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Sample records for cloudy days estimated

  1. Increasing the solar photovoltaic energy capture on sunny and cloudy days

    SciTech Connect

    Kelly, Nelson A.; Gibson, Thomas L.

    2011-01-15

    This report analyzes an extensive set of measurements of the solar irradiance made using four identical solar arrays and associated solar sensors (collectively referred to as solar collectors) with different tilt angles relative to the earth's surface, and thus the position of the sun, in order to determine an optimal tracking algorithm for capturing solar radiation. The study included a variety of ambient conditions including different seasons and both cloudy and cloud-free conditions. One set of solar collectors was always approximately pointed directly toward the sun (DTS) for a period around solar noon. These solar collectors thus captured the direct beam component of the solar radiation that predominates on sunny days. We found that on sunny days, solar collectors with a DTS configuration captured more solar energy in accordance with the well-known cosine dependence for the response of a flat-surfaced solar collector to the angle of incidence with direct beam radiation. In particular, a DTS orientation was found to capture up to twice as much solar energy as a horizontal (H) orientation in which the array is tilted toward the zenith. Another set of solar collectors always had an H orientation, and this best captured the diffuse component of the solar radiation that predominates on cloudy days. The dependence of the H/DTS ratio on the solar-collector tilt angle was in approximate agreement with the Isotropic Diffuse Model derived for heavily overcast conditions. During cloudy periods, we found that an H configuration increased the solar energy capture by nearly 40% compared to a DTS configuration during the same period, and we estimate the solar energy increase of an H configuration over a system that tracks the obscured solar disk could reach 50% over a whole heavily-overcast day. On an annual basis the increase is predicted to be much less, typically only about 1%, because the contribution of cloudy days to the total annual solar energy captured by a

  2. Estimation of the influence of cloudiness on the Earth observation from space through a gap in a cloudy field

    NASA Astrophysics Data System (ADS)

    Belov, V. V.; Kirnos, I. V.; Tarasenkov, M. V.

    2015-11-01

    For atmospheric correction of satellite images, the problem is formulated to estimate the distance from a cloud at which its influence on the satellite image of the Earth surface can be neglected. The Monte Carlo method of conjugate trajectories is used. The gap radius in the field of continuous cloudiness at which the influence of the cloudy medium on the received signal intensity does not exceed 10 % is obtained. It is revealed that for the Lambert law of radiation reflection from the Earth surface, the curve of the dependence of the received signal intensity on the gap radius has a maximum caused by the opposite influence of light scattering by the cloudy medium and radiation reflection by the surface (adjacency effect). To further generalize the examined problem to a stochastic cloud field, the method of direct simulation of photon trajectories in a stochastic medium is compared with G. A. Titov's method of closed equations in the gap vicinity. A comparison is carried out with the model of the stochastic medium in the form of a cloud field of constant geometric thickness consisting of rectangular clouds whose boundaries are determined by the stationary Poisson flow of points. It is demonstrated that results of calculations can differ at most by 20‒30 %; however, in some cases (for some sets of initial data), the difference for the entire region of cloud cover indices is within 7 %.

  3. Quantitative Estimates of Cloudiness over the Gulf Stream Locale Using GOES VAS Observations.

    NASA Astrophysics Data System (ADS)

    Alliss, Randall J.; Raman, Sethu

    1995-02-01

    Fields of cloudiness derived from the Geostationary Operational Environmental Satellite VISSR (Visible Infrared Spin Scan Radiometer) Atmospheric Sounder are analyzed over the Gulf Stream locale (GSL) to investigate seasonal and geographical variations. The GSL in this study is defined as the region bounded from 31° to 38°N and 82° to 66°W. This region covers an area that includes the United States mid-Atlantic coast states, the Gulf Stream, and portions of the Sargasso Sea. Clouds over the GSL are found approximately three-quarters of the time between 1985 and 1993. However, large seasonal variations in the frequency of cloudiness exist. These seasonal variations show a distinct relationship to gradients in sea surface temperature (SST). For example, during winter when large SST gradients are present, large gradients in cloudiness are found. Clouds are observed least often during summer over the ocean portion of the GSL. This minimum coincides with an increase in atmospheric stability due to large-scale subsidence. Cloudiness is also found over the GSL in response to mesoscale convergence areas induced by sea surface temperature gradients. Geographical variations in cloudiness are found to be related to the meteorology of the region. During periods of cold-air advection, which are found most frequently in winter, clouds are found less often between the coastline and the core of the Gulf Stream and more often over the Sargasso Sea. During cyclogenesis, large cloud shields often develop and cover the entire domain.Satellite estimates of cloudiness are found to be least reliable over land at night during the cold months. In these situations, the cloud retrieval algorithm often mistakes clear sky for low clouds. Satellite-derived cloudiness over land is compared with daytime surface observations of cloudiness. Results indicate that retrieved cloudiness agrees well with surface observations. Relative humidity fields taken from global analyses are compared with

  4. Using Microwave Observations to Estimate Land Surface Temperature during Cloudy Conditions

    NASA Astrophysics Data System (ADS)

    Holmes, T. R.; Crow, W. T.; Hain, C.; Anderson, M. C.

    2014-12-01

    Land surface temperature (LST), a key ingredient for physically-based retrieval algorithms of hydrological states and fluxes, remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observations and passive microwave observations (MW). TIR is the most commonly used approach and the method of choice to provide standard LST products for various satellite missions. MW-based LST retrievals on the other hand are not as widely adopted for land applications; currently their principle use is in soil moisture retrieval algorithms. MW and TIR technologies present two highly complementary and independent means of measuring LST. MW observations have a high tolerance to clouds but a low spatial resolution, and TIR has a high spatial resolution with temporal sampling restricted to clear skies. The nature of the temperature at the very surface layer of the land makes it difficult to combine temperature estimates between different methods. The skin temperature is characterized by a strong diurnal cycle that is dependant in timing and amplitude on the exact sensing depth and thermal properties of the vegetation. This paper builds on recent progress in characterizing the main structural components of the DTC that explain differences in TIR and MW estimates of LST. Spatial patterns in DTC timing (phase lag with solar noon) and DTC amplitude have been calculated for TIR, MW and compared to weather prediction estimates. Based on these comparisons MW LST can be matched to the TIR record. This paper will compare in situ measurements of LST with satellite estimates from (downscaled) TIR and (reconciled) MW products. By contrasting the validation results of clear sky days with those of cloudy days the expected tolerance to clouds of the MW observations will be tested. The goal of this study is to determine the weather conditions in which MW can supplement the TIR LST record.

  5. Estimating the UV diffuse fraction of solar radiation under partly cloudy skies

    NASA Astrophysics Data System (ADS)

    Grant, Richard H.; Gao, Wei

    2002-01-01

    A major limitation in predicting the ultraviolet-B (UVB) irradiance on humans, plant leaves and flowers and aquatic organisms is the difficulty in determining the UVB under partly cloudy sky conditions. This study analyzes the UV diffuse fractions under partly cloudy and clear conditions for nine locations in the USA over a period of 1997 through 1999. Radiation measurements, made as part of the United States Department of Agriculture UVB Monitoring Program using multi-filter rotating shadow band radiometers, were paired with cloud cover and other atmospheric measurements made with National Weather Service Automated Surface Observation Systems within 30 km of the radiation measurement location to evaluate the accuracy of using a relatively simple model to describe the diffuse fraction of UV radiation under partly-cloudy skies. The diffuse fraction was modeled as the summation of clear and overcast sky diffuse fractions, weighted by the probability of the sun's direct beam being obstructed or not for a given cloud cover fraction. For the nine locations evaluated, the model had a mean bias error (MBE) of 0.0037 and a root mean squared error (RMSE) of 0.0361. Simplifying the model by assuming a diffuse fraction of 1 for the overcast sky resulted in a slightly higher error (MBE error of -0.0045 and an RMSE of 0.0387). Model errors were greatest for low solar zenith angles and high cloud fractions. The greatest error, associated with overcast sky conditions, appeared to be a result of scattering off the clouds during the period of time where the sun's beam was unobstructed. Error analysis also showed that the diffuse fraction of partly cloudy skies when the sun's beam was not obstructed is well approximated by the clear sky condition to within approximately 0.1, supporting the use of aerosol optical thickness estimates by Langley plot under partly cloudy skies.

  6. Solar energy distribution over Egypt using cloudiness from Meteosat photos

    SciTech Connect

    Mosalam Shaltout, M.A.; Hassen, A.H. )

    1990-01-01

    In Egypt, there are 10 ground stations for measuring the global solar radiation, and five stations for measuring the diffuse solar radiation. Every day at noon, the Meteorological Authority in Cairo receives three photographs of cloudiness over Egypt from the Meteosat satellite, one in the visible, and two in the infra-red bands (10.5-12.5 {mu}m) and (5.7-7.1 {mu}m). The monthly average cloudiness for 24 sites over Egypt are measured and calculated from Meteosat observations during the period 1985-1986. Correlation analysis between the cloudiness observed by Meteosat and global solar radiation measured from the ground stations is carried out. It is found that, the correlation coefficients are about 0.90 for the simple linear regression, and increase for the second and third degree regressions. Also, the correlation coefficients for the cloudiness with the diffuse solar radiation are about 0.80 for the simple linear regression, and increase for the second and third degree regression. Models and empirical relations for estimating the global and diffuse solar radiation from Meteosat cloudiness data over Egypt are deduced and tested. Seasonal maps for the global and diffuse radiation over Egypt are carried out.

  7. Hot, Dry and Cloudy

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Hot, Dry and Cloudy

    This artist's concept shows a cloudy Jupiter-like planet that orbits very close to its fiery hot star. NASA's Spitzer Space Telescope was recently used to capture spectra, or molecular fingerprints, of two 'hot Jupiter' worlds like the one depicted here. This is the first time a spectrum has ever been obtained for an exoplanet, or a planet beyond our solar system.

    The ground-breaking observations were made with Spitzer's spectrograph, which pries apart infrared light into its basic wavelengths, revealing the 'fingerprints' of molecules imprinted inside. Spitzer studied two planets, HD 209458b and HD 189733b, both of which were found, surprisingly, to have no water in the tops of their atmospheres. The results suggest that the hot planets are socked in with dry, high clouds, which are obscuring water that lies underneath. In addition, HD209458b showed hints of silicates, suggesting that the high clouds on that planet contain very fine sand-like particles.

    Capturing the spectra from the two hot-Jupiter planets was no easy feat. The planets cannot be distinguished from their stars and instead appear to telescopes as single blurs of light. One way to get around this is through what is known as the secondary eclipse technique. In this method, changes in the total light from a so-called transiting planet system are measured as a planet is eclipsed by its star, vanishing from our Earthly point of view. The dip in observed light can then be attributed to the planet alone.

    This technique, first used by Spitzer in 2005 to directly detect the light from an exoplanet, currently only works at infrared wavelengths, where the differences in brightness between the planet and star are less, and the planet's light is easier to pick out. For example, if the experiment had been done in visible light, the total light from the system would appear to be unchanged

  8. Empirical Estimates and Observations of 0Day Vulnerabilities

    SciTech Connect

    Miles A. McQueen; Trevor A. McQueen; Wayne F. Boyer; May R. Chaffin

    2009-01-01

    We define a 0Day vulnerability to be any vulnerability, in deployed software, that has been discovered by at least one person but has not yet been publicly announced or patched. These 0Day vulnerabilities are of particular interest when assessing the risk to a system from exploit of vulnerabilities which are not generally known to the public or, most importantly, to the owners of the system. Using the 0Day definition given above, we analyzed the 0Day lifespans of 491 vulnerabilities and conservatively estimated that in the worst year there were on average 2500 0Day vulnerabilities in existence on any given day. Then using a small but intriguing set of 15 0Day vulnerability lifespans representing the time from actual discovery to public disclosure, we made a more aggressive estimate. In this case, we estimated that in the worst year there were, on average, 4500 0Day vulnerabilities in existence on any given day.

  9. pyCloudy: Tools to manage astronomical Cloudy photoionization code

    NASA Astrophysics Data System (ADS)

    Morisset, Christophe

    2013-04-01

    PyCloudy is a Python library that handles input and output files of the Cloudy photoionization code (Gary Ferland). It can also generate 3D nebula from various runs of the 1D Cloudy code. pyCloudy allows you to: define and write input file(s) for Cloudy code. As you can have it in a code, you may generate automatically sets of input files, changing parameters from one to the other.read the Cloudy output files and play with the data: you will be able to plot line emissivity ratio vs. the radius of the nebula, the electron temperature, or any Cloudy output.build pseudo-3D models, a la Cloudy_3D, by running a set of models, changing parameters (e.g. inner radius, density) following angular laws, reading the outputs of the set of models and interpolating the results (Te, ne, line emissivities) in a 3D cube.

  10. Empirical Estimates of 0Day Vulnerabilities in Control Systems

    SciTech Connect

    Miles A. McQueen; Wayne F. Boyer; Sean M. McBride; Trevor A. McQueen

    2009-01-01

    We define a 0Day vulnerability to be any vulnerability, in deployed software, which has been discovered by at least one person but has not yet been publicly announced or patched. These 0Day vulnerabilities are of particular interest when assessing the risk to well managed control systems which have already effectively mitigated the publicly known vulnerabilities. In these well managed systems the risk contribution from 0Days will have proportionally increased. To aid understanding of how great a risk 0Days may pose to control systems, an estimate of how many are in existence is needed. Consequently, using the 0Day definition given above, we developed and applied a method for estimating how many 0Day vulnerabilities are in existence on any given day. The estimate is made by: empirically characterizing the distribution of the lifespans, measured in days, of 0Day vulnerabilities; determining the number of vulnerabilities publicly announced each day; and applying a novel method for estimating the number of 0Day vulnerabilities in existence on any given day using the number of vulnerabilities publicly announced each day and the previously derived distribution of 0Day lifespans. The method was first applied to a general set of software applications by analyzing the 0Day lifespans of 491 software vulnerabilities and using the daily rate of vulnerability announcements in the National Vulnerability Database. This led to a conservative estimate that in the worst year there were, on average, 2500 0Day software related vulnerabilities in existence on any given day. Using a smaller but intriguing set of 15 0Day software vulnerability lifespans representing the actual time from discovery to public disclosure, we then made a more aggressive estimate. In this case, we estimated that in the worst year there were, on average, 4500 0Day software vulnerabilities in existence on any given day. We then proceeded to identify the subset of software applications likely to be used in some

  11. Common Day Care Safety Renovations: Descriptions, Explanations and Cost Estimates.

    ERIC Educational Resources Information Center

    Spack, Stan

    This booklet explains some of the day care safety features specified by the new Massachusetts State Building Code (January 1, 1975) which must be met before a new day care center can be licensed. The safety features described are those which most often require renovation to meet the building code standards. Best estimates of the costs involved in…

  12. Autumnal Mixed-Phase Cloudy Boundary Layers in the Arctic.

    NASA Astrophysics Data System (ADS)

    Pinto, James O.

    1998-06-01

    Two mixed-phase cloudy boundary layer events observed over the Arctic ice pack in autumn are extensively analyzed. The local dynamic and thermodynamic structure of the boundary layers is determined from aircraft measurements including analysis of turbulence, longwave radiative transfer, and cloud microphysics. The large-scale forcing is determined from the National Centers for Environmental Prediction reanalysis fields while mesoscale forcing is estimated from 40-km aircraft box patterns. The two cases differed somewhat in their local static stability, surface characteristics, and large-scale forcing. One case was characterized by a stably stratified cloudy boundary layer over a heterogeneous surface containing numerous open leads. The other case occurred over a fairly homogenous surface of multiyear ice and consisted of a surface-based stable layer surmounted by a low-level jet and a cloud-topped mixed layer. An important large-scale factor in the development of low clouds appears to have been water vapor advection. Low clouds formed irrespective of the sign of the large-scale vertical velocity. Observed flux profiles indicate that both cloudy boundary layers are cooled through turbulent eddies except at cloud top where entrainment of warm moist air aloft occurs. Maximum turbulent kinetic energy occurs near cloud top where turbulent motions are driven by strong radiative cooling (>70 K day1) and in the vicinity of the low-level jet where turbulence is shear induced. The presence of both liquid and ice in the cloud layers appears to be a nearly steady-state feature at temperatures between 13° and 20°C. Results of a simple condensed water budget indicate that these colloidally unstable mixed-phase clouds may be maintained through strong cloud-top radiative cooling. The isobaric cooling rate required to maintain the presence of both liquid and ice in a stratiform cloud is quite sensitive to variations in the highly uncertain concentration of ice-forming nuclei.

  13. A CLOUDY/XSPEC Interface

    NASA Technical Reports Server (NTRS)

    Porter, R. L.; Ferland, G. J.; Kraemer, S. B.; Armentrout, B. K.; Arnaud, K. A.; Turner, T. J.

    2007-01-01

    We discuss new functionality of the spectral simulation code CLOUDY which allows the user to calculate grids with one or more initial parameters varied and formats the predicted spectra in the standard FITS format. These files can then be imported into the x-ray spectral analysis software XSPEC and used as theoretical models for observations. We present and verify a test case. Finally, we consider a few observations and discuss our results.

  14. Total gaseous mercury exchange between water and air during cloudy weather conditions over Hongfeng Reservoir, Guizhou, China

    NASA Astrophysics Data System (ADS)

    Feng, Xinbin; Wang, Shaofeng; Qiu, Guangle; He, Tianrong; Li, Guanghui; Li, Zhonggen; Shang, Lihai

    2008-08-01

    Total gaseous mercury (TGM) exchange fluxes between air and water surface were measured using a dynamic flux chamber (DFC) coupled with a gaseous mercury analyzer at two sampling sites of Hongfeng reservoir in cloudy and rainy weather conditions. The concentrations of dissolved gaseous mercury (DGM) in water were also measured and indicated that DGM was supersaturated at most time during the sampling periods, which implied that the water body acted primarily as a source of mercury to the atmosphere. In general, TGM fluxes displayed a consistent diurnal pattern with peak fluxes at noon and minimum levels at early morning or night. However, this diurnal pattern was not clear when the weather was heavily cloudy and rainy with the maximum solar radiation of less than 140 W m-2. At this specific weather condition, a significantly positive correlation between TGM flux and relative humidity was observed. The behaviors of TGM flux over Hongfeng reservoir observed at cloudy weather conditions were some what different from those observed during mostly sunny weather conditions in Northern America and Europe. The empirical model developed based on the correlation between TGM flux and solar radiation during sunny days in Northern America was not applicable for estimation of TGM flux at cloudy and rainy weather conditions.

  15. Cloudy Image of Cerberus Rupes Dark Lineation

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Second Science Phasing Orbits (SPO-2) period of the Mars Global Surveyor mission began at the end of May 1998. These orbits are morning orbits. That is, the local time on the planet beneath Mars Global Surveyor is in the morning. During the first part of June 1998, the local time on the ground was approximately 9:30 a.m. The Mars Orbiter Camera (MOC) has observed that this time of day is quite cloudy this year.

    Clouds have thus posed a real challenge for the MOC team, who are targeting high resolution images almost every day. Many of the high resolution images that were returned to Earth in early June 1998 were nearly white with clouds and haze. Very little detail could be seen on the ground.

    The above picture illustrates one of the better cloudy images obtained by MOC. The haze was too thick to show much detail on the surface in the raw image, but in this case at least a dark lineation could be seen in part of the image. The full frame was nearly white everywhere except in the vicinity of the dark lineation. The MOC image, #35003, was obtained on Mars Global Surveyor's 350th orbit about the planet. The picture was taken around 4:00 a.m. PDT on June 7, 1998. The center of this subframe is at 8.03oN, 194.30oW. The dark lineation is one of the Cerberus Rupes--a set of dark lines (ridges or fractures) that cross the region southeast of the Elysium volcanic rise.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  16. Trade-Wind Cloudiness and Climate

    NASA Technical Reports Server (NTRS)

    Randall, David A.

    1997-01-01

    Closed Mesoscale Cellular Convection (MCC) consists of mesoscale cloud patches separated by narrow clear regions. Strong radiative cooling occurs at the cloud top. A dry two-dimensional Bousinesq model is used to study the effects of cloud-top cooling on convection. Wide updrafts and narrow downdrafts are used to indicate the asymmetric circulations associated with the mesoscale cloud patches. Based on the numerical results, a conceptual model was constructed to suggest a mechanism for the formation of closed MCC over cool ocean surfaces. A new method to estimate the radioative and evaporative cooling in the entrainment layer of a stratocumulus-topped boundary layer has been developed. The method was applied to a set of Large-Eddy Simulation (LES) results and to a set of tethered-balloon data obtained during FIRE. We developed a statocumulus-capped marine mixed layer model which includes a parameterization of drizzle based on the use of a predicted Cloud Condensation Nuclei (CCN) number concentration. We have developed, implemented, and tested a very elaborate new stratiform cloudiness parameterization for use in GCMs. Finally, we have developed a new, mechanistic parameterization of the effects of cloud-top cooling on the entrainment rate.

  17. Retrieval of intensive aerosol properties from MFRSR observations: partly cloudy cases

    NASA Astrophysics Data System (ADS)

    Kassianov, Evgueni; Barnard, James; Berg, Larry K.; Flynn, Connor; Long, Charles

    2010-10-01

    An approach for the obtaining column intensive aerosol properties, namely the single scattering albedo (SSA) and asymmetry parameter (ASP), from the Multi-Filter Rotating Shadowband Radiometer (MFRSR) spectral observations under partly cloudy conditions is described. The approach involves the MFRSR-based aerosol retrieval for clear-sky periods and an interpolation of the retrieved column aerosol properties for cloudy periods. The observed weak diurnal variability of SSA and ASP at the surface and the close association of the surface intensive aerosol properties with their column counterparts form the basis of such interpolation. The approach is evaluated by calculating the corresponding clear-sky total, direct and diffuse fluxes at five wavelengths (415, 500, 615, 673 and 870 nm) and compare them with the observed fluxes. The aerosol properties provided by this approach are applied for (i) an examination of the statistical relationship between spectral (visible range) and broadband values of the total normalized cloud radiative forcing and (ii) an estimation of the fractional sky cover. Data collected during 13 days with single-layer cumulus clouds observed at U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during summer 2007 are applied to illustrate the performance and application of this approach.

  18. Retrieval of Intensive Aerosol Properties from MFRSR observations: Partly Cloudy Cases

    SciTech Connect

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

    2010-09-30

    An approach for the obtaining column intensive aerosol properties, namely the single scattering albedo (SSA) and asymmetry parameter (ASP), from the Multi-Filter Rotating Shadowband Radiometer (MFRSR) spectral observations under partly cloudy conditions is described. The approach involves the MFRSR-based aerosol retrieval for clear-sky periods and an interpolation of the retrieved column aerosol properties for cloudy periods. The observed weak diurnal variability of SSA and ASP at the surface and the close association of the surface intensive aerosol properties with their column counterparts form the basis of such interpolation. The approach is evaluated by calculating the corresponding clear-sky total, direct and diffuse fluxes at five wavelengths (415, 500, 615, 673 and 870 nm) and compare them with the observed fluxes. The aerosol properties provided by this approach are applied for (i) an examination of the statistical relationship between spectral (visible spectral range) and broadband values of the total normalized cloud radiative forcing and (ii) an estimation of the fractional sky cover. Data collected during 13 days with single-layer cumulus clouds observed at U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during summer 2007 are applied to illustrate the performance and application of this approach.

  19. Bioactive compounds and quality parameters of natural cloudy lemon juices.

    PubMed

    Uçan, Filiz; Ağçam, Erdal; Akyildiz, Asiye

    2016-03-01

    In this study, bioactive compounds (phenolic and carotenoid) and some quality parameters (color, browning index and hydroxymethylfurfural (HMF)) of natural cloudy lemon juice, pasteurized (90 °C/15 s) and storage stability of concentrated lemon juice (-25 °C/180 days) were carried out. Fifteen phenolic compounds were determined in the lemon juice and the most abounded phenolic compounds were hesperidin, eriocitrin, chlorogenic acid and neoeriocitrin. In generally, phenolic compound concentrations of lemon juice samples increased after the pasteurization treatment. Four carotenoid compounds (β-carotene, β-cryptoxanthin, lutein and zeaxanthin) were detected in natural cloudy lemon juice. Lutein and β-cryptoxanthin were the most abounded carotenoid compounds in the lemon juice. Color values of the lemon juices were not affected by processing and storage periods. HMF and browning index of the lemon juices increased with concentration and storage. According to the results, storing at -25 °C was considered as sufficient for acceptable quality limits of natural cloudy lemon juice. PMID:27570271

  20. An evaluation of study design for estimating a time-of-day noise weighting

    NASA Technical Reports Server (NTRS)

    Fields, J. M.

    1986-01-01

    The relative importance of daytime and nighttime noise of the same noise level is represented by a time-of-day weight in noise annoyance models. The high correlations between daytime and nighttime noise were regarded as a major reason that previous social surveys of noise annoyance could not accurately estimate the value of the time-of-day weight. Study designs which would reduce the correlation between daytime and nighttime noise are described. It is concluded that designs based on short term variations in nighttime noise levels would not be able to provide valid measures of response to nighttime noise. The accuracy of the estimate of the time-of-day weight is predicted for designs which are based on long term variations in nighttime noise levels. For these designs it is predicted that it is not possible to form satisfactorily precise estimates of the time-of-day weighting.

  1. Estimation of Genetic Parameters for First Lactation Monthly Test-day Milk Yields using Random Regression Test Day Model in Karan Fries Cattle.

    PubMed

    Singh, Ajay; Singh, Avtar; Singh, Manvendra; Prakash, Ved; Ambhore, G S; Sahoo, S K; Dash, Soumya

    2016-06-01

    A single trait linear mixed random regression test-day model was applied for the first time for analyzing the first lactation monthly test-day milk yield records in Karan Fries cattle. The test-day milk yield data was modeled using a random regression model (RRM) considering different order of Legendre polynomial for the additive genetic effect (4th order) and the permanent environmental effect (5th order). Data pertaining to 1,583 lactation records spread over a period of 30 years were recorded and analyzed in the study. The variance component, heritability and genetic correlations among test-day milk yields were estimated using RRM. RRM heritability estimates of test-day milk yield varied from 0.11 to 0.22 in different test-day records. The estimates of genetic correlations between different test-day milk yields ranged 0.01 (test-day 1 [TD-1] and TD-11) to 0.99 (TD-4 and TD-5). The magnitudes of genetic correlations between test-day milk yields decreased as the interval between test-days increased and adjacent test-day had higher correlations. Additive genetic and permanent environment variances were higher for test-day milk yields at both ends of lactation. The residual variance was observed to be lower than the permanent environment variance for all the test-day milk yields. PMID:26954137

  2. Estimation of Genetic Parameters for First Lactation Monthly Test-day Milk Yields using Random Regression Test Day Model in Karan Fries Cattle

    PubMed Central

    Singh, Ajay; Singh, Avtar; Singh, Manvendra; Prakash, Ved; Ambhore, G. S.; Sahoo, S. K.; Dash, Soumya

    2016-01-01

    A single trait linear mixed random regression test-day model was applied for the first time for analyzing the first lactation monthly test-day milk yield records in Karan Fries cattle. The test-day milk yield data was modeled using a random regression model (RRM) considering different order of Legendre polynomial for the additive genetic effect (4th order) and the permanent environmental effect (5th order). Data pertaining to 1,583 lactation records spread over a period of 30 years were recorded and analyzed in the study. The variance component, heritability and genetic correlations among test-day milk yields were estimated using RRM. RRM heritability estimates of test-day milk yield varied from 0.11 to 0.22 in different test-day records. The estimates of genetic correlations between different test-day milk yields ranged 0.01 (test-day 1 [TD-1] and TD-11) to 0.99 (TD-4 and TD-5). The magnitudes of genetic correlations between test-day milk yields decreased as the interval between test-days increased and adjacent test-day had higher correlations. Additive genetic and permanent environment variances were higher for test-day milk yields at both ends of lactation. The residual variance was observed to be lower than the permanent environment variance for all the test-day milk yields. PMID:26954137

  3. A GIS Tool To Estimate West Nile Virus Risk based On A Degree-Day Model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    West Nile virus(Flaviviridae: Flavivirus) is a serious infectious disease that recently spread across the North America continent. A spatial analysis tool was developed on the ARCMap 9.x platform to estimate potential West Nile virus activitiy using a spatially explicit degree-day model. The mdoel...

  4. Comparison of the egg flotation and egg candling techniques for estimating incubation day of Canada Goose nests

    USGS Publications Warehouse

    Reiter, M.E.; Andersen, D.E.

    2008-01-01

    Both egg flotation and egg candling have been used to estimate incubation day (often termed nest age) in nesting birds, but little is known about the relative accuracy of these two techniques. We used both egg flotation and egg candling to estimate incubation day for Canada Geese (Branta canadensis interior) nesting near Cape Churchill, Manitoba, from 2000 to 2007. We modeled variation in the difference between estimates of incubation day using each technique as a function of true incubation day, as well as, variation in error rates with each technique as a function of the true incubation day. We also evaluated the effect of error in the estimated incubation day on estimates of daily survival rate (DSR) and nest success using simulations. The mean difference between concurrent estimates of incubation day based on egg flotation minus egg candling at the same nest was 0.85 ?? 0.06 (SE) days. The positive difference in favor of egg flotation and the magnitude of the difference in estimates of incubation day did not vary as a function of true incubation day. Overall, both egg flotation and egg candling overestimated incubation day early in incubation and underestimated incubation day later in incubation. The average difference between true hatch date and estimated hatch date did not differ from zero (days) for egg flotation, but egg candling overestimated true hatch date by about 1 d (true - estimated; days). Our simulations suggested that error associated with estimating the incubation day of nests and subsequently exposure days using either egg candling or egg flotation would have minimal effects on estimates of DSR and nest success. Although egg flotation was slightly less biased, both methods provided comparable and accurate estimates of incubation day and subsequent estimates of hatch date and nest success throughout the entire incubation period. ?? 2008 Association of Field Ornithologists.

  5. Influences of the day-night differences of ionosphere on the GPS DCB estimation

    NASA Astrophysics Data System (ADS)

    Zhang, Donghe; Zhang, Shunrong; Coster, Anthea; Hao, Yongqiang; Xiao, Zuo

    2016-04-01

    The estimation of differential code bias (DCB) of GPS system is one of the necessary steps for total electron content (TEC) derivation from GPS measurements. Usually, the method for estimating the GPS DCBs follows the assumption of the gentle temporal and spatial variation of the ionosphere, but this assumption is just an approximation because of the ionosphere's inherent variability. It has been indicated that the estimated GPS satellite DCBs are sometimes influenced by the ionospheric conditions. Here, we demonstrate a possible influence of ionospheric condition that differs between day and night on the estimated DCBs from measurements of a single GPS station. It is found that the average standard deviations (STDs) of the satellite DCBs estimated with daytime data are higher than that with the nighttime data. To reduce this day-night difference effect on GPS DCB determination, we use an improved estimation method based on the primary features of the ionospheric variability with local time. A local time dependent weighting function was introduced into the original least-squared DCBs estimation algorithm. A test with data for BJFS station (39.60°N, 115.89°E) in 2001 indicates that the STD of the DCBs decreases from 2.533 TECU to 2.308 TECU, or by 8.9%, after the improved method was applied. For comparison, another test for the same station in 2009 indicates that the STD decreases from 1.344TECU to 1.295 TECU. Reference Li, LX. DH. Zhang., SR. Zhang., et al. Influences of the day-night differences of ionospheric variability on the estimation of GPS differential code bias, Radio Science, 2015, DOI: 10.1002/2014RS005565 Zhang D H, Shi H, Jin Y Q, et al. The variation of the estimated GPS instrumental bias and its possible connection with ionospheric variability. Sci China Tech Sci, 2014, 57: 67-79, doi: 10.1007/s11431-013-5419-7 Zhang D H, Zhang W,Li Q., Accuracy analysis of the GPS instrumental bias estimated from observations in middle and low latitudes

  6. Optimized fractional cloudiness determination from five ground-based remote sensing techniques

    SciTech Connect

    Boers, R.; de Haij, M. J.; Wauben, W.M.F.; Baltink, Henk K.; van Ulft, L. H.; Savenije, M.; Long, Charles N.

    2010-12-23

    A one-year record of fractional cloudiness at 10 minute intervals was generated for the Cabauw Experimental Site for Atmospheric Research [CESAR] (51°58’N, 4° 55’E) using an integrated assessment of five different observational methods. The five methods are based on active as well as passive systems and use either a hemispheric or column remote sensing technique. The one-year instrumental cloudiness data were compared against a 30 year climatology of Observer data in the vicinity of CESAR [1971- 2000]. In the intermediate 2 - 6 octa range, most instruments, but especially the column methods, report lower frequency of occurrence of cloudiness than the absolute minimum values from the 30 year Observer climatology. At night, the Observer records less clouds in the 1, 2 octa range than during the day, while the instruments registered more clouds. During daytime the Observer also records much more 7 octa cloudiness than the instruments. One column method combining a radar with a lidar outstrips all other techniques in recording cloudiness, even up to height in excess of 9 km. This is mostly due to the high sensitivity of the radar that is used in the technique. A reference algorithm was designed to derive a continuous and optimized record of fractional cloudiness. Output from individual instruments were weighted according to the cloud base height reported at the observation time; the larger the height, the lower the weight. The algorithm was able to provide fractional cloudiness observations every 10 minutes for 98% of the total period of 12 months [15 May 2008 - 14 May 2009].

  7. A cloudiness transition in a marine boundary layer

    NASA Technical Reports Server (NTRS)

    Betts, Alan K.; Boers, Reinout

    1990-01-01

    Boundary layer cloudiness plays several important roles in the energy budget of the earth. Low level stratocumulus are highly reflective clouds which reduce the net incoming shortwave radiation at the earth's surface. Climatically, the transition to a small area fraction of scattered cumulus clouds occurs as the air flows over warmer water. Although these clouds reflect less sunlight, they still play an important role in the boundary layer equilibrium by transporting water vapor upwards, and enhancing the surface evaporation. The First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) included a marine stratocumulus experiment off the southern California coast from June 29 to July 19, 1987. The objectives of this experiment were to study the controls on fractional cloudiness, and to assess the role of cloud-top entrainment instability (CTEI) and mesoscale structure in determining cloud type. The focus is one research day, July 7, 1987, when coordinated aircraft missions were flown by four research aircraft, centered on a LANDSAT scene at 1830 UTC. The remarkable feature of this LANDSAT scene is the transition from a clear sky in the west through broken cumulus to solid stratocumulus in the east. The dynamic and thermodynamic structure of this transition in cloudiness is analyzed using data from the NCAR Electra. By averaging the aircraft data, the internal structure of the different cloud regimes is documented, and it is shown that the transition between broken cumulus and stratocumulus is associated with a change in structure with respect to the CTEI condition. However, this results not from sea surface temperature changes, but mostly from a transition in the air above the inversion, and the breakup appears to be at a structure on the unstable side of the wet virtual adiabat.

  8. Estimating Hourly All-Sky Solar Irradiation Components from Meteorological Data.

    NASA Astrophysics Data System (ADS)

    Kermel, F.

    1988-02-01

    A new method to calculate hourly direct beam and diffuse irradiation on a horizontal surface using 3-h standard meteorological data is described. Comparisons of computed and observed irradiations are made with hourly data obtained in Carpentras over the 10 yr period 1971-80.For cloudless days it is found that a good estimate of lower-layer aerosol extinction can be calculated using water-vapor pressure and half-daily sunshine duration. For cloudy days a good estimate of hourly atmospheric transmittance can be estimated from total cloudiness, cloud type and half daily sunshine duration.

  9. Stochastic Radiative transfer and real cloudiness

    SciTech Connect

    Evans, F.

    1995-09-01

    Plane-parallel radiative transfer modeling of clouds in GCMs is thought to be an inadequate representation of the effects of real cloudiness. A promising new approach for studying the effects of cloud horizontal inhomogeneity is stochastic radiative transfer, which computes the radiative effects of ensembles of cloud structures described by probability distributions. This approach is appropriate because cloud information is inherently statistical, and it is the mean radiative effect of complex 3D cloud structure that is desired. 2 refs., 1 fig.

  10. Aerosols, cloud microphysics, and fractional cloudiness.

    PubMed

    Albrecht, B A

    1989-09-15

    Increases in aerosol concentrations over the oceans may increase the amount of low-level cloudiness through a reduction in drizzle-a process that regulates the liquid-water content and the energetics of shallow marine clouds. The resulting increase in the global albedo would be in addition to the increase due to enhancement in reflectivity associated with a decrease in droplet size and would contribute to a cooling of the earth's surface. PMID:17747885

  11. A New Algorithm for Detection of Cloudiness and Moon Affect Area

    NASA Astrophysics Data System (ADS)

    Dindar, Murat; Helhel, Selcuk; Ünal Akdemir, Kemal

    2016-07-01

    Cloud detection is a crucial issue for observatories already operating and during phase of the site selection. Sky Quality Meter (SQM) devices mostly use to determine parameters of the quality of sky such as cloudiness, light flux. But, those parameters do not give us exact information about the cloudiness and moon affects. In this study we improved a new cloudiness and moon affects area detection algorithm. The algorithm is based on image processing methods and different approaches applied to both day time and night time images to calculate the sky coverage. The new algorithm also implemented with Matlab by using the images taken by all sky camera located at TÜBİTAK National Observatory and results were given.

