WorldWideScience

Sample records for surface energy balances

  1. Surface Energy Balance System (SEBS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    A Surface Energy Balance System (SEBS) has been installed collocated with each deployed Eddy Correlation Flux Measurement System (ECOR) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, North Slope of Alaska (NSA) site, first ARM Mobile Facility (AMF1), second ARM Mobile Facility (AMF2), and third ARM Mobile Facility (AMF3) at Oliktok Point (OLI). A SEBS was also deployed with the Tropical Western Pacific (TWP) site, before it was decommissioned. Data from these sites, including the retired TWP, are available in the ARM Data Archive. The SEBS consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.

  2. SURFACE ENERGY BALANCE OVER ORANGE ORCHARD USING SURFACE RENEWAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Salvatore Barbagallo

    2009-12-01

    Full Text Available Reliable estimation of surface sensible and latent heat flux is the most important process to appraise energy and mass exchange among atmosphere and biosphere. In this study the surface energy fluxes were measured over an irrigated orange orchard during 2005-2008 monitoring periods using a Surface Renewal- Energy Balance approach. The experimental area is located in a representative orchard growing area of eastern Sicily (Italy. The performance of Surface Renewal (SR analysis for estimating sensible heat flux (H was analysed and evaluated in terms of correlation with H fluxes from the eddy covariance (EC method. Study revealed that the mean available energy (RN- G and latent heat flux (LE were of about 300 W m-2 and 237 W m-2, respectively, during dry periods and unstable-case atmospheric conditions. The estimated crop coefficient Kc values for the orchard crop averaged close to 0.80, which is considerably higher than previous FAO studies that found the value to be 0.65 for citrus with 70% of ground cover. The intercepted photosynthetically active radiation (LI PAR by the crop was measured and relationships between LAI and crop coefficient (Kc were established.

  3. The energy balance of the earth's surface : a practical approach

    NARCIS (Netherlands)

    Bruin, de H.A.R.

    1982-01-01

    This study is devoted to the energy balance of the earth's surface with a special emphasis on practical applications. A simple picture of the energy exchange processes that take place at the ground is the following. Per unit time and area an amount of radiant energy is supplied to the surface. This

  4. Soil heat flux and day time surface energy balance closure

    Indian Academy of Sciences (India)

    Soil heat flux is an important input component of surface energy balance. Estimates of soil heat flux were made in the year 2008 using soil temperature data at Astronomical Observatory, Thiruvananthapuram, south Kerala. Hourly values of soil heat flux from 00 to 24 LST are presented for selected days typical of the winter, ...

  5. Seasonal contrast in the surface energy balance of the Sahel

    Science.gov (United States)

    Miller, R. L.; Slingo, A.; Barnard, J. C.; Kassianov, E.

    2009-07-01

    Over much of the world, heating of the surface by sunlight is balanced predominately by evaporative cooling. However, at the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) in Niamey, Niger, evaporation makes a significant contribution to the surface energy balance only at the height of the rainy season, when precipitation has replenished the reservoir of soil moisture. The AMF was placed at Niamey from late 2005 to early 2007 to provide measurements of surface fluxes in coordination with geostationary satellite retrievals of radiative fluxes at the top of the atmosphere, as part of the RADAGAST experiment to calculate atmospheric radiative divergence. We use observations at the mobile facility to investigate how the surface adjusts to radiative forcing throughout the year. The surface response to solar heating varies with changes in atmospheric water vapor associated with the seasonal reversal of the West African monsoon, which modulates the greenhouse effect and the ability of the surface to radiate thermal energy directly to space. During the dry season, sunlight is balanced mainly by longwave radiation and the turbulent flux of sensible heat. The ability of longwave radiation to cool the surface drops after the onset of southwesterly surface winds at Niamey, when moist, oceanic air flows onshore, increasing local column moisture and atmospheric opacity. Following the onset of southwesterly flow, evaporation remains limited by the supply of moisture from precipitation. By the height of the rainy season, however, sufficient precipitation has accumulated that evaporation is controlled by incident sunlight, and radiative forcing of the surface is balanced comparably by the latent, sensible, and longwave fluxes. Evaporation increases with the leaf area index, suggesting that plants are a significant source of atmospheric moisture and may tap moisture stored beneath the surface that accumulated during a previous rainy season. Surface radiative forcing

  6. Energy and water cycle over the Tibetan plateau : surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Zhongbo; Zhang, Ting; Ma, Yaoming; Jia, Li; Wen, Jun

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy

  7. Energy and water cycle over the Tibetan Plateau: surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Z.; Zhang, T.; Ma, Y.; Jia, L.; Wen, J.

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy

  8. A Surface Temperature Initiated Closure (STIC) for surface energy balance fluxes

    DEFF Research Database (Denmark)

    Mallick, Kaniska; Jarvis, Andrew J.; Boegh, Eva

    2014-01-01

    The use of Penman–Monteith (PM) equation in thermal remote sensing based surface energy balance modeling is not prevalent due to the unavailability of any direct method to integrate thermal data into the PM equation and due to the lack of physical models expressing the surface (or stomatal) and b...

  9. Summertime influences of tidal energy advection on the surface energy balance in a mangrove forest

    Directory of Open Access Journals (Sweden)

    J. G. Barr

    2013-01-01

    Full Text Available Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive 10-day study was conducted in a mangrove forest located along the Shark River in the Everglades National Park, FL, USA. Forest–atmosphere turbulent exchanges of energy were quantified with an eddy covariance system installed on a 30-m-tall flux tower. Energy transport associated with tidal activity was calculated based on a coupled mass and energy balance approach. The mass balance included tidal flows and accumulation of water on the forest floor. The energy balance included temporal changes in enthalpy, resulting from tidal flows and temperature changes in the water column. By serving as a net sink or a source of available energy, flood waters reduced the impact of high radiational loads on the mangrove forest. Also, the regression slope of available energy versus sink terms increased from 0.730 to 0.754 and from 0.798 to 0.857, including total enthalpy change in the water column in the surface energy balance for 30-min periods and daily daytime sums, respectively. Results indicated that tidal inundation provides an important mechanism for heat removal and that tidal exchange should be considered in surface energy budgets of coastal ecosystems. Results also demonstrated the importance of including tidal energy advection in mangrove biophysical models that are used for predicting ecosystem

  10. CERES Energy Balanced and Filled(EBAF) Surface Monthly means data in netCDF

    Data.gov (United States)

    National Aeronautics and Space Administration — The Clouds and the Earth's Radiant Energy System (CERES) Energy Balanced and Filled (EBAF) Surface product provides computed monthly mean surface radiative fluxes...

  11. The Global Energy Balance Archive (GEBA): A database for the worldwide measured surface energy fluxes

    Science.gov (United States)

    Wild, Martin; Ohmura, Atsumu; Schär, Christoph; Müller, Guido; Hakuba, Maria Z.; Mystakidis, Stefanos; Arsenovic, Pavle; Sanchez-Lorenzo, Arturo

    2017-02-01

    The Global Energy Balance Archive (GEBA) is a database for the worldwide measured energy fluxes at the Earth's surface. GEBA is maintained at ETH Zurich (Switzerland) and has been founded in the 1980s by Prof. Atsumu Ohmura. It has continuously been updated and currently contains around 2500 stations with 500`000 monthly mean entries of various surface energy balance components. Many of the records extend over several decades. The most widely measured quantity available in GEBA is the solar radiation incident at the Earth's surface ("global radiation"). The data sources include, in addition to the World Radiation Data Centre (WRDC) in St. Petersburg, data reports from National Weather Services, data from different research networks (BSRN, ARM, SURFRAD), data published in peer-reviewed publications and data obtained through personal communications. Different quality checks are applied to check for gross errors in the dataset. GEBA is used in various research applications, such as for the quantification of the global energy balance and its spatiotemporal variation, or for the estimation of long-term trends in the surface fluxes, which enabled the detection of multi-decadal variations in surface solar radiation, known as "global dimming" and "brightening". GEBA is further extensively used for the evaluation of climate models and satellite-derived surface flux products. On a more applied level, GEBA provides the basis for engineering applications in the context of solar power generation, water management, agricultural production and tourism. GEBA is publicly accessible over the internet via www.geba.ethz.ch.

  12. Modelling evapotranspiration using the surface energy balance systems (sebs) and landsat tm data (rabat region, morocco)

    NARCIS (Netherlands)

    Kwast, J. van der; Jong, S.M. de

    2004-01-01

    Modelling and understanding the surface energy balance is important for assessing the re-distribution of moisture and heat in soil and atmosphere. The Surface Energy Balance System (SEBS) estimates turbulent heat fluxes using satellite earth observation data in the visible, near infrared, and

  13. Surface energy balance measurements in the Mexico City: a review

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda Martinez, A. [Universidad Veracruzana, Xalapa, Veracruz (Mexico); Jauregui Ostos, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, UNAM, Mexico, D.F. (Mexico)

    2005-01-01

    During the last decade of the 20th Century, diverse campaigns for measuring the atmospheric energy balance were performed in downtown Mexico City (School of Mines and Preparatory School No. 7), in the southern suburbs (University Reserve) and in the surrounding rural areas (Plan Texcoco), in addition to a campaign carried out in 1985 in the Tacubaya district, a suburban western peripheral site. The objective was to obtain data for a better understanding of the climatic alterations due to urbanization, particularly to describe the role that the modification of the natural ground cover has played as a result of paving and the construction of urban canyons. In this paper, a review of these campaigns is presented. Energy partitioning in some areas (Tacubaya and Preparatory School No.7) is similar to that observed in urban centers of middle latitudes, whereas the major contrast was observed between Texcoco, with maximum energy consumption through evaporation, and School of Mines, where the latent heat is as low as in a desert. From the values of the correlations among the different components of energy balance, it may be possible to attempt the modeling of the diverse components of energy balance by means of regression equations starting from the net radiation. Those same coefficients distinguish the type of environment: urban, suburban or rural. [Spanish] Las primeras mediciones de balance energetico en la Ciudad de Mexico se realizaron en 1985 en un suburbio al poniente de la ciudad (el observatorio de Tacubaya). Ya en la decada de los anos noventa del siglo XX, dichas observaciones se multiplicaron tanto en el centro historico (antigua Escuela de Minas y en el edificio de la Preparatoria No. 7), como en otros sitios al sur (en terrenos de Ciudad Universitaria) y en la periferia rural (Plan Texcoco). El proposito de estas mediciones ha sido tener un mejor entendimiento de las alteraciones climaticas debidas a la urbanizacion. En este trabajo se presenta una revision

  14. Improvement of a land surface model for accurate prediction of surface energy and water balances

    International Nuclear Information System (INIS)

    Katata, Genki

    2009-02-01

    In order to predict energy and water balances between the biosphere and atmosphere accurately, sophisticated schemes to calculate evaporation and adsorption processes in the soil and cloud (fog) water deposition on vegetation were implemented in the one-dimensional atmosphere-soil-vegetation model including CO 2 exchange process (SOLVEG2). Performance tests in arid areas showed that the above schemes have a significant effect on surface energy and water balances. The framework of the above schemes incorporated in the SOLVEG2 and instruction for running the model are documented. With further modifications of the model to implement the carbon exchanges between the vegetation and soil, deposition processes of materials on the land surface, vegetation stress-growth-dynamics etc., the model is suited to evaluate an effect of environmental loads to ecosystems by atmospheric pollutants and radioactive substances under climate changes such as global warming and drought. (author)

  15. The Global Energy Balance Archive (GEBA) version 2017: a database for worldwide measured surface energy fluxes

    Science.gov (United States)

    Wild, Martin; Ohmura, Atsumu; Schär, Christoph; Müller, Guido; Folini, Doris; Schwarz, Matthias; Zyta Hakuba, Maria; Sanchez-Lorenzo, Arturo

    2017-08-01

    The Global Energy Balance Archive (GEBA) is a database for the central storage of the worldwide measured energy fluxes at the Earth's surface, maintained at ETH Zurich (Switzerland). This paper documents the status of the GEBA version 2017 dataset, presents the new web interface and user access, and reviews the scientific impact that GEBA data had in various applications. GEBA has continuously been expanded and updated and contains in its 2017 version around 500 000 monthly mean entries of various surface energy balance components measured at 2500 locations. The database contains observations from 15 surface energy flux components, with the most widely measured quantity available in GEBA being the shortwave radiation incident at the Earth's surface (global radiation). Many of the historic records extend over several decades. GEBA contains monthly data from a variety of sources, namely from the World Radiation Data Centre (WRDC) in St. Petersburg, from national weather services, from different research networks (BSRN, ARM, SURFRAD), from peer-reviewed publications, project and data reports, and from personal communications. Quality checks are applied to test for gross errors in the dataset. GEBA has played a key role in various research applications, such as in the quantification of the global energy balance, in the discussion of the anomalous atmospheric shortwave absorption, and in the detection of multi-decadal variations in global radiation, known as global dimming and brightening. GEBA is further extensively used for the evaluation of climate models and satellite-derived surface flux products. On a more applied level, GEBA provides the basis for engineering applications in the context of solar power generation, water management, agricultural production and tourism. GEBA is publicly accessible through the internet via http://www.geba.ethz.ch. Supplementary data are available at https://doi.org/10.1594/PANGAEA.873078.

  16. A land surface scheme for atmospheric and hydrologic models: SEWAB (Surface Energy and Water Balance)

    Energy Technology Data Exchange (ETDEWEB)

    Mengelkamp, H.T.; Warrach, K.; Raschke, E. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    A soil-vegetation-atmosphere-transfer scheme is presented here which solves the coupled system of the Surface Energy and Water Balance (SEWAB) equations considering partly vegetated surfaces. It is based on the one-layer concept for vegetation. In the soil the diffusion equations for heat and moisture are solved on a multi-layer grid. SEWAB has been developed to serve as a land-surface scheme for atmospheric circulation models. Being forced with atmospheric data from either simulations or measurements it calculates surface and subsurface runoff that can serve as input to hydrologic models. The model has been validated with field data from the FIFE experiment and has participated in the PILPS project for intercomparison of land-surface parameterization schemes. From these experiments we feel that SEWAB reasonably well partitions the radiation and precipitation into sensible and latent heat fluxes as well as into runoff and soil moisture Storage. (orig.) [Deutsch] Ein Landoberflaechenschema wird vorgestellt, das den Transport von Waerme und Wasser zwischen dem Erdboden, der Vegetation und der Atmosphaere unter Beruecksichtigung von teilweise bewachsenem Boden beschreibt. Im Erdboden werden die Diffusionsgleichungen fuer Waerme und Feuchte auf einem Gitter mit mehreren Schichten geloest. Das Schema SEWAB (Surface Energy and Water Balance) beschreibt die Landoberflaechenprozesse in atmosphaerischen Modellen und berechnet den Oberflaechenabfluss und den Basisabfluss, die als Eingabedaten fuer hydrologische Modelle genutzt werden koennen. Das Modell wurde mit Daten des FIFE-Experiments kalibriert und hat an Vergleichsexperimenten fuer Landoberflaechen-Schemata im Rahmen des PILPS-Projektes teilgenommen. Dabei hat sich gezeigt, dass die Aufteilung der einfallenden Strahlung und des Niederschlages in den sensiblen und latenten Waermefluss und auch in Abfluss und Speicherung der Bodenfeuchte in SEWAB den beobachteten Daten recht gut entspricht. (orig.)

  17. Surface layer scintillometry for estimating the sensible heat flux component of the surface energy balance

    Directory of Open Access Journals (Sweden)

    M. J. Savage

    2010-01-01

    Full Text Available The relatively recently developed scintillometry method, with a focus on the dual-beam surface layer scintillometer (SLS, allows boundary layer atmospheric turbulence, surface sensible heat and momentum flux to be estimated in real-time. Much of the previous research using the scintillometer method has involved the large aperture scintillometer method, with only a few studies using the SLS method. The SLS method has been mainly used by agrometeorologists, hydrologists and micrometeorologists for atmospheric stability and surface energy balance studies to obtain estimates of sensible heat from which evaporation estimates representing areas of one hectare or larger are possible. Other applications include the use of the SLS method in obtaining crucial input parameters for atmospheric dispersion and turbulence models. The SLS method relies upon optical scintillation of a horizontal laser beam between transmitter and receiver for a separation distance typically between 50 and 250 m caused by refractive index inhomogeneities in the atmosphere that arise from turbulence fluctuations in air temperature and to a much lesser extent the fluctuations in water vapour pressure. Measurements of SLS beam transmission allow turbulence of the atmosphere to be determined, from which sub-hourly, real-time and in situ path-weighted fluxes of sensible heat and momentum may be calculated by application of the Monin-Obukhov similarity theory. Unlike the eddy covariance (EC method for which corrections for flow distortion and coordinate rotation are applied, no corrections to the SLS measurements, apart from a correction for water vapour pressure, are applied. Also, path-weighted SLS estimates over the propagation path are obtained. The SLS method also offers high temporal measurement resolution and usually greater spatial coverage compared to EC, Bowen ratio energy balance, surface renewal and other sensible heat measurement methods. Applying the shortened surface

  18. The surface energy balance of a polygonal tundra site in northern Siberia – Part 2: Winter

    Directory of Open Access Journals (Sweden)

    J. Boike

    2011-06-01

    Full Text Available In this study, we present the winter time surface energy balance at a polygonal tundra site in northern Siberia based on independent measurements of the net radiation, the sensible heat flux and the ground heat flux from two winter seasons. The latent heat flux is inferred from measurements of the atmospheric turbulence characteristics and a model approach. The long-wave radiation is found to be the dominant factor in the surface energy balance. The radiative losses are balanced to about 60 % by the ground heat flux and almost 40 % by the sensible heat fluxes, whereas the contribution of the latent heat flux is small. The main controlling factors of the surface energy budget are the snow cover, the cloudiness and the soil temperature gradient. Large spatial differences in the surface energy balance are observed between tundra soils and a small pond. The ground heat flux released at a freezing pond is by a factor of two higher compared to the freezing soil, whereas large differences in net radiation between the pond and soil are only observed at the end of the winter period. Differences in the surface energy balance between the two winter seasons are found to be related to differences in snow depth and cloud cover which strongly affect the temperature evolution and the freeze-up at the investigated pond.

  19. Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland

    DEFF Research Database (Denmark)

    Lund, Magnus; Stiegler, Christian; Abermann, Jakob

    2017-01-01

    The surface energy balance (SEB) is essential for understanding the coupled cryosphere–atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt....... For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during...

  20. SEMIC: an efficient surface energy and mass balance model applied to the Greenland ice sheet

    Directory of Open Access Journals (Sweden)

    M. Krapp

    2017-07-01

    Full Text Available We present SEMIC, a Surface Energy and Mass balance model of Intermediate Complexity for snow- and ice-covered surfaces such as the Greenland ice sheet. SEMIC is fast enough for glacial cycle applications, making it a suitable replacement for simpler methods such as the positive degree day (PDD method often used in ice sheet modelling. Our model explicitly calculates the main processes involved in the surface energy and mass balance, while maintaining a simple interface and requiring minimal data input to drive it. In this novel approach, we parameterise diurnal temperature variations in order to more realistically capture the daily thaw–freeze cycles that characterise the ice sheet mass balance. We show how to derive optimal model parameters for SEMIC specifically to reproduce surface characteristics and day-to-day variations similar to the regional climate model MAR (Modèle Atmosphérique Régional, version 2 and its incorporated multilayer snowpack model SISVAT (Soil Ice Snow Vegetation Atmosphere Transfer. A validation test shows that SEMIC simulates future changes in surface temperature and surface mass balance in good agreement with the more sophisticated multilayer snowpack model SISVAT included in MAR. With this paper, we present a physically based surface model to the ice sheet modelling community that is general enough to be used with in situ observations, climate model, or reanalysis data, and that is at the same time computationally fast enough for long-term integrations, such as glacial cycles or future climate change scenarios.

  1. Surface Energy Balance in Jakarta and Neighboring Regions As Simulated Using Fifth Mesoscale Model (MM5

    Directory of Open Access Journals (Sweden)

    Yopi Ilhamsyah

    2014-04-01

    Full Text Available The objective of the present research was to assess the surface energy balance particularly in terms of the computed surface energy and radiation balance and the development of boundary layer over Jakarta and Neighboring Regions (JNR by means of numerical model of fifth generation of Mesoscale Model (MM5. The MM5 with four domains of 9 kilometers in spatial resolution presenting the outermost and the innermost of JNR is utilized. The research focuses on the third and fourth domains covering the entire JNR. The description between radiation and energy balance at the surface is obtained from the model. The result showed that energy balance is higher in the city area during daytime. Meanwhile, energy components, e.g., surface sensible and latent heat flux showed that at the sea and in the city areas were higher than other areas. Moreover, ground flux showed eastern region was higher than others. In general, radiation and energy balance was higher in the daytime and lower in the nighttime for all regions. The calculation of Bowen Ratio, the ratio of surface sensible and latent heat fluxes, was also higher in the city area, reflecting the dominations of urban and built-up land in the region. Meanwhile, Bowen Ratio in the rural area dominated by irrigated cropland was lower. It is consistent with changes of land cover properties, e.g. albedo, soil moisture, and thermal characteristics. In addition, the boundary layer is also higher in the city. Meanwhile western region dominated by suburban showed higher boundary layer instead of eastern region.

  2. Performance of five surface energy balance models for estimating daily evapotranspiration in high biomass sorghum

    Science.gov (United States)

    Wagle, Pradeep; Bhattarai, Nishan; Gowda, Prasanna H.; Kakani, Vijaya G.

    2017-06-01

    Robust evapotranspiration (ET) models are required to predict water usage in a variety of terrestrial ecosystems under different geographical and agrometeorological conditions. As a result, several remote sensing-based surface energy balance (SEB) models have been developed to estimate ET over large regions. However, comparison of the performance of several SEB models at the same site is limited. In addition, none of the SEB models have been evaluated for their ability to predict ET in rain-fed high biomass sorghum grown for biofuel production. In this paper, we evaluated the performance of five widely used single-source SEB models, namely Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET with Internalized Calibration (METRIC), Surface Energy Balance System (SEBS), Simplified Surface Energy Balance Index (S-SEBI), and operational Simplified Surface Energy Balance (SSEBop), for estimating ET over a high biomass sorghum field during the 2012 and 2013 growing seasons. The predicted ET values were compared against eddy covariance (EC) measured ET (ETEC) for 19 cloud-free Landsat image. In general, S-SEBI, SEBAL, and SEBS performed reasonably well for the study period, while METRIC and SSEBop performed poorly. All SEB models substantially overestimated ET under extremely dry conditions as they underestimated sensible heat (H) and overestimated latent heat (LE) fluxes under dry conditions during the partitioning of available energy. METRIC, SEBAL, and SEBS overestimated LE regardless of wet or dry periods. Consequently, predicted seasonal cumulative ET by METRIC, SEBAL, and SEBS were higher than seasonal cumulative ETEC in both seasons. In contrast, S-SEBI and SSEBop substantially underestimated ET under too wet conditions, and predicted seasonal cumulative ET by S-SEBI and SSEBop were lower than seasonal cumulative ETEC in the relatively wetter 2013 growing season. Our results indicate the necessity of inclusion of soil moisture or plant water stress

  3. Surface energy balance of fresh and saline waters : AquaSEBS

    NARCIS (Netherlands)

    Abdelrady, A.R.; Timmermans, J.; Vekerdy, Z.; Salama, M.S.

    2016-01-01

    Current earth observation models do not take into account the influence of water salinity on the evaporation rate, even though the salinity influences the evaporation rate by affecting the density and latent heat of vaporization. In this paper, we adapt the SEBS (Surface Energy Balance System) model

  4. Soil heat flux and day time surface energy balance closure at ...

    Indian Academy of Sciences (India)

    Soil heat flux is a critical component of the surface energy balance along with the ... and prediction techniques. Evaporation measured .... Both incident and reflected solar radiation sensors are developed using wide spectrum photodiodes. The accuracy, resolution and range of the sensors used in the hydro-meteorological ...

  5. A high performance GPU implementation of Surface Energy Balance System (SEBS) based on CUDA-C

    NARCIS (Netherlands)

    Abouali, Mohammad; Timmermans, J.; Castillo, Jose E.; Su, Zhongbo

    2013-01-01

    This paper introduces a new implementation of the Surface Energy Balance System (SEBS) algorithm harnessing the many cores available on Graphics Processing Units (GPUs). This new implementation uses Compute Unified Device Architecture C (CUDA-C) programming model and is designed to be executed on a

  6. Surface energy balance of seasonal snow cover for snow-melt ...

    Indian Academy of Sciences (India)

    This study describes time series analysis of snow-melt, radiation data and energy balance for a seasonal snow cover at Dhundi field station of SASE, which lies in Pir Panjal range of the. N–W Himalaya, for a winter season from 13 January to 12 April 2005. The analysis shows that mean snow surface temperature remains ...

  7. Daily cycle of the surface energy balance in Antarctica and the influence of clouds

    NARCIS (Netherlands)

    van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Reijmer, C.H.|info:eu-repo/dai/nl/229345956; van As, D.; Boot, W.

    2006-01-01

    We present the summertime daily cycle of the Antarctic surface energy balance (SEB) and its sensitivity to cloud cover. We use data of automatic weather stations (AWS) located in four major Antarctic climate zones: the coastal ice shelf, the coastal and interior katabatic wind zone and the interior

  8. Soil heat flux and day time surface energy balance closure at ...

    Indian Academy of Sciences (India)

    Soil heat flux is an important input component of surface energy balance. Estimates of soil heat flux were made in the year 2008 using soil temperature data at Astronomical Observatory, Thiruvananthapuram, south Kerala. Hourly values of soil heat flux from 00 to 24 LST are presented for selected days typical of the winter, ...

  9. The Influence of Rain Sensible Heat and Subsurface Energy Transport on the Energy Balance at the Land Surface

    NARCIS (Netherlands)

    Kollet, S.J.; Cvijanovic, I.; Schüttemeyer, D.; Maxwell, R.M.; Moene, A.F.; Bayer, P.

    2009-01-01

    In land surface models, which account for the energy balance at the land surface, subsurface heat transport is an important component that reciprocally influences ground, sensible, and latent heat fluxes and net radiation. In most models, subsurface heat transport parameterizations are commonly

  10. Topographic forcing and related uncertainties on glacier surface energy balance in High Mountain Asia

    Science.gov (United States)

    Olson, M.; Rupper, S.; Shean, D. E.

    2017-12-01

    Topography directly influences the amount of global radiation, as well as other key energy flux terms, arriving on a glacier surface. This is particularly important in regions of variable and complex topography such as High Mountain Asia (HMA). In this region surface energy and mass balance estimates often rely heavily on modeling, and thus require accurate accounting of topography through available remote sensing platforms. Our previous work shows that topographic shading from surrounding terrain can alter the mean daily potential direct shortwave radiation by upwards of 20% for some valley glaciers. In this work, we find in regions of high topographic relief that shading frequently dominates in the ablation zone rather than the accumulation zone, contrary to the findings of some previous studies. This however, is largely dependent on the valley aspect and relative relief of nearby terrain. In addition, we examine the impact of topography, primarily topographic shading, on components of surface energy balance for a large sample of glaciers across different regions in HMA. Our results show that while the impact of topographic shading is highly variable throughout HMA, the magnitude of influence can often be predicted based on simple characteristics such as latitude, valley aspect, and orientation of the immediate surrounding topography. We also explore the uncertainty in topographic shading and in calculated surface energy due to the spatial resolution and accuracy of DEMs. In particular, we compare the shading and energy balance results utilizing a suite of DEMs, including 2 m, 8 m, and 30 m World View DEMs, 30 m ASTER GDEM, 30 m SRTM DEM, and 30 m ALOS DEM. These results will help us improve glacier energy and mass balance modeling accuracy, and demonstrate limitations and uncertainties when modeling changes in surface energy fluxes due to surrounding topography for mountain glaciers.

  11. Modeling Plant-Atmosphere Interactions and Ramifications on the Surface Energy Balance in Arctic Ecosystems

    Science.gov (United States)

    Linn, R.; Cunningham, P.; Wilson, C. J.

    2011-12-01

    There is broad recognition that the melting of the permafrost in arctic landscapes could have pronounced global climatological impacts. The evolution of the permafrost and its impacts on the carbon and water balances is directly related to balances in the surface energy budget. There are a number of factors that are expected to impact the net heat flux at the surface of the soil including regional atmospheric conditions. However, ultimately this surface energy balance is controlled by local processes including evaporation from the surface, transpiration from vegetation as well as radiative and convective heat transfer. These four processes are directly impacted by coupling between the vegetation and atmosphere, and thus depend heavily upon the horizontal and vertical vegetation structure. If shrubs replace grasses in the arctic ecosystem there will be net shifts in the heat transfer to the ground. For example, the solar radiation that is absorbed by shrubs is separated from the soil by a stem space through which winds blow. In order for the energy to reach the soil it must warm the air and then warm the soil, however some of the warm air is mixed into the atmosphere and diffused. This structural feature can act in a fashion similar to a closed canopy forest, which frequently have cooler temperatures below the canopy than nearby grasslands An atmospheric hydrodynamics model, HIGRAD, has been enhanced to simulate complex, three-dimensional plant-atmosphere interactions at extremely high resolution (~0.1 m in all three directions). The model represents the transport of momentum, heat, moisture, and CO2 and their exchange between the vegetation and surrounding air. HIGRAD was used to simulate coupled atmosphere/vegetation systems representative of heterogeneous shrub and tussock grass surrounding a thermokarst. In these simulations shrubs, uneven grasses, and a thermokarst depression are explicitly resolved, and atmospheric conditions are similar to those of summer

  12. Botswana water and surface energy balance research program. Part 2: Large scale moisture and passive microwaves

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Chang, A. T. C.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. The research program consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components are explained in general and activities performed within the passive microwave research component are summarized. The microwave theory is discussed taking into account: soil dielectric constant, emissivity, soil roughness effects, vegetation effects, optical depth, single scattering albedo, and wavelength effects. The study site is described. The soil moisture data and its processing are considered. The relation between observed large scale soil moisture and normalized brightness temperatures is discussed. Vegetation characteristics and inverse modeling of soil emissivity is considered.

  13. Microclimatic models. Estimation of components of the energy balance over land surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Heikinheimo, M.; Venaelaeinen, A.; Tourula, T. [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Dept.

    1996-12-31

    Climates at regional scale are strongly dependent on the interaction between atmosphere and its lower boundary, the oceans and the land surface mosaic. Land surfaces influence climate through their albedo, and the aerodynamic roughness, the processes of the biosphere and many soil hydrological properties; all these factors vary considerably geographically. Land surfaces receive a certain portion of the solar irradiance depending on the cloudiness, atmospheric transparency and surface albedo. Short-wave solar irradiance is the source of the heat energy exchange at the earth`s surface and also regulates many biological processes, e.g. photosynthesis. Methods for estimating solar irradiance, atmospheric transparency and surface albedo were reviewed during the course of this project. The solar energy at earth`s surface is consumed for heating the soil and the lower atmosphere. Where moisture is available, evaporation is one of the key components of the surface energy balance, because the conversion of liquid water into water vapour consumes heat. The evaporation process was studied by carrying out field experiments and testing parameterisation for a cultivated agricultural surface and for lakes. The micrometeorological study over lakes was carried out as part of the international `Northern Hemisphere Climatic Processes Experiment` (NOPEX/BAHC) in Sweden. These studies have been aimed at a better understanding of the energy exchange processes of the earth`s surface-atmosphere boundary for a more accurate and realistic parameterisation of the land surface in atmospheric models

  14. The relevance of rooftops: Analyzing the microscale surface energy balance in the Chicago region

    Science.gov (United States)

    Khosla, Radhika

    Spatial structure in climate variables often exist over very short length scales within an urban area, and this structure is a result of various site-specific features. In order to analyze the seasonal and diurnal energy flows that take place at a microclimatic surface, this work develops a semi-empirical energy balance model. For this, radiation fluxes and meteorological measurements are determined by direct observation; sensible heat and latent heat fluxes by parameterizations; and the heat storage flux by a 1-D mechanistic model that allows analysis of the temperature profile and heat storage within an underlying slab. Two sites receive detailed study: an anthropogenic site, being a University of Chicago building rooftop, and a natural site, outside Chicago in the open country. Two identical sets of instruments record measurements contemporaneously from these locations during June-November 2007, the entire period for which analyses are carried out. The study yields seasonal trends in surface temperature, surface-to-air temperature contrast and net radiation. At both sites, a temporal hysteresis between net radiation and heat storage flux indicates that surplus energy absorbed during daylight is released to the atmosphere later in the evening. The surface energy balance model responds well to site specific features for both locations. An analysis of the surface energy balance shows that the flux of sensible heat is the largest non-radiative contributor to the roof's surface cooling, while the flux of latent heat (also referred to as evaporative cooling) is the largest heat sink for the soil layer. In the latter part of the study, the surface energy balance model is upgraded by adding the capability to compute changes in surface temperature and non-radiative fluxes for any specified set of thermal and reflective roof properties. The results of this analysis allow an examination of the relationship between the roof temperature, the heat flux entering the building

  15. Botswana water and surface energy balance research program. Part 1: Integrated approach and field campaign results

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Vugts, H. F.; Ramothwa, G. K.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. Results of the first part of the program (Botswana 1) which ran from 1 Jan. 1988 - 31 Dec. 1990 are summarized. Botswana 1 consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components in general are described and activities performed during the surface energy modeling component including the extensive field campaign are summarized. The results of the passive microwave component are summarized. The key of the field campaign was a multilevel approach, whereby measurements by various similar sensors were made at several altitudes and resolution. Data collection was performed at two adjacent sites of contrasting surface character. The following measurements were made: micrometeorological measurements, surface temperatures, soil temperatures, soil moisture, vegetation (leaf area index and biomass), satellite data, aircraft data, atmospheric soundings, stomatal resistance, and surface emissivity.

  16. Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland

    DEFF Research Database (Denmark)

    Lund, Magnus; Stiegler, Christian; Abermann, Jakob

    2017-01-01

    The surface energy balance (SEB) is essential for understanding the coupled cryosphere–atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt....... For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during...... summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled...

  17. Evapotranspiration and surface energy balance across an agricultural-urban landscape gradient in Southern California, USA.

    Science.gov (United States)

    Shiflett, S. A.; Anderson, R. G.; Jenerette, D.

    2014-12-01

    Urbanization substantially affects energy, surface and air temperature, and hydrology due to extensive modifications in land surface properties such as vegetation, albedo, thermal capacity and soil moisture. The magnitude and direction of these alterations depends heavily on the type of urbanization that occurs. We investigated energy balance variation in a local network of agricultural and urban ecosystems using the eddy covariance method to better understand how vegetation fraction and degree of urbanization affects energy exchanges between the land surface and the atmosphere. We deployed eddy flux systems within a well-irrigated, agricultural citrus orchard, a moderately developed urban zone with a substantial amount of local vegetative cover, and an intensely developed urban zone with minimal vegetative cover and increased impervious surfaces relative to the other two sites. Latent energy (LE) fluxes in the agricultural area ranged from 7.9 ± 1.4 W m-2 (nighttime) to 168.7 ± 6.2 W m-2 (daytime) compared to 10.2 ± 3.5 W m-2 and 40.6 ± 4.1 W m-2, respectively, for the moderately developed urban area. Sensible energy (H) fluxes ranged from -9.1 ± 1.0 W m-2 (nighttime) to 119 ± 7.0 W m-2 (daytime) in the agricultural area compared to 9.6 ± 2.6 W m-2 and 134 ± 6.0 W m-2, respectively, for the moderately developed urban zone. Daytime LE is reduced with increasing urbanization; however, daily cycles of LE are less recognizable in urban areas compared to distinct daily cycles obtained above a mature citrus crop. In contrast, both daytime and nighttime H increases with increasing degree of urbanization. Reduction in vegetation and increases in impervious surfaces along an urbanization gradient leads to alterations in energy balance, which are associated with microclimate and water use changes.

  18. Reconnoitering the effect of shallow groundwater on land surface temperature and surface energy balance using MODIS and SEBS

    Directory of Open Access Journals (Sweden)

    F. Alkhaier

    2012-07-01

    Full Text Available The possibility of observing shallow groundwater depth and areal extent using satellite measurements can support groundwater models and vast irrigation systems management. Moreover, these measurements can help to include the effect of shallow groundwater on surface energy balance within land surface models and climate studies, which broadens the methods that yield more reliable and informative results. To examine the capacity of MODIS in detecting the effect of shallow groundwater on land surface temperature and the surface energy balance in an area within Al-Balikh River basin in northern Syria, we studied the interrelationship between in-situ measured water table depths and land surface temperatures measured by MODIS. We, also, used the Surface Energy Balance System (SEBS to calculate surface energy fluxes, evaporative fraction and daily evaporation, and inspected their relationships with water table depths. We found out that the daytime temperature increased while the nighttime temperature decreased when the depth of the water table increased. And, when the water table depth increased, net radiation, latent and ground heat fluxes, evaporative fraction and daily evaporation decreased, while sensible heat flux increased. This concords with the findings of a companion paper (Alkhaier et al., 2012. The observed clear relationships were the result of meeting both conditions that were concluded in the companion paper, i.e. high potential evaporation and big contrast in day-night temperature. Moreover, the prevailing conditions in this study area helped SEBS to yield accurate estimates. Under bare soil conditions and under the prevailing weather conditions, we conclude that MODIS is suitable for detecting the effect of shallow groundwater because it has proper imaging times and adequate sensor accuracy; nevertheless, its coarse spatial resolution is disadvantageous.

  19. Reconnoitering the effect of shallow groundwater on land surface temperature and surface energy balance using MODIS and SEBS

    Science.gov (United States)

    Alkhaier, F.; Su, Z.; Flerchinger, G. N.

    2012-07-01

    The possibility of observing shallow groundwater depth and areal extent using satellite measurements can support groundwater models and vast irrigation systems management. Moreover, these measurements can help to include the effect of shallow groundwater on surface energy balance within land surface models and climate studies, which broadens the methods that yield more reliable and informative results. To examine the capacity of MODIS in detecting the effect of shallow groundwater on land surface temperature and the surface energy balance in an area within Al-Balikh River basin in northern Syria, we studied the interrelationship between in-situ measured water table depths and land surface temperatures measured by MODIS. We, also, used the Surface Energy Balance System (SEBS) to calculate surface energy fluxes, evaporative fraction and daily evaporation, and inspected their relationships with water table depths. We found out that the daytime temperature increased while the nighttime temperature decreased when the depth of the water table increased. And, when the water table depth increased, net radiation, latent and ground heat fluxes, evaporative fraction and daily evaporation decreased, while sensible heat flux increased. This concords with the findings of a companion paper (Alkhaier et al., 2012). The observed clear relationships were the result of meeting both conditions that were concluded in the companion paper, i.e. high potential evaporation and big contrast in day-night temperature. Moreover, the prevailing conditions in this study area helped SEBS to yield accurate estimates. Under bare soil conditions and under the prevailing weather conditions, we conclude that MODIS is suitable for detecting the effect of shallow groundwater because it has proper imaging times and adequate sensor accuracy; nevertheless, its coarse spatial resolution is disadvantageous.

  20. Surface Energy and Mass Balance Model for Greenland Ice Sheet and Future Projections

    Science.gov (United States)

    Liu, Xiaojian

    The Greenland Ice Sheet contains nearly 3 million cubic kilometers of glacial ice. If the entire ice sheet completely melted, sea level would raise by nearly 7 meters. There is thus considerable interest in monitoring the mass balance of the Greenland Ice Sheet. Each year, the ice sheet gains ice from snowfall and loses ice through iceberg calving and surface melting. In this thesis, we develop, validate and apply a physics based numerical model to estimate current and future surface mass balance of the Greenland Ice Sheet. The numerical model consists of a coupled surface energy balance and englacial model that is simple enough that it can be used for long time scale model runs, but unlike previous empirical parameterizations, has a physical basis. The surface energy balance model predicts ice sheet surface temperature and melt production. The englacial model predicts the evolution of temperature and meltwater within the ice sheet. These two models can be combined with estimates of precipitation (snowfall) to estimate the mass balance over the Greenland Ice Sheet. We first compare model performance with in-situ observations to demonstrate that the model works well. We next evaluate how predictions are degraded when we statistically downscale global climate data. We find that a simple, nearest neighbor interpolation scheme with a lapse rate correction is able to adequately reproduce melt patterns on the Greenland Ice Sheet. These results are comparable to those obtained using empirical Positive Degree Day (PDD) methods. Having validated the model, we next drove the ice sheet model using the suite of atmospheric model runs available through the CMIP5 atmospheric model inter-comparison, which in turn built upon the RCP 8.5 (business as usual) scenarios. From this exercise we predict how much surface melt production will increase in the coming century. This results in 4-10 cm sea level equivalent, depending on the CMIP5 models. Finally, we try to bound melt water

  1. Fluvial and climate controls on the surface energy balance in a large lowland river

    Science.gov (United States)

    Bray, E. N.; Dunne, T.; Dozier, J.

    2013-12-01

    Partitioning of radiant and turbulent energy into evaporation and absorption in a river channel is controlled by climate and streamflow characteristics, and controls the water and energy balance. Atmosphere-surface interactions, coupled with advective processes, drive the heterogeneity of heat storage and exchange over longitudinal profiles whose hydraulic and thermal patterns are crucial for survival of migratory and resident fishes and subject to alteration by humans. Over 100 large-scale flow experiments have been conducted globally to measure abiotic and biotic responses to streamflow, yet none has been utilized to elucidate large-scale physical controls on the surface energy balance of a river. In this paper, we describe a synoptic method by which net solar radiation and turbulent heat fluxes were calculated over the length of a river from time series of hydroclimatological and fluvial conditions measured during a long-term large-scale flow experiment. We examine what are the dominant physical controls to the surface energy balance in a lowland river when surface water stage varies with flow releases in a 240-km reach of the San Joaquin River, California, USA. We developed an energy balance model integrated with advective exchange of heat utilizing spatially-distributed predictions of water surface elevation, inundated surface area, and velocity from an existing hydraulic model that accounts for losses and gains over the length of the river. Absorption of radiation along the river is determined by the wavelength-dependent index of refraction, expressed by the angle of refraction and the optical depth as a function of physical depth and the absorption coefficient. Results show that over the solar spectrum, the absorption coefficient varies by seven orders of magnitude, while flow depth varies by two orders of magnitude over time and distance. Observations and modeling show that (1) discharge is controlled mainly by flow releases, diversions, and exchanges with

  2. The role of clouds in the surface energy balance over the Amazon forest

    International Nuclear Information System (INIS)

    Eltahir, E.A.B.; Humphries, E.J. Jr.

    1998-01-01

    Deforestation in the Amazon region will initially impact the energy balance at the land surface through changes in land cover and surface hydrology. However, continuation of this human activity will eventually lead to atmospheric feedbacks, including changes in cloudiness which may play an important role in the final equilibrium of solar and terrestrial radiation at the surface. In this study, the different components of surface radiation over an undisturbed forest in the Amazon region are computed using data from the Amazon region micrometerological experiment (ARME). Several measures of cloudiness are defined: two estimated from the terrestrial radiation measurements, and one from the solar radiation measurements. The sensitivity of the surface fluxes of solar and terrestrial radiation to natural variability in cloudiness is investigated to infer the potential role of the cloudiness feedback in the surface energy balance. The results of this analysis indicate that a 1% decrease in cloudiness would increase net solar radiation by ca. 1.6 W/m 2 . However, the overall magnitude of this feedback, due to total deforestation of the Amazon forest, is likely to be of the same order as the magnitude of the decrease in net solar radiation due to the observed increase in surface albedo following deforestation. Hence, the total change in net solar radiation is likely to have a negligible magnitude. In contrast to this conclusion, we find that terrestrial radiation is likely to be more strongly affected; reduced cloudiness will decrease net terrestrial radiation; a 1% decrease in cloudiness induces a reduction in net terrestrial radiation of ca. 0.7 W/m 2 ; this process augments the similar effects of the predicted warming and drying in the boundary layer. Due to the cloudiness feedback, the most significant effect of large-scale deforestation on the surface energy balance is likely to be in the modification of the terrestrial radiation field rather than the classical albedo

  3. Detailed balance, internal consistency, and energy conservation in fragment orbital-based surface hopping

    Science.gov (United States)

    Carof, Antoine; Giannini, Samuele; Blumberger, Jochen

    2017-12-01

    We have recently introduced an efficient semi-empirical non-adiabatic molecular dynamics method for the simulation of charge transfer/transport in molecules and molecular materials, denoted fragment orbital-based surface hopping (FOB-SH) [J. Spencer et al., J. Chem. Phys. 145, 064102 (2016)]. In this method, the charge carrier wavefunction is expanded in a set of charge localized, diabatic electronic states and propagated in the time-dependent potential due to classical nuclear motion. Here we derive and implement an exact expression for the non-adiabatic coupling vectors between the adiabatic electronic states in terms of nuclear gradients of the diabatic electronic states. With the non-adiabatic coupling vectors (NACVs) available, we investigate how different flavours of fewest switches surface hopping affect detailed balance, internal consistency, and total energy conservation for electron hole transfer in a molecular dimer with two electronic states. We find that FOB-SH satisfies detailed balance across a wide range of diabatic electronic coupling strengths provided that the velocities are adjusted along the direction of the NACV to satisfy total energy conservation upon a surface hop. This criterion produces the right fraction of energy-forbidden (frustrated) hops, which is essential for correct population of excited states, especially when diabatic couplings are on the order of the thermal energy or larger, as in organic semiconductors and DNA. Furthermore, we find that FOB-SH is internally consistent, that is, the electronic surface population matches the average quantum amplitudes, but only in the limit of small diabatic couplings. For large diabatic couplings, inconsistencies are observed as the decrease in excited state population due to frustrated hops is not matched by a corresponding decrease in quantum amplitudes. The derivation provided here for the NACV should be generally applicable to any electronic structure approach where the electronic

  4. The Global Energy Balance Archive (GEBA version 2017: a database for worldwide measured surface energy fluxes

    Directory of Open Access Journals (Sweden)

    M. Wild

    2017-08-01

    Full Text Available The Global Energy Balance Archive (GEBA is a database for the central storage of the worldwide measured energy fluxes at the Earth's surface, maintained at ETH Zurich (Switzerland. This paper documents the status of the GEBA version 2017 dataset, presents the new web interface and user access, and reviews the scientific impact that GEBA data had in various applications. GEBA has continuously been expanded and updated and contains in its 2017 version around 500 000 monthly mean entries of various surface energy balance components measured at 2500 locations. The database contains observations from 15 surface energy flux components, with the most widely measured quantity available in GEBA being the shortwave radiation incident at the Earth's surface (global radiation. Many of the historic records extend over several decades. GEBA contains monthly data from a variety of sources, namely from the World Radiation Data Centre (WRDC in St. Petersburg, from national weather services, from different research networks (BSRN, ARM, SURFRAD, from peer-reviewed publications, project and data reports, and from personal communications. Quality checks are applied to test for gross errors in the dataset. GEBA has played a key role in various research applications, such as in the quantification of the global energy balance, in the discussion of the anomalous atmospheric shortwave absorption, and in the detection of multi-decadal variations in global radiation, known as global dimming and brightening. GEBA is further extensively used for the evaluation of climate models and satellite-derived surface flux products. On a more applied level, GEBA provides the basis for engineering applications in the context of solar power generation, water management, agricultural production and tourism. GEBA is publicly accessible through the internet via http://www.geba.ethz.ch. Supplementary data are available at https://doi.org/10.1594/PANGAEA.873078.

  5. Effect of Fractal Geometry on the Energy Balance at the Ground Surface

    Science.gov (United States)

    Sakai, S.; Iizawa, I.; Onishi, M.; Nakamura, M.; Kobayashi, K.; Mitsunaga, M.; Furuya, K.

    2008-12-01

    The surfaces of the urban areas are covered by large flat surfaces such as roads and walls of buildings while those of the rural areas are covered by many plants which have fractal structures. This difference in the surface geometry has great impact on the energy balance at the ground surface. A small leaf has large thermal conductivity to the surrounding air flow comparing with a anthropogenic large flat surface in an urban area even when the transpiration effect is ignored. For a cluster of many small leaves, the conductivity can be reduced by the interference, but trees have a structure to minimize its effect. We have conducted 3-dimensional laser measurements and analyzed their fractal dimensions. The analysis revealed that the trees have a fractal dimension of 2 although they are spread in a 3-dimensional space. Mathematically speaking, it means that the trees have 2-dimensional areas but do not have volume, in the limit of infinite self similarity. This geometry is favorable to absorb the sunlight using 2-dimensional area with minimum interruption of the 3-dimensional air flow. Being motivated by the results above, we have constructed a fractal sun roof consists of Sierpinski"fs tetrahedrons which have fractal dimension of 2. The roof covers an area of 100m2. The result shows that the surface temperature of the fractal roof is lower than the large flat surface with same material by more than 10 degrees.

  6. Inter-comparison of energy balance and hydrological models for land surface energy flux estimation over a whole river catchment

    DEFF Research Database (Denmark)

    Guzinski, R.; Nieto, H.; Stisen, S.

    2015-01-01

    , distributed hydrological model, while the energy-balance approach is often used with remotely sensed observations of, for example, the land surface temperature (LST) and the state of the vegetation. In this study we compare the catchment-scale output of two remote sensing models based on the two-source energy......-balance (TSEB) scheme, against a hydrological model, MIKE SHE, calibrated over the Skjern river catchment in western Denmark. The three models utilize different primary inputs to estimate ET (LST from different satellites in the case of remote sensing models and modelled soil moisture and heat flux in the case....... The temporal patterns produced by the remote sensing and hydrological models are quite highly correlated (r ≈ 0.8). This indicates potential benefits to the hydrological modelling community of integrating spatial information derived through remote sensing methodology (contained in the ET maps...

  7. The ground surface energy balance in modelling horizontal ground heat exchangers

    Science.gov (United States)

    Bortoloni, M.; Bottarelli, M.; Su, Y.

    2017-01-01

    The performance of horizontal ground heat exchangers (HGHEs) is strongly dependent on climatic conditions, due to the low installation depth. In numerical modelling of HGHEs, the estimation of shallow soil temperature distribution is a key issue, therefore the boundary condition (BC) at the ground surface should be assigned carefully. With this in mind, a model of the energy balance at the ground surface (GSEB), based on weather variables, was developed. The model was tested as the 3rd kind BC at ground surface in modelling HGHEs by means of the FEM code Comsol Multiphysics, solving the unsteady heat transfer problem in a 2D domain. The GSEB model was calibrated and validated with the observed soil temperature at different depths. In addition, the effect on numerical solutions of different BCs, when assigned at the ground surface, was analysed. Three different simulations were carried out applying the GSEB model, the equivalent surface heat flux and temperature as boundary conditions of the 1st, 2nd and 3rd kind, respectively. The results of this study indicate that the use of the GSEB model is a preferable approach to the problem and that the use of the equivalent surface temperature can be considered as a reasonable simplification.

  8. Uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model at multiple flux tower sites

    Science.gov (United States)

    Chen, Mingshi; Senay, Gabriel B.; Singh, Ramesh K.; Verdin, James P.

    2016-01-01

    Evapotranspiration (ET) is an important component of the water cycle – ET from the land surface returns approximately 60% of the global precipitation back to the atmosphere. ET also plays an important role in energy transport among the biosphere, atmosphere, and hydrosphere. Current regional to global and daily to annual ET estimation relies mainly on surface energy balance (SEB) ET models or statistical and empirical methods driven by remote sensing data and various climatological databases. These models have uncertainties due to inevitable input errors, poorly defined parameters, and inadequate model structures. The eddy covariance measurements on water, energy, and carbon fluxes at the AmeriFlux tower sites provide an opportunity to assess the ET modeling uncertainties. In this study, we focused on uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model for ET estimation at multiple AmeriFlux tower sites with diverse land cover characteristics and climatic conditions. The 8-day composite 1-km MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) was used as input land surface temperature for the SSEBop algorithms. The other input data were taken from the AmeriFlux database. Results of statistical analysis indicated that the SSEBop model performed well in estimating ET with an R2 of 0.86 between estimated ET and eddy covariance measurements at 42 AmeriFlux tower sites during 2001–2007. It was encouraging to see that the best performance was observed for croplands, where R2 was 0.92 with a root mean square error of 13 mm/month. The uncertainties or random errors from input variables and parameters of the SSEBop model led to monthly ET estimates with relative errors less than 20% across multiple flux tower sites distributed across different biomes. This uncertainty of the SSEBop model lies within the error range of other SEB models, suggesting systematic error or bias of the SSEBop model is within

  9. Analysis of meteorological data and the surface energy balance of Keqicar Glacier, Tien Shan, China

    Science.gov (United States)

    Zhang, Y.; Liu, S.; Fujita, K.; Han, H.; Li, J.

    2009-04-01

    Northwestern China currently experiences a climate change with fundamental consequences for the hydrological cycle. In the strongly arid region where water resources are essential for agriculture and food production, glaciers represent important water resources, contributing significantly to streamflow. The debris is an important glaciological feature of the region and has major impact on melt rates. It is essential to understand and quantify the interaction of climate and sub-debris melt in order to assess the current situation and to predict future water yield. Note that the surface energy balance determines glacier melt. However, little is known about the variability characteristics of the surface energy fluxes in this region. For this reason, we set up two automatic weather stuation (AWSs) in the ablation area of Keqicar Glacier. Keqicar Glacier is located in the Tarim River basin (largest inland river basin in China), southwestern Tien Shan, China. It is a representative debris-covered glacier with a length of 26.0 km and a total surface area of 83.6 km2. The thickness of the debris layer varies from 0.0 to 2.50 m in general. In some places large rocks are piled up to several meters. In this study, we report on analysis of meteorological data for the period 1 July-13 September 2003, from two automatic weather stations, aimed at studying the relationship between climate and ablation. One station is located on the lower part of the ablation area where the glacier is covered by debris layer, and the other near the equilibrium line altitude (ELA). All sensors were sampled every 10 seconds, and data were stored as hourly averages. The stations were visited regularly for maintenance at two weeks intervals depending on the weather conditions and location of the AWS. A total of 17 ablation stakes were drilled into the glacier at different elevations to monitor glacier melt during the study period. Readings were taken regularly in connection with AWS maintenance. The

  10. Modelling surface energy fluxes over a Dehesa ecosystem using a two-source energy balance model.

    Science.gov (United States)

    Andreu, Ana; Kustas, William. P.; Anderson, Martha C.; Carrara, Arnaud; Patrocinio Gonzalez-Dugo, Maria

    2013-04-01

    The Dehesa is the most widespread agroforestry land-use system in Europe, covering more than 3 million hectares in the Iberian Peninsula and Greece (Grove and Rackham, 2001; Papanastasis, 2004). It is an agro-silvo-pastural ecosystem consisting of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs, and it is recognized as an example of sustainable land use and for his importance in the rural economy (Diaz et al., 1997; Plieninger and Wilbrand, 2001). The ecosystem is influenced by a Mediterranean climate, with recurrent and severe droughts. Over the last decades the Dehesa has faced multiple environmental threats, derived from intensive agricultural use and socio-economic changes, which have caused environmental degradation of the area, namely reduction in tree density and stocking rates, changes in soil properties and hydrological processes and an increase of soil erosion (Coelho et al. 2004; Schnabel and Ferreira, 2004; Montoya 1998; Pulido and Díaz, 2005). Understanding the hydrological, atmospheric and physiological processes that affect the functioning of the ecosystem will improve the management and conservation of the Dehesa. One of the key metrics in assessing ecosystem health, particularly in this water-limited environment, is the capability of monitoring evaporation (ET). To make large area assessments requires the use of remote sensing. Thermal-based energy balance techniques that distinguish soil/substrate and vegetation contributions to the radiative temperature and radiation/turbulent fluxes have proven to be reliable in such semi-arid sparse canopy-cover landscapes. In particular, the two-source energy balance (TSEB) model of Norman et al. (1995) and Kustas and Norman (1999) has shown to be robust for a wide range of partially-vegetated landscapes. The TSEB formulation is evaluated at a flux tower site located in center Spain (Majadas del Tietar, Caceres). Its application in this environment is

  11. The need for surface-parallel sensor orientation to address energy balance closure on mountain slopes

    Science.gov (United States)

    Serrano-Ortiz, Penelope; Sánchez-Cañete, Enrique P.; Pérez-Priego, Óscar; Carrara, Arnaud; Metzger, Stefan; Kowalski, Andrew S.

    2014-05-01

    Measurements of turbulent fluxes in varying environments are one of the tools scientists and decision makers rely on for assessing and forecasting global warming. Thus, in the last two decades eddy-covariance (EC) towers have proliferated around the globe. Yet, ideal sites are rarely found, and there is a great need to extend the EC method and its theoretical underpinning to more complex terrain. In particular, several principal challenges are aggravated by sloping terrain. Nevertheless, various studies have concluded that the EC method is a useful tool to determine ecosystem energy and CO2/H2O fluxes on mountain slopes. Following the first law of thermodynamics, the validity of EC measurements is often evaluated in terms of their ability to close the balance of energy entering [net radiation minus the soil heat flux] and leaving [sum of the latent and sensible heat, measured by EC] an ecosystem. In sloping terrain, this criterion is applied with results comparable to sites located in more ideal terrain. Arguably, fluxes perpendicular to the surface are needed to assess the energy budget. However, even in sloping terrain instrument installations are frequently referenced perpendicular to the geo-potential (e.g. using a bubble level). Here, we demonstrate several advantages of installing the net radiometer and soil heat flux instruments parallel to a 16% slope with a southwest orientation. Our results reveal a diurnal hysteresis in the energy balance closure as large as 30% when net radiometer and soil heat flux instruments are installed perpendicular to the geo-potential. Installing the net radiometer and soil heat flux instruments slope-parallel mitigates this discrepancy.

  12. Future projections of the Greenland ice sheet energy balance driving the surface melt

    Directory of Open Access Journals (Sweden)

    B. Franco

    2013-01-01

    Full Text Available In this study, simulations at 25 km resolution are performed over the Greenland ice sheet (GrIS throughout the 20th and 21st centuries, using the regional climate model MAR forced by four RCP scenarios from three CMIP5 global circulation models (GCMs, in order to investigate the projected changes of the surface energy balance (SEB components driving the surface melt. Analysis of 2000–2100 melt anomalies compared to melt results over 1980–1999 reveals an exponential relationship of the GrIS surface melt rate simulated by MAR to the near-surface air temperature (TAS anomalies, mainly due to the surface albedo positive feedback associated with the extension of bare ice areas in summer. On the GrIS margins, the future melt anomalies are preferentially driven by stronger sensible heat fluxes, induced by enhanced warm air advection over the ice sheet. Over the central dry snow zone, the surface albedo positive feedback induced by the increase in summer melt exceeds the negative feedback of heavier snowfall for TAS anomalies higher than 4 °C. In addition to the incoming longwave flux increase associated with the atmosphere warming, GCM-forced MAR simulations project an increase of the cloud cover decreasing the ratio of the incoming shortwave versus longwave radiation and dampening the albedo feedback. However, it should be noted that this trend in the cloud cover is contrary to that simulated by ERA-Interim–forced MAR for recent climate conditions, where the observed melt increase since the 1990s seems mainly to be a consequence of more anticyclonic atmospheric conditions. Finally, no significant change is projected in the length of the melt season, which highlights the importance of solar radiation absorbed by the ice sheet surface in the melt SEB.

  13. Surface energy balances of three general circulation models: Current climate and response to increasing atmospheric CO2

    International Nuclear Information System (INIS)

    Gutowski, W.J.; Gutzler, D.S.; Portman, D.; Wang, W.C.

    1988-04-01

    The surface energy balance simulated by state-of-the-art general circulation models at GFDL, GISS and NCAR for climates with current levels of atmospheric CO 2 concentration (control climate) and with twice the current levels. The work is part of an effort sponsored by the US Department of Energy to assess climate simulations produced by these models. The surface energy balance enables us to diagnose differences between models in surface temperature climatology and sensitivity to doubling CO 2 in terms of the processes that control surface temperature. Our analysis compares the simulated balances by averaging the fields of interest over a hierarchy of spatial domains ranging from the entire globe down to regions a few hundred kilometers across

  14. Potential evaporation estimation through an unstressed surface energy balance and its sensitivity to climate change

    Science.gov (United States)

    Barella-Ortiz, A.; Polcher, J.; Tuzet, A.; Laval, K.

    2013-06-01

    Potential evaporation (ETP) is a basic input for hydrological and agronomic models, as well as a key variable in most actual evaporation estimations. It has been approached through several diffusive and energy balance methods, out of which the Penman-Monteith equation is recommended as the standard one. In order to deal with the diffusive approach, ETP must be estimated at a sub-diurnal frequency, as currently done in land surface models (LSM). This study presents an improved method, developed in the ORCHIDEE LSM, which consists in estimating ETP through an unstressed surface energy balance (USEB method). The results confirm the quality of the estimation which is currently implemented in the model (Milly, 1992). ETP has also been estimated using a reference equation (computed at a daily time step) provided by the Food and Agriculture Organization (FAO). First, a comparison for a reference period under current climate conditions, shows that both formulations differ, specially in arid areas. However, they supply similar values when FAO's assumption of neutral stability conditions is relaxed, by replacing FAO's aerodynamic resistance by the model's one. Furthermore, if the vapour pressure deficit (VPD) estimated for FAO's equation, is substituted by ORCHIDEE's VPD or its humidity gradient, the daily mean estimate is further improved. In a second step, ETP's sensitivity to climate change is assessed comparing trends in both formulations for the 21st Century. It is found that the USEB method shows a higher sensitivity. Both VPD and the model's humidity gradient, as well as the aerodynamic resistance have been identified as key parameters in governing ETP trends. Finally, the sensitivity study is extended to three empirical approximations based on temperature, net radiation and mass transfer (Hargreaves, Priestley-Taylor and Rohwer, respectively). The sensitivity of these methods is compared to the USEB method's one to test if simplified equations are able to reproduce

  15. Parameter uncertainty, refreezing and surface energy balance modelling at Austfonna ice cap, Svalbard, over 2004–2008

    NARCIS (Netherlands)

    Oestby, T.I.; Schuler, T.V.; Hagen, J.O.; Hock, Regine; Reijmer, C.H.

