2013-04-02

    ... From the Federal Register Online via the Government Publishing Office FARM CREDIT ADMINISTRATION Farm Credit Administration Board; Sunshine Act; Regular Meeting AGENCY: Farm Credit Administration... the Farm Credit Administration Board (Board). DATE AND TIME: The regular meeting of the Board will be...

  17. 76 FR 6473 - Sunshine Act; FCC To Hold Open Commission Meeting Tuesday, February 8, 2011

    Science.gov (United States)

    2011-02-04

    ... COMMISSION Sunshine Act; FCC To Hold Open Commission Meeting Tuesday, February 8, 2011 February 1, 2011. The... Competition Title: Reform of the FCC Form 477 Data Program (WC Docket No. 11-10); Development of Nationwide... impossible to fill. Send an e-mail to: fcc504@fcc.gov or call the Consumer & Governmental Affairs Bureau...

  18. 78 FR 51192 - World War I Centennial Commission; Notification of Upcoming Public Advisory Meeting; Sunshine Act...

    Science.gov (United States)

    2013-08-20

    ... From the Federal Register Online via the Government Publishing Office GENERAL SERVICES ADMINISTRATION World War I Centennial Commission; Notification of Upcoming Public Advisory Meeting; Sunshine Act Meetings Time and Date: Open: 9:30 a.m.-5:30 p.m. (Central Time) on Friday, September 13, 2013. Place: The...

  19. A Multi-view Interpretation of Sunshine Sketches of a Little Town

    Institute of Scientific and Technical Information of China (English)

    Li Jie

    2015-01-01

    Stephen Leacock's masterpiece Sunshine Sketches of a Little Town is considered as one of the most enduring classics of Canadian humorous literature.This paper discusses the novel from the viewpoints of character analysis,Mariposa understanding and humor explanation to help the readers gain a better knowledge.

  20. 78 FR 8193 - Sunshine Act Meeting; Finance, Budget & Program Committee Meeting of the Board of Directors

    Science.gov (United States)

    2013-02-05

    ... From the Federal Register Online via the Government Publishing Office NEIGHBORHOOD REINVESTMENT CORPORATION Sunshine Act Meeting; Finance, Budget & Program Committee Meeting of the Board of Directors TIME & DATE: 2:00 p.m., Wednesday, February 13, 2013. PLACE: 1325 G Street NW., Suite 800, Boardroom...

  1. 77 FR 24538 - Sunshine Act; Audit Committee Meeting of the Board of Directors

    Science.gov (United States)

    2012-04-24

    ... Audit Director IV. Executive Session with Officers: Pending Litigation V. Internal Audit Report with Management's Response VI. Amendment to the FY 2012 Internal Audit Plan VII. FY'13 Risk Assessment & DRAFT... CORPORATION Sunshine Act; Audit Committee Meeting of the Board of Directors TIME AND DATE: 2 p.m.,...

  2. 78 FR 24438 - Board of Directors Audit Committee; Sunshine Act Meeting

    Science.gov (United States)

    2013-04-25

    ... Communication VII. FY 2014 Risk Assessment & Draft Internal Audit Plan VIII. Internal Audit Status Reports IX... CORPORATION Board of Directors Audit Committee; Sunshine Act Meeting TIME and DATE: 2:00 p.m., Tuesday, April... . AGENDA: I. CALL TO ORDER II. Executive Session with Internal Audit Director III. Mid Year Discussion...

  3. 77 FR 56238 - Audit Committee Meeting of the Board of Directors; Sunshine Act

    Science.gov (United States)

    2012-09-12

    ... Charter VI. Internal Audit Response with Management's Response VII. FY 2013 Risk Assessment & Internal... CORPORATION Audit Committee Meeting of the Board of Directors; Sunshine Act TIME & DATE: 1 p.m., Friday....org . AGENDA: I. Call to Order II. Executive Session with Internal Audit Director III....

  4. 76 FR 72220 - Board of Directors Audit Committee Meeting; Sunshine Act

    Science.gov (United States)

    2011-11-22

    ... Related to Pending Litigation IV. Internal Audit Report with Management's Response V. FY '12 Risk Assessment and Internal Audit Plan VI. FY '12 EHLP Risk Assessment and Internal Audit Plan VII. Five Year... CORPORATION Board of Directors Audit Committee Meeting; Sunshine Act TIME AND DATE: 1 p.m., Tuesday,...