  12. Variations in daylight as a contextual cue for estimating season, time of day, and weather conditions.

    PubMed

    Granzier, Jeroen J M; Valsecchi, Matteo

    2014-01-01

    Experience and experiments on human color constancy (i.e., Arend & Reeves, 1986; Craven & Foster, 1992) tell us that we are capable of judging the illumination. However, when asked to make a match of the illuminant's color and brightness, human observers seem to be quite poor (Granzier, Brenner, & Smeets, 2009a). Here we investigate whether human observers use (rather than match) daylight for estimating ecologically important dimensions: time of year, time of day, and outdoor temperature. In the first three experiments we had our observers evaluate calibrated color images of an outdoor urban scene acquired throughout a year. Although some observers could estimate the month and the temperature, overall they were quite poor at judging the time of day. In particular, observers were not able to discriminate between morning and afternoon pictures even when they were allowed to compare multiple images captured on the same day (Experiment 3). However, observers could distinguish between midday and sunset and sunrise daylight. Classification analysis showed that, given a perfect knowledge of its variation, an ideal observer could have performed the task over chance only considering the average chromatic variation in the picture. Instead, our observers reported using shadows to detect the position of the sun in order to estimate the time of day. However, this information is highly unreliable without knowledge of the orientation of the scene. In Experiment 4 we used an LED chamber in order to present our observers with lights whose chromaticity and illuminance varied along the daylight locus, thus isolating the light cues from the sun position cue. We conclude that discriminating the slight variations in chromaticity and brightness, which potentially distinguish morning and afternoon illuminations, lies beyond the ability of human observers. PMID:24464161

  13. A new perspective on the relationship between cloud shade and point cloudiness

    NASA Astrophysics Data System (ADS)

    Brabec, Marek; Badescu, Viorel; Paulescu, Marius; Dumitrescu, Alexandru

    2016-05-01

    Several simple relationships between cloud shade and point cloudiness have been proposed in the last few decades. The present approach is fundamentally different in that it captures some of the hard restrictions dictated by the bounded range (0, 1)of the cloud shade. Three different models are proposed. The main aim is to produce estimates of the whole conditional distribution of the cloud shade for a given point cloudiness value. The beta-inflated model, which takes into account natural physical constraints of the cloud shade, provides the best results.

  14. View-angle-dependent AIRS Cloudiness and Radiance Variance: Analysis and Interpretation

    NASA Technical Reports Server (NTRS)

    Gong, Jie; Wu, Dong L.

    2013-01-01

    Upper tropospheric clouds play an important role in the global energy budget and hydrological cycle. Significant view-angle asymmetry has been observed in upper-level tropical clouds derived from eight years of Atmospheric Infrared Sounder (AIRS) 15 um radiances. Here, we find that the asymmetry also exists in the extra-tropics. It is larger during day than that during night, more prominent near elevated terrain, and closely associated with deep convection and wind shear. The cloud radiance variance, a proxy for cloud inhomogeneity, has consistent characteristics of the asymmetry to those in the AIRS cloudiness. The leading causes of the view-dependent cloudiness asymmetry are the local time difference and small-scale organized cloud structures. The local time difference (1-1.5 hr) of upper-level (UL) clouds between two AIRS outermost views can create parts of the observed asymmetry. On the other hand, small-scale tilted and banded structures of the UL clouds can induce about half of the observed view-angle dependent differences in the AIRS cloud radiances and their variances. This estimate is inferred from analogous study using Microwave Humidity Sounder (MHS) radiances observed during the period of time when there were simultaneous measurements at two different view-angles from NOAA-18 and -19 satellites. The existence of tilted cloud structures and asymmetric 15 um and 6.7 um cloud radiances implies that cloud statistics would be view-angle dependent, and should be taken into account in radiative transfer calculations, measurement uncertainty evaluations and cloud climatology investigations. In addition, the momentum forcing in the upper troposphere from tilted clouds is also likely asymmetric, which can affect atmospheric circulation anisotropically.

  15. Estimation of duration and mental workload at differing times of day by males and females

    NASA Technical Reports Server (NTRS)

    Hancock, P. A.; Rodenburg, G. J.; Mathews, W. D.; Vercruyssen, M.

    1988-01-01

    Two experiments are reported which investigated whether male and female operator duration estimation and subjective workload followed conventional circadian fluctuation. In the first experiment, twenty-four subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800, 1200, 1600, and 2000 h. In the second experiment, twelve subjects performed an unfilled time estimation task in similar conditions at 0900, 1400, and 1900 h. At the termination of all experimental sessions, participants completed the NASA TLX workload assessment questionnaire as a measure of perceived mental workload. Results indicated that while physiological response followed an expected pattern, estimations of duration and subjective perception of workload showed no significant effects for time-of-day. In each of the experiments, however, there were significant differences in durational estimates and mental workload response depending upon the gender of the participant. Results are taken to support the assertion that subjective workload is responsive largely to task-related factors and indicates the important differences that may be expected due to operator gender.

  16. Number of accelerometer monitoring days needed for stable group-level estimates of activity.

    PubMed

    Wolff-Hughes, Dana L; McClain, James J; Dodd, Kevin W; Berrigan, David; Troiano, Richard P

    2016-09-01

    To determine the number and distribution of days required to produce stable group-level estimates of a 7 d mean for common accelerometer-derived activity measures. Data from the 2003-2006 NHANES were used in this analysis. The sample included 986 youth (6-19 year) and 2532 adults (⩾20 year) with 7 d of  ⩾10 h of wear. Accelerometer measures included minutes of inactive, light physical activity, moderate-to-vigorous physical activity (MVPA); and total activity counts/d. Twenty-five alternative protocols were bootstrapped with 50 000 samples drawn for each protocol. Alternative protocols included: 1-6 random days, Saturday plus 1-5 random weekdays (WD), Sunday plus 1-5 random WD, 1 random weekend day (WE) plus 1-5 WD, and both WE plus 1-4 random WD. Relative difference was calculated between the 7 d mean and alternative protocol mean (((alternative protocol mean - 7 d mean)/7 d mean) (*) 100). Adult MVPA is used as an example; however, similar trends were observed across age groups and variables except adult inactive time, which was stable across protocols. The 7 d mean for adult MVPA was 44.1(0.9) min d(-1). The mean bias for any 1-6 random days ranged from  -0.0(0.3) to 0.0(0.2) min d(-1) with a relative difference of  -0.1 to 0.0%. For protocols with non-random components, bias ranged from  -1.4(0.2) to 0.6(0.1) min d(-1) with relative difference ranging from  -7.2 to 3.1%. Simulation data suggest that stable estimates of group-level means can be obtained from as few as one randomly selected monitoring day from a sampled week. On the other hand, estimates using non-random selection of weekend days may be significantly biased. Purposeful sampling that disproportionally forces inclusion of weekend data in analyses should be discouraged. PMID:27510765

  17. One-day rate measurements for estimating net nitrification potential in humid forest soils

    USGS Publications Warehouse

    Ross, D.S.; Fredriksen, G.; Jamison, A.E.; Wemple, B.C.; Bailey, S.W.; Shanley, J.B.; Lawrence, G.B.

    2006-01-01

    Measurements of net nitrification rates in forest soils have usually been performed by extended sample incubation (2-8 weeks), either in the field or in the lab. Because of disturbance effects, these measurements are only estimates of nitrification potential and shorter incubations may suffice. In three separate studies of northeastern USA forest soil surface horizons, we found that laboratory nitrification rates measured over 1 day related well to those measured over 4 weeks. Soil samples of Oa or A horizons were mixed by hand and the initial extraction of subsamples, using 2 mol L-1 KCl, occurred in the field as soon as feasible after sampling. Soils were kept near field temperature and subsampled again the following day in the laboratory. Rates measured by this method were about three times higher than the 4-week rates. Variability in measured rates was similar over either incubation period. Because NO3- concentrations were usually quite low in the field, average rates from 10 research watersheds could be estimated with only a single, 1-day extraction. Methodological studies showed that the concentration of NH4+ increased slowly during contact time with the KCl extractant and, thus, this contact time should be kept similar during the procedure. This method allows a large number of samples to be rapidly assessed. ?? 2006 Elsevier B.V. All rights reserved.

  18. Estimation of regional evapotranspiration for clear sky days over the North China Plain

    NASA Astrophysics Data System (ADS)

    Shu, Y.; Stisen, S.; Sandholt, I.; Jensen, K. H.

    2009-04-01

    The triangle method combined with thermal inertia for estimation of regional evapotranspiration based on Feng Yun-2C(FY-2C) satellite data and MODIS products over the North China Plain is presented. FY-2C, China's first operational geostationary meteorological satellite which features 5 spectral bands (1 VIS and 4 IR), can acquire one full disc image of China (60° N - 60° S ,45° E - 165° E) per hour every day. Two thermal red channels (IR1: 10.3-11.3 μm) and (IR2:11.5-12.5 μm) were used for surface temperature estimation using a split window algorithm originally proposed for the MSG-SEVIRI sensor assuming the channel response function range of the two split-window channels for MSG SEVIRI and FY-2C are similar and that the center of channels are the same. For application of the improved triangle method taking thermal inertia into account, the surface-air temperature gradient in the Ts-NDVI space, was replaced by the surface temperature temporal change estimated from the Land Surface Temperature at hours 8:00 and 12:00 in local time (ΔTs). Combined with the 16 days composite MODIS Vegetation Indices product (MOD 13) at spatial resolution of 5 km, evaporative fraction was estimated by interpolation in the ΔTs-NDVI triangular-shaped parameter space. Subsequently, regional actual evapotranspiration was estimated based on the derived evaporative fraction and available energy estimated from satellite data. In the piedmont plain with high NDVI and low ΔTs, evapotranspiration rate is high because of irrigation of winter wheat. In the coastal plain NDVI is low and also ΔTs is low as high evapotranspiration rates are sustained water supply from shallow water table. Ground-based measurements of evapotranspiration were retrieved from a lysimeter at the Luancheng eco-agricultural station of China Academy of Sciences. These data are representative for evapotranspiration in the piedmont plain and were used for validation of the actual evapotranspiration retrievals from

  19. A pragmatic approach to estimate the number of days in exceedance of PM10 limit value

    NASA Astrophysics Data System (ADS)

    Beauchamp, Maxime; Malherbe, Laure; de Fouquet, Chantal

    2015-06-01

    European legislation on ambient air quality requests that Member States report the annual number of exceedances of short-term concentration regulatory thresholds for PM10 and delimit the concerned areas. Measurements at the monitoring stations do not allow to fully describe those areas. We present a methodology to estimate the number of exceedances of the daily limit value over a year, that can be extended to any similar issue. This methodology is applied to PM10 concentrations in France for which the daily limit value is 50 μg m-3, not to be exceeded more that 35 days. A probabilistic model is built using preliminary mapping of daily mean concentrations. First, daily atmospheric concentration fields are estimated at 1 km resolution by external drift kriging, combining surface monitoring observations and outputs from the CHIMERE chemistry transport model. Setting a conventional Gaussian hypothesis for the estimation error, the kriging variance is used to compute the probability of exceeding the daily limit value and to identify three areas: those where we can suppose as certain that the concentrations exceed or not the daily limit value and those where the situation is indeterminate because of the estimation uncertainty. Then, from the set of 365 daily mappings of the probability to exceed the daily limit value, the parameters of a translated Poisson distribution is fitted on the annual number of exceedances of the daily limit value at each grid cell, which enables to compute the probability for this number to exceed 35. The methodology is tested for three years (2007, 2009 and 2011) which present numerous exceedances of the daily limit concentration at some monitoring stations. A cross-validation analysis is carried out to check the efficiency of the methodology. The way to interpret probability maps is discussed. A comparison is made with simpler kriging approaches using indicator kriging of exceedances. Lastly, estimation of the population exposed to PM10

  20. Effects of stage of pregnancy on variance components, daily milk yields and 305-day milk yield in Holstein cows, as estimated by using a test-day model.

    PubMed

    Yamazaki, T; Hagiya, K; Takeda, H; Osawa, T; Yamaguchi, S; Nagamine, Y

    2016-08-01

    Pregnancy and calving are elements indispensable for dairy production, but the daily milk yield of cows decline as pregnancy progresses, especially during the late stages. Therefore, the effect of stage of pregnancy on daily milk yield must be clarified to accurately estimate the breeding values and lifetime productivity of cows. To improve the genetic evaluation model for daily milk yield and determine the effect of the timing of pregnancy on productivity, we used a test-day model to assess the effects of stage of pregnancy on variance component estimates, daily milk yields and 305-day milk yield during the first three lactations of Holstein cows. Data were 10 646 333 test-day records for the first lactation; 8 222 661 records for the second; and 5 513 039 records for the third. The data were analyzed within each lactation by using three single-trait random regression animal models: one model that did not account for the stage of pregnancy effect and two models that did. The effect of stage of pregnancy on test-day milk yield was included in the model by applying a regression on days pregnant or fitting a separate lactation curve for each days open (days from calving to pregnancy) class (eight levels). Stage of pregnancy did not affect the heritability estimates of daily milk yield, although the additive genetic and permanent environmental variances in late lactation were decreased by accounting for the stage of pregnancy effect. The effects of days pregnant on daily milk yield during late lactation were larger in the second and third lactations than in the first lactation. The rates of reduction of the 305-day milk yield of cows that conceived fewer than 90 days after the second or third calving were significantly (P<0.05) greater than that after the first calving. Therefore, we conclude that differences between the negative effects of early pregnancy in the first, compared with later, lactations should be included when determining the optimal number of days open

  1. Oxyresveratrol as an antibrowning agent for cloudy apple juices and fresh-cut apples.

    PubMed

    Li, Haitao; Cheng, Ka-Wing; Cho, Chi-Hin; He, Zhendan; Wang, Mingfu

    2007-04-01

    Antibrowning activities of Morus alba L. twig extracts, oxyresveratrol, and mulberroside A isolated from mulberry twig on cloudy apple juices and fresh-cut apple slices were evaluated by monitoring the change of a* value, total color difference (DeltaE), and visual observation. It was found, similar to 4-hexylresorcinol, that oxyresveratrol could effectively inhibit browning in cloudy apple juices at a concentration as low as 0.01% and that mulberry twig extract also showed remarkable antibrowning effects on cloudy apple juices. However, for fresh-cut apple slices, mulberry twig extract and oxyresveratrol needed to be used in combination at least with ascorbic acid to exhibit their antibrowning effects. Apple slice samples treated by dipping in a solution containing 0.001 M oxyresveratrol, 0.5 M isoascorbic acid, 0.05 M calcium chloride, and 0.025 M acetylcysteine did not undergo any substantial browning reaction for 28 days at 4 degrees C. However mulberroside A did not show antibrowning effects on cloudy apple juices although it is also a good mushroom tyrosinase inhibitor. PMID:17335224

  2. The cloudy state of interstellar matter

    NASA Technical Reports Server (NTRS)

    Clayton, D. D.

    1978-01-01

    The expression 'cloudy state' is used to describe the state of the diffuse interstellar matter, with emphasis on its denser and more opaque regions. Questions of morphology with respect to the Galaxy are examined, taking into account neutral hydrogen, molecular regions, H II regions, infrared sources and masers, coronal gas in the Galaxy, and the major components of the interstellar medium. Aspects of dynamics are also considered, giving attention to the two-phase interstellar medium, the three-phase interstellar medium, the density-wave compression of clouds, and problems related to the concept of collapsing clouds. Developments concerning chemistry are explored. Radioactive chronologies are discussed along with isotopic anomalies and aspects of interstellar chemistry.

  3. Aerosol buffering of marine boundary layer cloudiness

    NASA Astrophysics Data System (ADS)

    Kazil, J.; Feingold, G.; Wang, H.

    2010-12-01

    The role of aerosol particles in maintaining a cloudy boundary layer in the remote marine environment is explored. It has previously been shown that precipitation can result in the transition from a closed- to open-cellular state but that the boundary layer cannot maintain this open-cell state without a resupply of particles. Potential sources include wind-driven production of sea salt particles from the ocean, nucleation from the gas phase, and entrainment from the free troposphere. Here we investigate with model simulations how the interplay of cloud properties, aerosol production, and boundary layer dynamics results in aerosol sources acting as a buffer against processes that destabilize cloudiness and the dynamic state of the marine boundary layer. For example, at nighttime, cloud liquid water increases in the absence of solar heating, resulting in increased precipitation, stronger cloud top cooling, accelerated boundary layer turbulence, and faster surface wind speeds. Faster surface wind speeds drive an enhanced flux of sea salt aerosol, at a time when aerosol particles are scavenged more readily by enhanced precipitation. In contrast, absorption of solar radiation during daytime reduces cloud water, decelerates boundary layer turbulence, reduces surface wind speeds, and therefore slows surface emissions. This is compensated by nucleation of small aerosol particles from the gas phase in response to the nigh complete removal of cloud condensation nuclei in precipitating open cell walls. These newly formed particles need to grow to larger sizes before they can serve as cloud condensation nuclei (CCN), but will likely contribute to the CCN population during the nighttime and, together with ocean emissions, buffer the system against precipitation removal.

  4. ATTENUATION OF VISIBLE SUNLIGHT BY LIMITED VISIBILITY AND CLOUDINESS

    EPA Science Inventory

    Variability in the irradiance measurements arises from systematic changes in the solar zenith angle (SZA), cloudiness and changing visibility. Measurements in the wavelength band centered on 612 nm serve as a reference for the initial characterization of the effects of cloudy ...

  5. Reported energy intake by weight status, day and estimated energy requirement among adults: NHANES 2003-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: To describe energy intake reporting by gender, weight status, and interview sequence and to compare reported intakes to the Estimated Energy Requirement at different levels of physical activity. Methods: Energy intake was self-reported by 24-hour recall on two occasions (day 1 and day 2)...

  6. Estimates of genetic parameters for Holstein cows for test-day yield traits with a random regression cubic spline model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic parameters were estimated with REML for individual test-day milk, fat, and protein yields and SCS with a random regression cubic spline model. Test-day records of Holstein cows that calved from 1994 through early 1999 were obtained from Dairy Records Management Systems in Raleigh, North Car...

  7. ESTIMATES OF GENETIC PARAMETERS FOR FIRST LACTATION TEST-DAY YIELDS OF HOLSTEIN COWS WITH A CUBIC SPLINE MODEL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to estimate genetic parameters for individual test-day milk, fat, and protein yields with a cubic spline model. A total of 196,687 test-day records in the first 305-d of 38,172 first lactation Holstein cows that calved between 1994 and early 1999 were obtained from Dairy Records Ma...

  8. Analysis of global cloudiness comparison of meteor, Nimbus 7, and international satellite cloud climatology project (ISCCP) satellite data

    SciTech Connect

    Mokhov, I.I.; Schlesinger, M.E.

    1993-07-20

    In this first paper of a three-part series on cloudienss we intercompare the simultaneous cloudiness data obtained from Meteor satellites, Nimbus 7, and the International Satellite Cloud Climatology Project (ISCCP) for the one-year period, July 1983 to June 1984. Four versions of ISCCP cloudiness are obtained from analyses of the ISCCP-C1 data. These versions differ in their requirements for temporal and spectral sampling. ISCCPs 1 and 2 require for each 2.5{degree} x 2.5{degree} latitude-longitude cell that there be observations at least (N{sub d} = ) 20 of the 28-31 possible days per month and at least (N{sub h} = ) 5 of the 8 possible 3 hourly times each such day; ISCCPs 3 and 4 require only N{sub d} = 1 and N{sub h} = 1. The ISCCP 1-4 intercomparison shows that (1) the cloudiness differences due to the above temporal sampling are smaller than those due to the above spectral sampling; (2) both spectral and temporal sampling effects are larger for the northern hemisphere than for the southern hemisphere; and (3) the difference between zonal mean cloudiness with and without visible information generally increases with latitude from polar night to about 60{degree} latitude in the summer hemisphere. A special observational program in both the Arctic and the Antarctic is proposed to resolve the discrepancies among the satellite and ground-based cloudiness observations in polar latitudes.

  9. Spectral distribution of solar radiation on clear days - A comparison between measurements and model estimates

    NASA Astrophysics Data System (ADS)

    Hansen, V.

    1984-05-01

    The distribution of direct and scattered solar radiant energy in the UV (295-385-nm), blue (385-495-nm), green-orange (495-630-nm), red (630-695-nm), and IR (695-2800-nm) bands commonly used in precision spectral pyranometers is estimated for clear sky conditions as a function of solar height, using a plane-parallel atmosphere model and data on the seasonal variation of the UV component at latitude 59.7 deg N. Integrated daily fluxes are also calculated for selected days of the year, and the results are compared with experimental measurements in graphs and tables. The model is found to give reasonable agreement with the observations, but fails to account for a significant blue shift with increasing solar height at heights above 15 deg. The measured distribution for March is given as UV 4.2, blue 8.9, green-orange 21.8, red 12.4, and IR 52.9 percent; for July, the respective values are 4.6, 16.1, 18.0, 10.7, and 50.6 percent.

  10. Number of Days Required to Estimate Habitual Activity Using Wrist-Worn GENEActiv Accelerometer: A Cross-Sectional Study

    PubMed Central

    Dillon, Christina B.; Fitzgerald, Anthony P.; Kearney, Patricia M.; Perry, Ivan J.; Rennie, Kirsten L.; Kozarski, Robert; Phillips, Catherine M.

    2016-01-01

    Introduction Objective methods like accelerometers are feasible for large studies and may quantify variability in day-to-day physical activity better than self-report. The variability between days suggests that day of the week cannot be ignored in the design and analysis of physical activity studies. The purpose of this paper is to investigate the optimal number of days needed to obtain reliable estimates of weekly habitual physical activity using the wrist-worn GENEActiv accelerometer. Methods Data are from a subsample of the Mitchelstown cohort; 475 (44.6% males; mean aged 59.6±5.5 years) middle-aged Irish adults. Participants wore the wrist GENEActiv accelerometer for 7-consecutive days. Data were collected at 100Hz and summarised into a signal magnitude vector using 60s epochs. Each time interval was categorised according to intensity based on validated cut-offs. Spearman pairwise correlations determined the association between days of the week. Repeated measures ANOVA examined differences in average minutes across days. Intraclass correlations examined the proportion of variability between days, and Spearman-Brown formula estimated intra-class reliability coefficient associated with combinations of 1–7 days. Results Three hundred and ninety-seven adults (59.7±5.5yrs) had valid accelerometer data. Overall, men were most sedentary on weekends while women spent more time in sedentary behaviour on Sunday through Tuesday. Post hoc analysis found sedentary behaviour and light activity levels on Sunday to differ to all other days in the week. Analysis revealed greater than 1 day monitoring is necessary to achieve acceptable reliability. Monitoring frame duration for reliable estimates varied across intensity categories, (sedentary (3 days), light (2 days), moderate (2 days) and vigorous activity (6 days) and MVPA (2 days)). Conclusion These findings provide knowledge into the behavioural variability in weekly activity patterns of middle-aged adults. Since Sunday

  11. Observed and modeled patterns of covariability between low-level cloudiness and the structure of the trade-wind layer

    SciTech Connect

    Nuijens, Louise; Medeiros, Brian; Sandu, Irina; Ahlgrimm, Maike

    2015-11-06

    We present patterns of covariability between low-level cloudiness and the trade-wind boundary layer structure using long-term measurements at a site representative of dynamical regimes with moderate subsidence or weak ascent. We compare these with ECMWF’s Integrated Forecast System and 10 CMIP5 models. By using single-time step output at a single location, we find that models can produce a fairly realistic trade-wind layer structure in long-term means, but with unrealistic variability at shorter-time scales. The unrealistic variability in modeled cloudiness near the lifting condensation level (LCL) is due to stronger than observed relationships with mixed-layer relative humidity (RH) and temperature stratification at the mixed-layer top. Those relationships are weak in observations, or even of opposite sign, which can be explained by a negative feedback of convection on cloudiness. Cloudiness near cumulus tops at the tradewind inversion instead varies more pronouncedly in observations on monthly time scales, whereby larger cloudiness relates to larger surface winds and stronger trade-wind inversions. However, these parameters appear to be a prerequisite, rather than strong controlling factors on cloudiness, because they do not explain submonthly variations in cloudiness. Models underestimate the strength of these relationships and diverge in particular in their responses to large-scale vertical motion. No model stands out by reproducing the observed behavior in all respects. As a result, these findings suggest that climate models do not realistically represent the physical processes that underlie the coupling between trade-wind clouds and their environments in present-day climate, which is relevant for how we interpret modeled cloud feedbacks.

  12. Observed and modeled patterns of covariability between low-level cloudiness and the structure of the trade-wind layer

    DOE PAGESBeta

    Nuijens, Louise; Medeiros, Brian; Sandu, Irina; Ahlgrimm, Maike

    2015-11-06

    We present patterns of covariability between low-level cloudiness and the trade-wind boundary layer structure using long-term measurements at a site representative of dynamical regimes with moderate subsidence or weak ascent. We compare these with ECMWF’s Integrated Forecast System and 10 CMIP5 models. By using single-time step output at a single location, we find that models can produce a fairly realistic trade-wind layer structure in long-term means, but with unrealistic variability at shorter-time scales. The unrealistic variability in modeled cloudiness near the lifting condensation level (LCL) is due to stronger than observed relationships with mixed-layer relative humidity (RH) and temperature stratificationmore » at the mixed-layer top. Those relationships are weak in observations, or even of opposite sign, which can be explained by a negative feedback of convection on cloudiness. Cloudiness near cumulus tops at the tradewind inversion instead varies more pronouncedly in observations on monthly time scales, whereby larger cloudiness relates to larger surface winds and stronger trade-wind inversions. However, these parameters appear to be a prerequisite, rather than strong controlling factors on cloudiness, because they do not explain submonthly variations in cloudiness. Models underestimate the strength of these relationships and diverge in particular in their responses to large-scale vertical motion. No model stands out by reproducing the observed behavior in all respects. As a result, these findings suggest that climate models do not realistically represent the physical processes that underlie the coupling between trade-wind clouds and their environments in present-day climate, which is relevant for how we interpret modeled cloud feedbacks.« less

  13. Observed and modeled patterns of covariability between low-level cloudiness and the structure of the trade-wind layer

    NASA Astrophysics Data System (ADS)

    Nuijens, Louise; Medeiros, Brian; Sandu, Irina; Ahlgrimm, Maike

    2015-12-01

    We present patterns of covariability between low-level cloudiness and the trade-wind boundary layer structure using long-term measurements at a site representative of dynamical regimes with moderate subsidence or weak ascent. We compare these with ECMWF's Integrated Forecast System and 10 CMIP5 models. By using single-time step output at a single location, we find that models can produce a fairly realistic trade-wind layer structure in long-term means, but with unrealistic variability at shorter-time scales. The unrealistic variability in modeled cloudiness near the lifting condensation level (LCL) is due to stronger than observed relationships with mixed-layer relative humidity (RH) and temperature stratification at the mixed-layer top. Those relationships are weak in observations, or even of opposite sign, which can be explained by a negative feedback of convection on cloudiness. Cloudiness near cumulus tops at the trade-wind inversion instead varies more pronouncedly in observations on monthly time scales, whereby larger cloudiness relates to larger surface winds and stronger trade-wind inversions. However, these parameters appear to be a prerequisite, rather than strong controlling factors on cloudiness, because they do not explain submonthly variations in cloudiness. Models underestimate the strength of these relationships and diverge in particular in their responses to large-scale vertical motion. No model stands out by reproducing the observed behavior in all respects. These findings suggest that climate models do not realistically represent the physical processes that underlie the coupling between trade-wind clouds and their environments in present-day climate, which is relevant for how we interpret modeled cloud feedbacks.

  14. Estimating Monthly, Annual, and Low 7-Day, 10-Year Streamflows for Ungaged Rivers in Maine

    USGS Publications Warehouse

    Dudley, Robert W.

    2004-01-01

    Regression equations to estimate monthly, annual, and low 7-day, 10-year (7Q10) streamflows were derived for rivers in Maine. The derived regression equations for estimating mean monthly, mean annual, median monthly, median annual, and low 7Q10 streamflows for ungaged rivers in Maine presented in this report supersede those derived in previous studies. Twenty-six U.S. Geological Survey streamflow-gaging stations on unregulated, rural rivers in Maine with 10 years or more of recorded streamflow were used to develop the regression equations. Ordinary least squares (OLS) regression techniques were used to select the explanatory variables (basin and climatic characteristics) that would appear in the final regression equations. OLS regression of all possible subsets was done with 62 explanatory variables for each of 27 response variables. Five explanatory variables were chosen for the final regression equations: drainage basin area, areal fraction of the drainage basin underlain by sand and gravel aquifers, distance from the coast to the drainage basin centroid, mean drainage basin annual precipitation, and mean drainage basin winter precipitation (the sum of mean monthly precipitation for December, January, and February). Generalized least-squares regression techniques were used to derive the final coefficients and measures of uncertainty for the regression equations. The forms of many of the derived regression equations indicate some physical, mechanistic processes. Drainage basin area is the most statistically important explanatory variable and appears in all derived regression equations. Monthly streamflows are related inversely to the distance from the coast to the drainage basin centroid during December, January, February, and March; that is, the closer a river basin is to the coast, the higher monthly streamflows are per unit drainage basin area during the winter. The relation reverses in May when higher streamflows are attributed to basins farther from the coast

  15. Winter cloudiness variability over Northern Eurasia related to the Siberian High during 1966-2010

    NASA Astrophysics Data System (ADS)

    Chernokulsky, Alexander; Mokhov, Igor I.; Nikitina, Natalia

    2013-12-01

    This letter presents an assessment of winter cloudiness variability over Northern Eurasia regions related to the Siberian High intensity (SHI) variations during 1966-2010. An analysis of cloud fraction and the occurrence of different cloud types was carried out based on visual observations from almost 500 Russian meteorological stations. The moonlight criterion was implemented to reduce the uncertainty of night observations. The SHI was defined based on sea-level pressure fields from different reanalyses. We found a statistically significant negative correlation of cloud cover with the SHI over central and southern Siberia and the southern Urals with regression coefficients around 3% hPa-1 for total cloud fraction (TCF) for particular stations near the Siberian High center. Cross-wavelet analysis of TCF and SHI revealed a long-term relationship between cloudiness and the Siberian High. Generally, the Siberian High intensification by 1 hPa leads to a replacement of one overcast day with one day without clouds, which is associated mainly with a decrease in precipitating and stratiform clouds. These changes point to a positive feedback between cloudiness and the Siberian High.

  16. Estimating Activity Duration by Momentary Time-Sampling of Part or All of the Day

    ERIC Educational Resources Information Center

    Mansell, Jim; Beadle-Brown, Julie

    2011-01-01

    Background: Studies of engagement in meaningful activity often focus on a short period during the afternoon. The question arises whether this produces different results from studies covering the whole day. Methods: Data collected for 18 individuals using a 20-s momentary time-sample from 08:00 to 19:00 over a number of days for each person were…

  17. Estimating 11-year solar UV variations using 27-day response as a guide to isolate trends in total column ozone

    NASA Technical Reports Server (NTRS)

    Keating, G. M.; Brasseur, G. P.; Chiou, L. S.; Hsu, N. C.

    1994-01-01

    The total column ozone response to 11-year solar ultraviolet (UV) variations is estimated here from the observed response to 27-day solar variations adjusted for the theoretical difference between the 27-day response and 11-year response. The estimate is tested by comparing two data sets where long-term drifts have been removed, the Nimbus 7 TOMS Version 6 total column ozone and the 280 nm core-to-wing ratio (a proxy for solar UV variations). The 365-day running means of data area-weighted between 40 deg N to 40 deg S latitude give a 1.9% ozone variation related to the 11-year solar cycle compared with the estimate of 1.8%. Estimates of linear trends were reduced by a factor of 2 by including solar effects. The standard deviation from the empirical model was reduced from 1.0 to 0.6 Dobson Units, by including the quasi-biennial oscillation (QBO), but the QBO did not significantly alter trend estimates. Both the ozone responses to 27-day and 11-year solar variations were considerably stronger than predicted by a 2-D theoretical model.

  18. Technical note: Large-eddy simulation of cloudy boundary layer with the Advanced Research WRF model

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Takanobu; Feingold, Graham

    2012-03-01

    A thorough evaluation of the large-eddy simulation (LES) mode of the Advanced Research WRF model is performed with use of three cloudy boundary layer cases developed as LES intercomparison cases by the GEWEX Cloud System Study. Our evaluation reveals two problems that must be recognized and carefully addressed before proceeding with production runs. These are (i) sensitivity of results to the prescribed number of acoustic time steps per physical time step; and (ii) the assumption of saturation adjustment in the initial cloudy state. A temporary, but effective method of how to cope with these issues is suggested. With the proper treatment, the simulation results are comparable to the ensemble mean of the other LES models, and sometimes closer to the observational estimate than the ensemble mean. In order to ease the burden for configuration and post-processing, two new packages are developed and implemented. A detailed description of each package is presented. These packages are freely available to the public.

  19. Assessment of clear and cloudy sky parameterizations for daily downwelling longwave radiation over different land surfaces in Florida, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clear sky downwelling longwave radiation and cloudy sky downwelling longwave radiation formulas were tested across eleven sites in Florida. The Sellers equation, using air vapor pressure and temperature measurements, provides the best estimates of clear sky downwelling longwave radiation with a roo...

  20. USE OF CLIMATIC DATA IN ESTIMATING STORAGE DAYS FOR SOILS TREATMENT SYSTEMS

    EPA Science Inventory

    Computer programs have been developed to estimate storage needs for Soil Treatment Systems from analyses of daily climatological data. One program uses a set of thresholds for temperature, precipitation and/or snow depth to estimate storage needs in colder regions. A second progr...

  1. Quantitative analysis of night skyglow amplification under cloudy conditions

    NASA Astrophysics Data System (ADS)

    Kocifaj, Miroslav; Solano Lamphar, Héctor Antonio

    2014-10-01

    The radiance produced by artificial light is a major source of nighttime over-illumination. It can, however, be treated experimentally using ground-based and satellite data. These two types of data complement each other and together have a high information content. For instance, the satellite data enable upward light emissions to be normalized, and this in turn allows skyglow levels at the ground to be modelled under cloudy or overcast conditions. Excessive night lighting imposes an unacceptable burden on nature, humans and professional astronomy. For this reason, there is a pressing need to determine the total amount of downwelling diffuse radiation. Undoubtedly, cloudy periods can cause a significant increase in skyglow as a result of amplification owing to diffuse reflection from clouds. While it is recognized that the amplification factor (AF) varies with cloud cover, the effects of different types of clouds, of atmospheric turbidity and of the geometrical relationships between the positions of an individual observer, the cloud layer, and the light source are in general poorly known. In this paper the AF is quantitatively analysed considering different aerosol optical depths (AODs), urban layout sizes and cloud types with specific albedos and altitudes. The computational results show that the AF peaks near the edges of a city rather than at its centre. In addition, the AF appears to be a decreasing function of AOD, which is particularly important when modelling the skyglow in regions with apparent temporal or seasonal variability of atmospheric turbidity. The findings in this paper will be useful to those designing engineering applications or modelling light pollution, as well as to astronomers and environmental scientists who aim to predict the amplification of skyglow caused by clouds. In addition, the semi-analytical formulae can be used to estimate the AF levels, especially in densely populated metropolitan regions for which detailed computations may be CPU

  2. A methodology to estimate the potential to move inpatient to one day surgery

    PubMed Central

    Gilliard, Nicolas; Eggli, Yves; Halfon, Patricia

    2006-01-01

    Background The proportion of surgery performed as a day case varies greatly between countries. Low rates suggest a large growth potential in many countries. Measuring the potential development of one day surgery should be grounded on a comprehensive list of eligible procedures, based on a priori criteria, independent of local practices. We propose an algorithmic method, using only routinely available hospital data to identify surgical hospitalizations that could have been performed as one day treatment. Methods Moving inpatient surgery to one day surgery was considered feasible if at least one surgical intervention was eligible for one day surgery and if none of the following criteria were present: intervention or affection requiring an inpatient stay, patient transferred or died, and length of stay greater than four days. The eligibility of a procedure to be treated as a day case was mainly established on three a priori criteria: surgical access (endoscopic or not), the invasiveness of the procedure and the size of the operated organ. Few overrides of these criteria occurred when procedures were associated with risk of immediate complications, slow physiological recovery or pain treatment requiring hospital infrastructure. The algorithm was applied to a random sample of one million inpatient US stays and more than 600 thousand Swiss inpatient stays, in the year 2002. Results The validity of our method was demonstrated by the few discrepancies between the a priori criteria based list of eligible procedures, and a state list used for reimbursement purposes, the low proportion of hospitalizations eligible for one day care found in the US sample (4.9 versus 19.4% in the Swiss sample), and the distribution of the elective procedures found eligible in Swiss hospitals, well supported by the literature. There were large variations of the proportion of candidates for one day surgery among elective surgical hospitalizations between Swiss hospitals (3 to 45.3%). Conclusion

  3. Present-day groundwater recharge estimation in parts of the Indian Sub-Continent

    NASA Astrophysics Data System (ADS)

    Bhanja, S. N.; Mukherjee, A.; Wada, Y.; Scanlon, B. R.; Taylor, R. G.; Rodell, M.; Malakar, P.

    2015-12-01

    Large part of global population has been dependent on groundwater as a source of fresh water. The demand would further increase with increasing population and stress associated with climate change. We tried to provide regional-scale groundwater recharge estimates in a large part of Indian Sub-Continent. A combination of ground-based, satellite-based and numerical model simulated recharge estimates were presented in the densely populated region. Three different methods: an intense network of observational wells (n>13,000 wells), a satellite (TRMM) and global land-surface model (CLM) outputs, and a global-scale hydrological model (PCR GLOBWB) were employed to calculate recharge estimates. Groundwater recharge values exhibit large spatial variations over the entire region on the basis of aquifer hydrogeology, precipitation and groundwater withdrawal patterns. Groundwater recharge estimates from all three estimation techniques were found to be higher (>300 mm/year) in fertile planes of Indus-Ganges-Brahmaputra (IGB) river basins. A combination of favorable hydrogeologic conditions (porosity, permeability etc.), comparatively higher rates of precipitation, and return flow from rapidly withdrawn irrigation water might influence occurrence of high recharge rates. However, central and southern study area experiences lower recharge rates (<200 mm/year), might be associated with unfavorable hydrogeologic conditions associated with cratonic provinces. Statistical analysis of inter-comparison between the three different recharge estimates show good matches in some of the areas. Recharge estimates indicate dynamic nature of groundwater recharge as a function of precipitation, land use pattern, and hydrogeologic parameters. On a first hand basis, the estimates will help policy makers to understand groundwater recharge process over the densely populated region and finally would facilitate to implement sustainable policy for securing water security.