    2013-01-01

    We apply a physically based coupled surface energy balance and snowpack model to a site close to the equilibrium line on Austfonna ice cap, Svalbard, over the 2004–08 melt seasons, to explain contributions to the energy available for melting and to quantify the significance of refreezing. The model

  16. Downscaling Satellite Land Surface Temperatures in Urban Regions for Surface Energy Balance Study and Heat Index Development

    Science.gov (United States)

    Norouzi, H.; Bah, A.; Prakash, S.; Nouri, N.; Blake, R.

    2017-12-01

    A great percentage of the world's population reside in urban areas that are exposed to the threats of global and regional climate changes and associated extreme weather events. Among them, urban heat islands have significant health and economic impacts due to higher thermal gradients of impermeable surfaces in urban regions compared to their surrounding rural areas. Therefore, accurate characterization of the surface energy balance in urban regions are required to predict these extreme events. High spatial resolution Land surface temperature (LST) in the scale of street level in the cities can provide wealth of information to study surface energy balance and eventually providing a reliable heat index. In this study, we estimate high-resolution LST maps using combination of LandSat 8 and infrared based satellite products such as Moderate Resolution Imaging Spectroradiometer (MODIS) and newly launched Geostationary Operational Environmental Satellite-R Series (GOES-R). Landsat 8 provides higher spatial resolution (30 m) estimates of skin temperature every 16 days. However, MODIS and GOES-R have lower spatial resolution (1km and 4km respectively) with much higher temporal resolution. Several statistical downscaling methods were investigated to provide high spatiotemporal LST maps in urban regions. The results reveal that statistical methods such as Principal Component Analysis (PCA) can provide reliable estimations of LST downscaling with 2K accuracy. Other methods also were tried including aggregating (up-scaling) the high-resolution data to a coarse one to examine the limitations and to build the model. Additionally, we deployed flux towers over distinct materials such as concrete, asphalt, and rooftops in New York City to monitor the sensible and latent heat fluxes through eddy covariance method. To account for the incoming and outgoing radiation, a 4-component radiometer is used that can observe both incoming and outgoing longwave and shortwave radiation. This

  17. Shallow groundwater effect on land surface temperature and surface energy balance under bare soil conditions: modeling and description

    Directory of Open Access Journals (Sweden)

    F. Alkhaier

    2012-07-01

    Full Text Available Understanding when and how groundwater affects surface temperature and energy fluxes is significant for utilizing remote sensing in groundwater studies and for integrating aquifers within land surface models. To investigate the shallow groundwater effect under bare soil conditions, we numerically exposed two soil profiles to identical metrological forcing. One of the profiles had shallow groundwater. The different responses that the two profiles manifested were inspected regarding soil moisture, temperature and energy balance at the land surface. The findings showed that the two profiles differed in three aspects: the absorbed and emitted amounts of energy, the portioning out of the available energy and the heat fluency in the soil. We concluded that due to their lower albedo, shallow groundwater areas reflect less shortwave radiation and consequently get a higher magnitude of net radiation. When potential evaporation demand is sufficiently high, a large portion of the energy received by these areas is consumed for evaporation. This increases the latent heat flux and reduces the energy that could have heated the soil. Consequently, lower magnitudes of both sensible and ground heat fluxes are caused to occur. The higher soil thermal conductivity in shallow groundwater areas facilitates heat transfer between the top soil and the subsurface, i.e. soil subsurface is more thermally connected to the atmosphere. For the reliability of remote sensors in detecting shallow groundwater effect, it was concluded that this effect can be sufficiently clear to be detected if at least one of the following conditions occurs: high potential evaporation and high contrast between day and night temperatures. Under these conditions, most day and night hours are suitable for shallow groundwater depth detection.

  18. National Energy Balance - 1985

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The National Energy Balance - 1985 shows energy fluxes of several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, since 1974 to 1984 (E.G.) [pt

  19. National Energy Balance - 1984

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The National Energy Balance - 1984 shows energy fluxes of several primary and secondary energy sources, since the productions to final consumption in the main economic sectors, since 1973 to 1983. (E.G.) [pt

  20. National Energy Balance-1987

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The National Energy Balance - 1987 showns energy fluxes of several primary and secondary energy sources, since the production to final consumption in the main economic sectors, since 1971 to 1986. (E.G.) [pt

  1. A Web Application for Validating and Disseminating Surface Energy Balance Evapotranspiration Estimates for Hydrologic Modeling Applications

    Science.gov (United States)

    Schneider, C. A.; Aggett, G. R.; Nevo, A.; Babel, N. C.; Hattendorf, M. J.

    2008-12-01

    The western United States face an increasing threat from drought - and the social, economic, and environmental impacts that come with it. The combination of diminished water supplies along with increasing demand for urban and other uses is rapidly depleting surface and ground water reserves traditionally allocated for agricultural use. Quantification of water consumptive use is increasingly important as water resources are placed under growing tension by increased users and interests. Scarce water supplies can be managed more efficiently through use of information and prediction tools accessible via the internet. METRIC (Mapping ET at high Resolution with Internalized Calibration) represents a maturing technology for deriving a remote sensing-based surface energy balance for estimating ET from the earth's surface. This technology has the potential to become widely adopted and used by water resources communities providing critical support to a host of water decision support tools. ET images created using METRIC or similar remote- sensing based processing systems could be routinely used as input to operational and planning models for water demand forecasting, reservoir operations, ground-water management, irrigation water supply planning, water rights regulation, and for the improvement, validation, and use of hydrological models. The ET modeling and subsequent validation and distribution of results via the web presented here provides a vehicle through which METRIC ET parameters can be made more accessible to hydrologic modelers. It will enable users of the data to assess the results of the spatially distributed ET modeling and compare with results from conventional ET estimation methods prior to assimilation in surface and ground water models. In addition, this ET-Server application will provide rapid and transparent access to the data enabling quantification of uncertainties due to errors in temporal sampling and METRIC modeling, while the GIS-based analytical

  2. On the Capabilities of Using AIRSAR Data in Surface Energy/Water Balance Studies

    Science.gov (United States)

    Moreno, Jose F.; Saatchi, Susan S.

    1996-01-01

    The capabilities of using remote sensing data, and in particular multifrequency/multipolarization SAR data, like AIRSAR, for the retrieval of surface parameters, depend considerably on the specificity of each application. The potentials, and limitations, of SAR data in ecological investigations are well known. Because the chemistry is a major component in such studies and because of the almost lacking chemical information at the wavelengths of SAR data, the capabilities of using SAR-derived information in such studies are considerably limited. However, in the case of surface energy/water balance studies, the determination of the amount of water content, both in the soil and in the plants, is a major component in all modeling approaches. As the information about water content is present in the SAR signal, then the role of SAR data in studies where water content is to be determined becomes clearly predominant. Another situation where the role of SAR data becomes dominant over other remote sensing systems is the case of dense canopies. Because of the penetration capabilities of microwave data, which is especially superior as compared to optical data, information about the canopy as a whole and even the underlying soil is contained in the SAR data, while only the top canopy provides the information content in the case of optical data. In the case of relatively dense canopies, as has been demonstrated in this study, such different penetration capabilities provide very different results in terms of the derived total canopy water content, for instance. However, although all such capabilities are well known, unfortunately there are also well known limitations. Apart from calibration-related aspects (that we will not consider in this study), and apart from other intrinsic problems (like image noise, topographic corrections, etc.) which also significantly affect the derived results, we will concentrate on the problem of extracting information from the data. Even at this

  3. Potential evaporation estimation through an unstressed surface-energy balance and its sensitivity to climate change

    Science.gov (United States)

    Barella-Ortiz, A.; Polcher, J.; Tuzet, A.; Laval, K.

    2013-11-01

    Potential evaporation (ETP) is a basic input for many hydrological and agronomic models, as well as a key variable in most actual evaporation estimations. It has been approached through several diffusive and energy balance methods, out of which the Penman-Monteith equation is recommended as the standard one. In order to deal with the diffusive approach, ETP must be estimated at a sub-diurnal frequency, as currently done in land surface models (LSMs). This study presents an improved method, developed in the ORCHIDEE LSM, which consists of estimating ETP through an unstressed surface-energy balance (USEB method). The results confirm the quality of the estimation which is currently implemented in the model (Milly, 1992). The ETP underlying the reference evaporation proposed by the Food and Agriculture Organization, FAO, (computed at a daily time step) has also been analysed and compared. First, a comparison for a reference period under current climate conditions shows that USEB and FAO's ETP estimations differ, especially in arid areas. However, they produce similar values when the FAO's assumption of neutral stability conditions is relaxed, by replacing FAO's aerodynamic resistance by that of the model's. Furthermore, if the vapour pressure deficit (VPD) estimated for the FAO's equation, is substituted by ORCHIDEE's VPD or its humidity gradient, the agreement between the daily mean estimates of ETP is further improved. In a second step, ETP's sensitivity to climate change is assessed by comparing trends in these formulations for the 21st century. It is found that the USEB method shows a higher sensitivity than the FAO's. Both VPD and the model's humidity gradient, as well as the aerodynamic resistance have been identified as key parameters in governing ETP trends. Finally, the sensitivity study is extended to two empirical approximations based on net radiation and mass transfer (Priestley-Taylor and Rohwer, respectively). The sensitivity of these ETP estimates is

  4. Actual evapotranspiration modeling using the operational Simplified Surface Energy Balance (SSEBop) approach

    Science.gov (United States)

    Savoca, Mark E.; Senay, Gabriel B.; Maupin, Molly A.; Kenny, Joan F.; Perry, Charles A.

    2013-01-01

    Remote-sensing technology and surface-energy-balance methods can provide accurate and repeatable estimates of actual evapotranspiration (ETa) when used in combination with local weather datasets over irrigated lands. Estimates of ETa may be used to provide a consistent, accurate, and efficient approach for estimating regional water withdrawals for irrigation and associated consumptive use (CU), especially in arid cropland areas that require supplemental water due to insufficient natural supplies from rainfall, soil moisture, or groundwater. ETa in these areas is considered equivalent to CU, and represents the part of applied irrigation water that is evaporated and/or transpired, and is not available for immediate reuse. A recent U.S. Geological Survey study demonstrated the application of the remote-sensing-based Simplified Surface Energy Balance (SSEB) model to estimate 10-year average ETa at 1-kilometer resolution on national and regional scales, and compared those ETa values to the U.S. Geological Survey’s National Water-Use Information Program’s 1995 county estimates of CU. The operational version of the operational SSEB (SSEBop) method is now used to construct monthly, county-level ETa maps of the conterminous United States for the years 2000, 2005, and 2010. The performance of the SSEBop was evaluated using eddy covariance flux tower datasets compiled from 2005 datasets, and the results showed a strong linear relationship in different land cover types across diverse ecosystems in the conterminous United States (correlation coefficient [r] ranging from 0.75 to 0.95). For example, r for woody savannas (0.75), grassland (0.75), forest (0.82), cropland (0.84), shrub land (0.89), and urban (0.95). A comparison of the remote-sensing SSEBop method for estimating ETa and the Hamon temperature method for estimating potential ET (ETp) also was conducted, using regressions of all available county averages of ETa for 2005 and 2010, and yielded correlations of r = 0

  5. Potential Evaporation Computation through an Unstressed Surface Energy Balance and its Sensitivity to Climate Change Effect

    Science.gov (United States)

    Barella-Ortiz, Anaïs; Polcher, Jan; Tuzet, Andrée; Laval, Katia

    2013-04-01

    Potential evaporation (ETP) is a basic input for hydrological and agronomic models, as well as a key variable in most actual evaporation estimations. It has been approached through several diffusive and energy balance methods, out of which the Penman-Monteith equation is recommended as the standard one. In order to deal with the diffusive approach, ETP must be estimated at a sub-diurnal frequency, as currently done in land surface models (LSM). This study presents an improved method, developed in the ORCHIDEE LSM, which consists in estimating ETP through an unstressed surface energy balance (USEB method). The values provided confirm the quality of the estimation which is currently implemented (Milly, 1992). ETP has also been estimated using a reference equation (computed at a daily time step) provided by the Food and Agriculture Organization (FAO). In the first place, a comparison for a reference period of 11 years shows that both formulations differ, specially in arid areas. However, they supply similar values when FAO's assumption of neutral stability conditions is relaxed, by replacing FAO's aerodynamic resistance by the model's one. Additionally, if the vapour pressure deficit (VPD) is also substituted by either ORCHIDEE's VPD or its humidity gradient, the daily mean estimate is further improved. ETP's sensitivity to climate change is assessed comparing trends in both formulations for the 21st Century. It is found that the USEB method shows a higher sensitivity mainly due to FAO's assumption of neutral stability conditions and to a lesser extent, to the approximation proposed for the VPD. Both FAO's VPD and the model's humidity gradient, as well as ORCHIDEE's aerodynamic resistance have been identified as key parameters in governing ETP trends. Finally, the sensitivity study is extended to 3 empirical approximations based on temperature, net radiation and mass transfer (Hargreaves, Priestley - Taylor and Rohwer, respectively). When compared to the USEB method

  6. Energy balance measurement

    DEFF Research Database (Denmark)

    Dhurandhar, N V; Schoeller, D; Brown, A W

    2015-01-01

    Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self......-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific research on EI and PAEE. While new strategies for objectively determining energy balance...... of energy balance....

  7. Assessing actual evapotranspiration via surface energy balance aiming to optimize water and energy consumption in large scale pressurized irrigation systems

    Science.gov (United States)

    Awada, H.; Ciraolo, G.; Maltese, A.; Moreno Hidalgo, M. A.; Provenzano, G.; Còrcoles, J. I.

    2017-10-01

    Satellite imagery provides a dependable basis for computational models that aimed to determine actual evapotranspiration (ET) by surface energy balance. Satellite-based models enables quantifying ET over large areas for a wide range of applications, such as monitoring water distribution, managing irrigation and assessing irrigation systems' performance. With the aim to evaluate the energy and water consumption of a large scale on-turn pressurized irrigation system in the district of Aguas Nuevas, Albacete, Spain, the satellite-based image-processing model SEBAL was used for calculating actual ET. The model has been applied to quantify instantaneous, daily, and seasonal actual ET over high- resolution Landsat images for the peak water demand season (May to September) and for the years 2006 - 2008. The model provided a direct estimation of the distribution of main energy fluxes, at the instant when the satellite overpassed over each field of the district. The image acquisition day Evapotranspiration (ET24) was obtained from instantaneous values by assuming a constant evaporative fraction (Λ) for the entire day of acquisition; then, monthly and seasonal ET were estimated from the daily evapotranspiration (ETdaily) assuming that ET24 varies in proportion to reference ET (ETr) at the meteorological station, thus accounting for day to day variation in meteorological forcing. The comparison between the hydrants water consumption and the actual evapotranspiration, considering an irrigation efficiency of 85%, showed that a considerable amount of water and energy can be saved at district level.

  8. Surface Energy Balance of Fresh and Saline Waters: AquaSEBS

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelrady

    2016-07-01

    Full Text Available Current earth observation models do not take into account the influence of water salinity on the evaporation rate, even though the salinity influences the evaporation rate by affecting the density and latent heat of vaporization. In this paper, we adapt the SEBS (Surface Energy Balance System model for large water bodies and add the effect of water salinity to the evaporation rate. Firstly, SEBS is modified for fresh-water whereby new parameterizations of the water heat flux and sensible heat flux are suggested. This is achieved by adapting the roughness heights for momentum and heat transfer. Secondly, a salinity correction factor is integrated into the adapted model. Eddy covariance measurements over Lake IJsselmeer (The Netherlands are carried out and used to estimate the roughness heights for momentum (~0.0002 m and heat transfer (~0.0001 m. Application of these values over the Victoria and Tana lakes (freshwater in Africa showed that the calculated latent heat fluxes agree well with the measurements. The root mean-square of relative-errors (rRMSE is about 4.1% for Lake Victoria and 4.7%, for Lake Tana. Verification with ECMWF data showed that the salinity reduced the evaporation at varying levels by up to 27% in the Great Salt Lake and by 1% for open ocean. Our results show the importance of salinity to the evaporation rate and the suitability of the adapted-SEBS model (AquaSEBS for fresh and saline waters.

  9. Soil heat flux and day time surface energy balance closure at ...

    Indian Academy of Sciences (India)

    energy balance along with the net radiation (R), latent heat flux (L), sensible heat flux (H), and in some cases, canopy storage and photosynthesis. (Cobos and Baker 2003). The influence of soil heat flux on chemical reactions and microclimate are self evident. On a wet or full-vegetation-covered sur- face, the soil heat flux is ...

  10. Estimation of actual evapotranspiration of Mediterranean perennial crops by means of remote-sensing based surface energy balance models

    Directory of Open Access Journals (Sweden)

    G. Rallo

    2009-07-01

    Full Text Available Actual evapotranspiration from typical Mediterranean crops has been assessed in a Sicilian study area by using surface energy balance (SEB and soil-water balance models. Both modelling approaches use remotely sensed data to estimate evapotranspiration fluxes in a spatially distributed way. The first approach exploits visible (VIS, near-infrared (NIR and thermal (TIR observations to solve the surface energy balance equation whereas the soil-water balance model uses only VIS-NIR data to detect the spatial variability of crop parameters. Considering that the study area is characterized by typical spatially sparse Mediterranean vegetation, i.e. olive, citrus and vineyards, alternating bare soil and canopy, we focused the attention on the main conceptual differences between one-source and two-sources energy balance models. Two different models have been tested: the widely used one-source SEBAL model, where soil and vegetation are considered as the sole source (mostly appropriate in the case of uniform vegetation coverage and the two-sources TSEB model, where soil and vegetation components of the surface energy balance are treated separately. Actual evapotranspiration estimates by means of the two surface energy balance models have been compared vs. the outputs of the agro-hydrological SWAP model, which was applied in a spatially distributed way to simulate one-dimensional water flow in the soil-plant-atmosphere continuum. Remote sensing data in the VIS and NIR spectral ranges have been used to infer spatially distributed vegetation parameters needed to set up the upper boundary condition of SWAP. Actual evapotranspiration values obtained from the application of the soil water balance model SWAP have been considered as the reference to be used for energy balance models accuracy assessment.

    Airborne hyperspectral data acquired during a NERC (Natural Environment Research Council, UK campaign in 2005 have been used. The results of this

  11. Estimation of Land Surface Energy Balance Using Satellite Data of Spatial Reduced Resolution

    Science.gov (United States)

    Vintila, Ruxandra; Radnea, Cristina; Savin, Elena; Poenaru, Violeta

    2010-12-01

    The paper presents preliminary results concerning the monitoring at national level of several geo-biophysical variables retrieved by remote sensing, in particular those related to drought or aridisation. The study, which is in progress, represents also an exercise for to the implementation of a Land Monitoring Core Service for Romania, according to the Kopernikus Program and in compliance with the INSPIRE Directive. The SEBS model has been used to retrieve land surface energy balance variables, such as turbulent heat fluxes, evaporative fraction and daily evaporation, based on three information types: (1) surface albedo, emissivity, temperature, fraction of vegetation cover (fCover), leaf area index (LAI) and vegetation height; (2) air pressure, temperature, humidity and wind speed at the planetary boundary layer (PBL) height; (3) downward solar radiation and downward longwave radiation. AATSR and MERIS archived reprocessed images have provided several types of information. Thus, surface albedo, emissivity, and land surface temperature have been retrieved from AATSR, while LAI and fCover have been estimated from MERIS. The vegetation height has been derived from CORINE Land Cover and PELCOM Land Use databases, while the meteorological information at the height of PBL have been estimated from the measurements provided by the national weather station network. Other sources of data used during this study have been the GETASSE30 digital elevation model with 30" spatial resolution, used for satellite image orthorectification, and the SIGSTAR-200 geographical information system of soil resources of Romania, used for water deficit characterisation. The study will continue by processing other AATSR and MERIS archived images, complemented by the validation of SEBS results with ground data collected on the most important biomes for Romania at various phenological stages, and the transformation of evaporation / evapotranspiration into a drought index using the soil texture

  12. Quantifying the impacts of snow on surface energy balance through assimilating snow cover fraction and snow depth

    Science.gov (United States)

    Meng, Chunlei

    2017-10-01

    Seasonal snow plays an important part in Earth's climate system. Snow cover regulates the land surface energy balance through altering the albedo of the land surface. To utilize the satellite-retrieved snow cover fraction (SCF) and snow depth (SD) data sufficiently and avoid inconsistency, this paper developed a very simple but robust quality control method to assimilate Fengyun satellite-retrieved SCF and SD simultaneously. The results show that the assimilation method which this paper implemented can not only utilize the satellite-retrieved SCF and SD data sufficiently but also avoid the inconsistency of them. Two experiments were designed and performed to quantify the impacts of snow on land surface energy balance using the integrated urban land model. With the increase of the SCF and SD, the net radiation decreased significantly during the day and increased a little at night; the sensible heat flux decreased significantly during the day; the evapotranspiration and ground heat flux decreased during the day too.

  13. Energy balances 2000

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The energy balances of the Danish Statistical Office are the designation of the goods balances, which are tabulated for each energy article in both physical entities (quantities) and in base rates (values). The balance concept is connected to the definition supply = use, which is the basis for the construction of the system. The supply is determined as the sum of two items: import and production while the total use is the sum of 138 items: export, waste and transmission loss, stock increase, input in lack of the 130 industries, and private consumption divided into 5 consumption groups. The statistical analysis is performed yearly in both quantities and values for 35 energy articles. Values are computed for base rates, profits, taxes, VAT and market prices (buyer's price), respectively. The energy balances from 1975 to 2000 are presented for comparison. (EHS)

  14. National energy balance - 1977

    International Nuclear Information System (INIS)

    1977-01-01

    The national energy balance of the 1976 shows several modifications in relation to the last year. The historical serie is based in more confiable information, from several energy companies. The most greater modifications are on energy source of hard control, such as lignite and charcoal for non-siderurgic uses. (E.G.) [pt

  15. National energy balance - 1978

    International Nuclear Information System (INIS)

    1978-01-01

    The national energy balance of 1978 shows some modifications in relation to the last year. New tables were included aiming to show the brazilian energy situation, such as the hydraulic potential and the non-renewable energy resources. (E.G.) [pt

  16. National Energy Balance - 1986

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The National Energy Balance - 1986 shows energy fluxes of several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, since 1970 to 1985. The incorporation of a new brazilian information is done. (E.G.) [pt

  17. National Energy Balance - 1981

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The National Energy Balance - 1981, shows a new metodology and information in level of several economic sectors, as well as a separation of primary and secondary energy sources, its energy fluxes, i.e. production, imports, exports, consumption, etc...(E.G.) [pt

  18. National energy balance - 1976

    International Nuclear Information System (INIS)

    1976-01-01

    Based on available data from IBGE, CNP/Petrobras, Eletrobras, Nuclebras and other governmental enterprises the National Energy Balance was done. This publication covers since 1965 to 1975. In conformity to the international rules, the energy resources used for non-energy purposes were excluded. The energy production and consumption for the next ten years were forecasted, considering the actual brazilian energy policy. (E.G.) [pt

  19. Energy balance of Georgia

    Directory of Open Access Journals (Sweden)

    Demur Chomakhidze

    2016-09-01

    It is shown that, traditionally, the energy balance of Georgia is in deep deficit. The suggestions for its improvement are provided in the Article. The country imports almost all amount of oil and natural gas. Electricity balance is relatively stable. In the recent years, some amount of electricity is exported to the neighboring countries. Generally, the country satisfies only 30–35% of own energy consumption by local generation, and the rest amount of resources are imported from abroad. The reason of deficit to some extent is irrational and wasteful consumption of energy resources. The article examines the organizational difficulties in drawing up energy balance of Georgia and statistical problems of recording of energy production and consumption at the initial stage of market economy.

  20. The response of surface mass and energy balance of a continental glacier to climate variability, western Qilian Mountains, China

    Science.gov (United States)

    Sun, Weijun; Qin, Xiang; Wang, Yetang; Chen, Jizu; Du, Wentao; Zhang, Tong; Huai, Baojuan

    2017-08-01

    To understand how a continental glacier responds to climate change, it is imperative to quantify the surface energy fluxes and identify factors controlling glacier mass balance using surface energy balance (SEB) model. Light absorbing impurities (LAIs) at the glacial surface can greatly decrease surface albedo and increase glacial melt. An automatic weather station was set up and generated a unique 6-year meteorological dataset for the ablation zone of Laohugou Glacier No. 12. Based on these data, the surface energy budget was calculated and an experiment on the glacial melt process was carried out. The effect of reduced albedo on glacial melting was analyzed. Owing to continuous accumulation of LAIs, the ablation zone had been darkening since 2010. The mean value of surface albedo in melt period (June through September) dropped from 0.52 to 0.43, and the minimum of daily mean value was as small as 0.1. From the records of 2010-2015, keeping the clean ice albedo fixed in the range of 0.3-0.4, LAIs caused an increase of +7.1 to +16 W m-2 of net shortwave radiation and an removal of 1101-2663 mm water equivalent. Calculation with the SEB model showed equivalent increases in glacial melt were obtained by increasing air temperature by 1.3 and 3.2 K, respectively.

  1. SUNYA Regional Climate Model Simulations of East Asia Summer Monsoon: Effects of Cloud Vertical Structure on the Surface Energy Balance

    Directory of Open Access Journals (Sweden)

    Wei Gong Wei-Chyung Wang

    2007-01-01

    Full Text Available We used the State University of New York at Albany (SUNYA regional climate model to study the effect of cloud vertical distribution in affecting the surface energy balance of the East Asia summer monsoon (EASM. Simulations were conducted for the summers of 1988 and 1989, during which large contrast in the intra-seasonal cloud radiative forcing (CRF was observed at the top of the atmosphere.

  2. Latent Heat Flux Estimate Through an Energy Water Balance Model and Land Surface Temperature from Remote Sensing

    Science.gov (United States)

    Corbari, Chiara; Sobrino, Jose A.; Mancini, Marco; Hidalgo, Victoria

    2011-01-01

    Soil moisture plays a key role in the terrestrial water cycle and is responsible for the partitioning of precipitation between runoff and infiltration. Moreover, surface soil moisture controls the redistribution of the incoming solar radiation on land surface into sensible and latent heat fluxes. Recent developments have been made to improve soil moisture dynamics predictions with hydrologic land surface models (LSMs) that compute water and energy balances between the land surface and the low atmosphere. However, most of the time soil moisture is confined to an internal numerical model variable mainly due to its intrinsic space and time variability and to the well known difficulties in assessing its value from remote sensing as from in situ measurements. In order to exploit the synergy between hydrological distributed models and thermal remote sensed data, FEST-EWB, a land surface model that solves the energy balance equation, was developed. In this hydrological model, the energy budget is solved looking for the representative thermodynamic equilibrium temperature (RET) defined as the land surface temperature that closes the energy balance equation. So using this approach, soil moisture is linked to the latent heat flux and then to LST. In this work the relationship between land surface temperature and soil moisture is analysed using LST from AHS (airborne hyperspectral scanner), with a spatial resolution of 2-4 m, LST from MODIS, with a spatial resolution of 1000 m, and thermal infrared radiometric ground measurements that are compared with the thermodynamic equilibrium temperature from the energy water balance model. Moreover soil moisture measurements were carried out during the airborne overpasses and then compared with SM from the hydrological model. An improvement of this well known inverse relationship between soil moisture and land surface temperature is obtained when the thermodynamic approach is used. The analysis of the scale effects of the different

  3. Energy balances 2005

    International Nuclear Information System (INIS)

    Anon.

    2006-01-01

    Denmark's energy consumption was 800 PJ in 2005 when corrected for the fuel consumption used for producing electricity for export. The consumption is 0,5 % higher than in 2004. Since 1975, the energy consumption has been on the same level with minor fluctuations which are mainly due to the climate. The energy balances is an account of production, import and export, and consumption of energy. The consumption is accounted as physical amounts as well as gross consumption. Also, accounts are presented of the costs of energy in basis prices and in market prices, including excises on energy, CO 2 , and SO 2 . (LN)

  4. Regional Estimation of Remotely Sensed Evapotranspiration Using the Surface Energy Balance-Advection (SEB-A Method

    Directory of Open Access Journals (Sweden)

    Suhua Liu

    2016-08-01

    Full Text Available Evapotranspiration (ET is an essential part of the hydrological cycle and accurately estimating it plays a crucial role in water resource management. Surface energy balance (SEB models are widely used to estimate regional ET with remote sensing. The presence of horizontal advection, however, perturbs the surface energy balance system and contributes to the uncertainty of energy influxes. Thus, it is vital to consider horizontal advection when applying SEB models to estimate ET. This study proposes an innovative and simplified approach, the surface energy balance-advection (SEB-A method, which is based on the energy balance theory and also takes into account the horizontal advection to determine ET by remote sensing. The SEB-A method considers that the actual ET consists of two parts: the local ET that is regulated by the energy balance system and the exotic ET that arises from horizontal advection. To evaluate the SEB-A method, it was applied to the middle region of the Heihe River in China. Instantaneous ET for three days were acquired and assessed with ET measurements from eddy covariance (EC systems. The results demonstrated that the ET estimates had a high accuracy, with a correlation coefficient (R2 of 0.713, a mean average error (MAE of 39.3 W/m2 and a root mean square error (RMSE of 54.6 W/m2 between the estimates and corresponding measurements. Percent error was calculated to more rigorously assess the accuracy of these estimates, and it ranged from 0% to 35%, with over 80% of the locations within a 20% error. To better understand the SEB-A method, the relationship between the ET estimates and land use types was analyzed, and the results indicated that the ET estimates had spatial distributions that correlated with vegetation patterns and could well demonstrate the ET differences caused by different land use types. The sensitivity analysis suggested that the SEB-A method requested accurate estimation of the available energy, R n − G

  5. Single-source surface energy balance algorithms to estimate evapotranspiration from satellite-based remotely sensed data

    Science.gov (United States)

    Bhattarai, Nishan

    The flow of water and energy fluxes at the Earth's surface and within the climate system is difficult to quantify. Recent advances in remote sensing technologies have provided scientists with a useful means to improve characterization of these complex processes. However, many challenges remain that limit our ability to optimize remote sensing data in determining evapotranspiration (ET) and energy fluxes. For example, periodic cloud cover limits the operational use of remotely sensed data from passive sensors in monitoring seasonal fluxes. Additionally, there are many remote sensing-based single-source surface energy balance (SEB) models, but no clear guidance on which one to use in a particular application. Two widely used models---surface energy balance algorithm for land (SEBAL) and mapping ET at high resolution with internalized calibration (METRIC)---need substantial human-intervention that limits their applicability in broad-scale studies. This dissertation addressed some of these challenges by proposing novel ways to optimize available resources within the SEB-based ET modeling framework. A simple regression-based Landsat-Moderate Resolution Imaging Spectroradiometer (MODIS) fusion model was developed to integrate Landsat spatial and MODIS temporal characteristics in calculating ET. The fusion model produced reliable estimates of seasonal ET at moderate spatial resolution while mitigating the impact that cloud cover can have on image availability. The dissertation also evaluated five commonly used remote sensing-based single-source SEB models and found the surface energy balance system (SEBS) may be the best overall model for use in humid subtropical climates. The study also determined that model accuracy varies with land cover type, for example, all models worked well for wet marsh conditions, but the SEBAL and simplified surface energy balance index (S-SEBI) models worked better than the alternatives for grass cover. A new automated approach based on

  6. A one-layer satellite surface energy balance for estimating evapotranspiration rates and crop water stress indexes.

    Science.gov (United States)

    Barbagallo, Salvatore; Consoli, Simona; Russo, Alfonso

    2009-01-01

    Daily evapotranspiration fluxes over the semi-arid Catania Plain area (Eastern Sicily, Italy) were evaluated using remotely sensed data from Landsat Thematic Mapper TM5 images. A one-source parameterization of the surface sensible heat flux exchange using satellite surface temperature has been used. The transfer of sensible and latent heat is described by aerodynamic resistance and surface resistance. Required model inputs are brightness, temperature, fractional vegetation cover or leaf area index, albedo, crop height, roughness lengths, net radiation, air temperature, air humidity and wind speed. The aerodynamic resistance (r(ah)) is formulated on the basis of the Monin-Obukhov surface layer similarity theory and the surface resistance (r(s)) is evaluated from the energy balance equation. The instantaneous surface flux values were converted into evaporative fraction (EF) over the heterogeneous land surface to derive daily evapotranspiration values. Remote sensing-based assessments of crop water stress (CWSI) were also made in order to identify local irrigation requirements. Evapotranspiration data and crop coefficient values obtained from the approach were compared with: (i) data from the semi-empirical approach "K(c) reflectance-based", which integrates satellite data in the visible and NIR regions of the electromagnetic spectrum with ground-based measurements and (ii) surface energy flux measurements collected from a micrometeorological tower located in the experiment area. The expected variability associated with ET flux measurements suggests that the approach-derived surface fluxes were in acceptable agreement with the observations.

  7. Impact of highway construction on land surface energy balance and local climate derived from LANDSAT satellite data.

    Science.gov (United States)

    Nedbal, Václav; Brom, Jakub

    2018-03-26

    Extensive construction of highways has a major impact on the landscape and its structure. They can also influence local climate and heat fluxes in the surrounding area. After the removal of vegetation due to highway construction, the amount of solar radiation energy used for plant evapotranspiration (latent heat flux) decreases, bringing about an increase in landscape surface temperature, changing the local climate and increasing surface run-off. In this study, we evaluated the impact of the D8 highway construction (Central Bohemia, Czech Republic) on the distribution of solar radiation energy into the various heat fluxes (latent, sensible and ground heat flux) and related surface functional parameters (surface temperature and surface wetness). The aim was to describe the severity of the impact and the distance from the actual highway in which it can be observed. LANDSAT multispectral satellite images and field meteorological measurements were used to calculate surface functional parameters and heat balance before and during the highway construction. Construction of a four-lane highway can influence the heat balance of the landscape surface as far as 90m in the perpendicular direction from the highway axis, i.e. up to 75m perpendicular from its edge. During a summer day, the decrease in evapotranspired water can reach up to 43.7m 3 per highway kilometre. This means a reduced cooling effect, expressed as the decrease in latent heat flux, by an average of 29.7MWh per day per highway kilometre and its surroundings. The loss of the cooling ability of the land surface by evaporation can lead to a rise in surface temperature by as much as 7°C. Thus, the results indicate the impact of extensive line constructions on the local climate. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Components of near-surface energy balance derived from satellite soundings – Part 1: Net available energy

    OpenAIRE

    K. Mallick; A. Jarvis; G. Wohlfahrt; G. Kiely; T. Hirano; A. Miyata; S. Yamamoto; L. Hoffmann

    2014-01-01

    This paper introduces a relatively simple method for recovering global fields of near-surface net available energy (the sum of the sensible and latent heat flux or the difference between the net radiation and surface heat accumulation) using satellite visible and infra-red products derived from the AIRS (Atmospheric Infrared Sounder) and MODIS (MOderate Resolution Imaging Spectroradiometer) platforms. The method focuses on first specifying net surface radiation by con...

  9. The Effects of Great Plains Irrigation on the Surface Energy Balance, Regional Circulation, and Precipitation

    Directory of Open Access Journals (Sweden)

    David B. Huber

    2014-05-01

    Full Text Available Irrigation provides a needed source of water in regions of low precipitation. Adding water to a region that would otherwise see little natural precipitation alters the partitioning of surface energy fluxes, the evolution of the planetary boundary layer, and the atmospheric transport of water vapor. The effects of irrigation are investigated in this paper through the employment of the Advanced Research (ARW Weather Research and Forecasting Model (WRF using a pair of simulations representing the extremes of an irrigated and non-irrigated U.S. Great Plains region. In common with previous studies, irrigation in the Great Plains alters the radiation budget by increasing latent heat flux and cooling the surface temperatures. These effects increase the net radiation at the surface, channeling that energy into additional latent heat flux, which increases convective available potential energy and provides downstream convective systems with additional energy and moisture. Most noteworthy in this study is the substantial influence of irrigation on the structure of the Great Plains Low-level Jet (GPLLJ. The simulation employing irrigation is characterized by a positive 850-mb geopotential height anomaly, a result interpreted by quasi-geostrophic theory to be a response to low-level irrigation-induced cooling. The modulation of the regional-scale height pattern associated with the GPLLJ results in weaker flow southeast of the 850-mb anomaly and stronger flow to the northwest. Increased latent heat flux in the irrigated simulation is greater than the decrease in regional transport, resulting in a net increase in atmospheric moisture and a nearly 50% increase in July precipitation downstream of irrigated regions without any change to the number of precipitation events.

  10. How accurately are climatological characteristics and surface water and energy balances represented for the Colombian Caribbean Catchment Basin?

    Science.gov (United States)

    Hoyos, Isabel; Baquero-Bernal, Astrid; Hagemann, Stefan

    2013-09-01

    In Colombia, the access to climate related observational data is restricted and their quantity is limited. But information about the current climate is fundamental for studies on present and future climate changes and their impacts. In this respect, this information is especially important over the Colombian Caribbean Catchment Basin (CCCB) that comprises over 80 % of the population of Colombia and produces about 85 % of its GDP. Consequently, an ensemble of several datasets has been evaluated and compared with respect to their capability to represent the climate over the CCCB. The comparison includes observations, reconstructed data (CPC, Delaware), reanalyses (ERA-40, NCEP/NCAR), and simulated data produced with the regional climate model REMO. The capabilities to represent the average annual state, the seasonal cycle, and the interannual variability are investigated. The analyses focus on surface air temperature and precipitation as well as on surface water and energy balances. On one hand the CCCB characteristics poses some difficulties to the datasets as the CCCB includes a mountainous region with three mountain ranges, where the dynamical core of models and model parameterizations can fail. On the other hand, it has the most dense network of stations, with the longest records, in the country. The results can be summarised as follows: all of the datasets demonstrate a cold bias in the average temperature of CCCB. However, the variability of the average temperature of CCCB is most poorly represented by the NCEP/NCAR dataset. The average precipitation in CCCB is overestimated by all datasets. For the ERA-40, NCEP/NCAR, and REMO datasets, the amplitude of the annual cycle is extremely high. The variability of the average precipitation in CCCB is better represented by the reconstructed data of CPC and Delaware, as well as by NCEP/NCAR. Regarding the capability to represent the spatial behaviour of CCCB, temperature is better represented by Delaware and REMO, while

  11. Satellite estimation of the surface energy balance, moisture availability and thermal inertia

    Science.gov (United States)

    Carlson, T. N.; Dodd, J. K.; Benjamin, S. G.; Cooper, J. N.

    1981-01-01

    A method for inferring the distribution of surface heat and evaporative fluxes and the ground moisture availability and thermal inertia (ground conductive capacity) is used to analyze two urbanized areas, Los Angeles and St. Louis. The technique employs infrared satellite temperature measurements in conjunction with a one-dimensional boundary-layer model. Results show that there is a marked reduction of evaporation and moisture availability and a corresponding elevation of sensible heat flux over urbanized areas and over cropped areas with low vegetative cover. Conversely, low heat flux and high evaporation characterize vegetated and, especially, forested areas. Warm urban centers appear directly related to a reduction in vegetation, which normally allows for a greater fraction of available radiant energy to be converted into latent heat flux. The distribution of thermal inertia was surprisingly ill-defined and its variation between urban and rural areas was quite small. Thus, the increased heat storage within the urban fabric, which has been proposed as the underlying cause of the nocturnal heat island, may be caused mainly by enhanced daytime surface heating which occurs because of surface dryness, rather than by large spatial variations in the conductivity of the surface.

  12. Estimation of Surface Soil Moisture in Irrigated Lands by Assimilation of Landsat Vegetation Indices, Surface Energy Balance Products, and Relevance Vector Machines

    Directory of Open Access Journals (Sweden)

    Alfonso F. Torres-Rua

    2016-04-01

    Full Text Available Spatial surface soil moisture can be an important indicator of crop conditions on farmland, but its continuous estimation remains challenging due to coarse spatial and temporal resolution of existing remotely-sensed products. Furthermore, while preceding research on soil moisture using remote sensing (surface energy balance, weather parameters, and vegetation indices has demonstrated a relationship between these factors and soil moisture, practical continuous spatial quantification of the latter is still unavailable for use in water and agricultural management. In this study, a methodology is presented to estimate volumetric surface soil moisture by statistical selection from potential predictors that include vegetation indices and energy balance products derived from satellite (Landsat imagery and weather data as identified in scientific literature. This methodology employs a statistical learning machine called a Relevance Vector Machine (RVM to identify and relate the potential predictors to soil moisture by means of stratified cross-validation and forward variable selection. Surface soil moisture measurements from irrigated agricultural fields in Central Utah in the 2012 irrigation season were used, along with weather data, Landsat vegetation indices, and energy balance products. The methodology, data collection, processing, and estimation accuracy are presented and discussed.

  13. SUNYA Regional Climate Model Simulations of East Asia Summer Monsoon: Effects of Cloud Vertical Structure on the Surface Energy Balance

    Directory of Open Access Journals (Sweden)

    Wei Gong and Wei-Chyung Wang

    2007-01-01

    Full Text Available We used the State University of New York at Albany (SUNYA regional climate model to study the effect of cloud vertical distribution in affecting the surface energy balance of the East Asia summer monsoon (EASM. Simulations were conducted for the summers of 1988 and 1989, during which large contrast in the intra-seasonal cloud radiative forcing (CRF was observed at the top of the atmosphere. The model results indicate that both the high and low clouds are persistent throughout the summer months in both years. Because of large cloud water, low clouds significantly reduce the solar radiation flux reaching the surface, which nevertheless still dominate the surface energy balance, accounting for more than 50% of the surface heating. The low clouds also contribute significantly the downward longwave radiation to the surface with values strongly dependent on the cloud base temperature. The presence of low clouds effectively decreases the temperature and moisture gradients near surface, resulting in a substantial decrease in the sensible and latent heat fluxes from surface, which partially compensate the decrease of the net radiative cooling of the surface. For example, in the two days, May 8 and July 11 of 1988, the total cloud cover of 80% is simulated, but the respective low cloud cover (water was 63% (114 gm-2 and 22% (21 gm-2. As a result, the downward solar radiation is smaller by 161 Wm-2 in May 8. On the other hand, the cloud temperature was _ lower, yielding 56 Wm-2 smaller downward longwave radiation. The near surface temperature and gradient is more than _ smaller (and moisture gradient, leading to 21 and 81 Wm-2 smaller sensible heat and latent heat fluxes. It is also demonstrated that the model is capable to reproduce the intraseasonal variation of shortwave CRF, and catches the relationship between total cloud cover and SW CRF. The model results show the dominance of high cloud on the regional mean longwave CRF and low cloud on the intra

  14. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA to estimate actual evapotranspiration over heterogeneous terrain

    Directory of Open Access Journals (Sweden)

    Z. Q. Gao

    2011-01-01

    Full Text Available Evapotranspiration (ET may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial coverage in the study areas. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at different temporal and spatial scales under heterogeneous terrain with varying elevations, slopes and aspects. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA. With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM, and the vegetation cover derived from satellite images, the SEBTA can account for the dynamic impacts of heterogeneous terrain and changing land cover with some varying kinetic parameters (i.e., roughness and zero-plane displacement. Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.

  15. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA) to estimate actual evapotranspiration over heterogeneous terrain

    Science.gov (United States)

    Gao, Z. Q.; Liu, C. S.; Gao, W.; Chang, N.-B.

    2011-01-01

    Evapotranspiration (ET) may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial coverage in the study areas. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at different temporal and spatial scales under heterogeneous terrain with varying elevations, slopes and aspects. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA). With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM), and the vegetation cover derived from satellite images, the SEBTA can account for the dynamic impacts of heterogeneous terrain and changing land cover with some varying kinetic parameters (i.e., roughness and zero-plane displacement). Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.

  16. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA) to estimate actual evapotranspiration under complex terrain

    Science.gov (United States)

    Gao, Z. Q.; Liu, C. S.; Gao, W.; Chang, N. B.

    2010-07-01

    Evapotranspiration (ET) may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial scales. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at varying temporal and spatial scales under complex terrain. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA). With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM), and the vegetation cover derived from satellite images, the SEBTA can fully account for the dynamic impacts of complex terrain and changing land cover in concert with some varying kinetic parameters (i.e., roughness and zero-plane displacement) over time. Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.

  17. Inter-comparison of four remote sensing based surface energy balance methods to retrieve surface evapotranspiration and water stress of irrigated fields in semi-arid climate

    Science.gov (United States)

    Chirouze, J.; Boulet, G.; Jarlan, L.; Fieuzal, R.; Rodriguez, J. C.; Ezzahar, J.; Er-Raki, S.; Bigeard, G.; Merlin, O.; Garatuza-Payan, J.; Watts, C.; Chehbouni, G.

    2013-01-01

    Remotely sensed surface temperature can provide a good proxy for water stress level and is therefore particularly useful to estimate spatially distributed evapotranspiration. Instantaneous stress levels or instantaneous latent heat flux are deduced from the surface energy balance equation constrained by this equilibrium temperature. Pixel average surface temperature depends on two main factors: stress and vegetation fraction cover. Methods estimating stress vary according to the way they treat each factor. Two families of methods can be defined: the contextual methods, where stress levels are scaled on a given image between hot/dry and cool/wet pixels for a particular vegetation cover, and single-pixel methods which evaluate latent heat as the residual of the surface energy balance for one pixel independently from the others. Four models, two contextual (S-SEBI and a triangle method, inspired by Moran et al., 1994) and two single-pixel (TSEB, SEBS) are applied at seasonal scale over a four by four km irrigated agricultural area in semi-arid northern Mexico. Their performances, both at local and spatial standpoints, are compared relatively to energy balance data acquired at seven locations within the area, as well as a more complex soil-vegetation-atmosphere transfer model forced with true irrigation and rainfall data. Stress levels are not always well retrieved by most models, but S-SEBI as well as TSEB, although slightly biased, show good performances. Drop in model performances is observed when vegetation is senescent, mostly due to a poor partitioning both between turbulent fluxes and between the soil/plant components of the latent heat flux and the available energy. As expected, contextual methods perform well when extreme hydric and vegetation conditions are encountered in the same image (therefore, esp. in spring and early summer) while they tend to exaggerate the spread in water status in more homogeneous conditions (esp. in winter).

  18. Actual Evapotranspiration in the Al-Khazir Gomal Basin (Northern Iraq Using the Surface Energy Balance Algorithm for Land (SEBAL and Water Balance

    Directory of Open Access Journals (Sweden)

    Hussein Jassas

    2015-04-01

    Full Text Available Increasing dependence on groundwater requires a detailed determination of the different outputs and inputs of a basin for better water management. Determination of spatial and temporal actual evapotranspiration (ETa, in this regard, is of vital importance as there is significant water loss from drainage basins. This research paper uses the Surface Energy Balance Algorithm for Land (SEBAL, as well as the water balance, to estimate the spatial and temporal ETa in the Al-Khazir Gomal Basin, Northern Iraq. To compensate for the shortage in rainfall, and to irrigate summer crops, farmers in this basin have been depending, to a large extent, on groundwater extracted from the underlying unconfined aquifer, which is considered the major source for both domestic and agricultural uses in this basin. Rainfed farming of wheat and barley is one of the most important activities in the basin in the winter season, while in the summer season, agricultural activity is limited to small rice fields and narrow strips of vegetable cultivation along the Al-Khazir River. The Landsat Thematic Mapper images (TM5 acquired on 21 November 2006, 9 March 2007, 5 May 2007, 21 July 2007, and 23 September 2007 were used, along with a digital elevation model (DEM and ground-based meteorological data, measured within the area of interest. Estimation of seasonal ETa from periods between satellite overpasses was computed using the evaporative fraction (Ʌ. The water balance approach was utilized, using meteorological data and river hydrograph analysis, to estimate the ETa as the only missing input in the predefined water balance equation. The results of the two applied methods were comparable. SEBAL results were compared with the land use land cover (LULC map. The river showed the highest ETa, as evaporation from the free-water surface. Rice fields, irrigated in the summer season, have a high ETa in the images, as these fields are immersed in water during June, July and August

  19. Comparison of the meteorology and surface energy balance at Storbreen and Midtdalsbreen, two glaciers in southern Norway

    Directory of Open Access Journals (Sweden)

    R. H. Giesen

    2009-03-01

    Full Text Available We compare 5 years of meteorological records from automatic weather stations (AWSs on Storbreen and Midtdalsbreen, two glaciers in southern Norway, located approximately 120 km apart. The records are obtained from identical AWSs with an altitude difference of 120 m and cover the period September 2001 to September 2006. Air temperature at the AWS locations is found to be highly correlated, even with the seasonal cycle removed. The most striking difference between the two sites is the difference in wind climate. Midtdalsbreen is much more under influence of the large-scale circulation with wind speeds on average a factor 1.75 higher. On Storbreen, weaker katabatic winds are dominant. The main melt season is from May to September at both locations. During the melt season, incoming and net solar radiation are larger on Midtdalsbreen, whereas incoming and net longwave radiation are larger on Storbreen, primarily caused by thicker clouds on the latter. The turbulent fluxes are a factor 1.7 larger on Midtdalsbreen, mainly due to the higher wind speeds. Inter-daily fluctuations in the surface energy fluxes are very similar at the AWS sites. On average, melt energy is a factor 1.3 larger on Midtdalsbreen, a result of both larger net radiation and larger turbulent fluxes. The relative contribution of net radiation to surface melt is larger on Storbreen (76% than on Midtdalsbreen (66%. As winter snow depth at the two locations is comparable in most years, the larger amount of melt energy results in an earlier disappearance of the snowpack on Midtdalsbreen and 70% more ice melt than on Storbreen. We compare the relative and absolute values of the energy fluxes on Storbreen and Midtdalsbreen with reported values for glaciers at similar latitudes. Furthermore, a comparison is made with meteorological variables measured at two nearby weather stations, showing that on-site measurements are essential for an accurate calculation of the surface energy balance and

  20. Evaluating five remote sensing based single-source surface energy balance models for estimating daily evapotranspiration in a humid subtropical climate

    Science.gov (United States)

    Bhattarai, Nishan; Shaw, Stephen B.; Quackenbush, Lindi J.; Im, Jungho; Niraula, Rewati

    2016-07-01

    In the last two decades, a number of single-source surface energy balance (SEB) models have been proposed for mapping evapotranspiration (ET); however, there is no clear guidance on which models are preferable under different conditions. In this paper, we tested five models-Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET at high Resolution with Internalized Calibration (METRIC), Simplified Surface Energy Balance Index (S-SEBI), Surface Energy Balance System (SEBS), and operational Simplified Surface Energy Balance (SSEBop)-to identify the single-source SEB models most appropriate for use in the humid southeastern United States. ET predictions from these models were compared with measured ET at four sites (marsh, grass, and citrus surfaces) for 149 cloud-free Landsat image acquisition days between 2000 and 2010. The overall model evaluation statistics showed that SEBS generally outperformed the other models in terms of estimating daily ET from different land covers (e.g., the root mean squared error (RMSE) was 0.74 mm day-1). SSEBop was consistently the worst performing model and overestimated ET at all sites (RMSE = 1.67 mm day-1), while the other models typically fell in between SSEBop and SEBS. However, for short grass conditions, SEBAL, METRIC, and S-SEBI appear to work much better than SEBS. Overall, our study suggests that SEBS may be the best SEB model in humid regions, although it may require modifications to work better over short vegetation.

  1. Surface energy balance of an extensive green roof as quantified by full year eddy-covariance measurements.

    Science.gov (United States)

    Heusinger, Jannik; Weber, Stephan

    2017-01-15

    Green roofs are discussed as a promising type of green infrastructure to lower heat stress in cities. In order to enhance evaporative cooling, green roofs should ideally have similar Bowen ratio (β=sensible heat flux/latent heat flux) characteristics such as rural sites, especially during summer periods with high air temperatures. We use the eddy-covariance (EC) method to quantify the energy balance of an 8600m 2 extensive, non-irrigated green roof at the Berlin Brandenburg Airport, Germany over a full annual cycle. To understand the influence of water availability on green roof-atmosphere energy exchange, we studied dry and wet periods and looked into functional relationships between leaf area, volumetric water content (VWC) of the substrate, shortwave radiation and β. The surface energy balance was dominated by turbulent heat fluxes in comparison to conductive substrate heat fluxes. The Bowen ratio was slightly below unity on average but highly variable due to ambient meteorology and substrate water availability, i.e. β increased to 2 in the summer season. During dry periods mean daytime β was 3, which is comparable to typical values of urban instead of rural sites. In contrast, mean daytime β was 0.3 during wet periods. Following a summer wet period the green roof maximum daily evapotranspiration (ET) was 3.3mm, which is a threefold increase with respect to the mean summer ET. A multiple regression model indicated that the substrate VWC at the present site has to be >0.11m 3 m -3 during summer high insolation periods (>500Wm -2 ) in order to maintain favourable green roof energy partitioning, i.e. mid-day β<1. The microclimate benefit of urban green roofs can be significantly optimised by using sustainable irrigation approaches. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Modelling surface energy fluxes over a dehesa ecosystem using a two-source energy balance model and medium resolution satellite data

    Science.gov (United States)

    Andreu, A.; González-Dugo, M. P.; Kustas, William P.; Polo, M. J.; Anderson, M. C.

    2013-10-01

    The dehesa, the most widespread agroforest ecosystem in Europe (≍ 3 million ha), is recognized as an example of sustainable land use and for its importance in rural economy. It is characterized by widely-spaced oak trees (mostly Quercus Ilex L.), combined with crops, pasture and shrubs in the sub-canopy region. The estimation of the ecosystem evapotranspiration (ET) using remote sensing may assist the monitoring of its state from local to regional scales, improving the management and the conservation of the ecosystem. Thermal-based energy balance techniques which distinguish soil/substrate and vegetation contributions to the radiative temperature and radiation/turbulent fluxes have proven to be reliable in the estimation of the energy surface fluxes, and therefore in the estimation of ET. In particular, the two-source energy balance (TSEB) model of Norman et al. and Kustas and Norman has shown to be robust for semi-arid sparse canopy-cover landscapes. With the objective of evaluating the model over this environment, an energy flux measurement system has been used. It was installed in a dehesa located in Southern Spain (38°12' N; 4°17' W, 736m a.s.l) with 1 km homogeneous fetch in wind direction. The quality of the measured data fluxes has been tested with the energy-balance closure criterion yielding an average closure of 86% which is within the error range found in similar studies. The TSEB model was evaluated in the area for 2012 summer season, using images from MODIS (Moderate Resolution Imaging Spectroradiometer) sensor and ground measured meteorological data. The half-hourly estimates were compared with the flux tower measurements, obtaining a RMSD between modeled and measured energy fluxes within the closure balance error.

  3. Surface energy balance of seasonal snow cover for snow-melt ...

    Indian Academy of Sciences (India)

    ... surface at this station received a mean short wave radiation of 430 W m−2, out of which 298 W m−2 was re flected back by the snow surface with mean albedo value of 0.70. The high average temperature and more absorption of solar radiation resulted in higher thermal state of the snowpack which was further responsible ...

  4. Energy balance climate models

    Science.gov (United States)

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1981-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved, and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  5. Surface Energy Balance Closure and Turbulent Flux Parameterization on a Mid-Latitude Mountain Glacier, Purcell Mountains, Canada

    Directory of Open Access Journals (Sweden)

    Noel Fitzpatrick

    2017-09-01

    Full Text Available In the majority of glacier surface energy balance studies, parameterization rather than direct measurement is used to estimate one or more of the individual heat fluxes, with others, such as the rain and ground heat fluxes, often deemed negligible. Turbulent fluxes of sensible and latent heat are commonly parameterized using the bulk aerodynamic technique. This method was developed for horizontal, uniform surfaces rather than sloped, inhomogeneous glacier terrain, and significant uncertainty remains regarding the selection of appropriate roughness length values, and the validity of the atmospheric stability functions employed. A customized weather station, designed to measure all relevant heat fluxes, was installed on an alpine glacier over the 2014 melt season. Eddy covariance techniques were used to observe the turbulent heat fluxes, and to calculate site-specific roughness values. The obtained dataset was used to drive a point ablation model, and to evaluate the most commonly used bulk methods and roughness length schemes in the literature. Modeled ablation showed good agreement with observed rates at seasonal, daily, and sub-daily timescales, effectively closing the surface energy balance, and giving a high level of confidence in the flux observation method. Net radiation was the dominant contributor to melt energy over the season (65.2%, followed by the sensible heat flux (29.7%, while the rain heat flux was observed to be a significant contributor on daily timescales during periods of persistent heavy rain (up to 20% day−1. Momentum roughness lengths observed for the study surface (snow: 10−3.8 m; ice: 10−2.2 m showed general agreement with previous findings, while the scalar values (temperature: 10−4.6 m; water vapor: 10−6 m differed significantly from those for momentum, disagreeing with the assumption of equal roughness lengths. Of the three bulk method stability schemes tested, the functions based on the Monin-Obukhov length

  6. Energy balance at the soil atmosphere interface

    NARCIS (Netherlands)

    Sedighi, M; Hepburn, B.D.P.; Thomas, HR; Vardon, P.J.

    2016-01-01

    Soil atmospheric interactions play an important role within the thermal energy balance and seasonal temperature variations of the ground. This paper presents a formulation for the surface boundary conditions related to interactions between soil and atmosphere. The boundary condition formulated

  7. Energy balance of a glacier surface: analysis of Automatic Weather Station data from the Morteratschgletscher, Switzerland

    NARCIS (Netherlands)

    Oerlemans, J.; Klok, E.J.

    2002-01-01

    We describe and analyze a complete 1-yr data set from an automatic weather station (AWS) located on the snout of the Morteratschgletscher, Switzerland. The AWS stands freely on the glacier surface and measures pressure, windspeed, wind direction, air temperature and humidity, incoming and

  8. Use of ground-based remotely sensed data for surface energy balance evaluation of a semiarid rangeland

    Science.gov (United States)

    Moran, M.S.; Kustas, William P.; Vidal, A.; Stannard, D.I.; Blanford, J.H.; Nichols, W.D.

    1994-01-01

    An interdisciplinary field experiment was conducted to study the water and energy balance of a semiarid rangeland watershed in southeast Arizona during the summer of 1990. Two subwatersheds, one grass dominated and the other shrub dominated, were selected for intensive study with ground-based remote sensing systems and hydrometeorological instrumentation. Surface energy balance was evaluated at both sites using direct and indirect measurements of the turbulent fluxes (eddy correlation, variance, and Bowen ratio methods) and using an aerodynamic approach based on remote measurements of surface reflectance and temperature and conventional meteorological information. Estimates of net radiant flux density (Rn), derived from measurements of air temperature, incoming solar radiation, and surface temperature and radiance compared well with values measured using a net radiometer (mean absolute difference (MAD) ≃ 50 W/m2 over a range from 115 to 670 W/m2). Soil heat flux density (G) was estimated using a relation between G/Rn and a spectral vegetation index computed from the red and near-infrared surface reflectance. These G estimates compared well with conventional measurements of G using buried soil heat flux plates (MAD ≃ 20 W/m2 over a range from −13 to 213 W/m2). In order to account for the effects of sparse vegetation, semiempirical adjustments to the single-layer bulk aerodynamic resistance approach were required for evaluation of sensible heat flux density (H). This yielded differences between measurements and remote estimates of H of approximately 33 W/m2 over a range from 13 to 303 W/m2. The resulting estimates of latent heat flux density, LE, were of the same magnitude and trend as measured values; however, a significant scatter was still observed: MAD ≃ 40 W/m2 over a range from 0 to 340 W/m2. Because LE was solved as a residual, there was a cumulative effect of errors associated with remote estimates of Rn, G, and H.

  9. Simulation of Forest Evapotranspiration Using Time-Series Parameterization of the Surface Energy Balance System (SEBS over the Qilian Mountains

    Directory of Open Access Journals (Sweden)

    Xin Tian

    2015-11-01

    Full Text Available We propose a long-term parameterization scheme for two critical parameters, zero-plane displacement height (d and aerodynamic roughness length (z0m, that we further use in the Surface Energy Balance System (SEBS. A sensitivity analysis of SEBS indicated that these two parameters largely impact the estimated sensible heat and latent heat fluxes. First, we calibrated regression relationships between measured forest vertical parameters (Lorey’s height and the frontal area index (FAI and forest aboveground biomass (AGB. Next, we derived the interannual Lorey’s height and FAI values from our calibrated regression models and corresponding forest AGB dynamics that were converted from interannual carbon fluxes, as simulated from two incorporated ecological models and a 2009 forest basis map These dynamic forest vertical parameters, combined with refined eight-day Global LAnd Surface Satellite (GLASS LAI products, were applied to estimate the eight-day d, z0m, and, thus, the heat roughness length (z0h. The obtained d, z0m and z0h were then used as forcing for the SEBS model in order to simulate long-term forest evapotranspiration (ET from 2000 to 2012 within the Qilian Mountains (QMs. As compared with MODIS, MOD16 products at the eddy covariance (EC site, ET estimates from the SEBS agreed much better with EC measurements (R2 = 0.80 and RMSE = 0.21 mm·day−1.