  5. 75 FR 47316 - National Science Board; Sunshine Act Meetings; Notice (Subject Matter Revised From Earlier Notice)

    Science.gov (United States)

    2010-08-05

    ... National Science Board; Sunshine Act Meetings; Notice (Subject Matter Revised From Earlier Notice) The... National Science Board business and other matters specified, as follows: Date and Time: August 12, 2010, at 3 p.m. EDT. Subject Matter: Review and Discussion of Current Mid-Scale Research Funding Support...

  6. 78 FR 67344 - Sunshine Act Meeting; New Time and Date of Proceeding

    Science.gov (United States)

    2013-11-12

    ... Federal Register due to the shutdown. The Board has now decided on a new time and date for the proceeding... SAFETY BOARD Sunshine Act Meeting; New Time and Date of Proceeding AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Notice of Public Meeting and Hearing; New Time and Date. SUMMARY: The Defense...

  7. 77 FR 24492 - Employee Thrift Advisory Council Meeting; Notice of Sunshine Act Meeting

    Science.gov (United States)

    2012-04-24

    ... From the Federal Register Online via the Government Publishing Office FEDERAL RETIREMENT THRIFT INVESTMENT BOARD Employee Thrift Advisory Council Meeting; Notice of Sunshine Act Meeting TIME AND DATE: 9 a.m. (Eastern Time) April 30, 2012. PLACE: 10th Floor Training Room, 77 K Street NE., Washington,...

  8. 75 FR 33307 - Employee Thrift Advisory Council Meeting; Sunshine Act; Notice of Meeting

    Science.gov (United States)

    2010-06-11

    ... From the Federal Register Online via the Government Publishing Office FEDERAL RETIREMENT THRIFT INVESTMENT BOARD Employee Thrift Advisory Council Meeting; Sunshine Act; Notice of Meeting Time and Date: 10 a.m. (Eastern Time), June 24, 2010. Place: 4th Floor, Conference Room, 1250 H Street,...

  9. 76 FR 20351 - Employee Thrift Advisory Council; Sunshine Act Meeting Notice

    Science.gov (United States)

    2011-04-12

    ... From the Federal Register Online via the Government Publishing Office FEDERAL RETIREMENT THRIFT INVESTMENT BOARD Employee Thrift Advisory Council; Sunshine Act Meeting Notice TIME AND DATE: 9 a.m. (Eastern Time) April 18, 2011. PLACE: 2nd Floor Training Room, 1250 H Street, NW., Washington, DC 20005....

  10. 75 FR 11887 - Sunshine Act Meeting; Open Commission Meeting; Tuesday, March 16, 2010

    Science.gov (United States)

    2010-03-12

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION Sunshine Act Meeting; Open Commission Meeting; Tuesday, March 16, 2010 Date: March 9, 2010. The Federal Communications Commission will hold an Open Meeting on the subject listed below on Tuesday,...

  11. 75 FR 40754 - Government in the Sunshine Act Regulations of the National Science Board

    Science.gov (United States)

    2010-07-14

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION 45 CFR Part 614 RIN 3145-AA53 Government in the Sunshine Act Regulations of the National Science Board AGENCY: National Science Board (NSB), National Science Foundation (NSF). ACTION: Direct final...

  12. The Research of Sunshine Sports to Psychologically Healthy to Shanghai University Students

    Science.gov (United States)

    Huang-sheng, Kong

    2012-01-01

    This article used self-reporting inventory, self-test questionnaire, and other methods, chose four vocational schools in Shanghai for comparing experimental study of mental health, conducted experiments on experimental group and control group, and analyzed the current mental health of young students in Shanghai. It shows that the sunshine sports…

  13. Exposure to sunshine early in life prevented development of type 1 diabetes in Danish boys

    DEFF Research Database (Denmark)

    Jacobsen, Ramune; Frederiksen, Peder; Heitmann, Berit L

    2015-01-01

    BACKGROUND: We aimed to assess the association between exposure to sunshine during gestation and the risk of type 1 diabetes (T1D) in Danish children. METHODS: The study population included 331,623 individuals born in Denmark from 1983 to 1988; 886 (0.26%) developed T1D by the age of 15 years. Th...

  14. Geologic map of the Sunshine 7.5' quadrangle, Taos County, New Mexico

    Science.gov (United States)

    Thompson, Ren A.; Turner, Kenzie J.; Shroba, Ralph R.; Cosca, Michael A.; Ruleman, Chester A.; Lee, John P.; Brandt, Theodore R.