  4. Methods for estimating magnitude and frequency of 1-, 3-, 7-, 15-, and 30-day flood-duration flows in Arizona

    USGS Publications Warehouse

    Kennedy, Jeffrey R.; Paretti, Nicholas V.; Veilleux, Andrea G.

    2014-01-01

    Regression equations, which allow predictions of n-day flood-duration flows for selected annual exceedance probabilities at ungaged sites, were developed using generalized least-squares regression and flood-duration flow frequency estimates at 56 streamgaging stations within a single, relatively uniform physiographic region in the central part of Arizona, between the Colorado Plateau and Basin and Range Province, called the Transition Zone. Drainage area explained most of the variation in the n-day flood-duration annual exceedance probabilities, but mean annual precipitation and mean elevation were also significant variables in the regression models. Standard error of prediction for the regression equations varies from 28 to 53 percent and generally decreases with increasing n-day duration. Outside the Transition Zone there are insufficient streamgaging stations to develop regression equations, but flood-duration flow frequency estimates are presented at select streamgaging stations.

  5. Estimating Criminal Justice System Costs and Cost-Savings Benefits of Day Reporting Centers

    ERIC Educational Resources Information Center

    Craddock, Amy

    2004-01-01

    This paper reports on the net cost-savings benefits (loss) to the criminal justice system of one rural and one urban day reporting center, both of which serve high risk/high need probationers. It also discusses issues of conducting criminal justice system cost studies of community corrections programs. The average DRC participant in the rural…

  6. A neural network based intelligent predictive sensor for cloudiness, solar radiation and air temperature.

    PubMed

    Ferreira, Pedro M; Gomes, João M; Martins, Igor A C; Ruano, António E

    2012-01-01

    Accurate measurements of global solar radiation and atmospheric temperature,as well as the availability of the predictions of their evolution over time, are important for different areas of applications, such as agriculture, renewable energy and energy management, or thermal comfort in buildings. For this reason, an intelligent, light-weight and portable sensor was developed, using artificial neural network models as the time-series predictor mechanisms. These have been identified with the aid of a procedure based on the multi-objective genetic algorithm. As cloudiness is the most significant factor affecting the solar radiation reaching a particular location on the Earth surface, it has great impact on the performance of predictive solar radiation models for that location. This work also represents one step towards the improvement of such models by using ground-to-sky hemispherical colour digital images as a means to estimate cloudiness by the fraction of visible sky corresponding to clouds and to clear sky. The implementation of predictive models in the prototype has been validated and the system is able to function reliably, providing measurements and four-hour forecasts of cloudiness, solar radiation and air temperature. PMID:23202230

  7. A Neural Network Based Intelligent Predictive Sensor for Cloudiness, Solar Radiation and Air Temperature

    PubMed Central

    Ferreira, Pedro M.; Gomes, João M.; Martins, Igor A. C.; Ruano, António E.

    2012-01-01

    Accurate measurements of global solar radiation and atmospheric temperature, as well as the availability of the predictions of their evolution over time, are important for different areas of applications, such as agriculture, renewable energy and energy management, or thermal comfort in buildings. For this reason, an intelligent, light-weight and portable sensor was developed, using artificial neural network models as the time-series predictor mechanisms. These have been identified with the aid of a procedure based on the multi-objective genetic algorithm. As cloudiness is the most significant factor affecting the solar radiation reaching a particular location on the Earth surface, it has great impact on the performance of predictive solar radiation models for that location. This work also represents one step towards the improvement of such models by using ground-to-sky hemispherical colour digital images as a means to estimate cloudiness by the fraction of visible sky corresponding to clouds and to clear sky. The implementation of predictive models in the prototype has been validated and the system is able to function reliably, providing measurements and four-hour forecasts of cloudiness, solar radiation and air temperature. PMID:23202230

  8. Evaluation of total cloudiness and its variability in the atmospheric model intercomparison project

    SciTech Connect

    Weare, B.C.; Mokhov, I.I.

    1995-09-01

    Total cloudiness of 29 models participating in the Atmospheric Model Intercomparison Project is compared with the ISCCP C2 as well as the Nimbus-7 and Meteor observational estimates. The root-mean-square differences between the annual means of the model calculations and the C2 observations vary from about twice to nearly four times the difference between the C2 and Meteor observations. The large differences are in some cases due to the fact that although a model qualitatively has patterns of spatial variations similar to those of the observations, the magnitude of those variations is much too small. In other cases the models have produced the approximate magnitude of the spatial variability of the observations but display sizable errors in the pattern of that variability. Deficiencies with respect to the model simulations of the mean seasonal cycle are also pronounced. For instance, the differences between the zonal averages of total cloudiness for contrasting seasons suggest that near 60{degrees} most models predict minima in cloudiness in summer, whereas observations strongly suggest the opposite. Smoothed seasonal cycle analyses suggest that a portion of these deficiencies in some models is the result of a simulated seasonal cycle that lead that of the observations by about two months. However, some models, which appear to have the proper phase of the seasonal cycle, still show large root-mean-squared differences and small correlations when compared with the smoothed seasonal cycle of the C2 observations. The C2 and Meteor observations show a modest signal in total cloudiness for the only important interannual variation during the July 1983 through June 1988 observation period-the 1986/87 ENSO event. A few models reproduce this event about as well as do the Meteor observations, whereas many models fail to show any evidence of it. Overall, models that better reproduce the ENSO results also tend to do well with seasonal variations. 32 refs., 12 figs., 1 tab.

  9. Variability of Cloudiness at Airline Cruise Altitudes from GASP Measurements.

    NASA Astrophysics Data System (ADS)

    Jasperson, William H.; Nastrom, Gregory D.; Davis, Richard E.; Holdeman, James D.

    1985-01-01

    A climatology of high-altitude cloud encounters using data obtained between 1975 and 1979 from commercial airliners participating in the Global Atmospheric Sampling Program (GASP) is presented. The statistics are based on three different measures of cloudiness derived from the GASP data set. This climatology depicts the seasonal, latitudinal and altitudinal variation in the cloudiness parameters, as well as differences in the high-altitude cloud structure attributed to cyclone- and convective cloud-generation mechanisms. A qualitative agreement was found between the latitudinal distribution of cloud cover derived from the GASP data and satellite-derived high-altitude cloud statistics available in the literature. Relationships between the three different measures of cloudiness and the relative vorticity at high altitudes, stratified by season, latitude and distance from the tropopause are also presented. In midlatitudes, for example, the average cloudiness, when stratified by the sign of the relative vorticity, exhibits a seasonal cycle with the 1argest differences occurring in the layer 0-1.5 km below the tropopause. Seasonal and latitudinal patterns can also be seen in the other cloudiness parameters.

  10. Modelling Scalar Skewness in Cloudy Boundary Layers

    NASA Astrophysics Data System (ADS)

    Mironov, Dmitrii; Machulskaya, Ekaterina; Naumann, Ann Kristin; Seifert, Axel; Mellado, Juan Pedro

    2015-04-01

    Following the pioneering work of Sommeria and Deardorff (1977), statistical cloud schemes are widely used in numerical weather prediction (NWP) and climate models to parameterize the effect of shallow clouds on turbulent mixing and radiation fluxes. Statistical cloud schemes compute the cloud fraction, the amount of cloud condensate and the effect clouds on the buoyancy flux in a given atmospheric-model grid box. This is done with due regard for the sub-grid scale (SGS) fluctuations of temperature and humidity (and possibly the vertical velocity), thus providing an important coupling between cloudiness and the SGS mixing processes. The shape of the PDF of fluctuating fields is assumed, whereas the PDF moments should be provided to the cloud scheme as an input. For non-precipitation clouds, the mixing schemes are usually formulated in terms of quasi-conservative variable, e.g. the liquid (total) water potential temperature and the total water specific humidity. Then, the cloud schemes are conveniently cast in terms of the linearized saturation deficit, referred to as the "s" variable (Mellor 1977), that accounts for the combined effect of the two scalars. If a simple two-parameter single-Gaussian PDF is used, the only "turbulence" parameter to be provided to the cloud scheme is the variance of s. The single-Gaussian PDF ignores the skewed nature of SGS motions and fails to describe many important regimes, e.g. shallow cumuli. A number of more flexible skewed PDFs have been proposed to date. A three-parameter PDF, based on a double-Gaussian distribution and diagnostic relations between some PDF parameters derived from LES and observational data (Naumann et al. 2013), appears to be a good compromise between physical realism and computational economy. A crucial point is that the cloud schemes using non-Gaussian PDFs require the scalar skewness as an input. Using rather mild non-restrictive assumptions, we develop a transport equation for the s-variable triple

  11. Influences of the day-night differences of ionospheric variability on the estimation of GPS differential code bias

    NASA Astrophysics Data System (ADS)

    Li, L. X.; Zhang, D. H.; Zhang, S. R.; Coster, A. J.; Hao, Y. Q.; Xiao, Z.

    2015-04-01

    The estimation of differential code bias (DCB) of GPS system is one of the necessary steps for total electron content (TEC) derivation from GPS measurements. Usually, the method for estimating the GPS DCBs follows the assumption of the gentle temporal and spatial variation of the ionosphere, but this assumption is just an approximation because of the ionosphere's inherent variability. It has been indicated that the estimated GPS satellite DCBs are sometimes influenced by the ionospheric conditions. In this paper, we demonstrate a possible influence of ionospheric variability that differs between day and night on the estimated DCBs from measurements of a single GPS station. It is found that the average standard deviations (STDs) of the satellite DCBs estimated with daytime data are higher than that with the nighttime data. To reduce this day-night difference effect on GPS DCB determination, we use an improved estimation method based on the primary features of the ionospheric variability with local time. A local time dependent weighting function was introduced into the original least squares DCBs estimation algorithm. A test with data for BJFS station (39.60°N, 115.89°E) in 2001 indicates that the STD of the DCBs decreases from 2.533 TECU (total electron content unit, 1 TECU = 1016 el m-2) to 2.308 TECU, or by 8.9%, after the improved method was applied. For comparison, another test for the same station in 2009 indicates that the STD decreases from 1.344 TECU to 1.295 TECU. The amplitude of the 2009 improvement is very limited, only about 3.6%. The difference of the percentage improvements can probably be attributed to the different ionospheric conditions between 2001 and 2009.

  12. Estimating Sun Exposure of Children in Day Care Nurseries in South Oxfordshire, UK.

    PubMed

    Baczynska, Katarzyna A; Price, Luke L A; Higlett, Michael P; O'Hagan, John B

    2016-01-01

    Exposure to ultraviolet radiation and sunburn during childhood and adolescence is linked to increased risks of melanoma and basal cell carcinoma later in life. Infants and toddlers are thought to be unusually vulnerable to UVR because of lower levels of melanin, a thinner stratum corneum and a higher surface area/body mass ratio. The aim of this study was to assess variations in the available erythema effective radiant doses to young children in day care nurseries in South Oxfordshire, UK over 7 years between 2008 and 2014. The data were analyzed in three distinct seasons according to a series of realistic exposure scenarios taking into account nursery routines. The results indicate the time of year when high doses are to be expected and provide strong support for arguments in favor of raising public awareness of sun protection earlier in the year. PMID:26452244

  13. Variability of cloudiness at airline cruise altitudes from GASP measurements

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    Additional statistics relating to the climatology of cloud cover at airline cruise altitudes are presented. The data were obtained between 1975 and 1979 from commercial airliners participating in the Global Atmospheric Sampling Program (GASP). The statistics describe the seasonal, latitudinal and altitudinal variation in cloudiness parameters as well as differences in the high-altitude cloud structure attributed to cyclone and convective-cloud generation processes. The latitudinal distribution of cloud cover derived form the GASP data was found to agree with high-altitude satellite observations. The relationships between three different measures of cloudiness and the relative vorticity at high altitudes is also discussed.

  14. Ultrafast High Accuracy PCRTM_SOLAR Model for Cloudy Atmosphere

    NASA Technical Reports Server (NTRS)

    Yang, Qiguang; Liu, Xu; Wu, Wan; Yang, Ping; Wang, Chenxi

    2015-01-01

    An ultrafast high accuracy PCRTM_SOLAR model is developed based on PCA compression and principal component-based radiative transfer model (PCRTM). A fast algorithm for simulation of multi-scattering properties of cloud and/or aerosols is integrated into the fast infrared PCRTM. We completed radiance simulation and training for instruments, such as IASI, AIRS, CrIS, NASTI and SHIS, under diverse conditions. The new model is 5 orders faster than 52-stream DISORT with very high accuracy for cloudy sky radiative transfer simulation. It is suitable for hyperspectral remote data assimilation and cloudy sky retrievals.

  15. Aerosol optical depth increase in partly cloudy conditions

    SciTech Connect

    Chand, Duli; Wood, R.; Ghan, Steven J.; Wang, Minghuai; Ovchinnikov, Mikhail; Rasch, Philip J.; Miller, Steven D.; Schichtel, Bret; Moore, Tom

    2012-09-14

    Remote sensing observations of aerosol from surface and satellite instruments are extensively used for atmospheric and climate research. From passive sensors, the apparent cloud-free atmosphere in the vicinity of clouds often appears to be brighter then further away from the clouds, leading to an enhancement in the retrieved aerosol optical depth. Mechanisms contributing to this enhancement, including contamination by undetected clouds, hygroscopic growth of aerosol particles, and meteorological conditions, have been debated in recent literature, but an extent to which each of these factors influence the observed enhancement is poorly known. Here we used 11 years of daily global observations at 10x10 km2 resolution from the MODIS on the NASA Terra satellite to quantify as a function of cloud fraction (CF). Our analysis reveals that, averaged over the globe, the clear sky is enhanced by ? = 0.05 which corresponds to relative enhancements of 25% in cloudy conditions (CF=0.8-0.9) compared with relatively clear conditions (CF=0.1-0.2). Unlike the absolute enhancement ?, the relative increase in ? is rather consistent in all seasons and is 25-35% in the subtropics and 15-25% at mid and higher latitudes. Using a simple Gaussian probability density function model to connect cloud cover and the distribution of relative humidity, we argue that much of the enhancement is consistent with aerosol hygroscopic growth in the humid environment surrounding clouds. Consideration of these cloud-dependent effects will facilitate understanding aerosol-cloud interactions and reduce the uncertainty in estimates of aerosol radiative forcing by global climate models.

  16. Estimating the postmortem interval (PMI) using accumulated degree-days (ADD) in a temperate region of South Africa.

    PubMed

    Myburgh, Jolandie; L'Abbé, Ericka N; Steyn, Maryna; Becker, Piet J

    2013-06-10

    The validity of the method in which total body score (TBS) and accumulated degree-days (ADD) are used to estimate the postmortem interval (PMI) is examined. TBS and ADD were recorded for 232 days in northern South Africa, which has temperatures between 17 and 28 °C in summer and 6 and 20 °C in winter. Winter temperatures rarely go below 0°C. Thirty pig carcasses, which weighed between 38 and 91 kg, were used. TBS was scored using the modified method of Megyesi et al. [1]. Temperature was acquired from an on site data logger and the weather station bureau; differences between these two sources were not statistically significant. Using loglinear random-effects maximum likelihood regression, an r(2) value for ADD (0.6227) was produced and linear regression formulae to estimate PMI from ADD with a 95% prediction interval were developed. The data of 16 additional pigs that were placed a year later were then used to validate the accuracy of this method. The actual PMI and ADD were compared to the estimated PMI and ADD produced by the developed formulae as well as the estimated PMIs within the 95% prediction interval. A validation of the study produced poor results as only one pig of 16 fell within the 95% interval when using the formulae, showing that ADD has limited use in the prediction of PMI in a South African setting. PMID:23601149

  17. Random regression models to estimate genetic parameters for test-day milk yield in Brazilian Murrah buffaloes.

    PubMed

    Sesana, R C; Bignardi, A B; Borquis, R R A; El Faro, L; Baldi, F; Albuquerque, L G; Tonhati, H

    2010-10-01

    The objective of this work was to estimate covariance functions for additive genetic and permanent environmental effects and, subsequently, to obtain genetic parameters for buffalo's test-day milk production using random regression models on Legendre polynomials (LPs). A total of 17 935 test-day milk yield (TDMY) from 1433 first lactations of Murrah buffaloes, calving from 1985 to 2005 and belonging to 12 herds located in São Paulo state, Brazil, were analysed. Contemporary groups (CGs) were defined by herd, year and month of milk test. Residual variances were modelled through variance functions, from second to fourth order and also by a step function with 1, 4, 6, 22 and 42 classes. The model of analyses included the fixed effect of CGs, number of milking, age of cow at calving as a covariable (linear and quadratic) and the mean trend of the population. As random effects were included the additive genetic and permanent environmental effects. The additive genetic and permanent environmental random effects were modelled by LP of days in milk from quadratic to seventh degree polynomial functions. The model with additive genetic and animal permanent environmental effects adjusted by quintic and sixth order LP, respectively, and residual variance modelled through a step function with six classes was the most adequate model to describe the covariance structure of the data. Heritability estimates decreased from 0.44 (first week) to 0.18 (fourth week). Unexpected negative genetic correlation estimates were obtained between TDMY records at first weeks with records from middle to the end of lactation, being the values varied from -0.07 (second with eighth week) to -0.34 (1st with 42nd week). TDMY heritability estimates were moderate in the course of the lactation, suggesting that this trait could be applied as selection criteria in milking buffaloes. PMID:20831561

  18. Estimating hypothetical present-day insured losses for past intense hurricanes in the French Antilles

    NASA Astrophysics Data System (ADS)

    Thornton, James; Desarthe, Jérémy; Naulin, Jean-Philippe; Garnier, Emmanuel; Liu, Ye; Moncoulon, David

    2015-04-01

    On the islands of the French Antilles, the period for which systematic meteorological measurements and historic event loss data are available is short relative to the recurrence intervals of very intense, damaging hurricanes. Additionally, the value of property at risk changes through time. As such, the recent past can only provide limited insight into potential losses from extreme storms in coming years. Here we present some research that seeks to overcome, as far as is possible, the limitations of record length in assessing the possible impacts of near-future hurricanes on insured properties. First, using the archives of the French overseas departments (which included administrative and weather reports, inventories of damage to houses, crops and trees, as well as some meteorological observations after 1950) we reconstructed the spatial patterns of hazard intensity associated with three historical events. They are: i) the 1928 Hurricane (Guadeloupe), ii) Hurricane Betsy (1956, Guadeloupe) and iii) Hurricane David (1979, Martinique). These events were selected because all were damaging, and the information available on each is rich. Then, using a recently developed catastrophe model for hurricanes affecting Guadeloupe, Martinique, Saint-Barthélemy and Saint-Martin, we simulated the hypothetical losses to insured properties that the reconstructed events might cause if they were to reoccur today. The model simulated damage due to wind, rainfall-induced flooding and storm surge flooding. These 'what if' scenarios provided an initial indication of the potential present-day exposure of the insurance industry to intense hurricanes. However, we acknowledge that historical events are unlikely to repeat exactly. We therefore extended the study by producing a stochastic event catalogue containing a large number of synthetic but plausible hurricane events. Instrumental data were used as a basis for event generation, but importantly the statistical methods we applied permit

  19. Cloudy's Journey from FORTRAN to C, Why and How

    NASA Astrophysics Data System (ADS)

    Ferland, G. J.

    Cloudy is a large-scale plasma simulation code that is widely used across the astronomical community as an aid in the interpretation of spectroscopic data. The cover of the ADAS VI book featured predictions of the code. The FORTRAN 77 source code has always been freely available on the Internet, contributing to its widespread use. The coming of PCs and Linux has fundamentally changed the computing environment. Modern Fortran compilers (F90 and F95) are not freely available. A common-use code must be written in either FORTRAN 77 or C to be Open Source/GNU/Linux friendly. F77 has serious drawbacks - modern language constructs cannot be used, students do not have skills in this language, and it does not contribute to their future employability. It became clear that the code would have to be ported to C to have a viable future. I describe the approach I used to convert Cloudy from FORTRAN 77 with MILSPEC extensions to ANSI/ISO 89 C. Cloudy is now openly available as a C code, and will evolve to C++ as gcc and standard C++ mature. Cloudy looks to a bright future with a modern language.

  20. Dynamics of a supernova envelope in a cloudy interstellar medium

    NASA Astrophysics Data System (ADS)

    Korolev, V. V.; Vasiliev, E. O.; Kovalenko, I. G.; Shchekinov, Yu. A.

    2015-07-01

    The evolution of a supernova remnant in a cloudy medium as a function of the volume filling factor of the clouds is studied in a three-dimensional axially symmetrical model. The model includes the mixing of heavy elements (metals) ejected by the supernova and their contribution to radiative losses. The interaction of the supernova envelope with the cloudy phase of the interstellar medium leads to nonsimultaneous, and on average earlier, onsets of the radiative phase in different parts of the supernova envelope. Growth in the volume filling factor f leads to a decrease in the time for the transition of the envelope to the radiative phase and a decrease in the envelope's mean radius, due to the increased energy losses by the envelope in the cloudy medium. When the development of hydrodynamical instabilities in the supernova envelope is efficient, the thermal energy falls as E t ~ t -2.3, for the propagation of the supernova remnant through either a homogeneous or a cloudy medium. When the volume filling factor is f ≳ 0.1, a layer with excess kinetic energy andmomentumforms far behind the global shock front from the supernova, which traps the hot gas of the cavity in the central part of the supernova remnant. Metals ejected by the supernova are also enclosed in the central region of the remnant, where the initial (high) metallicity is essentially preserved. Thus, the interaction of the supernova envelope with the cloudy interstellar medium appreciably changes the dynamics and structure of the distribution of the gas in the remnant. This affects the observational characteristics of the remnant, in particularly, leading to substantial fluctuations of the emissionmeasure of the gas with T > 105 K and the velocity dispersion of the ionized gas.

  1. Diurnal heating and cloudiness in the NCAR Community Climate Model (CCM2)

    NASA Technical Reports Server (NTRS)

    Lieberman, Ruth S.; Leovy, Conway B.; Boville, Byron A.; Briegleb, Bruce P.

    1994-01-01

    In this paper, the authors assess the suitability of the heating fileds in the latest version of the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM2) for modeling the thermal forcing of atmospheric tides. Accordingly, diurnal variations of the surface pressure, outgoing longwave radiation (OLR), cloudiness, and precipitation are examined in the CCM2. The fields of radiative, sensible, and latent heating are similarly analyzed. These results are subjectively compared with available data. Equatorial diurnal surface pressure tides are fairly well simulated by CCM2. The model successfully reproduces the semidiurnal surface pressure tides; however, this may result in part from reflection of wave energy at the upper boundary. The CCM2 large-scale diurnal OLR is generally consistent with observations. The moist-convective scheme in the model is able to reproduce the diurnally varying cloudiness and precipitation patterns associated with land-sea contrasts; however, the amplitudes of CCM2 diurnal continental convective cloudiness are weaker than observations. The CCM2 boundary-layer sensible heating is consistent with a very limited set of observations, and with estimates obtained from simple models of diffusive heating. Although the CCM2 tropospheric solar radiative heating is similar in magnitude to previous estimates, there are substantial differences in the vertical structures. A definitive assessment of the validity of the CCM2 diurnal cycle is precluded by the lack of detailed observations and the limitations of our CCM2 sample. Nevertheless, the authors conclude that the global-scale components of the CCM2 diurnal heating are useful proxies for the true diurnal forcing of the tides.

  2. Direction and movement angular velocity determining of cloudiness with panoramic images of the sky

    NASA Astrophysics Data System (ADS)

    Galileiskii, Viktor P.; Elizarov, Alexey I.; Kokarev, Dmitrii V.; Morozov, Aleksandr M.

    2014-11-01

    This article gives a short overview to method of direction determining and visible angular velocity of movement determining of cloudiness based on set of panoramic images of cloudy sky, obtained by "Fisheye" wide-angle lens.

  3. Intakes of culinary herbs and spices from a food frequency questionnaire evaluated against 28-days estimated records

    PubMed Central

    2011-01-01

    Background Worldwide, herbs and spices are much used food flavourings. However, little data exist regarding actual dietary intake of culinary herbs and spices. We developed a food frequency questionnaire (FFQ) for the assessment of habitual diet the preceding year, with focus on phytochemical rich food, including herbs and spices. The aim of the present study was to evaluate the intakes of herbs and spices from the FFQ with estimates of intake from another dietary assessment method. Thus we compared the intake estimates from the FFQ with 28 days of estimated records of herb and spice consumption as a reference method. Methods The evaluation study was conducted among 146 free living adults, who filled in the FFQ and 2-4 weeks later carried out 28 days recording of herb and spice consumption. The FFQ included a section with questions about 27 individual culinary herbs and spices, while the records were open ended records for recording of herbs and spice consumption exclusively. Results Our study showed that the FFQ obtained slightly higher estimates of total intake of herbs and spices than the total intake assessed by the Herbs and Spice Records (HSR). The correlation between the two assessment methods with regard to total intake was good (r = 0.5), and the cross-classification suggests that the FFQ may be used to classify subjects according to total herb and spice intake. For the 8 most frequently consumed individual herbs and spices, the FFQ obtained good estimates of median frequency of intake for 2 herbs/spices, while good estimates of portion sizes were obtained for 4 out of 8 herbs/spices. Conclusions Our results suggested that the FFQ was able to give good estimates of frequency of intake and portion sizes on group level for several of the most frequently used herbs and spices. The FFQ was only able to fairly rank subjects according to frequency of intake of the 8 most frequently consumed herbs and spices. Other studies are warranted to further explore the

  4. Random regression test day models to estimate genetic parameters for milk yield and milk components in Philippine dairy buffaloes.

    PubMed

    Flores, E B; van der Werf, J

    2015-08-01

    Heritabilities and genetic correlations for milk production traits were estimated from first-parity test day records on 1022 Philippine dairy buffalo cows. Traits analysed included milk (MY), fat (FY) and protein (PY) yields, and fat (Fat%) and protein (Prot%) concentrations. Varying orders of Legendre polynomials (Leg(m)) as well as the Wilmink function (Wil) were used in random regression models. These various models were compared based on log likelihood, Akaike's information criterion, Bayesian information criterion and genetic variance estimates. Six residual variance classes were sufficient for MY, FY, PY and Fat%, while seven residual classes for Prot%. Multivariate analysis gave higher estimates of genetic variance and heritability compared with univariate analysis for all traits. Heritability estimates ranged from 0.25 to 0.44, 0.13 to 0.31 and 0.21 to 0.36 for MY, FY and PY, respectively. Wilmink's function was the better fitting function for additive genetic effects for all traits. It was also the preferred function for permanent environment effects for Fat% and Prot%, but for MY, FY and PY, the Legm was the appropriate function. Genetic correlations of MY with FY and PY were high and they were moderately negative with Fat% and Prot%. To prevent deterioration in Fat% and Prot% and improve milk quality, more weight should be applied to milk component traits. PMID:25727642

  5. Boundary Layer Cloudiness Parameterizations Using ARM Observations

    SciTech Connect

    Bruce Albrecht

    2004-09-15

    This study used DOE ARM data and facilities to: (1) study macroscopic properties of continental stratus clouds at SGP and the factors controlling these properties, (2) develop a scientific basis for understanding the processes responsible for the formation of boundary layer clouds using ARM observations in conjunction with simple parametric models and LES, and (3) evaluate cumulus cloud characteristics retrieved from the MMCR operating at TWP-Nauru. In addition we have used high resolution 94 GHz observations of boundary layer clouds and precipitation to: (1) develop techniques for using high temporal resolution Doppler velocities to study large-eddy circulations and turbulence in boundary layer clouds and estimate the limitations of using current and past MMCR data for boundary layer cloud studies, (2) evaluate the capability and limitations of the current MMCR data for estimating reflectivity, vertical velocities, and spectral under low- signal-to-noise conditions associated with weak no n-precipitating clouds, (3) develop possible sampling modes for the new MMCR processors to allow for adequate sampling of boundary layer clouds, and (4) retrieve updraft and downdraft structures under precipitating conditions.

  6. Genetic parameters for test-day yield of milk, fat and protein in buffaloes estimated by random regression models.

    PubMed

    Aspilcueta-Borquis, Rúsbel R; Araujo Neto, Francisco R; Baldi, Fernando; Santos, Daniel J A; Albuquerque, Lucia G; Tonhati, Humberto

    2012-08-01

    The test-day yields of milk, fat and protein were analysed from 1433 first lactations of buffaloes of the Murrah breed, daughters of 113 sires from 12 herds in the state of São Paulo, Brazil, born between 1985 and 2007. For the test-day yields, 10 monthly classes of lactation days were considered. The contemporary groups were defined as the herd-year-month of the test day. Random additive genetic, permanent environmental and residual effects were included in the model. The fixed effects considered were the contemporary group, number of milkings (1 or 2 milkings), linear and quadratic effects of the covariable cow age at calving and the mean lactation curve of the population (modelled by third-order Legendre orthogonal polynomials). The random additive genetic and permanent environmental effects were estimated by means of regression on third- to sixth-order Legendre orthogonal polynomials. The residual variances were modelled with a homogenous structure and various heterogeneous classes. According to the likelihood-ratio test, the best model for milk and fat production was that with four residual variance classes, while a third-order Legendre polynomial was best for the additive genetic effect for milk and fat yield, a fourth-order polynomial was best for the permanent environmental effect for milk production and a fifth-order polynomial was best for fat production. For protein yield, the best model was that with three residual variance classes and third- and fourth-order Legendre polynomials were best for the additive genetic and permanent environmental effects, respectively. The heritability estimates for the characteristics analysed were moderate, varying from 0·16±0·05 to 0·29±0·05 for milk yield, 0·20±0·05 to 0·30±0·08 for fat yield and 0·18±0·06 to 0·27±0·08 for protein yield. The estimates of the genetic correlations between the tests varied from 0·18±0·120 to 0·99±0·002; from 0·44±0·080 to 0·99±0·004; and from 0·41±0·080 to

  7. Estimating present day extreme water level exceedance probabilities around the coastline of Australia: tropical cyclone-induced storm surges

    NASA Astrophysics Data System (ADS)

    Haigh, Ivan D.; MacPherson, Leigh R.; Mason, Matthew S.; Wijeratne, E. M. S.; Pattiaratchi, Charitha B.; Crompton, Ryan P.; George, Steve

    2014-01-01

    The incidence of major storm surges in the last decade have dramatically emphasized the immense destructive capabilities of extreme water level events, particularly when driven by severe tropical cyclones. Given this risk, it is vitally important that the exceedance probabilities of extreme water levels are accurately evaluated to inform risk-based flood and erosion management, engineering and for future land-use planning and to ensure the risk of catastrophic structural failures due to under-design or expensive wastes due to over-design are minimised. Australia has a long history of coastal flooding from tropical cyclones. Using a novel integration of two modeling techniques, this paper provides the first estimates of present day extreme water level exceedance probabilities around the whole coastline of Australia, and the first estimates that combine the influence of astronomical tides, storm surges generated by both extra-tropical and tropical cyclones, and seasonal and inter-annual variations in mean sea level. Initially, an analysis of tide gauge records has been used to assess the characteristics of tropical cyclone-induced surges around Australia. However, given the dearth (temporal and spatial) of information around much of the coastline, and therefore the inability of these gauge records to adequately describe the regional climatology, an observationally based stochastic tropical cyclone model has been developed to synthetically extend the tropical cyclone record to 10,000 years. Wind and pressure fields derived for these synthetically generated events have then been used to drive a hydrodynamic model of the Australian continental shelf region with annual maximum water levels extracted to estimate exceedance probabilities around the coastline. To validate this methodology, selected historic storm surge events have been simulated and resultant storm surges compared with gauge records. Tropical cyclone induced exceedance probabilities have been combined with

  8. CLOUDY 90: Numerical Simulation of Plasmas and Their Spectra

    NASA Astrophysics Data System (ADS)

    Ferland, G. J.; Korista, K. T.; Verner, D. A.; Ferguson, J. W.; Kingdon, J. B.; Verner, E. M.

    1998-07-01

    CLOUDY is a large-scale spectral synthesis code designed to simulate fully physical conditions within an astronomical plasma and then predict the emitted spectrum. Here we describe version 90 (C90) of the code, paying particular attention to changes in the atomic database and numerical methods that have affected predictions since the last publicly available version, C84. The computational methods and uncertainties are outlined together with the direction future development will take. The code is freely available and is widely used in the analysis and interpretation of emission-line spectra. Web access to the Fortran source for CLOUDY, its documentation Hazy, and an independent electronic form of the atomic database is also described.

  9. Aerosol Retrievals under Partly Cloudy Conditions: Challenges and Perspectives

    SciTech Connect

    Kassianov, Evgueni I.; Ovchinnikov, Mikhail; Berg, Larry K.; Flynn, Connor J.

    2011-06-01

    There are lots of interesting and intriguing features of aerosols near clouds – many of which can be quite engaging, as well being useful and climate-related. Exploring aerosol with the aid of the remote sensing, in situ observations and numerical modeling has piqued our curiosity and led to improve insights into the nature of aerosol and clouds and their complex relationship. This chapter conveys the outstanding issues of cloudy-sky aerosol retrievals of important climate properties and outlines their fruitful connections to other research areas such as in situ measurements and model simulations. The chapter focuses mostly on treating the inverse problems in the context of the passive satellite remote sensing and how they can improve our understanding of the cloud-aerosol interactions. The presentation includes a basis in the inverse problem theory, reviews available approaches and discusses their applications to partly cloudy situations. Potential synergy of observations and model simulations is described as well.

  10. Quark-meson coupling model with the cloudy bag

    SciTech Connect

    Nagai, S.; Miyatsu, T.; Saito, Kenji; Tsushima, Kazuo

    2008-07-01

    Using the volume coupling version of the cloudy bag model, the quark-meson coupling model is extended to study the role of pion field and the properties of nuclear matter. The extended model includes the effect of gluon exchange as well as the pion-cloud effect, and provides a good description of the nuclear matter properties. The relationship between the extended model and the EFT approach to nuclear matter is also discussed.

  11. Interannual variability in stratiform cloudiness and sea surface temperature

    SciTech Connect

    Norris, J.R.; Leovy, C.B.

    1994-12-01

    Marine stratiform cloudiness (MSC)(stratus, stratocumulus, and fog) is widespread over subtropical oceans west of the continents and over midlatitude oceans during summer, the season when MSC has maximum influence on surface downward radiation and is most influenced by boundary-layer processes. Long-term datasets of cloudiness and sea surface teperature (SST) from surface observations from 1952 to 1981 are used to examine interannual variations in MSC and SST. Linear correlations of anomalies in seasonal MSC amount with seasonal SST anomalies are negative and significant in midlatitude and eastern subtropical oceans, especially during summer. Significant negative correlations between SST and nimbostratus and nonprecipitating midlevel cloudiness are also observed at midlatitudes during summer, suggesting that summer storm tracks shift from year to year following year-to-year meridional shifts in the SST gradient. Over the 30-yr period, there are significant upward trends in MSC amount over the northern midlatitude oceans and a significant downward trend off the coast of California. The highest correlations and trends occur where gradients in MSC and SST are strongest. During summer, correlations between SST and MSC anomalies peak at zero lag in midlatitudes where warm advection prevails, but SST lags MSC in subtropical regions where cold advection predominates. This difference is attributed to a tendency for anomalies in latent heat flux to compensate anomalies in surface downward radiation in warm advection regions but not in cold advection regions.

  12. Interannual variability in stratiform cloudiness and sea surface temperature

    NASA Technical Reports Server (NTRS)

    Norris, Joel R.; Leovy, Conway B.

    1994-01-01

    Marine stratiform cloudiness (MSC)(stratus, stratocumulus, and fog) is widespread over subtropical oceans west of the continents and over midlatitude oceans during summer, the season when MSC has maximum influence on surface downward radiation and is most influenced by boundary-layer processes. Long-term datasets of cloudiness and sea surface teperature (SST) from surface observations from 1952 to 1981 are used to examine interannual variations in MSC and SST. Linear correlations of anomalies in seasonal MSC amount with seasonal SST anomalies are negative and significant in midlatitude and eastern subtropical oceans, especially during summer. Significant negative correlations between SST and nimbostratus and nonprecipitating midlevel cloudiness are also observed at midlatitudes during summer, suggesting that summer storm tracks shift from year to year following year-to-year meridional shifts in the SST gradient. Over the 30-yr period, there are significant upward trends in MSC amount over the northern midlatitude oceans and a significant downward trend off the coast of California. The highest correlations and trends occur where gradients in MSC and SST are strongest. During summer, correlations between SST and MSC anomalies peak at zero lag in midlatitudes where warm advection prevails, but SST lags MSC in subtropical regions where cold advection predominates. This difference is attributed to a tendency for anomalies in latent heat flux to compensate anomalies in surface downward radiation in warm advection regions but not in cold advection regions.

  13. Changes in Extratropical Storm Track Cloudiness 1983-2008: Observational Support for a Poleward Shift

    NASA Technical Reports Server (NTRS)

    Bender, Frida A-M.; Rananathan, V.; Tselioudis, G.