  10. The impact of elevated CO2 on the energy and water balance over terrestrial surfaces

    Science.gov (United States)

    Roderick, Michael; Donohue, Randall; Yang, Yuting; McVicar, Tim

    2017-04-01

    When we think of the enhanced greenhouse effect, the tendency is to focus on the effects on near-surface air temperature and the consequence impacts. On that approach the underlying cause of the enhanced greenhouse effect, that is, increasing atmospheric CO2 tends to be ignored. But laboratory experiments have long shown that increasing CO2 has a large impact on vegetation gas exchange, by, for example, increasing water use efficiency of photosynthesis. This tends to be a forgotten factor in the meteorological and hydrologic sciences. In this talk we outline some key expected effects of atmospheric CO2 on leaf-, canopy- and catchment-scale fluxes and compare those expectations with both site- (e.g. FACE) and catchment-scale observations. We find the expected effects have been observed over undisturbed vegetation. However, we find the effects of elevated CO2 are more complex in disturbed vegetation that is actively regrowing, This finding suggests the disturbance history will be a key factor on the canopy- and catchment-scale responses to elevated CO2.

  11. Genera of minimal balance surfaces

    International Nuclear Information System (INIS)

    Fischer, W.; Koch, E.

    1989-01-01

    The genus of a three-periodic intersection-free surface in R 3 refers to a primitive unit cell of its symmetry group. Two procedures for the calculation of the genus are described: (1) by means of labyrinth graphs; (2) via the Euler characteristic derived from a tiling on the surface. In both cases new formulae based on crystallographic concepts are given. For all known minimal balance surfaces the genera and the labyrinth graphs are tabulated. (orig.)

  12. The seasonal cycle and interannual variability of surface energy balance and melt in the ablation zone of the west Greenland ice sheet

    NARCIS (Netherlands)

    van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Smeets, C.J.P.P.|info:eu-repo/dai/nl/191522236; van de Wal, R.S.W.|info:eu-repo/dai/nl/101899556

    2011-01-01

    We present the seasonal cycle and interannual variability of the surface energy balance (SEB) in the ablation zone of the west Greenland ice sheet, using seven years (September 2003–August 2010) of hourly observations from three automatic weather stations (AWS). The AWS are situated along the 67◦ N

  13. Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

    Science.gov (United States)

    The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI) was utilized to estimate CWSI in rain-fed switchgrass (Panicum virgatum L.) usin...

  14. Air-sea heat flux climatologies in the Mediterranean Sea: Surface energy balance and its consistency with ocean heat storage

    Science.gov (United States)

    Song, Xiangzhou; Yu, Lisan

    2017-05-01

    This study provides an analysis of the Mediterranean Sea surface energy budget using nine surface heat flux climatologies. The ensemble mean estimation shows that the net downward shortwave radiation (192 ± 19 W m-2) is balanced by latent heat flux (-98 ± 10 W m-2), followed by net longwave radiation (-78 ± 13 W m-2) and sensible heat flux (-13 ± 4 W m-2). The resulting net heat budget (Qnet) is 2 ± 12 W m-2 into the ocean, which appears to be warm biased. The annual-mean Qnet should be -5.6 ± 1.6 W m-2 when estimated from the observed net transport through the Strait of Gibraltar. To diagnose the uncertainty in nine Qnet climatologies, we constructed Qnet from the heat budget equation by using historic hydrological observations to determine the heat content changes and advective heat flux. We also used the Qnet from a data-assimilated global ocean state estimation as an additional reference. By comparing with the two reference Qnet estimates, we found that seven products (NCEP 1, NCEP 2, CFSR, ERA-Interim, MERRA, NOCSv2.0, and OAFlux+ISCCP) overestimate Qnet, with magnitude ranging from 6 to 27 W m-2, while two products underestimate Qnet by -6 W m-2 (JRA55) and -14 W m-2 (CORE.2). Together with the previous warm pool work of Song and Yu (2013), we show that CFSR, MERRA, NOCSv2.0, and OAFlux+ISCCP are warm-biased not only in the western Pacific warm pool but also in the Mediterranean Sea, while CORE.2 is cold-biased in both regions. The NCEP 1, 2, and ERA-Interim are cold-biased over the warm pool but warm-biased in the Mediterranean Sea.

  15. A comparison of consumptive-use estimates derived from the simplified surface energy balance approach and indirect reporting methods

    Science.gov (United States)

    Maupin, Molly A.; Senay, Gabriel B.; Kenny, Joan F.; Savoca, Mark E.

    2012-01-01

    Recent advances in remote-sensing technology and Simplified Surface Energy Balance (SSEB) methods can provide accurate and repeatable estimates of evapotranspiration (ET) when used with satellite observations of irrigated lands. Estimates of ET are generally considered equivalent to consumptive use (CU) because they represent the part of applied irrigation water that is evaporated, transpired, or otherwise not available for immediate reuse. The U.S. Geological Survey compared ET estimates from SSEB methods to CU data collected for 1995 using indirect methods as part of the National Water Use Information Program (NWUIP). Ten-year (2000-2009) average ET estimates from SSEB methods were derived using Moderate Resolution Imaging Spectroradiometer (MODIS) 1-kilometer satellite land surface temperature and gridded weather datasets from the Global Data Assimilation System (GDAS). County-level CU estimates for 1995 were assembled and referenced to 1-kilometer grid cells to synchronize with the SSEB ET estimates. Both datasets were seasonally and spatially weighted to represent the irrigation season (June-September) and those lands that were identified in the county as irrigated. A strong relation (R2 greater than 0.7) was determined between NWUIP CU and SSEB ET data. Regionally, the relation is stronger in arid western states than in humid eastern states, and positive and negative biases are both present at state-level comparisons. SSEB ET estimates can play a major role in monitoring and updating county-based CU estimates by providing a quick and cost-effective method to detect major year-to-year changes at county levels, as well as providing a means to disaggregate county-based ET estimates to sub-county levels. More research is needed to identify the causes for differences in state-based relations.

  16. Scale - dependent effects on the surface energy fluxes modelling in Iberian oak-savanna (dehesa) using the Two-Source Energy Balance (TSEB)

    Science.gov (United States)

    Andreu, Ana; Nieto, Hector; Gómez-Giráldez, Pedro; González-Dugo, Maria P.

    2017-04-01

    Iberian semi-arid oak-savannas (dehesas) are complex ecosystems where bare soil and different layers of vegetation (grass/scrubs/trees) are distributed following heterogeneous patterns. An assumption of the two source energy balance models is that the effective source/sink for turbulent flux exchange at the surface(canopy/soil) is described by a bulk radiometric surface temperature (TRAD) and resistance. Therefore, the agreement of the TRAD used as an input to these models, with the "bulk" concept (determined by the spatial resolution), will influence the final energy fluxes estimations. The representativeness of the field-ground measurements, the spatial resolution of sensors, the averaging and the up-scaling of TRAD and the ecosystem vegetation parameters, will be crucial for the precision of the results, more than in homogeneous landscapes. The aim of this study is to analyze the scale-effects derived from TSEB application, comparing the observed energy fluxes and the estimated ones obtained from multiple TRAD data sources of different nature: tree/grass/soil ground-based observations, tower footprint, hyperspectral reflectance imagery acquired with an airborne platform, medium (Landsat) and low spatial resolution satellite data (Sentinel 3, MODIS), and how the up-scaling of the vegetation structural characteristics contribute to the discrepancies. The study area selected for this purpose is a dehesa site (Santa Clotilde, Cordoba), which present canopy mosaics (oak, annual grasses and bushes) differing in phenology, physiology and functioning, and bare soil, all of them influencing the turbulent and radiative exchanges.

  17. Climate of the Greenland ice sheet using a high-resolution climate model – Part 2: Near-surface climate and energy balance

    Directory of Open Access Journals (Sweden)

    J. Ettema

    2010-12-01

    Full Text Available The spatial variability of near-surface variables and surface energy balance components over the Greenland ice sheet are presented, using the output of a regional atmospheric climate model for the period 1958–2008. The model was evaluated in Part 1 of this paper.

    The near-surface temperature over the ice sheet is affected by surface elevation, latitude, longitude, large-scale and small-scale advection, occurrence of summer melt and mesoscale topographical features. The atmospheric boundary layer is characterised by a strong temperature inversion, due to continuous longwave cooling of the surface. In combination with a gently sloping surface the radiative loss maintains a persistent katabatic wind. This radiative heat loss is mainly balanced by turbulent sensible heat transport towards the surface. In summer, the surface is near radiative balance, resulting in lower wind speeds. Absorption of shortwave radiation and a positive subsurface heat flux due to refreezing melt water are heat sources for surface sublimation and melt.

    The strongest temperature deficits (>13 °C are found on the northeastern slopes, where the strongest katabatic winds (>9 m s−1 and lowest relative humidity (<65% occur. Due to strong large scale winds, clear sky (cloud cover <0.5 and a concave surface, a continuous supply of cold dry air is generated, which enhances the katabatic forcing and suppresses subsidence of potentially warmer free atmosphere air.

  18. Energy balances 1997 and 1998

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    The energy balances of the Danish Statistical Office are the designation of the goods balances, which are tabulated for each energy article in both physical entities (quantities) and in base rates (values). The balance concept is connected to the definition supply = use, which is the basis for the construction of the system. The supply is determined as the sum of two items: import and production while the total use is the sum of 138 items: export, waste and transmission loss, stock increase, input in lack of the 130 industries, and private consumption divided into 5 consumption groups. The statistical analysis is performed yearly in both quantities and values for 35 energy articles. Values are computed for base rates, profits, taxes, VAT and market prices (buyer's price), respectively. The energy balances from 1975 to 1998 are presented for comparison. (EHS)

  19. Energy balances 1998 and 1999

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The energy balances of the Danish Statistical Office are the designation of the goods balances, which are tabulated for each energy article in both physical entities (quantities) and in base rates (values). The balance concept is connected to the definition supply = use, which is the basis for the construction of the system. The supply is determined as the sum of two items: import and production while the total use is the sum of 138 items: export, waste and transmission loss, stock increase, input in lack of the 130 industries, and private consumption divided into 5 consumption groups. The statistical analysis is performed yearly in both quantities and values for 35 energy articles. Values are computed for base rates, profits, taxes, VAT and market prices (buyer's price), respectively. The energy balances from 1975 to 1998 are presented for comparison. (EHS)

  20. National Energy Balance - 1980

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The energy fluxes of several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, are presented. The forecasting of uranium concentrate consumption and production is made for six years - 1980 to 1985. (E.G.) [pt

  1. National energy balance

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The energy fluxes of the several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, are presented. A historical series covering ten years - 1973 to 1982, and the information retrieval related to the year of 1970 are also presented. (EG) [pt

  2. A statistical adjustment approach for climate projections of snow conditions in mountain regions using energy balance land surface models

    Science.gov (United States)

    Verfaillie, Deborah; Déqué, Michel; Morin, Samuel; Lafaysse, Matthieu

    2017-04-01

    Projections of future climate change have been increasingly called for lately, as the reality of climate change has been gradually accepted and societies and governments have started to plan upcoming mitigation and adaptation policies. In mountain regions such as the Alps or the Pyrenees, where winter tourism and hydropower production are large contributors to the regional revenue, particular attention is brought to current and future snow availability. The question of the vulnerability of mountain ecosystems as well as the occurrence of climate-related hazards such as avalanches and debris-flows is also under consideration. In order to generate projections of snow conditions, however, downscaling global climate models (GCMs) by using regional climate models (RCMs) is not sufficient to capture the fine-scale processes and thresholds at play. In particular, the altitudinal resolution matters, since the phase of precipitation is mainly controlled by the temperature which is altitude-dependent. Simulations from GCMs and RCMs moreover suffer from biases compared to local observations, due to their rather coarse spatial and altitudinal resolution, and often provide outputs at too coarse time resolution to drive impact models. RCM simulations must therefore be adjusted using empirical-statistical downscaling and error correction methods, before they can be used to drive specific models such as energy balance land surface models. In this study, time series of hourly temperature, precipitation, wind speed, humidity, and short- and longwave radiation were generated over the Pyrenees and the French Alps for the period 1950-2100, by using a new approach (named ADAMONT for ADjustment of RCM outputs to MOuNTain regions) based on quantile mapping applied to daily data, followed by time disaggregation accounting for weather patterns selection. We first introduce a thorough evaluation of the method using using model runs from the ALADIN RCM driven by a global reanalysis over the

  3. Dairy Proteins and Energy Balance

    DEFF Research Database (Denmark)

    Bendtsen, Line Quist

    High protein diets affect energy balance beneficially through decreased hunger, enhanced satiety and increased energy expenditure. Dairy products are a major source of protein. Dairy proteins are comprised of two classes, casein (80%) and whey proteins (20%), which are both of high quality......, but casein is absorbed slowly and whey is absorbed rapidly. The present PhD study investigated the effects of total dairy proteins, whey, and casein, on energy balance and the mechanisms behind any differences in the effects of the specific proteins. The results do not support the hypothesis that dairy...... proteins, whey or casein are more beneficial than other protein sources in the regulation of energy balance, and suggest that dairy proteins, whey or casein seem to play only a minor role, if any, in the prevention and treatment of obesity....

  4. Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa

    Science.gov (United States)

    Majozi, Nobuhle P.; Mannaerts, Chris M.; Ramoelo, Abel; Mathieu, Renaud; Nickless, Alecia; Verhoef, Wouter

    2017-07-01

    Flux towers provide essential terrestrial climate, water, and radiation budget information needed for environmental monitoring and evaluation of climate change impacts on ecosystems and society in general. They are also intended for calibration and validation of satellite-based Earth observation and monitoring efforts, such as assessment of evapotranspiration from land and vegetation surfaces using surface energy balance approaches. In this paper, 15 years of Skukuza eddy covariance data, i.e. from 2000 to 2014, were analysed for surface energy balance closure (EBC) and partitioning. The surface energy balance closure was evaluated using the ordinary least squares regression (OLS) of turbulent energy fluxes (sensible (H) and latent heat (LE)) against available energy (net radiation (Rn) less soil heat (G)), and the energy balance ratio (EBR). Partitioning of the surface energy during the wet and dry seasons was also investigated, as well as how it is affected by atmospheric vapour pressure deficit (VPD), and net radiation. After filtering years with low-quality data (2004-2008), our results show an overall mean EBR of 0.93. Seasonal variations of EBR also showed the wet season with 1.17 and spring (1.02) being closest to unity, with the dry season (0.70) having the highest imbalance. Nocturnal surface energy closure was very low at 0.26, and this was linked to low friction velocity during night-time, with results showing an increase in closure with increase in friction velocity. The energy partition analysis showed that sensible heat flux is the dominant portion of net radiation, especially between March and October, followed by latent heat flux, and lastly the soil heat flux, and during the wet season where latent heat flux dominated sensible heat flux. An increase in net radiation was characterized by an increase in both LE and H, with LE showing a higher rate of increase than H in the wet season, and the reverse happening during the dry season. An increase in

  5. Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa

    Directory of Open Access Journals (Sweden)

    N. P. Majozi

    2017-07-01

    Full Text Available Flux towers provide essential terrestrial climate, water, and radiation budget information needed for environmental monitoring and evaluation of climate change impacts on ecosystems and society in general. They are also intended for calibration and validation of satellite-based Earth observation and monitoring efforts, such as assessment of evapotranspiration from land and vegetation surfaces using surface energy balance approaches. In this paper, 15 years of Skukuza eddy covariance data, i.e. from 2000 to 2014, were analysed for surface energy balance closure (EBC and partitioning. The surface energy balance closure was evaluated using the ordinary least squares regression (OLS of turbulent energy fluxes (sensible (H and latent heat (LE against available energy (net radiation (Rn less soil heat (G, and the energy balance ratio (EBR. Partitioning of the surface energy during the wet and dry seasons was also investigated, as well as how it is affected by atmospheric vapour pressure deficit (VPD, and net radiation. After filtering years with low-quality data (2004–2008, our results show an overall mean EBR of 0.93. Seasonal variations of EBR also showed the wet season with 1.17 and spring (1.02 being closest to unity, with the dry season (0.70 having the highest imbalance. Nocturnal surface energy closure was very low at 0.26, and this was linked to low friction velocity during night-time, with results showing an increase in closure with increase in friction velocity. The energy partition analysis showed that sensible heat flux is the dominant portion of net radiation, especially between March and October, followed by latent heat flux, and lastly the soil heat flux, and during the wet season where latent heat flux dominated sensible heat flux. An increase in net radiation was characterized by an increase in both LE and H, with LE showing a higher rate of increase than H in the wet season, and the reverse happening during the dry season. An

  6. The method ADAMONT v1.0 for statistical adjustment of climate projections applicable to energy balance land surface models

    Directory of Open Access Journals (Sweden)

    D. Verfaillie

    2017-11-01

    Full Text Available We introduce the method ADAMONT v1.0 to adjust and disaggregate daily climate projections from a regional climate model (RCM using an observational dataset at hourly time resolution. The method uses a refined quantile mapping approach for statistical adjustment and an analogous method for sub-daily disaggregation. The method ultimately produces adjusted hourly time series of temperature, precipitation, wind speed, humidity, and short- and longwave radiation, which can in turn be used to force any energy balance land surface model. While the method is generic and can be employed for any appropriate observation time series, here we focus on the description and evaluation of the method in the French mountainous regions. The observational dataset used here is the SAFRAN meteorological reanalysis, which covers the entire French Alps split into 23 massifs, within which meteorological conditions are provided for several 300 m elevation bands. In order to evaluate the skills of the method itself, it is applied to the ALADIN-Climate v5 RCM using the ERA-Interim reanalysis as boundary conditions, for the time period from 1980 to 2010. Results of the ADAMONT method are compared to the SAFRAN reanalysis itself. Various evaluation criteria are used for temperature and precipitation but also snow depth, which is computed by the SURFEX/ISBA-Crocus model using the meteorological driving data from either the adjusted RCM data or the SAFRAN reanalysis itself. The evaluation addresses in particular the time transferability of the method (using various learning/application time periods, the impact of the RCM grid point selection procedure for each massif/altitude band configuration, and the intervariable consistency of the adjusted meteorological data generated by the method. Results show that the performance of the method is satisfactory, with similar or even better evaluation metrics than alternative methods. However, results for air temperature are generally

  7. The method ADAMONT v1.0 for statistical adjustment of climate projections applicable to energy balance land surface models

    Science.gov (United States)

    Verfaillie, Deborah; Déqué, Michel; Morin, Samuel; Lafaysse, Matthieu

    2017-11-01

    We introduce the method ADAMONT v1.0 to adjust and disaggregate daily climate projections from a regional climate model (RCM) using an observational dataset at hourly time resolution. The method uses a refined quantile mapping approach for statistical adjustment and an analogous method for sub-daily disaggregation. The method ultimately produces adjusted hourly time series of temperature, precipitation, wind speed, humidity, and short- and longwave radiation, which can in turn be used to force any energy balance land surface model. While the method is generic and can be employed for any appropriate observation time series, here we focus on the description and evaluation of the method in the French mountainous regions. The observational dataset used here is the SAFRAN meteorological reanalysis, which covers the entire French Alps split into 23 massifs, within which meteorological conditions are provided for several 300 m elevation bands. In order to evaluate the skills of the method itself, it is applied to the ALADIN-Climate v5 RCM using the ERA-Interim reanalysis as boundary conditions, for the time period from 1980 to 2010. Results of the ADAMONT method are compared to the SAFRAN reanalysis itself. Various evaluation criteria are used for temperature and precipitation but also snow depth, which is computed by the SURFEX/ISBA-Crocus model using the meteorological driving data from either the adjusted RCM data or the SAFRAN reanalysis itself. The evaluation addresses in particular the time transferability of the method (using various learning/application time periods), the impact of the RCM grid point selection procedure for each massif/altitude band configuration, and the intervariable consistency of the adjusted meteorological data generated by the method. Results show that the performance of the method is satisfactory, with similar or even better evaluation metrics than alternative methods. However, results for air temperature are generally better than for

  8. Intercomparison of four remote-sensing-based energy balance methods to retrieve surface evapotranspiration and water stress of irrigated fields in semi-arid climate

    Science.gov (United States)

    Chirouze, J.; Boulet, G.; Jarlan, L.; Fieuzal, R.; Rodriguez, J. C.; Ezzahar, J.; Er-Raki, S.; Bigeard, G.; Merlin, O.; Garatuza-Payan, J.; Watts, C.; Chehbouni, G.

    2014-03-01

    Instantaneous evapotranspiration rates and surface water stress levels can be deduced from remotely sensed surface temperature data through the surface energy budget. Two families of methods can be defined: the contextual methods, where stress levels are scaled on a given image between hot/dry and cool/wet pixels for a particular vegetation cover, and single-pixel methods, which evaluate latent heat as the residual of the surface energy balance for one pixel independently from the others. Four models, two contextual (S-SEBI and a modified triangle method, named VIT) and two single-pixel (TSEB, SEBS) are applied over one growing season (December-May) for a 4 km × 4 km irrigated agricultural area in the semi-arid northern Mexico. Their performance, both at local and spatial standpoints, are compared relatively to energy balance data acquired at seven locations within the area, as well as an uncalibrated soil-vegetation-atmosphere transfer (SVAT) model forced with local in situ data including observed irrigation and rainfall amounts. Stress levels are not always well retrieved by most models, but S-SEBI as well as TSEB, although slightly biased, show good performance. The drop in model performance is observed for all models when vegetation is senescent, mostly due to a poor partitioning both between turbulent fluxes and between the soil/plant components of the latent heat flux and the available energy. As expected, contextual methods perform well when contrasted soil moisture and vegetation conditions are encountered in the same image (therefore, especially in spring and early summer) while they tend to exaggerate the spread in water status in more homogeneous conditions (especially in winter). Surface energy balance models run with available remotely sensed products prove to be nearly as accurate as the uncalibrated SVAT model forced with in situ data.

  9. Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

    Science.gov (United States)

    Bhattarai, Nishan; Wagle, Pradeep; Gowda, Prasanna H.; Kakani, Vijaya G.

    2017-11-01

    The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass (Panicum virgatum L.) has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI; 0 = extremely wet or no water stress condition and 1 = extremely dry or no transpiration) was utilized to estimate CWSI in rain-fed switchgrass using Landsat-derived evapotranspiration (ET) from five remote sensing based single-source SEB models, namely Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET with Internalized Calibration (METRIC), Surface Energy Balance System (SEBS), Simplified Surface Energy Balance Index (S-SEBI), and Operational Simplified Surface Energy Balance (SSEBop). CWSI estimates from the five SEB models and a simple regression model that used normalized difference vegetation index (NDVI), near-surface temperature difference, and measured soil moisture (SM) as covariates were compared with those derived from eddy covariance measured ET (CWSIEC) for the 32 Landsat image acquisition dates during the 2011 (dry) and 2013 (wet) growing seasons. Results indicate that most SEB models can predict CWSI reasonably well. For example, the root mean square error (RMSE) ranged from 0.14 (SEBAL) to 0.29 (SSEBop) and the coefficient of determination (R2) ranged from 0.25 (SSEBop) to 0.72 (SEBAL), justifying the added complexity in CWSI modeling as compared to results from the simple regression model (R2 = 0.55, RMSE = 0.16). All SEB models underestimated CWSI in the dry year but the estimates from SEBAL and S-SEBI were within 7% of the mean CWSIEC and explained over 60% of variations in CWSIEC. In the wet year, S-SEBI mostly overestimated CWSI (around 28%), while estimates from METRIC, SEBAL, SEBS, and SSEBop were within 8% of the mean CWSIEC. Overall, SEBAL was the most robust model under all conditions followed by METRIC, whose performance was slightly worse and better than SEBAL in dry and wet years

  10. An energy balance model exploration of the impacts of interactions between surface albedo, cloud cover and water vapor on polar amplification

    Science.gov (United States)

    Södergren, A. Helena; McDonald, Adrian J.; Bodeker, Gregory E.

    2017-11-01

    We examine the effects of non-linear interactions between surface albedo, water vapor and cloud cover (referred to as climate variables) on amplified warming of the polar regions, using a new energy balance model. Our simulations show that the sum of the contributions to surface temperature changes due to any variable considered in isolation is smaller than the temperature changes from coupled feedback simulations. This non-linearity is strongest when all three climate variables are allowed to interact. Surface albedo appears to be the strongest driver of this non-linear behavior, followed by water vapor and clouds. This is because increases in longwave radiation absorbed by the surface, related to increases in water vapor and clouds, and increases in surface absorbed shortwave radiation caused by a decrease in surface albedo, amplify each other. Furthermore, our results corroborate previous findings that while increases in cloud cover and water vapor, along with the greenhouse effect itself, warm the polar regions, water vapor also significantly warms equatorial regions, which reduces polar amplification. Changes in surface albedo drive large changes in absorption of incoming shortwave radiation, thereby enhancing surface warming. Unlike high latitudes, surface albedo change at low latitudes are more constrained. Interactions between surface albedo, water vapor and clouds drive larger increases in temperatures in the polar regions compared to low latitudes. This is in spite of the fact that, due to a forcing, cloud cover increases at high latitudes and decreases in low latitudes, and that water vapor significantly enhances warming at low latitudes.

  11. Variations of Near Surface Energy Balance Caused by Land Cover Changes in the Semiarid Grassland Area of China

    Directory of Open Access Journals (Sweden)

    Qun’ou Jiang

    2014-01-01

    Full Text Available This study applies the Dynamics of Land System (DLS model to simulating the land cover under the designed scenarios and then analyzes the effects of land cover conversion on energy flux in the semiarid grassland area of China with the Weather Research and Forecasting (WRF model. The results indicate that the grassland will show a steadily upgrowing trend under the coordinated environmental sustainability (CES scenario. Compared to the CES scenario, the rate of increase in grassland cover is lower, while the rate of increase in urban land cover will be higher under the rapid economic growth (REG scenario. Although the conversion from cropland to grassland will reduce the energy flux, the expansion of urban area and decreasing of forestry area will bring about more energy flux. As a whole, the energy flux of near surface will obviously not change under the CES scenario, and the climate therefore will not be possible to be influenced greatly by land cover change. The energy flux under the REG scenario is higher than that under the CES scenario. Those research conclusions can offer valuable information for the land use planning and climate change adaptation in the semiarid grassland area of China.

  12. Large surface meltwater discharge from the Kangerlussuaq sector of the Greenland ice sheet during the record-warm year 2010 explained by detailed energy balance observations

    Directory of Open Access Journals (Sweden)

    D. van As

    2012-02-01

    Full Text Available This study uses data from six on-ice weather stations, calibrated MODIS-derived albedo and proglacial river gauging measurements to drive and validate an energy balance model. We aim to quantify the record-setting positive temperature anomaly in 2010 and its effect on mass balance and runoff from the Kangerlussuaq sector of the Greenland ice sheet. In 2010, the average temperature was 4.9 °C (2.7 standard deviations above the 1974–2010 average in Kangerlussuaq. High temperatures were also observed over the ice sheet, with the magnitude of the positive anomaly increasing with altitude, particularly in August. Simultaneously, surface albedo was anomalously low in 2010, predominantly in the upper ablation zone. The low albedo was caused by high ablation, which in turn profited from high temperatures and low winter snowfall. Surface energy balance calculations show that the largest melt excess (∼170% occurred in the upper ablation zone (above 1000 m, where higher temperatures and lower albedo contributed equally to the melt anomaly. At lower elevations the melt excess can be attributed to high atmospheric temperatures alone. In total, we calculate that 6.6 ± 1.0 km3 of surface meltwater ran off the ice sheet in the Kangerlussuaq catchment in 2010, exceeding the reference year 2009 (based on atmospheric temperature measurements by ∼150%. During future warm episodes we can expect a melt response of at least the same magnitude, unless a larger wintertime snow accumulation delays and moderates the melt-albedo feedback. Due to the hypsometry of the ice sheet, yielding an increasing surface area with elevation, meltwater runoff will be further amplified by increases in melt forcings such as atmospheric heat.

  13. Evaluation of Modeling Schemes to Estimate Evapotranspiration and Root Zone Soil Water Content over Vineyard using a Scintillometer and Remotely Sensed Surface Energy Balance

    Science.gov (United States)

    Geli, H. M. E.; Gonzalez-Piqueras, J.; Isidro, C., Sr.

    2016-12-01

    Actual crop evapotranspiration (ETa) and root zone soil water content (SMC) are key operational variable to monitor water consumption and water stress condition for improve vineyard grapes productivity and quality. This analysis, evaluates the estimation of ETa and SMC based on two modeling approaches. The first approach is a hybrid model that couples a thermal-based two source energy balance (TSEB) model (Norman et al. 1995) and water balance model to estimate the two variable (Geli 2012). The second approach is based on Large Aperture Scintillometer (LAS)-based estimates of sensible heat flux. The LAS-based estimates of sensible heat fluxes were used to calculate latent heat flux as the residual of surface energy balance equation on hourly basis which was converted to daily ETa. The calculated ETa from the scintillometer was then couple with the water balance approach to provide updated ETa_LAS and SMC_LAS. Both estimates of ETa and SMC based on LAS (i.e. ETa_LAS and SMC_LAS) and TSEB (ETa_TSEB and SMC_TSEB) were compared with ground-based observation from eddy covariance and soil water content measurements at multiple depths. The study site is an irrigated vineyard located in Central Spain Primary with heterogeneous surface conditions in term of irrigation practices and the ground based observation over the vineyard were collected during the summer of 2007. Preliminary results of the inter-comparison of the two approaches suggests relatively good between both modeling approaches and ground-based observations with RMSE lower than 1.2 mm/day for ETa and lower than 20% for SMC. References Norman, J. M., Kustas, W. P., & Humes, K. S. (1995). A two-source approach for estimating soil and vegetation energy fluxes in observations of directional radiometric surface temperature. Agricultural and Forest Meteorology, 77, 263293. Geli, Hatim M. E. (2012). Modeling spatial surface energy fluxes of agricultural and riparian vegetation using remote sensing, Ph. D. dissertation

  14. Fire-induced albedo change and surface radiative forcing in sub-Saharan Africa savanna ecosystems: Implications for the energy balance

    Science.gov (United States)

    Dintwe, Kebonye; Okin, Gregory S.; Xue, Yongkang

    2017-06-01

    Surface albedo is a critical parameter that controls surface energy balance. In dryland ecosystems, fires play a significant role in decreasing surface albedo, resulting in positive radiative forcing. Here we investigate the long-term effect of fire on surface albedo. We devised a method to calculate short-, medium-, and long-term effect of fire-induced radiative forcing and their relative effects on energy balance. We used Moderate Resolution Imaging Spectroradiometer (MODIS) data in our analysis, covering different vegetation classes in sub-Saharan Africa (SSA). Our analysis indicated that mean short-term fire-induced albedo change in SSA was -0.022, -0.035, and -0.041 for savannas, shrubland, and grasslands, respectively. At regional scale, mean fire-induced albedo change in savannas was -0.018 and -0.024 for northern sub-Saharan of Africa and the southern hemisphere Africa, respectively. The short-term mean fire-induced radiative forcing in burned areas in sub-Saharan Africa (SSA) was 5.41 W m-2, which contributed continental and global radiative forcings of 0.25 and 0.058 W m-2, respectively. The impact of fire in surface albedo has long-lasting effects that varies with vegetation type. The long-term energetic effects of fire-induced albedo change and associated radiative forcing were, on average, more than 19 times greater across SSA than the short-term effects, suggesting that fires exerted far more radiative forcing than previously thought. Taking into account the actual duration of fire's effect on surface albedo, we conclude that the contribution of SSA fires, globally and throughout the year, is 0.12 W m-2. These findings provide crucial information on possible impact of fire on regional climate variability.

  15. The Impact of Föhn Winds on Surface Energy Balance During the 2010-2011 Melt Season Over Larsen C Ice Shelf, Antarctica

    Science.gov (United States)

    King, J. C.; Kirchgaessner, A.; Bevan, S.; Elvidge, A. D.; Kuipers Munneke, P.; Luckman, A.; Orr, A.; Renfrew, I. A.; van den Broeke, M. R.

    2017-11-01

    We use model data from the Antarctic Mesoscale Prediction System (AMPS), measurements from automatic weather stations and satellite observations to investigate the association between surface energy balance (SEB), surface melt, and the occurrence of föhn winds over Larsen C Ice Shelf (Antarctic Peninsula) over the period November 2010 to March 2011. Föhn conditions occurred for over 20% of the time during this period and are associated with increased air temperatures and decreased relative humidity (relative to nonföhn conditions) over the western part of the ice shelf. During föhn conditions, the downward turbulent flux of sensible heat and the downwelling shortwave radiation both increase. However, in AMPS, these warming tendencies are largely balanced by an increase in upward latent heat flux and a decrease in downwelling longwave radiation so the impact of föhn on the modeled net SEB is small. This balance is highly sensitive to the representation of surface energy fluxes in the model, and limited validation data suggest that AMPS may underestimate the sensitivity of SEB and melt to föhn. There is broad agreement on the spatial pattern of melt between the model and satellite observations but disagreement in the frequency with which melt occurs. Satellite observations indicate localized regions of persistent melt along the foot of the Antarctic Peninsula mountains which are not simulated by the model. Furthermore, melt is observed to persist in these regions during extended periods when föhn does not occur, suggesting that other factors may be important in controlling melt in these regions.

  16. Introduction to energy balance of biomass production

    International Nuclear Information System (INIS)

    Manzanares, P.

    1997-01-01

    During last years, energy crops have been envisaged as an interesting alternative to biomass residues utilization as renewable energy source. In this work, main parameters used in calculating the energy balance of an energy crop are analyzed. The approach consists of determining energy equivalents for the different inputs and outputs of the process, thus obtaining energy ratios of the system, useful to determine if the energy balance is positive, that is, if the system generates energy. Energy costs for inputs and assessment approaches for energy crop yields (output) are provided. Finally, as a way of illustration, energy balances of some representative energy crops are shown. (Author) 15 refs

  17. Influence of inhomogeneous surface heat capacity on the estimation of radiative response coefficients in a two-zone energy balance model

    Science.gov (United States)

    Park, Jungmin; Choi, Yong-Sang

    2018-04-01

    Observationally constrained values of the global radiative response coefficient are pivotal to assess the reliability of modeled climate feedbacks. A widely used approach is to measure transient global radiative imbalance related to surface temperature changes. However, in this approach, a potential error in the estimate of radiative response coefficients may arise from surface inhomogeneity in the climate system. We examined this issue theoretically using a simple two-zone energy balance model. Here, we dealt with the potential error by subtracting the prescribed radiative response coefficient from those calculated within the two-zone framework. Each zone was characterized by the different magnitude of the radiative response coefficient and the surface heat capacity, and the dynamical heat transport in the atmosphere between the zones was parameterized as a linear function of the temperature difference between the zones. Then, the model system was forced by randomly generated monthly varying forcing mimicking time-varying forcing like an observation. The repeated simulations showed that inhomogeneous surface heat capacity causes considerable miscalculation (down to -1.4 W m-2 K-1 equivalent to 31.3% of the prescribed value) in the global radiative response coefficient. Also, the dynamical heat transport reduced this miscalculation driven by inhomogeneity of surface heat capacity. Therefore, the estimation of radiative response coefficients using the surface temperature-radiation relation is appropriate for homogeneous surface areas least affected by the exterior.

  18. Brazilian energy balance 2008 - year 2007

    International Nuclear Information System (INIS)

    2008-01-01

    The Brazilian energy balance - BEB - is divided into eight chapters and eleven annexes, whose contents are as follow: chapter 1 - energy analysis and aggregated data; chapter 2 - energy supply and demand by source; chapter 3 - energy consumption by sector; chapter 4 - energy imports and exports; chapter 5 - balance of transformation centers; chapter 6 - energy resources and reserves; chapter 7 - energy and socioeconomics; chapter 8 - state energy data; annex I - installed capacity; annex II - self-generation of electricity; annex III - world energy data; annex IV - world energy evolution; annex V - useful energy balance; annex VI - general structure of the BEN; annex VII - treatment of information; annex VIII - units; annex IX - conversion factors; annex X - consolidated energy balances 1970/2007; annex XI - energy balance 2007. (author)

  19. Energy Balance Bowen Ratio Station (EBBR) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, DR

    2011-02-23

    The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

  20. Energy Balance Bowen Ratio (EBBR) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    The Energy Balance Bowen Ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

  1. Temperate forest impacts on maritime snowpacks across an elevation gradient: An assessment of the snow surface energy balance and airborne lidar derived forest structure

    Science.gov (United States)

    Roth, T. R.; Nolin, A. W.

    2016-12-01

    Temperate forests modify snow evolution patterns both spatially and temporally relative to open areas. Dense, warm forests both impede snow accumulation through increased canopy snow interception and increase sub-canopy longwave energy inputs onto the snow surface. These process modifications vary in magnitude and duration depending on climatic, topographic and forest characteristics. Here we present results from a four year study of paired forested and open sites at three elevations, Low - 1150 m, Mid - 1325 m and High - 1465 m. Snowpacks are deeper and last up to 3-4 weeks longer at the Low and Mid elevation Open sites relative to the adjacent Forest sites. Conversely, at the High Forest site, snow is retained 2-4 weeks longer than the Open site. This change in snowpack depth and persistence is attributed to deposition patterns at higher elevations and forest structure differences that alter the canopy interception efficiency and the sub-canopy energy balance. Canopy interception efficiency (CIE) in the Low and Mid Forest sites, over the duration of the study were 79% and 76% of the total event snowfall, whereas CIE was 31% at the High Forest site. Longwave radiation in forested environments is the primary energy component across each elevation band due to the warm winter environment and forest presence, accounting for 82%, 88%, and 59% of the energy balance at the Low, Mid, and High Forest sites, respectively. High wind speeds in the High elevation Open site significantly increases the turbulent energy and creates preferential snowfall deposition in the nearby Forest site. These results show the importance of understanding the effects of forest cover on sub-canopy snowpack evolution and highlight the need for improved forest cover model representation to accurately predict water resources in maritime forests.

  2. Energy-balance climate models

    Science.gov (United States)

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1980-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  3. Uncertainty in regional and zonal monthly mean downward surface irradiances from Edition 4.0 CERES Energy Balanced and Filled (EBAF) data product

    Science.gov (United States)

    Kato, S.; Rutan, D. A.; Rose, F. G.; Loeb, N. G.

    2017-12-01

    The surface of the Earth receives solar radiation (shortwave) and emission from the atmosphere (longwave). At a global and annual mean approximately 12% of solar radiation incident on the surface is reflected and the rest is absorbed by the surface. The surface emits radiation proportional to the forth power of the temperature. Although the uncertainty in global and annual mean surface irradiances is estimated in earlier studies (Zhang et al. 1995, 2004; L'Ecuyer et al. 2008; Stephens et al. 2012; Kato et al. 2012), only a few studies estimated the uncertainty in computed surface irradiances at smaller spatial and temporal scales (Zhang et al. 1995, 2004; Kato et al. 2012). We use surface observations at 46 buoys and 36 land sites and newly released the Edition 4.0 Clouds and the Earth's Radiant Energy System (CERES) Energy Balanced and Filled (EBAF)-surface data product to estimate the uncertainty in regional and zonal monthly mean downward shortwave and longwave surface irradiances. The root-mean-square difference of monthly mean computed and observed irradiances is used for the regional uncertainty. The uncertainty is separated into bias and spatially random components. The random component decreases when irradiances are averaged over a larger area, nearly inversely proportional to the number of surface observation sites. The presentation provides the uncertainty in the regional and zonal monthly mean downward surface irradiances over ocean and land. ReferencesKato, S. and N.G.Loeb, D. A.Rutan, F. G. Rose, S. Sun-Mack,W.F.Miller, and Y. Chen, 2012. Surv. Geophys., 33, 395-412, doi:10.1007/s10712-012-9179-x. L'Ecuyer, T. S., N. B. Wood, T. Haladay, G. L. Stephens, and P. W. Stackhouse Jr., 2008, J. Geophys. Res., 113, D00A15, doi:10.1029/2008JD009951. Stephens, G. L. and Coauthors, 2012, Nat. Geosci., 5, 691-696, doi:10.1038/ngeo1580. Zhang, Y., W. B. Rossow, A. A. Lacis, V. Oinas, and M. I. Mishchenko, 2004, J. Geophys. Res., 109, D19105, doi:10.1029/2003JD

  4. France's energy balance for 2012

    International Nuclear Information System (INIS)

    Louati, Sami; Ouradou, Frederic; Rouquette, Celine; Cadin, Didier; Korman, Bernard; Lauverjat, Jean; Martin, Jean-Philippe; Rabai, Yacine; Reynaud, Didier; Thienard, Helene; Wong, Florine; Albertini, Jean-Paul; Bottin, Anne; Reperant, Patricia; Grosset, Catherine

    2013-07-01

    in the 13 of July act of Parliament outlining energy programming and policy, which aims for a 2% reduction per year in final energy intensity by 2015. The slighter drop in energy intensity is no doubt the result of the economic stagnation in 2012: in crisis periods industry does not run at full capacity, with adverse consequences for efficiency. According to SOeS' partial and provisional calculations, CO 2 emissions from combustion for energy production, after correction for climate variations, decreased by 3.1%. They have shown a clear fall over 5 years, with an average decrease of 2.2% per year since 2007. In 2012, emission levels were 8.8% lower than those of 1990. They remained stable in 2012 in real data terms. In addition to these data for the energy balance calculated in accordance with international norms, the European directive on renewable energy requires indicators specific to it, and with different calculation methods and scope. According to those indicators, in 2012 France fell slightly short of the final consumption target set by the national renewable energy action plan required by the directive. For 2012, it was 22.9 Mtoe of renewable energy, in comparison with 22.0 Mtoe actually achieved. Over the 2005-2012 period, final consumption of renewable energy grew by 6.2 Mtoe, instead of the expected 7.1 Mtoe. The shortfall observed relates to both the electrical and thermal components: it was 3 points for renewable electricity, as a result of the wind power sector where the target shortfall was 21 points. It was 4 points for thermal renewable energies, as the winter of 2012, more severe than that of 2011, mobilised more fuel-wood and heat pumps. For biofuels, consumption of bio-diesel is very close to the patterns indicated, unlike bio-ethanol where the difference is far greater

  5. Particle and energy balances in tokamak plasmas

    International Nuclear Information System (INIS)

    Tazima, Teruhiko

    1978-06-01

    Computational and experimental studies on particle and energy balances in tokamak plasmas are described. Firstly, concerning the modeling of tokamak plasmas, the particle balance considering diffusion and recycling, and the energy balance considering transport and energy losses due to impurities are discussed. Production mechanisms of gaseous and metallic impurities, which play important role in tokamak plasmas, are also discussed from a viewpoint of plasma-wall interactions. Scaling laws of density, temperature and energy confinement time are shown on the basis of recent data. Secondarily, tokamak plasmas are simulated with the above model, and anomalous diffusion and electron thermal conduction are indicated. Characteristics of a future tokamak plasma are also simulated. Stationary impurity density distributions and related energy losses, such as bremsstrahlung, ionization and excitation, are calculated taking into account diffusion and ionization processes. Edge cooling by oxygen impurities is described quantitatively compared with experiments. Permissible impurity levels of carbon, oxygen and iron in future large tokamaks are estimated. Thirdly, experimental studies on surface cleaning methods of the first wall are described; discharge cleaning in JFT-2, baking effect on the outgassing rates of wall materials, surface treatment of high-temperature molybdenum by oxygen and hydrogen gases, and in-situ coating of molybdenum by a coaxial magnetron sputter method. Lastly, problems in future large tokamaks aiming at break-even or self-ignited plasma are discussed quantitatively, such as trapped particle instabilities, impurities and additional heating. It is predicted that new conceptions will be necessary to overcome the problems and attain the fusion goal. (auth.)

  6. Large surface meltwater discharge from the Kangerlussuaq sector of the Greenland ice sheet during the record-warm year 2010 explained by detailed energy balance observations

    NARCIS (Netherlands)

    van As, D.; Hubbard, A.L.; Hasholt, B.; Mikkelsen, A.B.; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Fausto, R.S.

    2012-01-01

    This study uses data from six on-ice weather stations, calibrated MODIS-derived albedo and proglacial river gauging measurements to drive and validate an energy balance model. We aim to quantify the record-setting positive temperature anomaly in 2010 and its effect on mass balance and runoff from

  7. Brazilian energy balance 1996: calendar year 1995

    International Nuclear Information System (INIS)

    1996-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  8. Brazilian energy balance 1998: calendar year 1997

    International Nuclear Information System (INIS)

    1998-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  9. Brazilian energy balance 1999: calendar year 1998

    International Nuclear Information System (INIS)

    1999-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1998. It is divided into nine sections: a summary from 1983 to 1998; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  10. Brazilian energy balance 1995: calendar year 1994

    International Nuclear Information System (INIS)

    1995-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1998. It is divided into nine sections: a summary from 1979 to 1994; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  11. Brazilian energy balance 1997: calendar year 1996

    International Nuclear Information System (INIS)

    1997-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1998. It is divided into nine sections: a summary from 1981 to 1996; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  12. Brazilian energy balance 2000: calendar year 1999

    International Nuclear Information System (INIS)

    2000-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1999. It is divided into nine sections: a summary from 1984 to 1999; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  13. The estimation of the surface energy balance of the North American Laurentian Great Lakes using satellite remote sensing and MERRA reanalysis

    Science.gov (United States)

    Moukomla, Sitthisak

    The Surface Energy Balance (SEB) of the Great Lakes (GL) is a key to understanding the effects of climate change on the GL. There is a high possibility of underestimating the SEB of the GL when using existing methodologies with inputs from near-shore and land-based meteorological data. This study provides the first technique to investigate the SEB over the GL from July 2001 to December 2014 using a combination of data from satellite remote sensing, reanalysis data sets, and direct measurements. The pixel-based Great Lake Surface Temperature (GLST) under all-sky conditions were well correlated with the in situ observations (R2 = 0.9102) with a cool bias of -1.10 °C and a root mean square error (RMSE) of 1.39 °C. Contrary to expectations, the long-term trends of GLST decreased slightly due to the impact of an anomalously cold winter in 2013-2014. The components of the surface radiation budget estimated from the proposed method showed a good statistical agreement. Monthly spatial variations of net shortwave radiation varied with cloud cover and surface albedo while net longwave radiation varied with the temperature difference between the water surface and the atmosphere. We evaluated the feasibility of three different techniques for the estimation of the turbulent heat fluxes over the GL: i) the Bowen Ratio Energy Balance method; ii) the bulk aerodynamic approach and; iii) turbulent fluxes from MERRA (Modern Era Retrospective Analysis). Turbulent heat fluxes from those methods were compared with the direct eddy covariance measurements. The best statistical agreement amongst the three approaches was the bulk aerodynamic approach. Turbulent fluxes estimate from MERRA were not recommended due to the poor statistic agreement with the direct measurements. Using the bulk aerodynamic or direct eddy covariance measurements, the over-lake evaporation peaked during winter. From MERRA, the over-lake precipitation is uniformly spread throughout the year. The Great Lakes Net

  14. Energy balance closure at FLUXNET sites

    NARCIS (Netherlands)

    Wilson, K.B.; Goldstein, A.; Falge, E.; Aubinet, M.; Baldocchi, D.D.; Berbigier, P.; Bernhofer, C.; Ceulemans, R.; Dolman, A.J.; Field, C.; Grelle, A.; Ibrom, A.; Law, B.E.; Kowalski, A.; Meyers, T.; Monchieff, J.; Monson, R.; Oechel, W.; Tenhunen, J.; Valentini, R.; Verma, S.

    2002-01-01

    A comprehensive evaluation of energy balance closure is performed across 22 sites and 50 site-years in FLUXNET, a network of eddy covariance sites measuring long-term carbon and energy fluxes in contrasting ecosystems and climates. Energy balance closure was evaluated by statistical regression of

  15. A new diagram of the global energy balance

    Science.gov (United States)

    Wild, Martin; Folini, Doris; Schär, Christoph; Loeb, Norman; Dutton, Ellsworth G.; König-Langlo, Gert

    2013-05-01

    Here we provide a new assessment of the global mean energy fluxes from a surface perspective and present an associated diagram of the global mean energy balance, adapted from the study by Wild et al. (2013) [1] with two slight modifications as outlined in this paper. The radiative energy exchanges between Sun, Earth and space are now accurately quantified from new satellite missions. Much less has been known about the magnitude of the energy flows within the climate system and at the Earth surface, which cannot be directly measured by satellites. In addition to satellite observations, we make extensive use of the growing number of surface observations to constrain the global energy balance not only from space, but also from the surface. We combine these observations with the latest modeling efforts performed for the 5th IPCC assessment report to infer best estimates for the global mean surface radiative components. Our analyses favor global mean downward surface solar and thermal radiation values near 185 and 342 Wm-2, respectively, which are most compatible with surface observations. Combined with an estimated surface absorbed solar radiation and thermal emission of 161 Wm-2 and 398 Wm-2, respectively, this leaves 105 Wm-2 of surface net radiation available for distribution amongst the non-radiative surface energy balance components. Considering an imbalance of 0.6 Wm-2, the global mean sensible and latent heat fluxes are estimated at 20 and 84 Wm-2, respectively, to close the surface energy balance. The global mean surface radiative fluxes derived here in combination with a latent heat flux of 84 Wm-2 may be able to reconcile currently disputed inconsistencies between energy and water cycle estimates. The findings of this study are compiled into a new global energy balance diagram.

  16. The seasonal cycle and interannual variability of surface energy balance and melt in the ablation zone of the west Greenland ice sheet

    Directory of Open Access Journals (Sweden)

    M. R. van den Broeke

    2011-05-01

    Full Text Available We present the seasonal cycle and interannual variability of the surface energy balance (SEB in the ablation zone of the west Greenland ice sheet, using seven years (September 2003–August 2010 of hourly observations from three automatic weather stations (AWS. The AWS are situated along the 67° N latitude circle at elevations of 490 m a.s.l. (S5, 1020 m a.s.l. (S6 and 1520 m a.s.l. (S9 at distances of 6, 38 and 88 km from the ice sheet margin. The hourly AWS data are fed into a model that calculates all SEB components and melt rate; the model allows for shortwave radiation penetration in ice and time-varying surface momentum roughness. Snow depth is prescribed from albedo and sonic height ranger observations. Modelled and observed surface temperatures for non-melting conditions agree very well, with RMSE's of 0.97–1.26 K. Modelled and observed ice melt rates at the two lowest sites also show very good agreement, both for total cumulative and 10-day cumulated amounts. Melt frequencies and melt rates at the AWS sites are discussed. Although absorbed shortwave radiation is the most important energy source for melt at all three sites, interannual melt variability at the lowest site is driven mainly by variability in the turbulent flux of sensible heat. This is explained by the quasi-constant summer albedo in the lower ablation zone, limiting the influence of the melt-albedo feedback, and the proximity of the snow free tundra, which heats up considerably in summer.

  17. Balancing energy strategies in electricity portfolio management

    International Nuclear Information System (INIS)

    Moeller, Christoph; Rachev, Svetlozar T.; Fabozzi, Frank J.

    2011-01-01

    Traditional management of electricity portfolios is focused on the day-ahead market and futures of longer maturity. Within limits, market participants can however also resort to the balancing energy market to close their positions. In this paper, we determine strategic positions in the balancing energy market and identify corresponding economic incentives in an analysis of the German balancing energy demand. We find that those strategies allow an economically optimal starting point for real-time balancing and create a marketplace for flexible capacity that is more open than alternative marketplaces. The strategies we proffer in this paper we believe will contribute to an effective functioning of the electricity market. (author)

  18. Impact of errors in the downwelling irradiances on simulations of snow water equivalent, snow surface temperature, and the snow energy balance

    Science.gov (United States)

    Lapo, Karl E.; Hinkelman, Laura M.; Raleigh, Mark S.; Lundquist, Jessica D.

    2015-03-01

    The forcing irradiances (downwelling shortwave and longwave irradiances) are the primary drivers of snowmelt; however, in complex terrain, few observations, the use of estimated irradiances, and the influence of topography and elevation all lead to uncertainties in these radiative fluxes. The impact of uncertainties in the forcing irradiances on simulations of snow is evaluated in idealized modeling experiments. Two snow models of contrasting complexity, the Utah Energy Balance Model (UEB) and the Snow Thermal Model (SNTHERM), are forced with irradiances with prescribed errors of the structure and magnitude representative of those found in methods for estimating the downwelling irradiances. Relatively modest biases have substantial impacts on simulated snow water equivalent (SWE) and surface temperature (Ts) across a range of climates, whereas random noise at the daily scale has a negligible effect on modeled SWE and Ts. Shortwave biases have a smaller SWE impact, due to the influence of albedo, and Ts impact, due to their diurnal cycle, compared to equivalent longwave biases. Warmer sites exhibit greater sensitivity to errors when evaluated using SWE, while colder sites exhibit more sensitivity as evaluated using Ts. The two models displayed different sensitivity and responses to biases. The stability feedback in the turbulent fluxes explains differences in Ts between models in the negative longwave bias scenarios. When the models diverge during melt events, differences in the turbulent fluxes and internal energy change of the snow are found to be responsible. From this analysis, we suggest model evaluations use Ts in addition to SWE.

  19. Energy balances (1970 to 1990)

    International Nuclear Information System (INIS)

    1992-01-01

    Annual statistical data on french energy economy are presented for 1990. Consumption evolution of the principal users (industry, residential, transport and agriculture) during the last 21 years is made energy by energy (coal, petroleum, gas, electricity and renewable energy)

  20. Brazilian energy balance 2004: calendar year 2003

    International Nuclear Information System (INIS)

    2004-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 2003. It is divided into nine sections: a summary from 1970 to 2003; energy supply and demand by source, from 1988 to 2003; energy consumption by sector from 1988 to 2003; energy foreign trading also from 1988 to 2003; transformation centers balances in the same period; energy resources and reserves from 1973 to 2003; energy and socio-economy from 1988 to 2003; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances. It also presents analytical texts on the main energy numbers for 2003 and also energy evolution in Brazil and energy expansion all over the world

  1. 2000 energy balances and electricity profiles

    International Nuclear Information System (INIS)

    2004-01-01

    This is the eleventh issue of Energy Balances and Electricity Profiles published by the Statistics Division of the United Nations Secretariat. Like previous issues, this volume presents energy data for selected countries in a format which shows the overall picture of energy production, conversion and consumption for fuels utilised in the country. Such a publication is useful in assessing and analysing production and consumption patterns in detail on an internationally comparable basis. Since it began publishing energy balances, the Statistics Division has adopted the matrix type of overall energy balance that shows energy sources in the columns and energy flows in the rows. The format is described in detail in the technical report entitled Concepts and Methods in Energy Statistics, with Special Reference to Energy Accounts and Balances and is also discussed in the publication, Energy Statistics: A Manual for Developing Countries. The level of detail of this matrix structure takes into account the need for disaggregation of the energy sector and final demand, while at the same time, owing to the limitations in the quantity and quality of the currently available energy information, coverage has to be restricted to the main sectors only. Furthermore, it should be recognized that unlike national energy balances designed for individual countries' various specific needs, the energy balance format of the Statistics Division has to accommodate the whole spectrum of national energy data which it receives from national statistical offices and through official national publications. Inasmuch as information on electricity is generally available in greater detail than that for other energy forms, the Statistics Division decided to present special electricity profiles for an additional group of countries and areas, thereby covering at least part of their energy conversion and consumption activities. World energy data is published by the Statistics Division in the Energy

  2. 1998 energy balances and electricity profiles

    International Nuclear Information System (INIS)

    2001-01-01

    This is the tenth issue of Energy Balances and Electricity Profiles published by the Statistics Division of the United Nations Secretariat. Like previous issues, this volume presents energy data for selected countries in a format which shows the overall picture of energy production, conversion and consumption for fuels utilised in the country. Such a publication is useful in assessing and analysing production and consumption patterns in detail on an internationally comparable basis. Since it began publishing energy balances, the Statistics Division has adopted the matrix type of overall energy balance that shows energy sources in the columns and energy flows in the rows. The format is described in detail in the technical report entitled Concepts and Methods in Energy Statistics, with Special Reference to Energy Accounts and Balances and is also discussed in the publication, Energy Statistics: A Manual for Developing Countries. The level of detail of this matrix structure takes into account the need for disaggregation of the energy sector and final demand, while at the same time, owing to the limitations in the quantity and quality of the currently available energy information, coverage has to be restricted to the main sectors only. Furthermore, it should be recognized that unlike national energy balances designed for individual countries' various specific needs, the energy balance format of the Statistics Division has to accommodate the whole spectrum of national energy data which it receives from national statistical offices and through official national publications. Inasmuch as information on electricity is generally available in greater detail than that for other energy forms, the Statistics Division decided to present special electricity profiles for an additional group of countries and areas, thereby covering at least part of their energy conversion and consumption activities. World energy data is published by the Statistics Division in the Energy Statistics

  3. 2002 energy balances and electricity profiles

    International Nuclear Information System (INIS)

    2005-01-01

    This is the twelfth issue of Energy Balances and Electricity Profiles published by the Statistics Division of the United Nations Secretariat. Like previous issues, this volume presents energy data for selected countries in a format which shows the overall picture of energy production, conversion and consumption for fuels utilised in the country. Such a publication is useful in assessing and analysing production and consumption patterns in detail on an internationally comparable basis. Since it began publishing energy balances, the Statistics Division has adopted the matrix type of overall energy balance that shows energy sources in the columns and energy flows in the rows. The format is described in detail in the technical report entitled Concepts and Methods in Energy Statistics, with Special Reference to Energy Accounts and Balances and is also discussed in the publication, Energy Statistics: A Manual for Developing Countries. The level of detail of this matrix structure takes into account the need for disaggregation of the energy sector and final demand, while at the same time, owing to the limitations in the quantity and quality of the currently available energy information, coverage has to be restricted to the main sectors only. Furthermore, it should be recognized that unlike national energy balances designed for individual countries' various specific needs, the energy balance format of the Statistics Division has to accommodate the whole spectrum of national energy data which it receives from national statistical offices and through official national publications. Inasmuch as information on electricity is generally available in greater detail than that for other energy forms, the Statistics Division decided to present special electricity profiles for an additional group of countries and areas, thereby covering at least part of their energy conversion and consumption activities. World energy data is published by the Statistics Division in the Energy

  4. Brazilian energy balance 2010 - year 2009

    International Nuclear Information System (INIS)

    2010-01-01

    The Brazilian energy balance - BEB - is divided into eight chapters and ten annexes, whose contents are as follow: chapter 1 - energy analysis and aggregated data - presents energy highlights per source in 2009 and analyses the evolution of the internal offer of energy and its relationship with economic growth in 2009; chapter 2 - energy supply and demand by source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country; chapter 3 - energy consumption by sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy; chapter 4 - energy imports and exports - presents the evolution of the data on the import and export of energy and the dependence on external energy; chapter 5 - balance of transformation centers - presents the energy balances for the energy transformation centers including their losses; chapter 6 - energy resources and reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources, with the evolution of the data from 1974 to 2009, through graphs and tables; chapter 7 - energy and socioeconomics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; Chapter 8 - state energy data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. (author)

  5. Brazilian energy balance 2009 - year 2008

    International Nuclear Information System (INIS)

    2009-01-01

    The Brazilian energy balance - BEB - is divided into eight chapters and ten annexes, whose contents are as follow: Chapter 1 - Energy Analysis and Aggregated Data - presents energy highlights per source in 2008 and analyses the evolution of the internal offer of energy and its relationship with economic growth in 2008; Chapter 2 - Energy Supply and Demand by Source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country; Chapter 3 - Energy Consumption by Sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy; Chapter 4 - Energy Imports and Exports - presents the evolution of the data on the import and export of energy and the dependence on external energy; Chapter 5 - Balance of Transformation Centers - presents the energy balances for the energy transformation centers including their losses; Chapter 6 - Energy Resources and Reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources, with the evolution of the data from 1974 to 2008, through graphs and tables; Chapter 7 - Energy and Socioeconomics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; Chapter 8 - State Energy Data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. (author)

  6. A review of surface energy balance models for estimating actual evapotranspiration with remote sensing at high spatiotemporal resolution over large extents

    Science.gov (United States)

    McShane, Ryan R.; Driscoll, Katelyn P.; Sando, Roy

    2017-09-27

    Many approaches have been developed for measuring or estimating actual evapotranspiration (ETa), and research over many years has led to the development of remote sensing methods that are reliably reproducible and effective in estimating ETa. Several remote sensing methods can be used to estimate ETa at the high spatial resolution of agricultural fields and the large extent of river basins. More complex remote sensing methods apply an analytical approach to ETa estimation using physically based models of varied complexity that require a combination of ground-based and remote sensing data, and are grounded in the theory behind the surface energy balance model. This report, funded through cooperation with the International Joint Commission, provides an overview of selected remote sensing methods used for estimating water consumed through ETa and focuses on Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) and Operational Simplified Surface Energy Balance (SSEBop), two energy balance models for estimating ETa that are currently applied successfully in the United States. The METRIC model can produce maps of ETa at high spatial resolution (30 meters using Landsat data) for specific areas smaller than several hundred square kilometers in extent, an improvement in practice over methods used more generally at larger scales. Many studies validating METRIC estimates of ETa against measurements from lysimeters have shown model accuracies on daily to seasonal time scales ranging from 85 to 95 percent. The METRIC model is accurate, but the greater complexity of METRIC results in greater data requirements, and the internalized calibration of METRIC leads to greater skill required for implementation. In contrast, SSEBop is a simpler model, having reduced data requirements and greater ease of implementation without a substantial loss of accuracy in estimating ETa. The SSEBop model has been used to produce maps of ETa over very large extents (the

  7. The interactions between soil-biosphere-atmosphere land surface model with a multi-energy balance (ISBA-MEB) option in SURFEXv8 - Part 1: Model description

    Science.gov (United States)

    Boone, Aaron; Samuelsson, Patrick; Gollvik, Stefan; Napoly, Adrien; Jarlan, Lionel; Brun, Eric; Decharme, Bertrand

    2017-02-01

    Land surface models (LSMs) are pushing towards improved realism owing to an increasing number of observations at the local scale, constantly improving satellite data sets and the associated methodologies to best exploit such data, improved computing resources, and in response to the user community. As a part of the trend in LSM development, there have been ongoing efforts to improve the representation of the land surface processes in the interactions between the soil-biosphere-atmosphere (ISBA) LSM within the EXternalized SURFace (SURFEX) model platform. The force-restore approach in ISBA has been replaced in recent years by multi-layer explicit physically based options for sub-surface heat transfer, soil hydrological processes, and the composite snowpack. The representation of vegetation processes in SURFEX has also become much more sophisticated in recent years, including photosynthesis and respiration and biochemical processes. It became clear that the conceptual limits of the composite soil-vegetation scheme within ISBA had been reached and there was a need to explicitly separate the canopy vegetation from the soil surface. In response to this issue, a collaboration began in 2008 between the high-resolution limited area model (HIRLAM) consortium and Météo-France with the intention to develop an explicit representation of the vegetation in ISBA under the SURFEX platform. A new parameterization has been developed called the ISBA multi-energy balance (MEB) in order to address these issues. ISBA-MEB consists in a fully implicit numerical coupling between a multi-layer physically based snowpack model, a variable-layer soil scheme, an explicit litter layer, a bulk vegetation scheme, and the atmosphere. It also includes a feature that permits a coupling transition of the snowpack from the canopy air to the free atmosphere. It shares many of the routines and physics parameterizations with the standard version of ISBA. This paper is the first of two parts; in part one

  8. Energy balance in solid state fermentation processes

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.J.A.; Torres, A.; Echevarria, J.; Saura, G. (Instituto Cubano de Investigaciones de los Derivados de la Cana de Azucar (ICIDCA), La Habana (Cuba))

    1991-01-01

    It was applied a macroscopic energy balance to a solid state fermentation process and an electron balance in order to estimate the temperature and the heat evolved in the process. There were employed several equations that describe the development of the system and offer the possibility to design or control such fermentations. (orig.).