    2014-01-01

    The Sunshine 7.5' quadrangle is located in the south-central part of the San Luis Basin of northern New Mexico, in the Rio Grande del Norte National Monument, and contains deposits that record volcanic, tectonic, and associated alluvial and colluvial processes over the past four million years. Sunshine Valley, named for the small locale of Sunshine, is incised by a series of northeast-trending drainages cut into Tertiary and Quaternary alluvial deposits forming an extensive alluvial apron between the east flank of the Sangre de Cristo Mountains and the Rio Grande. These deposits predominantly overlie gently eastward-dipping lava flows of Pliocene Servilleta Basalt erupted from centers west of the map area. Servilleta Basalt lava flows terminate to the south against the elevated topography of three volcanic centers of the Taos Plateau volcanic field. From west to east these are Cerro de la Olla, Cerro Chiflo, and Guadalupe Mountain that are exposed in the southern part of the map area. Remnants of Miocene volcanic rocks are exposed near the southwestern edge of the map area and record evidence of an eroded volcanic terrain underlying deposits of the Taos Plateau volcanic field. These deposits are likely fault bounded to the east, roughly coincident with north to northwest trending, down-to-east faults in the southwestern quarter of the map area. The down-to-east normal faults reflect the basinward migration of the western margin of the Sunshine Valley sub-basin of the southern San Luis Basin.

  15. 76 FR 55138 - Sunshine Notice; Board of Directors Meeting; September 22, 2011

    Science.gov (United States)

    2011-09-06

    ... (202) 336-8438. Connie M. Downs, Corporate Secretary, Overseas Private Investment Corporation. BILLING... From the Federal Register Online via the Government Publishing Office OVERSEAS PRIVATE INVESTMENT CORPORATION Sunshine Notice; Board of Directors Meeting; September 22, 2011 TIME AND DATE: Thursday, September...

  16. A Multi-view Interpretation of Sunshine Sketches of a Little Town

    Institute of Scientific and Technical Information of China (English)

    Li; Jie

    2015-01-01

    Stephen Leacock’s masterpiece Sunshine Sketches of a Little Town is considered as one of the most enduring classics of Canadian humorous literature.This paper discusses the novel from the viewpoints of character analysis,Mariposa understanding and humor explanation to help the readers gain a better knowledge.

  17. 75 FR 32816 - Sunshine Act Meeting of the Board of Directors Finance Committee Amended Notice

    Science.gov (United States)

    2010-06-09

    ... From the Federal Register Online via the Government Publishing Office LEGAL SERVICES CORPORATION Sunshine Act Meeting of the Board of Directors Finance Committee Amended Notice Changes to the Meeting Date... (202) 295-1500 or FR_NOTICE_QUESTIONS@lsc.gov . Dated: June 4, 2010. Patricia D. Batie, Corporate...

  18. 78 FR 65716 - Sunshine Act Meeting; Finance, Budget & Program Committee Meeting of the Board of Directors

    Science.gov (United States)

    2013-11-01

    ... From the Federal Register Online via the Government Publishing Office NEIGHBORHOOD REINVESTMENT CORPORATION Sunshine Act Meeting; Finance, Budget & Program Committee Meeting of the Board of Directors TIME.... Corporate Scorecard Report D. HUD Counseling Rule E. Grants Report VIII. Adjournment Jeffrey T. Bryson...

  19. 78 FR 24438 - Board of Directors Finance, Budget & Program Committee: Sunshine Act Meeting

    Science.gov (United States)

    2013-04-25

    ... CORPORATION Board of Directors Finance, Budget & Program Committee: Sunshine Act Meeting TIME AND DATE: 1:00 p.... STATUS: Open. CONTACT PERSON FOR MORE INFORMATION: Erica Hall, Assistant Corporate Secretary (202) 220... NC Grants V. FY 2014 Budget VI. Financial Report VII. DC Move Update VIII. FY 13 Corporate Milestone...

  20. 77 FR 22755 - Sunshine Act Meeting; Notice of Meeting of the Broadcasting Board of Governors

    Science.gov (United States)

    2012-04-17

    ... From the Federal Register Online via the Government Publishing Office BROADCASTING BOARD OF GOVERNORS Sunshine Act Meeting; Notice of Meeting of the Broadcasting Board of Governors DATE AND TIME: Friday, April 20, 2012, 10 a.m. PLACE: Office of Cuba Broadcasting, 4201 NW. 77th Ave., Miami, FL...