    2012-01-01

    Climate model simulations suggest that the extratropical storm tracks will shift poleward as a consequence of global warming. In this study the northern and southern hemisphere storm tracks over the Pacific and Atlantic ocean basins are studied using observational data, primarily from the International Satellite Cloud Climatology Project, ISCCP. Potential shifts in the storm tracks are examined using the observed cloud structures as proxies for cyclone activity. Different data analysis methods are employed, with the objective to address difficulties and uncertainties in using ISCCP data for regional trend analysis. In particular, three data filtering techniques are explored; excluding specific problematic regions from the analysis, regressing out a spurious viewing geometry effect, and excluding specific cloud types from the analysis. These adjustments all, to varying degree, moderate the cloud trends in the original data but leave the qualitative aspects of those trends largely unaffected. Therefore, our analysis suggests that ISCCP data can be used to interpret regional trends in cloudiness, provided that data and instrumental artefacts are recognized and accounted for. The variation in magnitude between trends emerging from application of different data correction methods, allows us to estimate possible ranges for the observational changes. It is found that the storm tracks, here represented by the extent of the midlatitude-centered band of maximum cloud cover over the studied ocean basins, experience a poleward shift as well as a narrowing over the 25 year period covered by ISCCP. The observed magnitudes of these effects are larger than in current generation climate models (CMIP3). The magnitude of the shift is particularly large in the northern hemisphere Atlantic. This is also the one of the four regions in which imperfect data primarily prevents us from drawing firm conclusions. The shifted path and reduced extent of the storm track cloudiness is accompanied

  14. Cardiovascular responses to noise: Effects of self-estimated sensitivity to noise, sex, and time of the day

    NASA Astrophysics Data System (ADS)

    di Nisi, J.; Muzet, A.; Weber, L. D.

    1987-04-01

    Eighty subjects of both sexes were selected according to their self-estimated high or low sensitivity to noise. Noise exposure took place during a mental task ("sound" condition) or during a video film illustrating the noises ("sound and video" condition). The experiments were conducted between 0900 and 1100 hours or between 1500 and 1700 hours. Heart rate response and finger pulse response amplitudes were averaged separately for "sound" and "sound and video" conditions. In the "sound" condition, the average amplitude of the heart rate response differed significantly between noise-sensitivity groups: the low sensitivity group showed a lower average amplitude of heart rate response than the high sensitivity group. A significant interaction between sex and time of the day (morning or afternoon) was observed in both "sound" and "sound and video" conditions. In the "sound" condition, the percentage of noises inducing a finger pulse response appeared higher in female than in male subjects.

  15. Computation of Solar Radiative Fluxes by 1D and 3D Methods Using Cloudy Atmospheres Inferred from A-train Satellite Data

    NASA Technical Reports Server (NTRS)

    Barker, Howard W.; Kato, Serji; Wehr, T.

    2012-01-01

    The main point of this study was to use realistic representations of cloudy atmospheres to assess errors in solar flux estimates associated with 1D radiative transfer models. A scene construction algorithm, developed for the EarthCARE satellite mission, was applied to CloudSat, CALIPSO, and MODIS satellite data thus producing 3D cloudy atmospheres measuring 60 km wide by 13,000 km long at 1 km grid-spacing. Broadband solar fluxes and radiances for each (1 km)2 column where then produced by a Monte Carlo photon transfer model run in both full 3D and independent column approximation mode (i.e., a 1D model).

  16. A novel GIS-based tool for estimating present-day ocean reference depth using automatically processed gridded bathymetry data

    NASA Astrophysics Data System (ADS)

    Jurecka, Mirosława; Niedzielski, Tomasz; Migoń, Piotr

    2016-05-01

    This paper presents a new method for computing the present-day value of the reference depth (dr) which is an essential input information for assessment of past sea-level changes. The method applies a novel automatic geoprocessing tool developed using Python script and ArcGIS, and uses recent data about ocean floor depth, sediment thickness, and age of oceanic crust. The procedure is multi-step and involves creation of a bathymetric dataset corrected for sediment loading and isostasy, delineation of subduction zones, computation of perpendicular sea-floor profiles, and statistical analysis of these profiles versus crust age. The analysis of site-specific situations near the subduction zones all around the world shows a number of instances where the depth of the oceanic crust stabilizes at a certain level before reaching the subduction zone, and this occurs at depths much lower than proposed in previous approaches to the reference depth issue. An analysis of Jurassic and Cretaceous oceanic lithosphere shows that the most probable interval at which the reference depth occurs is 5300-5800 m. This interval is broadly consistent with dr estimates determined using the Global Depth-Heatflow model (GDH1), but is significantly lower than dr estimates calculated on a basis of the Parsons-Sclater Model (PSM).

  17. An extended cumulative logit model for detecting a shift in frequencies of sky-cloudiness conditions

    NASA Astrophysics Data System (ADS)

    Lu, Qiqi; Wang, Xiaolan L.

    2012-08-01

    In Canada, sky-cloudiness (or cloud cover) condition is reported in terms of tenths of the sky dome covered by clouds and hence has 11 categories (0/10 for clear sky, 1/10 for one tenth of the sky dome covered by clouds, …, and 10/10 for overcast). The cloud cover data often contain temporal discontinuities (changepoints) and present a large amount of observational uncertainty. Detecting changepoints in a sequence of continuous random variables has been extensively explored in both statistics and climatology literature. However, changepoint analyses of a multinomial sequence data with extra variabilities are relatively sparse. This study develops a likelihood ratio test for detecting a sudden change in parameters of the cumulative logit model for a multinomial sequence. The extra-multinomial variation is accounted for by allowing an overdispersion parameter in the model fitting. Moreover, the empirical distribution of the estimated changepoint is approximated by a bootstrap method. An application of this new technique to real sky cloudiness data in Canada is presented.

  18. Cloudy 94 and Applications to Quasar Emission Line Regions

    NASA Technical Reports Server (NTRS)

    Ferland, Gary J.

    2000-01-01

    This review discusses the most recent developments of the plasma simulation code Cloudy and its application to the, emission-line regions of quasars. The longterm goal is to develop the tools needed to determine the chemical composition of the emitting gas and the luminosity of the central engine for any emission line source. Emission lines and the underlying thermal continuum are formed in plasmas that are far from thermodynamic equilibrium. Their thermal and ionization states are the result of a balance of a vast set of microphysical processes. Once produced, radiation must, propagate out of the (usually) optically thick source. No analytic solutions are possible, and recourse to numerical simulations is necessary. I am developing the large-scale plasma simulation code Cloudy as an investigative tool for this work, much as an observer might build a spectrometer. This review describes the current version of Cloudy, version 94. It describes improvements made since the, release of the previous version, C90. The major recent, application has been the development of the "Locally Optimally-Emitting Cloud" (LOC) model of AGN emission line regions. Powerful selection effects, introduced by the atomic physics and line formation process, permit individual lines to form most efficiently only near certain selected parameters. These selection effects, together with the presence of gas with a wide range of conditions, are enough to reproduce the spectrum of a typical quasar with little dependence on details. The spectrum actually carries little information to the identity of the emitters. I view this as a major step forward since it provides a method to handle accidental details at the source, so that we can concentrate on essential information such as the luminosity or chemical composition of the quasar.

  19. Climatic change by cloudiness linked to the spatial variability of sea surface temperatures

    NASA Technical Reports Server (NTRS)

    Otterman, J.

    1975-01-01

    An active role in modifying the earth's climate is suggested for low cloudiness over the circumarctic oceans. Such cloudiness, linked to the spatial differences in ocean surface temperatures, was studied. The temporal variations from year to year of ocean temperature patterns can be pronounced and therefore, the low cloudiness over this region should also show strong temporal variations, affecting the albedo of the earth and therefore the climate. Photographs are included.

  20. Cloudiness over the Amazon rainforest: Meteorology and thermodynamics

    NASA Astrophysics Data System (ADS)

    Collow, Allison B. Marquardt; Miller, Mark A.; Trabachino, Lynne C.

    2016-07-01

    Comprehensive meteorological observations collected during GOAmazon2014/15 using the Atmospheric Radiation Measurement Mobile Facility no. 1 and assimilated observations from the Modern-Era Retrospective Analysis for Research and Applications, Version 2 are used to document the seasonal cycle of cloudiness, thermodynamics, and precipitation above the Amazon rainforest. The reversal of synoptic-scale vertical motions modulates the transition between the wet and dry seasons. Ascending moist air during the wet season originates near the surface of the Atlantic Ocean and is advected into the Amazon rainforest, where it experiences convergence and, ultimately, precipitates. The dry season is characterized by weaker winds and synoptic-scale subsidence with little or no moisture convergence accompanying moisture advection. This combination results in the drying of the midtroposphere during June through October as indicated by a decrease in liquid water path, integrated water, and the vertical profile of water vapor mixing ratio. The vertical profile of cloud fraction exhibits a relatively consistent decline in cloud fraction from the lifting condensation level (LCL) to the freezing level where a minimum is observed, unlike many other tropical regions. Coefficients of determination between the LCL and cloud fractional coverage suggest a relatively robust relationship between the LCL and cloudiness beneath 5 km during the dry season (R2 = 0.42) but a weak relationship during the wet season (0.12).

  1. Regime-based evaluation of cloudiness in CMIP5 models

    NASA Astrophysics Data System (ADS)

    Jin, Daeho; Oreopoulos, Lazaros; Lee, Dongmin

    2016-04-01

    The concept of cloud regimes (CRs) is used to develop a framework for evaluating the cloudiness of 12 fifth Coupled Model Intercomparison Project (CMIP5) models. Reference CRs come from existing global International Satellite Cloud Climatology Project (ISCCP) weather states. The evaluation is made possible by the implementation in several CMIP5 models of the ISCCP simulator generating in each grid cell daily joint histograms of cloud optical thickness and cloud top pressure. Model performance is assessed with several metrics such as CR global cloud fraction (CF), CR relative frequency of occurrence (RFO), their product [long-term average total cloud amount (TCA)], cross-correlations of CR RFO maps, and a metric of resemblance between model and ISCCP CRs. In terms of CR global RFO, arguably the most fundamental metric, the models perform unsatisfactorily overall, except for CRs representing thick storm clouds. Because model CR CF is internally constrained by our method, RFO discrepancies yield also substantial TCA errors. Our results support previous findings that CMIP5 models underestimate cloudiness. The multi-model mean performs well in matching observed RFO maps for many CRs, but is still not the best for this or other metrics. When overall performance across all CRs is assessed, some models, despite shortcomings, apparently outperform Moderate Resolution Imaging Spectroradiometer cloud observations evaluated against ISCCP like another model output. Lastly, contrasting cloud simulation performance against each model's equilibrium climate sensitivity in order to gain insight on whether good cloud simulation pairs with particular values of this parameter, yields no clear conclusions.

  2. Gait, estimated net cost of transport and heat production at different speeds in three-day-event horses.

    PubMed

    Schroter, R C; Baylis, E; Marlin, D J

    1996-07-01

    Heart rate and gait characteristics (stride length and frequency) were studied in 6 horses subjected to a standardised incremental exercise test, involving moving at the trot and increasing speeds up to a fast gallop and subsequently during the steeplechase phase of a 3-day-event. The studies were performed in hot conditions. Appropriate scaling, based on hindleg length (hh), stride length (L), stride frequency (f) and speed (Sp) for nondimensional stride length (lambda = (L/hh), nondimensional stride frequency (phi = f(hh/g)1/2) and nondimensional velocity (û = Sp/(ghh)1/2), where g is the gravitational acceleration, demonstrated that there were no major differences in characteristics over the full range studied lambda = 2.3 û0.68. However, there were subtle differences in some horses that could endow a benefit in locomotory efficiency when compared to others exercising at the same absolute speed. There were clear changes in the relationship between nondimensional stride length and frequency with increasing speed, from trot to canter (at û approximately 1.4) and to full gallop (at û approximately 2.3); when trotting, lambda was less than 2.2 and the transition from canter to gallop took place at lambda approximately 3.2. The cost of transport/kg/m, estimated from the heart rates measured continuously during each study, decreased with increasing speed and bodyweight. In some animals, there appeared to be a weak minimum around the canter-gallop transition speed. When interpreted as oxygen cost, using published values for the oxygen consumption-heart rate relationship, the cost fell from an average of 0.201 ml/kg/m at the trot to 0.161 mlO2/kg/m when galloping during the incremental exercise tests. During the steeplechase, the cost was approximately 7.5% higher than at the same speed in the exercise tests; this was probably due to jumping effort. Estimated power consumption increased linearly with speed. In the steeplechase, power consumption was also 7.5% higher

  3. The Effect of Cloudiness on New Particle Formation: Investigation of Radiation Levels

    NASA Astrophysics Data System (ADS)

    baranizadeh, E.; Arola, A. T.; Hamed, A.; Nieminen, T.; Virtanen, A.; Kulmala, M. T.; Laaksonen, A. J.

    2013-12-01

    The seasonal cloud effects on NPF events (E) and the radiation levels during the nucleation have not been systematically investigated. In this research, we study the cloudiness effects on E using a relative radiation intensity parameter I/Imax as an indicator of cloudiness level. The I/Imax parameter has been defined as the ratio of measured global-radiation I (w m-2) at a given time of day divided by the modeled clear-sky global radiation Imax (w m-2) at the same time. The ratio data are provided for all days including E, non-event (NE) and undefined (i.e. neither E nor NE) days during 2002-2012 for SMEAR II located in Hyytiälä , Southern Finland and during March 2002- April 2005 for San Pietro Capofiume (SPC) measurement station, Po Vally, Italy. We analysed the ratio I/Imax only for the duration between nucleation start and end times for Es, and from one hour after sunrise until noon for NE and undefined days. We averaged the ratio I/Imax values of each day over the determined time windows (average ratio) for E and NEs, and calculated the fraction (%) of days which are E (ΔE) or NE (ΔNE) in the given ranges of average ratio with the interval widths of 0.05. The results show that the higher (lower) the average I/Imax ranges, the higher (lower) ΔE (ΔNE) values. The ΔE values in the ranges lower than 0.95 in particular low ranges (i.e. the presence of cloud) is much less than Hyytiälä, indicating that presence of cloud during the period when E is going on is much more probable in Hyytiälä than SPC. We have investigated the seasonal distribution of Δ values in Hyytiälä. Interestingly, ΔE statistics in the ranges with interval widths 0.05 limited to 0.5-0.9, in autumn and spring is much higher than summer. In addition, the ΔE values have plateaued in the ranges with the intervals 0.05 limited to [0.65-0.8] in summer (201 Es), in contrast to spring (442 Es) and autumn (164 Es) where an increasing trend is observed. A few Es in which Clouds are present

  4. Evaluation of the Impact of AlRS Radiance and Profile Data Assimilation in Partly Cloudy Regions

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradely; Srikishen, Jayanthi; Jedlovec, Gary

    2013-01-01

    Parallel experiments using AIRS L1B and L2 retrieved profiles were run for 29 case study days for early Winter 2011. Forecasts over and downstream regions of low, opaque cloudy regions yield improved T and Z anomaly correlations when non-thinned set of profiles is assimilated instead of radiances. Initial results indicate that GSI does a good job on the whole of determining cloud-free radiances there are some areas coincident with areas of larger profile impact that are misrepresented (compared to MODIS) that may result in reduced analysis impact.

  5. Cloudy corneas as an initial presentation of multiple myeloma

    PubMed Central

    Sharma, Priyanka; Madi, Haifa A; Bonshek, Richard; Morgan, Stephen J

    2014-01-01

    Summary We report a case of previously unsuspected myeloma, presenting with cornea verticillata due to intracorneal paraprotein deposition. History An 85-year-old female presented via her optician with a 4-month history of cloudy vision. She had undergone an uneventful bilateral phacoemulsification surgery 7 years earlier. Extensive spiraling corneal epithelial opacification was noted on slit-lamp examination. On further investigation, she was found to have a previously unsuspected low-grade multiple myeloma. We established the nature of the corneal deposits with corneal epithelial biopsy histopathology and electron microscopy. It is very rare for multiple myeloma to present in this fashion. Ophthalmologists should be aware that such a presentation may rarely be due to systemic multiple myeloma. PMID:24812487

  6. Deterministic and fuzzy verification of the cloudiness of High Resolution operational models

    NASA Astrophysics Data System (ADS)

    Amodei, M.; Sanchez, I.; Stein, J.

    2009-09-01

    The brightness temperature (BT) observed by the Infrared channel of SEVIRI, present in Meteosat 9 is used to verify the forecast qualities of 2 high resolution models Aladin (horizontal mesh 10 km) and Arome (2.5 km) operational in Meteo-France. The observed temperatures are directly related to the atmosphere cloudiness and their forecasted counterparts are obtained through the radiative transfer model RTTOV. The temporal period used for the comparison is summer and autumn 2008. 2x2 tables of contingences are built for different thresholds (defining the events) covering the range data and used to compute deterministic scores. A fuzzy approach is performed by transforming the deterministic forecast in frequencies of events in a neighbourhood around the observation point. Brier skill scores against the persistence forecast are obtained by comparing theses frequencies either to the local yes or no observation or to the observed frequency in the neighbourhood (Amodei and Stein 2009). The stratification of the results in function of BT allows to document the relative merits of the forecasts all along the troposphere. Thus, it is shown that both models under-estimate the real BT by lack of cloudiness and especially the Arome model for large scale perturbations. Moreover, the high-tropospheric clouds are quasi-absent in the Aladin forecasts and Arome bias is better for this category in convective situations but its clouds are often displaced leading to poor deterministic scores. This drawback is corrected by the fuzzy approach and its probabilistic scores beats the Aladin counterparts. This conclusion is in complete accordance with the verification of the precipitation performed over the same period.

  7. Atmospheric conditions governing anomalies of the summer and winter cloudiness in Spitsbergen

    NASA Astrophysics Data System (ADS)

    Bednorz, Ewa; Kaczmarek, Dominika; Dudlik, Przemysław

    2016-01-01

    The study is based on data concerning cloudiness for the years 1981-2010 from Svalbard Lufthavn. Atmospheric circulation was characterized using a catalogue of circulation types developed by Niedźwiedź (2013) and average daily values of atmospheric pressure. Intensive cyclogenesis taking place over the north Atlantic expressed by lower-than-normal sea level pressure (SLP), particularly over the Fram Strait and over the east coast of Greenland, enhances the meridional air transport from the southern sector which conveys positive anomalies of cloudiness, namely a very cloudy weather. Negative anomalies of cloudiness over Svalbard Lufthavn occur in the winter when the north Atlantic cyclone path is shifted to the south and goes along the northern Norwegian shore towards the south Barents Sea. In summer, the influence of pressure patterns on cloudiness is weaker than in winter and different circulation patterns induce negative extremes of cloudiness. In the warm season, sunny weather occurs when a distinct anticyclone spreads over the Svalbard Archipelago and to its west, over the Fram Strait and the northern outskirts of the Greenland Sea. Extremely cloudy weather occurs in summer when a weak anticyclone spreads over the Barents Sea, the Novaya Zemlya archipelago and the Kara Sea, while slightly lower-than-normal pressure is observed over Greenland. Such a pressure pattern enhances southerly and south-westerly flow of air masses, bringing humid air. The results obtained in this study demonstrate that cloudiness over Spitsbergen is strongly controlled by the air circulation arising from pressure patterns.

  8. On the assimilation of satellite sounder data in cloudy skies in numerical weather prediction models

    NASA Astrophysics Data System (ADS)

    Li, Jun; Wang, Pei; Han, Hyojin; Li, Jinlong; Zheng, Jing

    2016-04-01

    Satellite measurements are an important source of global observations in support of numerical weather prediction (NWP). The assimilation of satellite radiances under clear skies has greatly improved NWP forecast scores. However, the application of radiances in cloudy skies remains a significant challenge. In order to better assimilate radiances in cloudy skies, it is very important to detect any clear field-of-view (FOV) accurately and assimilate cloudy radiances appropriately. Research progress on both clear FOV detection methodologies and cloudy radiance assimilation techniques are reviewed in this paper. Overview on approaches being implemented in the operational centers and studied by the satellite data assimilation research community is presented. Challenges and future directions for satellite sounder radiance assimilation in cloudy skies in NWP models are also discussed.

  9. PyCloudy: a new tool to model 3D nebulae

    NASA Astrophysics Data System (ADS)

    Morisset, C.

    2014-04-01

    I present in this poster the python based library pyCloudy, allowing to run the Cloudy photoionization code and to: * Define and write input file(s) for Cloudy code. As one can have it in a code, one may generate automatically sets of input files, changing parameters from one to the other: easy to make grids * Read the Cloudy output files and play with the data: one will be able to plot line emissivity ratio vs. the radius of the nebula, the electron temperature, or any Cloudu output. * Build pseudo-3D models, a la Cloudy_3D. This means: run a set of models, changing parameters (e.g. inner radius, density) following angular laws, read the outputs of the set of models and interpolate the results (Te, ne, line emissivities) in a 3D cube. * PV-diagnrams and line profiles through any slit can also be computed

  10. Usual Dietary Intakes: SAS Macros for Estimating Ratios of Two Dietary Components that are Consumed Nearly Every Day

    Cancer.gov

    The following SAS macros can be used to create a bivariate distribution of usual intake of two dietary components that are consumed nearly every day and to calculate percentiles of the population distribution of the ratio of usual intakes.

  11. Estimations of historical atmospheric mercury concentrations from mercury refining and present-day soil concentrations of total mercury in Huancavelica, Peru.

    PubMed

    Robins, Nicholas A; Hagan, Nicole; Halabi, Susan; Hsu-Kim, Heileen; Gonzales, Ruben Dario Espinoza; Morris, Mark; Woodall, George; Richter, Daniel deB; Heine, Paul; Zhang, Tong; Bacon, Allan; Vandenberg, John

    2012-06-01

    Detailed Spanish records of cinnabar mining and mercury production during the colonial period in Huancavelica, Peru were examined to estimate historical health risks to the community from exposure to elemental mercury (Hg) vapor resulting from cinnabar refining operations. Between 1564 and 1810, nearly 17,000 metric tons of Hg were released to the atmosphere in Huancavelica from Hg production. AERMOD was used with estimated emissions and source characteristics to approximate historic atmospheric concentrations of mercury vapor. Modeled 1-hour and long-term concentrations were compared with present-day inhalation reference values for elemental Hg. Estimated 1-hour maximum concentrations for the entire community exceeded present-day occupational inhalation reference values, while some areas closest to the smelters exceeded present-day emergency response guideline levels. Estimated long-term maximum concentrations for the entire community exceeded the EPA Reference Concentration (RfC) by a factor of 30 to 100, with areas closest to the smelters exceeding the RfC by a factor of 300 to 1000. Based on the estimated historical concentrations of Hg vapor in the community, the study also measured the extent of present-day contamination throughout the community through soil sampling and analysis. Total Hg in soils sampled from 20 locations ranged from 1.75 to 698 mg/kg and three adobe brick samples ranging from 47.4 to 284 mg/kg, consistent with other sites of mercury mining and use. The results of the soil sampling indicate that the present-day population of Huancavelica is exposed to levels of mercury from legacy contamination which is currently among the highest worldwide, consequently placing them at potential risk of adverse health outcomes. PMID:22542225

  12. Estimation of Trans Fatty Acid Intake in Japanese Adults Using 16-Day Diet Records Based on a Food Composition Database Developed for the Japanese Population

    PubMed Central

    Yamada, Mai; Sasaki, Satoshi; Murakami, Kentaro; Takahashi, Yoshiko; Okubo, Hitomi; Hirota, Naoko; Notsu, Akiko; Todoriki, Hidemi; Miura, Ayako; Fukui, Mitsuru; Date, Chigusa

    2010-01-01

    Background The Standard Tables of Food Composition in Japan do not include information on trans fatty acids. Previous studies estimating trans fatty acid intake among Japanese have limitations regarding the databases utilized and diet assessment methodologies. We developed a comprehensive database of trans fatty acid food composition, and used this database to estimate intake among a Japanese population. Methods The database was developed using analytic values from the literature and nutrient analysis software encompassing foods in the US, as well as values estimated from recipes or nutrient compositions. We collected 16-day diet records from 225 adults aged 30 to 69 years living in 4 areas of Japan. Trans fatty acid intake was estimated based on the database and the 16-day diet records. Results Mean total fat and trans fatty acid intake was 56.9 g/day (27.7% total energy) and 1.7 g/day (0.8% total energy), respectively, for women and 66.8 g/day (25.5% total energy) and 1.7 g/day (0.7% total energy) for men. Trans fatty acid intake accounted for greater than 1% of total energy intake, which is the maximum recommended according to the World Health Organization, in 24.4% of women and 5.7% of men, and was particularly high among women living in urban areas and those aged 30–49 years. The largest contributors to trans fatty acid intake were confectionaries in women and fats and oils in men. Conclusions Although mean trans fatty acid intake was below the maximum recommended intake of the World Health Organization, intake among subgroups was of concern. Further public health efforts to reduce trans fatty acid intake should be encouraged. PMID:20037259

  13. DayCent model simulations for estimating soil carbon dynamics and greenhouse gas fluxes from agricultural production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DayCent is a biogeochemical model of intermediate complexity used to simulate carbon, nutrient, and greenhouse gas fluxes for crop, grassland, forest, and savanna ecosystems. Model inputs include: soil texture and hydraulic properties, current and historical land use, vegetation cover, daily maximum...

  14. Psychophysical study of the visual sun location in pictures of cloudy and twilight skies inspired by Viking navigation

    NASA Astrophysics Data System (ADS)

    Barta, András; Horváth, Gábor; Benno Meyer-Rochow, Victor

    2005-06-01

    In the late 1960s it was hypothesized that Vikings had been able to navigate the open seas, even when the sun was occluded by clouds or below the sea horizon, by using the angle of polarization of skylight. To detect the direction of skylight polarization, they were thought to have made use of birefringent crystals, called "sunstones," and a large part of the scientific community still firmly believe that Vikings were capable of polarimetric navigation. However, there are some critics who treat the usefulness of skylight polarization for orientation under partly cloudy or twilight conditions with extreme skepticism. One of their counterarguments has been the assumption that solar positions or solar azimuth directions could be estimated quite accurately by the naked eye, even if the sun was behind clouds or below the sea horizon. Thus under partly cloudy or twilight conditions there might have been no serious need for a polarimetric method to determine the position of the sun. The aim of our study was to test quantitatively the validity of this qualitative counterargument. In our psychophysical laboratory experiments, test subjects were confronted with numerous 180° field-of-view color photographs of partly cloudy skies with the sun occluded by clouds or of twilight skies with the sun below the horizon. The task of the subjects was to guess the position or the azimuth direction of the invisible sun with the naked eye. We calculated means and standard deviations of the estimated solar positions and azimuth angles to characterize the accuracy of the visual sun location. Our data do not support the common belief that the invisible sun can be located quite accurately from the celestial brightness and/or color patterns under cloudy or twilight conditions. Although our results underestimate the accuracy of visual sun location by experienced Viking navigators, the mentioned counterargument cannot be taken seriously as a valid criticism of the theory of the alleged

  15. Psychophysical study of the visual sun location in pictures of cloudy and twilight skies inspired by Viking navigation.

    PubMed

    Barta, András; Horváth, Gábor; Meyer-Rochow, Victor Benno

    2005-06-01

    In the late 1960s it was hypothesized that Vikings had been able to navigate the open seas, even when the sun was occluded by clouds or below the sea horizon, by using the angle of polarization of skylight. To detect the direction of skylight polarization, they were thought to have made use of birefringent crystals, called "sun-stones," and a large part of the scientific community still firmly believe that Vikings were capable of polarimetric navigation. However, there are some critics who treat the usefulness of skylight polarization for orientation under partly cloudy or twilight conditions with extreme skepticism. One of their counterarguments has been the assumption that solar positions or solar azimuth directions could be estimated quite accurately by the naked eye, even if the sun was behind clouds or below the sea horizon. Thus under partly cloudy or twilight conditions there might have been no serious need for a polarimetric method to determine the position of the sun. The aim of our study was to test quantitatively the validity of this qualitative counterargument. In our psychophysical laboratory experiments, test subjects were confronted with numerous 180 degrees field-of-view color photographs of partly cloudy skies with the sun occluded by clouds or of twilight skies with the sun below the horizon. The task of the subjects was to guess the position or the azimuth direction of the invisible sun with the naked eye. We calculated means and standard deviations of the estimated solar positions and azimuth angles to characterize the accuracy of the visual sun location. Our data do not support the common belief that the invisible sun can be located quite accurately from the celestial brightness and/or color patterns under cloudy or twilight conditions. Although our results underestimate the accuracy of visual sun location by experienced Viking navigators, the mentioned counterargument cannot be taken seriously as a valid criticism of the theory of the alleged

  16. What a Difference a Day Makes: Estimating Daily Learning Gains during Kindergarten and First Grade Using a Natural Experiment

    ERIC Educational Resources Information Center

    Fitzpatrick, Maria D.; Grissmer, David; Hastedt, Sarah

    2011-01-01

    Knowing whether time spent in formal schooling increases student achievement, and by how much, is important for policymakers interested in determining efficient use of resources. Using the ECLS-K, we exploit quasi-randomness in the timing of assessment dates to examine this question. Conservative estimates suggest a year of school results in gains…

  17. An estimate of equatorial wave energy flux at 9- to 90-day periods in the Central Pacific

    NASA Technical Reports Server (NTRS)

    Eriksen, Charles C.; Richman, James G.

    1988-01-01

    Deep fluctuations in current along the equator in the Central Pacific are dominated by coherent structures which correspond closely to narrow-band propagating equatorial waves. Currents were measured roughly at 1500 and 3000 m depths at five moorings between 144 and 148 deg W from January 1981 to March 1983, as part of the Pacific Equatorial Ocean Dynamics program. In each frequency band resolved, a single complex empirical orthogonal function accounts for half to three quarters of the observed variance in either zonal or meridional current. Dispersion for equatorial first meridional Rossby and Rossby gravity waves is consistent with the observed vertical-zonal coherence structure. The observations indicate that energy flux is westward and downward in long first meridional mode Rossby waves at periods 45 days and longer, and eastward and downward in short first meridional mode Rossby waves and Rossby-gravity waves at periods 30 days and shorter. A local minimum in energy flux occurs at periods corresponding to a maximum in upper-ocean meridional current energy contributed by tropical instability waves. Total vertical flux across the 9- to 90-day period range is 2.5 kW/m.

  18. Retrieving Aerosol in a Cloudy Environment: Aerosol Availability as a Function of Spatial and Temporal Resolution

    NASA Technical Reports Server (NTRS)

    Remer, Lorraine A.; Mattoo, Shana; Levy, Robert C.; Heidinger, Andrew; Pierce, R. Bradley; Chin, Mian

    2011-01-01

    The challenge of using satellite observations to retrieve aerosol properties in a cloudy environment is to prevent contamination of the aerosol signal from clouds, while maintaining sufficient aerosol product yield to satisfy specific applications. We investigate aerosol retrieval availability at different instrument pixel resolutions, using the standard MODIS aerosol cloud mask applied to MODIS data and a new GOES-R cloud mask applied to GOES data for a domain covering North America and surrounding oceans. Aerosol availability is not the same as the cloud free fraction and takes into account the technqiues used in the MODIS algorithm to avoid clouds, reduce noise and maintain sufficient numbers of aerosol retrievals. The inherent spatial resolution of each instrument, 0.5x0.5 km for MODIS and 1x1 km for GOES, is systematically degraded to 1x1 km, 2x2 km, 4x4 km and 8x8 km resolutions and then analyzed as to how that degradation would affect the availability of an aerosol retrieval, assuming an aerosol product resolution at 8x8 km. The results show that as pixel size increases, availability decreases until at 8x8 km 70% to 85% of the retrievals available at 0.5 km have been lost. The diurnal pattern of aerosol retrieval availability examined for one day in the summer suggests that coarse resolution sensors (i.e., 4x4 km or 8x8 km) may be able to retrieve aerosol early in the morning that would otherwise be missed at the time of current polar orbiting satellites, but not the diurnal aerosol properties due to cloud cover developed during the day. In contrast finer resolution sensors (i.e., 1x1 km or 2x2 km) have much better opportunity to retrieve aerosols in the partly cloudy scenes and better chance of returning the diurnal aerosol properties. Large differences in the results of the two cloud masks designed for MODIS aerosol and GOES cloud products strongly reinforce that cloud masks must be developed with specific purposes in mind and that a generic cloud mask

  19. Variability of orographic cloudiness over the Western Ghats

    NASA Astrophysics Data System (ADS)

    Nair, U. S.; Ray, D. K.; Manoharan, V.

    2011-12-01

    Tropical Montane Cloud Forest (TMCF) ecosystems are characterized by frequent and prolonged immersion in orographic clouds. Topographical gradients and associated microclimatic variation leads to ecological niche differentiation and existence of unique species in such ecosystems. However, this also leads to TMCFs being sensitive to climate perturbations, especially those that alter orographic cloud formation. In this context, it is important to understand the variability of orographic cloudiness associated with TMCFs. Results from such an analysis conducted for Western Ghats, southwestern India is discussed. Note that this region is one of the 34 primary global biodiversity hotspots whose spatial extent has been considerably reduced due to land use pressure. Using remote sensing data from multiple satellites, cloud climatology is developed for Western Ghats and the following questions are addressed: (1) What are the diurnal and seasonal variations of orographic clouds?; (2) How does orographic cloud cover change as a function of large scale flow regimes?; (3) Where are TMCFs located and what is the variability of cloud immersion within these areas?. In addition, numerical simulation analysis will be used to address the impact of land cover and land use change on orographic cloud cover and precipitation over Western Ghats.

  20. The albedo of snow for partially cloudy skies

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.; Chang, A. T. C.

    1981-01-01

    The albedo of snow is defined as the ratio of reflected to incident solar energy, and it is an important parameter in the earth's radiation budget analysis and in the study of snowpack's thermal conditions. An approximate model for calculating the incident spectral flux for partially cloudy skies is presented. The input parameters for the calculation are atmospheric precipitable water, turbidity, ozone content, surface pressure, the optical thickness of clouds, and the grain size of snow crystals. The spectral snow reflectance model considers both specular surface reflection and volumetric multiple scattering. The surface reflection is calculated by using a crystal-shape-dependent bidirectional reflectance distribution function; the volumetric multiple scattering is calculated by using a crystal-size-dependent approximate solution in the radiative transfer equation. The model yields spectral and integrated solar flux and snow reflectance as a function of solar elevation and fractional cloud-cover. The illustrative insolation and albedo values were obtained from spectral reflectance and incident flux for representative parameters of Antarctic coastal regions. A simple relationship between grain size and the overcast albedo was obtained. For a set of grain size and shape, the albedo as a function of solar elevation and fractional cloud cover was tabulated.

  1. Laser Experiments with ARTEMIS Satellite in Cloudy Conditions

    NASA Astrophysics Data System (ADS)

    Kuzkov, Volodymyr; Sodnik, Zoran; Kuzkov, Sergii; Caramia, Vincenzo

    2014-05-01

    In July 2001, the ARTEMIS satellite with laser communication terminal OPALE on board was launched. 1789 laser communications sessions were performed between ARTEMIS and SPOT-4 (PASTEL) from 01 April 2003 to 09 January 2008 with total duration of 378 hours. In addition ESA's Optical Ground Station (OGS) performed laser communication experiments with OPALE in various atmospheric conditions. Since the launch of ARTEMIS, the amount of information handled by geostationary telecommunication satellites has increased dramatically and so has the demand for data rate that needs to be transmitted from ground. With limited bandwidth allocations in the radio frequency bands interest has grown for laser communication feeder link technology. In this respect there is interest to compare the influence of atmosphere conditions in different atmospheric regions with respect to laser transmission. Two locations are being compared, namely ESA's OGS (located in an altitude of 2400 m above sea level) and the Main Astronomical Observatory of Ukraine (MAO) (located at an altitude of 190 m above sea level). In 2002 MAO started the development of a ground laser communication system for the AZT-2 telescope. The MAO developed compact laser communication system is called LACES (Laser Atmosphere and Communication Experiments with Satellites) [1] and the work was supported by the National Space Agency of Ukraine and by ESA. The beacon laser from OPALE was occasionally detected even in cloudy conditions and an anomalous atmospheric refraction at low elevation angles was observed. The main results of laser experiments with ARTEMIS through clouds are presented in the paper.

  2. Preliminary Estimates of Loss of Juvenile Anadromous Salmonids to Predators in John Day Reservoir and Development of a Predation Model : Interim Report, 1986.

    SciTech Connect

    Rieman, Bruce E.

    1986-03-01

    We made preliminary estimates of the loss of juvenile salmonids to predation by walleye, Stizostedion v. vitreum, and northern squawfish, Ptychocheilus oregonensis, in John Day Reservoir in 1984 and 1985 using estimates of predator abundance and daily prey consumption rates. Preliminary estimates may be biased and may be adjusted as much as 30%, but indications are that predation could account for the majority of unexplained loss of juvenile salmonids in John Day Reservoir. Total loss was estimated at 4.1 million in 1984 and 3.3 million in 1985. Northern squawfish consumed 76% and 92% of these totals, respectively. The majority of loss occurred in mid reservoir areas, but loss in a small area, the boat-restricted zone immediately below McNary Dam, was disproportionately large. Peaks in loss in May and July corresponded with peaks in availability of salmonids. Estimated mortality from predation for April through June in 1984 and 1985 was 9% and 7% respectively, for chinook salmon, Oncorhynchus tshawytscha, and 10% and 15% for steelhead, Salmogairdneri. Mortality was variable with time but tended to increase over the period of migration. Mortality of chinook was estimated at 26% to 55% during July and August. A model of predation in John Day Reservoir is outlined. The model includes a predation submodel that can calculate loss from predator number and consumption rate; a population submodel that can relate predator abundance and population structure to recruitment, exploitation, natural mortality and growth; and a distribution submodel that can apportion predators among areas of the reservoir over time. Applications of the model are discussed for projecting expected changes in predation over time and identifying management alternatives that might limit the impact of predation.