  9. Brazilian Energy Balance 2016 - calendar year 2015

    International Nuclear Information System (INIS)

    2016-01-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow. Chapter 1 - Energy Analysis and Aggregated Data - presents energy highlights per source in 2015 and analyses the evolution of the domestic energy supply and its relationship with economic growth. Chapter 2 - Energy Supply and Demand by Source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments and total consumption disaggregated per socioeconomic sector in the country. Chapter 3 - Energy Consumption by Sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy. Chapter 4 - Energy Imports and Exports - presents the evolution of the data on the import and export of energy and the dependence on external energy. Chapter 5 - Balance of Transformation Centers - presents the energy balances for the energy transformation centers including their losses. Chapter 6 - Energy Resources and Reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources. Chapter 7 - Energy and Socioeconomics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports. Chapter 8 - State Energy Data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. Relating to annexes the current structure is presented bellow: Annex I - Installed Capacity - shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining. Annex II - Self-production of Electricity - presents disaggregated data of self-production, considering sources and sectors. Annex III - World Energy Data - presents the main indicators for the production, import, export and consumption per energy source

  10. Hydrocarbons and new energy balances

    International Nuclear Information System (INIS)

    Chevallier, Bruno; Bouchard, Georges; Jones, Richard; ); Percebois, Jacques; Minster, Jean-Francois

    2012-01-01

    This article reports the content of interventions which commented different scenarios and outlooks about energy. A first one commented the 'World energy outlook 2012' and a study on Iraq. It addressed the growth of energy demand in different countries and regions and the motors of this growth, the shares of primary energy demand for oil, coal, gas, renewable energies and nuclear energy, the levels of gas and oil production, and their perspectives for 2035 (including shale gases). A second one commented the content of the 'Energy 2050' study which contained objectives in terms of energy transition, and therefore different possible strategies for nuclear reactor. This survey comprised eight scenarios, namely Negawatt, Negatep, Areva, CEA, UFE, DGEC/Enerdata, Global Chance and RTE. Results are compared in terms of costs, jobs, GDP, tariffs. A last part addressed technological breakthroughs and energy scenarios in a historical perspective: difficulty to assess final costs, technological difficulties and consequences, benefit of advanced technologies, energy efficiency not enough taken into account in future scenarios

  11. Energy Landscape of Social Balance

    Science.gov (United States)

    Marvel, Seth A.; Strogatz, Steven H.; Kleinberg, Jon M.

    2009-11-01

    We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social “balance” allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

  12. Energy balance of pregnant diabetic rats.

    Science.gov (United States)

    Yamada, Ruth; Griggio, Mauro A; Luz, Jacqueline

    2002-05-01

    Pregnancy and diabetes lead to metabolic alterations in the energy balance that may not be completely independent. The objective of the present study was to look at the alterations induced by type 1 diabetes mellitus on the energy balance of pregnant rats and the offspring. Diabetes was induced by streptozotocin injection 15 d before the starting of pregnancy. The rats had their energy balance variables followed for 21 d. Protein, fat and energy content of dams was determined from samples of the carcasses. Pregnancy led to increased energy intake, energy gain and energy expenditure as well as higher gross food efficiency than non-pregnant counterparts. Diabetes increased metabolizable energy intake but not the energy gain of the animals: they had very high energy expenditure, so that diabetes blocked the improvement in gross food efficiency shown during pregnancy. Offspring from diabetic dams were born with lower body weight. Pregnant animals did not present the usual energy storage as seen by lower energy gain of diabetic dams as well as by the lower fat content in the carcasses of pregnant diabetic rats. It is concluded that diabetes impairs the energy variables usually enhanced by pregnancy alone.

  13. France's energy balance for 2013

    International Nuclear Information System (INIS)

    Albertini, Jean-Paul; Dussud, Francois-Xavier; Louati, Sami; Mordant, Guillaume; Rouquette, Celine; Cadin, Didier; Collet, Isabelle; Fratacci, Lisa; Lauverjat, Jean; Martin, Jean-Philippe; Rabai, Yacine; Reynaud, Didier; Wong, Florine; Bottin, Anne; Reperant, Patricia; Grosset, Catherine

    2014-07-01

    As in 2012, activity in France increased slightly (+0.3%), thanks to an upturn in the second half. Fossil energy prices on the international markets took a downward turn in 2013 under the influence of the morose world economic climate, dropping sharply for oil and coal and rising, but at a slowed rate, for gas. Quoted prices nonetheless remained high: the Brent price remained well above US$100/barrel and steam coal above US$ 80/ton. Conversely, the price of natural gas took an upward path three years ago in continental Europe. Electricity prices dropped on the European markets, notably as a result of strong production of renewable energy in Germany and Spain. Energy prices in France continued to increase but at a slowed rate and more slowly than the prices for goods and services as a whole for the first time in 10 years. Prices for oil products saw a downturn, something which had not happened since 2009 but gas and electricity prices rose sharply. French households' average gasoline and diesel oil expenditure was euro 60 less in 2013 than in 2012, due almost entirely to the price drop. Spending on energy for household use increased by euro 100 under the combined effect of price increase and greater heating needs. French people's expenditure for energy represented 6.2% of their effective consumption. 2013 was characterised by a colder first half which induced an additional need for heating of 3.1 Mtoe in 2013 in relation to the previous year. The physical foreign trade gap, structurally biased towards imports, accordingly widened slightly in 2013 to 124 Mtoe, as a result of the refined oil products, and additional purchasing of coal made necessary by greater use of thermal power plants. The effect of decreasing international energy prices outweighed the physical flows: France's energy bill reduced by 4.6% in relation to the record 2012, reaching euro 66 billion. The oil bill was therefore significantly reduced as a result of the dual decrease in volume and price

  14. Energy Balance in an Electrostatic Accelerator

    OpenAIRE

    Zolotorev, Max S.; McDonald, Kirk T.

    2000-01-01

    The principle of an electrostatic accelerator is that when a charge e escapes from a conducting plane that supports a uniform electric field of strength E_0, then the charge gains energy e E_0 d as it moves distance d from the plane. Where does this energy come from? We that the mechanical energy gain of the electron is balanced by the decrease in the electrostatic field energy of the system.

  15. Orexins, feeding, and energy balance

    NARCIS (Netherlands)

    Girault, Elodie M.; Yi, Chun-Xia; Fliers, Eric; Kalsbeek, Andries

    2012-01-01

    In this chapter, we give an overview of the current status of the role of orexins in feeding and energy homeostasis. Orexins, also known as hypocretins, initially were discovered in 1998 as hypothalamic regulators of food intake. A little later, their far more important function as regulators of

  16. Dairy beverages and energy balance

    DEFF Research Database (Denmark)

    Astrup, Arne; Chaput, Jean-Philippe; Gilbert, Jo-Anne

    2010-01-01

    to exist. We have found that high versus low calcium intakes from dairy products had no effect on 24-h energy expenditure or substrate oxidation rates, but fecal fat excretion increased approximately 2.5-fold on the high-calcium diets. In a meta-analysis of intervention studies we found that increasing...... dairy calcium intake by 1200mg/day resulted in increased fecal fat excretion by 5.2 (1.6-8.8) g/day. Newer research shows that humans possess taste receptors for calcium in the gastrointestinal tract and that signaling may be linked to appetite regulation. A new line of evidence suggests...... that an inadequate calcium intake during an energy restricted weight loss program may trigger hunger and impair compliance to the diet. These mechanisms may be part of the explanation for the protective effects of dairy products with regard to obesity and metabolic syndrome....

  17. Annual Energy Balance Sheets 2001-2002

    International Nuclear Information System (INIS)

    2004-01-01

    During the year 2002 the primary supply of energy reached 629 TWh, which is 7.7 TWh less than 2001. The decrease originates mainly from the reduced electricity production from water power. Also the electricity production in nuclear power plants decreased by 4.5 TWh. If we were to look at the supplied energy for final consumption we will find a slightly rise by 1.8 TWh. The year 2002 was warmer than a 'normal' year and that consequently brings lower energy needs. Compared with 2001, 2002 was not warmer and a net electricity import of 5.4 TWh covered the energy needs. The energy use increased by 3.3 TWh between 2002 and 2001. The industry sector shows the largest rise by 2.9 TWh, nearly 2 per cent. Within that sector, energy from biomass fuel had a rise by 6.7 per cent. The household sector decreases its energy use by 2.7 per cent, and oil and electricity show the largest decrease. The proportionately high electricity price probably had a slowing down effect on the electricity use. The balance sheets of energy sources are showing the total supply and consumption of energy sources expressed in original units, i.e. units recorded in the primary statistics - mainly commercial units. The production of derived energy commodities is recorded on the supply - side of the balance sheets of energy sources, which is not the case in the energy balance sheets. The balance sheets of energy sources also include specifications of input--output and energy consumption in energy conversion industries. The energy balance sheets are based on primary data recorded in the balance sheets of energy sources, here expressed in a common energy unit, TJ. The production of derived energy is recorded in a second flow-step comprising energy turnover in energy conversion and is also specified in complementary input - output tables for energy conversion industries. The following items are shown in the energy balance sheets. 1.1 Inland supply of primary energy; 1.3 Import; 1.4 Export; 1.5 Changes in

  18. Energy Balance of Rural Ecosystems In India

    Science.gov (United States)

    Chhabra, A.; Madhava Rao, V.; Hermon, R. R.; Garg, A.; Nag, T.; Bhaskara Rao, N.; Sharma, A.; Parihar, J. S.

    2014-11-01

    India is predominantly an agricultural and rural country. Across the country, the villages vary in geographical location, area, human and livestock population, availability of resources, agricultural practices, livelihood patterns etc. This study presents an estimation of net energy balance resulting from primary production vis-a-vis energy consumption through various components in a "Rural Ecosystem". Seven sites located in different agroclimatic regions of India were studied. An end use energy accounting "Rural Energy Balance Model" is developed for input-output analysis of various energy flows of production, consumption, import and export through various components of crop, trees outside forest plantations, livestock, rural households, industry or trade within the village system boundary. An integrated approach using field, ancillary, GIS and high resolution IRS-P6 Resourcesat-2 LISS IV data is adopted for generation of various model inputs. The primary and secondary field data collection of various energy uses at household and village level were carried out using structured schedules and questionnaires. High resolution multi-temporal Resourcesat-2 LISS IV data (2013-14) was used for generating landuse/landcover maps and estimation of above-ground Trees Outside Forests phytomass. The model inputs were converted to energy equivalents using country-specific energy conversion factors. A comprehensive geotagged database of sampled households and available resources at each study site was also developed in ArcGIS framework. Across the study sites, the estimated net energy balance ranged from -18.8 Terra Joules (TJ) in a high energy consuming Hodka village, Gujarat to 224.7 TJ in an agriculture, aquaculture and plantation intensive Kollaparru village, Andhra Pradesh. The results indicate that the net energy balance of a Rural Ecosystem is largely driven by primary production through crops and natural vegetation. This study provides a significant insight to policy

  19. 1994 energy balances and electricity profiles

    International Nuclear Information System (INIS)

    1996-01-01

    This is the eighth issue of Energy Balances and Electricity Profiles published by the Statistics Division of the United Nations Secretariat. Like previous issues, this volume presents energy data for selected countries and areas in a format which shows the overall picture of energy production, conversion and consumption for each fuel utilized in the country. Such a publication is useful in assessing and analyzing production and consumption patterns in detail on an internationally comparable basis

  20. 1992 energy balances and electricity profiles

    International Nuclear Information System (INIS)

    1994-01-01

    This is the seventh issue of Energy Balances and Electricity Profiles published by the Statistical Division of the United Nations Secretariat. Like previous issues, this volume presents energy data for selected developing countries and areas in a format which shows the overall picture of energy production, conversion and consumption for each fuel utilised in the country. Such a publication is useful in assessing and analyzing production and consumption patterns in detail on an internationally comparable basis

  1. Offshore wind energy : balancing risk and reward

    International Nuclear Information System (INIS)

    Nerland, C.

    2010-01-01

    Offshore wind energy developments are expected to increase as the demand for renewable energy sources grows. This poster presentation described a method of balancing risk and reward in offshore wind energy projects. The method was based on risk assessment strategies used by the oil and gas industry. The dedicated framework considered schedules; budgets; performance; and operating and maintenance costs. A value chain assessment method was used to optimize the balance between risk and reward by evaluating uncertainties and risk related to each project element and its relationship to other elements within an integrated dynamic model designed to determine the net present value of a project. The decision-making criteria included the RISKEX risk expenditure strategy designed to consider the balance between risk exposure, capital expenditures, and operational expenditures in relation to the statistical cost of unplanned repairs, and lost production capacity. A case study of a large offshore wind farm was used to demonstrate the method. tabs., figs.

  2. 1970-1997 energy balance-sheets

    International Nuclear Information System (INIS)

    1998-01-01

    The aim of this document is to bring together a consistent and harmonized set of statistical data on energy economics in the French territory. The information is based on the global and structural approach of the different energy balance-sheets published between 1970 and 1997. The first chapter gives a general idea of the energy situation of the passed year and outlines the evolution of the main aggregates (production, primary and final consumption etc..) comparatively to those of the general economy. The second chapter is devoted to the history of energy economics. Time series of indicators and diagrams allow to precise the structural modifications that occurred during the last decades. The main transformations in the national energy production and the development of the different energy sources in the industry, the residential and tertiary sectors and in the transportation sector are described too. The third chapter gives numerical data on energy for the last 28 years using the common Mtpe unit (million of tons of petroleum equivalent). These balance sheets are based on new energy keeping methods and use identical equivalence coefficients. The last chapter presents the energy balance sheets for the last three years, using the proper units for coal, petroleum, gas and electricity. (J.S.)

  3. Glial cells and energy balance.

    Science.gov (United States)

    Argente-Arizón, Pilar; Guerra-Cantera, Santiago; Garcia-Segura, Luis Miguel; Argente, Jesús; Chowen, Julie A

    2017-01-01

    The search for new strategies and drugs to abate the current obesity epidemic has led to the intensification of research aimed at understanding the neuroendocrine control of appetite and energy expenditure. This intensified investigation of metabolic control has also included the study of how glial cells participate in this process. Glia, the most abundant cell type in the central nervous system, perform a wide spectrum of functions and are vital for the correct functioning of neurons and neuronal circuits. Current evidence indicates that hypothalamic glia, in particular astrocytes, tanycytes and microglia, are involved in both physiological and pathophysiological mechanisms of appetite and metabolic control, at least in part by regulating the signals reaching metabolic neuronal circuits. Glia transport nutrients, hormones and neurotransmitters; they secrete growth factors, hormones, cytokines and gliotransmitters and are a source of neuroprogenitor cells. These functions are regulated, as glia also respond to numerous hormones and nutrients, with the lack of specific hormonal signaling in hypothalamic astrocytes disrupting metabolic homeostasis. Here, we review some of the more recent advances in the role of glial cells in metabolic control, with a special emphasis on the differences between glial cell responses in males and females. © 2017 Society for Endocrinology.

  4. 2004 energy balances and electricity profiles

    International Nuclear Information System (INIS)

    2007-02-01

    The Energy Balances and Electricity Profiles 2004 is the thirteenth issue in an internationally series of comparable energy data for selected developing countries. The data are arranged to show energy production, trade, conversion and consumption for each fuel used in the country. This publication is a source of overall consumption statistics of energy commodities in all sectors. Special electricity profiles for an additional group of countries are published to cover, exclusively, detailed information on production, trade and consumption of electricity, net installed capacity and thermal power plant input for selected developing countries

  5. Balancing the Energy-Water Nexus

    Energy Technology Data Exchange (ETDEWEB)

    Dell, Jan

    2010-09-15

    Optimizing the complex tradeoffs in the Energy-Water Nexus requires quantification of energy use, carbon emitted and water consumed. Water is consumed in energy production and is often a constraint to operations. More global attention and investment has been made on reducing carbon emissions than on water management. Review of public reporting by the largest 107 global power producers and 50 companies in the oil/gas industry shows broad accounting on carbon emissions but only partial reporting on water consumption metrics. If the Energy-Water Nexus is to be balanced, then water must also be measured to be optimally managed with carbon emissions.

  6. Kisspeptin and energy balance in reproduction.

    Science.gov (United States)

    De Bond, Julie-Ann P; Smith, Jeremy T

    2014-03-01

    Kisspeptin is vital for the neuroendocrine regulation of GNRH secretion. Kisspeptin neurons are now recognized as a central pathway responsible for conveying key homeostatic information to GNRH neurons. This pathway is likely to mediate the well-established link between energy balance and reproductive function. Thus, in states of severely altered energy balance (either negative or positive), fertility is compromised, as is Kiss1 expression in the arcuate nucleus. A number of metabolic modulators have been proposed as regulators of kisspeptin neurons including leptin, ghrelin, pro-opiomelanocortin (POMC), and neuropeptide Y (NPY). Whether these regulate kisspeptin neurons directly or indirectly will be discussed. Moreover, whether the stimulatory role of leptin on reproduction is mediated by kisspeptin directly will be questioned. Furthermore, in addition to being expressed in GNRH neurons, the kisspeptin receptor (Kiss1r) is also expressed in other areas of the brain, as well as in the periphery, suggesting alternative roles for kisspeptin signaling outside of reproduction. Interestingly, kisspeptin neurons are anatomically linked to, and can directly excite, anorexigenic POMC neurons and indirectly inhibit orexigenic NPY neurons. Thus, kisspeptin may have a direct role in regulating energy balance. Although data from Kiss1r knockout and WT mice found no differences in body weight, recent data indicate that kisspeptin may still play a role in food intake and glucose homeostasis. Thus, in addition to regulating reproduction, and mediating the effect of energy balance on reproductive function, kisspeptin signaling may also be a direct regulator of metabolism.

  7. Energy balance of ENDF/B-VI

    International Nuclear Information System (INIS)

    MacFarlane, R.E.

    1994-01-01

    ENDF/B-VI through Release 2 has been tested for neutron-photon energy balance using the Heater module of the NJOY nuclear data procesing system. The situation is much improved over ENDF/B-V, but there are still a number of maerials that show problems

  8. Nexus of Poverty, Energy Balance and Health

    Science.gov (United States)

    Mishra, C. P.

    2012-01-01

    Since the inception of planning process in India, health planning was an integral component of socio-economic planning. Recommendations of several committees, policy documents and Millennium development goals were instrumental in development of impressive health infrastructure. Several anti-poverty and employment generation programmes were instituted to remove poverty. Spectacular achievements took place in terms of maternal and child health indicators and expectancy of life at birth. However, communicable diseases and undernutrition remain cause of serious concern and non-communicable diseases are imposing unprecedented challenge to planners and policy makers. Estimates of poverty based on different criteria point that it has remained a sustained problem in the country and emphasizes on revisiting anti-poverty programmes, economic policies and social reforms. Poverty affects purchasing power and thereby, food consumption. Energy intake data has inherent limitations. It must be assessed in terms of energy expenditure. Energy balance has been least explored area of research. The studies conducted in three different representative population group of Eastern Uttar Pradesh revealed that 69.63% rural adolescent girls (10-19 years), 79.9% rural reproductive age group females and 62.3% rural geriatric subjects were in negative energy balance. Negative energy balance was significantly less in adolescent girls belonging to high SES (51.37%), having main occupation of family as business (55.3%), and highest per capita income group (57.1%) with respect to their corresponding sub-categories. In case of rural reproductive age groups, this was maximum (93.0%) in SC/ST category and least (65.7%) in upper caste group. In case of geriatric group, higher adjusted Odd's Ratio for negative energy balance for subjects not cared by family members (AOR 23.43, CI 3.93-139.56), not kept money (AOR 5.27, CI 1.58-17.56), belonging to lower and upper middle SES by Udai Pareekh Classification

  9. Nexus of poverty, energy balance and health

    Directory of Open Access Journals (Sweden)

    C P Mishra

    2012-01-01

    Full Text Available Since the inception of planning process in India, health planning was an integral component of socio-economic planning. Recommendations of several committees, policy documents and Millennium development goals were instrumental in development of impressive health infrastructure. Several anti-poverty and employment generation programmes were instituted to remove poverty. Spectacular achievements took place in terms of maternal and child health indicators and expectancy of life at birth. However, communicable diseases and undernutrition remain cause of serious concern and non-communicable diseases are imposing unprecedented challenge to planners and policy makers. Estimates of poverty based on different criteria point that it has remained a sustained problem in the country and emphasizes on revisiting anti-poverty programmes, economic policies and social reforms. Poverty affects purchasing power and thereby, food consumption. Energy intake data has inherent limitations. It must be assessed in terms of energy expenditure. Energy balance has been least explored area of research. The studies conducted in three different representative population group of Eastern Uttar Pradesh revealed that 69.63% rural adolescent girls (10-19 years, 79.9% rural reproductive age group females and 62.3% rural geriatric subjects were in negative energy balance. Negative energy balance was significantly less in adolescent girls belonging to high SES (51.37%, having main occupation of family as business (55.3%, and highest per capita income group (57.1% with respect to their corresponding sub-categories. In case of rural reproductive age groups, this was maximum (93.0% in SC/ST category and least (65.7% in upper caste group. In case of geriatric group, higher adjusted Odd′s Ratio for negative energy balance for subjects not cared by family members (AOR 23.43, CI 3.93-139.56, not kept money (AOR 5.27, CI 1.58-17.56, belonging to lower and upper middle SES by Udai Pareekh

  10. Solar energy resources not accounted in Brazilian National Energy Balance

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Paulo Cesar da Costa [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica], Emails: pinheiro@netuno.Lcc.ufmg.br, pinheiro@demec.ufmg.br

    2009-07-01

    The main development vector of a society is the energy. The solar energy is the main energy source on the planet earth. Brazil is a tropical country, and the incident solar energy on its soil (15 trillion MWh/year) is 20,000 times its annual oil production. Several uses of solar energy are part of our lives in a so natural way that it despised in the consumption and use energy balance. In Brazil, solar energy is used directly in many activities and not accounted for in Energy Balance (BEN 2007), consisting of a virtual power generation. This work aims to make a preliminary assessment of solar energy used in different segments of the Brazilian economy. (author)

  11. Annual Energy Balance Sheets 2003-2004

    International Nuclear Information System (INIS)

    2005-01-01

    During the year 2004 the supply of primary energy reached 657.6 TWh. That is an increased supply by 16 TWh compared with 2003, The electricity production in hydropower and wind power stations increased by 7 TWh, to 61 TWh during the year 2004. The electricity generated in nuclear power plants was 77.5 TWh, an increase by 10 TWh. During the year 2004 Sweden net exported 2.1 TWh electricity. But in year 2003 we net imported 12.8 TWh electricity. The energy use increased from 406 TWh to 409 TWh between year 2003 and year 2004. The use of coal and coke in manufacturing increased by 22 per cent, and the use of oil products in transport sector increased by 4 per cent. The energy balance sheets are based on data primary recorded in the balance sheets of energy sources, here expressed in a common energy unit, TJ. The production of derived energy is here recorded in a second flow-step comprising energy turnover in energy conversion and is also specified in complementary input-output tables for energy conversion industries

  12. Neuropeptides controlling energy balance: orexins and neuromedins

    Science.gov (United States)

    Nixon, Joshua P.; Kotz, Catherine M.; Novak, Colleen M.; Billington, Charles J.; Teske, Jennifer A.

    2016-01-01

    In this section we review the feeding and energy expenditure effects of orexin (also known as hypocretin) and neuromedin. Orexins are multifunctional neuropeptides that affect energy balance by participating in regulation of appetite, arousal, and spontaneous physical activity. Central orexin signaling for all functions originates in the lateral hypothalamus–perifornical area, and is likely functionally differentiated based on site of action and on interacting neural influences. The effect of orexin on feeding is likely related to arousal in some ways, but is nonetheless a separate neural process that depends on interactions with other feeding related neuropeptides. In a pattern distinct from other neuropeptides, orexin stimulates both feeding and energy expenditure. Orexin increases in energy expenditure are mainly by increasing spontaneous physical activity, and this energy expenditure effect is more potent than the effect on feeding. Global orexin manipulations, such as in transgenic models, produce energy balance changes consistent with a dominant energy expenditure effect of orexin. Neuromedins are gut-brain peptides that reduce appetite. There are gut sources of neuromedin, but likely the key appetite related neuromedin producing neurons are in hypothalamus and parallel other key anorectic neuropeptide expression in the arcuate to paraventricular hypothalamic projection. As with other hypothalamic feeding related peptides, hindbrain sites are likely also important sources and targets of neuromedin anorectic action. Neuromedin increases physical activity in addition to reducing appetite, thus producing a consistent negative energy balance effect. Together with the various other neuro-peptides, -transmitters, -modulators and –hormones, neuromedin and orexin act in the appetite network to produce changes in food intake and energy expenditure, which ultimately influences the regulation of body weight. PMID:22249811

  13. Importance of energy balance in agriculture.

    Science.gov (United States)

    Meco, R.; Moreno, M. M.; Lacasta, C.; Tarquis, A. M.; Moreno, C.

    2012-04-01

    Since the beginning, man has tried to control nature and the environment, and the use of energy, mainly from non-renewable sources providing the necessary power for that. The consequences of this long fight against nature has reached a critical state of unprecedented worldwide environmental degradation, as evidenced by the increasing erosion of fertile lands, the deforestation processes, the pollution of water, air and land by agrochemicals, the loss of plant and animal species, the progressive deterioration of the ozone layer and signs of global warming. This is exacerbated by the increasing population growth, implying a steady increase in consumption, and consequently, in the use of energy. Unfortunately, all these claims are resulting in serious economic and environmental problems worldwide. Because the economic and environmental future of the countries is interrelated, it becomes necessary to adopt sustainable development models based on the use of renewable and clean energies, the search for alternative resources and the use of productive systems more efficient from an energy standpoint, always with a reduction of greenhouse gas emissions. In relation to the agricultural sector, the question we ask is: how long can we keep the current energy-intensive agricultural techniques in developed countries? To analyze this aspect, energy balance is a very helpful tool because can lead to more efficient, sustainable and environment-friendly production systems for each agro-climatic region. This requires the identification of all the inputs and the outputs involved and their conversion to energy values by means of corresponding energy coefficients or equivalents (International Federation of Institutes for Advanced Studies). Energy inputs (EI) can be divided in direct (energy directly used in farms as fuel, machines, fertilizers, seeds, herbicides, human labor, etc.) and indirect (energy not consumed in the farm but in the elaboration, manufacturing or manipulation of

  14. Balancing Energy Processes in Turbine Engines

    Directory of Open Access Journals (Sweden)

    Balicki Włodzimierz

    2015-01-01

    Full Text Available The article discusses the issue of balancing energy processes in turbine engines in operation in aeronautic and marine propulsion systems with the aim to analyse and evaluate basic operating parameters. The first part presents the problem of enormous amounts of energy needed for driving fans and compressors of the largest contemporary turbofan engines commonly used in long-distance aviation. The amounts of the transmitted power and the effect of flow parameters and constructional properties of the engines on their performance and real efficiency are evaluated. The second part of the article, devoted to marine applications of turbine engines, presents the energy balance of the kinetic system of torque transmission from main engine turbines to screw propellers in the combined system of COGAG type. The physical model of energy conversion processes executed in this system is presented, along with the physical model of gasodynamic processes taking place in a separate driving turbine of a reversing engine. These models have made the basis for formulating balance equations, which then were used for analysing static and dynamic properties of the analysed type of propulsion, in particular in the aspect of mechanical loss evaluation in its kinematic system.

  15. The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling

    NARCIS (Netherlands)

    Oerlemans, J.

    1991-01-01

    The sensitivity of the mass balance of the Greenland ice sheet to climate change is studied with an energy-balance model of the ice/snow surface, applied at 200 m elevation intervals for four characteristic regions of the ice sheet. Solar radiation, longwave radiation, turbulent heat fluxes

  16. Sustainable Urban Regeneration Based on Energy Balance

    Directory of Open Access Journals (Sweden)

    Sacha Silvester

    2012-07-01

    Full Text Available In this paper, results are reported of a technology assessment of the use and integration of decentralized energy systems and storage devices in an urban renewal area. First the general context of a different approach based on 'rethinking' and the incorporation of ongoing integration of coming economical and environmental interests on infrastructure, in relation to the sustainable urban development and regeneration from the perspective of the tripod people, technology and design is elaborated. However, this is at different scales, starting mainly from the perspective of the urban dynamics. This approach includes a renewed look at the ‘urban metabolism’ and the role of environmental technology, urban ecology and environment behavior focus. Second, the potential benefits of strategic and balanced introduction and use of decentralized devices and electric vehicles (EVs, and attached generation based on renewables are investigated in more detail in the case study of the ‘Merwe-Vierhaven’ area (MW4 in the Rotterdam city port in the Netherlands. In order to optimize the energy balance of this urban renewal area, it is found to be impossible to do this by tuning the energy consumption. It is more effective to change the energy mix and related infrastructures. However, the problem in existing urban areas is that often these areas are restricted to a few energy sources due to lack of available space for integration. Besides this, energy consumption in most cases is relatively concentrated in (existing urban areas. This limits the potential of sustainable urban regeneration based on decentralized systems, because there is no balanced choice regarding the energy mix based on renewables and system optimization. Possible solutions to obtain a balanced energy profile can come from either the choice to not provide all energy locally, or by adding different types of storage devices to the systems. The use of energy balance based on renewables as a

  17. Energy-balanced algorithm for RFID estimation

    Science.gov (United States)

    Zhao, Jumin; Wang, Fangyuan; Li, Dengao; Yan, Lijuan

    2016-10-01

    RFID has been widely used in various commercial applications, ranging from inventory control, supply chain management to object tracking. It is necessary for us to estimate the number of RFID tags deployed in a large area periodically and automatically. Most of the prior works use passive tags to estimate and focus on designing time-efficient algorithms that can estimate tens of thousands of tags in seconds. But for a RFID reader to access tags in a large area, active tags are likely to be used due to their longer operational ranges. But these tags use their own battery as energy supplier. Hence, conserving energy for active tags becomes critical. Some prior works have studied how to reduce energy expenditure of a RFID reader when it reads tags IDs. In this paper, we study how to reduce the amount of energy consumed by active tags during the process of estimating the number of tags in a system and make the energy every tag consumed balanced approximately. We design energy-balanced estimation algorithm that can achieve our goal we mentioned above.

  18. Yearly energy balance sheets 1998-1999

    International Nuclear Information System (INIS)

    2001-01-01

    The objective of the presented statistics is to give a total picture of the Swedish energy supply and consumption 1998-1999. Compared to the regularly published energy balance sheets based on short periodic statistics, this publication is more disaggregated in the field of final energy consumption. The data are mainly based on yearly statistics on energy consumption in different sectors. The broad statistical base has made it possible to compile data for consumer categories on a fairly detailed level. In cases where direct statistical information is lacking or is insufficient, indirect calculation methods have been used for estimations or recalculations of basic statistics. Revisions and improvements of statistical sources as well as calculation methods will be performed successively. As a consequence of this, the statistics presented here could be revised in future publications

  19. Yearly energy balance sheets 1996-1998

    International Nuclear Information System (INIS)

    2000-01-01

    The objective of the presented statistics is to give a total picture of the Swedish energy supply and consumption 1996-1998. Compared to the regularly published energy balance sheets based on short periodic statistics, this publication is more disaggregated in the field of final energy consumption. The data are mainly based on yearly statistics on energy consumption in different sectors. The broad statistical base has made it possible to compile data for consumer categories on a fairly detailed level. In cases where direct statistical information is lacking or is insufficient, indirect calculation methods have been used for estimations or recalculations of basic statistics. Revisions and improvements of statistical sources as well as calculation methods will be performed successively. As a consequence of this, the statistics presented here could be revised in future publications

  20. Power and energy balances. Forecast 2008

    International Nuclear Information System (INIS)

    2005-01-01

    Both the energy and power balance in 2008 is slightly better than the former Nordel estimate for 2007. This is due to additional investments in new generation capacity, new interconnections of total 1 000 MW to outside Nordel and reduced demand forecast in Sweden. The Nordic electricity system is able to meet the estimated consumption and the corresponding typical power demand pattern in average conditions. In long term the market is expected to maintain a reasonable balance between supply, imports and demand. Lower precipitation or colder temperature result in higher market prices that give incentives for increased imports, demand response and investments. This is expected to maintain the balance between supply and demand in the short and long term even in extreme situations. Allocation between imports and demand response in reality depends on the prevailing market prices and available generation resources outside Nordel. The interconnection capacities are expected to enable import volumes that can meet the increased peak demand. Some Nordic areas can be exposed to a risk for rationing or other measures because of extremely low precipitation. Nordic transmission capacities may prevent full utilization of Nordic thermal power in certain areas. The planned reinforcements in the 'five prioritised cross-sections' will improve the situation. The power balance and the internal bottlenecks in the continental Europe can have an effect on the import possibilities to the Nordic countries. The annual energy consumption in the Nordic market is estimated to grow by 20 TWh by year 2008 (1.2%la) from 395 TWh in 2004 (temperature corrected). In the three year period investments in power generation is expected to increase the available generation capacity and capability by 1500 MW and 10 TWhla in average conditions. Iceland is not included in the figures. The annual energy consumption in Iceland is estimated to grow by about 6.8 TWh by year 2008 (15 %la) due to two new aluminium

  1. A balanced energy budget plan for hydrogen production and distribution

    Science.gov (United States)

    Williscroft, R. G.

    An integrated plan for hydrogen production and distribution within a balanced energy budget is outlined. Primary energy source is the sun, concentrated in earth orbit by satellite and beamed to selected planetside marine locations for hydrogen production from sea water. Primary distribution via already existent natural gas pipeline networks upgraded for hydrogen transmission is augmented by local network extensions and by surface marine transport using modified LNG carriers. The economic, social and environmental impact of this integrated approach is examined in its relationship to continued reliance upon fossil fuel and expanded use of nuclear fission, to increasing reliance upon so-called alternative energy sources, and to the forthcoming nuclear fusion option.

  2. The Energy Balance Study: The Design and Baseline Results for a Longitudinal Study of Energy Balance

    Science.gov (United States)

    Hand, Gregory A.; Shook, Robin P.; Paluch, Amanda E.; Baruth, Meghan; Crowley, E. Patrick; Jaggers, Jason R.; Prasad, Vivek K.; Hurley, Thomas G.; Hebert, James R.; O'Connor, Daniel P.; Archer, Edward; Burgess, Stephanie; Blair, Steven N.

    2013-01-01

    Purpose: The Energy Balance Study (EBS) was a comprehensive study designed to determine over a period of 12 months the associations of caloric intake and energy expenditure on changes in body weight and composition in a population of healthy men and women. Method: EBS recruited men and women aged 21 to 35 years with a body mass index between 20…

  3. Energy balance in the WTC collapse

    Science.gov (United States)

    Zhu, Kaiqi; Xu, Kang; Ansourian, Peter; Tahmasebinia, Faham; Alonso-Marroquin, Fernando

    2016-08-01

    The main aim of this report is to provide an analysis of Twin Towers of the New York City's World Trade Centre collapsed after attacked by two jet aircrafts. The approach mainly focused on the effect of temperature on mechanical properties of the building, by modelling heat energy in the south tower. Energy balance during the collapse between the energy inputs by aircraft petrol and the transient heat to the towers was conducted. Both the overall structure between 80 to 83 stories and individual elements was modelled. The main elements contributed to the heat transition includes external and internal columns. Heat applied in 2D and 3D models for single elements was through convection and conduction. Analysis of transient heat was done using Strand7.

  4. Energy Balance over One Athletic Season.

    Science.gov (United States)

    Silva, Analiza M; Matias, Catarina N; Santos, Diana A; Thomas, Diana; Bosy-Westphal, Anja; Müller, Manfred J; Heymsfield, Steven B; Sardinha, Luís B

    2017-08-01

    Magnitude and variation in energy balance (EB) components over an athletic season are largely unknown. We investigated the longitudinal changes in EB over one season and explored the association between EB variation and change in the main fat-free mass (FFM) components in highly trained athletes. Eighty athletes (54 males; handball, volleyball, basketball, triathlete, and swimming) were evaluated from the beginning of the season to the main competition stage. Resting and total energy expenditure (REE and TEE, respectively) were assessed by indirect calorimetry and doubly labeled water, respectively. Physical activity energy expenditure was calculated as TEE - 0.1 TEE - REE. Fat mass (FM), FFM, and bone mineral were evaluated with dual-energy x-ray absorptiometry; changed body energy stores were calculated as 1.0(ΔFFM/Δtime) + 9.5(ΔFM/Δtime). Total-body water (TBW) and its compartments were assessed through dilution techniques, and total-body protein was calculated from a four-compartment model, with body volume assessed by air displacement plethysmography. Although a negative EB of -17.4 ± 72.7 kcal·d was observed (P sports and across sex groups resulting in a net weight increase (0.7 ± 2.3 kg) that is attributable to significant changes in FFM (1.2 ± 1.6 kg) and FM (-0.7 ± 1.5 kg) (P sports, and age. The mean negative EB observed over the season resulted from the rate of FM use and FFM accretion, but with a large variation by sex and sports. TBW, but not total-body protein or mineral balance, explained the magnitude of EB, which means that athletes under a positive or a negative EB showed a TBW expansion or shrinkage, respectively, specifically within the cells, over one athletic season.

  5. Nutrient balances in the forest energy cycle

    International Nuclear Information System (INIS)

    Olsson, Bengt

    2006-02-01

    In Sweden, recycling of stabilised wood-ashes to forests is considered to compensate for nutrient removals from whole-tree harvesting (i.e. use of harvest residues - slash - for energy purposes). This study has analysed nutrient fluxes through the complete forest energy cycle and estimated mass balances of nutrients in harvested biomass with those in ashes, to investigate the realism in large-scale nutrient compensation with wood-ash. Expected nutrient fluxes from forests through energy plants were calculated based on nutrient and biomass data of forest stands in the Nordic countries, and from data on nutrient fluxes through CFB-plants. The expected stoichiometric composition of wood-ashes was compared with the composition of CFB-fly ashes from various Swedish energy plants. Nutrient contents for different tree fractions were calculated to express the average nutrient concentrations in slash and stems with bark, respectively. A nutrient budget synthesis of the effects of whole-tree harvesting on base cation turnover in the following stand was presented for two experimental sites. Major conclusions from the study are: In the CFB-scenario, where the bottom ash is deposited and only the fly ash can be applied to forests, the fly ash from the slash do not meet the demands for nutrient compensation for slash harvesting. Stem material (50% wood, 50% bark) must be added at equivalent amounts, as the slash to produce the amounts of fly ash needed for compensation of slash harvesting. In the scenario where more stem material was added (75% of total fuel load), the amounts of fly ashes produced hardly compensated for nutrient removals with both stem and slash harvesting. The level of nutrient compensation was lowest for potassium. The stoichiometric nutrient composition of CFB-fly ashes from Swedish energy plants is not similar with the nutrient composition of tree biomass. The higher Ca/P ratio in ashes is only partly explained by the mixture of fuels (e.g. increasing bark

  6. Obtaining evapotranspiration and surface energy fluxes with ...

    African Journals Online (AJOL)

    In this study, SEBAL (Surface Energy Balance Algorithm for Land), a remote sensing based evapotranspiration model, has been applied with Landsat ETM+ sensor for the estimation of actual ... The land uses in this study area consists of irrigated agriculture, rain-fed agriculture and livestock grazing. The obtained results ...

  7. Energy Balance of the Santa Catarina State - Series 1980 -1996

    International Nuclear Information System (INIS)

    1997-01-01

    This energy balance of the Santa Catarina State presents the following main topics that can be outstanding: economic aspects; supply and demand of energy by source 1980-1996; energy consumption by sector 1980/1996; energy interchange; and balance of the transformation centers 1980/1996

  8. The importance of accurate glacier albedo for estimates of surface mass balance on Vatnajökull: evaluating the surface energy budget in a regional climate model with automatic weather station observations

    Science.gov (United States)

    Steffensen Schmidt, Louise; Aðalgeirsdóttir, Guðfinna; Guðmundsson, Sverrir; Langen, Peter L.; Pálsson, Finnur; Mottram, Ruth; Gascoin, Simon; Björnsson, Helgi

    2017-07-01

    A simulation of the surface climate of Vatnajökull ice cap, Iceland, carried out with the regional climate model HIRHAM5 for the period 1980-2014, is used to estimate the evolution of the glacier surface mass balance (SMB). This simulation uses a new snow albedo parameterization that allows albedo to exponentially decay with time and is surface temperature dependent. The albedo scheme utilizes a new background map of the ice albedo created from observed MODIS data. The simulation is evaluated against observed daily values of weather parameters from five automatic weather stations (AWSs) from the period 2001-2014, as well as in situ SMB measurements from the period 1995-2014. The model agrees well with observations at the AWS sites, albeit with a general underestimation of the net radiation. This is due to an underestimation of the incoming radiation and a general overestimation of the albedo. The average modelled albedo is overestimated in the ablation zone, which we attribute to an overestimation of the thickness of the snow layer and not taking the surface darkening from dirt and volcanic ash deposition during dust storms and volcanic eruptions into account. A comparison with the specific summer, winter, and net mass balance for the whole of Vatnajökull (1995-2014) shows a good overall fit during the summer, with a small mass balance underestimation of 0.04 m w.e. on average, whereas the winter mass balance is overestimated by on average 0.5 m w.e. due to too large precipitation at the highest areas of the ice cap. A simple correction of the accumulation at the highest points of the glacier reduces this to 0.15 m w.e. Here, we use HIRHAM5 to simulate the evolution of the SMB of Vatnajökull for the period 1981-2014 and show that the model provides a reasonable representation of the SMB for this period. However, a major source of uncertainty in the representation of the SMB is the representation of the albedo, and processes currently not accounted for in RCMs

  9. The importance of accurate glacier albedo for estimates of surface mass balance on Vatnajökull: evaluating the surface energy budget in a regional climate model with automatic weather station observations

    Directory of Open Access Journals (Sweden)

    L. S. Schmidt

    2017-07-01

    Full Text Available A simulation of the surface climate of Vatnajökull ice cap, Iceland, carried out with the regional climate model HIRHAM5 for the period 1980–2014, is used to estimate the evolution of the glacier surface mass balance (SMB. This simulation uses a new snow albedo parameterization that allows albedo to exponentially decay with time and is surface temperature dependent. The albedo scheme utilizes a new background map of the ice albedo created from observed MODIS data. The simulation is evaluated against observed daily values of weather parameters from five automatic weather stations (AWSs from the period 2001–2014, as well as in situ SMB measurements from the period 1995–2014. The model agrees well with observations at the AWS sites, albeit with a general underestimation of the net radiation. This is due to an underestimation of the incoming radiation and a general overestimation of the albedo. The average modelled albedo is overestimated in the ablation zone, which we attribute to an overestimation of the thickness of the snow layer and not taking the surface darkening from dirt and volcanic ash deposition during dust storms and volcanic eruptions into account. A comparison with the specific summer, winter, and net mass balance for the whole of Vatnajökull (1995–2014 shows a good overall fit during the summer, with a small mass balance underestimation of 0.04 m w.e. on average, whereas the winter mass balance is overestimated by on average 0.5 m w.e. due to too large precipitation at the highest areas of the ice cap. A simple correction of the accumulation at the highest points of the glacier reduces this to 0.15 m w.e. Here, we use HIRHAM5 to simulate the evolution of the SMB of Vatnajökull for the period 1981–2014 and show that the model provides a reasonable representation of the SMB for this period. However, a major source of uncertainty in the representation of the SMB is the representation of the albedo, and processes

  10. Energy Balance Models and Planetary Dynamics

    Science.gov (United States)

    Domagal-Goldman, Shawn

    2012-01-01

    We know that planetary dynamics can have a significant affect on the climate of planets. Planetary dynamics dominate the glacial-interglacial periods on Earth, leaving a significant imprint on the geological record. They have also been demonstrated to have a driving influence on the climates of other planets in our solar system. We should therefore expect th.ere to be similar relationships on extrasolar planets. Here we describe a simple energy balance model that can predict the growth and thickness of glaciers, and their feedbacks on climate. We will also describe model changes that we have made to include planetary dynamics effects. This is the model we will use at the start of our collaboration to handle the influence of dynamics on climate.

  11. Balance: Hydroelectricity impacts on energy systems

    International Nuclear Information System (INIS)

    Baptista, V.; Baia, L.; Azevedo, H.

    1997-01-01

    The VALORAGUA (Value of Water in Portuguese) computer model was developed by Electricidade de Portugal (EDP) in order to determine the optimal operation strategy of a mixed hydro-thermal power system with an important share of hydroelectricity generation such as the one of Portugal. The model has become the main tool used by EDP for planning the development and operation of its power system. In recent years, EDP has acquired the ENPEP package and has become acquainted with its use for integrated energy and electricity planning. The main goal of this effort has been to incorporate in EDP's planning procedure an integrated approach for determining the possible role of electricity in meeting the overall requirements for energy of the country, with due account to the impacts (resource requirements and environmental emissions) of alternative energy and electricity systems. This paper concentrates on a comparison of the results of the BALANCE module of ENPEP for the electricity sector against the simulation results provided by VALORAGUA. Suggested improvements to the methodologies in order to overcome the divergences in results from these two models are also advanced in the paper. (author). 15 figs

  12. Balance Function in High-Energy Collisions

    International Nuclear Information System (INIS)

    Tawfik, A.; Shalaby, Asmaa G.

    2015-01-01

    Aspects and implications of the balance functions (BF) in high-energy physics are reviewed. The various calculations and measurements depending on different quantities, for example, system size, collisions centrality, and beam energy, are discussed. First, the different definitions including advantages and even short-comings are highlighted. It is found that BF, which are mainly presented in terms of relative rapidity, and relative azimuthal and invariant relative momentum, are sensitive to the interaction centrality but not to the beam energy and can be used in estimating the hadronization time and the hadron-quark phase transition. Furthermore, the quark chemistry can be determined. The chemical evolution of the new-state-of-matter, the quark-gluon plasma, and its temporal-spatial evolution, femtoscopy of two-particle correlations, are accessible. The production time of positive-negative pair of charges can be determined from the widths of BF. Due to the reduction in the diffusion time, narrowed widths refer to delayed hadronization. It is concluded that BF are powerful tools characterizing hadron-quark phase transition and estimating some essential properties

  13. Brazilian energy balance 1999: 1983 to 1998 period

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the 1983 to 1998 period. It is divided into nine chapters, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy import and export; transformation centers balances; energy resources and reserves; energy and socio economy; energy data relating to brazilian states; and appendices - installed capacity, world data, general structure of the balance, information processing, conversion units and consolidated energy balance.

  14. Brazilian energy balance 1999: 1983 to 1998 period

    International Nuclear Information System (INIS)

    1999-01-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the 1983 to 1998 period. It is divided into nine chapters, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy import and export; transformation centers balances; energy resources and reserves; energy and socio economy; energy data relating to brazilian states; and appendices - installed capacity, world data, general structure of the balance, information processing, conversion units and consolidated energy balance

  15. Provisional energy balance-sheet of France in 1999

    International Nuclear Information System (INIS)

    2000-03-01

    This document presents a first and provisional analysis of the energy balance-sheet in France during the year 1999. the main conclusions concern: the energy mastership, the primary energy consumption, the energy intensity, the climatic conditions, the nuclear energy production, the energy independence, the carbon dioxide emissions and the energy bill. Many tables and charts are provided. (A.L.B.)

  16. Sleep and energy balance: Interactive homeostatic systems.

    Science.gov (United States)

    Vanitallie, Theodore B

    2006-10-01

    For early humans, acquisition of food by hunting and/or gathering was a hunger-driven process requiring vigilance and (often) strenuous physical effort during daylight hours. To sustain such activities, hunter-gatherers also needed periodic rest and sleep-pursuits most effectively undertaken at night. In recent years, research has given us new insights into the physiologic underpinnings of these behaviors. Specifically, evidence has been uncovered indicating that the homeostatic regulation of food intake on the one hand and that of sleep on the other hand, are intertwined. Thus, carefully performed studies of eating behavior in rats indicate that duration of sleep after ingestion of a meal is closely correlated to the meal's energy content. In 1999, it was discovered that mice and dogs functionally deficient in the appetite-stimulating hormone, hypocretin-1, become narcoleptic, suggesting the existence of a "hard-wired" connection between regulation of hunger and satiety and regulation of sleep. Administered into the nucleus accumbens shell, hypocretin-1 induces feeding and locomotor activity in Sprague-Dawley rats. Hypocretin neurons in the hypothalamus are responsive to metabolic cues capable of signaling nutritional status. The suprachiasmatic nucleus, the body's principal circadian clock, exchanges information with the hypocretin system about the light/dark cycle and the body's metabolic condition. Circadian Clock mutant mice exhibit an attenuated diurnal feeding rhythm and become hyperphagic and obese. Both disruption of the circadian cycle and sleep deprivation can affect energy balance and, over time, may bring about substantial changes in body composition. Although there is growing evidence that interleukin-6 and several other proinflammatory cytokines are "sleep factors" that also affect energy balance, any possible role they might have in coordinating sleep/wakefulness with food-motivated behavior awaits clarification. Yet, the evidence is increasingly

  17. Investigating the Interdependencies of the Energy Balance Closure and the Turbulent Kinetic Energy Budget.

    Science.gov (United States)

    Banerjee, T.; Zeeman, M. J.; De Roo, F.; Brugger, P.; Mauder, M.

    2016-12-01

    The energy balance residual (EBR), defined as the difference between the available energy (sum of net radiation and ground heat flux) and the turbulent fluxes of latent and sensible heat, is often found to have a large positive value. Several land surface experiments and flux networks report an average energy balance closure of approximately 80%. Although different factors can influence the energy balance closure across measurement campaigns, a significant EBR even when sites are horizontally with short canopies indicates of a systematic bias resulting from the general underestimation of the aerodynamic transport of energy, especially horizontal divergence of the mean advective fluxes and transport by low-frequency motions generally called `secondary circulations'. These low frequency local transports can occur from various processes such as coherent large scale organized motions, convective cells and even significant transient changes. Thus, we decided to study the budget of the turbulent kinetic energy (TKE) in conjunction with the energy balance closure. In the current work, this interdependency has been investigated using surface flux (Eddy Covariance) and remote sensing based measurements (triple 3d Doppler LiDAR, thermal imagery) from the ScaleX campaigns at the TERENO pre-alpine observatory Fendt in Southern Germany (with gentle topography), coupled with large eddy simulations (LES). Statistical methods ranging from dimensional reduction techniques to information theory has been used to extract the effects and significance of aforementioned processes towards explaining the observed annual average EBR of about 50 Wm-2. Initial results indicate a high correlation between EBR and the TKE dissipation rate, as well as the skewness of vertical velocity, confirming the role of secondary circulations. The role of transport and the advection terms will also be investigated. Overall, improved understanding of such connections between the fundamental mechanisms of TKE

  18. Height, surface firmness, and visual reference effects on balance control.

    Science.gov (United States)

    Simeonov, P; Hsiao, H

    2001-09-01

    To investigate the effects of height, surface firmness, and visual reference on standing balance in construction workers. Controlled laboratory study with balanced repeated measures. Twenty four construction workers. Test subjects performed standing tasks at ground level as well as at 3 m and 9 m high balconies on firm or deformable surfaces with close visual references included or excluded from their visual field. Standing balance was determined from center of pressure as measured by a force platform. Dependent variables were root mean square of sway in medial-lateral and anterior-posterior directions, area of sway, and velocity of sway. Heights without close visual references significantly increased all sway parameters. The effect of height in conditions without close visual references increased dramatically on deformable surfaces. Elevated work environments and deformable work surfaces negatively affect balance and may be associated with increased risk of fall incidents. Appropriate close visual references increase the ability to maintain balance.

  19. Interpretation of colloidal dyeing of polyester fabrics pretreated with ethyl xanthogenate in terms of zeta potential and surface free energy balance.

    Science.gov (United States)

    Espinosa-Jiménez, M; Padilla-Weigand, R; Ontiveros-Ortega, A; Ramos-Tejada, M M; Perea-Carpio, R

    2003-09-15

    Data are presented on the adsorption of the colloidal dye Disperse Blue 3 onto polyester fabric (Dacron 54, Stile 777), the fabric being pretreated with different amounts of the surfactant potassium ethyl xanthogenate (PEX). This study has been made by means of both the evolution of the zeta potential of the fiber/dye interface and the behaviour of the surface free energy components of the above systems. The kinetics of adsorption of the process of dyeing, using 10(-4) M of PEX in the pretreatment of the fabric, shows that increasing temperature of adsorption decrease the amount of colloidal dye adsorbed onto the fabric. This fact shows that the principal mechanism involved in this adsorption process is physical in nature. The adsorption isotherms of the colloidal dye onto polyester pretreated with different amounts of PEX, shows that the adsorption of the dye is favored with the increase in the concentration of the surfactant used in the pretreatment. This fact shows that the pretreatment with PEX is a very interesting aspect of interest in textile industry. The zeta potential of the system fabric/surfactant shows that this parameter is negative (about -25 mV) for the untreated fiber and decreases in absolute value for increasing concentration of the surfactant on the fiber, the value of the zeta potential of the system being -5 mV for 10(-2) M of PEX. This behavior can be explained for the chemical reaction nucleophilic attack between the carboxyl groups of polyester, ionized at pH 8, and the thiocarbonyl group of the xanthogenate ion. On the other hand, the zeta potential of the system polyester pretreated with PEX/Disperse Blue 3 at increasing concentrations of the surfactant and the dye shows that this parameter increases its negative value strongly with increasing concentration of the surfactant used in the treatment. This can be explained for the hydrogen bonds between the hydroxy groups of the dye and the S- ions of the thiocarbonyl group of the surfactant

  20. An energy balance climate model with cloud feedbacks

    Science.gov (United States)

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

    1984-01-01

    The present two-level global climate model, which is based on the atmosphere-surface energy balance, includes physically based parameterizations for the exchange of heat and moisture across latitude belts and between the surface and the atmosphere, precipitation and cloud formation, and solar and IR radiation. The model field predictions obtained encompass surface and atmospheric temperature, precipitation, relative humidity, and cloudiness. In the model integrations presented, it is noted that cloudiness is generally constant with changing temperature at low latitudes. High altitude cloudiness increases with temperature, although the cloud feedback effect on the radiation field remains small because of compensating effects on thermal and solar radiation. The net global feedback by the cloud field is negative, but small.

  1. An energy balance perspective on regional CO2-induced temperature changes in CMIP5 models

    OpenAIRE

    Räisänen, Jouni

    2017-01-01

    An energy balance decomposition of temperature changes is conducted for idealized transient CO2-only simulations in the fifth phase of the Coupled Model Intercomparison Project. The multimodel global mean warming is dominated by enhanced clear-sky greenhouse effect due to increased CO2 and water vapour, but other components of the energy balance substantially modify the geographical and seasonal patterns of the change. Changes in the net surface energy flux are important over the oceans, bein...

  2. Brazilian energy balance 1996: 1980 to 1995 period

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the 1980 to 1995 period. It`s divided into nine chapters, as follows: summary; energy supply and consumption by source; energy import and export; transformation centers balances; energy sources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances 1 fig., 68 graphs., 145 tabs.

  3. How will land use affect air temperature in the surface boundary layer? Lessons learned from a comparative study on the energy balance of an oak savanna and annual grassland in California, USA

    Directory of Open Access Journals (Sweden)

    Dennis Baldocchi

    2013-06-01

    Full Text Available We investigated the effect of land use on differences in air temperature. We based our analysis on a decade of weather and energy flux measurements, collected over two contrasting landscapes, an oak savanna and an annual grassland, growing under the same climate conditions. Over the decade, the daily-averaged, potential air temperature above the aerodynamically rougher and optically darker oak savanna was 0.5°C warmer than that above the aerodynamically smoother and optically brighter annual grassland. However, air temperature differences were seasonal. Smallest differences in potential air temperature occurred towards the end of spring, when much of the soil moisture reservoir was depleted. Largest differences in potential air temperature occurred during the winter rain season when the grass was green and transpiring and when the trees were senescent or deciduous. To understand the effect of land use on the local climate, we examined the concomitant changes in net radiation, sensible and latent heat exchange, the aerodynamic roughness (R a, the surface resistance to water transfer (R s, aerodynamic surface temperature and the growth of the planetary boundary layer, with measurements and model computations. Overall, these biophysical variables provide us with mechanistic information to diagnose and predict how changes in air temperature will follow changes in land use or management. In conclusion, land use change is responsible for having a marked impact on the local climate of a region. At the local level, the change in the surface energy balance, towards a darker and rougher surface, will produce an additive increment to climate warming induced by a greater greenhouse gas burden in the atmosphere.

  4. Surface Energy and Setting Process of Contacting Surfaces

    Directory of Open Access Journals (Sweden)

    M. V. Musokhranov

    2014-01-01

    Full Text Available The paper deals with a challenge in terms of ensuring an accuracy of the relative position of the conjugated surfaces that is to determine a coefficient of friction. To solve it, there is a proposal to use the surface energy, as a tool that influences the contacting parts nature. Presently, energy of the surface layers at best is only stated, but not used in practice.Analysis of the conditions of interaction between two contacting surfaces, such as seizing and setting cannot be explained only from the position of the roughness parameters. It is found that these phenomena are explained by the appearing gripe (setting bridges, which result from the energy of interaction between two or more adjacent surfaces. The emerging phenomenon such as micro welding, i.e. occurring bonds, is caused by the overflow of energy, according to the theory of physics, from the surface with a high level of energy to the surface with the smaller one to balance the system as a whole.The paper shows that through the use of process, controlling the depth of the surface layer and creating a certain structure, the energy level of the material as a whole can be specified. And this will allow us to provide the necessary performance and mechanical properties. It means to create as many gripe bridges as possible to ensure continuous positioning i.e. a fixed connection of the contacting surfaces.It was determined that to increase a value of the friction coefficient, the physical and mechanical properties of the surface layer of the parts material must be taken into account, namely, in the part body accumulate the energy to be consumed for forming the surface.The paper gives recommendations for including the parts of the surface energy in the qualitative indicators of characteristics. This will make a technologist, when routing a process, to choose such operations and modes to provide the designer-specified parameters not only of the accuracy and surface finish, but also of the

  5. The interactions between soil-biosphere-atmosphere (ISBA) land surface model multi-energy balance (MEB) option in SURFEXv8 - Part 2: Introduction of a litter formulation and model evaluation for local-scale forest sites

    Science.gov (United States)

    Napoly, Adrien; Boone, Aaron; Samuelsson, Patrick; Gollvik, Stefan; Martin, Eric; Seferian, Roland; Carrer, Dominique; Decharme, Bertrand; Jarlan, Lionel

    2017-04-01

    Land surface models (LSMs) need to balance a complicated trade-off between computational cost and complexity in order to adequately represent the exchanges of energy, water and matter with the atmosphere and the ocean. Some current generation LSMs use a simplified or composite canopy approach that generates recurrent errors in simulated soil temperature and turbulent fluxes. In response to these issues, a new version of the interactions between soil-biosphere-atmosphere (ISBA) land surface model has recently been developed that explicitly solves the transfer of energy and water from the upper canopy and the forest floor, which is characterized as a litter layer. The multi-energy balance (MEB) version of ISBA is first evaluated for three well-instrumented contrasting local-scale sites, and sensitivity tests are performed to explore the behavior of new model parameters. Second, ISBA-MEB is benchmarked against observations from 42 forested sites from the global micro-meteorological network (FLUXNET) for multiple annual cycles.It is shown that ISBA-MEB outperforms the composite version of ISBA in improving the representation of soil temperature, ground, sensible and, to a lesser extent, latent heat fluxes. Both versions of ISBA give comparable results in terms of simulated latent heat flux because of the similar formulations of the water uptake and the stomatal resistance. However, MEB produces a better agreement with the observations of sensible heat flux than the previous version of ISBA for 87.5 % of the simulated years across the 42 forested FLUXNET sites. Most of this improvement arises owing to the improved simulation of the ground conduction flux, which is greatly improved using MEB, especially owing to the forest litter parameterization. It is also shown that certain processes are also modeled more realistically (such as the partitioning of evapotranspiration into transpiration and ground evaporation), even if certain statistical performances are neutral. The

  6. Energy balance of the Sao Paulo State - 1990

    International Nuclear Information System (INIS)

    1992-01-01

    This document informs the energetic balance for Sao Paulo State - 1990, with information referring to the year 1989, containing the energy fluxes from primary and secondary energy sources in the main sectors of Sao Paulo economy. 32 figs., 99 tabs

  7. Provisional energy balance of France for 2002

    International Nuclear Information System (INIS)

    2003-01-01

    A provisional energy accounting in France for 2002 is presented. Statistical data and diagrams are provided to detail and discuss the economical and energy context, the primary energy consumption, the national production and the energy dependence, the primary energy consumption for each energy source, the sectorial analysis of the energy consumption and the carbon dioxide emissions. (A.L.B.)