  1. 78 FR 68100 - Sunshine Act Meeting of the National Museums and Library Services Board

    Science.gov (United States)

    2013-11-13

    ... ARTS AND THE HUMANITIES Institute of Museum and Library Services Sunshine Act Meeting of the National Museums and Library Services Board AGENCY: Institute of Museum and Library Services (IMLS), NFAH. ACTION: Notice of Meeting. SUMMARY: The National Museum and Library Services Board, which advises the Director...

  2. Percent Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCT) generally indicate healthier ecosystems and cleaner surface water. More...

  3. Saturated Domino Coverings

    CERN Document Server

    Buchanan, Andrew; Ryba, Alex

    2011-01-01

    A domino covering of a board is saturated if no domino is redundant. We introduce the concept of a fragment tiling and show that a minimal fragment tiling always corresponds to a maximal saturated domino covering. The size of a minimal fragment tiling is the domination number of the board. We define a class of regular boards and show that for these boards the domination number gives the size of a minimal X-pentomino covering. Natural sequences that count maximal saturated domino coverings of square and rectangular boards are obtained. These include the new sequences A193764, A193765, A193766, A193767, and A193768 of OEIS.

  4. Percent Forest Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCTFuture) generally indicate healthier ecosystems and cleaner surface water....

  5. Microphysical effects determine macrophysical response for aerosol impacts on deep convective clouds.

    Science.gov (United States)

    Fan, Jiwen; Leung, L Ruby; Rosenfeld, Daniel; Chen, Qian; Li, Zhanqing; Zhang, Jinqiang; Yan, Hongru

    2013-11-26

    Deep convective clouds (DCCs) play a crucial role in the general circulation, energy, and hydrological cycle of our climate system. Aerosol particles can influence DCCs by altering cloud properties, precipitation regimes, and radiation balance. Previous studies reported both invigoration and suppression of DCCs by aerosols, but few were concerned with the whole life cycle of DCC. By conducting multiple monthlong cloud-resolving simulations with spectral-bin cloud microphysics that capture the observed macrophysical and microphysical properties of summer convective clouds and precipitation in the tropics and midlatitudes, this study provides a comprehensive view of how aerosols affect cloud cover, cloud top height, and radiative forcing. We found that although the widely accepted theory of DCC invigoration due to aerosol's thermodynamic effect (additional latent heat release from freezing of greater amount of cloud water) may work during the growing stage, it is microphysical effect influenced by aerosols that drives the dramatic increase in cloud cover, cloud top height, and cloud thickness at the mature and dissipation stages by inducing larger amounts of smaller but longer-lasting ice particles in the stratiform/anvils of DCCs, even when thermodynamic invigoration of convection is absent. The thermodynamic invigoration effect contributes up to ~27% of total increase in cloud cover. The overall aerosol indirect effect is an atmospheric radiative warming (3-5 W m(-2)) and a surface cooling (-5 to -8 W m(-2)). The modeling findings are confirmed by the analyses of ample measurements made at three sites of distinctly different environments.

  6. Intergalactic HI Clouds

    CERN Document Server

    Briggs, F H

    2005-01-01

    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.

  7. Cloud Computing Bible

    CERN Document Server

    Sosinsky, Barrie

    2010-01-01

    The complete reference guide to the hot technology of cloud computingIts potential for lowering IT costs makes cloud computing a major force for both IT vendors and users; it is expected to gain momentum rapidly with the launch of Office Web Apps later this year. Because cloud computing involves various technologies, protocols, platforms, and infrastructure elements, this comprehensive reference is just what you need if you'll be using or implementing cloud computing.Cloud computing offers significant cost savings by eliminating upfront expenses for hardware and software; its growing popularit

  8. Cloud Computing Quality

    Directory of Open Access Journals (Sweden)

    Anamaria Şiclovan

    2013-02-01

    Full Text Available Cloud computing was and it will be a new way of providing Internet services and computers. This calculation approach is based on many existing services, such as the Internet, grid computing, Web services. Cloud computing as a system aims to provide on demand services more acceptable as price and infrastructure. It is exactly the transition from computer to a service offered to the consumers as a product delivered online. This paper is meant to describe the quality of cloud computing services, analyzing the advantages and characteristics offered by it. It is a theoretical paper.Keywords: Cloud computing, QoS, quality of cloud computing

  9. Cloud Computing Technologies

    Directory of Open Access Journals (Sweden)

    Sean Carlin

    2012-06-01

    Full Text Available This paper outlines the key characteristics that cloud computing technologies possess and illustrates the cloud computing stack containing the three essential services (SaaS, PaaS and IaaS that have come to define the technology and its delivery model. The underlying virtualization technologies that make cloud computing possible are also identified and explained. The various challenges that face cloud computing technologies today are investigated and discussed. The future of cloud computing technologies along with its various applications and trends are also explored, giving a brief outlook of where and how the technology will progress into the future.