  3. Estimation of ground heat flux from soil temperature over a bare soil

    NASA Astrophysics Data System (ADS)

    An, Kedong; Wang, Wenke; Wang, Zhoufeng; Zhao, Yaqian; Yang, Zeyuan; Chen, Li; Zhang, Zaiyong; Duan, Lei

    2016-05-01

    Ground soil heat flux, G 0, is a difficult-to-measure but important component of the surface energy budget. Over the past years, many methods were proposed to estimate G 0; however, the application of these methods was seldom validated and assessed under different weather conditions. In this study, three popular models (force-restore, conduction-convection, and harmonic) and one widely used method (plate calorimetric), which had well performance in publications, were investigated using field data to estimate daily G 0 on clear, cloudy, and rainy days, while the gradient calorimetric method was regarded as the reference for assessing the accuracy. The results showed that harmonic model was well reproducing the G 0 curve for clear days, but it yielded large errors on cloudy and rainy days. The force-restore model worked well only under rainfall condition, but it was poor to estimate G 0 under rain-free conditions. On the contrary, the conduction-convection model was acceptable to determine G 0 under rain-free conditions, but it generated large errors on rainfall days. More importantly, the plate calorimetric method was the best to estimate G 0 under different weather conditions compared with the three models, but the performance of this method is affected by the placement depth of the heat flux plate. As a result, the heat flux plate was recommended to be buried as close as possible to the surface under clear condition. But under cloudy and rainy conditions, the plate placed at depth of around 0.075 m yielded G 0 well. Overall, the findings of this paper provide guidelines to acquire more accurate estimation of G 0 under different weather conditions, which could improve the surface energy balance in field.

  4. Absorption of Sunlight in Clear and Cloudy Atmospheres: A Solution to the Cloud Absorption Anomaly

    NASA Technical Reports Server (NTRS)

    Crisp, D.

    1997-01-01

    To identify the origin of this mission absorption, a spectrum-resolving (line-by-line) multiple scattering model was used to derive solar radiances, fluxes, and heating rates for realistic clear and cloudy atmospheres.

  5. Dynamic Trip Attraction Estimation with Location Based Social Network Data Balancing Between Time of Day Variations and Zonal Differences

    NASA Astrophysics Data System (ADS)

    Hu, N. W.; Jin, P. J.

    2015-07-01

    The emergence of location based social network (LBSN) services make it accessible and affordable to study individuals' mobility patterns in a fine-grained level. Via mobile devices, LBSN enables the availability of large-scale location-sensitive data with spatial and temporal context dimensions, which is capable of the potential to provide traffic patterns with significantly higher spatial and temporal resolution at a much lower cost than can be achieved by traditional methods. In this paper, the Foursquare LBSN data was applied to analyze the trip attraction for the urban area in Austin, Texas, USA. We explore one time-dependent function to validate the LBSN's data with the origin-destination matrix regarded as the ground truth data. The objective of this paper is to investigate one new validation method for trip distribution. The results illustrate the promising potential of studying the dynamic trip attraction estimation with LBSN data for urban trip pattern analysis and monitoring.

  6. Discriminating between Cloudy, Hazy, and Clear Sky Exoplanets Using Refraction

    NASA Astrophysics Data System (ADS)

    Misra, Amit K.; Meadows, Victoria S.

    2014-11-01

    We propose a method to distinguish between cloudy, hazy, and clear sky (free of clouds and hazes) exoplanet atmospheres that could be applicable to upcoming large aperture space- and ground-based telescopes such as the James Webb Space Telescope (JWST) and the European Extremely Large Telescope (E-ELT). These facilities will be powerful tools for characterizing transiting exoplanets, but only after a considerable amount of telescope time is devoted to a single planet. A technique that could provide a relatively rapid means of identifying haze-free targets (which may be more valuable targets for characterization) could potentially increase the science return for these telescopes. Our proposed method utilizes broadband observations of refracted light in the out-of-transit spectrum. Light refracted through an exoplanet atmosphere can lead to an increase of flux prior to ingress and subsequent to egress. Because this light is transmitted at pressures greater than those for typical cloud and haze layers, the detection of refracted light could indicate a cloud- or haze-free atmosphere. A detection of refracted light could be accomplished in <10 hr for Jovian exoplanets with JWST and <5 hr for super-Earths/mini-Neptunes with E-ELT. We find that this technique is most effective for planets with equilibrium temperatures between 200 and 500 K, which may include potentially habitable planets. A detection of refracted light for a potentially habitable planet would strongly suggest the planet was free of a global cloud or haze layer, and therefore a promising candidate for follow-up observations.

  7. DISCRIMINATING BETWEEN CLOUDY, HAZY, AND CLEAR SKY EXOPLANETS USING REFRACTION

    SciTech Connect

    Misra, Amit K.; Meadows, Victoria S.

    2014-11-01

    We propose a method to distinguish between cloudy, hazy, and clear sky (free of clouds and hazes) exoplanet atmospheres that could be applicable to upcoming large aperture space- and ground-based telescopes such as the James Webb Space Telescope (JWST) and the European Extremely Large Telescope (E-ELT). These facilities will be powerful tools for characterizing transiting exoplanets, but only after a considerable amount of telescope time is devoted to a single planet. A technique that could provide a relatively rapid means of identifying haze-free targets (which may be more valuable targets for characterization) could potentially increase the science return for these telescopes. Our proposed method utilizes broadband observations of refracted light in the out-of-transit spectrum. Light refracted through an exoplanet atmosphere can lead to an increase of flux prior to ingress and subsequent to egress. Because this light is transmitted at pressures greater than those for typical cloud and haze layers, the detection of refracted light could indicate a cloud- or haze-free atmosphere. A detection of refracted light could be accomplished in <10 hr for Jovian exoplanets with JWST and <5 hr for super-Earths/mini-Neptunes with E-ELT. We find that this technique is most effective for planets with equilibrium temperatures between 200 and 500 K, which may include potentially habitable planets. A detection of refracted light for a potentially habitable planet would strongly suggest the planet was free of a global cloud or haze layer, and therefore a promising candidate for follow-up observations.

  8. Dependence of global radiation on cloudiness and surface albedo in Tartu, Estonia

    NASA Astrophysics Data System (ADS)

    Tooming, H.

    The dependence of global and diffuse radiation on surface albedo due to multiple reflection of radiation between the surface and the atmosphere (base of clouds) is found on the basis of data obtained at the Tartu-Tõravere Actinometric Station over the period 1955-2000. It is found that the monthly totals of global radiation increase by up to 1.38-1.88 times, particularly in the winter half-year between November and March, when snow cover albedo may be high. A semi-empirical formula is derived for calculating with sufficient accuracy the monthly totals of global radiation, considering the amount of cloudiness and the surface albedo. In the time series of the monthly total by global radiation a downward trend occurs in winter months. A decrease in global radiation by up to 20% in the past 46 years can be explained primarily by a relatively high negative trend in the snow cover duration and surface albedo (up to -0.24). As a result, days are growing darker, a new phenomenon associated with climate change, which undoubtedly affects human mood to some extent.

  9. Day to Day

    ERIC Educational Resources Information Center

    Jurecki, Dennis

    2006-01-01

    A clean, healthy and safe school provides students, faculty and staff with an environment conducive to learning and working. However, budget and staff reductions can lead to substandard cleaning practices and unsanitary conditions. Some school facility managers have been making the switch to a day-schedule to reduce security and energy costs, and…

  10. Estimating historical atmospheric mercury concentrations from silver mining and their legacies in present-day surface soil in Potosí, Bolivia

    NASA Astrophysics Data System (ADS)

    Hagan, Nicole; Robins, Nicholas; Hsu-Kim, Heileen; Halabi, Susan; Morris, Mark; Woodall, George; Zhang, Tong; Bacon, Allan; Richter, Daniel De B.; Vandenberg, John

    2011-12-01

    Detailed Spanish records of mercury use and silver production during the colonial period in Potosí, Bolivia were evaluated to estimate atmospheric emissions of mercury from silver smelting. Mercury was used in the silver production process in Potosí and nearly 32,000 metric tons of mercury were released to the environment. AERMOD was used in combination with the estimated emissions to approximate historical air concentrations of mercury from colonial mining operations during 1715, a year of relatively low silver production. Source characteristics were selected from archival documents, colonial maps and images of silver smelters in Potosí and a base case of input parameters was selected. Input parameters were varied to understand the sensitivity of the model to each parameter. Modeled maximum 1-h concentrations were most sensitive to stack height and diameter, whereas an index of community exposure was relatively insensitive to uncertainty in input parameters. Modeled 1-h and long-term concentrations were compared to inhalation reference values for elemental mercury vapor. Estimated 1-h maximum concentrations within 500 m of the silver smelters consistently exceeded present-day occupational inhalation reference values. Additionally, the entire community was estimated to have been exposed to levels of mercury vapor that exceed present-day acute inhalation reference values for the general public. Estimated long-term maximum concentrations of mercury were predicted to substantially exceed the EPA Reference Concentration for areas within 600 m of the silver smelters. A concentration gradient predicted by AERMOD was used to select soil sampling locations along transects in Potosí. Total mercury in soils ranged from 0.105 to 155 mg kg-1, among the highest levels reported for surface soils in the scientific literature. The correlation between estimated air concentrations and measured soil concentrations will guide future research to determine the extent to which the

  11. Drivers of Intra-Summer Seasonality and Daily Variability of Coastal Low Cloudiness in California Subregions

    NASA Astrophysics Data System (ADS)

    Schwartz, R. E.; Iacobellis, S.; Gershunov, A.; Williams, P.; Cayan, D. R.

    2014-12-01

    Summertime low cloud intrusion into the terrestrial west coast of North America impacts human, ecological, and logistical systems. Over a broad region of the West Coast, summer (May - September) coastal low cloudiness (CLC) varies coherently on interannual to interdecadal timescales and has been found to be organized by North Pacific sea surface temperature. Broad-scale studies of low stratiform cloudiness over ocean basins also find that the season of maximum low stratus corresponds to the season of maximum lower tropospheric stability (LTS) or estimated inversion strength. We utilize a 18-summer record of CLC derived from NASA/NOAA Geostationary Operational Environmental Satellite (GOES) at 4km resolution over California (CA) to make a more nuanced spatial and temporal examination of intra-summer variability in CLC and its drivers. We find that uniform spatial coherency over CA is not apparent for intra-summer variability in CLC. On monthly to daily timescales, at least two distinct subregions of coastal California (CA) can be identified, where relationships between meteorology and stratus variability appear to change throughout summer in each subregion. While north of Point Conception and offshore the timing of maximum CLC is closely coincident with maximum LTS, in the Southern CA Bight and northern Baja region, maximum CLC occurs up to about a month before maximum LTS. It appears that summertime CLC in this southern region is not as strongly related as in the northern region to LTS. In particular, although the relationship is strong in May and June, starting in July the daily relationship between LTS and CLC in the south begins to deteriorate. Preliminary results indicate a moderate association between decreased CLC in the south and increased precipitable water content above 850 hPa on daily time scales beginning in July. Relationships between daily CLC variability and meteorological variables including winds, inland temperatures, relative humidity, and

  12. Relationship between high daily erythemal UV doses, total ozone, surface albedo and cloudiness: An analysis of 30 years of data from Switzerland and Austria

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Staehelin, J.; Weihs, P.; Vuilleumier, L.; Maeder, J. A.; Holawe, F.; Blumthaler, M.; Lindfors, A.; Peter, T.; Simic, S.; Spichtinger, P.; Wagner, J. E.; Walker, D.; Ribatet, M.

    2010-10-01

    This work investigates the occurrence frequency of days with high erythemal UV doses at three stations in Switzerland and Austria (Davos, Hoher Sonnblick and Vienna) for the time period 1974-2003. While several earlier studies have reported on increases in erythemal UV dose up to 10% during the last decades, this study focuses on days with high erythemal UV dose, which is defined as a daily dose at least 15% higher than for 1950s clear-sky conditions (which represent preindustrial conditions with respect to anthropogenic chlorine). Furthermore, the influence of low column ozone, clear-sky/partly cloudy conditions and surface albedo on UV irradiance has been analyzed on annual and seasonal basis. The results of this study show that in the Central Alpine Region the number of days with high UV dose increased strongly in the early 1990s. A large fraction of all days with high UV dose occurring in the period 1974-2003 was found especially during the years 1994-2003, namely 40% at Davos, 54% at Hoher Sonnblick and 65% at Vienna. The importance of total ozone, clear-sky/partly cloudy conditions and surface albedo (e.g. in dependence of snow cover) varies strongly among the seasons. However, overall the interplay of low total ozone and clear-sky/partly cloudy conditions led to the largest fraction of days showing high erythemal UV dose. Furthermore, an analysis of the synoptic weather situation showed that days with high erythemal UV dose, low total ozone and high relative sunshine duration occur at all three stations more frequently during situations with low pressure gradients or southerly advection.

  13. Analysis of the magnitude and frequency of the 4-day annual low flow and regression equations for estimating the 4-day, 3-year low-flow frequency at ungaged sites on unregulated streams in New Mexico

    USGS Publications Warehouse

    Waltemeyer, Scott D.

    2002-01-01

    Two regression equations were developed for estimating the 4- day, 3-year (4Q3) low-flow frequency at ungaged sites on unregulated streams in New Mexico. The first, a statewide equation for estimating the 4Q3 low-flow frequency from drainage area and average basin mean winter precipitation, was developed from the data for 50 streamflow-gaging stations that had non-zero 4Q3 low-flow frequency. The 4Q3 low-flow frequency for the 50 gaging stations ranged from 0.08 to 18.7 cubic feet per second. For this statewide equation, the average standard error of estimate was 126 percent and the coefficient of determination was 0.48. The second, an equation for estimating the 4Q3 low-flow frequency in mountainous regions from drainage area, average basin mean winter precipitation, and average basin slope, was developed from the data for 40 gaging stations located above 7,500 feet in elevation. For this regression equation, the average standard error of estimate was 94 percent and the coefficient of determination was 0.66. A U.S. Geological Survey computer-program interface for a geographical information system (GIS), called the GIS Weasel, was used to determine basin and climatic characteristics for 84 gaging stations that were not affected by regulation. Mean monthly precipitation estimates from 1961 to 1990 were used in the GIS Weasel to compute the climatic characteristics of average basin winter precipitation and annual mean precipitation. The U.S. Geological Survey National Elevation Dataset, which currently consists of the 7.5-minute, 30-meter digital elevation model for each State, was used in the GIS Weasel to compute the basin characteristics of drainage area, average basin slope, average basin elevation, and average basin aspect. Basin and climatic characteristics that were statistically significant in the regression equation with the 4Q3 low-flow frequency were drainage area, which ranged from 1.62 to 5,900 square miles; average basin mean winter precipitation, which

  14. A Cloudiness Index for Transiting Exoplanets Based on the Sodium and Potassium Lines: Tentative Evidence for Hotter Atmospheres Being Less Cloudy at Visible Wavelengths

    NASA Astrophysics Data System (ADS)

    Heng, Kevin

    2016-07-01

    We present a dimensionless index that quantifies the degree of cloudiness of the atmosphere of a transiting exoplanet. Our cloudiness index is based on measuring the transit radii associated with the line center and wing of the sodium or potassium line. In deriving this index, we revisited the algebraic formulae for inferring the isothermal pressure scale height from transit measurements. We demonstrate that the formulae of Lecavelier et al. and Benneke & Seager are identical: the former is inferring the temperature while assuming a value for the mean molecular mass and the latter is inferring the mean molecular mass while assuming a value for the temperature. More importantly, these formulae cannot be used to distinguish between cloudy and cloud-free atmospheres. We derive values of our cloudiness index for a small sample of seven hot Saturns/Jupiters taken from Sing et al. We show that WASP-17b, WASP-31b, and HAT-P-1b are nearly cloud-free at visible wavelengths. We find the tentative trend that more irradiated atmospheres tend to have fewer clouds consisting of sub-micron-sized particles. We also derive absolute sodium and/or potassium abundances ˜102 cm‑3 for WASP-17b, WASP-31b, and HAT-P-1b (and upper limits for the other objects). Higher-resolution measurements of both the sodium and potassium lines, for a larger sample of exoplanetary atmospheres, are needed to confirm or refute this trend.

  15. A Cloudiness Index for Transiting Exoplanets Based on the Sodium and Potassium Lines: Tentative Evidence for Hotter Atmospheres Being Less Cloudy at Visible Wavelengths

    NASA Astrophysics Data System (ADS)

    Heng, Kevin

    2016-07-01

    We present a dimensionless index that quantifies the degree of cloudiness of the atmosphere of a transiting exoplanet. Our cloudiness index is based on measuring the transit radii associated with the line center and wing of the sodium or potassium line. In deriving this index, we revisited the algebraic formulae for inferring the isothermal pressure scale height from transit measurements. We demonstrate that the formulae of Lecavelier et al. and Benneke & Seager are identical: the former is inferring the temperature while assuming a value for the mean molecular mass and the latter is inferring the mean molecular mass while assuming a value for the temperature. More importantly, these formulae cannot be used to distinguish between cloudy and cloud-free atmospheres. We derive values of our cloudiness index for a small sample of seven hot Saturns/Jupiters taken from Sing et al. We show that WASP-17b, WASP-31b, and HAT-P-1b are nearly cloud-free at visible wavelengths. We find the tentative trend that more irradiated atmospheres tend to have fewer clouds consisting of sub-micron-sized particles. We also derive absolute sodium and/or potassium abundances ∼102 cm‑3 for WASP-17b, WASP-31b, and HAT-P-1b (and upper limits for the other objects). Higher-resolution measurements of both the sodium and potassium lines, for a larger sample of exoplanetary atmospheres, are needed to confirm or refute this trend.

  16. Cloudy - simulating the non-equilibrium microphysics of gas and dust, and its observed spectrum

    NASA Astrophysics Data System (ADS)

    Ferland, Gary J.

    2014-01-01

    Cloudy is an open-source plasma/spectral simulation code, last described in the open-access journal Revista Mexicana (Ferland et al. 2013, 2013RMxAA..49..137F). The project goal is a complete simulation of the microphysics of gas and dust over the full range of density, temperature, and ionization that we encounter in astrophysics, together with a prediction of the observed spectrum. Cloudy is one of the more widely used theory codes in astrophysics with roughly 200 papers citing its documentation each year. It is developed by graduate students, postdocs, and an international network of collaborators. Cloudy is freely available on the web at trac.nublado.org, the user community can post questions on http://groups.yahoo.com/neo/groups/cloudy_simulations/info, and summer schools are organized to learn more about Cloudy and its use (http://cloud9.pa.uky.edu gary/cloudy/CloudySummerSchool/). The code’s widespread use is possible because of extensive automatic testing. It is exercised over its full range of applicability whenever the source is changed. Changes in predicted quantities are automatically detected along with any newly introduced problems. The code is designed to be autonomous and self-aware. It generates a report at the end of a calculation that summarizes any problems encountered along with suggestions of potentially incorrect boundary conditions. This self-monitoring is a core feature since the code is now often used to generate large MPI grids of simulations, making it impossible for a user to verify each calculation by hand. I will describe some challenges in developing a large physics code, with its many interconnected physical processes, many at the frontier of research in atomic or molecular physics, all in an open environment.

  17. Validation of the Risk Estimator Decision aid for Atrial Fibrillation (RED-AF) for Predicting 30-Day Adverse Events in Emergency Department Patients With Atrial Fibrillation

    PubMed Central

    Barrett, Tyler W.; Jenkins, Cathy A.; Self, Wesley H.

    2014-01-01

    Objective Nearly 70% of emergency departments (ED) visits for atrial fibrillation (AF) result in hospitalization. The incidence of serious 30-day adverse events following an ED evaluation for AF remains low. This study’s goal was to prospectively validate our previously reported Risk Estimator Decision aid for AF (RED-AF) model for estimating a patient’s risk of experiencing a 30-day adverse event. Methods This was a prospective cohort study, which enrolled a convenience sample of ED patients presenting with AF. RED-AF, previously derived from a retrospective cohort of 832 patients, assigns points based on age, sex, coexisting disease (heart failure, hypertension, chronic obstructive pulmonary disease), smoking, home medications (beta blocker, diuretic), physical examination findings (dyspnea, palpitations, peripheral edema), and adequacy of ED ventricular rate control. Primary outcome was occurrence of ≥1 AF-related adverse outcome (ED visits, rehospitalization, cardiovascular complications, death) within 30 days. We identified a clinically relevant threshold and measured RED-AF’s performance in this prospective cohort, assessing its calibration, discrimination, and diagnostic accuracy. Results The study enrolled 497 patients between June 2010 and February 2013. Of these, 120 (24%) had ≥1 adverse event within 30 days. A RED-AF score of 87 was identified as an optimal threshold, resulting in sensitivity (95% CI) and specificity (95%CI) of 96% (91–98) and 19% (15–23), respectively. Positive and negative predictive values were 27% (23–32) and 93% (85–97), respectively. The c-statistic for RED-AF was 0.65 (95% CI, 0.59 to 0.71). Conclusion In this separate validation cohort, RED-AF performed moderately well and similar to the original derivation cohort for identifying the risk of short-term AF-related adverse events in ED patients diagnosed with AF. PMID:25245277

  18. Analysis of global cloudiness. 2: Comparison of ground-based and satellite-based cloud climatologies

    SciTech Connect

    Mokhov, I.I.; Schlesinger, M.E. |

    1994-08-01

    Cloud climatologies are developed and intercompared for International Satellite Cloud Climatology Project (ISCCO) (1983-1988), Meteor I (1971-1980), Meteor II (1979-1988), and Nimbus 7 (1979-1985) satellite observations, and for Berlyand and Strokina (1975, 1980) and Warren et al. (1986, 1988) ground-based observations. The satellite annual-mean, global- mean cloudiness, 0.57 +/- 0.05, is less than the ground-based value, 0.61 +/- 0.01, predominantly because of the low value for Nimbus 7. There is agreement between the satellite means of ISCCP, 0.62, and Meteor II, 0.61, and the ground-based means of Warren et al., 0.62, and Berlyand and Strokina, 0.60. Each satellite- and ground-based climatology shows that the hemispheric- mean cloudiness is larger in summer than that in winter in both the northern and southern hemispheres. Excluding Nimbus 7 observations, the zonal- mean cloudiness distributions for January, July, and July minus January display reasonably good agreement between 60 deg S and 60 deg N. In polar latitudes there is significant disagreement among the different climatologies, even in the sign of cloudiness changes from winter to summer. This evinces the need for special cloudiness experiments in polar regions, particularly in winter and summer.

  19. Estimating present day extreme water level exceedance probabilities around the coastline of Australia: tides, extra-tropical storm surges and mean sea level

    NASA Astrophysics Data System (ADS)

    Haigh, Ivan D.; Wijeratne, E. M. S.; MacPherson, Leigh R.; Pattiaratchi, Charitha B.; Mason, Matthew S.; Crompton, Ryan P.; George, Steve

    2014-01-01

    The occurrence of extreme water levels along low-lying, highly populated and/or developed coastlines can lead to considerable loss of life and billions of dollars of damage to coastal infrastructure. Therefore it is vitally important that the exceedance probabilities of extreme water levels are accurately evaluated to inform risk-based flood management, engineering and future land-use planning. This ensures the risk of catastrophic structural failures due to under-design or expensive wastes due to over-design are minimised. This paper estimates for the first time present day extreme water level exceedence probabilities around the whole coastline of Australia. A high-resolution depth averaged hydrodynamic model has been configured for the Australian continental shelf region and has been forced with tidal levels from a global tidal model and meteorological fields from a global reanalysis to generate a 61-year hindcast of water levels. Output from this model has been successfully validated against measurements from 30 tide gauge sites. At each numeric coastal grid point, extreme value distributions have been fitted to the derived time series of annual maxima and the several largest water levels each year to estimate exceedence probabilities. This provides a reliable estimate of water level probabilities around southern Australia; a region mainly impacted by extra-tropical cyclones. However, as the meteorological forcing used only weakly includes the effects of tropical cyclones, extreme water level probabilities are underestimated around the western, northern and north-eastern Australian coastline. In a companion paper we build on the work presented here and more accurately include tropical cyclone-induced surges in the estimation of extreme water level. The multi-decadal hindcast generated here has been used primarily to estimate extreme water level exceedance probabilities but could be used more widely in the future for a variety of other research and practical

  20. Estimating heat stress from climate-based indicators: present-day biases and future spreads in the CMIP5 global climate model ensemble

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Ducharne, A.; Sultan, B.; Braconnot, P.; Vautard, R.

    2015-08-01

    The increased exposure of human populations to heat stress is one of the likely consequences of global warming, and it has detrimental effects on health and labor capacity. Here, we consider the evolution of heat stress under climate change using 21 general circulation models (GCMs). Three heat stress indicators, based on both temperature and humidity conditions, are used to investigate present-day model biases and spreads in future climate projections. Present day estimates of heat stress indicators from observational data shows that humid tropical areas tend to experience more frequent heat stress than other regions do, with a total frequency of heat stress 250-300 d yr-1. The most severe heat stress is found in the Sahel and south India. Present-day GCM simulations tend to underestimate heat stress over the tropics due to dry and cold model biases. The model based estimates are in better agreement with observation in mid to high latitudes, but this is due to compensating errors in humidity and temperature. The severity of heat stress is projected to increase by the end of the century under climate change scenario RCP8.5, reaching unprecedented levels in some regions compared with observations. An analysis of the different factors contributing to the total spread of projected heat stress shows that spread is primarily driven by the choice of GCMs rather than the choice of indicators, even when the simulated indicators are bias-corrected. This supports the utility of the multi-model ensemble approach to assess the impacts of climate change on heat stress.

  1. Earth radiation budget and cloudiness simulations with a general circulation model

    NASA Technical Reports Server (NTRS)

    HARSHVARDHAN; Randall, David A.; Corsetti, Thomas G.; Dazlich, Donald A.

    1989-01-01

    A GCM with new parameterizations of solar and terrestrial radiation, parameterized cloud optical properties, and a simple representation of the cloud liquid water feedback is used with several observational data sets to analyze the effects of cloudiness on the earth's radiation budget. The January and July results from the model are in reasonable agreement with data from Nimbus-7. It is found that the simulated cloudiness overpredicts subtropical and midlatitude cloudiness. The simulated atmospheric cloud radiative forcing is examined. The clear-sky radiation fields obtained by two methods of Cess and Potter (1987) are compared. Also, a numerical experiment was performed to determine the effects of the water vapor continuum on the model results.

  2. Analysis of a resistance-energy balance method for estimating daily evaporation from wheat plots using one-time-of-day infrared temperature observations

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.; Idso, S. B.; Reginato, R. J.

    1986-01-01

    Accurate estimates of evaporation over field-scale or larger areas are needed in hydrologic studies, irrigation scheduling, and meteorology. Remotely sensed surface temperature might be used in a model to calculate evaporation. A resistance-energy balance model, which combines an energy balance equation, the Penman-Monteith (1981) evaporation equation, and van den Honert's (1948) equation for water extraction by plant roots, is analyzed for estimating daily evaporation from wheat using postnoon canopy temperature measurements. Additional data requirements are half-hourly averages of solar radiation, air and dew point temperatures, and wind speed, along with reasonable estimates of canopy emissivity, albedo, height, and leaf area index. Evaporation fluxes were measured in the field by precision weighing lysimeters for well-watered and water-stressed wheat. Errors in computed daily evaporation were generally less than 10 percent, while errors in cumulative evaporation for 10 clear sky days were less than 5 percent for both well-watered and water-stressed wheat. Some results from sensitivity analysis of the model are also given.

  3. Estimation of daily average net radiation from MODIS data and DEM over the Baiyangdian watershed in North China for clear sky days

    NASA Astrophysics Data System (ADS)

    Long, Di; Gao, Yanchun; Singh, Vijay P.

    2010-07-01

    SummaryDaily average net radiation (DANR) is a critical variable for estimation of daily evapotranspiration (ET) from remote sensing techniques at watershed or regional scales, and in turn for hydrological modeling and water resources management. This study attempts to comprehensively analyze physical mechanisms governing the variation of each component of DANR during a day, with the objective to improve parameterization schemes for daily average net shortwave radiation (DANSR) and daily average net longwave radiation (DANLR) using MODIS (MODerate Resolution Imaging Spectroradiometer) data products, DEM, and minimum meteorological data in order to map spatially consistent and reasonably distributed DANR at watershed scales for clear sky days. First, a geometric model for simulating daily average direct solar radiation by accounting for the effects of terrain factors (slope, azimuth and elevation) on the availability of direct solar radiation for sloping land surfaces is adopted. Specifically, the magnitudes of sunrise and sunset angles, the frequencies of a sloping surface being illuminated as well as the potential sunshine duration for a given sloping surface are computed on a daily basis. The geometric model is applied to the Baiyangdian watershed in North China, with showing the capability to distinctly characterize the spatial pattern of daily average direct solar radiation for sloping land surfaces. DANSR can then be successfully derived from simulated daily average direct solar radiation by means of the geometric model and the characteristics of nearly invariant diffuse solar radiation during daytime in conjunction with MCD43A1 albedo products. Second, four observations of Terra-MODIS and Aqua-MODIS land surface temperature (LST) and surface emissivities in band 31 and band 32 from MOD11A1, MYD11A1 and MOD11_L2 data products for six clear sky days from April to September in the year 2007, are utilized to simulate daily average LST to improve the accuracy of

  4. Prediction of high spatio-temporal resolution land surface temperature under cloudy conditions using microwave vegetation index and ANN

    NASA Astrophysics Data System (ADS)

    Shwetha, H. R.; Kumar, D. Nagesh

    2016-07-01

    limits. Under cloudy conditions, results of microwave derived LST were evaluated with air temperature (Ta) and indicate that the approach performed well with RMSE values lesser than the results obtained under clear sky conditions for land cover classes for both day and nighttimes.

  5. Parameterization of cloudiness as a function of temperature for use in a thermodynamic model

    SciTech Connect

    Garduno, R.; Adem, J.

    1993-06-01

    Based on a parameterization by Adem (1967), the authors developed a formula of balance among the horizontal fraction of cloudiness and the vertical profiles of temperature and relative humidity, in which the authors now apply the usual hypothesis that the atmospheric relative humidity remains fixed in a climate change. The result is a negative correlation between the increments of cloudiness and temperature. The authors have incorporated this negative feedback mechanism in the Adem thermodynamic model and used it in the computation of climate change due to the atmospheric CO[sub 2] increase.

  6. Radiative Susceptibility of Cloudy Atmospheres to Droplet Number Perturbations: 1. Theoretical Analysis and Examples from MODIS

    NASA Technical Reports Server (NTRS)

    Platnick, Steven; Oreopoulos, Lazaros

    2008-01-01

    Theoretical and satellite-based assessments of the sensitivity of broadband shortwave radiative fluxes in cloudy atmospheres to small perturbations in the cloud droplet number concentration (N) of liquid water clouds under constant water conditions are performed. Two approaches to study this sensitivity are adopted: absolute increases in N, for which the radiative response is referred to as absolute cloud susceptibility, and relative increases in N or relative cloud susceptibility. Estimating the former is more challenging as it requires an assumed value for either cloud liquid water content or geometrical thickness; both susceptibilities require an assumed relationship between the droplet volume and effective radius. Expanding upon previous susceptibility studies, present radiative calculations include the effect of AN perturbations on droplet asymmetry parameter and single-scattering albedo, in addition to extinction. Absolute cloud susceptibility has a strong nonlinear dependence on the droplet effective radius as expected, while relative cloud susceptibility is primarily dependent on optical thickness. Molecular absorption and reflecting surfaces both reduce the relative contribution of the cloud to the top-of-atmosphere (TOA) flux and therefore also reduce the TOA albedo susceptibility. Transmittance susceptibilities are negative with absolute values similar to albedo susceptibility, while atmospheric absorptance susceptibilities are about an order of magnitude smaller than albedo susceptibilities and can be either positive or negative. Observation-based susceptibility calculations are derived from MODIS pixel-level retrievals of liquid water cloud optical thickness, effective radius, and cloud top temperature; two data granule examples are shown. Susceptibility quantifies the aerosol indirect effect sensitivity in a way that can be easily computed from model fields. As such, susceptibilities derived from MODIS observations provide a higher-order test of model

  7. Online Dietary Intake Estimation: Reproducibility and Validity of the Food4Me Food Frequency Questionnaire Against a 4-Day Weighed Food Record

    PubMed Central

    Fallaize, Rosalind; Forster, Hannah; Macready, Anna L; Walsh, Marianne C; Mathers, John C; Brennan, Lorraine; Gibney, Eileen R; Gibney, Michael J

    2014-01-01

    Background Advances in nutritional assessment are continuing to embrace developments in computer technology. The online Food4Me food frequency questionnaire (FFQ) was created as an electronic system for the collection of nutrient intake data. To ensure its accuracy in assessing both nutrient and food group intake, further validation against data obtained using a reliable, but independent, instrument and assessment of its reproducibility are required. Objective The aim was to assess the reproducibility and validity of the Food4Me FFQ against a 4-day weighed food record (WFR). Methods Reproducibility of the Food4Me FFQ was assessed using test-retest methodology by asking participants to complete the FFQ on 2 occasions 4 weeks apart. To assess the validity of the Food4Me FFQ against the 4-day WFR, half the participants were also asked to complete a 4-day WFR 1 week after the first administration of the Food4Me FFQ. Level of agreement between nutrient and food group intakes estimated by the repeated Food4Me FFQ and the Food4Me FFQ and 4-day WFR were evaluated using Bland-Altman methodology and classification into quartiles of daily intake. Crude unadjusted correlation coefficients were also calculated for nutrient and food group intakes. Results In total, 100 people participated in the assessment of reproducibility (mean age 32, SD 12 years), and 49 of these (mean age 27, SD 8 years) also took part in the assessment of validity. Crude unadjusted correlations for repeated Food4Me FFQ ranged from .65 (vitamin D) to .90 (alcohol). The mean cross-classification into “exact agreement plus adjacent” was 92% for both nutrient and food group intakes, and Bland-Altman plots showed good agreement for energy-adjusted macronutrient intakes. Agreement between the Food4Me FFQ and 4-day WFR varied, with crude unadjusted correlations ranging from .23 (vitamin D) to .65 (protein, % total energy) for nutrient intakes and .11 (soups, sauces and miscellaneous foods) to .73 (yogurts

  8. The behavior of trade-wind cloudiness in observations and models: The major cloud components and their variability

    NASA Astrophysics Data System (ADS)

    Nuijens, Louise; Medeiros, Brian; Sandu, Irina; Ahlgrimm, Maike

    2015-06-01

    Guided by ground-based radar and lidar profiling at the Barbados Cloud Observatory (BCO), this study evaluates trade-wind cloudiness in ECMWF's Integrated Forecast System (IFS) and nine CMIP5 models using their single-timestep output at selected grid points. The observed profile of cloudiness is relatively evenly distributed between two important height levels: the lifting condensation level (LCL) and the tops of the deepest cumuli near the trade-wind inversion (2-3 km). Cloudiness at the LCL dominates the total cloud cover, but is relatively invariant. Variance in cloudiness instead peaks at the inversion. The IFS reproduces the depth of the cloud field and its variability, but underestimates cloudiness at the LCL and the inversion. A few CMIP5 models produce a single stratocumulus-like layer near the LCL, but more than half of the CMIP5 models reproduce the observed cloud layer depth in long-term mean profiles. At single-time steps, however, half of the models do not produce cloudiness near cloud tops along with the (almost ever-present) cloudiness near the LCL. In seven models, cloudiness is zero at both levels 10 to 65% of the time, compared to 3% in the observations. Models therefore tend to overestimate variance in cloudiness near the LCL. This variance is associated with longer time scales than in observations, which suggests that modeled cloudiness is too sensitive to large-scale processes. To conclude, many models do not appear to capture the processes that underlie changes in cloudiness, which is relevant for cloud feedbacks and climate prediction.

  9. Methods for Cloud Cover Estimation

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Several methods for cloud cover estimation are described relevant to assessing the performance of a ground-based network of solar observatories. The methods rely on ground and satellite data sources and provide meteorological or climatological information. One means of acquiring long-term observations of solar oscillations is the establishment of a ground-based network of solar observatories. Criteria for station site selection are: gross cloudiness, accurate transparency information, and seeing. Alternative methods for computing this duty cycle are discussed. The cycle, or alternatively a time history of solar visibility from the network, can then be input to a model to determine the effect of duty cycle on derived solar seismology parameters. Cloudiness from space is studied to examine various means by which the duty cycle might be computed. Cloudiness, and to some extent transparency, can potentially be estimated from satellite data.

  10. Estimation of minimum 7-day, 2-year discharge for selected stream sites, and associated low-flow water-quality data, southeast Texas, 1997-98

    USGS Publications Warehouse

    East, Jeffery W.

    1999-01-01

    The U.S. Geological Survey (USGS) operates a network of streamflow-gaging stations in Texas that provides discharge data used for water-management decisions and various other purposes. Operating stations at all locations where discharge data are needed is not feasible, but the statistical characteristics of the network station data can be used to estimate discharge characteristics at ungaged sites. Regionalization techniques such as regression analyses relate discharge-frequency characteristics to selected physical and climatic characteristics of drainage basins. A particular discharge-frequency characteristic that can be regionalized is the minimum 7-day, 2-year discharge1 (7Q2). In Texas, the 7Q2 is used at stream sites to analyze permit applications for water allocation, water-supply planning, aquatic maintenance (instream flow) requirements, and waste-load allocation for point and nonpoint source discharges.