  8. The energy cost for balance control during upright standing

    NARCIS (Netherlands)

    Houdijk, J.H.P.; Fickert, R.; van Velzen, J.; van Bennekom, C.A.M.

    2009-01-01

    The aim of this study was to investigate whether balance control during a static upright standing task with and without balance perturbations elicits a significant and meaningful metabolic energy demand and to test whether this energy demand correlates with conventional posturography measures for

  9. Cognitive determinants of energy balance-related behaviours : measurement issues

    NARCIS (Netherlands)

    Kremers, Stef P J; Visscher, Tommy L S; Seidell, Jacob C; van Mechelen, Willem; Brug, Johannes

    2005-01-01

    The burden of disease as a result of overweight and obesity calls for in-depth examination of the main causes of behavioural actions responsible for weight gain. Since weight gain is the result of a positive energy balance, these behavioural actions are referred to as 'energy balance-related

  10. Stomach regulates energy balance via acylated ghrelin and desacyl ghrelin

    OpenAIRE

    Asakawa, A; Inui, A; Fujimiya, M; Sakamaki, R; Shinfuku, N; Ueta, Y; Meguid, M M; Kasuga, M

    2005-01-01

    Background/Aims: The gastric peptide ghrelin, an endogenous ligand for growth-hormone secretagogue receptor, has two major molecular forms: acylated ghrelin and desacyl ghrelin. Acylated ghrelin induces a positive energy balance, while desacyl ghrelin has been reported to be devoid of any endocrine activities. The authors examined the effects of desacyl ghrelin on energy balance.

  11. Surface Meteorology and Solar Energy

    Data.gov (United States)

    National Aeronautics and Space Administration — Surface Meteorology and Solar Energy data - over 200 satellite-derived meteorology and solar energy parameters, monthly averaged from 22 years of data, global solar...

  12. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    Science.gov (United States)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

    Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions

  13. Brazilian energy balance 2013 - calendar year 2012: final report

    International Nuclear Information System (INIS)

    2013-01-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow: Chapter 1- Energy analysis and aggregated data- presents energy highlights per source in 2012 and analyses the evolution of the domestic energy supply and its relationship with economic growth in 2012; Chapter 2- Energy supply and demand by source- has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country; Chapter 3- Energy consumption by sector- presents the final energy consumption classified by primary and secondary source for each sector of the economy; Chapter 4- Energy imports and exports- presents the evolution of the data on the import and export of energy and the dependence on external energy; Chapter 5- Balance of transformation centers- presents the energy balances for the energy transformation centers including their losses; Chapter 6- Energy resources and reserves- has the basic concepts use in the survey of resources and reserves of primary energy sources; Chapter 7- Energy and socioeconomics- contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; Chapter 8- State energy data- presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential; Relating to annexes the current structure is presented bellow: Annex 1- Installed capacity- shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining; Annex 2- Self-production of electricity- presents disaggregated data of self-production, considering sources and sectors. Annex 3- World energy data- presents the main indicators for the production, import, export and consumption per energy source and region; Annex 4- Useful

  14. Brazilian energy balance 2014 - calendar year 2013: final report

    International Nuclear Information System (INIS)

    2014-01-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow: Chapter 1- Energy analysis and aggregated data- presents energy highlights per source in 2012 and analyses the evolution of the domestic energy supply and its relationship with economic growth in 2013; Chapter 2- Energy supply and demand by source- has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country; Chapter 3- Energy consumption by sector- presents the final energy consumption classified by primary and secondary source for each sector of the economy; Chapter 4- Energy imports and exports- presents the evolution of the data on the import and export of energy and the dependence on external energy; Chapter 5- Balance of transformation centers- presents the energy balances for the energy transformation centers including their losses; Chapter 6- Energy resources and reserves- has the basic concepts use in the survey of resources and reserves of primary energy sources; Chapter 7- Energy and socioeconomics- contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; Chapter 8- State energy data- presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential; Relating to annexes the current structure is presented bellow: Annex 1- Installed capacity- shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining.; Annex 2- Self-production of electricity- presents disaggregated data of self-production, considering sources and sectors. Annex 3- World energy data- presents the main indicators for the production, import, export and consumption per energy source and region; Annex 4- Useful

  15. Brazilian energy balance 2012 - calendar year 2011: final report

    International Nuclear Information System (INIS)

    2012-01-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow: Chapter 1- energy analysis and aggregated data- presents energy highlights per source in 2012 and analyses the evolution of the domestic energy supply and its relationship with economic growth in 2011; Chapter 2 - Energy supply and demand by source- has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country; Chapter 3 - Energy consumption by sector- presents the final energy consumption classified by primary and secondary source for each sector of the economy; Chapter 4 - Energy imports and exports- presents the evolution of the data on the import and export of energy and the dependence on external energy; Chapter 5 - Balance of transformation centers - presents the energy balances for the energy transformation centers including their losses; Chapter 6 - Energy resources and reserves- has the basic concepts use in the survey of resources and reserves of primary energy sources; Chapter 7- Energy and socioeconomics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; Chapter 8- State energy data- presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential; Relating to annexes the current structure is presented bellow: Annex 1- Installed capacity- shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining.; Annex 2- Self-production of electricity- presents disaggregated data of self-production, considering sources and sectors. Annex 3- World energy data- presents the main indicators for the production, import, export and consumption per energy source and region; Annex 4

  16. Serotonin and the regulation of mammalian energy balance.

    Directory of Open Access Journals (Sweden)

    Michael H Donovan

    2013-03-01

    Full Text Available Maintenance of energy balance requires regulation of the amount and timing of food intake. Decades of experiments utilizing pharmacological and later genetic manipulations have demonstrated the importance of serotonin signaling in this regulation. Much progress has been made in recent years in understanding how central nervous system serotonin systems acting through a diverse array of serotonin receptors impact feeding behavior and metabolism. Particular attention has been paid to mechanisms through which serotonin impacts energy balance pathways within the hypothalamus. How upstream factors relevant to energy balance regulate the release of hypothalamic serotonin is less clear, but work addressing this issue is underway. Generally, investigation into the central serotonergic regulation of energy balance has had a predominantly hypothalamocentric focus, yet nonhypothalamic structures that have been implicated in energy balance regulation also receive serotonergic innervation and express multiple subtypes of serotonin receptors. Moreover, there is a growing appreciation of the diverse mechanisms through which peripheral serotonin impacts energy balance regulation. Clearly, the serotonergic regulation of energy balance is a field characterized by both rapid advances and by an extensive and diverse set of central and peripheral mechanisms yet to be delineated.

  17. The Precession Index and a Nonlinear Energy Balance Climate Model

    Science.gov (United States)

    Rubincam, David

    2004-01-01

    A simple nonlinear energy balance climate model yields a precession index-like term in the temperature. Despite its importance in the geologic record, the precession index e sin (Omega)S, where e is the Earth's orbital eccentricity and (Omega)S is the Sun's perigee in the geocentric frame, is not present in the insolation at the top of the atmosphere. Hence there is no one-for-one mapping of 23,000 and 19,000 year periodicities from the insolation to the paleoclimate record; a nonlinear climate model is needed to produce these long periods. A nonlinear energy balance climate model with radiative terms of form T n, where T is surface temperature and n less than 1, does produce e sin (omega)S terms in temperature; the e sin (omega)S terms are called Seversmith psychroterms. Without feedback mechanisms, the model achieves extreme values of 0.64 K at the maximum orbital eccentricity of 0.06, cooling one hemisphere while simultaneously warming the other; the hemisphere over which perihelion occurs is the cooler. In other words, the nonlinear energy balance model produces long-term cooling in the northern hemisphere when the Sun's perihelion is near northern summer solstice and long-term warming in the northern hemisphere when the aphelion is near northern summer solstice. (This behavior is similar to the inertialess gray body which radiates like T 4, but the amplitude is much lower for the energy balance model because of its thermal inertia.) This seemingly paradoxical behavior works against the standard Milankovitch model, which requires cool northern summers (Sun far from Earth in northern summer) to build up northern ice sheets, so that if the standard model is correct it must be more efficient than previously thought. Alternatively, the new mechanism could possibly be dominant and indicate southern hemisphere control of the northern ice sheets, wherein the southern oceans undergo a long-term cooling when the Sun is far from the Earth during northern summer. The cold

  18. FOOD VERSUS BIOFUELS – AN ENERGY BALANCE APPROACH

    Directory of Open Access Journals (Sweden)

    Ionut PURICA

    2014-11-01

    Full Text Available In recent years the production of fuels for transportation has seen first an almost exponential increase then a sort of saturation given by the adverse effect on the agriculture of food products. Since both biofuels and agro products are expressed in energy units, we try here to make a balance in terms of energy units that are correlated to land surface available for food and biofuels in given economies e.g. the Romanian and the USA ones, such that to identify the optimal division of agricultural land to cover both the basic food needs and the biofuel ones. In this first approach food is measured in human daily energy intake converted to equivalent corn and biofuel is measured in the needed fuel for cars also converted in equivalent corn. These two corn quantities are then expressed in the land surface needed to cultivate them, followed by a dynamic analysis of the optimal partition between feeding the population and supplying the cars.

  19. Estimation of surface energy fluxes under complex terrain of Mt. Qomolangma over the Tibetan Plateau

    NARCIS (Netherlands)

    Chen, Xuelong; Su, Zhongbo; Ma, Y.; Yang, K.; Wang, B.

    2013-01-01

    Surface solar radiation is an important parameter in surface energy balance models and in estimation of evapotranspiration. This study developed a DEM based radiation model to estimate instantaneous clear sky solar radiation for surface energy balance system to obtain accurate energy absorbed by the

  20. Modeling Surface Energy Fluxes over a Dehesa (Oak Savanna Ecosystem Using a Thermal Based Two Source Energy Balance Model (TSEB II—Integration of Remote Sensing Medium and Low Spatial Resolution Satellite Images

    Directory of Open Access Journals (Sweden)

    Ana Andreu

    2018-04-01

    Full Text Available Dehesas are highly valuable agro-forestry ecosystems, widely distributed over Mediterranean-type climate areas, which play a key role in rural development, basing their productivity on a sustainable use of multiple resources (crops, livestock, wildlife, etc.. The information derived from remote sensing based models addressing ecosystem water consumption, at different scales, can be used by institutions and private landowners to support management decisions. In this study, the Two-Source Energy Balance (TSEB model is analyzed over two Spanish dehesa areas integrating multiple satellites (MODIS and Landsat for estimating water use (ET, vegetation ground cover, leaf area and phenology. Instantaneous latent heat (LE values are derived on a regional scale and compared with eddy covariance tower (ECT measurements, yielding accurate results (RMSDMODIS Las Majadas 44 Wm−2, Santa Clotilde RMSDMODIS 47 Wm−2 and RMSDLandsat 64 Wm−2. Daily ET(mm is estimated using daily return interval of MODIS for both study sites and compared with the flux measurements of the ECTs, with RMSD of 1 mm day−1 over Las Majadas and 0.99 mm day−1 over Santa Clotilde. Distributed ET over Andalusian dehesa (15% of the region is successfully mapped using MODIS images, as an approach to monitor the ecosystem status and the vegetation water stress on a regular basis.

  1. The surface energy of metals

    DEFF Research Database (Denmark)

    Vitos, Levente; Ruban, Andrei; Skriver, Hans Lomholt

    1998-01-01

    We have used density functional theory to establish a database of surface energies for low index surfaces of 60 metals in the periodic table. The data may be used as a consistent starting point for models of surface science phenomena. The accuracy of the database is established in a comparison...

  2. Windows with an improved energy balance of 30%

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe

    The aim of the project has been to investigate and to develop thermally improved windows based on an evaluation of the energy balance of the window, i.e. the total influence of the window on the energy consumption for space heating. The energy balance is the net heat flow per window area which...... carried out in the project. The large glass distance helps to reduce the traditional thermal bridge effect of the spacer and the integrated frame leads to an increase in transmitted solar energy. Furthermore, a controlled air exchange in case of pressure differences between the enclosures in the glazing...... means that both energy losses and transmittance of solar radiation is considered.The final goal of the project was to improve the energy balance of a window with at least 30%. As reference is chosen a common low energy glazing mounted in a wooden frame construction measuring 1188 × 1188 mm2...

  3. An energy balance model for the Greenland ice sheet

    NARCIS (Netherlands)

    Wal, R.S.W. van de; Oerlemans, J.

    1994-01-01

    The sensitivity of the mass balance of the Greenland Ice Sheet is studied by means of an energy balance model. The model calculates the shortwave and longwave radiation and the turbulent fluxes on a grid with a grid point spacing of 20 km. Special attention is given to the parameterization of the

  4. Provisional energy balance for the year 1998

    International Nuclear Information System (INIS)

    1999-01-01

    After a recall of the international and national economical context of 1998, this report makes a statement of the French energy consumption, demand, import and export during the year 1998. Details are given for primary energy (consumption, prices, national production, energy independence, energy shares in the consumption), and separately for coal, petroleum, natural gas and renewable energies. A sectoral analysis of the structure of the final consumption (industry, agriculture, residential-tertiary, transports) is presented in tables and the evolution of CO 2 emissions are briefly evoked (J.S.)

  5. Top 10 Research Questions Related to Energy Balance

    Science.gov (United States)

    Shook, Robin P.; Hand, Gregory A.; Blair, Steven N.

    2014-01-01

    Obesity is the result of a mismatch between the amount of calories consumed and the amount of calories expended during an extended period of time. This relationship is described by the energy balance equation, which states the rate of change in energy storage depots in the body are equal to the rate of energy intake minus the rate of energy…

  6. Energy balance of the Parana State - 1980-1994

    International Nuclear Information System (INIS)

    1995-01-01

    This document presents the energetic balance of Parana State - 1980/1994, including the energy fluxes from primary and secondary energy sources in the main sectors of Parana economy. It informs consumption, production and energy external dependence. 26 figs., 88 tabs

  7. A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity

    DEFF Research Database (Denmark)

    Stoy, Paul C.; Mauder, Matthias; Foken, Thomas

    2013-01-01

    The energy balance at most surface-atmosphere flux research sites remains unclosed. The mechanisms underlying the discrepancy between measured energy inputs and outputs across the global FLUXNET tower network are still under debate. Recent reviews have identified exchange processes and turbulent...... motions at large spatial and temporal scales in heterogeneous landscapes as the primary cause of the lack of energy balance closure at some intensively-researched sites, while unmeasured storage terms cannot be ruled out as a dominant contributor to the lack of energy balance closure at many other sites....... We analyzed energy balance closure across 173 ecosystems in the FLUXNET database and explored the relationship between energy balance closure and landscape heterogeneity using MODIS products and GLOBEstat elevation data. Energy balance closure per research site (CEB,s) averaged 0.84±0.20, with best...

  8. Preliminary approach of the MELiSSA loop energy balance

    Science.gov (United States)

    Poulet, Lucie; Lamaze, Brigitte; Lebrun, Jean

    Long duration missions, such as the establishment of permanent bases on the lunar surface or the travel to Mars, require a huge amount of life support consumables (e.g. food, water and oxygen). Current rockets are at the moment unable to launch such a mass from Earth. Consequently Regenerative Life Support Systems are necessary to sustain long-term manned space mission to increase recycling rates and so reduce the launched mass. Thus the European and Canadian research has been concentrating on the MELiSSA (Micro-Ecological Life Support System Alternative) project over the last 20 years. MELiSSA is an Environmental Controlled Life Support System (ECLSS), i.e. a closed regenerative loop inspired of a lake ecosystem. Using light as a source of energy, MELiSSA's goal is the recovery of food, water and oxygen from CO2 and organic wastes, using microorganisms and higher plants. The architecture of a ECLSS depends widely on the mission scenario. To compare several ECLSS architectures and in order to be able to evaluate them, ESA is developing a multi criteria evaluation tool: ALISSE (Advanced LIfe Support System Evaluator). One of these criteria is the energy needed to operate the ECLSS. Unlike other criteria like the physical mass, the energy criterion has not been investigated yet and needs hence a detailed analysis. It will consequently be the focus of this study. The main objective of the work presented here is to develop a dynamic tool able to estimate the energy balance for several configurations of the MELiSSA loop. The first step consists in establishing the energy balance using concrete figures from the MELiSSA Pilot Plant (MPP). This facility located at the Universitat Autonoma de Barcelona (UAB) is aimed at the ground demonstration of the MELiSSA loop. The MELiSSA loop is structured on several subsystems; each of them is characterized by supplies, exhausts and process reactions. For the purpose of this study (i.e. a generic tool) the solver EES (Engineering

  9. Energy balance from Bahia state 2011 - series: 1994-2010

    International Nuclear Information System (INIS)

    2011-01-01

    The present Energy Balance is constituted of six chapters, as follows: the chapter 1 approaches the profile of the energy system, showing the structure of the Bahia state energy matrix i n the year of 2010, and the modifications occurred during the period of 1994-2010; the chapter 2 analyses the evolution during the period of 1994-2010 of the energy offer with aspects of production, exports, imports and consumption; the chapter 3 comprised the evolution of energy consumption by sources and social-economic sectors; chapter 4 focus the evolution of state energy self-sufficiency, confronting the primary energy production with the energy total demand; the chapter 5 contains the balance of the energy transformation centers of the Bahia state; and the chapter 6 contains the consolidated matrixes expressed in the period of 1980, 1985 and 1990-2010

  10. Investigations of a Cost-Optimal Zero Energy Balance

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Nørgaard, Jesper; Heiselberg, Per

    2012-01-01

    The Net Zero Energy Building (Net ZEB) concept is worldwide recognised as a promising solution for decreasing buildings’ energy use. Nevertheless, a consistent definition of the Net ZEB concept is constantly under discussion. One of the points on the Net ZEB agenda is the zero energy balance......, in particular the types of energy use that should be included in it. Since the user perspective and the cost of energy-efficiency technologies is so crucial for the successful adaptation of energy-conservation solutions, such like the Net ZEB concept, this paper has deployed the Life Cycle Cost (LCC) analysis...... and taken a view point of private building owner to investigate what types of energy uses should be included in the cost-optimal zero energy balance. The analysis is conducted for five renewable energy supply systems and five user profiles with a study case of a multi-storey residential Net ZEB. The results...

  11. Energy balances of OECD countries 1970/1982

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The present volume provides standardized energy balance sheets expressed in a common unit of tons of oil equivalent for all OECD Countries. It covers the years 1970 to 1982 year by year and includes many revisions and additions to data previously published. The balances in the present volume are based on data published in OECD Energy Statistics 1971-1981 and OECD Energy Statistics 1981-1982. Tables for each OECD Country include production, import, export, consumption by the different industries, transportation, agriculture, residential sector of the different energies: solid fuels, petroleum, gas, nuclear power and hydroelectricity [fr

  12. Toward buildings with a positive energy balance

    International Nuclear Information System (INIS)

    Visier, Jean-Christophe

    2008-01-01

    As the results of the recent 'Grenelle of the Environment', which assembled French officials and organizations for a wide-ranging discussion of ecological issues, enter into application, buildings should gradually switch from being the foremost consumers of energy to becoming producers of energy. The stakes, technically, economically and socially, are enormous

  13. France's 2014 energy balance

    International Nuclear Information System (INIS)

    Cadin, Didier; Collet, Isabelle; Delamare, Karine; Dussud, Francois-Xavier; Gong, Zheng; Hagege, Claire; Lauverjat, Jean; Lepoittevin, Daniel; Louati, Sami; Martin, Jean-Philippe; Misak, Evelyne; Reynaud, Didier; Rouquette, Celine; Wong, Florine; Monnoyer-Smith, Laurence; Mordant, Guillaume; Bottin, Anne; Reperant, Patricia; Grosset, Catherine

    2015-07-01

    2014 was the warmest year since 1900 in France and in the rest of the world. In particular, the mild winter led to heating needs 7 million tonnes of oil equivalent (Mtoe) lower than the needs in an average year. Real primary energy consumption fell below the symbolic 250 Mtoe level, a low it had not reached since 1995. Although energy demand decreased, national primary energy production increased for the second year running, reaching 139 Mtoe, a little over 1 Mtoe higher than in 2013. This rise in production is explained by nuclear generated electricity. The 2014 physical trade deficit for energy therefore decreased significantly, by 10 Mtoe, to below 114 Mtoe. Such a low level had not been observed since 1988. The level of energy self-sufficiency rose sharply in 2014, to 55.8%, a level not hitherto reached. The decrease in net energy imports was accompanied by a drop in quoted prices for energy products on the European and international markets. As a result, France's energy bill was 17% lower than in 2013. At around euro 55 billion, it fell to a level close to that of the early 1980s. Even excluding the effects of the higher temperatures in 2014, thereby adjusting for climate variations, primary energy went from 275 Mtoe - its maximum, reached in 2005 - to 257 Mtoe, with an average annual decrease of -2 Mtoe, confirming the downward trend initiated in the mid-2000's. Final energy consumption was 150 Mtoe in 2014, the lowest level since 1996. It decreased by a little more than 1% in relation to 2013, with reductions in all sectors except for transport, where consumption remained stable

  14. Biomass energy and the global carbon balance

    International Nuclear Information System (INIS)

    Hall, D.O.; House, J.I.

    1994-01-01

    Studies on climate change and energy production increasingly recognise the crucial role of biological systems. Carbon sinks in forests (above and below ground), CO 2 emissions from deforestation, planting trees for carbon storage, and biomass as a substitute for fossil fuels are some of the key issues which arise. Halting deforestation is of paramount importance, but there is also great potential for reforestation of degraded lands, agroforestry and improved forest management. It is concluded that biomass energy plantations and other types of energy cropping could be a more effective strategy for carbon mitigation than simply growing trees as a carbon store, particularly on higher productivity lands. Use of the biomass produced as an energy source has the added advantage of a wide range of other environmental, social and economic benefits. (author)

  15. Introduction to energy balance of biomass production; Introduccion al calculo del balance energetico de la produccion de Biomasa

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares, P.

    1997-11-01

    During last years, energy crops have been envisaged as an interesting alternative to biomass residues utilization as renewable energy source. In this work, main parameters used in calculating the energy balance of an energy crop are analyzed. The approach consists of determining energy equivalents for the different inputs and outputs of the process, thus obtaining energy ratios of the system, useful to determine if the energy balance is positive, that is, if the system generates energy. Energy costs for inputs and assessment approaches for energy crop yields (output) are provided. Finally, as a way of illustration, energy balances of some representative energy crops are shown. (Author) 15 refs.

  16. National energy balance 1979-1998 Chile

    International Nuclear Information System (INIS)

    1998-01-01

    The present document summarizes the historic document related to energy production, transformation and consumption in the country between 1979 and 1998. The manner the figures are presented allows their usage for diverse analyses. Certain modifications have been added to this introduction according to the suggestions received due to the publication of the 1977-1996 statement. This work will be periodically updated, including possible new energy sources as well as new consumption sectors

  17. National energy balance - 1977-1996 - Chile

    International Nuclear Information System (INIS)

    1997-01-01

    The present document summarizes the historic document related to energy production, transformation and consumption in the country between 1977 and 1996. The manner the figures are presented allows their usage for diverse analyses. Certain modifications have been added to this introduction according to the suggestions received due to the publication of the 1975-1994 statement. This work will be periodically updated, including possible new energy sources as well as new consumption sectors

  18. National energy balance - 1977-1996 - Chile

    International Nuclear Information System (INIS)

    1997-01-01

    The present document summarizes the historic document related to energy production, transformation and consumption in the country between 1977 and 1996. The manner the figures are presented allows their usage for diverse analyses. Certain modifications have been added to this introduction according to the suggestions received due to the publication of the 1975-1994 statement. This work will be periodically updated, including possible new energy sources as well as new consumption sectors. (author)

  19. Brazilian energy balance 2015: year 2014 - final report

    International Nuclear Information System (INIS)

    2015-01-01

    The Balance (BEB) contains the accounting relative to energy supply and consumption, as well the conversion processes and foreign trade. It presents in a single document the historical series of these operations and information about reserves, installed capacities and Federal States data. The BEB is divided into eight chapters and ten annexes, whose contents are as follow. Chapters' content can be described as follows: Chapter 1 - Energy Analysis and Aggregated Data - presents energy highlights per source in 2014 and analyses the evolution of the domestic energy supply and its relationship with economic growth. Chapter 2 - Energy Supply and Demand by Source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country. Chapter 3 - Energy Consumption by Sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy. Chapter 4 - Energy Imports and Exports - presents the evolution of the data on the import and export of energy and the dependence on external energy. Chapter 5 - Balance of Transformation Centers - presents the energy balances for the energy transformation centers including their losses. Chapter 6 - Energy Resources and Reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources. Chapter 7 - Energy and Socio economics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports. Chapter 8 - State Energy Data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. Relating to annexes the current structure is presented bellow: Annex I - Installed Capacity - shows the installed capacity of electricity generation, the installed

  20. Greenhouse gas balances of biomass energy systems

    International Nuclear Information System (INIS)

    Marland, G.; Schlamadinger, B.

    1996-01-01

    A full energy-cycle analysis of greenhouse gas emissions of biomass energy systems requires analysis well beyond the energy sector. For example, production of biomass fuels impacts on the global carbon cycle by altering the amount of carbon stored in the biosphere and often by producing a stream of by-products or co-products which substitute for other energy-intensive products like cement, steel, concrete or, in case of ethanol form corn, animal feed. It is necessary to distinguish between greenhouse gas emissions associated with the energy product as opposed to those associated with other products. Production of biomass fuels also has an opportunity cost because it uses large land areas which could have been used otherwise. Accounting for the greenhouse gas emissions from biomass fuels in an environment of credits and debits creates additional challenges because there are large non-linearities in carbon flows over time. This paper presents some of the technical challenges of comprehensive greenhouse gas accounting and distinguishes between technical and public policy issues. (author). 5 refs, 5 figs

  1. Greenhouse gas balances of biomass energy systems

    International Nuclear Information System (INIS)

    Marland, G.; Schlamadinger, B.

    1994-01-01

    A full energy-cycle analysis of greenhouse gas emissions of biomass energy systems requires analysis well beyond the energy sector. For example, production of biomass fuels impacts on the global carbon cycle by altering the amount of carbon stored in the biosphere and often by producing a stream of by-products or co-products which substitute for other energy-intensive products like cement, steel, concrete or, in case of ethanol from corn, animal feed. It is necessary to distinguish between greenhouse gas emissions associated with the energy product as opposed to those associated with other products. Production of biomass fuels also has an opportunity cost because it uses large land areas which could have been used otherwise. Accounting for the greenhouse gas emissions from biomass fuels in an environment of credits and debits creates additional challenges because there are large nonlinearities in the carbon flows over time. This paper presents some of the technical challenges of comprehensive greenhouse gas accounting and distinguishes between technical and public policy issues

  2. Nuclear energy: A balance of power

    International Nuclear Information System (INIS)

    1992-01-01

    The Forum was attended by public information officers of the Member States' atomic energy commissions and agencies; public relations and information representatives of the international nuclear industry, including vendors, utilities and information dispersal groups; scientific societies; and trade associations. The Forum provided an international opportunity for those working in nuclear energy public information programmes to learn from one another, and to exchange ideas and methods on how best to demystify this form of energy and reach the public for better general understanding of the issues involved. The described report of the Forum consists of two parts. One is designed to represent the conclusions, recommendations and specific activities from the strategy sessions. It is followed by examples provided by the participants. An individual section is intended as a ready resources for up-to-date information on non-proliferation and radiation and health. A separate abstract was prepared for each of the presentations

  3. Energy balance in coherent electromagnetic radiation

    CERN Document Server

    Coisson, R

    1994-01-01

    Bunched charges, as in the 'free electron laser', radiate more energy than unbunched ones. For a better understanding of how the forces between particles determine the conservation of energy, we take the simple model of two charges within a wavelength of a sinusodoidal wave, and show that the relative phase of the particle's motion with respect to the wave is modified by the force between the two particles, and this explains the extra work done by the wave. The phase shift is proportional to the emitted field and depends on the retardation (particle distance divided by speed of light), and turns out to be independent of distance. (author)

  4. On the measurement of the surface energy budget over a land ...

    Indian Academy of Sciences (India)

    The measurement of surface energy balance over a land surface in an open area in Bangalore is reported. Measurements of all variables needed to calculate the surface energy balance on time scales longer than a week are made. Components of radiative fluxes are measured while sensible and latent heat fluxes are ...

  5. Energy balance of the Sao Paulo State - 1995

    International Nuclear Information System (INIS)

    1996-01-01

    This work informs the energetic balance of Sao Paulo State - 1995, with information referring to the year 1994, containing the energy fluxes from primary and secondary energy sources in the main sectors of Sao Paulo economy. An electronic version for windows environment is also available. 81 figs., 179 tabs

  6. Energy balance evaluation of industrial buildings with an office complex

    Directory of Open Access Journals (Sweden)

    Juozas Bielskus

    2015-10-01

    Full Text Available While evaluating the energy savings potential in buildings of different function we face the energy balance of current situation evaluation problem. Generally the data of energy flows quantities and the nature of their dynamics are agregated and do not reflect the indicators of the achieved microclimate. Therefore this article analyses the energy balance following the example of one-year data collection analysis in a company’s building complex. The investigated problem is evaluated by the system analysis approach, i.e. the analysed object system is divided into separate subsystems which have been simulated individually but considering the subsystems joint relations in the system. The methods applied in this work are heat and mass balance of separate subsystems and statistical analysis method. The statistical analysis was used for the evaluation of the statistical reliability of the accumulated indicators (temperature, relative humidity, etc..

  7. Sustainable urban regeneration based on energy balance

    NARCIS (Netherlands)

    Van Timmeren, A.; Zwetsloot, J.; Brezet, H.; Silvester, S.

    2012-01-01

    In this paper, results are reported of a technology assessment of the use and integration of decentralized energy systems and storage devices in an urban renewal area. First the general context of a different approach based on 'rethinking' and the incorporation of ongoing integration of coming

  8. Net Balanced Floorplanning Based on Elastic Energy Model

    DEFF Research Database (Denmark)

    Liu, Wei; Nannarelli, Alberto

    2008-01-01

    Floorplanning is becoming more and more important in VLSI design flows, especially for system-on-chip (SoC) designs where IP blocks dominate standard cells. Moreover, in deep sub-micron technologies, where process variations can introduce extra signal skew, it is desirable to have floorplans...... with balanced net delays to increase the safety margins of the design. In this paper, we investigate the properties of floorplanning based on the elastic energy model. The B*-tree, which is based on an ordered binary tree, is used for circuit representation and the elastic energy is used as the cost function....... To evaluate how well a net is balanced, we introduced a new metric 'unbalancing'. A more balanced net would have a smaller 'unbalancing' value. Experimental results show that our approach can not only meet fixed-outline constraints, but also achieve significant improvements in net balance for all the circuits...

  9. Development of Energy Balances for the State of California

    Energy Technology Data Exchange (ETDEWEB)

    Murtishaw, Scott; Price, Lynn; de la Rue du Can, Stephane; Masanet, Eric; Worrell, Ernst; Sahtaye, Jayant

    2005-12-01

    Analysts assessing energy policies and energy modelers forecasting future trends need to have access to reliable and concise energy statistics. Lawrence Berkeley National Laboratory evaluated several sources of California energy data, primarily from the California Energy Commission and the U.S. Energy Information Administration, to develop the California Energy Balance Database (CALEB). This database manages highly disaggregated data on energy supply, transformation, and end-use consumption for each type of energy commodity from 1990 to the most recent year available (generally 2001) in the form of an energy balance, following the methodology used by the International Energy Agency. This report presents the data used for CALEB and provides information on how the various data sources were reconciled. CALEB offers the possibility of displaying all energy flows in numerous ways (e.g.,physical units, Btus, petajoules, different levels of aggregation), facilitating comparisons among the different types of energy commodities and different end-use sectors. In addition to displaying energy data, CALEB can also be used to calculate state-level energy-related carbon dioxide emissions using the methodology of the Intergovernmental Panel on Climate Change.

  10. National energy balance - 1995 of Brazil. Based on 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Consolidated data of production, consumption and external dependence of energy are presented, as also the sectorial composition of the consumption of the different groups of energy sources. For each primary and secondary source the production, import, export, variations in inventories, losses, adjustments and total consumption are analyzed. Balances of transformation centers, characterizing the energy the energy processed, the energy produced and the respective losses in transformation are shown. Finally energy resources and reserves of primary sources are described with respective methodologies for estimating them. 60 figs., 107 tabs.

  11. National energy balance - 1995 of Brazil. Based on 1994

    International Nuclear Information System (INIS)

    1995-01-01

    Consolidated data of production, consumption and external dependence of energy are presented, as also the sectorial composition of the consumption of the different groups of energy sources. For each primary and secondary source the production, import, export, variations in inventories, losses, adjustments and total consumption are analyzed. Balances of transformation centers, characterizing the energy the energy processed, the energy produced and the respective losses in transformation are shown. Finally energy resources and reserves of primary sources are described with respective methodologies for estimating them. 60 figs., 107 tabs

  12. Energy balance in high-power CO2 laser welding

    Science.gov (United States)

    Del Bello, Umberto; Rivela, Cristina; Cantello, Maichi; Penasa, Mauro

    1991-10-01

    The laser energy impinging on a metal workpiece is partially absorbed and partially reflected by the material surface. This work is aimed at gaining a better insight into the energy balance of the process, and it can also provide the correct input for process modeling and the optimum choice of parameters for increasing welding efficiency. Measurements of the absorption coefficient were made using platinum-platinum rhodium thermocouples which monitored the temperature rise. The radiation backscattered by the workpiece or plasma plume was also recorded, and tests were performed to measure the total amount of material lost by evaporation during laser welding. All the tests were performed on austenitic stainless steel. The resulting absorption curves show different behavior at low or high speed and this can be explained only by taking into account the influence on the process of both the size and inclination of the keyhole. To conserve the keyhole, the interaction process must be rapidly interrupted so as to freeze the molten material and preserve the cavity in the form assumed during the process. A fast mechanical switch has been devised and tests seem to confirm the assumption made.

  13. International bioenergy transport costs and energy balance

    International Nuclear Information System (INIS)

    Hamelinck, Carlo N.; Suurs, Roald A.A.; Faaij, Andre P.C.

    2005-01-01

    To supply biomass from production areas to energy importing regions, long-distance international transport is necessary, implying additional logistics, costs, energy consumption and material losses compared to local utilisation. A broad variety of bioenergy chains can be envisioned, comprising different biomass feedstock production systems, pre-treatment and conversion operations, and transport of raw and refined solid biomass and liquid bio-derived fuels. A tool was developed to consistently compare the possible bioenergy supply chains and assess the influence of key parameters, such as distance, timing and scale on performance. Chains of European and Latin American bioenergy carriers delivered to Western Europe were analysed using generic data. European biomass residues and crops can be delivered at 90 and 70 euros/tonne dry (4.7 and 3.7 euros/GJ HHV ) when shipped as pellets. South American crops are produced against much lower costs. Despite the long shipping distance, the costs in the receiving harbour can be as low as 40 euros/tonne dry or 2.1 euros/GJ HHV ; the crop's costs account for 25-40% of the delivered costs. The relatively expensive truck transport from production site to gathering point restricts the size of the production area; therefore, a high biomass yield per hectare is vital to enable large-scale systems. In all, 300 MW HHV Latin American biomass in biomass integrated gasification/combined cycle plants may result in cost of electricity as little as 3.5 euros cent/kWh, competitive with fossil electricity. Methanol produced in Latin America and delivered to Europe may cost 8-10 euros/GJ HHV , when the pellets to methanol conversion is done in Europe the delivered methanol costs are higher. The energy requirement to deliver solid biomass from both crops and residues from the different production countries is 1.2-1.3 MJ primary /MJ delivered (coal ∼ 1.1 MJ/MJ). International bioenergy trade is possible against low costs and modest energy loss

  14. The energy balance within a bubble column evaporator

    Science.gov (United States)

    Fan, Chao; Shahid, Muhammad; Pashley, Richard M.

    2018-05-01

    Bubble column evaporator (BCE) systems have been studied and developed for many applications, such as thermal desalination, sterilization, evaporative cooling and controlled precipitation. The heat supplied from warm/hot dry bubbles is to vaporize the water in various salt solutions until the solution temperature reaches steady state, which was derived into the energy balance of the BCE. The energy balance and utilization involved in each BCE process form the fundamental theory of these applications. More importantly, it opened a new field for the thermodynamics study in the form of heat and vapor transfer in the bubbles. In this paper, the originally derived energy balance was reviewed on the basis of its physics in the BCE process and compared with new proposed energy balance equations in terms of obtained the enthalpy of vaporization (Δ H vap) values of salt solutions from BCE experiments. Based on the analysis of derivation and Δ H vap values comparison, it is demonstrated that the original balance equation has high accuracy and precision, within 2% over 19-55 °C using improved systems. Also, the experimental and theoretical techniques used for determining Δ H vap values of salt solutions were reviewed for the operation conditions and their accuracies compared to the literature data. The BCE method, as one of the most simple and accurate techniques, offers a novel way to determine Δ H vap values of salt solutions based on its energy balance equation, which had error less than 3%. The thermal energy required to heat the inlet gas, the energy used for water evaporation in the BCE and the energy conserved from water vapor condensation were estimated in an overall energy balance analysis. The good agreement observed between input and potential vapor condensation energy illustrates the efficiency of the BCE system. Typical energy consumption levels for thermal desalination for producing pure water using the BCE process was also analyzed for different inlet air

  15. The energy balance within a bubble column evaporator

    Science.gov (United States)

    Fan, Chao; Shahid, Muhammad; Pashley, Richard M.

    2017-11-01

    Bubble column evaporator (BCE) systems have been studied and developed for many applications, such as thermal desalination, sterilization, evaporative cooling and controlled precipitation. The heat supplied from warm/hot dry bubbles is to vaporize the water in various salt solutions until the solution temperature reaches steady state, which was derived into the energy balance of the BCE. The energy balance and utilization involved in each BCE process form the fundamental theory of these applications. More importantly, it opened a new field for the thermodynamics study in the form of heat and vapor transfer in the bubbles. In this paper, the originally derived energy balance was reviewed on the basis of its physics in the BCE process and compared with new proposed energy balance equations in terms of obtained the enthalpy of vaporization (ΔH vap) values of salt solutions from BCE experiments. Based on the analysis of derivation and ΔH vap values comparison, it is demonstrated that the original balance equation has high accuracy and precision, within 2% over 19-55 °C using improved systems. Also, the experimental and theoretical techniques used for determining ΔH vap values of salt solutions were reviewed for the operation conditions and their accuracies compared to the literature data. The BCE method, as one of the most simple and accurate techniques, offers a novel way to determine ΔH vap values of salt solutions based on its energy balance equation, which had error less than 3%. The thermal energy required to heat the inlet gas, the energy used for water evaporation in the BCE and the energy conserved from water vapor condensation were estimated in an overall energy balance analysis. The good agreement observed between input and potential vapor condensation energy illustrates the efficiency of the BCE system. Typical energy consumption levels for thermal desalination for producing pure water using the BCE process was also analyzed for different inlet air

  16. Impact of Energy Losses Due to Failures on Photovoltaic Plant Energy Balance

    OpenAIRE

    Isidoro Lillo-Bravo; Pablo González-Martínez; Miguel Larrañeta; José Guasumba-Codena

    2018-01-01

    Photovoltaic (PV) plant failures have a significant influence on PV plant security, reliability, and energy balance. Energy losses produced by a PV plant are due to two large causes: failures and inefficiencies. Knowing the relative influence of energy losses due to failures and energy losses due to inefficiencies on the PV plant energy balance contribute to the optimization of its design, commissioning, and maintenance tasks. This paper estimates the failure rates, grouped by components, and...

  17. Support Surface and Attention Focus Effects on Elderly Balance

    Directory of Open Access Journals (Sweden)

    Mohsen Sarhadi

    2008-10-01

    Full Text Available Objectives: Verbal instructions related to directing the focus of attention to the movement itself or to its effects on or outcomes in the environment affects learning and performing movement skills. The pattern of these effects differs with increase in task difficulty. The goal of this study was to explore the effects of support surface and attention focus on the balance in elderly. Methods & Materials: Twenty-eight elderly (65 & older with a history of one or more falls in the last year were participated in the study. The design of the study was two factors within group with repeated measures. Participants were tested in two conditions of moving and stable support surface and three conditions of baseline, internal, and external focus of attention. Results: Difference in support surface from stable to moving (i.e. increasing task difficulty generally decreased the level of performance. There was a strong interaction between conditions off support surface and conditions of attention focus (P<0.001. The maximum decrease in performance happened in internal focus of attention/moving support surface and the minimum decrease occurred in external focus of attention/moving support surface. Conclusion: The effectiveness of the external focus of attention was most significant and more beneficial to the balance performance in the moving unstable support surface (increased task difficulty than other conditions of attention focus. The interesting finding was that not instructing at all is more effective on balance performance than internal focus of attention instruction in elderly people with a history of falling.

  18. Energy balance at a crossroads: translating the science into action.

    Science.gov (United States)

    Manore, Melinda M; Brown, Katie; Houtkooper, Linda; Jakicic, John; Peters, John C; Smith Edge, Marianne; Steiber, Alison; Going, Scott; Gable, Lisa Guillermin; Krautheim, Ann Marie

    2014-07-01

    One of the major challenges facing the United States is the high number of overweight and obese adults and the growing number of overweight and unfit children and youth. To improve the nation's health, young people must move into adulthood without the burden of obesity and its associated chronic diseases. To address these issues, the American College of Sports Medicine, the Academy of Nutrition and Dietetics, and the US Department of Agriculture/Agriculture Research Service convened an expert panel meeting in October 2012 titled "Energy Balance at a Crossroads: Translating the Science into Action." Experts in the fields of nutrition and exercise science came together to identify the biological, lifestyle, and environmental changes that will most successfully help children and families attain and manage energy balance and tip the scale toward healthier weights. Two goals were addressed: 1) professional training and 2) consumer/community education. The training goal focused on developing a comprehensive strategy to facilitate the integration of nutrition and physical activity (PA) using a dynamic energy balance approach for regulating weight into the training of undergraduate and graduate students in dietetics/nutrition science, exercise science/PA, and pre-K-12 teacher preparation programs and in training existing cooperative extension faculty. The education goal focused on developing strategies for integrating dynamic energy balance into nutrition and PA educational programs for the public, especially programs funded by federal/state agencies. The meeting expert presenters and participants addressed three key areas: 1) biological and lifestyle factors that affect energy balance, 2) undergraduate/graduate educational and training issues, and 3) best practices associated with educating the public about dynamic energy balance. Specific consensus recommendations were developed for each goal.

  19. Fat intake and energy-balance effects.

    Science.gov (United States)

    Westerterp-Plantenga, M S

    2004-12-30

    This paper focuses on the effects of dietary fats or fatty acids on key targets of metabolic intermediates for body-weight control, i.e. satiety, thermogenesis, fat oxidation and body composition. With respect to sensory satiety, it appeared, e.g. that linoleic acid tasters showed a different mechanism for meal termination than non-tasters did. They stopped eating linoleic acid containing food based upon satiety, whereas the non-tasters stopped eating based upon the change in pleasantness of taste. Moreover, in the normal range of body mass index, an inverse relationship was shown between % 'tasters' and BMI. In a high fat diet vs. a low fat high protein high carbohydrate diet, metabolic satiety appeared to be continuously lower and correlated positively to diet-induced energy expenditure. However, with respect to the intermeal interval, satiety appeared to be more sustained following a high fat vs. a high CHO preload, resulting in a lower meal frequency. Covert fat replacement during breakfast by sucrose polyester was successful in combination with dietary restraint, yet overt fat replacement in snacks was successful in the dietary-unrestrained subjects, i.e. those who habitually ate snacks. With respect to fat oxidation, from a respiration-chamber experiment on the effects of diacylglycerol compared (DG) to triacylglycerol (TG) intake, it was concluded that consumption of DG increased fat oxidation and beta-hydroxy-butyrate levels, but did not affect energy metabolism or triacylglycerol level. Parameters of appetite were all lowered by DG compared to TG. With respect to body composition, the effects of 13 weeks CLA supplementation in overweight subjects during weight regain were assessed. Although CLA did not affect %body-weight regain, the regain of fat-free mass was increased by CLA, independently of %body-weight regain and physical activity, and as a consequence resting metabolic rate was increased. At the same time, appetite was reduced and satiety and

  20. Endocrine-disrupting chemicals and the regulation of energy balance.

    Science.gov (United States)

    Nadal, Angel; Quesada, Ivan; Tudurí, Eva; Nogueiras, Rubén; Alonso-Magdalena, Paloma

    2017-09-01

    Energy balance involves the adjustment of food intake, energy expenditure and body fat reserves through homeostatic pathways. These pathways include a multitude of biochemical reactions, as well as hormonal cues. Dysfunction of this homeostatic control system results in common metabolism-related pathologies, which include obesity and type 2 diabetes mellitus. Metabolism-disrupting chemicals (MDCs) are a particular class of endocrine-disrupting chemicals that affect energy homeostasis. MDCs affect multiple endocrine mechanisms and thus different cell types that are implicated in metabolic control. MDCs affect gene expression and the biosynthesis of key enzymes, hormones and adipokines that are essential for controlling energy homeostasis. This multifaceted spectrum of actions precludes compensatory responses and favours metabolic disorders. Herein, we review the main mechanisms used by MDCs to alter energy balance. This work should help to identify new MDCs, as well as novel targets of their action.

  1. Energy balance and deformation mechanisms of duplexes

    Science.gov (United States)

    Mitra, Gautam; Boyer, Steven E.

    A duplex consists of a series of imbricate faults that are asymptotic to a roof thrust and a floor thrust. Depending on the final orientations of the imbricate faults and the final position of the branch lines, a duplex may be hinterland-dipping, foreland-dipping, or an antiformal stack. The exact geometry depends on various factors such as the initial dimensions of the individual slices (horses), their lithology, the amount of displacement (normalized to size of horse) on each fault, and the mechanics of movement along each fault. The energy required in duplex formation can be determined by calculating the total work involved in emplacing each horse: this is given by where W t=W p+W b+W g+W iWp is the work involved in initiating and propagating a fracture. Wb is the work involved in basal sliding, which may be frictional or some form of ductile flow, Wg is the work done against gravity during the emplacement of the horse, and Wi is the work involved in the internal deformation of the horse. By calculating and comparing these work terms it is possible to predict the conditions under which the different types of duplexes will form. Normally, the development of a hinterland-dipping duplex is most likely. However, if deformation conditions are favorable, displacements on individual imbricate faults may be very large compared to the size of the horses, leading to the formation of either antiformal stacks or foreland-dipping duplexes.

  2. Balancing the supply mix to meet tomorrow's energy needs

    International Nuclear Information System (INIS)

    Wiggin, M.

    2004-01-01

    This presentation emphasized the need to balance the power supply mix to ensure future energy needs. A balanced supply includes generation supply options that include renewable energy sources, natural gas, oil or coal. The role of combined heat and power (CHP) and district energy in this supply mix is considered to be a potential generation solution. The challenge facing Ontario's Independent Electricity Market Operator (IMO) is to balance supply and demand, phase out coal, promote renewables, diminish demand and determine the new role for natural gas. A graph by the National Energy Board depicting Canada's energy future and scenarios for supply and demand to 2025 indicates that gas yields from the Western Canada Sedimentary Basin are declining. It is expected that with growing demands for natural gas, prices will remain high and there will be a need for new generation capacity. The viable options for energy supply include a re-examination of the district energy advantage through industrial waste heat, biomass and other renewables, and the integration of industrial and community energy systems. Other options include the continued recognition of distributed generation in the form of combined heat and power. 4 figs

  3. The Spanish Wind Energy Market. Balance and Outlooks; El Mercado Eolico Espanol. Balance y Perspectivas

    Energy Technology Data Exchange (ETDEWEB)

    Varela, M. [CIEMAT. Madrid (Spain)

    1999-06-01

    The present work accomplishes a revision to the situation of the wind market in Spain, its recent evolution, its regional distribution, the principal actors of the market (manufacturers, promoters). The balance includes a review of the programs of institutional support to wind energy, an analysis of the current installation costs and electricity production costs. Finally, other variables related the integration of wind energy are analysed, as the potential of employment generation or the associated environmental factors. (Author) 5 refs.

  4. Energy expenditure and balance during spaceflight on the space shuttle

    Science.gov (United States)

    Stein, T. P.; Leskiw, M. J.; Schluter, M. D.; Hoyt, R. W.; Lane, H. W.; Gretebeck, R. E.; LeBlanc, A. D.

    1999-01-01

    The objectives of this study were as follows: 1) to measure human energy expenditure (EE) during spaceflight on a shuttle mission by using the doubly labeled water (DLW) method; 2) to determine whether the astronauts were in negative energy balance during spaceflight; 3) to use the comparison of change in body fat as measured by the intake DLW EE, 18O dilution, and dual energy X-ray absorptiometry (DEXA) to validate the DLW method for spaceflight; and 4) to compare EE during spaceflight against that found with bed rest. Two experiments were conducted: a flight experiment (n = 4) on the 16-day 1996 life and microgravity sciences shuttle mission and a 6 degrees head-down tilt bed rest study with controlled dietary intake (n = 8). The bed rest study was designed to simulate the flight experiment and included exercise. Two EE determinations were done before flight (bed rest), during flight (bed rest), and after flight (recovery). Energy intake and N balance were monitored for the entire period. Results were that body weight, water, fat, and energy balance were unchanged with bed rest. For the flight experiment, decreases in weight (2.6 +/- 0.4 kg, P balance of 1,355 +/- 80 kcal/day (-15. 7 +/- 1.0 kcal. kg-1. day-1, P body fat, which was within experimental error of the fat loss determined by 18O dilution (-1.4 +/- 0.5 kg) and DEXA (-2.4 +/- 0.4 kg). All three methods showed no change in body fat with bed rest. In conclusion, 1) the DLW method for measuring EE during spaceflight is valid, 2) the astronauts were in severe negative energy balance and oxidized body fat, and 3) in-flight energy (E) requirements can be predicted from the equation: E = 1.40 x resting metabolic rate + exercise.

  5. Power and energy balances, today and three years ahead

    International Nuclear Information System (INIS)

    Borg, Trygve; Maula, H.; Pedersen, Jens; Soendergren, C.; Waegelund, G.; Granlund, K.

    2003-06-01

    Energy scenario 2006: In normal conditions the Nordel system is balancing well. It is expected that the Nordel system will cope with a single dry year situation. if a year with extreme low hydropower production or a combination of two dry years in succession occurs, the result may be a very serious balance deficit. For part of the Nordel system it is possible that market cannot solve the problem and the situation will demand various forms of rationing or other measures. Power balance winter peak demand 2006/07: During a normal winter, peak demand will be handled without difficulties. If a ten years winter occurs the power balance is expected to come under strain and the Nordic power system is dependent on import from Europe via strong interconnections. The forecast shows that there probably is enough production capacity and import possibilities from countries outside Nordel. (BA)

  6. Provincial Energy Balance Analysis: Karabük Sample

    Directory of Open Access Journals (Sweden)

    Seyfi ŞEVİK

    2017-12-01

    Full Text Available The purpose of this study; to reveal the energy supply-demand balance of the Karabük province, to evaluate their overall trends and the share of brown and green energy in the balance and to create an energy flowchart. Karabük province has an installed capacity of 122 MW with 4 licensed and 1 unlicensed power plants. It is carried out about 530 GWh of electricity generation annually. With this generation, 45% of own electricity consumption can be met. Ratio of Karabük electricity installed capacity to installed capacity of Turkey is 0.17%, it's ratio is 0.21% to consumption in Turkey. While share in the total installed capacity of renewable energy is 58.8%, the share in total energy generation is 32%. Karabük haven't energy resources however, fossil fuel consumption is also very high. Province of Karabük is characterized by a heavy exploitation of non-domestic energy resources. Karabük does not have sufficient energy sources. Effective energy efficiency programs and renewable energy can reduce country's reliance on non-domestic energy sources.

  7. Surface energy of explosive nanoparticles

    Science.gov (United States)

    Pineau, Nicolas; Bidault, Xavier; Soulard, Laurent

    2017-06-01

    Recent experimental studies show that nanostructuration has a substantial impact on the detonation of high explosives: a nanostructured one leads to smaller nanodiamonds than a microstructured one. Whether it comes from a higher surface energy or from porosity, the origin of these different behaviors must be investigated. The surface energy of TATB nanoparticles with a radius from 2 nm upto 60 nm has been determined by means of ReaxFF-based simulations. Then, using the Rankine-Hugoniot relations and the equation of states of the bulk material, the contribution of this excess energy to the heating of a shock-compressed nanostructured (and porous) material is evaluated and compared to the thermal effect due to its porosity collapse. A maximum temperature increase of 50 K is found for 4-nm nanoparticles, which remains negligible when compared to the few hundred degrees induced by the compaction work.

  8. Solar energy and global heat balance of a city

    Energy Technology Data Exchange (ETDEWEB)

    Roulet, Claude-Alain [Ecole Polytechnique Federale, Lab. d' Energie Solaire et de Physique du Batiment, Lausanne (Switzerland)

    2001-07-01

    The global energy balance of a city involves numerous energy flows and is rather complex. It includes, among others, the absorbed solar radiation and the energy fuels on one hand, and the heat loss to the environment --- by radiation, convection and evaporation --- on the other hand. This balance generally results in a temperature in the town that is slightly higher than in the surrounding country. Using solar energy saves imported fuels on one hand, but increases the absorption of solar radiation on the other hand. Simple, steady state models are used to assess the change of heat released to the environment when replacing the use of classical fuels by solar powered plants, on both the global and city scale. The conclusion is that, in most cases, this will reduce the heat released to the environment. The exception is cooling, for which a good solar alternative does not exist today. (Author)

  9. Energy balance of hydro-aggregate with Pelton water turbine

    International Nuclear Information System (INIS)

    Obretenov, V.

    2005-01-01

    One of the major tasks in the field of hydraulic power engineering refers to machines and equipment modernization in the hydropower plants and pumped storage power plants commissioned more than 20 years ago. The increase of hydraulic units operation efficiency will allow in a number of cases to substantially reduce the specific water consumption and to drive the output of electric energy up. In these cases it is crucial to find out the operational efficiency of individual system elements and to precisely focus the modernization endeavours on such elements where the energy losses go beyond all admissible limits. Besides, the determination of the energy losses in the hydro energy turbo system will allow valid defining of hydraulic units operational scope. This work treats the methods of balance study of a hydraulic unit with Peiton water turbine. The experimental results of the balance study of Belmeken pumped storage power plant hydraulic unit No 5 under turbine operational mode are presented

  10. Energy balance from Bahia state 2013 - series 1996-2012

    International Nuclear Information System (INIS)

    2013-01-01

    This Energy Balance from Bahia, Brazil, presents six chapters, as follows: the chapter 1 approaches the profile of the energy system, showing the structure of the Bahia state energy matrix in the year of 2012, and the modifications occurred during the period of 1996-2012. Then the consolidated information are presented, from production to final consumption, for the set of primary and secondary sources, as well as comparative tables of states x national production of major energy production; the chapter 2 analyses the development, during the period of 1996-2012, in energy supply according to the Primary and Secondary sources; the chapter 3 comprised the evolution of energy consumption by sources and according the social-economic sectors; chapter 4 focus, within a broader view, the evolution of self-sufficiency energy state, confronting the production of primary energy to the total energy demand; in chapter 5 is given the status of the Energy Transformation Centers of the state, highlighting the balances of the Refinery Landulpho Alves (RLAM) and the Power Plants of Public Service and Self-Producer and the chapter 6 contains the consolidated matrixes expressed in the years of 1980, 1985 and 1990-2012

  11. Assessment of actual evapotranspiration over a semiarid heterogeneous land surface by means of coupled low-resolution remote sensing data with an energy balance model: comparison to extra-large aperture scintillometer measurements

    Science.gov (United States)

    Saadi, Sameh; Boulet, Gilles; Bahir, Malik; Brut, Aurore; Delogu, Émilie; Fanise, Pascal; Mougenot, Bernard; Simonneaux, Vincent; Lili Chabaane, Zohra

    2018-04-01

    In semiarid areas, agricultural production is restricted by water availability; hence, efficient agricultural water management is a major issue. The design of tools providing regional estimates of evapotranspiration (ET), one of the most relevant water balance fluxes, may help the sustainable management of water resources. Remote sensing provides periodic data about actual vegetation temporal dynamics (through the normalized difference vegetation index, NDVI) and water availability under water stress (through the surface temperature Tsurf), which are crucial factors controlling ET. In this study, spatially distributed estimates of ET (or its energy equivalent, the latent heat flux LE) in the Kairouan plain (central Tunisia) were computed by applying the Soil Plant Atmosphere and Remote Sensing Evapotranspiration (SPARSE) model fed by low-resolution remote sensing data (Terra and Aqua MODIS). The work's goal was to assess the operational use of the SPARSE model and the accuracy of the modeled (i) sensible heat flux (H) and (ii) daily ET over a heterogeneous semiarid landscape with complex land cover (i.e., trees, winter cereals, summer vegetables). SPARSE was run to compute instantaneous estimates of H and LE fluxes at the satellite overpass times. The good correspondence (R2 = 0.60 and 0.63 and RMSE = 57.89 and 53.85 W m-2 for Terra and Aqua, respectively) between instantaneous H estimates and large aperture scintillometer (XLAS) H measurements along a path length of 4 km over the study area showed that the SPARSE model presents satisfactory accuracy. Results showed that, despite the fairly large scatter, the instantaneous LE can be suitably estimated at large scales (RMSE = 47.20 and 43.20 W m-2 for Terra and Aqua, respectively, and R2 = 0.55 for both satellites). Additionally, water stress was investigated by comparing modeled (SPARSE) and observed (XLAS) water stress values; we found that most points were located within a 0.2 confidence interval, thus the

  12. Seasonal changes in energy balance of rural Beninese women

    NARCIS (Netherlands)

    Schultink, J.W.

    1991-01-01

    This thesis reports on human energy balance in relation to seasonal changes in food availability of rural populations in developing countries.

    Body weight measurements were carried out every two weeks among Beninese subsistence farmers who live in two different climatological zones (one and

  13. Energy Balance Education in Schools: The Role of Student Knowledge

    Science.gov (United States)

    Chen, Senlin; Nam, Yoon Ho

    2017-01-01

    Obesity prevention and control have been identified as top public health priorities in modern societies. Sport and exercise science researchers from multiple perspectives (e.g. behavioral, pedagogical, psychological, and physiological) have been active contributors addressing this topic. This paper examines the importance of energy balance (EB)…

  14. Energy balance of Lower Saxony 1994; Niedersaechsische Energiebilanz 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The energy balance of Lower Saxony is presented in physical units, in terrajoule and in coal equivalent to show supply, conversion, and consumption of primary and secondary energy sources in the year under report. (orig.) [Deutsch] Die Energiebilanz des Landes Niedersachsen in physikalischen Einheiten, in Terrajoule und in Steinkohleeinheiten stellt das Energieaufkommen, die Energieumwandlung und den Energieverbrauch fuer Primaer- und Sekundaerenergietraeger im Berichtsjahr dar. (orig.)

  15. The energy and pressure balance in the corona

    International Nuclear Information System (INIS)

    McWhirter, R.W.P.; Wilson, R.

    1976-01-01

    This paper reviews theoretical models for the solar corona based on energy and pressure calculations. Processes included in these calculations are: (a) heating of the outer corona by mechanical waves; (b) convective out-flow of gas giving rise to the solar wind; (c) thermal conductions; (d) radiated power loss. Possible observations to help answer some of the outstanding questions about the energy balance are suggested. (author)

  16. The Spanish Wind Energy Market. Balance and Outlooks

    International Nuclear Information System (INIS)

    Varela, M.

    1999-01-01

    The present work accomplishes a revision to the situation of the wind market in Spain, its recent evolution, its regional distribution, the principal actors of the market (manufacturers, promoters). The balance includes a review of the programs of institutional support to wind energy, an analysis of the current installation costs and electricity production costs. Finally, other variables related the integration of wind energy are analysed, as the potential of employment generation or the associated environmental factors. (Author) 5 refs

  17. A Thermal-based Two-Source Energy Balance Model for Estimating Evapotranspiration over Complex Canopies

    Science.gov (United States)

    Kustas, William; Anderson, Martha; Nieto, Hector; Andreu, Ana; Yang, Yun; Cammalleri, Carmelo; Alfieri, Joseph; Gao, Feng; Hain, Christopher; Torres-Rua, Alfonso

    2017-04-01

    Land surface temperature (LST) provides valuable information for quantifying root-zone water availability, evapotranspiration (ET) and crop condition as well as providing useful information for constraining prognostic land surface models. This presentation describes a robust but relatively simple LST-based land surface model called the Two-Source Energy Balance (TSEB) model. The TSEB algorithms solve for the soil/substrate and canopy temperatures that achieves a balance in the radiation and turbulent heat flux exchange for the soil/substrate and vegetation elements coupled to the lower atmosphere. As a result, the TSEB modeling framework is applicable to a wide range of environmental and canopy cover conditions, which has been a limitation in many other LST-based energy balance approaches. This is particularly relevant in applying surface energy balance models using LST over heterogeneous landscapes with complex vegetation distribution and architecture/structure. An overview of applications of the TSEB modeling framework to a variety of landscapes will be presented. In addition, a modeling system will be described called the Atmosphere-Land Exchange Inverse (ALEXI) that couples the TSEB scheme with an atmospheric boundary layer model in time-differencing mode to routinely map continental-scale daily ET at 5 to 10-km resolution using geostationary satellites. A related algorithm (DisALEXI) spatially disaggregates ALEXI output down to finer spatial resolutions using polar orbiting satellites such as Landsat, which provides pixel resolutions at the scale of human management activities affecting land use⪉nd cover.