  10. 75 FR 63204 - Sunshine Act Meeting of the Board of Directors and Its Committees; Amended Notice; Changes to...

    Science.gov (United States)

    2010-10-14

    ... term ``meeting'' and, therefore, the requirements of the Sunshine Act do not apply to such portion of... Governance & Performance Review Committee. 16. Consider and act on Resolution 2010-XXX Authorizing the Board..., Corporate Secretary. BILLING CODE 7050-01-P...

  11. correlation between sunshine hours and climatic parameters at four ...

    African Journals Online (AJOL)

    Mgina

    Department of Soil Science, Makerere University, P.O.Box 7062, Kampala Uganda. ABSTRACT ... Climatic data for the meteorological stations of Entebbe, Mbarara, Tororo and Makerere, extending over a .... Monthly averages were got and analyzed in. SPSS 10.0 ..... The clouds are created and loose rain on the westerly.

  12. CLOUD COMPUTING SECURITY

    Directory of Open Access Journals (Sweden)

    Ştefan IOVAN

    2016-05-01

    Full Text Available Cloud computing reprentes the software applications offered as a service online, but also the software and hardware components from the data center.In the case of wide offerd services for any type of client, we are dealing with a public cloud. In the other case, in wich a cloud is exclusively available for an organization and is not available to the open public, this is consider a private cloud [1]. There is also a third type, called hibrid in which case an user or an organization might use both services available in the public and private cloud. One of the main challenges of cloud computing are to build the trust and ofer information privacy in every aspect of service offerd by cloud computingle. The variety of existing standards, just like the lack of clarity in sustenability certificationis not a real help in building trust. Also appear some questions marks regarding the efficiency of traditionsecurity means that are applied in the cloud domain. Beside the economic and technology advantages offered by cloud, also are some advantages in security area if the information is migrated to cloud. Shared resources available in cloud includes the survey, use of the "best practices" and technology for advance security level, above all the solutions offered by the majority of medium and small businesses, big companies and even some guvermental organizations [2].

  13. Land Cover Characterization Program

    Science.gov (United States)

    ,

    1997-01-01

    The U.S. Geological Survey (USGS) has a long heritage of leadership and innovation in land use and land cover mapping. The USGS Anderson system defined the principles for land use and land cover mapping that have been the model both nationally and internationally for more than 20 years. The Land Cover Characterization Program (LCCP) is founded on the premise that the Nation's needs for land cover and land use data are diverse and increasingly sophisticated. The range of projects, programs, and organizations that use land cover data to meet their planning, management, development, and assessment objectives has expanded significantly. The reasons for this are numerous, and include the improved capabilities provided by geographic information systems, better and more data-intensive analytic models, and increasing requirements for improved information for decision making. The overall goals of the LCCP are to:

  14. Land Cover Trends Project

    Science.gov (United States)

    Acevedo, William

    2006-01-01

    The Land Cover Trends Project is designed to document the types, rates, causes, and consequences of land cover change from 1973 to 2000 within each of the 84 U.S. Environmental Protection Agency (EPA) Level III ecoregions that span the conterminous United States. The project's objectives are to: * Develop a comprehensive methodology using probability sampling and change analysis techniques and Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper (ETM) data for estimating regional land cover change. * Characterize the spatial and temporal characteristics of conterminous U.S. land cover change for five periods from 1973 to 2000 (nominally 1973, 1980, 1986, 1992, and 2000). * Document the regional driving forces and consequences of change. * Prepare a national synthesis of land cover change.

  15. Flat covers of modules

    CERN Document Server

    Xu, Jinzhong

    1996-01-01

    Since the injective envelope and projective cover were defined by Eckmann and Bas in the 1960s, they have had great influence on the development of homological algebra, ring theory and module theory. In the 1980s, Enochs introduced the flat cover and conjectured that every module has such a cover over any ring. This book provides the uniform methods and systematic treatment to study general envelopes and covers with the emphasis on the existence of flat cover. It shows that Enochs' conjecture is true for a large variety of interesting rings, and then presents the applications of the results. Readers with reasonable knowledge in rings and modules will not have difficulty in reading this book. It is suitable as a reference book and textbook for researchers and graduate students who have an interest in this field.