  11. A new database of cloudiness for Italy from instrumental time series since the late 19th century

    NASA Astrophysics Data System (ADS)

    Manara, Veronica; Brunetti, Michele; Maugeri, Maurizio; Sanchez-Lorenzo, Arturo

    2015-04-01

    Italy has a very important role in the development of meteorological observations. Consequently, a heritage of data of enormous value has been accumulated in Italy over the last three centuries. However, only a small fraction of Italian data is available in computer readable form and the available records mainly concern temperature, precipitation and pressure. Within this context, we set up a project to recover as much as possible cloudiness Italian records. The goal is to consider total cloud cover (TCC), low and middle cloud cover, and cloud types. The data source we are using include the former national central office for meteorology (now CRA-CMA), the national air force meteorological and climatological service and some of the oldest Italian observatories as Milan, Rome, Turin and Venice. The database contains sub-daily (from 3 to 8 observations per day for each station) information about TCC but also about the amount and the type of low, middle and high cloud in the sky. The oldest records start at about 1858 and about 30 records start in the 1880s. Currently quality check and test for temporal homogeneity is in progress. Then the monthly records will be completed by means of the neighboring records and averaged in order to get national and regional records for Italy and its main climatic areas. This new dataset will be presented and the results of the first analyses will be discussed. The study of cloudiness records for Italy is important also to better understand the behavior of sunshine duration, which shows a rather peculiar behaviour, especially in northern Italy. In this area, in fact, we observe a statistically significant increasing tendency during the period 1936-2103, that most publications do not report, as a consequence of a strong increase starting from the 1980 and a less evident decrease in the previous period.

  12. Changes in Cirrus Cloudiness and their Relationship to Contrails

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Ayers, J. Kirk; Palikonda, Rabindra; Doelling, David R.; Schumann, Ulrich; Gierens, Klaus

    2001-01-01

    Condensation trails, or contrails, formed in the wake of high-altitude aircraft have long been suspected of causing the formation of additional cirrus cloud cover. More cirrus is possible because 10 - 20% of the atmosphere at typical commercial flight altitudes is clear but ice-saturated. Since they can affect the radiation budget like natural cirrus clouds of equivalent optical depth and microphysical properties, contrail -generated cirrus clouds are another potential source of anthropogenic influence on climate. Initial estimates of contrail radiative forcing (CRF) were based on linear contrail coverage and optical depths derived from a limited number of satellite observations. Assuming that such estimates are accurate, they can be considered as the minimum possible CRF because contrails often develop into cirrus clouds unrecognizable as contrails. These anthropogenic cirrus are not likely to be identified as contrails from satellites and would, therefore, not contribute to estimates of contrail coverage. The mean lifetime and coverage of spreading contrails relative to linear contrails are needed to fully assess the climatic effect of contrails, but are difficult to measure directly. However, the maximum possible impact can be estimated using the relative trends in cirrus coverage over regions with and without air traffic. In this paper, the upper bound of CRF is derived by first computing the change in cirrus coverage over areas with heavy air traffic relative to that over the remainder of the globe assuming that the difference between the two trends is due solely to contrails. This difference is normalized to the corresponding linear contrail coverage for the same regions to obtain an average spreading factor. The maximum contrail-cirrus coverage, estimated as the product of the spreading factor and the linear contrail coverage, is then used in the radiative model to estimate the maximum potential CRF for current air traffic.

  13. The use of partial cloudiness in a warm-rain parameterization: A subgrid-scale precipitation scheme

    SciTech Connect

    Bechtold, P.; Pinty, J.P.; Mascart, P.

    1993-12-01

    A method is proposed on how to handle the effects of partial cloudiness in a warm-rain microphysical scheme and how to generate subgrid-scale precipitation. The method is simple and concerns essentially two ideas: The use of the vertical distribution of the partial cloudiness and the use of environmental and cloud-scale values for the thermodynamic variables instead of their grid-mean values. It applies to any microphysical scheme. The method has been applied to a warm-rain parameterization scheme that has been implemented in a mesoscale model using a statistical partial cloudiness scheme. Numerical tests have been done for two one-dimensional cases of boundary-layer cloudiness: A cumulus case and a case of a decoupled stratocumulus layer. The results show that the correct coupling of a partial cloudiness scheme and a microphysical scheme allows for a better description of the actual cloudiness and precipitation fields by ensuring a consistent computation of partial cloudiness, cloud water, and rainwater in partly cloudy regions. 20 refs., 14 figs.

  14. Effects of cloudy/clear air mixing and droplet pH on sulfate aerosol formation in a coupled chemistry/climate global model

    SciTech Connect

    Molenkamp, C.R.; Atherton, C.A.; Penner, J.E.; Walton, J.J.

    1996-10-01

    In this paper we will briefly describe our coupled ECHAM/GRANTOUR model, provide a detailed description of our atmospheric chemistry parameterizations, and discuss a couple of numerical experiments in which we explore the influence of assumed pH and rate of mixing between cloudy and clear air on aqueous sulfate formation and concentration. We have used our tropospheric chemistry and transport model, GRANTOUR, to estimate the life cycle and global distributions of many trace species. Recently, we have coupled GRANTOUR with the ECHAM global climate model, which provides several enhanced capabilities in the representation of aerosol interactions.

  15. Employment from Solar Energy: A Bright but Partly Cloudy Future.

    ERIC Educational Resources Information Center

    Smeltzer, K. K.; Santini, D. J.

    A comparison of quantitative and qualitative employment effects of solar and conventional systems can prove the increased employment postulated as one of the significant secondary benefits of a shift from conventional to solar energy use. Current quantitative employment estimates show solar technology-induced employment to be generally greater…

  16. Fluid and mineral inclusions in cloudy diamonds from Koffiefontein, South Africa

    NASA Astrophysics Data System (ADS)

    Izraeli, Elad S.; Harris, Jeffrey W.; Navon, Oded

    2004-06-01

    Silicates, carbonates and brine were detected in microinclusions in cloudy diamonds from Koffiefontein. The silicates belong to either the eclogitic or the peridotitic paragenesis. They are similar in composition to the larger mineral inclusions found in other Koffiefontein diamonds and record similar pressures and temperatures of formation (1000-1200°C, 4-6 GPa). The clouds also carry additional mineral phases that were not detected before in Koffiefontein: phlogopite, high-Si mica, an Al-Mg-rich phase and carbonates. In many cases silicate minerals coexist together with brine in individual microinclusions. Brines associated with either eclogitic or peridotitic minerals have similar composition and both are rich in water, Cl, K and carbonates ( Izraeli et al., 2001). The above findings, together with the high proportion of cloudy diamonds in Koffiefontein, suggest that brine penetration into neighboring peridotitic and eclogitic rocks was pervasive. The high carbon content of the brine (as dissolved carbonates) initiated diamond growth in both rock types, most, on preexisting diamonds that now form inclusion-free cores. The low aggregation state of nitrogen in the cloudy diamonds, relative to other diamonds from Koffiefontein indicates either a somewhat lower temperature of storage in the mantle (which may be the reason for the presence of brine rather than melt) or a young event of cloudy diamond formation.

  17. On the Analysis of the Climatology of Cloudiness of the Arabian Peninsula

    NASA Astrophysics Data System (ADS)

    Yousef, L. A.; Temimi, M.

    2015-12-01

    This study aims to determine the climatology of cloudiness over the Arabian Peninsula. The determined climatology will assist solar energy resource assessment in the region. The seasonality of cloudiness and its spatial variability will also help guide several cloud seeding operational experiments in the region. Cloud properties from the International Satellite Cloud Climatology Project (ISCCP) database covering the time period from 1983 through 2009 are analyzed. Time series of low, medium, high, and total cloud amounts are investigated, in addition to cloud optical depth and total column water vapor. Initial results show significant decreasing trends in the total and middle cloud amounts, both annually and seasonally, at a 95% confidence interval. The relationship between cloud amounts and climate oscillations known to affect the region is explored. Climate indices exhibiting significant correlations with the total cloud amounts include the Pacific Decadal Oscillation (PDO) index. The study also includes a focus on the United Arab Emirates (UAE), comparing the inferred cloudiness data to in situ rainfall measurements taken from rain gauges across the UAE. To assess the impact of cloudiness on solar power resources in the country, time series of cloud amounts and Direct Normal Irradiance (DNI), obtained from the UAE Solar Atlas, are compared.

  18. Local effects of partly cloudy skies on solar and emitted radiations

    NASA Technical Reports Server (NTRS)

    Whitney, D. A.; Venable, D. D.

    1981-01-01

    Solar radiation measurements are made on a routine basis. Global solar, atmospheric emitted, downwelled diffuse solar, and direct solar radiation measurement systems are fully operational with the first two in continuous operation. Fractional cloud cover measurements are made from GOES imagery or from ground based whole sky photographs. Normalized global solar irradiance values for partly cloudy skies were correlated to fractional cloud cover.

  19. Operational data fusion framework for building frequent Landsat-like imagery in a cloudy region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An operational data fusion framework is built to generate dense time-series Landsat-like images for a cloudy region by fusing Moderate Resolution Imaging Spectroradiometer (MODIS) data products and Landsat imagery. The Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) is integrated in ...

  20. Towards the automatic identification of cloudiness condition by means of solar global irradiance measurements

    NASA Astrophysics Data System (ADS)

    Sanchez, G.; Serrano, A.; Cancillo, M. L.

    2010-09-01

    This study focuses on the design of an automatic algorithm for classification of the cloudiness condition based only on global irradiance measurements. Clouds are a major modulating factor for the Earth radiation budget. They attenuate the solar radiation and control the terrestrial radiation participating in the energy balance. Generally, cloudiness is a limiting factor for the solar radiation reaching the ground, highly contributing to the Earth albedo. Additionally it is the main responsible for the high variability shown by the downward irradiance measured at ground level. Being a major source for the attenuation and high-frequency variability of the solar radiation available for energy purposes in solar power plants, the characterization of the cloudiness condition is of great interest. This importance is even higher in Southern Europe, where very high irradiation values are reached during long periods within the year. Thus, several indexes have been proposed in the literature for the characterization of the cloudiness condition of the sky. Among these indexes, those exclusively involving global irradiance are of special interest since this variable is the most widely available measurement in most radiometric stations. Taking this into account, this study proposes an automatic algorithm for classifying the cloudiness condition of the sky into three categories: cloud-free, partially cloudy and overcast. For that aim, solar global irradiance was measured by Kipp&Zonen CMP11 pyranometer installed on the terrace of the Physics building in the Campus of Badajoz (Spain) of the University of Extremadura. Measurements were recorded at one-minute basis for a period of study extending from 23 November 2009 to 31 March 2010. The algorithm is based on the clearness index kt, which is calculated as the ratio between the solar global downward irradiance measured at ground and the solar downward irradiance at the top of the atmosphere. Since partially cloudy conditions

  1. Using microwave observations to estimate land surface temperature during cloudy conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST), a key ingredient for physically-based retrieval algorithms of hydrological states and fluxes, remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observations and...

  2. Properties of marine stratocumulus obtained with partly cloudy pixel retrievals and found in the MODIS MOD06 cloud product

    NASA Astrophysics Data System (ADS)

    Boeke, Robyn C.; Allan, Andrea M.; Coakley, James A.

    2016-06-01

    Partly cloudy pixel retrievals (PCPRs) of cloud properties for marine stratocumulus were compared with those of the 1 km Moderate Resolution Imaging Spectroradiometer (MODIS) cloud product (MOD06). In addition, the fractional cloud cover obtained from the PCPRs applied to 1 km MODIS radiances was compared with that derived from the 250 m cloud mask (MOD35). The comparisons were made for pixels that were overcast and pixels that were only partially covered by clouds. Accounting for failed retrievals in both the MOD06 cloud properties and those obtained with the PCPRs leads to the suggestion that regional cloud cover be estimated in terms of lower and upper limits. The average could serve as the best estimate of the cloud cover, and the difference between the average and an extreme could serve as the uncertainty. The comparisons reveal that the overcast assumption used in the MODIS cloud property retrievals leads to cloud cover, droplet effective radii, and cloud top temperatures that are overestimated and, shortwave optical depths, liquid water paths that are underestimated. These biases persist when the properties are averaged to form spatial and temporal means. Owing to significant horizontal variations of cloud liquid water within the 1 km MODIS pixels, visible optical depths, droplet effective radii, and liquid water paths derived from the PCPRs show similar biases. The trends of the biases with pixel-scale and regional-scale cloud cover suggest that estimates of the aerosol indirect radiative forcing derived from satellites have been overestimated.

  3. Application of remote sensing in estimating evapotranspiration in the Platte river basin

    NASA Technical Reports Server (NTRS)

    Blad, B. L.; Rosenberg, N. J.

    1976-01-01

    A 'resistance model' and a mass transport model for estimating evapotranspiration (ET) were tested on large fields of naturally subirrigated alfalfa. Both models make use of crop canopy temperature data. Temperature data were obtained with an IR thermometer and with leaf thermocouples. A Bowen ratio-energy balance (BREB) model, adjusted to account for underestimation of ET during periods of strong sensible heat advection, was used as the standard against which the resistance and mass transport models were compared. Daily estimates by the resistance model were within 10% of estimates made by the BREB model. Daily estimates by the mass transport model did not agree quite as well. Performance was good on clear and cloudy days and also during periods of non-advection and strong advection of sensible heat. The performance of the mass transport and resistance models was less satisfactory for estimation of fluxes of latent heat for short term periods. Both models tended to overestimate at low LE fluxes.

  4. Kindergarten: All Day Every Day?

    ERIC Educational Resources Information Center

    Oelerich, Marjorie L.

    This paper reports findings that all-day every-day educational programs have positive effects on kindergarten children. Also included is a Minnesota Association for Childhood Education (MACE) position paper which advocates the provision of full-day kindergarten programs and details seven criteria that a quality full-day program must meet. Efforts…

  5. Estimation of seasonal and annual acidic deposition through aggregation of three-day episodic periods. Report for February 1989-1991

    SciTech Connect

    Samson, P.J.; Brook, J.R.; Sillman, S.

    1990-08-01

    A method for aggregating episodic deposition estimates has been developed and used to identify which meteorological situations merit simulation by RADM based on their likelihood of producing sulfate (SO4(-2)) wet deposition at multiple locations across eastern North America, their frequency of occurrence, and their seasonality. The aggregation technique has been performed using four years (1982 - 1985) of precipitation chemistry data from the Utility Acid Precipitation Sampling Program (UAPSP). The method developed during the project improves upon random selection. It is based on the stratification of three-day periods into categories of similar 850 mb wind flow across eastern North America. The aggregation project has provided the RADM project with a list of simulation periods which represent the range of meteorological patterns over eastern North America. The selection of storm types was based on their likelihood of producing SO4(-2) wet deposition at multiple locations across eastern North America, their frequency of occurrence, and their seasonality. The project has also provided the RADM project with scaling factors for use in weighing episodic simulation results to seasonal and annual deposition.

  6. An Improved Method for Estimating Aerosol Optical Thickness from Artificial Light Sources Observed by the Visible/Infrared Imaging Radiometer Suite Day/Night Band

    NASA Astrophysics Data System (ADS)

    McHardy, Theodore Mitchell

    Using Visible/Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) data, a method, dubbed the "variance method", is developed for retrieving nighttime aerosol optical thickness (AOT) values based on the dispersion of radiance values above an artificial light source. An improvement of a previous algorithm, this updated method derives a semi-quantitative indicator of nighttime AOT using artificial light sources. Nighttime AOT retrievals from the newly developed method are inter-compared with an interpolated value from late afternoon and early morning ground observations from four AErosol RObotic NETwork (AERONET) sites as well as column-integrated Aerosol Optical Depth (AOD) from one High Spectral Resolution LiDAR (HSRL) site at Huntsville, AL during the NASA Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign, providing full diel coverage. This method does not account for lunar reflectance from either the surface or the aerosol layer. Sensitivity tests do no indicate large systematic or random errors associated with lunar illumination. VIIRS AOT retrievals yield a coefficient of determination (r2) of 0.60 and a root-mean-squared-error (RMSE) of 0.18 when compared against straddling daytime-averaged AERONET AOT values. Preliminary results suggest that artificial light sources can be used for estimating regional and global nighttime aerosol distributions in the future.

  7. Regression equations to estimate seasonal flow duration, n-day high-flow frequency, and n-day low-flow frequency at sites in North Dakota using data through water year 2009

    USGS Publications Warehouse

    Williams-Sether, Tara; Gross, Tara A.

    2016-01-01

    Seasonal mean daily flow data from 119 U.S. Geological Survey streamflow-gaging stations in North Dakota; the surrounding states of Montana, Minnesota, and South Dakota; and the Canadian provinces of Manitoba and Saskatchewan with 10 or more years of unregulated flow record were used to develop regression equations for flow duration, n-day high flow and n-day low flow using ordinary least-squares and Tobit regression techniques. Regression equations were developed for seasonal flow durations at the 10th, 25th, 50th, 75th, and 90th percent exceedances; the 1-, 7-, and 30-day seasonal mean high flows for the 10-, 25-, and 50-year recurrence intervals; and the 1-, 7-, and 30-day seasonal mean low flows for the 2-, 5-, and 10-year recurrence intervals. Basin and climatic characteristics determined to be significant explanatory variables in one or more regression equations included drainage area, percentage of basin drainage area that drains to isolated lakes and ponds, ruggedness number, stream length, basin compactness ratio, minimum basin elevation, precipitation, slope ratio, stream slope, and soil permeability. The adjusted coefficient of determination for the n-day high-flow regression equations ranged from 55.87 to 94.53 percent. The Chi2 values for the duration regression equations ranged from 13.49 to 117.94, whereas the Chi2 values for the n-day low-flow regression equations ranged from 4.20 to 49.68.

  8. Computation of averaged monthly zonal albedo utilizing the solar zenith angle, properties of clear and cloudy atmospheres

    NASA Technical Reports Server (NTRS)

    Dhuria, H.

    1981-01-01

    The zonal temporal averages of albedos at the top of the atmosphere were considered as a function of the length of the day. The length of the day were used to determine the average daily values of mu sub 0(=Cos of the solar zenith angle, theta sub 0). Polynominal fits of the slope and intercept functions of A sub s (cloud-free albedo) and A sub c(cloud albedo) as function of Cos theta sub 0 were obtained by using the sample values of albedo corresponding to solar zenith angles from 0 to 90 deg with interval of 5 deg. The daily zonal values of mu sub 0 and the surface albedos were used to compute the daily zonal values of albedos at the top of the clear and cloudy atmosphere. The monthly zonal cloud fractions were used to compute planetary albedo A at the top of the atmosphere. The global values of monthly albedos A sub s, A sub c and A were computed by using the weighting function defined as the difference of the sins of zonal values of latitudes. The computer program implementation is also described.

  9. Changepoint Detection in Multinomial Logistic Regression with Application to Sky-Cloudiness Conditions in Canada

    NASA Astrophysics Data System (ADS)

    Lu, Q.; Wang, X. L.

    2009-04-01

    Detecting changepoints in a sequence of continuous random variables has been extensively explored in both statistics and climatology literature. There is little, however, for studying the case with multicategory random variables. For instance, the sky-cloudiness condition in Canada is reported in tenths of the sky dome and thus has 11 categories (from 0 for clear sky, to 10 tenths for overcast). This study develops an overall likelihood-ratio test statistic for detecting a sudden change in the parameters of the continuation-ratio logit random intercept model for a sequence of multinomial variables. A method of partitioning the overall test statistic is also proposed, which allows one to assess the significance of the effect of the detected change on individual categories. An application of this new technique to real sky cloudiness data is also presented.

  10. Bilateral cloudy cornea: is the usual suspect congenital hereditary endothelial dystrophy or stromal dystrophy?

    PubMed

    Acar, Banu Torun; Bozkurt, Kansu Tahir; Duman, Erkan; Acar, Suphi

    2016-01-01

    We provide the diagnosis, treatment and follow-up period of a patient with cloudy cornea in both eyes from birth. A 4-year-old girl presented with blurring in both eyes. Penetrating keratoplasty (PK) was performed with the preliminary diagnosis of congenital hereditary endothelial dystrophy in June 2012. According to the pathology report for extracted host tissue, the Descemet's membrane (DM) and endothelium were healthy and diagnosis was reported to be congenital hereditary stromal dystrophy. Deep anterior lamellar keratoplasty was performed on the left eye. The DM was transparent at follow-up. Cornea transplantation is the only choice to provide visual rehabilitation in children with congenital cloudy cornea. However, it is known that the prognosis of traditional PK in the paediatric age group is not good. Therefore, when using alternative keratoplasty (deep anterior lamellar keratoplasty, Descemet's stripping automated endothelial keratoplasty) options, pathological examination of the host tissue should be made. PMID:27107055

  11. Limb Correction of Infrared Imagery in Cloudy Regions for the Improved Interpretation of RGB Composites

    NASA Technical Reports Server (NTRS)

    Elmer, Nicholas J.; Berndt, Emily; Jedlovec, Gary J.

    2016-01-01

    Red-Green-Blue (RGB) composites (EUMETSAT User Services 2009) combine information from several channels into a single composite image. RGB composites contain the same information as the original channels, but presents the information in a more efficient manner. However, RGB composites derived from infrared imagery of both polar-orbiting and geostationary sensors are adversely affected by the limb effect, which interferes with the qualitative interpretation of RGB composites at large viewing zenith angles. The limb effect, or limb-cooling, is a result of an increase in optical path length of the absorbing atmosphere as viewing zenith angle increases (Goldberg et al. 2001; Joyce et al. 2001; Liu and Weng 2007). As a result, greater atmospheric absorption occurs at the limb, causing the sensor to observe anomalously cooler brightness temperatures. Figure 1 illustrates this effect. In general, limb-cooling results in a 4-11 K decrease in measured brightness temperature (Liu and Weng 2007) depending on the infrared band. For example, water vapor and ozone absorption channels display much larger limb-cooling than infrared window channels. Consequently, RGB composites created from infrared imagery not corrected for limb effects can only be reliably interpreted close to nadir, which reduces the spatial coverage of the available imagery. Elmer (2015) developed a reliable, operational limb correction technique for clear regions. However, many RGB composites are intended to be used and interpreted in cloudy regions, so a limb correction methodology valid for both clear and cloudy regions is needed. This paper presents a limb correction technique valid for both clear and cloudy regions, which is described in Section 2. Section 3 presents several RGB case studies demonstrating the improved functionality of limb-corrected RGBs in both clear and cloudy regions, and Section 4 summarizes and presents the key conclusions of this work.

  12. A Quality Control study of the distribution of NOAA MIRS Cloudy retrievals during Hurricane Sandy

    NASA Astrophysics Data System (ADS)

    Fletcher, S. J.

    2013-12-01

    Cloudy radiance present a difficult challenge to data assimilation (DA) systems, through both the radiative transfer system as well the hydrometers required to resolve the cloud and precipitation. In most DA systems the hydrometers are not control variables due to many limitations. The National Oceanic and Atmospheric Administration's (NOAA) Microwave Integrated Retrieval System (MIRS) is producing products from the NPP-ATMS satellite where the scene is cloud and precipitation affected. The test case that we present here is the life time of Hurricane and then Superstorm Sandy in October 2012. As a quality control study we shall compare the retrieved water vapor content during the lifetime of Sandy with the first guess and the analysis from the NOAA Gridpoint Statistical Interpolation (GSI) system. The assessment involves the gross error check system against the first guess with different values for the observational error's variance to see if the difference is within three standard deviations. We shall also compare against the final analysis at the relevant cycles to see if the products which have been retrieved through a cloudy radiance are similar, given that the DA system does not assimilate cloudy radiances yet.

  13. Performance of greenhouse gas profiling by infrared-laser and microwave occultation in cloudy air

    NASA Astrophysics Data System (ADS)

    Proschek, V.; Kirchengast, G.; Emde, C.; Schweitzer, S.

    2012-12-01

    ACCURATE is a proposed future satellite mission enabling simultaneous measurements of greenhouse gases (GHGs), wind and thermodynamic variables from Low Earth Orbit (LEO). The measurement principle is a combination of LEO-LEO infrared-laser occultation (LIO) and microwave occultation (LMO), the LMIO method, where the LIO signals are very sensitive to clouds. The GHG retrieval will therefore be strongly influenced by clouds in parts of the troposphere. The IR-laser signals, at wavelengths within 2--2.5μ m, are chosen to measure six GHGs (H2O, CO2, CH4, N2O, O3, CO; incl.~key isotopes 13CO2, C18OO, HDO). The LMO signals enable to co-measure the thermodynamic variables. In this presentation we introduce the algorithm to retrieve GHG profiles under cloudy-air conditions by using quasi-realistic forward simulations, including also influence of Rayleigh scattering, scintillations and aerosols. Data from CALIPSO--Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations--with highest vertical resolution of about 60 m and horizontal resolution of about 330 m were used for simulation of clouds. The IR-laser signals consist for each GHG of a GHG-sensitive and a close-by reference signal. The key process, ``differencing'' of these two signals, removes the atmospheric ``broadband'' effects, resulting in a pure GHG transmission profile. Very thin ice clouds, like sub-visible cirrus, are fairly transparent to the IR-laser signals, thicker and liquid water clouds block the signals. The reference signal is used to produce a cloud layering profile from zero to blocking clouds and is smoothed in a preprocess to suppress scintillations. Sufficiently small gaps, of width <2 km in the cloud layering profile, are found to enable a decent retrieval of entire GHG profiles over the UTLS under broken cloudiness and are therefore bridged by interpolation. Otherwise in case of essentially continuous cloudiness the profiles are found to terminate at cloud top level. The accuracy of

  14. Dinosaur Day!

    ERIC Educational Resources Information Center

    Nakamura, Sandra; Baptiste, H. Prentice

    2006-01-01

    In this article, the authors describe how they capitalized on their first-grade students' love of dinosaurs by hosting a fun-filled Dinosaur Day in their classroom. On Dinosaur Day, students rotated through four dinosaur-related learning stations that integrated science content with art, language arts, math, and history in a fun and time-efficient…

  15. CEMI Days

    SciTech Connect

    2015-07-01

    CEMI Days are an important channel of engagement between DOE and the manufacturing industry to identify challenges and opportunities for increasing U.S. manufacturing competitiveness. CEMI Days that are held at manufacturing companies’ facilities can include tours of R&D operations or other points of interest determined by the host company.

  16. Day Care.

    ERIC Educational Resources Information Center

    Merro, John; And Others

    Interviews on the quality of day care in the United States are presented in this transcript of a program broadcast in the National Public Radio weekly series, "Options in Education." Writers, day care center personnel and others describe and evaluate the current situation. Federal legislation concerning children is examined, and researchers…

  17. Estimating Locations of Perennial Streams in Idaho Using a Generalized Least-Squares Regression Model of 7-Day, 2-Year Low Flows

    USGS Publications Warehouse

    Wood, Molly S.; Rea, Alan; Skinner, Kenneth D.; Hortness, Jon E.

    2009-01-01

    Many State and Federal agencies use information regarding the locations of streams having intermittent or perennial flow when making management and regulatory decisions. For example, the application of some Idaho water quality standards depends on whether streams are intermittent. Idaho Administrative Code defines an intermittent stream as one having a 7-day, 2-year low flow (7Q2) less than 0.1 ft3/s. However, there is a general recognition that the cartographic representation of perennial/intermittent status of streams on U.S. Geological Survey (USGS) topographic maps is not as accurate or consistent as desirable from one map to another, which makes broad management and regulatory assessments difficult and inconsistent. To help resolve this problem, the USGS has developed a methodology for predicting the locations of perennial streams based on regional generalized least-squares (GLS) regression equations for Idaho streams for the 7Q2 low-flow statistic. Using these regression equations, the 7Q2 streamflow may be estimated for naturally flowing streams in most areas in Idaho. The use of these equations in conjunction with a geographic information system (GIS) technique known as weighted flow accumulation allows for an automated and continuous estimation of 7Q2 streamflow at all points along stream reaches. The USGS has developed a GIS-based map of the locations of streams in Idaho with perennial flow based on a 7Q2 of 0.1 ft3/s and a transition zone of plus or minus 1 standard error. Idaho State cooperators plan to use this information to make regulatory and water-quality management decisions. Originally, 7Q2 equations were developed for eight regions of similar hydrologic characteristics in the study area, using long-term data from 234 streamflow-gaging stations. Equations in five of the regions were revised based on spatial patterns observed in the initial perennial streams map and unrealistic behavior of the equations in extrapolation. The standard errors of

  18. Estimating Risks of Heat Strain by Age and Sex: A Population-Level Simulation Model

    PubMed Central

    Glass, Kathryn; Tait, Peter W.; Hanna, Elizabeth G.; Dear, Keith

    2015-01-01

    Individuals living in hot climates face health risks from hyperthermia due to excessive heat. Heat strain is influenced by weather exposure and by individual characteristics such as age, sex, body size, and occupation. To explore the population-level drivers of heat strain, we developed a simulation model that scales up individual risks of heat storage (estimated using Myrup and Morgan’s man model “MANMO”) to a large population. Using Australian weather data, we identify high-risk weather conditions together with individual characteristics that increase the risk of heat stress under these conditions. The model identifies elevated risks in children and the elderly, with females aged 75 and older those most likely to experience heat strain. Risk of heat strain in males does not increase as rapidly with age, but is greatest on hot days with high solar radiation. Although cloudy days are less dangerous for the wider population, older women still have an elevated risk of heat strain on hot cloudy days or when indoors during high temperatures. Simulation models provide a valuable method for exploring population level risks of heat strain, and a tool for evaluating public health and other government policy interventions. PMID:25993102

  19. Cloudy cornea

    MedlinePlus

    ... Injury to the eye, including chemical burns and welding injury Scarring Clouding may affect all or part ... examine your eyes and ask about your medical history. The two main questions will be if your ...

  20. Cloudy cornea

    MedlinePlus

    ... Do you wear contact lenses? Is there any history of injury to the eye? Has there been any discomfort? If so, is there anything that helps? Tests may include: Biopsy of lid tissue Computer mapping of the cornea (corneal topography) Schirmer's test ...

  1. Career Day

    NASA Video Gallery

    NASA's 2013 Career Days was a joint collaboration between NASA Langley and the Newport News Shipbuilding where 600 high school students from Virginia took on two design challenges -- designing a ca...

  2. A New Retrieval of Aerosol Optical Depth under Partly Cloudy Conditions with Multi-Spectral Measurements of Reflectance

    SciTech Connect

    Kassianov, Evgueni I.; Ovtchinnikov, Mikhail; Berg, Larry K.; McFarlane, Sally A.; Flynn, Connor J.

    2009-02-01

    The three-dimensional (3D) radiative effects may cause large uncertainties of satellite aerosol retrievals under partly cloudy conditions [1,2]. For example, analysis of multi-year aerosol statistics derived from the MODerate-Resolution Imaging Spectroradiometer (MODIS) data in clear patches of cloud fields suggests that aerosol product may be in a large error (up to 140%) as a result of 3D cloud-induced enhancement of clear sky reflectance [3]. Retrievals of AOD τa from satellite observations consist of two basic steps: (1) sampling, which includes detection of clear pixels and (2) and application of an algorithm, which estimates AOD in these pixels. The quality of the final product depends on both steps [4]. The largest errors occur for pixels located within areas of sunlight and shadows where the 3D radiative effects have the greatest impacts on the AOD retrievals [2]. To reduce the 3D radiative effects, clear pixels have to be selected far away (~1-2 km) from clouds and their shadows [3]. For selected clear pixels, the independent pixel approximation approach (IPA) [5] is used to estimate the AOD. Since the IPA ignores the 3D cloud-induced enhancement, the IPA-based retrievals can substantially overestimate AOD even for these clear pixels. To take into account such enhancement, a simple parameterization has been suggested [6]. Here we introduce an approach [7], that provides an effective way to avoid the 3D cloud effects, and illustrate with a model-output inverse problem its capability to detect clear pixels (outside of shadows) and estimate their AOD.

  3. Estimation of daily global solar irradiation under different sky conditions in central and southern Iran

    NASA Astrophysics Data System (ADS)

    Didari, Shohreh; Zand-Parsa, Shahrokh

    2015-10-01

    Daily global solar irradiation (R s) is one of the main inputs in environmental modeling. Because of the lack of its measuring facilities, high-quality and long-term data are limited. In this research, R s values were estimated based on measured sunshine duration and cloud cover of our synoptic meteorological stations in central and southern Iran during 2008, 2009, and 2011. Clear sky solar irradiation was estimated from linear regression using extraterrestrial solar irradiation as the independent variable with normalized root mean square error (NRMSE) of 4.69 %. Daily R s was calibrated using measured sunshine duration and cloud cover data under different sky conditions during 2008 and 2009. The 2011 data were used for model validation. According to the results, in the presence of clouds, the R s model using sunshine duration data was more accurate when compared with the model using cloud cover data (NRMSE = 11. 69 %). In both models, with increasing sky cloudiness, the accuracy decreased. In the study region, more than 92 % of sunshine durations were clear or partly cloudy, which received close to 95 % of total solar irradiation. Hence, it was possible to estimate solar irradiation with a good accuracy in most days with the measurements of sunshine duration.

  4. STS-113 Flight Day 9 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This video shows the activities of the STS-113 (Jim Wetherbee, Commander; Paul Lockhart, Pilot; Michael Lopez-Alegria, John Herrington, Mission Specialists) crew during flight day 9. Also seen are the outgoing Expedition 5 (Valeri Korzun, Commander; Peggy Whitsun, ISS Science Officer/Flight Engineer; Sergei Treschev, Flight Engineer) and incoming Expedition 6 (Kenneth Bowersox, Commander; Donald Pettit, Nikolai Budarin, Flight Engineers) crews of the ISS (International Space Station). Flight day 9 is a relatively inactive day, with some off-time scheduled for crew bonding and enjoying views. Seven of the joint crew members, including Lopez-Alegria, Wetherbee, Herrington, and Whitsun, pose together and answer questions. Footage shows ISS Science Officers Whitsun and Pettit troubleshooting equipment. The video also contains a clear view of southern South America, a cloudy view of the South Pacific, and external footage of the ISS including the Canadarm robotic arm. The payload bay of the shuttle Endeavour is also shown.

  5. Evaluation of GCM Column Radiation Models Under Cloudy Conditions with The Arm BBHRP Value Added Product

    SciTech Connect

    Oreopoulos, Lazaros; Norris, Peter M.

    2010-03-14

    The overarching goal of the project was to improve the transfer of solar and thermal radiation in the most sophisticated computer tools that are currently available for climate studies, namely Global Climate Models (GCMs). This transfer can be conceptually separated into propagation of radiation under cloudy and under cloudless conditions. For cloudless conditions, the factors that affect radiation propagation are gaseous absorption and scattering, aerosol particle absorption and scattering and surface albedo and emissivity. For cloudy atmospheres the factors are the various cloud properties such as cloud fraction, amount of cloud condensate, the size of the cloud particles, and morphological cloud features such as cloud vertical location, cloud horizontal and vertical inhomogeneity and cloud shape and size. The project addressed various aspects of the influence of the above contributors to atmospheric radiative transfer variability. In particular, it examined: (a) the quality of radiative transfer for cloudless and non-complex cloudy conditions for a substantial number of radiation algorithms used in current GCMs; (b) the errors in radiative fluxes from neglecting the horizontal variabiity of cloud extinction; (c) the statistical properties of cloud horizontal and vertical cloud inhomogeneity that can be incorporated into radiative transfer codes; (d) the potential albedo effects of changes in the particle size of liquid clouds; (e) the gaseous radiative forcing in the presence of clouds; and (f) the relative contribution of clouds of different sizes to the reflectance of a cloud field. To conduct the research in the various facets of the project, data from both the DOE ARM project and other sources were used. The outcomes of the project will have tangible effects on how the calculation of radiative energy will be approached in future editions of GCMs. With better calculations of radiative energy in GCMs more reliable predictions of future climate states will be

  6. Inter-Calibration and Concatenation of Climate Quality Infrared Cloudy Radiances from Multiple Instruments

    NASA Technical Reports Server (NTRS)

    Behrangi, Ali; Aumann, Hartmut H.

    2013-01-01

    A change in climate is not likely captured from any single instrument, since no single instrument can span decades of time. Therefore, to detect signals of global climate change, observations from many instruments on different platforms have to be concatenated. This requires careful and detailed consideration of instrumental differences such as footprint size, diurnal cycle of observations, and relative biases in the spectral brightness temperatures. Furthermore, a common basic assumption is that the data quality is independent of the observed scene and therefore can be determined using clear scene data. However, as will be demonstrated, this is not necessarily a valid assumption as the globe is mostly cloudy. In this study we highlight challenges in inter-calibration and concatenation of infrared radiances from multiple instruments by focusing on the analysis of deep convective or anvil clouds. TRMM/VIRS is potentially useful instrument to make correction for observational differences in the local time and foot print sizes, and thus could be applied retroactively to vintage instruments such as AIRS, IASI, IRIS, AVHRR, and HIRS. As the first step, in this study, we investigate and discuss to what extent AIRS and VIRS agree in capturing deep cloudy radiances at the same local time. The analysis also includes comparisons with one year observations from CrIS. It was found that the instruments show calibration differences of about 1K under deep cloudy scenes that can vary as a function of land type and local time of observation. The sensitivity of footprint size, view angle, and spectral band-pass differences cannot fully explain the observed differences. The observed discrepancies can be considered as a measure of the magnitude of issues which will arise in the comparison of legacy data with current data.

  7. Evaluation of 20-min and Annual Radiation Budget Components and Cloudiness in a Mountainous Valley

    NASA Astrophysics Data System (ADS)

    Malek, E.