  18. Energy balance and obesity: what are the main drivers?

    Science.gov (United States)

    Romieu, Isabelle; Dossus, Laure; Barquera, Simón; Blottière, Hervé M; Franks, Paul W; Gunter, Marc; Hwalla, Nahla; Hursting, Stephen D; Leitzmann, Michael; Margetts, Barrie; Nishida, Chizuru; Potischman, Nancy; Seidell, Jacob; Stepien, Magdalena; Wang, Youfa; Westerterp, Klaas; Winichagoon, Pattanee; Wiseman, Martin; Willett, Walter C

    2017-03-01

    The aim of this paper is to review the evidence of the association between energy balance and obesity. In December 2015, the International Agency for Research on Cancer (IARC), Lyon, France convened a Working Group of international experts to review the evidence regarding energy balance and obesity, with a focus on Low and Middle Income Countries (LMIC). The global epidemic of obesity and the double burden, in LMICs, of malnutrition (coexistence of undernutrition and overnutrition) are both related to poor quality diet and unbalanced energy intake. Dietary patterns consistent with a traditional Mediterranean diet and other measures of diet quality can contribute to long-term weight control. Limiting consumption of sugar-sweetened beverages has a particularly important role in weight control. Genetic factors alone cannot explain the global epidemic of obesity. However, genetic, epigenetic factors and the microbiota could influence individual responses to diet and physical activity. Energy intake that exceeds energy expenditure is the main driver of weight gain. The quality of the diet may exert its effect on energy balance through complex hormonal and neurological pathways that influence satiety and possibly through other mechanisms. The food environment, marketing of unhealthy foods and urbanization, and reduction in sedentary behaviors and physical activity play important roles. Most of the evidence comes from High Income Countries and more research is needed in LMICs.

  19. Comparison of four different energy balance models for estimating evapotranspiration in the Midwestern United States

    Science.gov (United States)

    Singh, Ramesh K.; Senay, Gabriel B.

    2016-01-01

    The development of different energy balance models has allowed users to choose a model based on its suitability in a region. We compared four commonly used models—Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) model, Surface Energy Balance Algorithm for Land (SEBAL) model, Surface Energy Balance System (SEBS) model, and the Operational Simplified Surface Energy Balance (SSEBop) model—using Landsat images to estimate evapotranspiration (ET) in the Midwestern United States. Our models validation using three AmeriFlux cropland sites at Mead, Nebraska, showed that all four models captured the spatial and temporal variation of ET reasonably well with an R2 of more than 0.81. Both the METRIC and SSEBop models showed a low root mean square error (0.80), whereas the SEBAL and SEBS models resulted in relatively higher bias for estimating daily ET. The empirical equation of daily average net radiation used in the SEBAL and SEBS models for upscaling instantaneous ET to daily ET resulted in underestimation of daily ET, particularly when the daily average net radiation was more than 100 W·m−2. Estimated daily ET for both cropland and grassland had some degree of linearity with METRIC, SEBAL, and SEBS, but linearity was stronger for evaporative fraction. Thus, these ET models have strengths and limitations for applications in water resource management.

  20. Reassessing the effect of cloud type on Earth's energy balance

    Science.gov (United States)

    Hang, A.; L'Ecuyer, T.

    2017-12-01

    Cloud feedbacks depend critically on the characteristics of the clouds that change, their location and their environment. As a result, accurately predicting the impact of clouds on future climate requires a better understanding of individual cloud types and their spatial and temporal variability. This work revisits the problem of documenting the effects of distinct cloud regimes on Earth's radiation budget distinguishing cloud types according to their signatures in spaceborne active observations. Using CloudSat's multi-sensor radiative fluxes product that leverages high-resolution vertical cloud information from CloudSat, CALIPSO, and MODIS observations to provide the most accurate estimates of vertically-resolved radiative fluxes available to date, we estimate the global annual mean net cloud radiative effect at the top of the atmosphere to be -17.1 W m-2 (-44.2 W m-2 in the shortwave and 27.1 W m-2 in the longwave), slightly weaker than previous estimates from passive sensor observations. Multi-layered cloud systems, that are often misclassified using passive techniques but are ubiquitous in both hemispheres, contribute about -6.2 W m-2 of the net cooling effect, particularly at ITCZ and higher latitudes. Another unique aspect of this work is the ability of CloudSat and CALIPSO to detect cloud boundary information providing an improved capability to accurately discern the impact of cloud-type variations on surface radiation balance, a critical factor in modulating the disposition of excess energy in the climate system. The global annual net cloud radiative effect at the surface is estimated to be -24.8 W m-2 (-51.1 W m-2 in the shortwave and 26.3 W m-2 in the longwave), dominated by shortwave heating in multi-layered and stratocumulus clouds. Corresponding estimates of the effects of clouds on atmospheric heating suggest that clouds redistribute heat from poles to equator enhancing the general circulation.

  1. Greenhouse gas emissions and energy balance of palm oil biofuel

    Energy Technology Data Exchange (ETDEWEB)

    de Souza, Simone Pereira; Pacca, Sergio [Graduate Program on Environmental Engineering Science, School of Engineering of Sao Carlos, University of Sao Paulo, Rua Arlindo Bettio, 1000 Sao Paulo (Brazil); de Avila, Marcio Turra; Borges, Jose Luiz B. [Brazilian Agricultural Research Corporation (Embrapa - Soja) (Brazil)

    2010-11-15

    The search for alternatives to fossil fuels is boosting interest in biodiesel production. Among the crops used to produce biodiesel, palm trees stand out due to their high productivity and positive energy balance. This work assesses life cycle emissions and the energy balance of biodiesel production from palm oil in Brazil. The results are compared through a meta-analysis to previous published studies: Wood and Corley (1991) [Wood BJ, Corley RH. The energy balance of oil palm cultivation. In: PORIM intl. palm oil conference - agriculture; 1991.], Malaysia; Yusoff and Hansen (2005) [Yusoff S, Hansen SB. Feasibility study of performing an life cycle assessment on crude palm oil production in Malaysia. International Journal of Life Cycle Assessment 2007;12:50-8], Malaysia; Angarita et al. (2009) [Angarita EE, Lora EE, Costa RE, Torres EA. The energy balance in the palm oil-derived methyl ester (PME) life cycle for the cases in Brazil and Colombia. Renewable Energy 2009;34:2905-13], Colombia; Pleanjai and Gheewala (2009) [Pleanjai S, Gheewala SH. Full chain energy analysis of biodiesel production from palm oil in Thailand. Applied Energy 2009;86:S209-14], Thailand; and Yee et al. (2009) [Yee KF, Tan KT, Abdullah AZ, Lee KT. Life cycle assessment of palm biodiesel: revealing facts and benefits for sustainability. Applied Energy 2009;86:S189-96], Malaysia. In our study, data for the agricultural phase, transport, and energy content of the products and co-products were obtained from previous assessments done in Brazil. The energy intensities and greenhouse gas emission factors were obtained from the Simapro 7.1.8. software and other authors. These factors were applied to the inputs and outputs listed in the selected studies to render them comparable. The energy balance for our study was 1:5.37. In comparison the range for the other studies is between 1:3.40 and 1:7.78. Life cycle emissions determined in our assessment resulted in 1437 kg CO{sub 2}e/ha, while our analysis

  2. Energy balance in IPM rice farms compared to conventional farms

    Directory of Open Access Journals (Sweden)

    Mehdi Fazeli

    2017-06-01

    Full Text Available Integrated Pest Management based on Farmer Field Schools (IPM/FFS is a program aimed to guide farmers toward managing agricultural pests in an environmentally responsible manner. This program has been in practice during the recent decade in the north of Iran. A study was conducted to evaluate the overall impacts of IPM/FFS program on energy balance and economic revenue of paddy (Oryza sativa L. farms compared with conventional farms (no IPM. The data of inputs, management practices, and output (yield of 238 paddy farms (135 IPM farms and 103 conventional farms located in a semi-Mediterranean climate were collected in 2010 and 2011. Total energy input, energy output, energy efficiency, and energy productivity were determined as indicators of energy balance. The total energy requirement for paddy production in IPM system was 48756 MJ ha−1, indicating that 8% more energy was used in IPM farms than that in conventional farms. It was noticed that IPM program in this region failed to reduce the consumption of chemical pesticides in paddy farms and the conventional system was more energy efficient than IPM system. Although paddy yield of the two systems was similar, the economic net return in IPM system was almost 20% higher than the conventional system due to the higher price of paddy produced in IPM system.

  3. Energy balance in the watershed of Ipê, Northwestern São Paulo State, Brazil

    Science.gov (United States)

    Feitosa, Diego G.; T. Hernandez, Fernando B.; Franco, Renato A. M.; Teixeira, Antonio H. C.; Neale, Christopher M.

    2016-10-01

    The region of Ilha Solteira, in the Northwestern of São Paulo State, has been undergoing significant changes in agricultural land use and cover since 2006, as pasture fields have been replaced by sugarcane crop. This drastic change can lead to a disturbance in the energy balance, affecting the local climate. The aim of this paper was to assess some parameters related to the energy balance of Ipê's watershed, that changed since no sugarcane cultivation in 2006 to 2,164 hectares in 2011, occupying 31% of the catchment area with this important energy crop for the economy and the environment of Brazil. This study was carried out using remote sensing combined with weather data and using the SAFER (Simple Algorithm for Retrieving Evapotranspiration) model applied in 9 Landsat images collected between 2003 and 2011. The results showed a wide variation between the components of energy balance and when considering only the sugarcane crop were verified the increase values of ETa (Actual Evapotranspiration), H/Rn (Sensible Heat Flux/Net Radiation), TS (Surface Temperature), Rl↑ (Emitted longwave), Rl↓ (Incidente longwave) and surface albedo after the sugarcane production over these years. On the other hand, the NDVI, λE/Rn (Latent Heat Flux/Net Radiation) and Rn values (data) decreased in the same period. Also there was satisfactory correlation between NDVI and ETa. The SAFER model showed satisfactory results for studies of energy balance applied in the Northwestern of São Paulo State.

  4. The mass and energy balance of ice within the Eisriesenwelt cave, Austria

    Directory of Open Access Journals (Sweden)

    F. Obleitner

    2011-03-01

    Full Text Available Meteorological measurements were performed in a prominent ice cave (Eisriesenwelt, Austria during a full annual cycle. The data show the basic features of a dynamically ventilated cave system with a well distinguished winter and summer regime.

    The calculated energy balance of the cave ice is largely determined by the input of long-wave radiation originating at the host rock surface. On average the turbulent fluxes withdraw energy from the surface. This is more pronounced during winter due to enhanced circulation and lower humidity. During summer the driving gradients reverse sign and the associated fluxes provide energy for melt.

    About 4 cm of ice were lost at the measurement site during a reference year. This was due to some sublimation during winter, while the major loss resulted from melt during summer. Small amounts of accumulation occurred during spring due to refreezing of seepage water.

    These results are largely based on employing a numerical mass and energy balance model. Sensitivity studies prove reliability of the calculated energy balance regarding diverse measurement uncertainties and show that the annual mass balance of the ice strongly depends on cave air temperature during summer and the availability of seepage water in spring.

  5. Net energy balance of tokamak fusion power plants

    International Nuclear Information System (INIS)

    Buende, R.

    1981-10-01

    The net energy balance for a tokamak fusion power plant was determined by using a PWR power plant as reference system, replacing the fission-specific components by fusion-specific components and adjusting the non-reactor-specific components to altered conditions. For determining the energy input to the fusion plant a method was developed that combines the advantages of the energetic input-output method with those of process chain analysis. A comparison with PWR, HTR, FBR, and coal-fired power plants is made. As a result the net energy balance of the fusion power plant turns out to be more advantageous than that of an LWR, HTR or coal-fired power plant and nearly in the same range as FBR power plants. (orig.)

  6. Energy balance of a sparse coniferous high-latitude forest under winter conditions

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Batchvarova, E.; Bruin, H.A.R. de

    2001-01-01

    and night were about equally long. At low solar elevation angles the forest shades most of the snow surface. Therefore an important part of the radiation never reaches the snow surface but is absorbed by the forest. The sensible heat flux above the forest was fairly large, reaching more than 100 W m(-2......). The measurements of sensible heat flux within and above the forest revealed that the sensible heat flux from the snow surface is negligible and the sensible heat flux above the forest stems from warming of the trees. A simple model for the surface energy balance of a sparse forest is presented. The model treats...

  7. The influence of changes in glacier extent and surface elevation on modeled mass balance

    Directory of Open Access Journals (Sweden)

    F. Paul

    2010-12-01

    Full Text Available Glaciers are widely recognized as unique demonstration objects for climate change impacts, mostly due to the strong change of glacier length in response to small climatic changes. However, glacier mass balance as the direct response to the annual atmospheric conditions can be better interpreted in meteorological terms. When the climatic signal is deduced from long-term mass balance data, changes in glacier geometry (i.e. surface extent and elevation must be considered as such adjustments form an essential part of the glacier reaction to new climatic conditions. In this study, a set of modelling experiments is performed to assess the influence of changes in glacier geometry on mass balance for constant climatic conditions. The calculations are based on a simplified distributed energy/mass balance model in combination with information on glacier extent and surface elevation for the years 1850 and 1973/1985 for about 60 glaciers in the Swiss Alps. The results reveal that over this period about 50–70% of the glacier reaction to climate change (here a one degree increase in temperature is "hidden" in the geometric adjustment, while only 30–50% can be measured as the long-term mean mass balance. For larger glaciers, the effect of the areal change is partly reduced by a lowered surface elevation, which results in a slightly more negative balance despite a potential increase of topographic shading. In view of several additional reinforcement feedbacks that are observed in periods of strong glacier decline, it seems that the climatic interpretation of long-term mass balance data is rather complex.

  8. Surface meteorology and Solar Energy

    Science.gov (United States)

    Stackhouse, Paul W. (Principal Investigator)

    The Release 5.1 Surface meteorology and Solar Energy (SSE) data contains parameters formulated for assessing and designing renewable energy systems. Parameters fall under 11 categories including: Solar cooking, solar thermal applications, solar geometry, tilted solar panels, energy storage systems, surplus product storage systems, cloud information, temperature, wind, other meteorological factors, and supporting information. This latest release contains new parameters based on recommendations by the renewable energy industry and it is more accurate than previous releases. On-line plotting capabilities allow quick evaluation of potential renewable energy projects for any region of the world. The SSE data set is formulated from NASA satellite- and reanalysis-derived insolation and meteorological data for the 10-year period July 1983 through June 1993. Results are provided for 1 degree latitude by 1 degree longitude grid cells over the globe. Average daily and monthly measurements for 1195 World Radiation Data Centre ground sites are also available. [Mission Objectives] The SSE project contains insolation and meteorology data intended to aid in the development of renewable energy systems. Collaboration between SSE and technology industries such as the Hybrid Optimization Model for Electric Renewables ( HOMER ) may aid in designing electric power systems that employ some combination of wind turbines, photovoltaic panels, or diesel generators to produce electricity. [Temporal_Coverage: Start_Date=1983-07-01; Stop_Date=1993-06-30] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180].

  9. Dissipation and energy balance in electronic dynamics of Na clusters

    Science.gov (United States)

    Vincendon, Marc; Suraud, Eric; Reinhard, Paul-Gerhard

    2017-06-01

    We investigate the impact of dissipation on the energy balance in the electron dynamics of metal clusters excited by strong electro-magnetic pulses. The dynamics is described theoretically by Time-Dependent Density-Functional Theory (TDDFT) at the level of Local Density Approximation (LDA) augmented by a self interaction correction term and a quantum collision term in Relaxation-Time Approximation (RTA). We evaluate the separate contributions to the total excitation energy, namely energy exported by electron emission, potential energy due to changing charge state, intrinsic kinetic and potential energy, and collective flow energy. The balance of these energies is studied as function of the laser parameters (frequency, intensity, pulse length) and as function of system size and charge. We also look at collisions with a highly charged ion and here at the dependence on the impact parameter (close versus distant collisions). Dissipation turns out to be small where direct electron emission prevails namely for laser frequencies above any ionization threshold and for slow electron extraction in distant collisions. Dissipation is large for fast collisions and at low laser frequencies, particularly at resonances. Contribution to the Topical Issue "Dynamics of Systems at the Nanoscale", edited by Andrey Solov'yov and Andrei Korol.

  10. Greenland Surface Mass Balance as Simulated by the Community Earth System Model. Part II: Twenty-First-Century Changes

    NARCIS (Netherlands)

    Vizcaino, M.; Lipscomb, W.H.; Sacks, W.J.; van den Broeke, M.R.

    2014-01-01

    This study presents the first twenty-first-century projections of surface mass balance (SMB) changes for the Greenland Ice Sheet (GIS) with the Community Earth System Model (CESM), which includes a new ice sheet component. For glaciated surfaces, CESM includes a sophisticated calculation of energy

  11. The role of snacking in energy balance: a biobehavioral approach.

    Science.gov (United States)

    Chapelot, Didier

    2011-01-01

    Snacking is often presumed to contribute to obesity, but to date, studies have not demonstrated such a causal relationship, probably because a clear definition of snacking is still elusive. The usual one, i.e. any intake between traditional meals, has no physiological basis. Moreover, because some evidence suggests that frequent meals may prevent overweight, any confusion between snacks and meals may mask the deleterious effect of snacks on energy balance. Therefore, we developed a biobehavioral approach to assess whether objective criteria for eating a meal and snacking could be determined. Our main findings were that regardless of the time of consumption or macronutrient composition, snacks exerted a weak satiety effect, with those higher in protein having the strongest. The energy content of snacks was never compensated for at the next meal and led consistently to a positive energy balance compared with no-snack conditions. Biologically, the snack-induced insulin secretion suppressed the late increase in plasma FFA, which may have contributed to the inhibition of satiety. Lastly, snacking was not preceded by the glucose and insulin profile observed prior to a spontaneously requested meal. In conclusion, further studies on the role of snacking in energy balance should include criteria other than nutrient composition or consumption between meals for defining these eating occasions as snacks.

  12. Hypothalamic Inflammation and Energy Balance Disruptions: Spotlight on Chemokines

    Directory of Open Access Journals (Sweden)

    Ophélia Le Thuc

    2017-08-01

    Full Text Available The hypothalamus is a key brain region in the regulation of energy balance as it controls food intake and both energy storage and expenditure through integration of humoral, neural, and nutrient-related signals and cues. Many years of research have focused on the regulation of energy balance by hypothalamic neurons, but the most recent findings suggest that neurons and glial cells, such as microglia and astrocytes, in the hypothalamus actually orchestrate together several metabolic functions. Because glial cells have been described as mediators of inflammatory processes in the brain, the existence of a causal link between hypothalamic inflammation and the deregulations of feeding behavior, leading to involuntary weight loss or obesity for example, has been suggested. Several inflammatory pathways that could impair the hypothalamic control of energy balance have been studied over the years such as, among others, toll-like receptors and canonical cytokines. Yet, less studied so far, chemokines also represent interesting candidates that could link the aforementioned pathways and the activity of hypothalamic neurons. Indeed, chemokines, in addition to their role in attracting immune cells to the inflamed site, have been suggested to be capable of neuromodulation. Thus, they could disrupt cellular activity together with synthesis and/or secretion of multiple neurotransmitters/mediators involved in the maintenance of energy balance. This review discusses the different inflammatory pathways that have been identified so far in the hypothalamus in the context of feeding behavior and body weight control impairments, with a particular focus on chemokines signaling that opens a new avenue in the understanding of the major role played by inflammation in obesity.

  13. On Averaging Timescales for the Surface Energy Budget Closure Problem

    Science.gov (United States)

    Grachev, A. A.; Fairall, C. W.; Persson, O. P. G.; Uttal, T.; Blomquist, B.; McCaffrey, K.

    2017-12-01

    An accurate determination of the surface energy budget (SEB) and all SEB components at the air-surface interface is of obvious relevance for the numerical modelling of the coupled atmosphere-land/ocean/snow system over different spatial and temporal scales, including climate modelling, weather forecasting, environmental impact studies, and many other applications. This study analyzes and discusses comprehensive measurements of the SEB and the surface energy fluxes (turbulent, radiative, and ground heat) made over different underlying surfaces based on the data collected during several field campaigns. Hourly-averaged, multiyear data sets collected at two terrestrial long-term research observatories located near the coast of the Arctic Ocean at Eureka (Canadian Archipelago) and Tiksi (East Siberia) and half-hourly averaged fluxes collected during a year-long field campaign (Wind Forecast Improvement Project 2, WFIP 2) at the Columbia River Gorge (Oregon) in areas of complex terrain. Our direct measurements of energy balance show that the sum of the turbulent sensible and latent heat fluxes systematically underestimate the available energy at half-hourly and hourly time scales by around 20-30% at these sites. This imbalance of the surface energy budget is comparable to other terrestrial sites. Surface energy balance closure is a formulation of the conservation of energy principle (the first law of thermodynamics). The lack of energy balance closure at hourly time scales is a fundamental and pervasive problem in micrometeorology and may be caused by inaccurate estimates of the energy storage terms in soils, air and biomass in the layer below the measurement height and above the heat flux plates. However, the residual energy imbalance is significantly reduced at daily and monthly timescales. Increasing the averaging time to daily scales substantially reduces the storage terms because energy locally entering the soil, air column, and vegetation in the morning is

  14. Energy Balance, Climate, and Life - Work of M. Budyko

    Science.gov (United States)

    Cahalan, Robert F.

    2004-01-01

    This talk will review the work of Mikhail I. Budyko, author of "Climate and Life" and many other works, who died recently at age 81, in St Petersburg, Russia. He directed the Division for Climate Change Research at the State Hydrological Institute. We will explore Budyko's work in clarifying the role of energy balance in determining planetary climate, and the role of climate in regulating Earth s biosphere.

  15. Energy balance in turbulent weakly ionized ionospheric plasma

    International Nuclear Information System (INIS)

    Dyatko, N.A.; Mishin, E.V.; Telegin, V.A.

    1994-01-01

    On the base of numerical solution of the Boltzmann equation are determined the electron distribution function and energy balance in the case if the longitudinal current exceeds the critical one and the resistance becames anomalously high one. In the equation are accounted for both electron scattering by plasma density fluctuations and electron elastic and inelastic collisions with atoms and molecules and electron-electron collisions

  16. Serotonin and the regulation of mammalian energy balance

    OpenAIRE

    Donovan, Michael H.; Tecott, Laurence H.

    2013-01-01

    Maintenance of energy balance requires regulation of the amount and timing of food intake. Decades of experiments utilizing pharmacological and later genetic manipulations have demonstrated the importance of serotonin signaling in this regulation. Much progress has been made in recent years in understanding how central nervous system (CNS) serotonin systems acting through a diverse array of serotonin receptors impact feeding behavior and metabolism. Particular attention has been paid to mecha...

  17. Impact of the daily meal pattern on energy balance

    OpenAIRE

    Bellisle, France

    2008-01-01

    The daily distribution of food intake can influence the regulation of energy balance and, in consequence, the control of body weight. Two aspects of this question must be considered: the daily number of eating occasions and their temporal distribution. Since the 1960s, epidemiological studies have reported an inverse relationship between frequency of eating and body weight, suggesting that a ‘‘nibbling’’ pattern could help to prevent obesity. This notion has later been...

  18. Energy saving in greenhouses can be obtained by energy balance-controlled screens

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, N. E. (Univ. of Aarhus, Faculty of Agricultural Sciences, Dept. of Horticulture, Aarslev (Denmark)), e-mail: niels.andersson@agrsci.dk

    2011-03-15

    The energy screens in two greenhouses, one clad with double acrylic and one with single glass, were controlled by an energy balance model. The parameters in the model were heat transmission coefficients, air temperature in the greenhouse and outdoors, irradiance and a single constant for the solar energy efficiency. The energy consumption, screen movements and daily light integral were compared with a glass greenhouse in which the energy screens were controlled by irradiance. In the greenhouse with light-controlled screens the set point for opening and closing of the screens was 5 Wm-2. The energy-saving screens controlled by the energy balance model opened later and closed earlier than in the greenhouse with light-controlled screens. When using the energy balance model the energy saving was 14% for the glass greenhouse and 41% for the double acrylic greenhouse compared with the glass greenhouse with light-controlled screens. The air temperature was on average similar in the three greenhouses, but when the screens were controlled by energy balance the daily light integral was approximately 10% lower and the number of hours the screens were closed was prolonged with 35% for the glass-covered greenhouse and 25% for the double acrylic-covered greenhouse compared with the greenhouse with light-controlled screens. Energy peaks in connection with operation of the screens were not reduced. During the experiment Begonia elatior, Dendranthema grandiflora (Chrysanthemum), Hedera helix, Helianthus annuus, Gerbera jamesonii and Kalanchoe blossfeldiana were grown in the greenhouses. There was a trend in prolongation of the production time when the plants were grown in the glass greenhouse with energy balance control of the screens. A lower number of flowers or inflorescences were observed for some of the plant species produced in the greenhouses with energy balance-controlled screens

  19. Japanese energy balances after the Great East Japan Earthquake

    International Nuclear Information System (INIS)

    Tsuzuki, Kazuhiro; Moriyama, Ryo; Ishimoto, Yuki; Tomikatsu, Koji; Hagiwara, Naoto

    2012-01-01

    After the Great East Japan Earthquake, disaster response and risk of nuclear accident became a new issue and the public against nuclear power was increasing with knowing a long-term period required for restoration from Fukushima accident. This article described effects of 'de-nuclear power' policy with no additional plants on energy balances in 2030 and 2050 with simulated energy model based on government's long-term energy supply-demand outlook issued in 2009. Main assumed conditions were as follows; (1) nuclear power of case B) 40 years operation and C) 60 years operation, (2) share of photovoltaic and wind power was assumed to be 9% of total power generation and the same as planned before the earthquake disaster, which could not replace nuclear power and (3) final consumption of case 2) 8% saving and 3) 20% saving. Effects of 'de-nuclear power' in 2030 were (1) CO 2 emission difference between B) and C) was 50 Mt and (2) estimated cost increase between B) and C) was 0.1 T yen/year for CO 2 emission, 1 T yen/year for LNG procurement and 2.4 T yen for thermal power construction. Energy balances in 2050 were much influenced by trend of renewable energy technology development and fossil energy procurement and use. Sophisticated power change measures using storage battery for renewable energy should be developed, otherwise if power change were dealt with thermal power, share would be limited to 15-20% of total power generation. If CO 2 emission in 2050 was limited to 50% instead of formally announced 80% of CO 2 emission in 1990, share of non-fossil power (nuclear power + renewable energy) became almost 100% for case 3). Base technology of nuclear power should remain as option for the case where fossil energy procurement and CO 2 emission limit became restrictive in 2050. (T. Tanaka)

  20. Compensatory Changes in Energy Balance Regulation over One Athletic Season.

    Science.gov (United States)

    Silva, Analiza M; Matias, Catarina N; Santos, Diana A; Thomas, Diana; Bosy-Westphal, Anja; MüLLER, Manfred J; Heymsfield, Steven B; Sardinha, LUíS B

    2017-06-01

    Mechanisms in energy balance (EB) regulation may include compensatory changes in energy intake (EI) and metabolic adaption (MA), but information is unavailable in athletes who often change EB components. We aim to investigate EB regulation compensatory mechanisms over one athletic season. Fifty-seven athletes (39 males/18 females; handball, volleyball, basketball, triathlon, and swimming) were evaluated from the beginning to the competitive phase of the season. Resting and total energy expenditure (REE and TEE, respectively) were assessed by indirect calorimetry and doubly labeled water, respectively, and physical activity energy expenditure was determined as TEE - 0.1(TEE) - REE. Fat mass (FM) and fat-free mass (FFM) were evaluated by dual-energy x-ray absorptiometry and changed body energy stores was determined by 1.0(ΔFFM/Δtime) + 9.5(ΔFM/Δtime). EI was derived as TEE + EB. REE was predicted from baseline FFM, FM, sex, and sports. %MA was calculated as 100(measured REE/predicted REE-1) and MA (kcal) as %MA/100 multiplied by baseline measured REE. Average EI minus average physical activity energy expenditure was computed as a proxy of average energy availability, assuming that a constant nonexercise EE occurred over the season. Body mass increased by 0.8 ± 2.5 kg (P sports and the demanding workloads these athletes are exposed to highlight the need for sport-specific energy requirements.

  1. Model Property Based Material Balance and Energy Conservation Analysis for Process Industry Energy Transfer Systems

    Directory of Open Access Journals (Sweden)

    Fumin Ma

    2015-10-01

    Full Text Available Conventional historical data based material and energy balance analyses are static and isolated computations. Such methods cannot embody the cross-coupling effect of energy flow, material flow and information flow in the process industry; furthermore, they cannot easily realize the effective evaluation and comparison of different energy transfer processes by alternating the model module. In this paper, a novel method for material balance and energy conservation analysis of process industry energy transfer system is developed based on model property. Firstly, a reconfigurable energy transfer process model, which is independent of energy types and energy-consuming equipment, is presented from the viewpoint of the cross-coupling effect of energy flow, material flow and information flow. Thereafter the material balance determination is proposed based on both a dynamic incidence matrix and dynamic balance quantity. Moreover, the model-weighted conservation determination theorem is proved, and the energy efficiency analysis method is also discussed. Results confirmed the efficacy of the proposed methods, confirming its potential for use by process industry in energy efficiency analyses.

  2. Forecast of wind energy production and ensuring required balancing power

    International Nuclear Information System (INIS)

    Merkulov, M.

    2010-01-01

    The wind energy is gaining larger part of the energy mix around the world as well as in Bulgaria. Having in mind the irregularity of the wind, we are in front of a challenge for management of the power grid in new unknown conditions. The world's experience has proven that there could be no effective management of the grid without forecasting tools, even with small scale of wind power penetration. Application of such tools promotes simple management of large wind energy production and reduction of the quantities of required balancing powers. The share of the expenses and efforts for forecasting of the wind energy is incomparably small in comparison with expenses for keeping additional powers in readiness. The recent computers potential allow simple and rapid processing of large quantities of data from different sources, which provides required conditions for modeling the world's climate and producing sophisticated forecast. (author)

  3. Energy Efficient Routing in Wireless Sensor Networks Through Balanced Clustering

    Directory of Open Access Journals (Sweden)

    Christos Douligeris

    2013-01-01

    Full Text Available The wide utilization of Wireless Sensor Networks (WSNs is obstructed by the severely limited energy constraints of the individual sensor nodes. This is the reason why a large part of the research in WSNs focuses on the development of energy efficient routing protocols. In this paper, a new protocol called Equalized Cluster Head Election Routing Protocol (ECHERP, which pursues energy conservation through balanced clustering, is proposed. ECHERP models the network as a linear system and, using the Gaussian elimination algorithm, calculates the combinations of nodes that can be chosen as cluster heads in order to extend the network lifetime. The performance evaluation of ECHERP is carried out through simulation tests, which evince the effectiveness of this protocol in terms of network energy efficiency when compared against other well-known protocols.

  4. Carbon and energy balances for a range of biofuels options

    Energy Technology Data Exchange (ETDEWEB)

    Elsayed, M.A.; Matthews, R.; Mortimer, N.D.

    2003-03-01

    This is the final report of a project to produce a set of baseline energy and carbon balances for a range of electricity, heat and transport fuel production systems based on biomass feedstocks. A list of 18 important biofuel technologies in the UK was selected for study of their energy and carbon balances in a consistent approach. Existing studies on these biofuel options were reviewed and their main features identified in terms of energy input, greenhouse gas emissions (carbon dioxide, methane, nitrous oxide and total), transparency and relevance. Flow charts were produced to represent the key stages of the production of biomass and its conversion to biofuels. Outputs from the study included primary energy input per delivered energy output, carbon dioxide outputs per delivered energy output, methane output per delivered energy output, nitrous oxide output per delivered energy output and total greenhouse gas requirements. The net calorific value of the biofuel is given where relevant. Biofuels studied included: biodiesel from oilseed rape and recycled vegetable oil; combined heat and power (CHP) by combustion of wood chip from forestry residues; CHP by gasification of wood chip from short rotation coppice; electricity from the combustion of miscanthus, straw, wood chip from forestry residues and wood chip from short rotation coppice; electricity from gasification of wood chip from forestry residues and wood chip from short rotation coppice; electricity by pyrolysis of wood chip from forestry residues and wood chip from short rotation coppice; ethanol from lignocellulosics, sugar beet and wheat; heat (small scale) from combustion of wood chip from forestry residues and wood chip from short rotation coppice; and rapeseed oil from oilseed rape.

  5. Prediction Based Energy Balancing Forwarding in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yang Jian-Jun

    2017-01-01

    Full Text Available In the recent cellular network technologies, relay stations extend cell coverage and enhance signal strength for mobile users. However, busy traffic makes the relay stations in hot area run out of energy quickly. Energy is a very important factor in the forwarding of cellular network since mobile users(cell phones in hot cells often suffer from low throughput due to energy lack problems. In many situations, the energy lack problems take place because the energy loading is not balanced. In this paper, we present a prediction based forwarding algorithm to let a mobile node dynamically select the next relay station with highest potential energy capacity to resume communication. Key to this strategy is that a relay station only maintains three past status, and then it is able to predict the potential energy capacity. Then, the node selects the next hop with potential maximal energy. Moreover, a location based algorithm is developed to let the mobile node figure out the target region in order to avoid flooding. Simulations demonstrate that our approach significantly increase the aggregate throughput and decrease the delay in cellular network environment.

  6. Energy-balance and melt contributions of supraglacial lakes, Langtang Khola, Nepal

    Science.gov (United States)

    Miles, E. S.; Willis, I. C.; Pellicciotti, F.; Steiner, J. F.; Buri, P.; Arnold, N. S.

    2014-12-01

    As Himalayan debris-covered glaciers retreat and thin in response to climate warming, their long, low-gradient tongues generate substantial meltwater which often collects to form surface lakes. Supraglacial lakes on debris covered glaciers present a mechanism of atmosphere-glacier energy transfer that is poorly-studied, and only conceptually included in mass-balance studies. The ponded water can enhance energy transfer as compared to dry debris cover, while also acting as a reservoir of melt-available energy. Supraglacial lakes occur in association with debris-free ice cliffs, another poorly-constrained but critical component of glacier melt. Understanding the role of supraglacial lakes requires precise monitoring of lake volume, estimation of inlet and outlet flows, and consideration of the energy balance across three surfaces: atmosphere-lake, lake-ice, and lake-saturated debris layer. This research progresses previous modeling work on the energy and mass balance of such supraglacial lakes. Lakes were monitored during the monsoon of 2013 on Lirung Glacier in the Langtang Himal of Nepal with pressure transducers and temperature sensors, while UAV-derived DEMs were used to determine lake geometry. Lake albedo was measured to vary between 0.08 and 0.12, and a nearby on-glacier AWS was used to drive the energy balance. Results indicate that the lakes act as a significant recipient of energy, and suggest that lakes are an important part of an active supraglacial hydrologic system during the monsoon. Melt generated by the lake in contact with bare ice is calculated to be 3-5 cm/day, while energy conducted through saturated lake-bottom debris only resulted in 1-2 mm/day melt. The subaqueous melt rates are of similar magnitude to observed ice-cliff melt rates, allowing lake-cliff systems to persist. Energy leaving the lake system through englacial conduits may be the most important contribution to the glacier's mass balance, driving surface evolution to form new ice

  7. [Energy balance, body composition and the female athlete triad syndrome].

    Science.gov (United States)

    Weinstein, Yitzhak; Weinstein, Ayelet

    2012-02-01

    With the rising participation of women in sports events, the prevalence of eating disorders and the female athlete triad (FTS), a syndrome of disordered eating, amenorrhea, and osteoporosis, have also increased in recent years. FTS is often seen in sports that emphasize thinness (e.g. gymnastics, figure skating and dancing) and also in endurance events. Elements of the FTS are pathophysiologically linked, leading to several disease risks and even to mortality. In spite of the considerable knowledge about sports nutrition, there is no consensus as to the correct nutrition regime for the female athlete. There is consensus that minimizing fluctuations in 'target-body-weight' is an indication of a long-term energy balance. Female athletes (e.g. in endurance events and gymnastics) are less likely to achieve the recommended carbohydrates (CHO) and fat consumption due to chronic or episodic constraints of total energy intake while struggling to achieve or maintain low levels of body fat. It is recommended that dietary CHO and fat content be increased to preserve fat-free mass thus enhancing health and performance. Energy balance should also be maintained during recesses. Furthermore, within-day episodes of energy deficits/surplus (measured by the frequency and/or magnitude of the episodes) should be monitored and treated closest to the time of the incidents.

  8. Essential role of UCP1 modulating the central effects of thyroid hormones on energy balance

    Directory of Open Access Journals (Sweden)

    Mayte Alvarez-Crespo

    2016-04-01

    Conclusions: We conclude that UCP1 is essential for mediation of the central effects of thyroid hormones on energy balance, and we suggest that similar UCP1-dependent effects may underlie central energy balance effects of other agents.

  9. Influence of snow cover changes on surface radiation and heat balance based on the WRF model

    Science.gov (United States)

    Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

    2017-10-01

    The snow cover extent in mid-high latitude areas of the Northern Hemisphere has significantly declined corresponding to the global warming, especially since the 1970s. Snow-climate feedbacks play a critical role in regulating the global radiation balance and influencing surface heat flux exchange. However, the degree to which snow cover changes affect the radiation budget and energy balance on a regional scale and the difference between snow-climate and land use/cover change (LUCC)-climate feedbacks have been rarely studied. In this paper, we selected Heilongjiang Basin, where the snow cover has changed obviously, as our study area and used the WRF model to simulate the influences of snow cover changes on the surface radiation budget and heat balance. In the scenario simulation, the localized surface parameter data improved the accuracy by 10 % compared with the control group. The spatial and temporal analysis of the surface variables showed that the net surface radiation, sensible heat flux, Bowen ratio, temperature and percentage of snow cover were negatively correlated and that the ground heat flux and latent heat flux were positively correlated with the percentage of snow cover. The spatial analysis also showed that a significant relationship existed between the surface variables and land cover types, which was not obviously as that for snow cover changes. Finally, six typical study areas were selected to quantitatively analyse the influence of land cover types beneath the snow cover on heat absorption and transfer, which showed that when the land was snow covered, the conversion of forest to farmland can dramatically influence the net radiation and other surface variables, whereas the snow-free land showed significantly reduced influence. Furthermore, compared with typical land cover changes, e.g., the conversion of forest into farmland, the influence of snow cover changes on net radiation and sensible heat flux were 60 % higher than that of land cover changes

  10. The global mean energy balance under cloud-free conditions

    Science.gov (United States)

    Wild, Martin; Hakuba, Maria; Folini, Dois; Ott, Patricia; Long, Charles

    2017-04-01

    är, C., Loeb, N., Dutton, E.G., and König-Langlo, G., 2013: The global energy balance from a sur

  11. The Impact of Anthropogenic Heat on Formation of Urban Heat Island and Energy Consumption Balance

    Directory of Open Access Journals (Sweden)

    P. Shahmohamadi

    2011-01-01

    Full Text Available This paper investigates the impact of anthropogenic heat on formation of urban heat island (UHI and also determines which factors can directly affect energy use in the city. It explores literally the conceptual framework of confliction between anthropogenic heat and urban structure, which produced UHI intensity and affected energy consumption balance. It then discusses how these two factors can be affected and gives implication to the city and then focuses on whether actions should be taken for balancing adaptation and mitigation of UHI effects. It will be concluded by making the three important strategies to minimise the impact of UHI on energy consumption: landscaping, using albedo materials on external surfaces of buildings and urban areas, and promoting natural ventilation.

  12. Application of He’s Energy Balance Method to Duffing-Harmonic Oscillators

    DEFF Research Database (Denmark)

    Momeni, M.; Jamshidi, j.; Barari, Amin

    2011-01-01

    In this article, He's energy balance method is applied for calculating angular frequencies of nonlinear Duffing oscillators. This method offers a promising approach by constructing a Hamiltonian for the nonlinear oscillator. We illustrate that the energy balance is very effective and convenient...... and does not require linearization or small perturbation. Contrary to the conventional methods, in energy balance, only one iteration leads to high accuracy of the solutions. It is predicted that the energy balance method finds wide applications in engineering problems....

  13. Energy balances of OECD countries, 2001-2002. 2004 edition

    International Nuclear Information System (INIS)

    2004-01-01

    This volume contains data on the supply and consumption of coal, oil, gas, electricity, heat, renewables and waste presented as comprehensive energy balances expressed in million tonnes of oil equivalent. Historical tables summarize production, trade and final consumption data as well as key energy and economic indicators. The book also includes definitions of products and flows, explanatory notes on the individual country data and conversion factors from original units to tonnes of oil equivalent. More detailed data in original units are published in Energy Statistics of OECD Countries 2001-2002, the sister volume of this publication. Bi-lingual edition: English - French. The CD-Rom and on-line service contain detailed time series back to 1960 for most OECD countries

  14. Net energy balance of tokamak fusion power plants

    International Nuclear Information System (INIS)

    Buende, R.

    1983-01-01

    The net energy balance for a tokamak fusion power plant of present day design is determined by using a PWR power plant as reference system, replacing the fission-specific components by fusion-specific components and adjusting the non-reactor-specific components to altered conditions. For determining the energy input to the fusion plant a method was developed that combines the advantages of the energetic input-output method with those of process chain analysis. A comparison with PWR, HTR, FBR, and coal-fired power plants is made. As a result the energy expenditures of the fusion power plant turn out to be lower than that of an LWR, HTR, or coal-fired power plant of equal net electric power output and nearly in the same range as FBR power plants. (orig.)

  15. Impact of Energy Losses Due to Failures on Photovoltaic Plant Energy Balance

    Directory of Open Access Journals (Sweden)

    Isidoro Lillo-Bravo

    2018-02-01

    Full Text Available Photovoltaic (PV plant failures have a significant influence on PV plant security, reliability, and energy balance. Energy losses produced by a PV plant are due to two large causes: failures and inefficiencies. Knowing the relative influence of energy losses due to failures and energy losses due to inefficiencies on the PV plant energy balance contribute to the optimization of its design, commissioning, and maintenance tasks. This paper estimates the failure rates, grouped by components, and the relative impact of the failures on the PV plant energy balance through real operation and maintenance follow-up data of 15 PV plants in Spain and Italy for 15 months. Results show that the influence of failures in energy losses of all analysed PV plants is low, reaching a maximum value of 0.96% of the net energy yield. Solar field energy losses only represent 4.26% of all failure energy losses. On the other hand, energy losses due to inefficiencies have represented between 22.34% and 27.58% of the net energy yield.

  16. Energy conservation potential of surface modification technologies

    Energy Technology Data Exchange (ETDEWEB)

    Le, H.K.; Horne, D.M.; Silberglitt, R.S.

    1985-09-01

    This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

  17. 21st century changes in the surface mass balance of the Greenland ice sheet simulated with the global model CESM

    Science.gov (United States)

    Vizcaíno, M.; Lipscomb, W. H.; Van den Broeke, M.

    2012-04-01

    We present here the first projections of 21st century surface mass balance change of the Greenland ice sheet simulated with the Community Earth System Model (CESM). CESM is a fully-coupled, global climate model developed at many research centers and universities, primarily in the U.S. The model calculates the surface mass balance in the land component (the Community Land Model, CLM), at the same resolution as the atmosphere (1 degree), with an energy-balance scheme. The snow physics included in CLM for non-glaciated surfaces (SNiCAR model, Flanner and Zender, 2005) are used over the ice sheet. The surface mass balance is calculated for 10 elevation classes, and then downscaled to the grid of the ice sheet model (5 km in this case) via vertical linear interpolation between elevation classes combined with horizontal bilinear interpolation. The ice sheet topography is fixed at present-day values for the simulations presented here. The use of elevation classes reduces computational costs while giving results that reproduce well the mass balance gradients at the steep margins of the ice sheet. The simulated present-day surface mass balance agrees well with results from regional models. We focus on the regional model RACMO (Ettema et al. 2009) to compare the results on 20th-century surface mass balance evolution and two-dimensional patterns. The surface mass balance of the ice sheet under RCP8.5. forcing becomes negative in the last decades of the 21st century. The equilibrium line becomes ~500 m higher on average. Accumulation changes are positive in the accumulation zone. We examine changes in refreezing, accumulation, albedo, surface fluxes, and the timing of the melt season.

  18. Improving the Xin'anjiang hydrological model based on mass–energy balance

    Directory of Open Access Journals (Sweden)

    Y.-H. Fang

    2017-07-01

    Full Text Available Conceptual hydrological models are preferable for real-time flood forecasting, among which the Xin'anjiang (XAJ model has been widely applied in humid and semi-humid regions of China. Although the relatively simple mass balance scheme ensures a good performance of runoff simulation during flood events, the model still has some defects. Previous studies have confirmed the importance of evapotranspiration (ET and soil moisture content (SMC in runoff simulation. In order to add more constraints to the original XAJ model, an energy balance scheme suitable for the XAJ model was developed and coupled with the original mass balance scheme of the XAJ model. The detailed parameterizations of the improved model, XAJ-EB, are presented in the first part of this paper. XAJ-EB employs various meteorological forcing and remote sensing data as input, simulating ET and runoff yield using a more physically based mass–energy balance scheme. In particular, the energy balance is solved by determining the representative equilibrium temperature (RET, which is comparable to land surface temperature (LST. The XAJ-EB was evaluated in the Lushui catchment situated in the middle reach of the Yangtze River basin for the period between 2004 and 2007. Validation using ground-measured runoff data proves that the XAJ-EB is capable of reproducing runoff comparable to the original XAJ model. Additionally, RET simulated by XAJ-EB agreed well with moderate resolution imaging spectroradiometer (MODIS-retrieved LST, which further confirms that the model is able to simulate the mass–energy balance since LST reflects the interactions among various processes. The validation results prove that the XAJ-EB model has superior performance compared with the XAJ model and also extends its applicability.

  19. A closed-loop energy price controlling method for real-time energy balancing in a smart grid energy market

    International Nuclear Information System (INIS)

    Alagoz, B. Baykant; Kaygusuz, Asim; Akcin, Murat; Alagoz, Serkan

    2013-01-01

    Future smart grids will require a flexible, observable, and controllable network for reliable and efficient energy delivery under uncertain generation and demand conditions. One of the mechanisms for efficient and reliable energy generation is dynamic demand-responsive generation management based on energy price adjustments that creates a balance in energy markets. This study presents a closed-loop PID (proportional–integral–derivative) controller-based price control method for autonomous and real-time balancing of energy demand and generation in smart grid electricity markets. The PID control system can regulate energy prices online to respond dynamically and instantaneously to the varying energy demands of grid consumers. Independent energy suppliers in the smart grid decide whether to sell their energy to the grid according to the energy prices declared by the closed-loop PID controller system. Energy market simulations demonstrate that PID-controlled energy price regulation can effectively maintain an energy balance for hourly demand fluctuations of consumers. - Highlights: • This study presents a control theoretic approach for management of energy balance. • A closed-loop PID controller-based price controlling method is used in smart grid. • The simulation results demonstrate advantages of PID-based energy price control. • This method is appropriate for demand responsive management of smart grid markets

  20. Dietary carbohydrates, components of energy balance, and associated health outcomes.

    Science.gov (United States)

    Smith, Harry A; Gonzalez, Javier T; Thompson, Dylan; Betts, James A

    2017-10-01

    The role of dietary carbohydrates in the development of obesity and associated metabolic dysfunction has recently been questioned. Within the last decade, the Scientific Advisory Committee on Nutrition carried out a comprehensive evaluation of the role of dietary carbohydrates in human health. The current review aims to complement and extend this report by providing specific consideration of the effects of the component parts of energy balance, their interactions, and their culmination on energy storage and health. PubMed was searched for all published trials that had a minimum follow-up period of 3 months and were designed to manipulate dietary carbohydrate intake, irrespective of resultant differences in absolute carbohydrate dose (grams per day). Dietary carbohydrate manipulation has little effect on the individual components of energy balance that have been assessed. However, the role of dietary carbohydrates in influencing physical activity has yet to be assessed using gold-standard measurement tools. Moreover, adherence to a diet of modified carbohydrate content has not been found to result in a consistent pattern of changes in weight or indirect measures of metabolic health. However, certain markers of cardiovascular disease risk (ie, blood triglycerides and high-density lipoprotein cholesterol) may respond positively to a reduction in dietary carbohydrates. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Models and mechanisms of energy balance regulation in the young.

    Science.gov (United States)

    Mercer, Julian G

    2008-11-01

    The proportion of the child and adolescent population that is in appropriate energy balance is declining throughout the developed world, and childhood obesity is a particular problem in the UK relative to other northern European countries. Assessment of the underlying causes of obesity, and the different routes to its development, may assist in the definition of successful intervention strategies. The network of peripheral and central (brain) regulatory systems that underlie energy balance and body weight and composition can, for the most part, only be approached experimentally through the study of appropriate laboratory animal models. This problem is particularly acute when the target is overweight and obesity in the young. Some of the mechanisms underlying the development of energy imbalance and specifically the onset of overweight and obesity in the young, and the metabolic health consequences of obesity, can be addressed by examination of experimental rodent models in which mutation of a single gene causes early-onset extreme obesity, genetic susceptibility to obesity is revealed in an obesogenic environment or early-life nutritional experience programmes susceptibility to obesity or metabolic problems in later life. These studies highlight genes that are essential to normal body-weight regulation in rodents and man, the impact of diet and diet-induced obesity on regulatory systems in the young and the potential sensitivity of developing regulatory systems to nutritional experiences in utero and during early life.

  2. Energy balance of Sao Paulo state, Brazil 2007. Calendar year 2006

    International Nuclear Information System (INIS)

    2007-01-01

    This document presents an abstract of the analyzed period as follows: supply and demand of the energy by source; energy consumption by sector; external commerce of energy; balances of the transformation centers; energy and social economy; energy resources and reserves. The annexes show the regional and historical aspects, the installed capacity, the CO 2 emissions, the general structure of the balance, the information treatment, the conversion factors and the consolidated energy balance

  3. Control and perception of balance at elevated and sloped surfaces.

    Science.gov (United States)

    Simeonov, Peter I; Hsiao, Hongwei; Dotson, Brian W; Ammons, Douglas E

    2003-01-01

    Understanding roof-work-related risk of falls and developing low-cost, practical engineering controls for reducing this risk remain in high demand in the construction industry. This study investigated the effects of the roof work environment characteristics of surface slope, height, and visual reference on standing balance in construction workers. The 24 participants were tested in a laboratory setting at 4 slopes (0 degrees, 18 degrees, 26 degrees, and 34 degrees), 2 heights (0, 3 m), and 2 visual conditions (with and without visual references). Postural sway characteristics were calculated using center of pressure recordings from a force platform. Workers' perceptions of postural sway and instability were also evaluated. The results indicated that slope and height synergistically increased workers' standing postural instability. Workers recognized the individual destabilizing effects of slope and height but did not recognize the synergistic effect of the two. Visual references significantly reduced the destabilizing effects of height and slope. Actual and potential applications of this research include the use of temporary level work surfaces and proximal vertical reference structures as postural instability control measures during roofing work.

  4. Energy balance of a wood biomass combustion process

    International Nuclear Information System (INIS)

    Baggio, P.; Cemin, A.; Grigiante, M.; Ragazzi, M.

    2001-01-01

    This article reports the results of a project developed at the University of Trent dealing with some wood biomass combustion processes. The project has been particularly dedicated to the study of the energetic analysis of the combustion processes that occur on a gasified wood stove of advanced combustion technologies. A considerable number of experimental tests has been carried out making use of different type of wood widely in use in Trentino region. The wood stove is a part of a pilot plant providing an hydraulic circuit equipped with a specific apparatus to measure all the necessary data to determine the energy balance required and specifically the thermal efficiency of the plant [it

  5. Comparison of surface energy fluxes with satellite-derived surface energy flux estimates from a shrub-steppe

    Energy Technology Data Exchange (ETDEWEB)

    Kirkham, Randy R. [Univ. of Washington, Seattle, WA (United States)

    1993-12-01

    This thesis relates the components of the surface energy balance (i.e., net radiation, sensible and latent heat flux densities, soil heat flow) to remotely sensed data for native vegetation in a semi-arid environment. Thematic mapper data from Landsat 4 and 5 were used to estimate net radiation, sensible heat flux (H), and vegetation amount. Several sources of ground truth were employed. They included soil water balance using the neutron thermalization method and weighing lysimeters, and the measurement of energy fluxes with the Bowen ratio energy balance (BREB) technique. Sensible and latent heat flux were measured at four sites on the U.S. Department of Energy`s Hanford Site using a weighing lysimeter and/or BREB stations. The objective was to calibrate an aerodynamic transport equation that related H to radiant surface temperature. The transport equation was then used with Landsat thermal data to generate estimates of H and compare these estimates against H values obtained with BREB/lysimeters at the time of overflight. Landsat and surface meteorologic data were used to estimate the radiation budget terms at the surface. Landsat estimates of short-wave radiation reflected from the surface correlate well with reflected radiation measured using inverted Eppley pyranometers. Correlation of net radiation estimates determined from satellite data, pyranometer, air temperature, and vapor pressure compared to net radiometer values obtained at time of overflight were excellent for a single image, but decrease for multiple images. Soil heat flux, GT, is a major component of the energy balance in arid systems and G{sub T} generally decreases as vegetation cover increases. Normalized difference vegetation index (NDVI) values generated from Landsat thermatic mapper data were representative of field observations of the presence of green vegetation, but it was not possible to determine a single relationship between NDVI and GT for all sites.

  6. Energy balance, carbon emissions, and costs of sortyard debris disposal

    International Nuclear Information System (INIS)

    MacDonald, A.J.

    2001-01-01

    The Forest Engineering Research Institute of Canada (FERIC), with funding from Natural Resources Canada, conducted this study to determine the main environmental and energy use issues regarding the landfilling, burning or processing of dryland sortyard debris accumulated in the wood products industry. The wood residues that are generated when logs are processed, sorted and remanufactured, have traditionally been burned or landfilled. This is no longer appropriate. Converting the large woody debris into usable products such as hog fuel or compost requires grinding, smashing or chipping into small pieces to facilitate transportation. In order to make smart decisions about alternative methods of handling sortyard debris, information is needed about the comparative amount of fuel used and carbon dioxide produced. This study compared the treatment alternatives with respect to fuel consumption, net energy balance, carbon dioxide emissions and environmental impact. Recommendations were then presented for the treatment of debris from the point of view of net energy balance and environmental impact. Life cycle techniques were used to determine the environmental impact of alternatives for managing sortyard debris. It was determined that wood wastes are valuable as hog fuel for power generation. Burning hog fuel to recover its energy offsets the need to supply energy from other sources such as natural gas. This reduces the total carbon emissions by the amount of debris that would have been burned as waste. Annual carbon emissions can be reduced by nearly half by switching from a maximize burn strategy to a maximize hog strategy that combines composting of fine materials. 2 refs., 1 tab., 1 fig

  7. An energy balance perspective on regional CO2-induced temperature changes in CMIP5 models

    Science.gov (United States)

    Räisänen, Jouni

    2017-05-01

    An energy balance decomposition of temperature changes is conducted for idealized transient CO2-only simulations in the fifth phase of the Coupled Model Intercomparison Project. The multimodel global mean warming is dominated by enhanced clear-sky greenhouse effect due to increased CO2 and water vapour, but other components of the energy balance substantially modify the geographical and seasonal patterns of the change. Changes in the net surface energy flux are important over the oceans, being especially crucial for the muted warming over the northern North Atlantic and for the seasonal cycle of warming over the Arctic Ocean. Changes in atmospheric energy flux convergence tend to smooth the gradients of temperature change and reduce its land-sea contrast, but they also amplify the seasonal cycle of warming in northern North America and Eurasia. The three most important terms for intermodel differences in warming are the changes in the clear-sky greenhouse effect, clouds, and the net surface energy flux, making the largest contribution to the standard deviation of annual mean temperature change in 34, 29 and 20 % of the world, respectively. Changes in atmospheric energy flux convergence mostly damp intermodel variations of temperature change especially over the oceans. However, the opposite is true for example in Greenland and Antarctica, where the warming appears to be substantially controlled by heat transport from the surrounding sea areas.

  8. Energy balance of a corn residue-covered field during snowmelt

    International Nuclear Information System (INIS)

    Sauer, T.J.; Hatfield, J.L.; Prueger, J.H.; Logsdon, S.D.

    1998-01-01

    Transport of agricultural chemicals in runoff and recharge waters from snowmelt and soil thawing may represent a significant event in terms of annual contaminant loadings in temperate regions. Improved understanding of the melt dynamics of shallow snowpacks is necessary to fully assess the implications for water quality. The objective of this study was to measure the energy balance components of a corn (Zea mays L.) stubble field during the melting of its snowcover. Net radiation (Rn), soil (G), sensible (H), and latent (Q) best fluxes were measured in a field near Ames, Iowa, during the winter of 1994-1995. Energy consumed by melting including change in energy storage of the snowpack was determined as the residual of the measured energy balance. There was continuous snowcover at the field site for 71 days (maximum depth = 222 m) followed by an open period of 11 days before additional snowfall and a second melt period. The net radiation and snowmelt/energy storage change (S) terms dominated the energy balance during both measurement intervals. Peak daily sensible and latent best fluxes were below 100 W m(-2) on all days except the last day of the second melt period. There was good agreement between predicted and measured values of H and Q during the melting of an aged snow layer but poorer agreement during the melt of fresh snow. Both snowpacks melted rapidly and coincident changes in soil moisture storage were observed. Improved estimates of Q and H, especially for partially open surfaces, will require better characterization of the surface aerodynamic properties and spatially-representative surface temperature measurements

  9. Surface energy budget and turbulent fluxes at Arctic terrestrial sites

    Science.gov (United States)

    Grachev, Andrey; Persson, Ola; Uttal, Taneil; Konopleva-Akish, Elena; Crepinsek, Sara; Cox, Christopher; Fairall, Christopher; Makshtas, Alexander; Repina, Irina

    2017-04-01

    Determination of the surface energy budget (SEB) and all SEB components at the air-surface interface are required in a wide variety of applications including atmosphere-land/snow simulations and validation of the surface fluxes predicted by numerical models over different spatial and temporal scales. Here, comparisons of net surface energy budgets at two Arctic sites are made using long-term near-continuous measurements of hourly averaged surface fluxes (turbulent, radiation, and soil conduction). One site, Eureka (80.0 N; Nunavut, Canada), is located in complex topography near a fjord about 200 km from the Arctic Ocean. The other site, Tiksi (71.6 N; Russian East Siberia), is located on a relatively flat coastal plain less than 1 km from the shore of Tiksi Bay, a branch of the Arctic Ocean. We first analyzed diurnal and annual cycles of basic meteorological parameters and key SEB components at these locations. Although Eureka and Tiksi are located on different continents and at different latitudes, the annual course of the surface meteorology and SEB components are qualitatively similar. Surface energy balance closure is a formulation of the conservation of energy principle. Our direct measurements of energy balance for both Arctic sites show that the sum of the turbulent sensible and latent heat fluxes and the ground (conductive) heat flux systematically underestimate the net radiation by about 25-30%. This lack of energy balance closure is a fundamental and pervasive problem in micrometeorology. We discuss a variety of factors which may be responsible for the lack of SEB closure. In particular, various storage terms (e.g., air column energy storage due to radiative and/or sensible heat flux divergence, ground heat storage above the soil flux plate, energy used in photosynthesis, canopy biomass heat storage). For example, our observations show that the photosynthesis storage term is relatively small (about 1-2% of the net radiation), but about 8-12% of the

  10. Energy Balance of the Sao Paulo State -1997. Base year 1996

    International Nuclear Information System (INIS)

    1997-01-01

    This energy balance of the Santa Catarina State presents the following main topics that can be outstanding: panorama of the energy matrix; supply and demand of energy by source 1983-1996; energy consumption by sector 1983/1996; socio-economic aspects; resources and reserves energy; and balance of the transformation centers 1984/1996

  11. Energy Balance of the Sao Paulo State -1998 Base year 1997

    International Nuclear Information System (INIS)

    1998-01-01

    This energy balance of the Sao Paulo State presents the following main topics that can be outstanding: panorama of the energy matrix; supply and demand of energy by source 1983-1997; energy consumption by sector 1983/1997; economic aspects; resources and reserves energy; and balance of the transformation centers 1983/1997

  12. Energy balance of forage consumption by phyllophagous insects: optimization model

    Directory of Open Access Journals (Sweden)

    O. V. Tarasova

    2015-06-01

    Full Text Available The model of optimal food consumption by phytophagous insects proposed, in which the metabolic costs are presented in the form of two components – the cost of food utilization and costs for proper metabolism of the individuals. Two measures were introduced – the «price» of food conversion and the «price» of biomass synthesis of individuals to assess the effectiveness of food consumption by caterpillars. The proposed approach to the description of food consumption by insects provides the exact solutions of the equation of energy balance of food consumption and determining the effectiveness of consumption and the risk of death of the individual. Experiments on larvae’s feeding in laboratory conditions were carried out to verify the model. Caterpillars of Aporia crataegi L. (Lepidoptera, Pieridae were the research subjects. Supply­demand balance, calculated value of the environmental price of consumption and efficiency of food consumption for each individual were determined from experimental data. It was found that the fertility of the female does not depend on the weight of food consumed by it, but is linearly dependent on the food consumption efficiency index. The greater the efficiency of food consumption by an individual, the higher its fertility. The data obtained in the course of experiments on the feeding caterpillars Aporia crataegi were compared with the data presented in the works of other authors and counted in the proposed model of consumption. Calculations allowed estimation of the critical value of food conversion price below which the energy balance is negative and the existence of an individual is not possible.