  16. Impact of decadal cloud variations on the Earth's energy budget

    Science.gov (United States)

    Zhou, Chen; Zelinka, Mark D.; Klein, Stephen A.

    2016-12-01

    Feedbacks of clouds on climate change strongly influence the magnitude of global warming. Cloud feedbacks, in turn, depend on the spatial patterns of surface warming, which vary on decadal timescales. Therefore, the magnitude of the decadal cloud feedback could deviate from the long-term cloud feedback. Here we present climate model simulations to show that the global mean cloud feedback in response to decadal temperature fluctuations varies dramatically due to time variations in the spatial pattern of sea surface temperature. We find that cloud anomalies associated with these patterns significantly modify the Earth's energy budget. Specifically, the decadal cloud feedback between the 1980s and 2000s is substantially more negative than the long-term cloud feedback. This is a result of cooling in tropical regions where air descends, relative to warming in tropical ascent regions, which strengthens low-level atmospheric stability. Under these conditions, low-level cloud cover and its reflection of solar radiation increase, despite an increase in global mean surface temperature. These results suggest that sea surface temperature pattern-induced low cloud anomalies could have contributed to the period of reduced warming between 1998 and 2013, and offer a physical explanation of why climate sensitivities estimated from recently observed trends are probably biased low.

  17. Community Cloud Computing

    CERN Document Server

    Marinos, Alexandros

    2009-01-01

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

  18. Why does Rhinopithecus bieti prefer the highest elevation range in winter? A test of the sunshine hypothesis.

    Directory of Open Access Journals (Sweden)

    Rui-Chang Quan

    Full Text Available Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti. We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1 R. bieti used the high altitude range between 4100-4400 m in winter although the yearly home range spanned from 3500-4500 m; 2 both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3 within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4 monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding

  19. A blending snow cover data base on MODIS and AMSR-E snow cover in Qinghai-Tibet Plateau

    Science.gov (United States)

    Xiaohua, H.; Wang, J.; Che, T.; Dai, L. Y.

    2012-04-01

    The algorithms of MODIS Terra and MODIS Aqua versions of the snow products have been developed by the NASA National Snow and Ice Data Center (NSIDC). The MODIS global snow-cover products have been available through the NSIDC Distributed Active Archive Center (DAAC) since February 24, 2000 to Terra and July 4, 2002 to Aqua. The MODIS snow-cover maps represent a potential improvement relative to hemispheric-scale snow maps that are available today mainly because of the improved spatial resolution and snow/cloud discrimination capabilities of MODIS, and the frequent global coverage. In China, the snow distribution is different to other regions. Their accuracy on Qinghai-Tibet Plateau (QTP), however, has not yet been established. There are some drawbacks about NSIDC global snow cover products on QTP: 1. The characteristics of snow depth distribution on QTP: Thin, discontinuous. Our research indicated the MODIS snow-cover products underestimated the snow cover area in QTP. 2. The daily snow cover product from MODIS-Terra and Aqua can include the data gaps. 3. The snow products can separate snow from most obscuring clouds. However, there are still many cloud pixels in daily snow cover products. The study developed a new blending daily snow cover algorithm through improving the NSIDC snow algorithms and combining MODIS and AMSR-E data in QTP. The new snow cover products will provide daily snow cover at 500-m resolution in QTP. The new snow cover algorithm employs a grouped-criteria technique using the Normalized Difference Snow Index (NDSI) and other spectral threshold tests and image fusion technology to identify and classify snow on a pixel-by-pixel basis. The usefulness of the NDSI is based on the fact that snow and ice are considerably more reflective in the visible than in the shortwave IR part of the spectrum, and the reflectance of most clouds remains high in the short-wave IR, while the reflectance of snow is low. We propose a set of three steps, based on a

  20. Installing and Scaling out Ubuntu Enterprise Cloud in Virtual Environment, Supplement to “Guidelines for Building a Private Cloud Infrastructure

    DEFF Research Database (Denmark)

    Pantić, Zoran; Ali Babar, Muhammad

    2012-01-01

    This document contains the supplemental material to the book “Guidelines for Building a Private Cloud Infrastructure”. This document provides guidance on how to install Ubuntu Enterprise Cloud in virtual environment, and afterwards how to scale out when needed. The purpose of this supplemental book...... is to provide a practical, step-by-step, detailed guide on how to dimension and install the machines and network. Some initial steps of configuring the cloud are also covered. The installation is performed in a virtual environment based on Windows 7 and VMware Workstation 7. The cloud installation is performed...... cloud, both using the command line tools, and GUI based tool HybridFox....