    2007-05-01

    Logan, Utah (USA) is among cities located in the mountainous valley in the western portion of Rocky Mountains in North America. It is the county seat of Cache Valley, a metropolitan area with a population of about 100,000. The valley had the polluted air in the USA during January 2004. To evaluate the daily and annual radiation budget and cloudiness in this mountainous valley, we set up a radiation station in the middle of the valley to measure the 20- min radiation budget components namely: incoming (Rso) and outgoing (Rso) solar or shortwave radiation, using to CM21 Kipp and Zonen (one inverted) and incoming (Rli) (or atmospheric) and outgoing (Rlo) or terrestrial) longwave radiation using two CG1 Kipp and Zonen Pyrgeometers (one inverted) during the year of 2003. All pyranometers and Pyrgeometers were ventilated with four CV2 Kipp and Zonen ventilation systems throughout the year to prevent deposition of dew, frost and snow, which otherwise would disturb the measurements. We also measured the 2-m air temperature and relative humidity along with surface temperature. All measurements were taken every 2 s, averaged to 20 min, continuously throughout the year 2000. A Met One heated rain gauge measured precipitation. Comparison of the annual radiation budget components indicates that about 25% of the annual Rsi (5848.6 MJ/ (squared m-y)) was reflected back to sky as Rso. Rli and Rlo amounted to 9968.7 and 13303.5 MJ/ (squared m-y)), respectively. This yielded about 1364.9 MJ/ (squared m- y)) available energy (Rn). Having the 2-m air temperature and moisture data and comparison between the theoretical and the measured longwave radiation, we evaluated the 20-m cloudy conditions throughout the year of 2003. The average cloud base height was 587 m (ranged from zero for foggy conditions to about 3000 m). Annual cloudiness contributed about 139.1 MJ/ (squared m-y)) more energy in this valley.

  8. Intercalibration and concatenation of climate quality infrared cloudy radiances from multiple instruments

    NASA Astrophysics Data System (ADS)

    Behrangi, Ali; Aumann, Hartmut H.

    2013-09-01

    A change in climate is not likely captured from any single instrument, since no single instrument can span decades of time. Therefore, to detect signals of global climate change, observations from many instruments on different platforms have to be concatenated. This requires careful and detailed consideration of instrumental differences such as footprint size, diurnal cycle of observations, and relative biases in the spectral brightness temperatures. Furthermore, a common basic assumption is that the data quality is independent of the observed scene and therefore can be determined using clear scene data. However, as will be demonstrated, this is not necessarily a valid assumption as the globe is mostly cloudy. In this study we highlight challenges in inter-calibration and concatenation of infrared radiances from multiple instruments by focusing on the analysis of deep convective or anvil clouds. TRMM/VIRS is potentially useful instrument to make correction for observational differences in the local time and footprint sizes, and thus could be applied retroactively to vintage instruments such as AIRS, IASI, IRIS, AVHRR, and HIRS. As the first step, in this study, we investigate and discuss to what extent AIRS and VIRS agree in capturing deep cloudy radiances at the same local time. The analysis also includes comparisons with one year observations from CrIS. It was found that the instruments show calibration differences of about 1K under deep cloudy scenes that can vary as a function of land type and local time of observation. The sensitivity of footprint size, view angle, and spectral band-pass differenceartmut h. Aumanns cannot fully explain the observed differences. The observed discrepancies can be considered as a measure of the magnitude of issues which will arise in the comparison of legacy data with current data.

  9. NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR CALCULATING INGESTION EXPOSURE FROM DAY 4 COMPOSITE MEASUREMENTS, THE DIRECT METHOD OF EXPOSURE ESTIMATION (IIT-A-6.0)

    EPA Science Inventory

    The purpose of this SOP is to describe the procedures undertaken for calculating ingestion exposure from Day 4 composite measurements from duplicate diet using the direct method of exposure estimation. This SOP uses data that have been properly coded and certified with appropria...

  10. An efficient routine for infrared radiative transfer in a cloudy atmosphere

    NASA Technical Reports Server (NTRS)

    Chou, M. D.; Kouvaris, L.

    1981-01-01

    A FORTRAN program that calculates the atmospheric cooling rate and infrared fluxes for partly cloudy atmospheres is documented. The IR fluxes in the water bands and the 9.6 and 15 micron bands are calculated at 15 levels ranging from 1.39 mb to the surface. The program is generalized to accept any arbitrary atmospheric temperature and humidity profiles and clouds as input and return the cooling rate and fluxes as output. Sample calculations for various atmospheric profiles and cloud situations are demonstrated.

  11. Understanding the Greenhouse Effect Using Clear vs Cloudy Sky Diurnal Temperature Observations

    NASA Astrophysics Data System (ADS)

    Tayor, S. V.

    2006-12-01

    Standard meteorological observations from local airports can provide a tangible example of how the greenhouse effect is a part of everyday life. In the exercise outlined here, students plot diurnal temperature observations to compare the relative magnitude of the greenhouse effect under clear and cloudy-sky conditions, gaining insight into the strength of the greenhouse effect. Contemplation of the relation of surface temperature and humidity with cloud cover leads to a further understading of important atmospheric processes involving the Clausius-Clapeyron equation and terrestrial and solar radiation effects.

  12. Characteristics of a persistent "pool of inhibited cloudiness" and its genesis over the Bay of Bengal associated with the Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Nair, Anish Kumar M.; Rajeev, K.; Sijikumar, S.; Meenu, S.

    2011-07-01

    Using spatial and vertical distributions of clouds derived from multi-year spaceborne observations, this paper presents the characteristics of a significant "pool of inhibited cloudiness" covering an area of >106 km2 between 3-13° N and 77-90° E over the Bay of Bengal (BoB), persisting throughout the Asian summer monsoon season (ASM). Seasonal mean precipitation rate over the "pool" is <3 mm day-1 while that over the surrounding regions is mostly in the range of 6-14 mm day-1. Frequency of occurrence of clouds in this "pool" is ~20-40 % less than that over the surrounding deep convective regions. Zonal and meridional cross sections of the altitude distribution of clouds derived from CloudSat data reveal a vault-like structure at the "pool" with little cloudiness below ~7 km, indicating that this "pool" is almost fully contributed by the substantially reduced or near-absence of low- and middle-level clouds. This suggest the absence of convection in the "pool" region. Spaceborne scatterometer observations show divergence of surface wind at the "pool" and convergence at its surroundings, suggesting the existence of a mini-circulation embedded in the large-scale monsoon circulation. Reanalysis data shows a mini-circulation extending between the surface and ~3 km altitude, but its spatial structure does not match well with that inferred from the above observations. Sea surface at the south BoB during ASM is sufficiently warm to trigger convection, but is inhibited by the subsidence associated with the mini-circulation, resulting in the "pool". This mini-circulation might be a dynamical response of the atmosphere to the substantial spatial gradient of latent heating by large-scale cloudiness and precipitation at the vast and geographically fixed convective zones surrounding the "pool". Subsidence at the "pool" might contribute to the maintenance of convection at the above zones and be an important component of ASM that is overlooked hitherto.

  13. Inspire Day

    ERIC Educational Resources Information Center

    Bohach, Barbara M.; Meade, Birgitta

    2014-01-01

    The authors collaborated on hosting a "Spring Inspire Day." planned and delivered by preservice elementary teachers as a social studies/science methods project. Projects that have authentic application opportunities can make learning meaningful for prospective teachers as well as elementary students. With the impetus for an integrated…

  14. Estimated loss of juvenile salmonids to predation by northern squawfish, walleyes, and smallmouth bass in John Day Reservoir, Columbia River. [Oncorhynchus spp. ; Ptychocheilus oregonensis; Stizostedion vitreum; Micropterus dolomieu; O. tshawytscha

    SciTech Connect

    Rieman, B.E.; Beamesderfer, R.C. ); Vigg, S.; Poe, T.P. )

    1991-07-01

    The authors estimated the loss of juvenile salmonids Oncorhynchus spp. to predation by northern squawfish Ptychocheilus oregonensis, walleyes Stizostedion vitreum, and smallmouth bass Micropterus dolomieu in John Day Reservoir during 1983-1986. Their estimates were based on measures of daily prey consumption, predator numbers, and numbers of juvenile salmonids entering the reservoir during the April-August period of migration. They estimated the mean annual loss was 2.7 million juvenile salmonids. Northern squawfish were responsible for 78% of the total loss; walleyes accounted for 13% and smallmouth bass for 9%. Twenty-one percent of the loss occurred in a small area immediately below McNary Dam at the head of John Day Reservoir. The authors estimated that the three predator species consumed 14% of all juvenile salmonids that entered the reservoir. Mortality changed by month and increased late in the migration season. Monthly mortality estimates ranged from 7% in June and 61% in August. Mortality from predation was highest for chinook salmon O. tshawytscha, which migrated in July and August. Despite uncertainties in the estimates, it is clear that predation by resident fish predators can easily account for previously explained mortality of out-migrating juvenile salmonids. Alteration of the Columbia River by dams and a decline in the number of salmonids could have increased the fraction of mortality caused by predation over what is was in the past.

  15. Wind Profile Retrieval Method for Incoherent Doppler LIDAR in Partly Cloudy Conditions

    NASA Astrophysics Data System (ADS)

    Feng, Changzhong; Liu, Bingyi; Liu, Zhishen

    2014-11-01

    After the launch of ESA’s spaceborne Doppler lidar ALADIN, Ocean University of China is going to perform the ground validation using a ground based Doppler wind lidar which utilizes an iodine absorption filter as frequency discriminator to derive Doppler frequency shift of atmospheric wind from combined molecular and aerosol backscatter. Under circumstance of non-uniform aerosol horizontal distribution, such as partly cloudy conditions, the accuracy of wind measurements is seriously influenced. Therefore, an improved VAD (Velocity-Azimuth Display) method for retrieving wind profiles is developed, which significantly increases the accuracy. With the atmospheric return signal obtained from the line-of-sight velocity PPI (Plan Position Indicator) measurements, the spatial distribution of aerosol optical parameters can be derived and considered as a reference for the quality control of line-of-sight velocity. Consequently, the wind profile in partly cloudy conditions can be retrieved by using the quality controlled line-of-sight velocity. As a result, the applicability of the ground based Doppler lidar is improved.

  16. Assimilation of thermodynamic information from advanced infrared sounders under partially cloudy skies for regional NWP

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Li, Jun; Goldberg, Mitchell D.; Schmit, Timothy J.; Lim, Agnes H. N.; Li, Zhenglong; Han, Hyojin; Li, Jinlong; Ackerman, Steve A.

    2015-06-01

    Generally, only clear-infrared spectral radiances (not affected by clouds) are assimilated in weather analysis systems. This is due to difficulties in modeling cloudy radiances as well as in observing their vertical structure from space. To take full advantage of the thermodynamic information in advanced infrared (IR) sounder observations requires assimilating radiances from cloud-contaminated regions. An optimal imager/sounder cloud-clearing technique has been developed by the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin-Madison. This technique can be used to retrieve clear column radiances through combining collocated multiband imager IR clear radiances and the sounder cloudy radiances; no background information is needed in this method. The imager/sounder cloud-clearing technique is similar to that of the microwave/IR cloud clearing in the derivation of the clear-sky equivalent radiances. However, it retains the original IR sounder resolution, which is critical for regional numerical weather prediction applications. In this study, we have investigated the assimilation of cloud-cleared IR sounder radiances using Atmospheric Infrared Sounder (AIRS)/Moderate Resolution Imaging Spectroradiometer for three hurricanes, Sandy (2012), Irene (2011), and Ike (2008). Results show that assimilating additional cloud-cleared AIRS radiances reduces the 48 and 72 h temperature forecast root-mean-square error by 0.1-0.3 K between 300 and 850 hPa. Substantial improvement in reducing track forecasts errors in the range of 10 km to 50 km was achieved.

  17. Effect of mash maceration on the polyphenolic content and visual quality attributes of cloudy apple juice.

    PubMed

    Mihalev, Kiril; Schieber, Andreas; Mollov, Plamen; Carle, Reinhold

    2004-12-01

    The effects of enzymatic mash treatments on yield, turbidity, color, and polyphenolic content of cloudy apple juice were studied. Using HPLC-ESI-MS, cryptochlorogenic acid was identified in cv. Brettacher cloudy apple juice for the first time. Commercial pectolytic enzyme preparations with different levels of secondary protease activity were tested under both oxidative and nonoxidative conditions. Without the addition of ascorbic acid, oxidation substantially decreased chlorogenic acid, epicatechin, and procyanidin B2 contents due to enzymatic browning. The content of chlorogenic acid as the major polyphenolic compound was also influenced by the composition of pectolytic enzyme preparations because the presence of secondary protease activity resulted in a rise of chlorogenic acid. The latter effect was probably due to the inhibited protein-polyphenol interactions, which prevented binding of polyphenolic compounds to the matrix, thus increasing their antioxidative potential. The results obtained clearly demonstrate the advantage of the nonoxidative mash maceration for the production of cloud-stable apple juice with a high polyphenolic content, particularly in a premature processing campaign. PMID:15563212

  18. A Fast Visible-Infrared Imaging Radiometer Suite Simulator for Cloudy Atmopheres

    NASA Technical Reports Server (NTRS)

    Liu, Chao; Yang, Ping; Nasiri, Shaima L.; Platnick, Steven; Meyer, Kerry G.; Wang, Chen Xi; Ding, Shouguo

    2015-01-01

    A fast instrument simulator is developed to simulate the observations made in cloudy atmospheres by the Visible Infrared Imaging Radiometer Suite (VIIRS). The correlated k-distribution (CKD) technique is used to compute the transmissivity of absorbing atmospheric gases. The bulk scattering properties of ice clouds used in this study are based on the ice model used for the MODIS Collection 6 ice cloud products. Two fast radiative transfer models based on pre-computed ice cloud look-up-tables are used for the VIIRS solar and infrared channels. The accuracy and efficiency of the fast simulator are quantify in comparison with a combination of the rigorous line-by-line (LBLRTM) and discrete ordinate radiative transfer (DISORT) models. Relative errors are less than 2 for simulated TOA reflectances for the solar channels and the brightness temperature differences for the infrared channels are less than 0.2 K. The simulator is over three orders of magnitude faster than the benchmark LBLRTM+DISORT model. Furthermore, the cloudy atmosphere reflectances and brightness temperatures from the fast VIIRS simulator compare favorably with those from VIIRS observations.

  19. Using a thermal-based two source energy balance model with time-differencing to estimate surface energy fluxes with day-night MODIS observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dual Temperature Difference (DTD) model, introduced by [Norman et al.(2000)], uses a two source energy balance modelling scheme driven by remotely sensed observations of diurnal changes in land surface temperature (LST) to estimate surface energy fluxes. By using a time differential temperature ...

  20. Estimation of large scale daily evapotranspiration using geostationary meteorological satellite observations

    NASA Astrophysics Data System (ADS)

    Jia, L.; Daamen, M.

    2009-04-01

    reconstruct gap-filled time series of instantaneous ET along a day. In the end, daily evapotranspiration is calculated from the reconstructed gap-filled time series of instantaneous estimation of evapotranspiration. The algorithm validation was done using data from limited number of flux tower sites of CarboEurope project in Europe by comparing the energy balance flux components estimated by SEBS with tower flux measurements. Analyses of daily variation of estimated surface heat fluxes show that the proposed method is able to generate large scale net radiation, sensible, latent, and soil heat fluxes that follow closely daily variation of the courses of these flux components as observed by ground measurements. It was found that abnormal values in the estimated latent heat flux are observed near cloudy pixels. It indicates that pixels close to cloudy pixels may be affected by clouds but not masked in the MSG land surface temperature product. In general, reconstruction of evapotranspiration time-series using HANTS algorithm is demonstrated to be a promising technique to overcome the interference of clouds and preserve inherent trends of evapotranspiration process over a day when applied to a large-scale. HANTS reconstruction is capable to maintain daily variation of evapotranspiration on less cloudy days by keeping good correlation with the ground measurements. However, the technique has proven to be limited to areas with cloud cover less than 60% along a day course. Comparison of the daily total ET estimated from SEBS/MSG/HANTS technique with daily ET calculated using conventional method (using one-time measurements of a day and assuming clear sky throughout a day) has shown that the former is less affected by the intensity of cloud interference along the day.

  1. Seasonal size distribution of airborne culturable bacteria and fungi and preliminary estimation of their deposition in human lungs during non-haze and haze days

    NASA Astrophysics Data System (ADS)

    Gao, Min; Jia, Ruizhi; Qiu, Tianlei; Han, Meilin; Song, Yuan; Wang, Xuming

    2015-10-01

    In recent years, haze events in Beijing have significantly increased in frequency. On haze days, airborne microorganisms are considered to be a potential risk factor for various health concerns. However, limited information on bioaerosols has prevented our proper understanding of the possible threat to human health due to these bioaerosols. In this study, we used a six-stage impactor for sampling culturable bioaerosols and the LUDEP 2.07 computer-based model for calculating their deposition on human lungs to investigate seasonal concentration, size distribution, and corresponding deposition efficiency and flux in the human respiratory tract during different haze-level events. The current results of the analysis of 398 samples over four seasons indicate that the concentration of culturable airborne bacteria decreased with increasing haze severity. The bioaerosol concentration ratio was skewed towards larger particle sizes on heavy haze days leading to larger bioaerosol aerodynamic diameters than on non-haze days. During nasal breathing by an adult male engaged in light exercise in an outdoor environment, the total deposition efficiency of culturable bioaerosols is 80-90% including approximately 70% in the upper respiratory tract, 5-7% in the alveoli, and about 3% in the bronchial couple with bronchiolar regions. Although the difference in culturable bioaerosol aerodynamic diameters at different haze levels was not large enough to cause obvious differences in lung deposition efficiency, the deposition fluxes clearly varied with the degree of haze owing to the varied concentration of culturable airborne bacteria and fungi. The results here could improve our understanding of the seasonal health threat due to culturable bioaerosols during non-haze and haze days.

  2. Surface-observed and satellite-retrieved cloudiness compared for the 1983 ISCCP Special Study Area in Europe

    NASA Astrophysics Data System (ADS)

    Henderson-Sellers, A.; SéZe, G.; Drake, F.; Desbois, M.

    1987-04-01

    A comparison has been undertaken between surface-observed total low- and high-cloud amount and retrievals from METEOSAT radiance data made using the cluster technique of Desbois et al. (1982). The aim of the study was to establish whether surface-observed cloud information could be usefully exploited to benefit satellite-based cloud retrievals. Observations from 124 surface stations at 1200 UT for the 20-day period from July 22 to August 10, 1983, were compared with retrievals made from METEOSAT radiances measured at 1130 UT. The comparisons for total and low-cloud amount are made for France and southern Britain. The high-cloud amount comparison was limited to 34 stations in southern Britain. The location and time period were selected to coincide with one of the regions designated for special study in the International Satellite Cloud Climatology Project (ISCCP) (Schiffer, 1982). For total cloud amount, 29% of the retrievals were fully in agreement with the surface observations and 64% of differences were within ±1 okta (±1 eighth of sky cover). In the case of layer cloud amounts, 64% of the low-cloud amount differences and 50% of the high-cloud amount differences were within ±1 okta, although many of these successes (71% in the low-cloud amount) were for cases of totally clear or totally cloudy skies. Surface observations, which offer the only source of accurate low-cloud amount evaluation in any multilayered situation, were found to identify thin cirrus which was not detected by the satellite retrieval and to detect small gaps in cloud decks and small clouds missed by the satellite retrieval. In addition, cloud retrievals in coastal locations seemed to be more successfully accomplished by surface observers than by the satellite retrieval algorithm used here, which does not take into account land-sea partition.

  3. Estimates of genetic parameters for 320-day pelvic measurements of males and females and calving ease of 2-year-old females.

    PubMed

    Kriese, L A; Van Vleck, L D; Gregory, K E; Boldman, K G; Cundiff, L V; Koch, R M

    1994-08-01

    Records from 12 breed groups collected from 1983 to 1991, included in the Germ Plasm Utilization project at the U.S. Meat Animal Research Center, were analyzed separately by breed group and combined to estimate heritabilities and genetic correlations for 320-d male and female pelvic width, height, and area, and for 320-d male pelvic and female 2-yr-old calving ease. Calving ease was analyzed as a trait of the dam using 1) actual and 2) binary scale calving ease scores with a covariate of calf birth weight. A bivariate animal model and derivative-free REML incorporating sparse matrix techniques were used. When breed groups were analyzed separately, heritability estimates of male and female 320-d pelvic traits varied by breed group and sex. Average genetic correlations between male and female 320-d pelvic width, pelvic height, and pelvic area were large and positive. When breed groups were combined (n = 26,071), heritability estimates for 320-d pelvic traits were moderate in size. Genetic correlations of .68, .48, and .61, between male and female 320-d pelvic width, height, and area, respectively, suggest male and female pelvic traits are largely under the same genetic control but are correlated traits rather than the same trait. Heritability estimates for actual calving ease in 2-yr-olds ranged from .00 to .49 in separate breed group analyses, and from .00 to .37 for binary measures. When breed groups were combined, heritability was .11 for actual calving ease and was .09 on the binary scale.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7982822

  4. Valentine's Day

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02174 Valentine's Day

    This isolated mesa [lower left center of the image] has an almost heart-shaped margin. Happy Valentine's Day from Mars.

    Image information: VIS instrument. Latitude 29.4N, Longitude 79.1E. 18 meter/pixel resolution.

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

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

  5. Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Yu, G.-R.; Zhang, L.-M.; Sun, X.-M.; Wen, X.-F.; Han, S.-J.; Yan, J.-H.

    2010-02-01

    Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE) in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS) and a subtropical evergreen broad-leaved forest at Dinghushan (DHS), based on the flux data obtained during June-August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR) differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (Pec,max) at CBS under cloudy skies during mid-growing season (from June to August) increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, Pec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (kt) ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when kt exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD) and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP) and greater increase in ecosystem respiration (Re) at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in cloudiness is an important factor that should be included in evaluating regional carbon budgets under climate change

  6. Hydrology day

    NASA Astrophysics Data System (ADS)

    Morel-Seytoux, H. J.

    Registration for the Hydrology Day sponsored by the Front Range Branch of AGU on April 23 at Colorado State University in Fort Collins, Colorado, totaled 121 participants, of whom 61 were students.Thirty-one individuals joined the Front Range Branch. Three students from Colorado State University won the awards for best paper in their category: Thomas W. Anzia (Sr.), ‘A Comprehensive Table of Standard Deviates for Confidence Limits on Extreme Events’ Victor Nazareth (M.S.), ‘Aquifer Properties from Single-Hole Aquifer Tests’ and Roy W. Koch (Ph.D.), ‘A Physically Based Derivation of the Distribution of Excess Precipitation.’ Judges for the awards were Dr. Bittinger, Resource Consultants, Fort Collins; George Leavesley and Daniel Bauer, USGS, Water Resources Division, Denver; Scott Tucker, Executive Director, Denver Urban Drainage and Flood Control District; Charles Brendecke, Department of Civil Engineering, Univ. of Colorado, Boulder.

  7. The northward march of summer low cloudiness along the California coast

    NASA Astrophysics Data System (ADS)

    Clemesha, Rachel E. S.; Gershunov, Alexander; Iacobellis, Sam F.; Williams, A. Park; Cayan, Daniel R.

    2016-02-01

    A new satellite-derived low cloud retrieval reveals rich spatial texture and coherent space-time propagation in summertime California coastal low cloudiness (CLC). Throughout the region, CLC is greatest during May-September but has considerable monthly variability within this summer season. On average, June is cloudiest along the coast of southern California and northern Baja, Mexico, while July is cloudiest along northern California's coast. Over the course of the summer, the core of peak CLC migrates northward along coastal California, reaching its northernmost extent in late July/early August, then recedes while weakening. The timing and movement of the CLC climatological structure is related to the summer evolution of lower tropospheric stability and both its component parts, sea surface temperature and potential temperature at 700 hPa. The roughly coincident seasonal timing of peak CLC with peak summertime temperatures translates into the strongest heat-modulating capacity of CLC along California's north coast.

  8. Representation of Clear and Cloudy Boundary Layers in Climate Models. Chapter 14

    NASA Technical Reports Server (NTRS)

    Randall, D. A.; Shao, Q.; Branson, M.

    1997-01-01

    The atmospheric general circulation models which are being used as components of climate models rely on their boundary layer parameterizations to produce realistic simulations of the surface turbulent fluxes of sensible heat. moisture. and momentum: of the boundary-layer depth over which these fluxes converge: of boundary layer cloudiness: and of the interactions of the boundary layer with the deep convective clouds that grow upwards from it. Two current atmospheric general circulation models are used as examples to show how these requirements are being addressed: these are version 3 of the Community Climate Model. which has been developed at the U.S. National Center for Atmospheric Research. and the Colorado State University atmospheric general circulation model. The formulations and results of both models are discussed. Finally, areas for future research are suggested.

  9. Absorption of Solar Radiation by the Cloudy Atmosphere Interpretations of Collocated Aircraft Measurements

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.; Cess, Robert D.; Zhang, Minghua; Pope, Shelly K.; Bucholtz, Anthony; Bush, Brett; Vitko, John, Jr.

    1997-01-01

    As part of the Atmospheric Radiation Measurement (ARM) Enhanced Shortwave Experiment (ARESE), we have obtained and analyzed measurements made from collocated aircraft of the absorption of solar radiation within the atmospheric column between the two aircraft. The measurements were taken during October 1995 at the ARM site in Oklahoma. Relative to a theoretical radiative transfer model, we find no evidence for excess solar absorption in the clear atmosphere and significant evidence for its existence in the cloudy atmosphere. This excess cloud solar absorption appears to occur in both visible (0.224-0.68 microns) and near-infrared (0.68-3.30 microns) spectral regions, although not at 0.5 microns for the visible contribution, and it is shown to be true absorption rather than an artifact of sampling errors caused by measuring three-dimensional clouds.

  10. Validation and Improvement of CERES Surface Radiation Budget Algorithms: Extension of Dusty and Cloudy Scenes

    NASA Technical Reports Server (NTRS)

    Ramanathan, V.; Inamdar, Anand K.

    2005-01-01

    Our main task was to validate and improve the generation of surface long wave fluxes from the CERES TOA window channel flux measurements. We completed this task successfully for the clear sky fluxes in the presence of aerosols including dust during the first year of the project. The algorithm we developed for CERES was remarkably successful for clear sky fluxes and we have no further tasks that need to be performed past the requested termination date of December 31, 2004. We found that the information contained in the TOA fluxes was not sufficient to improve upon the current CERES algorithm for cloudy sky fluxes. Given this development and given our success in clear sky fluxes, we do not see any reason to continue our validation work beyond what we have completed. Specific details are given.

  11. Formation of spectral lines in planetary atmospheres. I - Theory for cloudy atmospheres: Application to Venus.

    NASA Technical Reports Server (NTRS)

    Hunt, G. E.

    1972-01-01

    The theory of the formation of spectral lines in a cloudy planetary atmosphere is studied in detail. It is shown that models based upon homogeneous, isotropically scattering atmospheres cannot be used to reproduce observed spectroscopic features of phase effect and the shape of spectral lines for weak and strong bands. The theory must, therefore, be developed using an inhomogeneous (gravitational) model of a planetary atmosphere, accurately incorporating all the physical processes of radiative transfer. Such a model of the lower Venus atmosphere, consistent with our present knowledge, is constructed. The results discussed in this article demonstrate the effects of the parameters that describe the atmospheric model on the spectroscopic features of spectral line profile and phase effect, at visible and near infrared wavelengths. This information enables us to develop a comprehensive theory of line formation in a Venus atmosphere.

  12. Nucleon-nucleon potential calculated for the cloudy bag and related to effective OBE parameters

    NASA Astrophysics Data System (ADS)

    Kahler, Richard

    1995-05-01

    The nucleon nucleon potential is calculated in the context of the cloudy bag model. The one pion exchange diagram is used to determine the pion quark coupling. Two pion exchange diagrams, box and crossed box, including the delta isobar, produce additional central, spin-spin, and tensor couplings. Using non-relativistic approximations to the OBE model potentials, the two pion exchange contributions are related to the masses and couplings of σ, ω, δ, and ρ mesons. It is found that the two pion exchange generates essentially all of the σ contribution required by the OBE model, that there is a large δ contribution at a lower mass than expected, and that the ω and ρ contributions, while significant, are not able to provide what is required by the OBE model.

  13. Interpretation of satellite-measured bidirectional reflectance from Cirrus cloudy atmospheres

    NASA Technical Reports Server (NTRS)

    Takano, Y.; Liou, K. N.; Minnis, Patrick

    1990-01-01

    The interpretation of the observed bidirectional reflectance from cirrus cloudy atmospheres is presented. A theoretical model was developed for the computation of the transfer of solar radiation in an anisotropic medium with particular applications to oriented ice crystals in cirrus clouds. In this model, the adding principle for radiative transfer was used with modifications to account for the anisotropy of scattering particles and the associated scattering phase matrix. The single-scattering properties, including the phase function, single-scattering albedo, and extinction cross sections, were used for randomly and horizontally oriented hexagonal ice crystals in radiative transfer computations. The radiative transfer model developed for the cirrus clouds was modified to account for the scattering contributions from the atmosphere and the surface. In order to test the relevance and significance of the ice crystal model for the interpretation of observed bidirectional reflectance from satellites, visible radiances collected on the half hour by the GOES series were selected. The data are calibrated and corrected with the proper filter functions, then navigated to match selected landmark data. A number of clear and cloudy cases during the cirrus IFO of the Fire experiment were chosen for theoretical analyses. The cloud particle shape and size distributions that were taken during satellite overpasses are used in radiative transfer calculations. The sensitivities of the shape, orientation, and size distribution of ice crystals on the reflected intensities at the top of the atmosphere are investigated. Finally, the relative importance of these cloud microphysical properties in the interpretation of satellite bidirectional reflectance are assessed and presented.

  14. Investigation of the environment around close-in transiting exoplanets using CLOUDY

    NASA Astrophysics Data System (ADS)

    Turner, Jake D.; Christie, Duncan; Arras, Phil; Johnson, Robert E.; Schmidt, Carl

    2016-06-01

    It has been suggested that hot stellar wind gas in a bow shock around an exoplanet is sufficiently opaque to absorb stellar photons and give rise to an observable transit depth at optical and UV wavelengths. In the first part of this paper, we use the CLOUDY plasma simulation code to model the absorption from X-ray to radio wavelengths by 1D slabs of gas in coronal equilibrium with varying densities (104-108 cm-3) and temperatures (2000-106 K) illuminated by a solar spectrum. For slabs at coronal temperatures (106 K) and densities even orders of magnitude larger than expected for the compressed stellar wind (104-105 cm-3), we find optical depths orders of magnitude too small (>3 × 10-7) to explain the ˜3 per cent UV transit depths seen with Hubble. Using this result and our modelling of slabs with lower temperatures (2000-104K), the conclusion is that the UV transits of WASP-12b and HD 189733b are likely due to atoms originating in the planet, as the stellar wind is too highly ionized. A corollary of this result is that transport of neutral atoms from the denser planetary atmosphere outward must be a primary consideration when constructing physical models. In the second part of this paper, additional calculations using CLOUDY are carried out to model a slab of planetary gas in radiative and thermal equilibrium with the stellar radiation field. Promising sources of opacity from the X-ray to radio wavelengths are discussed, some of which are not yet observed.

  15. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2012-07-01 2012-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  16. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2010-07-01 2010-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  17. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2014-07-01 2013-07-01 true Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  18. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2011-07-01 2010-07-01 true Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  19. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2013-07-01 2013-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  20. Estimation of acute oral toxicity using the No Observed Adverse Effect Level (NOAEL) from the 28 day repeated dose toxicity studies in rats.

    PubMed

    Bulgheroni, Anna; Kinsner-Ovaskainen, Agnieszka; Hoffmann, Sebastian; Hartung, Thomas; Prieto, Pilar

    2009-02-01

    Acute systemic toxicity is one of the areas of particular concern due to the 2009 deadline set by the 7th Amendment of the Cosmetics Directive (76/768/EEC), which introduces a testing and marketing ban of cosmetic products with ingredients tested on animals. The scientific community is putting considerable effort into developing and validating non-animal alternatives in this area. However, it is unlikely that validated and regulatory accepted alternative methods and/or strategies will be available in March 2009. Following the initiatives undertaken in the pharmaceutical industry to waive the acute oral toxicity testing before going to clinical studies by using information from other in vivo studies, we proposed an approach to identify non-toxic compounds (LD50>2000mg/kg) using information from 28 days repeated dose toxicity studies. Taking into account the high prevalence of non-toxic substances (87%) in the New Chemicals Database, it was possible to set a NOAEL threshold of 200mg/kg that allowed the correct identification of 63% of non-toxic compounds, while <1% of harmful compounds were misclassified as non-toxic. Since repeated dose toxicity studies can be performed in vivo until 2013, the proposed approach could have an immediate impact for the testing of cosmetic ingredients. PMID:18977273

  1. Absorption of Sunlight by Water Vapor in Cloudy Conditions: A Partial Explaination for the Cloud Absorption Anomaly

    NASA Technical Reports Server (NTRS)

    Crisp, D.

    1996-01-01

    The atmospheric radiative transfer algorithms used in most global general circulation models underestimate the globally-averaged solar energy absorbed by cloudy atmospheres by up to 25 Wm(sup -2)...Here, a sophisticated atmospheric radiative transfer model was used to provide a more comprehensive description of the physical processes that contribute to the absorption of solar radiation by the Earth's atmosphere.

  2. Variation between Hospitals with Regard to Diagnostic Practice, Coding Accuracy, and Case-Mix. A Retrospective Validation Study of Administrative Data versus Medical Records for Estimating 30-Day Mortality after Hip Fracture

    PubMed Central

    Kristoffersen, Doris Tove; Skyrud, Katrine Damgaard; Lindman, Anja Schou

    2016-01-01

    Background The purpose of this study was to assess the validity of patient administrative data (PAS) for calculating 30-day mortality after hip fracture as a quality indicator, by a retrospective study of medical records. Methods We used PAS data from all Norwegian hospitals (2005–2009), merged with vital status from the National Registry, to calculate 30-day case-mix adjusted mortality for each hospital (n = 51). We used stratified sampling to establish a representative sample of both hospitals and cases. The hospitals were stratified according to high, low and medium mortality of which 4, 3, and 5 hospitals were sampled, respectively. Within hospitals, cases were sampled stratified according to year of admission, age, length of stay, and vital 30-day status (alive/dead). The final study sample included 1043 cases from 11 hospitals. Clinical information was abstracted from the medical records. Diagnostic and clinical information from the medical records and PAS were used to define definite and probable hip fracture. We used logistic regression analysis in order to estimate systematic between-hospital variation in unmeasured confounding. Finally, to study the consequences of unmeasured confounding for identifying mortality outlier hospitals, a sensitivity analysis was performed. Results The estimated overall positive predictive value was 95.9% for definite and 99.7% for definite or probable hip fracture, with no statistically significant differences between hospitals. The standard deviation of the additional, systematic hospital bias in mortality estimates was 0.044 on the logistic scale. The effect of unmeasured confounding on outlier detection was small to moderate, noticeable only for large hospital volumes. Conclusions This study showed that PAS data are adequate for identifying cases of hip fracture, and the effect of unmeasured case mix variation was small. In conclusion, PAS data are adequate for calculating 30-day mortality after hip-fracture as a quality

  3. Nanopaleomagnetism of Meteoritic Fe-Ni: the Potential for Time-Resolved Remanence Records within the Cloudy Zone

    NASA Astrophysics Data System (ADS)

    Harrison, R. J.; Bryson, J. F.; Kasama, T.; Church, N. S.; Herrero Albillos, J.; Kronast, F.; Ghidini, M.; Redfern, S. A.; van der Laan, G.; Tyliszczak, T.

    2013-12-01

    Paleomagnetic signals recorded by meteorites provide compelling evidence that the liquid cores of differentiated asteroids generated magnetic dynamo fields. Here we argue that magnetic nanostructures unique to meteoritic Fe-Ni metal are capable of carrying a time-resolved record of asteroid dynamo activity, a prospect that could revolutionise our understanding of the thermochemical conditions of differentiated bodies in the early solar system. Using a combination of high-resolution magnetic imaging techniques (including electron holography, magnetic force microscopy, X-ray photoemission electron microscopy and scanning transmission X-ray microscopy) we reveal the origins of the dramatic changes in magnetic properties that are associated with the transition from kamacite - tetrataenite rim - cloudy zone - plessite, typical of Fe-Ni intergrowths. The cloudy zone is comprised of nanoscale islands of tetrataenite (FeNi) coherently intergrown with a hitherto unobserved soft magnetic phase (Fe3Ni). The tetrataenite island diameter decreases with increasing lateral distance from the tetrataenite rim. Exchange coupling between the hard tetrataenite islands and the soft matrix phase leads to an exchange spring effect that lowers the tetrataenite switching field and causes a systematic variation in microcoercivity throughout the cloudy zone. The cloudy zone displays a complex interlocking magnetic domain pattern caused by uniaxial single domain tetrataenite islands with easy axes distributed along all three of the possible <100> crystallographic orientations. The coarse and intermediate cloudy zones contain a random distribution of all three easy axes. The fine cloudy zone, on the other hand, contains one dominant easy axis direction. This easy axis distribution suggests that strong interaction fields (either magnetic or stress) were present in this region at the time of tetrataenite formation, which likely originated from the neighbouring plessite. The easy axis

  4. Total cloudiness over the Arctic in winter: an intercomparison of different climatologies, an assessment of inter-annual variability and connection with surface air temperature

    NASA Astrophysics Data System (ADS)

    Chernokulsky, Alexander; Esau, Igor; Mokhov, Igor I.