  13. Mechanisms linking energy balance and reproduction: impact of prenatal environment.

    Science.gov (United States)

    Rhinehart, Erin M

    2016-01-01

    The burgeoning field of metabolic reproduction regulation has been gaining momentum due to highly frequent discoveries of new neuroendocrine factors regulating both energy balance and reproduction. Universally throughout the animal kingdom, energy deficits inhibit the reproductive axis, which demonstrates that reproduction is acutely sensitive to fuel availability. Entrainment of reproductive efforts with energy availability is especially critical for females because they expend large amounts of energy on gestation and lactation. Research has identified an assortment of both central and peripheral factors involved in the metabolic regulation of reproduction. From an evolutionary perspective, these mechanisms likely evolved to optimize reproductive fitness in an environment with an unpredictable food supply and regular bouts of famine. To be effective, however, the mechanisms responsible for the metabolic regulation of reproduction must also retain developmental plasticity to allow organisms to adapt their reproductive strategies to their particular niche. In particular, the prenatal environment has emerged as a critical developmental window for programming the mechanisms responsible for the metabolic control of reproduction. This review will discuss the current knowledge about hormonal and molecular mechanisms that entrain reproduction with prevailing energy availability. In addition, it will provide an evolutionary, human life-history framework to assist in the interpretation of findings on gestational programming of the female reproductive function, with a focus on pubertal timing as an example. Future research should aim to shed light on mechanisms underlying the prenatal modulation of the adaptation to an environment with unstable resources in a way that optimizes reproductive fitness.

  14. Heparanase affects food intake and regulates energy balance in mice.

    Directory of Open Access Journals (Sweden)

    Linda Karlsson-Lindahl

    Full Text Available Mutation of the melanocortin-receptor 4 (MC4R is the most frequent cause of severe obesity in humans. Binding of agouti-related peptide (AgRP to MC4R involves the co-receptor syndecan-3, a heparan sulfate proteoglycan. The proteoglycan can be structurally modified by the enzyme heparanase. Here we tested the hypothesis that heparanase plays a role in food intake behaviour and energy balance regulation by analysing body weight, body composition and food intake in genetically modified mice that either lack or overexpress heparanase. We also assessed food intake and body weight following acute central intracerebroventricular administration of heparanase; such treatment reduced food intake in wildtype mice, an effect that was abolished in mice lacking MC4R. By contrast, heparanase knockout mice on a high-fat diet showed increased food intake and maturity-onset obesity, with up to a 40% increase in body fat. Mice overexpressing heparanase displayed essentially the opposite phenotypes, with a reduced fat mass. These results implicate heparanase in energy balance control via the central melanocortin system. Our data indicate that heparanase acts as a negative modulator of AgRP signaling at MC4R, through cleavage of heparan sulfate chains presumably linked to syndecan-3.

  15. Characterization of a Hormone Dependent Module Regulating Energy Balance

    Science.gov (United States)

    Wang, Biao; Moya, Noel; Niessen, Sherry; Hoover, Heather; Mihaylova, Maria M.; Shaw, Reuben J.; Yates, John R.; Fischer, Wolfgang H.; Thomas, John B.; Montminy, Marc

    2011-01-01

    SUMMARY Under fasting conditions, metazoans maintain energy balance by shifting from glucose to fat burning. In the fasted state, SIRT1 promotes catabolic gene expression by deacetylating the forkhead factor FOXO in response to stress and nutrient deprivation. The mechanisms by which hormonal signals regulate FOXO deacetylation remain unclear, however. We identified a hormone-dependent module, consisting of the Ser/Thr kinase SIK3 and the class IIa deacetylase HDAC4, which regulates FOXO activity in Drosophila. During feeding, HDAC4 is phosphorylated and sequestered in the cytoplasm by SIK3, whose activity is upregulated in response to insulin. SIK3 is inactivated during fasting, leading to the de-phosphorylation and nuclear translocation of HDAC4, and to FOXO deacetylation. SIK3 mutant flies are starvation-sensitive, reflecting FOXO-dependent increases in lipolysis that deplete triglyceride stores; reducing HDAC4 expression restored lipid accumulation. Our results reveal a hormone-regulated pathway that functions in parallel with the nutrient-sensing SIRT1 pathway to maintain energy balance. PMID:21565616

  16. A hormone-dependent module regulating energy balance.

    Science.gov (United States)

    Wang, Biao; Moya, Noel; Niessen, Sherry; Hoover, Heather; Mihaylova, Maria M; Shaw, Reuben J; Yates, John R; Fischer, Wolfgang H; Thomas, John B; Montminy, Marc

    2011-05-13

    Under fasting conditions, metazoans maintain energy balance by shifting from glucose to fat burning. In the fasted state, SIRT1 promotes catabolic gene expression by deacetylating the forkhead factor FOXO in response to stress and nutrient deprivation. The mechanisms by which hormonal signals regulate FOXO deacetylation remain unclear, however. We identified a hormone-dependent module, consisting of the Ser/Thr kinase SIK3 and the class IIa deacetylase HDAC4, which regulates FOXO activity in Drosophila. During feeding, HDAC4 is phosphorylated and sequestered in the cytoplasm by SIK3, whose activity is upregulated in response to insulin. SIK3 is inactivated during fasting, leading to the dephosphorylation and nuclear translocation of HDAC4 and to FOXO deacetylation. SIK3 mutant flies are starvation sensitive, reflecting FOXO-dependent increases in lipolysis that deplete triglyceride stores; reducing HDAC4 expression restored lipid accumulation. Our results reveal a hormone-regulated pathway that functions in parallel with the nutrient-sensing SIRT1 pathway to maintain energy balance. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Robust energy storage scheduling for imbalance reduction of strategically formed energy balancing groups

    International Nuclear Information System (INIS)

    Chakraborty, Shantanu; Okabe, Toshiya

    2016-01-01

    Imbalance (on-line energy gap between contracted supply and actual demand, and associated cost) reduction is going to be a crucial service for a Power Producer and Supplier (PPS) in the deregulated energy market. PPS requires forward market interactions to procure energy as precisely as possible in order to reduce imbalance energy. This paper presents, 1) (off-line) an effective demand aggregation based strategy for creating a number of balancing groups that leads to higher predictability of group-wise aggregated demand, 2) (on-line) a robust energy storage scheduling that minimizes the imbalance energy and cost of a particular balancing group considering the demand prediction uncertainty. The group formation is performed by a Probabilistic Programming approach using Bayesian Markov Chain Monte Carlo (MCMC) method after applied on the historical demand statistics. Apart from the group formation, the aggregation strategy (with the help of Bayesian Inference) also clears out the upper-limit of the required storage capacity for a formed group, fraction of which is to be utilized in on-line operation. For on-line operation, a robust energy storage scheduling method is proposed that minimizes expected imbalance energy and cost (a non-linear function of imbalance energy) while incorporating the demand uncertainty of a particular group. The proposed methods are applied on the real apartment buildings' demand data in Tokyo, Japan. Simulation results are presented to verify the effectiveness of the proposed methods. - Highlights: • Strategic method for intelligent energy balancing group formation using Bayesian MCMC. • Stochastic programming based robust and online energy storage (battery) scheduling. • Imbalance cost (regulation) and energy reduction of a balancing group. • Imbalance cost reduction of 80% attainable by considerably lower battery capacity.

  18. Determining water use of sorghum from two-source energy balance and radiometric temperatures

    Directory of Open Access Journals (Sweden)

    J. M. Sánchez

    2011-10-01

    Full Text Available Estimates of surface actual evapotranspiration (ET can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (Sorghum bicolor field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h−1 and ±1.0 mm d−1 were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management.

  19. Adhesion energy, surface traction and surface tension in liquid xenon

    Indian Academy of Sciences (India)

    Abstract. We calculated the adhesion energy, the surface traction and the surface energy of liquid xenon using molecular dynamics (MD) simulation. The value of the adhesion energy for liquid xenon at a reduced density of 0.630 was found to be 0.591 J/m2 and the surface traction has a peak at z = 3.32 Å. It was observed ...

  20. Adhesion energy, surface traction and surface tension in liquid xenon

    Indian Academy of Sciences (India)

    We calculated the adhesion energy, the surface traction and the surface energy of liquid xenon using molecular dynamics (MD) simulation. The value of the adhesion energy for liquid xenon at a reduced density of 0.630 was found to be 0.591 J/m2 and the surface traction has a peak at = 3.32 Å. It was observed that the ...

  1. BALANCE

    Science.gov (United States)

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  2. Exercise, energy expenditure and energy balance, as measured with doubly labelled water.

    Science.gov (United States)

    Westerterp, Klaas R

    2018-02-01

    The doubly labelled water method for the measurement of total daily energy expenditure (TDEE) over 1-3 weeks under daily living conditions is the indicated method to study effects of exercise and extreme environments on energy balance. Subjects consume a measured amount of doubly labelled water (2H2 18O) to increase background enrichment of body water for 18O and 2H, and the subsequent difference in elimination rate between 18O and 2H, as measured in urine, saliva or blood samples, is a measure for carbon dioxide production and thus allows calculation of TDEE. The present review describes research showing that physical activity level (PAL), calculated as TDEE (assessed with doubly labelled water) divided by resting energy expenditure (REE, PAL = TDEE/REE), reaches a maximum value of 2·00-2·40 in subjects with a vigorously active lifestyle. Higher PAL values, while maintaining energy balance, are observed in professional athletes consuming additional energy dense foods to compete at top level. Exercise training can increase TDEE/REE in young adults to a value of 2·00-2·40, when energy intake is unrestricted. Furthermore, the review shows an exercise induced increase in activity energy expenditure can be compensated by a reduction in REE and by a reduction in non-exercise physical activity, especially at a negative energy balance. Additionally, in untrained subjects, an exercise-induced increase in activity energy expenditure is compensated by a training-induced increase in exercise efficiency.

  3. Comparison of surface energy fluxes with satellite-derived surface energy flux estimates from a shrub-steppe

    International Nuclear Information System (INIS)

    Kirkham, R.R.

    1993-12-01

    This thesis relates the components of the surface energy balance (i.e., net radiation, sensible and latent heat flux densities, soil heat flow) to remotely sensed data for native vegetation in a semi-arid environment. Thematic mapper data from Landsat 4 and 5 were used to estimate net radiation, sensible heat flux (H), and vegetation amount. Several sources of ground truth were employed. They included soil water balance using the neutron thermalization method and weighing lysimeters, and the measurement of energy fluxes with the Bowen ratio energy balance (BREB) technique. Sensible and latent heat flux were measured at four sites on the U.S. Department of Energy's Hanford Site using a weighing lysimeter and/or BREB stations. The objective was to calibrate an aerodynamic transport equation that related H to radiant surface temperature. The transport equation was then used with Landsat thermal data to generate estimates of H and compare these estimates against H values obtained with BREB/lysimeters at the time of overflight. Landsat and surface meteorologic data were used to estimate the radiation budget terms at the surface. Landsat estimates of short-wave radiation reflected from the surface correlate well with reflected radiation measured using inverted Eppley pyranometers. Correlation of net radiation estimates determined from satellite data, pyranometer, air temperature, and vapor pressure compared to net radiometer values obtained at time of overflight were excellent for a single image, but decrease for multiple images. Soil heat flux, G T , is a major component of the energy balance in arid systems and G T generally decreases as vegetation cover increases. Normalized difference vegetation index (NDVI) values generated from Landsat thermatic mapper data were representative of field observations of the presence of green vegetation, but it was not possible to determine a single relationship between NDVI and G T for all sites

  4. Potential energy surfaces for chemical reactions

    International Nuclear Information System (INIS)

    Schaefer, H.F. III.

    1976-01-01

    Research into potential energy surfaces for chemical reactions at Lawrence Berkeley Laboratory during 1976 is described. Topics covered include: the fuzzy interface between surface chemistry catalysis and organometallic chemistry; potential energy surfaces for elementary fluorine hydrogen reactions; structure, energetics, and reactivity of carbenes; and the theory of self-consistent electron pairs

  5. Parameter studies on the energy balance closure problem using large-eddy simulation

    Science.gov (United States)

    De Roo, Frederik; Banerjee, Tirtha; Mauder, Matthias

    2017-04-01

    The imbalance of the surface energy budget in eddy-covariance measurements is still a pending problem. A possible cause is the presence of land surface heterogeneity. Heterogeneities of the boundary layer scale or larger are most effective in influencing the boundary layer turbulence, and large-eddy simulations have shown that secondary circulations within the boundary layer can affect the surface energy budget. However, the precise influence of the surface characteristics on the energy imbalance and its partitioning is still unknown. To investigate the influence of surface variables on all the components of the flux budget under convective conditions, we set up a systematic parameter study by means of large-eddy simulation. For the study we use a virtual control volume approach, and we focus on idealized heterogeneity by considering spatially variable surface fluxes. The surface fluxes vary locally in intensity and these patches have different length scales. The main focus lies on heterogeneities of length scales of the kilometer scale and one decade smaller. For each simulation, virtual measurement towers are positioned at functionally different positions. We discriminate between the locally homogeneous towers, located within land use patches, with respect to the more heterogeneous towers, and find, among others, that the flux-divergence and the advection are strongly linearly related within each class. Furthermore, we seek correlators for the energy balance ratio and the energy residual in the simulations. Besides the expected correlation with measurable atmospheric quantities such as the friction velocity, boundary-layer depth and temperature and moisture gradients, we have also found an unexpected correlation with the temperature difference between sonic temperature and surface temperature. In additional simulations with a large number of virtual towers, we investigate higher order correlations, which can be linked to secondary circulations. In a companion

  6. Energy Balance of Triathletes during an Ultra-Endurance Event

    Directory of Open Access Journals (Sweden)

    Anna Barrero

    2014-12-01

    Full Text Available The nutritional strategy during an ultra-endurance triathlon (UET is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE and the fluid balance through the race. Methods: Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI during the race. The EE was estimated from heart rate (HR recordings during the race, using the individual HR-oxygen uptake (Vo2 regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM, total body water (TBW and intracellular (ICW and extracellular water (ECW were assessed before and after the race using a multifrequency bioimpedance device (BIA. Results: Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%. BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Conclusions: Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.

  7. Energy balance of triathletes during an ultra-endurance event.

    Science.gov (United States)

    Barrero, Anna; Erola, Pau; Bescós, Raúl

    2014-12-31

    The nutritional strategy during an ultra-endurance triathlon (UET) is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE) and the fluid balance through the race. Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI) during the race. The EE was estimated from heart rate (HR) recordings during the race, using the individual HR-oxygen uptake (Vo2) regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM), total body water (TBW) and intracellular (ICW) and extracellular water (ECW) were assessed before and after the race using a multifrequency bioimpedance device (BIA). Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%). BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.

  8. Energy Balance of Triathletes during an Ultra-Endurance Event

    Science.gov (United States)

    Barrero, Anna; Erola, Pau; Bescós, Raúl

    2014-01-01

    The nutritional strategy during an ultra-endurance triathlon (UET) is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE) and the fluid balance through the race. Methods: Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI) during the race. The EE was estimated from heart rate (HR) recordings during the race, using the individual HR-oxygen uptake (Vo2) regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM), total body water (TBW) and intracellular (ICW) and extracellular water (ECW) were assessed before and after the race using a multifrequency bioimpedance device (BIA). Results: Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%). BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Conclusions: Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit. PMID:25558906

  9. Improving and validating 3D models for the leaf energy balance in canopy-scale problems with complex geometry

    Science.gov (United States)

    Bailey, B.; Stoll, R., II; Miller, N. E.; Pardyjak, E.; Mahaffee, W.

    2014-12-01

    Plants cover the majority of Earth's land surface, and thus play a critical role in the surface energy balance. Within individual plant communities, the leaf energy balance is a fundamental component of most biophysical processes. Absorbed radiation drives the energy balance and provides the means by which plants produce food. Available energy is partitioned into sensible and latent heat fluxes to determine surface temperature, which strongly influences rates of metabolic activity and growth. The energy balance of an individual leaf is coupled with other leaves in the community through longwave radiation emission and advection through the air. This complex coupling can make scaling models from leaves to whole-canopies difficult, specifically in canopies with complex, heterogeneous geometries. We present a new three-dimensional canopy model that simultaneously resolves sub-tree to whole-canopy scales. The model provides spatially explicit predictions of net radiation exchange, boundary-layer and stomatal conductances, evapotranspiration rates, and ultimately leaf surface temperature. The radiation model includes complex physics such as anisotropic emission and scattering. Radiation calculations are accelerated by leveraging graphics processing unit (GPU) technology, which allows canopy-scale problems to be performed on a standard desktop workstation. Since validating the three-dimensional distribution of leaf temperature can be extremely challenging, we used several independent measurement techniques to quantify errors in measured and modeled values. When compared with measured leaf temperatures, the model gave a mean error of about 2°C, which was close to the estimated measurement uncertainty.

  10. Fuzzy droop control loops adjustment for stored energy balance in distributed energy storage system

    DEFF Research Database (Denmark)

    Aldana, Nelson Leonardo Diaz; Wu, Dan; Dragicevic, Tomislav

    2015-01-01

    The study of isolated AC microgrid has been under high interest due to the integration of renewable energy resources especially for remote areas, or to improve the local energy reliability. The current trend is oriented to distributed renewable energy sources and their corresponding energy storage...... system, in order to smooth the variations at the prime energy generator. In this paper, a decentralized strategy based on fuzzy logic is proposed in order to balance the state of charge of distributed energy storage systems in lowvoltage three phase AC microgrid. The proposed method weights the action...... of conventional droop control loops for battery based distributed energy storage systems, in order to equalize their stored energy. The units are selfcontrolled by using local variables, hence, the microgrid can operate without communication systems. Frequency and voltage bus signaling are used in order...

  11. The control of vineyard energy balance by sprinkling irrigation

    International Nuclear Information System (INIS)

    Pitacco, A.; Giulivo, C.; Iacono, F.

    1999-01-01

    A theoretical model to understand and analyse the cooling effect of overhead sprinkling irrigation is proposed, founded on physical principles determining the canopy energy balance. It can predict maximum cooling of foliage starting from fundamental micro meteorological variables (net radiation, air temperature and humidity, windspeed) and aerodynamic characteristics of the canopy. In order to test it, the algorithms have been implemented in an automated system to control irrigation in a vineyard in Trentino region. Results confirmed the possibility of a good control of foliage thermal regime, cooling it down even respect to control plots maintained at an optimal water supply. The use of the proposed algorithms allowed a good overall efficiency of the irrigation system. However, the effects of cooling on grape quality have been slight, since conditioning started after veraison [it

  12. CO2 balance in production of energy based on biogas

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts; Holm-Nielsen, J.B.

    1997-01-01

    Biogas is an essential biomass source for achieving a reduction of CO2 emission by 50% in year 2030 in Denmark. The physical potential for biogas production in Denmark is more than 10 times the present biogas production in Denmark. In Denmark the largest part of the biogas production is produced...... at 19 decentralised joint biogas plants involving a varying number of farms (5-100). All of these plants use to some extent co-fermentation with industrial organic waste to increase biogas yield.A fuel chain approach for utilisation of biogas for energy purposes is carried out for determining the role...... of increased transportation distances at large biogas plants on the total CO2 balance of the biogas plant. The advantage of constructing large biogas plants is the cost-effective possibility of using industrial organic waste to increase biogas production. In some cases co-fermentation increases biogas...

  13. Obstructive sleep apnea and energy balance regulation: A systematic review.

    Science.gov (United States)

    Shechter, Ari

    2017-08-01

    Obesity and obstructive sleep apnea (OSA) have a reciprocal relationship. Sleep disruptions characteristic of OSA may promote behavioral, metabolic, and/or hormonal changes favoring weight gain and/or difficulty losing weight. The regulation of energy balance (EB), i.e., the relationship between energy intake (EI) and energy expenditure (EE), is complex and multi-factorial, involving food intake, hormonal regulation of hunger/satiety/appetite, and EE via metabolism and physical activity (PA). The current systematic review describes the literature on how OSA affects EB-related parameters. OSA is associated with a hormonal profile characterized by abnormally high leptin and ghrelin levels, which may encourage excess EI. Data on actual measures of food intake are lacking, and not sufficient to make conclusions. Resting metabolic rate appears elevated in OSA vs. Findings on PA are inconsistent, but may indicate a negative relationship with OSA severity that is modulated by daytime sleepiness and body weight. A speculative explanation for the positive EB in OSA is that the increased EE via metabolism induces an overcompensation in the drive for hunger/food intake, which is larger in magnitude than the rise in EI required to re-establish EB. Understanding how OSA affects EB-related parameters can help improve weight loss efforts in these patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Energy year 2005 - how is the energy balance in Rogaland and what are the implications?

    International Nuclear Information System (INIS)

    2006-01-01

    The topic of the lunch meeting is the current and future energy balance in the county of Rogaland, Norway. The question of how to meet the future's increased energy demand is treated. An assessment of the energy situation in the years 2005-2015 is made. Regional projects are presented in the forms of coal fired power station, gasworks and wind power projects. The presented projects are Haugaland Kraft's coal-fired power station, Naturkraft's gas fired power plant and Norsk Vind Energi's wind turbine plants (ml)

  15. Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

    DEFF Research Database (Denmark)

    Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker

    2016-01-01

    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in g...

  16. Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

    NARCIS (Netherlands)

    Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker; Ahlstrøm, Andreas P.; Abermann, Jakob; Andersen, Morten L.; Andersen, Signe B.; Bjørk, Anders A.; Box, Jason E.; Braithwaite, Roger J.; Bøggild, Carl E.; Citterio, Michele; Clement, Poul; Colgan, William; Fausto, Robert S.; Gleie, Karin; Gubler, Stefanie; Hasholt, Bent; Hynek, Bernhard; Knudsen, Niels T.; Larsen, Signe H.; Mernild, Sebastian H.; Oerlemans, Johannes; Oerter, Hans; Olesen, Ole B.; Smeets, C. J P Paul; Steffen, Konrad; Stober, Manfred; Sugiyama, Shin; Van As, Dirk; Van Den Broeke, Michiel R.; Van De Wal, Roderik S W

    2016-01-01

    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in

  17. Surface energy and surface tension of liquid metal nanodrops

    Directory of Open Access Journals (Sweden)

    Shebzukhov A.A.

    2011-05-01

    Full Text Available A unitary approach has been proposed for the calculation of surface energy and surface tension of nanoparticle being in equilibrium with its saturated vapor on both flat and curved surfaces at given temperature. The final equations involve parameters dependent on the type of premelting structure: bcc, fcc or hcp.

  18. Surface energy and surface tension of liquid metal nanodrops

    Science.gov (United States)

    Shebzukhova, M. A.; Shebzukhov, A. A.

    2011-05-01

    A unitary approach has been proposed for the calculation of surface energy and surface tension of nanoparticle being in equilibrium with its saturated vapor on both flat and curved surfaces at given temperature. The final equations involve parameters dependent on the type of premelting structure: bcc, fcc or hcp.

  19. Surface energy and surface tension of liquid metal nanodrops

    OpenAIRE

    Shebzukhov A.A.; Shebzukhova M.A.

    2011-01-01

    A unitary approach has been proposed for the calculation of surface energy and surface tension of nanoparticle being in equilibrium with its saturated vapor on both flat and curved surfaces at given temperature. The final equations involve parameters dependent on the type of premelting structure: bcc, fcc or hcp.

  20. Executive summary of the energy balance from Sao Paulo State, Brazil, 1996. Base year: 1995

    International Nuclear Information System (INIS)

    1996-01-01

    This document presents a executive summary of the energy balance in the year 1995, reporting the energy consumption considering the energy market dynamics and increasing ratio in the residential, public, commercial, agricultural, cattle breeding, transportation and industry areas

  1. The evaporative fraction as a measure of surface energy partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, W.E. [Pacific Northwest Lab., Richland, WA (United States); Cuenca, R.H. [Oregon State Univ., Corvallis, OR (United States)

    1990-12-31

    The evaporative fraction is a ratio that expresses the proportion of turbulent flux energy over land surfaces devoted to evaporation and transpiration (evapotranspiration). It has been used to characterize the energy partition over land surfaces and has potential for inferring daily energy balance information based on mid-day remote sensing measurements. The HAPEX-MOBILHY program`s SAMER system provided surface energy balance data over a range of agricultural crops and soil types. The databases from this large-scale field experiment was analyzed for the purpose of studying the behavior and daylight stability of the evaporative fraction in both ideal and general meteorological conditions. Strong linear relations were found to exist between the mid-day evaporative fraction and the daylight mean evaporative fraction. Statistical tests however rejected the hypothesis that the two quantities were equal. The relations between the evaporative fraction and the surface soil moisture as well as soil moisture in the complete vegetation root zone were also explored.

  2. The evaporative fraction as a measure of surface energy partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, W.E. (Pacific Northwest Lab., Richland, WA (United States)); Cuenca, R.H. (Oregon State Univ., Corvallis, OR (United States))

    1990-01-01

    The evaporative fraction is a ratio that expresses the proportion of turbulent flux energy over land surfaces devoted to evaporation and transpiration (evapotranspiration). It has been used to characterize the energy partition over land surfaces and has potential for inferring daily energy balance information based on mid-day remote sensing measurements. The HAPEX-MOBILHY program's SAMER system provided surface energy balance data over a range of agricultural crops and soil types. The databases from this large-scale field experiment was analyzed for the purpose of studying the behavior and daylight stability of the evaporative fraction in both ideal and general meteorological conditions. Strong linear relations were found to exist between the mid-day evaporative fraction and the daylight mean evaporative fraction. Statistical tests however rejected the hypothesis that the two quantities were equal. The relations between the evaporative fraction and the surface soil moisture as well as soil moisture in the complete vegetation root zone were also explored.

  3. Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

    DEFF Research Database (Denmark)

    Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker

    2016-01-01

    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes...... in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of similar to 3000 measurements from......-term time series of which there are only two exceeding 20 a. We use the data to analyse uncertainties in point measurements of surface mass balance, as well as to estimate surface mass-balance profiles for most regions of Greenland....

  4. Energy, fiscal balances and national sharing : research report

    International Nuclear Information System (INIS)

    Mansell, R.; Anderson, J.; Schlenker, R.; Calgary Univ., AB

    2005-01-01

    In recent years, the large fiscal surpluses of the Alberta government have attracted considerable attention. The economies of this major oil and gas producing region in Canada have expanded due to rising energy demand and high prices. The province accounts for nearly 75 per cent of Canada's oil and gas production, while its energy sector accounts for more than 50 per cent of the Alberta economy. Non-renewable resource revenue for the provincial government has increased along with gains in output and employment. There are some concerns that the strength in Alberta's fiscal position and in the economy may undermine Canada's fiscal equalization regime. Proposed solutions include federal policies that transfer more of Alberta's wealth to other regions. Alberta is concerned that a national fiscal, energy or environmental policy that transfers huge amounts of income out of the province would result in bankruptcies and a legacy of mistrust. There is also growing awareness in the province that it will be difficult to maintain a strong economy and that revenues will decline as reserves of conventional oil and gas are depleted. Presently, it is more challenging to develop unconventional energy supplies due to labour, environmental, technology and infrastructure constraints. This paper examined the record of fiscal redistribution across regions in Canada along with the future of Alberta's resource revenues in an effort to pursue informed discussion on these issues. The authors indicated that the province is already the largest net contributor to federal fiscal balances and redistribution to other regions. Alberta's net contributions are greater than what one would expect given accepted measures of fairness and the same standards applied to other regions. It was suggested that asking Albertans to make even larger net fiscal contributions to the benefit of other regions is not consistent with any standard of fairness. 12 refs., 3 tabs., 4 figs

  5. Parametrisation of the variety of human behaviour related to building energy consumption in the Town Energy Balance (SURFEX-TEB v. 8.2

    Directory of Open Access Journals (Sweden)

    R. Schoetter

    2017-07-01

    Full Text Available The anthropogenic heat flux can be an important part of the urban surface energy balance. Some of it is due to energy consumption inside buildings, which depends on building use and human behaviour, both of which are very heterogeneous in most urban areas. Urban canopy parametrisations (UCP, such as the Town Energy Balance (TEB, parametrise the effect of the buildings on the urban surface energy balance. They contain a simple building energy model. However, the variety of building use and human behaviour at grid point scale has not yet been represented in state of the art UCPs. In this study, we describe how we enhance the Town Energy Balance in order to take fractional building use and human behaviour into account. We describe how we parametrise different behaviours and initialise the model for applications in France. We evaluate the spatio-temporal variability of the simulated building energy consumption for the city of Toulouse. We show that a more detailed description of building use and human behaviour enhances the simulation results. The model developments lay the groundwork for simulations of coupled urban climate and building energy consumption which are relevant for both the urban climate and the climate change mitigation and adaptation communities.

  6. Parametrisation of the variety of human behaviour related to building energy consumption in the Town Energy Balance (SURFEX-TEB v. 8.2)

    Science.gov (United States)

    Schoetter, Robert; Masson, Valéry; Bourgeois, Alexis; Pellegrino, Margot; Lévy, Jean-Pierre

    2017-07-01

    The anthropogenic heat flux can be an important part of the urban surface energy balance. Some of it is due to energy consumption inside buildings, which depends on building use and human behaviour, both of which are very heterogeneous in most urban areas. Urban canopy parametrisations (UCP), such as the Town Energy Balance (TEB), parametrise the effect of the buildings on the urban surface energy balance. They contain a simple building energy model. However, the variety of building use and human behaviour at grid point scale has not yet been represented in state of the art UCPs. In this study, we describe how we enhance the Town Energy Balance in order to take fractional building use and human behaviour into account. We describe how we parametrise different behaviours and initialise the model for applications in France. We evaluate the spatio-temporal variability of the simulated building energy consumption for the city of Toulouse. We show that a more detailed description of building use and human behaviour enhances the simulation results. The model developments lay the groundwork for simulations of coupled urban climate and building energy consumption which are relevant for both the urban climate and the climate change mitigation and adaptation communities.

  7. Energy and water balance determination in an advective environment:From direct measurement to microclimate based estimation

    Science.gov (United States)

    The contributions of John Monteith are perhaps nowhere more widely acknowledged than in the community of scientists and engineers concerned with estimation of evapotranspiration. His addition of surface energy balance flux resistance formulations to the evaporation estimation formula of Penman presa...

  8. Modelling the water and energy balances of Amazonian rainforest and pasture using Anglo-Brazilian Amazonian climate observation study data

    NARCIS (Netherlands)

    Ashby, M.

    1999-01-01

    A soil-vegetation-atmosphere transfer model, SWAPS, is introduced. The model is based on existing models for two-layer evaporation and energy balance, interception evaporation and unsaturated soil moisture transport. The model includes a physically based parameterisation for the soil surface

  9. Energy-balance climate models: stability experiments with a refined albedo and updated coefficients for infrared emission

    NARCIS (Netherlands)

    Oerlemans, J.

    1978-01-01

    A zonally averaged' climate model of the energy-balance type is examined. Recently published satellite measurements were used to improve existing parameterizations of planetary albedo and outgoing radiation in terms of surface and sea level temperature. A realistic constant for the diffusion of

  10. CRTC3 links catecholamine signalling to energy balance.

    Science.gov (United States)

    Song, Youngsup; Altarejos, Judith; Goodarzi, Mark O; Inoue, Hiroshi; Guo, Xiuqing; Berdeaux, Rebecca; Kim, Jeong-Ho; Goode, Jason; Igata, Motoyuki; Paz, Jose C; Hogan, Meghan F; Singh, Pankaj K; Goebel, Naomi; Vera, Lili; Miller, Nina; Cui, Jinrui; Jones, Michelle R; Chen, Yii-Der I; Taylor, Kent D; Hsueh, Willa A; Rotter, Jerome I; Montminy, Marc

    2010-12-16

    The adipose-derived hormone leptin maintains energy balance in part through central nervous system-mediated increases in sympathetic outflow that enhance fat burning. Triggering of β-adrenergic receptors in adipocytes stimulates energy expenditure by cyclic AMP (cAMP)-dependent increases in lipolysis and fatty-acid oxidation. Although the mechanism is unclear, catecholamine signalling is thought to be disrupted in obesity, leading to the development of insulin resistance. Here we show that the cAMP response element binding (CREB) coactivator Crtc3 promotes obesity by attenuating β-adrenergic receptor signalling in adipose tissue. Crtc3 was activated in response to catecholamine signals, when it reduced adenyl cyclase activity by upregulating the expression of Rgs2, a GTPase-activating protein that also inhibits adenyl cyclase activity. As a common human CRTC3 variant with increased transcriptional activity is associated with adiposity in two distinct Mexican-American cohorts, these results suggest that adipocyte CRTC3 may play a role in the development of obesity in humans.

  11. Brazilian energy balance 1996: calendar year 1995; Balanco energetico nacional 1996: ano base 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances.

  12. Brazilian energy balance 1998: calendar year 1997; Balanco energetico nacional 1998: ano base 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances.

  13. Temporal and Spatial Variations of Energy Balance Closure across FLUXNET Research Sites

    Science.gov (United States)

    Chui, T. F. M.; CUI, W.

    2017-12-01

    The surface energy balance at most measurement sites is not closed and the reason behind the discrepancy between available energy and output energy is always under debate. Based on the FLUXNET database and MODIS product, this study analyzed the energy balance closure (EBC) of around 100 sites covering nine vegetation types in different latitudes and explored the possible relationships between EBC and environmental variables. The results showed that EBC is closely related with precipitation, friction velocity, vapor pressure deficit (VPD) and enhanced vegetation index (EVI). The EBC, computed at 30-min intervals, of different land covers increased with the friction velocity and was highest when the air temperature was between 10 and 20 and the VPD was less than 5 hPa. There was no obvious difference in the seasonal variation of EBC among different land covers. However, for most land covers in the boreal region, the worst EBC usually occurred in November, December and January when EVI was minimum, and the best closure occurred in June and July when EVI was maximum. Moreover, the EBC in the lower latitude was better than that in higher latitude, which could be related with the large uncertainty in ground heat flux measurement due to soil freezing and thawing in the high latitude. This study evaluated the temporal and spatial variations of EBC and investigated the physical explanation behind the energy imbalance based on vegetation growth and climates in different latitudes. It shed some insights regarding the energy imbalance issue and the energy flux between the atmosphere and land surface.

  14. Energy balance for Sachsen-Anhalt 2010; Energiebilanz Sachsen-Anhalt 2010

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    The energy balance of Saxony-Anhalt is presented in physical units, in terrajoule and in coal equivalent to show supply, conversion, and consumption of primary and secondary energy sources in the year under report 2010 Energy balance for Sachsen-Anhalt.

  15. A novel determination of energy expenditure efficiency during a balance task using accelerometers. A pilot study.

    Science.gov (United States)

    Caña-Pino, Alejandro; Apolo-Arenas, Maria Dolores; Moral-Blanco, Javier; De la Cruz-Sánchez, Ernesto; Espejo-Antúnez, Luis

    2017-08-18

    The objectives of this study are to determine the displacement of the center of pressure (CoP) and its association with the spectral energy density of the acceleration required for the maintenance of postural balance in different standing positions in healthy participants using design observational and setting laboratorial studies. Participants were 30 healthy university students aged between 18 and 32 years old (mean [M] ± standard deviation [SD] = 21,57 ± 3,31 years). Triaxial accelerometer and a pressure platform were used in order to obtain energy spectral density and CoP sway measurements during four balance tasks. Statistically significant differences were found for anteroposterior (p = 0.002) and mediolateral (p = 0.009) CoP displacement between the conditions eyes closed and stable surface and the conditions eyes closed and unstable surface. A statistically significant correlation was also observed between Z-axis (anterior-posterior) of the accelerometer and mediolateral axis of the CoP (r = 0.465; p = 0.01) and between Y-axis accelerometer (mediolateral) and displacement of the CoP in the anteroposterior axis (r = 0.413; p = 0.023). Spectral energy density appears to be associated with the displacement of CoP in healthy participants.

  16. Scheduling algorithms for saving energy and balancing load

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Antonios

    2012-08-03

    In this thesis we study problems of scheduling tasks in computing environments. We consider both the modern objective function of minimizing energy consumption, and the classical objective of balancing load across machines. We first investigate offline deadline-based scheduling in the setting of a single variable-speed processor that is equipped with a sleep state. The objective is that of minimizing the total energy consumption. Apart from settling the complexity of the problem by showing its NP-hardness, we provide a lower bound of 2 for general convex power functions, and a particular natural class of schedules called s{sub crit}-schedules. We also present an algorithmic framework for designing good approximation algorithms. For general convex power functions our framework improves the best known approximation-factor from 2 to 4/3. This factor can be reduced even further to 137/117 for a specific well-motivated class of power functions. Furthermore, we give tight bounds to show that our framework returns optimal s{sub crit}-schedules for the two aforementioned power-function classes. We then focus on the multiprocessor setting where each processor has the ability to vary its speed. Job migration is allowed, and we again consider classical deadline-based scheduling with the objective of energy minimization. We first study the offline problem and show that optimal schedules can be computed efficiently in polynomial time for any convex and non-decreasing power function. Our algorithm relies on repeated maximum flow computations. Regarding the online problem and power functions P(s) = s{sup {alpha}}, where s is the processor speed and {alpha} > 1 a constant, we extend the two well-known single-processor algorithms Optimal Available and Average Rate. We prove that Optimal Available is {alpha}{sup {alpha}}-competitive as in the single-processor case. For Average Rate we show a competitive factor of (2{alpha}){sup {alpha}}/2 + 1, i.e., compared to the single

  17. How effective would solar geoengineering be at offsetting surface mass balance losses of the ice-sheets?

    Science.gov (United States)

    Irvine, P. J.; Keith, D.

    2016-12-01

    Studies of the sea-level rise response to solar geoengineering suggest that it could be highly effective at reducing sea-level rise by reducing thermal expansion of ocean waters and reducing the melting of land ice. However, all studies to date have employed simplistic treatments of surface mass balance where melt is a function only of surface air temperature and many have not had explicit treatments of accumulation. Solar geoengineering would counteract the longwave forcing of elevated greenhouse gas concentrations by reducing incoming solar radiation, changing the seasonal, latitudinal and vertical distribution of energy within the climate system. Climate model simulations suggest that solar geoengineering deployed to counter future warming from rising greenhouse gas concentrations could partially offset many climate trends associated with rising greenhouse gas concentrations, however it would lead to a suppression of the hydrological cycle as well as leading to substantial residual regional climate changes. In this study the response of the surface mass balance of the Greenland and Antarctic ice sheets to solar geoengineering will be investigated. Multi-model results from G1, the idealized solar insolation reduction experiment of the Geoengineering Model Intercomparison Project (GeoMIP), will be compared against results from the abrupt4×CO2 and piControl experiment. The energy and mass balance of the ice sheets, as well as the broader climate response in the polar regions will be analysed in the GeoMIP ensemble. This analysis will be complemented by offline surface mass balance simulations, including both those which directly simulate the energy balance and by those which use approximations based on surface air temperatures. This analysis will help to determine whether previous studies have over- or under-estimated the efficacy of solar geoengineering at offsetting future sea-level rise.

  18. An efficient regional energy-moisture balance model for simulation of the Greenland Ice Sheet response to climate change

    Directory of Open Access Journals (Sweden)

    A. Robinson

    2010-04-01

    Full Text Available In order to explore the response of the Greenland ice sheet (GIS to climate change on long (centennial to multi-millennial time scales, a regional energy-moisture balance model has been developed. This model simulates seasonal variations of temperature and precipitation over Greenland and explicitly accounts for elevation and albedo feedbacks. From these fields, the annual mean surface temperature and surface mass balance can be determined and used to force an ice sheet model. The melt component of the surface mass balance is computed here using both a positive degree day approach and a more physically-based alternative that includes insolation and albedo explicitly. As a validation of the climate model, we first simulated temperature and precipitation over Greenland for the prescribed, present-day topography. Our simulated climatology compares well to observations and does not differ significantly from that of a simple parameterization used in many previous simulations. Furthermore, the calculated surface mass balance using both melt schemes falls within the range of recent regional climate model results. For a prescribed, ice-free state, the differences in simulated climatology between the regional energy-moisture balance model and the simple parameterization become significant, with our model showing much stronger summer warming. When coupled to a three-dimensional ice sheet model and initialized with present-day conditions, the two melt schemes both allow realistic simulations of the present-day GIS.

  19. Energy Balance After Sodium-Glucose Cotransporter 2 Inhibition.

    Science.gov (United States)

    Ferrannini, Giulia; Hach, Thomas; Crowe, Susanne; Sanghvi, Arjun; Hall, Kevin D; Ferrannini, Ele

    2015-09-01

    Sodium-glucose cotransporter 2 (SGLT2) inhibitors cause substantially less weight loss than expected from the energy excreted via glycosuria. Our aim was to analyze this phenomenon quantitatively. Eighty-six patients with type 2 diabetes (HbA1c 7.8 ± 0.8% [62 ± 9 mmol/mol], estimated glomerular filtration rate [eGFR] 89 ± 19 mL ⋅ min(-1) ⋅ 1.73 m(-2)) received empagliflozin (25 mg/day) for 90 weeks with frequent (n = 11) assessments of body weight, eGFR, and fasting plasma glucose (FPG). Time-dependent glucose filtration was calculated as the product of eGFR and FPG; time-dependent glycosuria was estimated from previous direct measurements. The relation of calorie-to-weight changes was estimated using a mathematical model of human energy metabolism that simulates the time course of weight change for a given change in calorie balance and calculates the corresponding energy intake changes. At week 90, weight loss averaged -3.2 ± 4.2 kg (corresponding to a median calorie deficit of 51 kcal/day [interquartile range (IQR) 112]). However, the observed calorie loss through glycosuria (206 kcal/day [IQR 90]) was predicted to result in a weight loss of -11.3 ± 3.1 kg, assuming no compensatory changes in energy intake. Thus, patients lost only 29 ± 41% of the weight loss predicted by their glycosuria; the model indicated that this difference was accounted for by a 13% (IQR 12) increase in calorie intake (269 kcal/day [IQR 258]) coupled with a 2% (IQR 5) increase in daily energy expenditure (due to diet-induced thermogenesis). This increased calorie intake was inversely related to baseline BMI (partial r = -0.34, P restriction is expected to be associated with major weight loss. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  20. Energy balance in high-quality cutting of steel by fiber and CO2 lasers

    Science.gov (United States)

    Fomin, V. M.; Golyshev, A. A.; Orishich, A. M.; Shulyat'ev, V. B.

    2017-03-01

    The energy balance of laser cutting of low-carbon and stainless steel sheets with the minimum roughness of the cut surface is experimentally studied. Experimental data obtained in wide ranges of cutting parameters are generalized with the use of dimensionless parameters (Peclet number and absorbed laser energy). It is discovered for the first time that the minimum roughness is ensured at a certain value of energy per unit volume of the melt (approximately 26 J/mm3), regardless of the gas type (oxygen or nitrogen) and laser type (fiber laser with a wavelength of 1.07 μm or CO2 laser with a wavelength of 10.6 μm).

  1. Relationships between energy balance and health traits of dairy cattle in early lactation.

    Science.gov (United States)

    Collard, B L; Boettcher, P J; Dekkers, J C; Petitclerc, D; Schaeffer, L R

    2000-11-01

    The objective of the study was to calculate phenotypic relationships between energy balance in early lactation and health and reproduction in that lactation. Data were 26,701 daily records of dry matter intake and milk production, periodic measures of milk composition and body weight, and all health and reproductive information from 140 multiparous Holstein cows. Daily energy balance was calculated by multiplying feed intake by the concentration of energy of the ration and subtracting the amount of energy required for maintenance (based on parity and body weight) and for milk production (based on yield and concentrations of fat, protein, and lactose). Six measures of energy balance were defined: mean daily energy balance during the first 20, 50, and 100 d of lactation; minimum daily energy balance; days in negative energy balance; and total energy deficit. Measures of health were the numbers of occurrences of each of the following during lactation: all udder problems, mastitis, all locomotive problems, laminitis, digestive problems, and reproductive problems. Reproductive traits were the number of days to first observed estrus and number of inseminations. Several significant relationships between energy balance and health were observed. Increased digestive and locomotive problems were associated with longer and more extreme periods of negative energy balance.

  2. Dike propagation energy balance from deformation modeling and seismic release

    Science.gov (United States)

    Bonaccorso, Alessandro; Aoki, Yosuke; Rivalta, Eleonora

    2017-06-01

    Magma is transported in the crust mainly by dike intrusions. In volcanic areas, dikes can ascend toward the free surface and also move by lateral propagation, eventually feeding flank eruptions. Understanding dike mechanics is a key to forecasting the expected propagation and associated hazard. Several studies have been conducted on dike mechanisms and propagation; however, a less in-depth investigated aspect is the relation between measured dike-induced deformation and the seismicity released during its propagation. We individuated a simple x that can be used as a proxy of the expected mechanical energy released by a propagating dike and is related to its average thickness. For several intrusions around the world (Afar, Japan, and Mount Etna), we correlate such mechanical energy to the seismic moment released by the induced earthquakes. We obtain an empirical law that quantifies the expected seismic energy released before arrest. The proposed approach may be helpful to predict the total seismic moment that will be released by an intrusion and thus to control the energy status during its propagation and the time of dike arrest.Plain Language SummaryDike propagation is a dominant mechanism for magma ascent, transport, and eruptions. Besides being an intriguing physical process, it has critical hazard implications. After the magma intrusion starts, it is difficult to predict when and where a specific horizontal dike is going to halt and what its final length will be. In our study, we singled an equation that can be used as a proxy of the expected mechanical energy to be released by the opening dike. We related this expected energy to the seismic moment of several eruptive intrusions around the world (Afar region, Japanese volcanoes, and Mount Etna). The proposed novel approach is helpful to estimate the total seismic moment to be released, therefore allowing potentially predicting when the dike will end its propagation. The approach helps answer one of the

  3. Modeling Transport of Turbulent Fluxes in a Heterogeneous Urban Canopy Using a Spatially Explicit Energy Balance

    Science.gov (United States)

    Moody, M.; Bailey, B.; Stoll, R., II

    2017-12-01

    Understanding how changes in the microclimate near individual plants affects the surface energy budget is integral to modeling land-atmosphere interactions and a wide range of near surface atmospheric boundary layer phenomena. In urban areas, the complex geometry of the urban canopy layer results in large spatial deviations of turbulent fluxes further complicating the development of models. Accurately accounting for this heterogeneity in order to model urban energy and water use requires a sub-plant level understanding of microclimate variables. We present analysis of new experimental field data taken in and around two Blue Spruce (Picea pungens) trees at the University of Utah in 2015. The test sites were chosen in order study the effects of heterogeneity in an urban environment. An array of sensors were placed in and around the conifers to quantify transport in the soil-plant-atmosphere continuum: radiative fluxes, temperature, sap fluxes, etc. A spatial array of LEMS (Local Energy Measurement Systems) were deployed to obtain pressure, surrounding air temperature and relative humidity. These quantities are used to calculate the radiative and turbulent fluxes. Relying on measurements alone is insufficient to capture the complexity of microclimate distribution as one reaches sub-plant scales. A spatially-explicit radiation and energy balance model previously developed for deciduous trees was extended to include conifers. The model discretizes the tree into isothermal sub-volumes on which energy balances are performed and utilizes incoming radiation as the primary forcing input. The radiative transfer component of the model yields good agreement between measured and modeled upward longwave and shortwave radiative fluxes. Ultimately, the model was validated through an examination of the full energy budget including radiative and turbulent fluxes through isolated Picea pungens in an urban environment.

  4. A Mixed Transmission Strategy to Achieve Energy Balancing in Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Liu, Tong; Gu, Tao; Jin, Ning

    2017-01-01

    lifetime, and hence, it has many practical implications for sensor network design and deployment. The traditional hop-by-hop transmission model allows a sensor node to propagate its packets in a hop-by-hop manner toward the sink, resulting in poor energy balancing for the entire network. To address......In this paper, we investigate the problem of energy balanced data collection in wireless sensor networks, aiming to balance energy consumption among all sensor nodes during the data propagation process. Energy balanced data collection can potentially save energy consumption and prolong network...... the problem, we apply a slice-based energy model, and divide the problem into inter-slice and intra-slice energy balancing problems. We then propose a probability-based strategy named inter-slice mixed transmission protocol and an intra-slice forwarding technique to address each of the problems. We propose...

  5. Radiation and energy balance of lettuce culture inside a polyethylene greenhouse

    International Nuclear Information System (INIS)

    Frisina, V. de A.; Escobedo, J.F.

    1999-01-01

    The objective of this paper was to describe the radiation and energy balance, during the lettuce (Lactuca sativa, L. cv. Verônica) crop cycle inside a polyethylene greenhouse. The radiation and energy balance was made inside a tunnel greenhouse with polyethylene cover (100 mm) and in an external area, both areas with 35 m 2 . Global, reflected and net radiation, soil heat flux and air temperature (dry and humid) were measured during the crop cycle. A Datalogger, which operated at 1 Hz frequency, storing 5 minutes averages was utilized. The global (K↓) and reflected (K) radiations showed that the average transmission of global radiation (K↓in / K↓ex) was almost constant, near to 79.59%, while the average ratio of reflected radiation (Kin / Kex) was 69.21% with 8.47% standard-deviation. The normalized curves of short-wave net radiation, in relation to the global radiation (K*/ K↓), found for both environments, were almost constant at the beginning of cycle; this relation decreased in the final stage of culture. The normalized relation (Rn/ K↓) was bigger in the external area, about 12%, when the green culture covered the soil surface. The long-wave radiation balance average (L*) was bigger outside, about 50%. The energy balance, estimated in terms of vertical fluxes, showed that, for the external area, in average, 83.07% of total net radiation was converted in latent heat evaporation (LE), and 18% in soil heat flux (G), and 9.96% in sensible heat (H), while inside of the greenhouse, 58.71% of total net radiation was converted in LE, 42.68% in H, and 28.79% in G. (author) [pt

  6. Development of balanced downflow type surface condensers, (2)

    International Nuclear Information System (INIS)

    Tomida, Akira; Oshima, Yoshikuni; Okochi, Isao; Izumi, Kenkichi.

    1976-01-01

    As the size of the condensers for power generation plants grew large, the new balanced downflow type condenser was developed and completed on the basis of the experiment on steam flow according to the two-dimensional flow model, the analysis of the performance in a tube nest with a computer, and the studies on the effect of outside liquid film and the reheating deaeration of condensate. When the balanced downflow type condensers were adopted for actual plants, the construction, strength and production method were examined, and the reliability of the new condenser was confirmed by the thermal characteristic experiment with the model similar to the actual machine. The condenser comprises a condenser body, supporting plates, cooling tubes, tube plates, water chambers, and reinforcements, and the cooling tubes are arranged so as to exchange heat effectively. The arrangement of tubes is divided into three regions, namely radiation portion, densely arranged portion, and air cooling portion. In the balanced downflow type condensers, the dilution by utilizing condensate is provided against ammonia attack. The apparatuses for the thermal characteristic experiment and the experimental results, and the results of the performance test on the actual balanced downflow type condenser are reported. (Kako, I.)

  7. Hohlraums energy balance and x-ray drive

    International Nuclear Information System (INIS)

    Kilkenny, J.D.

    1994-01-01

    For many years there has been an active ICF program in the US concentrating on x-ray drive. X-ray drive is produced by focusing laser beams into a high Z hohlraum. Conceptually, the radiation field comes close to thermodynamic equilibrium, that is it becomes isotropic and Planckian. These properties lead to the benefits of x-ray drive--it is relatively easy to obtain drive symmetry on a capsule with no small scalelengths drive perturbations. Other advantages of x-ray drive is the higher mass ablation rate, leading to lower growth rates for hydrodynamic instabilities. X-ray drive has disadvantages, principally the loss of energy to the walls of the hohlraum. This report is divided into the following sections: (1) review of blackbody radiation; (2) laser absorption and conversion to x-rays; (3) x-ray absorption coefficient in matter and Rosseland mean free path; (4) Marshak waves in high Z material; (5) x-ray albedo; and (6) power balance and hohlraum temperature

  8. Energy balance affected by electrolyte recirculation and operating modes in microbial fuel cells.

    Science.gov (United States)

    Jacobson, Kyle S; Kelly, Patrick T; He, Zhen

    2015-03-01

    Energy recovery and consumption in a microbial fuel cell (MFC) can be significantly affected by the operating conditions. This study investigated the effects of electrolyte recirculation and operation mode (continuous vs sequence batch reactor) on the energy balance in a tubular MFC. It was found that decreasing the anolyte recirculation also decreased the energy recovery. Because of the open environment of the cathode electrode, the catholyte recirculation consumed 10 to 50 times more energy than the anolyte recirculation, and resulted in negative energy balances despite the reduction of the anolyte recirculation. Reducing the catholyte recirculation to 20% led to a positive energy balance of 0.0288 kWh m(-3). The MFC operated as a sequence batch reactor generated less energy and had a lower energy balance than the one with continuous operation. Those results encourage the further development of MFC technology to achieve neutral or even positive energy output.

  9. Solar energy converter using surface plasma waves

    Science.gov (United States)

    Anderson, L. M. (Inventor)

    1984-01-01

    Sunlight is dispersed over a diffraction grating formed on the surface of a conducting film on a substrate. The angular dispersion controls the effective grating period so that a matching spectrum of surface plasmons is excited for parallel processing on the conducting film. The resulting surface plasmons carry energy to an array of inelastic tunnel diodes. This solar energy converter does not require different materials for each frequency band, and sunlight is directly converted to electricity in an efficient manner by extracting more energy from the more energetic photons.

  10. Energy and Greenhouse gas balances of the utilisation of biogas for energy

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts; Karlsson, Kenneth Bernard; Holm-Nielsen, Jens Bo

    1998-01-01

    of the implementation programmes has been on development of technologies for joint biogas plants, where more than one farm supplies the animal slurry. The joint biogas plants are dependent on industrial organic wastes to obtain high biogas yields for making the biogas plant economical. The industrial organic waste will...... biogas for energy. Two different Danish joint biogas plants are evaluated with the aim of determining the role of transportation and co-fermentation on the energy and the balance of greenhouse gases from the biogas fuel cycle....

  11. MRD-CI potential surfaces using balanced basis sets. IV. The H2 molecule and the H3 surface

    International Nuclear Information System (INIS)

    Wright, J.S.; Kruus, E.

    1986-01-01

    The utility of midbond functions in molecular calculations was tested in two cases where the correct results are known: the H 2 potential curve and the collinear H 3 potential surface. For H 2 , a variety of basis sets both with and without bond functions was compared to the exact nonrelativistic potential curve of Kolos and Wolniewicz [J. Chem. Phys. 43, 2429 (1965)]. It was found that optimally balanced basis sets at two levels of quality were the double zeta single polarization plus sp bond function basis (BF1) and the triple zeta double polarization plus two sets of sp bond function basis (BF2). These gave bond dissociation energies D/sub e/ = 4.7341 and 4.7368 eV, respectively (expt. 4.7477 eV). Four basis sets were tested for basis set superposition errors, which were found to be small relative to basis set incompleteness and therefore did not affect any conclusions regarding basis set balance. Basis sets BF1 and BF2 were used to construct potential surfaces for collinear H 3 , along with the corresponding basis sets DZ*P and TZ*PP which contain no bond functions. Barrier heights of 12.52, 10.37, 10.06, and 9.96 kcal/mol were obtained for basis sets DZ*P, TZ*PP, BF1, and BF2, respectively, compared to an estimated limiting value of 9.60 kcal/mol. Difference maps, force constants, and relative rms deviations show that the bond functions improve the surface shape as well as the barrier height

  12. On the impact of clouds on the energy balance of the Antarctic Peninsula Ice Sheet

    Science.gov (United States)

    Caballero, Marta; Braun, Matthias; Mölg, Thomas

    2017-04-01

    Radiative effects of clouds play a key role in the energy balance of the atmosphere and have a critical influence on the ice sheet's radiation budget, causing a warming effect (by absorption and emission of longwave radiation) or cooling effect (by reducing the downwelling shortwave radiation) at the surface. On the Antarctic Peninsula, changes in the glacier system have been observed, such as the disintegration of ice shelves, acceleration and thinning of glaciers, variations in the limits between glacier faces and retreat of glacier fronts. However, rising surface air and ocean temperatures, as well as substantially increased snow fall in some regions, are also known. These tendencies were linked to changes in atmospheric circulation. Hence, a better understanding of the processes and mechanisms leading to such changes is required. The role of clouds has not been well studied yet in this context. Here, preliminary retrievals of satellite-derived cloud macrophysical and microphysical properties in the Antarctic Peninsula will be presented. The data will be analyzed in the special light of improving parameterizations in the Polar Weather Research and Forecasting model. This has the goal to ultimately enhance our understanding of how variations in the cloud cover and properties impact the energy balance on the Antarctic Peninsula at regional scales.

  13. Improving snow albedo processes in WRF/SSiB regional climate model to assess impact of dust and black carbon in snow on surface energy balance and hydrology over western U.S.

    OpenAIRE

    Oaida, CM; Xue, Y; Flanner, MG; Skiles, SMK; De Sales, F; Painter, TH

    2015-01-01

    © 2015. American Geophysical Union. All Rights Reserved. Two important factors that control snow albedo are snow grain growth and presence of light-absorbing impurities (aerosols) in snow. However, current regional climate models do not include such processes in a physically based manner in their land surface models. We improve snow albedo calculations in the Simplified Simple Biosphere (SSiB) land surface model coupled with the Weather Research and Forecasting (WRF) regional climate model (R...

  14. Towards a Sustainable Energy Balance: Progressive Efficiency and the Return of Energy Conservation

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, Rick; Harris, Jeff; Diamond, Rick; Iyer, Maithili; Payne, Christopher; Blumstein, Carl; Siderius, Hans-Paul

    2007-08-13

    We argue that a primary focus on energy efficiency may not be sufficient to slow (and ultimately reverse) the growth in total energy consumption and carbon emissions. Instead, policy makers need to return to an earlier emphasis on"conservation," with energy efficiency seen as a means rather than an end in itself. We briefly review the concept of"intensive" versus"extensive" variables (i.e., energy efficiency versus energy consumption), and why attention to both consumption and efficiency is essential for effective policy in a carbon- and oil-constrained world with increasingly brittle energy markets. To start, energy indicators and policy evaluation metrics need to reflect energy consumption as well as efficiency. We introduce the concept of"progressive efficiency," with the expected or required level of efficiency varying as a function of house size, appliance capacity, or more generally, the scale of energy services. We propose introducing progressive efficiency criteria first in consumer information programs (including appliance labeling categories) and then in voluntary rating and recognition programs such as ENERGY STAR. As acceptance grows, the concept could be extended to utility rebates, tax incentives, and ultimately to mandatory codes and standards. For these and other programs, incorporating criteria for consumption as well as efficiency offers a path for energy experts, policy-makers, and the public to begin building consensus on energy policies that recognize the limits of resources and global carrying-capacity. Ultimately, it is both necessary and, we believe, possible to manage energy consumption, not just efficiency in order to achieve a sustainable energy balance. Along the way, we may find it possible to shift expectations away from perpetual growth and toward satisfaction with sufficiency.

  15. Surface N Balances in Agricultural Crop production systems in China for the period 1980-2015

    NARCIS (Netherlands)

    Sun, B.; Shen, R.P.; Bouwman, A.F.

    2008-01-01

    Surface nitrogen (N) balances for China's crop production systems were estimated using statistical data collected from 1980 to 2004 at the national and provincial scale and from 1994 to 1999 at the county level. There was a surplus N balance throughout these periods, but the surplus was nearly

  16. Energy balance of the Rio de Janeiro State - 1980/1994

    International Nuclear Information System (INIS)

    1995-01-01

    This document informs the energetic balance for Rio de Janeiro State -1980/1994, containing the energy fluxes from primary and secondary energy sources in the main sectors of Rio de Janeiro economy. 50 figs., 139 tabs

  17. Proposal for a refinement of the National Energy Balance (BEN) and Useful Energy Balance (BEU); Proposta de refinamento do Balanco Energetico Nacional e do Balanco de Energia Util

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Alvaro Afonso Furtado [Universidade Estadual de Santa Cruz (DCET/UESC), Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas], email: aafleite@uesc.br; Bajay, Sergio Valdir [Universidade Estadual de Campinas (NIPE/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Nucleo Interdisciplinar de Planejamento Energetico], email: bajay@fem.unicamp.br

    2010-07-01

    The need to discuss the reformulation of two important tools for the Brazilian energy planning - the National Energy Balance (BEN) and the Useful Energy Balance (BEU) - was the motivation to carry out the study reported in this paper. The concepts embodied in the BEN were set out in the seventies, while those structuring the BEU were defined in the eighties. Since then, the ways to produce, trade and consume energy underwent important changes in Brazil and the expansion planning of the national energy system requires, nowadays, more detailed information and, in some cases, more reliable data than those currently provided by the two balances. They need, thus, to be refined, and this paper aims to contribute towards this goal. (author)

  18. Diagnosis, balances and energy indicators in municipalities of 'BASAL' project

    International Nuclear Information System (INIS)

    Pérez Martín, David; Soler Iglesias, Belkis; López López, Ileana; Moreno, Helsy; Matos, Yamilexis; Sanfiel, Caridad; Román, José Enrique

    2015-01-01

    Under the 'Basis for Environmental Sustainability Local Food' project (BASAL)) transverse energy-related activities were conducted. In this work we are analyzed and presented energy diagnoses in municipalities Los Palacios, Guira de Melena and Jimaguayú, capturing energy statistics in the 3 municipalities, energy balances and key energy indicators compared to support sustainability and decision making. (full text)

  19. Measuring surface energy and evapotranspiration across Caribbean mangrove forests

    Science.gov (United States)

    Lagomasino, D.; Fatoyinbo, T. E.; Price, R.