    2013-04-01

    An increase of air temperature in the Arctic is accompanied with changes in other climate variables, particularly with a decrease of the Arctic sea ice extent and cloud cover changes. The sensitivity of the cloud radiative forcing is about 1 Watt per square meter per 1% of cloud cover in the Arctic. Thus, relatively small changes in cloud fraction could result in an sufficient climate forcing. Considering an importance of clouds in the Arctic, it is crucial to know exactly when and where clouds exist and how cloud cover is changing in time. Here, we analyze climatology of winter cloudiness over the entire Arctic (north of 60N), its interannual variability in the Norwegian Sea - Kara Sea region and its connection with surface air temperature. Based an intercomparison of 16 cloud climatologies (including satellite and surface observations as well as reanalyses data), we show significant distinctions among different cloud climatologies based on various observations and reanalyses. Clouds cover 55-72% of the Arctic according to surface and satellite observations and 47-93% according to reanalyses. Coefficient of spatial correlation of different observation-derived cloud climatologies varies from 0.7 to 0.95 over the ocean and from 0.3 to 0.75 over land and it is negative for particular reanalyses. In general, winter cloud climatologies from reanalyses are in a bad agreement with observational ones. We use long-term visual observations from Norwegian and Russian meteorological stations in the Norwegian Sea - Kara Sea region to assess cloud interannual variability during the last century and its connection with surface air temperature. We find that a number of warm and overcast winter days is higher in the recent warming than during the cooling of 60-80s years of the 20th century. However, the early 20th century warming was even more cloudy then the recent warming. In general, surface air temperature in the ice band regions and during the cold periods is more sensitive

  5. Solar activity cloudiness effect on NH warming for 1980-2095

    NASA Astrophysics Data System (ADS)

    Mendoza, Víctor M.; Mendoza, Blanca; Garduño, René; Villanueva, Elba E.; Adem, Julián

    2016-03-01

    We use a Thermodynamic Climate Model (TCM) to compute the Northern Hemisphere temperature anomaly for the period 1980-2095, corresponding to the global warming (GW) by the increase of the atmospheric CO2; the GW is in turn diminished as a consequence of the negative anomaly of the solar activity (SA), giving a warming reduction (WR). So the CO2 and the SA represent external climate forcings. The total solar irradiance (TSI) is the main manifestation of the SA and of course is the climate driver; the SA produces besides the solar wind that modulates the flux of galactic cosmic rays (GCR), which in turn modifies the low cloud cover, that by itself influences inversely the mid cloud cover; the combination of both cloudiness yields the so called relevant cloud cover. The GCR-cloudiness effect has a delay of ∼1 yr with respect to TSI effect, which is the time for a SA change to reach the heliopause carried by the solar wind. In order to incorporate this climate mechanism, the TCM now includes the warming due to the vapor condensation by GCR, which causes a decrease in the magnitude of the WR. The TCM was improved by incorporating it new parameterizations of three mechanisms, which are activated by the GW: the atmospheric lapse rate changes; the water vapor emissivity between 8 and 12.5μ is computed with the E-Trans/HITRAN calculator; and changes in this emissivity band according to the relative humidity changes. The 11-yr variability of the TSI time series is filtered to get the trend along 21st century. Two IPCC (2001, 2007) CO2 emission scenarios are used: the high A1FI and the low A1T. Emphasis is made on the results for two particular years: one corresponding to the deepest part of the TSI grand solar minimum in the year 2029, and the other to the end of the century, 2095. The main thermal feedbacks included in TCM are those due to the atmospheric greenhouse effect by water vapor, to the cryosphere-albedo and to cloudiness-albedo. By 2100 the GW from the TCM is 5

  6. Coherent Cloudiness Variability from Sierra Nevada to the Sea in California

    NASA Astrophysics Data System (ADS)

    Sumargo, E.; Cayan, D. R.

    2015-12-01

    Cloud variability serves as the principal modulator of incoming solar radiation. These cloud effects are particularly important in mountain settings such as the Sierra Nevada in California, because the solar irradiance is a primary input to the snowpack energy balance. An important, unanswered question is whether the mountain clouds over the Sierra Nevada are only one part of a larger-scale system or whether they vary distinctly from cloud patterns upstream over the Central Valley and coastal areas. To address this question we investigate cloud variability over California using 19 years (1996-2014) of GOES visible albedo product with 4-km spatial and 30-minute temporal resolutions. Two domains are considered: high elevations in which only higher (>800m) elevations are included, thus excluding the coast and valley clouds, and all elevations which includes all elevations from the offshore North Pacific to Nevada. Our focus is on the spring and early summer period, which is crucial because it includes much of the snowmelt runoff from the Sierra Nevada. Inter-annual variation of cloudiness, represented by the coefficient of variation of cloud albedo, reveals the highest relative variability from California coasts and lowlands in the winter and spring to highlands and mountains in the summer and autumn. This pattern also occurs across shorter to longer time-scales, with coefficient of variation ranging from 30-180% on daily scale to 5-40% on seasonal scale. Considering the spatial structure of anomalous cloudiness, rotated EOF (REOF) analyses of de-seasonalized daily cloud albedo in the high elevation domain yields patterns and temporal variations that are well correlated with those from the all elevation domain. This indicates that, to a large degree, the mountain clouds co-vary with those over the Central Valley and the California coast, even though the valley and coastal clouds include low stratus clouds. The monthly standard deviations of the amplitudes of the time

  7. Assimilation of hyperspectral infrared sounder radiances under cloudy skies in a regional NWP model

    NASA Astrophysics Data System (ADS)

    Wang, Pei

    Satellite measurements are an important source of global observations in support of numerical weather prediction (NWP). The assimilation of satellite radiances under clear skies has greatly improved NWP forecast scores. Since most of the data assimilation models are used for the clear radiances assimilation, an important step for satellite radiances assimilation is the clear location detection. Good clear detection could effectively remove the cloud contamination and keep the clear observations for assimilation. In this dissertation, a new detection method uses collocated high spatial resolution imager data onboard the same platform as the satellite sounders to help IR sounders subpixel cloud detection, such as the Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS), the Crosstrack Infrared Sounder (CrIS) and Visible Infrared Imaging Radiometer Suite (VIIRS). The MODIS cloud mask provides a level of confidence for the observed skies to help AIRS Field-of-View (FOVs) cloud detection. By reducing the cloud contamination, a cold bias in the temperature field and a wet bias in the moisture field are corrected for the atmospheric analysis fields. These less cloud affected analysis fields further improve hurricane track and intensity forecast. The availability of satellite observations that can be assimilated in the model is limited if only the clear radiances are assimilation. An effective way to use the thermodynamic information under partially cloudy regions is to assimilate the "cloud-cleared" radiances (CCRs); CCRs are also called clear equivalent radiances. Because the CCRs are the equivalent clear radiances from the partially cloudy FOVs, they can be directly assimilated into the current data assimilation models without modifications. The AIRS CCRs are assimilated and compared with the AIRS using stand-alone cloud detection and collocated cloud detection. The assimilation of AIRS cloud-cleared radiances directly affects

  8. Using CLOUDY to investigate the physical characteristics in the vicinity of transiting hot Jupiters

    NASA Astrophysics Data System (ADS)

    Turner, Jake; Christie, Duncan; Johnson, Robert; Arras, Phil

    2014-11-01

    Detecting and studying the magnetic fields of exoplanets will allow for the investigation of their interior structure, rotation period, atmospheric retention, moons, and habitability. In this study we simulate the plasma, chemistry, radiation transport, and dynamics of the plasma characteristics in the vicinity of the exoplanet using the code CLOUDY. We previously observed the primary transits of 18 exoplanets in the near-UV photometric band in an attempt to detect their magnetic fields and to search for a wavelength dependence in their planetary radii in order to constrain their atmospheric compositions (Turner et al. 2013, Pearson et al. 2014). It was postulated by Vidotto et al. (2011) that the magnetic fields of all our targets could be constrained if their near-UV light curves show an early ingress compared to their optical light curves, while their egress remains unattenuated. The early near-UV ingress is caused by the presence of a bow shock in front of the planet formed by interactions between the stellar coronal material and the planet’s magnetosphere. If the shocked material is sufficiently optically thick, it will absorb starlight and cause an early ingress in the near-UV light curve. We do not observe an early ingress in any of our targets, but determine upper limits on their magnetic field strengths. All our magnetic field upper limits are well below the predicted magnetic field strengths for hot Jupiters. Vidotto et al. (2011) originally predicted 69 planets should exhibit near-UV asymmetries and currently 19 of those show non-detections. Our result implies that hot Jupiters and hot Neptunes may have abnormally low magnetic field strengths. It may also indicate that the techniques outlined by Vidotto et al. (2011) can only be used in narrow-band spectroscopy and not broad-band photometry or that there is no absorbing species in our wavelength range. Using CLOUDY we have investigated whether there is an absorption species in the bow shock to cause an

  9. On the Interaction between Marine Boundary Layer Cellular Cloudiness and Surface Heat Fluxes

    SciTech Connect

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

    2014-01-02

    The interaction between marine boundary layer cellular cloudiness and surface uxes of sensible and latent heat is investigated. The investigation focuses on the non-precipitating closed-cell state and the precipitating open-cell state at low geostrophic wind speed. The Advanced Research WRF model is used to conduct cloud-system-resolving simulations with interactive surface fluxes of sensible heat, latent heat, and of sea salt aerosol, and with a detailed representation of the interaction between aerosol particles and clouds. The mechanisms responsible for the temporal evolution and spatial distribution of the surface heat fluxes in the closed- and open-cell state are investigated and explained. It is found that the horizontal spatial structure of the closed-cell state determines, by entrainment of dry free tropospheric air, the spatial distribution of surface air temperature and water vapor, and, to a lesser degree, of the surface sensible and latent heat flux. The synchronized dynamics of the the open-cell state drives oscillations in surface air temperature, water vapor, and in the surface fluxes of sensible and latent heat, and of sea salt aerosol. Open-cell cloud formation, cloud optical depth and liquid water path, and cloud and rain water path are identified as good predictors of the spatial distribution of surface air temperature and sensible heat flux, but not of surface water vapor and latent heat flux. It is shown that by enhancing the surface sensible heat flux, the open-cell state creates conditions by which it is maintained. While the open-cell state under consideration is not depleted in aerosol, and is insensitive to variations in sea-salt fluxes, it also enhances the sea-salt flux relative to the closed-cell state. In aerosol-depleted conditions, this enhancement may replenish the aerosol needed for cloud formation, and hence contribute to the perpetuation of the open-cell state as well. Spatial homogenization of the surface fluxes is found to have

  10. How to distinguish between cloudy mini-Neptunes and water/volatile-dominated super-Earths

    SciTech Connect

    Benneke, Björn; Seager, Sara

    2013-12-01

    One of the most profound questions about the newly discovered class of low-density super-Earths is whether these exoplanets are predominately H{sub 2}-dominated mini-Neptunes or volatile-rich worlds with gas envelopes dominated by H{sub 2}O, CO{sub 2}, CO, CH{sub 4}, or N{sub 2}. Transit observations of the super-Earth GJ 1214b rule out cloud-free H{sub 2}-dominated scenarios, but are not able to determine whether the lack of deep spectral features is due to high-altitude clouds or the presence of a high mean molecular mass atmosphere. Here, we demonstrate that one can unambiguously distinguish between cloudy mini-Neptunes and volatile-dominated worlds based on wing steepness and relative depths of absorption features in moderate-resolution near-infrared transmission spectra (R ∼ 100). In a numerical retrieval study, we show for GJ 1214b that an unambiguous distinction between a cloudy H{sub 2}-dominated atmosphere and cloud-free H{sub 2}O atmosphere will be possible if the uncertainties in the spectral transit depth measurements can be reduced by a factor of ∼3 compared to the published Hubble Space Telescope Wide-Field Camera 3 and Very Large Telescope transit observations by Berta et al. and Bean et al. We argue that the required precision for the distinction may be achievable with currently available instrumentation by stacking 10-15 repeated transit observations. We provide a scaling law that scales our quantitative results to other transiting super-Earths and Neptunes such as HD 97658b, 55 Cnc e, GJ 3470b and GJ 436b. The analysis in this work is performed using an improved version of our Bayesian atmospheric retrieval framework. The new framework not only constrains the gas composition and cloud/haze parameters, but also determines our confidence in having detected molecules and cloud/haze species through Bayesian model comparison. Using the Bayesian tool, we demonstrate quantitatively that the subtle transit depth variation in the Berta et al. data is

  11. Water ice clouds on Mars: a study of partial cloudiness with a global climate model and MARCI data

    NASA Astrophysics Data System (ADS)

    Pottier, Alizée; Montmessin, Franck; Forget, François; Wolff, Mike; Navarro, Thomas; Millour, Ehouarn; Madeleine, Jean-Baptiste; Spiga, Aymeric; Bertrand, Tanguy

    2015-04-01

    There is a large reservoir of water ice on Mars in the polar caps, that sublimates in summer and releases water vapor. Water is then advected in the atmospheric circulation that evolves seasonally. This vapor forms clouds, frost, and can also be adsorbed in the soil. In a global study of the water cycle, water ice clouds play a key part in the martian climate. There is a need to understand better their distribution and radiative effect. The tool used in this study is the global climate model (GCM) of the Laboratoire de Météorologie Dynamique. It is made up of a core that computes fluid dynamics, and a physical part that gathers a number of parametrised processes. It includes tracers and the condensation and sublimation of water in the atmosphere and on the ground, allowing a study of the complete water cycle. To improve the representation of water ice clouds in the model, a new parametrisation of partial cloudiness has been implemented and will be presented. Indeed, model cells are hundreds of kilometers wide, and it is quite unrealistic to suppose that cloud coverage is always uniform in them. Furthermore, the model was quite unstable since the implementation of the radiative effect of clouds, and partial cloudiness had the effect of reducing this instability. In practice, a subgrid temperature distribution is supposed, and the temperature computed in the model is interpreted as its mean. The subgrid scale temperature distribution is simple, and its width is a free parameter. Using this distribution, the fraction of the grid cells under the water vapor condensation temperature is interpreted as the fraction of the cell in which clouds form (or cloud fraction). From these fractions at each height a total partial cloudiness (the clouds as seen from the orbit) is deduced. The radiative transfer is computed twice, for the clear area and for the cloudy one. Observing the water cycle with this new parametrisation, some differences are seen with standard runs. These

  12. The SunCloud project: worldwide compilation of long-term series of sunshine duration and cloudiness observations

    NASA Astrophysics Data System (ADS)

    Sanchez-Lorenzo, Arturo; Pallé, Enric; Wild, Martin; Calbó, Josep; Brunetti, Michelle; Stanhill, Gerald; Brázdil, Rudolf; Barriendos, Mariano; Pereira, Paulo; Azorin-Molina, César

    2010-05-01

    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. Equally, we plan to calibrate sunshine duration measurements against planetary albedo estimations from the Earthshine measurements and other satellite radiation data. 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 abstract we seek to encourage the climate community to contribute with their own local datasets to the SunCloud project. In the near future we will create a webpage with the main details of this project.

  13. Photon path length distributions for cloudy skies  oxygen A-Band measurements and model calculations

    NASA Astrophysics Data System (ADS)

    Funk, O.; Pfeilsticker, K.

    2003-03-01

    This paper addresses the statistics underlying cloudy sky radiative transfer (RT) by inspection of the distribution of the path lengths of solar photons. Recent studies indicate that this approach is promising, since it might reveal characteristics about the diffusion process underlying atmospheric radiative transfer (Pfeilsticker, 1999). Moreover, it uses an observable that is directly related to the atmospheric absorption and, therefore, of climatic relevance. However, these studies are based largely on the accuracy of the measurement of the photon path length distribution (PPD). This paper presents a refined analysis method based on high resolution spectroscopy of the oxygen A-band. The method is validated by Monte Carlo simulation atmospheric spectra. Additionally, a new method to measure the effective optical thickness of cloud layers, based on fitting the measured differential transmissions with a 1-dimensional (discrete ordinate) RT model, is presented. These methods are applied to measurements conducted during the cloud radar inter-comparison campaign CLARE’98, which supplied detailed cloud structure information, required for the further analysis. For some exemplary cases, measured path length distributions and optical thicknesses are presented and backed by detailed RT model calculations. For all cases, reasonable PPDs can be retrieved and the effects of the vertical cloud structure are found. The inferred cloud optical thicknesses are in agreement with liquid water path measurements.

  14. Two-dimensional radiative transfer in cloudy atmospheres - The spherical harmonic spatial grid method

    NASA Technical Reports Server (NTRS)

    Evans, K. F.

    1993-01-01

    A new two-dimensional monochromatic method that computes the transfer of solar or thermal radiation through atmospheres with arbitrary optical properties is described. The model discretizes the radiative transfer equation by expanding the angular part of the radiance field in a spherical harmonic series and representing the spatial part with a discrete grid. The resulting sparse coupled system of equations is solved iteratively with the conjugate gradient method. A Monte Carlo model is used for extensive verification of outgoing flux and radiance values from both smooth and highly variable (multifractal) media. The spherical harmonic expansion naturally allows for different levels of approximation, but tests show that the 2D equivalent of the two-stream approximation is poor at approximating variations in the outgoing flux. The model developed here is shown to be highly efficient so that media with tens of thousands of grid points can be computed in minutes. The large improvement in efficiency will permit quick, accurate radiative transfer calculations of realistic cloud fields and improve our understanding of the effect of inhomogeneity on radiative transfer in cloudy atmospheres.

  15. Evaluation of the Impact of AIRS Radiance and Profile Data Assimilation in Partly Cloudy Regions

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi; Jedlovec, Gary

    2013-01-01

    Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) are run to examine the impact AIRS radiances and retrieved profiles. Statistical evaluation of a long-term series of forecast runs will be compared along with preliminary results of in-depth investigations for select case comparing the analysis increments in partly cloudy regions and short-term forecast impacts.

  16. Light-pollution model for cloudy and cloudless night skies with ground-based light sources.

    PubMed

    Kocifaj, Miroslav

    2007-05-20

    The scalable theoretical model of light pollution for ground sources is presented. The model is successfully employed for simulation of angular behavior of the spectral and integral sky radiance and/or luminance during nighttime. There is no restriction on the number of ground-based light sources or on the spatial distribution of these sources in the vicinity of the measuring point (i.e., both distances and azimuth angles of the light sources are configurable). The model is applicable for real finite-dimensional surface sources with defined spectral and angular radiating properties contrary to frequently used point-source approximations. The influence of the atmosphere on the transmitted radiation is formulated in terms of aerosol and molecular optical properties. Altitude and spectral reflectance of a cloud layer are the main factors introduced for simulation of cloudy and/or overcast conditions. The derived equations are translated into numerically fast code, and it is possible to repeat the entire set of calculations in real time. The parametric character of the model enables its efficient usage by illuminating engineers and/or astronomers in the study of various light-pollution situations. Some examples of numerical runs in the form of graphical results are presented. PMID:17514252

  17. Acceleration of pH variation in cloudy apple juice using electrodialysis with bipolar membranes.

    PubMed

    Lam Quoc, A; Lamarche, F; Makhlouf, J

    2000-06-01

    The purpose of this study was to accelerate pH variation in cloudy apple juice using electrodialysis (ED). The testing was conducted using two ED configurations. The bipolar and cationic membrane configuration showed that reducing the spacing from 8 to 0.75 mm had little effect on treatment time, whereas stacking eight bipolar membranes reduced acidification time by 30%, although the treatment still took too long (21 min). Furthermore, it was not possible to acidify apple juice to a pH of 2.0 to completely inhibit enzymatic browning. The bipolar and anionic membrane configuration helped to accelerate the acidification step by a factor of 3, increasing the yield from 3.3 to 10 L of juice/m(2) membrane/min. Moreover, treatment time was inversely proportional to the size of the membrane stack. The speed at which the pH of acidified juice returned to its initial value was, however, 4 times slower than the speed of acidification, giving a yield of 2.5 L of juice/m(2) membrane/min. By accelerating the acidification step, ED treatment with bipolar and anionic membranes results in more effective polyphenol oxidase activity and more rapid control of juice browning at pH 2.0. Also, the treatment has very little effect on the chemical composition and organoleptic quality of apple juice. PMID:10888515

  18. A comparative study between spiral-filter press and belt press implemented in a cloudy apple juice production process.

    PubMed

    De Paepe, Domien; Coudijzer, Katleen; Noten, Bart; Valkenborg, Dirk; Servaes, Kelly; De Loose, Marc; Diels, Ludo; Voorspoels, Stefan; Van Droogenbroeck, Bart

    2015-04-15

    In this study, advantages and disadvantages of the innovative, low-oxygen spiral-filter press system were studied in comparison with the belt press, commonly applied in small and medium size enterprises for the production of cloudy apple juice. On the basis of equivalent throughput, a higher juice yield could be achieved with spiral-filter press. Also a more turbid juice with a higher content of suspended solids could be produced. The avoidance of enzymatic browning during juice extraction led to an attractive yellowish juice with an elevated phenolic content. Moreover, it was found that juice produced with spiral-filter press demonstrates a higher retention of phenolic compounds during the downstream processing steps and storage. The results demonstrates the advantage of the use of a spiral-filter press in comparison with belt press in the production of a high quality cloudy apple juice rich in phenolic compounds, without the use of oxidation inhibiting additives. PMID:25466116

  19. Pilot-scale production of cloudy juice from low-quality pear fruit under low-oxygen conditions.

    PubMed

    De Paepe, Domien; Coudijzer, Katleen; Noten, Bart; Valkenborg, Dirk; Servaes, Kelly; De Loose, Marc; Diels, Ludo; Voorspoels, Stefan; Van Droogenbroeck, Bart

    2015-04-15

    In this study, a process for the production of premium quality yellowish, cloudy pear juice from low-quality fruit under low-oxygen conditions was developed. The production process consisted of (1) shredding, (2) pressing with spiral-filter technology including a vacuumised extraction cell, (3) holding in an inert gas buffer tank, (4) pasteurisation, (5) and refrigerated storage. First, the system parameters of a spiral-filter press were optimised with the aim of producing a yellowish, cloudy pear juice with the highest possible juice yield. A maximum juice yield of 78% could be obtained. Enzymatic browning during juice extraction could be suppressed as a result of the fast processing and the low air (oxygen) levels in the extraction chamber of the spiral-filter press. Furthermore, we observed that instantaneous pasteurisation at 107 °C for 6s, subsequent aluminium laminate packaging and cold storage had only a minimum effect on the phenolic composition. PMID:25466096

  20. Validation of Nimbus-7 temperature-humidity infrared radiometer estimates of cloud type and amount

    NASA Technical Reports Server (NTRS)

    Stowe, L. L.

    1982-01-01

    Estimates of clear and low, middle and high cloud amount in fixed geographical regions approximately (160 km) squared are being made routinely from 11.5 micron radiance measurements of the Nimbus-7 Temperature-Humidity Infrared Radiometer (THIR). The purpose of validation is to determine the accuracy of the THIR cloud estimates. Validation requires that a comparison be made between the THIR estimates of cloudiness and the 'true' cloudiness. The validation results reported in this paper use human analysis of concurrent but independent satellite images with surface meteorological and radiosonde observations to approximate the 'true' cloudiness. Regression and error analyses are used to estimate the systematic and random errors of THIR derived clear amount.

  1. Prevention of conglomerate formation in not-from-concentrate single-cultivar cloudy apple juice by using different treatment methods.

    PubMed

    Schnürer, Monika; Vogl, Karl; Gössinger, Manfred

    2013-02-01

    Conglomerates may form at the bottom of bottles containing not-from-concentrate (NFC) cloudy apple juice obtained from a single apple cultivar. Since dissociation or dispersion of these conglomerates cannot be achieved by shaking, the juice appears unsightly, and consumers can mistake the product as being spoilt. Juice from Elstar and Braeburn apples was treated with selected enzymes (gluco-amylase, alpha-amylase, pectin lyase, polygalacturonase and protease) and by using bentonite and a separator. The effects of these treatments on the formation of conglomerates in cloudy apple juice have been studied, and the treatment effects on turbidity and cloud stability have been documented. Conglomerates were observed in juices treated with protease or bentonite and in control juices. However, no conglomerates were observed in the juice samples treated with gluco-amylase, alpha-amylase, pectin lyase or pectin lyase in combination with polygalacturonase. The results obtained after treatment with a separator were not consistent. It is supposed that carbohydrate fractions play a more important role in conglomerate formation than proteins and phenols. Gluco-amylase and alpha-amylase treatment also provides good cloud stability, and thus can be a suitable method for preventing conglomerate formation in single-cultivar NFC cloudy apple juice. PMID:23239759

  2. Radiative Susceptibility of Cloudy Atmospheres to Droplet Number Perturbations: 2. Global analysis from MODIS

    NASA Technical Reports Server (NTRS)

    Oreopoulos, Lazaros; Platnick, Steven

    2008-01-01

    Global distributions of albedo susceptibility for areas covered by liquid clouds are presented for 4 months in 2005. The susceptibility estimates are based on expanded definitions presented in a companion paper and include relative cloud droplet number concentration (CDNC) changes, perturbations in cloud droplet asymmetry parameter and single-scattering albedo, atmospheric/surface effects, and incorporation of the full solar spectrum. The cloud properties (optical thickness and effective radius) used as input in the susceptibility calculations come from MODIS Terra and Aqua Collection 5 gridded data. Geographical distributions of susceptibility corresponding to absolute ( absolute cloud susceptibility ) and relative ( relative cloud susceptibility ) CDNC changes are markedly different indicating that the detailed nature of the cloud microphysical perturbation is important for determining the radiative forcing associated with the first indirect aerosol effect. However, both types of susceptibility exhibit common characteristics such as significant reductions when perturbations in single-scattering properties are omitted, significant increases when atmospheric absorption and surface albedo effects are ignored, and the tendency to decrease with latitude, to be higher over ocean than over land, and to be statistically similar between the morning and afternoon MODIS overpasses. The satellite-based susceptibility analysis helps elucidate the role of present-day cloud and land surface properties in indirect aerosol forcing responses. Our realistic yet moderate CDNC perturbations yield forcings on the order of 1-2 W/sq m for cloud optical property distributions and land surface spectral albedos observed by MODIS. Since susceptibilities can potentially be computed from model fields, these results have practical application in assessing the reasonableness of model-generated estimates of the aerosol indirect radiative forcing.

  3. A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion.

    PubMed

    Sing, David K; Fortney, Jonathan J; Nikolov, Nikolay; Wakeford, Hannah R; Kataria, Tiffany; Evans, Thomas M; Aigrain, Suzanne; Ballester, Gilda E; Burrows, Adam S; Deming, Drake; Désert, Jean-Michel; Gibson, Neale P; Henry, Gregory W; Huitson, Catherine M; Knutson, Heather A; des Etangs, Alain Lecavelier; Pont, Frederic; Showman, Adam P; Vidal-Madjar, Alfred; Williamson, Michael H; Wilson, Paul A

    2016-01-01

    Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1-1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet's formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3-5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures. PMID:26675732

  4. Getting Students to Observe the Night Sky, Even When Your Sky is Cloudy Half the Time

    NASA Astrophysics Data System (ADS)

    Shipman, Harry L.

    2010-01-01

    Teachers of introductory astronomy classes often wish to get our students to look at the night sky However, most educational institutions in America are located in regions where cloudy nights are relatively common. This paper describes a low cost way to integrate observations into a course which lacks a dedicated astronomy lab. Students in two large. general science classes in fall 2008 and spring 2009 were asked to participate in one of two global star-counting projects. The fall project was coordinated by UCAR and asked for observations of the constellation Cygnus (http://www.windows.ucar.edu/citizen_science/starcount/results.html). The spring project was run by Project Globe and asked for observations of the constellation Orion. (http://www.globe.gov/GaN/ ). In both cases, students simply find the constellation, match the star pattern to charts that go to different limiting magnitudes, and report the data to the coordinating organization. A copy of the report is sent to the course instructor. The instructor can ask for additional information. Did it work? The success of this project was evaluated by analyzing the e-mail messages that students returned in response to the assignment. In both courses, a very large majority of the students actually did the exercise and submitted a report. Students reported that observing the sky in this way was satisfying to them., and sometimes the reports were quite enthusiastic. In spring 2009, some preparatory activies were conducted during class that were designed to sensitize students to the beauty of the sky. Analysis of student reports indicated that these preparatory activities were helpful, but not as helpful as the instructor would like. This research is part of the Teacher Professional Continuum project at the University of Delaware, which is supported by the National Science Foundation.

  5. Consistency of ARESE II Cloud Absorption Estimates and Sampling Issues

    NASA Technical Reports Server (NTRS)

    Oreopoulos, L.; Marshak, A.; Cahalan, R. F.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Data from three cloudy days (March 3, 21, 29, 2000) of the ARM Enhanced Shortwave Experiment II (ARESE II) were analyzed. Grand averages of broadband absorptance among three sets of instruments were compared. Fractional solar absorptances were approx. 0.21-0.22 with the exception of March 3 when two sets of instruments gave values smaller by approx. 0.03-0.04. The robustness of these values was investigated by looking into possible sampling problems with the aid of 500 nm spectral fluxes. Grand averages of 500 nm apparent absorptance cover a wide range of values for these three days, namely from a large positive (approx. 0.011) average for March 3, to a small negative (approximately -0.03) for March 21, to near zero (approx. 0.01) for March 29. We present evidence suggesting that a large part of the discrepancies among the three days is due to the different nature of clouds and their non-uniform sampling. Hence, corrections to the grand average broadband absorptance values may be necessary. However, application of the known correction techniques may be precarious due to the sparsity of collocated flux measurements above and below the clouds. Our analysis leads to the conclusion that only March 29 fulfills all requirements for reliable estimates of cloud absorption, that is, the presence of thick, overcast, homogeneous clouds.

  6. CU AMAX-DOAS applications in cloud-free and cloudy atmospheres: innovative Scattered Sun Light observations of trace gases and aerosol extinction

    NASA Astrophysics Data System (ADS)

    Volkamer, R.; Baidar, S.; Coburn, S.; Dix, B. K.; Oetjen, H.; Ortega, I.; Sinreich, R.; Atmospeclab

    2011-12-01

    An innovative airborne scanning multi-axis differential optical absorption spectroscopy (CU AMAX-DOAS) instrument has been developed at the University of Colorado, Boulder. The instrument collects scattered sunlight spectra in a sequence of discrete viewing angles, and employs the DOAS method (inherently calibrated, and selective) to simultaneously retrieve multiple trace gases, e.g., nitrogen dioxide (NO2), nitrous acid (HONO), formaldehyde (HCHO), glyoxal (CHOCHO), bromine oxide (BrO), iodine oxide (IO), chlorine dioxide (OClO), water vapor (H2O), and oxygen dimers (O4, at 360nm, 477nm, and 632nm) differential slant column densities (dSCD). Vertical profiles of these gases and multi-spectral aerosol extinction are inferred by combining Monte-Carlo Radiative Transfer Modelling (RTM) and optimal estimation techniques to construct a model atmosphere that can in principle represent 3D clouds and aerosols. The atmospheric state of this model atmosphere is constrained by observations of O4 dSCDs, Raman Scattering Probability (RSP), and intensity ratios, i.e., quantities that depend solely on relative intensity changes, without need for a direct sun view, or absolute radiance calibration. We show results from ongoing validation efforts (NOAA TwinOtter aircraft during CalNex and CARES), and demonstrate vertical profile retrievals (NSF/NCAR GV over the tropical Pacific Ocean) in both cloud-free and cloudy atmospheres.

  7. Methane and carbon dioxide total column retrievals from cloudy GOSAT soundings over the oceans

    NASA Astrophysics Data System (ADS)

    Schepers, D.; Butz, A.; Hu, H.; Hasekamp, O. P.; Arnold, S. G.; Schneider, M.; Feist, D. G.; Morino, I.; Pollard, D.; Aben, I.; Landgraf, J.

    2016-05-01

    We present a novel physics-based retrieval method to infer total column mixing ratios of methane (XCH4) and carbon dioxide (XCO2) from space-borne short-wavelength infrared (SWIR) Earth radiance observations over the cloud-covered ocean. In nadir observing geometry in the SWIR spectral range, backscattering at the ocean surface is negligible. Hence, space-borne radiance measurements of ocean scenes generally do not provide sufficient level to retrieve XCO2 and XCH4. Our approach specifically targets cloudy GOSAT ocean soundings to provide sufficient radiance signal in nadir soundings in ocean areas. Currently, exploiting space-borne SWIR soundings over oceans relies on soundings in Sun glint geometry, observing the specular solar reflection at the ocean surface. The glint observation mode requires cloud-free conditions and a suitable observation geometry, severely limiting their number and geographical coverage. The proposed method is based on the existing RemoTeC algorithm that is extensively used to retrieve CH4 and CO2 columns from GOSAT SWIR measurements over land. For ocean pixels, we describe light scattering by clouds and aerosols by a single-layer water cloud with Gaussian height distribution. We infer the height and the geometrical thickness of the cloud layer jointly with the droplet size and the number density and the column abundances of CO2, CH4, and H2O. The CO2 and CH4 column product is validated with ground-based total column measurements performed at eight stations from the TCCON network that are geographically close to an ocean coastline. For the TCCON site with the most robust statistics (Lauder, New Zealand), we find a retrieval bias of 0.36% for XCH4 combined with a standard deviation of retrieval errors of 1.12%. For XCO2, the bias is 0.51% combined with a standard deviation of 1.03%. Averaged over all TCCON sites, our retrievals are biased -0.01% for XCO2 and -0.32% for XCH4. The standard deviation of station biases amounts to 0.45% for XCO2

  8. Multi scale imaging of the Cloudy Zone in the Tazewell IIICD Meteorite

    NASA Astrophysics Data System (ADS)

    Einsle, J. F.; Harrison, R. J.; Nichols, C. I. O.; Blukis, R.; Midgley, P. A.; Eggeman, A.; Saghi, Z.; Bagot, P.

    2015-12-01

    Paleomagnetic studies of iron and stony iron meteorites suggest that many small planetary bodies possessed molten cores resulting in the generation of a magnetic field. As these bodies cooled, Fe-Ni metal trapped within their mantle underwent a series of low-temperature transitions, leading to the familiar Widmanstatten intergrowth of kamacite and taenite. Adjacent to the kamacite/taenite interface is the so-called "cloudy zone" (CZ): a nanoscale intergrowth of tetrataenite islands in an Fe-rich matrix phase formed via spinodal decomposition. It has recently been shown (Bryson et al. 2015, Nature) that the CZ encodes a time-series record of the evolution of the magnetic field generated by the molten core of the planetary body. Extracting meaningful paleomagnetic data from the CZ relies, on a thorough understanding of the 3D chemical and magnetic properties of the intergrowth focsusing on the interactions between the magnetically hard tetrataenite islands and the magnetically soft matrix. Here we present a multi scale study of the chemical and crystallographic make up of the CZ in the Tazewell IIICD meteorite, using a range of advanced microscopy techniques. The results provide unprecedented insight into the architecture of the CZ, with implications for how the CZ acquires chemical transformation remanance during cooling on the parent body. Previous 2D transmission electron microscope studies of the CZ suggested that the matrix is an ordered Fe3Ni phase with the L12 structure. Interpretation of the electron diffraction patterns and chemical maps in these studies was hindered by a failure to resolve signals from overlapping island and matrix phases. Here we obtain high resolution electron diffraction and 3D chemical maps with near atomic resolution using a combination of scanning precession electron diffraction, 3D STEM EDS and atom probe tomography. Using this combined methodology we reslove for the first time the phenomena of secondary precipitation in the

  9. A Fast Radiative Transfer Parameterization Under Cloudy Condition in Solar Spectral Region

    NASA Astrophysics Data System (ADS)

    Yang, Q.; Liu, X.; Yang, P.; Wang, C.

    2014-12-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) system, which is proposed and developed by NASA, will directly measure the Earth's thermal infrared spectrum (IR), the spectrum of solar radiation reflected by the Earth and its atmosphere (RS), and radio occultation (RO). IR, RS, and RO measurements provide information on the most critical but least understood climate forcings, responses, and feedbacks associated with the vertical distribution of atmospheric temperature and water vapor, broadband reflected and emitted radiative fluxes, cloud properties, surface albedo, and surface skin temperature. To perform Observing System Simulation Experiments (OSSE) for long term climate observations, accurate and fast radiative transfer models are needed. The principal component-based radiative transfer model (PCRTM) is one of the efforts devoted to the development of fast radiative transfer models for simulating radiances and reflecatance observed by various hyperspectral instruments. Retrieval algorithm based on PCRTM forward model has been developed for AIRS, NAST, IASI, and CrIS. It is very fast and very accurate relative to the training radiative transfer model. In this work, we are extending PCRTM to UV-VIS-near IR spectral region. To implement faster cloudy radiative transfer calculations, we carefully investigated the radiative transfer process under cloud condition. The cloud bidirectional reflectance was parameterized based on off-line 36-stream multiple scattering calculations while few other lookup tables were generated to describe the effective transmittance and reflectance of the cloud-clear-sky coupling system in solar spectral region. The bidirectional reflectance or the irradiance measured by satellite may be calculated using a simple fast radiative transfer model providing the type of cloud (ice or water), optical depth of the cloud, optical depth of both atmospheric trace gases above and below clouds, particle size of the cloud, as well

  10. STS-107 Flight Day 8 Highlights

    NASA Astrophysics Data System (ADS)

    2003-01-01

    This video shows the activities of the STS-107 crew (Rick Husband, Commander; William McCool, Pilot; Kalpana Chawla, David Brown, Michael Anderson, Laurel Clark, Mission Specialists, Ilan Ramon, Payload Specialist) during flight day 8 of the Columbia orbiter's final flight. The primary activities of flight day 8 are spaceborne experiments. Some background information is given on the SOFBALL (Structure of Flame Balls at Low Lewis-Number) microgravity experiment as footage of the flame balls is shown. The video also shows the MEIDEX (Mediterranean Israeli Dust Experiment) calibrating on the Moon. The six STARS (Space Technology and Research Students) international student experiments are profiled, including experiments on carpenter bees (Liechtenstein), spiders (Australia), silkworms (China), ants (United States), crystal growth (Israel), and fish embryos (Japan). A commercial experiment on roses is also profiled. Astronaut Clark gives a tour of the SpaceHab RDM (Research Double Module), in the space shuttle's payload bay. Astronauts McCool and Ramon take turns on an exercise machine. The video includes a partly cloudy view of the Pacific Ocean.