    2014-12-01

    Coastal mangroves lose large amounts of water through evapotranspiration (ET) that can be equivalent to the amount of annual rainfall in certain years. Satellite remote sensing has been used to estimate surface energy and ET variability in many forested ecosystems, yet has been widely overlooked in mangrove forests. Using a combination of long-term datasets (30-year) acquired from the NASA Landsat 5 and 7 satellite databases, the present study investigated ET and surface energy balance variability between two mangrove forest sites in the Caribbean: 1) Everglades National Park (ENP; Florida, USA) and 2) Sian Ka'an Biosphere Reserve (SKBR; Quintana Roo, Mexico). A satellite-derived surface energy balance model was used to estimate ET in tall and scrub mangroves environments at ENP and SKBR. Results identified significant differences in soil heat flux measurements and ET between the tall and scrub mangrove environments. Scrub mangroves exhibited the highest soil heat flux coincident with the lowest biophysical indices (i.e., Fractional Vegetation Cover, Normalized Difference Vegetation Index, and Soil-Adjusted Vegetation Index) and ET rates. Mangrove damage and mortality was observed on the satellite images following strong tropical storms and associated with anthropogenic modifications and resulted in low values in spectral vegetation indices, higher soil heat flux, and higher ET. Recovery of the spectral characteristics, soil heat flux and ET was within 1-2 years following hurricane disturbance while, degradation caused by human disturbance persisted for many years. Remotely sensed ET of mangrove forests can provide estimates over a few decades and provide us with some understanding of how these environments respond to disturbances to the landscape in periods where no ground data exists or in locations that are difficult to access. Moreover, relationships between energy and water balance components developed for the coastal mangroves of Florida and Mexico could be

  20. Water and energy balance in the cultivated and bake soil in a montane area in Paraiba, Brazil

    International Nuclear Information System (INIS)

    Lima, Jose Romualdo de Sousa

    2004-02-01

    In the areas of rain fed agriculture it is very important to quantify losses of water by evapotranspiration and soil evaporation. The methods used for measuring evapotranspiration and/or evaporation varies from direct measurements techniques, using lysimeters, to measurements of the water and energy balances. The precision lysimeters have high cost, being only used for research purposes. The water and energy balances methods have been very used due the simplicity, robustness and lower cost. Therefore, the objective of this study was to assess the water and energy balance components in the soil cultivated with cowpea (Vigna unguiculata (L) Walp) and without vegetation, besides comparing the methods used to determine the cowpea evapotranspiration. Two experiments (2002 and 2003) were performed in the 4 ha area of the Centro de Ciencias Agrarias, UFPB, municipality of Areia, Paraiba State (6 deg C 58 S, 5 deg C 41 W). To determine the energy balance, the area was instrumented with a rain gauge, a pyrano meter, a net radiometer, and sensors for measuring air temperature and humidity, and wind speed in two levels. Two locals, in the soil, were instrumented with two temperature sensors located at 2.0 cm and 8.0 cm below soil surface and one heat flux plate placed at 5.0 cm below soil surface. The measurements were recorded every 30 minutes on a data logger. To determine the water balance, three plots were installed, composed one-meter access tube for neutron probe measurements, and 8 tensiometers. The results show very good correlation between the aerodynamic method and the Bowen ration energy balance method, for all atmospherics and soil water conditions. For the two years, in average 72% of the net radiation was used by crop evapotranspiration. The energy and water balance can be used, the determine the crop evapotranspiration and soil evaporation, and regardless of the method used, the major water use by crop occurred in the reproductive stage. In the year of 2002

  1. Neutron balance as indicator of long-term resource availability in growing nuclear energy system

    Energy Technology Data Exchange (ETDEWEB)

    Blandinskiy, Victor [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

    2017-09-15

    The article describes neutron balance in nuclear energy system as necessary but not sufficient indicator of long-term sustainability. Three models are introduced to evaluate neutron balance based on nuclide chain evolution and reaction rates comparison. The indicator introduced is used to compare several nuclear energy systems consisting of thermal, fast and molten salt reactors.

  2. On Energy Balance and Production Costs in Tubular and Flat Panel Photobioreactors

    NARCIS (Netherlands)

    Norsker, N.H.; Barbosa, M.J.; Vermue, M.H.; Wijffels, R.H.

    2012-01-01

    Reducing mixing in both flat panel and tubular photobioreactors can result in a positive net energy balance with state-of-the-art technology and Dutch weather conditions. In the tubular photobioreactor, the net energy balance becomes positive at velocities <0.3 ms-1, at which point the biomass

  3. Refined energy-balance modelling of a supraglacial pond, Langtang Khola, Nepal

    NARCIS (Netherlands)

    Miles, Evan S.; Pellicciotti, Francesca; Willis, Ian C.; Steiner, Jakob F.; Buri, Pascal; Arnold, Neil S.

    2016-01-01

    Supraglacial ponds on debris-covered glaciers present a mechanism of atmosphere/glacier energy transfer that is poorly studied, and only conceptually included in mass-balance studies of debris-covered glaciers. This research advances previous efforts to develop a model of mass and energy balance for

  4. Socioecological correlates of energy balance using urinary C-peptide measurements in wild female mountain gorillas.

    Science.gov (United States)

    Grueter, Cyril C; Deschner, Tobias; Behringer, Verena; Fawcett, Katie; Robbins, Martha M

    2014-03-29

    Maintaining a balanced energy budget is important for survival and reproduction, but measuring energy balance in wild animals has been fraught with difficulties. Female mountain gorillas are interesting subjects to examine environmental correlates of energy balance because their diet is primarily herbaceous vegetation, their food supply shows little seasonal variation and is abundant, yet they live in cooler, high-altitude habitats that may bring about energetic challenges. Social and reproductive parameters may also influence energy balance. Urinary C-peptide (UCP) has emerged as a valuable non-invasive biomarker of energy balance in primates. Here we use this method to investigate factors influencing energy balance in mountain gorillas of the Virunga Volcanoes, Rwanda. We examined a range of socioecological variables on energy balance in adult females in three groups monitored by the Karisoke Research Center over nine months. Three variables had significant effects on UCP levels: habitat (highest levels in the bamboo zone), season (highest levels in November during peak of the bamboo shoot availability) and day time (gradually increasing from early morning to early afternoon). There was no significant effect of reproductive state and dominance rank. Our study indicates that even in species that inhabit an area with a seemingly steady food supply, ecological variability can have pronounced effects on female energy balance. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Experimental study on comprehensive utilization of solar energy and energy balance in an integrated solar house

    International Nuclear Information System (INIS)

    Chang, Huawei; Liu, Yuting; Shen, Jinqiu; Xiang, Can; He, Sinian; Wan, Zhongmin; Jiang, Meng; Duan, Chen; Shu, Shuiming

    2015-01-01

    Highlights: • Active and passive solar house technology is integrated in the solar house. • Solar thermal system and solar photoelectric system are measured and analyzed. • Energy balance and energy consumption are analyzed with valuable experimental data. • “Zero energy consumption” is truly achieved with the solar supply rate of 1.19 in winter. - Abstract: An integrated solar house with numerous advanced envelops is designed and constructed to investigate the comprehensive utilization of solar energy, energy efficiency and energy balance, which combines active solar house technology with passive solar house technology including solar photovoltaic system, solar water heating system, direct-gain door and windows. Solar radiation intensity, performance of the photovoltaic system, water temperature, and indoor and outdoor temperature are measured, results of the experiments indicate that solar glass window on the south wall can maintain the average indoor temperature at 21.4 °C in the case of average outdoor temperature at 11.2 °C without any external heat supply. The output current of the solar photovoltaic system shows the same trend as solar radiation intensity. When the intensity is 619.7 W/m 2 , the instantaneous generation power could reach a value of 781.9 W, cumulative capacity throughout the day achieves 4.56 kW h and photovoltaic conversion efficiency 9.8%. When the average intensity throughout a day is 358 W/m 2 , the solar water heating system could help to raise the temperature of 450 L water by 30 °C with its heat collecting efficiency being 37.4%. Through the analysis of the overall energy system in the solar house, it can be derived that this solar house could achieve “zero energy consumption” in winter with the solar supply rate at 1.19.

  6. Surface energy of metal alloy nanoparticles

    Science.gov (United States)

    Takrori, Fahed M.; Ayyad, Ahmed

    2017-04-01

    The measurement of surface energy of alloy nanoparticles experimentally is still a challenge therefore theoretical work is necessary to estimate its value. In continuation of our previous work on the calculation of the surface energy of pure metallic nanoparticles we have extended our work to calculate the surface energy of different alloy systems, namely, Co-Ni, Au-Cu, Cu-Al, Cu-Mg and Mo-Cs binary alloys. It is shown that the surface energy of metallic binary alloy decreases with decreasing particle size approaching relatively small values at small sizes. When both metals in the alloy obey the Hume-Rothery rules, the difference in the surface energy is small at the macroscopic as well as in the nano-scale. However when the alloy deviated from these rules the difference in surface energy is large in the macroscopic and in the nano scales. Interestingly when solid solution formation is not possible at the macroscopic scale according to the Hume-Rothery rules, it is shown it may form at the nano-scale. To our knowledge these findings here are presented for the first time and is challenging from fundamental as well as technological point of views.

  7. Energy budget and greenhouse gas balance evaluation of sustainable coppice systems for electricity production

    International Nuclear Information System (INIS)

    Lettens, Suzanna; Muys, Bart; Ceulemans, Reinhart; Moons, Ellen; Garcia, Juan; Coppin, Pol

    2003-01-01

    The use of bio-energy crops for electricity production is considered an effective means to mitigate the greenhouse effect, mainly due to its ability to substitute fossil fuels. A whole range of crops qualify for bio-energy production and a rational choice is not readily made. This paper evaluates the energy and greenhouse gas balance of a mixed indigenous hardwood coppice as an extensive, low-input bio-energy crop. The impact on fossil energy use and greenhouse gas emission is calculated and discussed by comparing its life cycle (cultivation, processing and conversion into energy) with two conventional bio-energy crops (short rotation systems of willow and Miscanthus). For each life cycle process, the flows of fossil energy and greenhouse gas that are created for the production of one functional unit are calculated. The results show that low-input bio-energy crops use comparatively less fossil fuel and avoid more greenhouse gas emission per unit of produced energy than conventional bio-energy crops during the first 100 yr. Where the mixed coppice system avoids up till 0.13 t CO 2 eq./GJ, Miscanthus does not exceed 0.07 t CO 2 eq./GJ. After 100 yr their performances become comparable, amounting to 0.05 t CO 2 eq./ha/GJ. However, if the land surface itself is chosen as a functional unit, conventional crops perform better with respect to mitigating the greenhouse effect. Miscanthus avoids a maximum of 12.9 t CO 2 eq./ha/yr, while mixed coppice attains 9.5 t CO 2 eq./ha/yr at the most

  8. The National Energy Strategy: A balanced program?. Proceedings of the nineteenth annual Illinois energy conference

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    The Nineteenth Annual Illinois Energy Conference was held in Chicago, Illinois November 1991. It was organized by the Energy Resources Center, University of Illinois at Chicago with major support provided by the US Environmental Protection Agency, the US Department of Energy, the Illinois Commerce Commission, the Illinois Department of Energy and Natural Resources, and the Citizens Council on Energy Resources. The conference program was developed by a planning committee who drew upon Illinois energy and environmental specialists from the major sectors including energy industries, environmental organizations, research universities, utility companies, federal, state and local government agencies, and public interest groups. The members of the planning committee were brought together for a full-day session where they were asked to assess the political, economic, and social impacts of the proposed National Energy Strategy as it relates to Illinois and the Midwest region. Within this context, the planning committee identified several major issues including: (1) Is the proposed plan a balanced strategy; (2) What are the NES impacts on the transportation sector; (3) What are the opportunities for improved efficiency in the Electric Utility Sector; and (4) What is the role of advanced research and development.

  9. Estimating Evapotranspiration from an Improved Two-Source Energy Balance Model Using ASTER Satellite Imagery

    Directory of Open Access Journals (Sweden)

    Qifeng Zhuang

    2015-11-01

    Full Text Available Reliably estimating the turbulent fluxes of latent and sensible heat at the Earth’s surface by remote sensing is important for research on the terrestrial hydrological cycle. This paper presents a practical approach for mapping surface energy fluxes using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER images from an improved two-source energy balance (TSEB model. The original TSEB approach may overestimate latent heat flux under vegetative stress conditions, as has also been reported in recent research. We replaced the Priestley-Taylor equation used in the original TSEB model with one that uses plant moisture and temperature constraints based on the PT-JPL model to obtain a more accurate canopy latent heat flux for model solving. The collected ASTER data and field observations employed in this study are over corn fields in arid regions of the Heihe Watershed Allied Telemetry Experimental Research (HiWATER area, China. The results were validated by measurements from eddy covariance (EC systems, and the surface energy flux estimates of the improved TSEB model are similar to the ground truth. A comparison of the results from the original and improved TSEB models indicates that the improved method more accurately estimates the sensible and latent heat fluxes, generating more precise daily evapotranspiration (ET estimate under vegetative stress conditions.

  10. Sorption Energy Maps of Clay Mineral Surfaces

    International Nuclear Information System (INIS)

    Cygan, Randall T.; Kirkpatrick, R. James

    1999-01-01

    A molecular-level understanding of mineral-water interactions is critical for the evaluation and prediction of the sorption properties of clay minerals that may be used in various chemical and radioactive waste disposal methods. Molecular models of metal sorption incorporate empirical energy force fields, based on molecular orbital calculations and spectroscopic data, that account for Coulombic, van der Waals attractive, and short-range repulsive energies. The summation of the non-bonded energy terms at equally-spaced grid points surrounding a mineral substrate provides a three dimensional potential energy grid. The energy map can be used to determine the optimal sorption sites of metal ions on the exposed surfaces of the mineral. By using this approach, we have evaluated the crystallographic and compositional control of metal sorption on the surfaces of kaolinite and illite. Estimates of the relative sorption energy and most stable sorption sites are derived based on a rigid ion approximation

  11. Understanding the Relationship Between Food Variety, Food Intake, and Energy Balance.

    Science.gov (United States)

    Raynor, Hollie A; Vadiveloo, Maya

    2018-03-01

    In accordance with US dietary guidance, incorporating variety into the diet can align with energy balance, though greater food variety in some categories may make energy balance more challenging. Thus, experimental and epidemiologic evidence is summarized on the relationship between food variety, food and energy intake, and energy balance. Lab-based, experimental research consistently demonstrates that greater variety within foods or sensory characteristics of food increases food and energy intake within an eating occasion. Epidemiologic evidence is less consistent, potentially driven by differing methodologies, particularly in defining and measuring food variety. Moreover, the effect of variety on energy balance appears to be moderated by food energy density. Integrating insights from experimental and epidemiologic research are essential for strengthening food variety guidance including developing evidence-based definitions of food variety, understanding moderators of the relationship, and developing practical guidance interpretable to consumers.

  12. System analysis of a bio-energy plantation: full greenhouse gas balance and energy accounting (POPFULL)

    Science.gov (United States)

    Ceulemans, R.; Janssens, I.; Berhongaray, G.; Broeckx, L.; De Groote, T.; ElKasmioui, O.; Fichot, R.; Njakou Djomo, S.; Verlinden, M.; Zona, D.

    2011-12-01

    In recent year the environmental impact of fossil fuels and their reduced availability are leading to an increasing interest in renewable energy sources, among them bio-energy. However, the cost/benefit in establishing, managing, and using these plantations for energy production should be quantified together with their environmental impact. In this project we are performing a full life cycle analysis (LCA) balance of the most important greenhouse gases (CO2, CH4, N2O, H2O and O3), together with full energy accounting of a short-rotation coppice (SRC) plantation with fast-growing trees. We established the plantation two years ago and we have been monitoring net fluxes of CO2, N2O, CH4, and O3, in combination with biomass pools (incl. soil) and fluxes, and volatile organic carbon (VOCs). This poplar plantation will be monitored for another two years then harvested and transformed into bio-energy. For the energy accounting we are performing a life cycle analysis and energy efficiency assessments over the entire cycle of the plantation until the production of electricity and heat. Here we present an overview of the results from the first two years from the plantation establishment, and some of the projections based on these first results.

  13. Energy balance of Sao Paulo State, Brazil 2012. Calendar year 2011

    International Nuclear Information System (INIS)

    2012-01-01

    The document presents the consolidated annual energy balances, which encompasses: Executive Summary; Participation of the Sao Paulo's Electric Energy in the National Context; Overview Energy Mix of the State of Sao Paulo; Final Consumption by Source; Final Consumption by Sectors in 2011; Contents of the Energy Balance for the State of Sao Paulo; Methodology; Summary of the period in analysis; Supply and Demand of energy by source; External trade of energy; Energy imports and export; Transformation center balances; Energy and Economy and Resources and energy Reserves. In this 2012 edition, we highlight the growth of gasoline consumption at the expense of ethanol, compared with previous years. The fall harvest of cane sugar and federal policies aimed at artificially support the price of gasoline are some of the factors that led to the fall in competitiveness of ethanol. Nowadays, it is up to the government to create policies to stimulate the supply of renewable fuels to replace fossil fuels. (author)

  14. Use of MODIS Images to Quantify the Radiation and Energy Balances in the Brazilian Pantanal

    Directory of Open Access Journals (Sweden)

    Antônio H. de C. Teixeira

    2015-11-01

    Full Text Available MODIS images during the year 2012 were used for modelling of the radiation and energy balance components with the application of the SAFER algorithm (Simple Algorithm for Evapotranspiration Retrieving in the Brazilian Pantanal area. Pixels from the main sub-regions of Barão de Melgaço (BR, Paiaguás (PA and Nhecolândia (NH were extracted in order to process microclimatic comparisons. In general, the net radiation (Rn relied much more on the global solar radiation (RG levels than on water conditions and ecosystem types, in accordance with the low Rn standard deviation values. The fraction of the available energy used as latent heat flux (λE were, on average, 65, 50 and 49% for the BR, PA and NH sub-regions, respectively. Horizontal heat advection, identified by the negative values of sensible heat flux (H, made several pixels with λE values higher than those for Rn in the middle of the year. Taking the evaporative fraction (Ef as a surface moisture indicator, the Tree-Lined Savanna (TLS was considered the moister ecosystem class, with 58% of the available energy being used as λE, while the driest one was the modified ecosystem Anthropogenic Changes (AC, presenting a λE/Rn fraction of 0.46. According to the spatial and temporal consistencies, and after comparisons with other previous point and large-scale studies, the SAFER algorithm proved to have sensibility to quantify and compare the large-scale radiation and energy balance components in the different ecosystems of the Brazilian Pantanal. The algorithm is useful for monitoring the energy exchange dynamics among the different terrestrial and aquatic ecosystem types throughout the seasons of the year.

  15. Converting Paddy Rice Field to Urban Use Dramatically Altered the Water and Energy Balances in Southern China

    Science.gov (United States)

    Hao, L.; Sun, G.; Liu, Y.; Qin, M.; Huang, X.; Fang, D.

    2017-12-01

    Paddy rice wetlands are the main land use type across southern China, which impact the regional environments by affecting evapotranspiration (ET) and other water and energy related processes. Our study focuses on the effects of land-cover change on water and energy processes in the Qinhuai River Basin, a typical subtropical humid region that is under rapid ecological and economical transformations. This study integrates multiple methods and techniques including remote sensing, water and energy balance model (i.e., Surface Energy Balance Algorithm for Land, SEBAL), ecohydrological model (i.e., Soil and Water Assessment Tool, SWAT), and ground observation (Eddy Covariance measurement, etc.). We found that conversion of paddy rice field to urban use led to rise in vapor pressure deficit (VPD) and reduction in ET, and thus resulted in changes in local and regional water and heat balance. The effects of the land-use change on ET and VPD overwhelmed the effects of regional climate warming and climate variability. We conclude that the ongoing large-scale urbanization of the rice paddy-dominated regions in humid southern China and East Asia will likely exacerbate environmental consequences (e.g., elevated storm-flow volume, aggravated flood risks, and intensified urban heat island and urban dry island effects). The potential role of vegetated land cover in moderating water and energy balances and maintaining a stable climate should be considered in massive urban planning and global change impact assessment in southern China.

  16. Balancing Area Coordination: Efficiently Integrating Renewable Energy Into the Grid, Greening the Grid

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Jessica; Denholm, Paul; Cochran, Jaquelin

    2015-06-01

    Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. Coordinating balancing area operation can promote more cost and resource efficient integration of variable renewable energy, such as wind and solar, into power systems. This efficiency is achieved by sharing or coordinating balancing resources and operating reserves across larger geographic boundaries.

  17. Surface energy and viscoelasticity influence caramel adhesiveness.

    Science.gov (United States)

    Wagoner, Ty B; Foegeding, Edward Allen

    2017-08-26

    Adhesion is an important textural attribute that directs consumer eating patterns and behaviors and can be a negative attribute during food processing. The objectives of this study were to modify caramel formulation and compare adhesion to different materials to quantify the influence of surface energetics and viscoelasticity on caramel adhesiveness. Mechanical adhesion was viewed in the context of pressure sensitive tack theory, where adhesion is controlled by viscoelasticity of the adhesive material and the surface energy relationship of material and probe. Caramel samples varied in total amount of fat and protein, and mechanical adhesion was measured using a series of materials with total surface energies of 39.7-53.2 mJ/m 2 . Adhesiveness decreased as fat and protein content increased, with a significant effect of total surface energy. Viscoelasticity was modeled using creep recovery data fit to a four-element Burger mechanistic model. Burger model parameters representing retarded elasticity correlated strongly with adhesiveness. The results suggest two zones of adhesion based on formulation, one driven by both surface energy relationships-most notably dispersive and total surface energy-and viscoelasticity, and the other driven solely by viscoelasticity. Relationships between mechanical properties and adhesion have been explored but are still not well understood, and could aid in the design of food products with a controlled level of adhesion. The results of this study indicate the importance of considering material surface energy when measuring mechanical adhesion or texture profile analysis. Understanding the relationships between viscoelastic behavior and adhesion can be used to make inferences on perceived texture. © 2017 Wiley Periodicals, Inc.

  18. Evaluation of Satellite-Based Surface Energy Budget Products with Surface Measurements Over the Great Lakes

    Science.gov (United States)

    Wang, H.; Loeb, N. G.; Lenters, J. D.; Spence, C.; Blanken, P.

    2017-12-01

    Earth's climate is fundamentally driven by the global energy balance. While Earth's energy budget at the top-of-atmosphere (TOA) is well understood, satellite-based estimates of the global mean surface energy budget yield an imbalance of 15-20 Wm-2. The data products used to infer the components of the surface energy budget are often based upon physical or empirical models and ancillary input data sets of varying quality. In order to make progress, comparisons between satellite-based estimates of the surface energy budget components and direct surface measurements are critically needed. This study evaluates surface radiative fluxes from NASA CERES EBAF and surface turbulent heat fluxes from OAFLUX by comparing them with surface station measurements from the Great Lakes Evaporation Network (GLEN). The GLEN measurements are collected using instruments on lighthouses in the Great Lakes, and include surface evaporation measurement via eddy covariance technique. The evaluation is performed for 3 offshore and 1 nearshore Great Lakes sites. We highlight results for Stannard Rock in Lake Superior, which is the farthest lighthouse from shore ( 40km from the nearest land). Relative to the GLEN observations, the OAFLUX underestimates latent heat flux by 12 Wm-2 (19 Wm-2) at Stannard Rock (4-station average), in part due to its weaker near surface wind speed, and overestimates sensible heat flux by 12 Wm-2 (6 Wm-2), which is partly contributed by its colder surface air temperature. The CERES EBAF-Surface overestimates the surface downward all-sky shortwave (longwave) flux by 8 Wm-2 (7 Wm-2) at Stannard Rock, and is comparable to the 4-station average. As a result, the surface estimated using EBAF-Surface and OAFLUX receives 16 Wm-2 (13 Wm-2) more than the GLEN observations at Stannard Rock (4-station average). The above surface energy flux differences will be further discussed based on a comparison between the input data sets used in the satellite-based estimates and

  19. On the measurement of the surface energy budget over a land ...

    Indian Academy of Sciences (India)

    e-mail: bhat@caos.iisc.ernet.in. The measurement of surface energy balance over a land surface in an open area in Bangalore is .... Sensors used in the present experimental setup and their specifications. These instruments were procured .... the value of the scalar at the roughness height zos. ψm and ψs are the M–O ...

  20. Towards a sustainable global energy supply infrastructure: Net energy balance and density considerations

    International Nuclear Information System (INIS)

    Kessides, Ioannis N.; Wade, David C.

    2011-01-01

    This paper employs a framework of dynamic energy analysis to model the growth potential of alternative electricity supply infrastructures as constrained by innate physical energy balance and dynamic response limits. Coal-fired generation meets the criteria of longevity (abundance of energy source) and scalability (ability to expand to the multi-terawatt level) which are critical for a sustainable energy supply chain, but carries a very heavy carbon footprint. Renewables and nuclear power, on the other hand, meet both the longevity and environmental friendliness criteria. However, due to their substantially different energy densities and load factors, they vary in terms of their ability to deliver net excess energy and attain the scale needed for meeting the huge global energy demand. The low power density of renewable energy extraction and the intermittency of renewable flows limit their ability to achieve high rates of indigenous infrastructure growth. A significant global nuclear power deployment, on the other hand, could engender serious risks related to proliferation, safety, and waste disposal. Unlike renewable sources of energy, nuclear power is an unforgiving technology because human lapses and errors can have ecological and social impacts that are catastrophic and irreversible. Thus, the transition to a low carbon economy is likely to prove much more challenging than early optimists have claimed. - Highlights: → We model the growth potential of alternative electricity supply infrastructures. → Coal is scalable and abundant but carries a heavy carbon footprint. → Renewables and nuclear meet the longevity and environmental friendliness criteria. → The low power density and intermittency of renewables limit their growth potential. → Nuclear power continues to raise concerns about proliferation, safety, and waste.

  1. Adhesion energy, surface traction and surface tension in liquid xenon

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Home; Journals; Pramana – Journal of Physics; Volume 77; Issue 6. Adhesion energy, surface ... 2 G A Adebayo1. Department of Physics, University of Agriculture, Abeokuta, Nigeria; Department of Pure and Applied Physics, College of Pure and Applied Science, Caleb University, Imota, Lagos, Nigeria ...

  2. Surface Plasmon-Assisted Solar Energy Conversion.

    Science.gov (United States)

    Dodekatos, Georgios; Schünemann, Stefan; Tüysüz, Harun

    2016-01-01

    The utilization of localized surface plasmon resonance (LSPR) from plasmonic noble metals in combination with semiconductors promises great improvements for visible light-driven photocatalysis, in particular for energy conversion. This review summarizes the basic principles of plasmonic photocatalysis, giving a comprehensive overview about the proposed mechanisms for enhancing the performance of photocatalytically active semiconductors with plasmonic devices and their applications for surface plasmon-assisted solar energy conversion. The main focus is on gold and, to a lesser extent, silver nanoparticles in combination with titania as semiconductor and their usage as active plasmonic photocatalysts. Recent advances in water splitting, hydrogen generation with sacrificial organic compounds, and CO2 reduction to hydrocarbons for solar fuel production are highlighted. Finally, further improvements for plasmonic photocatalysts, regarding performance, stability, and economic feasibility, are discussed for surface plasmon-assisted solar energy conversion.

  3. Glacier surface mass balance and freshwater runoff modeling for the entire Andes Cordillera

    Science.gov (United States)

    Mernild, Sebastian H.; Liston, Glen E.; Yde, Jacob C.

    2017-04-01

    Glacier surface mass balance (SMB) observations for the Andes Cordillera are limited and, therefore, estimates of the SMB contribution from South America to sea-level rise are highly uncertain. Here, we simulate meteorological, snow, glacier surface, and hydrological runoff conditions and trends for the Andes Cordillera (1979/80-2013/14), covering the tropical latitudes in the north down to the sub-polar latitudes in the far south, including the Northern Patagonia Ice Field (NPI) and Southern Patagonia Ice Field (SPI). SnowModel - a fully integrated energy balance, blowing-snow distribution, multi-layer snowpack, and runoff routing model - was used to simulate glacier SMBs for the Andes Cordillera. The Randolph Glacier Inventory and NASA Modern-Era Retrospective Analysis for Research and Applications products, downscaled in SnowModel, allowed us to conduct relatively high-resolution simulations. The simulated glacier SMBs were verified against independent directly-observed and satellite gravimetry and altimetry-derived SMB, indicating a good statistical agreement. For glaciers in the Andes Cordillera, the 35-year mean annual SMB was found to be -1.13 m water equivalent. For both NPI and SPI, the mean SMB was positive (where calving is the likely reason for explaining why geodetic estimates are negative). Further, the spatio-temporal freshwater river runoff patterns from individual basins, including their runoff magnitude and change, were simulated. For the Andes Cordillera rivers draining to the Pacific Ocean, 86% of the simulated runoff originated from rain, 12% from snowmelt, and 2% from ice melt, whereas, for example, for Chile, the water-source distribution was 69, 24, and 7%, respectively. Along the Andes Cordillera, the 35-year mean basin outlet-specific runoff (L s-1 km-2) showed a characteristic regional hourglass shape pattern with highest runoff in both Colombia and Ecuador and in Patagonia, and lowest runoff in the Atacama Desert area.

  4. Surface Mass Balance Distributions: Downscaling of Coarse Climates to drive Ice Sheet Models realistically

    Science.gov (United States)

    Rodehacke, Christian; Mottram, Ruth; Langen, Peter; Madsen, Marianne; Yang, Shuting; Boberg, Fredrik; Christensen, Jens

    2017-04-01

    The surface mass balance (SMB) is the most import boundary conditions for the state of glaciers and ice sheets. Hence its representation in numerical model simulations is of highest interest for glacier, ice cap and ice sheet modeling efforts. While descent SMB distributions of the current climate could be interfered with the help of various observation techniques and platforms, its construction for older past and future climates relies on input from spatially coarse resolved global climate models or reconstructions. These coarse SMB estimates with a footprint in the order of 100 km could hardly resolve the marginal ablations zones where the Greenland ice sheets, for instance, loses snow and ice. We present a downscaling method that is based on the physical calculation of the surface mass and energy balance. By the consequent application of universal and computationally cheap parameterizations we get an astonishing good representation of the SMB distribution including its marginal ablation zone. However the method has its limitations; for example wrong accumulation rates due to an insufficient precipitation field leaves its imprint on the SMB distribution. Also the still not satisfactory description of the bare ice albedo, in particular, in parts of Greenland is a challenge. We inspect our Greenland SMB fields' for various forcings and compare them with some widely used reference fields in the community to highlight the weakness and strength of our approach. We use the ERA-Interim reanalyzes period starting in 1979 directly as well as dynamically downscaled by our regional climate model HIRHAM (5 km resolution). Also SMB distributions obtained from the climate model EC-Earth with a resolution of T159 (approx. 125 km resolution in Greenland) are used either directly or downscaled with our regional climate model HIRHAM. Model-based End-of-the-century SMB estimates give an outlook of the future.

  5. Analysis of hohlraum energetics of the SG series and the NIF experiments with energy balance model

    Directory of Open Access Journals (Sweden)

    Guoli Ren

    2017-01-01

    Full Text Available The basic energy balance model is applied to analyze the hohlraum energetics data from the Shenguang (SG series laser facilities and the National Ignition Facility (NIF experiments published in the past few years. The analysis shows that the overall hohlraum energetics data are in agreement with the energy balance model within 20% deviation. The 20% deviation might be caused by the diversity in hohlraum parameters, such as material, laser pulse, gas filling density, etc. In addition, the NIF's ignition target designs and our ignition target designs given by simulations are also in accordance with the energy balance model. This work confirms the value of the energy balance model for ignition target design and experimental data assessment, and demonstrates that the NIF energy is enough to achieve ignition if a 1D spherical radiation drive could be created, meanwhile both the laser plasma instabilities and hydrodynamic instabilities could be suppressed.

  6. European energy balance research to prevent excessive weight gain among youth (ENERGY) project

    DEFF Research Database (Denmark)

    Stralen, Maartje M. van; Velde, Saskia J. te; Singh, Amika S.

    2011-01-01

    Background: Obesity treatment is by large ineffective long term, and more emphasis on the prevention of excessive weight gain in childhood and adolescence is warranted. To inform energy balance related behaviour (EBRB) change interventions, insight in the potential personal, family and school...... environmental correlates of these behaviours is needed. Studies on such multilevel correlates of EBRB among schoolchildren in Europe are lacking. The ENERGY survey aims to (1) provide up-to-date prevalence rates of measured overweight, obesity, self-reported engagement in EBRBs, and objective accelerometer...... as assessing a range of EBRBs and their potential correlates at the personal, family and school level, among 10-12 year old children in seven European countries. This study will result in a unique dataset, enabling cross country comparisons in overweight, obesity, risk behaviours for these conditions as well...

  7. A NetCDF version of the two-dimensional energy balance model based on the full multigrid algorithm

    Directory of Open Access Journals (Sweden)

    Kelin Zhuang

    2017-01-01

    Full Text Available A NetCDF version of the two-dimensional energy balance model based on the full multigrid method in Fortran is introduced for both pedagogical and research purposes. Based on the land–sea–ice distribution, orbital elements, greenhouse gases concentration, and albedo, the code calculates the global seasonal surface temperature. A step-by-step guide with examples is provided for practice.

  8. The former USSR: an energy balance in urgent need of improvement

    International Nuclear Information System (INIS)

    Provost, H.

    1993-01-01

    The energy balance of the former USSR is a decisive factor in the economies of the countries now remaining. This balance is facing a crunch due to excessive consumption of liquid hydrocarbons, combined with a downswing in production since 1988. There is a pressing need to open up the petroleum industries to Western technologies and partnerships. 1 fig., 4 tabs

  9. Brazilian Energy Balance 2016 - calendar year 2015; Balanco energetico nacional 2016 - ano base 2015

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-07-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow. Chapter 1 - Energy Analysis and Aggregated Data - presents energy highlights per source in 2015 and analyses the evolution of the domestic energy supply and its relationship with economic growth. Chapter 2 - Energy Supply and Demand by Source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments and total consumption disaggregated per socioeconomic sector in the country. Chapter 3 - Energy Consumption by Sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy. Chapter 4 - Energy Imports and Exports - presents the evolution of the data on the import and export of energy and the dependence on external energy. Chapter 5 - Balance of Transformation Centers - presents the energy balances for the energy transformation centers including their losses. Chapter 6 - Energy Resources and Reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources. Chapter 7 - Energy and Socioeconomics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports. Chapter 8 - State Energy Data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. Relating to annexes the current structure is presented bellow: Annex I - Installed Capacity - shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining. Annex II - Self-production of Electricity - presents disaggregated data of self-production, considering sources and sectors. Annex III - World Energy Data - presents the main indicators for the production, import, export and consumption per energy source

  10. Mapping the Habitable Zone of Exoplanets with a 2D Energy Balance Model

    Science.gov (United States)

    Moon, Nicole Taylor; Dr. Lisa Kaltenegger, Dr. Ramses Ramirez

    2018-01-01

    Traditionally, the habitable zone has been defined as the distance at which liquid water could exist on the surface of a rocky planet. However, different complexity models (simplified and fast:1D, and complex and time-intense:3D) models derive different boundaries for the habitable zone. The goal of this project was to test a new intermediate complexity 2D Energy Balance model, add a new ice albedo feedback mechanism, and derive the habitable zone boundaries. After completing this first project, we also studied how other feedback mechanisms, such as the presence of clouds and the carbonate-silicate cycle, effected the location of the habitable zone boundaries using this 2D model. This project was completed as part of a 2017 summer REU program hosted by Cornell's Center for Astrophysics and Plantary Sciecne and in partnership with the Carl Sagan Institute.

  11. Energy, environment and economics: greenhouse policy in the balance

    International Nuclear Information System (INIS)

    Wilkenfeld, G.L.

    1990-01-01

    Taking New South Wales as a case study, this paper reviews the government's major economic and environmental concerns, and analyses how they bear on energy and greenhouse policy options. The government's economic strategy emphasises the continuing importance of primary resources, minerals processing and energy-intensive manufacturing, where the State is perceived to have a competitive advantage because of its extensive coal resources. The implications of these trends for the energy utilities and for greenhouse energy policy are analysed. 22 refs., 1 tab

  12. A Survey on an Energy-Efficient and Energy-Balanced Routing Protocol for Wireless Sensor Networks

    Science.gov (United States)

    Ogundile, Olayinka O.; Alfa, Attahiru S.

    2017-01-01

    Wireless sensor networks (WSNs) form an important part of industrial application. There has been growing interest in the potential use of WSNs in applications such as environment monitoring, disaster management, health care monitoring, intelligence surveillance and defence reconnaissance. In these applications, the sensor nodes (SNs) are envisaged to be deployed in sizeable numbers in an outlying area, and it is quite difficult to replace these SNs after complete deployment in many scenarios. Therefore, as SNs are predominantly battery powered devices, the energy consumption of the nodes must be properly managed in order to prolong the network lifetime and functionality to a rational time. Different energy-efficient and energy-balanced routing protocols have been proposed in literature over the years. The energy-efficient routing protocols strive to increase the network lifetime by minimizing the energy consumption in each SN. On the other hand, the energy-balanced routing protocols protract the network lifetime by uniformly balancing the energy consumption among the nodes in the network. There have been various survey papers put forward by researchers to review the performance and classify the different energy-efficient routing protocols for WSNs. However, there seems to be no clear survey emphasizing the importance, concepts, and principles of load-balanced energy routing protocols for WSNs. In this paper, we provide a clear picture of both the energy-efficient and energy-balanced routing protocols for WSNs. More importantly, this paper presents an extensive survey of the different state-of-the-art energy-efficient and energy-balanced routing protocols. A taxonomy is introduced in this paper to classify the surveyed energy-efficient and energy-balanced routing protocols based on their proposed mode of communication towards the base station (BS). In addition, we classified these routing protocols based on the solution types or algorithms, and the input decision

  13. A Survey on an Energy-Efficient and Energy-Balanced Routing Protocol for Wireless Sensor Networks.

    Science.gov (United States)

    Ogundile, Olayinka O; Alfa, Attahiru S

    2017-05-10

    Wireless sensor networks (WSNs) form an important part of industrial application. There has been growing interest in the potential use of WSNs in applications such as environment monitoring, disaster management, health care monitoring, intelligence surveillance and defence reconnaissance. In these applications, the sensor nodes (SNs) are envisaged to be deployed in sizeable numbers in an outlying area, and it is quite difficult to replace these SNs after complete deployment in many scenarios. Therefore, as SNs are predominantly battery powered devices, the energy consumption of the nodes must be properly managed in order to prolong the network lifetime and functionality to a rational time. Different energy-efficient and energy-balanced routing protocols have been proposed in literature over the years. The energy-efficient routing protocols strive to increase the network lifetime by minimizing the energy consumption in each SN. On the other hand, the energy-balanced routing protocols protract the network lifetime by uniformly balancing the energy consumption among the nodes in the network. There have been various survey papers put forward by researchers to review the performance and classify the different energy-efficient routing protocols for WSNs. However, there seems to be no clear survey emphasizing the importance, concepts, and principles of load-balanced energy routing protocols for WSNs. In this paper, we provide a clear picture of both the energy-efficient and energy-balanced routing protocols for WSNs. More importantly, this paper presents an extensive survey of the different state-of-the-art energy-efficient and energy-balanced routing protocols. A taxonomy is introduced in this paper to classify the surveyed energy-efficient and energy-balanced routing protocols based on their proposed mode of communication towards the base station (BS). In addition, we classified these routing protocols based on the solution types or algorithms, and the input decision

  14. Energy balance from Parana State - 1980-1992

    International Nuclear Information System (INIS)

    1993-01-01

    The energy flows of primary and secondary energy sources since the production to the end consumption in the main sectors of Parana State economy during 1980 to 1992, are presented. The supply and demand, consumption and production of energy sources are shown. Some information about resources and reserves are also cited. (C.G.C.)

  15. Computed potential energy surfaces for chemical reactions

    Science.gov (United States)

    Walch, Stephen P.; Levin, Eugene

    1993-01-01

    A new global potential energy surface (PES) is being generated for O(P-3) + H2 yields OH + H. This surface is being fit using the rotated Morse oscillator method, which was used to fit the previous POL-CI surface. The new surface is expected to be more accurate and also includes a much more complete sampling of bent geometries. A new study has been undertaken of the reaction N + O2 yields NO + O. The new studies have focused on the region of the surface near a possible minimum corresponding to the peroxy form of NOO. A large portion of the PES for this second reaction has been mapped out. Since state to state cross sections for the reaction are important in the chemistry of high temperature air, these studies will probably be extended to permit generation of a new global potential for reaction.

  16. Climate and Physical Disturbance Effects on the Spectral Signatures of Biological Soil Crusts: Implications for Future Dryland Energy Balance

    Science.gov (United States)

    Rutherford, W. A.; Flagg, C.; Painter, T. H.; Okin, G. S.; Belnap, J.; Reed, S.

    2014-12-01

    Drylands comprise ≈40% of the terrestrial Earth surface and observations suggest they can respond markedly to climate change. A vital component of dryland ecosystems are biological soil crusts (biocrusts) - a network of surface soil lichens, mosses, and cyanobacteria - that perform critical ecosystem functions, such as stabilizing soil and fixing carbon and nitrogen. Yet, our understanding of the role biocrusts play in dryland energy balance remains poor. Changes in climate can rapidly affect biocrust communities and we have long known that biocrusts respond dramatically to physical disturbance, such as human trampling and grazing animals. Associated changes in biocrust cover often result in increased bare soil; creating higher surface reflectance. We used spectral solar reflectance measurements in two manipulative experiments to compare the effects of climate and physical disturbance on biocrusts of the Colorado Plateau We measured reflectance at two heights: at crust surface and 1 m above. The climate disturbance site has four treatments: control, warming (4°C), altered precipitation, and warming plus altered precipitation. The physical disturbance site was trampled by foot annually since 1998. At the climate experiment, the largest change in reflectance was in the altered precipitation treatment (35% increase) at the surface-level, and the smallest difference was in the warmed (17% increase) at the meter-level. Physical disturbance differences were 10% at meter-level and 25% at surface-level. Unexpectedly, these results suggest that, via effects on biocrust communities, climate change could have a larger effect on dryland energy balance relative to physical disturbance, and result in more radiation from drylands returned to the atmosphere. Biocrusts cover large portions of the Earth's surface and, to our knowledge, these are the first data showing climate-induced changes to biocrust reflectance, with negative feedback in the global energy balance.

  17. Potential energy surface of alanine polypeptide chains

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.

    2006-01-01

    The multidimensional potential energy surfaces of the peptide chains consisting of three and six alanine (Ala) residues have been studied with respect to the degrees of freedom related to the twist of these molecules relative to the peptide backbone (these degrees of freedom are responsible...

  18. Process evaluation of a workplace health promotion intervention aimed at improving work engagement and energy balance

    NARCIS (Netherlands)

    Berkel, J. van; Boot, C.R.L.; Proper, K.I.; Bongers, P.M.; Beek, A.J. van der

    2013-01-01

    OBJECTIVE:: To evaluate the process of the implementation of an intervention aimed at improving work engagement and energy balance, and to explore associations between process measures and compliance. METHODS:: Process measures were assessed using a combination of quantitative and qualitative

  19. Process Evaluation of a Workplace Health Promotion Intervention Aimed at Improving Work Engagement and Energy Balance

    NARCIS (Netherlands)

    van Berkel, J.; Boot, C.R.L.; Proper, K.I.; Bongers, P.M.; van der Beek, A.J.

    2013-01-01

    OBJECTIVE:: To evaluate the process of the implementation of an intervention aimed at improving work engagement and energy balance, and to explore associations between process measures and compliance. METHODS:: Process measures were assessed using a combination of quantitative and qualitative

  20. Developmental programming of energy balance regulation: Is physical activity more "programmable" than food intake

    Science.gov (United States)

    Extensive human and animal model data show that environmental influences during critical periods of prenatal and early postnatal development can cause persistent alterations in energy balance regulation. Although a potentially important factor in the worldwide obesity epidemic, the fundamental mecha...

  1. Energy Balance Comparison and Closure at a Moist Desert Playa: The Importance of Ground Heat Storage and Flux Estimation

    Science.gov (United States)

    Huntington, J. L.; Rajagopal, S.; Allen, R. G.; Mihevc, T. M.; Schumer, R.; Caldwell, T.; deBruin, H.

    2012-12-01

    Given increasing demands on finite water supplies in arid environments, the need for accurate estimates of sustainable groundwater resources is greater than ever. Many drainages in desert environments are considered hydrologically closed, where the entire groundwater recharge volume is consumed by evaporation and evapotranspiration along mountain front and valley floor areas. The amount of groundwater recharge that occurs in a given hydrographic basin is difficult to accurately estimate and is therefore commonly quantified by estimating the groundwater discharge using micrometeorological, and remote and in situ energy balance methods. Large playas are common features in desert environments, and the phreatic surface is often less than a few meters below land surface, creating nearly saturated conditions at the land surface through capillary rise. At first glance one might conclude that evaporation is high due to the nearly saturated surface, however, playa surfaces are commonly sealed by thin salt crusts, inhibiting evaporation. In this work we use eddy covariance, scintillometer, and four component radiometer measurements, and present a novel ground heat flux analysis using multiple ground heat flux plates and heat-pulse sensors to assess energy balance closure and uncertainties on estimated evaporation in Dixie Valley, Nevada. Results indicate that greater than 50 percent of daytime net radiation is partitioned into ground heat flux, and almost all of the available energy is portioned into sensible heat as determined from eddy covariance, and confirmed with scintillometer estimates. Utilizing heat pulse derived soil thermal properties and high density discrete soil temperature measurements allowed for estimation of soil heat storage and flux using a finite difference solution to the transient heat flow equation. This approach improved energy balance closure by 20 percent (achieving 90 percent closure) when compared to traditional calorimetric soil heat storage and

  2. To Ingest or Rest? Specialized Roles of Lateral Hypothalamic Area Neurons in Coordinating Energy Balance

    Directory of Open Access Journals (Sweden)

    Juliette A. Brown

    2015-02-01

    Full Text Available Survival depends on an organism’s ability to sense nutrient status and accordingly regulate intake and energy expenditure behaviors. Uncoupling of energy sensing and behavior, however, underlies energy balance disorders such as anorexia or obesity. The hypothalamus regulates energy balance, and in particular the lateral hypothalamic area (LHA is poised to coordinate peripheral cues of energy status and behaviors that impact weight, such as drinking, locomotor behavior, arousal/sleep and autonomic output. There are several populations of LHA neurons that are defined by their neuropeptide content and contribute to energy balance. LHA neurons that express the neuropeptides melanin-concentrating hormone (MCH or orexins/hypocretins (OX are best characterized and these neurons play important roles in regulating ingestion, arousal, locomotor behavior and autonomic function via distinct neuronal circuits. Recently, another population of LHA neurons containing the neuropeptide Neurotensin (Nts has been implicated in coordinating anorectic stimuli and behavior to regulate hydration and energy balance. Understanding the specific roles of MCH, OX and Nts neurons in harmonizing energy sensing and behavior thus has the potential to inform pharmacological strategies to modify behaviors and treat energy balance disorders.

  3. Effects of winter military training on energy balance, whole-body protein balance, muscle damage, soreness, and physical performance.

    Science.gov (United States)

    Margolis, Lee M; Murphy, Nancy E; Martini, Svein; Spitz, Marissa G; Thrane, Ingjerd; McGraw, Susan M; Blatny, Janet-Martha; Castellani, John W; Rood, Jennifer C; Young, Andrew J; Montain, Scott J; Gundersen, Yngvar; Pasiakos, Stefan M

    2014-12-01

    Physiological consequences of winter military operations are not well described. This study examined Norwegian soldiers (n = 21 males) participating in a physically demanding winter training program to evaluate whether short-term military training alters energy and whole-body protein balance, muscle damage, soreness, and performance. Energy expenditure (D2(18)O) and intake were measured daily, and postabsorptive whole-body protein turnover ([(15)N]-glycine), muscle damage, soreness, and performance (vertical jump) were assessed at baseline, following a 4-day, military task training phase (MTT) and after a 3-day, 54-km ski march (SKI). Energy intake (kcal·day(-1)) increased (P soreness increased and performance decreased progressively (P < 0.05). The physiological consequences observed during short-term winter military training provide the basis for future studies to evaluate nutritional strategies that attenuate protein loss and sustain performance during severe energy deficits.

  4. Balancing energy, development and climate priorities in India. Current trends and future projections

    International Nuclear Information System (INIS)

    Shukla, P.R.; Garg, A.; Dhar, S.; Halsnaes, K.

    2007-09-01

    This report gives a short introduction to the project: Projecting future energy demand: Balancing development, energy and climate priorities in large developing countries. Furthermore, the report analyses Indian energy, development and climate change, followed by an assessment of cross-country results that gives a range of key indicators of the relationship between economic growth, energy, and local and global pollutants. The focus is on the energy sector policies that mainstream climate interests within development choices. (BA)

  5. Sleep restriction is not associated with a positive energy balance in adolescent boys

    DEFF Research Database (Denmark)

    Klingenberg, Lars; Chaput, Jean-Philippe; Holmbäck, Ulf

    2012-01-01

    A short sleep (SS) duration has been linked to obesity in observational studies. However, experimental evidence of the potential mechanisms of sleep restriction on energy balance is conflicting and, to our knowledge, nonexistent in adolescents.......A short sleep (SS) duration has been linked to obesity in observational studies. However, experimental evidence of the potential mechanisms of sleep restriction on energy balance is conflicting and, to our knowledge, nonexistent in adolescents....

  6. Systems-design and energy-balance considerations for impact fusion

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.

    1979-01-01

    Areas of concern and potential problems for impact fusion are qualitatively considered within an overall systems context. A parametric and qualitative description of the general energy balance and systems considerations for an Impact Fusion Reactor (IFR) design is discussed. Reactor systems design considerations for an IFR are presented. An attempt to assess the IFR viability is made based on highly simplified but limiting projectile-target energy balances and thermonuclear burn models

  7. Green IGP Link Weights for Energy-efficiency and Load-balancing in IP Backbone Networks

    OpenAIRE

    Francois, Frederic; Wang, Ning; Moessner, Klaus; Georgoulas, Stylianos; Xu, Ke

    2013-01-01

    The energy consumption of backbone networks has become a primary concern for network operators and regulators due to the pervasive deployment of wired backbone networks to meet the requirements of bandwidth-hungry applications. While traditional optimization of IGP link weights has been used in IP based load-balancing operations, in this paper we introduce a novel link weight setting algorithm, the Green Load-balancing Algorithm (GLA), which is able to jointly optimize both energy efficiency ...

  8. Skeletal Muscle Responses to Negative Energy Balance: Effects of Dietary Protein12

    OpenAIRE

    Carbone, John W.; McClung, James P.; Pasiakos, Stefan M.

    2012-01-01

    Sustained periods of negative energy balance decrease body mass due to losses of both fat and skeletal muscle mass. Decreases in skeletal muscle mass are associated with a myriad of negative consequences, including suppressed basal metabolic rate, decreased protein turnover, decreased physical performance, and increased risk of injury. Decreases in skeletal muscle mass in response to negative energy balance are due to imbalanced rates of muscle protein synthesis and degradation. However, the ...

  9. Potential energy surface of triplet O4.

    Science.gov (United States)

    Paukku, Yuliya; Varga, Zoltan; Truhlar, Donald G

    2018-03-28

    We present a global ground-state potential energy surface (PES) for the triplet spin state of O 4 that is suitable for treating high-energy vibrational-rotational energy transfer and collision-induced dissociation in electronically adiabatic spin-conserving O 2 -O 2 collisions. The surface is based on MS-CASPT2/maug-cc-pVTZ electronic structure calculations with scaled external correlation; the active space has 16 electrons in 12 orbitals. The global ground-state potential energy surface was fitted by a many-body approach with an accurate O-O pairwise interaction and a fit of the many-body interaction potential to 10 180 electronic structure data points. The many-body fit is based on permutationally invariant polynomials in terms of bond-order functions of the six interatomic distances; the bond-order functions are mixed exponential-Gaussian functions. The geometries calculated and used for the fit include geometry scans corresponding to dissociative and vibrationally excited diatom-diatom collisions of O 2 , scans corresponding to O 3 interacting with O, additional geometries identified by running trajectories, and geometries along linear synchronous transit paths connecting randomly selected points. The global O 4 PES includes subsurfaces describing the interaction of diatomic molecules with other diatomic molecules or interactions of triatomic molecules and an atom. The interaction of ozone with a ground-state oxygen atom occurs on the triplet O 4 surface, and our surface includes high-energy points with O 3 -O geometries as well as O 2 -O 2 geometries and O 2 -O-O geometries.

  10. Energy balance of maize production in Brazil: the energetic constraints of a net positive outcome

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Luis Henrique de Barros; Alves, Bruno Jose Rodrigues; Urquiaga, Segundo

    2008-07-01

    Among the factors used to analyze and to establish the sustainability of a whole agricultural production system, the energy balance is one of the most powerful and robust. The maize production in Brazil is surely the reflex of an energy intensive system that demands many field operations and heavy fertilizer applications, notably nitrogen in urea form. This work presents an energy balance of this major crop adjusted to the Brazilian conditions of cultivation. The input components were grouped based on their energy contents, and the possible improvements in the agricultural practices that could improve energy balance and net energy withdrawn from the farming were considered. The replacement of N synthetic fertilizer by biological nitrogen fixation, whether the process is directly carried out by endophytic diazotroph bacteria or by means of a N{sub 2}- fixing legume culture planted before the main crop as a green-manure is also discussed. (author)

  11. Regulation of energy balance in Caenorhabditis elegans 

    OpenAIRE

    Sheng, Ming

    2015-01-01

    Obesity is a medical condition in which excess body fat has been accumulated. It is most commonly caused by imbalance between energy intake and energy expenditure (lack of physical activity and lower metabolic rate, etc.). The control of energy metabolism involves multiple tissues and signalling pathways and there is a great need for further understanding of these different interactions. In this study, I use Caenorhabditis elegans to study these complex pathways at the level of a whole organi...

  12. A novel load balanced energy conservation approach in WSN using biogeography based optimization

    Science.gov (United States)

    Kaushik, Ajay; Indu, S.; Gupta, Daya

    2017-09-01

    Clustering sensor nodes is an effective technique to reduce energy consumption of the sensor nodes and maximize the lifetime of Wireless sensor networks. Balancing load of the cluster head is an important factor in long run operation of WSNs. In this paper we propose a novel load balancing approach using biogeography based optimization (LB-BBO). LB-BBO uses two separate fitness functions to perform load balancing of equal and unequal load respectively. The proposed method is simulated using matlab and compared with existing methods. The proposed method shows better performance than all the previous works implemented for energy conservation in WSN

  13. Sensitivity of Greenland Ice Sheet surface mass balance to surface albedo parameterization: a study with a regional climate model

    NARCIS (Netherlands)

    van Angelen, J.H.|info:eu-repo/dai/nl/325922470; Lenaerts, J.T.M.|info:eu-repo/dai/nl/314850163; Lhermitte, S.; Fettweis, X.; Kuipers Munneke, P.|info:eu-repo/dai/nl/304831891; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; van Meijgaard, E.; Smeets, C.J.P.P.|info:eu-repo/dai/nl/191522236

    2012-01-01

    We present a sensitivity study of the surface mass balance (SMB) of the Greenland Ice Sheet, as modeled using a regional atmospheric climate model, to various parameter settings in the albedo scheme. The snow albedo scheme uses grain size as a prognostic variable and further depends on cloud cover,

  14. Rainfall interception and the coupled surface water and energy balance

    NARCIS (Netherlands)

    Van Dijk, A.I.J.M.; et al., et al.; Moors, E.J.

    2015-01-01

    Evaporation from wet canopies (. E) can return up to half of incident rainfall back into the atmosphere and is a major cause of the difference in water use between forests and short vegetation. Canopy water budget measurements often suggest values of E during rainfall that are several times greater

  15. Energy and greenhouse gas balances of cassava-based ethanol

    NARCIS (Netherlands)

    Thanh, Le L.; Ierland, van E.C.; Zhu, X.; Wesseler, J.H.H.

    2013-01-01

    Biofuel production has been promoted to save fossil fuels and reduce greenhouse gas (GHG) emissions. However, there have been concerns about the potential of biofuel to improve energy efficiency and mitigate climate change. This paper investigates energy efficiency and GHG emission saving of

  16. Increased protein intake and meal frequency reduces abdominal fat during energy balance and energy deficit.

    Science.gov (United States)

    Arciero, Paul J; Ormsbee, Michael J; Gentile, Christopher L; Nindl, Bradley C; Brestoff, Jonathan R; Ruby, Maxwell

    2013-07-01

    Unrefined, complex carbohydrates and lean protein diets are used to combat obesity, although it's unknown whether more frequent meals may improve this response. The effects of consuming traditional (~15%) versus higher (~35%) protein intakes as three or six meals/day on abdominal fat, postprandial thermogenesis (TEM), and cardiometabolic biomarkers in overweight individuals during 28 days of energy balance (BAL) and deficit (NEG), respectively were compared. Overweight individuals (n = 30) were randomized into three groups: two high-protein groups (35% of energy) consumed as three (HP3) or six (HP6) meals/day and one group consumed three meals/day of a traditional intake (TD3). Following a 5-day baseline control (CON), subjects consumed their respective diets throughout a 56-day intervention consisting of two, 28 day phases: a BAL followed by a NEG phase (75% of energy needs). Total body fat (BF) and abdominal BF (ABF), body weight (BW), TEM, and fasting biomarkers were assessed at the end of CON, BAL, and NEG phases. BW remained stable throughout CON and BAL in all groups, whereas BF (P meals/day in overweight individuals during both BAL and NEG. Copyright © 2013 The Obesity Society.

  17. Neuronal energy-sensing pathway promotes energy balance by modulating disease tolerance.

    Science.gov (United States)

    Shen, Run; Wang, Biao; Giribaldi, Maria G; Ayres, Janelle; Thomas, John B; Montminy, Marc

    2016-06-07

    The starvation-inducible coactivator cAMP response element binding protein (CREB)-cAMP-regulated transcription coactivator (Crtc) has been shown to promote starvation resistance in Drosophila by up-regulating CREB target gene expression in neurons, although the underlying mechanism is unclear. We found that Crtc and its binding partner CREB enhance energy homeostasis by stimulating the expression of short neuropeptide F (sNPF), an ortholog of mammalian neuropeptide Y, which we show here is a direct target of CREB and Crtc. Neuronal sNPF was found to promote energy homeostasis via gut enterocyte sNPF receptors, which appear to maintain gut epithelial integrity. Loss of Crtc-sNPF signaling disrupted epithelial tight junctions, allowing resident gut flora to promote chronic increases in antimicrobial peptide (AMP) gene expression that compromised energy balance. Growth on germ-free food reduced AMP gene expression and rescued starvation sensitivity in Crtc mutant flies. Overexpression of Crtc or sNPF in neurons of wild-type flies dampens the gut immune response and enhances starvation resistance. Our results reveal a previously unidentified tolerance defense strategy involving a brain-gut pathway that maintains homeostasis through its effects on epithelial integrity.

  18. Brazilian national energy balance 2007. Calendar year 2006[Includes executive summary 2007]; Balanco energetico nacional 2007. Ano base 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This document reports the activities of the Ministry of Mine and Energy, during the calendar year 2006 as follows: energy analysis and aggregated data; supply and demand of energy according to source; energy consumption according to sector; energy external trading; transformation center balance; energy resources and reserves; energy and social economics; state energy data; installed capacity; energy world data.

  19. Solar energy research and development: program balance. Annex, Volume II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-02-01

    Each of the seven solar energy technologies that have been assessed in the study are treated: photovoltaic devices, solar thermal power systems, wind energy systems, solar heating and cooling systems, agricultural and industrial heat processes, biomass conversion technologies, and ocean thermal energy conversion systems. A brief technical overview of storage for solar electric technologies is presented and some principles concerning how different levels of success on electrical storage can affect the commercial viability of solar electric options are discussed. A description is given of the solar penetration model that was developed and applied as an analytical tool in the study. This computer model has served the primary purpose of evaluating the competiveness of the solar energy systems in the markets in which they are expected to compete relative to that of the alternative energy sources. This is done under a variety of energy supply, demand, and price conditions. The seven sections treating the solar energy technologies contain discussions on each of six subject areas: description of the technology; economic projections; the potential contribution of the technology in different marketplaces; environmental considerations; international potential; and the present and possible future emphases within the RD and D program. The priority item for each of the technology sections has been the documentation of the economic projections.

  20. Renewable energy resources and their role in the energy balance of the country

    International Nuclear Information System (INIS)

    Ivanov, P.; Trifonova, L.

    2001-01-01

    The role of the renewable energy sources in the energy production sector is discussed. The main features of solar, wind and biomass energy are reviewed. Studies for Bulgaria show a total solar radiation above 1600 kWh/m 2 for the Southern regions. The assessment of the solar resources, made by the DOE gives about 170 000 TWh/y for the whole territory. The economically advantageous resources for passive heating are 10.6 TWh till 2020. For the same period the utilization of 0.92 TWh solar energy is possible. Solar installations with surface about 14 000 m 2 are currently in operation. 54% of them are in the tourism sphere and only 8% are in industry (due to some economical difficulties about 44% of the industrial installations are shut down). On the base of processing of the data from more that 100 meteorological stations on the country territory, a spatial assessment of the resources has been done. For the whole territory the wind potential is estimated to about 15800 GW. Theoretical average annual wind resources at 10 km above the surface are 125 000 TWh. There are several areas with wind velocity 5-6 m/s which are suitable for wind energy production. The energy resources of biomass for the country are large - around 35.5 TWh. Under the programmes 'Country Study Project' and PHARE, different scenarii for the renewable